A Search for Displaced Leptons in the ATLAS Detector

A Search for Displaced Leptons in the ATLAS Detector
Author: Lesya Horyn
Publisher: Springer Nature
Total Pages: 146
Release: 2022-02-07
Genre: Science
ISBN: 3030916723

This thesis presents a search for long-lived particles decaying into displaced electrons and/or muons with large impact parameters. This signature provides unique sensitivity to the production of theoretical lepton-partners, sleptons. These particles are a feature of supersymmetric theories, which seek to address unanswered questions in nature. The signature searched for in this thesis is difficult to identify, and in fact, this is the first time it has been probed at the Large Hadron Collider (LHC). It covers a long-standing gap in coverage of possible new physics signatures. This thesis describes the special reconstruction and identification algorithms used to select leptons with large impact parameters and the details of the background estimation. The results are consistent with background, so limits on slepton masses and lifetimes in this model are calculated at 95% CL, drastically improving on the previous best limits from the Large Electron Positron Collider (LEP).

QCD Hard Hadronic Processes

QCD Hard Hadronic Processes
Author: Bradley Cox
Publisher: Springer Science & Business Media
Total Pages: 548
Release: 2012-12-06
Genre: Science
ISBN: 1468488422

The Advanced Research Workshop on QeD Hard Hadronic Processes was held on 8-13 October 1987 at Hotel on the Cay, St. Croix, U. S. Virgin Islands. The underlying theme of the workshop, the first in a series, was an examination, both theoretical and experimental, of the state of understanding of Quantum Chromodynamics. Because of the pervasiveness of the strong interactions in all aspects of high energy physics, QCD is central to many problems in elementary particle physics. Therefore, this workshop was organized to provide a forum in which the theory Quantum Chromodynamics cou 1 d be confronted with experi ment. The workshop was organ i zed in four sessions, each of which concentrated on a major experimental arena in which a hard QCD process can be measured experimentally. A fifth session was rlevoted to global issues which effect all QCD processes. Each session began with a survey of the theoretical developments in the particular area and concluded with a round table which discussed the various information presented in the course of the discussions. A session of the workshop was devoted to the direct production of high transverse momentum photons in hadronic interactions. Data from several experiments, either completed or in progress at CERN (NA3, NA24, WA70, UA6, CCOR, R806, AFS, RllO, UA1 and UA2), were di scussed and the prospects for two new upcomi ng experi ments from Fermil ab (E-705, E-706) were presented.

Particle Physics Reference Library

Particle Physics Reference Library
Author: Christian W. Fabjan
Publisher: Springer Nature
Total Pages: 1083
Release: 2020
Genre: Elementary particles (Physics).
ISBN: 3030353184

This second open access volume of the handbook series deals with detectors, large experimental facilities and data handling, both for accelerator and non-accelerator based experiments. It also covers applications in medicine and life sciences. A joint CERN-Springer initiative, the "Particle Physics Reference Library" provides revised and updated contributions based on previously published material in the well-known Landolt-Boernstein series on particle physics, accelerators and detectors (volumes 21A, B1,B2,C), which took stock of the field approximately one decade ago. Central to this new initiative is publication under full open access