Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC



Acharya, S, Acosta, FT, Adamova, D, Adolfsson, J, Aggarwal, MM, Rinella, G Aglieri, Agnello, M, Agrawal, N, Ahammed, Z, Ahn, SU
et al (show 1004 more authors) (2018) Transverse momentum spectra and nuclear modification factors of charged particles in pp, p-Pb and Pb-Pb collisions at the LHC. JOURNAL OF HIGH ENERGY PHYSICS, 2018 (11). 13-.

Access the full-text of this item by clicking on the Open Access link.

Abstract

<jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>We report the measured transverse momentum (<jats:italic>p</jats:italic> <jats:sub>T</jats:sub>) spectra of primary charged particles from pp, p-Pb and Pb-Pb collisions at a center-of-mass energy <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s_{\mathrm{NN}}}=5.02 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:msub> <mml:mi>s</mml:mi> <mml:mrow> <mml:mi>N</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:msub> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>5.02</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV in the kinematic range of 0<jats:italic>.</jats:italic>15 <jats:italic>&lt; p</jats:italic> <jats:sub>T</jats:sub> <jats:italic>&lt;</jats:italic> 50 GeV/<jats:italic>c</jats:italic> and |<jats:italic>η</jats:italic>| <jats:italic>&lt;</jats:italic> 0<jats:italic>.</jats:italic>8. A significant improvement of systematic uncertainties motivated the reanalysis of data in pp and Pb-Pb collisions at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s_{\mathrm{NN}}}=2.76 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:msub> <mml:mi>s</mml:mi> <mml:mrow> <mml:mi>N</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:msub> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>2.76</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV, as well as in p-Pb collisions at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s_{\mathrm{NN}}}=5.02 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:msub> <mml:mi>s</mml:mi> <mml:mrow> <mml:mi>N</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:msub> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>5.02</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV, which is also presented. Spectra from Pb-Pb collisions are presented in nine centrality intervals and are compared to a reference spectrum from pp collisions scaled by the number of binary nucleon-nucleon collisions. For central collisions, the <jats:italic>p</jats:italic> <jats:sub>T</jats:sub> spectra are suppressed by more than a factor of 7 around 6–7 GeV/<jats:italic>c</jats:italic> with a significant reduction in suppression towards higher momenta up to 30 GeV/<jats:italic>c</jats:italic>. The nuclear modification factor <jats:italic>R</jats:italic> <jats:sub>pPb</jats:sub>, constructed from the pp and p-Pb spectra measured at the same collision energy, is consistent with unity above 8 GeV/<jats:italic>c</jats:italic>. While the spectra in both pp and Pb-Pb collisions are substantially harder at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s_{\mathrm{NN}}}=5.02 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:msub> <mml:mi>s</mml:mi> <mml:mrow> <mml:mi>N</mml:mi> <mml:mi>N</mml:mi> </mml:mrow> </mml:msub> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>5.02</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV compared to 2.76 TeV, the nuclear modification factors show no significant collision energy dependence. The obtained results should provide further constraints on the parton energy loss calculations to determine the transport properties of the hot and dense QCD matter. </jats:p>

Item Type: Article
Uncontrolled Keywords: Heavy Ion Experiments, Heavy-ion collision
Depositing User: Symplectic Admin
Date Deposited: 10 May 2019 08:37
Last Modified: 14 Mar 2024 21:16
DOI: 10.1007/JHEP11(2018)013
Open Access URL: https://doi.org/10.1007/JHEP11(2018)013
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3040570