Publikationsserver der RWTH Aachen University
Resonant second generation slepton production at the tevatron
Abstract
dc:descriptionIn this thesis a search for R-parity violating supersymmetry is presented. Two different approaches, determined by the event topologies, are chosen to search for resonant slepton production and for the pair and associated production of gauginos. To the resonant slepton production three different signal channels contribute; (i) ~mu->~chi^0_1 mu, (ii) ~mu->~chi^0_2 mu and (iii) ~nu_mu->~chi^+-_1 mu. These three channels are analyzed separately. The slepton-mass -- gaugino-mass plane ist scanned systematically for an excess in the data. Effective 2-dimensional cuts have been developed, to separate signal-like events from background. The analysis profits from the ability to reconstruct the neutralino as well as the slepton mass. The 2D cuts must be very flexible, to account for the different event topologies in the three channels, while scanning the slepton- and gaugino-masses from a few GeV to several hundred GeV. The pair and associated production of gauginos and their decay via any LQD coupling lambda'_2ij with j=1,2 and k=1,2,3 does not comprise a resonance. Therefore the search is not able to benefit from a mass reconstruction. The two muon charges are not correlated, so that the selection of only like-sign di-muon final states is the chosen method to suppress Standard Model background processes. No indication of RPV supersymmetry production or any disagreement between data and Standard Model expectation have been found. Therefore exclusion limits with 95% confidence level (CL) have been calculated. Model independent limits on cross section times branching ratio are given. These limits only depend on the masses of the contributing particles of the process. The predicted cross section of any given model can be compared to these cross section limits to determine the exclusion contour in that model. The three resonant slepton production channels i, ii, and iii are combined within the minimal super gravity (mSUGRA) model to the world's best limit on the relevant coupling lambda'_211 in dependence of the neutralino and the slepton masses. A lower bound on the slepton mass depending only on lambda'_211 is derived. If any LQD coupling lambda'_2ij with j=1,2 and k=1,2,3 is larger than 0.01, then neutralino masses below 41.5 GeV and gluino masses below 285 GeV can be excluded within mSUGRA. This result is a significant extension of the D0 Run I bounds.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2006
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Autermann, Christian
- Contributors dc:contributor
-
- Hebbeker, Thomas
Subjects
dc:subject × 11Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- eng
Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:publications.rwth-aachen.de:61586