Hadron spectroscopy and the new unexpected resonances

Decay widths of an N* state with hidden strangeness

Not scheduled

30m

Villas de Paraty

Speaker

Breno Agatao Garcia (Universidade de São Paulo)

Description

The study of exotic hadrons and their properties has recently experienced a colossal boom. The development in this area is so tremendous that studying exotic hadrons has become one of the main, and more prolific, research lines at experimental facilities like BES and LHC. There is an intrinsic challenge when studying these particles as they belong to the non-perturbative region of QCD. The use of effective Lagrangians to study hadron systems at such energies is a very powerful tool nowadays. By using these Lagrangians with the relevant symmetries for the system is possible to calculate the corresponding $T$-matrix in a coupled channel approach and obtain physical observables such as invariant mass distributions, cross sections and decay widths. In particular, through the vector meson and baryon dynamics was observed a N${}^{\ast }$ resonance, thus isospin $1/2$, with spin-parity $J^P={\frac{3}{2}}^{-}$, mass $M_{{\text{N}}^{\ast }}=2071$ MeV and decay width ${\displaystyle \frac{{\mathrm{\Gamma }}_{{\text{N}}^{\ast }}}{2}=70}$ MeV. The properties of this state were in agreement with those of the N${}^{\ast }(2080)$ listed by the PDG, however, nowadays, this entry among others nucleonic resonances have been compacted into the N${}^{\ast }(2120)$ state. The interesting fact of the above mentioned state is that it can be the hidden-strange partner of some of the $P_c$ states recently discovered by the LHCb collaboration. In order to further investigate the properties of the N${}^{\ast }$ resonance, or $P_s$ state, we calculate the decay widths to pseudoscalar meson and baryonic resonance as a consequence of the exotic nature of the state. In the same way, it is possible to obtain the decay widths to pseudoscalar meson and baryon channels. Once obtained, it is possible to determine which invariant mass of two hadrons could be the most promising to observe the properties of the $P_s$ state.