High Energy Physics Seminar

The accurate determination of the free neutron lifetime 𝜏n is of particular interest in low-energy precision particle physics. The Standard Model relates the neutron lifetime 𝜏n to the CKM matrix element 𝑉ud and the ratio 𝜆= 𝑔V /𝑔A through precisely calculated radiative corrections. A neutron-based determination of 𝑉ud provides a nuclear-structure free input to the test of the CKM matrix unitarity. The 𝜏SPECT experiment pursues the approach of suspending ultracold neutrons in a three-dimensional fully magnetic trap with the goal to determine 𝜏n with an uncertainty of < 0.3 s. Magnetic storage minimizes experimental systematic uncertainties related to neutron losses on material walls. We present the status of 𝜏SPECT currently operated at the Paul Scherrer Institute (PSI) in Switzerland. We address the optimization of UCN loading, systematic studies, and comparisons with simulations. Ideas for experimental developments for future improvements below <0.3 s will be presented.

The talk is in 469 Lauritsen.

Contact [email protected] for Zoom link.