Article

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

Yongxin SongInstitute of Theoretical Physics, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, 730070, ChinaDuojie JiaInstitute of Theoretical Physics, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, 730070, ChinaWen-Xuan ZhangInstitute of Theoretical Physics, College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, 730070, ChinaAtsushi HosakaResearch Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka, 567-0047, Japan

2023lv

ABI

Abstract

Abstract In framework of heavy-diquark–light-quark endowed with heavy-pair binding, we explore excited baryons $$QQ^{\prime }q$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Q</mml:mi> <mml:msup> <mml:mi>Q</mml:mi> <mml:mo>′</mml:mo> </mml:msup> <mml:mi>q</mml:mi> </mml:mrow> </mml:math> containing two heavy quarks ( $$QQ^{\prime }=cc,bb,bc$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>Q</mml:mi> <mml:msup> <mml:mi>Q</mml:mi> <mml:mo>′</mml:mo> </mml:msup> <mml:mo>=</mml:mo> <mml:mi>c</mml:mi> <mml:mi>c</mml:mi> <mml:mo>,</mml:mo> <mml:mi>b</mml:mi> <mml:mi>b</mml:mi> <mml:mo>,</mml:mo> <mml:mi>b</mml:mi> <mml:mi>c</mml:mi> </mml:mrow> </mml:math> ) 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 $$\Xi _{cc}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>Ξ</mml:mi> <mml:mrow> <mml:mi>cc</mml:mi> </mml:mrow> </mml:msub> </mml:math> 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 $$\Xi _{QQ^{\prime }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>Ξ</mml:mi> <mml:mrow> <mml:mi>Q</mml:mi> <mml:msup> <mml:mi>Q</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:mrow> </mml:msub> </mml:math> and $$\Omega _{QQ^{\prime }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>Ω</mml:mi> <mml:mrow> <mml:mi>Q</mml:mi> <mml:msup> <mml:mi>Q</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:mrow> </mml:msub> </mml:math> 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.

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Identifiers

DOI: 10.1140/epjc/s10052-022-11136-9

Citations and references

Cited by 40 references

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