Eur. Phys. J. A (2015) 51: 152
https://doi.org/10.1140/epja/i2015-15152-6

Regular Article - Theoretical Physics

Phenomenology of P_c(4380)⁺, P_c(4450)⁺ and related states

Department of Physics, Swansea University, Singleton Park, SA2 8PP, Swansea, UK

^* e-mail: t.burns@swansea.ac.uk

Received: 2 October 2015
Accepted: 10 November 2015
Published online: 30 November 2015

Abstract

The and states recently discovered at LHCb have masses close to several relevant thresholds, which suggests they can be described in terms of meson-baryon degrees of freedom. This article explores the phenomenology of these states, and their possible partners, from this point of view. Competing models can be distinguished by the masses of the neutral partners which have yet to be observed, and the existence or otherwise of further partners with different isospin, spin, and parity. Future experimental studies in different decay channels can also discriminate among models, using selection rules and algebraic relations among decays. Among the several possible meson-baryon pairs which could be important, one implies that the states are mixtures of isospins 1/2 and 3/2, with characteristic signatures in production and decay. A previous experimental study of a Cabibbo-suppressed decay showed no evidence for the states, and further analysis is required to establish the significance of this non-observation. Several intriguing similarities suggest that is related to the meson.