קולוקוויום בפיזיקה לזכרו של אביבי יבין: Fundamentally cool physics with trapped atoms and ions

Abstract:

Nuclear decay has a long-standing history of shaping and testing the standard model of particle physics, and it continues to this day with elegant, ultra-precise low-energy nuclear measurements. Experiments observing the angular correlations between the electron, neu-trino and recoil momenta following nuclear decay can be used to search for exotic currents contributing to the dominant (V − A) structure of the weak interaction. Precision mea-surements of the correlation parameters to < 0.1% would be sensitive to (or meaningfully constrain) new physics, complementing other searches at large-scale facilities like the LHC.

Atom and ion traps provide an ideal source of very cold, short-lived radioactive nuclei in an extremely clean and open environment. As such, they are invaluable tools for precision measurements of -decay parameters. At the Cyclotron Institute, we have built the Texas A&M University Penning trap (TAMUTRAP) facility which will be used to study -delayed proton decays of neutron-deficient isotopes. The TRIUMF Neutral Atom Trap (TRINAT) collaboration utilizes neutral atom-trapping techniques with optical pumping methods to highly polarize (> 99%) 37K atoms. Recently, we determined the asymmetry parameter, A , to 0.3%, which is comparable to or better than any other nuclear measuement, including the neutron. In terms of minimal left-right symmetric models, this implies a limit of 351 GeV for the mass of a possible right-handed W. Alternatively, one may interpret the result as a 4.4× better measurement of Vud from 37K: 0.9745(25) s.

This talk will explain how we take advantage of modern trapping techniques to measure the angular distribution of -decaying nuclei. I will cover the progress that has been made on TAMUTRAP, and discuss in more detail the recent polarization and A measurements made by TRINAT.

מארגן האירוע: פרופ' מרק קרלינר