May 20

Cosying up with CMS monte carlo data

AllSigMu+Mu-, originally uploaded by NDeRC2.

Following Kate Rueff’s example, I’m spending the last few minutes of my day providing others with some glimpse into the rest of it. I work with I2U2, a virtual organization building online learning environments for K-12 students and teachers. One of our environments (called “e-Labs”) is for the CMS detector. This plot, with three noteworthy features over background, shows peaks for J-Psi (a bound state of charm/anticharm quarks) at 3 GeV; Upsilon (bottom/antibottom quarks) at 9 GeV, and the Z zero (a fundamental particle) at 91 GeV. These are the parent particles which decay into muon pairs (actually, a muon and an antimuon) whose total energy (called “mass” by particle physicists) reflects the rest mass of the short-lived parent particles whose decays produced them. Interesting stuff, and enough for a late night glimpse into the events of the day.