Isospin mass splittings of heavy baryons in heavy quark symmetry

Abstract

In this paper, the electromagnetic mass differences of heavy hadrons are discussed, while ignoring the relevant hyperfine interactions. The effects of one-photon exchange interaction and up-down quark mass difference are parameterized. Two mass difference equationsfor the heavy baryons are obtained. In addition, the masses of Σ 0 b , Ξ 0 b , and Ξ ++ cc are predicted based on the known experimental data.

A Doubly Charming Particle

“…40 . This difference would imply an isospin splitting vastly larger than that seen in any other baryon system and is inconsistent with the expected size of a few MeV=c 2 [34][35][36]. Consequently, while the state reported here is consistent with most theoretical expectations for the Ξ þþ cc baryon, it is inconsistent with being an isospin partner to the Ξ þ cc state reported previously by the SELEX Collaboration.…”

“…In most cases, the masses of the Ξ cc states are predicted to lie in the range 3500 to 3700 MeV=c 2 . The masses of the Ξ þþ cc and Ξ þ cc states are expected to differ by only a few MeV=c 2 , due to approximate isospin symmetry [34][35][36]. Most predictions for the lifetime of the Ξ þ cc baryon are in the range 50 to 250 fs, and the lifetime of the Ξ þþ cc baryon is expected to be three to four times longer at 200 to 700 fs [10,11,19,24,[37][38][39][40].…”

Exclusivec→s,dsemileptonic decays of ground-state spin-1/2and spin-Albertus1, Hernández2, Nieves3 2012Phys. Rev. D

“…[21] in chiral perturbation theory to leading one-loop order. Based on the known experimental data they get M Σ 0 b = 5810.5 ± 2.2 MeV [20] and M Σ 0 b = 5810.3 ± 1.9 MeV [21], their central values being 1 MeV lower than the value one would obtain from the less accurate relation…”

“…Here we shall use the value M Σ 0 b = 5810.5 MeV given in Ref. [20]. For the Ξ ′ b , Ξ * b , Ω * b we take our predictions in Ref.…”

“…For the Σ 0 b case, corrections to the analogous relation, due to the electromagnetic interaction between the two light quarks in the heavy baryon, have been evaluated in Ref. [20] using heavy quark effective theory and in Ref. [21] in chiral perturbation theory to leading one-loop order.…”