Higher-order moments of the elliptic flow distribution in PbPb collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 2024 (2024) 106, 2024.
Inspire Record 2724506 DOI 10.17182/hepdata.132638

The hydrodynamic flow-like behavior of charged hadrons in high-energy lead-lead collisions is studied through multiparticle correlations. The elliptic anisotropy values based on different orders of multiparticle cumulants, $v_{2}\{2k\}$, are measured up to the tenth order ($k$ = 5) as functions of the collision centrality at a nucleon-nucleon center-of-mass energy of $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV. The data were recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 0.607 nb$^{-1}$. A hierarchy is observed between the coefficients, with $v_{2}\{2\} > v_{2}\{4\} \gtrsim v_{2}\{6\} \gtrsim v_{2}\{8\} \gtrsim v_{2}\{10\}$. Based on these results, centrality-dependent moments for the fluctuation-driven event-by-event $v_{2}$ distribution are determined, including the skewness, kurtosis and, for the first time, superskewness. Assuming a hydrodynamic expansion of the produced medium, these moments directly probe the initial-state geometry in high-energy nucleus-nucleus collisions.

8 data tables

The $v_2\{2k\}$ ($k = 1, ..., 5$) values as functions of centrality in PbPb collisions at $\sqrt{s_{NN}}=5.02~\textrm{Te}\textrm{V}$. The measurement is performed with charged particles within the acceptance region.

The relative differences $(v_2\{2k\}-v_2\{10\})/v_2\{10\}$ ($k = 1, ..., 4$) as functions of centrality in PbPb collisions at $\sqrt{s_{NN}}=5.02~\textrm{Te}\textrm{V}$. The measurement is performed with charged particles within the acceptance region.

The $h_1$ and the $h_2$ hydrodynamic probes as functions of centrality in PbPb collisions at $\sqrt{s_{NN}}=5.02~\textrm{Te}\textrm{V}$. The measurement is performed with charged particles within the acceptance region.

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Study of charm hadronization with prompt $\Lambda^+_\mathrm{c}$ baryons in proton-proton and lead-lead collisions at $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 01 (2024) 128, 2024.
Inspire Record 2679262 DOI 10.17182/hepdata.135973

The production of prompt $\Lambda^+_\mathrm{c}$ baryons is measured via the exclusive decay channel $\Lambda^+_\mathrm{c}$$\to$ pK$^-\pi^+$ at a center-of-mass energy per nucleon pair of 5.02 TeV, using proton-proton (pp) and lead-lead (PbPb) collision data collected by the CMS experiment at the CERN LHC. The pp and PbPb data were obtained in 2017 and 2018 with integrated luminosities of 252 and 0.607 nb$^{-1}$, respectively. The measurements are performed within the $\Lambda^+_\mathrm{c}$ rapidity interval $\vert y \vert$$\lt$ 1 with transverse momentum ($p_\mathrm{T}$) ranges of 3-30 and 6-40 GeV/$c$ for pp and PbPb collisions, respectively. Compared to the yields in pp collisions scaled by the expected number of nucleon-nucleon interactions, the observed yields of $\Lambda^+_\mathrm{c}$ with $p_\mathrm{T}$$\gt$ 10 GeV/$c$ are strongly suppressed in PbPb collisions. The level of suppression depends significantly on the collision centrality. The $\Lambda^+_\mathrm{c}$ / D$^0$ production ratio is similar in PbPb and pp collisions at $p_\mathrm{T}$$\gt$ 10 GeV/$c$, suggesting that the coalescence process does not play a dominant role in prompt $\Lambda^+_\mathrm{c}$ baryon production at higher $p_\mathrm{T}$.

6 data tables

The product of acceptance and efficiency ($A \epsilon$) as a function of $p_{\mathrm{T}}$ for prompt $\Lambda^+_c$ in pp collisions and within centrality regions of 0-90, 0-10, 10-30, 30-50 and 50-90% in PbPb collisions.

The $p_{\mathrm{T}}$ differential cross sections for prompt $\Lambda^+_c$ production in pp collisions. The global fit uncertainty is 8.6%.

The $\mathrm{T_{AA}}$-scaled $\Lambda^+_c$ yields as a function of $p_{\mathrm{T}}$ for PbPb collisions within centrality regions of 0-90, 0-10, 10-30, 30-50 and 50-90%.

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Measurement of prompt ${ D_{s}^{+}}$ production in pp and PbPb collisions at $\sqrt{s_{_{\text{NN}}}}$ = 5.02 TeV

The CMS collaboration
CMS-PAS-HIN-18-017, 2019.
Inspire Record 1766111 DOI 10.17182/hepdata.88295

The transverse momentum (pT) spectra of prompt D+ s mesons and charge conjugates are measured in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair using the CMS detector at the LHC. The measurement is performed through the D+ s !fp+ !K+K􀀀p+ decay channels with the D+ s rapidity range jyj < 1.0. The D+ s production in the pT range from 2 (6) GeV/c to 40 GeV/c in pp (PbPb) collisions is measured. Suppression of the D+ s nuclear modification factor (RAA) in PbPb collisions suggests a strong interaction between charm quarks and the quarkgluon plasma. The double ratio of prompt D+ s to prompt D0 production in pp and PbPb is consistent with a PHSD model calculation and consistent with unity, which indicates that strange charm meson enhancement in PbPb collisions is not significant in the measured D+ s pT interval.

5 data tables

$p_T$ differential cross section of $D^+_s$ s in pp and PbPb at 5.02 TeV. The $p_T$-differential cross section of $D^+_s$ in pp collisions and $p_T$-differential corrected yield of $D^+_s$ mesons scaled by T$_\text{AA}$ in PbPb collisions are shown.

The ratio between $p_T$-differential cross section of $D^+_s$ in pp collisions and $p_T$-differential corrected yield of $D^+_s$ mesons scaled by T$_\text{AA}$ in PbPb collisions over PYTHIA8 are shown.

The nuclear modification factor (R$_\text{AA}$) of $D^+_s$.

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