Optimising the ATLAS Level-1 Calorimeter Trigger and Top-Antitop Charge Asymmetry

Lead Research Organisation: University of Birmingham
Department Name: School of Physics and Astronomy

Abstract

The last year I have been working on a scenario where the luminosity at the ATLAS experiment becomes high enough that we need to apply harsher cuts on the trigger selection. I used a sample of background QCD jets (events we don't want to keep) and a sample of electrons from Z bosons (that we do want to keep) to reduce the rate of data-taking but keeping the efficiency as high as possible. A set of cuts were thus deduced and have been placed in the trigger menu which may be used for this year's running of the LHC.
I am further involved with an analysis on top-antitop quark charge asymmetry. Here we are looking at the decay products of the two particles and observing their respective boosts (rapidities) in the detector to see if their values differ from those predicted by the Standard Model of Particle Physics. Some models beyond the Standard Model predict different behaviour. Currently, I am comparing methods which reconstruct the top quarks from their decay products, seeing how well they perform, using Monte-Carlo data to test them.
My main thesis topic is yet to be decided but will be a larger analysis on top quarks, perhaps even a continuation of charge asymmetry with all of the LHC run 2 data.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/N503939/1 01/10/2015 30/09/2020
1843685 Studentship ST/N503939/1 01/10/2016 31/03/2020 Robert Adam Vallance
 
Description ATLAS experiment tour guide 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Worked as a tour guide for the ATLAS experiment during the winter months when the LHC was switched off. Took members of the public (and other scientists) down to the underground cavern, showing them the ATLAS experiment, talking about it's main workings and my work on my PhD / at CERN. Received lots of positive comments and questions during the tours, helping the public to understand what CERN and the LHC is about.
Year(s) Of Engagement Activity 2017,2018
 
Description Particle Physics Open Day / Interview Day help 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Assisted with open days and postgrad interview days at the University of Birmingham. Demonstrated some of the experiments in the showroom and chatted to prospective students on university/undergrad/postgrad life. Aim to encourage students to apply to the university or answer any questions about the department during the interview days.
Year(s) Of Engagement Activity 2017,2019
 
Description Talking to school groups visiting CERN 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Spoke with school groups from the UK visiting CERN. Worked with a few other academics and postgrad students to chat to the students around tables or stand up in front of them in Q&A sessions, talking about experiences at CERN and life as a researcher. Received glowing comments from the teachers, including cards/gifts from our efforts. I hope this will have inspired more younger people to go into science.
Year(s) Of Engagement Activity 2017,2018