FSQ-13-009

FSQ-13-009

# Measurement of exclusive $\PgU$ photoproduction from protons in $\Pp$Pb
collisions at $\sqrtsNN=5.02\TeV$

The CMS Collaboration

###### Abstract

The exclusive photoproduction of $\PgU\mathrm{(nS)}$ meson states from
protons, $\PGg\Pp\to\PgU\mathrm{(nS)}\,\Pp$ (with $\mathrm{n}=1,2,3$), is
studied in ultraperipheral $\Pp$Pb collisions at a centre-of-mass energy per
nucleon pair of $\sqrtsNN=5.02\TeV$. The measurement is performed using the
$\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}$ decay mode, with data collected by the
CMS experiment corresponding to an integrated luminosity of 32.6. Differential
cross sections as functions of the $\PgU\mathrm{(nS)}$ transverse momentum
squared $\pt^{2}$, and rapidity $y$, are presented. The $\PgUa$
photoproduction cross section is extracted in the rapidity range
$\abs{y}<2.2$, which corresponds to photon-proton centre-of-mass energies in
the range $91<W_{\PGg\Pp}<826\GeV$. The data are compared to theoretical
predictions based on perturbative quantum chromodynamics and to previous
measurements.

##  0.1 Introduction

This paper reports a first measurement of the exclusive photoproduction of
$\PgU$ mesons from protons in $\Pp$Pb collisions at a nucleon-nucleon centre-
of-mass energy of $\sqrtsNN=5.02\TeV$, performed at the CERN LHC with the CMS
detector. Exclusive photoproduction of vector mesons can be studied at the LHC
in ultraperipheral collisions (UPCs) of protons and/or ions occurring at
impact parameters larger than the sum of their radii, thereby largely
suppressing their hadronic interaction [1]. In such UPCs, one of the incoming
hadrons emits a quasi-real photon that converts into a $\qqbar$ (vector meson)
bound state following a colour-singlet gluon exchange with the other “target”
proton or ion [2, 3]. Since the incoming hadrons remain intact after the
interaction and only the vector meson is produced in the event, the process is
called “exclusive”. Given that the photon flux scales with the square of the
emitting electric charge, the radiation of quasi-real photons from the Pb ion
is strongly enhanced compared to that from the proton. Figure 1a shows the
dominant diagram for the exclusive $\PgU$ photoproduction signal in $\Pp$Pb
collisions, $\Pp\mathrm{Pb}\to(\PGg\Pp)\mathrm{Pb}\to\Pp\,\PgU\,\mathrm{Pb}$.
If the $\PgU$ photoproduction is followed by the proton breakup, the process
is called “semiexclusive” (Fig. 1b). The exchanged photon can also interact
with a photon radiated from the proton [1, 4]. This two-photon collision can
produce an exclusive dimuon state, as shown in Fig. 1c. Since we are
interested in studying exclusive $\PgU$ production via its dimuon decay, the
latter quantum electrodynamics (QED) continuum production constitutes a
background process.

Figure 1: Diagrams representing (a) exclusive $\PgU$ photoproduction, (b)
proton dissociative , or “semiexclusive”, $\PgU$ photoproduction, and (c)
exclusive dimuon QED continuum production in $\Pp$Pb collisions.

The study of exclusive photoproduction of quarkonia offers a clean probe of
the target hadron structure [1, 3, 5], with the large mass of the $\cPJgy$ and
$\PgU$ mesons providing a hard scale for calculations based on perturbative
quantum chromodynamics (pQCD) [6, 7, 8, 9]. In the kinematic region studied
here, the photoproduction of $\cPJgy$ and $\PgU$ mesons from protons is
sensitive to generalized parton distributions (GPDs), which can be
approximated by the square of the gluon density in the proton [6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19]. Experimentally, exclusive $\cPJgy$ and
$\PgU$ photoproduction cross sections have been observed to rise with photon-
proton centre-of-mass energy $W_{\PGg\Pp}$, following a power-law dependence
$W_{\PGg\Pp}^{\delta}$ with $\delta=0.7$–1.2 [20, 21]. This reflects the steep
rise of the underlying gluon density in the proton for decreasing values of
the momentum fraction $x$ of the proton carried by the struck parton. The
dependence of the exclusive vector meson photoproduction cross section on the
squared four-momentum transfer at the proton vertex $t$, parameterized at low
values of $\abs{t}$ with an exponential function of the form $\exp(-b\abs{t})$
[22, 20, 23, 24], has also often been studied; the $b$ slope parameter
provides valuable information on the parton transverse density profile of the
proton [7, 25, 8].

Exclusive $\PgU$ meson photoproduction was first observed in electron-proton
collisions at HERA [22, 20, 21, 24] with the quasi-real photon radiated from
the electron. At the CERN LHC, the LHCb [26, 27, 28], CMS [29], and ALICE [30,
31, 32, 33] experiments have measured exclusive photoproduction of $\cPJgy$
mesons in ultraperipheral proton-proton and nuclear collisions. The LHCb
experiment has also reported the measurement of the exclusive $\PgU$
photoproduction cross section in $\Pp\Pp$ collisions at $\sqrt{s}=7$ and 8
[34]. The larger mass of the $\PgU$ meson provides a larger perturbative scale
at which the gluon distribution in the proton is sampled, and thereby reduces
theoretical uncertainties in pQCD calculations. This allows the data to
constrain the gluon distributions at low values of Bjorken $x$ in global PDF
fits for the first time [35]. The present paper reports the measurement of
$\PgU$ photoproduction in $\Pp$Pb UPCs that probes the gluon density of the
proton in the region $x=m_{\PgU}^{2}/W_{\PGg\Pp}^{2}=10^{-4}$–$10^{-2}$ [3],
where $m_{\PgU}$ is the $\PgU$ meson mass. This CMS measurement spans a
previously unexplored low-$x$ region between the HERA and LHCb data, and
provides additional experimental insights on the gluon content in the proton.
In this low-$x$ regime, nonlinear QCD effects (gluon recombination) may become
important, possibly leading to the saturation of the parton distribution
functions (PDFs) [36, 37, 38].

The measurements presented here are carried out using the $\mu^{+}\mu^{-}$
decays of the $\PgU\mathrm{(nS)}$ ($\mathrm{n}=1$, 2, 3) bottomonium mesons in
the rapidity range $\abs{y}<2.2$ in the laboratory frame. These include
differential cross sections as functions of the $\PgU$ rapidity and transverse
momentum squared $\pt^{2}$ (which approximates the absolute value of the four-
momentum transfer squared at the proton vertex, $\abs{t}$), as well as the
total $\PgUa$ cross section as a function of $W_{\PGg\Pp}$. The results are
compared to previous measurements and to theoretical predictions based on
leading order (LO) and next-to-leading-order (NLO) pQCD calculations [10], as
well as on colour dipole [15, 16] and gluon saturation [17, 18, 15, 16, 19]
approaches.

##  0.2 Experimental setup

The central feature of the CMS apparatus is a superconducting solenoid of 6m
internal diameter, providing a magnetic field of 3.8T. Within the solenoid
volume are a silicon pixel and strip tracker, a lead tungstate crystal
electromagnetic calorimeter (ECAL), and a brass and scintillator hadron
calorimeter (HCAL), each composed of a barrel and two endcap sections. The
silicon pixel and strip tracker measures charged-particle trajectories within
the pseudorapidity range $\abs{\eta}<2.5$. It consists of 66 million pixel and
10 million strip sensor elements. For charged particles with $1<\pt<10\GeV$
and $\abs{\eta}<1.4$, the track resolutions are typically 1.5% in [39].

Muons are measured in gas-ionisation detectors embedded in the steel flux-
return yoke outside the solenoid over the range $\abs{\eta}<2.4$, with
detection planes based on three technologies: drift tubes, cathode strip
chambers, and resistive-plate chambers. The reconstruction algorithm considers
all tracks in the silicon tracker and identifies them as muons by looking for
compatible signatures in the calorimeters and in the muon system. Because of
the strong magnetic field and the fine granularity of the tracker, the muon
measurement based on information from the tracker alone has a good resolution
[40].

Extensive forward calorimetry, based on Cherenkov radiation detectors,
complements the coverage provided by the barrel and endcap calorimeters. Two
hadron forward (HF) calorimeters, consisting of iron absorbers and embedded
radiation-hard quartz fibres, cover $2.9<\abs{\eta}<5.2$, and two zero-degree
calorimeters (ZDCs), with alternating layers of tungsten and quartz fibers,
are sensitive to neutrons and photons with $\abs{\eta}>8.3$ [41].

The data are collected with a two-level trigger system. The first level of the
CMS trigger system, composed of custom hardware processors, uses information
from the calorimeters and muon detectors to select the most interesting events
[42]. The high-level trigger (HLT) processor farm runs a version of the full
event reconstruction software optimized for fast processing. A more detailed
description of the CMS detector, together with a definition of the coordinate
system used and the relevant kinematic variables, can be found in Ref. [43].

##  0.3 Data sample and Monte Carlo simulation

The data set used in this analysis corresponds to 32.6of integrated luminosity
collected in $\Pp$Pb collisions by the CMS experiment in 2013, with beam
energies of 4for the protons and 1.58per nucleon for the lead nuclei,
resulting in a nucleon-nucleon centre-of-mass energy of $\sqrtsNN=5.02\TeV$.
The data are the sum of the collected $\Pp$Pb and Pb$\Pp$ collision samples,
with the incoming Pb ion going in the $+z$ and $-z$ beam directions,
corresponding to integrated luminosities of 18.8 and 13.8, respectively.

The photon-proton centre-of-mass energy, $W_{\PGg\Pp}$, is related to the
rapidity $y$ of the $\PgU$ meson in the laboratory frame by
$W_{\PGg\Pp}^{2}=2E_{\Pp}m_{\PgU}\exp(\pm y)$, where $E_{\Pp}$ is the proton
energy, and the $+(-)$ sign corresponds to the $\Pp$Pb (Pb$\Pp$) beam
configuration. This formula, derived neglecting the transverse momenta
involved in the interaction, approximates the true value of $W_{\PGg\Pp}$ to
better than 1 per mille in the $W_{\PGg\Pp}$ range of this measurement. The
data span the range $91<W_{\PGg\Pp}<826\GeV$, with the limits given by the
maximum and minimum rapidities, over $\abs{y}<2.2$, of the $\PgU$ mesons.
Because the CMS detector is symmetric along $z$, the $\Pp$Pb and Pb$\Pp$ data
samples are merged in this analysis after changing the sign of $p_{z}$ of the
final state particles in the Pb$\Pp$ sample.

The starlight (v3.07) [44, 45] Monte Carlo (MC) event generator is used to
simulate exclusive $\PgU\mathrm{(nS)}$ photoproduction events (Fig. 1a) and
the exclusive QED background (Fig. 1c). The starlight MC assumes that the
photon flux from the incoming hadron(s) is described by the
Weizsäcker–Williams equivalent photon approximation [46, 47], and uses an
empirical fit of the exclusive vector meson photoproduction cross sections to
the existing HERA $\PGg\Pp$ data. In the $\PgU\mathrm{(nS)}$ sample, two
contributions are simulated, with the photon being emitted either from the Pb
ion or from the proton. The $\PGg\Pp$ events where the photon is emitted from
the Pb ion constitute the signal, while the small fraction of
$\gamma\mathrm{Pb}$ events with the photon emitted from the proton is treated
as a background. The signal events in the starlight MC are simulated assuming
a $\abs{t}$-differential cross section following an $\exp(-b\abs{t})$
dependence, and a power law dependence of the cross section on the photon-
proton centre-of-mass energy, $W_{\PGg\Pp}^{\delta}$, with the exponent
$\delta$. In this study, the $b$ and $\delta$ parameters are tuned to
reproduce the data through a reweighting procedure described in Section 0.4.
The backgrounds from inclusive and semiexclusive $\PgU$ and dimuon production
processes are obtained using templates derived from control samples in the
data, as explained in the next section. All simulated events are passed
through the -based [48, 49, 50] detector simulation and the event
reconstruction chain of CMS.

##  0.4 Event selection and background estimation

The $\PgU\mathrm{(nS)}$ states are studied in their dimuon decay channel. The
UPC dimuon events are selected at the trigger level with a dedicated HLT
algorithm, requiring at least one muon and at least one, but not more than
six, tracks in the event. At the offline level, additional selection criteria
for muon quality requirements, are applied [40, 51]. In order to minimize the
uncertainties related to the low-$\pt$ muon reconstruction inefficiencies,
muons with $\pt^{\mu}>3.3\GeV$ are selected in the region
$\abs{\eta^{\mu}}<2.2$ in the laboratory frame. Exclusive events are selected
by requiring two opposite-charge muons with a single vertex and no extra
charged particles with $\pt>0.1\GeV$ associated with it. In addition, no
energy deposits in the HF calorimeters are allowed. This is achieved by
requiring that the largest HF tower energy deposit be smaller than 5. The HF
energy threshold is set to be larger than the detector noise, and is
determined from the energy distributions collected in dedicated data taking
with no LHC beams. Furthermore, the rapidity of the muon pair is required to
be in the region $\abs{y}<2.2$ in the laboratory frame. Only events with the
$\pt$ of the muon pair between 0.1 and 1are considered, thereby reducing the
contamination from QED pairs at very low $\pt$ and from $\PgU$ meson
production in inclusive and semiexclusive (where the proton dissociates into a
low-mass hadronic system, Fig. 1b) processes that dominate the region of large
dimuon $\pt>1\GeV$.

Figure 2 shows the invariant mass distribution of $\mu^{+}\mu^{-}$ pairs in
the range between 8 and 12that satisfy the selection criteria described above.
An unbinned likelihood fit to the spectrum is performed using RooFit [52] with
a linear function to describe the QED $\gamma\gamma\to\mu^{+}\mu^{-}$
continuum background, where the background slope parameter is fixed to the
starlight $\gamma\gamma\to\mu^{+}\mu^{-}$ simulation, plus three Gaussian
functions for the three $\PgU$ signal peaks, since the natural widths of the
$\PgU\mathrm{(nS)}$ states are much smaller than their (Gaussian) experimental
invariant mass resolutions. The six free parameters of the fit are the
normalizations of the background and the three signal peaks, as well as the
mass and the width of the $\PgUa$ resonance. The $\PgUb-\PgUa$ and
$\PgUc-\PgUa$ mass differences are fixed to their PDG values [53], while the
widths of $\PgUb$ and $\PgUc$ are expressed in terms of the $\PgUa$ width
scaled by the ratio of their masses. The parameters describing the background
plus the $\PgUa$ and $\PgUb$ resonances do not change if the $\PgUc$ signal is
neglected in the fit. The statistical significance of the $\PgUa+\PgUb$ peaks
over the background is $3.9\sigma$. The apparent excess at $8.5\GeV$ has a
local significance of $1.6\sigma$, and is consistent with a statistical
fluctuation. Because of the overall small number of events in the data sample,
a determination of the separate $\PgU\mathrm{(nS)}$ differential cross
sections by fitting the invariant mass spectrum in each $\pt^{2}$ and $y$ bin
leads to results with large statistical fluctuations. Instead, the cross
sections are extracted by adding up the events, after background subtraction,
in the 9.1–10.6mass region corresponding to the three $\PgU$ states combined,
and the $\PgUa$ yield is derived from the $\PgUa$/$\PgU\mathrm{(sum)}$ ratio,
where $\PgU\mathrm{(sum)}=\PgUa+\PgUb+\PgUc$, as described in Section 0.5.

Figure 2: Invariant mass distribution of the exclusive muon pair candidates in
the range $8<m_{\mu^{+}\mu^{-}}<12\GeV$ that pass all the selection criteria,
fitted to a linear function for the two-photon QED continuum (blue dashed
line) plus three Gaussian distributions corresponding to the $\PgUa$, $\PgUb$,
and $\PgUc$ mesons (dashed-dotted-red curves).

Figure 3: Distributions of the (a) transverse momentum squared $\pt^{2}$, and
(b) rapidity $y$ of exclusive muon pairs with invariant mass
$9.1<m_{\mu^{+}\mu^{-}}<10.6~{}\GeV$ after all selection criteria have been
applied. Both distributions are compared to the expectations of signal and
background contributions discussed in the text.

Figure 3 shows the dimuon $\pt^{2}$ and rapidity distributions in the
invariant mass interval $9.1<m_{\mu^{+}\mu^{-}}<10.6\GeV$ for events passing
all the selection criteria for the combined $\Pp$Pb and Pb$\Pp$ samples. The
data, uncorrected for detector effects, are compared to the starlight
simulation for exclusive $\PgU\mathrm{(nS)}$ and QED dimuon production,
normalized to the recorded integrated luminosity, together with the inclusive
and semiexclusive backgrounds derived from the data themselves as discussed
below. The simulated $\PgU\mathrm{(nS)}$ events from starlight are shown
separately for the $\PGg\Pp$ and $\PGg\mathrm{Pb}$ processes; the latter (with
much smaller cross sections) are considered as a background in this analysis.
The $\PgU\mathrm{(nS)}$ events generated with starlight are reweighted to
describe the data, using the parameters $b=5.8\GeV^{-2}$ for the $\abs{t}$
distribution slope, and $\delta=0.99$ for the cross section energy dependence.
These parameters minimize the $\chi^{2}$ goodness-of-fit value calculated
using the data and MC distributions of Fig. 3. The minimization is performed
as a function of the rapidity simultaneously for the $\PGg\Pp$ and
$\PGg\mathrm{Pb}$ samples, and as a function of $\pt^{2}$ for the $\PGg\Pp$
events. For $\PGg\mathrm{Pb}$ events, the default starlight $\pt$ spectrum is
used.

In order to extract the exclusive $\PGg\Pp\to\PgU(\mu^{+}\mu^{-})\Pp$ signal
events, the exclusive QED and other nonexclusive background contributions need
to be subtracted. The QED $\gamma\gamma\to\mu^{+}\mu^{-}$ continuum under the
$\PgU\mathrm{(nS)}$ peaks is estimated with the starlight MC simulation. The
absolute prediction of the cross section from this generator is cross-checked
by comparing the data and the simulation in a control region, corresponding to
small values of dimuon $\pt$, $\pt<0.15\GeV$, and away from the $\PgU$
resonances, $8<m_{\mu^{+}\mu^{-}}<9.1\GeV$ and
$10.6<m_{\mu^{+}\mu^{-}}<12\GeV$, where the QED process is dominant. The ratio
of the measured yields in the data to those from the starlight MC in the
control region is measured to be $1.03\pm 0.10$, confirming that this event
generator reproduces the QED background well, as observed previously in
$\Pp$Pb and PbPb collisions at the LHC [29, 32, 30, 31]. The QED contribution,
estimated from the starlight MC in the signal region, amounts to 40% (64 and
8% in the lowest and highest dimuon $\pt^{2}$ bins of the corresponding
differential cross section, respectively).

Backgrounds to the exclusive $\PgU\to\mu^{+}\mu^{-}$ signal also originate
from semiexclusive and inclusive $\PgU$ meson and Drell–Yan (DY) continuum
production, where any additional hadronic activity falls outside the detector
acceptance or below the detection thresholds. These background contributions
are estimated from the data, by removing selectively the neutral or charged
exclusivity requirements. A template dominated by semiexclusive contributions
is constructed using events with only two muon tracks in the tracker
accompanied by at least one HF tower having an energy deposit larger than the
noise threshold of 5, in the direction of the outgoing proton. Events with two
muons satisfying the selection criteria, but with at least one additional
track with $\pt>0.1\GeV$, are used to build a template dominated by inclusive
DY production events. The normalizations of the two templates are obtained
from a fit to the measured $\pt^{2}$ distribution extended up to
$\pt^{2}=10\GeV^{2}$, where proton dissociation and inclusive events dominate,
as seen in the tail of the distribution of Fig. 3a. The combination of the
normalized inclusive and semiexclusive templates describes the region of high
dimuon $\pt^{2}$ well in the data in all four $y$ bins used for the cross
section extraction. The overall fraction of both backgrounds in the signal
sample is estimated to be 11% (3 and 48% in the lowest and highest dimuon
$\pt^{2}$ bin, respectively). As an extra cross check of the nonexclusive
background subtraction, the signal extraction is repeated by requiring in
addition no neutron detection in the ZDC calorimeters [29]. The extracted
yield of exclusive $\PgU$ candidates at low $\pt$ is found to be consistent
with the nominal results without applying the ZDC veto requirement, thereby
confirming the efficiency of the nonexclusive background rejection.

An additional background in this analysis originates from a small contribution
of exclusive $\PGg\mathrm{Pb}\to\PgU\mathrm{Pb}$ events. It is estimated using
the reweighted starlight $\PgU$ MC sample, and amounts to 6% (16 and 1% in the
lowest and highest dimuon $\pt^{2}$ bin, respectively) of the $\PGg\Pp$ MC
signal. Relative to the data, this contribution amounts to 3% (5 and 1% at the
lowest and highest dimuon $\pt^{2}$ bin, respectively). These simulation-based
fractions are used to subtract the $\PGg\mathrm{Pb}\to\PgU\mathrm{Pb}$
contribution from the data.

##  0.5 Extraction of cross sections

The dimuon events selected as described above are used to determine the
differential $\PgU$ photoproduction cross sections in four bins of $\pt^{2}$
over $\pt^{2}=0.01$–$1\GeV{}^{2}$, and in four bins of $y$ over $\abs{y}<2.2$.
Because of the limited size of the data sample, we first extract the
differential cross sections for all $\PgU\mathrm{(nS)}$ resonances combined.
Then, the total cross section as a function of $W_{\PGg\Pp}$ is extracted for
the $\PgUa$ state alone, as described below, and is compared with previous
experimental measurements and theoretical predictions.

The background-subtracted $\pt^{2}$ and $y$ distributions are first unfolded
over the region $0.01<\pt^{2}<1\GeV{}^{2}$, $\abs{y}<2.2$, and muon
$\pt^{\mu}>3.3\GeV$, by using the Bayesian iterative unfolding technique [54],
as implemented in the RooUnfold package [55], with four iterations. This
procedure corrects for detector effects and data migration between bins. The
response matrix is obtained from the starlight $\PGg\Pp$ simulation. The
differential cross section $\rd\sigma/\rd\pt^{2}$ is further extrapolated to
the full range of single-muon $\pt$ by means of an acceptance correction
factor
$A^{\text{corr}}=N_{\PgU\mathrm{(nS)}}(\pt^{\mu}>3.3\GeV$$)/N_{\PgU\mathrm{(nS)}}(\pt^{\mu}>0)$,
estimated with the starlight $\PGg\Pp$ simulation. The measured
$\rd\sigma/{\rd}y$ values in each rapidity bin are also similarly extrapolated
down to zero dimuon $\pt$. The $A^{\text{corr}}\approx 0.6$ factor does not
significantly depend on $\pt^{2}$ but varies as a function of $y$ as shown
later in Table 0.7.1. The $\pt^{2}$\- and $y$-differential cross sections,
multiplied by the dimuon branching fraction, are extracted for the three
$\PgU\mathrm{(nS)}$ states combined as follows,

$\displaystyle\sum_{\mathrm{n}}\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\,\frac{\rd\sigma_{\PgU\mathrm{(nS)}}}{\rd\pt^{2}}$
$\displaystyle=$
$\displaystyle\frac{N^{\text{corr}}_{\PgU\mathrm{(sum)}}}{\mathcal{L}\,\Delta\pt^{2}},$
(1)
$\displaystyle\sum_{\mathrm{n}}\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\,\frac{\rd\sigma_{\PgU\mathrm{(nS)}}}{{\rd}y}$
$\displaystyle=$
$\displaystyle\frac{N^{\text{corr}}_{\PgU\mathrm{(sum)}}}{\mathcal{L}\,\Delta
y}.$

Here $N^{\text{corr}}_{\PgU\mathrm{(sum)}}$ denotes the background-subtracted,
unfolded, and acceptance-corrected number of $\PgUa$, $\PgUb$ and $\PgUc$
signal events in each $\pt^{2}$ and $y$ bin, $\mathcal{L}$ is the integrated
luminosity, $\Delta\pt^{2}$ and $\Delta y$ are the widths of the $\pt^{2}$ and
$y$ bins, and $\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}$ is the dimuon
branching fraction [53]. The differential $\PgUa$ photoproduction cross
section $\rd\sigma_{\PgU{\mathrm{(1S)}}}/{\rd}y$ is then extracted via

$\frac{\rd\sigma_{\PgUa}}{{\rd}y}=\frac{f_{\PgUa}}{\mathcal{B}_{\PgUa\to\mu^{+}\mu^{-}}(1+f_{\text{FD}})}\left[\sum_{\mathrm{n}}\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\frac{\rd\sigma_{\PgU\mathrm{(nS)}}}{{\rd}y}\right],$
(2)

where the factor $f_{\PgUa}$ is the ratio of $\PgUa$ to
$\PgU\mathrm{(sum)}=\PgUa+\PgUb+\PgUc$ events, $f_{\text{FD}}$ is the feed-
down contribution to the $\PgUa$ events originating from the $\PgUb\to\PgUa+X$
decays (where $X=\pi^{+}\pi^{-}$ or $\pi^{0}\pi^{0}$), and
$\mathcal{B}_{\PgUa\to\mu^{+}\mu^{-}}=(2.48\pm 0.05)\%$ [53] is the branching
fraction for the dimuon $\PgUa$ meson decay channel.

The fraction of $\PgUa$ to $\PgU\mathrm{(sum)}=\PgUa+\PgUb+\PgUc$ yields is
first derived from the event yield ratios $r_{21}=N_{\PgUb}/N_{\PgUa}=0.78\pm
0.31$ and $r_{31}=N_{\PgUc}/N_{\PgUa}=0.21\pm 0.22$ extracted from the
invariant mass fit shown in Fig. 2, giving
$f_{\PgUa}=(1+r_{21}+r_{31})^{-1}=0.50\pm 0.09$, where the correlation between
the two fitted parameters was not taken into account. Since this fraction has
a relatively large statistical uncertainty, we use the value derived from the
analysis [51] of inclusive $\PgU\mathrm{(nS)}$ meson production instead, which
is performed at the same nucleon-nucleon collision centre-of-mass energy and
in a similar $\PgU$ rapidity range as the current $\Pp$Pb measurement, in
which the fraction is expressed as a function of the number of additional
charged particles in the event ($N_{\text{ch}}$) and extrapolated to
$N_{\text{ch}}=0$. This procedure yields $f_{\PgUa}=0.68\pm 0.04$, consistent
within statistical uncertainties with the factor obtained from the current
data, as well as with the $f_{\PgUa}=0.71\pm 0.03$ and $0.73\pm 0.05$ values
obtained in the measurements based on proton-(anti)proton data by LHCb [34]
and CDF [56], at very forward and central $\PgU$ rapidities, respectively.

The feed-down contribution is estimated using the MC simulation in the
following way: the initial $\PgUb$ $\pt$ and $y$ distributions are taken from
the starlight generator, and their $\PgUa+\pi\pi$ decays, followed by
$\PgUa\to\mu^{+}\mu^{-}$ are simulated with 6.4 [57]. After applying all
selections, the fraction of dimuon events from $\PgUb$ feed-down is found to
be 8% of the exclusive signal $\PgUa$ events reconstructed using the starlight
simulation. The contribution from feed-down of exclusive $\PGcb$ states is
neglected because these mesons can only be produced in double-pomeron exchange
processes (or in pairs, via $\gamma\gamma\to\PGcb\PGcb$, with very small cross
sections), which have comparatively much smaller yields in proton-nucleus
collisions [58, 59].

Finally, the exclusive $\PgUa$ photoproduction cross section as a function of
$W_{\PGg\Pp}$, is obtained from the $\rd\sigma_{\PgUa}/{\rd}y$ cross section
via the relation

$\sigma_{\gamma\Pp\to\PgUa\Pp}(W_{\PGg\Pp}^{2})=\frac{1}{\Phi}\frac{\rd\sigma_{\PgUa}}{{\rd}y},$
(3)

in four different rapidity bins, with associated $W_{\PGg\Pp}$ intervals,
given in Table 0.7.1. The cross sections are given at the value $W_{0}$, which
corresponds to the average rapidity over a bin, $\langle y\rangle$. The photon
flux $\Phi$ in Eq. (3), evaluated at $\langle y\rangle$, is obtained from the
starlight simulation and calculated in the impact parameter space requiring
the $\Pp$Pb separation to be larger than the sum of their radii.

##  0.6 Systematic uncertainties

The following sources of systematic uncertainty are taken into account in the
measurements of all differential and total $\PgU$ meson production cross
sections, as well as for the extraction of the exponential slope $b$ of the
$\pt^{2}$ spectrum:

  * •

The muon reconstruction and selection efficiency has three components: the
efficiency to find a track in the inner tracker, the efficiency to pass the
track quality requirements, and the probability to pass the HLT selection.
These efficiencies are estimated following the ”tag-and-probe” method [51],
using first a sample of inclusive $\PgUa$ events selected with a trigger that
requires two muons (to determine track and muon-quality efficiencies), and
second a $\PgUa$ event sample similar to the one used in the nominal analysis,
but collected with an independent trigger (to determine the trigger
efficiency). The associated systematic uncertainty is evaluated from the
difference in efficiencies obtained from the data and simulation, and it leads
to uncertainties of $10.5\%$, $4.1\%$ and $1.7\%$ for track, muon-quality and
trigger component, respectively. The overall uncertainty is estimated by
adding the three numbers in quadrature, and leads to an $11\%$ uncertainty in
the normalization of the cross sections, but no effect on the $b$ slope
measurement.

  * •

To estimate the systematic uncertainty due to the model dependence of the
acceptance correction, the parameters $b$ and $\delta$ of the simulated
starlight spectra are changed by $\pm$30% (chosen conservatively by the
uncertainties of the corresponding fits to the data), and the resulting MC
distributions are used for the determination of the extrapolation factor
$A^{\mathrm{corr}}$, the unfolding, and the
$\PGg\mathrm{Pb}\to\PgU\mathrm{Pb}$ background subtraction, resulting in 2–3%
changes in the measured observables.

  * •

The uncertainty due to the unfolding procedure is studied by modifying the
number of iterations used for the Bayesian unfolding from the nominal value of
$4$ to $3$ and $5$, resulting in an uncertainty of $1\%$ for the $\pt^{2}$
spectrum, $0.2\%$ for the $b$ slope, and no change for the much flatter
$\rd\sigma/{\rd}y$ distribution, which has negligible net bin-to-bin
migrations.

  * •

The uncertainty associated with the exclusive QED background contribution is
estimated by comparing the starlight simulation to the data in sideband
regions of the invariant mass distribution, $8.0<m_{\mu^{+}\mu^{-}}<9.1\GeV$
and $10.6<m_{\mu^{+}\mu^{-}}<12.0\GeV$, for $\pt<0.15\GeV$. The ratio of the
simulation to the data in that region is found to be unity with a statistical
uncertainty of 5%. To estimate the uncertainty due to the QED background
subtraction, the MC normalization is scaled by $\pm$5%, resulting in 3–4%
changes in the experimental observables.

  * •

The uncertainty in the nonexclusive background contributions is estimated by
varying the HF energy threshold by $\pm$10%. The resulting uncertainties of
the observables vary between 3% and 6%.

  * •

The uncertainty introduced by the $\PgUb\to\PgUa+X$ decays is estimated by
modifying the values of the $b$ and $\delta$ parameters of the $\PgUb$ spectra
in the starlight MC to those obtained from the reweighting described in
Section 0.4. This resulted in a $\pm$2% variation of the $\PgUa$ cross
sections. The uncertainty in $f_{\PgUa}=\PgUa/\PgU\mathrm{(sum)}$ is 7%,
estimated as the quadratic sum of the uncertainty obtained from the
extrapolation discussed in Section 0.5 and from the difference between this
result and that obtained by LHCb in Ref. [34]. The latter takes into account
possible differences between inclusive and exclusive processes in proton-
proton and proton-lead collisions. An additional 2% uncertainty in the
$\PgUa\to\mu^{+}\mu^{-}$ branching fraction is taken from the PDG world
average [53]. All these uncertainties affect only the $\PgUa$ cross sections.

  * •

The theoretical uncertainty in the photon flux affects only the total cross
section $\sigma_{\PGg\Pp\to\PgUa\Pp}$ and is estimated by changing the Pb
radius by $\pm$0.5fm, conservatively covering different estimates of the
neutron skin thickness [60]. It amounts to 2, 3, 3, and 9% in the four $y$
bins, respectively. The photon flux uncertainty (listed in the bottom row of
Table 0.7.1) is larger for higher photon energies as they are dominated by
smaller impact parameters.

  * •

A systematic normalization uncertainty of $\pm$4% associated with the
integrated luminosity [61] is assigned to the measurement of differential and
total cross sections, with no effect on the $b$ slope uncertainty.

Relative systematic uncertainties in percent in the measurements of
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\rd\sigma/\rd\pt^{2}$,
the exponential $b$ slope of the $\pt^{2}$ spectrum,
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\rd\sigma/{\rd}y$,
$\rd\sigma_{\PgUa}/{\rd}y$, and $\sigma_{\PGg\Pp\to\PgUa\Pp}$. Individual
contributions, as well as total systematic uncertainties added in quadrature
are presented. For the $\pt^{2}$\- and $y$-differential cross sections, the
values averaged over all bins are shown.  Source
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\rd\sigma/\rd\pt^{2}$ $b$
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\rd\sigma/{\rd}y$
$\rd\sigma_{\PgUa}/{\rd}y$ $\sigma_{\PGg\Pp\to\PgUa\Pp}$ Muon efficiency
$\pm$11 — $\pm$11 $\pm$11 $\pm$11 Acceptance $\pm$3 $\pm$2 $\pm$2 $\pm$2
$\pm$2 Unfolding $\pm$1 $\pm$0.2 — — — Exclusive QED background $\pm$4 $\pm$3
$\pm$4 $\pm$4 $\pm$4 Nonexclusive background $\pm$3 $\pm$3 $\pm$6 $\pm$6
$\pm$6 Integrated luminosity $\pm$4 — $\pm$4 $\pm$4 $\pm$4 Feed-down — — —
$\pm$2 $\pm$2 Branching fraction $\mathcal{B}_{\PgUa}\to\mu^{+}\mu^{-}$ — — —
$\pm$2 $\pm$2 $f_{\PgUa}$ fraction — — — $\pm$7 $\pm$7 Photon flux $\Phi$ — —
— — $\pm$4 Total $\pm$13 $\pm$5 $\pm$14 $\pm$16 $\pm$16

The summary of the systematic uncertainties for all measurements is presented
in Table 0.6. The dominant sources are the muon reconstruction efficiency and
the modeling of the nonexclusive backgrounds. The total uncertainty is
calculated by adding in quadrature the individual contributions, and varies
between $\pm$5% for the $b$ slope to $\pm$16% for
$\sigma_{\PGg\Pp\to\PgUa\Pp}$. Given the limited integrated luminosity
available, the measurements are dominated by statistical uncertainties.

##  0.7 Results

###  0.7.1 Differential cross section as a function of $\pt^{2}$ and $y$

The differential cross sections (multiplied by the dimuon branching fractions)
for exclusive $\PgU\mathrm{(nS)}$ photoproduction,
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\rd\sigma_{\PgU\mathrm{(nS)}}/\rd\pt^{2}$
and
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\rd\sigma_{\PgU\mathrm{(nS)}}/{\rd}y$,
measured over $\abs{y}<2.2$, are shown in Fig. 4 and tabulated in Table 0.7.1.
The $\pt^{2}$-differential cross section is fitted with an exponential
function in the region $0.01<\pt^{2}<1.0\GeV$2, using a $\chi^{2}$ goodness-
of-fit minimization method. A slope of $b=6.0\pm 2.1\stat\pm
0.3\syst\GeV^{-2}$ is extracted, in agreement with the value
$b=4.3^{+2.0}_{-1.3}\stat{}^{+0.5}_{-0.6}\syst\GeV^{-2}$ measured by the ZEUS
experiment [24] in the photon-proton centre-of-mass energy range
$60<W_{\PGg\Pp}<220\GeV$, and with the predictions of pQCD-based models [10].

Figure 4: Differential $\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}$ photoproduction
cross section as a function of (a) $\pt^{2}$ and (b) rapidity $y$, measured in
$\Pp$Pb collisions at $\sqrtsNN=5.02\TeV$. In the left plot, the data points
are placed along the abscissa following the prescription of [62], and the
solid line is an exponential fit of the form $e^{-b\pt^{2}}$. In the right
plot, the horizontal bars are shown to indicate the width of each $y$ bin. In
both plots, the vertical bars represent the statistical uncertainties and the
boxes represent the systematic uncertainties.

Differential exclusive $\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}$ photoproduction
cross sections in four $\pt^{2}$ and $y$ bins. The first and second
uncertainties correspond to statistical and systematic components,
respectively.  $\pt^{2}$ bin ($\GeVns^{2}$)
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\,\rd\sigma_{\PgU\mathrm{(nS)}}/\rd\pt^{2}$
(nb/$\GeVns^{2}$) $y$ bin
$\sum\mathcal{B}_{\PgU\mathrm{(nS)}\to\mu^{+}\mu^{-}}\,\rd\sigma_{\PgU\mathrm{(nS)}}/{\rd}y$
(nb) (0.01,0.05) $25.4\pm 14.8\pm 4.9$ $(-2.2,-0.7)$ $0.8\pm 0.4\pm 0.1$
(0.05,0.20) $9.5\pm 3.4\pm 1.1$ $(-0.7,0.0)$ $0.9\pm 0.5\pm 0.1$ (0.20,0.35)
$4.4\pm 2.4\pm 0.5$ $(0.0,0.7)$ $1.2\pm 0.5\pm 0.1$ (0.35,1.00) $0.7\pm 0.6\pm
0.1$ $(0.7,2.2)$ $0.7\pm 0.2\pm 0.1$

Figure 5 shows the rapidity distribution of the $\PgUa$ state obtained
according to Eq. (2). The values of all relevant parameters needed to compute
the $\PgUa$ cross sections in the four rapidity bins under consideration are
listed in Table 0.7.1. The CMS measurements are compared to the following
theoretical predictions:

  * •

The JMRT model [10], a pQCD approach that uses standard (collinear) PDFs with
a skewness factor to approximate GPDs, including LO and NLO corrections, and a
gap survival factor to account for the exclusive production;

  * •

The factorized impact parameter saturation model, fIPsat, with an eikonalized
gluon distribution function that uses the colour glass condensate (CGC)
formalism to incorporate gluon saturation at low $x$ [17, 18];

  * •

the Iancu, Itakura and Munier (IIM) colour dipole formalism [63] with two sets
of meson wave functions, boosted Gaussian (BG) and light-cone Gaussian (LCG),
which also incorporate saturation effects [15, 16];

  * •

the impact parameter CGC model (bCGC), which takes into account the
$t$-dependence of the differential cross section, using the BG wave function
[19, 64].

As shown in Fig. 5, most theoretical predictions are consistent with the data,
within the relatively large experimental uncertainties, with the JMRT-LO
results being systematically above the data points as well as all the other
calculations.

Figure 5: Differential $\PgUa$ photoproduction cross section as a function of
rapidity measured in $\Pp$Pb collisions at $\sqrtsNN=5.02\TeV$ in the dimuon
rapidity region $\abs{y}<2.2$, compared to various theoretical predictions
[10, 17, 18, 15, 16, 19]. The horizontal bars are plotted to indicate the
width of each $y$ bin. The vertical bars represent the statistical
uncertainties and the boxes represent the systematic uncertainties.

Values of the $\PgUa$ photoproduction cross section in four rapidity $y$ bins,
corresponding to four photon-proton $W_{\PGg\Pp}$ centre-of-mass energy ranges
(with central $W_{0}$ value obtained following the procedure outlined in Ref.
[62]), in $\Pp$Pb collisions at $\sqrtsNN=5.02\TeV$. The symbols
$N_{\PgU\mathrm{(sum)}}^{\text{back-sub}}$,
$N_{\PgU\mathrm{(sum)}}^{\text{unfol}}$, and
$N_{\PgU\mathrm{(sum)}}^{\text{corr}}$ represent the numbers of
$\PgU\mathrm{(sum)}=\PgUa+\PgUb+\PgUc$ candidates after background
subtraction, unfolding, and extrapolation with the $A^{\text{corr}}$ factor,
respectively; $N_{\PgUa}$ is the extracted number of $\PgUa$ mesons, and
$\Phi$ is the theoretical effective photon flux (see text). The first (second,
if given) uncertainty quoted corresponds to the statistical (systematic)
component.  $y$ range $(-2.2,-0.7)$ $(-0.7,0.0)$ $(0.0,0.7)$ $(0.7,2.2)$
$\langle y\rangle$ $-1.45$ $-0.35$ $0.35$ $1.45$
$N_{\PgU\mathrm{(sum)}}^{\text{back-sub}}$ $14\pm 6$ $9\pm 5$ $12\pm 5$ $12\pm
5$ $N_{\PgU\mathrm{(sum)}}^{\text{unfol}}$ $19\pm 9$ $13\pm 7$ $17\pm 7$
$16\pm 6$ $A^{\text{corr}}$ $0.46\pm 0.01$ $0.61\pm 0.01$ $0.61\pm 0.01$
$0.50\pm 0.01$ $N_{\PgU\mathrm{(sum)}}^{\text{corr}}$ $41\pm 19\pm 7$ $21\pm
11\pm 3$ $28\pm 11\pm 4$ $33\pm 13\pm 5$
$N_{\PgUa}=\frac{f_{\PgUa}N_{\PgU\mathrm{(sum)}}}{(1+f_{\mathrm{FD})}}$ $26\pm
12\pm 4$ $13\pm 7\pm 2$ $18\pm 7\pm 2$ $21\pm 8\pm 3$
$\rd\sigma_{\PgUa}/{\rd}y$ (nb) $21\pm 10\pm 4$ $23\pm 12\pm 3$ $31\pm 12\pm
4$ $17\pm 7\pm 3$ $W_{\PGg\Pp}$ range () 91–194 194–275 275–390 390–826
$W_{0}$ () 133 231 328 568 Photon flux ($\Phi$) $102.2\pm 2.0$ $68.3\pm 2.0$
$46.9\pm 1.4$ $17.9\pm 1.6$ $\sigma_{\PGg\Pp\to\PgUa\Pp}$ (pb) $208\pm 96\pm
37$ $343\pm 180\pm 51$ $663\pm 260\pm 93$ $956\pm 376\pm 162$

###  0.7.2 Cross section as a function of $W_{\PGg\Pp}$

The values of the $\sigma_{\PGg\Pp\to\PgUa\Pp}$ cross section obtained via Eq.
(3) are plotted as a function of $W_{\PGg\Pp}$ in Fig. 6, together with the
previous measurements from H1 [20], ZEUS [22, 21], and LHCb [34], and the five
model predictions described in the previous section. The CMS results (listed
in Table 0.7.1) cover the range of energies between the HERA and LHCb data. As
$\sigma(W_{\PGg\Pp})$ is, to first approximation, proportional to the square
of the gluon density of the proton, and since the gluon distribution at low
Bjorken $x$ is well described by a power law, the cross section also follows a
power-law energy dependence. A fit of the extracted CMS
$\sigma_{\PGg\Pp\to\PgUa\Pp}$ cross section with a function of the form
$A\,(W_{\PGg\Pp}[\GeVns]/400)^{\delta}$ (with the constant $A$ corresponding
to the cross section at the middle value, $W_{\PGg\Pp}=400\GeV$, over the
range of energies covered) gives $\delta=1.08\pm 0.42$ and $A=690\pm
183\unit{pb}$ (black solid line in Fig 6), consistent with the value
$\delta=1.2\pm 0.8$ obtained by ZEUS [21]. A similar fit to the CMS, H1 [20],
and ZEUS [21] data together gives $\delta=0.99\pm 0.27$, in good agreement
with the results of the fit to the CMS data alone. The fit over the whole
kinematic range, including the higher-$W_{\PGg\Pp}$ LHCb data, yields an
exponent of $\delta=0.77\pm 0.14$, consistent with the collision-energy
dependence of the $\cPJgy$ photoproduction and light vector meson
electroproduction cross sections [65].

Figure 6: Cross section for exclusive $\PgUa$ photoproduction,
$\PGg\Pp\to\PgUa\Pp$, as a function of photon-proton centre-of-mass energy,
$W_{\PGg\Pp}$, compared to previous HERA [20, 22, 21] and LHCb [34] data as
well as to various theoretical predictions [10, 17, 18, 15, 16, 19]. The
vertical bars represent the statistical uncertainties and the boxes represent
the systematic uncertainties.

The data are compared to the predictions of the JMRT model, including LO and
NLO corrections. A fit with the power-law function in the entire $W_{\PGg\Pp}$
range of the data yields $\delta=1.39$ and $\delta=0.84$ for the LO and NLO
calculations, respectively. The LO predictions show a steeper increase of the
cross section with energy than seen in the data over the full kinematic range.
The NLO prediction reproduces the measured rise of the cross section with
$W_{\PGg\Pp}$. The recent LHCb results at higher $W_{\PGg\Pp}$ [34] also
disfavour the JMRT LO prediction. Figure 6 shows theoretical predictions from
the fIPsat, IIM, and bCGC models, which overall bracket the combined HERA and
LHC results. The fIPsat calculations are consistent with the CMS measurement,
but predict a somewhat higher cross section than that measured by LHCb. The
IIM and bCGC predictions satisfactorily describe the rise of the cross section
with $\PGg\Pp$ centre-of-mass energy. As discussed in Ref. [10], the gluon PDF
associated with the JMRT NLO prediction, which is consistent with the CMS+LHCb
data presented here, has a somewhat different shape at low-$x$ than that
predicted by standard pQCD collinear fits used at the LHC such as CT14 [66],
NNPDF3.0 [67], and MMHT [68]. However, given the currently large statistical
uncertainty of the results presented here, an improved understanding of the
low-$x$ gluon density, and its evolution with energy scale, will require more
precise measurements with larger integrated luminosities and/or at higher
centre-of-mass energies.

##  0.8 Summary

The first study of the exclusive photoproduction of $\PgU$(1S,2S,3S) mesons,
in the $\mu^{+}\mu^{-}$ decay mode, from protons in ultraperipheral $\Pp$Pb
collisions at $\sqrtsNN=5.02\TeV$, has been reported using data collected with
the CMS detector corresponding to an integrated luminosity of 32.6. The
differential cross section $\rd\sigma/\rd\pt^{2}$ and associated exponential
slope $b$ have been measured in the squared transverse momentum range
$\pt^{2}<1.0\GeV^{2}$. The extracted value of $b=6.0\pm 2.1\stat\pm
0.3\syst\GeV^{-2}$ is consistent with the slope measurement at other centre-
of-mass energies. The exclusive $\PgUa$ photoproduction cross sections,
differential in rapidity $y$ and as a function of the photon-proton centre-of-
mass energy $W_{\PGg\Pp}$, have been measured in the range
$91<W_{\PGg\Pp}<826\GeV$. Such measurements probe the region of parton
fractional momenta $x\approx 10^{-4}$–$10^{-2}$ in the proton, bridging a
previously unexplored region between the HERA and LHCb measurements. The
dependence of $\sigma_{\PGg\Pp\to\PgUa\Pp}$ on $W_{\PGg\Pp}$ is well described
by a power law with an exponent smaller than that predicted by leading order
perturbative quantum chromodynamics (pQCD) approaches. The exponent is,
however, consistent with that extracted from a fit to the HERA and LHCb data,
and with that predicted by next-to-leading-order pQCD calculations. The data,
within their currently large statistical uncertainties, are consistent with
various pQCD approaches that model the behaviour of the low-$x$ gluon density,
and provide new insights on the gluon distribution in the proton in this
poorly explored region.

###### Acknowledgements.

We congratulate our colleagues in the CERN accelerator departments for the
excellent performance of the LHC and thank the technical and administrative
staffs at CERN and at other CMS institutes for their contributions to the
success of the CMS effort. In addition, we gratefully acknowledge the
computing centres and personnel of the Worldwide LHC Computing Grid for
delivering so effectively the computing infrastructure essential to our
analyses. Finally, we acknowledge the enduring support for the construction
and operation of the LHC and the CMS detector provided by the following
funding agencies: BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq,
CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST,
and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF
(Cyprus); SENESCYT (Ecuador); MoER, ERC IUT, and ERDF (Estonia); Academy of
Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and
HGF (Germany); GSRT (Greece); NKFIA (Hungary); DAE and DST (India); IPM
(Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES
(Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT,
LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC
(Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom,
RAS, RFBR, and NRC KI (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI, and FEDER
(Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST
(Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK
(Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA).
Individuals have received support from the Marie-Curie programme and the
European Research Council and Horizon 2020 Grant, contract No. 675440
(European Union); the Leventis Foundation; the A. P. Sloan Foundation; the
Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office;
the Fonds pour la Formation à la Recherche dans l’Industrie et dans
l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en
Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the
“Excellence of Science - EOS” - be.h project n. 30820817; the Ministry of
Education, Youth and Sports (MEYS) of the Czech Republic; the Lendület
(“Momentum”) Programme and the János Bolyai Research Scholarship of the
Hungarian Academy of Sciences, the New National Excellence Program ÚNKP, the
NKFIA research grants 123842, 123959, 124845, 124850 and 125105 (Hungary); the
Council of Science and Industrial Research, India; the HOMING PLUS programme
of the Foundation for Polish Science, cofinanced from European Union, Regional
Development Fund, the Mobility Plus programme of the Ministry of Science and
Higher Education, the National Science Center (Poland), contracts Harmonia
2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and
2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities
Research Program by Qatar National Research Fund; the Programa Estatal de
Fomento de la Investigación Científica y Técnica de Excelencia María de
Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de
Asturias; the Thalis and Aristeia programmes cofinanced by EU-ESF and the
Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship,
Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century
Project Advancement Project (Thailand); the Welch Foundation, contract C-1845;
and the Weston Havens Foundation (USA).

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##  .9 The CMS Collaboration

Yerevan Physics Institute, Yerevan, Armenia
A.M. Sirunyan, A. Tumasyan Institut für Hochenergiephysik, Wien, Austria
W. Adam, F. Ambrogi, E. Asilar, T. Bergauer, J. Brandstetter, E. Brondolin, M.
Dragicevic, J. Erö, A. Escalante Del Valle, M. Flechl, M. Friedl, R.
Frühwirth1, V.M. Ghete, J. Grossmann, J. Hrubec, M. Jeitler1, A. König, N.
Krammer, I. Krätschmer, D. Liko, T. Madlener, I. Mikulec, E. Pree, N. Rad, H.
Rohringer, J. Schieck1, R. Schöfbeck, M. Spanring, D. Spitzbart, A. Taurok, W.
Waltenberger, J. Wittmann, C.-E. Wulz1, M. Zarucki Institute for Nuclear
Problems, Minsk, Belarus
V. Chekhovsky, V. Mossolov, J. Suarez Gonzalez Universiteit Antwerpen,
Antwerpen, Belgium
E.A. De Wolf, D. Di Croce, X. Janssen, J. Lauwers, M. Pieters, M. Van De
Klundert, H. Van Haevermaet, P. Van Mechelen, N. Van Remortel Vrije
Universiteit Brussel, Brussel, Belgium
S. Abu Zeid, F. Blekman, J. D’Hondt, I. De Bruyn, J. De Clercq, K. Deroover,
G. Flouris, D. Lontkovskyi, S. Lowette, I. Marchesini, S. Moortgat, L.
Moreels, Q. Python, K. Skovpen, S. Tavernier, W. Van Doninck, P. Van Mulders,
I. Van Parijs Université Libre de Bruxelles, Bruxelles, Belgium
D. Beghin, B. Bilin, H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, B.
Dorney, G. Fasanella, L. Favart, R. Goldouzian, A. Grebenyuk, A.K. Kalsi, T.
Lenzi, J. Luetic, T. Seva, E. Starling, C. Vander Velde, P. Vanlaer, D.
Vannerom, R. Yonamine Ghent University, Ghent, Belgium
T. Cornelis, D. Dobur, A. Fagot, M. Gul, I. Khvastunov2, D. Poyraz, C. Roskas,
D. Trocino, M. Tytgat, W. Verbeke, B. Vermassen, M. Vit, N. Zaganidis
Université Catholique de Louvain, Louvain-la-Neuve, Belgium
H. Bakhshiansohi, O. Bondu, S. Brochet, G. Bruno, C. Caputo, A. Caudron, P.
David, S. De Visscher, C. Delaere, M. Delcourt, B. Francois, A. Giammanco, G.
Krintiras, V. Lemaitre, A. Magitteri, A. Mertens, M. Musich, K. Piotrzkowski,
L. Quertenmont, A. Saggio, M. Vidal Marono, S. Wertz, J. Zobec Centro
Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
W.L. Aldá Júnior, F.L. Alves, G.A. Alves, L. Brito, G. Correia Silva, C.
Hensel, A. Moraes, M.E. Pol, P. Rebello Teles Universidade do Estado do Rio de
Janeiro, Rio de Janeiro, Brazil
E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato3, E. Coelho, E.M.
Da Costa, G.G. Da Silveira4, D. De Jesus Damiao, S. Fonseca De Souza, H.
Malbouisson, M. Medina Jaime5, M. Melo De Almeida, C. Mora Herrera, L. Mundim,
H. Nogima, L.J. Sanchez Rosas, A. Santoro, A. Sznajder, M. Thiel, E.J. Tonelli
Manganote3, F. Torres Da Silva De Araujo, A. Vilela Pereira Universidade
Estadual Paulista a, Universidade Federal do ABC b, São Paulo, Brazil
S. Ahujaa, C.A. Bernardesa, L. Calligarisa, T.R. Fernandez Perez Tomeia, E.M.
Gregoresb, P.G. Mercadanteb, S.F. Novaesa, SandraS. Padulaa, D. Romero Abadb,
J.C. Ruiz Vargasa Institute for Nuclear Research and Nuclear Energy, Bulgarian
Academy of Sciences, Sofia, Bulgaria
A. Aleksandrov, R. Hadjiiska, P. Iaydjiev, A. Marinov, M. Misheva, M. Rodozov,
M. Shopova, G. Sultanov University of Sofia, Sofia, Bulgaria
A. Dimitrov, L. Litov, B. Pavlov, P. Petkov Beihang University, Beijing, China
W. Fang6, X. Gao6, L. Yuan Institute of High Energy Physics, Beijing, China
M. Ahmad, J.G. Bian, G.M. Chen, H.S. Chen, M. Chen, Y. Chen, C.H. Jiang, D.
Leggat, H. Liao, Z. Liu, F. Romeo, S.M. Shaheen, A. Spiezia, J. Tao, C. Wang,
Z. Wang, E. Yazgan, H. Zhang, J. Zhao State Key Laboratory of Nuclear Physics
and Technology, Peking University, Beijing, China
Y. Ban, G. Chen, J. Li, Q. Li, S. Liu, Y. Mao, S.J. Qian, D. Wang, Z. Xu
Tsinghua University, Beijing, China
Y. Wang Universidad de Los Andes, Bogota, Colombia
C. Avila, A. Cabrera, C.A. Carrillo Montoya, L.F. Chaparro Sierra, C. Florez,
C.F. González Hernández, M.A. Segura Delgado University of Split, Faculty of
Electrical Engineering, Mechanical Engineering and Naval Architecture, Split,
Croatia
B. Courbon, N. Godinovic, D. Lelas, I. Puljak, P.M. Ribeiro Cipriano, T.
Sculac University of Split, Faculty of Science, Split, Croatia
Z. Antunovic, M. Kovac Institute Rudjer Boskovic, Zagreb, Croatia
V. Brigljevic, D. Ferencek, K. Kadija, B. Mesic, A. Starodumov7, T. Susa
University of Cyprus, Nicosia, Cyprus
M.W. Ather, A. Attikis, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos,
P.A. Razis, H. Rykaczewski Charles University, Prague, Czech Republic
M. Finger8, M. Finger Jr.8 Universidad San Francisco de Quito, Quito, Ecuador
E. Carrera Jarrin Academy of Scientific Research and Technology of the Arab
Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt
S. Khalil9, M.A. Mahmoud10,11, Y. Mohammed10 National Institute of Chemical
Physics and Biophysics, Tallinn, Estonia
S. Bhowmik, R.K. Dewanjee, M. Kadastik, L. Perrini, M. Raidal, C. Veelken
Department of Physics, University of Helsinki, Helsinki, Finland
P. Eerola, H. Kirschenmann, J. Pekkanen, M. Voutilainen Helsinki Institute of
Physics, Helsinki, Finland
J. Havukainen, J.K. Heikkilä, T. Järvinen, V. Karimäki, R. Kinnunen, T.
Lampén, K. Lassila-Perini, S. Laurila, S. Lehti, T. Lindén, P. Luukka, T.
Mäenpää, H. Siikonen, E. Tuominen, J. Tuominiemi Lappeenranta University of
Technology, Lappeenranta, Finland
T. Tuuva IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
M. Besancon, F. Couderc, M. Dejardin, D. Denegri, J.L. Faure, F. Ferri, S.
Ganjour, S. Ghosh, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry,
C. Leloup, E. Locci, M. Machet, J. Malcles, G. Negro, J. Rander, A. Rosowsky,
M.Ö. Sahin, M. Titov Laboratoire Leprince-Ringuet, Ecole polytechnique,
CNRS/IN2P3, Université Paris-Saclay, Palaiseau, France
A. Abdulsalam12, C. Amendola, I. Antropov, S. Baffioni, F. Beaudette, P.
Busson, L. Cadamuro, C. Charlot, R. Granier de Cassagnac, M. Jo, I. Kucher, S.
Lisniak, A. Lobanov, J. Martin Blanco, M. Nguyen, C. Ochando, G. Ortona, P.
Paganini, P. Pigard, R. Salerno, J.B. Sauvan, Y. Sirois, A.G. Stahl Leiton, Y.
Yilmaz, A. Zabi, A. Zghiche Université de Strasbourg, CNRS, IPHC UMR 7178,
Strasbourg, France
J.-L. Agram13, J. Andrea, D. Bloch, J.-M. Brom, E.C. Chabert, C. Collard, E.
Conte13, X. Coubez, F. Drouhin13, J.-C. Fontaine13, D. Gelé, U. Goerlach, M.
Jansová, P. Juillot, A.-C. Le Bihan, N. Tonon, P. Van Hove Centre de Calcul de
l’Institut National de Physique Nucleaire et de Physique des Particules,
CNRS/IN2P3, Villeurbanne, France
S. Gadrat Université de Lyon, Université Claude Bernard Lyon 1, CNRS-IN2P3,
Institut de Physique Nucléaire de Lyon, Villeurbanne, France
S. Beauceron, C. Bernet, G. Boudoul, N. Chanon, R. Chierici, D. Contardo, P.
Depasse, H. El Mamouni, J. Fay, L. Finco, S. Gascon, M. Gouzevitch, G.
Grenier, B. Ille, F. Lagarde, I.B. Laktineh, H. Lattaud, M. Lethuillier, L.
Mirabito, A.L. Pequegnot, S. Perries, A. Popov14, V. Sordini, M. Vander
Donckt, S. Viret, S. Zhang Georgian Technical University, Tbilisi, Georgia
T. Toriashvili15 Tbilisi State University, Tbilisi, Georgia
Z. Tsamalaidze8 RWTH Aachen University, I. Physikalisches Institut, Aachen,
Germany
C. Autermann, L. Feld, M.K. Kiesel, K. Klein, M. Lipinski, M. Preuten, M.P.
Rauch, C. Schomakers, J. Schulz, M. Teroerde, B. Wittmer, V. Zhukov14 RWTH
Aachen University, III. Physikalisches Institut A, Aachen, Germany
A. Albert, D. Duchardt, M. Endres, M. Erdmann, S. Erdweg, T. Esch, R. Fischer,
A. Güth, T. Hebbeker, C. Heidemann, K. Hoepfner, S. Knutzen, M. Merschmeyer,
A. Meyer, P. Millet, S. Mukherjee, T. Pook, M. Radziej, H. Reithler, M.
Rieger, F. Scheuch, D. Teyssier, S. Thüer RWTH Aachen University, III.
Physikalisches Institut B, Aachen, Germany
G. Flügge, B. Kargoll, T. Kress, A. Künsken, T. Müller, A. Nehrkorn, A.
Nowack, C. Pistone, O. Pooth, A. Stahl16 Deutsches Elektronen-Synchrotron,
Hamburg, Germany
M. Aldaya Martin, T. Arndt, C. Asawatangtrakuldee, K. Beernaert, O. Behnke, U.
Behrens, A. Bermúdez Martínez, A.A. Bin Anuar, K. Borras17, V. Botta, A.
Campbell, P. Connor, C. Contreras-Campana, F. Costanza, V. Danilov, A. De Wit,
C. Diez Pardos, D. Domínguez Damiani, G. Eckerlin, D. Eckstein, T. Eichhorn,
A. Elwood, E. Eren, E. Gallo18, J. Garay Garcia, A. Geiser, J.M. Grados
Luyando, A. Grohsjean, P. Gunnellini, M. Guthoff, A. Harb, J. Hauk, M.
Hempel19, H. Jung, M. Kasemann, J. Keaveney, C. Kleinwort, J. Knolle, I.
Korol, D. Krücker, W. Lange, A. Lelek, T. Lenz, K. Lipka, W. Lohmann19, R.
Mankel, I.-A. Melzer-Pellmann, A.B. Meyer, M. Meyer, M. Missiroli, G. Mittag,
J. Mnich, A. Mussgiller, D. Pitzl, A. Raspereza, M. Savitskyi, P. Saxena, R.
Shevchenko, N. Stefaniuk, H. Tholen, G.P. Van Onsem, R. Walsh, Y. Wen, K.
Wichmann, C. Wissing, O. Zenaiev University of Hamburg, Hamburg, Germany
R. Aggleton, S. Bein, V. Blobel, M. Centis Vignali, T. Dreyer, E. Garutti, D.
Gonzalez, J. Haller, A. Hinzmann, M. Hoffmann, A. Karavdina, G. Kasieczka, R.
Klanner, R. Kogler, N. Kovalchuk, S. Kurz, V. Kutzner, J. Lange, D. Marconi,
J. Multhaup, M. Niedziela, D. Nowatschin, T. Peiffer, A. Perieanu, A. Reimers,
C. Scharf, P. Schleper, A. Schmidt, S. Schumann, J. Schwandt, J. Sonneveld, H.
Stadie, G. Steinbrück, F.M. Stober, M. Stöver, D. Troendle, E. Usai, A.
Vanhoefer, B. Vormwald Karlsruher Institut fuer Technologie, Karlsruhe,
Germany
M. Akbiyik, C. Barth, M. Baselga, S. Baur, E. Butz, R. Caspart, T. Chwalek, F.
Colombo, W. De Boer, A. Dierlamm, N. Faltermann, B. Freund, R. Friese, M.
Giffels, M.A. Harrendorf, F. Hartmann16, S.M. Heindl, U. Husemann, F.
Kassel16, S. Kudella, H. Mildner, M.U. Mozer, Th. Müller, M. Plagge, G. Quast,
K. Rabbertz, M. Schröder, I. Shvetsov, G. Sieber, H.J. Simonis, R. Ulrich, S.
Wayand, M. Weber, T. Weiler, S. Williamson, C. Wöhrmann, R. Wolf Institute of
Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece
G. Anagnostou, G. Daskalakis, T. Geralis, A. Kyriakis, D. Loukas, I. Topsis-
Giotis National and Kapodistrian University of Athens, Athens, Greece
G. Karathanasis, S. Kesisoglou, A. Panagiotou, N. Saoulidou, E. Tziaferi
National Technical University of Athens, Athens, Greece
K. Kousouris, I. Papakrivopoulos University of Ioánnina, Ioánnina, Greece
I. Evangelou, C. Foudas, P. Gianneios, P. Katsoulis, P. Kokkas, S. Mallios, N.
Manthos, I. Papadopoulos, E. Paradas, J. Strologas, F.A. Triantis, D.
Tsitsonis MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös
Loránd University, Budapest, Hungary
M. Csanad, N. Filipovic, G. Pasztor, O. Surányi, G.I. Veres20 Wigner Research
Centre for Physics, Budapest, Hungary
G. Bencze, C. Hajdu, D. Horvath21, Á. Hunyadi, F. Sikler, T.Á. Vámi, V.
Veszpremi, G. Vesztergombi20 Institute of Nuclear Research ATOMKI, Debrecen,
Hungary
N. Beni, S. Czellar, J. Karancsi22, A. Makovec, J. Molnar, Z. Szillasi
Institute of Physics, University of Debrecen, Debrecen, Hungary
M. Bartók20, P. Raics, Z.L. Trocsanyi, B. Ujvari Indian Institute of Science
(IISc), Bangalore, India
S. Choudhury, J.R. Komaragiri National Institute of Science Education and
Research, HBNI, Bhubaneswar, India
S. Bahinipati23, P. Mal, K. Mandal, A. Nayak24, D.K. Sahoo23, S.K. Swain
Panjab University, Chandigarh, India
S. Bansal, S.B. Beri, V. Bhatnagar, S. Chauhan, R. Chawla, N. Dhingra, R.
Gupta, A. Kaur, M. Kaur, S. Kaur, R. Kumar, P. Kumari, M. Lohan, A. Mehta, S.
Sharma, J.B. Singh, G. Walia University of Delhi, Delhi, India
A. Bhardwaj, B.C. Choudhary, R.B. Garg, S. Keshri, A. Kumar, Ashok Kumar, S.
Malhotra, M. Naimuddin, K. Ranjan, Aashaq Shah, R. Sharma Saha Institute of
Nuclear Physics, HBNI, Kolkata, India
R. Bhardwaj25, R. Bhattacharya, S. Bhattacharya, U. Bhawandeep25, D. Bhowmik,
S. Dey, S. Dutt25, S. Dutta, S. Ghosh, N. Majumdar, K. Mondal, S.
Mukhopadhyay, S. Nandan, A. Purohit, P.K. Rout, A. Roy, S. Roy Chowdhury, S.
Sarkar, M. Sharan, B. Singh, S. Thakur25 Indian Institute of Technology
Madras, Madras, India
P.K. Behera Bhabha Atomic Research Centre, Mumbai, India
R. Chudasama, D. Dutta, V. Jha, V. Kumar, A.K. Mohanty16, P.K. Netrakanti,
L.M. Pant, P. Shukla, A. Topkar Tata Institute of Fundamental Research-A,
Mumbai, India
T. Aziz, S. Dugad, B. Mahakud, S. Mitra, G.B. Mohanty, N. Sur, B. Sutar Tata
Institute of Fundamental Research-B, Mumbai, India
S. Banerjee, S. Bhattacharya, S. Chatterjee, P. Das, M. Guchait, Sa. Jain, S.
Kumar, M. Maity26, G. Majumder, K. Mazumdar, N. Sahoo, T. Sarkar26, N.
Wickramage27 Indian Institute of Science Education and Research (IISER), Pune,
India
S. Chauhan, S. Dube, V. Hegde, A. Kapoor, K. Kothekar, S. Pandey, A. Rane, S.
Sharma Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
S. Chenarani28, E. Eskandari Tadavani, S.M. Etesami28, M. Khakzad, M.
Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi29, F. Rezaei
Hosseinabadi, B. Safarzadeh30, M. Zeinali University College Dublin, Dublin,
Ireland
M. Felcini, M. Grunewald INFN Sezione di Bari a, Università di Bari b,
Politecnico di Bari c, Bari, Italy
M. Abbresciaa,b, C. Calabriaa,b, A. Colaleoa, D. Creanzaa,c, L. Cristellaa,b,
N. De Filippisa,c, M. De Palmaa,b, A. Di Florioa,b, F. Erricoa,b, L. Fiorea,
A. Gelmia,b, G. Iasellia,c, S. Lezkia,b, G. Maggia,c, M. Maggia, B.
Marangellia,b, G. Minielloa,b, S. Mya,b, S. Nuzzoa,b, A. Pompilia,b, G.
Pugliesea,c, R. Radognaa, A. Ranieria, G. Selvaggia,b, A. Sharmaa, L.
Silvestrisa,16, R. Vendittia, P. Verwilligena, G. Zitoa INFN Sezione di
Bologna a, Università di Bologna b, Bologna, Italy
G. Abbiendia, C. Battilanaa,b, D. Bonacorsia,b, L. Borgonovia,b, S. Braibant-
Giacomellia,b, R. Campaninia,b, P. Capiluppia,b, A. Castroa,b, F.R. Cavalloa,
S.S. Chhibraa,b, G. Codispotia,b, M. Cuffiania,b, G.M. Dallavallea, F.
Fabbria, A. Fanfania,b, D. Fasanellaa,b, P. Giacomellia, C. Grandia, L.
Guiduccia,b, S. Marcellinia, G. Masettia, A. Montanaria, F.L. Navarriaa,b, F.
Odoricia, A. Perrottaa, A.M. Rossia,b, T. Rovellia,b, G.P. Sirolia,b, N. Tosia
INFN Sezione di Catania a, Università di Catania b, Catania, Italy
S. Albergoa,b, S. Costaa,b, A. Di Mattiaa, F. Giordanoa,b, R. Potenzaa,b, A.
Tricomia,b, C. Tuvea,b INFN Sezione di Firenze a, Università di Firenze b,
Firenze, Italy
G. Barbaglia, K. Chatterjeea,b, V. Ciullia,b, C. Civininia, R.
D’Alessandroa,b, E. Focardia,b, G. Latino, P. Lenzia,b, M. Meschinia, S.
Paolettia, L. Russoa,31, G. Sguazzonia, D. Stroma, L. Viliania INFN Laboratori
Nazionali di Frascati, Frascati, Italy
L. Benussi, S. Bianco, F. Fabbri, D. Piccolo, F. Primavera16 INFN Sezione di
Genova a, Università di Genova b, Genova, Italy
V. Calvellia,b, F. Ferroa, F. Raveraa,b, E. Robuttia, S. Tosia,b INFN Sezione
di Milano-Bicocca a, Università di Milano-Bicocca b, Milano, Italy
A. Benagliaa, A. Beschib, L. Brianzaa,b, F. Brivioa,b, V. Cirioloa,b,16, M.E.
Dinardoa,b, S. Fiorendia,b, S. Gennaia, A. Ghezzia,b, P. Govonia,b, M.
Malbertia,b, S. Malvezzia, R.A. Manzonia,b, D. Menascea, L. Moronia, M.
Paganonia,b, K. Pauwelsa,b, D. Pedrinia, S. Pigazzinia,b,32, S. Ragazzia,b, T.
Tabarelli de Fatisa,b INFN Sezione di Napoli a, Università di Napoli ’Federico
II’ b, Napoli, Italy, Università della Basilicata c, Potenza, Italy,
Università G. Marconi d, Roma, Italy
S. Buontempoa, N. Cavalloa,c, S. Di Guidaa,d,16, F. Fabozzia,c, F. Fiengaa,b,
G. Galatia,b, A.O.M. Iorioa,b, W.A. Khana, L. Listaa, S. Meolaa,d,16, P.
Paoluccia,16, C. Sciaccaa,b, F. Thyssena, E. Voevodinaa,b INFN Sezione di
Padova a, Università di Padova b, Padova, Italy, Università di Trento c,
Trento, Italy
P. Azzia, N. Bacchettaa, L. Benatoa,b, D. Biselloa,b, A. Bolettia,b, R.
Carlina,b, A. Carvalho Antunes De Oliveiraa,b, P. Checchiaa, P. De Castro
Manzanoa, T. Dorigoa, U. Dossellia, F. Gasparinia,b, U. Gasparinia,b, A.
Gozzelinoa, S. Lacapraraa, P. Lujan, M. Margonia,b, A.T. Meneguzzoa,b, N.
Pozzobona,b, P. Ronchesea,b, R. Rossina,b, F. Simonettoa,b, A. Tiko, M.
Zanettia,b, P. Zottoa,b, G. Zumerlea,b INFN Sezione di Pavia a, Università di
Pavia b, Pavia, Italy
A. Braghieria, A. Magnania, P. Montagnaa,b, S.P. Rattia,b, V. Rea, M.
Ressegottia,b, C. Riccardia,b, P. Salvinia, I. Vaia,b, P. Vituloa,b INFN
Sezione di Perugia a, Università di Perugia b, Perugia, Italy
L. Alunni Solestizia,b, M. Biasinia,b, G.M. Bileia, C. Cecchia,b, D.
Ciangottinia,b, L. Fanòa,b, P. Laricciaa,b, R. Leonardia,b, E. Manonia, G.
Mantovania,b, V. Mariania,b, M. Menichellia, A. Rossia,b, A. Santocchiaa,b, D.
Spigaa INFN Sezione di Pisa a, Università di Pisa b, Scuola Normale Superiore
di Pisa c, Pisa, Italy
K. Androsova, P. Azzurria,16, G. Bagliesia, L. Bianchinia, T. Boccalia, L.
Borrello, R. Castaldia, M.A. Cioccia,b, R. Dell’Orsoa, G. Fedia, L.
Gianninia,c, A. Giassia, M.T. Grippoa,31, F. Ligabuea,c, T. Lomtadzea, E.
Mancaa,c, G. Mandorlia,c, A. Messineoa,b, F. Pallaa, A. Rizzia,b, P.
Spagnoloa, R. Tenchinia, G. Tonellia,b, A. Venturia, P.G. Verdinia INFN
Sezione di Roma a, Sapienza Università di Roma b, Rome, Italy
L. Baronea,b, F. Cavallaria, M. Cipriania,b, N. Dacia, D. Del Rea,b, E. Di
Marcoa,b, M. Diemoza, S. Gellia,b, E. Longoa,b, B. Marzocchia,b, P.
Meridiania, G. Organtinia,b, F. Pandolfia, R. Paramattia,b, F. Preiatoa,b, S.
Rahatloua,b, C. Rovellia, F. Santanastasioa,b INFN Sezione di Torino a,
Università di Torino b, Torino, Italy, Università del Piemonte Orientale c,
Novara, Italy
N. Amapanea,b, R. Arcidiaconoa,c, S. Argiroa,b, M. Arneodoa,c, N. Bartosika,
R. Bellana,b, C. Biinoa, N. Cartigliaa, R. Castelloa,b, F. Cennaa,b, M.
Costaa,b, R. Covarellia,b, A. Deganoa,b, N. Demariaa, B. Kiania,b, C.
Mariottia, S. Masellia, E. Migliorea,b, V. Monacoa,b, E. Monteila,b, M.
Montenoa, M.M. Obertinoa,b, L. Pachera,b, N. Pastronea, M. Pelliccionia, G.L.
Pinna Angionia,b, A. Romeroa,b, M. Ruspaa,c, R. Sacchia,b, K. Shchelinaa,b, V.
Solaa, A. Solanoa,b, A. Staianoa INFN Sezione di Trieste a, Università di
Trieste b, Trieste, Italy
S. Belfortea, M. Casarsaa, F. Cossuttia, G. Della Riccaa,b, A. Zanettia
Kyungpook National University, Daegu, Korea
D.H. Kim, G.N. Kim, M.S. Kim, J. Lee, S. Lee, S.W. Lee, C.S. Moon, Y.D. Oh, S.
Sekmen, D.C. Son, Y.C. Yang Chonnam National University, Institute for
Universe and Elementary Particles, Kwangju, Korea
H. Kim, D.H. Moon, G. Oh Hanyang University, Seoul, Korea
J.A. Brochero Cifuentes, J. Goh, T.J. Kim Korea University, Seoul, Korea
S. Cho, S. Choi, Y. Go, D. Gyun, S. Ha, B. Hong, Y. Jo, Y. Kim, K. Lee, K.S.
Lee, S. Lee, J. Lim, S.K. Park, Y. Roh Seoul National University, Seoul, Korea
J. Almond, J. Kim, J.S. Kim, H. Lee, K. Lee, K. Nam, S.B. Oh, B.C. Radburn-
Smith, S.h. Seo, U.K. Yang, H.D. Yoo, G.B. Yu University of Seoul, Seoul,
Korea
H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park Sungkyunkwan University, Suwon, Korea
Y. Choi, C. Hwang, J. Lee, I. Yu Vilnius University, Vilnius, Lithuania
V. Dudenas, A. Juodagalvis, J. Vaitkus National Centre for Particle Physics,
Universiti Malaya, Kuala Lumpur, Malaysia
I. Ahmed, Z.A. Ibrahim, M.A.B. Md Ali33, F. Mohamad Idris34, W.A.T. Wan
Abdullah, M.N. Yusli, Z. Zolkapli Centro de Investigacion y de Estudios
Avanzados del IPN, Mexico City, Mexico
H. Castilla-Valdez, E. De La Cruz-Burelo, M.C. Duran-Osuna, I. Heredia-De La
Cruz35, R. Lopez-Fernandez, J. Mejia Guisao, R.I. Rabadan-Trejo, G. Ramirez-
Sanchez, R Reyes-Almanza, A. Sanchez-Hernandez Universidad Iberoamericana,
Mexico City, Mexico
S. Carrillo Moreno, C. Oropeza Barrera, F. Vazquez Valencia Benemerita
Universidad Autonoma de Puebla, Puebla, Mexico
J. Eysermans, I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada Universidad
Autónoma de San Luis Potosí, San Luis Potosí, Mexico
A. Morelos Pineda University of Auckland, Auckland, New Zealand
D. Krofcheck University of Canterbury, Christchurch, New Zealand
S. Bheesette, P.H. Butler National Centre for Physics, Quaid-I-Azam
University, Islamabad, Pakistan
A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, A. Saddique, M.A. Shah, M.
Shoaib, M. Waqas National Centre for Nuclear Research, Swierk, Poland
H. Bialkowska, M. Bluj, B. Boimska, T. Frueboes, M. Górski, M. Kazana, K.
Nawrocki, M. Szleper, P. Traczyk, P. Zalewski Institute of Experimental
Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
K. Bunkowski, A. Byszuk36, K. Doroba, A. Kalinowski, M. Konecki, J.
Krolikowski, M. Misiura, M. Olszewski, A. Pyskir, M. Walczak Laboratório de
Instrumentação e Física Experimental de Partículas, Lisboa, Portugal
P. Bargassa, C. Beirão Da Cruz E Silva, A. Di Francesco, P. Faccioli, B.
Galinhas, M. Gallinaro, J. Hollar, N. Leonardo, L. Lloret Iglesias, M.V.
Nemallapudi, J. Seixas, G. Strong, O. Toldaiev, D. Vadruccio, J. Varela Joint
Institute for Nuclear Research, Dubna, Russia
S. Afanasiev, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev,
V. Karjavin, A. Lanev, A. Malakhov, V. Matveev37,38, P. Moisenz, V. Palichik,
V. Perelygin, S. Shmatov, S. Shulha, N. Skatchkov, V. Smirnov, N. Voytishin,
A. Zarubin Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg),
Russia
Y. Ivanov, V. Kim39, E. Kuznetsova40, P. Levchenko, V. Murzin, V. Oreshkin, I.
Smirnov, D. Sosnov, V. Sulimov, L. Uvarov, S. Vavilov, A. Vorobyev Institute
for Nuclear Research, Moscow, Russia
Yu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, A. Karneyeu, M. Kirsanov,
N. Krasnikov, A. Pashenkov, D. Tlisov, A. Toropin Institute for Theoretical
and Experimental Physics, Moscow, Russia
V. Epshteyn, V. Gavrilov, N. Lychkovskaya, V. Popov, I. Pozdnyakov, G.
Safronov, A. Spiridonov, A. Stepennov, V. Stolin, M. Toms, E. Vlasov, A.
Zhokin Moscow Institute of Physics and Technology, Moscow, Russia
T. Aushev, A. Bylinkin38 P.N. Lebedev Physical Institute, Moscow, Russia
V. Andreev, M. Azarkin38, I. Dremin38, M. Kirakosyan38, S.V. Rusakov, A.
Terkulov Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State
University, Moscow, Russia
A. Baskakov, A. Belyaev, E. Boos, A. Ershov, A. Gribushin, L. Khein, V.
Klyukhin, O. Kodolova, I. Lokhtin, O. Lukina, I. Miagkov, S. Obraztsov, S.
Petrushanko, V. Savrin, A. Snigirev Novosibirsk State University (NSU),
Novosibirsk, Russia
V. Blinov41, D. Shtol41, Y. Skovpen41 Institute for High Energy Physics of
National Research Centre ’Kurchatov Institute’, Protvino, Russia
I. Azhgirey, I. Bayshev, S. Bitioukov, D. Elumakhov, A. Godizov, V. Kachanov,
A. Kalinin, D. Konstantinov, P. Mandrik, V. Petrov, R. Ryutin, A. Sobol, S.
Troshin, N. Tyurin, A. Uzunian, A. Volkov National Research Tomsk Polytechnic
University, Tomsk, Russia
A. Babaev University of Belgrade, Faculty of Physics and Vinca Institute of
Nuclear Sciences, Belgrade, Serbia
P. Adzic42, P. Cirkovic, D. Devetak, M. Dordevic, J. Milosevic Centro de
Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid,
Spain
J. Alcaraz Maestre, A. Álvarez Fernández, I. Bachiller, M. Barrio Luna, M.
Cerrada, N. Colino, B. De La Cruz, A. Delgado Peris, C. Fernandez Bedoya, J.P.
Fernández Ramos, J. Flix, M.C. Fouz, O. Gonzalez Lopez, S. Goy Lopez, J.M.
Hernandez, M.I. Josa, D. Moran, A. Pérez-Calero Yzquierdo, J. Puerta Pelayo,
I. Redondo, L. Romero, M.S. Soares, A. Triossi Universidad Autónoma de Madrid,
Madrid, Spain
C. Albajar, J.F. de Trocóniz Universidad de Oviedo, Oviedo, Spain
J. Cuevas, C. Erice, J. Fernandez Menendez, S. Folgueras, I. Gonzalez
Caballero, J.R. González Fernández, E. Palencia Cortezon, S. Sanchez Cruz, P.
Vischia, J.M. Vizan Garcia Instituto de Física de Cantabria (IFCA), CSIC-
Universidad de Cantabria, Santander, Spain
I.J. Cabrillo, A. Calderon, B. Chazin Quero, J. Duarte Campderros, M.
Fernandez, P.J. Fernández Manteca, A. García Alonso, J. Garcia-Ferrero, G.
Gomez, A. Lopez Virto, J. Marco, C. Martinez Rivero, P. Martinez Ruiz del
Arbol, F. Matorras, J. Piedra Gomez, C. Prieels, T. Rodrigo, A. Ruiz-Jimeno,
L. Scodellaro, N. Trevisani, I. Vila, R. Vilar Cortabitarte CERN, European
Organization for Nuclear Research, Geneva, Switzerland
D. Abbaneo, B. Akgun, E. Auffray, P. Baillon, A.H. Ball, D. Barney, J.
Bendavid, M. Bianco, A. Bocci, C. Botta, T. Camporesi, M. Cepeda, G.
Cerminara, E. Chapon, Y. Chen, D. d’Enterria, A. Dabrowski, V. Daponte, A.
David, M. De Gruttola, A. De Roeck, N. Deelen, M. Dobson, T. du Pree, M.
Dünser, N. Dupont, A. Elliott-Peisert, P. Everaerts, F. Fallavollita43, G.
Franzoni, J. Fulcher, W. Funk, D. Gigi, A. Gilbert, K. Gill, F. Glege, D.
Gulhan, J. Hegeman, V. Innocente, A. Jafari, P. Janot, O. Karacheban19, J.
Kieseler, V. Knünz, A. Kornmayer, M. Krammer1, C. Lange, P. Lecoq, C.
Lourenço, M.T. Lucchini, L. Malgeri, M. Mannelli, A. Martelli, F. Meijers,
J.A. Merlin, S. Mersi, E. Meschi, P. Milenovic44, F. Moortgat, M. Mulders, H.
Neugebauer, J. Ngadiuba, S. Orfanelli, L. Orsini, F. Pantaleo16, L. Pape, E.
Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfeiffer, M. Pierini, F.M.
Pitters, D. Rabady, A. Racz, T. Reis, G. Rolandi45, M. Rovere, H. Sakulin, C.
Schäfer, C. Schwick, M. Seidel, M. Selvaggi, A. Sharma, P. Silva, P.
Sphicas46, A. Stakia, J. Steggemann, M. Stoye, M. Tosi, D. Treille, A. Tsirou,
V. Veckalns47, M. Verweij, W.D. Zeuner Paul Scherrer Institut, Villigen,
Switzerland
W. Bertl${}^{\textrm{\textdagger}}$, L. Caminada48, K. Deiters, W. Erdmann, R.
Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski, U. Langenegger, T. Rohe,
S.A. Wiederkehr ETH Zurich - Institute for Particle Physics and Astrophysics
(IPA), Zurich, Switzerland
M. Backhaus, L. Bäni, P. Berger, B. Casal, N. Chernyavskaya, G. Dissertori, M.
Dittmar, M. Donegà, C. Dorfer, C. Grab, C. Heidegger, D. Hits, J. Hoss, T.
Klijnsma, W. Lustermann, M. Marionneau, M.T. Meinhard, D. Meister, F. Micheli,
P. Musella, F. Nessi-Tedaldi, J. Pata, F. Pauss, G. Perrin, L. Perrozzi, M.
Quittnat, M. Reichmann, D. Ruini, D.A. Sanz Becerra, M. Schönenberger, L.
Shchutska, V.R. Tavolaro, K. Theofilatos, M.L. Vesterbacka Olsson, R. Wallny,
D.H. Zhu Universität Zürich, Zurich, Switzerland
T.K. Aarrestad, C. Amsler49, D. Brzhechko, M.F. Canelli, A. De Cosa, R. Del
Burgo, S. Donato, C. Galloni, T. Hreus, B. Kilminster, I. Neutelings, D.
Pinna, G. Rauco, P. Robmann, D. Salerno, K. Schweiger, C. Seitz, Y. Takahashi,
A. Zucchetta National Central University, Chung-Li, Taiwan
V. Candelise, Y.H. Chang, K.y. Cheng, T.H. Doan, Sh. Jain, R. Khurana, C.M.
Kuo, W. Lin, A. Pozdnyakov, S.S. Yu National Taiwan University (NTU), Taipei,
Taiwan
P. Chang, Y. Chao, K.F. Chen, P.H. Chen, F. Fiori, W.-S. Hou, Y. Hsiung, Arun
Kumar, Y.F. Liu, R.-S. Lu, E. Paganis, A. Psallidas, A. Steen, J.f. Tsai
Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok,
Thailand
B. Asavapibhop, K. Kovitanggoon, G. Singh, N. Srimanobhas Çukurova University,
Physics Department, Science and Art Faculty, Adana, Turkey
A. Bat, F. Boran, S. Cerci50, S. Damarseckin, Z.S. Demiroglu, C. Dozen, I.
Dumanoglu, S. Girgis, G. Gokbulut, Y. Guler, I. Hos51, E.E. Kangal52, O. Kara,
U. Kiminsu, M. Oglakci, G. Onengut, K. Ozdemir53, D. Sunar Cerci50, B. Tali50,
U.G. Tok, H. Topakli54, S. Turkcapar, I.S. Zorbakir, C. Zorbilmez Middle East
Technical University, Physics Department, Ankara, Turkey
G. Karapinar55, K. Ocalan56, M. Yalvac, M. Zeyrek Bogazici University,
Istanbul, Turkey
I.O. Atakisi, E. Gülmez, M. Kaya57, O. Kaya58, S. Tekten, E.A. Yetkin59
Istanbul Technical University, Istanbul, Turkey
M.N. Agaras, S. Atay, A. Cakir, K. Cankocak, Y. Komurcu Institute for
Scintillation Materials of National Academy of Science of Ukraine, Kharkov,
Ukraine
B. Grynyov National Scientific Center, Kharkov Institute of Physics and
Technology, Kharkov, Ukraine
L. Levchuk University of Bristol, Bristol, United Kingdom
F. Ball, L. Beck, J.J. Brooke, D. Burns, E. Clement, D. Cussans, O. Davignon,
H. Flacher, J. Goldstein, G.P. Heath, H.F. Heath, L. Kreczko, D.M. Newbold60,
S. Paramesvaran, T. Sakuma, S. Seif El Nasr-storey, D. Smith, V.J. Smith
Rutherford Appleton Laboratory, Didcot, United Kingdom
K.W. Bell, A. Belyaev61, C. Brew, R.M. Brown, D. Cieri, D.J.A. Cockerill, J.A.
Coughlan, K. Harder, S. Harper, J. Linacre, E. Olaiya, D. Petyt, C.H.
Shepherd-Themistocleous, A. Thea, I.R. Tomalin, T. Williams, W.J. Womersley
Imperial College, London, United Kingdom
G. Auzinger, R. Bainbridge, P. Bloch, J. Borg, S. Breeze, O. Buchmuller, A.
Bundock, S. Casasso, D. Colling, L. Corpe, P. Dauncey, G. Davies, M. Della
Negra, R. Di Maria, Y. Haddad, G. Hall, G. Iles, T. James, M. Komm, R. Lane,
C. Laner, L. Lyons, A.-M. Magnan, S. Malik, L. Mastrolorenzo, T. Matsushita,
J. Nash62, A. Nikitenko7, V. Palladino, M. Pesaresi, A. Richards, A. Rose, E.
Scott, C. Seez, A. Shtipliyski, T. Strebler, S. Summers, A. Tapper, K. Uchida,
M. Vazquez Acosta63, T. Virdee16, N. Wardle, D. Winterbottom, J. Wright, S.C.
Zenz Brunel University, Uxbridge, United Kingdom
J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, A. Morton, I.D. Reid, L.
Teodorescu, S. Zahid Baylor University, Waco, USA
A. Borzou, K. Call, J. Dittmann, K. Hatakeyama, H. Liu, N. Pastika, C. Smith
Catholic University of America, Washington DC, USA
R. Bartek, A. Dominguez The University of Alabama, Tuscaloosa, USA
A. Buccilli, S.I. Cooper, C. Henderson, P. Rumerio, C. West Boston University,
Boston, USA
D. Arcaro, A. Avetisyan, T. Bose, D. Gastler, D. Rankin, C. Richardson, J.
Rohlf, L. Sulak, D. Zou Brown University, Providence, USA
G. Benelli, D. Cutts, M. Hadley, J. Hakala, U. Heintz, J.M. Hogan64, K.H.M.
Kwok, E. Laird, G. Landsberg, J. Lee, Z. Mao, M. Narain, J. Pazzini, S.
Piperov, S. Sagir, R. Syarif, D. Yu University of California, Davis, Davis,
USA
R. Band, C. Brainerd, R. Breedon, D. Burns, M. Calderon De La Barca Sanchez,
M. Chertok, J. Conway, R. Conway, P.T. Cox, R. Erbacher, C. Flores, G. Funk,
W. Ko, R. Lander, C. Mclean, M. Mulhearn, D. Pellett, J. Pilot, S. Shalhout,
M. Shi, J. Smith, D. Stolp, D. Taylor, K. Tos, M. Tripathi, Z. Wang, F. Zhang
University of California, Los Angeles, USA
M. Bachtis, C. Bravo, R. Cousins, A. Dasgupta, A. Florent, J. Hauser, M.
Ignatenko, N. Mccoll, S. Regnard, D. Saltzberg, C. Schnaible, V. Valuev
University of California, Riverside, Riverside, USA
E. Bouvier, K. Burt, R. Clare, J. Ellison, J.W. Gary, S.M.A. Ghiasi Shirazi,
G. Hanson, G. Karapostoli, E. Kennedy, F. Lacroix, O.R. Long, M. Olmedo
Negrete, M.I. Paneva, W. Si, L. Wang, H. Wei, S. Wimpenny, B.R. Yates
University of California, San Diego, La Jolla, USA
J.G. Branson, S. Cittolin, M. Derdzinski, R. Gerosa, D. Gilbert, B. Hashemi,
A. Holzner, D. Klein, G. Kole, V. Krutelyov, J. Letts, M. Masciovecchio, D.
Olivito, S. Padhi, M. Pieri, M. Sani, V. Sharma, S. Simon, M. Tadel, A.
Vartak, S. Wasserbaech65, J. Wood, F. Würthwein, A. Yagil, G. Zevi Della Porta
University of California, Santa Barbara - Department of Physics, Santa
Barbara, USA
N. Amin, R. Bhandari, J. Bradmiller-Feld, C. Campagnari, M. Citron, A. Dishaw,
V. Dutta, M. Franco Sevilla, L. Gouskos, R. Heller, J. Incandela, A.
Ovcharova, H. Qu, J. Richman, D. Stuart, I. Suarez, J. Yoo California
Institute of Technology, Pasadena, USA
D. Anderson, A. Bornheim, J. Bunn, J.M. Lawhorn, H.B. Newman, T.Q. Nguyen, C.
Pena, M. Spiropulu, J.R. Vlimant, R. Wilkinson, S. Xie, Z. Zhang, R.Y. Zhu
Carnegie Mellon University, Pittsburgh, USA
M.B. Andrews, T. Ferguson, T. Mudholkar, M. Paulini, J. Russ, M. Sun, H.
Vogel, I. Vorobiev, M. Weinberg University of Colorado Boulder, Boulder, USA
J.P. Cumalat, W.T. Ford, F. Jensen, A. Johnson, M. Krohn, S. Leontsinis, E.
MacDonald, T. Mulholland, K. Stenson, K.A. Ulmer, S.R. Wagner Cornell
University, Ithaca, USA
J. Alexander, J. Chaves, Y. Cheng, J. Chu, A. Datta, K. Mcdermott, N. Mirman,
J.R. Patterson, D. Quach, A. Rinkevicius, A. Ryd, L. Skinnari, L. Soffi, S.M.
Tan, Z. Tao, J. Thom, J. Tucker, P. Wittich, M. Zientek Fermi National
Accelerator Laboratory, Batavia, USA
S. Abdullin, M. Albrow, M. Alyari, G. Apollinari, A. Apresyan, A. Apyan, S.
Banerjee, L.A.T. Bauerdick, A. Beretvas, J. Berryhill, P.C. Bhat, G.
Bolla${}^{\textrm{\textdagger}}$, K. Burkett, J.N. Butler, A. Canepa, G.B.
Cerati, H.W.K. Cheung, F. Chlebana, M. Cremonesi, J. Duarte, V.D. Elvira, J.
Freeman, Z. Gecse, E. Gottschalk, L. Gray, D. Green, S. Grünendahl, O.
Gutsche, J. Hanlon, R.M. Harris, S. Hasegawa, J. Hirschauer, Z. Hu, B.
Jayatilaka, S. Jindariani, M. Johnson, U. Joshi, B. Klima, M.J. Kortelainen,
B. Kreis, S. Lammel, D. Lincoln, R. Lipton, M. Liu, T. Liu, R. Lopes De Sá, J.
Lykken, K. Maeshima, N. Magini, J.M. Marraffino, D. Mason, P. McBride, P.
Merkel, S. Mrenna, S. Nahn, V. O’Dell, K. Pedro, O. Prokofyev, G. Rakness, L.
Ristori, A. Savoy-Navarro66, B. Schneider, E. Sexton-Kennedy, A. Soha, W.J.
Spalding, L. Spiegel, S. Stoynev, J. Strait, N. Strobbe, L. Taylor, S.
Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, C. Vernieri, M. Verzocchi,
R. Vidal, M. Wang, H.A. Weber, A. Whitbeck, W. Wu University of Florida,
Gainesville, USA
D. Acosta, P. Avery, P. Bortignon, D. Bourilkov, A. Brinkerhoff, A. Carnes, M.
Carver, D. Curry, R.D. Field, I.K. Furic, S.V. Gleyzer, B.M. Joshi, J.
Konigsberg, A. Korytov, K. Kotov, P. Ma, K. Matchev, H. Mei, G. Mitselmakher,
K. Shi, D. Sperka, N. Terentyev, L. Thomas, J. Wang, S. Wang, J. Yelton
Florida International University, Miami, USA
Y.R. Joshi, S. Linn, P. Markowitz, J.L. Rodriguez Florida State University,
Tallahassee, USA
A. Ackert, T. Adams, A. Askew, S. Hagopian, V. Hagopian, K.F. Johnson, T.
Kolberg, G. Martinez, T. Perry, H. Prosper, A. Saha, A. Santra, V. Sharma, R.
Yohay Florida Institute of Technology, Melbourne, USA
M.M. Baarmand, V. Bhopatkar, S. Colafranceschi, M. Hohlmann, D. Noonan, T.
Roy, F. Yumiceva University of Illinois at Chicago (UIC), Chicago, USA
M.R. Adams, L. Apanasevich, D. Berry, R.R. Betts, R. Cavanaugh, X. Chen, S.
Dittmer, O. Evdokimov, C.E. Gerber, D.A. Hangal, D.J. Hofman, K. Jung, J.
Kamin, I.D. Sandoval Gonzalez, M.B. Tonjes, N. Varelas, H. Wang, Z. Wu, J.
Zhang The University of Iowa, Iowa City, USA
B. Bilki67, W. Clarida, K. Dilsiz68, S. Durgut, R.P. Gandrajula, M.
Haytmyradov, V. Khristenko, J.-P. Merlo, H. Mermerkaya69, A. Mestvirishvili,
A. Moeller, J. Nachtman, H. Ogul70, Y. Onel, F. Ozok71, A. Penzo, C. Snyder,
E. Tiras, J. Wetzel, K. Yi Johns Hopkins University, Baltimore, USA
B. Blumenfeld, A. Cocoros, N. Eminizer, D. Fehling, L. Feng, A.V. Gritsan,
W.T. Hung, P. Maksimovic, J. Roskes, U. Sarica, M. Swartz, M. Xiao, C. You The
University of Kansas, Lawrence, USA
A. Al-bataineh, P. Baringer, A. Bean, S. Boren, J. Bowen, J. Castle, S.
Khalil, A. Kropivnitskaya, D. Majumder, W. Mcbrayer, M. Murray, C. Rogan, C.
Royon, S. Sanders, E. Schmitz, J.D. Tapia Takaki, Q. Wang Kansas State
University, Manhattan, USA
A. Ivanov, K. Kaadze, Y. Maravin, A. Modak, A. Mohammadi, L.K. Saini, N.
Skhirtladze Lawrence Livermore National Laboratory, Livermore, USA
F. Rebassoo, D. Wright University of Maryland, College Park, USA
A. Baden, O. Baron, A. Belloni, S.C. Eno, Y. Feng, C. Ferraioli, N.J. Hadley,
S. Jabeen, G.Y. Jeng, R.G. Kellogg, J. Kunkle, A.C. Mignerey, F. Ricci-Tam,
Y.H. Shin, A. Skuja, S.C. Tonwar Massachusetts Institute of Technology,
Cambridge, USA
D. Abercrombie, B. Allen, V. Azzolini, R. Barbieri, A. Baty, G. Bauer, R. Bi,
S. Brandt, W. Busza, I.A. Cali, M. D’Alfonso, Z. Demiragli, G. Gomez Ceballos,
M. Goncharov, P. Harris, D. Hsu, M. Hu, Y. Iiyama, G.M. Innocenti, M. Klute,
D. Kovalskyi, Y.-J. Lee, A. Levin, P.D. Luckey, B. Maier, A.C. Marini, C.
Mcginn, C. Mironov, S. Narayanan, X. Niu, C. Paus, C. Roland, G. Roland,
G.S.F. Stephans, K. Sumorok, K. Tatar, D. Velicanu, J. Wang, T.W. Wang, B.
Wyslouch, S. Zhaozhong University of Minnesota, Minneapolis, USA
A.C. Benvenuti, R.M. Chatterjee, A. Evans, P. Hansen, S. Kalafut, Y. Kubota,
Z. Lesko, J. Mans, S. Nourbakhsh, N. Ruckstuhl, R. Rusack, J. Turkewitz, M.A.
Wadud University of Mississippi, Oxford, USA
J.G. Acosta, S. Oliveros University of Nebraska-Lincoln, Lincoln, USA
E. Avdeeva, K. Bloom, D.R. Claes, C. Fangmeier, F. Golf, R. Gonzalez Suarez,
R. Kamalieddin, I. Kravchenko, J. Monroy, J.E. Siado, G.R. Snow, B. Stieger
State University of New York at Buffalo, Buffalo, USA
A. Godshalk, C. Harrington, I. Iashvili, D. Nguyen, A. Parker, S. Rappoccio,
B. Roozbahani Northeastern University, Boston, USA
G. Alverson, E. Barberis, C. Freer, A. Hortiangtham, A. Massironi, D.M. Morse,
T. Orimoto, R. Teixeira De Lima, T. Wamorkar, B. Wang, A. Wisecarver, D. Wood
Northwestern University, Evanston, USA
S. Bhattacharya, O. Charaf, K.A. Hahn, N. Mucia, N. Odell, M.H. Schmitt, K.
Sung, M. Trovato, M. Velasco University of Notre Dame, Notre Dame, USA
R. Bucci, N. Dev, M. Hildreth, K. Hurtado Anampa, C. Jessop, D.J. Karmgard, N.
Kellams, K. Lannon, W. Li, N. Loukas, N. Marinelli, F. Meng, C. Mueller, Y.
Musienko37, M. Planer, A. Reinsvold, R. Ruchti, P. Siddireddy, G. Smith, S.
Taroni, M. Wayne, A. Wightman, M. Wolf, A. Woodard The Ohio State University,
Columbus, USA
J. Alimena, L. Antonelli, B. Bylsma, L.S. Durkin, S. Flowers, B. Francis, A.
Hart, C. Hill, W. Ji, T.Y. Ling, W. Luo, B.L. Winer, H.W. Wulsin Princeton
University, Princeton, USA
S. Cooperstein, O. Driga, P. Elmer, J. Hardenbrook, P. Hebda, S. Higginbotham,
A. Kalogeropoulos, D. Lange, J. Luo, D. Marlow, K. Mei, I. Ojalvo, J. Olsen,
C. Palmer, P. Piroué, J. Salfeld-Nebgen, D. Stickland, C. Tully University of
Puerto Rico, Mayaguez, USA
S. Malik, S. Norberg Purdue University, West Lafayette, USA
A. Barker, V.E. Barnes, S. Das, L. Gutay, M. Jones, A.W. Jung, A. Khatiwada,
D.H. Miller, N. Neumeister, C.C. Peng, H. Qiu, J.F. Schulte, J. Sun, F. Wang,
R. Xiao, W. Xie Purdue University Northwest, Hammond, USA
T. Cheng, J. Dolen, N. Parashar Rice University, Houston, USA
Z. Chen, K.M. Ecklund, S. Freed, F.J.M. Geurts, M. Guilbaud, M. Kilpatrick, W.
Li, B. Michlin, B.P. Padley, J. Roberts, J. Rorie, W. Shi, Z. Tu, J. Zabel, A.
Zhang University of Rochester, Rochester, USA
A. Bodek, P. de Barbaro, R. Demina, Y.t. Duh, T. Ferbel, M. Galanti, A.
Garcia-Bellido, J. Han, O. Hindrichs, A. Khukhunaishvili, K.H. Lo, P. Tan, M.
Verzetti The Rockefeller University, New York, USA
R. Ciesielski, K. Goulianos, C. Mesropian Rutgers, The State University of New
Jersey, Piscataway, USA
A. Agapitos, J.P. Chou, Y. Gershtein, T.A. Gómez Espinosa, E. Halkiadakis, M.
Heindl, E. Hughes, S. Kaplan, R. Kunnawalkam Elayavalli, S. Kyriacou, A. Lath,
R. Montalvo, K. Nash, M. Osherson, H. Saka, S. Salur, S. Schnetzer, D.
Sheffield, S. Somalwar, R. Stone, S. Thomas, P. Thomassen, M. Walker
University of Tennessee, Knoxville, USA
A.G. Delannoy, J. Heideman, G. Riley, K. Rose, S. Spanier, K. Thapa Texas A&M
University, College Station, USA
O. Bouhali72, A. Castaneda Hernandez72, A. Celik, M. Dalchenko, M. De Mattia,
A. Delgado, S. Dildick, R. Eusebi, J. Gilmore, T. Huang, T. Kamon73, R.
Mueller, Y. Pakhotin, R. Patel, A. Perloff, L. Perniè, D. Rathjens, A.
Safonov, A. Tatarinov Texas Tech University, Lubbock, USA
N. Akchurin, J. Damgov, F. De Guio, P.R. Dudero, J. Faulkner, E. Gurpinar, S.
Kunori, K. Lamichhane, S.W. Lee, T. Mengke, S. Muthumuni, T. Peltola, S.
Undleeb, I. Volobouev, Z. Wang Vanderbilt University, Nashville, USA
S. Greene, A. Gurrola, R. Janjam, W. Johns, C. Maguire, A. Melo, H. Ni, K.
Padeken, J.D. Ruiz Alvarez, P. Sheldon, S. Tuo, J. Velkovska, Q. Xu University
of Virginia, Charlottesville, USA
M.W. Arenton, P. Barria, B. Cox, R. Hirosky, M. Joyce, A. Ledovskoy, H. Li, C.
Neu, T. Sinthuprasith, Y. Wang, E. Wolfe, F. Xia Wayne State University,
Detroit, USA
R. Harr, P.E. Karchin, N. Poudyal, J. Sturdy, P. Thapa, S. Zaleski University
of Wisconsin - Madison, Madison, WI, USA
M. Brodski, J. Buchanan, C. Caillol, D. Carlsmith, S. Dasu, L. Dodd, S. Duric,
B. Gomber, M. Grothe, M. Herndon, A. Hervé, U. Hussain, P. Klabbers, A.
Lanaro, A. Levine, K. Long, R. Loveless, V. Rekovic, T. Ruggles, A. Savin, N.
Smith, W.H. Smith, N. Woods †: Deceased
1: Also at Vienna University of Technology, Vienna, Austria
2: Also at IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France
3: Also at Universidade Estadual de Campinas, Campinas, Brazil
4: Also at Federal University of Rio Grande do Sul, Porto Alegre, Brazil
5: Also at Universidade Federal de Pelotas, Pelotas, Brazil
6: Also at Université Libre de Bruxelles, Bruxelles, Belgium
7: Also at Institute for Theoretical and Experimental Physics, Moscow, Russia
8: Also at Joint Institute for Nuclear Research, Dubna, Russia
9: Also at Zewail City of Science and Technology, Zewail, Egypt
10: Also at Fayoum University, El-Fayoum, Egypt
11: Now at British University in Egypt, Cairo, Egypt
12: Also at Department of Physics, King Abdulaziz University, Jeddah, Saudi
Arabia
13: Also at Université de Haute Alsace, Mulhouse, France
14: Also at Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State
University, Moscow, Russia
15: Also at Tbilisi State University, Tbilisi, Georgia
16: Also at CERN, European Organization for Nuclear Research, Geneva,
Switzerland
17: Also at RWTH Aachen University, III. Physikalisches Institut A, Aachen,
Germany
18: Also at University of Hamburg, Hamburg, Germany
19: Also at Brandenburg University of Technology, Cottbus, Germany
20: Also at MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös
Loránd University, Budapest, Hungary
21: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary
22: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary
23: Also at Indian Institute of Technology Bhubaneswar, Bhubaneswar, India
24: Also at Institute of Physics, Bhubaneswar, India
25: Also at Shoolini University, Solan, India
26: Also at University of Visva-Bharati, Santiniketan, India
27: Also at University of Ruhuna, Matara, Sri Lanka
28: Also at Isfahan University of Technology, Isfahan, Iran
29: Also at Yazd University, Yazd, Iran
30: Also at Plasma Physics Research Center, Science and Research Branch,
Islamic Azad University, Tehran, Iran
31: Also at Università degli Studi di Siena, Siena, Italy
32: Also at INFN Sezione di Milano-Bicocca a, Università di Milano-Bicocca b,
Milano, Italy
33: Also at International Islamic University of Malaysia, Kuala Lumpur,
Malaysia
34: Also at Malaysian Nuclear Agency, MOSTI, Kajang, Malaysia
35: Also at Consejo Nacional de Ciencia y Tecnología, Mexico city, Mexico
36: Also at Warsaw University of Technology, Institute of Electronic Systems,
Warsaw, Poland
37: Also at Institute for Nuclear Research, Moscow, Russia
38: Now at National Research Nuclear University ’Moscow Engineering Physics
Institute’ (MEPhI), Moscow, Russia
39: Also at St. Petersburg State Polytechnical University, St. Petersburg,
Russia
40: Also at University of Florida, Gainesville, USA
41: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia
42: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia
43: Also at INFN Sezione di Pavia a, Università di Pavia b, Pavia, Italy
44: Also at University of Belgrade, Faculty of Physics and Vinca Institute of
Nuclear Sciences, Belgrade, Serbia
45: Also at Scuola Normale e Sezione dell’INFN, Pisa, Italy
46: Also at National and Kapodistrian University of Athens, Athens, Greece
47: Also at Riga Technical University, Riga, Latvia
48: Also at Universität Zürich, Zurich, Switzerland
49: Also at Stefan Meyer Institute for Subatomic Physics (SMI), Vienna,
Austria
50: Also at Adiyaman University, Adiyaman, Turkey
51: Also at Istanbul Aydin University, Istanbul, Turkey
52: Also at Mersin University, Mersin, Turkey
53: Also at Piri Reis University, Istanbul, Turkey
54: Also at Gaziosmanpasa University, Tokat, Turkey
55: Also at Izmir Institute of Technology, Izmir, Turkey
56: Also at Necmettin Erbakan University, Konya, Turkey
57: Also at Marmara University, Istanbul, Turkey
58: Also at Kafkas University, Kars, Turkey
59: Also at Istanbul Bilgi University, Istanbul, Turkey
60: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom
61: Also at School of Physics and Astronomy, University of Southampton,
Southampton, United Kingdom
62: Also at Monash University, Faculty of Science, Clayton, Australia
63: Also at Instituto de Astrofísica de Canarias, La Laguna, Spain
64: Also at Bethel University, St. Paul, USA
65: Also at Utah Valley University, Orem, USA
66: Also at Purdue University, West Lafayette, USA
67: Also at Beykent University, Istanbul, Turkey
68: Also at Bingol University, Bingol, Turkey
69: Also at Erzincan University, Erzincan, Turkey
70: Also at Sinop University, Sinop, Turkey
71: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey
72: Also at Texas A&M University at Qatar, Doha, Qatar
73: Also at Kyungpook National University, Daegu, Korea