[Triumf-seminars] TRIUMF Seminar today at 14:00

[postmaster at admin.triumf.ca]

Date/Time: Thu 2010-02-25 at 14:00

Location:  Auditorium          

Speaker:   Peter Blunden (University of Manitoba)

Title:     Recent progress on two-boson exchange effects in electron-proton scattering

Abstract: This talk will be a review of recent work by our group and others on the role of two-boson exchange in elastic electron-nucleon scattering, focusing in particular on hadronic frameworks suitable for describing data at low and moderate momentum transfer Q^2. This will include the effects of two-photon exchange (TPE) on elastic form factors, and the effects of both TPE and gamma Z exchange on electroweak form factors measured using parity-violating electron scattering.

Two-photon exchange is the leading candidate to explain an apparent discrepancy between measurements of the ratio of proton electric to magnetic form factors using traditional longitudinal-transverse separation, and using new techniques based on polarization transfer. gamma Z exchange contributes significantly to experiments underway at Jefferson Lab to measure the weak charge of the proton. I will describe calculations based on models, as well as those using dispersion relations based on cross section data at forward angles.

Stimulants available 15 minutes before the talk.

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