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Search for decaying neutralinos at HERA and clustering optimisation for the ZEUS Micro Vertex Detector
- Source :
- Hamburg : Deutsches Elektronen-Synchrotron, DESY 124 pp. (2010). doi:10.3204/DESY-THESIS-2010-009 = Universität Hamburg, Diss., 2010
- Publication Year :
- 2010
- Publisher :
- Deutsches Elektronen-Synchrotron, DESY, 2010.
-
Abstract
- Universität Hamburg, Diss., 2010; 124 pp., (2010). doi:10.3204/DESY-THESIS-2010-009<br />A search for gravitinos produced in supersymmetric events in electron proton collisions has been performed with data recorded with the ZEUS detector at HERA in the years 2003 to 2007. In R-parity violating supersymmetric models a neutralino can be produced by t-channel exchange of a selectron between the incoming electron and a quark of the proton. In the Gauge Mediated Supersymmetry Breaking model (GMSB), where the gravitino is the lightest supersymmetric particle, the neutralino in large regions of the parameter space dominantly decays into a gravitino and a photon, leading to events with an isolated high energetic photon and large missing transverse momentum. To separate signal and background, a multi-variate discriminant method was used. No evidence for supersymmetry was found, and limits were derived for the R-parity violating coupling strength and the masses of the selectron and the lightest neutralino. Moreover, the cluster position reconstruction system of the ZEUS experiment was improved by modifying and implementing an algorithm which uses estimated track angle and impact position from the pattern recognition phase of the tracking system to yield a better position resolution.<br />Published by Deutsches Elektronen-Synchrotron, DESY, Hamburg
- Subjects :
- electron p: deep inelastic scattering
transverse momentum: missing-energy
neutralino: mass
vertex detector
neutralino --> gravitino photon
selectron: mass
mass [selectron]
symmetry breaking [supersymmetry]
electron p --> neutralino quark anything
track data analysis: cluster
gravitino: LSP
cluster [track data analysis]
supersymmetry: symmetry breaking
318 GeV-cms
LSP [gravitino]
R parity: violation
violation [R parity]
neutralino: decay: measured
High Energy Physics::Phenomenology
thesis
bibliography
ZEUS
DESY HERA Stor
missing-energy [transverse momentum]
deep inelastic scattering [electron p]
decay: measured [neutralino]
semiconductor detector
High Energy Physics::Experiment
mass [neutralino]
experimental results
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Hamburg : Deutsches Elektronen-Synchrotron, DESY 124 pp. (2010). doi:10.3204/DESY-THESIS-2010-009 = Universität Hamburg, Diss., 2010
- Accession number :
- edsair.doi.dedup.....49192fcb4dece3fa78daf25eb4df8b52