arXiv subjects

WenXuan Zhang

Publications and source records attributed to WenXuan Zhang.

2 recordsLinked to original sources

arXiv2023

Masses and magnetic moments of exotic fully heavy pentaquarks

Inspired by the observation of a resonant state $X(6600)$ of fully charm tetraquark by the CMS experiment of LHCb Collaboration in double $J/ψ$ decay channel, we perform a systematical study of all configurations of fully heavy pentaquarks $P_{Q_{1}Q_{2}Q_{3}Q_{4}\bar{Q_{5}}}$ ($Q_{i}=c,b$%, $i=1,2,3,4,5$) in their ground states in unified framework of MIT bag model. The color-spin wavefunctions of pentaquarks, classified via Young tableau and presented in terms of the Young-Yamanouchi bases, are used to compute masses and magnetic moments of fully heavy pentaquarks via numerical variational method, predicting a set of masses ranging from $8.229$ GeV for the $P_{cccc\bar{c}}$ to $24.770$ GeV for the $P_{bbbb\bar{b}}$. Combining with computed masses of fully heavy mesons and baryons, we find that masses of fully heavy hadrons(mesons, baryons, tetraquarks and pentaquarks) with identical flavor rise almost linearly with the number of valence quarks in hadrons, being consistent with the heavy quark symmetry in the heavy-quark limit.

hep-ph↗

arXiv2023

Low-lying doubly heavy baryons: Regge relation and mass scaling

In framework of heavy-diquark$-$light-quark endowed with heavy-pair binding, we explore excited baryons $QQ^{\prime}q$ containing two heavy quarks ($QQ^{\prime}=cc,bb,bc$) by combining the method of Regge trajectory with the perturbative correction due to the heavy-pair interaction in baryons. Two Regge relations, one linear and the other nonlinear, are constructed semi-classically in the QCD string picture, and a mass scaling relation based on the heavy diquark-heavy antiquark symmetry are employed between the doubly heavy baryons and heavy mesons. We employ the ground-state mass estimates compatible with the observed doubly charmed baryon $Ξ_{cc}$ and spectra of the heavy quarkonia to determine the trajectory parameters and the binding energies of the heavy pair, and thereby compute the low-lying masses of the excited baryons $Ξ_{QQ^{\prime}}$ and $Ω_{QQ^{\prime}}$ up to 2S and 1P excitations of the light quark and heavy diquark. The level spacings of heavy diquark excitations are found to be smaller generally than that of the light-quark excitations, in according with the nature of adiabatic expansion between the heavy and light-quark dynamics.

hep-ph↗