EXO-18-013

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$Id:EXO-18-013.tex4918462019-03-1421:27:09Zhoepfner$

EXO-18-013

# Search for an excited lepton that decays via a contact interaction to a
lepton and two jets in proton-proton collisions at $\sqrt{s}=13\TeV$

###### Abstract

Results are presented from a search for events containing an excited lepton
(electron or muon) produced in association with an ordinary lepton of the same
flavor and decaying to a lepton and two hadronic jets. Both the production and
the decay of the excited leptons are assumed to occur via a contact
interaction with a characteristic energy scale $\Lambda$. The branching
fraction for the decay mode under study increases with the mass of the excited
lepton and is the most sensitive channel for very heavy excited leptons. The
analysis uses a sample of proton-proton collisions collected by the CMS
experiment at the LHC at $\sqrt{s}=13\TeV$, corresponding to an integrated
luminosity of 77.4. The four-body invariant mass of the two lepton plus two
jet system is used as the primary discriminating variable. No significant
excess of events beyond the expectation for standard model processes is
observed. Assuming that $\Lambda$ is equal to the mass of the excited leptons,
excited electrons and muons with masses below 5.6 and 5.7, respectively, are
excluded at 95% confidence level. These are the best limits to date.

##  0.1 Introduction

The standard model (SM) of particle physics accurately describes a broad range
of observations, but it does not provide an explanation for many of its own
features. Among the most prominent of these features is the existence of three
fermion generations, encompassing both leptons and quarks. Attempts to explain
the observed generation structure have led to a class of models postulating
that quarks and leptons are composite objects that consist of more fundamental
constituents [1, 2, 3, 4, 5, 6, 7, 8, 9]. In these models, the fundamental
constituents are bound by an asymptotically free gauge interaction that
becomes strong below a characteristic scale $\Lambda$. Such compositeness
models predict the existence of excited states of quarks ($\PQq^{*}$) and
leptons ($\ell^{*}$) at the characteristic scale of the new binding
interaction. Since these excited fermions couple to ordinary SM fermions, they
could be produced via contact interactions (CI) in collider experiments, with
subsequent decays to SM fermions through the gauge interactions (GIs), via the
emission of a or boson or a photon ($\gamma$), or via a CI to other fermions.

Figure 1: Feynman diagram for the production of an excited lepton in
association with an SM lepton in a hadron collider. The excited lepton decays
via a contact interaction to one SM lepton and two resolved jets, which result
from the hadronization of the quarks.

Searches at the CERN LEP [10, 11, 12, 13], DESY HERA [14], and the Fermilab
Tevatron [15, 16, 17, 18] have found no evidence for excited leptons. At the
CERN Large Hadron Collider (LHC), previous searches performed by the ATLAS
[19, 20, 21] and CMS collaborations [22, 23] have also found no evidence of
excited leptons. The maximum $\Lambda$ value excluded experimentally
corresponds to 25(for $M_{\ell^{*}}\approx 1\TeV$) from a recent CMS
$\ell\ell\gamma$ analysis using proton-proton (pp) collision data at
$\sqrt{s}=13\TeV$, corresponding to an integrated luminosity of 35.9 [24]. The
same analysis excluded excited electrons and muons with masses below 3.7 and
3.8, respectively, for $M_{\ell^{*}}=\Lambda$.

In this paper, a search for excited leptons ($\Pe^{*}$ and $\Pgm^{*}$) is
presented. This analysis focuses on the production of two same-flavor leptons
of which one is excited and the other one corresponds to an SM lepton. The
excited lepton is assumed to decay subsequently via a CI to an SM lepton of
the same flavor and a quark pair, yielding two jets. The process is
illustrated in Fig. 1.

The data used for this analysis were recorded with the CMS detector in pp
collisions at $\sqrt{s}=13\TeV$ during 2016 and 2017 and correspond to
integrated luminosities of 35.9 and 41.5, respectively, for a total of 77.4.

##  0.2 The CMS detector

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.
Extensive forward calorimetry complements the coverage provided by the barrel
and endcap detectors.

The silicon tracker measures charged particles within the pseudorapidity range
$\abs{\eta}<2.5$. It consists of silicon pixel and silicon strip detector
modules. The electromagnetic calorimeter consists of 75 848 lead tungstate
crystals that provide coverage in pseudorapidity $\abs{\eta}<1.48$ in a barrel
region and $1.48<\abs{\eta}<3.00$ in two endcap regions. The ECAL energy
resolution for electrons with a transverse momentum $\pt\approx 45\GeV$ from
$\PZ\to\Pe\Pe$ decays is better than 2% in the central region of the ECAL
barrel $(\abs{\eta}<0.8)$, and is between 2 and 5% elsewhere [25]. For high
energies, which are relevant for this analysis, the electron energy resolution
slightly improves [26].

Muons are measured in gas-ionization detectors embedded in the steel flux-
return yoke outside the solenoid, in the pseudorapidity range
$\abs{\eta}<2.4$. Detection is provided using three technologies: drift tubes
(DTs), cathode strip chambers (CSCs), and resistive-plate chambers (RPCs).
While the barrel region of $\abs{\eta}\leq 1.1$ is instrumented with DTs and
RPCs, the endcaps ($1.1<\abs{\eta}<2.4$) are equipped with CSCs and RPCs. A
muon from the interaction point will cross four layers of muon chambers,
interleaved with steel forming the return yoke of the magnetic field. Every
chamber provides reconstructed hits on several detection planes, which are
then combined into local track segments, forming the basis of muon
reconstruction inside the muon system. Matching muons to tracks measured in
the silicon tracker results in a relative transverse momentum resolution, for
muons with up to 100, of 1% in the barrel and 3% in the endcaps. The
resolution in the barrel is better than 7% for muons with up to 1 [27].

A particle-flow algorithm [28] aims to reconstruct and identify each
individual particle in an event, with an optimized combination of information
from the various elements of the CMS detector. The energy of photons is
obtained from the ECAL measurement. The energy of electrons is determined from
a combination of the electron momentum at the primary interaction vertex as
determined by the tracker, the energy of the corresponding ECAL cluster, and
the energy sum of all bremsstrahlung photons spatially compatible with
originating from the electron track. The muon is obtained from the curvature
of the corresponding track. The energy of charged hadrons is determined from a
combination of their momentum measured in the tracker and the matching ECAL
and HCAL energy deposits, corrected for zero-suppression effects and for the
response function of the calorimeters to hadronic showers. Finally, the energy
of neutral hadrons is obtained from the corresponding corrected ECAL and HCAL
energies.

The CMS experiment has a two-level trigger system [29]. The level-1 trigger,
composed of custom hardware processors, selects events of interest using
information from the calorimeters and muon detectors and reduces the readout
rate from the 40MHz bunch-crossing frequency to a maximum of 100kHz. The
software based high-level trigger uses the full event information, including
that from the inner tracker, to reduce the event rate to the 1kHz that is
recorded.

A more detailed description of the CMS detector can be found in Ref. [30].

##  0.3 Model and signal simulation

Excited leptons can be produced at a pp collider by a CI that is described by
an effective four-fermion Lagrangian

$\mathcal{L}_{\text{CI}}=\frac{g_{*}^{2}}{\Lambda^{2}}\frac{1}{2}j^{\mu}j_{\mu},$
(1)

with the coupling $g_{*}^{2}$ chosen to correspond to $4\pi$, fermion current
$j_{\mu}=\overline{\psi}\gamma_{\mu}\psi$, and $\Lambda$ representing the
compositeness scale [6]. The excited lepton, $\ell^{*}$, can decay to an SM
lepton via a CI $\ell^{*}\to\ell\psi\overline{\psi}$, where $\psi$ is a
fermion, or through the mediation of a gauge boson. This analysis complements
other searches for excited leptons in the $\ell\ell\gamma$ or $\ell\ell\PZ$
channels and is most sensitive at large values of $M_{\ell^{*}}$ and/or
$\Lambda$. Figure 2 illustrates the rapid increase of the branching fraction
of the CI decay to a lepton plus two jets as a function of
$M_{\ell^{*}}/\Lambda$.

Figure 2: Branching fractions, $\mathcal{B}$, of excited lepton decay channels
as a function of the ratio of the excited lepton mass ($M_{\ell^{*}}$) and
compositeness scale ($\Lambda$) for fixed values of the model parameters
$f=f^{\prime}$, which represent the couplings of excited leptons to SM
particles. The branching fraction calculation is based on Ref. [6]. The
contact interaction decay to one lepton and two jets, subject of this
analysis, is dominating the region of high $M_{\ell^{*}}$/$\Lambda$. Couplings
$f$ and $f^{\prime}$ are assumed to be equal to 1 in the left graph, and 0.1
in the right graph.

The GI transition of excited leptons to SM leptons is described by

$\mathcal{L}_{\text{GI}}=\frac{1}{2\Lambda}\overline{\psi}_{R}^{\star}\sigma^{\mu\nu}\left(gf\frac{\boldsymbol{\tau}}{2}\boldsymbol{W}_{\mu\nu}+g^{\prime}f^{\prime}\frac{Y}{2}B_{\mu\nu}\right)\psi_{L}+\text{h.c.},$
(2)

where $g$ and $g^{\prime}$ denote the couplings to the hypercharge and the
weak isospin current and $f$ and $f^{\prime}$ effectively scale the energy
scale of the interaction $\Lambda$ with respect to the CI [6]. Other
quantities are $\boldsymbol{W}_{\mu\nu}$ and $B_{\mu\nu}$ denoting the field
strength tensors of the $\text{SU}(2)$ and $\text{U}(1)$ gauge fields with
their generators $\boldsymbol{\tau}$ and $Y$. The partial width of the CI
decay is independent of $f$ and $f^{\prime}$. Interference between GI and CI
transitions is not considered [6]. Since the exact values for $f$ and
$f^{\prime}$ are not known, searches for excited leptons are typically
interpreted for two extreme values: $f=f^{\prime}=1$ and $f=-f^{\prime}=1$.
Gauge-interaction decays via photon emission are forbidden for
$f=-f^{\prime}$. Figure 2 shows the variation of the branching fractions of
the different decay channels as a function of $M_{\ell^{*}}$/$\Lambda$,
illustrated in Fig. 2 (left) for couplings of 1.0. Couplings below unity are
also possible and can have a significant impact on the branching fractions, as
seen in Fig. 2 (right) for couplings of 0.1. Weaker couplings reduce widths
for the gauge-interaction decays while enhancing the CI decays. A range of
couplings is included in the interpretation of the experimental results.

The production and decay of excited leptons are simulated at leading-order
precision with 8.212 [31] using the NNPDF2.3 [32] (in 2016) and NNPDF3.1 [33]
(in 2017) parton distribution functions (PDF) and tunes CUETP8M1 (2016) and
CP5 (2017) for the underlying event, respectively [34]. Simulated samples are
generated for $\ell^{*}$ masses of 200, 500, 750 and 1000and from 1 to 7in
steps of 0.5. In the simulation, all couplings are set to unity and $\Lambda$
to 10. The specific choice of $\Lambda$ in the simulation scales the overall
cross section for the process, while leaving the kinematic variables
unaffected. Hence, the simulated events can be reweighted in order to
represent different choices of the couplings and $\Lambda$. While the
resonance width depends on $\Lambda$, it is smaller than the detector
resolution for all values used in this analysis. For the example of a 5signal,
the width is of order 15% of the resolution.

At $\Lambda=10\TeV$ and $f=1$ the product of the cross section and branching
fraction for the channel under study ranges from 0.224fb
($M_{\ell^{*}}=200\GeV$), 1.115fb ($M_{\ell^{*}}=1\TeV$), 1.07 $\times
10^{-2}\unit{fb}$ ($M_{\ell^{*}}=5\TeV$) to 6.91 $\times 10^{-4}\unit{fb}$
($M_{\ell^{*}}=7\TeV$). For a high-mass $\ell^{*}$ signal, each of the decay
products will have a of approximately 1, and will tend to be in the central
part of the detector.

##  0.4 Event reconstruction

The candidate vertex with the largest value of summed physics-object $\pt^{2}$
is taken to be the primary $\Pp\Pp$ interaction vertex. Here the physics
objects are the jets, clustered using the jet finding algorithm [35, 36] with
the tracks assigned to the candidate vertices as inputs, and the associated
missing transverse momentum, taken as the negative vector sum of these jets.
In order to suppress background from cosmic ray muons, an event must have at
least one primary vertex, with at least five associated well-reconstructed
tracks that are within 24in the longitudinal and 2in the transverse direction
from the nominal interaction point.

Electrons are reconstructed as ECAL clusters that are matched to a central
track and their identification has been optimized for high-values [37]. In
order to differentiate between electrons and photons, the properties of the
track matched to the calorimeter measurement must be consistent with those of
an electron originating from the primary vertex. Specifically, there must be
$\leq$1 hit missing in the innermost tracker layers, and the transverse
distance to the primary vertex must be less than 2mm (barrel) or less than 5mm
(endcap). Electron candidates are required to have an electron-like shower
shape, and to be within the acceptance region of the barrel
($\abs{\eta}<1.44$) or the endcaps ($1.56<\abs{\eta}<2.50$), thus avoiding the
transition region between the barrel and the endcap parts of the ECAL. The
corresponding track matched to the ECAL cluster must be consistent with a
particle originating from the nominal interaction point. The associated energy
in the HCAL around the electron direction must be less than 5% of the
reconstructed energy of the electron, once noise and pileup are taken into
account. To ensure isolation, the scalar sum of the of all tracker and
calorimeter objects in a cone of radius $\Delta
R=\sqrt{\smash[b]{(\Delta\phi)^{2}+(\Delta\eta)^{2}}}<0.3$ where $\phi$ is
azimuthal angle in radians, must be less than 3% of the electron . Only well-
measured tracks that are consistent with originating from the same vertex as
the electron are included in the isolation cone.

The muon system covers the pseudorapidity region $\abs{\eta}<2.4$. The
reconstruction of muons is optimized for high-values [37]. Measurements from
the inner tracker and the outer muon system are combined. The tracker track
must have a transverse impact parameter $d_{xy}<2\unit{mm}$ with respect to
the primary vertex. The longitudinal distance of the tracker track from the
primary vertex must be less than 5mm. Each muon track is required to have at
least one hit in the pixel detector, at least six tracker layer hits, and
segments with hits in two or more muon detector stations. Since segments are
typically in consecutive layers separated by thick layers of steel, the latter
requirement significantly reduces the amount of hadronic punch-through [38].
In order to suppress muons with mismeasured , an additional requirement
$\sigma_{\pt}/\pt<0.3$ is applied, where $\sigma_{\pt}$ is the uncertainty
from the muon track reconstruction. Muon isolation requires that the scalar
sum of all tracks originating from the interaction vertex within a $\Delta
R<0.3$ cone around its direction, excluding the muon itself, is less than 10%
of the muon’s .

This analysis uses $\eta$\- and -dependent scale factors to correct the
simulated event yields for the measured differences in the trigger,
reconstruction, and identification efficiencies as compared with data.

For each event, hadronic jets are clustered from the reconstructed particle-
flow objects with the infrared and collinear safe anti-jet clustering
algorithm [35, 36] using a distance parameter of $R=0.4$. Jet momentum is
determined as the vectorial sum of all particle momenta in the jet, and is
found from simulation to be, on average, within 5 to 10% of the true momentum
over the whole spectrum and detector acceptance. Additional proton-proton
interactions within the same or nearby bunch crossings can contribute
additional tracks and calorimetric energy depositions, increasing the apparent
jet momentum. To mitigate this effect, tracks identified as originating from
pileup vertices (contributions from additional pp interactions in the same or
nearby bunch crossings) are discarded. Jet energy corrections are derived from
simulation studies so that the average measured response of jets becomes
identical to that of particle level jets. In situ measurements of the momentum
balance in dijet, photon+jet, +jet, and multijet events are used to determine
any residual differences between the jet energy scale in data and in
simulation, and appropriate corrections are made [39]. Additional selection
criteria are applied to each jet to remove jets potentially dominated by
instrumental effects or reconstruction failures.

##  0.5 Backgrounds

Because the final state contains two opposite-sign leptons, the main
background originates from Drell–Yan (DY) production. These events are
simulated using the NLO generator v2.2.2 [40, 41] with up to two final-state
partons, and are hadronized with 8.212. Because large mass lepton pairs
associated with large hadronic activity are a small fraction of all DY events,
additional high mass simulations are used to ensure sufficient statistics to
evaluate this background. The cross section is normalized to next-to-next-to-
leading-order (NNLO) QCD and next-to-leading-order (NLO) EWK using a di-lepton
mass-dependent K factor [37, 42].

Another important background is the process, which yields two prompt leptons
if both top quarks decay semi-leptonically. This becomes the dominant
background in the medium-mass validation region (VR), as will be described in
Section 0.6. It is simulated with 2.0 [43, 44, 45, 46, 47] in combination with
8.212 for hadronization. Dedicated high-mass samples are used to provide
sufficient number of events to estimate the background contribution to the
high-mass signal region, and are simulated with the same method as used for
the main sample. The cross section is normalized to NNLO [48]. Production of
single top quarks in association with a -boson or in the $t$-channel
production are simulated with . The single top $s$-channel is simulated with .

Several multi-boson processes can also yield at least two leptons. However,
because they have small cross sections, they are sub-dominant backgrounds in
this search. The $\PW\PW$, $\PW\PZ$, and $\PZ\PZ$ processes with at least two
leptons are simulated with and . Triple-boson processes are neglected because
of their small cross sections.

The $\PW$+jets production can contribute to the signal region when jets are
misidentified as electrons. In contrast, the misidentification of muons is
negligible. The $\PW$+jets production is simulated to leading order with
v2.2.2 [40, 41]. In addition, high-samples are also used, where is defined as
the sum of jet transverse momenta. The $\PW$+jets cross section is normalized
to NNLO by application of a K-factor of 1.21 [42].

The background samples are simulated using the NNPDF2.3 or NNPDF3.0 [49] PDF
sets with tune CUETP8M1 (in 2016) and the NNPDF3.1 (in 2017) PDF set with CP5
(2017) for the underlying event, respectively [34]. All generated events are
processed through a full simulation of the CMS detector based on [50], a
trigger emulation, and the event reconstruction chain. All simulated event
samples are normalized to the integrated luminosity of the recorded data. The
simulation of pileup is included in all events by superimposing simulated
minimum bias interactions. For the data set used, the average number of
interactions per bunch crossing after selection is about 23 in 2016 and about
30 in 2017, with maximum values of 55 and 70, respectively.

##  0.6 Event selection and validation regions

Events with electrons in the final state were selected using a trigger that
requires an electromagnetic cluster (electron or photon) with transverse
momenta larger than 175(for 2016) and 200(for 2017). Events with muons in the
final state were triggered with the single-muon trigger with a minimum of 50.
The electron (muon) efficiency plateaus at 98.5% (98%) [51] as a function of
above a turn-on region and is independent of $\eta,\phi$, and pileup.

Figure 3: Definition of the two validation regions (VR) and the high-mass
signal region (SRT).

Final state particles (electrons, muons and jets) are reconstructed as
described in Section 0.4. The two highest (leading) leptons are selected along
with the two leading jets. The thresholds for the leading lepton are
230(electron) and 53(muon), chosen to be above the respective trigger turn-on
regions. The subleading electrons or muons are required to have an offline of
at least 35 and 25, respectively. Jets are required to have a minimum of 50.
Events with more than two same-flavor leptons are rejected, to reduce
background from diboson production.

The majority of the DY background is suppressed by requiring
$M_{\ell\ell}>500\GeV$, constituting the high-mass signal region (SRT). Two
VRs are then defined, illustrated in Fig. 3, to verify agreement between data
and simulation in different mass regions. The low-mass VR with
$M_{\ell\ell}<200\GeV$ serves as the VR for DY, which is the dominant
background for this final state. The subleading background tends to populate
the medium-mass VR, which is defined by $200\GeV<M_{\ell\ell}<500\GeV$. While
the low-mass VR is nearly signal free, the medium-mass VR potentially contains
a very small fraction of signal events. The signal contamination in the medium
VR is far below 1% for the interesting mass range of $M_{\ell^{*}}$ above 3.8.

The invariant mass of the combination of both selected leptons and the two
leading jets, $M_{\ell\ell jj}$, is used as the discriminating variable as it
provides the best separation power between signal and background. The
distributions of other possible variables were studied, but their use yielded
lower signal significance. The event distributions as functions of the four-
body mass for the low-mass and medium-mass validation regions are shown in
Figs. 4 and 5, respectively. The good agreement between experimental and
simulated data justifies estimating the background expectation from
simulation.

Figure 4:  Event distributions as a function of the four-body invariant
$M_{\ell\ell jj}$ mass for the electron (left) and muon (right) channels, for
the low-mass validation region defined by $M_{\ell\ell}<200\GeV$. The lower
panels show the ratio of data to the simulated SM background, with the shaded
band representing the uncertainty.

Figure 5:  Event distribution as a function of the four-body invariant mass
$M_{\ell\ell jj}$ for the electron (left) and muon (right) channels, for the
medium-mass validation region defined by $200<M_{\ell\ell}<500\GeV$. The lower
panel shows the ratio of data to the simulated SM background, with the shaded
band representing the uncertainty.  Figure 6: Signal efficiency after all
selections are applied, as a function of the excited lepton mass
$M_{\ell^{*}}$, based on simulated events.

The signal efficiency, defined as the product of acceptance and detection
efficiency of the fraction of reconstructed 2$\ell$2j events, resulting from
these event selections is shown as a function of the simulated excited lepton
mass in Fig. 6. The uncertainties in the figure are only statistical
uncertainties. The systematic uncertainties on the product of acceptance and
efficiency are between 6 and 8%. The efficiency reaches a plateau of about 55%
for the electron channel and 73% for the muon channel. For lower masses, in
particular for $M_{\ell^{*}}<1\TeV$, the acceptance is reduced by the offline
thresholds on the objects but this mass region is not of primary interest
given previous exclusion limits. For masses above 6, the efficiency starts to
drop slightly because of a growing fraction of events produced off-shell. At
the given center-of-mass energy of the LHC, the available energy for
generating such heavy particles is limited.

##  0.7 Systematic uncertainties

Systematic uncertainties in this analysis can affect the overall normalization
and also the shape of the distributions. Uncertainties in the energy scale of
different physics objects are taken into account by analyzing the shape of the
four-body mass distributions, with the energy scale shifted up and down by
$1\,\sigma$. The electron energy scale uncertainty is estimated to be 0.2% in
the barrel and 0.3% in the endcap [52]. For muons, the momentum scale is
determined using the generalized endpoint method [27] and applied as a
function of the $\eta$ and $\phi$ of the muon. The studies indicate the
absence of a significant curvature bias, within an uncertainty of 0.02/in the
central region and up to 0.1/TeV in the more forward regions. For jets, the
uncertainties associated with the jet energy correction are used [39].

The simulated energy resolution is better than that measured in data. To
account for this, jet energy resolution corrections are applied to jets and
their uncertainties are considered as a systematic effect [39]. For electrons,
the momentum is smeared by 1.2 and 2.4% for barrel and endcaps, respectively
[52]. For muons, the momentum is smeared by 5% [27]. These three uncertainties
change the shape of the background.

There are systematic uncertainties on the scale factors applied to correct for
the differences in the triggering, reconstruction and identification
efficiencies between simulation and data. These uncertainties are typically a
few percent and are taken into account as normalization uncertainty [52, 27].
The integrated luminosity of the data collected has an uncertainty of 2.5 [53]
and 2.3% [54] for the 2016 and 2017 data sets, respectively. The uncertainty
due to the modeling of pileup is found to be less than 10% and is by derived
by calculating the pileup for the cases where the total inelastic cross
section is increased and decreased by 5% from the nominal value [55]. It is
treated as an uncertainty in the background shape.

The uncertainty associated with the choice of PDFs affects the cross section
of the simulated samples and is taken into account by following an approach
outlined by the PDF4LHC recipe [56]. The PDF set used to calculate the
variations is NNPDF3.0, for background and signal samples in 2016, and
NNPDF3.1, in 2017. Overall, the variation is found to range from 5% to 60% for
an excited lepton mass from 1to 6, respectively, as taken from LHAPDF6.2 [57].

The renormalization and factorization scales provide a handle to estimate the
uncertainty due to missing higher orders. Both scales are varied
simultaneously by a factor 2 up and down, resulting in different event-by-
event weights and an uncertainty of 10 to 30% between 1 and 6.

In the signal region, the limited number of simulated background events
results in a statistical uncertainty of up to 40% in the background
prediction.

Production of $\PW$+jets final states can contribute to the background when a
jet is misidentified as a lepton, albeit at a very small level. A conservative
systematic uncertainty of 100% is applied to the $\PW$+jets background
contribution and reflects the uncertainty in the lepton misidentification rate
in the simulation as compared with data.

For the SM background, the dominant sources of uncertainties are the
Monte–Carlo (MC) sample sizes and the PDF uncertainty.

##  0.8 Results

Event distributions for the signal regions as a function of the four-body
invariant mass are shown for the electron and muon channels in Fig. 7. The
final distribution is dominated by background in the low-mass region and DY
background in the high mass region despite being strongly suppressed by the
dilepton invariant mass cut. The expected background in the highest mass bin,
of more than 5width, is far less than one event. The analysis would not
benefit from reducing the background further at the cost of signal efficiency.
The event yields in data compared to the total expected SM backgrounds are
given in Table 0.8 for a number of bins of the discriminating four-body $2\ell
2j$ mass distribution. Also shown are the expectations for potential
$\ell^{*}$ signals with two different sets of model parameter values: a mass
$M_{\ell^{*}}$ of 2and compositeness scale $\Lambda$ of 10; and
$M_{\ell^{*}}=\Lambda=5\TeV$, which roughly corresponds to the maximum
sensitivity of this analysis.

Figure 7: Distribution of the two-lepton two-jet invariant mass in the signal
region ($M_{\ell\ell}>500\GeV$) for the electron (left) and muon (right)
channels. The example signal shape for two excited lepton masses is indicated
as a gray line with the parameters given in the legend and for the benchmark
case where the couplings $f$ and $f^{\prime}$ are set to unity. The lower
panels show the ratio of data to simulation with the total uncertainty in
gray.

Observed event yields in bins of four-body mass compared to the expected SM
background, for the $2e2j$ and $2\mu 2j$ final states. Also shown are the
expected event yields for two simulated signal samples with the given masses
and couplings. All yields are given in bins of the discriminating four-body
mass ($2\ell 2j$) distribution, with lower and upper value for each bin given
in units of GeV. Systematic uncertainties, as described in the text, are
shown.  Bins in $2\ell 2j$ mass () 800–1600 1600–2500 2500–3250 3250–4500
4500–10000 Data in $2e2j$ 359 70 6 5 0 SM prediction $362^{+58}_{-61}$ $65\pm
12$ $10.3^{+2.7}_{-2.8}$ $1.6^{+0.8}_{-0.7}$ $0.24^{+0.17}_{-0.24}$
$f=f^{\prime}=1$ $M_{\Pe^{*}}=2\TeV,\Lambda=10\TeV$ $0.17^{+0.01}_{-0.02}$
$4.5\pm 0.3$ $9.1\pm 0.6$ $7.4\pm 0.5$ $1.9\pm 0.2$
$M_{\Pe^{*}}=5\TeV,\Lambda=5\TeV$ $0.015^{+0.002}_{-0.003}$ $0.08\pm 0.01$
$0.15\pm 0.01$ $0.81^{+0.07}_{-0.06}$ $10.4\pm 0.7$ $f=f^{\prime}=0.1$
$M_{\Pe^{*}}=2\TeV,\Lambda=10\TeV$ $0.53\pm 0.05$ $13.6^{+1.0}_{-0.9}$
$27.8^{+1.7}_{-1.8}$ $22.6\pm 1.6$ $5.7\pm 0.5$
$M_{\Pe^{*}}=5\TeV,\Lambda=5\TeV$ $0.016^{+0.002}_{-0.003}$ $0.09\pm 0.01$
$0.16\pm 0.01$ $0.85^{+0.08}_{-0.07}$ $10.9\pm 0.8$ Data in $2\mu 2j$ 889 111
9 2 1 SM prediction $842^{+91}_{-102}$ $125^{+18}_{-19}$ $12.4\pm 3.3$
$2.4^{+0.9}_{-1.2}$ $0.47^{+0.31}_{-0.32}$ $f=f^{\prime}=1$
$M_{\Pgm^{*}}=2\TeV,\Lambda=10\TeV$ $0.30\pm 0.02$ $6.9^{+0.3}_{-0.2}$
$12.7^{+0.5}_{-0.4}$ $10.1^{+0.6}_{-0.4}$ $2.5\pm 0.2$
$M_{\Pgm^{*}}=5\TeV,\Lambda=5\TeV$ $0.021\pm 0.003$ $0.13\pm 0.01$
$0.27^{+0.02}_{-0.01}$ $1.4\pm 0.1$ $14.4^{+1.2}_{-0.4}$ $f=f^{\prime}=0.1$
$M_{\Pgm^{*}}=2\TeV,\Lambda=10\TeV$ $0.92^{+0.06}_{-0.05}$
$20.9^{+0.9}_{-0.7}$ $38.8^{+1.6}_{-1.1}$ $30.8^{+1.8}_{-1.1}$
$7.7^{+0.7}_{-0.5}$ $M_{\Pgm^{*}}=5\TeV,\Lambda=5\TeV$ $0.021\pm 0.003$
$0.14\pm 0.01$ $0.29^{+0.02}_{-0.01}$ $1.5\pm 0.1$ $15.1^{+1.2}_{-0.4}$

No indication of a signal is observed. The limits on the excited lepton mass,
$M_{\ell^{*}}$, are calculated using the Bayesian method [58] with a uniform
positive prior probability distribution for the signal cross section.
Systematic uncertainties in the expected signal and background yields are
included either via nuisance parameters with log-normal prior distributions or
with the shape of the distribution included through the use of a binned
likelihood.

Limits at 95% confidence level () on the product of cross section and
branching fraction assuming the proper branching fraction for $M_{\ell^{*}}$
=$\Lambda$ and $f=f^{\prime}=1$ are shown in Fig. 8, and range from 10 to
0.1fb, depending on the mass of the excited lepton.

This analysis excludes excited electrons and excited muons at 95% for values
of $M_{\ell^{*}}$ below 5.6 and 5.7, respectively, assuming that $\Lambda$ is
equal to the mass of the excited leptons. These are the best limits to date on
excited electrons and muons. At low masses, the sensitivity is determined by
the acceptance and analysis selection. At very high mass, the sensitivity
becomes limited by the cross section. The sensitivity to the maximum
$\ell^{*}$ mass is not affected by the coupling strength.

Figure 8: Limits at 95% on the product of the production cross section and
branching fraction for $\ell\ell^{*}\to\ell\ell jj$, as a function of the
excited lepton mass $M_{\ell^{*}}$, for the electron (left) and muon (right)
channels. The expectation from the model is represented for
$\abs{f}=\abs{f^{\prime}}=1$ by two cases, $\Lambda=10\TeV$, and
$\Lambda=M_{\ell^{*}}$.

Figure 9: Limits on the compositeness scale $\Lambda$ for the electron (left)
and muon (right) channels, as a function of the mass of the excited lepton,
for the benchmark case where the GI couplings $\abs{f}$ and $\abs{f^{\prime}}$
are set to one. The model is not valid in the hatched area.

Figure 10: Limits on the compositeness scale $\Lambda$ for the electron (left)
and muon (right) channels, as a function of the mass of the excited lepton,
for the case where the GI couplings $\abs{f}$ and $\abs{f^{\prime}}$ are set
to 0.1. The model is not valid in the hatched area.

Figure 11: Limits on the compositeness scale $\Lambda$ for the electron (left)
and muon (right) channels, as a function of the mass of the excited lepton,
for the benchmark case where the GI couplings $f$ and $f^{\prime}$ vanish. The
model is not valid in the hatched area.

The cross section limit can be re-evaluated in terms of the compositeness
scale $\Lambda$ as a function of the excited lepton mass. This sensitivity
does depend on the coupling strength. Figures 9–11 show the variations in the
compositeness scale $\Lambda$ for the gauge couplings $\abs{f}$ and
$\abs{f^{\prime}}$ equal to unity, for $\abs{f}$ and $\abs{f^{\prime}}$ equal
to 0.1, and for $f$ and $f^{\prime}$ equal to zero, respectively.
Compositeness scales below 5are excluded for all investigated $\ell^{*}$
masses. Maximum sensitivity to $\Lambda$ is reached at low masses, as is
typical for excited lepton searches. The exact mass for this peak sensitivity
depends on the coupling scenario, decreasing with weaker GI couplings, and can
easily be understood from Fig. 2. Detailed numbers are given in Table 0.9. In
the case of $f=f^{\prime}=1$, compositeness scales up to 11($\Pe^{*}$) and
12($\Pgm^{*}$) are excluded, with the maximum sensitivity for $\ell^{*}$
masses around 2. With values for $f=f^{\prime}=0.1$, the decay width to a CI
increases, yielding a higher $\Lambda$ sensitivity of 17($\Pe^{*}$) and
19($\Pgm^{*}$), respectively, for $\ell^{*}$ masses around 1.5. Assuming zero
GI couplings, the observed $\Lambda$ sensitivity increases to 18($\Pe^{*}$)
and 22($\Pgm^{*}$), respectively, for $\ell^{*}$ masses around 1. While the
expected sensitivities in the electron and muon channels are comparable, the
observed muon channel sensitivity is up to one standard deviation higher due
to fluctuations in the data. For $M_{\ell^{*}}$ above 2these are the best
limits to date. In the scenario $f=-f^{\prime}$, where $\ell\ell\gamma$ has no
sensitivity, this CI channel provides the best test of high compositeness
scales.

##  0.9 Summary

A search for excited leptons decaying via a contact interaction to final
states of two electrons or two muons and two resolved jets has been performed.
This channel complements other searches for excited leptons. It has greatest
sensitivity at large values of the excited lepton mass $M_{\ell^{*}}$. The
data for this analysis were recorded with the CMS detector in the years 2016
and 2017, corresponding to a total integrated luminosity of 77.4of proton-
proton collisions at a center-of-mass energy of 13.

No significant deviations from SM expectations are observed in the signal
region and 95% exclusion limits have been set. Excited electrons (muons) up to
masses of $M_{\Pe^{*}}=5.6\TeV$ ($M_{\Pgm^{*}}=5.7\TeV$) are excluded with the
usual assumption of $M_{\ell^{*}}=\Lambda$. These are the best limits to date.
The limit was also re-evaluated in terms of the substructure scale $\Lambda$,
leading to limits of $\Lambda=11$ and 12for excited electrons and muons,
respectively, for mass values around 2and couplings of unity. When studying
weaker gauge couplings, the limit on the maximum $M_{\ell^{*}}$ does not
change, but the larger cross section increases the $\Lambda$ sensitivity at
lower masses. For couplings around zero, where the $\ell\ell\gamma$ decay has
no sensitivity, limits around 20for the compositeness scale $\Lambda$ are
achieved.

Summary of the observed (expected) limits on $\ell^{*}$ mass, assuming
$M_{\ell^{*}}$ = $\Lambda$, for the cases $f=f^{\prime}$ and $f=-f^{\prime}$.
The limits evaluated in terms of the compositeness scale $\Lambda$ are shown
in the right column.  Search channel Coupling $M_{\ell^{*}}$ $=\Lambda$,
values in  Limit on $\Lambda$, in  strength $f=f^{\prime}$ $f=-f^{\prime}$
$\Pe\Pe^{*}\,\,\to 2\Pe 2j$ $f=1$ 5.6 (5.6) 5.6 (5.6) 11 (11) for
$M_{\ell^{*}}\approx 2\TeV$ $f=0.1$ 5.6 (5.6) 5.6 (5.6) 17 (18) for
$M_{\ell^{*}}\approx 1.5\TeV$ $f=0$ 5.6 (5.6) 5.6 (5.6) 18 (19) for
$M_{\ell^{*}}\approx 1\TeV$ $\Pgm\Pgm^{*}\to 2\Pgm 2j$ $f=1$ 5.7 (5.7) 5.7
(5.7) 12 (12) for $M_{\ell^{*}}\approx 2\TeV$ $f=0.1$ 5.7 (5.7) 5.7 (5.7) 19
(19) for $M_{\ell^{*}}\approx 1.5\TeV$ $f=0$ 5.7 (5.7) 5.7 (5.7) 22 (20) for
$M_{\ell^{*}}\approx 1\TeV$

###### 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 centers 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, PUT 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 (Ukraine); STFC (United Kingdom); DOE and NSF (USA).
Individuals have received support from the Marie-Curie program and the
European Research Council and Horizon 2020 Grant, contract Nos. 675440,
752730, and 765710 (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
Beijing Municipal Science & Technology Commission, No. Z191100007219010; the
Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the
Deutsche Forschungsgemeinschaft (DFG) under Germany’s Excellence Strategy –
EXC 2121 “Quantum Universe” – 390833306; the Lendület (“Momentum”) Program 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, 125105, 128713, 128786, and 129058 (Hungary); the
Council of Science and Industrial Research, India; the HOMING PLUS program of
the Foundation for Polish Science, cofinanced from European Union, Regional
Development Fund, the Mobility Plus program 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 Ministry of Science and
Education, grant no. 14.W03.31.0026 (Russia); 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 programs 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 Kavli Foundation; the Nvidia Corporation; the
SuperMicro Corporation; the Welch Foundation, contract C-1845; and the Weston
Havens Foundation (USA).

## References

  * [1] J. C. Pati, A. Salam, and J. A. Strathdee, “Are quarks composite?”,  Phys. Lett. B 59 (1975) 265, 10.1016/0370-2693(75)90042-8.
  * [2] H. Terazawa, M. Yasuè, K. Akama, and M. Hayshi, “Observable effects of the possible substructure of leptons and quarks”,  Phys. Lett. B 112 (1982) 387, 10.1016/0370-2693(82)91075-9.
  * [3] E. Eichten, K. D. Lane, and M. E. Peskin, “New tests for quark and lepton substructure”,  Phys. Rev. Lett. 50 (1983) 811, 10.1103/PhysRevLett.50.811.
  * [4] H. Harari, “Composite models for quarks and leptons”,  Phys. Rept. 104 (1984) 159, 10.1016/0370-1573(84)90207-2.
  * [5] K. D. Lane, F. E. Paige, T. Skwarnicki, and W. J. Womersley, “Simulations of supercollider physics”,  Phys. Rept. 278 (1997) 291, 10.1016/S0370-1573(96)00018-X, arXiv:hep-ph/9412280.
  * [6] U. Baur, M. Spira, and P. M. Zerwas, “Excited quark and lepton production at hadron colliders”,  Phys. Rev. D 42 (1990) 815, 10.1103/PhysRevD.42.815.
  * [7] O. W. Greenberg and C. A. Nelson, “Composite models of leptons”,  Phys. Rev. D 10 (1974) 2567, 10.1103/PhysRevD.10.2567.
  * [8] O. W. Greenberg and J. Sucher, “A quantum structure dynamic model of quarks, leptons, weak vector bosons, and Higgs mesons”,  Phys. Lett. B 99 (1981) 339, 10.1016/0370-2693(81)90113-1.
  * [9] S. Biondini, R. Leonardi, O. Panella, and M. Presilla, “Perturbative unitarity bounds for effective composite models”,  Phys. Lett. B 795 (2019) 644, 10.1016/j.physletb.2019.134990, arXiv:1903.12285. [Erratum: 10.1016/j.physletb.2019.06.042].
  * [10] ALEPH Collaboration, “Search for excited leptons at 130–140 GeV”,  Phys. Lett. B 385 (1996) 445, 10.1016/0370-2693(96)00961-6.
  * [11] DELPHI Collaboration, “Search for composite and exotic fermions at LEP 2”,  Eur. Phys. J. C 8 (1999) 41, 10.1007/s100529901074, arXiv:hep-ex/9811005.
  * [12] OPAL Collaboration, “Search for unstable heavy and excited leptons at LEP 2”,  Eur. Phys. J. C 14 (2000) 73, 10.1007/s100520050734, arXiv:hep-ex/0001056.
  * [13] L3 Collaboration, “Search for excited leptons at LEP”,  Phys. Lett. B 568 (2003) 23, 10.1016/j.physletb.2003.05.004, arXiv:hep-ex/0306016.
  * [14] H1 Collaboration, “Search for excited electrons in $ep$ collisions at HERA”,  Phys. Lett. B 666 (2008) 131, 10.1016/j.physletb.2008.07.014, arXiv:0805.4530.
  * [15] CDF Collaboration, “Search for excited and exotic electrons in the $\mathrm{e}\gamma$ decay channel in $\rm{p}\overline{\rm p}$ collisions at $\sqrt{s}$ = 1.96 TeV”,  Phys. Rev. Lett. 94 (2005) 101802, 10.1103/PhysRevLett.94.101802, arXiv:hep-ex/0410013.
  * [16] CDF Collaboration, “Search for excited and exotic muons in the $\mu\gamma$ decay channel in $\rm{p}\overline{\rm p}$ collisions at $\sqrt{s}$ = 1.96”,  Phys. Rev. Lett. 97 (2006) 191802, 10.1103/PhysRevLett.97.191802, arXiv:hep-ex/0606043.
  * [17] D0 Collaboration, “Search for excited muons in ${p}\overline{p}$ collisions at $\sqrt{s}=1.96$ TeV”,  Phys. Rev. D 73 (2006) 111102, 10.1103/PhysRevD.73.111102, arXiv:hep-ex/0604040.
  * [18] D0 Collaboration, “Search for excited electrons in ${p}\overline{p}$ collisions at $\sqrt{s}=1.96$ TeV”,  Phys. Rev. D 77 (2008) 091102, 10.1103/PhysRevD.77.091102, arXiv:0801.0877.
  * [19] ATLAS Collaboration, “Search for excited electrons and muons in $\sqrt{s}=8$ TeV proton-proton collisions with the ATLAS detector”,  New J. Phys. 15 (2013) 093011, 10.1088/1367-2630/15/9/093011, arXiv:1308.1364.
  * [20] ATLAS Collaboration, “A search for an excited muon decaying to a muon and two jets in pp collisions at $\sqrt{s}=8$ TeV with the ATLAS detector”,  New J. Phys. 18 (2016) 073021, 10.1088/1367-2630/18/7/073021, arXiv:1601.05627.
  * [21] ATLAS Collaboration, “Search for excited electrons singly produced in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS experiment at the LHC”,  Eur. Phys. J. C 79 (2019) 803, 10.1140/epjc/s10052-019-7295-1, arXiv:1906.03204.
  * [22] CMS Collaboration, “Search for excited leptons in pp collisions at $\sqrt{s}=7$ TeV”,  Phys. Lett. B 720 (2013) 309, 10.1016/j.physletb.2013.02.031, arXiv:1210.2422.
  * [23] CMS Collaboration, “Search for excited leptons in proton-proton collisions at $\sqrt{s}=8$ TeV”,  JHEP 03 (2016) 125, 10.1007/JHEP03(2016)125, arXiv:1511.01407.
  * [24] CMS Collaboration, “Search for excited leptons in $\ell\ell\gamma$ final states in proton-proton collisions at $\sqrt{s}=13$ TeV”,  JHEP 04 (2019) 015, 10.1007/JHEP04(2019)015, arXiv:1811.03052.
  * [25] CMS Collaboration, “Performance of photon reconstruction and identification with the CMS detector in proton-proton collisions at $\sqrt{s}$ = 8 TeV”,  JINST 10 (2015) P08010, 10.1088/1748-0221/10/08/P08010, arXiv:1502.02702.
  * [26] CMS Collaboration, “Search for heavy narrow dilepton resonances in pp collisions at $\sqrt{s}=7$ TeV and $\sqrt{s}=8$ TeV”,  Phys. Lett. B 720 (2013) 63, 10.1016/j.physletb.2013.02.003, arXiv:1212.6175.
  * [27] CMS Collaboration, “Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $\sqrt{s}=13$ TeV”,  JINST 13 (2018) P06015, 10.1088/1748-0221/13/06/P06015, arXiv:1804.04528.
  * [28] CMS Collaboration, “Particle-flow reconstruction and global event description with the CMS detector”,  JINST 12 (2017) P10003, 10.1088/1748-0221/12/10/P10003, arXiv:1706.04965.
  * [29] CMS Collaboration, “The CMS trigger system”,  JINST 12 (2017) P01020, 10.1088/1748-0221/12/01/P01020, arXiv:1609.02366.
  * [30] CMS Collaboration, “The CMS experiment at the CERN LHC”,  JINST 3 (2008) S08004, 10.1088/1748-0221/3/08/S08004.
  * [31] T. Sjöstrand et al., “An introduction to 8.2”,  Comp. Phys. Comm. 191 (2015) 159, 10.1016/j.cpc.2015.01.024, arXiv:1410.3012.
  * [32] NNPDF Collaboration, “Parton distributions with LHC data”,  Nucl. Phys. B 867 (2013) 244, 10.1016/j.nuclphysb.2012.10.003, arXiv:1207.1303.
  * [33] NNPDF Collaboration, “Parton distributions from high-precision collider data”,  Eur. Phys. J. C 77 (2017) 663, 10.1140/epjc/s10052-017-5199-5, arXiv:1706.00428.
  * [34] CMS Collaboration, “Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements”,  Eur. Phys. J. C 80 (2020) 4, 10.1140/epjc/s10052-019-7499-4, arXiv:1903.12179.
  * [35] M. Cacciari, G. P. Salam, and G. Soyez, “The anti-jet clustering algorithm”,  JHEP 04 (2008) 063, 10.1088/1126-6708/2008/04/063, arXiv:0802.1189.
  * [36] M. Cacciari, G. P. Salam, and G. Soyez, “FastJet user manual”,  Eur. Phys. J. C 72 (2012) 1896, 10.1140/epjc/s10052-012-1896-2, arXiv:1111.6097.
  * [37] CMS Collaboration, “Search for high-mass resonances in dilepton final states in proton-proton collisions at $\sqrt{s}=$ 13 TeV”,  JHEP 06 (2018) 120, 10.1007/JHEP06(2018)120, arXiv:1803.06292.
  * [38] CMS Collaboration, “Performance of CMS muon reconstruction in pp collision events at $\sqrt{s}=7$ TeV”,  JINST 7 (2012) P10002, 10.1088/1748-0221/7/10/P10002, arXiv:1206.4071.
  * [39] CMS Collaboration, “Jet energy scale and resolution in the CMS experiment in pp collisions at 8 TeV”,  JINST 12 (2017) P02014, 10.1088/1748-0221/12/02/P02014, arXiv:1607.03663.
  * [40] J. Alwall et al., “The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations”,  JHEP 07 (2014) 079, 10.1007/JHEP07(2014)079, arXiv:1405.0301.
  * [41] R. Frederix and S. Frixione, “Merging meets matching in ”,  JHEP 12 (2012) 061, 10.1007/JHEP12(2012)061, arXiv:1209.6215.
  * [42] R. Gavin, Y. Li, F. Petriello, and S. Quackenbush, “FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order”,  Comput. Phys. Commun. 182 (2011) 2388, 10.1016/j.cpc.2011.06.008, arXiv:1011.3540.
  * [43] P. Nason, “A new method for combining NLO QCD with shower Monte Carlo algorithms”,  JHEP 11 (2004) 040, 10.1088/1126-6708/2004/11/040, arXiv:hep-ph/0409146.
  * [44] S. Frixione, P. Nason, and C. Oleari, “Matching NLO QCD computations with parton shower simulations: the method”,  JHEP 11 (2007) 070, 10.1088/1126-6708/2007/11/070, arXiv:0709.2092.
  * [45] S. Alioli, P. Nason, C. Oleari, and E. Re, “A general framework for implementing NLO calculations in shower Monte Carlo programs: the BOX”,  JHEP 06 (2010) 043, 10.1007/JHEP06(2010)043, arXiv:1002.2581.
  * [46] E. Re, “Single-top Wt-channel production matched with parton showers using the method”,  Eur. Phys. J. C 71 (2011) 1547, 10.1140/epjc/s10052-011-1547-z, arXiv:1009.2450.
  * [47] S. Frixione, P. Nason, and G. Ridolfi, “A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction”,  JHEP 09 (2007) 126, 10.1088/1126-6708/2007/09/126, arXiv:0707.3088.
  * [48] M. Czakon, P. Fiedler, and A. Mitov, “Total top-quark pair-production cross section at hadron colliders through $\mathcal{O}({\alpha}_{S}^{4})$”,  Phys. Rev. Lett. 110 (2013) 252004, 10.1103/PhysRevLett.110.252004.
  * [49] NNPDF Collaboration, “Parton distributions for the LHC Run II”,  JHEP 04 (2015) 040, 10.1007/JHEP04(2015)040, arXiv:1410.8849.
  * [50] S. Agostinelli et al., “—a simulation toolkit”,  Nucl. Instrum. Meth. A 506 (2003) 250, 10.1016/S0168-9002(03)01368-8.
  * [51] CMS Collaboration, “Search for high-mass resonances in final states with a lepton and missing transverse momentum at $\sqrt{s}=13$ TeV”,  JHEP 06 (2018) 128, 10.1007/JHEP06(2018)128, arXiv:1803.11133.
  * [52] CMS Collaboration, “Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at $\sqrt{s}$ = 8 TeV”,  JINST 10 (2015) P06005, 10.1088/1748-0221/10/06/P06005, arXiv:1502.02701.
  * [53] CMS Collaboration, “CMS Luminosity Measurements for the 2016 Data Taking Period”, CMS Physics Analysis Summary, CMS-PAS-LUM-17-001, CERN, Geneva, 2017.
  * [54] CMS Collaboration, “CMS Luminosity Measurements for the 2017 Data Taking Period at $\sqrt{s}=13$ TeV”, CMS Physics Analysis Summary, CMS-PAS-LUM-17-004, CERN, Geneva, 2017\.
  * [55] CMS Collaboration, “Measurement of the inelastic proton-proton cross section at $\sqrt{s}=13\TeV$”,  JHEP 07 (2018) 161, 10.1007/JHEP07(2018)161, arXiv:1802.02613.
  * [56] J. Butterworth et al., “PDF4LHC recommendations for LHC Run II”,  J. Phys. G 43 (2016) 023001, 10.1088/0954-3899/43/2/023001, arXiv:1510.03865.
  * [57] A. Buckley et al., “LHAPDF6: parton density access in the LHC precision era”,  Eur. Phys. J. C 75 (2015) 132, 10.1140/epjc/s10052-015-3318-8, arXiv:1412.7420.
  * [58] Particle Data Group, M. Tanabashi et al., “Review of particle physics”,  Phys. Rev. D 98 (2018) 030001, 10.1103/PhysRevD.98.030001.

##  .10 The CMS Collaboration

Yerevan Physics Institute, Yerevan, Armenia
A.M. Sirunyan${}^{\textrm{\textdagger}}$, A. Tumasyan Institut für
Hochenergiephysik, Wien, Austria
W. Adam, F. Ambrogi, T. Bergauer, J. Brandstetter, M. Dragicevic, J. Erö, A.
Escalante Del Valle, M. Flechl, R. Frühwirth1, M. Jeitler1, N. Krammer, I.
Krätschmer, D. Liko, T. Madlener, I. Mikulec, N. Rad, J. Schieck1, R.
Schöfbeck, M. Spanring, D. Spitzbart, W. Waltenberger, C.-E. Wulz1, M. Zarucki
Institute for Nuclear Problems, Minsk, Belarus
V. Drugakov, V. Mossolov, J. Suarez Gonzalez Universiteit Antwerpen,
Antwerpen, Belgium
M.R. Darwish, E.A. De Wolf, D. Di Croce, X. Janssen, J. Lauwers, A. Lelek, M.
Pieters, H. Rejeb Sfar, H. Van Haevermaet, P. Van Mechelen, S. Van Putte, N.
Van Remortel Vrije Universiteit Brussel, Brussel, Belgium
F. Blekman, E.S. Bols, S.S. Chhibra, J. D’Hondt, J. De Clercq, 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, L. Favart, A. Grebenyuk, A.K. Kalsi, J. Luetic, A. Popov, N. Postiau,
E. Starling, L. Thomas, C. Vander Velde, P. Vanlaer, D. Vannerom, Q. Wang
Ghent University, Ghent, Belgium
T. Cornelis, D. Dobur, I. Khvastunov2, C. Roskas, D. Trocino, M. Tytgat, W.
Verbeke, B. Vermassen, M. Vit, N. Zaganidis Université Catholique de Louvain,
Louvain-la-Neuve, Belgium
O. Bondu, G. Bruno, C. Caputo, P. David, C. Delaere, M. Delcourt, A.
Giammanco, V. Lemaitre, A. Magitteri, J. Prisciandaro, A. Saggio, M. Vidal
Marono, P. Vischia, J. Zobec Centro Brasileiro de Pesquisas Fisicas, Rio de
Janeiro, Brazil
F.L. Alves, G.A. Alves, G. Correia Silva, C. Hensel, A. Moraes, 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, C. De Oliveira Martins, S.
Fonseca De Souza, L.M. Huertas Guativa, H. Malbouisson, J. Martins5, D. Matos
Figueiredo, M. Medina Jaime6, M. Melo De Almeida, C. Mora Herrera, L. Mundim,
H. Nogima, W.L. Prado Da Silva, 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, D.S. Lemos, P.G. Mercadanteb, S.F. Novaesa, SandraS. Padulaa
Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of
Sciences, Sofia, Bulgaria
A. Aleksandrov, G. Antchev, R. Hadjiiska, P. Iaydjiev, A. Marinov, M. Misheva,
M. Rodozov, M. Shopova, G. Sultanov University of Sofia, Sofia, Bulgaria
M. Bonchev, A. Dimitrov, T. Ivanov, L. Litov, B. Pavlov, P. Petkov Beihang
University, Beijing, China
W. Fang7, X. Gao7, L. Yuan Department of Physics, Tsinghua University,
Beijing, China
Z. Hu, Y. Wang Institute of High Energy Physics, Beijing, China
M. Ahmad, G.M. Chen, H.S. Chen, M. Chen, C.H. Jiang, D. Leggat, H. Liao, Z.
Liu, S.M. Shaheen8, A. Spiezia, J. Tao, E. Yazgan, H. Zhang, S. Zhang8, J.
Zhao State Key Laboratory of Nuclear Physics and Technology, Peking
University, Beijing, China
A. Agapitos, Y. Ban, G. Chen, A. Levin, J. Li, L. Li, Q. Li, Y. Mao, S.J.
Qian, D. Wang Universidad de Los Andes, Bogota, Colombia
C. Avila, A. Cabrera, L.F. Chaparro Sierra, C. Florez, C.F. González
Hernández, M.A. Segura Delgado Universidad de Antioquia, Medellin, Colombia
J. Mejia Guisao, J.D. Ruiz Alvarez, C.A. Salazar González, N. Vanegas Arbelaez
University of Split, Faculty of Electrical Engineering, Mechanical Engineering
and Naval Architecture, Split, Croatia
D. Giljanović, N. Godinovic, D. Lelas, I. Puljak, T. Sculac University of
Split, Faculty of Science, Split, Croatia
Z. Antunovic, M. Kovac Institute Rudjer Boskovic, Zagreb, Croatia
V. Brigljevic, S. Ceci, D. Ferencek, K. Kadija, B. Mesic, M. Roguljic, A.
Starodumov9, T. Susa University of Cyprus, Nicosia, Cyprus
M.W. Ather, A. Attikis, E. Erodotou, A. Ioannou, M. Kolosova, S. Konstantinou,
G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis, H.
Rykaczewski, D. Tsiakkouri Charles University, Prague, Czech Republic
M. Finger10, M. Finger Jr.10, A. Kveton, J. Tomsa Escuela Politecnica
Nacional, Quito, Ecuador
E. Ayala 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
Y. Assran11,12, S. Elgammal12 National Institute of Chemical Physics and
Biophysics, Tallinn, Estonia
S. Bhowmik, A. Carvalho Antunes De Oliveira, R.K. Dewanjee, K. Ehataht, M.
Kadastik, M. Raidal, C. Veelken Department of Physics, University of Helsinki,
Helsinki, Finland
P. Eerola, L. Forthomme, H. Kirschenmann, K. Osterberg, M. Voutilainen
Helsinki Institute of Physics, Helsinki, Finland
F. Garcia, 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, B. Fabbro, J.L. Faure, F.
Ferri, S. Ganjour, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry,
C. Leloup, E. Locci, J. Malcles, J. Rander, A. Rosowsky, M.Ö. Sahin, A. Savoy-
Navarro13, M. Titov Laboratoire Leprince-Ringuet, CNRS/IN2P3, Ecole
Polytechnique, Institut Polytechnique de Paris
C. Amendola, F. Beaudette, P. Busson, C. Charlot, B. Diab, G. Falmagne, R.
Granier de Cassagnac, I. Kucher, A. Lobanov, C. Martin Perez, M. Nguyen, C.
Ochando, P. Paganini, J. Rembser, R. Salerno, J.B. Sauvan, Y. Sirois, A. Zabi,
A. Zghiche Université de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France
J.-L. Agram14, J. Andrea, D. Bloch, G. Bourgatte, J.-M. Brom, E.C. Chabert, C.
Collard, E. Conte14, J.-C. Fontaine14, D. Gelé, U. Goerlach, M. Jansová, 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, C. Camen, N. Chanon, R. Chierici, D.
Contardo, P. Depasse, H. El Mamouni, J. Fay, S. Gascon, M. Gouzevitch, B.
Ille, Sa. Jain, F. Lagarde, I.B. Laktineh, H. Lattaud, M. Lethuillier, L.
Mirabito, S. Perries, V. Sordini, G. Touquet, M. Vander Donckt, S. Viret
Georgian Technical University, Tbilisi, Georgia
T. Toriashvili15 Tbilisi State University, Tbilisi, Georgia
Z. Tsamalaidze10 RWTH Aachen University, I. Physikalisches Institut, Aachen,
Germany
C. Autermann, L. Feld, M.K. Kiesel, K. Klein, M. Lipinski, D. Meuser, A.
Pauls, M. Preuten, M.P. Rauch, C. Schomakers, J. Schulz, M. Teroerde, B.
Wittmer RWTH Aachen University, III. Physikalisches Institut A, Aachen,
Germany
A. Albert, M. Erdmann, S. Erdweg, T. Esch, B. Fischer, R. Fischer, S. Ghosh,
T. Hebbeker, K. Hoepfner, H. Keller, L. Mastrolorenzo, M. Merschmeyer, A.
Meyer, P. Millet, G. Mocellin, S. Mondal, S. Mukherjee, D. Noll, A. Novak, T.
Pook, A. Pozdnyakov, T. Quast, M. Radziej, Y. Rath, H. Reithler, M. Rieger, J.
Roemer, A. Schmidt, S.C. Schuler, A. Sharma, S. Thüer, S. Wiedenbeck RWTH
Aachen University, III. Physikalisches Institut B, Aachen, Germany
G. Flügge, W. Haj Ahmad16, O. Hlushchenko, T. Kress, T. Müller, A. Nehrkorn,
A. Nowack, C. Pistone, O. Pooth, D. Roy, H. Sert, A. Stahl17 Deutsches
Elektronen-Synchrotron, Hamburg, Germany
M. Aldaya Martin, P. Asmuss, I. Babounikau, H. Bakhshiansohi, K. Beernaert, O.
Behnke, U. Behrens, A. Bermúdez Martínez, D. Bertsche, A.A. Bin Anuar, K.
Borras18, V. Botta, A. Campbell, A. Cardini, P. Connor, S. Consuegra
Rodríguez, C. Contreras-Campana, V. Danilov, A. De Wit, M.M. Defranchis, C.
Diez Pardos, D. Domínguez Damiani, G. Eckerlin, D. Eckstein, T. Eichhorn, A.
Elwood, E. Eren, E. Gallo19, A. Geiser, J.M. Grados Luyando, A. Grohsjean, M.
Guthoff, M. Haranko, A. Harb, A. Jafari, N.Z. Jomhari, H. Jung, A. Kasem18, M.
Kasemann, H. Kaveh, J. Keaveney, C. Kleinwort, J. Knolle, D. Krücker, W.
Lange, T. Lenz, J. Leonard, J. Lidrych, K. Lipka, W. Lohmann20, R. Mankel,
I.-A. Melzer-Pellmann, A.B. Meyer, M. Meyer, M. Missiroli, G. Mittag, J.
Mnich, A. Mussgiller, V. Myronenko, D. Pérez Adán, S.K. Pflitsch, D. Pitzl, A.
Raspereza, A. Saibel, M. Savitskyi, V. Scheurer, P. Schütze, C.
Schwanenberger, R. Shevchenko, A. Singh, H. Tholen, O. Turkot, A. Vagnerini,
M. Van De Klundert, G.P. Van Onsem, R. Walsh, Y. Wen, K. Wichmann, C. Wissing,
O. Zenaiev, R. Zlebcik University of Hamburg, Hamburg, Germany
R. Aggleton, S. Bein, L. Benato, A. Benecke, V. Blobel, T. Dreyer, A.
Ebrahimi, A. Fröhlich, C. Garbers, E. Garutti, D. Gonzalez, P. Gunnellini, J.
Haller, A. Hinzmann, A. Karavdina, G. Kasieczka, R. Klanner, R. Kogler, N.
Kovalchuk, S. Kurz, V. Kutzner, J. Lange, T. Lange, A. Malara, D. Marconi, J.
Multhaup, M. Niedziela, C.E.N. Niemeyer, D. Nowatschin, A. Perieanu, A.
Reimers, O. Rieger, C. Scharf, P. Schleper, S. Schumann, J. Schwandt, J.
Sonneveld, H. Stadie, G. Steinbrück, F.M. Stober, M. Stöver, B. Vormwald, I.
Zoi Karlsruher Institut fuer Technologie, Karlsruhe, Germany
M. Akbiyik, C. Barth, M. Baselga, S. Baur, T. Berger, E. Butz, R. Caspart, T.
Chwalek, W. De Boer, A. Dierlamm, K. El Morabit, N. Faltermann, M. Giffels, P.
Goldenzweig, A. Gottmann, M.A. Harrendorf, F. Hartmann17, U. Husemann, S.
Kudella, S. Mitra, M.U. Mozer, Th. Müller, M. Musich, A. Nürnberg, G. Quast,
K. Rabbertz, M. Schröder, I. Shvetsov, H.J. Simonis, R. Ulrich, M. Weber, C.
Wöhrmann, R. Wolf Institute of Nuclear and Particle Physics (INPP), NCSR
Demokritos, Aghia Paraskevi, Greece
G. Anagnostou, P. Asenov, G. Daskalakis, T. Geralis, A. Kyriakis, D. Loukas,
G. Paspalaki National and Kapodistrian University of Athens, Athens, Greece
M. Diamantopoulou, G. Karathanasis, P. Kontaxakis, A. Panagiotou, I.
Papavergou, N. Saoulidou, A. Stakia, K. Theofilatos, K. Vellidis National
Technical University of Athens, Athens, Greece
G. Bakas, K. Kousouris, I. Papakrivopoulos, G. Tsipolitis University of
Ioánnina, Ioánnina, Greece
I. Evangelou, C. Foudas, P. Gianneios, P. Katsoulis, P. Kokkas, S. Mallios, K.
Manitara, N. Manthos, I. Papadopoulos, J. Strologas, F.A. Triantis, D.
Tsitsonis MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös
Loránd University, Budapest, Hungary
M. Bartók21, M. Csanad, P. Major, K. Mandal, A. Mehta, M.I. Nagy, G. Pasztor,
O. Surányi, G.I. Veres Wigner Research Centre for Physics, Budapest, Hungary
G. Bencze, C. Hajdu, D. Horvath22, F. Sikler, T.Á. Vámi, V. Veszpremi, G.
Vesztergombi${}^{\textrm{\textdagger}}$ Institute of Nuclear Research ATOMKI,
Debrecen, Hungary
N. Beni, S. Czellar, J. Karancsi21, A. Makovec, J. Molnar, Z. Szillasi
Institute of Physics, University of Debrecen, Debrecen, Hungary
P. Raics, D. Teyssier, Z.L. Trocsanyi, B. Ujvari Eszterhazy Karoly University,
Karoly Robert Campus, Gyongyos, Hungary
T. Csorgo, W.J. Metzger, F. Nemes, T. Novak Indian Institute of Science
(IISc), Bangalore, India
S. Choudhury, J.R. Komaragiri, P.C. Tiwari National Institute of Science
Education and Research, HBNI, Bhubaneswar, India
S. Bahinipati24, C. Kar, G. Kole, P. Mal, V.K. Muraleedharan Nair Bindhu, A.
Nayak25, D.K. Sahoo24, 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, P. Kumari, M. Lohan, M. Meena, K. Sandeep,
S. Sharma, J.B. Singh, A.K. Virdi, G. Walia University of Delhi, Delhi, India
A. Bhardwaj, B.C. Choudhary, R.B. Garg, M. Gola, S. Keshri, Ashok Kumar, S.
Malhotra, M. Naimuddin, P. Priyanka, K. Ranjan, Aashaq Shah, R. Sharma Saha
Institute of Nuclear Physics, HBNI, Kolkata, India
R. Bhardwaj26, M. Bharti26, R. Bhattacharya, S. Bhattacharya, U. Bhawandeep26,
D. Bhowmik, S. Dey, S. Dutta, S. Ghosh, M. Maity27, K. Mondal, S. Nandan, A.
Purohit, P.K. Rout, G. Saha, S. Sarkar, T. Sarkar27, M. Sharan, B. Singh26, S.
Thakur26 Indian Institute of Technology Madras, Madras, India
P.K. Behera, P. Kalbhor, A. Muhammad, P.R. Pujahari, A. Sharma, A.K. Sikdar
Bhabha Atomic Research Centre, Mumbai, India
R. Chudasama, D. Dutta, V. Jha, V. Kumar, D.K. Mishra, P.K. Netrakanti, L.M.
Pant, P. Shukla Tata Institute of Fundamental Research-A, Mumbai, India
T. Aziz, M.A. Bhat, S. Dugad, G.B. Mohanty, N. Sur, RavindraKumar Verma Tata
Institute of Fundamental Research-B, Mumbai, India
S. Banerjee, S. Bhattacharya, S. Chatterjee, P. Das, M. Guchait, S. Karmakar,
S. Kumar, G. Majumder, K. Mazumdar, N. Sahoo, S. Sawant Indian Institute of
Science Education and Research (IISER), Pune, India
S. Chauhan, S. Dube, V. Hegde, A. Kapoor, K. Kothekar, S. Pandey, A. Rane, A.
Rastogi, 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, F. Rezaei Hosseinabadi 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, L. Fiorea, A. Gelmia,b, G.
Iasellia,c, M. Incea,b, S. Lezkia,b, G. Maggia,c, M. Maggia, G. Minielloa,b,
S. Mya,b, S. Nuzzoa,b, A. Pompilia,b, G. Pugliesea,c, R. Radognaa, A.
Ranieria, G. Selvaggia,b, L. Silvestrisa, R. Vendittia, P. Verwilligena 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,
C. Cioccaa, G. Codispotia,b, M. Cuffiania,b, G.M. Dallavallea, F. Fabbria, A.
Fanfania,b, E. Fontanesi, P. Giacomellia, C. Grandia, L. Guiduccia,b, F.
Iemmia,b, S. Lo Meoa,29, S. Marcellinia, G. Masettia, F.L. Navarriaa,b, A.
Perrottaa, F. Primaveraa,b, 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,30, S. Costaa,b, A. Di Mattiaa, R. Potenzaa,b, A. Tricomia,b,30,
C. Tuvea,b INFN Sezione di Firenze a, Università di Firenze b, Firenze, Italy
G. Barbaglia, R. Ceccarelli, K. Chatterjeea,b, V. Ciullia,b, C. Civininia, R.
D’Alessandroa,b, E. Focardia,b, G. Latino, P. Lenzia,b, M. Meschinia, S.
Paolettia, G. Sguazzonia, D. Stroma, L. Viliania INFN Laboratori Nazionali di
Frascati, Frascati, Italy
L. Benussi, S. Bianco, D. Piccolo INFN Sezione di Genova a, Università di
Genova b, Genova, Italy
M. Bozzoa,b, F. Ferroa, R. Mulargiaa,b, E. Robuttia, S. Tosia,b INFN Sezione
di Milano-Bicocca a, Università di Milano-Bicocca b, Milano, Italy
A. Benagliaa, A. Beschia,b, F. Brivioa,b, V. Cirioloa,b,17, S. Di Guidaa,b,17,
M.E. Dinardoa,b, P. Dinia, S. Fiorendia,b, S. Gennaia, A. Ghezzia,b, P.
Govonia,b, L. Guzzia,b, M. Malbertia, S. Malvezzia, D. Menascea, F. Montia,b,
L. Moronia, G. Ortonaa,b, M. Paganonia,b, D. Pedrinia, S. Ragazzia,b, T.
Tabarelli de Fatisa,b, D. Zuoloa,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, A. De Iorioa,b, A. Di Crescenzoa,b, F.
Fabozzia,c, F. Fiengaa, G. Galatia, A.O.M. Iorioa,b, L. Listaa,b, S.
Meolaa,d,17, P. Paoluccia,17, B. Rossia, C. Sciaccaa,b, E. Voevodinaa,b INFN
Sezione di Padova a, Università di Padova b, Padova, Italy, Università di
Trento c, Trento, Italy
P. Azzia, N. Bacchettaa, D. Biselloa,b, A. Bolettia,b, A. Bragagnolo, R.
Carlina,b, P. Checchiaa, P. De Castro Manzanoa, T. Dorigoa, U. Dossellia, F.
Gasparinia,b, U. Gasparinia,b, A. Gozzelinoa, S.Y. Hoh, P. Lujan, M.
Margonia,b, A.T. Meneguzzoa,b, J. Pazzinia,b, M. Presillab, P. Ronchesea,b, R.
Rossina,b, F. Simonettoa,b, A. Tiko, M. Tosia,b, M. Zanettia,b, P. Zottoa,b,
G. Zumerlea,b INFN Sezione di Pavia a, Università di Pavia b, Pavia, Italy
A. Braghieria, 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
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, G. Bagliesia, V. Bertacchia,c, L. Bianchinia, T.
Boccalia, R. Castaldia, M.A. Cioccia,b, R. Dell’Orsoa, G. Fedia, L.
Gianninia,c, A. Giassia, M.T. Grippoa, F. Ligabuea,c, E. Mancaa,c, G.
Mandorlia,c, A. Messineoa,b, F. Pallaa, A. Rizzia,b, G. Rolandi31, S. Roy
Chowdhury, A. Scribanoa, P. Spagnoloa, R. Tenchinia, G. Tonellia,b, N. Turini,
A. Venturia, P.G. Verdinia INFN Sezione di Roma a, Sapienza Università di Roma
b, Rome, Italy
F. Cavallaria, M. Cipriania,b, D. Del Rea,b, E. Di Marcoa,b, M. Diemoza, E.
Longoa,b, B. Marzocchia,b, P. Meridiania, G. Organtinia,b, F. Pandolfia, R.
Paramattia,b, C. Quarantaa,b, S. Rahatloua,b, C. Rovellia, F.
Santanastasioa,b, L. Soffia,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, A. Cappatia,b, N. Cartigliaa, S. Comettia, M.
Costaa,b, R. Covarellia,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, R. Salvaticoa,b, V.
Solaa, A. Solanoa,b, D. Soldia,b, A. Staianoa INFN Sezione di Trieste a,
Università di Trieste b, Trieste, Italy
S. Belfortea, V. Candelisea,b, M. Casarsaa, F. Cossuttia, A. Da Rolda,b, G.
Della Riccaa,b, F. Vazzolera,b, A. Zanettia Kyungpook National University,
Daegu, Korea
B. Kim, D.H. Kim, G.N. Kim, M.S. Kim, J. Lee, S.W. Lee, C.S. Moon, Y.D. Oh,
S.I. Pak, 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
B. Francois, T.J. Kim, J. Park Korea University, Seoul, Korea
S. Cho, S. Choi, Y. Go, D. Gyun, S. Ha, B. Hong, K. Lee, K.S. Lee, J. Lim, J.
Park, S.K. Park, Y. Roh Kyung Hee University, Department of Physics
J. Goh Sejong University, Seoul, Korea
H.S. Kim Seoul National University, Seoul, Korea
J. Almond, J.H. Bhyun, J. Choi, S. Jeon, J. Kim, J.S. Kim, H. Lee, K. Lee, S.
Lee, K. Nam, M. Oh, S.B. Oh, B.C. Radburn-Smith, U.K. Yang, H.D. Yoo, I. Yoon,
G.B. Yu University of Seoul, Seoul, Korea
D. Jeon, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, I. Watson Sungkyunkwan
University, Suwon, Korea
Y. Choi, C. Hwang, Y. Jeong, J. Lee, Y. Lee, I. Yu Riga Technical University,
Riga, Latvia
V. Veckalns32 Vilnius University, Vilnius, Lithuania
V. Dudenas, A. Juodagalvis, G. Tamulaitis, J. Vaitkus National Centre for
Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia
Z.A. Ibrahim, F. Mohamad Idris33, W.A.T. Wan Abdullah, M.N. Yusli, Z. Zolkapli
Universidad de Sonora (UNISON), Hermosillo, Mexico
J.F. Benitez, A. Castaneda Hernandez, J.A. Murillo Quijada, L. Valencia Palomo
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz34, R. Lopez-
Fernandez, A. Sanchez-Hernandez Universidad Iberoamericana, Mexico City,
Mexico
S. Carrillo Moreno, C. Oropeza Barrera, M. Ramirez-Garcia, 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 Montenegro, Podgorica, Montenegro
N. Raicevic 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, W.A. Khan, M.A. Shah, M. Shoaib,
M. Waqas AGH University of Science and Technology Faculty of Computer Science,
Electronics and Telecommunications, Krakow, Poland
V. Avati, L. Grzanka, M. Malawski National Centre for Nuclear Research,
Swierk, Poland
H. Bialkowska, M. Bluj, B. Boimska, M. Górski, M. Kazana, M. Szleper, P.
Zalewski Institute of Experimental Physics, Faculty of Physics, University of
Warsaw, Warsaw, Poland
K. Bunkowski, A. Byszuk35, 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
M. Araujo, P. Bargassa, D. Bastos, A. Di Francesco, P. Faccioli, B. Galinhas,
M. Gallinaro, J. Hollar, N. Leonardo, J. Seixas, K. Shchelina, G. Strong, O.
Toldaiev, J. Varela Joint Institute for Nuclear Research, Dubna, Russia
A. Baginyan, Y. Ershov, A. Golunov, I. Golutvin, I. Gorbunov, V. Karjavine, I.
Kashunin, V. Korenkov, A. Lanev, A. Malakhov, V. Matveev36,37, P. Moisenz, V.
Palichik, V. Perelygin, M. Savina, S. Shmatov, S. Shulha, O. Teryaev, N.
Voytishin, A. Zarubin Petersburg Nuclear Physics Institute, Gatchina (St.
Petersburg), Russia
L. Chtchipounov, V. Golovtsov, Y. Ivanov, V. Kim38, E. Kuznetsova39, P.
Levchenko, V. Murzin, V. Oreshkin, I. Smirnov, D. Sosnov, V. Sulimov, L.
Uvarov, 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 named by A.I. Alikhanov of NRC ‘Kurchatov Institute’,
Moscow, Russia
V. Epshteyn, V. Gavrilov, N. Lychkovskaya, A. Nikitenko40, V. Popov, I.
Pozdnyakov, G. Safronov, A. Spiridonov, A. Stepennov, M. Toms, E. Vlasov, A.
Zhokin Moscow Institute of Physics and Technology, Moscow, Russia
T. Aushev National Research Nuclear University ’Moscow Engineering Physics
Institute’ (MEPhI), Moscow, Russia
M. Chadeeva41, P. Parygin, D. Philippov, E. Popova, V. Rusinov P.N. Lebedev
Physical Institute, Moscow, Russia
V. Andreev, M. Azarkin, I. Dremin, M. Kirakosyan, A. Terkulov Skobeltsyn
Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow,
Russia
A. Baskakov, A. Belyaev, E. Boos, V. Bunichev, M. Dubinin42, L. Dudko, A.
Ershov, V. Klyukhin, O. Kodolova, I. Lokhtin, S. Obraztsov, V. Savrin, A.
Snigirev Novosibirsk State University (NSU), Novosibirsk, Russia
A. Barnyakov43, V. Blinov43, T. Dimova43, L. Kardapoltsev43, Y. Skovpen43
Institute for High Energy Physics of National Research Centre ‘Kurchatov
Institute’, Protvino, Russia
I. Azhgirey, I. Bayshev, S. Bitioukov, V. Kachanov, D. Konstantinov, P.
Mandrik, V. Petrov, R. Ryutin, S. Slabospitskii, A. Sobol, S. Troshin, N.
Tyurin, A. Uzunian, A. Volkov National Research Tomsk Polytechnic University,
Tomsk, Russia
A. Babaev, A. Iuzhakov, V. Okhotnikov Tomsk State University, Tomsk, Russia
V. Borchsh, V. Ivanchenko, E. Tcherniaev University of Belgrade: Faculty of
Physics and VINCA Institute of Nuclear Sciences
P. Adzic44, P. Cirkovic, D. Devetak, M. Dordevic, P. Milenovic, J. Milosevic,
M. Stojanovic Centro de Investigaciones Energéticas Medioambientales y
Tecnológicas (CIEMAT), Madrid, Spain
M. Aguilar-Benitez, J. Alcaraz Maestre, A. Álvarez Fernández, I. Bachiller, M.
Barrio Luna, J.A. Brochero Cifuentes, C.A. Carrillo Montoya, M. Cepeda, 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, Á. Navarro Tobar, A. Pérez-Calero Yzquierdo,
J. Puerta Pelayo, I. Redondo, L. Romero, S. Sánchez Navas, M.S. Soares, A.
Triossi, C. Willmott Universidad Autónoma de Madrid, Madrid, Spain
C. Albajar, J.F. de Trocóniz Universidad de Oviedo, Instituto Universitario de
Ciencias y Tecnologías Espaciales de Asturias (ICTEA), Oviedo, Spain
B. Alvarez Gonzalez, J. Cuevas, C. Erice, J. Fernandez Menendez, S. Folgueras,
I. Gonzalez Caballero, J.R. González Fernández, E. Palencia Cortezon, V.
Rodríguez Bouza, S. Sanchez Cruz 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, G. Gomez, C. Martinez
Rivero, P. Martinez Ruiz del Arbol, F. Matorras, J. Piedra Gomez, C. Prieels,
T. Rodrigo, A. Ruiz-Jimeno, L. Russo45, L. Scodellaro, N. Trevisani, I. Vila,
J.M. Vizan Garcia University of Colombo, Colombo, Sri Lanka
K. Malagalage University of Ruhuna, Department of Physics, Matara, Sri Lanka
W.G.D. Dharmaratna, N. Wickramage CERN, European Organization for Nuclear
Research, Geneva, Switzerland
D. Abbaneo, B. Akgun, E. Auffray, G. Auzinger, J. Baechler, P. Baillon, A.H.
Ball, D. Barney, J. Bendavid, M. Bianco, A. Bocci, E. Bossini, C. Botta, E.
Brondolin, T. Camporesi, A. Caratelli, G. Cerminara, E. Chapon, G. Cucciati,
D. d’Enterria, A. Dabrowski, N. Daci, V. Daponte, A. David, O. Davignon, A. De
Roeck, N. Deelen, M. Deile, M. Dobson, M. Dünser, N. Dupont, A. Elliott-
Peisert, F. Fallavollita46, D. Fasanella, G. Franzoni, J. Fulcher, W. Funk, S.
Giani, D. Gigi, A. Gilbert, K. Gill, F. Glege, M. Gruchala, M. Guilbaud, D.
Gulhan, J. Hegeman, C. Heidegger, Y. Iiyama, V. Innocente, P. Janot, O.
Karacheban20, J. Kaspar, J. Kieseler, M. Krammer1, C. Lange, P. Lecoq, C.
Lourenço, L. Malgeri, M. Mannelli, A. Massironi, F. Meijers, J.A. Merlin, S.
Mersi, E. Meschi, F. Moortgat, M. Mulders, J. Ngadiuba, S. Nourbakhsh, S.
Orfanelli, L. Orsini, F. Pantaleo17, L. Pape, E. Perez, M. Peruzzi, A.
Petrilli, G. Petrucciani, A. Pfeiffer, M. Pierini, F.M. Pitters, D. Rabady, A.
Racz, M. Rovere, H. Sakulin, C. Schäfer, C. Schwick, M. Selvaggi, A. Sharma,
P. Silva, W. Snoeys, P. Sphicas47, J. Steggemann, V.R. Tavolaro, D. Treille,
A. Tsirou, A. Vartak, M. Verzetti, W.D. Zeuner Paul Scherrer Institut,
Villigen, Switzerland
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, P. Berger, N. Chernyavskaya, G. Dissertori, M. Dittmar, M.
Donegà, C. Dorfer, T.A. Gómez Espinosa, C. Grab, D. Hits, T. Klijnsma, W.
Lustermann, R.A. Manzoni, M. Marionneau, M.T. Meinhard, F. Micheli, P.
Musella, F. Nessi-Tedaldi, F. Pauss, G. Perrin, L. Perrozzi, S. Pigazzini, M.
Reichmann, C. Reissel, T. Reitenspiess, D. Ruini, D.A. Sanz Becerra, M.
Schönenberger, L. Shchutska, 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, B. Kilminster, S. Leontsinis, V.M. Mikuni, I. Neutelings, G.
Rauco, P. Robmann, D. Salerno, K. Schweiger, C. Seitz, Y. Takahashi, S. Wertz,
A. Zucchetta National Central University, Chung-Li, Taiwan
T.H. Doan, C.M. Kuo, W. Lin, A. Roy, S.S. Yu National Taiwan University (NTU),
Taipei, Taiwan
P. Chang, Y. Chao, K.F. Chen, P.H. Chen, W.-S. Hou, Y.y. Li, R.-S. Lu, E.
Paganis, A. Psallidas, A. Steen Chulalongkorn University, Faculty of Science,
Department of Physics, Bangkok, Thailand
B. Asavapibhop, C. Asawatangtrakuldee, N. Srimanobhas, N. Suwonjandee Çukurova
University, Physics Department, Science and Art Faculty, Adana, Turkey
A. Bat, F. Boran, S. Cerci50, S. Damarseckin51, Z.S. Demiroglu, F. Dolek, C.
Dozen, I. Dumanoglu, E. Eskut, G. Gokbulut, EmineGurpinar Guler52, Y. Guler,
I. Hos53, C. Isik, E.E. Kangal54, O. Kara, A. Kayis Topaksu, U. Kiminsu, M.
Oglakci, G. Onengut, K. Ozdemir55, S. Ozturk56, A.E. Simsek, U.G. Tok, S.
Turkcapar, I.S. Zorbakir, C. Zorbilmez Middle East Technical University,
Physics Department, Ankara, Turkey
B. Isildak57, G. Karapinar58, M. Yalvac Bogazici University, Istanbul, Turkey
I.O. Atakisi, E. Gülmez, M. Kaya59, O. Kaya60, B. Kaynak, Ö. Özçelik, S.
Tekten, E.A. Yetkin61 Istanbul Technical University, Istanbul, Turkey
A. Cakir, K. Cankocak, Y. Komurcu, S. Sen62 Istanbul University, Istanbul,
Turkey
S. Ozkorucuklu 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, E. Bhal, S. Bologna, J.J. Brooke, D. Burns, E. Clement, D. Cussans,
H. Flacher, J. Goldstein, G.P. Heath, H.F. Heath, L. Kreczko, S. Paramesvaran,
B. Penning, T. Sakuma, S. Seif El Nasr-Storey, D. Smith, V.J. Smith, J.
Taylor, A. Titterton Rutherford Appleton Laboratory, Didcot, United Kingdom
K.W. Bell, A. Belyaev63, C. Brew, R.M. Brown, D. Cieri, D.J.A. Cockerill, J.A.
Coughlan, K. Harder, S. Harper, J. Linacre, K. Manolopoulos, D.M. Newbold, E.
Olaiya, D. Petyt, T. Reis, T. Schuh, C.H. Shepherd-Themistocleous, A. Thea,
I.R. Tomalin, T. Williams, W.J. Womersley Imperial College, London, United
Kingdom
R. Bainbridge, P. Bloch, J. Borg, S. Breeze, O. Buchmuller, A. Bundock,
GurpreetSingh CHAHAL64, D. Colling, P. Dauncey, G. Davies, M. Della Negra, R.
Di Maria, P. Everaerts, G. Hall, G. Iles, T. James, M. Komm, C. Laner, L.
Lyons, A.-M. Magnan, S. Malik, A. Martelli, V. Milosevic, J. Nash65, V.
Palladino, M. Pesaresi, D.M. Raymond, A. Richards, A. Rose, E. Scott, C. Seez,
A. Shtipliyski, M. Stoye, T. Strebler, S. Summers, A. Tapper, K. Uchida, T.
Virdee17, N. Wardle, D. Winterbottom, J. Wright, A.G. Zecchinelli, S.C. Zenz
Brunel University, Uxbridge, United Kingdom
J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, C.K. Mackay, A. Morton, I.D. Reid,
L. Teodorescu, S. Zahid Baylor University, Waco, USA
K. Call, J. Dittmann, K. Hatakeyama, C. Madrid, B. McMaster, N. Pastika, C.
Smith Catholic University of America, Washington, DC, USA
R. Bartek, A. Dominguez, R. Uniyal The University of Alabama, Tuscaloosa, USA
A. Buccilli, S.I. Cooper, C. Henderson, P. Rumerio, C. West Boston University,
Boston, USA
D. Arcaro, T. Bose, Z. Demiragli, D. Gastler, S. Girgis, D. Pinna, C.
Richardson, J. Rohlf, D. Sperka, I. Suarez, L. Sulak, D. Zou Brown University,
Providence, USA
G. Benelli, B. Burkle, X. Coubez, D. Cutts, Y.t. Duh, M. Hadley, J. Hakala, U.
Heintz, J.M. Hogan66, K.H.M. Kwok, E. Laird, G. Landsberg, J. Lee, Z. Mao, M.
Narain, S. Sagir67, R. Syarif, E. Usai, D. Yu University of California, Davis,
Davis, USA
R. Band, C. Brainerd, R. Breedon, M. Calderon De La Barca Sanchez, M. Chertok,
J. Conway, R. Conway, P.T. Cox, R. Erbacher, C. Flores, G. Funk, F. Jensen, W.
Ko, O. Kukral, R. Lander, M. Mulhearn, D. Pellett, J. Pilot, M. Shi, 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, W.A. Nash, S. Regnard, D. Saltzberg, C. Schnaible, B.
Stone, V. Valuev University of California, Riverside, Riverside, USA
K. Burt, R. Clare, J.W. Gary, S.M.A. Ghiasi Shirazi, G. Hanson, G.
Karapostoli, E. Kennedy, O.R. Long, M. Olmedo Negrete, M.I. Paneva, W. Si, L.
Wang, H. Wei, S. Wimpenny, B.R. Yates, Y. Zhang University of California, San
Diego, La Jolla, USA
J.G. Branson, P. Chang, S. Cittolin, M. Derdzinski, R. Gerosa, D. Gilbert, B.
Hashemi, D. Klein, V. Krutelyov, J. Letts, M. Masciovecchio, S. May, S. Padhi,
M. Pieri, V. Sharma, M. Tadel, F. Würthwein, A. Yagil, G. Zevi Della Porta
University of California, Santa Barbara - Department of Physics, Santa
Barbara, USA
N. Amin, R. Bhandari, C. Campagnari, M. Citron, V. Dutta, M. Franco Sevilla,
L. Gouskos, J. Incandela, B. Marsh, H. Mei, A. Ovcharova, H. Qu, J. Richman,
U. Sarica, D. Stuart, S. Wang, J. Yoo California Institute of Technology,
Pasadena, USA
D. Anderson, A. Bornheim, O. Cerri, I. Dutta, J.M. Lawhorn, N. Lu, J. Mao,
H.B. Newman, T.Q. Nguyen, J. Pata, M. Spiropulu, J.R. Vlimant, S. Xie, Z.
Zhang, R.Y. Zhu Carnegie Mellon University, Pittsburgh, USA
M.B. Andrews, T. Ferguson, T. Mudholkar, M. Paulini, M. Sun, I. Vorobiev, M.
Weinberg University of Colorado Boulder, Boulder, USA
J.P. Cumalat, W.T. Ford, A. Johnson, E. MacDonald, T. Mulholland, R. Patel, A.
Perloff, K. Stenson, K.A. Ulmer, S.R. Wagner Cornell University, Ithaca, USA
J. Alexander, J. Chaves, Y. Cheng, J. Chu, A. Datta, A. Frankenthal, K.
Mcdermott, N. Mirman, J.R. Patterson, D. Quach, A. Rinkevicius68, A. Ryd, S.M.
Tan, Z. Tao, J. Thom, 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, 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, AllisonReinsvold Hall, J. Hanlon, R.M.
Harris, S. Hasegawa, R. Heller, J. Hirschauer, B. Jayatilaka, S. Jindariani,
M. Johnson, U. Joshi, B. Klima, M.J. Kortelainen, B. Kreis, S. Lammel, J.
Lewis, D. Lincoln, R. Lipton, M. Liu, T. Liu, J. Lykken, K. Maeshima, J.M.
Marraffino, D. Mason, P. McBride, P. Merkel, S. Mrenna, S. Nahn, V. O’Dell, V.
Papadimitriou, K. Pedro, C. Pena, G. Rakness, F. Ravera, L. Ristori, B.
Schneider, E. Sexton-Kennedy, N. Smith, 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
University of Florida, Gainesville, USA
D. Acosta, P. Avery, P. Bortignon, D. Bourilkov, A. Brinkerhoff, L. Cadamuro,
A. Carnes, V. Cherepanov, D. Curry, F. Errico, R.D. Field, S.V. Gleyzer, B.M.
Joshi, M. Kim, J. Konigsberg, A. Korytov, K.H. Lo, P. Ma, K. Matchev, N.
Menendez, G. Mitselmakher, D. Rosenzweig, K. Shi, J. Wang, S. Wang, X. Zuo
Florida International University, Miami, USA
Y.R. Joshi Florida State University, Tallahassee, USA
T. Adams, A. Askew, S. Hagopian, V. Hagopian, K.F. Johnson, R. Khurana, T.
Kolberg, G. Martinez, T. Perry, H. Prosper, C. Schiber, R. Yohay, J. Zhang
Florida Institute of Technology, Melbourne, USA
M.M. Baarmand, V. Bhopatkar, M. Hohlmann, D. Noonan, M. Rahmani, M. Saunders,
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, C.
Mills, T. Roy, M.B. Tonjes, N. Varelas, H. Wang, X. Wang, Z. Wu The University
of Iowa, Iowa City, USA
M. Alhusseini, B. Bilki52, W. Clarida, K. Dilsiz69, S. Durgut, R.P.
Gandrajula, M. Haytmyradov, V. Khristenko, O.K. Köseyan, J.-P. Merlo, A.
Mestvirishvili70, A. Moeller, J. Nachtman, H. Ogul71, Y. Onel, F. Ozok72, A.
Penzo, C. Snyder, E. Tiras, J. Wetzel 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, M. Swartz, M. Xiao The University of
Kansas, Lawrence, USA
C. Baldenegro Barrera, P. Baringer, A. Bean, S. Boren, J. Bowen, A. Bylinkin,
T. Isidori, S. Khalil, J. King, G. Krintiras, A. Kropivnitskaya, C. Lindsey,
D. Majumder, W. Mcbrayer, N. Minafra, M. Murray, C. Rogan, C. Royon, S.
Sanders, E. Schmitz, J.D. Tapia Takaki, Q. Wang, J. Williams, G. Wilson Kansas
State University, Manhattan, USA
S. Duric, A. Ivanov, K. Kaadze, D. Kim, Y. Maravin, D.R. Mendis, T. Mitchell,
A. Modak, A. Mohammadi 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, N.J. Hadley, S. Jabeen,
G.Y. Jeng, R.G. Kellogg, J. Kunkle, A.C. Mignerey, S. Nabili, F. Ricci-Tam, M.
Seidel, Y.H. Shin, A. Skuja, S.C. Tonwar, K. Wong Massachusetts Institute of
Technology, Cambridge, USA
D. Abercrombie, B. Allen, A. Baty, R. Bi, S. Brandt, W. Busza, I.A. Cali, M.
D’Alfonso, G. Gomez Ceballos, M. Goncharov, P. Harris, D. Hsu, M. Hu, M.
Klute, D. Kovalskyi, Y.-J. Lee, P.D. Luckey, B. Maier, A.C. Marini, C. Mcginn,
C. Mironov, S. Narayanan, X. Niu, C. Paus, D. Rankin, C. Roland, G. Roland, Z.
Shi, G.S.F. Stephans, K. Sumorok, K. Tatar, D. Velicanu, J. Wang, T.W. Wang,
B. Wyslouch University of Minnesota, Minneapolis, USA
A.C. Benvenuti${}^{\textrm{\textdagger}}$, R.M. Chatterjee, A. Evans, S. Guts,
P. Hansen, J. Hiltbrand, Sh. Jain, S. Kalafut, Y. Kubota, Z. Lesko, J. Mans,
R. Rusack, M.A. Wadud University of Mississippi, Oxford, USA
J.G. Acosta, S. Oliveros University of Nebraska-Lincoln, Lincoln, USA
K. Bloom, D.R. Claes, C. Fangmeier, L. Finco, F. Golf, R. Gonzalez Suarez, R.
Kamalieddin, I. Kravchenko, J.E. Siado, G.R. Snow, B. Stieger State University
of New York at Buffalo, Buffalo, USA
G. Agarwal, C. Harrington, I. Iashvili, A. Kharchilava, C. Mclean, D. Nguyen,
A. Parker, J. Pekkanen, S. Rappoccio, B. Roozbahani Northeastern University,
Boston, USA
G. Alverson, E. Barberis, C. Freer, Y. Haddad, A. Hortiangtham, G. Madigan,
D.M. Morse, T. Orimoto, L. Skinnari, A. Tishelman-Charny, T. Wamorkar, B.
Wang, A. Wisecarver, D. Wood Northwestern University, Evanston, USA
S. Bhattacharya, J. Bueghly, T. Gunter, K.A. Hahn, N. Odell, M.H. Schmitt, K.
Sung, M. Trovato, M. Velasco University of Notre Dame, Notre Dame, USA
R. Bucci, N. Dev, R. Goldouzian, M. Hildreth, K. Hurtado Anampa, C. Jessop,
D.J. Karmgard, K. Lannon, W. Li, N. Loukas, N. Marinelli, I. Mcalister, F.
Meng, C. Mueller, Y. Musienko36, M. Planer, R. Ruchti, P. Siddireddy, G.
Smith, S. Taroni, M. Wayne, A. Wightman, M. Wolf, A. Woodard The Ohio State
University, Columbus, USA
J. Alimena, B. Bylsma, L.S. Durkin, S. Flowers, B. Francis, C. Hill, W. Ji, A.
Lefeld, T.Y. Ling, B.L. Winer Princeton University, Princeton, USA
S. Cooperstein, G. Dezoort, P. Elmer, J. Hardenbrook, N. Haubrich, S.
Higginbotham, A. Kalogeropoulos, S. Kwan, D. Lange, M.T. Lucchini, J. Luo, D.
Marlow, K. Mei, I. Ojalvo, J. Olsen, C. Palmer, P. Piroué, J. Salfeld-Nebgen,
D. Stickland, C. Tully, Z. Wang 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,
B. Mahakud, D.H. Miller, G. Negro, N. Neumeister, C.C. Peng, S. Piperov, 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
K.M. Ecklund, S. Freed, F.J.M. Geurts, M. Kilpatrick, Arun Kumar, W. Li, B.P.
Padley, R. Redjimi, J. Roberts, J. Rorie, W. Shi, A.G. Stahl Leiton, Z. Tu, A.
Zhang University of Rochester, Rochester, USA
A. Bodek, P. de Barbaro, R. Demina, J.L. Dulemba, C. Fallon, T. Ferbel, M.
Galanti, A. Garcia-Bellido, J. Han, O. Hindrichs, A. Khukhunaishvili, E.
Ranken, P. Tan, R. Taus Rutgers, The State University of New Jersey,
Piscataway, USA
B. Chiarito, J.P. Chou, A. Gandrakota, Y. Gershtein, E. Halkiadakis, A. Hart,
M. Heindl, E. Hughes, S. Kaplan, S. Kyriacou, I. Laflotte, A. Lath, R.
Montalvo, K. Nash, M. Osherson, H. Saka, S. Salur, S. Schnetzer, D. Sheffield,
S. Somalwar, R. Stone, S. Thomas, P. Thomassen University of Tennessee,
Knoxville, USA
H. Acharya, A.G. Delannoy, J. Heideman, G. Riley, S. Spanier Texas A&M
University, College Station, USA
O. Bouhali73, A. Celik, M. Dalchenko, M. De Mattia, A. Delgado, S. Dildick, R.
Eusebi, J. Gilmore, T. Huang, T. Kamon74, S. Luo, D. Marley, R. Mueller, D.
Overton, L. Perniè, D. Rathjens, A. Safonov Texas Tech University, Lubbock,
USA
N. Akchurin, J. Damgov, F. De Guio, S. Kunori, K. Lamichhane, S.W. Lee, T.
Mengke, S. Muthumuni, T. Peltola, S. Undleeb, I. Volobouev, Z. Wang, A.
Whitbeck Vanderbilt University, Nashville, USA
S. Greene, A. Gurrola, R. Janjam, W. Johns, C. Maguire, A. Melo, H. Ni, K.
Padeken, F. Romeo, P. Sheldon, S. Tuo, J. Velkovska, M. Verweij University of
Virginia, Charlottesville, USA
M.W. Arenton, P. Barria, B. Cox, G. Cummings, R. Hirosky, M. Joyce, A.
Ledovskoy, C. Neu, B. Tannenwald, 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
J. Buchanan, C. Caillol, D. Carlsmith, S. Dasu, I. De Bruyn, L. Dodd, F.
Fiori, C. Galloni, B. Gomber75, M. Herndon, A. Hervé, U. Hussain, P. Klabbers,
A. Lanaro, A. Loeliger, K. Long, R. Loveless, J. Madhusudanan Sreekala, T.
Ruggles, A. Savin, V. Sharma, W.H. Smith, D. Teague, S. Trembath-reichert, 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 UFMS, Nova Andradina, Brazil
6: Also at Universidade Federal de Pelotas, Pelotas, Brazil
7: Also at Université Libre de Bruxelles, Bruxelles, Belgium
8: Also at University of Chinese Academy of Sciences, Beijing, China
9: Also at Institute for Theoretical and Experimental Physics named by A.I.
Alikhanov of NRC ‘Kurchatov Institute’, Moscow, Russia
10: Also at Joint Institute for Nuclear Research, Dubna, Russia
11: Also at Suez University, Suez, Egypt
12: Now at British University in Egypt, Cairo, Egypt
13: Also at Purdue University, West Lafayette, USA
14: Also at Université de Haute Alsace, Mulhouse, France
15: Also at Tbilisi State University, Tbilisi, Georgia
16: Also at Erzincan Binali Yildirim University, Erzincan, Turkey
17: Also at CERN, European Organization for Nuclear Research, Geneva,
Switzerland
18: Also at RWTH Aachen University, III. Physikalisches Institut A, Aachen,
Germany
19: Also at University of Hamburg, Hamburg, Germany
20: Also at Brandenburg University of Technology, Cottbus, Germany
21: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary,
Debrecen, Hungary
22: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary
23: Also at MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös
Loránd University, Budapest, Hungary, Budapest, Hungary
24: Also at IIT Bhubaneswar, Bhubaneswar, India, Bhubaneswar, India
25: Also at Institute of Physics, Bhubaneswar, India
26: Also at Shoolini University, Solan, India
27: Also at University of Visva-Bharati, Santiniketan, India
28: Also at Isfahan University of Technology, Isfahan, Iran
29: Also at Italian National Agency for New Technologies, Energy and
Sustainable Economic Development, Bologna, Italy
30: Also at Centro Siciliano di Fisica Nucleare e di Struttura Della Materia,
Catania, Italy
31: Also at Scuola Normale e Sezione dell’INFN, Pisa, Italy
32: Also at Riga Technical University, Riga, Latvia, Riga, Latvia
33: Also at Malaysian Nuclear Agency, MOSTI, Kajang, Malaysia
34: Also at Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico
35: Also at Warsaw University of Technology, Institute of Electronic Systems,
Warsaw, Poland
36: Also at Institute for Nuclear Research, Moscow, Russia
37: Now at National Research Nuclear University ’Moscow Engineering Physics
Institute’ (MEPhI), Moscow, Russia
38: Also at St. Petersburg State Polytechnical University, St. Petersburg,
Russia
39: Also at University of Florida, Gainesville, USA
40: Also at Imperial College, London, United Kingdom
41: Also at P.N. Lebedev Physical Institute, Moscow, Russia
42: Also at California Institute of Technology, Pasadena, USA
43: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia
44: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia
45: Also at Università degli Studi di Siena, Siena, Italy
46: Also at INFN Sezione di Pavia a, Università di Pavia b, Pavia, Italy,
Pavia, Italy
47: Also at National and Kapodistrian University of Athens, Athens, Greece
48: Also at Universität Zürich, Zurich, Switzerland
49: Also at Stefan Meyer Institute for Subatomic Physics, Vienna, Austria,
Vienna, Austria
50: Also at Adiyaman University, Adiyaman, Turkey
51: Also at Şırnak University, Sirnak, Turkey
52: Also at Beykent University, Istanbul, Turkey, Istanbul, Turkey
53: Also at Istanbul Aydin University, Application and Research Center for
Advanced Studies (App. & Res. Cent. for Advanced Studies), Istanbul, Turkey
54: Also at Mersin University, Mersin, Turkey
55: Also at Piri Reis University, Istanbul, Turkey
56: Also at Gaziosmanpasa University, Tokat, Turkey
57: Also at Ozyegin University, Istanbul, Turkey
58: Also at Izmir Institute of Technology, Izmir, Turkey
59: Also at Marmara University, Istanbul, Turkey
60: Also at Kafkas University, Kars, Turkey
61: Also at Istanbul Bilgi University, Istanbul, Turkey
62: Also at Hacettepe University, Ankara, Turkey
63: Also at School of Physics and Astronomy, University of Southampton,
Southampton, United Kingdom
64: Also at IPPP Durham University, Durham, United Kingdom
65: Also at Monash University, Faculty of Science, Clayton, Australia
66: Also at Bethel University, St. Paul, Minneapolis, USA, St. Paul, USA
67: Also at Karamanoğlu Mehmetbey University, Karaman, Turkey
68: Also at Vilnius University, Vilnius, Lithuania
69: Also at Bingol University, Bingol, Turkey
70: Also at Georgian Technical University, Tbilisi, Georgia
71: Also at Sinop University, Sinop, Turkey
72: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey
73: Also at Texas A&M University at Qatar, Doha, Qatar
74: Also at Kyungpook National University, Daegu, Korea, Daegu, Korea
75: Also at University of Hyderabad, Hyderabad, India