skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Implications of current constraints on parton charge symmetry

Abstract

For the first time, charge symmetry breaking terms in parton distribution functions have been included in a global fit to high energy data. We review the results obtained for both valence and sea quark charge symmetry violation and compare these results with the most stringent experimental upper limits on charge symmetry violation for parton distribution functions, as well as with theoretical estimates of charge symmetry violation. The limits allowed in the global fit would tolerate a rather large violation of charge symmetry. We discuss the implications of this for various observables, including extraction of the Weinberg angle in neutrino DIS and the Gottfried and Adler sum rules.

Authors:
;
Publication Date:
Research Org.:
Office of Scientific and Technical Information, Oak Ridge, TN
Sponsoring Org.:
USDOE
OSTI Identifier:
860885
Report Number(s):
JLAB-THY-05-448; DOE/ER/40150-3636
Journal ID: JPGNE7; TRN: US0504968
DOE Contract Number:
AC05-84ER40150
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physics. G, Nuclear and Particle Physics. Supplement; Journal Volume: 31; Journal Issue: 11
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; DISTRIBUTION FUNCTIONS; NEUTRINOS; PARTONS; QUARKS; SEAS; SUM RULES; SYMMETRY; SYMMETRY BREAKING; VALENCE; WEINBERG ANGLE

Citation Formats

J. T. Londergan, and A. W. Thomas. Implications of current constraints on parton charge symmetry. United States: N. p., 2005. Web. doi:10.1088/0954-3899/31/11/003.
J. T. Londergan, & A. W. Thomas. Implications of current constraints on parton charge symmetry. United States. doi:10.1088/0954-3899/31/11/003.
J. T. Londergan, and A. W. Thomas. Tue . "Implications of current constraints on parton charge symmetry". United States. doi:10.1088/0954-3899/31/11/003. https://www.osti.gov/servlets/purl/860885.
@article{osti_860885,
title = {Implications of current constraints on parton charge symmetry},
author = {J. T. Londergan and A. W. Thomas},
abstractNote = {For the first time, charge symmetry breaking terms in parton distribution functions have been included in a global fit to high energy data. We review the results obtained for both valence and sea quark charge symmetry violation and compare these results with the most stringent experimental upper limits on charge symmetry violation for parton distribution functions, as well as with theoretical estimates of charge symmetry violation. The limits allowed in the global fit would tolerate a rather large violation of charge symmetry. We discuss the implications of this for various observables, including extraction of the Weinberg angle in neutrino DIS and the Gottfried and Adler sum rules.},
doi = {10.1088/0954-3899/31/11/003},
journal = {Journal of Physics. G, Nuclear and Particle Physics. Supplement},
number = 11,
volume = 31,
place = {United States},
year = {Tue Nov 01 00:00:00 EST 2005},
month = {Tue Nov 01 00:00:00 EST 2005}
}
  • For the first time, charge symmetry breaking terms in parton distribution functions have been included in a global fit to high energy data. We review the results obtained for both valence and sea quark charge symmetry violation, and we compare these results with the most stringent experimental upper limits on charge symmetry violation for parton distribution functions, and with theoretical estimates of charge symmetry violation. The limits allowed in the global fit would tolerate a rather large violation of charge symmetry. We discuss the implications of this for the extraction of the Weinberg angle in neutrino DIS by the NuTeVmore » collaboration.« less
  • Recently, a global phenomenological fit to high energy data has included charge symmetry breaking terms, leading to limits on the allowed magnitude of such effects. We discuss two possible experiments that could search for isospin violation in valence parton distributions. We show that, given the magnitude of charge symmetry violation consistent with existing global data, such experiments might expect to see effects at a level of several percent. Alternatively, such experiments could significantly decrease the upper limits on isospin violation in parton distributions.
  • Recent phenomenological work has examined two different ways of including charge symmetry violation in parton distribution functions. First, a global phenomenological fit to high energy data has included charge symmetry breaking terms, leading to limits on the magnitude of parton charge symmetry breaking. In a second approach, two groups have included the coupling of partons to photons in the QCD evolution equations. One possible experiment that could search for isospin violation in parton distributions is a measurement of the asymmetry in W production at a collider. In this work we include both of the postulated sources of parton charge symmetrymore » violation. We show that, given charge symmetry violation of a magnitude consistent with existing high energy data, the expected W production asymmetries would be quite small, generally less than one percent.« less
  • Recently, a global phenomenological fit to high energy data has included charge symmetry breaking terms, leading to limits on the allowed magnitude of such effects. We discuss two possible experiments that could search for isospin violation in valence parton distributions. We show that, given the magnitude of charge symmetry violation consistent with existing global data, such experiments might expect to see effects at a level of several percent. Alternatively, such experiments could significantly decrease the upper limits on isospin violation in parton distributions.