R-Parity Violating Supersymmetry

My research involves looking for R-parity violating supersymmetry at the Compact Muon Solenoid (CMS). Supersymmetry is a proposed symmetry between bosons and fermions. For every boson there is an undiscovered fermionic partner and vice versa. Standard Model particles have R-parity of 1 and supersymmetric particles have R-parity of -1. When R-parity is violated, supersymmetric particles may decay to Standard Model particles (i.e., before the decay the R-partity is -1 and after it is 1).

To produce these new particles (if they do exist), we use the Large Hadron Collider (LHC) located in Geneva, Switzerland. The LHC accelerates protons to large energies before colliding them inside detectors. As the quarks and gluons inside the protons interact, they create other particles that physicsts want to study. Those particles may then decay to other, lighter particles very quickly. Finally, a detector like CMS captures information about the particles that stream out of each collision. Many particles of interest (including what I study) decay too quickly to be directly detected. But the information about the final decay products that CMS detects is enough to reconstruct properties of the initial products of the proton-proton collision.

Hadronic Calorimeter Calibration

I work on calibrating CMS’s hadronic calorimeter (HCAL). The HCAL, like most of the CMS detector, is shaped like a cylinder. It is devided into 82 segments along the length of the cylinder and between 18 and 72 segments around. Each of these must be calibrated to ensure that jets are measured to have the same energy regardless of which part of the calorimeter they hit. I work on calibrating the HCAL along the length of the cylinder by using dijet balance.

Because of conservation of energy and momentum, the sum of momentum transverse to the particle beams will be zero. Therefore, if two jets are produced, the transverse momentum of one will equal the transverse momentum of the other. We can use this to propagate the calibration of the HCAL between the two locations of the jets.

Randall-Sundrum Gravitons

In the past I have done work related to Randall-Sundrum (RS) gravitons. For my undergraduate senior thesis, I looked at RS gravitons decaying to pairs of muons. As part of my qualifier at Rutgers, I examined the feasibility of setting limits on the mass of RS gravitons from decays to pairs of W bosons.

Software

The EventShape repository on my github calculates the sphericity, aplanarity, and other event shape quantities using ROOT and the CMSSW framework.