${\chi }_{c1}$ and ${\chi }_{c2}$ resonance parameters with the decays ${\chi }_{c1,c2}\to J/\psi {\mu }^{+}{\mu }^{-}$

Abstract

The decays ${\chi }_{c1}\to J/\psi {\mu }^{+}{\mu }^{-}$ and ${\chi }_{c2}\to J/\psi {\mu }^{+}{\mu }^{-}$ are observed and used to study the resonance parameters of the ${\chi }_{c1}$ and ${\chi }_{c2}$ mesons. The masses of these states are measured to be m(χ_{c1}) = 3510.71 \pm 0.04(stat) \pm 0.09(syst)MeV\,, m(χ_{c2}) = 3556.10 \pm 0.06(stat) \pm 0.11(syst)MeV\,, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference m(χ_{c2}) - m(χ_{c1}) = 45.39 \pm 0.07(stat) \pm 0.03(syst)MeV\,. The natural width of the ${\chi }_{c2}$ meson is measured to be $$\Gamma ({\chi }_{c2})=2.10\pm 0.20(stat)\pm 0.02(syst)MeV.$$ These results are in good agreement with and have comparable precision to the current world averages.

17 pages, 2 figures, 3 tables. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-036.html"

References in corpus (5)

• Heavy quarkonium: progress, puzzles, and opportunities
• Performance of the LHCb Vertex Locator
• QCD radiative corrections to ${\chi }_{cJ}$ production at hadron colliders
• Measurement of the relative prompt production rate of chi(c2) and chi(c1) in pp collisions at sqrt(s) = 7 TeV
• Measurement of chi_c1 and chi_c2 production with sqrt(s) = 7 TeV pp collisions at ATLAS

Cited by in corpus (5)

• Phenomenological NLO analysis of eta(c) production at the LHC in the collider and fixed-target modes
• Study of electromagnetic Dalitz decays ${\chi }_{cJ}\to {\mu }^{+}{\mu }^{-}J/\psi$
• Study of charmonium production using decays to hadronic final states with the LHCb experiment
• Observation of the decay ${\chi }_{c1}(3872)\to J/\psi {\mu }^{+}{\mu }^{-}$
• Precise Measurement of the ${\chi }_{c0}$ Resonance Parameters and Branching Fractions of ${\chi }_{c0,c2}\to {\pi }^{+}{\pi }^{-}/K^{+}{K}^{-}$