Identifying the Λ<i>_b</i>(6146)⁰ and Λ<i>_b</i>(6152)⁰ as <i>D</i>-Wave Bottom Baryons

Abstract

We study the Λ b ( 6146 ) 0 and Λ b ( 6152 ) 0 recently observed by LHCb using the method of Quantum Chromodynamics (QCD) sum rules within the framework of heavy quark effective theory. Our results suggest that they can be interpreted as D-wave bottom baryons of J P = 3 / 2 + and 5 / 2 + respectively, both of which contain two λ -mode excitations. We also investigate other possible assignments containing ρ -mode excitations. We extract all the parameters that are necessary to study their decay properties when using the method of light-cone sum rules. We predict masses of their strangeness partners to be m Ξ b ( 3 / 2 + ) = 6.26 − 0.14 + 0.11 GeV and m Ξ b ( 5 / 2 + ) = 6.26 − 0.14 + 0.11 GeV with the mass splitting Δ M = m Ξ b ( 5 / 2 + ) − m Ξ b ( 3 / 2 + ) = 4.5 − 1.5 + 1.9 MeV, and propose to search for them in future CMS, EIC, and LHCb experiments.

Keywords

• excited heavy baryons
• QCD sum rules
• heavy quark effective theory