2015 151 17 June

ALICE Collaboration††thanks: See Appendix A for the list of collaboration
members

ALICE Collaboration Centrality dependence of high-$p_{\rm T}$ ${\mathbf{\rm
D}}$ meson suppression

The nuclear modification factor, $R_{\rm AA}$, of the prompt charmed mesons
${\rm D^{0}}$, ${\rm D^{+}}$ and ${\rm D^{*+}}$, and their antiparticles, was
measured with the ALICE detector in Pb–Pb collisions at a centre-of-mass
energy $\sqrt{s_{\scriptscriptstyle\rm NN}}=2.76~{}\mathrm{TeV}$ in two
transverse momentum intervals, $5<p_{\rm T}<8~{}\mathrm{GeV}/c$ and $8<p_{\rm
T}<16~{}\mathrm{GeV}/c$, and in six collision centrality classes. The $R_{\rm
AA}$ shows a maximum suppression of a factor of 5–6 in the 10$\%$ most central
collisions. The suppression and its centrality dependence are compatible
within uncertainties with those of charged pions. A comparison with the
$R_{\rm AA}$ of non-prompt ${\rm J}/\psi$ from B meson decays, measured by the
CMS Collaboration, hints at a larger suppression of D mesons in the most
central collisions.

##  1 Introduction

When heavy nuclei collide at high energy, a state of strongly-interacting
matter with high energy density is expected to form. According to Quantum
Chromodynamics (QCD) calculations on the lattice, this state of matter, the
so-called Quark-Gluon Plasma (QGP) is characterised by the deconfinement of
the colour charge (see e.g. [1, 2, 3, 4]). High-momentum partons, produced at
the early stage of the nuclear collision, lose energy as they interact with
the QGP constituents. This energy loss is expected to proceed via both
inelastic (gluon radiation) [5, 6] and elastic (collisional) processes [7, 8,
9].

The nuclear modification factor $R_{\rm AA}$ is used to characterise parton
energy loss by comparing particle production yields in nucleus–nucleus
collisions to a scaled proton–proton (pp) reference, that corresponds to a
superposition of independent nucleon–nucleon collisions. $R_{\rm AA}$ is
defined as

$R_{\rm AA}={1\over\left\langle T_{\rm AA}\right\rangle}\cdot{{\rm d}N_{\rm
AA}/{\rm d}p_{\rm T}\over{\rm d}\sigma_{\rm pp}/{\rm d}p_{\rm T}}\,,$ (1)

where ${\rm d}\sigma_{\rm pp}/{\rm d}p_{\rm T}$ and ${\rm d}N_{\rm AA}/{\rm
d}p_{\rm T}$ are the transverse momentum ($p_{\rm T}$) differential cross
section and yield in proton–proton and nucleus–nucleus (AA) collisions,
respectively. $\left\langle T_{\rm AA}\right\rangle$ is the average nuclear
overlap function, estimated within the Glauber model of the nucleus–nucleus
collision geometry, and proportional to the average number of nucleon–nucleon
(binary) collisions [10, 11]. Energy loss shifts the momentum of quarks and
gluons, and thus hadrons, towards lower values, leading to a suppression of
hadron yields with respect to binary scaling at $p_{\rm T}$ larger than few
$~{}\mathrm{GeV}/c$ ($R_{\rm AA}<1$).

Energy loss is expected to be smaller for quarks than for gluons because the
colour charge factor of quarks is smaller than that of gluons [5, 6]. In the
energy regime of the Large Hadron Collider (LHC), light-flavour hadrons with
$p_{\rm T}$ ranging from 5 to $20~{}\mathrm{GeV}/c$ originate predominantly
from gluon fragmentation (see e.g. [12]). At variance, charmed mesons provide
an experimental tag for a quark parent. Because of their large mass $m_{\rm
c,b}$ ($m_{\rm c}\approx 1.3~{}\mathrm{GeV}/c^{2}$, $m_{\rm b}\approx
4.5~{}\mathrm{GeV}/c^{2}$ [13]), heavy quarks are produced at the initial
stage of heavy-ion collisions in hard scattering processes that are
characterised by a timescale $\Delta t<1/(2\,m_{\rm c,b})\sim
0.1\,(0.01)~{}{\rm fm}/c$ for c (b) quarks. This time is shorter than the
formation time of the QGP medium (a recent estimate for the LHC energy is
about $0.3~{}{\rm fm}/c$ [14]). As discussed in Ref. [15], this should be the
case also for charm and beauty quarks produced in gluon splitting processes,
if their transverse momentum is lower than about $50~{}\mathrm{GeV}/c$.
Therefore, the comparison of the heavy-flavour hadron $R_{\rm AA}$ with that
of pions allows the colour-charge dependence of parton energy loss to be
tested. The softer fragmentation of gluons than that of charm quarks, and the
observed increase of the charged hadron $R_{\rm AA}$ towards high $p_{\rm T}$
[16], tend to counterbalance the effect of the larger energy loss of gluons on
the $R_{\rm AA}$. The model predictions range from a rather moderate effect
$R_{\rm AA}^{\pi}<R_{\rm AA}^{\rm D}$ [17, 18, 19, 20] to an overall
compensation $R_{\rm AA}^{\pi}\approx R_{\rm AA}^{\rm D}$ (as recently shown
in [12]) in the $p_{\rm T}$ interval from 5 to about $15~{}\mathrm{GeV}/c$.

Several mass-dependent effects are expected to influence the energy loss for
quarks (see [15] for a recent review). The dead-cone effect should reduce
small-angle gluon radiation for quarks that have moderate energy-over-mass
values, i.e. for c and b quarks with momenta up to about 10 and
$30~{}\mathrm{GeV}/c$, respectively [21, 22, 23, 24, 18]. Likewise,
collisional energy loss is expected to be reduced for heavier quarks, because
the spatial diffusion coefficient that regulates the momentum exchange with
the medium is expected to scale as the inverse of the quark mass [25]. In the
$p_{\rm T}$ interval up to about $20~{}\mathrm{GeV}/c$, where the masses of
heavy quarks are not negligible with respect to their momenta, essentially all
models predict $R_{\rm AA}^{\rm D}<R_{\rm AA}^{\rm B}$ [18, 19, 20, 17, 26,
27, 28, 29, 30, 31, 32, 33, 34, 35], which stems directly from the mass
dependence of the quark–medium interaction and is only moderately affected by
the different production and fragmentation kinematics of c and b quarks (see
e.g. [36]).

A first comparison of light-flavour, charm and beauty hadron nuclear
modification factors based on measurements by the ALICE and CMS Collaborations
[16, 37, 38] from the 2010 LHC Pb–Pb data at a centre-of-mass energy
$\sqrt{s_{\scriptscriptstyle\rm NN}}=2.76~{}\mathrm{TeV}$ was presented in
[37]. In this paper we present the centrality dependence of the D meson
$R_{\rm AA}$ in Pb–Pb collisions at the same energy, measured with the ALICE
detector [39] using data from both 2010 and 2011 periods (integrated
luminosities of about 2.2 and 21 $\rm\mu b^{-1}$, respectively). The focus
here is on the study of the parton energy loss; therefore, the data are
presented for the high-$p_{\rm T}$ interval 5–16 $\mathrm{GeV}/c$, where the
largest suppression relative to binary scaling was observed [37]. The results
are compared with charged pions, measured by the ALICE Collaboration [40],
with non-prompt J/$\psi$ mesons, measured by the CMS Collaboration [38], and
with model predictions.

##  2 Experimental apparatus and data sample

The Pb–Pb collisions were recorded using a minimum-bias interaction trigger,
based on the information of the signal coincidence of the V0 scintillator
detectors that cover the full azimuth in the pseudo-rapidity intervals
$-3.7<\eta<-1.7$ and $2.8<\eta<5.1$ [41]. The measurement of the summed signal
amplitudes from the V0 detectors was used to sort the events in classes of
collision centrality, defined in terms of percentiles of the Pb–Pb hadronic
cross section [42]. The trigger efficiency is $100\%$ for the events
considered in this analysis, which correspond to the most central $80\%$ of
the Pb–Pb hadronic cross section. An online selection based on the information
of the V0 detectors was applied to increase the statistics of central
collisions for the 2011 data sample. An offline selection using the V0 and the
neutron Zero-Degree Calorimeters (ZDC) was applied to remove background from
interactions of the beams with residual atoms in the vacuum tube. Events with
a reconstructed primary vertex outside the interval $\pm 10$ cm from the
interaction point along the beam direction ($z$ coordinate) were removed. The
event sample used in the analysis corresponds to an integrated luminosity
$L_{\rm int}=(21.3\pm 0.7)$ $\rm\mu b^{-1}$ in the 0–10% centrality class
($16.4\times 10^{6}$ events) and $(5.8\pm 0.2)$ $\rm\mu b^{-1}$ in each of the
10–20%, 20–30%, 30–40%, 40–50% classes ($4.5\times 10^{6}$ events per class).
In the 50–80% class, where 2010 data were used, the analyzed event sample
corresponds to $(2.2\pm 0.1)$ $\rm\mu b^{-1}$ ($5.1\times 10^{6}$ events).

The decays ${\rm D}^{0}\to{\rm K}^{-}\pi^{+}$, ${\rm D}^{+}\to{\rm
K}^{-}\pi^{+}\pi^{+}$ and ${\rm D}^{*+}\to{\rm D}^{0}\pi^{+}$, and their
charge conjugates, were reconstructed as described in [37] using the central
barrel detectors, which are located in a solenoid that generates a 0.5 T
magnetic field parallel to the beam direction. Charged particle tracks were
reconstructed with the Time Projection Chamber (TPC) [43] and the Inner
Tracking System (ITS), which consists of six cylindrical layers of silicon
detectors [44]. Both detectors provide full azimuthal coverage in the interval
$|\eta|<0.9$. ${\rm D^{0}}$ and ${\rm D^{+}}$ candidates were formed from
pairs and triplets of tracks with $|\eta|<0.8$, $p_{\rm
T}>0.4~{}\mathrm{GeV}/c$, at least 70 associated space points in the TPC, and
at least two hits in the ITS, out of which one had to be in either of the two
innermost layers. ${\rm D^{*+}}$ candidates were formed by combining ${\rm
D^{0}}$ candidates with tracks with $|\eta|<0.8$, $p_{\rm
T}>0.1~{}\mathrm{GeV}/c$, and at least three associated hits in the ITS for
the 10% most central collisions (two in the other centrality classes). The
decay tracks of the candidate D mesons were identified on the basis of their
specific ionization energy deposition ${\rm d}E/{\rm d}x$ in the TPC and of
their flight times to the Time Of Flight (TOF) detector, which has the same
$\eta$ acceptance as the TPC. Particles were identified as pions (kaons) by
requiring the measured signal to be within three times the resolution ($\pm
3\,\sigma$) around the expected mean values of ${\rm d}E/{\rm d}x$ and time-
of-flight for pions (kaons). Only D meson candidates with rapidity $|y|<0.8$
were considered, because the acceptance decreases rapidly outside this
interval.

##  3 Data analysis

The selection of the D meson decay topology is mainly based on the
displacement of the decay tracks from the primary vertex, and on the pointing
of the reconstructed D meson momentum to the primary vertex [37]. The raw
yields were determined in each centrality and $p_{\rm T}$ interval using fits
to the distributions of invariant mass $M({\rm K^{-}\pi^{+}})$ and $M({\rm
K^{-}}\pi^{+}\pi^{+})$, in the case of ${\rm D^{0}}$ and ${\rm D^{+}}$ mesons,
and of the difference $M({\rm K^{-}}\pi^{+}\pi^{+})-M(\rm K^{-}\pi^{+})$ for
${\rm D^{*+}}$ mesons. The fit function is the sum of a Gaussian, for the
signal, and either an exponential function (${\rm D^{0}}$ and ${\rm D^{+}}$)
or a power-law multiplied with an exponential function (${\rm D^{*+}}$) to
describe the background distribution [37].

For ${\rm D^{0}}$ mesons, an additional term was included in the fit function
to account for the so-called ‘reflections’, i.e. signal candidates that are
present in the invariant mass distribution also when the ${\rm(K,\pi)}$ mass
hypothesis for the decay tracks is swapped. A large fraction (about 70%) of
these reflections is rejected by the particle identification selection. The
residual contribution was studied with Monte Carlo simulations (described
later in this section). It was found that the reflections have a broad
invariant mass distribution, which is well described by a sum of two
Gaussians, and its integral amounts to about 30% of the yield of the signal in
the $p_{\rm T}$ interval used in the analysis presented in this article. In
order to account for the contribution of reflections in the data, a template
consisting of two Gaussians was included in the fit. The centroids and widths,
as well as the ratios of the integrals of these Gaussians to the signal
integral, were fixed to the values obtained in the simulation (see [45] for
more details).

Figure 1: Distributions of the ${\rm K}\pi$ invariant mass for ${\rm D^{0}}$
candidates (upper panels) and ${\rm K}\pi\pi$ invariant mass for ${\rm D^{+}}$
candidates (central panels) and of the invariant mass difference $M({\rm
K}\pi\pi)-M({\rm K}\pi)$ for ${\rm D^{*+}}$ candidates (lower panels) and the
corresponding charge conjugates in two $p_{\rm T}$ intervals (left and right
panels) for $16.4\times 10^{6}$ Pb–Pb collisions in the 0–10% centrality
class. The curves show the fit functions described in the text. The red short-
dashed line represents the background fit function. For the ${\rm D^{0}}$
meson, the gray dashed line represents the background without the inclusion of
the template for the contribution of reflections, i.e. signal candidates with
swapped ${\rm(K,\pi)}$ mass hypothesis. The template is defined as the sum of
two Gaussians with parameters fixed to the values obtained in simulation.

In the most central centrality class (0–10%), the statistical significance of
the invariant mass signal peaks varies from 8 to 18 depending on the D meson
species and $p_{\rm T}$, while the signal-over-background ratio ranges from
0.1 to 0.4. In the most peripheral centrality class (50–80%), the statistical
significance varies from 4 to 11, while the signal-over-background ranges from
0.4 to 1.5. In Fig. 1 the invariant mass distributions of the three meson
species are shown in the 0–10% centrality class and in the transverse momentum
intervals $5<p_{\rm T}<8~{}\mathrm{GeV}/c$ and $8<p_{\rm
T}<16~{}\mathrm{GeV}/c$.

| $5<p_{\rm T}<8~{}\mathrm{GeV}/c$ | $8<p_{\rm T}<16~{}\mathrm{GeV}/c$
---|---|---
|  ${\rm D^{0}}$ |  ${\rm D^{+}}$ |  ${\rm D^{*+}}$ |  ${\rm D^{0}}$ |  ${\rm D^{+}}$ |  ${\rm D^{*+}}$
Pb–Pb yields: |  |  |  |  |  |
Yield Extraction | 6 | 8 | 6 | 7 | 8 | 7
Tracking efficiency | 10 | 15 | 15 | 10 | 15 | 15
PID identification | 5 | 5 | 5 | 5 | 5 | 5
Cut efficiency | 5 | 10 | 5 | 5 | 10 | 5
D $p_{\rm T}$ distribution in sim. | 2 | 2 | 2 | 2 | 2 | 2
Feed-down subtraction | ${}^{+12}_{-13}$ | ${}^{+10}_{-10}$ | ${}^{+6}_{-8}$ | ${}^{+12}_{-12}$ | ${}^{+10}_{-10}$ | ${}^{+\phantom{1}7}_{-10}$
$\left\langle T_{\rm AA}\right\rangle$ [42] | 4 | 4
pp reference | 16 | 20 | 17 | 16 | 19 | 17
Reference scaling in $\sqrt{s}$ | ${}^{+\phantom{1}6}_{-12}$ | ${}^{+5}_{-6}$
Centrality limits |  $<$ 0.1
Table 1: Systematic uncertainties (%) on $R_{\rm AA}$ of prompt D mesons with
$5<p_{\rm T}<8~{}\mathrm{GeV}/c$ and $8<p_{\rm T}<16~{}\mathrm{GeV}/c$ in the
0–10% centrality class.

The correction for acceptance and efficiency was determined using Monte Carlo
simulations. Pb–Pb events were simulated using the HIJING generator [46] and D
meson signals were added with the PYTHIA 6 generator [47]. The $p_{\rm T}$
distribution of the D mesons was weighted in order to match the shape measured
for $\rm D^{0}$ mesons in central Pb–Pb collisions [37]. A detailed
description of the detector response, based on the GEANT3 transport package
[48], was included. The contribution of feed-down from ${\rm B\to D}+X$ to the
inclusive D meson raw yield depends on $p_{\rm T}$ and on the geometrical
selection criteria, because the secondary vertices of D mesons from B-hadron
decays are typically more displaced from the primary vertex than those of
prompt D mesons. This contribution was subtracted using the beauty-hadron
production cross section in pp collisions from FONLL calculations [49],
convoluted with the decay kinematics as implemented in the EvtGen decay
package [50] and multiplied by the efficiency for feed-down D mesons from the
simulation, the average nuclear overlap function $\left\langle T_{\rm
AA}\right\rangle$ in each centrality class, and an assumed value for $R_{\rm
AA}$ of feed-down D-mesons [37]. On the basis of the comparison shown in this
paper, this assumption was taken as $R_{\rm AA}^{\textnormal{feed-down
D}}=2\,R_{\rm AA}^{\textnormal{prompt D}}$ and a systematic uncertainty was
estimated by varying it in the interval $1<R_{\rm AA}^{\textnormal{feed-down
D}}/R_{\rm AA}^{\textnormal{prompt D}}<3$. The feed-down contribution is about
20–25%, depending on the D meson species and on the $p_{\rm T}$ interval.

The $p_{\rm T}$-differential cross section of prompt D mesons with $|y|<0.5$
in pp collisions at $\sqrt{s}=2.76~{}\mathrm{TeV}$, used as reference for
$R_{\rm AA}$, was obtained by scaling the measurement at $\sqrt{s}=7$ TeV
[51]. The $p_{\rm T}$-dependent scaling factor and its uncertainty were
determined with FONLL calculations [52]. The result of the scaling was
validated by comparison with the measurement obtained from a smaller sample of
pp collisions at $\sqrt{s}=2.76$ TeV [53]. This measurement covers a reduced
$p_{\rm T}$ interval 1–12 $\mathrm{GeV}/c$ with a statistical uncertainty of
20–25 $\%$ and was, therefore, not used as a pp reference in the present
analysis. The yields in Pb–Pb collisions were normalized to the same rapidity
interval as the reference ($|y|<0.5$) by dividing them by $\Delta y=1.6$.

The systematic uncertainties were estimated as a function of $p_{\rm T}$ and
centrality using the procedure described in [37, 45] and briefly outlined in
the following. The sources of systematic uncertainty on the nuclear
modification factor are listed in Table 1, along with their values for the two
$p_{\rm T}$ intervals in the most central collisions (0–10%). The
uncertainties are approximately independent of centrality.

The systematic uncertainty on the yield extraction was estimated by varying
the fit conditions (fit interval and functional form used to describe the
background) or by considering, as an alternative method, the bin counting of
the invariant mass distribution obtained after subtracting the background
estimated from a fit in the side-bands of the signal peak. The uncertainty
amounts to about 6–8%. This includes in the case of the $\rm D^{0}$ a
contribution of about 5% obtained by varying the ratio of the integral of the
reflections to the integral of the signal by $\pm~{}50\%$.

The systematic uncertainty on the tracking efficiency correction was evaluated
by varying the track selection criteria and amounts to $5\%$ per track, thus
10% for the $\rm D^{0}$ (two-track final state) and 15% for the $\rm D^{+}$
and $\rm D^{*+}$ mesons (three-track final states). The correction for the
particle identification (PID) efficiency introduces a systematic uncertainty
of 5%, which was estimated by repeating the analysis without this selection
and comparing the corrected yields. A systematic uncertainty of 5–10$\%$
associated with the selection efficiency correction was estimated by varying
the D meson selection cuts. The D meson $p_{\rm T}$ distribution used in the
simulation to calculate the acceptance and efficiency was varied between the
measured distribution and the prediction of a theoretical calculation
including parton energy loss [54, 55, 32]. The resulting variation of 2$\%$ of
the efficiencies was assigned as a systematic uncertainty.

The systematic uncertainty on the correction for feed-down from B-hadron
decays was estimated, as described in [45], by varying the parameters of the
FONLL calculation and the hypothesis on the $R_{\rm AA}$ of the feed-down D
mesons in the range $1<R_{\rm AA}^{\textnormal{feed-down D}}/R_{\rm
AA}^{\textnormal{prompt D}}<3$. This variation yields the main contribution to
the uncertainty, which amounts to 6–13$\%$, depending on the D meson species
and $p_{\rm T}$ interval.

The contribution to the systematic uncertainty due to the 1.1$\%$ relative
uncertainty on the fraction of hadronic cross section used in the Glauber fit
to determine the centrality classes was obtained as in [37] and estimated to
be $<$ 0.1$\%$ in the central centrality class (0–10$\%$) and 3$\%$ in the
most peripheral centrality class (50–80$\%$).

The systematic uncertainties on the denominator of the nuclear modification
factor include the uncertainty on $\left\langle T_{\rm AA}\right\rangle$,
which ranges from 4% in the 0–10% centrality class to 7.5% in the 50–80%
centrality class [42], and the uncertainty on the pp reference. The latter has
a contribution of about 16–20% from the pp measurement at
$\sqrt{s}=7~{}\mathrm{TeV}$ and a contribution of ${}^{+12}_{-\phantom{1}6}\%$
from the energy scaling down to $\sqrt{s}=2.76~{}\mathrm{TeV}$.

##  4 Results and discussion

Figure 2 shows the $R_{\rm AA}$ as a function of centrality for ${\rm D^{0}}$,
${\rm D^{+}}$ and ${\rm D^{*+}}$ in the intervals $5<p_{\rm
T}<8~{}\mathrm{GeV}/c$ (left) and $8<p_{\rm T}<16~{}\mathrm{GeV}/c$ (right).
Centrality is quantified in terms of the average number of nucleons
participating in the collision in each multiplicity class, $\langle{N_{\rm
part}}\rangle$, evaluated with a Monte Carlo Glauber calculation [42]. The
bars represent the statistical uncertainties. The filled and empty boxes
represent the quadratic sum of the systematic uncertainties that are,
respectively, correlated between centrality intervals (pp reference, B-hadron
cross section used for feed-down correction, particle identification, track
reconstruction efficiency, $\langle T_{\rm AA}\rangle$) and uncorrelated
(yield extraction, selection efficiency corrections, value of feed-down D
meson $R_{\rm AA}$). The latter category also includes the systematic
uncertainties that are partially correlated between adjacent centrality
classes. The measurements for the three D meson species share part of the
systematic uncertainties and are consistent within statistical uncertainties.
The suppression increases with centrality and reaches a factor of 5–6 in the
most central collisions for both $p_{\rm T}$ intervals.

A weighted average of the $R_{\rm AA}$ of the three D meson species was
computed using the inverse of the relative statistical uncertainties as
weights. The systematic uncertainties of the weighted average were calculated
considering the contributions from the tracking efficiency, the feed-down
correction, and the reference energy scaling factor from 7 to 2.76 TeV as
fully correlated among the three D meson species.

Figure 2: $R_{\rm AA}$ as a function of centrality ($\langle N_{\rm
part}\rangle$, see text) of ${\rm D^{0}}$, ${\rm D^{+}}$ and ${\rm D^{*+}}$ in
$5<p_{\rm T}<8~{}\mathrm{GeV}/c$ (left) and $8<p_{\rm T}<16~{}\mathrm{GeV}/c$
(right). The bars represent the statistical uncertainty while the filled
(empty) boxes represent the systematic uncertainties that are correlated
(uncorrelated) among centrality intervals. The symbols for ${\rm D^{*+}}$ and
${\rm D^{+}}$ are shifted by $\langle N_{\rm part}\rangle$ = 10 for better
visibility.

Figure 3 shows the average of the ${\rm D^{0}}$, ${\rm D^{+}}$ and ${\rm
D^{*+}}$ nuclear modification factors as a function of centrality, for the
intervals $5<p_{\rm T}<8~{}\mathrm{GeV}/c$ (left) and $8<p_{\rm
T}<16~{}\mathrm{GeV}/c$ (right), compared with the $R_{\rm AA}$ of charged
pions with $|y|<0.8$ for the same $p_{\rm T}$ intervals111The charged pion
results were obtained with the analysis method described in [40]., and of non-
prompt ${\rm J}/\psi$ mesons measured by the CMS Collaboration for $6.5<p_{\rm
T}<30~{}\mathrm{GeV}/c$ in $|y|<2.4$ [38]. Care has to be taken when comparing
with the non-central CMS data point as it is plotted at the $N_{\rm part}$
mean value of the broad 20–100$\%$ centrality interval.

The $p_{\rm T}$ interval 8–16 GeV/$c$ for D mesons was chosen in order to
obtain a significant overlap with the $p_{\rm T}$ distribution of B mesons
decaying to ${\rm J}/\psi$ particles with $6.5<p_{\rm T}<30~{}\mathrm{GeV}/c$.
Using a simulation based on the FONLL calculation [49] and the EvtGen particle
decay package [50], it was estimated that about 70% of these parent B mesons
have $8<p_{\rm T}<16~{}\mathrm{GeV}/c$, with a median of the $p_{\rm T}$
distribution of about 11.3 $\mathrm{GeV}/c$. A median value of
$(9.5~{}\pm~{}0.5)~{}\mathrm{GeV}/c$ was estimated for D mesons with $8<p_{\rm
T}<16~{}\mathrm{GeV}/c$ in the 0–10% centrality class. The estimate was based
on the $p_{\rm T}$ distribution of $\rm D^{0}$ mesons in $p_{\rm T}$ intervals
with a width of $1~{}\mathrm{GeV}/c$. The effect of the different width of the
rapidity interval for D and non-prompt ${\rm J}/\psi$ mesons ($|y|<0.5$ and
$|y|<2.4$, respectively) is expected to be mild because the intervals are
partially overlapping and a preliminary measurement by the CMS Collaboration
does not indicate a significant $y$ dependence of the $R_{\rm AA}$ of non-
prompt ${\rm J}/\psi$ mesons in $|y|<2.4$ [56].

The nuclear modification factors of charged pions and D mesons are compatible
within uncertainties in all centrality classes and in the two $p_{\rm T}$
intervals. The value of the D meson $R_{\rm AA}$ in the centrality classes
0–10% and 10–20% for $8<p_{\rm T}<16~{}\mathrm{GeV}/c$ is lower than that of
non-prompt ${\rm J}/\psi$ mesons in the centrality class 0–20%. However, the
difference between the $R_{\rm AA}$ values is not larger than $3\,\sigma$,
considering the statistical and systematic uncertainties. A preliminary
higher-statistics measurement by the CMS Collaboration of non-prompt J/$\psi$
production in the same $p_{\rm T}$ interval (6.5–30 $\mathrm{GeV}/c$) and in a
narrower rapidity interval $(|y|<1.2)$ is also available [56]. Considering
this measurement, the average difference of the $R_{\rm AA}$ values of D
mesons and non-prompt ${\rm J}/\psi$ in the 0–10% and 10–20% centrality
classes is larger than zero with a significance of 3.5 $\sigma$, obtained
including the systematic uncertainties, and taking into account their
correlation between the two centrality classes.

Figure 3: Comparison of the D meson $R_{\rm AA}$ (average of ${\rm D^{0}}$,
${\rm D^{+}}$ and ${\rm D^{*+}}$) and of the charged pion $R_{\rm AA}$ [40] in
$5<p_{\rm T}<8~{}\mathrm{GeV}/c$ (left) and in $8<p_{\rm
T}<16~{}\mathrm{GeV}/c$ (right). The right panel also includes the $R_{\rm
AA}$ of non-prompt ${\rm J}/\psi$ mesons in $6.5<p_{\rm
T}<30~{}\mathrm{GeV}/c$ measured by the CMS Collaboration [38]. The vertical
bars represent the statistical uncertainties. The D meson systematic
uncertainties are displayed as in the previous figures. The total systematic
uncertainties of charged pions are shown by boxes. The centrality-dependent
systematic uncertainties are shown by boxes on the individual data points.

Figure 4: Comparison of the $R_{\rm AA}$ measurements with the calculations by
Djordjevic et al. [57] including radiative and collisional energy loss. Lines
of the same style enclose a band representing the theoretical uncertainty.
Left: D mesons and charged pions in $8<p_{\rm T}<16~{}\mathrm{GeV}/c$. Right:
D mesons in $8<p_{\rm T}<16~{}\mathrm{GeV}/c$ and non-prompt J/$\psi$ mesons
in $6.5<p_{\rm T}<30~{}\mathrm{GeV}/c$ [38]. For the latter, the model results
for the case in which the b quark interactions are calculated using the c
quark mass are shown as well [15].

Figure 5: Comparison of the $R_{\rm AA}$ measurements for D mesons ($8<p_{\rm
T}<16~{}\mathrm{GeV}/c$) and non-prompt J/$\psi$ mesons ($6.5<p_{\rm
T}<30~{}\mathrm{GeV}/c$) [38] with the MC@sHQ+EPOS2 model [58] including
radiative and collisional interactions (left) and with the TAMU elastic model
[29] including collisional interactions via in-medium resonance formation. For
both models, results for the case in which the b quark interactions are
calculated using the c quark mass are shown as well [15]. In the right-hand
panel, the band between lines with the same style represents the theoretical
uncertainty.

The nuclear modification factors of D mesons (average of ${\rm D^{0}}$, ${\rm
D^{+}}$ and ${\rm D^{*+}}$) and charged pions in the interval $8<p_{\rm
T}<16~{}\mathrm{GeV}/c$ and that of non-prompt J/$\psi$ mesons in $6.5<p_{\rm
T}<30~{}\mathrm{GeV}/c$ were compared with theoretical calculations. Figure 4
shows the comparison with the calculation by Djordjevic et al. [57]. This
model implements energy loss for gluons, light and heavy quarks, including
both radiative (DGLV formalism [23]) and collisional processes and considers
dynamical scattering centres in the medium. The heavy-quark production $p_{\rm
T}$-differential cross sections are obtained from FONLL calculations [49] and
hadronization assumes fragmentation outside the medium. In the left-hand
panel, the calculation closely describes the similarity of the D meson and
charged pion $R_{\rm AA}$ over the entire centrality range. As mentioned in
the introduction, in this calculation the colour-charge dependence of energy
loss introduces a sizeable difference in the suppression of the gluon and c
quark production. However, the softer fragmentation and $p_{\rm T}$ spectrum
of gluons with respect to those of c quarks, together with the increase of the
parton-level $R_{\rm AA}$ with increasing $p_{\rm T}$, lead to a compensation
effect that results in a very similar $R_{\rm AA}$ for D mesons and pions
[12]. As shown in the right-hand panel of the figure, this calculation results
in a larger suppression of D mesons with respect to non-prompt J/$\psi$, in
qualitative agreement with the data for the most central collisions. In order
to study the origin of this large difference in the calculation, the result
for a test case with the energy loss of b quarks calculated using the c quark
mass was considered [15]. In this case, the $R_{\rm AA}$ of non-prompt
J/$\psi$ was found to be quite close to that of D mesons. This indicates that,
in the calculation, the large difference in the $R_{\rm AA}$ of D mesons and
non-prompt J/$\psi$ derives predominantly from the quark mass dependence of
the parton energy loss.

In Fig. 5 the D meson and non-prompt J/$\psi$ data are compared with two
theoretical models that implement heavy-quark interactions in an expanding
hydrodynamical medium. The MC@sHQ+EPOS2 model [58], shown in the left-hand
panel, includes radiative and collisional energy loss. The hydrodynamical
evolution of the medium is simulated using the EPOS2 model [59, 60]. Heavy-
quark transport in the medium is based on the Boltzmann equation, with
collisional processes and radiative corrections. The TAMU elastic model [29],
shown in the right-hand panel, includes collisional (elastic) processes only.
In this model, the heavy-quark transport coefficient is calculated within a
non-perturbative $T$-matrix approach, where the interactions proceed via
resonance formation that transfers momentum from the heavy quarks to the
medium constituents. The model includes hydrodynamic medium evolution,
constrained by light-flavour hadron production data. Elastic diffusion of
heavy-flavour hadrons in the hadronic phase is included as well. In both
models, similarly to that of Djordjevic et al., the heavy-quark production
cross sections are obtained from the FONLL calculation [49]. Both models
implement a contribution of quark recombination in the hadronization of heavy
quarks, in addition to fragmentation outside the medium. The dotted lines
correspond to the test case in which the b quark mass is decreased to the c
quark mass value in the calculation of the in-medium interactions [15].

The MC@sHQ+EPOS2 model qualitatively describes the two measurements in these
$p_{\rm T}$ intervals. In this model a large difference in the suppression of
D mesons and non-prompt J/$\psi$ is caused by the mass dependence of energy
loss as in Djordjevic et al. model. The TAMU elastic model tends to
overestimate $R_{\rm AA}$ for both the non-prompt J/$\psi$ and the D mesons,
in particular in central collisions. At variance with the other two models, in
this case the quark mass effect accounts for only about half of the difference
in the suppression of D and non-prompt J/$\psi$ mesons. This model does not
include radiative energy loss, which is expected to have a strong mass
dependence.

The nuclear modification factors of D mesons and non-prompt J/$\psi$ are also
described by a model calculation by the Duke group [61], that includes
radiative and collisional energy loss within an hydro- dynamical medium and
performs the hadronization of heavy quarks using recombination and
fragmentation.

##  5 Summary

The centrality dependence of the nuclear modification factor of prompt D
mesons in Pb–Pb collisions at $\sqrt{s_{\scriptscriptstyle\rm
NN}}=2.76~{}\mathrm{TeV}$ was presented in the intervals $5<p_{\rm
T}<8~{}\mathrm{GeV}/c$ and $8<p_{\rm T}<16~{}\mathrm{GeV}/c$. A suppression is
observed already in the centrality class 50–80% and it increases towards more
central collisions, reaching a maximum of a factor about 5–6 in the most
central collisions.

The centrality dependence and the magnitude of the suppression are similar to
those of charged pions in the same $p_{\rm T}$ intervals. The comparison of
the D meson $R_{\rm AA}$ with the non-prompt J/$\psi$ meson $R_{\rm AA}$ hints
at a difference in the suppression of particles originating from c and b
quarks in the most central collisions.

These results are described by theoretical calculations in which in-medium
parton energy loss increases with increasing colour charge factor and
decreases with increasing quark mass. Calculations that include radiative
energy loss, in addition to collisional energy loss, provide a better
quantitative description of the data.

## 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: State
Committee of Science, World Federation of Scientists (WFS) and Swiss Fonds
Kidagan, Armenia, Conselho Nacional de Desenvolvimento Científico e
Tecnológico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundação de
Amparo à Pesquisa do Estado de São Paulo (FAPESP); National Natural Science
Foundation of China (NSFC), the Chinese Ministry of Education (CMOE) and the
Ministry of Science and Technology of China (MSTC); Ministry of Education and
Youth of the Czech Republic; Danish Natural Science Research Council, the
Carlsberg Foundation and the Danish National Research Foundation; The European
Research Council under the European Community’s Seventh Framework Programme;
Helsinki Institute of Physics and the Academy of Finland; French CNRS-IN2P3,
the ‘Region Pays de Loire’, ‘Region Alsace’, ‘Region Auvergne’ and CEA,
France; German Bundesministerium fur Bildung, Wissenschaft, Forschung und
Technologie (BMBF) and the Helmholtz Association; General Secretariat for
Research and Technology, Ministry of Development, Greece; Hungarian Orszagos
Tudomanyos Kutatasi Alappgrammok (OTKA) and National Office for Research and
Technology (NKTH); Department of Atomic Energy and Department of Science and
Technology of the Government of India; Istituto Nazionale di Fisica Nucleare
(INFN) and Centro Fermi - Museo Storico della Fisica e Centro Studi e Ricerche
”Enrico Fermi”, Italy; MEXT Grant-in-Aid for Specially Promoted Research,
Japan; Joint Institute for Nuclear Research, Dubna; National Research
Foundation of Korea (NRF); Consejo Nacional de Cienca y Tecnologia (CONACYT),
Direccion General de Asuntos del Personal Academico(DGAPA), México, Amerique
Latine Formation academique - European Commission (ALFA-EC) and the EPLANET
Program (European Particle Physics Latin American Network); Stichting voor
Fundamenteel Onderzoek der Materie (FOM) and the Nederlandse Organisatie voor
Wetenschappelijk Onderzoek (NWO), Netherlands; Research Council of Norway
(NFR); National Science Centre, Poland; Ministry of National
Education/Institute for Atomic Physics and National Council of Scientific
Research in Higher Education (CNCSI-UEFISCDI), Romania; Ministry of Education
and Science of Russian Federation, Russian Academy of Sciences, Russian
Federal Agency of Atomic Energy, Russian Federal Agency for Science and
Innovations and The Russian Foundation for Basic Research; Ministry of
Education of Slovakia; Department of Science and Technology, South Africa;
Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas
(CIEMAT), E-Infrastructure shared between Europe and Latin America (EELA),
Ministerio de Economía y Competitividad (MINECO) of Spain, Xunta de Galicia
(Consellería de Educación), Centro de Aplicaciones Tecnológicas y Desarrollo
Nuclear (CEADEN), Cubaenergía, Cuba, and IAEA (International Atomic Energy
Agency); Swedish Research Council (VR) and Knut $\&$ Alice Wallenberg
Foundation (KAW); Ukraine Ministry of Education and Science; United Kingdom
Science and Technology Facilities Council (STFC); The United States Department
of Energy, the United States National Science Foundation, the State of Texas,
and the State of Ohio; Ministry of Science, Education and Sports of Croatia
and Unity through Knowledge Fund, Croatia. Council of Scientific and
Industrial Research (CSIR), New Delhi, India

## References

  * [1] F. Karsch, “Lattice simulations of the thermodynamics of strongly interacting elementary particles and the exploration of new phases of matter in relativistic heavy ion collisions,” J.Phys.Conf.Ser. 46 (2006) 122–131, arXiv:hep-lat/0608003 [hep-lat].
  * [2] Wuppertal-Budapest Collaboration, S. Borsanyi et al., “Is there still any Tc mystery in lattice QCD? Results with physical masses in the continuum limit III,” JHEP 1009 (2010) 073, arXiv:1005.3508 [hep-lat].
  * [3] S. Borsanyi, Z. Fodor, C. Hoelbling, S. D. Katz, S. Krieg, et al., “Full result for the QCD equation of state with 2+1 flavors,” Phys.Lett. B730 (2014) 99–104, arXiv:1309.5258 [hep-lat].
  * [4] A. Bazavov, T. Bhattacharya, M. Cheng, C. DeTar, H. Ding, et al., “The chiral and deconfinement aspects of the QCD transition,” Phys.Rev. D85 (2012) 054503, arXiv:1111.1710 [hep-lat].
  * [5] M. Gyulassy and M. Plumer, “Jet Quenching in Dense Matter,” Phys.Lett. B243 (1990) 432–438.
  * [6] R. Baier, Y. L. Dokshitzer, A. H. Mueller, S. Peigne, and D. Schiff, “Radiative energy loss and pT broadening of high-energy partons in nuclei,” Nucl.Phys. B484 (1997) 265–282, arXiv:hep-ph/9608322 [hep-ph].
  * [7] M. H. Thoma and M. Gyulassy, “Quark Damping and Energy Loss in the High Temperature QCD,” Nucl.Phys. B351 (1991) 491–506.
  * [8] E. Braaten and M. H. Thoma, “Energy loss of a heavy quark in the quark-gluon plasma,” Phys.Rev. D44 (1991) 2625–2630.
  * [9] E. Braaten and M. H. Thoma, “Energy loss of a heavy fermion in a hot plasma,” Phys.Rev. D44 (1991) 1298–1310.
  * [10] ed. W. E. Brittin et al., “R. J. Glauber in Lectures in Theoretical Physics,” Interscience Publishers, NY, Vol. 1 (1959) 315.
  * [11] M. L. Miller, K. Reygers, S. J. Sanders, and P. Steinberg, “Glauber modeling in high energy nuclear collisions,” Ann.Rev.Nucl.Part.Sci. 57 (2007) 205–243, arXiv:nucl-ex/0701025 [nucl-ex].
  * [12] M. Djordjevic, “Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression and fragmentation,” Phys.Rev.Lett. 112 no. 4, (2014) 042302, arXiv:1307.4702 [nucl-th].
  * [13] Particle Data Group Collaboration, J. Beringer et al., “Review of Particle Physics (RPP),” Phys.Rev. D86 (2012) 010001.
  * [14] F.-M. Liu and S.-X. Liu, “Quark-gluon plasma formation time and direct photons from heavy ion collisions,” Phys.Rev. C89 no. 3, (2014) 034906, arXiv:1212.6587 [nucl-th].
  * [15] A. Andronic, F. Arleo, R. Arnaldi, A. Beraudo, E. Bruna, et al., “Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions,” arXiv:1506.03981 [nucl-ex].
  * [16] ALICE Collaboration, B. Abelev et al., “Centrality Dependence of Charged Particle Production at Large Transverse Momentum in Pb–Pb Collisions at $\sqrt{s_{\rm{NN}}}=2.76$ TeV,” Phys.Lett. B720 (2013) 52–62, arXiv:1208.2711 [hep-ex].
  * [17] N. Armesto, A. Dainese, C. A. Salgado, and U. A. Wiedemann, “Testing the color charge and mass dependence of parton energy loss with heavy-to-light ratios at RHIC and CERN LHC,” Phys.Rev. D71 ((2005)) 054027, arXiv:hep-ph/0501225 [hep-ph].
  * [18] S. Wicks, W. Horowitz, M. Djordjevic, and M. Gyulassy, “Elastic, inelastic, and path length fluctuations in jet tomography,” Nucl.Phys. A784 (2007) 426–442, arXiv:nucl-th/0512076 [nucl-th].
  * [19] W. Horowitz and M. Gyulassy, “The Surprising Transparency of the sQGP at LHC,” Nucl.Phys. A872 (2011) 265–285, arXiv:1104.4958 [hep-ph].
  * [20] W. Horowitz, “Testing pQCD and AdS/CFT Energy Loss at RHIC and LHC,” AIP Conf.Proc. 1441 (2012) 889–891, arXiv:1108.5876 [hep-ph].
  * [21] Y. L. Dokshitzer and D. Kharzeev, “Heavy quark colorimetry of QCD matter,” Phys.Lett. B519 (2001) 199–206, arXiv:hep-ph/0106202 [hep-ph].
  * [22] N. Armesto, C. A. Salgado, and U. A. Wiedemann, “Medium induced gluon radiation off massive quarks fills the dead cone,” Phys.Rev. D69 (2004) 114003, arXiv:hep-ph/0312106 [hep-ph].
  * [23] M. Djordjevic and M. Gyulassy, “Heavy quark radiative energy loss in QCD matter,” Nucl.Phys. A733 (2004) 265–298, arXiv:nucl-th/0310076 [nucl-th].
  * [24] B.-W. Zhang, E. Wang, and X.-N. Wang, “Heavy quark energy loss in nuclear medium,” Phys.Rev.Lett. 93 (2004) 072301, arXiv:nucl-th/0309040 [nucl-th].
  * [25] H. van Hees, V. Greco, and R. Rapp, “Heavy-quark probes of the quark-gluon plasma at RHIC,” Phys.Rev. C73 (2006) 034913, arXiv:nucl-th/0508055 [nucl-th].
  * [26] A. Adil and I. Vitev, “Collisional dissociation of heavy mesons in dense QCD matter,” Phys.Lett. B649 (2007) 139–146, arXiv:hep-ph/0611109 [hep-ph].
  * [27] R. Sharma, I. Vitev, and B.-W. Zhang, “Light-cone wave function approach to open heavy flavor dynamics in QCD matter,” Phys.Rev. C80 (2009) 054902, arXiv:0904.0032 [hep-ph].
  * [28] A. Buzzatti and M. Gyulassy, “A running coupling explanation of the surprising transparency of the QGP at LHC,” Nucl.Phys. A904-905 (2013) 779c–782c, arXiv:1210.6417 [hep-ph].
  * [29] M. He, R. J. Fries, and R. Rapp, “Non-perturbative Heavy-Flavor Transport at RHIC and LHC,” Nucl.Phys. A910-911 (2013) 409–412, arXiv:1208.0256 [nucl-th].
  * [30] M. He, R. J. Fries, and R. Rapp, “Heavy Flavor at the Large Hadron Collider in a Strong Coupling Approach,” Phys.Lett. B735 (2014) 445–450, arXiv:1401.3817 [nucl-th].
  * [31] P. Gossiaux, M. Nahrgang, M. Bluhm, T. Gousset, and J. Aichelin, “Heavy quark quenching from RHIC to LHC and the consequences of gluon damping,” Nucl.Phys. A904-905 (2013) 992c–995c, arXiv:1211.2281 [hep-ph].
  * [32] J. Uphoff, O. Fochler, Z. Xu, and C. Greiner, “Open Heavy Flavor in Pb+Pb Collisions at $\sqrt{s}=2.76$ TeV within a Transport Model,” Phys.Lett. B717 (2012) 430–435, arXiv:1205.4945 [hep-ph].
  * [33] W. Alberico, A. Beraudo, A. De Pace, A. Molinari, M. Monteno, et al., “Heavy flavors in $AA$ collisions: production, transport and final spectra,” Eur.Phys.J. C73 (2013) 2481, arXiv:1305.7421 [hep-ph].
  * [34] S. Cao, G.-Y. Qin, and S. A. Bass, “Heavy-quark dynamics and hadronization in ultrarelativistic heavy-ion collisions: Collisional versus radiative energy loss,” Phys.Rev. C88 no. 4, (2013) 044907, arXiv:1308.0617 [nucl-th].
  * [35] T. Lang, H. van Hees, J. Steinheimer, and M. Bleicher, “Heavy quark transport in heavy ion collisions at RHIC and LHC within the UrQMD transport model,” (2012) 20, arXiv:1211.6912 [hep-ph].
  * [36] N. Armesto, N. Borghini, S. Jeon, U. Wiedemann, S. Abreu, et al., “Heavy Ion Collisions at the LHC - Last Call for Predictions,” J.Phys. G35 (2008) 054001, arXiv:0711.0974 [hep-ph].
  * [37] ALICE Collaboration, B. Abelev et al., “Suppression of high transverse momentum D mesons in central Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV,” JHEP 1209 (2012) 112, arXiv:1203.2160 [nucl-ex].
  * [38] CMS Collaboration, S. Chatrchyan et al., “Suppression of non-prompt $J/\psi$, prompt $J/\psi$, and Y(1S) in PbPb collisions at $\sqrt{s_{NN}}=2.76$ TeV,” JHEP 1205 (2012) 063, arXiv:1201.5069 [nucl-ex].
  * [39] ALICE Collaboration, K. Aamodt et al., “The ALICE experiment at the CERN LHC,” JINST 3 (2008) S08002.
  * [40] ALICE Collaboration, B. B. Abelev et al., “Production of charged pions, kaons and protons at large transverse momenta in pp and Pb–Pb collisions at $\sqrt{s_{\rm NN}}$ =2.76 TeV,” Phys.Lett. B736 (2014) 196–207, arXiv:1401.1250 [nucl-ex].
  * [41] ALICE Collaboration, E. Abbas et al., “Performance of the ALICE VZERO system,” JINST 8 (2013) P10016, arXiv:1306.3130 [nucl-ex].
  * [42] ALICE Collaboration, B. Abelev et al., “Centrality determination of Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV with ALICE,” Phys.Rev. C88 no. 4, (2013) 044909, arXiv:1301.4361 [nucl-ex].
  * [43] J. Alme, Y. Andres, H. Appelshauser, S. Bablok, N. Bialas, et al., “The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events,” Nucl.Instrum.Meth. A622 (2010) 316–367, arXiv:1001.1950 [physics.ins-det].
  * [44] ALICE Collaboration, K. Aamodt et al., “Alignment of the ALICE Inner Tracking System with cosmic-ray tracks,” JINST 5 (2010) P03003, arXiv:1001.0502 [physics.ins-det].
  * [45] ALICE Collaboration, B. B. Abelev et al., “Azimuthal anisotropy of D meson production in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV,” Phys.Rev. C90 no. 3, (2014) 034904, arXiv:1405.2001 [nucl-ex].
  * [46] X.-N. Wang and M. Gyulassy, “HIJING: A Monte Carlo model for multiple jet production in p-p, p-A and A-A collisions,” Phys.Rev. D44 (1991) 3501–3516.
  * [47] T. Sjostrand, S. Mrenna, and P. Z. Skands, “PYTHIA 6.4 Physics and Manual,” JHEP 0605 (2006) 026, arXiv:hep-ph/0603175 [hep-ph].
  * [48] R. Brun, F. Carminati, and S. Giani, “GEANT Detector Description and Simulation Tool,” CERN-W5013, CERN-W-5013 (1994) .
  * [49] M. Cacciari, S. Frixione, N. Houdeau, M. L. Mangano, P. Nason, et al., “Theoretical predictions for charm and bottom production at the LHC,” JHEP 1210 (2012) 137, arXiv:1205.6344 [hep-ph].
  * [50] D. Lange, “The EvtGen particle decay simulation package,” Nucl.Instrum.Meth. A462 (2001) 152–155.
  * [51] ALICE Collaboration, B. Abelev et al., “Measurement of charm production at central rapidity in proton-proton collisions at $\sqrt{s}=7$ TeV,” JHEP 1201 (2012) 128, arXiv:1111.1553 [hep-ex].
  * [52] R. Averbeck, N. Bastid, Z. C. del Valle, P. Crochet, A. Dainese, et al., “Reference Heavy Flavour Cross Sections in pp Collisions at $\sqrt{s}=2.76TeV$, using a pQCD-Driven $\sqrt{s}-Scaling$ of ALICE Measurements at $\sqrt{s}=7TeV$,” arXiv:1107.3243 [hep-ph].
  * [53] ALICE Collaboration, B. Abelev et al., “Measurement of charm production at central rapidity in proton-proton collisions at $\sqrt{s}=2.76$ TeV,” JHEP 1207 (2012) 191, arXiv:1205.4007 [hep-ex].
  * [54] J. Uphoff, O. Fochler, Z. Xu, and C. Greiner, “Elliptic Flow and Energy Loss of Heavy Quarks in Ultra-Relativistic heavy Ion Collisions,” Phys.Rev. C84 (2011) 024908, arXiv:1104.2295 [hep-ph].
  * [55] O. Fochler, J. Uphoff, Z. Xu, and C. Greiner, “Jet quenching and elliptic flow at RHIC and LHC within a pQCD-based partonic transport model,” J.Phys. G38 (2011) 124152, arXiv:1107.0130 [hep-ph].
  * [56] CMS Collaboration, C. Collaboration, “$J/\psi$ results from CMS in PbPb collisions, with 150 $\mu b^{-1}$ data,” CMS-PAS-HIN-12-014 (2012) .
  * [57] M. Djordjevic, M. Djordjevic, and B. Blagojevic, “RHIC and LHC jet suppression in non-central collisions,” Phys.Lett. B737 (2014) 298–302, arXiv:1405.4250 [nucl-th].
  * [58] M. Nahrgang, J. Aichelin, P. B. Gossiaux, and K. Werner, “Influence of hadronic bound states above $T_{c}$ on heavy-quark observables in Pb+Pb collisions at at the CERN Large Hadron Collider,” Phys.Rev. C89 no. 1, (2014) 014905, arXiv:1305.6544 [hep-ph].
  * [59] K. Werner, I. Karpenko, T. Pierog, M. Bleicher, and K. Mikhailov, “Event-by-Event Simulation of the Three-Dimensional Hydrodynamic Evolution from Flux Tube Initial Conditions in Ultrarelativistic Heavy Ion Collisions,” Phys.Rev. C82 (2010) 044904, arXiv:1004.0805 [nucl-th].
  * [60] K. Werner, I. Karpenko, M. Bleicher, T. Pierog, and S. Porteboeuf-Houssais, “Jets, Bulk Matter, and their Interaction in Heavy Ion Collisions at Several TeV,” Phys.Rev. C85 (2012) 064907, arXiv:1203.5704 [nucl-th].
  * [61] S. Cao, G.-Y. Qin, and S. A. Bass, “Energy loss, hadronization and hadronic interactions of heavy flavors in relativistic heavy-ion collisions,” arXiv:1505.01413 [nucl-th].

##  Appendix A ALICE Collaboration

J. Adamorg40&D. Adamováorg83&M.M. Aggarwalorg87&G. Aglieri Rinellaorg36&M.
Agnelloorg111&N. Agrawalorg48&Z. Ahammedorg132&S.U. Ahnorg68&I.
Aimoorg94,org111&S. Aiolaorg137&M. Ajazorg16&A. Akindinovorg58&S.N.
Alamorg132&D. Aleksandrovorg100&B. Alessandroorg111&D. Alexandreorg102&R.
Alfaro Molinaorg64&A. Aliciorg105,org12&A. Alkinorg3&J.R.M. Almarazorg119&J.
Almeorg38&T. Altorg43&S. Altinpinarorg18&I. Altsybeevorg131&C. Alves Garcia
Pradoorg120&C. Andreiorg78&A. Andronicorg97&V. Anguelovorg93&J.
Anielskiorg54&T. Antičićorg98&F. Antinoriorg108&P. Antonioliorg105&L.
Aphecetcheorg113&H. Appelshäuserorg53&S. Arcelliorg28&N. Armestoorg17&R.
Arnaldiorg111&I.C. Arseneorg22&M. Arslandokorg53&B. Audurierorg113&A.
Augustinusorg36&R. Averbeckorg97&M.D. Azmiorg19&M. Bachorg43&A.
Badalàorg107&Y.W. Baekorg44&S. Bagnascoorg111&R. Bailhacheorg53&R.
Balaorg90&A. Baldisseriorg15&F. Baltasar Dos Santos Pedrosaorg36&R.C.
Baralorg61&A.M. Barbanoorg111&R. Barberaorg29&F. Barileorg33&G.G.
Barnaföldiorg136&L.S. Barnbyorg102&V. Barretorg70&P. Bartaliniorg7&K.
Barthorg36&J. Bartkeorg117&E. Bartschorg53&M. Basileorg28&N. Bastidorg70&S.
Basuorg132&B. Bathenorg54&G. Batigneorg113&A. Batista Camejoorg70&B.
Batyunyaorg66&P.C. Batzingorg22&I.G. Beardenorg80&H. Beckorg53&C.
Beddaorg111&N.K. Beheraorg48,org49&I. Belikovorg55&F. Belliniorg28&H. Bello
Martinezorg2&R. Bellwiedorg122&R. Belmontorg135&E. Belmont-Morenoorg64&V.
Belyaevorg76&G. Bencediorg136&S. Beoleorg27&I. Berceanuorg78&A.
Bercuciorg78&Y. Berdnikovorg85&D. Berenyiorg136&R.A. Bertensorg57&D.
Berzanoorg36,org27&L. Betevorg36&A. Bhasinorg90&I.R. Bhatorg90&A.K.
Bhatiorg87&B. Bhattacharjeeorg45&J. Bhomorg128&L. Bianchiorg122&N.
Bianchiorg72&C. Bianchinorg135,org57&J. Bielčíkorg40&J. Bielčíkováorg83&A.
Bilandzicorg80&R. Biswasorg4&S. Biswasorg79&S. Bjelogrlicorg57&F.
Blancoorg10&D. Blauorg100&C. Blumeorg53&F. Bockorg74,org93&A. Bogdanovorg76&H.
Bøggildorg80&L. Boldizsárorg136&M. Bombaraorg41&J. Bookorg53&H. Borelorg15&A.
Borissovorg96&M. Borriorg82&F. Bossúorg65&E. Bottaorg27&S. Böttgerorg52&P.
Braun-Munzingerorg97&M. Bregantorg120&T. Breitnerorg52&T.A. Brokerorg53&T.A.
Browningorg95&M. Brozorg40&E.J. Bruckenorg46&E. Brunaorg111&G.E. Brunoorg33&D.
Budnikovorg99&H. Bueschingorg53&S. Bufalinoorg36,org111&P. Buncicorg36&O.
Buschorg93,org128&Z. Butheleziorg65&J.B. Buttorg16&J.T. Buxtonorg20&D.
Caffarriorg36&X. Caiorg7&H. Cainesorg137&L. Calero Diazorg72&A. Calivaorg57&E.
Calvo Villarorg103&P. Cameriniorg26&F. Carenaorg36&W. Carenaorg36&J. Castillo
Castellanosorg15&A.J. Castroorg125&E.A.R. Casulaorg25&C. Cavicchioliorg36&C.
Ceballos Sanchezorg9&J. Cepilaorg40&P. Cerelloorg111&J. Cerkalaorg115&B.
Changorg123&S. Chapelandorg36&M. Chartierorg124&J.L. Charvetorg15&S.
Chattopadhyayorg132&S. Chattopadhyayorg101&V. Chelnokovorg3&M. Cherneyorg86&C.
Cheshkovorg130&B. Cheynisorg130&V. Chibante Barrosoorg36&D.D.
Chinellatoorg121&P. Chochulaorg36&K. Choiorg96&M. Chojnackiorg80&S.
Choudhuryorg132&P. Christakoglouorg81&C.H. Christensenorg80&P.
Christiansenorg34&T. Chujoorg128&S.U. Chungorg96&Z. Chunhuiorg57&C.
Cicaloorg106&L. Cifarelliorg12,org28&F. Cindoloorg105&J. Cleymansorg89&F.
Colamariaorg33&D. Colellaorg36,org59,org33&A. Colluorg25&M. Colocciorg28&G.
Conesa Balbastreorg71&Z. Conesa del Valleorg51&M.E. Connorsorg137&J.G.
Contrerasorg11,org40&T.M. Cormierorg84&Y. Corrales Moralesorg27&I. Cortés
Maldonadoorg2&P. Corteseorg32&M.R. Cosentinoorg120&F. Costaorg36&P.
Crochetorg70&R. Cruz Albinoorg11&E. Cuautleorg63&L. Cunqueiroorg36&T.
Dahmsorg92,org37&A. Daineseorg108&A. Danuorg62&D. Dasorg101&I.
Dasorg51,org101&S. Dasorg4&A. Dashorg121&S. Dashorg48&S. Deorg120&A. De
Caroorg31,org12&G. de Cataldoorg104&J. de Cuvelandorg43&A. De Falcoorg25&D. De
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Deistingorg97,org93&A. Delofforg77&E. Dénesorg136&G. D’Erasmoorg33&D. Di
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Dietelorg89&P. Dillensegerorg53&R. Diviàorg36&Ø. Djuvslandorg18&A.
Dobrinorg57,org81&T. Dobrowolskiorg770&D. Domenicis Gimenezorg120&B.
Dönigusorg53&O. Dordicorg22&A.K. Dubeyorg132&A. Dublaorg57&L. Ducrouxorg130&P.
Dupieuxorg70&R.J. Ehlersorg137&D. Eliaorg104&H. Engelorg52&B.
Erazmusorg36,org113&I. Erdemirorg53&F. Erhardtorg129&D. Eschweilerorg43&B.
Espagnonorg51&M. Estienneorg113&S. Esumiorg128&J. Eumorg96&D. Evansorg102&S.
Evdokimovorg112&G. Eyyubovaorg40&L. Fabbiettiorg37,org92&D. Fabrisorg108&J.
Faivreorg71&A. Fantoniorg72&M. Faselorg74&L. Feldkamporg54&D. Feleaorg62&A.
Felicielloorg111&G. Feofilovorg131&J. Ferenceiorg83&A. Fernández
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Feuillardorg15,org70&J. Figielorg117&M.A.S. Figueredoorg124&S.
Filchaginorg99&D. Finogeevorg56&E.M. Fioreorg33&M.G. Fleckorg93&M.
Florisorg36&S. Foertschorg65&P. Fokaorg97&S. Fokinorg100&E.
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Furgetorg71&A. Fursorg56&M. Fusco Girardorg31&J.J. Gaardhøjeorg80&M.
Gagliardiorg27&A.M. Gagoorg103&M. Gallioorg27&D.R. Gangadharanorg74&P.
Ganotiorg88&C. Gaoorg7&C. Garabatosorg97&E. Garcia-Solisorg13&C.
Gargiuloorg36&P. Gasikorg92,org37&M. Germainorg113&A. Gheataorg36&M.
Gheataorg62,org36&P. Ghoshorg132&S.K. Ghoshorg4&P. Gianottiorg72&P.
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Grahamorg102&A. Grelliorg57&A. Grigorasorg36&C. Grigorasorg36&V.
Grigorievorg76&A. Grigoryanorg1&S. Grigoryanorg66&B. Grinyovorg3&N.
Grionorg110&J.F. Grosse-Oetringhausorg36&J.-Y. Grossiordorg130&R.
Grossoorg36&F. Guberorg56&R. Guernaneorg71&B. Guerzoniorg28&K.
Gulbrandsenorg80&H. Gulkanyanorg1&T. Gunjiorg127&A. Guptaorg90&R.
Guptaorg90&R. Haakeorg54&Ø. Haalandorg18&C. Hadjidakisorg51&M. Haiducorg62&H.
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Hartmannorg43&A. Hartonorg13&D. Hatzifotiadouorg105&S. Hayashiorg127&S.T.
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Huangorg18&T.J. Humanicorg20&N. Hussainorg45&T. Hussainorg19&D.
Hutterorg43&D.S. Hwangorg21&R. Ilkaevorg99&I. Ilkivorg77&M. Inabaorg128&M.
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Izucheevorg112&P.M. Jacobsorg74&S. Jadlovskaorg115&C. Jahnkeorg120&H.J.
Jangorg68&M.A. Janikorg134&P.H.S.Y. Jayarathnaorg122&C. Jenaorg30&S.
Jenaorg122&R.T. Jimenez Bustamanteorg97&P.G. Jonesorg102&H. Jungorg44&A.
Juskoorg102&P. Kalinakorg59&A. Kalweitorg36&J. Kaminorg53&J.H. Kangorg138&V.
Kaplinorg76&S. Karorg132&A. Karasu Uysalorg69&O. Karavichevorg56&T.
Karavichevaorg56&L. Karayanorg97,org93&E. Karpechevorg56&U. Kebschullorg52&R.
Keidelorg139&D.L.D. Keijdenerorg57&M. Keilorg36&K.H. Khanorg16&M.M.
Khanorg19&P. Khanorg101&S.A. Khanorg132&A. Khanzadeevorg85&Y. Kharlovorg112&B.
Kilengorg38&B. Kimorg138&D.W. Kimorg44,org68&D.J. Kimorg123&H. Kimorg138&J.S.
Kimorg44&M. Kimorg44&M. Kimorg138&S. Kimorg21&T. Kimorg138&S. Kirschorg43&I.
Kiselorg43&S. Kiselevorg58&A. Kisielorg134&G. Kissorg136&J.L. Klayorg6&C.
Kleinorg53&J. Kleinorg36,org93&C. Klein-Bösingorg54&A. Klugeorg36&M.L.
Knichelorg93&A.G. Knospeorg118&T. Kobayashiorg128&C. Kobdajorg114&M.
Kofaragoorg36&T. Kolleggerorg97,org43&A. Kolojvariorg131&V.
Kondratievorg131&N. Kondratyevaorg76&E. Kondratyukorg112&A. Konevskikhorg56&M.
Kopcikorg115&M. Kourorg90&C. Kouzinopoulosorg36&O. Kovalenkoorg77&V.
Kovalenkoorg131&M. Kowalskiorg117&G. Koyithatta Meethaleveeduorg48&J.
Kralorg123&I. Králikorg59&A. Kravčákováorg41&M. Krelinaorg40&M. Kretzorg43&M.
Krivdaorg102,org59&F. Krizekorg83&E. Kryshenorg36&M. Krzewickiorg43&A.M.
Kuberaorg20&V. Kučeraorg83&T. Kugathasanorg36&C. Kuhnorg55&P.G. Kuijerorg81&I.
Kulakovorg43&A. Kumarorg90&J. Kumarorg48&L. Kumarorg79,org87&P.
Kurashviliorg77&A. Kurepinorg56&A.B. Kurepinorg56&A. Kuryakinorg99&S.
Kushpilorg83&M.J. Kweonorg50&Y. Kwonorg138&S.L. La Pointeorg111&P. La
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Laraorg52&A. Lardeuxorg15&A. Lattucaorg27&E. Laudiorg36&R. Leaorg26&L.
Leardiniorg93&G.R. Leeorg102&S. Leeorg138&I. Legrandorg36&F. Lehasorg81&R.C.
Lemmonorg82&V. Lentiorg104&E. Leograndeorg57&I. León Monzónorg119&M.
Leoncinoorg27&P. Lévaiorg136&S. Liorg7,org70&X. Liorg14&J. Lienorg42&R.
Lietavaorg102&S. Lindalorg22&V. Lindenstruthorg43&C. Lippmannorg97&M.A.
Lisaorg20&H.M. Ljunggrenorg34&D.F. Lodatoorg57&P.I. Loenneorg18&V.
Loginovorg76&C. Loizidesorg74&X. Lopezorg70&E. López Torresorg9&A.
Loweorg136&P. Luettigorg53&M. Lunardonorg30&G. Luparelloorg26&P.H.F.N.D.
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Malininaidp3797616,org66&D. Mal’Kevichorg58&P. Malzacherorg97&A.
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Marguttiorg57&A. Marínorg97&C. Markertorg118&M. Marquardorg53&N.A.
Martinorg97&J. Martin Blancoorg113&P. Martinengoorg36&M.I. Martínezorg2&G.
Martínez Garcíaorg113&M. Martinez Pedreiraorg36&Y. Martynovorg3&A.
Masorg120&S. Masciocchiorg97&M. Maseraorg27&A. Masoniorg106&L.
Massacrierorg113&A. Mastroserioorg33&H. Masuiorg128&A. Matyjaorg117&C.
Mayerorg117&J. Mazerorg125&M.A. Mazzoniorg109&D. Mcdonaldorg122&F.
Meddiorg24&Y. Melikyanorg76&A. Menchaca-Rochaorg64&E. Meninnoorg31&J. Mercado
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Mikhaylovorg58,org66&L. Milanoorg36&J. Milosevicorg22,org133&L.M.
Minerviniorg104,org23&A. Mischkeorg57&A.N. Mishraorg49&D. Miśkowiecorg97&J.
Mitraorg132&C.M. Mituorg62&N. Mohammadiorg57&B. Mohantyorg132,org79&L.
Molnarorg55&L. Montaño Zetinaorg11&E. Montesorg10&M. Morandoorg30&D.A. Moreira
De Godoyorg113,org54&S. Morettoorg30&A. Morrealeorg113&A. Morschorg36&V.
Mucciforaorg72&E. Mudnicorg116&D. Mühlheimorg54&S. Muhuriorg132&M.
Mukherjeeorg132&J.D. Mulliganorg137&M.G. Munhozorg120&S. Murrayorg65&L.
Musaorg36&J. Musinskyorg59&B.K. Nandiorg48&R. Naniaorg105&E. Nappiorg104&M.U.
Naruorg16&C. Nattrassorg125&K. Nayakorg79&T.K. Nayakorg132&S.
Nazarenkoorg99&A. Nedosekinorg58&L. Nellenorg63&F. Ngorg122&M.
Nicassioorg97&M. Niculescuorg62,org36&J. Niedzielaorg36&B.S. Nielsenorg80&S.
Nikolaevorg100&S. Nikulinorg100&V. Nikulinorg85&F. Noferiniorg105,org12&P.
Nomokonovorg66&G. Noorenorg57&J.C.C. Norisorg2&J. Normanorg124&A.
Nyaninorg100&J. Nystrandorg18&H. Oeschlerorg93&S. Ohorg137&S.K. Ohorg67&A.
Ohlsonorg36&A. Okatanorg69&T. Okuboorg47&L. Olahorg136&J. Oleniaczorg134&A.C.
Oliveira Da Silvaorg120&M.H. Oliverorg137&J. Onderwaaterorg97&C.
Oppedisanoorg111&R. Oravaorg46&A. Ortiz Velasquezorg63&A. Oskarssonorg34&J.
Otwinowskiorg117&K. Oyamaorg93&M. Ozdemirorg53&Y. Pachmayerorg93&P.
Paganoorg31&G. Paićorg63&C. Pajaresorg17&S.K. Palorg132&J. Panorg135&A.K.
Pandeyorg48&D. Pantorg48&P. Papcunorg115&V. Papikyanorg1&G.S.
Pappalardoorg107&P. Pareekorg49&W.J. Parkorg97&S. Parmarorg87&A.
Passfeldorg54&V. Paticchioorg104&R.N. Patraorg132&B. Paulorg101&T.
Peitzmannorg57&H. Pereira Da Costaorg15&E. Pereira De Oliveira Filhoorg120&D.
Peresunkoorg100,org76&C.E. Pérez Laraorg81&E. Perez Lezamaorg53&V.
Peskovorg53&Y. Pestovorg5&V. Petráčekorg40&V. Petrovorg112&M.
Petroviciorg78&C. Pettaorg29&S. Pianoorg110&M. Piknaorg39&P. Pillotorg113&O.
Pinazzaorg105,org36&L. Pinskyorg122&D.B. Piyarathnaorg122&M. Płoskońorg74&M.
Planinicorg129&J. Plutaorg134&S. Pochybovaorg136&P.L.M. Podesta-
Lermaorg119&M.G. Poghosyanorg84,org86&B. Polichtchoukorg112&N. Poljakorg129&W.
Poonsawatorg114&A. Poporg78&S. Porteboeuf-Houssaisorg70&J. Porterorg74&J.
Pospisilorg83&S.K. Prasadorg4&R. Preghenellaorg105,org36&F. Prinoorg111&C.A.
Pruneauorg135&I. Pshenichnovorg56&M. Puccioorg111&G. Pudduorg25&P.
Pujahariorg135&V. Puninorg99&J. Putschkeorg135&H. Qvigstadorg22&A.
Rachevskiorg110&S. Rahaorg4&S. Rajputorg90&J. Rakorg123&A.
Rakotozafindrabeorg15&L. Ramelloorg32&R. Raniwalaorg91&S. Raniwalaorg91&S.S.
Räsänenorg46&B.T. Rascanuorg53&D. Ratheeorg87&K.F. Readorg125&J.S.
Realorg71&K. Redlichorg77&R.J. Reedorg135&A. Rehmanorg18&P. Reicheltorg53&F.
Reidtorg93,org36&X. Renorg7&R. Renfordtorg53&A.R. Reolonorg72&A.
Reshetinorg56&F. Rettigorg43&J.-P. Revolorg12&K. Reygersorg93&V.
Riabovorg85&R.A. Ricciorg73&T. Richertorg34&M. Richterorg22&P. Riedlerorg36&W.
Rieglerorg36&F. Riggiorg29&C. Risteaorg62&A. Rivettiorg111&E. Roccoorg57&M.
Rodríguez Cahuantziorg2&A. Rodriguez Mansoorg81&K. Røedorg22&E.
Rogochayaorg66&D. Rohrorg43&D. Röhrichorg18&R. Romitaorg124&F.
Ronchettiorg72&L. Ronfletteorg113&P. Rosnetorg70&A. Rossiorg30,org36&F.
Roukoutakisorg88&A. Royorg49&C. Royorg55&P. Royorg101&A.J. Rubio
Monteroorg10&R. Ruiorg26&R. Russoorg27&E. Ryabinkinorg100&Y. Ryabovorg85&A.
Rybickiorg117&S. Sadovskyorg112&K. Šafaříkorg36&B. Sahlmullerorg53&P.
Sahooorg49&R. Sahooorg49&S. Sahooorg61&P.K. Sahuorg61&J. Sainiorg132&S.
Sakaiorg72&M.A. Salehorg135&C.A. Salgadoorg17&J. Salzwedelorg20&S.
Sambyalorg90&V. Samsonovorg85&X. Sanchez Castroorg55&L. Šándororg59&A.
Sandovalorg64&M. Sanoorg128&D. Sarkarorg132&E. Scapparoneorg105&F.
Scarlassaraorg30&R.P. Scharenbergorg95&C. Schiauaorg78&R. Schickerorg93&C.
Schmidtorg97&H.R. Schmidtorg35&S. Schuchmannorg53&J. Schukraftorg36&M.
Schulcorg40&T. Schusterorg137&Y. Schutzorg113,org36&K. Schwarzorg97&K.
Schwedaorg97&G. Scioliorg28&E. Scomparinorg111&R. Scottorg125&K.S.
Seederorg120&J.E. Segerorg86&Y. Sekiguchiorg127&D. Sekihataorg47&I.
Selyuzhenkovorg97&K. Senosiorg65&J. Seoorg96,org67&E. Serradillaorg64,org10&A.
Sevcencoorg62&A. Shabanovorg56&A. Shabetaiorg113&O. Shaduraorg3&R.
Shahoyanorg36&A. Shangaraevorg112&A. Sharmaorg90&M. Sharmaorg90&M.
Sharmaorg90&N. Sharmaorg125,org61&K. Shigakiorg47&K. Shtejerorg9,org27&Y.
Sibiriakorg100&S. Siddhantaorg106&K.M. Sielewiczorg36&T. Siemiarczukorg77&D.
Silvermyrorg84,org34&C. Silvestreorg71&G. Simatovicorg129&G. Simonettiorg36&R.
Singarajuorg132&R. Singhorg79&S. Singhaorg132,org79&V. Singhalorg132&B.C.
Sinhaorg132&T. Sinhaorg101&B. Sitarorg39&M. Sittaorg32&T.B. Skaaliorg22&M.
Slupeckiorg123&N. Smirnovorg137&R.J.M. Snellingsorg57&T.W. Snellmanorg123&C.
Søgaardorg34&R. Soltzorg75&J. Songorg96&M. Songorg138&Z. Songorg7&F.
Soramelorg30&S. Sorensenorg125&M. Spacekorg40&E. Spiritiorg72&I.
Sputowskaorg117&M. Spyropoulou-Stassinakiorg88&B.K. Srivastavaorg95&J.
Stachelorg93&I. Stanorg62&G. Stefanekorg77&M. Steinpreisorg20&E.
Stenlundorg34&G. Steynorg65&J.H. Stillerorg93&D. Stoccoorg113&P.
Strmenorg39&A.A.P. Suaideorg120&T. Sugitateorg47&C. Suireorg51&M.
Suleymanovorg16&R. Sultanovorg58&M. Šumberaorg83&T.J.M. Symonsorg74&A.
Szaboorg39&A. Szanto de Toledoorg1200&I. Szarkaorg39&A.
Szczepankiewiczorg36&M. Szymanskiorg134&J. Takahashiorg121&N.
Tanakaorg128&M.A. Tangaroorg33&J.D. Tapia Takakiidp5933408,org51&A. Tarantola
Peloniorg53&M. Tarhiniorg51&M. Tariqorg19&M.G. Tarzilaorg78&A. Tauroorg36&G.
Tejeda Muñozorg2&A. Telescaorg36&K. Terasakiorg127&C. Terrevoliorg30,org25&B.
Teyssierorg130&J. Thäderorg74,org97&D. Thomasorg118&R. Tieulentorg130&A.R.
Timminsorg122&A. Toiaorg53&S. Trogoloorg111&V. Trubnikovorg3&W.H.
Trzaskaorg123&T. Tsujiorg127&A. Tumkinorg99&R. Turrisiorg108&T.S.
Tveterorg22&K. Ullalandorg18&A. Urasorg130&G.L. Usaiorg25&A.
Utrobicicorg129&M. Vajzerorg83&M. Valaorg59&L. Valencia Palomoorg70&S.
Valleroorg27&J. Van Der Maarelorg57&J.W. Van Hoorneorg36&M. van
Leeuwenorg57&T. Vanatorg83&P. Vande Vyvreorg36&D. Vargaorg136&A. Vargasorg2&M.
Vargyasorg123&R. Varmaorg48&M. Vasileiouorg88&A. Vasilievorg100&A.
Vauthierorg71&V. Vecherninorg131&A.M. Veenorg57&M. Veldhoenorg57&A.
Velureorg18&M. Venaruzzoorg73&E. Vercellinorg27&S. Vergara Limónorg2&R.
Vernetorg8&M. Verweijorg135,org36&L. Vickovicorg116&G. Viestiorg300&J.
Viinikainenorg123&Z. Vilakaziorg126&O. Villalobos Baillieorg102&A.
Vinogradovorg100&L. Vinogradovorg131&Y. Vinogradovorg990&T. Virgiliorg31&V.
Vislaviciusorg34&Y.P. Viyogiorg132&A. Vodopyanovorg66&M.A. Völklorg93&K.
Voloshinorg58&S.A. Voloshinorg135&G. Volpeorg136,org36&B. von Hallerorg36&I.
Vorobyevorg37,org92&D. Vranicorg36,org97&J. Vrlákováorg41&B. Vulpescuorg70&A.
Vyushinorg99&B. Wagnerorg18&J. Wagnerorg97&H. Wangorg57&M. Wangorg7,org113&Y.
Wangorg93&D. Watanabeorg128&Y. Watanabeorg127&M. Weberorg36&S.G.
Weberorg97&J.P. Wesselsorg54&U. Westerhofforg54&J. Wiechulaorg35&J.
Wikneorg22&M. Wildeorg54&G. Wilkorg77&J. Wilkinsonorg93&M.C.S.
Williamsorg105&B. Windelbandorg93&M. Winnorg93&C.G. Yaldoorg135&H.
Yangorg57&P. Yangorg7&S. Yanoorg47&Z. Yinorg7&H. Yokoyamaorg128&I.-K.
Yooorg96&V. Yurchenkoorg3&I. Yushmanovorg100&A. Zaborowskaorg134&V.
Zaccoloorg80&A. Zamanorg16&C. Zampolliorg105&H.J.C. Zanoliorg120&S.
Zaporozhetsorg66&N. Zardoshtiorg102&A. Zarochentsevorg131&P. Závadaorg60&N.
Zaviyalovorg99&H. Zbroszczykorg134&I.S. Zguraorg62&M. Zhalovorg85&H.
Zhangorg18,org7&X. Zhangorg74&Y. Zhangorg7&C. Zhaoorg22&N. Zhigarevaorg58&D.
Zhouorg7&Y. Zhouorg80,org57&Z. Zhouorg18&H. Zhuorg18,org7&J. Zhuorg113,org7&X.
Zhuorg7&A. Zichichiorg12,org28&A. Zimmermannorg93&M.B.
Zimmermannorg54,org36&G. Zinovjevorg3&M. Zyzakorg43

## Affiliation notes

0Deceased

idp3797616Also at: M.V. Lomonosov Moscow State University, D.V. Skobeltsyn
Institute of Nuclear, Physics, Moscow, Russia

idp5933408Also at: University of Kansas, Lawrence, Kansas, United States

## 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, 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, USA

org14China Institute of Atomic Energy, Beijing, China

org15Commissariat à l’Energie Atomique, IRFU, Saclay, France

org16COMSATS Institute of Information Technology (CIIT), Islamabad, Pakistan

org17Departamento de Física de Partículas and IGFAE, Universidad de Santiago
de Compostela, Santiago de Compostela, Spain

org18Department of Physics and Technology, University of Bergen, Bergen,
Norway

org19Department of Physics, Aligarh Muslim University, Aligarh, India

org20Department of Physics, Ohio State University, Columbus, Ohio, United
States

org21Department of Physics, Sejong University, Seoul, South Korea

org22Department of Physics, University of Oslo, Oslo, Norway

org23Dipartimento di Elettrotecnica ed Elettronica del Politecnico, Bari,
Italy

org24Dipartimento di Fisica dell’Università ’La Sapienza’ and Sezione INFN
Rome, Italy

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

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

org27Dipartimento di Fisica dell’Università and Sezione INFN, Turin, Italy

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

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

org30Dipartimento di Fisica e Astronomia dell’Università and Sezione INFN,
Padova, Italy

org31Dipartimento di Fisica ‘E.R. Caianiello’ dell’Università and Gruppo
Collegato INFN, Salerno, Italy

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

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

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

org35Eberhard Karls Universität Tübingen, Tübingen, Germany

org36European Organization for Nuclear Research (CERN), Geneva, Switzerland

org37Excellence Cluster Universe, Technische Universität München, Munich,
Germany

org38Faculty of Engineering, Bergen University College, Bergen, Norway

org39Faculty of Mathematics, Physics and Informatics, Comenius University,
Bratislava, Slovakia

org40Faculty of Nuclear Sciences and Physical Engineering, Czech Technical
University in Prague, Prague, Czech Republic

org41Faculty of Science, P.J. Šafárik University, Košice, Slovakia

org42Faculty of Technology, Buskerud and Vestfold University College,
Vestfold, Norway

org43Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe-
Universität Frankfurt, Frankfurt, Germany

org44Gangneung-Wonju National University, Gangneung, South Korea

org45Gauhati University, Department of Physics, Guwahati, India

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 (IITI), India

org50Inha University, Incheon, South Korea

org51Institut de Physique Nucléaire d’Orsay (IPNO), Université Paris-Sud,
CNRS-IN2P3, Orsay, France

org52Institut für Informatik, Johann Wolfgang Goethe-Universität Frankfurt,
Frankfurt, Germany

org53Institut für Kernphysik, Johann Wolfgang Goethe-Universität Frankfurt,
Frankfurt, Germany

org54Institut für Kernphysik, Westfälische Wilhelms-Universität Münster,
Münster, Germany

org55Institut Pluridisciplinaire Hubert Curien (IPHC), Université de
Strasbourg, CNRS-IN2P3, Strasbourg, France

org56Institute for Nuclear Research, Academy of Sciences, Moscow, Russia

org57Institute for Subatomic Physics of Utrecht University, Utrecht,
Netherlands

org58Institute for Theoretical and Experimental Physics, Moscow, Russia

org59Institute of Experimental Physics, Slovak Academy of Sciences, Košice,
Slovakia

org60Institute of Physics, Academy of Sciences of the Czech Republic, Prague,
Czech Republic

org61Institute of Physics, Bhubaneswar, India

org62Institute of Space Science (ISS), Bucharest, Romania

org63Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México,
Mexico City, Mexico

org64Instituto de Física, Universidad Nacional Autónoma de México, Mexico
City, Mexico

org65iThemba LABS, National Research Foundation, Somerset West, South Africa

org66Joint Institute for Nuclear Research (JINR), Dubna, Russia

org67Konkuk University, Seoul, South Korea

org68Korea Institute of Science and Technology Information, Daejeon, South
Korea

org69KTO Karatay University, Konya, Turkey

org70Laboratoire de Physique Corpusculaire (LPC), Clermont Université,
Université Blaise Pascal, CNRS–IN2P3, Clermont-Ferrand, France

org71Laboratoire de Physique Subatomique et de Cosmologie, Université
Grenoble-Alpes, CNRS-IN2P3, Grenoble, France

org72Laboratori Nazionali di Frascati, INFN, Frascati, Italy

org73Laboratori Nazionali di Legnaro, INFN, Legnaro, Italy

org74Lawrence Berkeley National Laboratory, Berkeley, California, United
States

org75Lawrence Livermore National Laboratory, Livermore, California, United
States

org76Moscow Engineering Physics Institute, Moscow, Russia

org77National Centre for Nuclear Studies, Warsaw, Poland

org78National Institute for Physics and Nuclear Engineering, Bucharest,
Romania

org79National Institute of Science Education and Research, Bhubaneswar, India

org80Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark

org81Nikhef, Nationaal instituut voor subatomaire fysica, Amsterdam,
Netherlands

org82Nuclear Physics Group, STFC Daresbury Laboratory, Daresbury, United
Kingdom

org83Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Řež
u Prahy, Czech Republic

org84Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States

org85Petersburg Nuclear Physics Institute, Gatchina, Russia

org86Physics Department, Creighton University, Omaha, Nebraska, United States

org87Physics Department, Panjab University, Chandigarh, India

org88Physics Department, University of Athens, Athens, Greece

org89Physics Department, University of Cape Town, Cape Town, South Africa

org90Physics Department, University of Jammu, Jammu, India

org91Physics Department, University of Rajasthan, Jaipur, India

org92Physik Department, Technische Universität München, Munich, Germany

org93Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg,
Heidelberg, Germany

org94Politecnico di Torino, Turin, Italy

org95Purdue University, West Lafayette, Indiana, United States

org96Pusan National University, Pusan, South Korea

org97Research Division and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum
für Schwerionenforschung, Darmstadt, Germany

org98Rudjer Bošković Institute, Zagreb, Croatia

org99Russian Federal Nuclear Center (VNIIEF), Sarov, Russia

org100Russian Research Centre Kurchatov Institute, Moscow, Russia

org101Saha Institute of Nuclear Physics, Kolkata, India

org102School of Physics and Astronomy, University of Birmingham, Birmingham,
United Kingdom

org103Sección Física, Departamento de Ciencias, Pontificia Universidad
Católica del Perú, Lima, Peru

org104Sezione INFN, Bari, Italy

org105Sezione INFN, Bologna, Italy

org106Sezione INFN, Cagliari, Italy

org107Sezione INFN, Catania, Italy

org108Sezione INFN, Padova, Italy

org109Sezione INFN, Rome, Italy

org110Sezione INFN, Trieste, Italy

org111Sezione INFN, Turin, Italy

org112SSC IHEP of NRC Kurchatov institute, Protvino, Russia

org113SUBATECH, Ecole des Mines de Nantes, Université de Nantes, CNRS-IN2P3,
Nantes, France

org114Suranaree University of Technology, Nakhon Ratchasima, Thailand

org115Technical University of Košice, Košice, Slovakia

org116Technical University of Split FESB, Split, Croatia

org117The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy
of Sciences, Cracow, Poland

org118The University of Texas at Austin, Physics Department, Austin, Texas,
USA

org119Universidad Autónoma de Sinaloa, Culiacán, Mexico

org120Universidade de São Paulo (USP), São Paulo, Brazil

org121Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil

org122University of Houston, Houston, Texas, United States

org123University of Jyväskylä, Jyväskylä, Finland

org124University of Liverpool, Liverpool, United Kingdom

org125University of Tennessee, Knoxville, Tennessee, United States

org126University of the Witwatersrand, Johannesburg, South Africa

org127University of Tokyo, Tokyo, Japan

org128University of Tsukuba, Tsukuba, Japan

org129University of Zagreb, Zagreb, Croatia

org130Université de Lyon, Université Lyon 1, CNRS/IN2P3, IPN-Lyon,
Villeurbanne, France

org131V. Fock Institute for Physics, St. Petersburg State University, St.
Petersburg, Russia

org132Variable Energy Cyclotron Centre, Kolkata, India

org133Vinča Institute of Nuclear Sciences, Belgrade, Serbia

org134Warsaw University of Technology, Warsaw, Poland

org135Wayne State University, Detroit, Michigan, United States

org136Wigner Research Centre for Physics, Hungarian Academy of Sciences,
Budapest, Hungary

org137Yale University, New Haven, Connecticut, United States

org138Yonsei University, Seoul, South Korea

org139Zentrum für Technologietransfer und Telekommunikation (ZTT),
Fachhochschule Worms, Worms, Germany