Observation of new excited Bs0 states



Aaij, R, Beteta, C Abellan, Ackernley, T, Adeva, B, Adinolfi, M, Afsharnia, H, Aidala, CA, Aiola, S, Ajaltouni, Z, Akar, S
et al (show 972 more authors) (2021) Observation of new excited Bs0 states. EUROPEAN PHYSICAL JOURNAL C, 81 (7). 601-.

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Abstract

A structure is observed in the $B^+K^-$ mass spectrum in a sample of proton--proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb${}^-1$. The structure is interpreted as the result of overlapping excited $B_s^0$ states. With high significance, a two-peak hypothesis provides a better description of the data than a single resonance. Under this hypothesis the masses and widths of the two states, assuming they decay directly to $B^+K^-$, are determined to be $m_1 = 6063.5 \pm 1.2 \text{ (stat)} \pm 0.8\text{ (syst) MeV},$ $\Gamma_1 = 26 \pm 4 \text{ (stat)} \pm 4\text{ (syst) MeV},$ $m_2 = 6114 \pm 3 \text{ (stat)} \pm 5\text{ (syst) MeV},$ $\Gamma_2 = 66 \pm 18 \text{ (stat)} \pm 21\text{ (syst) MeV}.$ Alternative values assuming a decay through $B^{*+}K^-$, with a missing photon from the $B^{*+} \rightarrow B^+\gamma$ decay, which are shifted by approximately 45 MeV are also determined. The possibility of a single state decaying in both channels is also considered. The ratio of the total production cross-section times branching fraction of the new states relative to the previously observed $B_{s2}^{*0}$ state is determined to be $0.87 \pm 0.15 \text{ (stat)} \pm 0.19 \text{ (syst)}$.

Item Type: Article
Additional Information: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-026.html (LHCb public pages)
Uncontrolled Keywords: hep-ex, hep-ex
Divisions: Faculty of Science and Engineering > School of Physical Sciences
Depositing User: Symplectic Admin
Date Deposited: 02 Sep 2021 08:50
Last Modified: 18 Jan 2023 21:31
DOI: 10.1140/epjc/s10052-021-09305-3
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3134989