Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.
DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.
We search for the rare radiative decay D-0 -> gamma gamma using a data sample with an integrated luminosity of 832 fb(-1) recorded by the Belle detector at the KEKB e(+)e(-) asymmetric-energy collider. We find no statistically significant signal and set an upper limit on the branching fraction of B(D-0 -> gamma gamma) < 8.5 x 10(-7) at 90% confidence level. This is the most restrictive limit on the decay channel to date.
Jan Steggemann, Konstantin Androsov, Anna Mascellani
Jan Steggemann, Konstantin Androsov, Anna Mascellani, Joanna Malgorzata Wanczyk