0000000000330213
AUTHOR
A. Mart��nez Torres
Faddeev fixed-center approximation to the $N\bar{K}K$ system and the signature of a $N^*(1920)(1/2^+)$ state
We perform a calculation for the three body $N \bar{K} K$ scattering amplitude by using the fixed center approximation to the Faddeev equations, taking the interaction between $N$ and $\bar{K}$, $N$ and $K$, and $\bar{K}$ and $K$ from the chiral unitary approach. The resonant structures show up in the modulus squared of the three body scattering amplitude and suggest that a $N\bar{K}K$ hadron state can be formed. Our results are in agreement with others obtained in previous theoretical works, which claim a new $N^*$ resonance around 1920 MeV with spin-parity $J^P=1/2^+$. The existence of these previous works allows us to test the accuracy of the fixed center approximation in the present pro…
Reanalysis of lattice QCD spectra leading to the $D_{s0}^*(2317)$ and $D_{s1}^*(2460)$
We perform a reanalysis of the energy levels obtained in a recent lattice QCD simulation, from where the existence of bound states of $KD$ and $KD^*$ are induced and identified with the narrow $D_{s0}^*(2317)$ and $D_{s1}^*(2460)$ resonances. The reanalysis is done in terms of an auxiliary potential, employing a single-channel basis $KD^{(*)}$, and a two-channel basis $KD^{(*)}, \eta D_s^{(*)}$. By means of an extended L\"uscher method we determine poles of the continuum $t$-matrix, bound by about 40 MeV with respect to the $KD$ and $KD^*$ thresholds, which we identify with the $D_{s0}^*(2317)$ and $D_{s1}^*(2460)$ resonances. Using a sum rule that reformulates Weinberg compositeness condit…