| 51. |
- Acharya, S., et al.
(author)
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J/ψ production at midrapidity in p-Pb collisions at √sNN = 8.16 TeV
- 2023
-
In: Journal of High Energy Physics. - 1029-8479. ; 2023:7
-
Journal article (peer-reviewed)abstract
- The production of inclusive, prompt and non-prompt J/ψ was studied for the first time at midrapidity (−1.37 < y cms < 0.43) in p-Pb collisions at sNN = 8.16 TeV with the ALICE detector at the LHC. The inclusive J/ψ mesons were reconstructed in the dielectron decay channel in the transverse momentum (p T) interval 0 < p T < 14 GeV/c and the prompt and non-prompt contributions were separated on a statistical basis for p T > 2 GeV/c. The study of the J/ψ mesons in the dielectron channel used for the first time in ALICE online single-electron triggers from the Transition Radiation Detector, providing a data sample corresponding to an integrated luminosity of 689 ± 13 μb −1. The proton-proton reference cross section for inclusive J/ψ was obtained based on interpolations of measured data at different centre-of-mass energies and a universal function describing the p T-differential J/ψ production cross sections. The p T-differential nuclear modification factors R pPb of inclusive, prompt, and non-prompt J/ψ are consistent with unity and described by theoretical models implementing only nuclear shadowing. [Figure not available: see fulltext.] © 2023, The Author(s).
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| 52. |
- Acharya, S., et al.
(author)
-
Jet-like correlations with respect to KS0 and Λ (Λ ¯) in pp and central Pb–Pb collisions at √sNN=5.02 TeV
- 2023
-
In: European Physical Journal C. - 1434-6044. ; 83:6
-
Journal article (peer-reviewed)abstract
- Two-particle correlations with KS0 , Λ / Λ ¯ , and charged hadrons as trigger particles in the transverse momentum range 8 < pT , trig< 16 GeV/ c , and associated charged particles within 1 < pT , assoc< 8 GeV/ c , are studied at midrapidity in pp and central Pb–Pb collisions at a centre-of-mass energy per nucleon–nucleon collision sNN=5.02 TeV with the ALICE detector at the LHC. After subtracting the contributions of the flow background, the per-trigger yields are extracted on both the near and away sides, and the ratio in Pb–Pb collisions with respect to pp collisions (IAA) is computed. The per-trigger yield in Pb–Pb collisions on the away side is strongly suppressed to the level of IAA≈ 0.6 for pT , assoc> 3 GeV/ c as expected from strong in-medium energy loss, while an enhancement develops at low pT , assoc on both the near and away sides, reaching IAA≈ 1.8 and 2.7 respectively. These findings are in good agreement with previous ALICE measurements from two-particle correlations triggered by neutral pions (π –h) and charged hadrons (h–h) in Pb–Pb collisions at sNN=2.76 TeV. Moreover, the correlations with KS0 mesons and Λ / Λ ¯ baryons as trigger particles are compared to those of inclusive charged hadrons. The results are compared with the predictions of Monte Carlo models. © 2023, The Author(s).
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| 53. |
- Acharya, S., et al.
(author)
-
K∗(892)0 and φ(1020) production in p-Pb collisions at sNN =8.16 TeV
- 2023
-
In: Physical Review C. - 2469-9985. ; 107:5
-
Journal article (peer-reviewed)abstract
- The production of K∗(892)0and φ(1020)resonances has been measured in p-Pb collisions at sNN = 8.16 TeV using the ALICE detector. Resonances are reconstructed via their hadronic decay channels in the rapidity interval -0.5 < y < 0 and the transverse momentum spectra are measured for various multiplicity classes up to pT = 20 GeV/c for K∗(892)0and pT = 16 GeV/c for φ(1020). The pT-integrated yields and mean transverse momenta are reported and compared with previous results in pp, p-Pb and Pb-Pb collisions. The xT scaling for K∗(892)0and φ(1020)resonance production is newly tested in p-Pb collisions and found to hold in the high-pT region at Large Hadron Collider energies. The nuclear modification factors (RpPb) as a function of pT for K∗0 and φ at sNN = 8.16 TeV are presented along with the new RpPb measurements of K∗0, φ, Ξ, and ω at sNN = 5.02 TeV. At intermediate pT (2-8 GeV/c), RpPb of Ξ, ω show a Cronin-like enhancement, while K∗0 and φ show no or little nuclear modification. At high pT (>8 GeV/c), the RpPb values of all hadrons are consistent with unity within uncertainties. The RpPb of K∗(892)0and φ(1020)at sNN = 8.16 and 5.02 TeV show no significant energy dependence. © 2023 CERN.
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| 54. |
- Acharya, S., et al.
(author)
-
K*(892)± resonance production in Pb-Pb collisions at sNN =5.02 TeV
- 2024
-
In: Physical Review C. - 2469-9985. ; 109:4
-
Journal article (peer-reviewed)abstract
- The production of K∗(892)± meson resonance is measured at midrapidity (|y|8 GeV/c, consistent with measurements for other light-flavored hadrons. The smallest values are observed in most central collisions, indicating larger energy loss of partons traversing the dense medium. ©2024 CERN, for the ALICE Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
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| 55. |
- Acharya, S., et al.
(author)
-
KS0KS0 and KS0K± femtoscopy in pp collisions at s=5.02 and 13 TeV
- 2022
-
In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 833
-
Journal article (peer-reviewed)abstract
- Femtoscopic correlations with the particle pair combinations KS0KS0 and KS0K± are studied in pp collisions at s=5.02 and 13 TeV by the ALICE experiment. At both energies, boson source parameters are extracted for both pair combinations, by fitting models based on Gaussian size distributions of the sources, to the measured two-particle correlation functions. The interaction model used for the KS0KS0 analysis includes quantum statistics and strong final-state interactions through the f0(980) and a0(980) resonances. The model used for the KS0K± analysis includes only the final-state interaction through the a0 resonance. Source parameters extracted in the present work are compared with published values from pp collisions at s=7 TeV and the different pair combinations are found to be consistent. From the observation that the strength of the KS0KS0 correlations is significantly greater than the strength of the KS0K± correlations, the new results are compatible with the a0 resonance being a tetraquark state of the form (q1,q2‾,s,s‾), where q1 and q2 are u or d quarks.
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| 56. |
- Acharya, S., et al.
(author)
-
Light (anti)nuclei production in Pb-Pb collisions at sNN =5.02 TeV
- 2023
-
In: Physical Review C. - 2469-9985. ; 107:6
-
Journal article (peer-reviewed)abstract
- The measurement of the production of deuterons, tritons and He3 and their antiparticles in Pb-Pb collisions at sNN=5.02TeV is presented in this article. The measurements are carried out at midrapidity (|y|< 0.5) as a function of collision centrality using the ALICE detector. The pT-integrated yields, the coalescence parameters and the ratios to protons and antiprotons are reported and compared with nucleosynthesis models. The comparison of these results in different collision systems at different center-of-mass collision energies reveals a suppression of nucleus production in small systems. In the Statistical Hadronisation Model framework, this can be explained by a small correlation volume where the baryon number is conserved, as already shown in previous fluctuation analyses. However, a different size of the correlation volume is required to describe the proton yields in the same data sets. The coalescence model can describe this suppression by the fact that the wave functions of the nuclei are large and the fireball size starts to become comparable and even much smaller than the actual nucleus at low multiplicities. © 2023 CERN. for the ALICE Collaboration. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
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| 57. |
- Acharya, S., et al.
(author)
-
Longitudinal and azimuthal evolution of two-particle transverse momentum correlations in Pb-Pb collisions at √sNN= 2.76 TeV
- 2020
-
In: Physics Letters B. - : Elsevier BV. - 0370-2693. ; 804
-
Journal article (peer-reviewed)abstract
- This paper presents the first measurements of the charge independent (CI) and charge dependent (CD) two-particle transverse momentum correlators G2CI and G2CD in Pb–Pb collisions at √SNN=2.76 TeV by the ALICE collaboration. The two-particle transverse momentum correlator G2 was introduced as a measure of the momentum current transfer between neighboring system cells. The correlators are measured as a function of pair separation in pseudorapidity (Δη) and azimuth (Δφ) and as a function of collision centrality. From peripheral to central collisions, the correlator G2CI exhibits a longitudinal broadening while undergoing a monotonic azimuthal narrowing. By contrast, G2CD exhibits a narrowing along both dimensions. These features are not reproduced by models such as HIJING and AMPT. However, the observed narrowing of the correlators from peripheral to central collisions is expected to result from the stronger transverse flow profiles produced in more central collisions and the longitudinal broadening is predicted to be sensitive to momentum currents and the shear viscosity per unit of entropy density η/s of the matter produced in the collisions. The observed broadening is found to be consistent with the hypothesized lower bound of η/s and is in qualitative agreement with values obtained from anisotropic flow measurements.
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| 58. |
- Acharya, S., et al.
(author)
-
Measurement of anti-3He nuclei absorption in matter and impact on their propagation in the Galaxy
- 2023
-
In: Nature Physics. - : Springer Science and Business Media LLC. - 1745-2473 .- 1745-2481. ; 19:1, s. 61-71
-
Journal article (peer-reviewed)abstract
- In our Galaxy, light antinuclei composed of antiprotons and antineutrons can be produced through high-energy cosmic-ray collisions with the interstellar medium or could also originate from the annihilation of dark-matter particles that have not yet been discovered. On Earth, the only way to produce and study antinuclei with high precision is to create them at high-energy particle accelerators. Although the properties of elementary antiparticles have been studied in detail, the knowledge of the interaction of light antinuclei with matter is limited. We determine the disappearance probability of 3He ¯ when it encounters matter particles and annihilates or disintegrates within the ALICE detector at the Large Hadron Collider. We extract the inelastic interaction cross section, which is then used as an input to the calculations of the transparency of our Galaxy to the propagation of 3He ¯ stemming from dark-matter annihilation and cosmic-ray interactions within the interstellar medium. For a specific dark-matter profile, we estimate a transparency of about 50%, whereas it varies with increasing 3He ¯ momentum from 25% to 90% for cosmic-ray sources. The results indicate that 3He ¯ nuclei can travel long distances in the Galaxy, and can be used to study cosmic-ray interactions and dark-matter annihilation.
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| 59. |
- Acharya, S., et al.
(author)
-
Measurement of beauty production via non-prompt D0 mesons in Pb-Pb collisions at √sNN = 5.02 TeV
- 2022
-
In: Journal of High Energy Physics. - 1029-8479. ; 2022:12
-
Journal article (peer-reviewed)abstract
- The production of non-prompt D0 mesons from beauty-hadron decays was measured at midrapidity (|y| < 0.5) in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sNN = 5.02 TeV with the ALICE experiment at the LHC. Their nuclear modification factor (RAA), measured for the first time down to pT = 1 GeV/c in the 0–10% and 30–50% centrality classes, indicates a significant suppression, up to a factor of about three, for pT> 5 GeV/c in the 0–10% central Pb-Pb collisions. The data are described by models that include both collisional and radiative processes in the calculation of beauty-quark energy loss in the quark-gluon plasma, and quark recombination in addition to fragmentation as a hadronisation mechanism. The ratio of the non-prompt to prompt D0-meson RAA is larger than unity for pT> 4 GeV/c in the 0–10% central Pb-Pb collisions, as predicted by models in which beauty quarks lose less energy than charm quarks in the quark-gluon plasma because of their larger mass. [Figure not available: see fulltext.] © 2022, The Author(s).
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| 60. |
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