[Theory-seminars] Theory Center Seminar. Monday June 22. 1pm. Room L102.

[Cesar Fernandez-Ramirez]

Dear all,

On Monday June 22 Cintia Willemyns, who has been awarded this year's JSA/HUGS International Fellowship for Graduate Students in Developing Countries, will be delivering a theory seminar. One of the aims of the fellowship is to allow her to interact with theory center researchers over the next week so I encourage you to attend to her seminar and discuss physics with her. Please find title and abstract enclosed below.

Best regards,

Cesar

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Speaker: Cintia Willemyns (JSA/HUGS International Fellow, University of Buenos Aires)

Title: New mass relations for L=1 excited baryons

Abstract: It will be shown how  the  non-relativistic quark model,  with both flavor dependent and flavor independent effective quark-quark interactions, matches  to the $1/N_c$ quark operator basis.  Analytic expressions in terms of radial  integrals are obtained for the $1/N_c$ operator coefficients. Several new,  parameter free relations between the masses and the two mixing angles of the negative parity $L=1$ excited baryons will be presented.  They can discriminate between quark-quark interactions with different spin-flavor structures.
Within the present experimental uncertainties, consistency with the best values of the mixing angles, as determined by a recent global fit to masses and decays, does not exclude any of the two most extreme possibilities of flavor dependent (independent) quark-quark interactions, as generated by pion (gluon) exchange models.


-- 
César Fernández-Ramírez

Theory Center -- Jefferson Lab
12000 Jefferson Ave., Newport News, VA 23606, USA

Phone: (+1) 757-269-7844
Fax: (+1) 757-269-7002
E-mail: cesar at jlab.org