Christina Tsolanta

• Zurlo, N.; Zugravel, S. C.; Zingaretti, A.; Zhu, Y.; Zhu, S. & Zhu, J. [Vis alle 1 054 forfattere av denne artikkelen] (2026). Σ¯± production in pp and p-Pb collisions at √sNN = 5.02 TeV with ALICE. European Physical Journal C. ISSN 1434-6044. 86(2). doi: 10.1140/epjc/s10052-025-15129-2. Fulltekst i vitenarkiv
• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 081 forfattere av denne artikkelen] (2026). Space-time evolution of particle emission in p–Pb collisions at √sNN = 5.02 TeV with 3D kaon femtoscopy. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2026(4). doi: 10.1007/JHEP04(2026)113. Fulltekst i vitenarkiv Vis sammendrag

  The measurement of three-dimensional femtoscopic correlations between identical charged kaons (K±K±) produced in p–Pb collisions at center-of-mass energy per nucleon pair √sNN = 5.02TeV with ALICE at the LHC is presented for the first time. This measurement, supplementary to those in pp and Pb–Pb collisions, allows understanding the particle-production mechanisms at different charged-particle multiplicities and provides information on the dynamics of the source of particles created in p–Pb collisions, for which a general consensus does not yet exist. It is shown that the measured source sizes increase with charged-particle multiplicity and decrease with increasing pair transverse momentum. These trends for K±K± are similar to the ones observed earlier in identical charged-pion and K0sK0s correlations in Pb–Pb collisions at various energies and in π±π± correlations in p–Pb collisions at √sNN = 5.02TeV. At comparable multiplicity, the source sizes measured in p–Pb collisions agree within uncertainties with those observed in pp collisions, and there is an indication that they are smaller than those observed in Pb–Pb collisions. The obtained results are also compared with predictions from the hadronic interaction model EPOS 3, which tends to underestimate the source size for the most central collisions and agrees with the data for semicentral and peripheral events. Furthermore, the time of maximal emission for kaons is extracted. It turns out to be comparable with the value obtained in highly peripheral Pb–Pb collisions at the same energy, indicating that the kaon emission evolution is similar to that in p–Pb collisions.

• Abdelrahman, Omar; Rinella, Gianluca Aglieri; Aglietta, Luca; Alocco, Giacomo; Antonelli, Matias & Baccomi, Roberto [Vis alle 140 forfattere av denne artikkelen] (2026). Characterisation of the first wafer-scale prototype for the ALICE ITS3 upgrade: The monolithic stitched sensor (MOSS). Nuclear Instruments and Methods in Physics Research Section A : Accelerators, Spectrometers, Detectors and Associated Equipment. ISSN 0168-9002. 1086. doi: 10.1016/j.nima.2026.171297. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 059 forfattere av denne artikkelen] (2025). Measurement of ω meson production in pp collisions at √s = 13 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(4). doi: 10.1007/JHEP04(2025)067. Fulltekst i vitenarkiv Vis sammendrag

  The pT-differential cross section of ω meson production in pp collisions at √s = 13TeV at midrapidity (|y| < 0.5) was measured with the ALICE detector at the LHC, covering an unprecedented transverse-momentum range of 1.6 < pT < 50 GeV/c. The meson is reconstructed via the ω → π+π−π0 decay 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 incorporating ω fragmentation using a broken SU(3) model. The ω/π0 ratio is presented and compared with theoretical calculations and the available measurements at lower collision energies. The presented data triples the pT ranges of previously available measurements. A constant ratio of Cω/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.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 070 forfattere av denne artikkelen] (2025). Multiplicity-dependent jet modification from di-hadron correlations in pp collisions at √s = 13 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(3). doi: 10.1007/JHEP03(2025)194. Fulltekst i vitenarkiv Vis sammendrag

  Short-range correlations between charged particles are studied via two-particle angular correlations in pp collisions at √ s = 13 TeV. The correlation functions are measured as a function of the relative azimuthal angle ∆φ and the pseudorapidity separation ∆η for pairs of primary charged particles within the pseudorapidity interval |η| < 0.9 and the transversemomentum range 1 < pT < 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 (pT < 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.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 069 forfattere av denne artikkelen] (2025). Direct-photon production in inelastic and high-multiplicity proton–proton collisions at √s= 13 TeV. Physics Letters B. ISSN 0370-2693. 868. doi: 10.1016/j.physletb.2025.139645. Fulltekst i vitenarkiv Vis sammendrag

  In this letter, we present the first measurement of direct photons at the transverse momentum of 1 < 𝑝T < 6 GeV/𝑐 at √ midrapidity |𝜂| < 0.8 in inelastic and high-multiplicity proton–proton collisions at a centre-of-mass energy of 𝑠 = 13 TeV. The fraction of virtual direct photons in the inclusive virtual photon spectrum is obtained from a fit to the dielectron invariant mass spectrum. In the limit of zero invariant mass, this fraction is equal to the relative contribution of real direct photons in the inclusive real photon spectrum. Contributions from decays of lightflavour neutral mesons are estimated using independent measurements in proton–proton collisions at the same energy and the same event class. For the first time at the LHC energies, a direct-photon signal is observed at low 𝑝T in both inelastic and high-multiplicity event classes, with a significance of 3.2𝜎 and 1.9𝜎 in terms of standard deviations, correspondingly. The yield of direct photons in inelastic pp collisions is compared to perturbative QCD calculations. The integrated photon yield is studied as a function of charged-particle multiplicity and is compared to the results from other experiments and theoretical calculations. The results show a significant increase of directphoton yield with charged-particle multiplicity.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 079 forfattere av denne artikkelen] (2025). Coherent J/ψ photoproduction at midrapidity in Pb−Pb collisions at √sNN=5.02 TeV. Physics Letters B. ISSN 0370-2693. 871. doi: 10.1016/j.physletb.2025.139952. Fulltekst i vitenarkiv Vis sammendrag

  The coherent J∕𝜓 photoproduction cross section is measured for the first time at midrapidity in peripheral to semicentral Pb − Pb collisions at √𝑠NN = 5.02 TeV. The centrality differential cross section d𝜎∕d𝑦 is reported for the centrality range 40–90%, together with the doubly-differential cross section d2𝜎∕d𝑦d𝑝T, extracted in two peripheral centrality classes. The J∕𝜓 mesons are reconstructed in the dielectron channel, in the rapidity interval |𝑦| < 0.9 using the ALICE central barrel detectors. The J∕𝜓 cross section at midrapidity is statistically compatible to the earlier ALICE measurement at forward rapidity and at the same centre-of-mass energy, and shows only a mild centrality dependence over the covered range. Several sets of theoretical calculations taking into account the hadronic overlap in the collisions but ignoring possible final-state effects from a hot expanding medium are found to give a fairly good description of the current measurements within uncertainties.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 075 forfattere av denne artikkelen] (2025). First measurement of symmetric cumulants of hexagonal flow harmonics in Pb-Pb collisions at √sNN = 5.02 TeV. Physical Review C. ISSN 2469-9985. 112(2). doi: 10.1103/4ltm-g1qg. Fulltekst i vitenarkiv Vis sammendrag

  Correlations between event-by-event fluctuations of anisotropic flow harmonics are measured in Pb-Pb collisions at a center-of-mass energy per nucleon pair of 5.02 TeV, as recorded by the ALICE detector at the LHC. This study presents correlations up to the hexagonal flow harmonic v6, which was measured for the first time. The magnitudes of these higher-order correlations are found to vary as a function of collision centrality and harmonic order. These measurements are compared to viscous hydrodynamic model calculations with EKRT initial conditions and to the iEBE-VISHNU model with TRENTo initial conditions. The observed discrepancies between the data and the model calculations vary depending on the harmonic combinations. Due to the sensitivity of model parameters estimated with Bayesian analyses to these higher-order observables, the results presented in this work provide new and independent constraints on the initial conditions and transport properties in theoretical models used to describe the system created in heavy-ion collisions

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 067 forfattere av denne artikkelen] (2025). Multimuons in cosmic-ray events as seen in ALICE at the LHC. Journal of Cosmology and Astroparticle Physics (JCAP). 2025(4), s. 1–30. doi: 10.1088/1475-7516/2025/04/009. Fulltekst i vitenarkiv Vis sammendrag

  ALICE is a large experiment at the CERN Large Hadron Collider. Located 52 meters underground, its detectors are suitable to measure muons produced by cosmic-ray interactions in the atmosphere. In this paper, the studies of the cosmic muons registered by ALICE during Run 2 (2015–2018) are described. The analysis is limited to multimuon events defined as events with more than four detected muons (Nµ > 4) and in the zenith angle range 0 ◦ < θ < 50◦ . The results are compared with Monte Carlo simulations using three of the main hadronic interaction models describing the air shower development in the atmosphere: QGSJET-II-04, EPOS-LHC, and SIBYLL 2.3d. The interval of the primary cosmic-ray energy involved in the measured muon multiplicity distribution is about 4×1015 < Eprim < 6×1016 eV. In this interval none of the three models is able to describe precisely the trend of the composition of cosmic rays as the energy increases. However, QGSJET-II-04 is found to be the only model capable of reproducing reasonably well the muon multiplicity distribution, assuming a heavy composition of the primary cosmic rays over the whole energy range, while SIBYLL 2.3d and EPOS-LHC underpredict the number of muons in a large interval of multiplicity by more than 20% and 30%, respectively. The rate of high muon multiplicity events (Nµ > 100) obtained with QGSJET-II-04 and SIBYLL 2.3d is compatible with the data, while EPOS-LHC produces a significantly lower rate (55% of the measured rate). For both QGSJET-II-04 and SIBYLL 2.3d, the rate is close to the data when the composition is assumed to be dominated by heavy elements, an outcome compatible with the average energy Eprim ∼ 1017 eV of these events. This result places significant constraints on more exotic production mechanisms.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 074 forfattere av denne artikkelen] (2025). First Measurement of A = 4 Hypernuclei and Antihypernuclei at the LHC. Physical Review Letters. ISSN 0031-9007. 134(16). doi: 10.1103/PhysRevLett.134.162301. Fulltekst i vitenarkiv Vis sammendrag

  In this Letter, the first evidence of the 4 Λ¯ He antihypernucleus is presented, along with the first measurement at the LHC of the production of (anti)hypernuclei with mass number A ¼ 4, specifically ðantiÞ4 ΛH and ðantiÞ4 ΛHe. In addition, the antiparticle-to-particle ratios for both hypernuclei (4 Λ¯ H¯ =4 ΛH and 4 Λ¯ He=4 ΛHe) 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 ffiffiffiffiffiffiffi sNN p ¼ 5.02 TeV. The yields measured for the average of the charge-conjugated states are found to be ½0.78 0.19ðstatÞ 0.17ðsystÞ × 10−6 for the ðantiÞ4 ΛH and ½1.08 0.34ðstatÞ 0.20ðsystÞ × 10−6 for the ðantiÞ4 ΛHe, and the measured antiparticle-to-particle ratios are in agreement with unity. The presence of ðantiÞ4 ΛH and ðantiÞ4 ΛHe excited states is expected to strongly enhance the production yield of these hypernuclei. The yield values exhibit a combined deviation of 3.3σ from the theoretical ground-state-only expectation, while the inclusion of the excited states in the calculations leads to an agreement within 0.6σ with the present measurements. Additionally, the measured ðantiÞ4 ΛH and ðantiÞ4 ΛHe masses are compatible with the world-average values within the uncertainties

• Zurlo, N.; Zugravel, S. C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y. [Vis alle 1 069 forfattere av denne artikkelen] (2025). Measurements of differential two-particle number and transverse momentum correlation functions in pp collisions at √s = 13 TeV. European Physical Journal C. ISSN 1434-6044. 85(8). doi: 10.1140/epjc/s10052-025-14531-0. Fulltekst i vitenarkiv Vis sammendrag

  Differential two-particle normalized cumulants (R2 ) and transverse momentum correlations (P2 ) are mea- sured as a function of the relative pseudorapidity and azimuthal angle difference (η, ϕ) of charged particle pairs in minimum bias pp collisions at √s = 13 TeV. The mea- surements use charged hadrons in the pseudorapidity region of |η| < 0.8 and the transverse momentum range 0.2 < pT < 2.0 GeV/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 func- tions are reported for both unlike-sign and like-sign pairs and their charge-independent and charge-dependent combi- nations. Both the R2 and P2 measured in pp collisions exhibit features qualitatively similar to those observed in p–Pb and Pb–Pb collisions. The η and ϕ root mean square widths of the near-side peak of the correlation functions are evalu- ated 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 compar- ison of the measured correlation functions with predictions from PYTHIA8 shows that this model qualitatively captures their basic structure and characteristics but feature impor- tant differences. In addition, the RCD 2 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.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 078 forfattere av denne artikkelen] (2025). First measurement of 𝐷𝑠⁢1⁡(1+)⁢(2536)+ and 𝐷* 𝑠⁢2⁡(2+)⁢(2573)+ production in proton-proton collisions at √𝑠 =13  TeV at the LHC. Physical Review D. ISSN 2470-0010. 111(11). doi: 10.1103/PhysRevD.111.112005. Fulltekst i vitenarkiv Vis sammendrag

  The production yields of the orbitally excited charm-strange mesons Ds1ð1þÞð2536Þþ and D s2ð2þÞð2573Þþ were measured for the first time in proton-proton (pp) collisions at a center-of-mass energy of ffiffi s p ¼ 13 TeV with the ALICE experiment at the LHC. The Dþ s1 and Dþ s2 mesons were measured at midrapidity (jyj < 0.5) in minimum-bias and high-multiplicity pp collisions in the transverse-momentum interval 2 < pT < 24 GeV=c. Their production yields relative to the Dþ s ground-state yield were found to be compatible between minimum-bias and high-multiplicity collisions, as well as with previous measurements in ep and eþe− collisions. The measured Dþ s1=Dþ s and Dþ s2 =Dþ s yield ratios are described by statistical hadronization models and can be used to tune the parameters governing the production of excited charm-strange hadrons in Monte Carlo generators, such as PYTHIA 8.

• Zurlo, N.; Zugravel, S. C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y. [Vis alle 1 078 forfattere av denne artikkelen] (2025). Measurement of the production cross section of prompt Ξc0 baryons in p–Pb collisions at √sNN=5.02 TeV. European Physical Journal C. ISSN 1434-6044. 85(1). doi: 10.1140/epjc/s10052-024-13531-w. Fulltekst i vitenarkiv Vis sammendrag

  The transverse momentum (pT) differential production cross section of the promptly produced charm-strange baryon Ξ0c (and its charge conjugate Ξ0c) is measured at midrapidity via its hadronic decay into π+Ξ− in p–Pb collisions at a centre-of-mass energy per nucleon–nucleon collision sNN√ = 5.02 TeV with the ALICE detector at the LHC. The Ξ0c nuclear modification factor (RpPb), calculated from the cross sections in pp and p–Pb collisions, is presented and compared with the RpPb of Λ+c baryons. The ratios between the pT-differential production cross section of Ξ0c baryons and those of D0 mesons and Λ+c baryons are also reported and compared with results at forward and backward rapidity from the LHCb Collaboration. The measurements of the production cross section of prompt Ξ0c baryons are compared with a model based on perturbative QCD calculations of charm-quark production cross sections, which includes only cold nuclear matter effects in p–Pb collisions, and underestimates the measurement by a factor of about 50. This discrepancy is reduced when the data is compared with a model that includes string formation beyond leading-colour approximation or in which hadronisation is implemented via quark coalescence. The pT-integrated cross section of prompt Ξ0c-baryon production at midrapidity extrapolated down to pT = 0 is also reported. These measurements offer insights and constraints for theoretical calculations of the hadronisation process. Additionally, they provide inputs for the calculation of the charm production cross section in p–Pb collisions at midrapidity.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 071 forfattere av denne artikkelen] (2025). First observation of strange baryon enhancement with effective energy in pp collisions at the LHC. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(3). doi: 10.1007/JHEP03(2025)029. Fulltekst i vitenarkiv Vis sammendrag

  The production of (multi-)strange hadrons is measured at midrapidity in proton-proton collisions at = 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 , , and 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.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 079 forfattere av denne artikkelen] (2025). J/ψ-hadron correlations at midrapidity in pp collisions at √s = 13 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(7). doi: 10.1007/JHEP07(2025)023. Fulltekst i vitenarkiv Vis sammendrag

  We report on the measurement of inclusive, non-prompt, and prompt J/ψ-hadron correlations by the ALICE Collaboration at the CERN Large Hadron Collider in pp collisions at a center-of-mass energy of 13 TeV . The correlations are studied at midrapidity (|y| < 0.9) in the transverse momentum ranges pT < 40 GeV/c for the J/ψ and 0.15 < pT < 10 GeV/c and |η| < 0.9 for the associated hadrons. The measurement is based on minimum bias and high multiplicity data samples corresponding to integrated luminosities of Lint = 34 nb−1 and Lint = 6.9 pb−1, respectively. In addition, two more data samples are employed, requiring, on top of the minimum bias condition, a threshold on the tower energy of E = 4 and 9 GeV in the ALICE electromagnetic calorimeters, which correspond to integrated luminosities of Lint = 0.9 pb−1 and Lint = 8.4 pb−1, respectively. The azimuthally integrated near and away side yields of associated charged hadrons per J/ψ trigger are presented as a function of the J/ψ and associated hadron transverse momentum. The measurements are discussed in comparison to PYTHIA calculations.

• Zurlo, N.; Zugravel, S. C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Zhuo [Vis alle 1 067 forfattere av denne artikkelen] (2025). System size and energy dependence of the mean transverse momentum fluctuations at the LHC. European Physical Journal C. ISSN 1434-6044. 85(7). doi: 10.1140/epjc/s10052-025-14325-4. Fulltekst i vitenarkiv Vis sammendrag

  Event-by-event fluctuations of the event-wise mean transverse momentum, pT, of charged particles produced in proton–proton (pp) collisions at √ s =5.02TeV, Xe– Xe collisions at √ √ sNN = 5.44TeV, and Pb–Pb collisions at sNN = 5.02TeVare studied using the ALICE detector based on the integral correlator pTpT.The correlator strength is found to decreasemonotonically with increasing produced charged-particle multiplicity measured at midrapidity in all three systems. In Xe–Xe and Pb–Pb collisions, the multiplicity dependence of the correlator deviates significantly from a simple power-law scaling as well as from the predictions of theHIJING andAMPTmodels. The observed deviation from power-law scaling is expected from transverse radial flow in semicentral to central Xe–Xe and Pb–Pb collisions. In pp collisions, the correlation strength is also studied by classifying the events based on the transverse spherocity, S0, of the particle production at midrapidity, used as a proxy for the presence of a pronounced back-to-back jet topology. Lowspherocity (jetty) events feature a larger correlation strength than those with high spherocity (isotropic). The strength and multiplicity dependence of jetty and isotropic events are well reproduced by calculations with the PYTHIA 8 and EPOS LHC models.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 072 forfattere av denne artikkelen] (2025). Light neutral-meson production in pp collisions at √s = 13 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(8). doi: 10.1007/JHEP08(2025)035. Fulltekst i vitenarkiv Vis sammendrag

  The momentum-differential invariant cross sections of π0 and η mesons are reported for pp collisions at √s = 13 TeV at midrapidity (|y| < 0.8). The measurement is performed in a broad transverse-momentum range of 0.2 < pT < 200 GeV/c and 0.4 < pT < 60 GeV/c for the π0 and η, respectively, extending the pT coverage of previous measurements. Transverse-mass-scaling violation of up to 60% at low transverse momentum has been observed, agreeing with measurements at lower collision energies. Transverse Bjorken x (xT) scaling of the π0 cross sections at LHC energies is fulfilled with a power-law exponent of n = 5.01 ± 0.05, consistent with values obtained for charged pions at similar collision energies. The data are compared to predictions from next-to-leading order perturbative QCD calculations, where the π0 spectrum is best described using the CT18 parton distribution function and the NNFF1.0 or BDSS fragmentation function. Expectations from PYTHIA8 and EPOS LHC overestimate the spectrum for the π0 and are not able to describe the shape and magnitude of the η spectrum. The charged-particle multiplicity dependent π0 and η pT spectra show the expected change of the spectral shape, characterized by a flatter slope with increasing multiplicity. This is demonstrated across a broad transverse-momentum range and up to events with a charged-particle multiplicity exceeding five times the mean value in minimum bias collisions. The η/π0 ratio depends on the charged-particle multiplicity for pT < 4 GeV/c. PYTHIA8 and EPOS LHC qualitatively explain this behavior with an increasing contribution from the feed-down of heavier particles to the π0 spectrum.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 070 forfattere av denne artikkelen] (2025). Studying charm hadronisation into baryons with azimuthal correlations of Λ+ c with charged particles in pp collisions at √𝑠 = 13 TeV. Physics Letters B. ISSN 0370-2693. 868. doi: 10.1016/j.physletb.2025.139681. Fulltekst i vitenarkiv Vis sammendrag

  The distribution of angular correlations between prompt charm hadrons and primary charged particles in pp collisions is sensitive to the charm-quark hadronisation process. In this letter, charm-baryon correlations are measured for the first time by studying the azimuthal-angle difference between charged particles and prompt Λ+ c baryons produced in pp collisions at a centre-of-mass energy of √𝑠 = 13 TeV, with the ALICE detector. Λ+ c baryons are reconstructed at midrapidity (|𝑦| < 0.5) in the transverse-momentum interval 3 < 𝑝T < 16 GeV/𝑐, and correlated with charged particles with 𝑝T > 0.3 GeV/𝑐 and pseudorapidity |𝜂| < 0.8. For 3 < 𝑝Λ+ c ,D T < 5 GeV/𝑐, the comparison with published measurements of D-meson and charged-particle correlations in the same collision system hints at a larger number of low-momentum particles associated with Λ+ c -baryon triggers than with D-meson triggers, both in the collinear and opposite directions with respect to the trigger particle. These differences can be quantified by the comparison of the properties of the near- and away-side correlation peaks, and are not reproduced by predictions of various Monte Carlo event generators, generally underpredicting the associated particle yields at 𝑝assoc T < 1 GeV/𝑐. This tension between Λ+ c -baryon and D-meson associated peak yields could suggest a modified fragmentation of the charm quark, or a different hadronisation process, when a charm baryon is produced in the final state.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 070 forfattere av denne artikkelen] (2025). Multiplicity-dependent inclusive J/ψ production at forward rapidity in pp collisions at √s = 13 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(7). doi: 10.1007/JHEP07(2025)238. Fulltekst i vitenarkiv Vis sammendrag

  This paper presents a study of the inclusive forward J/ψ yield as a function of forward charged-particle multiplicity in pp collisions at √s = 13TeV using data collected by the ALICE experiment at the CERN LHC. The results are presented in terms of relative J/ψ 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 |η| < 1. The J/ψ mesons are reconstructed via their decay into μ+μ− pairs in the forward rapidity region (2.5 < y < 4). The relative multiplicity is estimated in the forward pseudorapidity range which overlaps with the J/ψ rapidity region. The results show a steeper-than-linear increase of the J/ψ yields versus the multiplicity. They are compared with previous measurements and theoretical model calculations.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 075 forfattere av denne artikkelen] (2025). Charged-particle multiplicity distributions over a wide pseudorapidity range in p–Pb collisions at √sNN = 5.02 TeV. European Physical Journal C. ISSN 1434-6044. 85(8). doi: 10.1140/epjc/s10052-025-14577-0. Fulltekst i vitenarkiv Vis sammendrag

  This paper presents the primary charged-particle multiplicity distributions in proton–lead collisions at a centre-of-mass energy per nucleon–nucleon collision of √sNN = 5.02 TeV. The distributions are reported for non-single diffractive collisions in different pseudorapidity ranges.The measurements are performed using the combined information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE. The multiplicity distributions are parametrised with a double negative binomial distribution function which provides satisfactory descriptions of the distributions for all the studied pseudorapidity intervals. The data are compared to models and analysed quantitatively, evaluating the first four moments (mean, standard deviation, skewness, and kurtosis). The shape evolution of the measured multiplicity distributions is studied in terms of KNO variables and it is found that none of the considered models reproduces the measurements. This paper also reports on the average charged-particle multiplicity, normalised by the average number of participating nucleon pairs, as a function of the collision energy. The multiplicity results are then compared to measurements made in proton–proton and nucleus–nucleus collisions across a wide range of collision energies.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 069 forfattere av denne artikkelen] (2025). First measurement of D*+vector meson spin alignment in Pb–Pb collisions at √sNN = 5.02TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(10). doi: 10.1007/JHEP10(2025)094. Fulltekst i vitenarkiv Vis sammendrag

  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 ρ00 of the diagonal spin-density matrix for prompt D∗+ mesons with 4 < pT < 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 √sNN = 5.02TeV. Evidence of spin alignment ρ00 > 1/3 has been found for pT > 15 GeV/c and 0.3 < |y| < 0.8 with a significance of 3.1σ. The measured spin alignment of prompt D∗+ mesons is compared with the one of inclusive J/ψ mesons measured at forward rapidity (2.5 < y < 4).

• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 068 forfattere av denne artikkelen] (2025). Exclusive photoproduction of excited ρ mesons decaying to four pions in ultraperipheral Pb–Pb collisions at √sNN = 5.02 TeV. Physics Letters B. ISSN 0370-2693. 872. doi: 10.1016/j.physletb.2025.140006. Fulltekst i vitenarkiv Vis sammendrag

  The intense photon fluxes from relativistic nuclei provide an opportunity to study photonuclear interactions in ultraperipheral collisions. In particular, it allows for the investigations of excited, light-flavour vector mesons. The measurement of coherently photoproduced 𝜋+𝜋−𝜋+𝜋− final states in ultraperipheral Pb–Pb collisions at √ 𝑠NN = 5.02 TeV is presented for the first time. The cross section, d𝜎/d𝑦, times the branching ratio (𝜌 → 𝜋+𝜋+𝜋−𝜋−) is found to be 47.8 ± 2.3 (stat.) ± 7.7 (syst.) mb in the rapidity interval |𝑦| < 0.5. The invariant mass distribution is not well described with a single Breit-Wigner resonance without an interference term. Including interference with a non-resonant contribution results in the mass and width values being too far from those reported in PDG, while the production of two interfering resonances, 𝜌(1450) and 𝜌(1700), also provides a good description of the data. The values of the masses (𝑚) and widths (Γ) of the resonances extracted from the fit assuming two interfering resonances are 𝑚1 = 1385 ± 14 (stat.) ± 3 (syst.) MeV/𝑐2, Γ1 = 431 ± 36 (stat.) ± 82 (syst.) MeV/𝑐2, 𝑚2 = 1663 ± 13 (stat.) ± 22 (syst.) MeV/𝑐2 and Γ2 = 357 ± 31 (stat.) ± 49 (syst.) MeV/𝑐2, respectively. The measured cross sections times the branching ratios are compared to recent theoretical predictions.

• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 071 forfattere av denne artikkelen] (2025). Measurement of correlations among net-charge, net-proton, and net-kaon multiplicity distributions in Pb-Pb collisions at √sNN = 5.02 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(8). doi: 10.1007/JHEP08(2025)210. Fulltekst i vitenarkiv Vis sammendrag

  Correlations among conserved quantum numbers, such as the net-electric charge, the net-baryon, and the net-strangeness in heavy-ion collisions, are crucial for exploring the QCD phase diagram. In this paper, these correlations are investigated using net-proton number (as a proxy for the net-baryon), net-kaon number (for the net-strangeness), and net-charged particle number in Pb-Pb collisions at √sNN = 5.02TeV with the ALICE detector. The observed correlations deviate from the Poissonian baseline, with a more pronounced deviation at LHC energies than at RHIC. Theoretical calculations of the Thermal-FIST hadron resonance gas model, HIJING, and EPOS LHC event generators are compared with experimental results, where a significant impact of resonance decays is observed. Thermal-FIST calculations under the grand canonical and canonical ensembles highlight significant differences, underscoring the role of local charge conservation in explaining the data. Recent lattice QCD studies have demonstrated that the magnetic field generated by spectator protons in heavy-ion collisions affects susceptibility ratios, in particular those related to the net-electric charge and the net-baryon numbers. The experimental findings are in qualitative agreement with the expectations of lattice QCD.

• Acharya, S.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M.; Agrawal, N. & Ahammed, Z. [Vis alle 1 076 forfattere av denne artikkelen] (2025). Femtoscopic study of the proton-proton and proton-deuteron systems in heavy-ion collisions at the LHC. Physics Letters B. ISSN 0370-2693. 871. doi: 10.1016/j.physletb.2025.139921. Fulltekst i vitenarkiv
• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 072 forfattere av denne artikkelen] (2025). Exploring nuclear structure with multiparticle azimuthal correlations at the LHC. Physics Letters B. ISSN 0370-2693. 869. doi: 10.1016/j.physletb.2025.139855. Fulltekst i vitenarkiv Vis sammendrag

  Details of the nuclear structure of 129Xe, such as the quadrupole deformation and the nuclear diffuseness, are studied by extensive measurements of anisotropic-flow-related observables in Xe–Xe collisions at a centre-of-mass energy per nucleon pair √𝑠NN = 5.44 TeV with the ALICE detector at the LHC. The results are compared with those from Pb–Pb collisions at √𝑠NN = 5.02 TeV for a baseline, given that the 208Pb nucleus exhibits a very weak deformation. Furthermore, comprehensive comparisons are performed with a state-of-the-art hybrid model using IP-Glasma+MUSIC+UrQMD. It is found that among various IP-Glasma+MUSIC+UrQMD calculations with different values of nuclear parameters, the one using a nuclear diffuseness parameter of 𝑎0 = 0.492 and a nuclear quadrupole deformation parameter of 𝛽2 = 0.207 provides a better description of the presented flow measurements. These studies represent the first systematic exploration of nuclear structure at TeV energies, utilizing a comprehensive set of anisotropic flow observables. The measurements serve as a critical experimental benchmark for rigorously testing the interplay between nuclear structure inputs and heavy-ion theoretical models.

• Zurlo, N.; Zugravel, S. C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y. [Vis alle 1 084 forfattere av denne artikkelen] (2025). Investigating the p–π± and p–p–π± dynamics with femtoscopy in pp collisions at √s = 13 TeV. European Physical Journal A. ISSN 1434-6001. 61(8). doi: 10.1140/epja/s10050-025-01615-4. Fulltekst i vitenarkiv
• Abualrob, I. J.; Acharya, S.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 068 forfattere av denne artikkelen] (2025). Study of ⟨pT⟩ and its higher moments, and extraction of the speed of sound in Pb-Pb collisions with ALICE. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(11). doi: 10.1007/JHEP11(2025)076. Fulltekst i vitenarkiv Vis sammendrag

  Ultrarelativistic heavy-ion collisions produce a state of hot and dense strongly interacting QCD matter called quark-gluon plasma (QGP). On an event-by-event basis, the volume of the QGP in ultracentral collisions is mostly constant, while its total entropy can vary significantly due to quantum fluctuations, leading to variations in the temperature of the system. Exploiting this unique feature of ultracentral collisions allows for the interpretation of the correlation of the mean transverse momentum of produced charged hadrons and the number of charged hadrons as a measure for the speed of sound, cs. This speed is related to the rate at which compression waves travel in the QGP and is determined by fitting the relative increase in with respect to the relative change in the average charged-particle density measured at mid-rapidity. This study reports the event-average of charged particles as well as the variance, skewness, and kurtosis of the event-by-event transverse momentum per charged particle distribution in ultracentral Pb-Pb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair using the ALICE detector. Different centrality estimators based on charged-particle multiplicity or the transverse energy of the event are used to select ultracentral collisions. By ensuring a pseudorapidity gap between the region used to define the centrality and the region used to perform the measurement, the influence of biases and their potential effects on the rise of the mean transverse momentum is tested. The measured is found to strongly depend on the exploited centrality estimator and ranges between 0.1146±0.0028 (stat.)±0.0065 (syst.) and 0.4374±0.0006 (stat.)±0.0184 (syst.) in natural units. The self-normalized variance shows a steep decrease towards ultracentral collisions, while the self-normalized skewness variables show a maximum, followed by a fast decrease. These non-Gaussian features are understood in terms of the vanishing of the impact-parameter fluctuations contributing to the event-to-event [pT] distribution.

• Zurlo, N.; Zugravel, S. C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y. [Vis alle 1 070 forfattere av denne artikkelen] (2025). Observation of deuteron and antideuteron formation from resonance-decay nucleons. Nature. ISSN 0028-0836. 648(8093), s. 306–311. doi: 10.1038/s41586-025-09775-5. Fulltekst i vitenarkiv
• Acharya, S.; Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 082 forfattere av denne artikkelen] (2025). Observation of the Ω⁡(2012) baryon at the LHC. Physical Review D. ISSN 2470-0010. 112(9). doi: 10.1103/v4mh-3r8z. Fulltekst i vitenarkiv
• Zurlo, N.; Zugravel, S. C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y. [Vis alle 1 075 forfattere av denne artikkelen] (2025). Measurement of isolated prompt photon production in pp and p–Pb collisions at the LHC. European Physical Journal C. ISSN 1434-6044. 85(12). doi: 10.1140/epjc/s10052-025-14802-w. Fulltekst i vitenarkiv
• Abualrob, I. J.; Acharya, S.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 044 forfattere av denne artikkelen] (2025). Multiplicity dependence of Ξ+ c and Ξ0 c production in pp collisions at √s = 13 TeV. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2025(12). doi: 10.1007/JHEP12(2025)038. Fulltekst i vitenarkiv
• Acharya, S.; Agarwal, A.; Rinella, G. Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 071 forfattere av denne artikkelen] (2025). D0-meson-tagged jet axes difference in proton-proton collisions at √s = 5.02 TeV. Physical Review D. ISSN 2470-0010. 112(9). doi: 10.1103/nt4q-7t77. Fulltekst i vitenarkiv
• Acharya, S.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 080 forfattere av denne artikkelen] (2025). Search for Quasiparticle Scattering in the Quark-Gluon Plasma with Jet Splittings in pp and Pb-Pb Collisions at sNN =5.02 TeV. Physical Review Letters. ISSN 0031-9007. 135(3). doi: 10.1103/PhysRevLett.135.031901. Fulltekst i vitenarkiv
• Zurlo, N.; Zugravel, S.C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y [Vis alle 1 067 forfattere av denne artikkelen] (2025). Measurement of the inclusive isolated-photon production cross section in pp and Pb–Pb collisions at sNN=5.02 TeV. European Physical Journal C. ISSN 1434-6044. 85(5). doi: 10.1140/epjc/s10052-025-13971-y. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 081 forfattere av denne artikkelen] (2025). Rapidity dependence of antideuteron coalescence in pp collisions at s=13 TeV with ALICE. Physics Letters B. ISSN 0370-2693. 860. doi: 10.1016/j.physletb.2024.139191. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 078 forfattere av denne artikkelen] (2025). Investigating Λ baryon production in p -Pb collisions in jets and the underlying event using angular correlations. Physical Review C. ISSN 2469-9985. 111(1). doi: 10.1103/PhysRevC.111.015201. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 082 forfattere av denne artikkelen] (2025). Measurement of HΛ3 production in Pb–Pb collisions at s<inf>NN</inf>=5.02 TeV. Physics Letters B. ISSN 0370-2693. 860. doi: 10.1016/j.physletb.2024.139066. Fulltekst i vitenarkiv Vis sammendrag

  The first measurement of and differential production with respect to transverse momentum and centrality in Pb–Pb collisions at TeV is presented. The has been reconstructed via its two-charged-body decay channel, i.e., . A Blast-Wave model fit of the -differential spectra of all nuclear species measured by the ALICE collaboration suggests that the kinetic freeze-out surface is consistent with that of other nuclei. The ratio between the integrated yields of and is compared to predictions from the statistical hadronisation model and the coalescence model, with the latter being favoured by the presented measurements.

• Acharya, S.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 065 forfattere av denne artikkelen] (2025). Medium-induced modification of groomed and ungroomed jet mass and angularities in Pb–Pb collisions at s<inf>NN</inf>=5.02 [Figure presented]. Physics Letters B. ISSN 0370-2693. 864. doi: 10.1016/j.physletb.2025.139409. Fulltekst i vitenarkiv
• Zurlo, N.; Zugravel, S.C.; Zhu, Y.; Zhu, S.; Zhu, J. & Zhou, Y [Vis alle 1 082 forfattere av denne artikkelen] (2025). Measurement of the inclusive isolated-photon production cross section in pp collisions at (Formula presented.) TeV. European Physical Journal C. ISSN 1434-6044. 85(1). doi: 10.1140/epjc/s10052-024-13506-x. Fulltekst i vitenarkiv
• Acharya, S.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 080 forfattere av denne artikkelen] (2025). Measurement of f1(1285) production in pp collisions at s = 13 TeV. Physics Letters B. ISSN 0370-2693. 866. doi: 10.1016/j.physletb.2025.139562. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 082 forfattere av denne artikkelen] (2025). Probing Strangeness Hadronization with Event-by-Event Production of Multistrange Hadrons. Physical Review Letters. ISSN 0031-9007. 134(2). doi: 10.1103/PhysRevLett.134.022303. Fulltekst i vitenarkiv
• Acharya, S.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L.; Agnello, M. & Agrawal, N. [Vis alle 1 067 forfattere av denne artikkelen] (2025). Proton emission in ultraperipheral Pb-Pb collisions at sNN =5.02 TeV. Physical Review C. ISSN 2469-9985. 111(5). doi: 10.1103/PhysRevC.111.054906. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 080 forfattere av denne artikkelen] (2025). Particle production as a function of charged-particle flattenicity in pp collisions at s =13 TeV. Physical Review D. ISSN 2470-0010. 111(1). doi: 10.1103/PhysRevD.111.012010. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 068 forfattere av denne artikkelen] (2024). Measurement of ω c0 baryon production and branching-fraction ratio BR (ω c0 → ω- e+ν e)/BR (ω c0 → ω-π+) in pp collisions at s =13 TeV. Physical Review D. ISSN 2470-0010. 110(3). doi: 10.1103/PhysRevD.110.032014. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 079 forfattere av denne artikkelen] (2024). Measurement of the production and elliptic flow of (anti)nuclei in Xe-Xe collisions at sNN =5.44 TeV. Physical Review C. ISSN 2469-9985. 110(6). doi: 10.1103/PhysRevC.110.064901. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 062 forfattere av denne artikkelen] (2024). Measurement of the impact-parameter dependent azimuthal anisotropy in coherent ρ⁰ photoproduction in Pb–Pb collisions at s<inf>NN</inf>=5.02 TeV. Physics Letters B. ISSN 0370-2693. 858. doi: 10.1016/j.physletb.2024.139017. Fulltekst i vitenarkiv
• Acharya, S.; Adamová, D.; Agarwal, A.; Rinella, Rinella Aglieri; Aglietta, L. & Agnello, M. [Vis alle 1 063 forfattere av denne artikkelen] (2024). Investigating strangeness enhancement with multiplicity in pp collisions using angular correlations. Journal of High Energy Physics (JHEP). ISSN 1126-6708. 2024(9). doi: 10.1007/JHEP09(2024)204. Fulltekst i vitenarkiv Vis sammendrag

  A study of strange hadron production associated with hard scattering processes and with the underlying event is conducted to investigate the origin of the enhanced production of strange hadrons in small collision systems characterised by large charged-particle multiplicities. For this purpose, the production of the single-strange meson K0 S and the double-strange baryon Ξ ± is measured, in each event, in the azimuthal direction of the highest-pT particle (“trigger” particle), related to hard scattering processes, and in the direction transverse to it in azimuth, associated with the underlying event, in pp collisions at √ s = 5.02 TeV and √ s = 13 TeV using the ALICE detector at the LHC. The per-trigger yields of K0 S and Ξ ± are dominated by the transverse-to-leading production (i.e., in the direction transverse to the trigger particle), whose contribution relative to the toward-leading production is observed to increase with the event charged-particle multiplicity. The transverseto-leading and the toward-leading Ξ ±/K0 S yield ratios increase with the multiplicity of charged particles, suggesting that strangeness enhancement with multiplicity is associated with both hard scattering processes and the underlying event. The relative production of Ξ ± with respect to K0 S is higher in transverse-to-leading processes over the whole multiplicity interval covered by the measurement. The K0 S and Ξ ± per-trigger yields and yield ratios are compared with predictions of three diferent phenomenological models, namely Pythia8.2 with the Monash tune, Pythia8.2 with ropes and EPOS LHC. The comparison shows that none of them can quantitatively describe either the transverse-to-leading or the toward-leading yields of K0 S and Ξ ±.

• Grigoryan, S.; Balis, B.; Gorgon, M.; Horzyk, A.; Jablonski, M. & Kitowski, J.P. [Vis alle 1 063 forfattere av denne artikkelen] (2024). Investigating strangeness enhancement in jet and medium via φ(1020) production in p-Pb collisions at √sNN=5.02 TeV. Physical Review C. ISSN 2469-9985. 110(6). doi: 10.1103/PhysRevC.110.064912. Fulltekst i vitenarkiv

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