Speaker
Mr
Nathan Callahan
(Indiana Univeristy)
Description
Precision measurements of the free neutron lifetime $\tau_n$, when combined with measurements of the axial vector coupling, can be used to test unitarity of the CKM matrix. Nonunitarity is a signal for physics Beyond the Standard Model (BSM). Sensitivity to BSM physics requires measurements of $\tau_n$ to a precision of 0.1 s. However, the two dominant techniques to measure $\tau_n$ (colloquially beam and bottle measurements) disagree by nearly 10 s. UCN$\tau$ is a neutron lifetime experiment using a magneto-gravitational trap and an $\textit{in-situ}$ neutron detector. Neutrons in this trap are not susceptible to loss on material walls as in previous bottle measurements. Additionally, the $\textit{in-situ}$ detector allows spectral monitoring of the trapped Ultracold Neutrons. In this talk, I will present our most recent result $\tau_n=877.7\pm0.7_\mathrm{(stat.)}+0.4/-0.2_\mathrm{(sys.)}$. I will also present Monte Carlo simulations of systematic effects in the experiment.
| nbcallah@indiana.edu | |
| Collaboration name | UCNtau |
Primary author
Mr
Nathan Callahan
(Indiana Univeristy)
