University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Wednesday, September 30th 2015
Speaker: Juliette Alimena, Brown University
Subject: Search for Stopped Particles from Decays to Delayed Muons
Note the change from the usual time, this week only

Massive, long-lived particles do not exist in the SM, and so any sign of them would be an 3 indication of new physics. There are many BSM theories that predict long-lived particles, including split SUSY, hidden valley scenarios, GUT theories, and various SUSY models. Long-lived particles could be sufficiently massive that they would loose sufficient energy through ionization or hadronization, depending on the type of particle, that they would come to rest inside the detector material. A search for long-lived particles that stop in the CMS detector and decay to muons was performed. The decays of the stopped particles could be observed when there are no pp collisions in the detector, namely during gaps between bunch crossings. The analysis uses 19.7 1/fb of 8 TeV data collected by CMS in 2012, during a search interval of 293 hours of trigger livetime. We also set cross section limits for each mchamp mass as a function of lifetime, for lifetimes between 100 ns and 10 days. These are the first limits for stopped particles that decay to muons, and they are also the first limits for lepton-like multiply charged particles that stop in the detector.

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.