0000000000613022
AUTHOR
Manuel J. Vicente Vacas
showing 3 related works from this author
Exploring hyperon structure with electromagnetic transverse densities
2018
We explore the structure of the spin-1/2 flavor-octet baryons (hyperons) through their electromagnetic transverse densities. The transverse densities describe the distribution of charge and magnetization at fixed light-front time and enable a spatial representation of the baryons as relativistic systems. At peripheral distances b~1/M_pi the transverse densities are computed using a new method that combines chiral effective field theory and dispersion analysis. The peripheral isovector densities arise from two-pion exchange, which includes the rho-meson resonance through elastic unitarity. The isoscalar densities are estimated from vector meson exchange (omega, phi). We find that the "pion c…
Threshold Neutral Pion Photoproduction on the Proton
2015
The neutral pion photoproduction on the proton near threshold has a very small scattering cross section when compared to the charged channels, which in ChPT is explained by strong cancellations between the lowest order pieces. Therefore it is very sensitive to higher-order corrections of chiral perturbation theory. We perform a fully covariant calculation up to chiral order p^3 and we investigate the effect of the inclusion of the Delta(1232) resonance as an explicit degree of freedom. We show that the convergence improves, leading to a much better agreement with data at a wide range of energies.
Watson's theorem and the $N\Delta(1232)$ axial transition
2015
17 latex pages.- 7 figures.- 2 tables.- Some typos corrected