PIRSA:15100084

Using energy-peaks to measure (new and old) particle masses

Agashe, K. (2015). Using energy-peaks to measure (new and old) particle masses. Perimeter Institute. https://pirsa.org/15100084

Agashe, Kaustubh. Using energy-peaks to measure (new and old) particle masses. Perimeter Institute, Oct. 16, 2015, https://pirsa.org/15100084 

          @misc{ pirsa_PIRSA:15100084,
            doi = {10.48660/15100084},
            url = {https://pirsa.org/15100084},
            author = {Agashe, Kaustubh},
            keywords = {Particle Physics},
            language = {en},
            title = {Using energy-peaks to measure (new and old) particle masses},
            publisher = {Perimeter Institute},
            year = {2015},
            month = {oct},
            note = {PIRSA:15100084 see, \url{https://pirsa.org}}
          }

Kaustubh Agashe

University of Maryland, College Park

Talk number
PIRSA:15100084
Collection
Talk Type
Subject
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 (in CMS-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.