Michael Carrigan Advisors: Kevin Black & Lidia Dell’Asta T-Prime Study Update Michael Carrigan Advisors: Kevin Black & Lidia Dell’Asta

Reminder I am using Monte Carlo simulated data to look for the signal of the T-Prime vector like quark (VLQ) Background is generated with center of mass energy 33TeV Signal is generated from 33TeV as well with a mass of 500 GeV and no pile up Looking at the T’-> tH decay b q W- g T’ H t W l ν

Roadblock 33 TeV background files are currently unavailable Owned by CMS and stored at Fermilab Currently working to get access to more than a few files In the mean time I have been working with ~3.5 million events on the BU SCC Backgrounds are BB, BBB, tB, ttB, tt All have 0 pile up and are generated with 33 TeV center of mass energy

Efficiency of Cuts Need to ensure the cuts we are making save as much signal as possible and eliminate as much background as possible Looking at efficiency as S’/√B’ S’ = εS * cross section * integrated luminosity B’ = εB * cross section * integrated luminosity ε = # of events before / # of events after

Efficiency of Cuts Decided that the most efficient cuts for: MET = 25 GeV HT = 600 GeV However our efficiency was still too low ≈0.00271 Looking for ways to improve the number of signal events kept

Signal Masses Before I was using a signal with a mass of 500 GeV Added in signal data with masses 1000, 1500, 2000, 2500 GeV This means the T-prime particle was simulated with these five different masses In general the efficiencies dropped for the greater masses

Number of b-jets The theory for T’ -> tH predicts that there will be 3 b-jets produced But after the b-jet cut we went from 80-90% of events to 1- 2% b q W- g T’ H t W l ν

Changing the b-jet Cut Decided to try requiring only 2 b-jets to allow for one jet being missed by the detector But the efficiency dropped lower -> need to keep the 3 b-jet requirement

Next Cut? Unfortunately the list of cuts doesn’t allow for many other changes

Ideas? Looking at the T’->tH decay but we have only looked at the decay that creates a Higgs that decays as H-> bb This is the most likely Higgs decay but not the only one we can look at

Higgs Decays

Next Steps While we wait for the background monte carlo samples I will be looking at different Higgs decays to see if there is a more efficient decay Most likely looking at H->gg Need a decay with a large branching ratio as well as decay products that are easy to see in ATLAS