Baryon states with hidden charm in the extended local hidden gauge approach

TL;DR

This paper investigates hidden charm baryon states using an extended local hidden gauge approach, revealing six possible states with specific quantum numbers and their couplings, advancing understanding of exotic baryons.

Contribution

It introduces a comprehensive coupled channels calculation including pion-exchange diagrams and vector-pseudoscalar mixing, identifying new potential hidden charm baryon states.

Findings

Six possible baryon states with specific angular momenta identified.

Four states are admixtures of DΣ_c and D*Σ_c with J^P=1/2^- and J^P=3/2^-.

Discovery of a D*Σ_c resonance and a degenerate bound state of D*Σ*_c with J^P=1/2^-, 5/2^-.

Abstract

The s-wave interaction of $\bar{D} \Lambda_c, \bar{D} \Sigma_c, \bar{D} \Lambda_c, \bar{D}{}^* \Sigma_c$ and $\bar{D}\Sigma^*_c, \bar{D}{}^*\Sigma^*_c$, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion-exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of $\bar{D}\Sigma_c$ - $\bar{D}{}^*\Sigma_c$ with $J^P = 1/2^-$, and two of $\bar{D}\Sigma^*_c$ - $\bar{D}{}^*\Sigma^*_c$ with $J^P = 3/2^-$. Moreover, we find a $\bar{D}{}^* \Sigma_c$ resonance which couples to the $\bar{D}\Lambda_c$ channel and one spin degenerated bound state of $\bar{D}{}^*\Sigma^*_c$ with $J^P = 1/2^-, 5/2^-$.