The validity of charge symmetry for parton distributions

Londergan, J. T.; Thomas, A. W.

doi:10.1016/s0146-6410(98)00055-6

Cited by 59 publications

(21 citation statements)

References 81 publications

(190 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is consistent with the treatment in previous experiments [1][2][3][4] and global fits [13][14][15]. The possibility that charge symmetry could be significantly violated (CSV) at the parton level has been discussed by several authors [30][31][32][33][34][35][36] and an extensive review was recently published [36].…”

Section: Charge Symmetry and Shadowingsupporting

confidence: 89%

Improved measurement of thed¯/ūasymmetry in the nucleon sea

et al. 2001

View full text Add to dashboard Cite

Measurements of the ratio of Drell-Yan yields from an 800 GeV/c proton beam incident on liquid hydrogen and deuterium targets are reported. Approximately 360,000 Drell-Yan muon pairs remained after all cuts on the data. ¿From these data, the ratio of anti-down (d) to anti-up (ū) quark distributions in the proton sea is determined over a wide range in Bjorken-x. These results confirm previous measurements by E866 and extend them to lower x. From these data, (d −ū) and (d −ū)dx are evaluated for 0.015 < x < 0.35. These results are compared with parameterizations of various parton distribution functions, models and experimental results from NA51, NMC and HERMES. 13.85.Qk; 14.20.Dh; 24.85.+p; 14.65.Bt

show abstract

Section: Charge Symmetry and Shadowingsupporting

confidence: 89%

Improved measurement of thed¯/ūasymmetry in the nucleon sea

et al. 2001

View full text Add to dashboard Cite

show abstract

“…A significantly larger CSV than the expectations of both theory [3][4][5][6][7][8] and other experiments [13] was found for the s ands distributions in the low-x region (x < 0.1). Any unexpected large CSV will greatly affect our understanding of non-perturbative dynamics and hadronic structure [2], and also the extraction of sin 2 θ W from neutrino scattering [3]. More recently, Boros, Steffens, Londergan and Thomas [14] performed a similar analysis to Ref.…”

Section: Introductionmentioning

confidence: 96%

“…It has been generally believed that charge symmetry (CS) was highly respected in the nucleon system. Most low energy experiments have shown that CS is satisfied within about 1% in reaction amplitudes [1], and most high energy tests are also consistent with the charge symmetry, although generally with less precision than the low energy tests (for a recent review see [2] and references therein). However some theoretical calculations have suggested that the CSV in the valence quark distributions may be as large as 5% − 10% [3][4][5][6][7][8] which is rather large compared with the low-energy results.…”

Section: Introductionmentioning

confidence: 99%

Charge symmetry violation in the parton distributions of the nucleon

Cao

Signal

2000

Phys. Rev. C

View full text Add to dashboard Cite

Private Bag 11 222, Palmerston North New ZealandWe point out that charge symmetry violation in both the valence and sea quark distributions of the nucleon has a non-perturbative source. We calculate this nonperturbative charge symmetry violation using the meson cloud model, which has earlier been successfully applied to both the study of SU(2) flavour asymmetry in the nucleon sea and quark-antiquark asymmetry in the nucleon. We find that the charge symmetry violation in the valence quark distribution is well below 1%, which is consistent with most low energy tests but significantly smaller than the quark model prediction about 5% − 10%. Our prediction for the charge symmetry violation in the sea quark distribution is also much smaller than the quark model calculation.

show abstract

“…Fe (x,Q 2 )ϭF 2 Fe (x,Q 2 ), with an analogous relation for xF 3 Fe (x,Q 2 ), then Eq. ͑6͒ would provide two linear equations in two unknowns.…”

Section: Strange Quark and Csv Contributions To Structure Functionsmentioning

confidence: 89%

Evidence for charge symmetry violation in parton distributions

1999

View full text Add to dashboard Cite

By comparing structure functions measured in neutrino and charged lepton deep inelastic scattering, one can test the validity of parton charge symmetry. New experiments allow us to make such tests, which set rather tight upper limits on parton charge symmetry violation ͑CSV͒ for intermediate Bjorken x, but which appear to show sizable CSV effects at small x. We show that neither nuclear shadowing nor contributions from strange and antistrange quark distributions can account for the experimentally observed difference between the two structure functions. We are therefore forced to consider the possibility of a large CSV effect in the nucleon sea quark distributions. We discuss the consequences of this effect for other observables, and we propose an experiment which could detect a large CSV component in the nucleon sea. ͓S0556-2821͑99͒03507-9͔

show abstract

The validity of charge symmetry for parton distributions

Cited by 59 publications

References 81 publications

Improved measurement of thed¯/ūasymmetry in the nucleon sea

Improved measurement of thed¯/ūasymmetry in the nucleon sea

Charge symmetry violation in the parton distributions of the nucleon

Evidence for charge symmetry violation in parton distributions

Contact Info

Product

Resources

About