Research articles

search articles

My Pages

Stat

Members: 3645
Articles: 2'504'928
Articles rated: 2609

26 April 2024

» pubmed » pmid15323904

Article overview

Measurement of strange-quark contributions to the nucleon's form factors at Q(2) = 0.230 (GeV/c)(2)
F E Maas ; P Achenbach ; K Aulenbacher ; S Baunack ; L Capozza ; J Diefenbach ; K Grimm ; Y Imai ; T Hammel ; D von Harrach ; E M Kabuss ; R Kothe ; J H Lee ; A Lorente ; A Lopes Ginja ; L Nungesser ; E Schilling ; G Stephan ; C Weinrich ; I Altarev ; J Arvieux ; B Collin ; R Frascaria ; M Guidal ; R Kunne ; D March ; M Morlet ; S Ong ; J van de Wiele ; S Kowalski ; B Plaster ; R Suleiman ; S Taylor ;
Date:	9 Jul 2004
Journal:	Phys Rev Lett, 93 (2), 022002
Abstract:	We report on a measurement of the parity-violating asymmetry in the scattering of longitudinally polarized electrons on unpolarized protons at a Q2 of 0.230 (GeV/c)(2) and a scattering angle of theta (e) = 30 degrees - 40 degrees. Using a large acceptance fast PbF2 calorimeter with a solid angle of delta omega = 0.62 sr, the A4 experiment is the first parity violation experiment to count individual scattering events. The measured asymmetry is A(phys)=(-5.44+/-0.54(stat)+/-0.26(sys))x10(-6). The standard model expectation assuming no strangeness contributions to the vector form factors is A(0) = (-6.30+/-0.43) x 10(-6). The difference is a direct measurement of the strangeness contribution to the vector form factors of the proton. The extracted value is G(s)(E) + 0.225G(s)(M) = 0.039+/-0.034 or F(s)(1) + 0.130F(s)(2) = 0.032+/-0.028.
Source:	PubMed, pmid15323904
Services:	Forum \| Review \| Favorites

No review found.

Did you like this article?

This article or document is ...
important:
of broad interest:
readable:
new:
correct:
Global appreciation:

Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.

browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)

ScienXe.org
» my Online CV
» Free

News, job offers and information for researchers and scientists:

home

contact

sitemap