Decay widths of the spin-2 partners of the X(3872)

Miguel Albaladejo; Feng-Kun Guo; Carlos Hidalgo-Duque; Juan Nieves; Manuel Pavón Valderrama

doi:10.1140/epjc/s10052-015-3753-6

EPJ

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2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2015) 75: 547
https://doi.org/10.1140/epjc/s10052-015-3753-6

Regular Article - Theoretical Physics

Decay widths of the spin-2 partners of the X(3872)

Miguel Albaladejo¹, Feng-Kun Guo²^,3^*, Carlos Hidalgo-Duque¹, Juan Nieves¹ and Manuel Pavón Valderrama⁴

¹ Instituto de Física Corpuscular (IFIC), Centro Mixto CSIC-Universidad de Valencia, Institutos de Investigación de Paterna, Aptd. 22085, 46071, Valencia, Spain
² State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190, China
³ Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, 53115, Bonn, Germany
⁴ Institut de Physique Nucléaire, Université Paris-Sud, IN2P3/CNRS, 91406, Orsay Cedex, France

^* e-mail: fkguo@itp.ac.cn

Received: 27 August 2015
Accepted: 22 October 2015
Published online: 24 November 2015

Abstract

We consider the X(3872) resonance as a $J^\mathrm{{PC}}=1^{++}$ $D\bar{D}^*$ hadronic molecule. According to heavy quark spin symmetry, there will exist a partner with quantum numbers $2^{++}$ , $X_{2}$ , which would be a $D^*\bar{D}^*$ loosely bound state. The $X_{2}$ is expected to decay dominantly into $D\bar{D}$ , $D\bar{D}^*$ and $\bar{D} D^*$ in d-wave. In this work, we calculate the decay widths of the $X_{2}$ resonance into the above channels, as well as those of its bottom partner, $X_{b2}$ , the mass of which comes from assuming heavy flavor symmetry for the contact terms. We find partial widths of the $X_{2}$ and $X_{b2}$ of the order of a few MeV. Finally, we also study the radiative $X_2\rightarrow D\bar{D}^{*}\gamma$ and $X_{b2} \rightarrow \bar{B} B^{*}\gamma$ decays. These decay modes are more sensitive to the long-distance structure of the resonances and to the $D\bar{D}^{*}$ or $B\bar{B}^{*}$ final state interaction.