[Jlab-seminars] Theory Center Seminar

[Mary Fox]

Theory Center Seminar
Friday, Feb. 5, 2010
11:00 a.m.
CEBAF Center, Room A110

*Renormalization of the One Boson Exchange Potential in the 1/Nc Expansion*

Álvaro Calle Cordón
Universidad de Granada, Spain


In this talk I will analyze the renormalization of the NN interaction
in the context of the Large Nc limit of QCD which has been received
much less attention in the past as compared to the chiral approach. By
using the dominant contributions in the 1/Nc expansion of the One
Boson Exchange (OBE) potential old nuclear Wigner SU(4) and Serber
symmetries can be understood as long distance symmetries. We proivde
sum rules for phase shifts and Vlowk potentials which are satisfied
phenomenologically and argue that they are in fact to be predictions
of the large Nc expansion.

Morevover, we adress the problem of phenomenological strong form
factors usually employed in the OBE. We show how invoking suitable
boundary conditions, neutron-proton phase shifts and deuteron
properties become largely insensitive to the form factors and to the
vector mesons. Actually, reasonable agreement with low energy data for
realistic values of the coupling constants (e.g. SU(3) values) is
achieved providing a solution for a long-standing problem.


I will also present preliminary calculations analyzing the interplay
between symmetry breaking and renormalization in the baryon-baryon
system for sâ^'waves, based in a short distance condition, where all
pp,pn,nn and Coulomb phases and low energy parameters can
successfully be related. Finally, some optimistic consequences of the
renormalization of Meson Exchange Currents (MEC) are shown.

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