已收录 272903 条政策
 政策提纲
  • 暂无提纲
Nucleon Structure Functions from ν_µ-Fe Interactions and a Study of the Valence Quark Distribution
[摘要]

Data were taken in 1979-80 by the CCFRR high energy neutrino experiment at Fermilab. A total of 150,000 neutrino and 23,000 antineutrino charged current events in the approximate energy range 25 < Ev < 250 GeV are measured and analyzed. The structure functions F2 and xF3 are extracted for three assumptions about σLT: R = 0., R = 0.1 and R = a QCD based expression. Systematic errors are estimated and their significance is discussed. Comparisons or the X and Q2 behaviour or the structure functions with results from other experiments are made.

We find that statistical errors currently dominate our knowledge of the valence quark distribution, which is studied in this thesis. xF3 from different experiments has, within errors and apart from level differences, the same dependence on x and Q2, except for the HPWF results. The CDHS F2 shows a clear fall-off at low-x from the CCFRR and EMC results, again apart from level differences which are calculable from cross-sections.

The result for the the GLS rule is found to be 2.83 ± .15 ± .09 ± .10 where the first error is statistical, the second is an overall level error and the third covers the rest of the systematic errors. QCD studies of xF3 to leading and second order have been done. The QCD evolution of xF3, which is independent of R and the strange sea, does not depend on the gluon distribution and fits yield

ʌLO = 88+163-78 +113-70MeV

The systematic errors are smaller than the statistical errors. Second order fits give somewhat different values of ʌ, although αs (at Q20 = 12.6 GeV2) is not so different.

A fit using the better determined F2 in place of xF3 for x > 0.4 i.e., q = 0 in that region, gives

ʌLO = 266+114-104 +85-79MeV

Again, the statistical errors are larger than the systematic errors. An attempt to measure R was made and the measurements are described. Utilizing the inequality q(x) ≥ 0 we find that in the region x > .4 R is less than 0.55 at the 90% confidence level.

[发布日期]  [发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy
[效力级别]  [学科分类] 
[关键词] Physics [时效性] 
   浏览次数:3      统一登录查看全文      激活码登录查看全文