High Energy Particle Studies for the Improvement of Missing Transverse Energy Calculations using a High Granularity Timing Detector

Presenter: Elizabeth Maynard

Faculty Mentor: Stephanie Majewski

Presentation Type: Poster 28

Primary Research Area: Science

Major: Physics

Funding Source: UROP Mini-grant, University of Oregon, $734.96

The purpose of this study is to discover if using a high granularity timing detector, which is a proposed upgrade for the ATLAS particle detection chamber, could improve missing transverse energy calculations. Missing transverse energy is a sign of the presence of particles that we cannot yet detect, and finding these particles could be proof of new physics. The hypothesis is that this detector could be used to identify, and thereby exclude, uninteresting particles (“pileup”) from the calculation of missing transverse energy.

To perform the study, particle collisions were simulated with a variety of parameters using the specialized computer programs ROOT and FastJet. Then, missing transverse energy was calculated after ‘cutting out’ particles based on their timing parameter, to simulate the addition of the timing detector. Currently, only the most basic particle collision types (QCD jets) have been studied. In this case, we expect the missing transverse energy to be close to zero for all events. Without the detector, 42% of events had an energy calculation greater than eighty giga-electron volts in the large pileup case, but with the timing detector this was reduced to 21%. Similarly, in the low pileup case, the percent above eighty GeV was reduced from 26% to 4%.

In conclusion, my study shows that for QCD type particle collisions, the addition of a high granularity timing detector improves missing transverse energy calculations by about 20%, which is a substantial improvement.

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