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Version 2
Inclusive and differential cross section measurements of $\mathrm{t\bar{t}b\bar{b}}$ production in the lepton+jets channel at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 05 (2024) 042, 2024.
Inspire Record 2703254 DOI 10.17182/hepdata.138416

Measurements of inclusive and normalized differential cross sections of the associated production of top quark-antiquark and bottom quark-antiquark pairs, ttbb, are presented. The results are based on data from proton-proton collisions collected by the CMS detector at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The cross sections are measured in the lepton+jets decay channel of the top quark pair, using events containing exactly one isolated electron or muon and at least five jets. Measurements are made in four fiducial phase space regions, targeting different aspects of the ttbb process. Distributions are unfolded to the particle level through maximum likelihood fits, and compared with predictions from several event generators. The inclusive cross section measurements of this process in the fiducial phase space regions are the most precise to date. In most cases, the measured inclusive cross sections exceed the predictions with the chosen generator settings. The only exception is when using a particular choice of dynamic renormalization scale, $\mu_\mathrm{R}=\frac{1}{2} \prod_{i = \mathrm{t, \bar{t}, b, \bar{b}}} m_{\mathrm{T},i}^{1/4}$, where $m_{\mathrm{T}, i}^2 = m_i^2 + p^2_{\mathrm{T}, i}$ are the transverse masses of top and bottom quarks. The differential cross sections show varying degrees of compatibility with the theoretical predictions, and none of the tested generators with the chosen settings simultaneously describe all the measured distributions.

114 data tables

Fiducial cross sections from the measurements of all observables, compared to predictions from different ttbb simulation approaches. For each of the normalized differential measurements the fiducial cross section in the respective phase space is also determined. In the paper only one representative observable is quoted for each fiducial phase space, while here the measured cross section with the uncertainties from the fit to the respective observable is summarized.

Compatibility of normalized differential cross section measurements with modeling predictions. The compatibility is quantified with z scores for each of the theoretical predictions, given the unfolded normalized differential cross sections and their covariances. A lower value indicates a better agreement between prediction and measurement. A value of z = 2 indicates a p-value of 5%. In the calculation of the z score only the measurement uncertainties and the statistical uncertainties of the modeling predictions are taken into account

Normalized differential cross section of $|\eta(\mathrm{b}^{\mathrm{add.}}_{1})|$ in $\geq 6$ jets: $\geq 4 \mathrm{b}$ phase space.

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Longitudinal and transverse spin transfer to $\Lambda$ and $\overline{\Lambda}$ hyperons in polarized $p$+$p$ collisions at $\sqrt{s} = 200$ GeV

The STAR collaboration Abdulhamid, Muhammad ; Aboona, Bassam ; Adam, Jaroslav ; et al.
Phys.Rev.D 109 (2024) 012004, 2024.
Inspire Record 2703253 DOI 10.17182/hepdata.144919

The longitudinal and transverse spin transfers to $\Lambda$ ($\overline{\Lambda}$) hyperons in polarized proton-proton collisions are expected to be sensitive to the helicity and transversity distributions, respectively, of (anti-)strange quarks in the proton, and to the corresponding polarized fragmentation functions. We report improved measurements of the longitudinal spin transfer coefficient, $D_{LL}$, and the transverse spin transfer coefficient, $D_{TT}$, to $\Lambda$ and $\overline{\Lambda}$ in polarized proton-proton collisions at $\sqrt{s}$ = 200 GeV by the STAR experiment at RHIC. The data set includes longitudinally polarized proton-proton collisions with an integrated luminosity of 52 pb$^{-1}$, and transversely polarized proton-proton collisions with a similar integrated luminosity. Both data sets have about twice the statistics of previous results and cover a kinematic range of $|\eta_{\Lambda(\overline{\Lambda})}|$$<$ 1.2 and transverse momentum $p_{T,{\Lambda(\overline{\Lambda})}}$ up to 8 GeV/$c$. We also report the first measurements of the hyperon spin transfer coefficients $D_{LL}$ and $D_{TT}$ as a function of the fractional jet momentum $z$ carried by the hyperon, which can provide more direct constraints on the polarized fragmentation functions.

35 data tables

'$D_{LL}$ as a function of $\cos\theta^{*}$ at $0 < \eta_{\Lambda(\overline{\Lambda})} < 1.2$ and $3 < p_{T} < 4 GeV/c$'

'$D_{TT}$ as a function of $\cos\theta^{*}$ at $0 < \eta_{jet} < 1.0$ and $0.5 < z < 0.7$'

'$\Lambda$ $D_{LL}$ as a function of $p_{T}$ at $0 < \eta_{\Lambda(\overline{\Lambda})} < 1.2$'

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Version 2
Reaction plane correlated triangular flow in Au+Au collisions at $\mathbf{\sqrt{s_{\textrm{NN}}}=3}$ GeV

The STAR collaboration Abdulhamid, Muhammad ; Aboona, Bassam ; Adam, Jaroslav ; et al.
Phys.Rev.C 109 (2024) 044914, 2024.
Inspire Record 2702151 DOI 10.17182/hepdata.144480

We measure triangular flow relative to the reaction plane at 3 GeV center-of-mass energy in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. A significant $v_3$ signal for protons is observed, which increases for higher rapidity, higher transverse momentum, and more peripheral collisions. The triangular flow is essentially rapidity-odd with a slope at mid-rapidity, $dv_3/dy|_{(y=0)}$, opposite in sign compared to the slope for directed flow. No significant $v_3$ signal is observed for charged pions and kaons. Comparisons with models suggest that a mean field potential is required to describe these results, and that the triangular shape of the participant nucleons is the result of stopping and nuclear geometry.

6 data tables

Event plane resolutions for calculating $v_3\{\Psi_1\}$ as a function of centrality from $\sqrt{s_{\textrm{NN}}}=3$ GeV Au+Au collisions at STAR.

$v_3\{\Psi_1\}$ vs. centrality for $\pi^+$, $\pi^-$, and protons using the event plane method in $\sqrt{s_{\textrm{NN}}}=3$ GeV Au+Au collisions at STAR.

$v_3\{\Psi_1\}$ vs. centrality for $K^+$, and $K^-$ using the event plane method in $\sqrt{s_{\textrm{NN}}}=3$ GeV Au+Au collisions at STAR.

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Measurement of the $\tau$ lepton polarization in Z boson decays in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
JHEP 01 (2024) 101, 2024.
Inspire Record 2702153 DOI 10.17182/hepdata.144221

The polarization of $\tau$ leptons is measured using leptonic and hadronic $\tau$ lepton decays in Z $\to$$\tau^+\tau^-$ events in proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded by CMS at the CERN LHC with an integrated luminosity of 36.3 fb$^{-1}$. The measured $\tau^-$ polarization at the Z boson mass pole is $\mathcal{P}_{\tau}$(Z) = $-$0.144 $\pm$ 0.006 (stat) $\pm$ 0.014 (syst) = $-$0.144 $\pm$ 0.015, in good agreement with the measurement of the $\tau$ lepton asymmetry parameter of $A_{\tau}$ = 0.1439 $\pm$ 0.0043 = $-\mathcal{P}_{\tau}$(Z) at LEP. The $\tau$ polarization depends on the ratio of the vector to axial-vector couplings of the $\tau$ leptons in the neutral current expression, and thus on the effective weak mixing angle $\sin^{2}\theta_\mathrm{W}^{\text{eff}}$, independently of the Z boson production mechanism. The obtained value $\sin^{2}\theta_\mathrm{W}^{\text{eff}}$ = 0.2319 $\pm$ 0.0008 (stat) $\pm$ 0.0018 (syst) = 0.2319 $\pm$ 0.0019 is in good agreement with measurements at e$^+$e$^-$ colliders.

3 data tables

Fit results for the average $\tau^{-}$ lepton polarization for the 11 event categories and the combined fit as the lowest point in the figure

Fit results for the average $\tau^{-}$ lepton polarization for categories grouped into 4 channels.

A comparison of the $\tau$ lepton asymmetry, $A_{\tau}$ measured from the tau lepton polarization in this paper and other measurements.


Evidence for the Higgs boson decay to a $Z$ boson and a photon at the LHC

The ATLAS & CMS collaborations Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Phys.Rev.Lett. 132 (2024) 021803, 2024.
Inspire Record 2666787 DOI 10.17182/hepdata.142406

The first evidence for the Higgs boson decay to a $Z$ boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton-proton collision data sets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018. These correspond to integrated luminosities of around 140 fb$^{-1}$ for each experiment, at a center-of-mass energy of 13 TeV. The measured signal yield is $2.2\pm0.7$ times the Standard Model prediction, and agrees with the theoretical expectation within 1.9 standard deviations.

1 data table

The negative profile log-likelihood test statistic, where $\Lambda$ represents the likelihood ratio, as a function of the signal strength $\mu$ derived from the ATLAS data, the CMS data, and the combined result.


Measurements of $\pi^\pm$, $K^\pm$, $p$ and $\bar{p}$ spectra in $^{40}$Ar+$^{45}$Sc collisions at 13$A$ to 150$A$ GeV/$c$

The NA61/SHINE collaboration Adhikary, H. ; Adrich, P. ; Allison, K.K. ; et al.
Eur.Phys.J.C 84 (2024) 416, 2024.
Inspire Record 2692441 DOI 10.17182/hepdata.151277

The NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of $\pi^\pm$, $K^\pm$, $p$ and $\bar{p}$ produced in $^{40}$Ar+$^{45}$Sc collisions at beam momenta of 13$A$, 19$A$, 30$A$, 40$A$, 75$A$ and 150$A$~\GeVc. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the $K^\pm$/$\pi^\pm$ ratios as well as of inverse slope parameters of the $K^\pm$ transverse mass distributions are placed in between those found in inelastic $p$+$p$ and central Pb+Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical or dynamical models.

139 data tables

Two-dimensional distributions ($y$ vs. $p_T$ ) of double differential yields of $p$ at 13$A$ GeV/c

Two-dimensional distributions ($y$ vs. $p_T$ ) of double differential yields of $\pi^+$ at 13$A$ GeV/c

Two-dimensional distributions ($y$ vs. $p_T$ ) of double differential yields of $\pi^-$ at 13$A$ GeV/c

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Measurement of the centrality dependence of the dijet yield in $p$+Pb collisions at $\sqrt{s_{_\text{NN}}}$ = 8.16 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abeling, Kira ; et al.
Phys.Rev.Lett. 132 (2024) 102301, 2024.
Inspire Record 2693068 DOI 10.17182/hepdata.151163

The measurement of hard scatterings in proton-nucleus collisions has resulted in a greater understanding of both the proton and nuclear structure. ATLAS measured the centrality dependence of the dijet yield using 165 nb$^{-1}$ of $p$+Pb data collected at $\sqrt{s_{_\text{NN}}}$ = 8.16 TeV in 2016. The event centrality, which reflects the $p$+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, $R_\mathrm{CP}$, is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The $R_\mathrm{CP}$ shows a scaling with the Bjorken-$x$ of the parton originating from the proton, $x_p$, while no such trend is observed as a function of $x_\mathrm{Pb}$. This analysis provides unique input to understanding the role of small proton spatial configurations in $p$+Pb collisions by covering parton momentum fractions from the valence region down to $x_p \sim 10^{-3}$ and $x_\mathrm{Pb}\sim 4\cdot10^{-4}$.

63 data tables

$R_\text{CP}$ plotted as a function of approximated $x_p$ for $-3.0 < y_b < -2.0$ and $0.0 < y^* < 1.0$, constructed using $\langle y_{\text{b}} \rangle$ and $\langle y^{*} \rangle$. The proton-going direction is defined by $y_{\text{b}} > 0$.

$R_\text{CP}$ plotted as a function of approximated $x_p$ for $-2.0 < y_b < -1.0$ and $0.0 < y^* < 1.0$, constructed using $\langle y_{\text{b}} \rangle$ and $\langle y^{*} \rangle$. The proton-going direction is defined by $y_{\text{b}} > 0$.

$R_\text{CP}$ plotted as a function of approximated $x_p$ for $-2.0 < y_b < -1.0$ and $1.0 < y^* < 2.0$, constructed using $\langle y_{\text{b}} \rangle$ and $\langle y^{*} \rangle$. The proton-going direction is defined by $y_{\text{b}} > 0$.

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Upper Limit on the Chiral Magnetic Effect in Isobar Collisions at the Relativistic Heavy-Ion Collider

The STAR collaboration Abdulhamid, M.I. ; Aboona, B.E. ; Adam, J. ; et al.
Phys.Rev.Res. 6 (2024) L032005, 2024.
Inspire Record 2692436 DOI 10.17182/hepdata.144262

The chiral magnetic effect (CME) is a phenomenon that arises from the QCD anomaly in the presence of an external magnetic field. The experimental search for its evidence has been one of the key goals of the physics program of the Relativistic Heavy-Ion Collider. The STAR collaboration has previously presented the results of a blind analysis of isobar collisions (${^{96}_{44}\text{Ru}}+{^{96}_{44}\text{Ru}}$, ${^{96}_{40}\text{Zr}}+{^{96}_{40}\text{Zr}}$) in the search for the CME. The isobar ratio ($Y$) of CME-sensitive observable, charge separation scaled by elliptic anisotropy, is close to but systematically larger than the inverse multiplicity ratio, the naive background baseline. This indicates the potential existence of a CME signal and the presence of remaining nonflow background due to two- and three-particle correlations, which are different between the isobars. In this post-blind analysis, we estimate the contributions from those nonflow correlations as a background baseline to $Y$, utilizing the isobar data as well as Heavy Ion Jet Interaction Generator simulations. This baseline is found consistent with the isobar ratio measurement, and an upper limit of 10% at 95% confidence level is extracted for the CME fraction in the charge separation measurement in isobar collisions at $\sqrt{s_{\rm NN}}=200$ GeV.

7 data tables

Figure 1a

Figure 1b

Figure 1c

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Measurement of in-medium jet modification using direct photon+jet and $\pi^{0}$+jet correlations in $p+p$ and central Au+Au collisions at $\sqrt{s_{\rm NN}} = 200$ GeV

The STAR collaboration Aboona, B.E. ; Adam, J. ; Adamczyk, L. ; et al.
Phys.Rev.Lett. 134 (2025) 232301, 2025.
Inspire Record 2693040 DOI 10.17182/hepdata.144263

The STAR Collaboration presents measurements of the semi-inclusive distribution of charged-particle jets recoiling from energetic direct-photon ($\gamma_{\rm dir}$) and neutral-pion ($\pi^{0}$) triggers in p+p and central Au+Au collisions at $\sqrt{s_\mathrm{NN}}$ GeV over a broad kinematic range, for jet resolution parameters $R$=0.2 and 0.5. Medium-induced jet yield suppression is observed to be larger for $R$=0.2 than for 0.5, reflecting the angular range of jet energy redistribution due to quenching. The predictions of model calculations incorporating jet quenching are not fully consistent with the observations. These results provide new insight into the physical origins of jet quenching.

8 data tables

I_{AA} of Au+Au 0%-15% collisions at sqrt{s_{NN}} = 200 GeV for R = 0.2 of gamma_{dir}+jet with E_{T,trig}= 15-20 GeV.

I_{AA} of Au+Au 0%-15% collisions at sqrt{s_{NN}} = 200 GeV for R = 0.5 of gamma_{dir}+jet with E_{T,trig}= 15-20 GeV.

I_{AA} of Au+Au 0%-15% collisions at sqrt{s_{NN}} = 200 GeV for R = 0.2 of pi^{0}+jet with E_{T,trig}= 11-15 GeV.

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Semi-inclusive direct photon+jet and $\pi^{0}$+jet correlations measured in $p+p$ and central Au+Au collisions at $\sqrt{s_\mathrm{NN}} = 200$ GeV

The STAR collaboration Aboona, B.E. ; Adam, J. ; Adamczyk, L. ; et al.
Phys.Rev.C 111 (2025) 064907, 2025.
Inspire Record 2693062 DOI 10.17182/hepdata.144264

The STAR experiment at RHIC reports new measurements of jet quenching based on the semi-inclusive distribution of charged-particle jets recoiling from direct photon ($\gamma_{\rm dir}$) and neutral pion ($\pi^{0}$) triggers in pp and central Au+Au collisions at $\sqrt{s_{\rm NN}}=200$ GeV, for triggers in the range $9<E_{\rm T}^{\rm trig}<20$ GeV. The datasets have integrated luminosities of 3.9$ {\rm nb}^{-1}$ for Au+Au and 23$ {\rm pb}^{-1}$ for pp collisions. Jets are reconstructed using the anti-$k_{\rm T}$ algorithm with resolution parameters $R$=0.2 and 0.5. The large uncorrelated jet background in central Au+Au collisions is corrected using a mixed-event approach, which enables precise charged-particle jet measurements at low transverse momentum $p_{\rm T,jet}^{\rm ch}$ and large $R$. Recoil-jet distributions are reported in the range $p_{\rm T,jet}^{\rm ch}<25$\gev. Comparison of the distributions measured in pp and Au+Au collisions reveals strong medium-induced jet yield suppression for $R=0.2$, with markedly less suppression for $R=0.5$. Comparison is also made to theoretical models incorporating jet quenching. These data provide new insight into the mechanisms underlying jet quenching and the angular dependence of medium-induced jet-energy transport, and provide new constraints on modelling such effects.

80 data tables

Rho distribution of SE recoil jet R=0.5 for AuAu 0-15% at sqrt{s_{NN}}=200 GeV from gamma_{rich}+jet event sample.

Rho distribution of ME recoil jet R=0.5 for AuAu 0-15% at sqrt{s_{NN}}=200 GeV from MB event sample.

Rho distribution of ME-30MeV recoil jet R=0.5 for AuAu 0-15% at sqrt{s_{NN}}=200 GeV from MB event sample.

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