Global fitting of single spin asymmetry: an attempt
We present an attempt of global analysis of Semi-Inclusive Deep Inelastic Scattering (SIDIS) $$\ell p^\uparrow \to \ell' \pi X$$ data on single spin asymmetries and data on left-right asymmetry $$A_N$$ in $$p^\uparrow p \to \pi X$$ in order to simultaneously extract information on Sivers function and twist-three quark-gluon Efremov-Teryaev-Qiu-Sterman (ETQS) function. We explore different possibilities such as node of Sivers function in $$x$$ or $$k_\perp$$ in order to explain ``sign mismatch'' between these functions. We show that $$\pi^\pm$$ SIDIS data and $$\pi^0$$ STAR data can be well described in a combined TMD and twist-3 fit, however $$\pi^\pm$$ BRAHMS data are not described in a satisfactory way. This leaves open a question to the solution of the ``sign mismatch''. Possible explanations are then discussed.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1053003
- Report Number(s):
- JLAB-THY-12-1497; DOE/OR/23177-2030; arXiv:1201.5427
- Journal Information:
- Phys. Rev. D, Vol. 85, Issue 07
- Country of Publication:
- United States
- Language:
- English
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