[Theory-seminars] HALL-B/JPAC Seminar. TODAY. Room L102. 4pm. Vladimir Braun

[Cesar Fernandez-Ramirez]

Dear Colleagues,

We will have the next Hall-B/JPAC Meeting focused on the QCD-based interpretation of gvNN* electrocouplings and access to the partonic structure of  N* states TODAY Wednesday, May 27th, 4 p.m. Room L102 CEBAF Center with the talk by Prof. Dr. V.Braun, Univ of Regensburg (Germany), entitled:

``Electroproduction of $N^\ast(1535)$ nucleon resonance at large momentum
transfers in QCD" (Please find the slide of the talk  https://userweb.jlab.org/~mokeev/HALLB_PAC_meetings/052715/)


Abstract:

Following the 12 GeV upgrade, a dedicated experiment is planned with the
Hall B CLAS12 detector
at  Jefferson Lab, with the aim to study electroproduction of nucleon
resonances at
high photon virtualities up to $Q^2 = 12$~GeV$^2$.
In this work we present a QCD-based approach to the theoretical
interpretation of these
upcoming results in the framework of light-cone sum rules.
The essence of this technique is that soft Feynman contributions to the
form factors
are calculated in terms of small transverse distance quantities using
dispersion relations and duality.
The form factors are thus expressed in terms of $N^\ast(1535)$ light-front
wave functions at small
transverse separations, called distribution amplitudes, without any
additional parameters.
Alternatively, the distribution amplitudes can be extracted from the
comparison with the
experimental data on form factors and compared to the results of lattice
QCD simulations.
The results of the corresponding next-to-leading order calculation are
presented and compared with the
existing data. We find that the form factors are dominated by the
next-to-leading twist-four distribution amplitudes
that are related to the $P$-wave three-quark wave functions of
$N^\ast(1535)$, i.e. contributions of orbital
angular momentum.

 


-- 
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