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The first measurements of proton emission accompanied by neutron emission in the electromagnetic dissociation (EMD) of ${}^{208}\mathrm{Pb}$nuclei in the ALICE experiment at the Large Hadron Collider are presented. The EMD protons and neutrons emitted at very forward rapidities are detected by the proton and neutron zero degree calorimeters of the ALICE experiment. The emission cross sections of zero, one, two, and three protons accompanied by at least one neutron were measured in ultraperipheral ${}^{208}\mathrm{Pb}\text{−}{}^{208}\mathrm{Pb}$collisions at a center-of-mass energy per nucleon pair $\sqrt{s_{NN}}=5.02\mathrm{TeV}$. The 0p and 3p cross sections are described by the RELDIS model within their measurement uncertainties, while the 1p and 2p cross sections are underestimated by the model by 17–25%. According to this model, these 0p, 1p, 2p, and 3p cross sections are associated, respectively, with the production of various isotopes of Pb, Tl, Hg, and Au in the EMD of ${}^{208}\mathrm{Pb}$. The cross sections of the emission of a single proton accompanied by the emission of one, two, or three neutrons in EMD were also measured. The data are significantly overestimated by the RELDIS model, which predicts that the (1p,1n), (1p,2n), and (1p,3n) cross sections are very similar to the cross sections for the production of the thallium isotopes ${}^{206,205,204}\mathrm{Tl}$. ©2025 CERN, for the ALICE Collaboration2025CERN 

Abstract The ALICE Collaboration at the CERN LHC has measured the inclusive production cross section of isolated photons at midrapidity as a function of the photon transverse momentum ($$p_{\textrm{T}}^{\gamma }$$ $p_{\text{T}}^{\gamma }$), in Pb–Pb collisions in different centrality intervals, and in pp collisions, at centre-of-momentum energy per nucleon pair of$$\sqrt{s_{\textrm{NN}}}~=~5.02$$ $\sqrt{s_{\text{NN}}}=5.02$ TeV. The photon transverse momentum range is between 10–14 and 40–140 GeV/$$c$$ $c$, depending on the collision system and on the Pb–Pb centrality class. The result extends to lower$$p_{\textrm{T}}^{\gamma }$$ $p_{\text{T}}^{\gamma }$than previously published results by the ATLAS and CMS experiments at the same collision energy. The covered pseudorapidity range is$$|\eta ^{\gamma } | <0.67$$ $|{\eta }^{\gamma }|<0.67$. The isolation selection is based on a charged particle isolation momentum threshold$$p_{\textrm{T}}^\mathrm{iso,~ch} = 1.5$$ $p_{\text{T}}^{\mathrm{iso},\mathrm{ch}}=1.5$ GeV/$$c$$ $c$within a cone of radii$$R=0.2$$ $R=0.2$and 0.4. The nuclear modification factor is calculated and found to be consistent with unity in all centrality classes, and also consistent with the HG-PYTHIA model, which describes the event selection and geometry biases that affect the centrality determination in peripheral Pb–Pb collisions. The measurement is compared to next-to-leading order perturbative QCD calculations and to the measurements of isolated photons and Z$$^{0}$$ $_{}^0$bosons from the CMS experiment, which are all found to be in agreement. 

A<sc>bstract</sc> Thep_T-differential cross section ofωmeson production in pp collisions at$$ \sqrt{s} $$ $\sqrt{s}$= 13 TeV at midrapidity (|y| <0.5) was measured with the ALICE detector at the LHC, covering an unprecedented transverse-momentum range of 1.6< p_T<50 GeV/c. The meson is reconstructed via theω→π⁺π⁻π⁰decay channel. The results are compared with various theoretical calculations: PYTHIA8.2 with the Monash 2013 tune overestimates the data by up to 50%, whereas good agreement is observed with Next-to-Leading Order (NLO) calculations incorporatingωfragmentation using a broken SU(3) model. Theω/π⁰ratio is presented and compared with theoretical calculations and the available measurements at lower collision energies. The presented data triples thep_Tranges of previously available measurements. A constant ratio ofC^ω/π0= 0.578 ± 0.006 (stat.) ± 0.013 (syst.) is found above a transverse momentum of 4 GeV/c, which is in agreement with previous findings at lower collision energies within the systematic and statistical uncertainties. 

In this Letter, the first evidence of the ${}_{\overline{\mathrm{\Lambda }}}{}^4\overline{\mathrm{He}}$antihypernucleus is presented, along with the first measurement at the LHC of the production of (anti)hypernuclei with mass number $A=4$, specifically $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{H}$and $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{He}$. In addition, the antiparticle-to-particle ratios for both hypernuclei ( ${}_{\overline{\mathrm{\Lambda }}}{}^4\overline{\mathrm{H}}/{}_{\mathrm{\Lambda }}{}^4\mathrm{H}$and ${}_{\overline{\mathrm{\Lambda }}}{}^4\overline{\mathrm{He}}/{}_{\mathrm{\Lambda }}{}^4\mathrm{He}$) are shown, which are sensitive to the baryochemical potential of the strongly interacting matter created in heavy-ion collisions. The results are obtained from a data sample of central Pb-Pb collisions, collected during the 2018 LHC data taking at a center-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}}=5.02\mathrm{TeV}$. The yields measured for the average of the charge-conjugated states are found to be $[0.78\pm 0.19\left(\mathrm{stat}\right)\pm 0.17\left(\mathrm{syst}\right)]\times {10}^{-6}$for the $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{H}$and $[1.08\pm 0.34\left(\mathrm{stat}\right)\pm 0.20\left(\mathrm{syst}\right)]\times {10}^{-6}$for the $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{He}$, and the measured antiparticle-to-particle ratios are in agreement with unity. The presence of $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{H}$and $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{He}$excited states is expected to strongly enhance the production yield of these hypernuclei. The yield values exhibit a combined deviation of $3.3\sigma$from the theoretical ground-state-only expectation, while the inclusion of the excited states in the calculations leads to an agreement within $0.6\sigma$with the present measurements. Additionally, the measured $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{H}$and $\left(\mathrm{anti}\right){}_{\mathrm{\Lambda }}{}^4\mathrm{He}$masses are compatible with the world-average values within the uncertainties. © 2025 CERN, for the ALICE Collaboration2025CERN 

We report an improved measurement of the valence $u$and $d$quark distributions from the forward-backward asymmetry in the Drell-Yan process using $8.6{\mathrm{fb}}^{-1}$of data collected with the D0 detector in $p\overline{p}$collisions at $\sqrt{s}=1.96$. This analysis provides the values of new structure parameters that are directly related to the valence up and down quark distributions in the proton. In other experimental results measuring the quark content of the proton, $d$quark contributions are mixed with those from other quark flavors. In this measurement, the $u$and $d$quark contributions are separately extracted by applying a factorization of the QCD and electroweak portions of the forward-backward asymmetry. Published by the American Physical Society2024 

A<sc>bstract</sc> The measurements of the Higgs boson (H) production cross sections performed by the CMS Collaboration in the four-lepton (4ℓ, ℓ= e,μ) final state at a center-of-mass energy$$\sqrt{s}$$= 13.6 TeV are presented. These measurements are based on data collected with the CMS detector at the CERN LHC in 2022, corresponding to an integrated luminosity of 34.7 fb⁻¹. Cross sections are measured in a fiducial region closely matching the experimental acceptance, both inclusively and differentially, as a function of the transverse momentum and the absolute value of the rapidity of the four-lepton system. The H → ZZ → 4ℓinclusive fiducial cross section is measured to be$${2.89}_{-0.49}^{+0.53}{\left({\text{stat}}\right)}_{-0.21}^{+0.29}\left({\text{syst}}\right)$$fb, in agreement with the standard model expectation of$${3.09}_{-0.24}^{+0.27}$$fb. 

A measurement of the Higgs boson mass and width via its decay to two $Z$bosons is presented. Proton-proton collision data collected by the CMS experiment, corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$at a center-of-mass energy of 13 TeV, is used. The invariant mass distribution of four leptons in the on-shell Higgs boson decay is used to measure its mass and constrain its width. This yields the most precise single measurement of the Higgs boson mass to date, $125.04\pm 0.12\mathrm{GeV}$, and an upper limit on the width ${\mathrm{\Gamma }}_H<330\mathrm{MeV}$at 95% confidence level. A combination of the on- and off-shell Higgs boson production decaying to four leptons is used to determine the Higgs boson width, assuming that no new virtual particles affect the production, a premise that is tested by adding new heavy particles in the gluon fusion loop model. This result is combined with a previous CMS analysis of the off-shell Higgs boson production with decay to two leptons and two neutrinos, giving a measured Higgs boson width of ${3.0}_{-1.5}^{+2.0}\mathrm{MeV}$, in agreement with the standard model prediction of 4.1 MeV. The strength of the off-shell Higgs boson production is also reported. The scenario of no off-shell Higgs boson production is excluded at a confidence level corresponding to 3.8 standard deviations. © 2025 CERN, for the CMS Collaboration2025CERN 

A<sc>bstract</sc> Short-range correlations between charged particles are studied via two-particle angular correlations in pp collisions at$$ \sqrt{s} $$ $\sqrt{s}$= 13 TeV. The correlation functions are measured as a function of the relative azimuthal angle ∆φand the pseudorapidity separation ∆ηfor pairs of primary charged particles within the pseudorapidity interval |η|<0.9 and the transverse-momentum range 1< p_T<8 GeV/c. Near-side (|∆φ|<1.3) peak widths are extracted from a generalised Gaussian fitted over the correlations in full pseudorapidity separation (|∆η|<1.8), while the per-trigger associated near-side yields are extracted for the short-range correlations (|∆η|<1.3). Both are evaluated as a function of charged-particle multiplicity obtained by two different event activity estimators. The width of the near-side peak decreases with increasing multiplicity, and this trend is reproduced qualitatively by the Monte Carlo event generators PYTHIA 8, AMPT, and EPOS. However, the models overestimate the width in the low transverse-momentum region (p_T<3 GeV/c). The per-trigger associated near-side yield increases with increasing multiplicity. Although this trend is also captured qualitatively by the considered event generators, the yield is mostly overestimated by the models in the considered kinematic range. The measurement of the shape and yield of the short-range correlation peak can help us understand the interplay between jet fragmentation and event activity, quantify the narrowing trend of the near-side peak as a function of transverse momentum and multiplicity selections in pp collisions, and search for final-state jet modification in small collision systems. 

A<sc>bstract</sc> The production of (multi-)strange hadrons is measured at midrapidity in proton-proton collisions at$$ \sqrt{s} $$ $\sqrt{s}$= 13 TeV as a function of the local charged-particle multiplicity in the pseudorapidity interval |η|<0.5 and of the very-forward energy measured by the ALICE Zero-Degree Calorimeters. The latter provides information on the effective energy, i.e. the energy available for particle production in the collision once subtracted from the centre-of-mass energy. The yields of$$ {\textrm{K}}_{\textrm{S}}^0 $$ $K_S^0$,$$ \Lambda +\overline{\Lambda} $$ $\Lambda +\overline{\Lambda }$, and$$ {\Xi}^{-}+{\overline{\Xi}}^{+} $$ ${\Xi }^{-}+{\overline{\Xi }}^{+}$per charged-particle increase with the effective energy. In addition, this work exploits a multi-differential approach to decouple the roles of local multiplicity and effective energy in such an enhancement. The results presented in this article provide new insights into the interplay between global properties of the collision, such as the initial available energy in the event, and the locally produced final hadronic state, connected to the charged-particle multiplicity at midrapidity. Notably, a strong increase of strange baryon production with effective energy is observed for fixed charged-particle multiplicity at midrapidity. These results are discussed within the context of existing phenomenological models of hadronisation implemented in different tunes of the PYTHIA 8 event generator. 

A<sc>bstract</sc> A search for heavy, long-lived, charged particles with large ionization energy loss within the silicon tracker of the CMS experiment is presented. A data set of proton-proton collisions at a center of mass energy at$$ \sqrt{s} $$ $\sqrt{s}$= 13 TeV, collected in 2017 and 2018 at the CERN LHC, corresponding to an integrated luminosity of 101 fb⁻¹, is used in this analysis. Two different approaches for the search are taken. A new method exploits the independence of the silicon pixel and strips measurements, while the second method improves on previous techniques using ionization to determine a mass selection. No significant excess of events above the background expectation is observed. The results are interpreted in the context of the pair production of supersymmetric particles, namely gluinos, top squarks, and tau sleptons, and of the Drell-Yan pair production of fourth generation (τ′) leptons with an electric charge equal to or twice the absolute value of the electron charge (e). An interpretation of a Z’ boson decaying to twoτ′ leptons with an electric charge equal to 2eis presented for the first time. The 95% confidence upper limits on the production cross section are extracted for each of these hypothetical particles.