dc.contributor.advisor Franklin, Melissa dc.contributor.author DiPetrillo, Karri Folan dc.date.accessioned 2019-12-12T08:40:07Z dc.date.created 2019-05 dc.date.issued 2019-05-17 dc.date.submitted 2019 dc.identifier.citation DiPetrillo, Karri Folan. 2019. Search for long-lived, massive particles in events with a displaced vertex and a displaced muon using sqrt{s} = 13 TeV pp-collisions with the ATLAS detector. Doctoral dissertation, Harvard University, Graduate School of Arts & Sciences. dc.identifier.uri http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029616 * dc.description.abstract A search for long-lived particles giving rise to displaced decays with at least one muon is presented. The analysis selects events that pass a muon or missing transverse energy trigger and contain a displaced muon and a displaced vertex with at least three tracks and a vertex visible invariant mass of at least 20~GeV. A data sample of $\sqrt{s} = 13$~TeV proton--proton collisions collected by the ATLAS detector between 2016 and 2018, corresponding to a total integrated luminosity of 136~fb$^{-1}$, is used for this search. The analysis employs dedicated reconstruction techniques that significantly increase the sensitivity to displaced decays. Background estimates for Standard Model processes and instrumental effects are extracted entirely from data. The observed event yields are compatible with those expected from background processes. Results are presented as limits at 95\% confidence level on the model-independent cross section for processes beyond the Standard Model, and interpreted as exclusion limits on scenarios with pair-production of long-lived stop squarks that decay via a small $R$-parity violating coupling to a quark and a muon. Stop squarks with a lifetime of 0.1 ns in these scenarios are excluded for masses up to 1.7 TeV. dc.description.sponsorship Physics dc.format.mimetype application/pdf dc.language.iso en dash.license LAA dc.subject CERN dc.subject ATLAS dc.subject High Energy Physics dc.subject Particle Physics dc.subject Supersymmetry dc.subject Long-lived particles dc.title Search for long-lived, massive particles in events with a displaced vertex and a displaced muon using sqrt{s} = 13 TeV pp-collisions with the ATLAS detector dc.type Thesis or Dissertation dash.depositing.author DiPetrillo, Karri Folan dc.date.available 2019-12-12T08:40:07Z thesis.degree.date 2019 thesis.degree.grantor Graduate School of Arts & Sciences thesis.degree.grantor Graduate School of Arts & Sciences thesis.degree.level Doctoral thesis.degree.level Doctoral thesis.degree.name Doctor of Philosophy thesis.degree.name Doctor of Philosophy dc.contributor.committeeMember Georgi, Howard dc.contributor.committeeMember Guenette, Roxanne dc.type.material text thesis.degree.department Physics thesis.degree.department Physics dash.identifier.vireo dash.author.email kdipetrillo@gmail.com
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