CLAS physics database search results Measurement E151M1453 EG4 Xiaochao Zheng 2016 cos(theta_pi+) phi(pi+) A_LL Stat. error Syst. error degrees 0.55 270 -0.6105 0.852 0.0465 0.55 294 -0.3528 0.7811 0.0363 0.65 282 0.3892 0.8282 0.0376 0.75 270 -1.4981 0.563 0.0921 0.75 282 -0.0193 0.8001 0.03 0.85 90 1.1399 0.9093 0.0728 0.85 102 -0.9965 0.8959 0.0652 0.85 126 -0.1815 0.9646 0.0318 0.85 306 -0.4811 0.8151 0.041 0.95 138 0.2964 0.7501 0.0346 0.35 282 -0.4286 0.6956 0.0395 0.45 270 -0.4415 0.6124 0.04 0.45 282 0.2098 0.7103 0.0325 0.45 294 -0.5743 0.614 0.0457 0.55 282 -0.7326 0.6586 0.0532 0.65 282 -0.3999 0.7006 0.0384 0.75 258 -0.6361 0.7464 0.0485 0.75 282 0.1837 0.6557 0.032 0.85 126 0.0522 0.6966 0.0302