Speaker
Ryo Katayama
(University of Tokyo)
Description
We report on the full simulation study of measuring the O(1 eV) mass of the stable very light gravitino. Such a light gravitino typically appears in GMSB scenarios and is attractive from the point of view of cosmological constraints. Assuming NLSP stau of ~120 GeV mass and ~100 um/c lifetime, we simulate stau pair creation events at Ecm=500 GeV ILC with the ILD detector model. Tau decays are reconstructed in the 1-prong mode. Using the impact parameter distribution, the accuracy of the stau lifetime measurement is estimated. Two methods of stau mass reconstruction are compared: from the edge scan of the energy of tau decay products, and the cross section scan near the production threshold around 250 GeV. The accuracy of the gravitino mass is estimated using its relation with the NLSP mass and lifetime.
