High precision determination of the $Q^2$-evolution of the Bjorken Sum
| Autor: | Deur, A., Prok, Y., Burkert, V., Crabb, D., Girod, F. -X., Griffioen, K. A., Guler, N., Kuhn, S. E., Kvaltine, N. |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 90, 012009 (2014) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.90.012009 |
| Popis: | We present a significantly improved determination of the Bjorken Sum for 0.6$\leq Q^{2}\leq$4.8 GeV$^{2}$ using precise new $g_{1}^{p}$ and $g_{1}^{d}$ data taken with the CLAS detector at Jefferson Lab. A higher-twist analysis of the $Q^{2}$-dependence of the Bjorken Sum yields the twist-4 coefficient $f_{2}^{p-n}=-0.064 \pm0.009\pm_{0.036}^{0.032}$. This leads to the color polarizabilities $\chi_{E}^{p-n}=-0.032\pm0.024$ and $\chi_{B}^{p-n}=0.032\pm0.013$. The strong force coupling is determined to be $\alpha_{s}^{\overline{\mbox{ MS}}}(M_{Z}^{2})=0.1124\pm0.0061$, which has an uncertainty a factor of 1.5 smaller than earlier estimates using polarized DIS data. This improvement makes the comparison between $\alpha_{s}$ extracted from polarized DIS and other techniques a valuable test of QCD. Comment: Published in Phys. Rev. D. V1: 8 pages, 3 figures. V2: Updated references; Included threshold matching in \alpha_s evolution. Corrected a typo on the uncertainty for \Lambda_QCD. V3: Published version |
| Databáze: | arXiv |
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