Academic Journal
Measurement of Strange Quark Contributions to the Nucleon's Form Factors at Q^2=0.230 (GeV/c)^2
| العنوان: | Measurement of Strange Quark Contributions to the Nucleon's Form Factors at Q^2=0.230 (GeV/c)^2 |
|---|---|
| المؤلفون: | Collaboration, A, Maas, FE, Achenbach, P, Aulenbacher, K, Baunack, S, Capozza, L, Diefenbach, J, Grimm, K, Imai, Y, Hammel, T, Harrach, DV, Kabuss, EM, Kothe, R, Lee, JH, Lorente, A, Ginja, AL, Nungesser, L, Schilling, E, Stephan, G, Weinrich, C, Altarev, I, Arvieux, J, Collin, B, Frascaria, R, Guidal, M, Kunne, R, Marchand, D, Morlet, M, Ong, S, Wiele, JVD, Kowalski, S, Plaster, B, Suleiman, R, Taylor, S |
| المصدر: | Physical Review Letters , 93 (2) (2004) |
| سنة النشر: | 2004 |
| المجموعة: | University College London: UCL Discovery |
| الوصف: | We report on a measurement of the parity-violating asymmetry in the scattering of longitudinally polarized electrons on unpolarized protons at a $Q^2$ of 0.230 (GeV/c)^2 and a scattering angle of \theta_e = 30^o - 40^o. Using a large acceptance fast PbF_2 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} +- 0.27_{\rm sys}) 10^{-6}. The Standard Model expectation assuming no strangeness contributions to the vector form factors is $A_0=(-6.30 +- 0.43) 10^{-6}$. 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 + 0.225 G^s_M = 0.039 +- 0.034 or F^s_1 + 0.130 F^s_2 = 0.032 +- 0.028. |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | https://discovery.ucl.ac.uk/id/eprint/1375195/1/1375195.pdf; https://discovery.ucl.ac.uk/id/eprint/1375195/ |
| الاتاحة: | https://discovery.ucl.ac.uk/id/eprint/1375195/1/1375195.pdf https://discovery.ucl.ac.uk/id/eprint/1375195/ |
| Rights: | open |
| رقم الانضمام: | edsbas.AF24AE13 |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |