HAPPEX: Strange Quarks in the Proton and 4He

Journal Article · Wed Jun 13 04:00:00 EDT 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2750880· OSTI ID:21064017

Michaels, Robert ^[1]

---

1. Thomas Jefferson National Accelerator Facility (United States)

HAPPEX results from our 2005 run for the parity-violating asymmetry A PV in elastic scattering of 3 GeV electrons off hydrogen and 4He targets at <{theta}lab> {approx_equal} 6.0 deg. are presented. The 4He result is APV (+6.40 {+-} 0.23 (stat) {+-} 0.12 (syst)) x 10-6. The hydrogen result is APV = (-1.58 {+-} 0.12 (stat) {+-} 0.04 (syst)) x 10-6. The asymmetry for hydrogen is a linear combination of G{sub E}{sup s} and G{sub M}{sup s}, the strange quark contributions to the electric and magnetic form factors of the nucleon, respectively, and that for 4He is a function of G{sub E}{sup s} alone. The measurements imply G{sub E}{sup s} + 0.09G{sub M}{sup s} = 0.007 {+-} 0.011 {+-} 0.006 at <Q2> = 0.109 GeV2 and G{sub E}{sup s} = 0.002 {+-} 0.014 {+-} 0.007 at <Q2> = 0.077 GeV2.

• OSTI ID: 21064017
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 915; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
ELASTIC SCATTERING
ELECTROMAGNETIC FORM FACTORS
ELECTRON REACTIONS
ELECTRONS
FOUR MOMENTUM TRANSFER
GEV RANGE
HELIUM 4
HELIUM 4 TARGET
HYDROGEN 1 TARGET
P INVARIANCE
PARITY
PARTICLE STRUCTURE
PROTONS
S QUARKS