CMS Calibration Studies: In order to believe in any science results, you must first believe that the instruments used are performing reliably over time. Calibrating the detector so that it enables "rediscovery" of previously measured results is an important part of the early scientific activity at CMS. You can participate in this process. Whether it is the confirmation of a mass of a previously measured particle mass, the relation between energy and momentum, or some other parameter, you are invited to choose some pathway to explore calibration of the CMS detector.

General Study Design Considerations: Which calibration parameter to begin with? Time periods — which do you want to monitor? Data quantity — how much data do you need?

PDG Live - Measurements of the properties of the elementary particles from the Particle Data Group

The Z boson (Z⁰), a neutral particle, is produced by the interaction of oppositely charged quarks (such as up and antiup.) It is short-lived, and decays immeasurably close to the primary collision vertex into pairs of particles. "Rediscovery" of the Z boson mass is an early measurement goal of CMS scientists as they verify the proper operation of the detector. From candidate Z -> di-muon data, you can determine whether CMS is measuring Z rest mass accurately. On the left is a single event display of a Z boson decaying into two muons.

Z mass study design considerations: - Which data runs to choose? How much data is sufficient for calibration purposes? Which dimuon pairings to select, and why? Which accepted value of the Z mass will you use, and how will you justify that choice?