On the hidden charm pentaquarks in decay

L. Roca; E. Oset

doi:10.1140/epjc/s10052-016-4407-z

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2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2016) 76: 591
https://doi.org/10.1140/epjc/s10052-016-4407-z

Regular Article - Theoretical Physics

On the hidden charm pentaquarks in $\Lambda _b \rightarrow J/\psi K^- p$ decay

L. Roca¹^* and E. Oset²

¹ Departamento de Física, Universidad de Murcia, 30100, Murcia, Spain
² Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC Institutos de Investigación de Paterna, Aptdo. 22085, 46071, Valencia, Spain

^* e-mail: luisroca@um.es

Received: 19 July 2016
Accepted: 26 September 2016
Published online: 28 October 2016

Abstract

In a previous work we presented a theoretical analysis of the $\Lambda _b \rightarrow J/\psi K^- p$ reaction based on which a recent experiment by the LHCb collaboration at CERN claimed the existence of two hidden charm pentaquarks, $$P_c(4380)^+$$ and $$P_c(4450)^+$$ . In that work we focused only on the $\Lambda (1405)$ and signals and discussed the possible explanation of this pentaquark state within the picture of a dynamical meson–baryon molecule made up mostly from $\bar{D}^* \Sigma _c$ and $\bar{D}^* \Sigma ^*_c$ components. In the present work we improve upon the previous one by considering the total $$K^- p$$ and $J/\psi p$ data including all the relevant resonances contributing to the spectra, and discuss the possible nature of both $$P_c(4380)^+$$ and $$P_c(4450)^+$$ . We also discuss several important topics, like the effect of the contact term in the reaction, the viability of reproducing the data without the and the possible quantum number assignment to these pentaquarks.