Colloquium: Stefan Meinel, November 19, 2015

Date: November 19
Speaker: Stefan Meinel (Arizona)
Title: Hints for physics beyond the Standard Model in decays of beauty quarks
Abstract: Astronomical observations and theoretical arguments both indicate that our current understanding of fundamental particle physics, the Standard Model, is still incomplete. A promising way of searching for physics beyond the Standard Model with particle collider experiments is the precision study of processes in which quarks change from one flavor to another. Such processes may receive observable quantum corrections from new elementary particles that so far have escaped direct detection. Recent measurements of decays of B mesons, in which a heavy beauty quark changes to a lighter flavor of quark, have revealed some tantalizing deviations from Standard-Model predictions, but the interpretation is still unclear. In this colloquium, I will show how complementary information on the same underlying quark transitions can be obtained by studying decays of Lambda_b baryons instead of B mesons. To interpret the experimental data, the contributions of the strong interaction need to be calculated numerically using lattice quantum chromodynamics on supercomputers.