Nuclear Seminar
Date/Time: | Thursday, 19 May 2011 from 4:10 pm to 5:10 pm |
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Location: | A401 Zaffarano Hall |
Contact: | Prof. James Vary |
Phone: | 515-294-8894 |
Channel: | College of Liberal Arts and Sciences |
Actions: | Download iCal/vCal | Email Reminder |
Gluonic pole matrix elements explain the appearance of single spin asymmetries (SSA) in high-energy scattering processes. They involve a combination of operators which are odd under time reversal (T-odd). Such matrix elements appear in principle both for parton distribution functions and parton fragmentation functions. We show that for parton fragmentation functions these gluonic pole matrix elements vanish as a consequence of the analytic structure of scattering amplitudes in Quantum Chromodynamics. This result is important in the study of the universality of transverse momentum dependent fragmentation functions.