CLAS physics database search results Measurement E151M1653 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 138 -0.8362 0.9853 0.0584 0.55 150 0.9724 0.9455 0.0656 0.55 222 -0.4077 0.8779 0.0387 0.65 126 0.3661 0.9799 0.0372 0.65 222 -0.5391 0.9171 0.0441 0.65 234 0.0043 1.0673 0.03 0.75 150 0.0842 0.8806 0.0304 0.75 222 0.0772 0.9663 0.0304 0.75 234 -0.1066 0.9869 0.0307 0.75 246 -0.9466 0.8102 0.0642 0.85 138 -0.7085 0.9319 0.052 0.85 234 -0.4419 0.8476 0.04 0.85 246 0.3219 0.8568 0.0357 0.55 234 0.1507 1.2447 0.0313 0.65 222 0.7569 1.1684 0.0533 0.65 234 -2.2372 0.8836 0.1335 0.75 150 1.6998 1.2495 0.1033 0.75 234 1.6445 0.9752 0.1002 0.75 246 -0.8126 0.8938 0.056 0.85 222 0.8259 0.9256 0.0566 0.85 234 -0.7214 1.2069 0.0516 0.85 246 -1.6418 0.7495 0.1001