2017 318 1 December Relative particle yield fluctuations in Pb–Pb collisions
ALICE Collaboration††thanks: See Appendix A for the list of collaboration
members ALICE Collaboration

First results on K/$\pi$, p/$\pi$ and K/p fluctuations are obtained with the
ALICE detector at the CERN LHC as a function of centrality in Pb–Pb collisions
at $\sqrt{s_{\rm{NN}}}$ $=2.76$ TeV. The observable $\nu_{\rm dyn}$, which is
defined in terms of the moments of particle multiplicity distributions, is
used to quantify the magnitude of dynamical fluctuations of relative particle
yields and also provides insight into the correlation between particle pairs.
This study is based on a novel experimental technique, called the Identity
Method, which allows one to measure the moments of multiplicity distributions
in case of incomplete particle identification. The results for p/$\pi$ show a
change of sign in $\nu_{\rm dyn}$ from positive to negative towards more
peripheral collisions. For central collisions, the results follow the smooth
trend of the data at lower energies and $\nu_{\rm dyn}$ exhibits a change in
sign for p/$\pi$ and K/p.

##  1 Introduction

The theory of strong interactions, Quantum Chromodynamics (QCD), predicts that
at sufficiently high energy density nuclear matter transforms into a
deconfined state of quarks and gluons known as Quark-Gluon Plasma (QGP) [1,
2]. One of the possible signatures of a transition between the hadronic and
partonic phases is the enhancement of fluctuations of the number of produced
particles in the hadronic final state of relativistic heavy-ion collisions [3,
4, 5]. Event-by-event fluctuations and correlations may show critical
behaviour near the phase boundary, including the crossover region where there
is no thermal singularity, in a strict sense, associated with the transition
from a QGP phase to a hadron-gas phase. A correlation analysis of event-by-
event abundances of pions, kaons and protons produced in Pb–Pb collisions at
LHC energies may provide a connection to fluctuations of globally conserved
quantities such as electric charge, strangeness and baryon number, and
therefore shed light on the phase structure of strongly interacting matter
[6].

In view of the predicted criticality signals at crossover for vanishing net-
baryon densities [7], event-by-event fluctuations of relative particle yields
are studied using the fluctuation measure $\nu_{\rm dyn}[A,B]$ [8] defined in
terms of moments of particle multiplicity distributions as

$\nu_{\rm dyn}[A,B]=\dfrac{\langle N_{A}(N_{A}-1)\rangle}{{\langle
N_{A}\rangle}^{2}}+\dfrac{\langle N_{B}(N_{B}-1)\rangle}{{\langle
N_{B}\rangle}^{2}}-2\dfrac{\langle N_{A}N_{B}\rangle}{\langle
N_{A}\rangle\langle N_{B}\rangle},$ (1)

where $N_{A}$ and $N_{B}$ are the multiplicities of particles $A$ and $B$
measured event-by-event in a given kinematic range. The $\nu_{\rm
dyn}[A,B]$111In this study, $\nu_{\rm dyn}[A,B]$ was taken to be $\nu_{\rm
dyn}[A+\overline{A},B+\overline{B}]$, where $\overline{A}$ and $\overline{B}$
are the anti-particles of $A$ and $B$, respectively. fluctuation measure
contrasts the relative strength of fluctuations of species $A$ and $B$ to the
relative strength of correlations between these two species. It vanishes when
the particles $A$ and $B$ are produced in a statistically independent way [8,
9].

This study at LHC energies is of particular importance for establishing the
energy and system size dependence of $\nu_{\rm dyn}$ in order to understand
the trend observed at lower collision energies from the RHIC Beam Energy Scan
(BES) results reported by the STAR collaboration [10]. Furthermore, the
advantage of this fluctuation measurement is its robustness against non-
dynamical contributions such as those stemming from participant nucleon
fluctuations and finite particle detection efficiencies [8, 11]. Measurements
of the $\nu_{\rm dyn}$ observable for net-charge fluctuations were already
published by ALICE [12]. Moreover, for identified particles, it was measured
at the Super Proton Synchrotron (SPS) [13] and at the Relativistic Heavy-Ion
Collider (RHIC) [10] in Pb–Pb and Au–Au collisions, respectively. The ALICE
detector at the LHC is ideally suited to extend these measurements to higher
collision energies. In particular, the excellent charged-particle tracking and
particle identification (PID) capabilities in the central barrel of the
detector allow for a precise and differential event-by-event analysis at
midrapidity and low transverse momentum ($p_{\rm T}$).

The paper is organized as follows. In Section 2, details about the ALICE
detector setup and the dataset are given. Section 3 discusses the event and
track selection criteria, particle identification procedure, and the analysis
method. Estimates of statistical and systematic uncertainties are given in
Section 4. Results on $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$,
$\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ and $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$
in Pb–Pb collisions at $\sqrt{s_{\rm{NN}}}$ $=2.76$ TeV are presented in
Section 5, and finally Section 6 summarizes the measurements presented in this
paper.

##  2 Experimental setup and dataset

ALICE is a general-purpose detector system designed, in particular, for the
study of collisions of heavy ions at the LHC. The design, components, and
performance of the ALICE detector have been reported elsewhere [14, 15]. The
ALICE detector is comprised of several detector components organized into a
central barrel detection system and forward/backward detectors. The main
tracking and PID devices in the central barrel of the experiment are the Inner
Tracking System (ITS) and the Time Projection Chamber (TPC), which are
operated inside a large solenoidal magnet with $B=0.5$ T. Two forward
scintillator arrays V0-A and V0-C are located on either side of the
interaction point and cover the pseudorapidity ($\eta$) intervals
$2.8<\eta<5.1$ and $-3.7<\eta<-1.7$. The V0 detectors and the two neutron Zero
Degree Calorimeters (ZDC), placed at $\pm$114 m from the interaction point,
were used for triggering and event selection.

The ITS-TPC tracking system covers the midrapidity region and provides
charged-particle tracking and momentum reconstruction down to $p_{\rm T}=100$
MeV/$c$. The ITS is employed to reconstruct the collision vertex with high
precision and to reject charged particles produced in secondary vertices.

The analysis presented in this paper is based on about 13 million minimum-bias
Pb–Pb collisions at $\sqrt{s_{\rm{NN}}}$ $=2.76$ TeV collected in the year
2010. The minimum-bias trigger condition is defined by the coincidence of hits
in both V0 detectors. In the offline event selection, V0 and ZDC timing
information is used to reject beam-gas background and parasitic beam-beam
interactions. The definition of the collision centrality is based on the
charged-particle multiplicity measured in the V0 detectors [14], which can be
related to collision geometry and the number of participating nucleons through
a Monte-Carlo (MC) simulation based on a Glauber model [16].

##  3 Data analysis

###  3.1 Event and track selection

Charged particles reconstructed in the TPC with full azimuthal acceptance and
in the pseudorapidity range of $|\eta|<$0.8 were used in this analysis. The
momentum range was restricted to $0.2<p<1.5$ GeV/$c$ in order to minimize
systematic uncertainties arising from the overlap of the d$E$/d$x$
distributions. Furthermore, the following track selection criteria were
applied to guarantee optimal d$E$/d$x$ and momentum resolution, which are
crucial for precise particle identification. Charged-particle tracks were
accepted in this analysis when they have at least 80 out of a maximum of 159
reconstructed space points in the TPC, and the $\chi^{2}$ per space point from
the track fit is less than 4. Daughter tracks from reconstructed secondary
weak-decay kink topologies were rejected. Additional suppression of secondary
particles was achieved by restricting the distance-of-closest-approach (DCA)
of the extrapolated trajectory to the primary vertex position to less than 2
cm along the beam direction. In the transverse plane the restriction in the
DCA depends on $p_{\rm T}$ in order to take into account the $p_{\rm T}$
dependence of the impact parameter resolution [17]. The remaining
contamination after the DCA cuts is typically less than 10% for the momentum
range covered in this work [18].

###  3.2 Identity Method

The standard approach of finding the moments $\langle N_{A}\rangle$, $\langle
N_{B}\rangle$, $\langle N_{A}(N_{A}-1)\rangle$ and $\langle
N_{B}(N_{B}-1)\rangle$ is to count the number of particles $N_{A}$ and $N_{B}$
event-by-event and calculate averages over the dataset. However, this approach
suffers from incomplete particle identification due to overlapping d$E$/d$x$
distribution functions, which could be circumvented by either selecting
suitable phase-space regions or by using additional detector information such
as time-of-flight measurements. These procedures reduce the overall phase-
space coverage and detection efficiencies. The present study is based on the
Identity Method [19, 20, 21] which overcomes the misidentification problem.

Figure 1: Distributions of $\omega$ and $W$ for pions (top), kaons (middle)
and protons (bottom) in the momentum interval of $0.3<p<0.8$ GeV/$c$ for 0–5%
central Pb–Pb events.

The Identity Method was proposed in Ref. [19] as a solution to the
misidentification problem for the analysis of events with two different
particle species. In Ref. [20], the method was developed further to calculate
the second moments of the multiplicity distributions of more than two particle
species. Subsequently, in Ref. [21], it was generalized to the first and
higher moments of the multiplicity distributions for an arbitrary number of
particle species. The first experimental results using the Identity Method
were published by the NA49 collaboration [13].

Instead of counting every detected particle event-by-event, the Identity
Method follows a probabilistic approach using two basic experimental per-track
and per-event observables, $\omega$ and $W$, respectively. They are defined as

$\omega_{j}(x_{i})=\dfrac{\rho_{j}(x_{i})}{\rho(x_{i})}\in[0,1],\quad\rho(x_{i})=\sum_{j}\rho_{j}(x_{i}),\quad
W_{j}\equiv\sum_{i=1}^{N(n)}\omega_{j}(x_{i}),$ (2)

where $x_{i}$ stands for the d$E$/d$x$ of a given track $i$, $\rho_{j}(x)$ is
the d$E$/d$x$ distribution of particle species $j$ within a given phase-space
bin and $N(n)$ is the number of tracks in the $n^{\rm th}$ event. The quantity
$\omega_{j}(x_{i})$ represents the probability that particle $i$ is of type
$j$. Thus, in case of perfect particle identification, one expects
$W_{j}=N_{j}$, while this does not hold in case of overlapping d$E$/d$x$
distributions. Figure 1 shows the $\omega$ and $W$ distributions for pions,
kaons and protons in the momentum interval of $0.3<p<0.8$ GeV/$c$. The $W$
distribution of protons shows a discrete structure because proton d$E$/d$x$
distributions have the least overlap.

The moments of the $W$ distributions can be constructed directly from
experimental data. The Identity Method calculates the moments of the particle
multiplicity distributions by unfolding the moments of the $W$ distributions
with the following matrix operation

$\langle\overrightarrow{N}\rangle=\textrm{A}^{-1}\langle\overrightarrow{W}\rangle,$
(3)

where $\langle\overrightarrow{W}\rangle$ and
$\langle\overrightarrow{N}\rangle$ are the vectors of the moments of $W$
quantities and unknown true multiplicity distributions, respectively. The
response matrix A is defined by the $\omega$ quantities. A detailed
description of the technique and a demonstration of its robustness can be
found in Refs [20, 21].

The d$E$/d$x$ measurements used as the only input for the Identity Method are
obtained from the TPC, which provides a momentum resolution of better than 2%
and a single-particle detection efficiency of up to 80% for the kinematic
range considered in this paper [14]. The Identity Method employs fits of
inclusive d$E$/d$x$ distributions for the calculation of the $\omega$
probabilities entering Eq. 3. Since the overlap regions in the d$E$/d$x$
distributions are also properly taken into account, a very good description of
the inclusive d$E$/d$x$ spectra, and therefore an excellent understanding of
the TPC detector response, is required over the full momentum range covered in
this analysis. To this end, the d$E$/d$x$ distributions of pre-selected
samples of pions, protons and electrons, identified by the reconstruction of
$\mathrm{K}_{S}^{0}$ and $\varLambda$ decays and photon conversions, were
fitted with a generalized Gaussian function of the form:

$f(x)=Ae^{-{\left(|x-\mu|/\sigma\right)}^{\beta}}{\left(1+\textrm{erf}\left(\alpha\dfrac{|x-\mu|}{\sigma\sqrt{2}}\right)\right)}$
(4)

where $A$, $\mu$, $\sigma$, $\alpha$ and $\beta$ stand for the abundance,
mean, width, skewness and kurtosis of the distribution, respectively. The
detector response functions obtained in this way were used later to fit the
inclusive d$E$/d$x$ spectra. To cope with the dependencies of the d$E$/d$x$ on
the track angle and particle multiplicity, fits were performed over the entire
pseudorapidity range of $|\eta|<0.8$ in steps of 0.1 units for each centrality
class. Moreover, the momentum intervals were chosen narrow enough to minimize
the effect of the momentum dependence on d$E$/d$x$, most particularly at low
momenta where the magnitude of d$E$/d$x$ varies rapidly with the momentum. An
example of a d$E$/d$x$ distribution in a given phase-space bin and the
corresponding fits are shown in Fig. 2.

Figure 2: Distributions of the TPC d$E$/d$x$ signal of pions, kaons, electrons
and protons fitted with the generalized Gaussian function in a given phase-
space bin. The residuals are defined as the difference between data points and
the total fit function normalized to the statistical error of the data points.

##  4 Statistical and systematic uncertainties

The statistical uncertainties were determined by the number of events in this
analysis and the finite number of tracks in each event. The number of events
also affects the uncertainty of the shape of the inclusive d$E$/d$x$ spectra,
which is determined by a fit. This uncertainty enters the calculation of
$\omega$ and $W$, and finally the computation of the moments of multiplicity
distributions with the Identity Method. Since standard error propagation is
impractical given the rather complicated numerical derivation of the final
result, the subsample method was chosen to evaluate the statistical
uncertainties. To this end, the data set was subdivided into $n=$ 25 random
subsamples $i$. The $\nu_{\rm dyn}$ values were reconstructed for each
subsample and the statistical uncertainty was obtained according to

$\sigma_{\langle\nu_{\mathrm{dyn}}\rangle}=\dfrac{\sigma}{\sqrt{n}},$ (5)

where

$\sigma=\sqrt{\dfrac{\sum_{i}(\nu_{\mathrm{dyn},i}-\langle\nu_{\mathrm{dyn}}\rangle)^{2}}{n-1}},\quad\quad\langle\nu_{\mathrm{dyn}}\rangle=\dfrac{1}{n}\sum_{i}\nu_{\mathrm{dyn},i}.$
(6)

The summary of all sources of systematic uncertainties is shown in Table 1 and
in the next paragraphs the main contributors to the systematics are detailed.

The largest contribution to the total systematic uncertainty is from the fits
of the measured particle d$E$/d$x$ distributions. The quality of the fits was
monitored by Kolmogorov-Smirnov (K-S) and $\chi^{2}$ tests. To study the
influence of possible systematic shifts in the fit parameters on $\nu_{\rm
dyn}$, the fit parameters of each particle in the overlap regions were varied
by about $\pm$0.5 %, which defines the boundaries where the K-S test fails at
90% confidence level. The observed maximum variations range from about 7% to
15% for $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ and $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$,
respectively.

Even though $\nu_{\rm dyn}$ is known to be robust against detection-efficiency
losses, it may show an explicit dependence if the detector response functions
differ from Binomial or the efficiencies exhibit large variations with
detector occupancy [8]. Therefore, one also has to investigate the uncertainty
resulting from the detection efficiency losses. For that, the $\nu_{\rm dyn}$
results reconstructed from a full Monte Carlo simulation of HIJING [22, 23]
events employing a GEANT3 [24] implementation of the ALICE detector were
compared to the analysis at the generator level, where in both generated and
reconstructed levels perfect PID information was used. The resulting
systematic uncertainty from the finite tracking efficiency is less than 6%.

Table 1: List of contributions to the systematic uncertainty of the particle
ratio fluctuations.

Uncertainty source |  $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ (%) |  $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ (%) |  $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$ (%)
---|---|---|---
Inclusive d$E$/d$x$ fits | 10–15 | 4–7 | 8–12
Detection efficiency | 0.5–6 | 0.5–4 | 0.5–5
DCA to vertex | 1–4 | 1–2 | 1–3
Vertex $z$ position | 0.5–2 | 0.5–1 | 0.5–2
TPC $\chi^{2}/d.o.f.$ | 1–3 | 1–2 | 1–3
Min. TPC space points | 0.5–3 | 0.5–2 | 0.5–3
B-field polarity | 0.5–2 | 0.5–1 | 0.5–2
Total systematic uncertainty | 10–17 | 4–9 | 8–14

The systematic uncertainties due to the track selection criteria were
estimated by a variation of the selection ranges. The systematics from
contamination of weak decays and other secondary particles were obtained by
varying the DCA cuts. Other contributions to the total systematic uncertainty
arise from the cuts applied on the maximum distance of the reconstructed
vertex to the nominal interaction point along the beam axis, the number of
required TPC space points per track and the $\chi^{2}$ per degree of freedom
of the track fit. Moreover, the effect of the magnetic field polarity was
investigated by separate analyses of data taken under two polarities. Neither
of these contributions to the total systematic uncertainty exceeds 5%. The
total systematic uncertainty was obtained by adding in quadrature the
individual maximum systematic variations from these different contributions.

##  5 Results

###  5.1 Centrality dependence and comparison to models

In this section, the results are presented as a function of collision
centrality and compared to calculations with the HIJING [22, 23] and AMPT [25]
models. The unscaled values of $\nu_{\rm dyn}$ for different combinations of
particles in each centrality class, together with the final statistical and
systematic uncertainties, are given in Table 2. Due to the intrinsic
multiplicity dependence of $\nu_{\rm dyn}$, discussed in Refs [26, 27], the
values of $\nu_{\rm dyn}$ were scaled further by the charged-particle
multiplicity density at midrapidity, d$N_{\rm ch}/$d$\eta$. The fully
corrected experimental d$N_{\rm ch}/$d$\eta$ values were taken from Ref [18].
Figure 3 shows measured values of $\nu_{\rm dyn}$ scaled by d$N_{\rm
ch}/$d$\eta$ as a function of the collision centrality expressed in terms of
d$N_{\rm ch}/$d$\eta$. The values for $\nu_{\rm dyn}$ and d$N_{\rm
ch}/$d$\eta$ for HIJING and AMPT were calculated by using corresponding
particle multiplicities at the generator level within the same experimental
acceptance. A flat behaviour is expected in this representation if a
superposition of independent particle sources is assumed, as in the Wounded
Nucleon Model (WNM) [28].

Table 2: Numerical values of $\nu_{\rm dyn}$ results for different particle
pairs. The first uncertainty is statistical and the second systematic.

Centrality (%) |  $\langle$d$N_{\rm ch}/$d$\eta$ $\rangle$ |  $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ ($10^{-3}$) |  $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ ($10^{-3}$) |  $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$ ($10^{-3}$)
---|---|---|---|---
0–5 | 1601$\pm$60 | 1.35 $\pm$0.08 $\pm$0.25 | 0.59 $\pm$0.08 $\pm$0.13 | 0.59 $\pm$0.08 $\pm$0.13
5–10 | 1294$\pm$49 | 1.22 $\pm$0.08 $\pm$0.22 | 0.19 $\pm$0.08 $\pm$0.06 | 0.46 $\pm$0.10 $\pm$0.11
10–20 | 966$\pm$37 | 1.35 $\pm$0.08 $\pm$0.21 | 0.38 $\pm$0.08 $\pm$0.12 | 0.98 $\pm$0.10 $\pm$0.17
20–30 | 649$\pm$23 | 1.69 $\pm$0.09 $\pm$0.21 | 0.29 $\pm$0.09 $\pm$0.15 | 1.76 $\pm$0.13 $\pm$0.34
30–40 | 426$\pm$15 | 2.27 $\pm$0.11 $\pm$0.25 | 0.01 $\pm$0.18 $\pm$0.18 | 2.39 $\pm$0.24 $\pm$0.40
40–50 | 261$\pm$9 | 3.52 $\pm$0.16 $\pm$0.37 | -0.49 $\pm$0.18 $\pm$0.22 | 3.64 $\pm$0.32 $\pm$0.57
50–60 | 149$\pm$6 | 6.43 $\pm$0.26 $\pm$0.96 | -1.38 $\pm$0.24 $\pm$0.29 | 6.54 $\pm$0.47 $\pm$0.92
60–70 | 76$\pm$4 | 11.91 $\pm$0.53 $\pm$2.1 | -4.90 $\pm$0.58 $\pm$0.56 | 10.34 $\pm$1.0 $\pm$1.8
70–80 | 35$\pm$2 | 29.99 $\pm$1.2 $\pm$4.0 | -16.02 $\pm$1.5 $\pm$1.1 | 17.93 $\pm$2.0 $\pm$3.3

Figure 3:  Results for $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$,
$\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ and $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$
scaled by the charged-particle density d$N_{\rm ch}/$d$\eta$. The ALICE data
are shown by red markers while the coloured lines indicate the HIJING [22, 23]
and AMPT [25] model calculations. The data are shown as a function of the
collision centrality, expressed in terms of d$N_{\rm ch}/$d$\eta$.

Measured values of $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ and
$\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$ are positive across the entire
centrality range, while $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ is negative for the
most peripheral collisions and changes sign at mid-central collisions. The
centrality dependencies observed in $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$
and $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ are similar in shape, being flat from
central to mid-central collisions and systematically decreasing for the most
peripheral ones. In contrast, $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ is almost
independent of centrality from most peripheral to mid-central collisions and
rises as the centrality increases. A similar qualitative behaviour is also
observed for $\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ within the kinematic range of
$|\eta|<1$ and $0.2<p<0.6$ GeV/$c$ as measured in Au–Au collisions at
$\sqrt{s_{\rm{NN}}}$ $=200$ GeV by the STAR collaboration. The difference in
the absolute values is, to a large extent, due to the increase in d$N_{\rm
ch}/$d$\eta$ by almost a factor of two between the two collision energies. The
same argument holds true for the most central STAR data at $62.4$ GeV,
although the centrality dependence is rather flat in this case [27]. The
overall behaviour is defined by the interplay between correlation and
fluctuation terms encoded in the definition of the $\nu_{\rm dyn}$ observable.
To disentangle these terms, one needs a dedicated study focusing on separate
charge combinations, which also makes it possible to investigate contributions
from resonance decays and global charge conservations.

An important characteristic of HIJING is that it treats nucleus-nucleus
collisions as an independent superposition of nucleon-nucleon interactions. As
such, it does not incorporate mechanisms for final-state interactions among
the produced particles and therefore phenomena such as equilibrium and
collectivity do not occur. The AMPT calculations are performed with three
different settings including (i) string melting, (ii) hadronic rescattering,
and (iii) string melting and hadronic rescattering. All three versions of the
AMPT model presented here use hard minijet partons and soft strings from
HIJING as initial conditions. Partonic evolution is described by Zhang’s
parton cascade (ZPC) [29] which is followed by a hadronization process. In the
last step, hadronic rescattering and the decay of resonances takes place. In
the default AMPT model, after minijet partons stop interacting with other
partons, they are combined with their parent strings to form excited strings,
which are then converted to hadrons according to the Lund string fragmentation
model [25]. However, in the string melting scenario, instead of employing the
Lund string fragmentation mechanism, hadronization is modeled via a quark
coalescence scheme by combining two nearest quarks into a meson and three
nearest quarks (antiquarks) into a baryon (antibaryon). This ultimately
reduces the correlation between produced hadrons.

HIJING produces positive values for the three particle pair combinations and
does not exhibit any non-monotonic behaviour as a function of centrality, even
though it implements exact global conservation laws. In contrast, hadronic
rescattering produces additional resonances at the hadronization phase thereby
introducing additional correlations between particles [25]. Consequently, the
AMPT configuration with hadronic rescattering drives the $\nu_{\rm dyn}$
results towards negative values as the collision centrality increases. In
particular, for $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$, contrary to the data, it
predicts negative values. On the other hand, the AMPT version with string
melting shows a weak centrality dependence for the three particle pair
combinations. None of the models investigated in this work give a reasonable
quantitative description of the measured data.

###  5.2 Energy dependence

Values of $\nu_{\rm dyn}$ measured in this work for the most central Pb–Pb
collisions were compared to NA49 and STAR data in Figure 4. Measurements from
NA49 and STAR show a smooth evolution of $\nu_{\rm dyn}$ with collision energy
and do not reveal any indications for critical behaviour in the range
$6.3<\sqrt{s_{\rm NN}}<200$ GeV. The apparent differences between NA49 and
STAR data for $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$ and
$\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ at $\sqrt{s_{\rm NN}}<10$ GeV were traced
back in Ref [13] to the dependence of $\nu_{\rm dyn}$ on the detector
acceptance. Above this energy, both experiments report positive values for
$\nu_{\rm{dyn}}[\pi,\mathrm{K}]$, and a weak dependence on the collision
energy, whereas $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$ is negative and
approaches zero as the collision energy increases.

Figure 4: Collision-energy dependence of $\nu_{\rm dyn}$. Results obtained
with the Identity Method in this work and by the NA49 collaboration [13] in
Pb–Pb collisions are shown with red circles and black squares, respectively,
while those obtained by the STAR collaboration [10] in Au–Au collisions are
shown with blue stars.

ALICE data are positive for the three particle pair combinations and follow
the trend observed at lower energies, involving a sign change for
$\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ and $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$
as a function of energy. Such a change of sign has been predicted by transport
models HSD [30] and UrQMD [31] in the RHIC energy regime [10]. Since neither
HSD nor UrQMD explicitly include the quark and gluon degrees of freedom, this
observation can be attributed to the particular realization of the string and
resonance dynamics used in the models [30]. Additionally, HIJING and AMPT
model calculations at LHC energies predict positive values except for
$\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ in the AMPT configuration with hadronic
rescattering and without string melting. To understand the difference between
the STAR and ALICE results, the acceptance dependence of $\nu_{\rm dyn}$ was
also investigated with the ALICE data by varying the phase-space coverage.
Opening the pseudorapidity window from $|\eta|<0.8$ up to $|\eta|<1$ yields a
reduction in $\nu_{\rm dyn}$ of 10-20%. However, this reduction is
insufficient to explain the difference between the ALICE and STAR results,
most particularly the sign change with increasing energy.

##  6 Summary

In summary, measurements of $\nu_{\rm dyn}$ in Pb–Pb collisions at
$\sqrt{s_{\rm{NN}}}$ $=2.76$ TeV for three specific particle pair combinations
using the Identity Method were presented. Values of $\nu_{\rm dyn}$, scaled by
the charged-particle density at midrapidity d$N_{\rm ch}/$d$\eta$, exhibit
finite variations with collision centrality. This is in contrast to
predictions by HIJING, which, for all three pair combinations, show
essentially constant as well as positive values. The results for
$\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ and $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$
are positive across the entire centrality range, while
$\nu_{\rm{dyn}}[\pi,\mathrm{p}]$ changes sign from positive to negative
towards more peripheral collisions suggesting differences in the production
dynamics of these pairs. The centrality dependence of
$\nu_{\rm{dyn}}[\pi,\mathrm{K}]$ shows a similar behaviour, increasing with
centrality, as measured in Au–Au collisions at $\sqrt{s_{\rm{NN}}}$ $=200$ GeV
by the STAR collaboration, while the data at $\sqrt{s_{\rm{NN}}}$ $=62.4$ GeV
shows no centrality dependence. Comparisons with calculations from the AMPT
model, using three distinct configurations, show that AMPT is unable to
reproduce measured data in this work. Calculations with quark coalescence show
only a very slight centrality dependence and no sign changes. On the other
hand, AMPT values with hadronic rescattering and no quark coalescence decrease
significantly with increasing collision centrality and exhibit a sign change
towards central collisions in the case of $\nu_{\rm{dyn}}[\pi,\mathrm{p}]$.
The evolution of $\nu_{\rm dyn}$ with collision energy shows that the particle
production dynamics changes significantly from that observed at lower
energies. Values of $\nu_{\rm dyn}$ measured with all three pair combinations
follow a smooth continuation of the data measured by STAR and exhibit a change
in sign for $\nu_{\rm{dyn}}[\mathrm{p},\mathrm{K}]$ and
$\nu_{\rm{dyn}}[\pi,\mathrm{p}]$. The analysis of $\nu_{\rm dyn}$ with
enlarged acceptance shows that the magnitude of $\nu_{\rm dyn}$ depends on the
kinematical limits but the change appears too small to explain the difference
with the STAR results. A more detailed analysis of fluctuations with charge
and species specific pairs is required to fully characterize the particle
production dynamics in heavy-ion collisions and understand, in particular, the
origin of the sign changes reported in this work.

## Acknowledgements

The ALICE Collaboration would like to thank all its engineers and technicians
for their invaluable contributions to the construction of the experiment and
the CERN accelerator teams for the outstanding performance of the LHC complex.
The ALICE Collaboration gratefully acknowledges the resources and support
provided by all Grid centres and the Worldwide LHC Computing Grid (WLCG)
collaboration. The ALICE Collaboration acknowledges the following funding
agencies for their support in building and running the ALICE detector: A. I.
Alikhanyan National Science Laboratory (Yerevan Physics Institute) Foundation
(ANSL), State Committee of Science and World Federation of Scientists (WFS),
Armenia; Austrian Academy of Sciences and Nationalstiftung für Forschung,
Technologie und Entwicklung, Austria; Ministry of Communications and High
Technologies, National Nuclear Research Center, Azerbaijan; Conselho Nacional
de Desenvolvimento Científico e Tecnológico (CNPq), Universidade Federal do
Rio Grande do Sul (UFRGS), Financiadora de Estudos e Projetos (Finep) and
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Brazil;
Ministry of Science & Technology of China (MSTC), National Natural Science
Foundation of China (NSFC) and Ministry of Education of China (MOEC) , China;
Ministry of Science, Education and Sport and Croatian Science Foundation,
Croatia; Ministry of Education, Youth and Sports of the Czech Republic, Czech
Republic; The Danish Council for Independent Research — Natural Sciences, the
Carlsberg Foundation and Danish National Research Foundation (DNRF), Denmark;
Helsinki Institute of Physics (HIP), Finland; Commissariat à l’Energie
Atomique (CEA) and Institut National de Physique Nucléaire et de Physique des
Particules (IN2P3) and Centre National de la Recherche Scientifique (CNRS),
France; Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie
(BMBF) and GSI Helmholtzzentrum für Schwerionenforschung GmbH, Germany;
General Secretariat for Research and Technology, Ministry of Education,
Research and Religions, Greece; National Research, Development and Innovation
Office, Hungary; Department of Atomic Energy Government of India (DAE),
Department of Science and Technology, Government of India (DST), University
Grants Commission, Government of India (UGC) and Council of Scientific and
Industrial Research (CSIR), India; Indonesian Institute of Science, Indonesia;
Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche Enrico
Fermi and Istituto Nazionale di Fisica Nucleare (INFN), Italy; Institute for
Innovative Science and Technology , Nagasaki Institute of Applied Science
(IIST), Japan Society for the Promotion of Science (JSPS) KAKENHI and Japanese
Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan;
Consejo Nacional de Ciencia (CONACYT) y Tecnología, through Fondo de
Cooperación Internacional en Ciencia y Tecnología (FONCICYT) and Dirección
General de Asuntos del Personal Academico (DGAPA), Mexico; Nederlandse
Organisatie voor Wetenschappelijk Onderzoek (NWO), Netherlands; The Research
Council of Norway, Norway; Commission on Science and Technology for
Sustainable Development in the South (COMSATS), Pakistan; Pontificia
Universidad Católica del Perú, Peru; Ministry of Science and Higher Education
and National Science Centre, Poland; Korea Institute of Science and Technology
Information and National Research Foundation of Korea (NRF), Republic of
Korea; Ministry of Education and Scientific Research, Institute of Atomic
Physics and Romanian National Agency for Science, Technology and Innovation,
Romania; Joint Institute for Nuclear Research (JINR), Ministry of Education
and Science of the Russian Federation and National Research Centre Kurchatov
Institute, Russia; Ministry of Education, Science, Research and Sport of the
Slovak Republic, Slovakia; National Research Foundation of South Africa, South
Africa; Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear (CEADEN),
Cubaenergía, Cuba and Centro de Investigaciones Energéticas, Medioambientales
y Tecnológicas (CIEMAT), Spain; Swedish Research Council (VR) and Knut & Alice
Wallenberg Foundation (KAW), Sweden; European Organization for Nuclear
Research, Switzerland; National Science and Technology Development Agency
(NSDTA), Suranaree University of Technology (SUT) and Office of the Higher
Education Commission under NRU project of Thailand, Thailand; Turkish Atomic
Energy Agency (TAEK), Turkey; National Academy of Sciences of Ukraine,
Ukraine; Science and Technology Facilities Council (STFC), United Kingdom;
National Science Foundation of the United States of America (NSF) and United
States Department of Energy, Office of Nuclear Physics (DOE NP), United States
of America.

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##  Appendix A The ALICE Collaboration

S. Acharyaorg137&D. Adamováorg94&J. Adolfssonorg34&M.M. Aggarwalorg99&G.
Aglieri Rinellaorg35&M. Agnelloorg31&N. Agrawalorg48&Z. Ahammedorg137&S.U.
Ahnorg79&S. Aiolaorg141&A. Akindinovorg64&M. Al-Turanyorg106&S.N.
Alamorg137&D.S.D. Albuquerqueorg122&D. Aleksandrovorg90&B. Alessandroorg58&R.
Alfaro Molinaorg74&Y. Aliorg15&A. Aliciorg12,org53,org27&A. Alkinorg3&J.
Almeorg22&T. Altorg70&L. Altenkamperorg22&I. Altsybeevorg136&C. Alves Garcia
Pradoorg121&C. Andreiorg87&D. Andreouorg35&H.A. Andrewsorg110&A.
Andronicorg106&V. Anguelovorg104&C. Ansonorg97&T. Antičićorg107&F.
Antinoriorg56&P. Antonioliorg53&L. Aphecetcheorg114&H. Appelshäuserorg70&S.
Arcelliorg27&R. Arnaldiorg58&O.W. Arnoldorg105,org36&I.C. Arseneorg21&M.
Arslandokorg104&B. Audurierorg114&A. Augustinusorg35&R. Averbeckorg106&M.D.
Azmiorg17&A. Badalàorg55&Y.W. Baekorg60,org78&S. Bagnascoorg58&R.
Bailhacheorg70&R. Balaorg101&A. Baldisseriorg75&M. Ballorg45&R.C.
Baralorg67,org88&A.M. Barbanoorg26&R. Barberaorg28&F. Barileorg33&L.
Barioglioorg26&G.G. Barnaföldiorg140&L.S. Barnbyorg93&V. Barretorg131&P.
Bartaliniorg7&K. Barthorg35&E. Bartschorg70&N. Bastidorg131&S. Basuorg139&G.
Batigneorg114&B. Batyunyaorg77&P.C. Batzingorg21&J.L. Bazo Albaorg111&I.G.
Beardenorg91&H. Beckorg104&C. Beddaorg63&N.K. Beheraorg60&I. Belikovorg133&F.
Belliniorg27,org35&H. Bello Martinezorg2&R. Bellwiedorg124&L.G.E.
Beltranorg120&V. Belyaevorg83&G. Bencediorg140&S. Beoleorg26&A.
Bercuciorg87&Y. Berdnikovorg96&D. Berenyiorg140&R.A. Bertensorg127&D.
Berzanoorg35&L. Betevorg35&A. Bhasinorg101&I.R. Bhatorg101&B.
Bhattacharjeeorg44&J. Bhomorg118&A. Bianchiorg26&L. Bianchiorg124&N.
Bianchiorg51&C. Bianchinorg139&J. Bielčíkorg39&J. Bielčíkováorg94&A.
Bilandzicorg36,org105&G. Biroorg140&R. Biswasorg4&S. Biswasorg4&J.T.
Blairorg119&D. Blauorg90&C. Blumeorg70&G. Bocaorg134&F. Bockorg35&A.
Bogdanovorg83&L. Boldizsárorg140&M. Bombaraorg40&G. Bonomiorg135&M.
Bonoraorg35&J. Bookorg70&H. Borelorg75&A. Borissovorg104,org19&M.
Borriorg126&E. Bottaorg26&C. Bourjauorg91&L. Bratrudorg70&P. Braun-
Munzingerorg106&M. Bregantorg121&T.A. Brokerorg70&M. Brozorg39&E.J.
Bruckenorg46&E. Brunaorg58&G.E. Brunoorg35,org33&D. Budnikovorg108&H.
Bueschingorg70&S. Bufalinoorg31&P. Buhlerorg113&P. Buncicorg35&O.
Buschorg130&Z. Butheleziorg76&J.B. Buttorg15&J.T. Buxtonorg18&J.
Cabalaorg116&D. Caffarriorg35,org92&H. Cainesorg141&A. Calivaorg63,org106&E.
Calvo Villarorg111&P. Cameriniorg25&A.A. Caponorg113&F. Carenaorg35&W.
Carenaorg35&F. Carnesecchiorg27,org12&J. Castillo Castellanosorg75&A.J.
Castroorg127&E.A.R. Casulaorg54&C. Ceballos Sanchezorg9&S. Chandraorg137&B.
Changorg125&W. Changorg7&S. Chapelandorg35&M. Chartierorg126&S.
Chattopadhyayorg137&S. Chattopadhyayorg109&A. Chauvinorg36,org105&C.
Cheshkovorg132&B. Cheynisorg132&V. Chibante Barrosoorg35&D.D.
Chinellatoorg122&S. Choorg60&P. Chochulaorg35&M. Chojnackiorg91&S.
Choudhuryorg137&T. Chowdhuryorg131&P. Christakoglouorg92&C.H.
Christensenorg91&P. Christiansenorg34&T. Chujoorg130&S.U. Chungorg19&C.
Cicaloorg54&L. Cifarelliorg12,org27&F. Cindoloorg53&J. Cleymansorg100&F.
Colamariaorg52,org33&D. Colellaorg35,org52,org65&A. Colluorg82&M.
Colocciorg27&M. Concasorg58orgI&G. Conesa Balbastreorg81&Z. Conesa del
Valleorg61&J.G. Contrerasorg39&T.M. Cormierorg95&Y. Corrales Moralesorg58&I.
Cortés Maldonadoorg2&P. Corteseorg32&M.R. Cosentinoorg123&F. Costaorg35&S.
Costanzaorg134&J. Crkovskáorg61&P. Crochetorg131&E. Cuautleorg72&L.
Cunqueiroorg95,org71&T. Dahmsorg36,org105&A. Daineseorg56&M.C.
Danischorg104&A. Danuorg68&D. Dasorg109&I. Dasorg109&S. Dasorg4&A.
Dashorg88&S. Dashorg48&S. Deorg49&A. De Caroorg30&G. de Cataldoorg52&C. de
Contiorg121&J. de Cuvelandorg42&A. De Falcoorg24&D. De Gruttolaorg30,org12&N.
De Marcoorg58&S. De Pasqualeorg30&R.D. De Souzaorg122&H.F. Degenhardtorg121&A.
Deistingorg106,org104&A. Delofforg86&C. Deplanoorg92&P. Dhankherorg48&D. Di
Bariorg33&A. Di Mauroorg35&P. Di Nezzaorg51&B. Di Ruzzaorg56&M.A. Diaz
Corcheroorg10&T. Dietelorg100&P. Dillensegerorg70&Y. Dingorg7&R. Diviàorg35&Ø.
Djuvslandorg22&A. Dobrinorg35&D. Domenicis Gimenezorg121&B. Dönigusorg70&O.
Dordicorg21&L.V.R. Doremalenorg63&A.K. Dubeyorg137&A. Dublaorg106&L.
Ducrouxorg132&S. Dudiorg99&A.K. Duggalorg99&M. Dukhishyamorg88&P.
Dupieuxorg131&R.J. Ehlersorg141&D. Eliaorg52&E. Endressorg111&H. Engelorg69&E.
Eppleorg141&B. Erazmusorg114&F. Erhardtorg98&B. Espagnonorg61&G.
Eulisseorg35&J. Eumorg19&D. Evansorg110&S. Evdokimovorg112&L.
Fabbiettiorg105,org36&J. Faivreorg81&A. Fantoniorg51&M. Faselorg95&L.
Feldkamporg71&A. Felicielloorg58&G. Feofilovorg136&A. Fernández
Téllezorg2&E.G. Ferreiroorg16&A. Ferrettiorg26&A. Festantiorg29,org35&V.J.G.
Feuillardorg75,org131&J. Figielorg118&M.A.S. Figueredoorg121&S.
Filchaginorg108&D. Finogeevorg62&F.M. Fiondaorg22,org24&M. Florisorg35&S.
Foertschorg76&P. Fokaorg106&S. Fokinorg90&E. Fragiacomoorg59&A.
Francesconorg35&A. Franciscoorg114&U. Frankenfeldorg106&G.G. Fronzeorg26&U.
Fuchsorg35&C. Furgetorg81&A. Fursorg62&M. Fusco Girardorg30&J.J.
Gaardhøjeorg91&M. Gagliardiorg26&A.M. Gagoorg111&K. Gajdosovaorg91&M.
Gallioorg26&C.D. Galvanorg120&P. Ganotiorg85&C. Garabatosorg106&E. Garcia-
Solisorg13&K. Gargorg28&C. Gargiuloorg35&P. Gasikorg105,org36&E.F.
Gaugerorg119&M.B. Gay Ducatiorg73&M. Germainorg114&J. Ghoshorg109&P.
Ghoshorg137&S.K. Ghoshorg4&P. Gianottiorg51&P. Giubellinoorg35,org106,org58&P.
Giubilatoorg29&E. Gladysz-Dziadusorg118&P. Glässelorg104&D.M. Goméz
Coralorg74&A. Gomez Ramirezorg69&A.S. Gonzalezorg35&V. Gonzalezorg10&P.
González-Zamoraorg10,org2&S. Gorbunovorg42&L. Görlichorg118&S.
Gotovacorg117&V. Grabskiorg74&L.K. Graczykowskiorg138&K.L. Grahamorg110&L.
Greinerorg82&A. Grelliorg63&C. Grigorasorg35&V. Grigorievorg83&A.
Grigoryanorg1&S. Grigoryanorg77&J.M. Gronefeldorg106&F. Grosaorg31&J.F.
Grosse-Oetringhausorg35&R. Grossoorg106&F. Guberorg62&R. Guernaneorg81&B.
Guerzoniorg27&K. Gulbrandsenorg91&T. Gunjiorg129&A. Guptaorg101&R.
Guptaorg101&I.B. Guzmanorg2&R. Haakeorg35&C. Hadjidakisorg61&H.
Hamagakiorg84&G. Hamarorg140&J.C. Hamonorg133&M.R. Haqueorg63&J.W.
Harrisorg141&A. Hartonorg13&H. Hassanorg81&D. Hatzifotiadouorg12,org53&S.
Hayashiorg129&S.T. Heckelorg70&E. Hellbärorg70&H. Helstruporg37&A.
Herghelegiuorg87&E.G. Hernandezorg2&G. Herrera Corralorg11&F.
Herrmannorg71&B.A. Hessorg103&K.F. Hetlandorg37&H. Hillemannsorg35&C.
Hillsorg126&B. Hippolyteorg133&B. Hohlwegerorg105&D. Horakorg39&S.
Hornungorg106&R. Hosokawaorg81,org130&P. Hristovorg35&C. Hughesorg127&T.J.
Humanicorg18&N. Hussainorg44&T. Hussainorg17&D. Hutterorg42&D.S.
Hwangorg20&S.A. Iga Buitronorg72&R. Ilkaevorg108&M. Inabaorg130&M.
Ippolitovorg83,org90&M.S. Islamorg109&M. Ivanovorg106&V. Ivanovorg96&V.
Izucheevorg112&B. Jacakorg82&N. Jacazioorg27&P.M. Jacobsorg82&M.B.
Jadhavorg48&S. Jadlovskaorg116&J. Jadlovskyorg116&S. Jaelaniorg63&C.
Jahnkeorg36&M.J. Jakubowskaorg138&M.A. Janikorg138&P.H.S.Y.
Jayarathnaorg124&C. Jenaorg88&M. Jercicorg98&R.T. Jimenez
Bustamanteorg106&P.G. Jonesorg110&A. Juskoorg110&P. Kalinakorg65&A.
Kalweitorg35&J.H. Kangorg142&V. Kaplinorg83&S. Karorg137&A. Karasu
Uysalorg80&O. Karavichevorg62&T. Karavichevaorg62&L. Karayanorg106,org104&P.
Karczmarczykorg35&E. Karpechevorg62&U. Kebschullorg69&R. Keidelorg143&D.L.D.
Keijdenerorg63&M. Keilorg35&B. Ketzerorg45&Z. Khabanovaorg92&P.
Khanorg109&S.A. Khanorg137&A. Khanzadeevorg96&Y. Kharlovorg112&A.
Khatunorg17&A. Khuntiaorg49&M.M. Kielbowiczorg118&B. Kilengorg37&B.
Kimorg130&D. Kimorg142&D.J. Kimorg125&H. Kimorg142&J.S. Kimorg43&J.
Kimorg104&M. Kimorg60&S. Kimorg20&T. Kimorg142&S. Kirschorg42&I. Kiselorg42&S.
Kiselevorg64&A. Kisielorg138&G. Kissorg140&J.L. Klayorg6&C. Kleinorg70&J.
Kleinorg35&C. Klein-Bösingorg71&S. Klewinorg104&A. Klugeorg35&M.L.
Knichelorg104,org35&A.G. Knospeorg124&C. Kobdajorg115&M. Kofaragoorg140&M.K.
Köhlerorg104&T. Kolleggerorg106&V. Kondratievorg136&N. Kondratyevaorg83&E.
Kondratyukorg112&A. Konevskikhorg62&M. Konyushikhinorg139&M. Kopcikorg116&M.
Kourorg101&C. Kouzinopoulosorg35&O. Kovalenkoorg86&V. Kovalenkoorg136&M.
Kowalskiorg118&G. Koyithatta Meethaleveeduorg48&I. Králikorg65&A.
Kravčákováorg40&L. Kreisorg106&M. Krivdaorg110,org65&F. Krizekorg94&E.
Kryshenorg96&M. Krzewickiorg42&A.M. Kuberaorg18&V. Kučeraorg94&C.
Kuhnorg133&P.G. Kuijerorg92&A. Kumarorg101&J. Kumarorg48&L. Kumarorg99&S.
Kumarorg48&S. Kunduorg88&P. Kurashviliorg86&A. Kurepinorg62&A.B.
Kurepinorg62&A. Kuryakinorg108&S. Kushpilorg94&M.J. Kweonorg60&Y.
Kwonorg142&S.L. La Pointeorg42&P. La Roccaorg28&C. Lagana Fernandesorg121&Y.S.
Laiorg82&I. Lakomovorg35&R. Langoyorg41&K. Lapidusorg141&C. Laraorg69&A.
Lardeuxorg21&A. Lattucaorg26&E. Laudiorg35&R. Lavickaorg39&R. Leaorg25&L.
Leardiniorg104&S. Leeorg142&F. Lehasorg92&S. Lehnerorg113&J.
Lehrbachorg42&R.C. Lemmonorg93&E. Leograndeorg63&I. León Monzónorg120&P.
Lévaiorg140&X. Liorg14&J. Lienorg41&R. Lietavaorg110&B. Limorg19&S.
Lindalorg21&V. Lindenstruthorg42&S.W. Lindsayorg126&C. Lippmannorg106&M.A.
Lisaorg18&V. Litichevskyiorg46&W.J. Llopeorg139&D.F. Lodatoorg63&P.I.
Loenneorg22&V. Loginovorg83&C. Loizidesorg95,org82&P. Loncarorg117&X.
Lopezorg131&E. López Torresorg9&A. Loweorg140&P. Luettigorg70&J.R.
Luhderorg71&M. Lunardonorg29&G. Luparelloorg59,org25&M. Lupiorg35&T.H.
Lutzorg141&A. Maevskayaorg62&M. Magerorg35&S.M. Mahmoodorg21&A.
Maireorg133&R.D. Majkaorg141&M. Malaevorg96&L. Malininaorg77orgII&D.
Mal’Kevichorg64&P. Malzacherorg106&A. Mamonovorg108&V. Mankoorg90&F.
Mansoorg131&V. Manzariorg52&Y. Maoorg7&M. Marchisoneorg132,org76,org128&J.
Marešorg66&G.V. Margagliottiorg25&A. Margottiorg53&J. Marguttiorg63&A.
Marínorg106&C. Markertorg119&M. Marquardorg70&N.A. Martinorg106&P.
Martinengoorg35&J.A.L. Martinezorg69&M.I. Martínezorg2&G. Martínez
Garcíaorg114&M. Martinez Pedreiraorg35&S. Masciocchiorg106&M. Maseraorg26&A.
Masoniorg54&E. Massonorg114&A. Mastroserioorg52&A.M. Mathisorg105,org36&P.F.T.
Matuokaorg121&A. Matyjaorg127&C. Mayerorg118&J. Mazerorg127&M.
Mazzilliorg33&M.A. Mazzoniorg57&F. Meddiorg23&Y. Melikyanorg83&A. Menchaca-
Rochaorg74&E. Meninnoorg30&J. Mercado Pérezorg104&M. Meresorg38&S.
Mhlangaorg100&Y. Miakeorg130&M.M. Mieskolainenorg46&D.L. Mihaylovorg105&K.
Mikhaylovorg77,org64&A. Mischkeorg63&A.N. Mishraorg49&D. Miśkowiecorg106&J.
Mitraorg137&C.M. Mituorg68&N. Mohammadiorg63&A.P. Mohantyorg63&B.
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Godoyorg71&L.A.P. Morenoorg2&S. Morettoorg29&A. Morrealeorg114&A.
Morschorg35&V. Mucciforaorg51&E. Mudnicorg117&D. Mühlheimorg71&S.
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Munzerorg70&H. Murakamiorg129&S. Murrayorg76&L. Musaorg35&J.
Musinskyorg65&C.J. Myersorg124&J.W. Myrchaorg138&D. Nagorg4&B. Naikorg48&R.
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Narayanorg48&M.U. Naruorg15&H. Natal da Luzorg121&C. Nattrassorg127&S.R.
Navarroorg2&K. Nayakorg88&R. Nayakorg48&T.K. Nayakorg137&S.
Nazarenkoorg108&R.A. Negrao De Oliveiraorg70,org35&L. Nellenorg72&S.V.
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Oeschlerorg19,org104org*&H. Ohorg142&A. Ohlsonorg104&T. Okuboorg47&L.
Olahorg140&J. Oleniaczorg138&A.C. Oliveira Da Silvaorg121&M.H. Oliverorg141&J.
Onderwaaterorg106&C. Oppedisanoorg58&R. Oravaorg46&M. Oravecorg116&A. Ortiz
Velasquezorg72&A. Oskarssonorg34&J. Otwinowskiorg118&K. Oyamaorg84&Y.
Pachmayerorg104&V. Pacikorg91&D. Paganoorg135&G. Paićorg72&P. Palniorg7&J.
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Pareekorg49&J. Parkorg60&S. Parmarorg99&A. Passfeldorg71&S.P.
Pathakorg124&R.N. Patraorg137&B. Paulorg58&H. Peiorg7&T. Peitzmannorg63&X.
Pengorg7&L.G. Pereiraorg73&H. Pereira Da Costaorg75&D. Peresunkoorg83,org90&E.
Perez Lezamaorg70&V. Peskovorg70&Y. Pestovorg5&V. Petráčekorg39&V.
Petrovorg112&M. Petroviciorg87&C. Pettaorg28&R.P. Pezziorg73&S. Pianoorg59&M.
Piknaorg38&P. Pillotorg114&L.O.D.L. Pimentelorg91&O. Pinazzaorg53,org35&L.
Pinskyorg124&D.B. Piyarathnaorg124&M. Płoskońorg82&M. Planinicorg98&F.
Pliquettorg70&J. Plutaorg138&S. Pochybovaorg140&P.L.M. Podesta-
Lermaorg120&M.G. Poghosyanorg95&B. Polichtchoukorg112&N. Poljakorg98&W.
Poonsawatorg115&A. Poporg87&H. Poppenborgorg71&S. Porteboeuf-Houssaisorg131&V.
Pozdniakovorg77&S.K. Prasadorg4&R. Preghenellaorg53&F. Prinoorg58&C.A.
Pruneauorg139&I. Pshenichnovorg62&M. Puccioorg26&V. Puninorg108&J.
Putschkeorg139&S. Rahaorg4&S. Rajputorg101&J. Rakorg125&A.
Rakotozafindrabeorg75&L. Ramelloorg32&F. Ramiorg133&D.B. Ranaorg124&R.
Raniwalaorg102&S. Raniwalaorg102&S.S. Räsänenorg46&B.T. Rascanuorg70&D.
Ratheeorg99&V. Ratzaorg45&I. Ravasengaorg31&K.F. Readorg127,org95&K.
Redlichorg86orgIV&A. Rehmanorg22&P. Reicheltorg70&F. Reidtorg35&X. Renorg7&R.
Renfordtorg70&A. Reshetinorg62&K. Reygersorg104&V. Riabovorg96&T.
Richertorg34,org63&M. Richterorg21&P. Riedlerorg35&W. Rieglerorg35&F.
Riggiorg28&C. Risteaorg68&M. Rodríguez Cahuantziorg2&K. Røedorg21&E.
Rogochayaorg77&D. Rohrorg35,org42&D. Röhrichorg22&P.S. Rokitaorg138&F.
Ronchettiorg51&E.D. Rosasorg72&P. Rosnetorg131&A. Rossiorg29,org56&A.
Rotondiorg134&F. Roukoutakisorg85&C. Royorg133&P. Royorg109&A.J. Rubio
Monteroorg10&O.V. Ruedaorg72&R. Ruiorg25&B. Rumyantsevorg77&A.
Rustamovorg89&E. Ryabinkinorg90&Y. Ryabovorg96&A. Rybickiorg118&S.
Saarinenorg46&S. Sadhuorg137&S. Sadovskyorg112&K. Šafaříkorg35&S.K.
Sahaorg137&B. Sahlmullerorg70&B. Sahooorg48&P. Sahooorg49&R. Sahooorg49&S.
Sahooorg67&P.K. Sahuorg67&J. Sainiorg137&S. Sakaiorg130&M.A. Salehorg139&J.
Salzwedelorg18&S. Sambyalorg101&V. Samsonovorg96,org83&A. Sandovalorg74&A.
Sarkarorg76&D. Sarkarorg137&N. Sarkarorg137&P. Sarmaorg44&M.H.P. Sasorg63&E.
Scapparoneorg53&F. Scarlassaraorg29&B. Schaeferorg95&H.S. Scheidorg70&C.
Schiauaorg87&R. Schickerorg104&C. Schmidtorg106&H.R. Schmidtorg103&M.O.
Schmidtorg104&M. Schmidtorg103&N.V. Schmidtorg95,org70&J. Schukraftorg35&Y.
Schutzorg35,org133&K. Schwarzorg106&K. Schwedaorg106&G. Scioliorg27&E.
Scomparinorg58&M. Šefčíkorg40&J.E. Segerorg97&Y. Sekiguchiorg129&D.
Sekihataorg47&I. Selyuzhenkovorg106,org83&K. Senosiorg76&S. Senyukovorg133&E.
Serradillaorg74,org10&P. Settorg48&A. Sevcencoorg68&A. Shabanovorg62&A.
Shabetaiorg114&R. Shahoyanorg35&W. Shaikhorg109&A. Shangaraevorg112&A.
Sharmaorg99&A. Sharmaorg101&M. Sharmaorg101&M. Sharmaorg101&N.
Sharmaorg99&A.I. Sheikhorg137&K. Shigakiorg47&S. Shirinkinorg64&Q. Shouorg7&K.
Shtejerorg9,org26&Y. Sibiriakorg90&S. Siddhantaorg54&K.M. Sielewiczorg35&T.
Siemiarczukorg86&S. Silaevaorg90&D. Silvermyrorg34&G. Simatovicorg92&G.
Simonettiorg35&R. Singarajuorg137&R. Singhorg88&V. Singhalorg137&T.
Sinhaorg109&B. Sitarorg38&M. Sittaorg32&T.B. Skaaliorg21&M. Slupeckiorg125&N.
Smirnovorg141&R.J.M. Snellingsorg63&T.W. Snellmanorg125&J. Songorg19&M.
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Sputowskaorg118&J. Stachelorg104&I. Stanorg68&P. Stankusorg95&E.
Stenlundorg34&D. Stoccoorg114&M.M. Storetvedtorg37&P. Strmenorg38&A.A.P.
Suaideorg121&T. Sugitateorg47&C. Suireorg61&M. Suleymanovorg15&M.
Suljicorg25&R. Sultanovorg64&M. Šumberaorg94&S. Sumowidagdoorg50&K.
Suzukiorg113&S. Swainorg67&A. Szaboorg38&I. Szarkaorg38&U. Tabassamorg15&J.
Takahashiorg122&G.J. Tambaveorg22&N. Tanakaorg130&M. Tarhiniorg61&M.
Tariqorg17&M.G. Tarzilaorg87&A. Tauroorg35&G. Tejeda Muñozorg2&A.
Telescaorg35&K. Terasakiorg129&C. Terrevoliorg29&B. Teyssierorg132&D.
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Tieulentorg132&A. Tikhonovorg62&A.R. Timminsorg124&A. Toiaorg70&M.
Toppiorg51&S.R. Torresorg120&S. Tripathyorg49&S. Trogoloorg26&G.
Trombettaorg33&L. Tropporg40&V. Trubnikovorg3&W.H. Trzaskaorg125&B.A.
Trzeciakorg63&T. Tsujiorg129&A. Tumkinorg108&R. Turrisiorg56&T.S.
Tveterorg21&K. Ullalandorg22&E.N. Umakaorg124&A. Urasorg132&G.L. Usaiorg24&A.
Utrobicicorg98&M. Valaorg116,org65&J. Van Der Maarelorg63&J.W. Van
Hoorneorg35&M. van Leeuwenorg63&T. Vanatorg94&P. Vande Vyvreorg35&D.
Vargaorg140&A. Vargasorg2&M. Vargyasorg125&R. Varmaorg48&M. Vasileiouorg85&A.
Vasilievorg90&A. Vauthierorg81&O. Vázquez Doceorg105,org36&V.
Vecherninorg136&A.M. Veenorg63&A. Velureorg22&E. Vercellinorg26&S. Vergara
Limónorg2&R. Vernetorg8&R. Vértesiorg140&L. Vickovicorg117&S. Vigoloorg63&J.
Viinikainenorg125&Z. Vilakaziorg128&O. Villalobos Baillieorg110&A. Villatoro
Telloorg2&A. Vinogradovorg90&L. Vinogradovorg136&T. Virgiliorg30&V.
Vislaviciusorg34&A. Vodopyanovorg77&M.A. Völklorg103&K. Voloshinorg64&S.A.
Voloshinorg139&G. Volpeorg33&B. von Hallerorg35&I. Vorobyevorg105,org36&D.
Voscekorg116&D. Vranicorg35,org106&J. Vrlákováorg40&B. Wagnerorg22&H.
Wangorg63&M. Wangorg7&D. Watanabeorg130&Y. Watanabeorg129,org130&M.
Weberorg113&S.G. Weberorg106&D.F. Weiserorg104&S.C. Wenzelorg35&J.P.
Wesselsorg71&U. Westerhofforg71&A.M. Whiteheadorg100&J. Wiechulaorg70&J.
Wikneorg21&G. Wilkorg86&J. Wilkinsonorg104,org53&G.A.
Willemsorg35,org71&M.C.S. Williamsorg53&E. Willsherorg110&B.
Windelbandorg104&W.E. Wittorg127&R. Xuorg7&S. Yalcinorg80&K. Yamakawaorg47&P.
Yangorg7&S. Yanoorg47&Z. Yinorg7&H. Yokoyamaorg130,org81&I.-K. Yooorg19&J.H.
Yoonorg60&E. Yunorg19&V. Yurchenkoorg3&V. Zaccoloorg58&A. Zamanorg15&C.
Zampolliorg35&H.J.C. Zanoliorg121&N. Zardoshtiorg110&A. Zarochentsevorg136&P.
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Zhangorg22,org7&X. Zhangorg7&Y. Zhangorg7&C. Zhangorg63&Z. Zhangorg7,org131&C.
Zhaoorg21&N. Zhigarevaorg64&D. Zhouorg7&Y. Zhouorg91&Z. Zhouorg22&H.
Zhuorg22&J. Zhuorg7&Y. Zhuorg7&A. Zichichiorg12,org27&M.B. Zimmermannorg35&G.
Zinovjevorg3&J. Zmeskalorg113&S. Zouorg7&

## Affiliation notes

org*Deceased

orgIDipartimento DET del Politecnico di Torino, Turin, Italy

orgIIM.V. Lomonosov Moscow State University, D.V. Skobeltsyn Institute of
Nuclear, Physics, Moscow, Russia

orgIIIDepartment of Applied Physics, Aligarh Muslim University, Aligarh, India

orgIVInstitute of Theoretical Physics, University of Wroclaw, Poland

## Collaboration Institutes

org1A.I. Alikhanyan National Science Laboratory (Yerevan Physics Institute)
Foundation, Yerevan, Armenia

org2Benemérita Universidad Autónoma de Puebla, Puebla, Mexico

org3Bogolyubov Institute for Theoretical Physics, Kiev, Ukraine

org4Bose Institute, Department of Physics and Centre for Astroparticle Physics
and Space Science (CAPSS), Kolkata, India

org5Budker Institute for Nuclear Physics, Novosibirsk, Russia

org6California Polytechnic State University, San Luis Obispo, California,
United States

org7Central China Normal University, Wuhan, China

org8Centre de Calcul de l’IN2P3, Villeurbanne, Lyon, France

org9Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear (CEADEN), Havana,
Cuba

org10Centro de Investigaciones Energéticas Medioambientales y Tecnológicas
(CIEMAT), Madrid, Spain

org11Centro de Investigación y de Estudios Avanzados (CINVESTAV), Mexico City
and Mérida, Mexico

org12Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche
“Enrico Fermi’, Rome, Italy

org13Chicago State University, Chicago, Illinois, United States

org14China Institute of Atomic Energy, Beijing, China

org15COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan

org16Departamento de Física de Partículas and IGFAE, Universidad de Santiago
de Compostela, Santiago de Compostela, Spain

org17Department of Physics, Aligarh Muslim University, Aligarh, India

org18Department of Physics, Ohio State University, Columbus, Ohio, United
States

org19Department of Physics, Pusan National University, Pusan, Republic of
Korea

org20Department of Physics, Sejong University, Seoul, Republic of Korea

org21Department of Physics, University of Oslo, Oslo, Norway

org22Department of Physics and Technology, University of Bergen, Bergen,
Norway

org23Dipartimento di Fisica dell’Università ’La Sapienza’ and Sezione INFN,
Rome, Italy

org24Dipartimento di Fisica dell’Università and Sezione INFN, Cagliari, Italy

org25Dipartimento di Fisica dell’Università and Sezione INFN, Trieste, Italy

org26Dipartimento di Fisica dell’Università and Sezione INFN, Turin, Italy

org27Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN,
Bologna, Italy

org28Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN,
Catania, Italy

org29Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN,
Padova, Italy

org30Dipartimento di Fisica ‘E.R. Caianiello’ dell’Università and Gruppo
Collegato INFN, Salerno, Italy

org31Dipartimento DISAT del Politecnico and Sezione INFN, Turin, Italy

org32Dipartimento di Scienze e Innovazione Tecnologica dell’Università del
Piemonte Orientale and INFN Sezione di Torino, Alessandria, Italy

org33Dipartimento Interateneo di Fisica ‘M. Merlin’ and Sezione INFN, Bari,
Italy

org34Division of Experimental High Energy Physics, University of Lund, Lund,
Sweden

org35European Organization for Nuclear Research (CERN), Geneva, Switzerland

org36Excellence Cluster Universe, Technische Universität München, Munich,
Germany

org37Faculty of Engineering, Bergen University College, Bergen, Norway

org38Faculty of Mathematics, Physics and Informatics, Comenius University,
Bratislava, Slovakia

org39Faculty of Nuclear Sciences and Physical Engineering, Czech Technical
University in Prague, Prague, Czech Republic

org40Faculty of Science, P.J. Šafárik University, Košice, Slovakia

org41Faculty of Technology, Buskerud and Vestfold University College,
Tonsberg, Norway

org42Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-
Universität Frankfurt, Frankfurt, Germany

org43Gangneung-Wonju National University, Gangneung, Republic of Korea

org44Gauhati University, Department of Physics, Guwahati, India

org45Helmholtz-Institut für Strahlen- und Kernphysik, Rheinische Friedrich-
Wilhelms-Universität Bonn, Bonn, Germany

org46Helsinki Institute of Physics (HIP), Helsinki, Finland

org47Hiroshima University, Hiroshima, Japan

org48Indian Institute of Technology Bombay (IIT), Mumbai, India

org49Indian Institute of Technology Indore, Indore, India

org50Indonesian Institute of Sciences, Jakarta, Indonesia

org51INFN, Laboratori Nazionali di Frascati, Frascati, Italy

org52INFN, Sezione di Bari, Bari, Italy

org53INFN, Sezione di Bologna, Bologna, Italy

org54INFN, Sezione di Cagliari, Cagliari, Italy

org55INFN, Sezione di Catania, Catania, Italy

org56INFN, Sezione di Padova, Padova, Italy

org57INFN, Sezione di Roma, Rome, Italy

org58INFN, Sezione di Torino, Turin, Italy

org59INFN, Sezione di Trieste, Trieste, Italy

org60Inha University, Incheon, Republic of Korea

org61Institut de Physique Nucléaire d’Orsay (IPNO), Université Paris-Sud,
CNRS-IN2P3, Orsay, France

org62Institute for Nuclear Research, Academy of Sciences, Moscow, Russia

org63Institute for Subatomic Physics of Utrecht University, Utrecht,
Netherlands

org64Institute for Theoretical and Experimental Physics, Moscow, Russia

org65Institute of Experimental Physics, Slovak Academy of Sciences, Košice,
Slovakia

org66Institute of Physics, Academy of Sciences of the Czech Republic, Prague,
Czech Republic

org67Institute of Physics, Bhubaneswar, India

org68Institute of Space Science (ISS), Bucharest, Romania

org69Institut für Informatik, Johann Wolfgang Goethe-Universität Frankfurt,
Frankfurt, Germany

org70Institut für Kernphysik, Johann Wolfgang Goethe-Universität Frankfurt,
Frankfurt, Germany

org71Institut für Kernphysik, Westfälische Wilhelms-Universität Münster,
Münster, Germany

org72Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México,
Mexico City, Mexico

org73Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS),
Porto Alegre, Brazil

org74Instituto de Física, Universidad Nacional Autónoma de México, Mexico
City, Mexico

org75IRFU, CEA, Université Paris-Saclay, Saclay, France

org76iThemba LABS, National Research Foundation, Somerset West, South Africa

org77Joint Institute for Nuclear Research (JINR), Dubna, Russia

org78Konkuk University, Seoul, Republic of Korea

org79Korea Institute of Science and Technology Information, Daejeon, Republic
of Korea

org80KTO Karatay University, Konya, Turkey

org81Laboratoire de Physique Subatomique et de Cosmologie, Université
Grenoble-Alpes, CNRS-IN2P3, Grenoble, France

org82Lawrence Berkeley National Laboratory, Berkeley, California, United
States

org83Moscow Engineering Physics Institute, Moscow, Russia

org84Nagasaki Institute of Applied Science, Nagasaki, Japan

org85National and Kapodistrian University of Athens, Physics Department,
Athens, Greece

org86National Centre for Nuclear Studies, Warsaw, Poland

org87National Institute for Physics and Nuclear Engineering, Bucharest,
Romania

org88National Institute of Science Education and Research, HBNI, Jatni, India

org89National Nuclear Research Center, Baku, Azerbaijan

org90National Research Centre Kurchatov Institute, Moscow, Russia

org91Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark

org92Nikhef, Nationaal instituut voor subatomaire fysica, Amsterdam,
Netherlands

org93Nuclear Physics Group, STFC Daresbury Laboratory, Daresbury, United
Kingdom

org94Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Řež
u Prahy, Czech Republic

org95Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States

org96Petersburg Nuclear Physics Institute, Gatchina, Russia

org97Physics Department, Creighton University, Omaha, Nebraska, United States

org98Physics department, Faculty of science, University of Zagreb, Zagreb,
Croatia

org99Physics Department, Panjab University, Chandigarh, India

org100Physics Department, University of Cape Town, Cape Town, South Africa

org101Physics Department, University of Jammu, Jammu, India

org102Physics Department, University of Rajasthan, Jaipur, India

org103Physikalisches Institut, Eberhard Karls Universität Tübingen, Tübingen,
Germany

org104Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg,
Heidelberg, Germany

org105Physik Department, Technische Universität München, Munich, Germany

org106Research Division and ExtreMe Matter Institute EMMI, GSI
Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany

org107Rudjer Bošković Institute, Zagreb, Croatia

org108Russian Federal Nuclear Center (VNIIEF), Sarov, Russia

org109Saha Institute of Nuclear Physics, Kolkata, India

org110School of Physics and Astronomy, University of Birmingham, Birmingham,
United Kingdom

org111Sección Física, Departamento de Ciencias, Pontificia Universidad
Católica del Perú, Lima, Peru

org112SSC IHEP of NRC Kurchatov institute, Protvino, Russia

org113Stefan Meyer Institut für Subatomare Physik (SMI), Vienna, Austria

org114SUBATECH, IMT Atlantique, Université de Nantes, CNRS-IN2P3, Nantes,
France

org115Suranaree University of Technology, Nakhon Ratchasima, Thailand

org116Technical University of Košice, Košice, Slovakia

org117Technical University of Split FESB, Split, Croatia

org118The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy
of Sciences, Cracow, Poland

org119The University of Texas at Austin, Physics Department, Austin, Texas,
United States

org120Universidad Autónoma de Sinaloa, Culiacán, Mexico

org121Universidade de São Paulo (USP), São Paulo, Brazil

org122Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil

org123Universidade Federal do ABC, Santo Andre, Brazil

org124University of Houston, Houston, Texas, United States

org125University of Jyväskylä, Jyväskylä, Finland

org126University of Liverpool, Liverpool, United Kingdom

org127University of Tennessee, Knoxville, Tennessee, United States

org128University of the Witwatersrand, Johannesburg, South Africa

org129University of Tokyo, Tokyo, Japan

org130University of Tsukuba, Tsukuba, Japan

org131Université Clermont Auvergne, CNRS/IN2P3, LPC, Clermont-Ferrand, France

org132Université de Lyon, Université Lyon 1, CNRS/IN2P3, IPN-Lyon,
Villeurbanne, Lyon, France

org133Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg,
France, Strasbourg, France

org134Università degli Studi di Pavia, Pavia, Italy

org135Università di Brescia, Brescia, Italy

org136V. Fock Institute for Physics, St. Petersburg State University, St.
Petersburg, Russia

org137Variable Energy Cyclotron Centre, Kolkata, India

org138Warsaw University of Technology, Warsaw, Poland

org139Wayne State University, Detroit, Michigan, United States

org140Wigner Research Centre for Physics, Hungarian Academy of Sciences,
Budapest, Hungary

org141Yale University, New Haven, Connecticut, United States

org142Yonsei University, Seoul, Republic of Korea

org143Zentrum für Technologietransfer und Telekommunikation (ZTT),
Fachhochschule Worms, Worms, Germany