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Title: Measurement of nuclear modification factors of $$\Upsilon$$(1S), $$\Upsilon$$(2S), and $$\Upsilon$$(3S) mesons in PbPb collisions at $$\sqrt{s_{_\mathrm{NN}}} =$$ 5.02 TeV

Abstract

The cross sections for $$\Upsilon$$(1S), $$\Upsilon$$(2S), and $$\Upsilon$$(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at $$\sqrt{s_{_\mathrm{NN}}} =$$ 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, R$$_\mathrm{AA}$$, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, R$$_\mathrm{AA}$$($$\Upsilon$$(1S)) $>$ R$$_\mathrm{AA}$$($$\Upsilon$$(2S)) $>$ R$$_\mathrm{AA}$$($$\Upsilon$$(3S)) . The suppression of $$\Upsilon$$(1S) is larger than that seen at $$\sqrt{s_{_\mathrm{NN}}} =$$ 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the R$$_\mathrm{AA}$$ of $$\Upsilon$$(3S) integrated over $$p_\mathrm{T}$$ and rapidity is 0.094 at 95% confidence level, which is the strongest suppression observed for any hadron species in heavy ion collisions to date.

Authors:
;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Org.:
CMS
OSTI Identifier:
1454708
Report Number(s):
FERMILAB-PUB-18-271-CMS; CMS-HIN-16-023; CERN-EP-2018-110; arXiv:1805.09215
1674529
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Resource Relation:
Journal Name: TBD
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Sirunyan, Albert M, and et al. Measurement of nuclear modification factors of $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) mesons in PbPb collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV. United States: N. p., 2018. Web.
Sirunyan, Albert M, & et al. Measurement of nuclear modification factors of $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) mesons in PbPb collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV. United States.
Sirunyan, Albert M, and et al. Wed . "Measurement of nuclear modification factors of $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) mesons in PbPb collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV". United States. doi:. https://www.osti.gov/servlets/purl/1454708.
@article{osti_1454708,
title = {Measurement of nuclear modification factors of $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) mesons in PbPb collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV},
author = {Sirunyan, Albert M and et al.},
abstractNote = {The cross sections for $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) production in lead-lead (PbPb) and proton-proton (pp) collisions at $\sqrt{s_{_\mathrm{NN}}} =$ 5.02 TeV have been measured using the CMS detector at the LHC. The nuclear modification factors, R$_\mathrm{AA}$, derived from the PbPb-to-pp ratio of yields for each state, are studied as functions of meson rapidity and transverse momentum, as well as PbPb collision centrality. The yields of all three states are found to be significantly suppressed, and compatible with a sequential ordering of the suppression, R$_\mathrm{AA}$($\Upsilon$(1S)) $>$ R$_\mathrm{AA}$($\Upsilon$(2S)) $>$ R$_\mathrm{AA}$($\Upsilon$(3S)) . The suppression of $\Upsilon$(1S) is larger than that seen at $\sqrt{s_{_\mathrm{NN}}} =$ 2.76 TeV, although the two are compatible within uncertainties. The upper limit on the R$_\mathrm{AA}$ of $\Upsilon$(3S) integrated over $p_\mathrm{T}$ and rapidity is 0.094 at 95% confidence level, which is the strongest suppression observed for any hadron species in heavy ion collisions to date.},
doi = {},
journal = {TBD},
number = ,
volume = ,
place = {United States},
year = {Wed May 23 00:00:00 EDT 2018},
month = {Wed May 23 00:00:00 EDT 2018}
}