[Theory-seminars] Theory Seminar: Monday Dec. 9, 2013 at 1pm

[Cesar Fernandez-Ramirez]

Dear all,

we will have the following Theory Center Seminar on Monday, Dec. 9,
at the CEBAF Center Auditorium, 1:00 p.m. (coffee at 12:45 p.m.)

Martin Hentschinski
Brookhaven National Laboratory

Proton Structure Functions at Small x Explored Through Linear Evolution 

Proton structure functions are currently described with excellent accuracy in terms of parton distribution functions, defined in terms of collinear factorization and DGLAP evolution. With decreasing x however, parton densities increase and are ultimately expected to saturate. In this regime DGLAP evolution is expected to break down and nonlinear evolution equations will take over. In the first part of the talk we present recent results on an implementation of physical DGLAP evolution. Unlike the conventional description in terms of parton distribution functions, the former describes directly the Q dependence of the measured structure functions and is therefore insensitive to factorization scheme and scale ambiguities. As a consequence it provides a more stringent test of DGLAP evolution and eases the manifestation of (nonlinear) small x effects. In the second part we present a recent analysis of the small x region of the combined HERA data on the structure function F2. We demonstrate that (linear) next-to-leading order BFKL evolution is able to describe the combined HERA data, once a resummation of collinear enhanced terms is included and the renormalization scale is fixed using the BLM optimal scale setting procedure. 


A complete list of upcoming theory seminars and talks from previous
seminars is available from: http://www.jlab.org/div_dept/theory/seminars/

César, Raúl, and Linguyn
JLab Theory Seminar Organizers

-- 
César Fernández-Ramírez

Center for Theoretical and Computational Physics
Thomas Jefferson National Accelerator Facility -- Jefferson Lab
12000 Jefferson Avenue, Newport News, VA 23606, USA

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