Friday, September 8, 2017 at 1:00pm
Physical Sciences Building, 120
245 East Avenue
Using Energy-Peaks to Measure (new and old) Particle Masses
Abstract: I will first analytically show a simple, yet subtle "invariance" of two-body decay kinematics for the case of a massless daughter and a mother particle which is unpolarized and has a *generic* boost distribution in the laboratory frame. Namely, the laboratory frame energy distribution of the massless decay product has a peak, whose location is identical to the (fixed) energy of that particle in the rest frame of the corresponding mother particle.
In turn, this value of the energy is a simple function of the other masses involved in the decay. As a proof of principle of the usefulness of this observation, I will then apply it for measuring the mass of the top quark at the LHC, using simulated data (including experimental effects). In fact, CMS collaboration (inCMS-PAS-TOP-15-002) has recently implemented our method for measuring the top quark mass! Finally, I will show how it can be used to measure all the superpartner masses in a cascade decay chain of the gluino.