[Hallc] Interview Seminar

[Stephanie Tysor]

Good morning,

Please plan on attending the next interview seminar being given on:
 

Today, May 25th: Mikhail Yurov @ 2:30pm in CEBAF center conference room L102

Title: "Two-photon exchange contribution to elastic electron-proton scattering"

Abstract:
Two experimental techniques, Rosenbluth separation and recoil polarization transfer, used to extract proton's electromagnetic form factors ratio $\frac{G_E}{G_M}$ yield markedly different results. Modern theoretical calculations suggest that two-photon exchange (TPE) might be responsible for the observed discrepancy and that it is $\varepsilon$ dependent.
Jefferson Lab Experiment E05-017 was designed to measure the TPE contribution over a wide range of $\varepsilon$ and $Q^2$. In contrast with the conventional Rosenbluth method, E05-017 detected the elastically scattered proton rather than the electron. This approach returns a much more precise extraction of the form factor ratios. While comparisons of $e^{+}p$ and $e^{-}p$ scattering have been used to constrain TPE at low Q^2, our measurements provide additional information on the $\varepsilon$ dependence at low $Q^2$, and can constrain the size of TPE at much larger $Q^2$ values.
After a brief description of the experimental goals and techniques, the current status of the analysis will be presented. Preliminary results will be shown.

Thank you,
Stephanie

-- 
Stephanie Tysor
Hall A Administrative Assistant
Thomas Jefferson National Accelerator Facility
(office)757-269-6005 (fax)757-269-5235