Study of D<sub>s1</sub>(2460)<sup>+</sup>→D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> in B→D‾<sup>(*)</sup>D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> decays.


LHCb collaboration (2025) Study of D<sub>s1</sub>(2460)<sup>+</sup>→D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> in B→D‾<sup>(*)</sup>D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> decays. Science bulletin, 70 (9). pp. 1432-1444. ISSN 2095-9273, 2095-9281

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Abstract

An amplitude analysis of the D<sub>s1</sub>(2460)<sup>+</sup>→D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> transition is performed simultaneously in B<sup>0</sup>→D<sup>-</sup>D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup>, B<sup>+</sup>→D‾<sup>0</sup>D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup>, and B<sup>0</sup>→D<sup>*-</sup>D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> decays. The study is based on a data sample of proton-proton collisions recorded with the LHCb detector at centre-of-mass energies of s=7,8, and 13TeV, corresponding to a total integrated luminosity of 9fb<sup>-1</sup>. A clear double-peak structure is observed in the m(π<sup>+</sup>π<sup>-</sup>) spectrum of the D<sub>s1</sub>(2460)<sup>+</sup>→D<sub>s</sub><sup>+</sup>π<sup>+</sup>π<sup>-</sup> decay. The data can be described either with a model including f<sub>0</sub>500,f<sub>0</sub>980, and f<sub>2</sub>(1270) resonances, in which the contributions of f<sub>0</sub>(980) and f<sub>2</sub>(1270) are unexpectedly large, or with a model including f<sub>0</sub>(500), a doubly charged open-charm tetraquark state T<sub>cs¯</sub><sup>++</sup> and its isospin partner T<sub>cs¯</sub><sup>0</sup>. If the former is considered implausible, the T<sub>cs¯</sub> states are observed with high significance, and the data are consistent with isospin symmetry. When imposing isospin constraints between the two T<sub>cs¯</sub> states, their mass and width are determined to be (2327±13±13) MeV and (96±16<sub>-23</sub><sup>+170</sup>) MeV, respectively, where the first uncertainty is statistical and the second is systematic. The mass is slightly below the DK threshold, and a spin-parity of 0<sup>+</sup> is favoured with high significance.

Item Type: Article
Uncontrolled Keywords: LHCb collaboration
Divisions: Faculty of Humanities and Social Sciences
Faculty of Science and Engineering
Faculty of Science and Engineering > School of Engineering
Faculty of Science and Engineering > School of Physical Sciences
Faculty of Humanities and Social Sciences > School of the Arts
Depositing User: Symplectic Admin
Date Deposited: 09 Jun 2025 10:12
Last Modified: 09 Jun 2025 10:12
DOI: 10.1016/j.scib.2025.02.025
Open Access URL: https://www.sciencedirect.com/science/article/pii/...
Related Websites:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3193118
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