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Title: First time measurements of polarization observables for the charged cascade hyperon in photoproduction

Abstract

The parity violating weak decay of hyperons offers a valuable means of measuring their polarization, providing insight into the production of strange quarks and the matter they compose. Jefferson Lab's CLAS collaboration has utilized this property of hyperons, publishing the most precise polarization measurements for the Lambda and Sigma in both photoproduction and electroproduction to date. In contrast, cascades, which contain two strange quarks, can only be produced through indirect processes and as a result, exhibit low cross sections thus remaining experimentally elusive. At present, there are two aspects in cascade physics where progress has been minimal: characterizing their production mechanism, which lacks theoretical and experimental developments, and observation of the numerous excited cascade resonances that are required to exist by flavor SU(3)F symmetry. However, CLAS data were collected in 2008 with a luminosity of 68 pb^-1 using a circularly polarized photon beam with energies up to 5.45 GeV, incident on a liquid hydrogen target. This dataset is, at present, the world's largest for meson photoproduction in its energy range and provides a unique opportunity to study cascade physics with polarization measurements. The current analysis explores hyperon production through the yp -> K^+ K^+ Xi^- reaction by providing the firstmore » ever determination of spin observables P, Cx and Cz for the cascade. Three of our primary goals are to test the only cascade photoproduction model in existence, examine the underlying processes that give rise to hyperon polarization, and to stimulate future theoretical developments while providing constraints for their parameters. Our research is part of a broader program to understand the production of strange quarks and hadrons with strangeness. The remainder of this document discusses the motivation behind such research, the method of data collection, details of their analysis, and the significance of our results.« less

Authors:
ORCiD logo [1]
  1. Florida Intl Univ., Miami, FL (United States)
Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
1435603
Report Number(s):
JLAB-PHY-14-2030; DOE/OR/23177-4432
DOE Contract Number:
AC05-06OR23177
Resource Type:
Thesis/Dissertation
Resource Relation:
Related Information: Jefferson Lab Hall B (CLAS) g12 experiment. Experiment numbers 04-005, 04-017, 08-003
Country of Publication:
United States
Language:
English

Citation Formats

Bono, Jason. First time measurements of polarization observables for the charged cascade hyperon in photoproduction. United States: N. p., 2014. Web. doi:10.2172/1435603.
Bono, Jason. First time measurements of polarization observables for the charged cascade hyperon in photoproduction. United States. doi:10.2172/1435603.
Bono, Jason. Sun . "First time measurements of polarization observables for the charged cascade hyperon in photoproduction". United States. doi:10.2172/1435603. https://www.osti.gov/servlets/purl/1435603.
@article{osti_1435603,
title = {First time measurements of polarization observables for the charged cascade hyperon in photoproduction},
author = {Bono, Jason},
abstractNote = {The parity violating weak decay of hyperons offers a valuable means of measuring their polarization, providing insight into the production of strange quarks and the matter they compose. Jefferson Lab's CLAS collaboration has utilized this property of hyperons, publishing the most precise polarization measurements for the Lambda and Sigma in both photoproduction and electroproduction to date. In contrast, cascades, which contain two strange quarks, can only be produced through indirect processes and as a result, exhibit low cross sections thus remaining experimentally elusive. At present, there are two aspects in cascade physics where progress has been minimal: characterizing their production mechanism, which lacks theoretical and experimental developments, and observation of the numerous excited cascade resonances that are required to exist by flavor SU(3)F symmetry. However, CLAS data were collected in 2008 with a luminosity of 68 pb^-1 using a circularly polarized photon beam with energies up to 5.45 GeV, incident on a liquid hydrogen target. This dataset is, at present, the world's largest for meson photoproduction in its energy range and provides a unique opportunity to study cascade physics with polarization measurements. The current analysis explores hyperon production through the yp -> K^+ K^+ Xi^- reaction by providing the first ever determination of spin observables P, Cx and Cz for the cascade. Three of our primary goals are to test the only cascade photoproduction model in existence, examine the underlying processes that give rise to hyperon polarization, and to stimulate future theoretical developments while providing constraints for their parameters. Our research is part of a broader program to understand the production of strange quarks and hadrons with strangeness. The remainder of this document discusses the motivation behind such research, the method of data collection, details of their analysis, and the significance of our results.},
doi = {10.2172/1435603},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Aug 31 00:00:00 EDT 2014},
month = {Sun Aug 31 00:00:00 EDT 2014}
}

Thesis/Dissertation:
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