title: Search for the Hypothetical pi -> mu x Decay

abstract:
  The KARMEN collaboration has reported the possible observation of a hitherto
unknown neutral and weakly interacting particle x, which is produced in the
decay pi -> mu + x with a mass m(x) = 33.9 MeV. We have searched for this
hypothetical decay branch by studying muons from pion decay in flight with the
LEPS spectrometer at the piE3 channel at PSI and find branching ratios BR(pi-
to mu- anti-x) < 4e-7 and BR(pi+ to mu+ x) < 7e-8 (95\% C.L.). Together with
the limit BR > 2e-8 derived in a recent theoretical paper our result would
leave only a narrow region for the existence of x if it is a heavy neutrino.


title: $^{6}$He + $\alpha$ clustering in $^{10}$Be

abstract:
  In a kinematically complete measurement of the
$^{7}$Li($^{7}$Li,$\alpha$$^{6}$He)$^4$He reaction at $E_{i}$ = 8 MeV it was
observed that the $^{10}$Be excited states at 9.6 and 10.2 MeV decay by
$^{6}$He emission. The state at 10.2 MeV may be a member of a rotational band
based on the 6.18 MeV 0$^+$ state.


title:
Neutrons from multiplicity-selected Au-Au collisions at 150, 250, 400,
  and 650 AMeV

abstract:
  We measured neutron triple-differential cross sections from
multiplicity-selected Au-Au collisions at 150, 250, 400, and 650 \AMeV. The
reaction plane for each collision was estimated from the summed transverse
velocity vector of the charged fragments emitted in the collision. We examined
the azimuthal distribution of the triple-differential cross sections as a
function of the polar angle and the neutron rapidity. We extracted the average
in--plane transverse momentum $\langle P_x\rangle$ and the normalized
observable $\langle P_x/P_\perp\rangle$, where $P_\perp$ is the neutron
transverse momentum, as a function of the neutron center-of-mass rapidity, and
we examined the dependence of these observables on beam energy. These
collective flow observables for neutrons, which are consistent with those of
protons plus bound nucleons from the Plastic Ball Group, agree with the
Boltzmann--Uehling--Uhlenbeck (BUU) calculations with a momentum--dependent
interaction. Also, we calculated the polar-angle-integrated maximum azimuthal
anisotropy ratio R from the value of $\langle P_x/P_\perp\rangle$.


title: A Procedure to Calibrate a Multi-Modular Telescope

abstract:
  A procedure has been developed for the charge, mass and energy calibration of
ions produced in nuclear heavy ion reactions. The charge and mass
identification are based on a $\Delta$E-E technique. A computer code determines
the conversion from ADC channels into energy values, atomic number and mass of
the detected fragments by comparing with energy loss calculations through a
minimization routine. The procedure does not need prior measurements with beams
of known energy and charge. An application of this technique to the calibration
of the MULTICS apparatus is described.


title: A search for stable strange quark matter nuggets in helium

abstract:
  A search for stable strange quark nuggets has been conducted in helium and
argon using a high sensitivity mass spectrometer. The search was guided by a
mass formula for strange quark nuggets which suggested that stable strange
helium might exist at a mass around 65 u. The chemical similarity of such
``strangelets'' to noble gas atoms and the gravitational unboundedness of
normal helium result in a large enhancement in the sensitivity of such a
search. An abundance limit of no more than $2 \cdot 10^{-11}$ strangelets per
normal nucleus is imposed by our search over a mass region from 42 to 82 u,
with much more stringent limits at most (non-integer) masses.


title: Calibration of Plastic Phoswich Detectors for Charged Particle Detection

abstract:
  The response of an array of plastic phoswich detectors to ions of $1\le Z\le
18$ has been measured from $E/A$=12 to 72 MeV. The detector response has been
parameterized by a three parameter fit which includes both quenching and high
energy delta-ray effects. The fits have a mean variation of $\le 4\%$ with
respect to the data.


title: Bounds on new Majoron models from the Heidelberg-Moscow-Experiment

abstract:
  In recent years several new Majoron models were invented to avoid
shortcomings of the classical models while leading to observable decay rates in
double beta experiments. We give the first experimental half life bounds on
double beta decays with new Majoron emission and derive bounds on the effective
neutrino--Majoron couplings from the data of the $^{76}Ge$ HEIDELBERG--MOSCOW
experiment. While stringent half life limits for all decay modes and the
coupling constants of the classical models were obtained, small matrix elements
and phase space integrals \cite{hir95,pae95} result in much weaker limits on
the effective coupling constants of the new Majoron models.


title: Superdeformation in $^{198}$Po

abstract:
  The $^{174}$Yb($^{29}$Si,5n) reaction at 148 MeV with thin targets was used
to populate high-angular momentum states in $^{198}$Po. Resulting $\gamma$ rays
were observed with Gammasphere. A weakly-populated superdeformed band of 10
$\gamma$-ray transitions was found and has been assigned to $^{198}$Po. This is
the first observation of a SD band in the $A \approx 190$ region in a nucleus
with $Z > 83$. The ${\cal J}^{(2)}$ of the new band is very similar to those of
the yrast SD bands in $^{194}$Hg and $^{196}$Pb. The intensity profile suggests
that this band is populated through states close to where the SD band crosses
the yrast line and the angular momentum at which the fission process dominates.


title:
Circumstantial Evidence for a Critical Behavior in Peripheral Au + Au
  Collisions at 35 MeV/nucleon

abstract:
  The fragmentation resulting from peripheral Au + Au collisions at an incident
energy of E = 35 MeV/nucleon is investigated. A power-law charge distribution,
$A^{-\tau}$ with $\tau \approx 2.2$, and an intermittency signal are observed
for events selected in the region of the Campi scatter plot where "critical"
behavior is expected.


title: Multifragment production in Au+Au at 35 MeV/u

abstract:
  Multifragment disintegration has been measured with a high efficiency
detection system for the reaction $Au + Au$ at $E/A = 35\ MeV$. From the event
shape analysis and the comparison with the predictions of a many-body
trajectories calculation the data, for central collisions, are compatible with
a fast emission from a unique fragment source.


title: Statistical Multifragmentation in Central Au+Au Collisions at 35 MeV/u

abstract:
  Multifragment disintegrations, measured for central Au + Au collisions at E/A
= 35 MeV, are analyzed with the Statistical Multifragmentation Model. Charge
distributions, mean fragment energies, and two-fragment correlation functions
are well reproduced by the statistical breakup of a large, diluted and
thermalized system slightly above the multifragmentation threshold.


title: 12C(p,n)12N reaction at 135 MeV

abstract:
  We report observations from the (p,n) reaction on 12C at 135 MeV. The
experiment was performed with the beam-swinger neutron time-of-flight system at
the Indiana University Cyclotron Facility. Neutrons were detected in
large-volume plastic scintillation detectors located in three detector stations
at 0 deg, 24 deg, and 45 deg with respect to the undeflected beam line; the
flight paths were 91 m, 91 m, and 74 m, respectively. Overall time resolutions
of about 825 ps provided energy resolutions of about 350 keV in the first two
stations and about 425 keV in the third station. The angular distributions for
states with excitation energies up to 10 MeV are presented and comparisons are
made with DWIA calculations that use one-body density matrices from 0hw and 1hw
shell-model calculations. New information is deduced on the excitation
energies, widths and spin-parity assignments for several energy levels of 12N.


title: SAMPLE: Parity Violating Electron Scattering from Hydrogen and Deuterium

abstract:
  Recently, there has been considerable theoretical interest in determining
strange quark contributions to hadronic matrix elements. Such matrix elements
can be accessed through the nucleon's neutral weak form factors as determined
in parity violating electron scattering. The SAMPLE experiment will measure the
strange magnetic form factor $G_M^s$ at low momentum transfer. By combining
measurements from hydrogen and deuterium the theoretical uncertainties in the
measurement can be greatly reduced and the result will be limited by
experimental errors only. A summary of recent progress on the SAMPLE experiment
is presented.


title: A High Power Hydrogen Target for Parity Violation Experiments

abstract:
  Parity-violating electron scattering measurements on hydrogen and deuterium,
such as those underway at the Bates and CEBAF laboratories, require
luminosities exceeding $10^{38}$cm$^{-2}$s$^{-1}$, resulting in large beam
power deposition into cryogenic liquid. Such targets must be able to absorb 500
watts or more with minimal change in target density. A 40~cm long liquid
hydrogen target, designed to absorb 500~watts of beam power without boiling,
has been developed for the SAMPLE experiment at Bates. In recent tests with
40~$\mu$A of incident beam, no evidence was seen for density fluctuations in
the target, at a sensitivity level of better than 1\%. A summary of the target
design and operational experience will be presented.


title:
Signals of a Critical Behavior in Peripheral Au + Au Collisions at 35
  MeV/nucleon

abstract:
  Multifragment events resulting from peripheral Au + Au collisions at 35
MeV/nucleon are analysed in terms of critical behavior. The analysis of most of
criticality signals proposed so far (conditional moments of charge
distributions, Campi scatter plot, fluctuations of the size of the largest
fragment, intermittency analysis) is consistent with the occurrence of a
critical behavior of the system.


title: Evidence for Neutrino Oscillations from Muon Decay at Rest

abstract:
  A search for nu_bar_mu to nu_bar_e oscillations has been conducted at the Los
Alamos Meson Physics Facility using nu_bar_mu from mu+ decay at rest. The
nu_bar_e are detected via the reaction (nu_bar_e,p) -> (e+,n), correlated with
the 2.2 MeV gamma from (n,p) -> (d,gamma). The use of tight cuts to identify e+
events with correlated gamma rays yields 22 events with e+ energy between 36
and 60 MeV and only 4.6 (+/- 0.6) background events. The probability that this
excess is due entirely to a statistical fluctuation is 4.1E-08. A chi^2 fit to
the entire e+ sample results in a total excess of 51.8 (+18.7) (-16.9) (+/-
8.0) events with e+ energy between 20 and 60 MeV. If attributed to nu_bar_mu ->
nu_bar_e oscillations, this corresponds to an oscillation probability (averaged
over the experimental energy and spatial acceptance) of 0.0031 (+0.0011)
(-0.0010) (+/- 0.0005).


title: The Liquid Scintillator Neutrino Detector and LAMPF Neutrino Source

abstract:
  A search for neutrino oscillations of the type nu_bar_mu to nu_bar_e has been
conducted at the Los Alamos Meson Physics Facility using nu_bar_mu from muon
decay at rest. Evidence for this transition has been reported previously. This
paper discusses in detail the experimental setup, detector operation and
neutrino source, including aspects relevant to oscillation searches in the muon
decay-at-rest and pion decay in flight channels.


title:
Evidence for $\bar\nu_\mu\to\bar\nu_e$ Oscillations from the LSND
  Experiment at LAMPF

abstract:
  A search for $\bar\nu_{\mu}\to \bar\nu_{e}$ oscillations has been conducted
at the Los Alamos Meson Physics Facility by using $\bar\nu_\mu$ from $\mu^+$
decay at rest. The $\bar\nu_e$ are detected via the reaction $\bar\nu_e\,p
\rightarrow e^{+}\,n$, correlated with a $\gamma$ from $np\rightarrow d\gamma$
($2.2\,{\rm MeV}$). The use of tight cuts to identify $e^+$ events with
correlated $\gamma$ rays yields 22 events with $e^+$ energy between 36 and
$60\,{\rm MeV}$ and only $4.6 \pm 0.6$ background events. A fit to the $e^+$
events between 20 and $60\,{\rm MeV}$ yields a total excess of
$51.8^{+18.7}_{-16.9} \pm 8.0$ events. If attributed to $\bar \nu_\mu
\rightarrow \bar \nu_e$ oscillations, this corresponds to an oscillation
probability of ($0.31^{+0.11}_{-0.10} \pm 0.05$)\%.


title:
Acceptance and resolution simulation studies for the dielectron
  spectrometer HADES at GSI

abstract:
  Design studies for a second generation Dilepton Spectrometer to be built at
the SIS accelerator of GSI are presented. The basic design parameters of this
system are specified and the different detector components for charged particle
tracking and for lepton identification are described. The geometrical
acceptance for lepton pairs is given. Results on single track momentum
resolution and on lepton pair mass resolution are reported.


title:
Test of Parity-Conserving Time-Reversal Invariance Using Polarized
  Neutrons and Nuclear Spin Aligned Holmium

abstract:
  A test of parity-conserving, time-reversal non-invariance (PC TRNI) has been
performed in 5.9 MeV polarized neutron transmission through nuclear spin
aligned holmium. The experiment searches for the T-violating five-fold
correlation via a double modulation technique - flipping the neutron spin while
rotating the alignment axis of the holmium. Relative cross sections for spin-up
and spin-down neutrons are found to be equal to within $1.2 \times 10^{-5}$
(80\% confidence). This is a two order of magnitude improvement compared to
traditional detailed balance studies of time reversal, and represents the most
precise test of PC TRNI in a dynamical process.


title:
Universality of Spectator Fragmentation at Relativistic Bombarding
  Energies

abstract:
  Multi-fragment decays of 129Xe, 197Au, and 238U projectiles in collisions
with Be, C, Al, Cu, In, Au, and U targets at energies between E/A = 400 MeV and
1000 MeV have been studied with the ALADIN forward-spectrometer at SIS. By
adding an array of 84 Si-CsI(Tl) telescopes the solid-angle coverage of the
setup was extended to \theta_lab = 16 degree. This permitted the complete
detection of fragments from the projectile-spectator source.
  The dominant feature of the systematic set of data is the Z_bound
universality that is obeyed by the fragment multiplicities and correlations.
These observables are invariant with respect to the entrance channel if plotted
as a function of Z_bound, where Z_bound is the sum of the atomic numbers Z_i of
all projectile fragments with Z_i \geq 2. No significant dependence on the
bombarding energy nor on the target mass is observed. The dependence of the
fragment multiplicity on the projectile mass follows a linear scaling law.
  The reasons for and the limits of the observed universality of spectator
fragmentation are explored within the realm of the available data and with
model studies. It is found that the universal properties should persist up to
much higher bombarding energies than explored in this work and that they are
consistent with universal features exhibited by the intranuclear cascade and
statistical multifragmentation models.
  PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-q


title:
The rp-process and new measurements of beta-delayed proton decay of
  light Ag and Cd isotopes

abstract:
  Recent network calculations suggest that a high temperature rp-process could
explain the abundances of light Mo and Ru isotopes, which have long challenged
models of p-process nuclide production. Important ingredients to network
calculations involving unstable nuclei near and at the proton drip line are
$\beta$-halflives and decay modes, i.e., whether or not $\beta$-delayed proton
decay takes place. Of particular importance to these network calculation are
the proton-rich isotopes $^{96}$Ag, $^{98}$Ag, $^{96}$Cd and $^{98}$Cd. We
report on recent measurements of $\beta$-delayed proton branching ratios for
$^{96}$Ag, $^{98}$Ag, and $^{98}$Cd at the on-line mass separator at GSI.


title: Determination of Critical Exponents in Nuclear Systems

abstract:
  Signatures of critical behaviour in nuclear fragmentation are often based on
arguments from percolation theory. We demonstrate with general thermodynamic
considerations and studies of the Ising model that the reliance on percolation
as a reference model bears the risk of missing parts of the essential physics.


title:
Last Minute from ALADIN: Temperature measurements in Au+Au reactions at
  relativistic energies

abstract:
  We report on temperature measurements of nuclear systems formed in the Au+Au
collisions at incident energies of 50, 100, 150, 200 and 1000 A MeV. The target
spectator matter was studied at the highest energy and the interacting zone
(participants) at the lower ones.The temperature deduced from the isotope
ratios was compared with the one deduced via the excited states population. An
unexpected disagreement was found between the two measurements.


title:
The Nuclear Liquid-Gas Phase Transition: Present Status and Future
  Perspectives

abstract:
  More than two decades ago, the van der Waals behavior of the nucleon -
nucleon force inspired the idea of a liquid-gas phase transition in nuclear
matter. Heavy-ion reactions at relativistic energies offer the unique
possibility for studying this phase transition in a finite, hadronic system. A
general overview of this subject is given emphasizing the most recent results
on nuclear calorimetry.


title: Scaling Laws and Transient Times in 3He Induced Nuclear Fission

abstract:
  Fission excitation functions of compound nuclei in a mass region where shell
effects are expected to be very strong are shown to scale exactly according to
the transition state prediction once these shell effects are accounted for. The
fact that no deviations from the transition state method have been observed
within the experimentally investigated excitation energy regime allows one to
assign an upper limit for the transient time of 10 zs.


title:
Charge correlations and dynamical instabilities in the multifragment
  emission process

abstract:
  A new, sensitive method allows one to search for the enhancement of events
with nearly equal-sized fragments as predicted by theoretical calculations
based on volume or surface instabilities. Simulations have been performed to
investigate the sensitivity of the procedure. Experimentally, charge
correlations of intermediate mass fragments emitted from heavy ion reactions at
intermediate energies have been studied. No evidence for a preferred breakup
into equal-sized fragments has been found.


title:
Comment on "Circumstantial Evidence for Critical Behavior in Peripheral
  Au+Au Collisions at 35 MeV/nucleon"

abstract:
  Mastinu et al. recently reported the observation of several positive signals
possibly indicating critical behavior in peripheral collisions of Au+Au at
$E/A$=35 MeV. In our comment, we examine the choice of variables used to
determine the presence (or absence) of critical behavior. We do this by
repeating the analysis the work of Mastinu et al. on "data" from a simulation
with no critical behavior.


title:
The energy dependence of flow in Ni induced collisions from 400 to 1970A
  MeV

abstract:
  We study the energy dependence of collective (hydrodynamic-like) nuclear
matter flow in 400-1970 A MeV Ni+Au and 1000-1970 A MeV Ni+Cu reactions. The
flow increases with energy, reaches a maximum, and then gradually decreases at
higher energies. A way of comparing the energy dependence of flow values for
different projectile-target mass combinations is introduced, which demonstrates
a common scaling behaviour among flow values from different systems.


title: Source size scaling of fragment production in projectile breakup

abstract:
  Fragment production has been studied as a function of the source mass and
excitation energy in peripheral collisions of $^{35}$Cl+$^{197}$Au at 43
MeV/nucleon and $^{70}$Ge+$^{nat}$Ti at 35 MeV/nucleon. The results are
compared to the Au+Au data at 600 MeV/nucleon obtained by the ALADIN
collaboration. A mass scaling, by $A_{source} \sim$ 35 to 190, strongly
correlated to excitation energy per nucleon, is presented, suggesting a thermal
fragment production mechanism. Comparisons to a standard sequential decay model
and the lattice-gas model are made. Fragment emission from a hot, rotating
source is unable to reproduce the experimental source size scaling.


title: Comment on ``Phase Coexistence in Multifragmentation''

abstract:
  This comment on Moretto et al.PRL 76:372,1996 argues that the IMF-charge
distribution may not be useful as signal for phase-transitions in nuclear
multifragmentation. Fluctuations of different origin may corrupt this signal.
Energy conservation is as important as charge conservation. The caloric
equation of state is more safe.


title:
Measurements of the Total Cross Section for the Scattering of Polarized
  Neutrons from Polarized $^3$He

abstract:
  Measurements of polarized neutron--polarized $^3$He scattering are reported.
The target consisted of cryogenically-polarized solid $^3$He, thickness 0.04
atom/b and polarization 40%. The longitudinal and transverse total
cross-section differences $\Delta\sigma_L$ and $\Delta\sigma_T$ were measured
for incident neutron energies 2-8 MeV. The results are compared to phase-shift
predictions based on four different analyses of n-$^3$He scattering. The best
agreement is obtained with a recent R-matrix analysis of A=4 scattering and
reaction data, lending strong suport to the $^4$He level scheme obtained in
that analysis.


title: Critical Behavior in Peripheral Au + Au Collisions at 35 MeV/u

abstract:
  The signals theoretically predicted for the occurrence of a critical behavior
(conditional moments of charge distributions, Campi scatter plot, fluctuations
of the size of the largest fragment, power law in the charge distribution,
intermittency) have been found for peripheral events in the reaction Au+Au at
35 MeV/u. The same signals have been studied with a dynamical model which
foresees phase transition, like the Classical Molecular Dynamics.


title:
Scaling laws, transient times and shell effects in helium induced
  nuclear fission

abstract:
  Fission excitation functions of He-3 and He-4 induced compound nuclei are
shown to scale exactly according to the Bohr-Wheeler transition state
prediction once the shell effects are accounted for. The presented method
furthermore allows one to model-independently extract values for the shell
effects which are in good agreement to those obtained from liquid-drop model
calculations. The fact that no deviations from the transition state method have
been observed within the experimentally investigated excitation energy regime
allows one to assign an upper limit for the transient time of 10 zs.


title:
The Role of Phase Space in Complex Fragment Emission from Low to
  Intermediate Energies

abstract:
  The experimental emission probabilities of complex fragments by low energy
compound nuclei and their dependence upon energy and atomic number are compared
to the transition state rates. Intermediate-mass-fragment multiplicity
distributions for a variety of reactions at intermediate energies are shown to
be binomial and thus reducible at all measured transverse energies. From these
distributions a single binary event probability can be extracted which has a
thermal dependence. A strong thermal signature is also found in the charge
distributions. The n-fold charge distributions are reducible to the 1-fold
charge distributions through a simple scaling dictated by fold number and
charge conservation.


title: Do phase transitions survive binomial reducibility and thermal scaling?

abstract:
  First order phase transitions are described in terms of the microcanonical
and canonical ensemble, with special attention to finite size effects.
Difficulties in interpreting a "caloric curve" are discussed. A robust
parameter indicating phase coexistence (univariance) or single phase
(bivariance) is extracted for charge distributions.


title: Double beta decay of $^{48}$Ca

abstract:
  $^{48}$Ca, the lightest double beta decay candidate, is the only one simple
enough to be treated exactly in the nuclear shell model. Thus, the
$\beta\beta(2\nu)$ half-life measurement, reported here, provides a unique test
of the nuclear physics involved in the $\beta\beta$ matrix element calculation.
Enriched $^{48}$Ca sources of two different thicknesses have been exposed in a
time projection chamber, and yield T$_{1/2}^{2\nu} = (4.3^{+2.4}_{-1.1} [{\rm
stat.}] \pm 1.4 [{\rm syst.}]) \times 10^{19}$ years, compatible with the shell
model calculations.


title:
Measurement of neutron capture on $^{48}$Ca at thermal and thermonuclear
  energies

abstract:
  At the Karlsruhe pulsed 3.75\,MV Van de Graaff accelerator the thermonuclear
$^{48}$Ca(n,$\gamma$)$^{49}$Ca(8.72\,min) cross section was measured by the
fast cyclic activation technique via the 3084.5\,keV $\gamma$-ray line of the
$^{49}$Ca-decay. Samples of CaCO$_3$ enriched in $^{48}$Ca by 77.87\,\% were
irradiated between two gold foils which served as capture standards. The
capture cross-section was measured at the neutron energies 25, 151, 176, and
218\,keV, respectively. Additionally, the thermal capture cross-section was
measured at the reactor BR1 in Mol, Belgium, via the prompt and decay
$\gamma$-ray lines using the same target material. The
$^{48}$Ca(n,$\gamma$)$^{49}$Ca cross-section in the thermonuclear and thermal
energy range has been calculated using the direct-capture model combined with
folding potentials. The potential strengths are adjusted to the scattering
length and the binding energies of the final states in $^{49}$Ca. The small
coherent elastic cross section of $^{48}$Ca+n is explained through the nuclear
Ramsauer effect. Spectroscopic factors of $^{49}$Ca have been extracted from
the thermal capture cross-section with better accuracy than from a recent (d,p)
experiment. Within the uncertainties both results are in agreement. The
non-resonant thermal and thermonuclear experimental data for this reaction can
be reproduced using the direct-capture model. A possible interference with a
resonant contribution is discussed. The neutron spectroscopic factors of
$^{49}$Ca determined from shell-model calculations are compared with the values
extracted from the experimental cross sections for $^{48}$Ca(d,p)$^{49}$Ca and
$^{48}$Ca(n,$\gamma$)$^{49}$Ca.


title: Statistical Binary Decay of $^{35}$Cl + $^{24}$Mg at 8 MeV/nucleon

abstract:
  The properties of the two-body channels in the $^{35}$Cl + $^{24}$Mg reaction
at a bombarding energy of 275 MeV have been investigated by using
fragment-fragment coincident techniques. The exclusive data show that the
majority of events arises from a binary-decay process. The rather large number
of secondary light charged-particles emitted from the two excited exit
fragments are cnsistent with the expectations of the Extended Hauser-Feshbach
Method. No evidence for the occurence of ternary break-up events is observed.


title: Pionic Fusion of Heavy Ions

abstract:
  We report the first experimental observation of the pionic fusion of two
heavy ions. The 12C(12C,24Mg)pi0 and 12C(12C,24Na)pi+ cross sections have been
measured to be 208 +/- 38 and 182 +/- 84 picobarns, respectively, at E_cm = 137
MeV. This cross section for heavy-ion pion production, at an energy just 6 MeV
above the absolute energy-conservation limit, constrains possible production
mechanisms to incorporate the kinetic energy of the entire projectile-target
system as well as the binding energy gained in fusion.


title: Radiative Muon Capture on Hydrogen and the Induced Pseudoscalar Coupling

abstract:
  The first measurement of the elementary process $\mu^- p \rightarrow
\nu_{\mu} n \gamma$ is reported. A photon pair spectrometer was used to measure
the partial branching ratio ($2.10 \pm 0.22) \times 10^{-8}$ for photons of k >
60 MeV. The value of the weak pseudoscalar coupling constant determined from
the partial branching ratio is $g_p(q^{2}=-0.88m_{\mu}^2) = (9.8 \pm 0.7 \pm
0.3) \cdot g_a(0)$, where the first error is the quadrature sum of statistical
and systematic uncertainties and the second error is due to the uncertainty in
$\lambda_{op}$, the decay rate of the ortho to para $p \mu p$ molecule. This
value of g_p is $\sim$1.5 times the prediction of PCAC and pion-pole dominance.


title: Hadron yields and spectra in Au+Au collisions at the AGS

abstract:
  Inclusive double differential multiplicities and rapidity density
distributions of hadrons are presented for 10.8 A GeV/c Au+Au collisions as
measured at the AGS by the E877 collaboration. The results indicate that large
amounts of stopping and collective transverse flow effects are present. The
data are also compared to the results from the lighter Si+Al system.


title: Degree to which CVC is Established Through Beta Decay Alone

abstract:
  Precision studies of $0^{+} \rightarrow 0^{+}$ superallowed $\beta$ decays
provide the necessary data to test stringently the CVC hypothesis. They will
also provide a value for the weak vector coupling constant and the $V_{ud}$
quark mixing element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. The
determination of this element is crucial for the test of the unitarity of the
CKM matrix, and the search for physics beyond the Standard Model. This paper
reviews the current status of $0^{+} \rightarrow 0^{+}$ $\beta$-decay data and
their implications, as well as some relevant data from the $\beta$ decay of
$^{19}$Ne and the neutron.


title: Measurement of direct neutron capture by neutron-rich sulfur isotopes

abstract:
  Thermal neutron capture cross sections for $^{34}$S(n,$\gamma$)$^{35}$S and
$^{36}$S(n,$\gamma$)$^{37}$S have been measured and spectroscopic factors of
the final states have been extracted. The calculated direct-capture cross
sections reproduce the experimental data.


title:
Characterization of nuclear physics targets using Rutherford
  backscattering and particle induced x-ray emission

abstract:
  Rutherford backscattering and particle induced x-ray emission have been
utilized to precisely characterize targets used in nuclear fission experiments.
The method allows for a fast and non destructive determination of target
thickness, homogeneity and element composition.


title: New Results on e+e- Line Emission in U+Ta Collisions

abstract:
  We present new results obtained from a series of follow-up e+e- coincidence
measurements in heavy-ion collisions, utilizing an improved experimental set-up
at the double-Orange beta-spectrometer of GSI. The collision system U+Ta was
reinvestigated in three independent runs at beam energies in the range
(6.0-6.4)xA MeV and different target thicknesses, with the objective to
reproduce a narrow sum-energy e+e- line at ~635 keV observed previously in this
collision system. At improved statistical accuracy, the line could not be found
in these new data. For the ''fission'' scenario, an upper limit (1 sigma) on
its production probability per collision of 1.3x10^{-8} can be set which has to
be compared to the previously reported value of [4.9 +- 0.8 (stat.) +- 1.0
(syst)]x10^{-7}. In the light of the new results, a reanalysis of the old data
shows that the continuous part of the spectrum at the line position is
significantly higher than previously assumed, thus reducing the production
probability of the line by a factor of two and its statistical significance to
< 3.4sigma.


title:
Simulation studies of the HADES first level trigger PART I: Performance
  in heavy-ion induced reaction

abstract:
  The first level trigger of the HADES spectrometer is studied for the
heavy-ion collision systems Au+Au and Ne+Ne. The trigger efficiency for central
events is given in dependence of the imposed charged particle multiplicity
condition. The timing properties of the trigger signal are described. The
losses due to deadtime are specified. Finally, the first level trigger rate is
reported.


title:
Simulation studies of the HADES first level trigger PART II: Performance
  in hadron induced reactions

abstract:
  The HADES first level trigger is studied for the system p+Ni at a beam energy
of 2 AGeV. The timing properties of the trigger signal are reported. The
efficiency loss due to deadtime is specified. A trigger requirement of a time
overlap window with the start detector is described. The trigger rates for
different overlap windows are given.


title:
Characterization of Solidified Gas Thin Film Targets via Alpha Particle
  Energy Loss

abstract:
  A method is reported for measuring the thickness and uniformity of thin films
of solidified gas targets. The energy of alpha particles traversing the film is
measured and the energy loss is converted to thickness using the stopping
power. The uniformity is determined by measuring the thickness at different
positions with an array of sources. Monte Carlo simulations have been performed
to study the film deposition mechanism. Thickness calibrations for a TRIUMF
solid hydrogen target system are presented.


title:
Observation of a unitary cusp in the threshold {\gamma}p -> \pi^{0}p
  reaction

abstract:
  A rigorous multipole analysis of the recent {\gamma}p -> \pi^{0}p cross
section measurement is presented. The data were taken using the photon
spectrometer TAPS at the tagged photon beam of the Mainz microtron. The s and p
wave multipoles were extracted using minimal model assumptions. The predicted
unitary cusp for the s wave multipole E_{0+} due to the two step {\gamma}p ->
\pi^{+}n -> \pi^{0}p reaction was observed. The results are consistent with one
loop chiral perturbation theory calculations for which three low energy
constants have been determined by a fit to the data. The uncertainties in the
analysis and the need for polarization observables are discussed.


title: Energy and Charged Particle Flow in 10.8 A GeV/c Au+Au Collisions

abstract:
  Experimental results and a detailed analysis are presented of the transverse
energy and charged particle azimuthal distributions measured by the E877
collaboration for different centralities of Au+Au collisions at a beam momentum
of 10.8 A GeV/c. The anisotropy of these distributions is studied with respect
to the reaction plane reconstructed on an event-by-event basis using the
transverse energy distribution measured by calorimeters. Results are corrected
for the reaction plane resolution. For semicentral events we observe directed
flow signals of up to ten percent. We observe a stronger anisotropy for slow
charged particles. For both the charged particle and transverse energy
distributions we observe a small but non zero elliptic anisotropy with the
major axis pointing into the reaction plane. Combining the information on
transverse energy and charged particle flow we obtain information on the flow
of nucleons and pions. The data are compared to event generators and the need
to introduce a mean field or nucleon-nucleon potential is discussed.


title: Particle Production and Flow at SIS Energies

abstract:
  An overview is given over recent measurements of flow and particle production
in the energy range from 0.1 to 2AGeV. Excitation functions for the directed
sideward and the azimuthally symmetric transverse flow are presented and show
the importance of flow phenomena in this incident energy regime. Rapidity
density distributions are indicative of a system size dependence of the
stopping process. The role of strange particles as a probe for the hot and
dense phase of hadronic matter is discussed with respect to the production and
propagation. The spectra of Kaons indicate an equilibration with the
surrounding baryons during the expansion while their directed flow pattern is
different from that of the nucleons.


title:
The Evolution of Nuclear Multifragmentation in the Temperature-Density
  Plane

abstract:
  The mean transverse kinetic energies of the fragments formed in the
interaction of 1 A GeV Au+C have been determined. An energy balance argument
indicates the presence of a collective energy which increases in magnitude with
increasing multiplicity and accounts for nearly half of the measured mean
transverse kinetic energy. The radial flow velocity associated with the
collective energy yields estimates for the time required to expand to the
freeze-out volume. Isentropic trajectories in the temperature-density plane are
shown for the expansion and indicate that the system goes through the critical
region at the same multiplicities as deduced from a statistical analysis. Here,
the expansion time is approximately 70 fm/c.


title: Central Collisions of Au on Au at 150, 250 and 400 A MeV

abstract:
  Collisions of Au on Au at incident energies of 150, 250 and 400 A MeV were
studied with the FOPI-facility at GSI Darmstadt. Nuclear charge (Z < 16) and
velocity of the products were detected with full azimuthal acceptance at
laboratory angles of 1-30 degrees. Isotope separated light charged particles
were measured with movable multiple telescopes in an angular range of 6-90
degrees. Central collisions representing about 1 % of the reaction cross
section were selected by requiring high total transverse energy, but vanishing
sideflow. The velocity space distributions and yields of the emitted fragments
are reported. The data are analysed in terms of a thermal model including
radial flow. A comparison with predictions of the Quantum Molecular Model is
presented.


title: Neutrino Oscillations and Moments of Electron Spectra

abstract:
  We show that the effects of neutrino oscillations on 8B solar neutrinos are
described well by the first two moments (the average and the variance) of the
energy distribution of scattered or recoil electrons. For the SuperKamiokande
and the Sudbury Neutrino Observatory experiments, the differences between the
moments calculated with oscillations and the standard, no-oscillation moments
are greater than 3 standard deviations for a significant fraction of the
neutrino mass-mixing (Delta m^2, sin^2 2 theta) parameter space.


title: Experimental Status of Parity Violating Electron Scattering

abstract:
  Recently, there has been considerable theoretical interest in determining
strange quark contributions to hadronic matrix elements. Such matrix elements
can be accessed through the nucleon's neutral weak form factors as determined
in parity violating electron scattering. A program of experiments is presently
underway or planned at the MIT-Bates, Mainz and Jefferson Laboratories. The
SAMPLE experiment at MIT-Bates will measure the strange magnetic form factor
$G_M^s$ at low momentum transfer. Two data taking periods have recently been
completed, representing about 15% of the desired data on hydrogen. A summary of
recent progress on the SAMPLE experiment is presented, along with future plans
at Jefferson Lab.


title: pi+ + d --> p + p reaction between 18 and 44 MeV

abstract:
  A study of the reaction pi+ + d --> p + p has been performed in the energy
range of 18 - 44 MeV. Total cross sections and differential cross sections at
six angles have been measured at 15 energies with an energy increment of 1 - 2
MeV. This is the most systematic data set in this energy range. No structure in
the energy dependence of the cross section has been observed within the
accuracy of this experiment.


title: Multifragmentation in Relativistic Heavy Ion Reactions

abstract:
  Multifragmentation is the dominant decay mode of heavy nuclear systems with
excitation energies near their binding energies and is characterized by a
multiple production of nuclear fragments with intermediate mass.
  At relativistic bombarding energies, multifragmentation may be observed in
peripheral collisions of heavy symmetric systems or more central collisions of
mass asymmetric systems. The decay properties indicate a high degree of
equilibration and are well described by statistical multifragmentation models.
  Multifragmentation has been linked to the liquid-gas phase transition in
finite nuclear systems. A caloric curve of nuclei has been obtained, and
signatures of critical phenomena in finite nuclear systems are searched for in
multifragmentation data.


title:
Direct experimental evidence of non-equilibrium energy sharing in
  dissipative collisions

abstract:
  Primary and secondary masses of heavy reaction products have been deduced
from kinematics and E-ToF measurements, respectively, for the direct and
reverse collisions of 100Mo with 120Sn at 14.1 A MeV. Direct experimental
evidence of the correlation of energy-sharing with net mass transfer and
model-independent results on the evolution of the average excitation from
equal-energy to equal-temperature partition are presented.


title: The magnetic form factor of the neutron

abstract:
  A review of neutron form factor measurements is given. We focus on recent
measurements of the neutron magnetic form factor $G_M^n$, and discuss in detail
our measurements of this quantity at momentum transfers Q^2=0.1-0.6 (GeV/c)^2.


title: Astrophysically Relevant Neutron Capture near the Border of Stability

abstract:
  The neutron capture cross section on $^{26}$Mg was measured in the
astrophysically relevant energy region from 25 keV to 220 keV. The experimental
results agree well with a calculation using the Direct Capture (DC) model
together with systematic folding potentials. This experiment confirms for the
$^{26}$Mg(n,$\gamma$)$^{27}$Mg reaction that the DC process is at least
comparable to the Compound--Nucleus (CN) process. The reliability of DC
calculations is discussed, and we present some ideas for future experiments
which could reduce the theoretical uncertainties of DC calculations.


title: Separating True V0's from Combinatoric Background with a Neural Network

abstract:
  A feedforward multilayered neural network has been trained to "recognize"
true V0's in the presence of a large combinatoric background using simulated
data for 2 GeV/nucleon Ni + Cu interactions. The resulting neural network
filter has been applied to actual data from the EOS TPC experiment. An
enhancement of signal to background over more traditional selection mechanisms
has been observed.


title:
Probing the quantum-mechanical equivalent-photon spectrum for
  electromagnetic dissociation of relativistic uranium projectiles

abstract:
  Electromagnetic fission cross sections for the reactions U + (Be, C, Al, Cu,
In, Au, U) at E/A = 0.6 and 1.0 GeV are compared to theoretical calculations
using recently proposed quantum-mechanical equivalent-photon spectra. In
contrast to semi-classical calculations, systematically lower cross sections
are obtained that cannot reproduce the experimental results. Furthermore, we
point out that the study of electromagnetic fission cross sections or
electromagnetic 1-neutron removal cross sections alone cannot provide
unambiguous information on the excitation of the double giant dipole resonance.


title:
The ^{144}Sm-\alpha optical potential at astrophysically relevant
  energies derived from ^{144}Sm(\alpha,\alpha)^{144}Sm elastic scattering

abstract:
  For the determination of the $^{144}Sm-\alpha$ optical potential we measured
the angular distribution of $^{144}Sm(\alpha,\alpha)^{144}Sm$ scattering at the
energy $E_{lab} = 20 MeV$ with high accuracy. Using the known systematics of
$\alpha$-nucleus optical potentials we are able to derive the $^{144}Sm-\alpha$
optical potential at the astrophysically relevant energy $E_{c.m.} = 9.5 MeV$
with very limited uncertainties.


title: Stable Coulomb bubbles ?

abstract:
  Coulomb bubbles, though stable against monopole displacement, are unstable at
least with respect to quadrupole and octupole distortions. We show that there
exists a temperature at which the pressure of the vapor filling the bubble
stabilizes all the radial modes. In extremely thin bubbles, the crispation
modes become unstable due to the surface-surface interaction.


title:
MSX - A Monte-Carlo Code for Neutron Efficiency Calculations for Large
  Volume Gd-loaded Liquid Scintillation Detectors

abstract:
  Some properties of the code newly developed to simulate the neutron detection
process in a neutron multiplicity meter are briefly described.


title: e+e- pairs from 238U + 206Pb collisions

abstract:
  We present the results from e+e- coincidence measurements in 238U + 206Pb
collisions at a beam energy of 5.93 MeV/u, using an improved experimental setup
at the double-Orange spectrometer of GSI. The capability of our device to
detect Internal-Pair-Conversion (IPC) e+e- pairs from discrete nuclear
transitions of a moving emitter is demonstrated by investigating the known
1.844 MeV (E1) transition in 206Pb and the 1.770 MeV (M1) transition in 207Pb,
excited via Coulomb excitation and a neutron transfer reaction, respectively.
The Doppler-shift corrected e+- sum-energy spectra show weak lines at the
expected energies with cross sections being consistent with the measured
excitation cross sections of the corresponding $\gamma$ lines and the
theoretically predicted IPC coefficients. No other e+e- sum-energy lines were
found in the measured spectra. The observed transfer cross sections show a
strong dependence on the distance of closest approach (R_min), thus signaling
also a strong dependence on the bombarding energy close to the Coulomb barrier.


title: Search for non-Poissonian behavior in nuclear beta-decay

abstract:
  We performed two independent counting experiments on a beta-emitting source
of Sm151 by measuring the gamma-photon emitted in a fraction of the decays. For
counting times ranging from 10**-3 to 5.12*10**4 seconds, our measurements show
no evidence of deviations from Poissonian behavior and, in particular, no sign
of 1/f noise. These measurements put strong limits on non-Poissonian components
of the fluctuations for the subset of decays accompanied by gamma, and
corresponding limits for the total number of beta-decays. In particular, the
magnitude of a hypothetical flicker floor is strongly bounded also for the
beta-decay. This result further constrains theories predicting anomalous
fluctuations in nuclear decays.

categories: nucl-ex cond-mat nucl-th physics.data-an


title:
Study of continuum nuclear structure of 12C via (p,p'X) at intermediate
  energies

abstract:
  The inclusive 12C(p,p') and exclusive 12C(p,p'X) reactions have been studied
with a beam energy of 156 MeV and for X = p and alpha. The study focuses on the
(p,p'X) reaction mechanism and on the structure of 12C just above the
particle-emission threshold, 14 < E_x < 28 MeV. Cross sections were
simultaneously measured for all three reactions. The exclusive data were
analyzed by making multiple-peak fits of the spectra and by Legendre-polynomial
fits of the angular correlations. Multiple-peak fits were also made of the
inclusive spectra. The resultant cross sections were compared to theoretical
calculations. An analysis of the results shows that this region of E_x consists
predominantly of resonant excitations, in contradiction to the findings of
previous analyses.


title: Muon Catalyzed Fusion in 3 K Solid Deuterium

abstract:
  Muon catalyzed fusion in deuterium has traditionally been studied in gaseous
and liquid targets. The TRIUMF solid-hydrogen-layer target system has been used
to study the fusion reaction rates in the solid phase of D_2 at a target
temperature of 3 K. Products of two distinct branches of the reaction were
observed; neutrons by a liquid organic scintillator, and protons by a silicon
detector located inside the target system. The effective molecular formation
rate from the upper hyperfine state of $\mu d$ and the hyperfine transition
rate have been measured: $\tilde{\lambda}_(3/2)=2.71(7)_{stat.}(32)_{syst.}
\mu/s$, and $\tilde{\lambda}_{(3/2)(1/2)} =34.2(8)_{stat.}(1)_{syst.} \mu /s$.
The molecular formation rate is consistent with other recent measurements, but
not with the theory for isolated molecules. The discrepancy may be due to
incomplete thermalization, an effect which was investigated by Monte Carlo
calculations. Information on branching ratio parameters for the s and p wave
d+d nuclear interaction has been extracted.


title:
Pion-nucleus elastic scattering on 12C, 40Ca, 90Zr, and 208Pb at 400 and
  500 MeV

abstract:
  Pion-nucleus elastic scattering at energies above the Delta(1232) resonance
is studied using both pi+ and pi- beams on 12C, 40Ca, 90Zr, and 208Pb. The
present data provide an opportunity to study the interaction of pions with
nuclei at energies where second-order corrections to impulse approximation
calculations should be small. The results are compared with other data sets at
similar energies, and with four different first-order impulse approximation
calculations. Significant disagreement exists between the calculations and the
data from this experiment.


title: Measurement of the Proton's Neutral Weak Magnetic Form Factor

abstract:
  We report the first measurement of the parity-violating asymmetry in elastic
electron scattering from the proton. The asymmetry depends on the neutral weak
magnetic form factor of the proton which contains new information on the
contribution of strange quark-antiquark pairs to the magnetic moment of the
proton. We obtain the value $G_M^Z= 0.34 \pm 0.09 \pm 0.04 \pm 0.05$ n.m. at
$Q^2=0.1$ (GeV/c)${}^2$.


title:
Dielectron Cross Section Measurements in Nucleus-Nucleus Reactions at
  1.0 A GeV

abstract:
  We present measured dielectron production cross sections for Ca+Ca, C+C,
He+Ca, and d+Ca reactions at 1.0 A GeV. Statistical uncertainties and
systematic effects are smaller than in previous DLS nucleus-nucleus data. For
pair mass < 0.35 GeV/c2 : 1) the Ca+Ca cross section is larger than the
previous DLS measurement and current model results, 2) the mass spectra suggest
large contributions from pi0 and eta Dalitz decays, and 3) dsigma/dM is
proportional to ApAt. For M > 0.5 GeV/c2 the Ca+Ca to C+C cross section ratio
is significantly larger than the ratio of ApAt values.


title: Eta-Helium Quasi-Bound States

abstract:
  The cross section and tensor analysing power t_20 of the d\vec{d}->eta 4He
reaction have been measured at six c.m. momenta, 10 < p(eta) < 90 MeV/c. The
threshold value of t_20 is consistent with 1/\sqrt{2}, which follows from
parity conservation and Bose symmetry. The much slower momentum variation
observed for the reaction amplitude, as compared to that for the analogous
pd->eta 3He case, suggests strongly the existence of a quasi-bound state in the
eta-4He system and optical model fits indicate that this probably also the case
for eta-3He.


title:
Comparison of low--energy resonances in 15N(alpha,gamma)19F and
  15O(alpha,gamma)19Ne and related uncertainties

abstract:
  A disagreement between two determinations of Gamma_alpha of the astro-
physically relevant level at E_x=4.378 MeV in 19F has been stated in two recent
papers by Wilmes et al. and de Oliveira et al. In this work the uncertainties
of both papers are discussed in detail, and we adopt the value
Gamma_alpha=(1.5^{+1.5}_{-0.8})10^-9eV for the 4.378 MeV state. In addition,
the validity and the uncertainties of the usual approximations for mirror
nuclei Gamma_gamma(19F) approx Gamma_gamma(19Ne), theta^2_alpha(19F) approx
theta^2_alpha(19Ne) are discussed, together with the resulting uncertainties on
the resonance strengths in 19Ne and on the 15O(alpha,gamma)19Ne rate.


title:
Breakup Temperature of Target Spectators in Au + Au Collisions at E/A =
  1000 MeV

abstract:
  Breakup temperatures were deduced from double ratios of isotope yields for
target spectators produced in the reaction Au + Au at 1000 MeV per nucleon.
Pairs of $^{3,4}$He and $^{6,7}$Li isotopes and pairs of $^{3,4}$He and H
isotopes (p, d and d, t) yield consistent temperatures after feeding
corrections, based on the quantum statistical model, are applied. The
temperatures rise with decreasing impact parameter from 4 MeV for peripheral to
about 10 MeV for the most central collisions.
  The good agreement with the breakup temperatures measured previously for
projectile spectators at an incident energy of 600 MeV per nucleon confirms the
observed universality of the spectator decay at relativistic bombarding
energies. The measured temperatures also agree with the breakup temperatures
predicted by the statistical multifragmentation model. For these calculations a
relation between the initial excitation energy and mass was derived which gives
good simultaneous agreement for the fragment charge correlations.
  The energy spectra of light charged particles, measured at $\theta_{lab}$ =
150$^{\circ}$, exhibit Maxwellian shapes with inverse slope parameters much
higher than the breakup temperatures. The statistical multifragmentation model,
because Coulomb repulsion and sequential decay processes are included, yields
light-particle spectra with inverse slope parameters higher than the breakup
temperatures but considerably below the measured values. The systematic
behavior of the differences suggests that they are caused by
light-charged-particle emission prior to the final breakup stage.
  PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-q


title: Source Temperatures and Sizes in Central Collisions

abstract:
  For midrapidity fragments from central 50-200 AMeV Au+Au collisions
temperatures from double ratios of isotopic yields were compared with
temperatures from particle unbound states. Temperatures from particle unbound
states with T = 4-5 MeV show with increasing beam energy an increasing
difference to temperatures from double ratios of isotopic yields, which
increase from T = 5MeV to T = 12MeV. The lower temperatures extracted from
particle unstable states can be explained by increasing cooling of the decaying
system due to expansion. This expansion is driven by the radial flow, and
freeze out of particle unstable states might depend on the dynamics of the
expanding system. Source sizes from pp-correlation functions were found to be 9
to 11 fm.


title:
Emission temperatures and freeze out densities from light particle
  correlation functions in Au+Au collisions at 1 A GeV

abstract:
  A study of emission temperatures extracted from excited state populations and
of freeze out radii from light particle intensity interferometry is presented.
Three high resolution dE-E-Hodoscopes with a total of 216 detectors are
combined with the ALADiN setup in order to study Au+Au collisions at 1 A GeV.
In contrast to measurements with the isotope thermometer the extracted apparent
temperatures do not vary with impact parameter thus with excitation energy.
From the extracted radii a freeze out density was determined which decreases
from $0.2\rho_0$ for the most peripheral to less than $0.1\rho_0$ for the most
central collisions. A density--dependent feeding correction is applied to the
different temperature measurements.


title: New Temperature Measurements in 197Au + 197Au Collisions

abstract:
  We report on new measurements of breakup temperatures for target spectators
from 197Au + 197Au reactions at 1000 MeV per nucleon. The temperatures rise
with decreasing impact parameter from 4 MeV for peripheral to about 10 MeV for
the most central collisions, in good agreement with previous results for
projectile spectators at 600 MeV per nucleon.
  The measured temperatures agree quantitatively with the breakup temperatures
predicted by the statistical multifragmentation model. For these calculations a
relation between the initial excitation energy and mass was derived which gives
good simultaneous agreement for the fragment charge correlations.
  The energy spectra of light charged particles and the behaviour of the mean
kinetic energies of neutrons indicate a substantial component of light particle
emission prior to the final breakup stage.


title: Flow Phenomena at AGS Energies

abstract:
  In this talk some of the latest data on directed sideward, elliptic, radial,
and longitudinal flow at AGS energies will be reviewed. A method to identify
the reaction plane event by event and the measurement of its resolution will be
discussed. The distributions of global observables (transverse energy E_T and
charged particle multiplicity N_c), as well as those of identified particles
will be shown. Finally, the data will be put in context with measurements at
other beam energies. These systematics will then be discussed in terms of
possible signatures of the QCD phase transition.


title:
K^+ production in the reaction $^{58}Ni+^{58}Ni$ at incident energies
  from 1 to 2 AGeV

abstract:
  Semi-inclusive triple differential multiplicity distributions of positively
charged kaons have been measured over a wide range in rapidity and transverse
mass for central collisions of $^{58}$Ni with $^{58}$Ni nuclei. The transverse
mass ($m_t$) spectra have been studied as a function of rapidity at a beam
energy 1.93 AGeV. The $m_t$ distributions of K^+ mesons are well described by a
single Boltzmann-type function. The spectral slopes are similar to that of the
protons indicating that rescattering plays a significant role in the
propagation of the kaon. Multiplicity densities have been obtained as a
function of rapidity by extrapolating the Boltzmann-type fits to the measured
distributions over the remaining phase space. The total K^+ meson yield has
been determined at beam energies of 1.06, 1.45, and 1.93 AGeV, and is presented
in comparison to existing data. The low total yield indicates that the K^+
meson can not be explained within a hadro-chemical equilibrium scenario,
therefore indicating that the yield does remain sensitive to effects related to
its production processes such as the equation of state of nuclear matter and/or
modifications to the K^+ dispersion relation.


title: On the normalization of the HBT correlation function

abstract:
  We discuss the question of the normalization of the correlation function and
its consistency with the often used form C(p1,p2) = 1+|f(p1,p2)|^2. We suggest
an event mixing method which allows one to obtain absolutely normalized
correlation functions from experimental data.


title:
First Energy and Angle differential Measurements of e^+e^- -pairs
  emitted by Internal Pair Conversion of excited Heavy Nuclei

abstract:
  We present the first energy and angle resolved measurements of e+e- pairs
emitted from heavy nuclei (Z>=40) at rest by internal pair conversion (IPC) of
transitions with energies of less than 2MeV as well as recent theoretical
results using the DWBA method, which takes full account of relativistic
effects, magnetic substates and finite size of the nucleus. The 1.76MeV E0
transition in Zr90 (Sr source) and the 1.77MeV M1 transition in Pb207 (Bi
source) have been investigated experimentally using the essentially improved
set-up at the double-ORANGE beta-spectrometer of GSI. The measurements prove
the capability of the setup to cleanly identify the IPC pairs in the presence
of five orders of magnitude higher beta- and gamma background from the same
source and to yield essentially background-free sum spectra despite the large
background. Using the ability of the ORANGE setup to directly determine the
opening angle of the e+e- pairs, the angular correlation of the emitted pairs
was measured. In the Zr90 case the correlation could be deduced for a wide
range of energy differences of the pairs. The Zr90 results are in good
agreement with recent theory. The angular correlation deduced for the M1
transition in Pb207 is in strong disagreement with theoretical predictions
derived within the Born approximation and shows almost isotropic character.
This is again in agreement with the new theoretical results.


title:
3He- and 4He-induced nuclear fission - a test of the transition state
  method

abstract:
  Fission in 3He and 4He induced reactions at excitation energies between the
fission barrier and 140 MeV has been investigated. Twentythree fission
excitation functions of various compound nuclei in different mass regions are
shown to scale exactly according to the transition state prediction once the
shell effects are accounted for. New precise measurements of excitation
functions in a mass region where shell effects are very strong, allow one to
test the predictions with an even higher accuracy. The fact that no deviations
from the transition state method have been observed within the experimentally
investigated excitation energy regime allows one to assign limits for the
fission transient time. The precise measurement of fission excitation functions
of neighboring isotopes enables us to experimentally estimate the first chance
fission probability. Even if only first chance fission is investigated, no
evidence for fission transient times larger than 30 zs can be found.


title: Charged pions from Ni on Ni collisions between 1 and 2 AGeV

abstract:
  Charged pions from Ni + Ni reactions at 1.05, 1.45 and 1.93 AGeV are measured
with the FOPI detector. The mean $\pi^{\pm}$ multiplicities per mean number of
participants increase with beam energy, in accordance with earlier studies of
the Ar + KCl and La + La systems. The pion kinetic energy spectra have concave
shape and are fitted by the superposition of two Boltzmann distributions with
different temperatures. These apparent temperatures depend only weakly on
bombarding energy. The pion angular distributions show a forward/backward
enhancement at all energies, but not the $\Theta = 90^0$ enhancement which was
observed in case of the Au + Au system. These features also determine the
rapidity distributions which are therefore in disagreement with the hypothesis
of one thermal source. The importance of the Coulomb interaction and of the
pion rescattering by spectator matter in producing these phenomena is
discussed.


title: Correlations in Nuclear Arrhenius-Type Plots

abstract:
  Arrhenius-type plots for multifragmentation process, defined as the
transverse energy dependence of the single-fragment emission-probability,
-ln(p_{b}) vs 1/sqrt(E_{t}), have been studied by examining the relationship of
the parameters p_{b} and E_{t} to the intermediate-mass fragment multiplicity
<n>. The linearity of these plots reflects the correlation of the fragment
multiplicity with the transverse energy. These plots may not provide thermal
scaling information about fragment production as previously suggested.


title:
Open charm contribution to dilepton spectra produced in nuclear
  collisions at SPS energies

abstract:
  Measurements of open charm hadro-production from CERN and Fermilab
experiments are reviewed, with particular emphasis on the absolute cross
sections and on their A and sqrt(s) dependences. Differential pt and xf cross
sections calculated with the Pythia event generator are found to be in
reasonable agreement with recent data. The calculations are scaled to
nucleus-nucleus collisions and the expected lepton pair yield is deduced. The
charm contribution to the low mass dilepton continuum observed by the CERES
experiment is found to be negligible. In particular, it is shown that the
observed low mass dilepton excess in S-Au collisions cannot be explained by
charm enhancement.


title:
Measurements of the reactions 12C + nu_e -> e- + 12N g.s. and 12C + nu_e
  -> e- + 12N

abstract:
  Charged current reactions of nu_e on 12C have been studied using a mu
decay-at-rest nu_e beam from the Los Alamos Meson Physics Facility. More than
500 events from the exclusive reaction 12C + nu_e -> e- + 12N g.s. were
measured in a large Liquid Scintillator Neutrino Detector (LSND). The observed
energy dependence of the cross section and the angular distribution of the
outgoing electron agree well with theoretical expectations. Measurements are
also presented for inclusive transitions to 12N excited states, 12C + nu_e ->
e- + 12N and compared with theoretical expectations. Results are consistent
with a recent Continuum Random Phase Approximation (CRPA) calculation.


title:
Measurements of the reactions 12C + nu_mue -> mu- + 12N g.s. and 12C +
  nu_mu -> mue- + 12N

abstract:
  Charged current scattering of nu_mu on 12C has been studied using a pi+
decay-in-flight nu_mu beam at the Los Alamos Meson Physics Facility. A sample
of 56.8 +- 9.6 events satisfying criteria for the exclusive reaction 12C +
nu_mu -> mu- + 12N_g.s. was obtained using the large Liquid Scintillator
Neutrino Detector (LSND). The observed flux-averaged cross section, (6.6 +- 1.0
+- 1.0) x 10^-41 cm^2, agrees well with reliable theoretical expectations. A
measurement was also obtained for the inclusive cross section to all accessible
12N states, 12C + nu_\mu -> mu- + X. This flux-averaged cross section is (11.2
+- 0.3 +- 1.8)x 10^-40 cm^2, which is approximately half of that given by a
recent Continuum Random Phase Approximation (CRPA) calculation.


title:
Abundance of Delta Resonances in 58Ni+58Ni Collisions between 1 and 2
  AGeV

abstract:
  Charged pion spectra measured in 58Ni-58Ni collisions at 1.06, 1.45 and 1.93
AGeV are interpreted in terms of a thermal model including the decay of Delta
resonances. The transverse momentum spectra of pions are well reproduced by
adding the pions originating from the Delta-resonance decay to the component of
thermal pions, deduced from the high transverse momentum part of the pion
spectra. About 10 and 18% of the nucleons are excited to Delta states at
freeze-out for beam energies of 1 and 2 AGeV, respectively.


title: Astrophysical neutron capture rates in s- and r-process nucleosynthesis

abstract:
  Astrophysical neutron capture rates of light and heavy nuclei have been
measured and calculated. For the measurements the activation technique was
applied at the 3.75 MV Karlsruhe Van de Graaff accelerator, and at the Geel
electron linear accelerator (GELINA) the time-of-flight (TOF) method was used.
The calculations were performed using direct and compound nuclear capture
models.


title: Direct neutron capture of 48Ca at kT = 52 keV

abstract:
  The neutron capture cross section of 48Ca was measured relative to the known
gold cross section at kT = 52 keV using the fast cyclic activation technique.
The experiment was performed at the Van-de-Graaff accelerator, Universitaet
Tuebingen. The new experimental result is in good agreement with a calculation
using the direct capture model. The 1/v behaviour of the capture cross section
at thermonuclear energies is confirmed, and the adopted reaction rate which is
based on several previous experimental investigations remains unchanged.


title:
Search for Charged Strange Quark Matter Produced in 11.5 A GeV/c Au + Pb
  Collisions

abstract:
  We present results of a search for strange quark matter (strangelets) in 11.5
A GeV/c Au+Pb collisions from the 1994 and 1995 runs of experiment E864 at
Brookhaven's AGS. We observe no strangelet candidates and set a 90% confidence
level upper limit of approximately 3x10**-8 per 10% central interaction for the
production of |Z|=1 and |Z|=2 strangelets over a large mass range and with
metastable lifetimes of about 50 ns or more. These results place constraints
primarily on quark-gluon plasma based production models for strangelets.


title: Double Beta Decays of Mo-100 and Nd-150

abstract:
  The double beta decays of Mo-100 and Nd-150 were studied in a time projection
chamber located 72 m underground. A 3275 h exposure of a 16.7 g sample of
metallic Mo enriched to 97.4 % in Mo-100 resulted in a two-neutrino half-life
of (6.82 + 0.38 - 0.53 +/- 0.68) * 10**18 y. Similarly, a 6287 h exposure of
15.5 g of Nd2O3 enriched to 91 % in Nd-150 yielded (6.75 + 0.37 - 0.42 +/-
0.68) * 10**18 y. Lower limits on half-lives for neutrinoless decay with and
without majoron emission also have been measured.


title:
Evidence for nu_mu -> nu_e Oscillations from Pion Decay in Flight
  Neutrinos

abstract:
  A search for nu_mu -> nu_e oscillations has been conducted at the Los Alamos
Meson Physics Facility using nu_mu from pi^+ decay in flight. An excess in the
number of beam-related events from the C(nu_e,e^-)X inclusive reaction is
observed. The excess is too large to be explained by normal nu_e contamination
in the beam at a confidence level greater than 99%. If interpreted as an
oscillation signal, the observed oscillation probability of (2.6 +- 1.0 +- 0.5)
x 10^{-3} is consistent with the previously reported nu_mu_bar -> nu_e_bar
oscillation evidence from LSND.


title: Protons, Deuterons and Flow

abstract:
  Proton and deuteron m_T spectra and rapidity densities at y=1.9-2.3 are
presented for central SS, SPb and PbPb collisions. The inverse slopes increase
with system size and mass. The radius parameter, R_G, extracted from ratios of
the spectra increases with system size. R_G is proportional to 1/\sqrt{m_T}
consistent with transverse flow and NA44's HBT results.


title: Strangeness Production in Relativistic Heavy Ion Experiments

abstract:
  The role of Strangeness as a signal of the Quark Gluon Plasma in relativistic
heavy ion experiments is discussed. The current experimental status is briefly
presented. Several scenarios which explain the CERN data are discussed.


title:
Weak e+e- lines from internal pair conversion observed in collisions of
  238U with heavy nuclei

abstract:
  We present the results of a Doppler-shift correction to the measured e+e-
sum-energy spectra obtained from e+e- coincidence measurements in 238U + 206Pb
and 238U + 181Ta collisions at beam energies close to the Coulomb barrier,
using an improved experimental setup at the double-Orange spectrometer of GSI.
Internal-Pair-Conversion (IPC) e+e- pairs from discrete nuclear transitions of
a moving emitter have been observed following Coulomb excitation of the 1.844
MeV (E1) transition in 206Pb and neutron transfer to the 1.770 MeV (M1)
transition in 207Pb. In the collision system 238U + 181Ta, IPC transitions were
observed from the Ta-like as well as from the U-like nuclei. In all systems the
Doppler-shift corrected e+e- sum-energy spectra show weak lines at the energies
expected from the corresponding $\gamma$-ray spectra with cross sections being
consistent with the measured excitation cross sections of the $\gamma$ lines
and the theoretically predicted IPC coefficients. No other than IPC e+e-
sum-energy lines were found in the measured spectra. The transfer cross
sections show a strong dependence on the distance of closest approach (R_min),
thus signaling also a strong dependence on the bombarding energy close to the
Coulomb barrier.


title: The TRIUMF Parity Violation Experiment

abstract:
  An experiment (E497) is underway at TRIUMF to measure the angle-integrated,
parity violating longitudinal analyzing power, Az, in proton-proton elastic
scattering, to a precision of +/- 0.2 x 10^-7. The experiment uses a 221 MeV
longitudinally polarized proton beam incident on a 40 cm liquid hydrogen
target. The beam energy is carefully chosen so that the contribution to Az from
the J=0 parity mixed partial wave (1S0-3P0) integrates to zero over the
acceptance of the apparatus, leaving the experiment sensitive mainly (>95%) to
Az arising from the 3P2-1D2, J=2 wave. To minimize sources of systematic error,
the TRIUMF ion source and cyclotron parameters have been refined to the extent
that helicity correlated beam changes are at an extremely low level, and
specialized instrumentation on the E497 beamline is able to measure residual
helicity correlated modulations to a precision consistent with the goals of the
experiment. A data taking run in February-March, 1997 logged approximately 12%
of the desired data and produced a preliminary result, Az = (1.1 +/- 0.4 +/-
0.4) x 10^-7, where the error is statistical only.


title:
A letter of intent for an experiment to measure nu_mu to nu_e
  oscillations and nu_mu disappearance at the Fermilab Booster (BooNE)

abstract:
  This Letter of Intent to the Fermilab Program Advisory Committee describes a
search for neutrino oscillations at the Fermilab booster. It is motivated by
the LSND observation of nu_mu -> nu_e appearance. The booster neutrino
experiment (BooNE) will be capable of observing both nu_mu -> nu_e appearance
and nu_mu disappearance. In addition, the experiment will be able to measure
Delta m^2 and sin^2(2theta) and search for CP violation in the lepton sector.


title:
Stopping and Radial Flow in Central 58Ni + 58Ni Collisions between 1 and
  2 AGeV

abstract:
  The production of charged pions, protons and deuterons has been studied in
central collisions of 58Ni on 58Ni at incident beam energies of 1.06, 1.45 and
1.93 AGeV. The dependence of transverse-momentum and rapidity spectra on the
beam energy and on the centrality of the collison is presented. It is shown
that the scaling of the mean rapidity shift of protons established for AGS and
SPS energies is valid down to 1 AGeV. The degree of nuclear stopping is
discussed; the IQMD transport model reproduces the measured proton rapidity
spectra for the most central events reasonably well, but does not show any
sensitivity between the soft and the hard equation of state (EoS). A radial
flow analysis, using the midrapidity transverse-momentum spectra, delivers
freeze-out temperatures T and radial flow velocities beta_r which increase with
beam energy up to 2 AGeV; in comparison to existing data of Au on Au over a
large range of energies only beta_r shows a system size dependence.


title:
Proton and Pion Production Relative to the Reaction Plane in Au + Au
  Collisions at AGS Energies

abstract:
  Results are presented of an analysis of proton and charged pion azimuthal
distributions measured with respect to the reaction plane in Au + Au collisions
at a beam momentum of about 11 AGeV/c. The azimuthal anisotropy is studied as a
function of particle rapidity and transverse momentum for different
centralities of the collisions. The triple differential (in rapidity,
transverse momentum, and azimuthal angle) distributions are reconstructed. A
comparison of the results with a previous analysis of charged particle and
transverse energy flow as well as with model predictions is presented.


title: The Cross Section of 3He(3He,2p)4He measured at Solar Energies

abstract:
  We report on the results of the \hethet\ experiment at the underground
accelerator facility LUNA (Gran Sasso). For the first time the lowest
projectile energies utilized for the cross section measurement correspond to
energies below the center of the solar Gamow peak ($E_{\rm 0}$=22 keV). The
data provide no evidence for the existence of a hypothetical resonance in the
energy range investigated. Although no extrapolation is needed anymore (except
for energies at the low-energy tail of the Gamow peak), the data must be
corrected for the effects of electron screening, clearly observed the first
time for the \hethet\ reaction. The effects are however larger than expected
and not understood, leading presently to the largest uncertainty on the quoted
$S_{\rm b}(E_{\rm 0})$ value for bare nuclides (=5.40 MeV b).


title: Evidence of Double Phonon Excitations in ^{16}O + ^{208}Pb Reaction

abstract:
  The fusion cross-sections for ^{16}O + ^{208}Pb, measured to high precision,
enable the extraction of the distribution of fusion barriers. This shows a
structure markedly different from the single-barrier which might be expected
for fusion of two doubly-closed shell nuclei. The results of exact coupled
channel calculations performed to understand the observations are presented.
These calculations indicate that coupling to a double octupole phonon excited
state in ^{208}Pb is necessary to explain the experimental barrier
distributions.


title: Barrier Distributions as a Tool to Investigate Fusion and Fission

abstract:
  The recent availability of precisely measured fusion cross-sections has
enabled the extraction of a representation of the distribution of barriers
encountered during fusion. These representations, obtained from a variety of
reactions, provide a direct observation of how the structure of the fusing
nuclei changes the inter-nuclear potential landscape, thus affecting the fusion
probability. Recent experiments showing the effects of static quadrupole and
hexadecapole deformation, single-- and double-phonon states, transfer of
nucleons between two nuclei, and high lying excited states are reviewed. The
application of these concepts to the explanation of the anomalous
fission-fragment anisotropies observed following reactions with actinides is
discussed.


title: A Xenon Solar Neutrino Detector

abstract:
  The neutrino capture by $^{131}$Xe with a threshold at 352 keV as reaction to
detect solar neutrinos is examined. The most important feature of this process
is its high sensitivity to beryllium neutrinos, which contribute approximately
40% to the total capture rate (45 SNU) assuming the fluxes predicted by the
Standard Solar Model.


title: Onset of Nuclear Matter Expansion in Au+Au Collisions

abstract:
  Using the FOPI detector at GSI Darmstadt, excitation functions of collective
flow components were measured for the Au+Au system, in the reaction plane and
out of this plane, at seven incident energies ranging from 100AMeV to 800AMeV.
The threshold energies, corresponding to the onset of sideward-flow (balance
energy) and squeeze-out effect (transition energy), are extracted from
extrapolations of these excitation functions toward lower beam energies for
charged products with Z>2. The transition energy is found to be larger than the
balance energy. The impact parameter dependence of both balance and transition
energies, when extrapolated to central collisions, suggests comparable although
slightly higher values than the threshold energy for the radial flow. The
relevant parameter seems to be the energy deposited into the system in order to
overcome the attractive nuclear forces.


title:
Comment on Constraints on the Low-Energy E1 Cross Section of
  12C(alpha,gamma)16O from the Beta-Delayed Alpha Spectrum of 16N

abstract:
  We dispute the alteration by Azuma et al. of the energy calibration of the
Mainz('71) data on the beta-delayed alpha-particle emission of $^{16}N$ as well
as the very justification of the recalibration. We use the unaltered data to
observe a pronounced disagreement between the TRIUMF('94) and Mainz('71) data
sets on both the high and low energy sides of the primary peak (at 2.36 MeV) of
the $^{16}N$ alpha-spectrum. We cannot support the dismissal of the Mainz('71)
spectrum by the TRIUMF collaboration and emphasize the need to include it in
R-matrix fits. We discuss the need for new improved data to resolve this
disagreement and its implication for the extracted p-wave astrophysical
S-factor of the $^{12}C(\alpha,\gamma)^{16}O$ reaction.


title: Search for Exotic Strange Quark Matter in High Energy Nuclear Reactions

abstract:
  We report on a search for metastable positively and negatively charged states
of strange quark matter in Au+Pb reactions at 11.6 A GeV/c in experiment E864.
We have sampled approximately six billion 10% most central Au+Pb interactions
and have observed no strangelet states (baryon number A < 100 droplets of
strange quark matter). We thus set upper limits on the production of these
exotic states at the level of 1-6 x 10^{-8} per central collision. These limits
are the best and most model independent for this colliding system. We discuss
the implications of our results on strangelet production mechanisms, and also
on the stability question of strange quark matter.


title:
Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam
  Energies from 1.04 to 4.88 GeV

abstract:
  Measurements of dielectron production in p+p and p+d collisions with beam
kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross
section is presented as a function of invariant pair mass, transverse momentum,
and rapidity. The shapes of the mass spectra and their evolution with beam
energy provide information about the relative importance of the various
dielectron production mechanisms in this energy regime. The p+d to p+p ratio of
the dielectron yield is also presented as a function of invariant pair mass,
transverse momentum, and rapidity. The shapes of the transverse momentum and
rapidity spectra from the p+d and p+p systems are found to be similar to one
another for each of the beam energies studied. The beam energy dependence of
the integrated cross sections is also presented.


title: Parity Violation in Proton-Proton Scattering

abstract:
  Measurements of parity-violating longitudinal analyzing powers (normalized
asymmetries) in polarized proton-proton scattering provide a unique window on
the interplay between the weak and strong interactions between and within
hadrons. Several new proton-proton parity violation experiments are presently
either being performed or are being prepared for execution in the near future:
at TRIUMF at 221 MeV and 450 MeV and at COSY (Kernforschungsanlage Juelich) at
230 MeV and near 1.3 GeV. These experiments are intended to provide stringent
constraints on the set of six effective weak meson-nucleon coupling constants,
which characterize the weak interaction between hadrons in the energy domain
where meson exchange models provide an appropriate description. The 221 MeV is
unique in that it selects a single transition amplitude (3P2-1D2) and
consequently constrains the weak meson-nucleon coupling constant h_rho{pp}. The
TRIUMF 221 MeV proton-proton parity violation experiment is described in some
detail. A preliminary result for the longitudinal analyzing power is Az = (1.1
+/-0.4 +/-0.4) x 10^-7. Further proton-proton parity violation experiments are
commented on. The anomaly at 6 GeV/c requires that a new multi-GeV
proton-proton parity violation experiment be performed.


title:
Search for extremely deformed fission fragment in ^{28}Si+^{28}Si with
  Eurogam Phase II

abstract:
  A high-resolution study of fragment-fragment-$\gamma$ triple coincident
measurements of the symmetric-mass fission exit-channel from the
^{28}Si+^{28}Si reaction has been performed at the VIVITRON Tandem facility by
using the EUROGAM Phase II $\gamma$-ray spectrometer. The bombarding energy
E_{lab}(^{28}Si) = 111.6 MeV has been chosen to populate a well known
quasi-molecular resonance in ^{56}Ni. Evidence is presented for a selective
population of states in ^{28}Si fragments arising from the symmetric-fission of
the ^{56}Ni compound nucleus. In the resonant region the enhanced population of
the K^{\pi} = 3_{1}^{-} band of the ^{28}Si nucleus, indicative of an oblate
deformed shape, appears to play a significant role in the collision processes.
The resonant behavior in the elastic and inelatic ^{28}Si+^{28}Si exit-channels
is found to be correlated to strong disalignment features of the di-nuclear
oblate-oblate system with an equator-equator stable configuration.


title: Lambda Hyperons in 2 A*GeV Ni + Cu Collisions

abstract:
  A sample of Lambda's produced in 2 A*GeV Ni + Cu collisions has been obtained
with the EOS Time Projection Chamber at the Bevalac. Low background in the
invariant mass distribution allows for the unambiguous demonstration of Lambda
directed flow. The transverse mass spectrum at mid-rapidity has the
characteristic shoulder-arm shape of particles undergoing radial transverse
expansion. A linear dependence of Lambda multiplicity on impact parameter is
observed, from which a total Lambda + Sigma^0 production cross section of $112
+/- 24 mb is deduced. Detailed comparisons with the ARC and RVUU models are
made.


title:
Reduciblity, Arrhenius plots and the Uroboros Dragon, a reply to the
  preprint "Correlations in Nuclear Arrhenius-Type Plots" by M.B. Tsang and P.
  Danielewicz

abstract:
  In a recent preprint by Tsang and Danielewicz, the authors attempt to give
alternative or trivial explanations for the reducible and "thermal" nature of
the intermediate mass fragment excitation functions reported previously (Phys.
Rev. Lett. 74, 1530 (1995), Phys. Lett B 361, 25 (1995), Phys. Rep. 287, 249
(1997)). We demonstrate that their proposed "self-correlation" explanation for
linear Arrhenius plots is based upon a flawed autocorrelation analysis
involving circular reasoning.


title:
Subthreshold K+ production in deuteron and alpha induced nuclear
  reactions

abstract:
  Double differential cross sections have been measured for pi+ and K+ emitted
around midraidity in d+A and He+A collisions at a beam kinetic energy of 1.15
GeV/nucleon. The total pi+ yield increases by a factor of about 2 when using an
alpha projectile instead of a deuteron whereas the K+ yield increases by a
factor of about 4. According to transport calculations, the K+ enhancement
depends both on the number of hadron-hadron collisions and on the energy
available in those collisions: their center-of-mass energy increases with
increasing number of projectile nucleons.


title:
A Measurement of the Interference Structure Function, R_LT, for the
  12C(e,e'p) reaction in the Quasielastic Region

abstract:
  The coincidence cross-section and the interference structure function, R_LT,
were measured for the 12C(e,e'p) 11B reaction at quasielastic kinematics and
central momentum transfer of q=400 MeV/c. The measurement was at an opening
angle of theta_pq=11 degrees, covering a range in missing energy of E_m = 0 to
65 MeV. The R_LT structure function is found to be consistent with zero for E_m
> 50 MeV, confirming an earlier study which indicated that R_L vanishes in this
region. The integrated strengths of the p- and s-shell are compared with a
Distorted Wave Impulse Approximation calculation. The s-shell strength and
shape are compared with a Hartree Fock-Random Phase Approximation calculation.
The DWIA calculation overestimates the cross sections for p- and s-shell proton
knockout as expected, but surprisingly agrees with the extracted R_LT value for
both shells. The HF-RPA calculation describes the data more consistently, which
may be due to the inclusion of 2-body currents in this calculation.


title: Azimuthal Anisotropies as Stringent Test for Nuclear Transport Models

abstract:
  Azimuthal distributions of charged particles and intermediate mass fragments
emitted in Au+Au collisions at 600AMeV have been measured using the FOPI
facility at GSI-Darmstadt. Data show a strong increase of the in-plane
azimuthal anisotropy ratio with the charge of the detected fragment.
Intermediate mass fragments are found to exhibit a strong momentum-space
alignment with respect of the reaction plane. The experimental results are
presented as a function of the polar center-of-mass angle and over a broad
range of impact parameters. They are compared to the predictions of the Isospin
Quantum Molecular Dynamics model using three different parametrisations of the
equation of state. We show that such highly accurate data provide stringent
test for microscopic transport models and can potentially constrain separately
the stiffness of the nuclear equation of state and the momentum dependence of
the nuclear interaction.


title: Antiproton Production in 11.5 A GeV/c Au+Pb Nucleus-Nucleus Collisions

abstract:
  We present the first results from the E864 collaboration on the production of
antiprotons in 10% central 11.5 A GeV/c Au+Pb nucleus collisions at the
Brookhaven AGS. We report invariant multiplicities for antiproton production in
the kinematic region 1.4<y<2.2 and 50<p_T<300 MeV/c, and compare our data with
a first collision scaling model and previously published results from the E878
collaboration. The differences between the E864 and E878 antiproton
measurements and the implications for antihyperon production are discussed.


title: Evidence for nu_mu -> nu_e Neutrino Oscillations from LSND

abstract:
  A search for nu_mu -> nu_e oscillations has been conducted with the LSND
apparatus at the Los Alamos Meson Physics Facility. Using nu_mu from pi^+ decay
in flight, the nu_e appearance is detected via the charged-current reaction
C(nu_e,e^-)X. Two independent analyses observe a total of 40 beam-on
high-energy electron events (60 < E_e < 200 MeV) consistent with the above
signature. This number is significantly above the 21.9 +- 2.1 events expected
from the nu_e contamination in the beam and the beam-off background. If
interpreted as an oscillation signal, the observed oscillation probability of
(2.6 +- 1.0 +- 0.5) x 10^{-3} is consistent with the previously reported
nu_mu_bar -> nu_e_bar oscillation evidence from LSND.


title: The $^4$He$(e,e'p)$ Cross Section at Large Missing Energy

abstract:
  The $(e,e'p)$ reaction on $^{4}{He}$ nuclei was studied in kinematics
designed to emphasize effects of nuclear short-range correlations. The measured
cross sections display a peak in the kinematical regions where two-nucleon
processes are expected to dominate. Theoretical models incorporating
short-range correlation effects agree reasonably with the data.


title: Antineutrino Geophysics with Liquid Scintillator Detectors

abstract:
  Detecting the antineutrinos emitted by the decay of radioactive elements in
the mantle and crust could provide a direct measurement of the total abundance
of uranium and thorium in the Earth. In calculating the antineutrino flux at
specific sites, the local geology of the crust and the background from the
world's nuclear power reactors are important considerations. Employing a global
crustal map, with type and thickness data, and using recent estimates of the
uranium and thorium distribution in the Earth, we calculate the antineutrino
event rate for two new neutrino detectors. We show that spectral features allow
terrestrial antineutrino events to be identified above reactor antineutrino
backgrounds and that the uranium and thorium contributions can be separately
determined.


title:
Measurement of quasi-elastic 12C(p,2p) scattering at high momentum
  transfer

abstract:
  We measured the high-momentum quasi-elastic 12C(p,2p) reaction (at center of
mass angle near 90 degrees) for 6 and 7.5 GeV/c incident protons. The
three-momentum components of both final state protons were measured and the
missing energy and momentum of the target proton in the nucleus were
determined.
  The validity of the quasi-elastic picture was verified up to Fermi momenta of
about 450 MeV/c, where it might be questionable. Transverse and longitudinal
Fermi momentum distributions of the target proton were measured and compared to
independent particle models which do not reproduce the large momentum tails. We
also observed that the transverse Fermi distribution gets wider as the
longitudinal component increases in the beam direction, in contrast to a simple
Fermi gas model.


title:
Measurements at low energies of the polarization-transfer coefficient
  Kyy' for the reaction 3H(p,n)3He at 0 degrees

abstract:
  Measurements of the transverse polarization coefficient Kyy' for the reaction
3H(p,n)3He are reported for outgoing neutron energies of 1.94, 5.21, and 5.81
MeV. This reaction is important both as a source of polarized neutrons for
nuclear physics experiments, and as a test of theoretical descriptions of the
nuclear four-body system. Comparison is made to previous measurements,
confirming the 3H(p,n)3He reaction can be used as a polarized neutron source
with the polarization known to an accuracy of approximately 5%. Comparison to
R-matrix theory suggests that the sign of the 3F3 phase-shift parameter is
incorrect. Changing the sign of this parameter dramatically improves the
agreement between theory and experiment.


title: Directed and Elliptic Flow in 158 GeV/Nucleon Pb + Pb Collisions

abstract:
  The directed and elliptic flow of protons and charged pions has been observed
from the semi-central collisions of a 158 GeV/nucleon Pb beam with a Pb target.
The rapidity and transverse momentum dependence of the flow has been measured.
The directed flow of the pions is opposite to that of the protons but both
exhibit negative flow at low pt. The elliptic flow of both is fairly
independent of rapidity but rises with pt.


title:
Fission Fragment Spectroscopy on a $^{28}$Si+$^{28}$Si Quasimolecular
  Resonance

abstract:
  Fragment-fragment-$\gamma$ triple coincident measurements of the $^{28}$Si +
$^{28}$Si reaction at E$_{lab.}$ = 111.6 MeV carefully chosen to populate J =
38$^{+}$ resonance have been performed at the VIVITRON tandem facility by using
Eurogam Phase II $\gamma$-ray spectrometer. In the $^{28}$Si + $^{28}$Si
exit-channel, the resonance behavior of the $^{28}$Si + $^{28}$Si reaction at
the beam energy is clearly confirmed. An unexpected spin disalignment has been
observed in the measured angular distributions in the elastic, inelastic, and
mutual excitation channels. This disalignment is found to be consistent with
particle-$\gamma$ angular correlations and supported by the molecular model
prediction of a "butterfly motion". The K$^{\pi}$ = 0$^{+}_{3}$ band
corresponding to the large prolate deformation of the $^{28}$Si is more
intensely fed in the resonance region. The selective population of high-excited
states are discussed within a statistical fusion-fission model. In the $^{32}$S
+ $^{24}$Mg exit-channel, the spectroscopic study of the $^{32}$S, has revealed
the contribution of a new $\gamma$-ray transition $0^{+} (8507.8 keV) \to
2^{+}_{1} (2230.2 keV) $.


title: Reconstructing azimuthal distributions in nucleus-nucleus collisions

abstract:
  Azimuthal distributions of particles produced in nucleus-nucleus collisions
are measured with respect to an estimated reaction plane which, because of
finite multiplicity fluctuations, differs in general from the true reaction
plane. It follows that the measured distributions do not coincide with the true
ones. I propose a general method of reconstructing the Fourier coefficients of
the true azimuthal distributions from the measured ones. This analysis suggests
that the Fourier coefficients are the best observables to characterize
azimuthal anisotropies because, unlike other observables such as the in-plane
anisotropy ratio or the squeeze-out ratio, they can be reconstructed
accurately.


title:
Proton and Antiproton Distributions at Mid-Rapidity in Proton-Nucleus
  and Sulphur-Nucleus Collisions

abstract:
  Experiment NA44 has measured proton and antiproton distributions at
mid-rapidity in sulphur and proton collisions with nuclear targets at 200 and
450 GeV/c per nucleon respectively. The inverse slopes of transverse mass
distributions increase with system size for both protons and antiprotons but
are slightly lower for antiprotons. this could happen if antiprotons are
annihilated in the nuclear medium. The antiproton yield increases with system
size and centrality and is largest at mid-rapdity. The proton yield also
increases with system size and centrality, but decreases from backward rapidity
to midrapidity. The stopping of protons at these energies lies between the full
stopping and nuclear transparency scenarios. The data are in reasonable
agreement with RQMD predictions except for the antiproton yields from
sulphur-nucleus collisions. PACS numbers 25.75.-q 13.85.-t 13.60.Rj


title:
Fusion and Binary-Decay Mechanisms in the $^{35}$Cl+$^{24}$Mg System at
  E/A $\approx$ 8 MeV/Nucleon

abstract:
  Compound-nucleus fusion and binary-reaction mechanisms have been investigated
for the $^{35}$Cl+$^{24}$Mg system at an incident beam energy of E$_{Lab}$= 282
MeV. Charge distributions, inclusive energy spectra, and angular distributions
have been obtained for the evaporation residues and the binary fragments.
Angle-integrated cross sections have been determined for evaporation residues
from both the complete and incomplete fusion mechanisms. Energy spectra for
binary fragment channels near to the entrance-channel mass partition are
characterized by an inelastic contribution that is in addition to a fully
energy damped component. The fully damped component which is observed in all
the binary mass channels can be associated with decay times that are comparable
to, or longer than the rotation period. The observed mass-dependent cross
sections for the fully damped component are well reproduced by the fission
transition-state model, suggesting a fusion followed by fission origin. The
present data cannot, however, rule out the possibility that a long-lived
orbiting mechanism accounts for part or all of this yield.


title: Strangelet Searches in High Energy Heavy Ion Collisions

abstract:
  In this contribution I concentrate on the recent results from experiment E864
at the BNL-AGS. E864's recent analysis have achieved sensitivities of
approximately $3\times 10^{-8}$ per 10% central interaction for the production
of charged strangelets and the first analysis for neutral strangelets is near
completion. I put the results in the context of coalescence and quark gluon
plasma strangelet production models.


title:
Measurement of the Induced Proton Polarization P_n in the
  12C(e,e'\vec{p}) Reaction

abstract:
  The first measurements of the induced proton polarization, P_n, for the 12C
(e,e'\vec{p}) reaction are reported. The experiment was performed at quasifree
kinematics for energy and momentum transfer (\omega,q) \approx (294 MeV, 756
MeV/c) and sampled a recoil momentum range of 0-250 MeV/c. The induced
polarization arises from final-state interactions and for these kinematics is
dominated by the real part of the spin-orbit optical potential. The
distorted-wave impulse approximation provides good agreement with data for the
1p_{3/2} shell. The data for the continuum suggest that both the 1s_{1/2} shell
and underlying l > 1 configurations contribute.


title: Progress In Nuclear Astrophysics Using Secondary Radioactive Beams

abstract:
  We review progress in studying two central problems in Nuclear Astrophysics:
The \be7pg reaction is one of the major source of uncertainties in estimating
the \b8 solar neutrino flux and is critical for the Solar Neutrino Problem. We
discuss a newly emerging method to extract this cross section from the Coulomb
dissociation of the radioactive beam of \b8. The Coulomb dissociation appears
to provide a viable alternative method for measuring the \be7pg reaction rate.
Several attempts to constrain the p-wave S-factor of the \c12ag reaction at
Helium burning temperatures (200 MK) using the beta-delayed alpha-particle
emission of \n16 have been made, and it is claimed that this S-factor is known,
as quoted by the TRIUMF collaboration. In contrast reanalyses (by G.M. hale) of
all thus far available data (including the \n16 data) does not rule out a small
S-factor solution. Furthermore, we improved our previous Yale-UConn study of
the beta-delayed alpha-particle emission of \n16. Our newly measured spectrum
of the beta-delayed alpha-particle emission of \n16 is not consistent with the
TRIUMF('94) data, but is consistent with the Seattle('95) data, as well as the
earlier (unaltered !) data of Mainz('71). The implication of this discrepancies
for the extracted astrophysical p-wave s-factor is briefly discussed.


title: New measurement and analysis of the 7Be(p,gamma)8B cross section

abstract:
  Cross sections for the 7Be(p,gamma)8B reaction have been measured for E_c.m.=
0.35-1.4 MeV using radioactive 7Be targets. Two independent measurements
carried out with different beam conditions, different targets and detectors are
in excellent agreement. A statistical comparison of these measurements with
previous results leads to a restricted set of consistent data. The deduced
zero-energy S-factor S(0) is found to be 15-20% smaller than the previously
recommended value. This implies a 8B solar neutrino flux lower than previously
predicted in various standard solar models.