You need JavaScript to view this

In search of new phenomena using polarization. HERA and ILC

Abstract

The longitudinal polarization of leptons can be used as an important tool in the search for new phenomena at particle colliders. In the first part of this thesis a search for first generation leptoquarks at the H1 experiment is presented. During the HERA-2 runperiod polarized lepton beams were used. The analysis presented herein utilizes this fact in order to enhance the sensitivity to these chirally coupling leptoquarks. Since no evidence for their existence is found, exclusion limits depending on the mass and Yukawa coupling are calculated. This analysis can exclude leptoquarks coupling at electromagnetic strength up to masses of 280-300 GeV, depending on the leptoquark quantum numbers. A new domain of physics is expected to be open to the planned electron positron linear collider ILC, where polarized lepton beams will play an important role. In order to fully exploit its physics potential, the polarization will have to be measured with an as yet unequaled precision of 0.25%, which is expected to be limited by systematic effects, like the nonlinearity of the photodetectors employed. In the second part of this thesis several methods are tested with respect to their capability to resolve photodetector nonlinearities at the permille level, and checked for  More>>
Publication Date:
Dec 15, 2009
Product Type:
Thesis/Dissertation
Report Number:
DESY-THESIS-2009-049
Resource Relation:
Other Information: TH: Diss.
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ACCURACY; ANTILEPTON-NEUTRON INTERACTIONS; CHARGED-CURRENT INTERACTIONS; COMPTON EFFECT; COUPLING CONSTANTS; ELECTRON ANTINEUTRINOS; ELECTRON-PROTON INTERACTIONS; ELECTRONS; ELECTROPRODUCTION; GEV RANGE 100-1000; GRAND UNIFIED THEORY; INTERMEDIATE BOSONS; LINEAR COLLIDERS; NEUTRAL-CURRENT INTERACTIONS; PHOTODETECTORS; PHOTON-ELECTRON INTERACTIONS; POLARIMETERS; POLARIZED BEAMS; POSITRONS; REST MASS
OSTI ID:
21270108
Research Organizations:
Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Department Physik
Country of Origin:
Germany
Language:
English
Other Identifying Numbers:
Other: ISSN 1435-8085; TRN: DE10F0832
Availability:
Commercial reproduction prohibited; INIS; OSTI as DE21270108
Submitting Site:
DEN
Size:
171 pages
Announcement Date:
Mar 04, 2010

Citation Formats

Helebrant, Christian. In search of new phenomena using polarization. HERA and ILC. Germany: N. p., 2009. Web.
Helebrant, Christian. In search of new phenomena using polarization. HERA and ILC. Germany.
Helebrant, Christian. 2009. "In search of new phenomena using polarization. HERA and ILC." Germany.
@misc{etde_21270108,
title = {In search of new phenomena using polarization. HERA and ILC}
author = {Helebrant, Christian}
abstractNote = {The longitudinal polarization of leptons can be used as an important tool in the search for new phenomena at particle colliders. In the first part of this thesis a search for first generation leptoquarks at the H1 experiment is presented. During the HERA-2 runperiod polarized lepton beams were used. The analysis presented herein utilizes this fact in order to enhance the sensitivity to these chirally coupling leptoquarks. Since no evidence for their existence is found, exclusion limits depending on the mass and Yukawa coupling are calculated. This analysis can exclude leptoquarks coupling at electromagnetic strength up to masses of 280-300 GeV, depending on the leptoquark quantum numbers. A new domain of physics is expected to be open to the planned electron positron linear collider ILC, where polarized lepton beams will play an important role. In order to fully exploit its physics potential, the polarization will have to be measured with an as yet unequaled precision of 0.25%, which is expected to be limited by systematic effects, like the nonlinearity of the photodetectors employed. In the second part of this thesis several methods are tested with respect to their capability to resolve photodetector nonlinearities at the permille level, and checked for their long term stability. With some of the methods presented herein it will be possible to measure and correct photodetector nonlinearities at a running ILC experiment with the accuracy required in order to achieve the aimed precision of the polarization measurement. (orig.)}
place = {Germany}
year = {2009}
month = {Dec}
}