Abstract
Invoked by the recent CMS observation regarding candidates of the $\chi_b(3P)$ multiplet, we analyze the ultrafine and mass splittings among $3P$ multiplet in our unquenched quark model (UQM) studies. The mass difference of $\chi_{b2}$ and $\chi_{b1}$ in $3P$ multiplet measured by CMS collaboration ($10.6 \pm 0.64 \pm 0.17$ MeV) is very close to our theoretical prediction ($12$ MeV). Our corresponding mass splitting of $\chi_{b1}$ and $\chi_{b0}$ enables us to predict more precisely the mass of $\chi_{b0}(3P)$ to be ($10490\pm 3$) MeV. Moreover, we predict ratios of the radiative decays of $\chi_{bJ}(nP)$ candidates, both in UQM and quark potential model. Our predicted relative branching fraction of $\chi_{b0}(3P)\to\Upsilon(3S)\gamma$ is one order of magnitude smaller than $\chi_{b2}(3P)$, this naturally explains the non-observation of $\chi_{b0}(3P)$ in recent CMS search. We hope these results might provide useful references for forthcoming experimental searches.
Highlights
The excited P-wave bottomonia, χbJð3PÞ, are of special interest since they provide a laboratory to test the nonperturbative spin-spin interactions of heavy quarks
The recent CMS study successfully distinguishes χb1ð3PÞ and χb2ð3PÞ for the first time and measures their mass splitting, which differs only 1 MeV from our unquenched quark model predictions. This measurement gives us confidence to predict the mass of the lowest candidate of the 3P multiplet to be M1⁄2χb0ð3PÞ 1⁄4 ð10490 Æ 3Þ MeV, based on our unquenched quark model results of the mass splittings of this multiplet
We analyze the hyperfine splittings of P-wave bottomonia up to n 1⁄4 3 in the framework of unquenched quark model (UQM) and put a constraint on them based on recent experimental corroboration
Summary
The excited P-wave bottomonia, χbJð3PÞ, are of special interest since they provide a laboratory to test (and model) the nonperturbative spin-spin interactions of heavy quarks. The CMS Collaboration observed two candidates of the bottomonium 3P multiplet, χb1ð3PÞ and χb2ð3PÞ, through their decays into Υð3SÞγ [1]. Their measured masses and mass splitting are. Heavy quarkonium states can couple to intermediate heavy mesons through the creation of the light quarkantiquark pair which enlarges the Fock space of the initial state; i.e., the initial state contains multiquark components These multiquark components will change the Hamiltonian of the potential model, causing the mass shift and mixing between states with the same quantum numbers or directly contributing to open channel strong decay if the initial state is above the threshold.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
