Aula Conversi (Dipartimento di Fisica - Ed. G. Marconi)
Aula Conversi
Dipartimento di Fisica - Ed. G. Marconi
Description
We study the possibility that at least one of the two pentaquark structures
recently reported by LHCb could be described as a compact pentaquark state,
and we give predictions for new channels that can be studied by the
experimentalists if this hypothesis is correct. We use very general arguments
dictated by symmetry considerations, in order to describe the pentaquark
states within a group theory approach. A complete classification of all
possible states and quantum numbers, which can be useful both to the
experimentalists in their search for new findings and to theoretical model
builders, is given, without the introduction of any particular dynamical
model. Some predictions are finally given using a simple Guersey and Radicati
inspired mass formula,that breaks the SU(4) symmetry. We reproduce the mass
and the quantum numbers of the lightest pentaquark state reported by LHCb
(the
J^P = 3/2^- state), with a parameter-free mass formula, fixed on
the
well-established baryons. We predict other pentaquark resonances (giving
their masses, and suggesting possible decay channels) which belong to the
same multiplet as the lightest one.
