English

Masses and decay widths of $\Xi_{c/b}$ and $\Xi^\prime_{c/b}$ baryons

High Energy Physics - Phenomenology 2021-10-26 v3

Abstract

In this article, we present a complete classification of the negative parity Ξc/b\Xi'_{c/b} and Ξc/b\Xi_{c/b} PP-wave states: 7 belonging to the SU(3)SU(3) flavor sextet and 7 to the flavor anti-triplet, the calculation of the Ξc/b\Xi'_{c/b} and Ξc/b\Xi_{c/b} strong partial decay widths into 2ΣcKˉ^2\Sigma_c \bar{K}, 2Ξcπ^2\Xi_c^{'} \pi, 2ΣcKˉ^2\Sigma_c \bar{K}, 4Ξcπ^4\Xi_c^{'} \pi, ΛcKˉ\Lambda_c^{'} \bar{K}, Ξcπ\Xi_c^{} \pi and Ξcη\Xi_c^{} \eta channels both within the Elementary Emission Model (EEM) and the 3P0^3P_0 model, and the calculation of the electromagnetic decay widths for Ξc/b\Xi'_{c/b} and Ξc/b\Xi_{c/b} radiative decays. By means of the equal-spacing mass rule and by the analysis of the strong partial decay widths, we suggest possible assignments for the new LHCb Ξc(2923)\Xi_{c}(2923), Ξc(2939)\Xi_{c}(2939), and Ξc(2965)\Xi_{c}(2965) states, as well as for the Ξc\Xi_{c}'s previously reported by Belle and BaBar. Our results can be tested by future experiments, at LHCb and Belle, disentangling the remaining missing piece of information, {\it i.e.} the quantum numbers. Finally, a comparison is made between a three-quark and a quark-diquark description of Ξc\Xi_c states. Very recently the LHCb collaboration reported the observation of two new Ξb\Xi_b states, namely Ξb(6327)0\Xi_b(6327)^{0} and Ξb(6333)\Xi_b(6333), in Λb0Kπ+\Lambda_b^0 K^{-} \pi^{+} channel with a statistical significance larger than nine standard deviations. The experimental masses and widths of these two states are consistent with our mass and width predictions for the doublet of D-wave excitations of the Ξb\Xi_b system with JΞb(6327)0P=32+J^{P}_{\Xi_b(6327)^{0}}=\frac{3}{2}^{+} and JΞb(6333)0P=52+J^{P}_{\Xi_b(6333)^{0}}=\frac{5}{2}^{+}.

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Cite

@article{arxiv.2010.12437,
  title  = {Masses and decay widths of $\Xi_{c/b}$ and $\Xi^\prime_{c/b}$ baryons},
  author = {Roelof Bijker and Hugo García-Tecocoatzi and Alessandro Giachino and Emmanuel Ortiz-Pacheco and Elena Santopinto},
  journal= {arXiv preprint arXiv:2010.12437},
  year   = {2021}
}

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