Medium Energy Physics Seminar

Conference Room R-150, Building 203, Argonne National Laboratory

Thursdays at 10:00 AM

Ron Gilman

Rutgers University

The Proton Radius Puzzle

Host: Paul Reimer

2 April 2015

In 2010, measurements of muonic hydrogen determined the proton radius about an order of magnitude more precisely than previous measurements with electrons--but the result was about 5 sigma smaller. This inconsistency has become known as the proton radius puzzle. More recent measurements have confirmed the puzzle and have increased the discrepancy to over 7 sigma. Various explanation have been proposed, including novel beyond-standard-model physics, novel conventional physics, and issues in determining the radius from experiments. No explanation has majority support in the community. I will describe the puzzle and the efforts underway to resolve it.

Kawtar Hafidi, MEP Seminar Chairwoman (630-252-4012, mail)

Debbie Beres, Secretary (630-252-4100, mail)

Paul E. Reimer
26 March 2015