University of Barcelona

HEP Seminar

QCD at small x: an introduction to high energy hadronic/nuclear collisions

By Jamal Jalilian-Marian (Baruch College, CUNY, New York and Ecole Polytechnique, Palaiseau)   

Thursday 23 Mar , 14:00:00

Place: Aula 507 (Pere Pascual)

We consider collisions of hadrons/nuclei at high energies. We show that at high energy a hadron/nucleus wave function contains many gluons which carry a small fraction x of the hadron's energy. This high occupancy state is approximated as a classical field and gives the dominant contribution to hadronic cross sections at high energy. A Wilsonian Renormalization Group approach is developed and used to investigate the energy dependence of QCD observables in this limit. Connections to interactions of ultra-high energy neutrinos and cosmic ray physics will be pointed out and applications to particle production in currently operating colliders such as RHIC and the LHC will be discussed.