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Measurements of the inclusive W and Z boson production cross sections and their ratios in proton-proton collisions at $\sqrt{s}$ = 13.6 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
CMS-SMP-22-017, 2025.
Inspire Record 2900021 DOI 10.17182/hepdata.157226

Measurements are presented of the W and Z boson production cross sections in proton-proton collisions at a center-of-mass energy of 13.6 TeV. Data collected in 2022 and corresponding to an integrated luminosity of 5.01 fb$^{-1}$ with one or two identified muons in the final state are analyzed. The results for the products of total inclusive cross sections and branching fractions for muonic decays of W and Z bosons are 11.93 $\pm$ 0.08 (syst) $\pm$ 0.17 (lumi) $^{+0.07}_{-0.07}$ (acc) nb for W$^+$ boson production, 8.86 $\pm$ 0.06 (syst) $\pm$ 0.12 (lumi) $^{+0.05}_{-0.06}$ (acc) nb for W$^-$ boson production, and 2.021 $\pm$ 0.009 (syst) $\pm$ 0.028 (lumi) $^{+0.011}_{-0.013}$ (acc) nb for the Z boson production in the dimuon mass range of 60-120 GeV, all with negligible statistical uncertainties. Furthermore, the corresponding fiducial cross sections, as well as cross section ratios for both fiducial and total phase space, are provided. The ratios include charge-separated results for W boson production (W$^+$ and W$^-$) and the sum of the two contributions (W$^\pm$), each relative to the measured Z boson production cross section. Additionally, the ratio of the measured cross sections for W$^+$ and W$^-$ boson production is reported. All measurements are in agreement with theoretical predictions, calculated at next-to-next-to-leading order accuracy in quantum chromodynamics.

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Measurement of the inclusive cross sections for W and Z boson production in proton-proton collisions at $\sqrt{s}$ = 5.02 and 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 04 (2025) 162, 2025.
Inspire Record 2816048 DOI 10.17182/hepdata.153468

Measurements of fiducial and total inclusive cross sections for W and Z boson production are presented in proton-proton collisions at $\sqrt{s}$ = 5.02 and 13 TeV. Electron and muon decay modes ($\ell$ = e or $\mu$) are studied in the data collected with the CMS detector in 2017, in dedicated runs with reduced instantaneous luminosity. The data sets correspond to integrated luminosities of 298 $\pm$ 6 pb$^{-1}$ at 5.02 TeV and 206 $\pm$ 5 pb$^{-1}$ at 13 TeV. Measured values of the products of the total inclusive cross sections and the branching fractions at 5.02 TeV are $\sigma$(pp $\to$ W+X) $\mathcal{B}$(W $\to$$\ell\nu$) = 7300 $\pm$ 10 (stat) $\pm$ 60 (syst) $\pm$ 140 (lumi) pb, and $\sigma$(pp $\to$ Z+X) $\mathcal{B}$(Z $\to$$\ell^+\ell^-$) = 669 $\pm$ 2 (stat) $\pm$ 6 (syst) $\pm$ 13 (lumi) pb for the dilepton invariant mass in the range of 60-120 GeV. The corresponding results at 13 TeV are 20480 $\pm$ 10 (stat) $\pm$ 170 (syst) $\pm$ 470 (lumi) pb and 1952 $\pm$ 4 (stat) $\pm$ 18 (syst) $\pm$ 45 (lumi) pb. The measured values agree with cross section calculations at next-to-next-to-leading-order in perturbative quantum chromodynamics. Fiducial and total inclusive cross sections, ratios of cross sections of W$^+$ and W$^-$ production as well as inclusive W and Z boson production, and ratios of these measurements at 5.02 and 13 TeV are reported.

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General balance functions of identified charged hadron pairs of $(\pi,{\rm K},{\rm p})$ in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 833 (2022) 137338, 2022.
Inspire Record 1943964 DOI 10.17182/hepdata.132486

First measurements of balance functions (BFs) of all combinations of identified charged hadron $(\pi,\rm K,\rm p)$ pairs in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV recorded by the ALICE detector are presented. The BF measurements are carried out as two-dimensional differential correlators versus the relative rapidity ($\Delta y$) and azimuthal angle ($\Delta\varphi$) of hadron pairs, and studied as a function of collision centrality. The $\Delta\varphi$ dependence of BFs is expected to be sensitive to the light quark diffusivity in the quark$-$gluon plasma. While the BF azimuthal widths of all pairs substantially decrease from peripheral to central collisions, the longitudinal widths exhibit mixed behaviors: BFs of $\pi\pi$ and cross-species pairs narrow significantly in more central collisions, whereas those of $\rm KK$ and $\rm pp$ are found to be independent of collision centrality. This dichotomy is qualitatively consistent with the presence of strong radial flow effects and the existence of two stages of quark production in relativistic heavy-ion collisions. Finally, the first measurements of the collision centrality evolution of BF integrals are presented, with the observation that charge balancing fractions are nearly independent of collision centrality in Pb$-$Pb collisions. Overall, the results presented provide new and challenging constraints for theoretical models of hadron production and transport in relativistic heavy-ion collisions.

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Charged-particle production as a function of the relative transverse activity classifier in pp, p$-$Pb, and Pb$-$Pb collisions at the LHC

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
JHEP 01 (2024) 056, 2024.
Inspire Record 2709103 DOI 10.17182/hepdata.146104

Measurements of charged-particle production in pp, p$-$Pb, and Pb$-$Pb collisions in the toward, away, and transverse regions with the ALICE detector are discussed. These regions are defined event-by-event relative to the azimuthal direction of the charged trigger particle, which is the reconstructed particle with the largest transverse momentum ($p_{\mathrm{T}}^{\rm trig}$) in the range $8<p_{\mathrm{T}}^{\rm trig}<15$ GeV$/c$. The toward and away regions contain the primary and recoil jets, respectively; both regions are accompanied by the underlying event (UE). In contrast, the transverse region perpendicular to the direction of the trigger particle is dominated by the so-called UE dynamics, and includes also contributions from initial- and final-state radiation. The relative transverse activity classifier, $R_{\mathrm{T}}=N_{\mathrm{ch}}^{\mathrm{T}}/\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle$, is used to group events according to their UE activity, where $N_{\mathrm{ch}}^{\mathrm{T}}$ is the charged-particle multiplicity per event in the transverse region and $\langle N_{\mathrm{ch}}^{\mathrm{T}}\rangle$ is the mean value over the whole analysed sample. The energy dependence of the $R_{\mathrm{T}}$ distributions in pp collisions at $\sqrt{s}=2.76$, 5.02, 7, and 13 TeV is reported, exploring the Koba-Nielsen-Olesen (KNO) scaling properties of the multiplicity distributions. The first measurements of charged-particle $p_{\rm T}$ spectra as a function of $R_{\mathrm{T}}$ in the three azimuthal regions in pp, p$-$Pb, and Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV are also reported. Data are compared with predictions obtained from the event generators PYTHIA 8 and EPOS LHC. This set of measurements is expected to contribute to the understanding of the origin of collective-like effects in small collision systems (pp and p$-$Pb).

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Charm production and fragmentation fractions at midrapidity in pp collisions at $\sqrt{s} = 13$ TeV

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Aglieri Rinella, Gianluca ; et al.
JHEP 12 (2023) 086, 2023.
Inspire Record 2697877 DOI 10.17182/hepdata.145759

Measurements of the production cross sections of prompt ${\rm D^0}$, ${\rm D^+}$, ${\rm D^{\ast +}}$, ${\rm D_s^+}$, ${\rm \Lambda_{c}^{+}}$, and ${\rm \Xi_{c}^{+}}$ charm hadrons at midrapidity in proton$-$proton collisions at $\sqrt{s}=13$ TeV with the ALICE detector are presented. The D-meson cross sections as a function of transverse momentum ($p_{\rm T}$) are provided with improved precision and granularity. The ratios of $p_{\rm T}$-differential meson production cross sections based on this publication and on measurements at different rapidity and collision energy provide a constraint on gluon parton distribution functions at low values of Bjorken-$x$ ($10^{-5}-10^{-4}$). The measurements of ${\rm \Lambda_{c}^{+}}$ (${\rm \Xi_{c}^{+}}$) baryon production extend the measured $p_{\rm T}$ intervals down to $p_{\rm T}=0(3)$~GeV$/c$. These measurements are used to determine the charm-quark fragmentation fractions and the ${\rm c\overline{c}}$ production cross section at midrapidity ($|y|<0.5$) based on the sum of the cross sections of the weakly-decaying ground-state charm hadrons ${\rm D^0}$, ${\rm D^+}$, ${\rm D_s^+}$, ${\rm \Lambda_{c}^{+}}$, ${\rm \Xi_{c}^{0}}$ and, for the first time, ${\rm \Xi_{c}^{+}}$, and of the strongly-decaying J/$psi$ mesons. The first measurements of ${\rm \Xi_{c}^{+}}$ and ${\rm \Sigma_{c}^{0,++}}$ fragmentation fractions at midrapidity are also reported. A significantly larger fraction of charm quarks hadronising to baryons is found compared to e$^+$e$^-$ and ep collisions. The ${\rm c\overline{c}}$ production cross section at midrapidity is found to be at the upper bound of state-of-the-art perturbative QCD calculations.

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Measurements of differential two-particle number and transverse momentum correlation functions in pp collisions at $\sqrt{\textit{s}}$ = 13 TeV

The ALICE collaboration Acharya, Shreyasi ; Agarwal, Apar ; Aglieri Rinella, Gianluca ; et al.
Eur.Phys.J.C 85 (2025) 866, 2025.
Inspire Record 2847021 DOI 10.17182/hepdata.159895

Differential two-particle normalized cumulants ($R_2$) and transverse momentum correlations ($P_2$) are measured as a function of the relative pseudorapidity and azimuthal angle difference $( Δη, Δφ)$ of charged particle pairs in minimum bias pp collisions at $\sqrt{\textit{s}}$ = 13 TeV. The measurements use charged hadrons in the pseudorapidity region of $|η| < 0.8$ and the transverse momentum range \mbox{0.2 $< \textit{p}_{\mathrm T} < $ 2.0 $\mathrm{GeV}/\textit{c}$} in order to focus on soft multiparticle interactions and to complement prior measurements of these correlation functions in p-Pb and Pb-Pb collisions. The correlation functions are reported for both unlike-sign and like-sign pairs and their charge-independent and charge-dependent combinations. Both the $R_2$ and $P_2$ measured in pp collisions exhibit features qualitatively similar to those observed in p--Pb and Pb--Pb collisions. The $Δη$ and $Δφ$ root mean square widths of the near-side peak of the correlation functions are evaluated and compared with those observed in p-Pb and Pb-Pb collisions and show smooth evolution with the multiplicity of charged particles produced in the collision. The comparison of the measured correlation functions with predictions from PYTHIA8 shows that this model qualitatively captures their basic structure and characteristics but feature important differences. In addition, the $R_2^{\rm CD}$ is used to determine the charge balance function of hadrons produced within the detector acceptance of the measurements. The integral of the balance function is found to be compatible with those reported by a previous measurement in Pb--Pb collisions.

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Elliptic flow of charged particles at midrapidity relative to the spectator plane in Pb-Pb and Xe-Xe collisions

The ALICE collaboration Acharya, Shreyasi ; Adamova, Dagmar ; Adler, Alexander ; et al.
Phys.Lett.B 846 (2023) 137453, 2023.
Inspire Record 2070420 DOI 10.17182/hepdata.134258

Measurements of the elliptic flow coefficient relative to the collision plane defined by the spectator neutrons $v_2${$\Psi_{\rm SP}$} in collisions of Pb ions at center-of-mass energy per nucleon-nucleon pair $\sqrt{s_{\rm NN}}$=2.76 TeV and Xe ions at $\sqrt{s_{\rm NN}}$=5.44 TeV are reported. The results are presented for charged particles produced at midrapidity as a function of centrality and transverse momentum. The ratio between $v_2${$\Psi_{\rm SP}$} and the elliptic flow coefficient relative to the participant plane $v_2$4, estimated using four-particle correlations, deviates by up to 20% from unity depending on centrality. This observation differs strongly from the magnitude of the corresponding eccentricity ratios predicted by the TRENTo and the elliptic power models of initial state fluctuations that are tuned to describe the participant plane anisotropies. The differences can be interpreted as a decorrelation of the neutron spectator plane and the reaction plane because of fragmentation of the remnants from the colliding nuclei, which points to an incompleteness of current models of initial state fluctuations. A significant transverse momentum dependence of the ratio $v_2${$\Psi_{\rm SP}$}/$v_2${4} is observed in all but the most central collisions, which may help to understand whether momentum anisotropies at low and intermediate transverse momentum have a common origin in initial state fluctuations. The ratios of $v_2${$\Psi_{\rm SP}$} and $v_2${4} to the corresponding initial state eccentricities for Xe-Xe and Pb-Pb collisions at similar initial entropy density show a difference of $(7.0 \pm 0.9)$% with an additional variation of +1.8% when including RHIC data in the TRENTo parameter extraction. These observations provide new experimental constraints for viscous effects in the hydrodynamic modeling of the expanding quark-gluon plasma.

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Study of dijet events with large rapidity separation in proton-proton collisions at $\sqrt{s}$ = 2.76 TeV

The CMS collaboration Tumasyan, Armen ; Adam, Wolfgang ; Andrejkovic, Janik Walter ; et al.
JHEP 03 (2022) 189, 2022.
Inspire Record 1963239 DOI 10.17182/hepdata.113660

The cross sections for inclusive and Mueller-Navelet dijet production are measured as a function of the rapidity separation between the jets in proton-proton collisions at $\sqrt{s} =$ 2.76 TeV for jets with transverse momentum $p_\mathrm{T}$$\gt$ 35 GeV and rapidity $\vert y\vert$$\lt$ 4.7. Various dijet production cross section ratios are also measured. A veto on additional jets with $p_\mathrm{T}$$\gt$ 20 GeV is introduced to improve the sensitivity to the effects of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution. The measurement is compared with the predictions of various Monte Carlo models based on leading-order and next-to-leading-order calculations including the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi leading-logarithm (LL) parton shower as well as the LL BFKL resummation.

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