Theoretical study on low-lying hidden-bottom and double-bottom tetraquark states

Lin-Juan Jiang; Chun-Sheng An; Cheng-Rong Deng; Gang Li; Ju-Jun Xie

doi:10.1140/epjc/s10052-024-13588-7

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2024) 84: 1214
https://doi.org/10.1140/epjc/s10052-024-13588-7

Regular Article

Theoretical study on low-lying hidden-bottom and double-bottom tetraquark states

Lin-Juan Jiang¹, Chun-Sheng An¹^a, Cheng-Rong Deng¹, Gang Li² and Ju-Jun Xie³^,4^,5

¹ School of Physical Science and Technology, Southwest University, 400715, Chongqing, China
² College of Physics and Engineering, Qufu Normal University, 273165, Qufu, China
³ Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
⁴ School of Nuclear Science and Technology, University of Chinese Academy of Sciences, 101408, Beijing, China
⁵ Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, 516000, Huizhou, China

^a ancs@swu.edu.cn

Received: 13 September 2024
Accepted: 6 November 2024
Published online: 25 November 2024

Abstract

We perform a theoretical study on the spectrum of the low-lying hidden-bottom ( $q \bar{q} b \bar{b}$ $q\bar{q}b\bar{b}$ with $q =$ $$q=$$ u, d and s) and double-bottom ( $q \bar{q} b b$ $q\bar{q}bb$ ) tetraquark states within a nonrelativistic quark model, in which the instanton-induced interaction is taken as the residual spin-dependent hyperfine interaction between quarks. All the model parameters are fixed by fitting the spectrum of the ground hadron states. The numerical results indicate that masses of several $X_{q \bar{q}}$ $X_{q\bar{q}}$ , $Z_{b}$ $Z_{b}$ , and $Z_{bs}$ $Z_{bs}$ tetraquark states are below and near thresholds of corresponding meson-meson channels, thus these states may form components of exotic meson states with reasonable probabilities. Especially, in present model, masses of several obtained states with quantum number $I^{G} (J^{P}) = 1^{+} (1^{+})$ $I^G(J^P)=1^+(1^{+})$ are close to $Z_{b}^{\pm} (10610)$ $Z_b^\pm (10610)$ , so one may expect these states to be non-negligible components of the experimentally observed $Z_{b}$ $Z_{b}$ states. Concerning to the double-bottom tetraquark states, the present results are in general consistent with other previous works. Two possible stable $T_{bb}$ $T_{bb}$ states with quark content $b b \bar{n} \bar{n}$ $bb\bar{n}\bar{n}$ ( $n = u$ $$n=u$$ or d quark) lying at energies 10558 MeV and 10650 MeV are found, and one possible stable $b b \bar{n} \bar{s}$ $bb\bar{n}\bar{s}$ state is found, whose energy is $\sim 10687$ $\sim 10687$ MeV.

© The Author(s) 2024

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