Date

Combination and interpretation of differential Higgs boson production cross sections in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
CMS-HIG-23-013, 2025.
Inspire Record 2913615 DOI 10.17182/hepdata.156816

Precision measurements of Higgs boson differential production cross sections are a key tool to probe the properties of the Higgs boson and test the standard model. New physics can affect both Higgs boson production and decay, leading to deviations from the distributions that are expected in the standard model. In this paper, combined measurements of differential spectra in a fiducial region matching the experimental selections are performed, based on analyses of four Higgs boson decay channels ($\gamma\gamma$, ZZ$^{(*)}$, WW$^{(*)}$, and $\tau\tau$) using proton-proton collision data recorded with the CMS detector at $\sqrt{s}$ = 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The differential measurements are extrapolated to the full phase space and combined to provide the differential spectra. A measurement of the total Higgs boson production cross section is also performed using the $\gamma\gamma$ and ZZ decay channels, with a result of 53.4$^{+2.9}_{-2.9}$ (stat)$^{+1.9}_{-1.8}$ (syst) pb, consistent with the standard model prediction of 55.6 $\pm$ 2.5 pb. The fiducial measurements are used to compute limits on Higgs boson couplings using the $\kappa$-framework and the SM effective field theory.

17 data tables

Observed best fit differential cross section for the $p_{T}^{H}$ observable

Observed best fit differential cross section for the $N_{jets}$ observable

Observed best fit differential cross section for the $p_{T}^{j1}$ (GeV) observable

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Search for $B^0 \to K^{\ast 0} \tau^+ \tau^-$ decays at the Belle II experiment

The Belle-II collaboration Adachi, I. ; Adamczyk, K. ; Aggarwal, L. ; et al.
Belle II Preprint 2025-010; KEK Preprint 2025-8, 2025.
Inspire Record 2911582 DOI 10.17182/hepdata.159541

We present a search for the rare flavor-changing neutral-current decay $B^0 \to K^{\ast 0} \tau^+ \tau^-$ with data collected by the Belle II experiment at the SuperKEKB electron-positron collider. The analysis uses a 365 fb$^{-1}$ data sample recorded at the center-of-mass energy of the $\Upsilon(4S)$ resonance. One of the $B$ mesons produced in the $\Upsilon(4S)\to B^0 \bar{B}^0$ process is fully reconstructed in a hadronic decay mode, while its companion $B$ meson is required to decay into a $K^{\ast 0}$ and two $\tau$ leptons of opposite charge. The $\tau$ leptons are reconstructed in final states with a single electron, muon, charged pion or charged $\rho$ meson, and additional neutrinos. We set an upper limit on the branching ratio of $BR(B^0 \to K^{\ast 0} \tau^+ \tau^-) < 1.8 \times 10^{-3}$ at the 90% confidence level, which is the most stringent constraint reported to date.

4 data tables

- - - - - - - - Overview of HEPData Record - - - - - - - -<br/><br/></ul><b>Post-fit yields:</b><ul><li><a href="159541?version=1&table=Postfit%20yields:%20fit%20variable">Fit variable $\eta(\rm{BDT})$</a></ul><b>Signal $q^{2}$:</b><ul><li><a href="159541?version=1&table=Generated%20$q^2$"> Generated $q^{2}$ distribution </a></ul><b>Signal selection efficiency:</b><ul><li><a href="159541?version=1&table=Selection%20efficiency"> Selection efficieny in signal region </a>

Observed yields and fit results in bins of $\eta(\rm{BDT})$ as obtained by the fit on the four signal categories, corresponding to an integrated luminosity of 365 fb$^{-1}$. The yields are shown for $B^0 \rightarrow K^{\ast 0}\tau\tau$ signal and the two background components ($B\bar{B}$ decays and $q\bar{q}$ continuum).

Distribution of the di-tau invariant mass squared $q^2$ assumed for the generated signal $B^0 \rightarrow K^{\ast 0}\tau\tau$ events.

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Search for charged-lepton flavour violation in top quark interactions with an up-type quark, a muon, and a $\tau$ lepton in proton-proton collisions at $\sqrt{s}$ = 13 TeV

The CMS collaboration Hayrapetyan, Aram ; Tumasyan, Armen ; Adam, Wolfgang ; et al.
CMS-TOP-22-011, 2025.
Inspire Record 2911292 DOI 10.17182/hepdata.153300

A search for charged-lepton flavour violation (CLFV) in top quark (t) production and decay is presented. The search uses proton-proton collision data corresponding to 138 fb$^{-1}$ collected with the CMS experiment at $\sqrt{s}$ = 13 TeV. The signal consists of the production of a single top quark via a CLFV interaction or top quark pair production followed by a CLFV decay. The analysis selects events containing a pair of oppositely charged muon and hadronically decaying $\tau$ lepton and at least three jets, where one has been identified to originate from the fragmentation of a bottom quark. Machine learning classification techniques are used to distinguish signal from standard model background events. The results of this search are consistent with the standard model expectations. The upper limits at 95% confidence level on the branching fraction $\mathcal{B}$ for CLFV top quark decays to a muon, a $\tau$ lepton, and an up or a charm quark are set at $\mathcal{B}$(t $\to \mu\tau$u) $\lt$ (0.040, 0.078, and 0.118) $\times$ 10$^{-6}$, and $\mathcal{B}$(t $\to\mu\tau$c) $\lt$ (0.810, 1.710, and 2.052) $\times$ 10$^{-6}$ for scalar, vector, and tensor-like operators, respectively.

2 data tables

The expected and observed upper limits on CLFV Wilson coefficients. The Limits on the Wilson coefficients are extracted from the upper limits on the cross sections.

The expected and observed upper limits on top quark CLFV branching fractions. The Limits on the top quark CLFV branching fractions are extracted from the upper limits on the Wilson coefficients.


Search for jet quenching with dijets from high-multiplicity pPb collisions at $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
JHEP 07 (2025) 118, 2025.
Inspire Record 2911293 DOI 10.17182/hepdata.156764

The first measurement of the dijet transverse momentum balance $x_j$ in proton-lead (pPb) collisions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_\mathrm{NN}}$ = 8.16 TeV is presented. The $x_j$ observable, defined as the ratio of the subleading over leading jet transverse momentum in a dijet pair, is used to search for jet quenching effects. The data, corresponding to an integrated luminosity of 174.6 nb$^{-1}$, were collected with the CMS detector in 2016. The $x_j$ distributions and their average values are studied as functions of the charged-particle multiplicity of the events and for various dijet rapidity selections. The latter enables probing hard scattering of partons carrying distinct nucleon momentum fractions $x$ in the proton- and lead-going directions. The former, aided by the high-multiplicity triggers, allows probing for potential jet quenching effects in high-multiplicity events (with up to 400 charged particles), for which collective phenomena consistent with quark-gluon plasma (QGP) droplet formation were previously observed. The ratios of $x_j$ distributions for high- to low-multiplicity events are used to quantify the possible medium effects. These ratios are consistent with simulations of the hard-scattering process that do not include QGP production. These measurements set an upper limit on medium-induced energy loss of the subleading jet of 1.26% of its transverse momentum at the 90% confidence level in high multiplicity pPb events.

22 data tables

The unfolded dijet balance distribution, $(1/N_{dijet})(dN_{dijet}/dx_{j})$, as function of $x_{j}$ for the $10-60$, $60-120$, $120-185$, $185-250$ and $250-400$ multiplicity ranges with both jets at the midrapidity regions.

The unfolded dijet balance distribution, $(1/N_{dijet})(dN_{dijet}/dx_{j})$, as function of $x_{j}$ for the $10-60$, $60-120$, $120-185$, $185-250$ and $250-400$ multiplicity ranges with leading and subleading jets at midrapidity and forward regions, respectively.

The unfolded dijet balance distribution, $(1/N_{dijet})(dN_{dijet}/dx_{j})$, as function of $x_{j}$ for the $10-60$, $60-120$, $120-185$, $185-250$ and $250-400$ multiplicity ranges with leading and subleading jets at midrapidity and backward regions, respectively.

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Observation of coherent $\phi$(1020) meson photoproduction in ultraperipheral PbPb collisions at $\sqrt{s_\text{NN}}$ = 5.36 TeV

The CMS collaboration Chekhovsky, Vladimir ; Hayrapetyan, Aram ; Makarenko, Vladimir ; et al.
CMS-HIN-24-009, 2025.
Inspire Record 2908607 DOI 10.17182/hepdata.156183

The first observation of coherent $\phi$(1020) meson photoproduction off heavy nuclei is presented using ultraperipheral lead-lead collisions at a center-of-mass energy per nucleon pair of 5.36 TeV. The data were collected by the CMS experiment and correspond to an integrated luminosity of 1.68 $\mu$b$^{-1}$. The $\phi$(1020) meson signals are reconstructed via the K$^+$K$^-$ decay channel. The production cross section is presented as a function of the $\phi$(1020) meson rapidity in the range 0.3 $\lt$$\lvert y\rvert$$\lt$ 1.0, probing gluons that carry a fraction of the nucleon momentum ($x$) around $10^{-4}$. The observed cross section exhibits little dependence on rapidity and is significantly suppressed, by a factor of ${\sim}$5, compared to a baseline model that treats a nucleus as a collection of free nucleons. Theoretical models that incorporate either nuclear shadowing or gluon saturation predict suppression of the $\phi$(1020) meson cross section with only a small dependence on rapidity, but the magnitude of the predicted suppression varies greatly. Models considering only nuclear shadowing effects result in the best agreement with the experimental data. This study establishes a powerful new tool for exploring nuclear effects and nuclear gluonic structure in the small-$x$ regime at a unique energy scale bridging the perturbative and nonperturbative quantum chromodynamics domains.

1 data table

The differential coherent $\phi$ photoproduction cross section and the nuclear suppression factor as a function of rapidity.


Revealing the microscopic mechanism of deuteron formation at the LHC

The ALICE collaboration Acharya, Shreyasi ; Agarwal, Apar ; Aglieri Rinella, Gianluca ; et al.
CERN-EP-2025-081, 2025.
Inspire Record 2907586 DOI 10.17182/hepdata.165804

The formation of light (anti)nuclei with mass number A of a few units (e.g., d, $^3$He, and $^4$He) in high-energy hadronic collisions presents a longstanding mystery in nuclear physics [1,2]. It is not clear how nuclei bound by a few MeV can emerge in environments characterized by temperatures above 100 MeV [3-5], about 100,000 times hotter than the center of the Sun. Despite extensive studies, this question remained unanswered. The ALICE Collaboration now addresses it with a novel approach using deuteron-pion momentum correlations in proton-proton (pp) collisions at the Large Hadron Collider (LHC). Our results provide model-independent evidence that about 80% of the observed (anti)deuterons are produced in nuclear fusion reactions [6] following the decay of short-lived resonances, such as the $\Delta (1232)$. These findings resolve a crucial gap in our understanding of nucleosynthesis in hadronic collisions. Beyond answering the fundamental question on how nuclei are formed in hadronic collisions, the results can be employed in the modeling of the production of light and heavy nuclei in cosmic rays [7] and dark matter decays [8,9].

7 data tables

Measured $\pi^{+}$–d$\oplus\pi^{-}$–$\overline{\mathrm{d}}$ (left panel) correlation function.

Measured $\pi^{-}$–d$\oplus\pi^{+}$–$\overline{\mathrm{d}}$ (right panel) correlation function.

The extracted kinetic decoupling temperature is derived from $\pi^{+}$–d correlation functions.

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D$^{0}$-meson-tagged jet axes difference in proton-proton collisions at $\mathbf{\sqrt{\textit{s}} = 5.02}$ TeV

The ALICE collaboration Acharya, Shreyasi ; Agarwal, Apar ; Aglieri Rinella, Gianluca ; et al.
CERN-EP-2025-083, 2025.
Inspire Record 2907593 DOI 10.17182/hepdata.165764

Heavy-flavor quarks produced in proton-proton (pp) collisions provide a unique opportunity to investigate the evolution of quark-initiated parton showers from initial hard scatterings to final-state hadrons. By examining jets that contain heavy-flavor hadrons, this study explores the effects of both perturbative and non-perturbative QCD on jet formation and structure. The angular differences between various jet axes, $\Delta R_{\rm axis}$, offer insight into the radiation patterns and fragmentation of charm quarks. The first measurement of D$^{0}$-tagged jet axes differences in pp collisions at $\sqrt{s}=5.02$ TeV by the ALICE experiment at the LHC is presented for jets with transverse momentum $p_{\rm T}^{\rm ch~jet} \geq 10$${\rm GeV}/c$ and D$^0$ mesons with $p_{\rm T}^{\rm D^{0}} \geq 5$${\rm GeV}/c$. In this D$^0$-meson-tagged jet measurement, three jet axis definitions, each with different sensitivities to soft, wide-angle radiation, are used: the Standard axis, Soft Drop groomed axis, and Winner-Takes-All axis. Measurements of the radial distributions of D$^0$ mesons with respect to the jet axes, $\Delta R_{\mathrm{axis-D^0}}$, are reported, along with the angle, $\Delta R_{\mathrm{axis}}$, between the three jet axes. The D$^{0}$ meson emerges as the leading particle in these jets, closely aligning with the Winner-Takes-All axis and diverging from the Standard jet axis. The results also examine how varying the sensitivity to soft radiation with grooming influences the orientation of the Soft Drop jet axis, and uncover that charm-jet structure is more likely to survive grooming when the Soft Drop axis is further from the D$^{0}$ direction, providing further evidence of the dead-cone effect recently measured by ALICE.

16 data tables

$\Delta R_{\rm axis}$ distribution for $\rm STD-D^0$ for $\rm D^0$-tagged jets of $R=0.4$, in the intervals $10<p_{\rm T}^{\rm ch \ jet}<20 \ {\rm GeV}/c$ and $5<p_{\rm T}^{\rm D^0}<20 \ {\rm GeV}/c$.

$\Delta R_{\rm axis}$ distribution for $\rm WTA-D^0$ for $\rm D^0$-tagged jets of $R=0.4$, in the intervals $10<p_{\rm T}^{\rm ch \ jet}<20 \ {\rm GeV}/c$ and $5<p_{\rm T}^{\rm D^0}<20 \ {\rm GeV}/c$.

$\Delta R_{\rm axis}$ distribution for $\rm STD-WTA$ for $\rm D^0$-tagged jets of $R=0.4$, in the intervals $10<p_{\rm T}^{\rm ch \ jet}<20 \ {\rm GeV}/c$ and $5<p_{\rm T}^{\rm D^0}<20 \ {\rm GeV}/c$.

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Multiplicity-dependent inclusive J/$\psi$ production at forward rapidity in pp collisions at $\mathbf{\sqrt{s} = 13}$ TeV

The ALICE collaboration Acharya, Shreyasi ; Agarwal, Apar ; Aglieri Rinella, Gianluca ; et al.
JHEP 07 (2025) 238, 2025.
Inspire Record 2906995 DOI 10.17182/hepdata.159409

This paper presents a study of the inclusive forward J/$\psi$ yield as a function of forward charged-particle multiplicity in pp collisions at $\sqrt{s} = 13$ TeV using data collected by the ALICE experiment at the CERN LHC. The results are presented in terms of relative J/$\psi$ yields and relative charged-particle multiplicities with respect to these quantities obtained in inelastic collisions having at least one charged particle in the pseudorapidity range $|\eta| < 1$. The J/$\psi$ mesons are reconstructed via their decay into $\mu^+ \mu^-$ pairs in the forward rapidity region ($2.5 < y < 4$). The relative multiplicity is estimated in the forward pseudorapidity range $-3.7 < \eta < -1.7$, which overlaps with the J/$\psi$ rapidity region. The results show a steeper-than-linear increase of the J/$\psi$ yields versus the multiplicity. They are compared with previous measurements and theoretical model calculations.

1 data table

Forward inclusive J/$\psi$ relative yield as a function of the relative multiplicity in −3.7 < $\eta$ < −1.7 in INEL > 0 pp collisions at $\sqrt{s}$ = 13 TeV.


First measurement of D$^{*+}$ vector spin alignment in Pb-Pb collisions at $\mathbf{\sqrt{s_{\rm NN}} = 5.02}$ TeV

The ALICE collaboration Acharya, Shreyasi ; Agarwal, Apar ; Aglieri Rinella, Gianluca ; et al.
CERN-EP-2025-072, 2025.
Inspire Record 2906994 DOI 10.17182/hepdata.165763

The first measurement of prompt D$^{*+}$-meson spin alignment in ultrarelativistic heavy-ion collisions with respect to the direction orthogonal to the reaction plane is presented. The spin alignment is quantified by measuring the element $\rho_{00}$ of the diagonal spin-density matrix for prompt D$^{*+}$ mesons with $4<p_{\rm T}<30$ GeV/$c$ in two rapidity intervals, $|y|<0.3$ and $0.3<|y|<0.8$, in central (0-10%) and midcentral (30-50%) Pb-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV. Evidence of spin alignment $\rho_{00}>1/3$ has been found for $p_{\rm T}>15$ GeV/$c$ and $0.3<|y|<0.8$ with a significance of $3.1\sigma$. The measured spin alignment of prompt D$^{*+}$ mesons is compared with the one of inclusive J/$\psi$ mesons measured at forward rapidity ($2.5 < y < 4$).

3 data tables

$\rho_{00}$ of prompt D$^{*\pm}$ mesons as a function of transverse momentum ($p_{\rm T}$) in the rapidity interval $0.0 < |y| < 0.3$ for mid-central (30--50\%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02~TeV$.

$\rho_{00}$ of prompt D$^{*\pm}$ mesons as a function of transverse momentum ($p_{\rm T}$) in the rapidity interval $0.3 < |y| < 0.8$ for mid-central (30--50\%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02~TeV$.

$\rho_{00}$ of prompt D$^{*\pm}$ mesons as a function of transverse momentum ($p_{\rm T}$) in the rapidity interval $0.0 < |y| < 0.3$ for central (0--10\%) Pb--Pb collisions at $\sqrt{s_{\rm NN}}=5.02~TeV$.


Evidence for the collective nature of radial flow in Pb+Pb collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-068, 2025.
Inspire Record 2907010 DOI 10.17182/hepdata.158359

Anisotropic flow and radial flow are two key probes of the expansion dynamics and properties of the quark-gluon plasma (QGP). While anisotropic flow has been extensively studied, radial flow, which governs the system's radial expansion, has received less attention. Notably, experimental evidence for the global and collective nature of radial flow has been lacking. This Letter presents the first measurement of transverse momentum ($p_{\mathrm{T}}$) dependence of radial flow fluctuations ($v_0(p_{\mathrm{T}})$) over $0.5<p_{\mathrm{T}}<10$ GeV, using a two-particle correlation method in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. The data reveal three key features supporting the collective nature of radial flow: long-range correlation in pseudorapidity, factorization in $p_{\mathrm{T}}$, and centrality-independent shape in $p_{\mathrm{T}}$. The comparison with a hydrodynamic model demonstrates the sensitivity of $v_0(p_{\mathrm{T}})$ to bulk viscosity, a crucial transport property of the QGP. These findings establish a new, powerful tool for probing collective dynamics and properties of the QGP.

99 data tables

Data from Figure 2, panel a, $v_{0}$

Data from Figure 2, panel c, upper panel, Normalized Covariance $\times 10^{3}$ in 0-5% Centrality

Data from Figure 2, panel c, lower panel, Normalized Covariance $\times 10^{3}$ in 50-60% Centrality

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