| 51. |
- A., Adare, et al.
(författare)
-
Transverse energy production and charged-particle multiplicity at midrapidity in various systems from sNN =7.7 to 200 GeV
- 2016
-
Ingår i: Physical Review C. - 2469-9985. ; 93:2
-
Tidskriftsartikel (refereegranskat)abstract
- Measurements of midrapidity charged-particle multiplicity distributions, dNch/dη, and midrapidity transverse-energy distributions, dET/dη, are presented for a variety of collision systems and energies. Included are distributions for Au+Au collisions at sNN=200, 130, 62.4, 39, 27, 19.6, 14.5, and 7.7 GeV, Cu+Cu collisions at sNN=200 and 62.4 GeV, Cu+Au collisions at sNN=200 GeV, U+U collisions at sNN=193 GeV, d+Au collisions at sNN=200 GeV, He3+Au collisions at sNN=200 GeV, and p+p collisions at sNN=200 GeV. Centrality-dependent distributions at midrapidity are presented in terms of the number of nucleon participants, Npart, and the number of constituent quark participants, Nqp. For all A+A collisions down to sNN=7.7 GeV, it is observed that the midrapidity data are better described by scaling with Nqp than scaling with Npart. Also presented are estimates of the Bjorken energy density, BJ, and the ratio of dET/dη to dNch/dη, the latter of which is seen to be constant as a function of centrality for all systems.
|
|
| 52. |
|
|
| 53. |
- Acharya, S, et al.
(författare)
-
Charged-particle multiplicity distributions over a wide pseudorapidity range in proton-proton collisions at √s= 0.9, 7, and 8 TeV
- 2017
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 77:12
-
Tidskriftsartikel (refereegranskat)abstract
- We present the charged-particle multiplicity distributions over a wide pseudorapidity range (-3.45.0) for pp collisions at s=0.9,7, and 8 TeV at the LHC. Results are based on information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE, extending the pseudorapidity coverage of the earlier publications and the high-multiplicity reach. The measurements are compared to results from the CMS experiment and to PYTHIA, PHOJET and EPOS LHC event generators, as well as IP-Glasma calculations. © 2017, CERN for the benefit of the ALICE collaboration.
|
|
| 54. |
- Acharya, S, et al.
(författare)
-
Constraining the magnitude of the Chiral Magnetic Effect with Event Shape Engineering in Pb–Pb collisions at sNN=2.76 TeV
- 2018
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 777, s. 151-162
-
Tidskriftsartikel (refereegranskat)abstract
- In ultrarelativistic heavy-ion collisions, the event-by-event variation of the elliptic flow v2 reflects fluctuations in the shape of the initial state of the system. This allows to select events with the same centrality but different initial geometry. This selection technique, Event Shape Engineering, has been used in the analysis of charge-dependent two- and three-particle correlations in Pb–Pb collisions at sNN=2.76 TeV. The two-particle correlator 〈cos(φα−φβ)〉 calculated for different combinations of charges α and β is almost independent of v2 (for a given centrality), while the three-particle correlator 〈cos(φα+φβ−2Ψ2)〉 scales almost linearly both with the event v2 and charged-particle pseudorapidity density. The charge dependence of the three-particle correlator is often interpreted as evidence for the Chiral Magnetic Effect (CME), a parity violating effect of the strong interaction. However, its measured dependence on v2 points to a large non-CME contribution to the correlator. Comparing the results with Monte Carlo calculations including a magnetic field due to the spectators, the upper limit of the CME signal contribution to the three-particle correlator in the 10–50% centrality interval is found to be 26–33% at 95% confidence level. © 2017 The Author(s)
|
|
| 55. |
- Acharya, S, et al.
(författare)
-
Constraints on jet quenching in p–Pb collisions at sNN=5.02 TeV measured by the event-activity dependence of semi-inclusive hadron-jet distributions
- 2018
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 783, s. 95-113
-
Tidskriftsartikel (refereegranskat)abstract
- The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high-transverse momentum trigger hadron in p–Pb collisions at sNN=5.02 TeV. Jets are reconstructed from charged-particle tracks using the anti-kT algorithm with resolution parameter R=0.2 and 0.4. A data-driven statistical approach is used to correct the uncorrelated background jet yield. Recoil jet distributions are reported for jet transverse momentum 15
|
|
| 56. |
- Acharya, S, et al.
(författare)
-
D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at s NN=5.02 TeV
- 2018
-
Ingår i: Physical Review Letters. - 1079-7114. ; 120:10
-
Tidskriftsartikel (refereegranskat)abstract
- The azimuthal anisotropy coefficient v2 of prompt D0, D+, D∗+, and Ds+ mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sNN=5.02 TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|
|
|
| 57. |
- Acharya, S, et al.
(författare)
-
Energy dependence and fluctuations of anisotropic flow in Pb-Pb collisions at √sNN=5.02 and 2.76 TeV
- 2018
-
Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2018:7
-
Tidskriftsartikel (refereegranskat)abstract
- Measurements of anisotropic flow coefficients with two- and multi-particle cumulants for inclusive charged particles in Pb-Pb collisions at sNN=5.02 and 2.76 TeV are reported in the pseudorapidity range |η| < 0.8 and transverse momentum 0.2 < pT < 50 GeV/c. The full data sample collected by the ALICE detector in 2015 (2010), corresponding to an integrated luminosity of 12.7 (2.0) μb−1 in the centrality range 0-80%, is analysed. Flow coefficients up to the sixth flow harmonic (v6) are reported and a detailed comparison among results at the two energies is carried out. The pT dependence of anisotropic flow coefficients and its evolution with respect to centrality and harmonic number n are investigated. An approximate power-law scaling of the form vn(pT) ∼ pT n/3 is observed for all flow harmonics at low pT (0.2 < pT < 3 GeV/c). At the same time, the ratios vn/vm n/ m are observed to be essentially independent of pT for most centralities up to about pT = 10 GeV/c. Analysing the differences among higher-order cumulants of elliptic flow (v2), which have different sensitivities to flow fluctuations, a measurement of the standardised skewness of the event-by-event v2 distribution P(v2) is reported and constraints on its higher moments are provided. The Elliptic Power distribution is used to parametrise P(v2), extracting its parameters from fits to cumulants. The measurements are compared to different model predictions in order to discriminate among initial-state models and to constrain the temperature dependence of the shear viscosity to entropy-density ratio.[Figure not available: see fulltext.]. © 2018, The Author(s).
|
|
| 58. |
- Acharya, S, et al.
(författare)
-
First measurement of jet mass in Pb–Pb and p–Pb collisions at the LHC
- 2018
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 776, s. 249-264
-
Tidskriftsartikel (refereegranskat)abstract
- This letter presents the first measurement of jet mass in Pb–Pb and p–Pb collisions at sNN=2.76 TeV and sNN=5.02 TeV, respectively. Both the jet energy and the jet mass are expected to be sensitive to jet quenching in the hot Quantum Chromodynamics (QCD) matter created in nuclear collisions at collider energies. Jets are reconstructed from charged particles using the anti-kT jet algorithm and resolution parameter R=0.4. The jets are measured in the pseudorapidity range |ηjet|<0.5 and in three intervals of transverse momentum between 60 GeV/c and 120 GeV/c. The measurement of the jet mass in central Pb–Pb collisions is compared to the jet mass as measured in p–Pb reference collisions, to vacuum event generators, and to models including jet quenching. It is observed that the jet mass in central Pb–Pb collisions is consistent within uncertainties with p–Pb reference measurements. Furthermore, the measured jet mass in Pb–Pb collisions is not reproduced by the quenching models considered in this letter and is found to be consistent with PYTHIA expectations within systematic uncertainties. © 2017 The Author
|
|
| 59. |
- Acharya, S, et al.
(författare)
-
First measurement of Ξc 0 production in pp collisions at s=7 TeV
- 2018
-
Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 781, s. 8-19
-
Tidskriftsartikel (refereegranskat)abstract
- The production of the charm-strange baryon Ξc 0 is measured for the first time at the LHC via its semileptonic decay into eΞ−+νe in pp collisions at s=7 TeV with the ALICE detector. The transverse momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 1
|
|
| 60. |
- Acharya, S, et al.
(författare)
-
Inclusive J/ψ production at forward and backward rapidity in p-Pb collisions at √sNN=8.16 TeV
- 2018
-
Ingår i: Journal of High Energy Physics. - 1029-8479. ; 2018:7
-
Tidskriftsartikel (refereegranskat)abstract
- Inclusive J/ψ production is studied in p-Pb interactions at a centre-of-mass energy per nucleon-nucleon collision sNN=8.16 TeV, using the ALICE detector at the CERN LHC. The J/ψ meson is reconstructed, via its decay to a muon pair, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, where positive and negative ycms refer to the p-going and Pb-going direction, respectively. The transverse momentum coverage is pT < 20 GeV/c. In this paper, ycms- and pT-differential cross sections for inclusive J/ψ production are presented, and the corresponding nuclear modification factors RpPb are shown. Forward results show a suppression of the J/ψ yield with respect to pp collisions, concentrated in the region pT ≲ 5 GeV/c. At backward rapidity no significant suppression is observed. The results are compared to previous measurements by ALICE in p-Pb collisions at sNN=5.02 TeV and to theoretical calculations. Finally, the ratios RFB between forward- and backward-ycmsRpPb values are shown and discussed.[Figure not available: see fulltext.]. © 2018, The Author(s).
|
|
