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Title: Observation of the $$\chi_\mathrm{b1}$$(3P) and $$\chi_\mathrm{b2}$$(3P) and measurement of their masses

Abstract

The $$\chi_\mathrm{b1}$$(3P) and $$\chi_\mathrm{b3}$$(3P) states are observed through their $$\Upsilon$$(3S) $$\gamma$$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$$^{-1}$$. The $$\Upsilon$$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$e$^-$ pairs in the silicon tracker, leading to a $$\chi_\mathrm{b}$$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$$\,$$513.42 $$\pm$$ 0.41 (stat) $$\pm$$ 0.18 (syst) MeV and 10$$\,$$524.02 $$\pm$$ 0.57 (stat) $$\pm$$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $$\Upsilon$$(3S) mass, which has an uncertainty of 0.5 MeV. The mass splitting is measured to be 10.60 $$\pm$$ 0.64 (stat) $$\pm$$ 0.17 (syst) MeV.

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:
1452827
Report Number(s):
FERMILAB-PUB-18-250-CMS; CMS-BPH-17-008; CERN-EP-2018-134; arXiv:1805.11192
1675256
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Resource Relation:
Journal Name: TBD
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Sirunyan, Albert M, and et al. Observation of the $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) and measurement of their masses. United States: N. p., 2018. Web.
Sirunyan, Albert M, & et al. Observation of the $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) and measurement of their masses. United States.
Sirunyan, Albert M, and et al. Mon . "Observation of the $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) and measurement of their masses". United States. doi:. https://www.osti.gov/servlets/purl/1452827.
@article{osti_1452827,
title = {Observation of the $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b2}$(3P) and measurement of their masses},
author = {Sirunyan, Albert M and et al.},
abstractNote = {The $\chi_\mathrm{b1}$(3P) and $\chi_\mathrm{b3}$(3P) states are observed through their $\Upsilon$(3S) $\gamma$ decays, using an event sample of proton-proton collisions collected by the CMS experiment at the CERN LHC. The data were collected at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 80.0 fb$^{-1}$. The $\Upsilon$(3S) mesons are identified through their dimuon decay channel, while the low-energy photons are detected after converting to e$^+$e$^-$ pairs in the silicon tracker, leading to a $\chi_\mathrm{b}$(3P) mass resolution of 2.2 MeV. This is the first time that the $J =$ 1 and 2 states are well resolved and their masses individually measured: 10$\,$513.42 $\pm$ 0.41 (stat) $\pm$ 0.18 (syst) MeV and 10$\,$524.02 $\pm$ 0.57 (stat) $\pm$ 0.18 (syst) MeV; they are determined with respect to the world-average value of the $\Upsilon$(3S) mass, which has an uncertainty of 0.5 MeV. The mass splitting is measured to be 10.60 $\pm$ 0.64 (stat) $\pm$ 0.17 (syst) MeV.},
doi = {},
journal = {TBD},
number = ,
volume = ,
place = {United States},
year = {Mon May 28 00:00:00 EDT 2018},
month = {Mon May 28 00:00:00 EDT 2018}
}