0000000001012692
AUTHOR
Alberto Martinez Torres
Theoretical study of incoherent phi photoproduction on a deuteron target
We study the photoproduction of phi mesons in deuteron, paying attention to the modification of the cross section from bound protons to the free ones with the aim of comparing with recent results at LEPS. For this purpose we take into account Fermi motion in single scattering and rescattering of the phi to account for phi absorption on a second nucleon as well as the rescattering of the proton. We find that the contribution of the double scattering is much smaller than the typical cross section of gamma p to phi p in free space, which implies a very small screening of the phi production in deuteron. The contribution from the proton rescattering, on the other hand, is found to be not negligi…
A new perspective on the $\Delta_{5/2^{+}}(2000)$ puzzle
We argue that $\Delta_{5/2^{+}}(2000)(\ast\ast),$ cataloged as a resonance in the Particle Data Book Review (PDG), should be interpreted instead as two distinctive resonances, $\Delta_{5/2^{+}}(\sim1740)$ and $\Delta_{5/2^{+}}(\sim2200)$. Our argument is based on a solution of the $\pi\Delta\rho$ problem in a Fixed Center Approximation (FCA) to the Fadeev equations. $\Delta_{5/2^{+}}(\sim1740)$ can then be interpreted as a $\pi-(\Delta \rho)_{N(1675)}$ bound state. As a corollary $\Delta_{1/2^{+}}(1750)(\ast)$ can be understood as a $\pi N_{1/2^{-}}(1650)$ bound state.