title:
Evidence for Different Freeze-Out Radii of High- and Low-Energy Pions
  Emitted in Au+Au Collisions at 1 GeV/nucleon

abstract:
  Double differential production cross sections of negative and positive pions
and the number of participating protons have been measured in central Au+Au
collisions at 1 GeV per nucleon incident energy. At low pion energies the pi^-
yield is strongly enhanced over the pi^+ yield. The energy dependence of the
pi^-/pi^+ ratio is assigned to the Coulomb interaction of the charged pions
with the protons in the reaction zone. The deduced Coulomb potential increases
with increasing pion c.m. energy. This behavior indicates different freeze-out
radii for different pion energies in the c.m.~frame.


title: Excited States in 52Fe and the Origin of the Yrast Trap at I=12+

abstract:
  Excited states in 52Fe have been determined up to spin 10\hbar in the
reaction 28Si + 28Si at 115 MeV by using \gamma-ray spectroscopy methods at the
GASP array. The excitation energy of the yrast 10+ state has been determined to
be 7.381 MeV, almost 0.5 MeV above the well known \beta+-decaying yrast 12+
state, definitely confirming the nature of its isomeric character. The mean
lifetimes of the states have been measured by using the Doppler Shift
Attenuation method. The experimental data are compared with spherical shell
model calculations in the full pf-shell.


title:
A Comparison of Polarization Observables in Electron Scattering from the
  Proton and Deuteron

abstract:
  Recoil proton polarization observables were measured for both the p($\vec
{\rm e}$,e$^\prime\vec{\rm p}\,$) and d($\vec {\rm e}$,e$^\prime\vec{\rm
p}\,)$n reactions at two values of Q$^2$ using a newly commissioned proton
Focal Plane Polarimeter at the M.I.T.-Bates Linear Accelerator Center. The
hydrogen and deuterium spin-dependent observables $D_{\ell\ell}$ and
$D_{{\ell}t}$, the induced polarization $P_n$ and the form factor ratio
$G^p_E/G^p_M$ were measured under identical kinematics. The deuterium and
hydrogen results are in good agreement with each other and with the plane-wave
impulse approximation (PWIA).


title:
Comment on "Halo Properties of the First 1/2+ State in 17F from the
  16O(p,gamma)17F Reaction''

abstract:
  The increase at low energy of the S-factor for the 16O(p,gamma)17F* reaction
claimed by Morlock et al. to be a new observation is well documented and
explained in the literature.


title:
Low-mass e+e- pair production in 158 A GeV Pb-Au collisions at the CERN
  SPS, its dependence on multiplicity and transverse momentum

abstract:
  We report a measurement of low-mass electron pairs observed in 158
GeV/nucleon Pb-Au collisions. The pair yield integrated over the range of
invariant masses 0.2 < m < 2.0 GeV is enhanced by a factor of 3.5 +/- 0.4
(stat) +/- 0.9 (syst) over the expectation from neutral meson decays. As
observed previously in S-Au collisions, the enhancement is most pronounced in
the invariant-mass region 300-700 MeV. For Pb-Au we find evidence for a strong
increase of the enhancement with centrality. In addition, we show that the
enhancement covers a wide range in transverse momentum, but is largest at the
lowest observed pt.


title:
Deuteron photo-disintegration with polarised photons in the energy range
  30 - 50 MeV

abstract:
  The reaction d(\vec\gamma,np) has been studied using the tagged and polarised
LADON gamma ray beam at an energy 30 - 50 MeV to investigate the existence of
narrow dibaryonic resonances recently suggested from the experimental
measurements in a different laboratory. The beam was obtained by Compton
back-scattering of laser light on the electrons of the storage ring ADONE.
Photo-neutron yields were measured at five neutron angle \vartheta_n = 22,
55.5, 90, 125 and 157 degrees in the center of mass system.Our results do not
support the existence of such resonances.


title:
Correlated forward-backward dissociation and neutron spectra as a
  luminosity monitor in heavy ion colliders

abstract:
  Detection in zero degree calorimeters of the correlated forward-backward
Coulomb or nuclear dissociation of two colliding nuclei is presented as a
practical luminosity monitor in heavy ion colliders. Complementary predictions
are given for total correlated Coulomb plus nuclear dissociation and for
correlated forward-backward single neutrons from the giant dipole peak.


title:
A direct measurement of short range NN correlations in nuclei via the
  reaction C(p,2p+n)

abstract:
  The reaction 12C(p,2p+n) was measured at beam momenta of 5.9 and 7.5 GeV/c..
We established the quasi-elastic character of the reaction C(p,2p) at
$\theta_{cm}\simeq 90^o$, in a kinematically complete measurement. The neutron
momentum was measured in triple coincidence with the two emerging high momentum
protons. We present the correlation between the momenta of the struck target
proton and the neutron. The events are associated with the high momentum
components of the nuclear wave function. We conclude that two-nucleon short
range correlations have been seen experimentally. The conclusion is based on
kinematical correlations and is not based on specific theoretical models.


title: A Large Scale Double Beta and Dark Matter Experiment: GENIUS

abstract:
  The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated
the large potential of double beta decay to search for new physics beyond the
Standard Model. To increase by a major step the present sensitivity for double
beta decay and dark matter search much bigger source strengths and much lower
backgrounds are needed than used in experiments under operation at present or
under construction. We present here a study of a project proposed recently,
which would operate one ton of 'naked' enriched GErmanium-detectors in liquid
NItrogen as shielding in an Underground Setup (GENIUS). It improves the
sensitivity to neutrino masses to 0.01 eV. A ten ton version would probe
neutrino masses even down to 10^-3 eV. The first version would allow to test
the atmospheric neutrino problem, the second at least part of the solar
neutrino problem. Both versions would allow in addition significant
contributions to testing several classes of GUT models. These are especially
tests of R-parity breaking supersymmetry models, leptoquark masses and
mechanism and right-handed W-boson masses comparable to LHC. The second issue
of the experiment is the search for dark matter in the universe. The entire
MSSM parameter space for prediction of neutralinos as dark matter particles
could be covered already in a first step of the full experiment - with the same
purity requirements but using only 100 kg of 76Ge or even of natural Ge -
making the experiment competitive to LHC in the search for supersymmetry.
  The layout of the proposed experiment is discussed and the shielding and
purity requirements are studied using GEANT Monte Carlo simulations. As a
demonstration of the feasibility of the experiment first results of operating a
'naked' Ge detector in liquid nitrogen are presented.


title: Search for Solar Axions Using Fe-57

abstract:
  We have made a search for Fe-57 gamma rays of energy 14.4 keV induced by
resonant absorption of monochromatic solar axions, as proposed by Moriyama. The
proposed axions are suggested to be emitted from the Sun, in M1 transitions
between the first, thermally excited state and the ground state of Fe-57. An
upper limit on hadronic axion mass of 745 eV is obtained at the 95% confidence
level, it being assumed that z=0.56 and S=0.5.


title: Temperatures of Exploding Nuclei

abstract:
  Breakup temperatures in central collisions of 197Au + 197Au at bombarding
energies E/A = 50 to 200 MeV were determined with two methods. Isotope
temperatures, deduced from double ratios of hydrogen, helium, and lithium
isotopic yields, increase monotonically with bombarding energy from 5 MeV to 12
MeV, in qualitative agreement with a scenario of chemical freeze-out after
adiabatic expansion. Excited-state temperatures, derived from yield ratios of
states in 4He, 5Li, 6Li, and 8Be, are about 5 MeV, independent of the
projectile energy, and seem to reflect the internal temperature of fragments at
their final separation from the system.
  PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.-q


title: Dileptons and Photons at the CERN SPS

abstract:
  The paper reviews all experimental results on dileptons with invariant mass m
< 3 GeV/c$^2$ and real photons obtained from the CERN SPS heavy-ion program
with S and Pb beams, together with the current attempts to understand them.


title: New Tool for "Old" Nuclear Physics: FEL gamma-Nucleus Colliders

abstract:
  A new method has been considered to investigate the scattering reactions with
photons on fully ionized nuclei. To induce $\gamma $-nucleus collisions a free
electron laser and a heavy ion synchrotron have been considered bringing them
together. Main parameters of the collider (especially LHC and HERA for the
acceleration of nuclei) have been estimated. Rough calculations have also been
made for the cross sections of the excited nuclei production. Finally, some
design problems involving the collider have been considered.


title: Alpha - 5He decaying states and the ground state rotational band of 9Be

abstract:
  In a measurement of the 9Be(7Li,alpha 7Li)n alpha reaction at E = 52 MeV it
is unambigously established for the first time that the 9Be excited states
around 6.5 and 11.3 MeV decay into the alpha + 5He channel. This fact may
support previous claims that the 11.3 MeV state is also a member of the ground
state rotational band.


title:
Anisotropic flow of identified particles in Au+Au collisions at AGS
  energy

abstract:
  Anisotropic flow of protons, $\pi^{\pm}$, $K^+$, deuterons, tritons, $^3$He,
and $^4$He is analyzed as a function of transverse momentum for different
centralities of the collision.


title:
Comparison of eta and eta' production in the pp -> pp eta(eta')
  reactions near threshold

abstract:
  The total cross section of the pp -> pp eta' reaction has been measured at
two energies near threshold by detecting the final protons in a magnetic
spectrometer. The values obtained are about a factor of 70 less than for the
corresponding eta production, in good agreement with the predictions of a
one-pion-exchange model.


title:
A versatile dielectron trigger for nucleon-nucleon and nucleus-nucleus
  collisions

abstract:
  A novel approach for a versatile first level dielectron trigger is presented.
This trigger operates in the low multiplicity environment of nucleon-nucleon
reactions as well as in the high multiplicity situation of nucleus-nucleus
collisions. For optimal trigger performance, time of flight conditions for the
two fastest particles of the event are combined with event multiplicity
requirements. The dielectron trigger efficiency is given. The event reduction
factor of such a trigger approach is studied for a low, a medium and a high
multiplicity environment. The impact parameter dependence of the event
reduction is given. 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: Au+Au Reactions at the AGS: Experiments E866 and E917

abstract:
  Particle production and correlation functions from Au+Au reactions have been
measured as a function of both beam energy (2-10.7AGeV) and impact parameter.
These results are used to probe the dynamics of heavy-ion reactions, confront
hadronic models over a wide range of conditions and to search for the onset of
new phenomena.


title: Flow systematics from SIS to SPS energies

abstract:
  The various flow phenomena observed at energies between 50 AMeV and 160 AGeV
are reviewed. I first define three types of flow: directed flow and elliptic
flow, which are the two first Fourier components of the azimuthal distribution
in non-central collisions; radial flow, which is deduced from an analysis of
transverse momentum spectra in central collisions. Then, I review the
observations of directed flow and elliptic flow, with emphasis on recent
results. I discuss their dependence on various parameters: global geometry
(impact parameter, mass numbers of colliding nuclei and bombarding energy) and
individual observables (rapidity, transverse momentum and particle type).
Finally, I explain how azimuthal distributions can be measured experimentally.


title:
Consistency of parity-violating pion-nucleon couplings extracted from
  measurements in 18F and 133Cs

abstract:
  The recent measurement of the nuclear anapole moment of 133Cs has been
interpreted to yield a value of the weak pion-nucleon coupling H_pi^1 which
contradicts the upper limit from the 18F experiments. We argue that because of
the sensitivity of the anapole moment to H_rho^0 in the odd proton nucleus
133Cs, there is a combination of weak meson-nucleon couplings which satisfies
both experiments and which is (barely) in agreement with theory. In addition,
the anapole moment measurement in 205Tl gives a constraint which is
inconsistent with the value from 133Cs, calling into question the theory of
nuclear anapole moments. We argue that measurements of directional asymmetry in
n+p-->d+gamma and in the photo-disintegration of the deuteron by circularly
polarized photons, combined with results from pp scattering, would determine
H_pi^1 and several other weak meson-nucleon couplings in a model-independent
way.


title:
Neutral pions and eta mesons as probes of the expanding hadronic
  fireball in nucleus-nucleus collisions at SIS

abstract:
  The production of neutral pions and eta mesons in collisions of light,
intermediate-mass, and heavy nuclei at beam energies between 0.8 A GeV and 2.0
A GeV is discussed in the framework of a model assuming equilibrium at
hadrochemical and thermal freeze-out, respectively. From the relative particle
yields temperatures of 56-90 MeV and baryon chemical potentials of 780-675 MeV
are deduced at chemical freeze-out. Midrapidity spectra of neutral pions and
eta mesons are consistent with the obtained temperatures if, in addition, the
measured transverse expansion of the collision zone is taken into account. In
contrast to results from similar analyses of AGS and SPS data the deduced
freeze-out parameters are far below the phase boundary between a hadron gas and
a quark-gluon plasma.


title:
$\eta^{\prime}$ production in proton-proton scattering close to
  threshold}

abstract:
  The $pp \to pp \eta^{\prime}$ (958) reaction has been measured at COSY using
the internal beam and the COSY-11 facility. The total cross sections at the
four different excess energies \mbox{$ Q = ~1.5 ~MeV, ~1.7 ~MeV, ~2.9 ~MeV,$
and $ ~4.1 MeV$} have been evaluated to be \mbox{$ \sigma = 2.5 \pm 0.5~nb$,
$~~~ 2.9 \pm 1.1~nb$, $~~~ 12.7 \pm 3.2~nb$, ~ and $~~~ 25.2 \pm 3.6 ~nb $},
respectively. In this region of excess energy the $\eta^{\prime}$ (958) cross
sections are much lower compared to those of the $\pi ^0$ and $\eta$
production.


title:
Total Cross Section of the Reaction pp \to pK^+\Lambda Close to
  Threshold

abstract:
  The energy dependence of the total cross section for the pp \to pK^+\Lambda
reaction was measured in the threshold region covering the excess energy range
up to 7MeV.
  Existing model calculations describe the slope of the measured cross sections
well, but are too low by a factor of two to three in rate.
  The data were used for a precise determination of the beam momentum of the
COSY-synchrotron.


title: Associated Strangeness Production in the Threshold Region

abstract:
  Associated strangeness production close to threshold is a particularly clean
example of how energy is converted into hadronic matter. Final results from the
completed experiments of the PS185 collaboration at LEAR/CERN, using the
antiproton-proton interaction to produce antihyperon-hyperon pairs, demonstrate
that such studies form a powerful tool. First results from the ongoing
investigations of the COSY-11 collaboration at COSY-J"ulich, measuring the
strangeness dissociation into both hyperon-kaon and kaon-kaon pairs from
proton-proton scattering, are presented and plans for further investigations
are discussed. Finally, an interesting possibility for future studies of the
strangeness production mechanism in the antiproton-proton interactions with
antiproton beams of momenta >5 GeV/c is suggested.


title: Spin-Alignment and Quasi-Molecular Resonances in Heavy-Ion Collision

abstract:
  Fragment-fragment-$\gamma$ triple coincidence measurements of the
$^{28}$Si~$+$~$^{28}$Si reaction at E$_{\rm c.m.}$~=~55.8 MeV, carefully chosen
to populate a well known quasi-molecular resonance in $^{56}$Ni, have been
performed at the VIVITRON tandem facility by using the Eurogam Phase~II
$\gamma$-ray spectrometer. In the $^{28}$Si~$+$~$^{28}$Si reaction, the
resonant behavior of the $^{28}$Si $+$ $^{28}$Si exit-channel is clearly
observed by the present fragment-fragment coincidence data. The more unexpected
result is the spin disalignment of the $^{28}$Si $+$ $^{28}$Si resonance. This
has been demonstrated first by the measured angular distributions of the
elastic 0$^{+}$, inelastic 2$^{+}$ and mutual excitation channels
2$^{+}-2^{+}$, which are dominated by a unique and pure partial wave with L =
38 ${\rm \hbar}$, and has been confirmed by measuring their particle-$\gamma$
angular correlations with Eurogam Phase II. The spin disalignment supports new
molecular model predictions, in which the observed resonance would correspond
to the ''Butterfly mode''. A discussion concerning the {\it spin alignment and
spin disalignment} for different systems : $^{12}$C~$+$~$^{12}$C,
$^{24}$Mg~$+$~$^{24}$Mg and $^{28}$Si~$+$~$^{28}$Si will be given.}


title:
Nuclear Matter Expansion Parameters from the Measurement of Differential
  Multiplicities for Lambda Production in Central Au+Au Collisions at AGS

abstract:
  The double differential multiplicities and rapidity distributions for Lambda
hyperon production in central Au+Au interactions at AGS in the range of
rapidities from 1.7 to 3.2 and the range of transverse kinetic energies from
0.0 to 0.7 GeV are parametrized in terms of the the Blast Wave approximation.
The longitudinal and transverse radial expansion parameters and the mean
temperature of Lambda hyperons after the freeze-out of the nuclear matter are
presented. The predictions of the RQMD model with and without mean field
potentials are compared to our data. Both variants of RQMD are parameterized in
terms of the Blast Wave model and the results of such parameterizations are
compared to the experimental ones. It is found that inclusion of the mean field
potentials in RQMD is essential to account for the strong expansion observed in
the data.


title: Breakup Conditions of Projectile Spectators from Dynamical Observables

abstract:
  Momenta and masses of heavy projectile fragments (Z >= 8), produced in
collisions of 197Au with C, Al, Cu and Pb targets at E/A = 600 MeV, were
determined with the ALADIN magnetic spectrometer at SIS. An analysis of
kinematic correlations between the two and three heaviest projectile fragments
in their rest frame was performed. The sensitivity of these correlations to the
conditions at breakup was verified within the schematic SOS-model. The data
were compared to calculations with statistical multifragmentation models and to
classical three-body calculations. Classical trajectory calculations reproduce
the dynamical observables. The deduced breakup parameters, however, differ
considerably from those assumed in the statistical multifragmentation models
which describe the charge correlations. If, on the other hand, the analysis of
kinematic and charge correlations is performed for events with two and three
heavy fragments produced by statistical multifragmentation codes, a good
agreement with the data is found with the exception that the fluctuation widths
of the intrinsic fragment energies are significantly underestimated. A new
version of the multifragmentation code MCFRAG was therefore used to investigate
the potential role of angular momentum at the breakup stage. If a mean angular
momentum of 0.75$\hbar$/nucleon is added to the system, the energy fluctuations
can be reproduced, but at the same time the charge partitions are modified and
deviate from the data.
  PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.Ld, 25.75.-q


title:
Low-Energy $\Lambda-\p$ Scattering Parameters from the $pp \to
  pK^+\Lambda$ Reaction

abstract:
  Constraints on the spin-averaged $\Lambda p$ scattering length and effective
range have been obtained from measurements of the $pp\to pK^+\Lambda$ reaction
close to the production threshold by comparing model phase-space Dalitz plot
occupations with experimental ones. The data fix well the position of the
virtual bound state in the $\Lambda p$ system. Combining this with information
from elastic $\Lambda p$ scattering measurements at slightly higher energies,
together with the fact that the hyperdeuteron is not bound, leads to a new
determination of the low energy $\Lambda p$ scattering parameters.


title:
A Computer Program for Relativistic Multiple Coulomb and Nuclear
  Excitation

abstract:
  A computer program is presented by which one may calculate the multiple
electric dipole, electric quadrupole and magnetic dipole Coulomb excitation
with relativistic heavy ions. The program applies to an arbitrary nucleus,
specified by the spins and energies of the levels and by all E1, E2 and M1
matrix elements. Nuclear excitation is calculated optionally for monopole,
dipole and quadrupole excitations and needs inputs of optical potentials. For
given bombarding conditions, the differential cross sections and statistical
tensors (useful to calculate gamma-ray angular distribution functions) are
computed.


title: Highlights on Dilepton and Photon Observables

abstract:
  The highlights of Quark Matter '97 on dileptons and direct photons are
presented.


title: Thermodynamic Variables from Spectator Decay

abstract:
  New results for the masses, excitation energies, temperatures, and densities
of excited spectator systems at breakup are presented. They were obtained in
two recent experiments with the ALADIN spectrometer at SIS in which reactions
of Au-197 on Au-197 in the regime of relativistic energies up to 1 GeV per
nucleon were studied. The methods used to extract these thermodynamic variables
are discussed.


title: Measurement of E2 Transitions in the Coulomb Dissociation of 8B

abstract:
  In an effort to understand the implications of Coulomb dissociation
experiments for the determination of the 7Be(p,gamma)8B reaction rate,
longitudinal momentum distributions of 7Be fragments produced in the Coulomb
dissociation of 44 and 81 MeV/nucleon 8B beams on a Pb target were measured.
These distributions are characterized by asymmetries interpreted as the result
of interference between E1 and E2 transition amplitudes in the Coulomb breakup.
At the lower beam energy, both the asymmetries and the measured cross sections
are well reproduced by perturbation theory calculations, allowing a
determination of the E2 strength.


title: Odd-spin yrast states as multiple quadrupole-phonon excitations

abstract:
  The wavefunctions of the lowest odd spin positive parity yrast states in the
IBA are shown to be nearly pure multiple quadrupole-phonon excitations even
outside the three dynamical symmetries. The empirical data for collective
nuclei with 30 < Z < 80 confirm these predictions. The quadrupole-phonon purity
of the 2^+_1 state can be measured from E2-branching ratios of the 3^+_1 state.
These data show a high correlation to the 2^+_1 Q-phonon purity deduced from
the E2-decay of 2^+ states.


title: Projectile fragmentation of 129Xe at Elab=790 AMeV

abstract:
  We have measured production yields and longitudinal momentum distributions of
projectile-like fragments in the reaction 129Xe + 27Al at an energy of Elab=790
AMeV. Production cross sections higher than expected from systematics were
observed for nuclei in the neutron-deficient tails of the isotopic
distributions. A comparison with previously measured data from the
fragmentation of 136Xe ions shows that the production yields strongly depend on
the neutron excess of the projectile with respect to the line of
beta-stability. The momentum distributions exhibit a dependence on the fragment
neutron-to-proton ratio in isobaric chains, which was not expected from
systematics so far. This can be interpreted by a higher excitation of the
projectile during the formation of neutron-deficient fragments.


title:
Dynamics of Ultra-Relativistic Nuclear Collisions with Heavy Beams: An
  Experimental Overview

abstract:
  We review, from an experimental point of view, the current status of
ultra-relativistic nuclear collisions with heavy beams.


title:
Progress toward a new measurement of the parity violating asymmetry in
  n+p-->d+gamma

abstract:
  We outline the motivation and conceptual design for a new experiment aimed at
a 10-fold improvement in the accuracy of the parity-violating asymmetry A_gamma
in the angular distribution of 2.2 MeV gamma rays from the n+p-->d+gamma
reaction. This observable is primarily sensitive to the weak pion-nucleon
coupling H_pi^1. A proof-of-principle experiment using unpolarized low-energy
neutron capture on polyethylene and an array of 12 CsI detectors operated in
current mode has been performed. Results of this test experiment including the
current mode signal, electronic noise and detector sensitivity to magnetic
fields are reported.


title: Possible three-nucleon force effects in D-P scattering at low energies

abstract:
  We present measurements of the analyzing powers Ay and iT11 for
proton-deuteron scattering at Ecm=432 keV. Calculations using a realistic
nucleon-nucleon potential (Argonne V18) are found to underpredict both
analyzing powers by 40. The inclusion of the Urbana three-nucleon interaction
does not significantly modify the calculated analyzing powers. Due to its short
range, it is difficult for this three-nucleon interaction to affect Ay and iT11
at this low energy. The origin of the discrepancy remains an open question.


title:
A Proposed Method for Measuring the Electric Dipole Moment of the
  Neutron Using Acceleration in an Electric-Field Gradient and Ultracold
  Neutron Interferometry

abstract:
  The use of an ultracold neutron interferometer incorporating an electrostatic
accelerator having a strong electric field gradient to accelerate neutrons by
their possible electric moments is proposed as a method of measuring the
neutron electric dipole moment. Such electrical acceleration, followed by an
amplifier and a generator of phase difference, could develop relatively large
phase differences and these could be measured by a Mach-Zehnder interferometer.
This method might extend the sensitivity of the measurement by several orders
of magnitude beyond the current limit of 10^{-25} e.cm. Furthermore the
systematic errors in such a measurement could be significantly different from
those of the current EDM experiments.


title: Study of the Fusion-Fission Process in the $^{35}Cl+^{24}Mg$ Reaction

abstract:
  Fusion-fission and fully energy-damped binary processes of the
$^{35}$Cl+$^{24}$Mg reaction were investigated using particle-particle
coincidence techniques at a $^{35}$Cl bombarding energy of E$_{lab}$ $\approx$
8 MeV/nucleon. Inclusive data were also taken in order to determine the partial
wave distribution of the fusion process. The fragment-fragment correlation data
show that the majority of events arises from a binary-decay process with a
relatively large multiplicity of secondary light-charged particles emitted by
the two primary excited fragments in the exit channel. No evidence is observed
for ternary-breakup processes, as expected from the systematics recently
established for incident energies below 15 MeV/nucleon and for a large number
of reactions. The binary-process results are compared with predictions of
statistical-model calculations. The calculations were performed using the
Extended Hauser-Feshbach method, based on the available phase space at the
scission point of the compound nucleus. This new method uses
temperature-dependent level densities and its predictions are in good agreement
with the presented experimental data, thus consistent with the fusion-fission
origin of the binary fully-damped yields.


title: Proton stopping in C+C, d+C, C+Ta and d+Ta collisions at 4.2A GeV/c

abstract:
  The shape of proton rapidity distributions is analysed in terms of their
Gaussian components, and the average rapidity loss is determined in order to
estimate the amount of stopping in C+C, d+C, C+Ta and d+Ta collisions at 4.2A
GeV/c. Three Gaussians correspond to the nuclear transparency and describe well
all peripheral and also C+C central collisions. Two-component shape is obtained
in case of d+C and C+Ta central collisions. Finally one Gaussian, found in d+Ta
central collisions, corresponds to the full stopping. The calculated values of
the average rapidity loss support the qualitative relationship between the
number of Gaussian components and the corresponding stopping power. It is also
observed, in central collisions, that the average rapidity loss increases with
the ratio of the number of target and the number of projectile participants.


title:
Methods for analyzing anisotropic flow in relativistic nuclear
  collisions

abstract:
  The strategy and techniques for analyzing anisotropic flow (directed,
elliptic, etc.) in relativistic nuclear collisions are presented. The emphasis
is on the use of the Fourier expansion of azimuthal distributions. We present
formulae relevant for this approach, and in particular, show how the event
multiplicity enters into the event plane resolution. We also discuss the role
of non-flow correlations and a method for introducing flow into a simulation.


title:
Z-dependent Barriers in Multifragmentation from Poissonian Reducibility
  and Thermal Scaling

abstract:
  We explore the natural limit of binomial reducibility in nuclear
multifragmentation by constructing excitation functions for intermediate mass
fragments (IMF) of a given element Z. The resulting multiplicity distributions
for each window of transverse energy are Poissonian. Thermal scaling is
observed in the linear Arrhenius plots made from the average multiplicity of
each element. ``Emission barriers'' are extracted from the slopes of the
Arrhenius plots and their possible origin is discussed.


title: Multifragmentation at Intermediate Energy: Dynamics or Statistics?

abstract:
  To make a statement about the nature and mechanism of fragmentation, it is
necessary to probe directly any competition, or lack thereof, between the
emission of various particle species as a function of excitation energy. The
task is then to find a global observable that best follows the increase in
excitation energy or dissipated energy. In the following, we will consider two
contradictory claims that have been advanced recently: 1) the claim for a
predominantly dynamical fragment production mechanism; and 2) the claim for a
dominant statistical and thermal process. We will present a new analysis in
terms of Poissonian reducibility and thermal scaling, which addresses some of
the criticisms of the binomial analysis.


title: Results from Searching for Muonium to Antimuonium Conversion

abstract:
  A new result from searching for muonium to antimuonium conversion is reported
which sets an upper limit on the coupling constant in an assumed $(V-A) \times
(V-A)$ type interaction of $G_{M\bar{M}} \leq 3\cdot 10^{-3} G_F$ ~ (90% C.L.).
  A particular Z_8 and a minimal 331 GUT model can be ruled out. Further new
and stringent limits can be set for masses of bileptonic gauge bosons and
$\lambda$ parameters in R-parity breaking supersymmetric models.


title: Improved upper limit on Muonium to Antimuonium Conversion

abstract:
  A new experiment has been set up at the Paul Scherrer Institut to search for
muonium to antimuonium conversion. No event was found to fulfil the requested
signature which consists of the coincident detection of both constituents of
the antiatom in its decay. Assuming an effective (V-A)$\times$(V-A) type
interaction an improved upper limit is established for the conversion
probability of ${\rm P_{M\bar{M}}} \leq 8 \cdot 10^{-9}$ (90%C.L.), which is
almost two orders of magnitude lower compared to previous results and provides
a sensitive test for theoretical extensions of the standard model.


title: Directed Flow of Light Nuclei in Au+Au Collisions at AGS Energies

abstract:
  Directed flow of deuterons, tritons, $^3$He, and $^4$He is studied in Au+Au
collisions at a beam momentum of about 10.8 $A$ GeV/c. Flow of all particles is
analyzed as a function of transverse momentum for different centralities of the
collision. The directed flow signal, $v_1(p_t)$, is found to increase with
particle mass. This mass dependence is strongest in the projectile rapidity
region.


title:
Transverse momentum distributions of neutral pions from nuclear
  collisions at 200 AGeV

abstract:
  New results on transverse mass spectra of neutral pions measured at central
rapidity are presented for impact parameter selected 200 AGeV S + S and S + Au
collisions. The spectra from all systems show a clear power-law like shape with
similar curvature. Collisions of S + Au exhibit a larger mean transverse
momentum than pp increasing with centrality. Predictions of string models and
by hydrodynamic approaches including collective expansion and decays of short
lived resonances are compared to the data and the implications are discussed.


title: Neutron capture of 26Mg at thermonuclear energies

abstract:
  The neutron capture cross section of 26Mg was measured relative to the known
gold cross section at thermonuclear energies using the fast cyclic activation
technique. The experiment was performed at the 3.75 MV Van-de-Graaff
accelerator, Forschungszentrum Karlsruhe. The experimental capture cross
section is the sum of resonant and direct contributions. For the resonance at
E(n,lab) = 220 keV our new results are in disagreement with the data from
Weigmann et al. An improved Maxwellian averaged capture cross section is
derived from the new experimental data taking into account s- and p-wave
capture and resonant contributions. The properties of so-called potential
resonances which influence the p-wave neutron capture of 26}Mg are discussed in
detail.


title:
A New Measurement of the Partial 0+->0+ Half Life of 10C with
  GAMMASPHERE

abstract:
  We report on a new measurement of the strength of the superallowed 0+->0+
transition in the beta-decay of 10C: 10C(0+,g.s.)->10B(0+,1.74MeV)+e+nu. The
experiment was done at the LBNL 88-inch cyclotron using forty seven GAMMASPHERE
germanium detectors. Precise knowledge of this branching ratio is necessary to
compute the superallowed Fermi ft, which gives the weak vector coupling
constant and the u to d element of the Cabibbo-Kobayashi- Maskawa quark mixing
matrix.


title: Recent Results from E866 at BNL

abstract:
  Recent and preliminary single-particle data are presented from the AGS
Experiment 866 at BNL. Emphasis is put on the transverse mass as well as the
rapidity distributions of charged pions, kaons, protons, deuterons and
anti-protons measured in the most central Au+Au collisions at an incident
kinetic energy of 10.8 AGeV. The data suggest a high degree of stopping power
present in these reactions. Applying an expanding fireball scenario to describe
the experimental distributions substantial transverse and longitudinal flow
velocities result.


title: The pi- p --> gamma gamma n Reaction and Pion Compton Scattering

abstract:
  We propose to measure the two--photon capture mode of pionic hydrogen using
the RMC pair spectrometer at the TRIUMF cyclotron. Currently, only an
experimental upper limit of B.R.<= 5.5E-4 is available for the two-gamma
capture mode. Our new data will critically test the theoretical calculations
and the intriguing predicted dominance of the pi pi --> gamma gamma
annihilation graph. More speculatively, since crossing symmetry relates pi pi
--> gamma gamma to gamma pi --> gamma pi, this threshold reaction may be a
novel probe of the pion's electric polarizability.
  We show results of our 1997 engineering run and Monte Carlo studies for the
two photon capture mode of pionic hydrogen and carbon. We also present our
preliminary upper limit for the pi- p --> gamma gamma n B.R. <= 2.8E-4.


title:
Centrality Dependence of Neutral Pion Production in 158 A GeV Pb + Pb
  Collisions

abstract:
  The production of neutral pions in 158AGeV Pb+Pb collisions has been studied
in the WA98 experiment at the CERN SPS. Transverse momentum spectra are studied
for the range 0.3 GeV/c < mT-m0 < 4.0 GeV/c. The results for central collisions
are compared to various models. The centrality dependence of the neutral pion
spectral shape and yield is investigated. An invariance of the spectral shape
and a simple scaling of the yield with the number of participating nucleons is
observed for centralities with greater than about 30 participating nucleons
which is most naturally explained by assuming an equilibrated system.


title: The Reaction 7Li(pi+,pi-)7B and its Implications for 7B

abstract:
  The reaction 7Li(pi+,pi-)7B has been measured at incident pion energies of
30-90 MeV. 7Li constitutes the lightest target nucleus, where the pionic charge
exchange may proceed as a binary reaction to a discrete final state. Like in
the Delta-resonance region the observed cross sections are much smaller than
expected from the systematics found for heavier nuclei. In analogy to the
neutron halo case of 11Li this cross section suppression is interpreted as
evidence for a proton halo in the particle-unstable nucleus 7B.


title:
Coulomb Effects in Charged Particle Spectra from Heavy Ion Collisions at
  AGS and SIS

abstract:
  Data from the AGS experiment E866 on charged particles emitted in central
Au+Au collisions at 10.8 AGeV incident energy is reviewed. The study of
spectral shapes indicates the presence of collective transverse flow and - in
particular for charged pions - of Coulomb final state interaction between
emitted particles and the nuclear charge distribution. The comparison to SIS
pion data measured with KaoS elucidates the role of charged pions to probe
nuclear reaction dynamics at lower incident energies.


title:
Dependence of pp->pp pi0 near Threshold on the Spin of the Colliding
  Nucleons

abstract:
  A polarized internal atomic hydrogen target and a stored, polarized beam are
used to measure the spin-dependent total cross section Delta_sigma_T/sigma_tot,
as well as the polar integrals of the spin correlation coefficient combination
A_xx-A_yy, and the analyzing power A_y for pp-> pp pi0 at four bombarding
energies between 325 and 400 MeV. This experiment is made possible by the use
of a cooled beam in a storage ring. The polarization observables are used to
study the contribution from individual partial waves.


title:
Enhanced Out-of-plane Emission of K+ Mesons observed in Au+Au Collisions
  at 1 AGeV

abstract:
  The azimuthal angular distribution of K+ mesons has been measured in Au + Au
collisions at 1 AGeV. In peripheral and semi-central collisions, K+ mesons
preferentially are emitted perpendicular to the reaction plane. The strength of
the azimuthal anisotropy of K+ emission is comparable to the one of pions. No
in-plane flow was found for K+ mesons near projectile and target rapidity.


title: Directed Flow in 158 A GeV Pb + Pb Collisions

abstract:
  The directed flow of protons and positive pions have been studied in 158 A
GeV Pb + Pb collisions. A directed flow analysis of the rapidity dependence of
the average transverse momentum projected onto the reaction plane is presented
for semi-central collisions with impact parameters of approximately 8 fm, where
the flow effect is largest. The magnitude of the directed flow is found to be
significantly smaller than observed at AGS energies and than RQMD model
predictions.


title: Evaporation of alpha particles from $^31$P nucleus

abstract:
  The energy spectra of alpha particles have been measured in coincidence with
the evaporation residues for the decay of the compound nucleus $^31$P produced
in the reaction $^19$F (96 MeV) + $^12$C. The data have been compared with the
predictions of the statistical model code CASCADE. It has been observed that
significant deformation effect in the compound nucleus need to be considered in
order to explain the shape of the evaporated alpha particle energy spectra.


title:
Rochester Reply to Phair et al. "Evidence for dynamical fragment
  production?"

abstract:
  It is shown that the Comment by Phair et al. on PRL 77, 3514 (1996) does not
challenge the paper by Tõke et al. It is, in fact, consistent with all
conclusions of the targeted paper. The Comment disputes claims never made.


title: Quasi-fission reactions as a probe of nuclear viscosity

abstract:
  Fission fragment mass and angular distributions were measured from the
^{64}Ni+^{197}Au reaction at 418 MeV and 383 MeV incident energy. A detailed
data analysis was performed, using the one-body dissipation theory implemented
in the code HICOL. The effect of the window and the wall friction on the
experimental observables was investigated. Friction stronger than one-body was
also considered. The mass and angular distributions were consistent with
one-body dissipation. An evaporation code DIFHEAT coupled to HICOL was
developed in order to predict reaction time scales required to describe
available data on pre-scission neutron multiplicities. The multiplicity data
were again consistent with one-body dissipation. The cross-sections for touch,
capture and quasi-fission were also obtained.


title:
Fission fragment mass reconstruction from Si surface barrier detector
  measurement

abstract:
  A method for plasma delay and pulse-height defect corrections for Si surface
barrier detectors (SBD) is presented. Based on known empirical formulae, simple
approximations involving the measured time-of-flight (TOF) and energy of the
ions were found and a mass reconstruction procedure was developed. The
procedure was applied for obtaining the fission fragment mass and angular
distributions from the $^{64}$ Ni+$^{197}$Au reaction at 418 MeV and 383 MeV
incident energy using an array of eight SBDs.


title: Measurements of Deuteron Photodisintegration up to 4.0 GeV

abstract:
  The first measurements of the differential cross section for the d(gamma,p)n
reaction up to 4.0 GeV were performed at Continuous Electron Beam Accelerator
Facility (CEBAF) at Jefferson Lab. We report the cross sections at the proton
center-of-mass angles of 36, 52, 69 and 89 degrees. These results are in
reasonable agreement with previous measurements at lower energy. The 89 and 69
degree data show constituent-counting-rule behavior up to 4.0 GeV photon
energy. The 36 and 52 degree data disagree with the counting rule behavior. The
quantum chromodynamics (QCD) model of nuclear reactions involving reduced
amplitudes disagrees with the present data.


title:
Charged Kaon and Pion Production at Midrapidity in Proton Nucleus and
  Sulphur Nucleus Collisions

abstract:
  The NA44 collaboration has measured charged kaon and pion distributions at
midrapidity in sulphur and proton collisions with nuclear targets at 200 and
450 GeV/c per nucleon, respectively. The inverse slopes of kaons are larger
than those of pions. The difference in the inverse slopes of pions, kaons and
protons, all measured in our spectrometer, increases with system size and is
consistent with the buildup of collective flow for larger systems. The target
dependence of both the yields and inverse slopes is stronger for the sulphur
beam suggesting the increased importance of secondary rescattering for SA
reactions. The rapidity density, dN/dy, of both K+ and K- increases more
rapidly with system size than for pi+ in a similar rapidity region. This trend
continues with increasing centrality, and according to RQMD, it is caused by
secondary reactions between mesons and baryons. The K-/K+ ratio falls with
increasing system size but more slowly than the pbar/p ratio. The pi-/pi+ ratio
is close to unity for all systems. From pBe to SPb the K+/p ratio decreases
while K-/pbar increases and ({K+*K-}/{p*pbar})**1/2 stays constant. These data
suggest that as larger nuclei collide, the resulting system has a larger
transverse expansion, baryon density and an increasing fraction of strange
quarks.


title:
Separation between sources of pions and protons in central Au+Au
  collisions at the AGS (E877)

abstract:
  Asymmetric peaks in the pion-proton correlation functions were observed. Such
an asymmetry indicates a displacement between the sources of the two particle
species.


title:
Competition between quasi-molecular resonances and fusion-fission in
  light dinuclear systems

abstract:
  The results presented in this paper clearly suggest that a coherent framework
may exist which connects the topics of heavy-ion molecular resonances,
hyperdeformation effects, and fission shape isomerism. New data on
particle-particle-$\gamma$ triple coincidences of the $^{28}$Si+$^{28}$Si
reaction at a beam energy corresponding to the population of a conjectured
J$^{\pi}$ = 38$^{+}$ resonance in $^{56}$Ni are presented. The absence of
alignment of the spins of the outgoing fragments with respect to the orbital
angular momentum is found to be in contrast with the alignment as measured for
the $^{24}$Mg+$^{24}$Mg resonances. A molecular-model picture is presented to
suggest a "butterfly" motion of two oblate $^{28}$Si nuclei interacting in a
equator-to-equator molecular configuration.


title: Composition of the nuclear periphery from antiproton absorption

abstract:
  Thirteen targets with mass numbers from 58 to 238 were irradiated with the
antiproton beam from the Low Energy Antiproton Ring facility at CERN leading to
the formation of antiprotonic atoms of these heavy elements. The antiproton
capture at the end of an atomic cascade results in the production of more or
less excited residual nuclei. The targets were selected with the criterion that
both reaction products with one nucleon less than the proton and neutron number
of the target be radioactive. The yield of these radioactive products after
stopped-antiproton annihilation was determined using gamma-ray spectroscopy
techniques. This yield is related to the proton and neutron density in the
target nucleus at a radial distance corresponding to the antiproton
annihilation site. The experimental data clearly indicate the existence of a
neutron-rich nuclear periphery, a "neutron halo", strongly correlated with the
target neutron separation energy Bn and observed for targets with Bn < 10 MeV.
For two-target nuclei 106Cd and 144Sm, with larger neutron binding energies, a
proton-rich nuclear periphery was observed. Most of the experimental data are
in reasonable agreement with calculations based on current antiproton-nucleus
and pion-nucleus interaction potentials and on nuclear densities deduced with
the help of the Hartree-Fock-Bogoliubov approach. This approach was, however,
unable to account for the 106Cd and 144Sm results.


title: HBT correlation in 158 AGeV Pb+Pb collisions

abstract:
  The large acceptance TPCs of the NA49 spectrometer allow for a systematic
multidimensional study of two-particle correlations in different part of phase
space. Results from Bertsch-Pratt and Yano-Koonin-Podgoretskii parametrizations
are presented differentially in transverse pair momentum and pair rapidity.
These studies give an insight into the dynamical space-time evolution of
relativistic Pb+Pb collisions, which is dominated by longitudinal expansion.


title: Strangeness production in high density baryon matter

abstract:
  Strangeness production in heavy-ion collisions, when compared to proton
proton collisions, is potentially a sensitive probe for collective energy
deposition and therefore for reaction mechanisms in general. It may therefore
provide insight into possible QGP formation in dense nuclear matter. To
establish an understanding of the observed yields, a systematic study of high
density baryon matter at different beam energies is essential. This might also
reveal possible discontinuities in the energy dependence of the reaction
mechanism. We present preliminary results for kaon production in Au+Au
collisions at beam kinetic energies of 6, 8, and 10.7 GeV/u obtained by the
E917 experiment at the AGS (BNL). These measurements complement those carried
out by the E866 collaboration at 2, 4, and 10.7 GeV/u with a significantly
enlarged data sample. In both experiments a large range of rapidities was
covered by taking data at different angular settings of the magnetic
spectrometer.


title:
How Well Do We Know the Beta-Decay of 16N and Oxygen Formation in Helium
  Burning

abstract:
  We review the status of the 12C(a,g)16O reaction rate, of importance for
stellar processes in a progenitor star prior to a super-nova collapse. Several
attempts to constrain the p-wave S-factor of the 12C(a,g)16O reaction at Helium
burning temperatures (200 MK) using the beta-delayed alpha-particle emission of
16N 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 16N 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 by improving our statistical sample (by
more than a factor of 5), improving the energy resolution of the experiment (by
20%), and in understanding our line shape, deduced from measured quantities.
Our newly measured spectrum of the beta-delayed alpha-particle emission of 16N
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:
Tensor Analyzing Powers for Quasi-Elastic Electron Scattering from
  Deuterium

abstract:
  We report on a first measurement of tensor analyzing powers in quasi-elastic
electron-deuteron scattering at an average three-momentum transfer of 1.7
fm$^{-1}$. Data sensitive to the spin-dependent nucleon density in the deuteron
were obtained for missing momenta up to 150 MeV/$c$ with a tensor polarized
$^2$H target internal to an electron storage ring. The data are well described
by a calculation that includes the effects of final-state interaction,
meson-exchange and isobar currents, and leading-order relativistic
contributions.


title: Asymptotic Normalization Coefficients for 13C+p->14N

abstract:
  The $^{13}C(^{14}N,^{13}C)^{14}N$ proton exchange reaction has been measured
at an incident energy of 162 MeV. Angular distributions were obtained for
proton transfer to the ground and low lying excited states in $^{14}N$. Elastic
scattering of $^{14}N$ on $^{13}C$ also was measured out to the rainbow angle
region in order to find reliable optical model potentials. Asymptotic
normalization coefficients for the system $^{13}C+p\to {}^{14}N$ have been
found for the ground state and the excited states at 2.313, 3.948, 5.106 and
5.834 MeV in $^{14}N$. These asymptotic normalization coefficients will be used
in a determination of the S-factor for $^{7}Be(p,\gamma)^{8}B$ at solar
energies from a measurement of the proton transfer reaction
$^{14}N(^{7}Be,^{8}B)^{13}C$.


title:
Dense, Strongly-Interacting Matter: Strangeness in Heavy-Ion Reactions
  1-10 AGeV

abstract:
  This talk reviews the physics of dense, strongly interacting matter. The
newly acquired experimental data on strangeness production in heavy-ion
reactions from 1-10 AGeV is used to probe the physics of in-medium properties
of kaons, multi-body collisions, and the search for the baryon-rich quark-gluon
plasma.


title:
Identification of baryon resonances in central heavy-ion collisions at
  energies between 1 and 2 AGeV

abstract:
  The mass distributions of baryon resonances populated in near-central
collisions of Au on Au and Ni on Ni are deduced by defolding the $p_t$ spectra
of charged pions by a method which does not depend on a specific resonance
shape. In addition the mass distributions of resonances are obtained from the
invariant masses of $(p, \pi^{\pm})$ pairs. With both methods the deduced mass
distributions are shifted by an average value of -60 MeV/c$^2$ relative to the
mass distribution of the free $\Delta(1232)$ resonance, the distributions
descent almost exponentially towards mass values of 2000 MeV/c^2. The observed
differences between $(p, \pi^-)$ and $(p, \pi^+)$ pairs indicate a contribution
of isospin $I = 1/2$ resonances. The attempt to consistently describe the
deduced mass distributions and the reconstructed kinetic energy spectra of the
resonances leads to new insights about the freeze out conditions, i.e. to
rather low temperatures and large expansion velocities.


title:
Role of the experimental filter in obtaining the Arrhenius plot in
  multifragmentation reactions

abstract:
  Recently it has been argued that the linear relation between the transverse
energy and the apparent probability to emit a fragment proves that the total
system is in thermal equilibrium. It is shown, for a specific reaction Xe+Sn at
50 A.MeV, that the same behavior is obtained in the context of Quantum
Molecular Dynamical without invoking the idea of equilibrium. The linear
dependance is shown to be a detector effect.


title:
How to Test the Existence of the Early Parton Cascade Using Photon HBT
  Correlations?

abstract:
  We report on a possible application of the HBT phenomenon in testing the
existence of two hypothetical phenomena. First, it is argued that the existence
of a rapidly developing parton cascade in the earliest stages of a high energy
nuclear collision process can be tested by studying two-photon HBT correlations
over a wide longitudinal momentum scale - corresponding to the early photon
emission time from the hypothetical parton system. This method provides the
needed selectivity for the early emitted photons, since the photons emitted at
later times correlate over progressively narrower momentum scales. Second, in a
similar way we argue that the existence of a hypothetic dark matter candidate,
the Weakly Interacting Massive Particle (WIMP), may be tested by studying HBT
correlations of cosmic gamma rays at a relatively long detection time scale -
corresponding to the very narrow spectral line of the photons emerging from
WIMP annihilations. Background photons leave no signature since they
essentially do not correlate.


title: Test of Time Reversal Invariance in Polarized Proton-Deuteron Scattering

abstract:
  A novel test of time-reversal invariance in proton-deuteron scattering is
planned as an internal target transmission experiment at the cooler synchrotron
COSY. The P-even, T-odd observable is the polarization correlation $A_{y,xz}$
of the total cross section measured using a polarized internal proton beam
(polarization $p_y$) and an internal polarized deuterium target (tensor
polarization $p_{xz}$). Measuring this observable is a true null test of time
reversal invariance and therefore allows to reach a high accuracy. Sufficient
luminosity can be obtained using a window-less storage cell placed on the axis
of the proton beam. Tensor polarized atoms are produced in an atomic beam
source based on Stern-Gerlach separation in permanent sextupole magnets and
adiabatic high frequency transitions. The total cross section correlation is
measured by monitoring the beam transmission in the COSY storage ring mode of
operation. The proton beam momentum will be in the range 2-3 GeV/c. This
momentum is ideally suited to test possible short range contributions, i.e.
natural parity charged $\rho$-type and unnatural parity $a_1$-type meson
exchange contributions. The feasibility of the experiment, systematic errors
and the expected accuracy are discussed.


title: Measurement of T20 in Elastic Electron-Deuteron Scattering

abstract:
  We report on a measurement of the tensor-analyzing power T20 in elastic
electron-deuteron scattering in the range of four-momentum transfer from 1.8 to
3.2 fm-1. Electrons of 704 MeV were scattered from a polarized deuterium
internal target. The tensor polarization of the deuterium nuclei was determined
with an ion-extraction system, allowing an absolute measurement of T20. The
data are described well by a non-relativistic calculation that includes the
effects of meson-exchange currents.


title: Xi and Xi-bar Production in 158 GeV/Nucleon Pb+Pb Collisions

abstract:
  We report measurements of Xi and Xi-bar hyperon absolute yields as a function
of rapidity in 158 GeV/c Pb+Pb collisions. At midrapidity, dN/dy = 2.29 +/-
0.12 for Xi, and 0.52 +/- 0.05 for Xi-bar, leading to the ratio of Xi-bar/Xi =
0.23 +/- 0.03. Inverse slope parameters fitted to the measured transverse mass
spectra are of the order of 300 MeV near mid-rapidity. The estimated total
yield of Xi particles in Pb+Pb central interactions amounts to 7.4 +/- 1.0 per
collision. Comparison to Xi production in properly scaled p+p reactions at the
same energy reveals a dramatic enhancement (about one order of magnitude) of Xi
production in Pb+Pb central collisions over elementary hadron interactions.


abstract:
  Spectra of coincident charged particles from the reactions induced by a 52
MeV 7Li beam incident on a beryllium target were measured. Strong contributions
of the 7Li quasi-free scattering off the alpha-cluster in 9Be nucleus were
observed. This observation supports the conclusions from the study of complete
fusion of weakly bound light nuclei at low energies that the "fragility" of the
nuclei makes their fusion less probable.


title: Hadronic Particle Production in Nucleus-Nucleus Collisions

abstract:
  Data on hadronic particle production in symmetric nuclear collisions from
SIS/BEVALAC to SPS energies are reviewed. The main emphasis is put on the
production of pions, kaons, and antibaryons. Global features will be discussed
in terms of rapidity and transverse momentum distributions and the total energy
stored in produced particles. Pion and kaon production probabilities are
studied as function of beam energy and their distribution in polar and
azimuthal angle. Special emphasis is put on medium effects expected for kaons
in dense nuclear matter at low energies. An enhanced strange particle yield is
found at all energies, its explanation at SPS energies is still controversial.
Experimental data on antibaryon and multistrange hyperon production is less
complete and does not allow for similar systematic studies.


title:
Experimental Chiral Dynamics: New Opportunities with Polarized Internal
  Targets and Almost-Real Photon Tagging

abstract:
  Experiments on pion (Goldstone Boson) photoproduction from the nucleon tests
the ability to make QCD predictions at confinement scale energies. Experiments
with both polarized beams and targets have the potential sensitivity to
demonstrate the dynamic isospin breaking effects of the up and down quark mass
difference, whereas experiments on Compton scattering from the nucleon will
incisively probe its chiral structure by measuring all of the spin dependent
amplitudes. These and other types of photo-induced measurements on nuclei could
be possible at BLAST with the addition of an almost-real photon tagging system
and a forward low energy recoil ion hodoscope.


title:
Observation of strong final-state effects in pi+ production in pp
  collisions at 400 MeV

abstract:
  Differential cross sections of the reactions $pp \to d\pi^+$ and $pp \to
pn\pi^+$ have been measured at $T_p = 400$ MeV by detecting the charged
ejectiles in the angular range $4^0 \leq \Theta_{Lab} \leq 21^\circ$. The
deduced total cross sections agree well with those published previously for
neighbouring energies. The invariant mass spectra are observed to be strongly
affected by $\Delta$ production and $NN$ final-state interaction. The data are
well described by Monte Carlo simulations including both these effects. The
ratio of $pp \to pn\pi^+$ and $pp \to d\pi^+$ cross sections also compares
favourably to a recent theoretical prediction which suggests a dominance of
$np$-production in the relative $^3S_1$-state.


title: Study of the ABC Enhancement in the d d -> alpha X reaction

abstract:
  The polarized d d -> alpha X reaction at beam energies close to the eta
threshold shows very strong structure in the missing mass corresponding to the
ABC enhancement. The deuteron tensor analysing power A_yy, and the slope of the
vector analysing power A_y with respect to angle, have been measured for this
reaction around the forward direction. Both signals are small, and their
variations with the alpha-particle momentum are in broad agreement with a
theoretical model in which each pair of nucleons in the projectile and target
deuterons undergoes pion production through the NN -> d pi reaction.


title:
Longitudinal momentum distributions of {16,18}C fragments after
  one-neutron removal from {17,19}C

abstract:
  The fragment separator FRS at GSI was used as an energy-loss spectrometer to
measure the longitudinal momentum distributions of {16,18}C fragments after
one-neutron removal reactions in {17,19}C impinging on a carbon target at about
910 MeV/u. The distributions in the projectile frames are characterized by a
FWHM of 141+-6 MeV/c for {16}C and 69+-3 MeV/c for {18}C. The results are
compared with experimental data obtained at lower energies and discussed within
existing theoretical models.


title: Measurement of the Neutral Weak Form Factors of the Proton

abstract:
  We have measured the parity-violating electroweak asymmetry in the elastic
scattering of polarized electrons from the proton. The kinematic point
(theta_lab = 12.3 degrees and Q^2=0.48 (GeV/c)^2) is chosen to provide
sensitivity, at a level that is of theoretical interest, to the strange
electric form factor G_E^s. The result, A=-14.5 +- 2.2 ppm, is consistent with
the electroweak Standard Model and no additional contributions from strange
quarks. In particular, the measurement implies G_E^s + 0.39G_M^s = 0.023 +-
0.034 (stat) +- 0.022 (syst) +- 0.026 (delta G_E^n), where the last uncertainty
arises from the estimated uncertainty in the neutron electric form factor.


title: Polarization Observables of pp -> pp pi0 Near Threshold

abstract:
  With the aim to study spin dependence of pion production near threshold, an
internal target facility and a forward detector have been installed in the
Cooler synchrotron ring at IUCF. The detector system comprises scintillators
and wire chambers. The target consists of a thin-walled open-ended storage cell
into which polarized atomic hydrogen is injected. Using a stored and cooled,
polarized proton beam, polarization observables of the reaction pp -> pp pi0
have been studied at energies between 21 and 55 MeV above the pion production
threshold in the center of mass system. We report here measurements of the spin
correlation parameters Axx and Ayy, and the analyzing power Ay, integrated over
the pion polar angle.


title:
Baryon Stopping and Charged Particle Distributions in Central Pb+Pb
  Collisions at 158 GeV per Nucleon

abstract:
  Net proton and negative hadron spectra for central \PbPb collisions at 158
GeV per nucleon at the CERN SPS were measured and compared to spectra from
lighter systems. Net baryon distributions were derived from those of net
protons, utilizing model calculations of isospin contributions as well as data
and model calculations of strange baryon distributions. Stopping (rapidity
shift with respect to the beam) and mean transverse momentum \meanpt of net
baryons increase with system size. The rapidity density of negative hadrons
scales with the number of participant nucleons for nuclear collisions, whereas
their \meanpt is independent of system size. The \meanpt dependence upon
particle mass and system size is consistent with larger transverse flow
velocity at midrapidity for \PbPb compared to \SS central collisions.


title: Photoabsorption on nuclei in the shadowing threshold region

abstract:
  The energy and nuclear mass dependences of the total hadronic cross section
in the energy range 0.5-2.6 GeV have been measured at Bonn using the SAPHIR
tagged photon beam. The measurement, performed on C, Al, Cu, Sn and Pb,
provides the first photoabsorption data in the region 1.2-1.7 GeV. The results
show a significant reduction of the photoabsorption strength on the bound
nucleon compared to the free nucleon case in the whole energy region. Above 1.2
GeV this reduction decreases with the nuclear density and can be interpreted as
a signature of a low energy onset of the shadowing effect.


title:
Measurement of the 6Li(e,e'p) reaction cross sections at low momentum
  transfer

abstract:
  The triple differential cross sections for the 6Li(e,e'p) reaction have been
measured in the excitation energy region from 27 to 46 MeV in a search for
evidence of the giant dipole resonance (GDR) in 6Li. The cross sections have no
distinct structures in this energy region, and decrease smoothly with the
energy transfer. Angular distributions are different from those expected with
the GDR. Protons are emitted strongly in the momentum-transfer direction. The
data are well reproduced by a DWIA calculation assuming a direct proton
knockout process.


title: A precise measurement of the deuteron elastic structure function A(Q^2)

abstract:
  The A(Q^2) structure function in elastic electron-deuteron scattering was
measured at six momentum transfers Q^2 between 0.66 and 1.80 (GeV/c)^2 in Hall
C at Jefferson Laboratory. The scattered electrons and recoil deuterons were
detected in coincidence, at a fixed deuteron angle of 60.5 degrees. These new
precise measurements resolve discrepancies between older sets of data. They put
significant constraints on existing models of the deuteron electromagnetic
structure, and on the strength of isoscalar meson exchange currents.


title: Is Strangeness still interesting at RHIC ?

abstract:
  With the advent of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven
National Laboratory (BNL), Heavy Ion Physics will enter a new energy regime.
The question is whether the signatures proposed for the discovery of a phase
transition from hadronic matter to a Quark Gluon Plasma (QGP), that were
established on the basis of collisions at the BEVALAC, the AGS, and the SPS,
respectively, are still useful and detectable at these high incident energies.
In the past two decades, measurements related to strangeness formation in the
collision were advocated as potential signatures and were tested in numerous
fixed target experiments at the AGS and the SPS. In this article I will review
the capabilities of the RHIC detectors to measure various aspects of
strangeness, and I will try to answer the question whether the information
content of those measurements is comparable to the one at lower energies.


title: Electroproduction of the S11(1535) Resonance at High Momentum Transfer

abstract:
  The differential cross section for the process p(e,e'p)eta has been measured
at Q^2 = 2.4 and 3.6 (GeV/c)^2 at center-of-mass energies encompassing the
S11(1535) resonance. The latter point is the highest-Q^2 exclusive measurement
of this process to date. The resonance width and the helicity-1/2 transition
amplitude are extracted from the data, and evidence for the possible onset of
scaling in this reaction is shown. A lower bound of approximately 0.45 is
placed on the S11(1535) to eta branching fraction.


title:
Antiproton Production and Antudeuteron Production Limits in Relativistic
  Heavy Ion Collisions

abstract:
  We present results from Experiment 864 for antiproton production and
antideuteron limits in Au + Pb collisions at 11.5 GeV/c per nucleon. We have
measured invariant multiplicities for antiprotons for rapidities 1.4<y<2.4 at
low transverse momentum as a function of collision geometry. When compared with
the results from Experiment 878 our measurements suggest a significant
contribution to the measured antiproton yield from the decay of strange
antibaryons. We have also searched for antideuterons and see no statistically
significant signal. Thus, we set upper limits on the production at
approximately 3 x 10^{-7} per 10% highest multiplicity Au + Pb interaction.


title: Higher Partial Waves in p+p->p+p+eta near Threshold

abstract:
  Exclusive measurements of the production of eta mesons in the p+p->p+p+eta
reaction have been carried out at excess energies of 16 and 37 MeV above
threshold. The deviations from phase space are dominated by the proton-proton
final state interaction and this influences particularly the energy
distribution of the eta meson. However, evidence is also presented at the
higher energy for the existence of an anisotropy in the angular distributions
of the eta meson and also of the final proton-proton pair, probably to be
associated with D-waves in this system interfering with the dominant S-wave
term. The sign of the eta angular anisotropy suggests that rho-exchange is
important for this reaction.


title:
Comparison of Lambda and Sigma(0) Threshold Production in Proton-Proton
  Collisions

abstract:
  Threshold measurements of the associated strangeness production reactions pp
--> p K(+) Lambda and pp --> p K(+) Sigma(0) are presented. Although slight
differences in the shapes of the excitation functions are observed, the most
remarkable feature of the data is that at the same excess energy the total
cross section for the Sigma(0) production appears to be about a factor of 28
smaller than the one for the Lambda particle. It is concluded that strong
Sigma(0)-p final state interactions, and in particular the Sigma-N --> Lambda-p
conversion reaction, are the likely cause of the depletion for the yield in the
Sigma signal. This hypothesis is in line with other experimental evidence in
the literature.


title: Tests of Transfer Reaction Determinations of Astrophysical S-Factors

abstract:
  The ${}^{16}O ({}^{3}He,d) {}^{17}F$ reaction has been used to determine
asymptotic normalization coefficients for transitions to the ground and first
excited states of ${}^{17}F$. The coefficients provide the normalization for
the tails of the overlap functions for ${}^{17}F \to{}^{16}O + p$ and allow us
to calculate the S-factors for ${}^{16}O (p,\gamma){}^{17}F$ at astrophysical
energies. The calculated S-factors are compared to measurements and found to be
in very good agreement. This provides the first test of this indirect method to
determine astrophysical direct capture rates using transfer reactions. In
addition, our results yield S(0) for capture to the ground and first excited
states in $^{17}F$, without the uncertainty associated with extrapolation from
higher energies.


title:
Search for positively charged strangelets and other related results with
  E864 at the AGS

abstract:
  We report on the latest results in the search for positively charged
strangelets from E864's 96/97 run at the AGS with sensitivity of about $8\times
10^{-9}$ per central collision. This contribution also contains new results of
a search for highly charged strangelets with $Z=+3$. Production of light
nuclei, such as $^6He$ and $^6Li$, is presented as well. Measurements of yields
of these rarely produced isotopes near midrapidity will help constrain the
production levels of strangelets via coalescence. E864 also measures antiproton
production which includes decays from antihyperons. Comparisons with antiproton
yields measured by E878 as a function of centrality indicate a large
antihyperon-to-antiproton ratio in central collisions.


title: Two-Photon Physics in Nucleus-Nucleus Collisions at RHIC

abstract:
  Ultra-relativistic heavy-ions carry strong electromagnetic and nuclear
fields. Interactions between these fields in peripheral nucleus-nucleus
collisions can probe many interesting physics topics. This presentation will
focus on coherent two-photon and photonuclear processes at RHIC. The rates for
these interactions will be high. The coherent coupling of all the protons in
the nucleus enhances the equivalent photon flux by a factor Z^2 up to an energy
of ~3 GeV. The plans for studying coherent interactions with the STAR
experiment will be discussed. Experimental techniques for separating signal
from background will be presented.


title: Inclusive Electron-Nucleus Scattering at Large Momentum Transfer

abstract:
  Inclusive electron scattering is measured with 4.045 GeV incident beam energy
from C, Fe and Au targets. The measured energy transfers and angles correspond
to a kinematic range for Bjorken $x > 1$ and momentum transfers from $Q^2 = 1 -
7 (GeV/c)^2$. When analyzed in terms of the y-scaling function the data show
for the first time an approach to scaling for values of the initial nucleon
momenta significantly greater than the nuclear matter Fermi-momentum (i.e. $>
0.3$ GeV/c).


title: Hypervelocity Impact Fusion with Compressed Deuterium-Tritium Targets

abstract:
  The neutron yields observed in inertial confinement fusion experiments for
higher convergence ratios are about two orders of magnitude smaller than the
neutron yields predicted by one-dimensional models, the discrepancy being
attributed to the development of instabilities. We consider the possibility
that ignition and a moderate gain could be achieved with existing laser
facilities if the laser driver energy is used to produce only the radial
compression of the fuel capsule to high densities but relatively low
temperatures, while the ignition of the fusion reactions in the compressed fuel
capsule will be effected by a synchronized hypervelocity impact. A
positively-charged incident projectile can be accelerated to velocities of 3.5
x 10^6 m/s, resulting in ignition temperatures of about 4 keV, by a
conventional low-beta linac having a length of 13 km if deuterium-tritium
densities of 570 g/cm^3 could be obtained by laser-driven compression.


title: Subthreshold rho^0 photoproduction on 3He

abstract:
  A large reduction of the rho^0 mass in the nuclear medium is reported,
inferred from dipion photoproduction spectra in the 1 GeV region, for the
reaction 3He(gamma,pi+ pi-)X with a 10% duty factor tagged-photon beam and the
TAGX multi-particle spectrometer. The energy range covered (800 < E(gamma) <
1120 MeV) lies mostly below the free rho^0 production threshold, a region which
is believed sensitive to modifications of light vector-meson properties at
nuclear-matter densities. The rho^0 masses extracted from the MC fitting of the
data, m*(rho^0) = 642 +/- 40, 669 +/- 32, and 682 +/- 56 MeV/c^2 for E(gamma)
in the 800-880, 880-960, and 960-1040 MeV regions respectively, are
independently corroborated by a measured, assumption-free, kinematical
observable. This mass shift, far exceeding current mean-field driven
theoretical predictions, may be suggestive of rho^0 decay within the range of
the nucleonic field.


title:
Probing the Concept of Statistical Independence of Intermediate-Mass
  Fragment Production in Heavy-Ion Collisions

abstract:
  It is found that the total IMF-transverse-energy (E_t) spectra in multi-IMF
events are well represented by synthetic spectra obtained by folding of the
single-IMF spectrum. Using the experimental IMF multiplicity distribution, the
observed trends in the IMF multiplicity distribution for fixed values of E_t
are reproduced. The synthetic distributions show binomial reducibility and
Arrhenius-like scaling, similar to that reported in the literature. Similar
results are obtained when the above folding-type synthesis is replaced with one
based on mixing events with different IMF multiplicities. For statistically
independent IMF emission, the observed binomial reducibility and Arrhenius-type
scaling are merely reflections of the shape of the single-IMF transverse-energy
spectrum. Hence, a valid interpretation of IMF distributions in terms of a
particular production scenario has to explain independently the observed shape
of the single-IMF E_t spectrum.


title: Quasielastic 12C(e,e'p) Reaction at High Momentum Transfer

abstract:
  We measured the 12C(e,e'p) cross section as a function of missing energy in
parallel kinematics for (q,w) = (970 MeV/c, 330 MeV) and (990 MeV/c, 475 MeV).
At w=475 MeV, at the maximum of the quasielastic peak, there is a large
continuum (E_m > 50 MeV) cross section extending out to the deepest missing
energy measured, amounting to almost 50% of the measured cross section. The
ratio of data to DWIA calculation is 0.4 for both the p- and s-shells. At w=330
MeV, well below the maximum of the quasielastic peak, the continuum cross
section is much smaller and the ratio of data to DWIA calculation is 0.85 for
the p-shell and 1.0 for the s-shell. We infer that one or more mechanisms that
increase with $\omega$ transform some of the single-nucleon-knockout into
multinucleon knockout, decreasing the valence knockout cross section and
increasing the continuum cross section.


title:
Neutrons from multiplicity-selected La-La and Nb-Nb collisions at 400A
  MeV and La-La collisions at 250A MeV

abstract:
  Triple-differential cross sections for neutrons from high-multiplicity La-La
collisions at 250 and 400 MeV per nucleon and Nb-Nb collisions at 400 MeV per
nucleon were measured at several polar angles as a function of the azimuthal
angle with respect to the reaction plane of the collision. The reaction plane
was determined by a transverse-velocity method with the capability of
identifying charged-particles with Z=1, Z=2, and Z > 2. The flow of neutrons
was extracted from the slope at mid-rapidity of the curve of the average
in-plane momentum vs the center-of-mass rapidity. The squeeze-out of the
participant neutrons was observed in a direction normal to the reaction plane
in the normalized momentum coordinates in the center-of-mass system.
Experimental results of the neutron squeeze-out were compared with BUU
calculations. The polar-angle dependence of the maximum azimuthal anisotropy
ratio $r(\theta)$ was found to be insensitive to the mass of the colliding
nuclei and the beam energy. Comparison of the observed polar-angle dependence
of the maximum azimuthal anisotropy ratio $r(\theta)$ with BUU calculations for
free neutrons revealed that $r(\theta)$ is insensitive also to the
incompressibility modulus in the nuclear equation of state.


title:
Na49 Results on Single Particle and Correlation Measurements in Central
  PB+PB Collisions

abstract:
  Single-particle spectra and two-particle correlation functions measured by
the NA49 collaboration in central Pb+Pb collisions at 158 GeV/nucleon are
presented. These measurements are used to study the kinetic and chemical
freeze-out conditions in heavy ion collisions. We conclude that large baryon
stopping, high baryon density and strong transverse radial flow are achieved in
central Pb+Pb collisions at the SPS.


title:
Large Momentum Transfer Measurements of the Deuteron Elastic Structure
  Function A(Q^2) at Jefferson Laboratory

abstract:
  The deuteron elastic structure function A(Q^2) has been extracted in the Q^2
range 0.7 to 6.0 (GeV/c)^2 from cross section measurements of elastic
electron-deuteron scattering in coincidence using the Hall A Facility of
Jefferson Laboratory. The data are compared to theoretical models based on the
impulse approximation with inclusion of meson-exchange currents, and to
predictions of quark dimensional scaling and perturbative quantum
chromodynamics


title:
Energy dependence of the isomeric cross section ratio in the
  $^{58}$Ni$(n,p)^{58}$Co$^{m,g}$ reactions

abstract:
  Excitation functions of the $^{58}$Ni$(n,p)^{58}$Co$^{m,g}$ reactions were
measured in the energy range from 2 to 15 MeV. The energy dependence of the
isomeric cross-section ratio R=sigma_m/(sigma_m+sigma_g) is deduced from the
measured data. The shape and magnitude of the R(E_n) function are described by
model calculations using a consistent parameter set. Questions of the input
level scheme were solved based on the accurate isomeric ratio measured at low
energy region.


title:
Search for DCC in Relativistic Heavy-Ion Collision Through Event Shape
  Analysis

abstract:
  Event shape analysis has been used to look for DCC signals in simulated
ultra-relativistic heavy-ion collision data at SPS energy. A simple
redistribution of particles, with two detectors to detect charged particles and
photons, is seen to result in the same flow direction with the flow angle
difference peaking at zero. However, events where the neutral pion fraction has
been modified according to the DCC probability distribution, show the flow
angles in two detectors to be almost $90^o$ apart. The results presented here
show that the technique is complementary to the one based on the discrete
wavelet transformation. Together the techniques are seen to provide a very
powerful tool for DCC search in ultra relativistic heavy ion collision.


title: Flow angle from intermediate mass fragment measurements

abstract:
  Directed sideward flow of light charged particles and intermediate mass
fragments was measured in different symmetric reactions at bombarding energies
from 90 to 800 AMeV. The flow parameter is found to increase with the charge of
the detected fragment up to Z = 3-4 and then turns into saturation for heavier
fragments. Guided by simple simulations of an anisotropic expanding thermal
source, we show that the value at saturation can provide a good estimate of the
flow angle, $\Theta_{flow}$, in the participant region. It is found that
$\Theta_{flow}$ depends strongly on the impact parameter. The excitation
function of $\Theta_{flow}$ reveals striking deviations from the ideal
hydrodynamical scaling. The data exhibit a steep rise of $\Theta_{\flow}$ to a
maximum at around 250-400 AMeV, followed by a moderate decrease as the
bombarding energy increases further.


title:
Absolute measurement of the 5/2+ resonance of 36Ar(p,gamma)37K at E_p =
  918 keV

abstract:
  The strength of the 5/2+ resonance of the reaction 36Ar(p,gamma)37K at E_p =
918 keV was measured absolutely: omega gamma = (258 \pm 24) meV. The new result
is consistent with previous results. This resonance was used in several
experiments as a calibration standard. Therefore we discuss our experimental
uncertainties in detail which is important for the reliability of previous
experiments and our new result.


title: Search for eta-mesic nuclei in photo-mesonic processes

abstract:
  Preliminary results of an experiment performed at the Lebedev Physical
Institute with the bremsstrahlung photon beams of the end-point energies 650
and 850 MeV are presented. Correlated pi+n pairs with the opening angle theta =
180 deg and the energies E_\pi = 300 MeV, E_n = 100 MeV from the process gamma
+ 12C -> N + eta(A-1) -> N + pi+ n + (A-2) were observed. They provide an
evidence for an existence of the eta-11B and eta-11C eta-mesic nuclei.


title: Decay of neutron-rich Mn nuclides and deformation of heavy Fe isotopes

abstract:
  The use of chemically selective laser ionization combined with beta-delayed
neutron counting at CERN/ISOLDE has permitted identification and half-life
measurements for 623-ms Mn-61 up through 14-ms Mn-69. The measured half-lives
are found to be significantly longer near N=40 than the values calculated with
a QRPA shell model using ground-state deformations from the FRDM and ETFSI
models. Gamma-ray singles and coincidence spectroscopy has been performed for
Mn-64 and Mn-66 decays to levels of Fe-64 and Fe-66, revealing a significant
drop in the energy of the first 2+ state in these nuclides that suggests an
unanticipated increase in collectivity near N=40.


title: Bremsstrahlung radiation by a tunneling particle

abstract:
  We study the bremsstrahlung radiation of a tunneling charged particle in a
time-dependent picture. In particular, we treat the case of bremsstrahlung
during alpha-decay, which has been suggested as a promissing tool to
investigate the problem of tunneling times. We show deviations of the numerical
results from the semiclassical estimates. A standard assumption of a preformed
particle inside the well leads to sharp high-frequency lines in the
bremsstrahlung emission. These lines correspond to "quantum beats" of the
internal part of the wavefunction during tunneling arising from the
interference of the neighboring resonances in the well.


title:
Statistical Exploration of Fragmentation Phase Space Source Sizes in
  Nuclear Multifragmentation

abstract:
  The multiplicity distributions for individual fragment Z values in nuclear
multifragmentation are binomial. The extracted maximum value of the
multiplicity is found to depend on Z according to m=Z_0/Z, where Z_0 is the
source size. This is shown to be a strong indication of statistical coverage of
fragmentation phase space. The inferred source sizes coincide with those
extracted from the analysis of fixed multiplicity charge distributions.


title:
P-wave dominance in the pd -> 3He pi+ pi- reaction near threshold
  measured with the MOMO experiment at COSY

abstract:
  The cross section of the pd -> 3He pi+ pi - reaction has been measured at the
MOMO facility in a kinematically complete experiment at a c. m. excess energy
of Q = 70 MeV. The energy and angular distributions show that the reaction is
dominated by p-wave pi+ pi- pairs. This is in complete contrast to the results
of inclusive measurements at somewhat higher energies which show a strong
s-wave ABC enhancement at low pi pi masses. There are however indications of
p-wave pion pairs from other experiments at low Q.


title:
Statistical and Dynamical Fluctuations in Heavy Ion Collisions: Role of
  Conservation Laws in Event-by-Event Analysis

abstract:
  The analysis of the statistical and dynamical fluctuations in nucleus-nucleus
collisions on an event-by-event basis strongly relies on a comparison with
specially constructed artificial events where statistical fluctuations and
kinematical correlations are under control. In this paper, we present a novel,
analytical method of constructing reference events based on independent
emission, modified by the energy/momentum constraint, which can lead to a
better understanding of the nature of the observed final-state fluctuations.
This approach can be easily used in the analysis of other topics in the heavy
ion field (e.g. flow, HBT etc.) allowing more precise measurements.


title:
Electromagnetic Polarizabilities of Nucleons bound in $^{40}$Ca,
  $^{16}$O and $^4$He

abstract:
  Differential cross sections for elastic scattering of photons have been
measured for $^{40}$Ca at energies of 58 and 74 MeV and for $^{16}$O and $^4$He
at 61 MeV, in the angular range from 45$^o$ to 150$^o$. Evidence is obtained
that there are no significant in-medium modifications of the electromagnetic
polarizabilities except for those originating from meson exchange currents.


title:
Fusion versus Breakup: Observation of Large Fusion Suppression for ^9Be
  + ^{208}Pb

abstract:
  Complete fusion excitation functions for $^{9}$Be + $^{208}$Pb have been
measured to high precision at near barrier energies. The experimental fusion
barrier distribution extracted from these data allows reliable prediction of
the expected complete fusion cross-sections. However, the measured
cross-sections are only 68% of those predicted. The large cross-sections
observed for incomplete fusion products support the interpretation that this
suppression of fusion is caused by $^{9}$Be breaking up into charged fragments
before reaching the fusion barrier. Implications for the fusion of radioactive
nuclei are discussed.


title:
Induced proton polarization for pi^0 electroproduction at Q^2 = 0.126
  (GeV/c)^2 around the Delta(1232) resonance

abstract:
  We present the first measurement of the induced proton polarization P_n in
pi^0 electroproduction on the proton around the Delta resonance. The
measurement was made at a central invariant mass and a squared four-momentum
transfer of W=1231 MeV and Q^2 = 0.126 (GeV/c)^2, respectively. We measured a
large induced polarization, P_n = -0.397 +/- 0.055 +/- 0.009. The data suggest
that the scalar background is larger than expected from a recent effective
Hamiltonian model.


title:
Medium Effects in Kaon and Antikaon Production in Nuclear Collisions at
  Subthreshold Beam Energies

abstract:
  Production cross sections of K$^+$ and K$^-$ mesons have been measured in C+C
collisions at beam energies per nucleon below and near the nucleon-nucleon
threshold. At a given beam energy, the spectral slopes of the K$^-$ mesons are
significantly steeper than the ones of the K$^+$ mesons. The excitation
functions for K$^+$ and K$^-$ mesons nearly coincide when correcting for the
threshold energy. In contrast, the K$^+$ yield exceeds the K$^-$ yield by a
factor of about 100 in proton-proton collisions at beam energies near the
respective nucleon-nucleon thresholds.


title: Role of deformation in the decay of $^{56}$Ni and $^{40}$Ca di-nuclei

abstract:
  Inclusive as well as exclusive energy spectra of the light charged particles
emitted in the $^{28}Si(E_{lab}=112.6 MeV) + ^{28}Si,^{12}C$ reactions have
been measured at the Strasbourg VIVITRON facility in the angular range 15^0 -
150^0, using the ICARE multidetector array. The experimental energy spectra of
$\alpha$-particles are generally well reproduced by the statistical model with
a spin-dependent level density indicating the onset of defomations at high
spin.


title:
Comment on "A proposed method for measuring the electric dipole moment
  of the neutron using acceleration in an electric field gradient and ultracold
  neutron interferometry"

abstract:
  We discuss the proposal of Freedman, Ringo, and Dombeck to search for the
neutron electric dipole moment use of the acceleration of neutrons in an
inhomogeneous electric field followed by amplification of the resulting
displacement by several methods involving spin independent interactions
(gravity) or reflection from curved (spin independent) mirrors. We show that
the proposed technique is inferior to the usual methods based on magnetic
resonance.


title: Strange Mesons as a Probe for Dense Nuclear Matter

abstract:
  The production and propagation of kaons and antikaons has been studied in
symmetric nucleus-nucleus collisions in the SIS energy range. The ratio of the
excitation functions of K^+ production in Au+Au and C+C collisions increases
with decreasing beam energy. This effect was predicted for a soft nuclear
equation-of-state. In noncentral Au+Au collisions, the K^+ mesons are
preferentially emitted perpendicular to the reaction plane. The K^-/K^+ ratio
from A+A collisions at beam energies which are equivalent with respect to the
threshold is found to be about two orders of magnitude larger than the
corresponding ratio from proton-proton collisions. Both effects are considered
to be experimental signatures for a modification of kaon properties in the
dense nuclear medium.


title: Freeze-Out Parameters in Central 158AGeV Pb+Pb Collisions

abstract:
  Neutral pion production in central 158AGeV Pb+Pb collisions has been studied
in the WA98 experiment at the CERN SPS. The pi0 transverse mass spectrum has
been analyzed in terms of a thermal model with hydrodynamic expansion. The high
accuracy and large kinematic coverage of the measurement allow to limit
previously noted ambiguities in the extracted freeze-out parameters. The
results are shown to be sensitive to the shape of the velocity distribution at
freeze-out.


title: Comprehensive evidences of octupole vibration in $^{158}$Gd

abstract:
  Comprehensive evidences of the SU(3) limit in the spdf interacting boson
model, a dynamical symmetry describing octupole vibration in rotational
nucleus, are found in the spectrum, E2 and E1 transition rates, and relative
intensities in $^{158}$Gd. This gives a good example of rotational nucleus with
octupole vibration in rare-earth region.


title: Study of supernarrow dibaryon production in process pd-->pX

abstract:
  The reactions p+d-> p+pX and p+d-> p+dX at 305 MeV are studied with the aim
to search for supernarrow dibaryons, decay of which into two nucleons is
suppressed by the Pauli principle. The experiment was carried out at the Moscow
Meson Factory using a spectrometer TAMS, which detected the scattered proton in
coincidence with the second charged particle (the proton or deuteron) at
various angles. Narrow peaks at 1905 and 1924 MeV with widths less than the
experimental resolution (3 MeV) have been observed in missing- mass spectra of
the process pd->pX. An analysis of the angular dependence of the experimental
data shows that the resonance at $M$=1905 MeV most likely corresponds to the
production of the isovector supernarrow dibaryon.


title:
Measuring centrality with slow protons in proton-nucleus collisions at
  the AGS

abstract:
  Experiment 910 has measured slow protons and deuterons from collisions of 18
GeV/c protons with Be, Cu, and Au targets at the BNL AGS. These correspond to
the ``grey tracks'' first observed in emulsion experiments. We report on their
momentum and angular distributions and investigate their use in measuring the
centrality of a collision, as defined by the mean number of projectile-nucleon
interactions. The relation between the measured Ngrey and the mean number of
interactions, nu(Ngrey), is studied using several simple models, one newly
proposed, as well as the RQMD event generator. RQMD is shown to reproduce the
Ngrey distribution, and exhibits a dependence of Ngrey on centrality that is
similar to the behavior of the simple models. We find a strong linear
dependence of average Ngrey on nu, with a constant of proportionality that
varies with target. For the Au target, we report a relative systematic error
for extracting nu(Ngrey) that lies between 10% and 20% over all Ngrey.


title:
First Measurement of the He3+He3-->He4+2p Cross Section down to the
  Lower Edge of the Solar Gamow Peak

abstract:
  We give the LUNA results on the cross section measurement of a key reaction
of the proton-proton chain strongly affecting the calculated neutrino
luminosity from the Sun: He3+He3-->He4+2p. Due to the cosmic ray suppression
provided by the Gran Sasso underground laboratory it has been possible to
measure the cross section down to the lower edge of the solar Gamow peak, i.e.
as low as 16.5 keV centre of mass energy. The data clearly show the cross
section increase due to the electron screening effect but they do not exhibit
any evidence for a narrow resonance suggested to explain the observed solar
neutrino flux.


title: Thermal neutron induced (n,p) and (n,alpha) reactions on 37Ar

abstract:
  The 37Ar(n_th,alpha)34S and 37Ar(n_th,p)37Cl reactions were studied at the
high flux reactor of the ILL in Grenoble. For the 37Ar(n_th,alpha_0) and
37Ar(n_th,p) reaction cross sections, values of (1070+/-80)b and (37+/-4)b,
respectively, were obtained. Both values are about a factor 2 smaller than
results of older measurements. The observed suppression of the 37(n_th,alpha_1)
transition could be verified from theoretical considerations. Finally, evidence
was found for the two-step 37Ar(n_th,gamma-alpha) process.


title: In-medium modification of the Delta(1232) resonance at SIS energies

abstract:
  From the pion production rates n_{pi} / A_{part} and the pion charge ratios
R_{pi} = n_{pi^-} / n_{pi^+} and S_{pi} = n_{pi^0} / (n_{pi^-} + n_{pi^+}),
measured in p + A and A + A reactions, it is concluded that the mass of the
Delta(1232) resonance is reduced in dense nuclear matter. This conclusion is
supported by the Delta(1232) mass distribution extracted from correlated
(p,pi^{+-}) pairs and the pi^{+-} transverse momentum distributions.


title:
Thermodynamical features of multifragmentation in peripheral Au + Au
  Collisions at 35 A.MeV

abstract:
  The distribution of fragments produced in events involving the
multifragmentation of excited sources is studied for peripheral Au + Au
reactions at 35 A.MeV.
  The Quasi-Projectile has been reconstructed from its de-excitation products.
An isotropic emission in its rest frame has been observed, indicating that an
equilibrated system has been formed. The excitation energy of the
Quasi-Projectile has been determined via calorimetry.
  A new event by event effective thermometer is proposed based on the energy
balance. A peak in the energy fluctuations is observed related to the heat
capacity, suggesting that the system undergoes a liquid-gas type phase
transition at an excitation energy about 5 A.MeV and a temperature 4 - 6 MeV,
dependent on the freeze-out hypothesis. By analyzing different regions of the
Campi-plot, the events associated with the liquid and gas phases as well as the
critical region are thermodynamically characterized.
  The critical exponents, tau, beta,gamma, extracted from the high moments of
the charge distribution are consistent with a liquid-gas type phase transition.


title: Studying Short-Range Dynamics in Few-Body Systems

abstract:
  I present the case for studying the nature of short-range internucleon
interactions with electron-scattering experiments on few-body nuclear targets.
I first review what electron-scattering studies have unearthed about the nature
of the interactions between nucleons in nuclei at small separation. Special
consideration is given to a couple of recent experiments. The results
essentially serve to construct a roadmap for future studies in this area. The
related experimental program at Jefferson Lab is presented, along with
suggestions for future theoretical work.


title:
Centrality dependence of Pi- Production and Stopping in p-A Collisions
  at 18 GeV/c

abstract:
  First results are presented from BNL experiment E910 on pion production and
stopping in proton-Be, Cu, and Au collisions at a beam momentum of 18 GeV/c. We
characterize the centrality of the collisions using the measured number of
"grey" tracks, Ngrey,and a derived quantity, nu, the number of inelastic
nucleon-nucleon scatterings suffered by the projectile during the collision. We
find that for the three targets the average backward rapidity shift of the
leading proton follows a common trend versus nu with the projectile losing, on
average, 2 units of rapidity in the first 2-3 scatterings. The average rapidity
shift increases more slowly with subsequent scatterings reaching a maximum of
2.5 units. The pi- multiplicity measured within the E910 acceptance saturates
with increasing nu in p-Au collisions while the pi- multiplicity in p-Be
collisions increases faster with nu than expected from the wounded-nucleon
model. Comparisons of our data with the RQMD cascade model suggest that in very
central p-Au collisions most of the pions are produced near zero rapidity in
the lab.