Improved measurement of the longitudinal spin transfer to Λ and \bar{\Lambda}$ hyperons in polarized proton-proton collisions at $\sqrt{s}$ = 200 GeV at RHIC

04/15/20201: updated polarization values in Figs. 3-4 using PDG 2020 αΛ: UPDATED DATA TABLE

Figure 1:a) The invariant mass distribution for $\Lambda$ and $\bar{\Lambda}$ candidates with 3 < p_T < $ 4 GeV/c in this analysis
mass window Number of Lambda Number of anti-lamdba
1.080 - 1.081 88 106
1.081 - 1.082 105 122
1.082 - 1.083 125 141
1.083 - 1.084 135 167
1.084 - 1.085 141 157
1.085 - 1.086 167 188
1.086 - 1.087 148 217
1.087 - 1.088 208 210
1.088 - 1.089 155 216
1.089 - 1.090 197 227
1.090 - 1.091 216 231
1.091 - 1.092 216 248
1.092 - 1.093 255 272
1.093 - 1.094 233 313
1.094 - 1.095 241 290
1.095 - 1.096 263 281
1.096 - 1.097 302 337
1.097 - 1.098 280 318
1.098 - 1.099 309 363
1.099 - 1.100 285 351
1.100 - 1.101 310 389
1.101 - 1.102 361 378
1.102 - 1.103 321 421
1.103 - 1.104 360 438
1.104 - 1.105 364 477
1.105 - 1.106 372 520
1.106 - 1.107 478 655
1.107 - 1.108 518 733
1.108 - 1.109 627 979
1.109 - 1.110 721 1246
1.110 - 1.111 994 1795
1.111 - 1.112 1484 2662
1.112 - 1.113 2301 4107
1.113 - 1.114 3499 6446
1.114 - 1.115 5320 10371
1.115 - 1.116 7232 14253
1.116 - 1.117 6066 12125
1.117 - 1.118 4134 8237
1.118 - 1.119 2879 5350
1.119 - 1.120 1999 3704
1.120 - 1.121 1480 2502
1.121 - 1.122 1065 1813
1.122 - 1.123 810 1366
1.123 - 1.124 714 1112
1.124 - 1.125 559 852
1.125 - 1.126 530 784
1.126 - 1.127 435 615
1.127 - 1.128 473 566
1.128 - 1.129 393 572
1.129 - 1.130 377 529
1.130 - 1.131 370 512
1.131 - 1.132 379 530
1.132 - 1.133 393 517
1.133 - 1.134 393 527
1.134 - 1.135 374 542
1.135 - 1.136 382 516
1.136 - 1.137 357 499
1.137 - 1.138 373 474
1.138 - 1.139 348 481
1.139 - 1.140 358 437
1.140 - 1.141 341 499
1.141 - 1.142 353 494
1.142 - 1.143 347 481
1.143 - 1.144 371 437
1.144 - 1.145 380 441
1.145 - 1.146 344 435
1.146 - 1.147 355 452
1.147 - 1.148 353 449
1.148 - 1.149 337 460
1.149 - 1.150 339 443
1.150 - 1.151 352 439
1.151 - 1.152 347 410
1.152 - 1.153 330 438
1.153 - 1.154 352 408
1.154 - 1.155 315 386
1.155 - 1.156 312 389
1.156 - 1.157 294 373
1.157 - 1.158 304 368
1.158 - 1.159 297 368
1.159 - 1.160 296 385
Figure 2: The raw spin transfer $D _{LL}^{raw}$ versus cos for a) Λ and b) antiΛ hyperons and c) the spin asymmetry ε_{LL} for the control sample of $K_S^0$ mesons versus cos/theta in the $p_T$ bin of (3,4) GeV/c for JP1 triggered sample. filename=JP1_FitDLL_NE3_lam34.root filename=JP1A_FitDLL_NE3_lam34.root filename=JP1_K0_FitDLL_NE4_lam34.root
cos&thea; bin Lambda DLL^raw for η > 0 Lambda DLL^raw for η < 0 AntiLambda DLL^raw for η > 0 AntiLambda DLL^raw for η < 0 K_S^0 ε_LL for η > 0 K_S^0 ε_LL for η < 0
-1.00 - -0.90 0.058 ± 0.081 -0.049 ± 0.081 0.055 ± 0.060 0.042 ± 0.060 0.020 ± 0.039 -0.000 ± 0.039
-0.90 - -0.80 -0.170 ± 0.082 0.092 ± 0.082 0.010 ± 0.060 0.015 ± 0.060 0.017 ± 0.030 0.006 ± 0.030
-0.80 - -0.70 0.181 ± 0.086 0.154 ± 0.087 0.044 ± 0.063 -0.043 ± 0.063 -0.018 ± 0.052 -0.005 ± 0.052
-0.70 - -0.60 -0.222 ± 0.096 -0.079 ± 0.097 -0.074 ± 0.070 -0.045 ± 0.070 0.141 ± 0.061 -0.064 ± 0.061
-0.60 - -0.50 0.064 ± 0.109 -0.063 ± 0.109 -0.238 ± 0.082 -0.083 ± 0.082 -0.057 ± 0.073 -0.075 ± 0.073
-0.50 - -0.40 -0.093 ± 0.134 0.191 ± 0.134 0.032 ± 0.099 -0.138 ± 0.099 -0.122 ± 0.088 -0.034 ± 0.088
-0.40 - -0.30 -0.112 ± 0.172 -0.250 ± 0.172 -0.189 ± 0.125 -0.115 ± 0.125 -0.046 ± 0.114 0.096 ± 0.114
-0.30 - -0.20 0.155 ± 0.242 -0.195 ± 0.241 0.217 ± 0.176 -0.090 ± 0.176 0.290 ± 0.159 0.116 ± 0.159
-0.20 - -0.10 -0.197 ± 0.394 0.031 ± 0.394 0.094 ± 0.284 0.195 ± 0.284 0.071 ± 0.267 -0.452 ± 0.267
-0.10 - 0.00 -0.616 ± 1.209 -0.466 ± 1.208 -0.890 ± 0.859 0.139 ± 0.859 -0.363 ± 0.795 -0.853 ± 0.795
0.00 - 0.10 -2.451 ± 1.152 0.180 ± 1.154 0.490 ± 0.850 -0.015 ± 0.850 0.712 ± 0.814 0.417 ± 0.814
0.10 - 0.20 -0.040 ± 0.388 0.044 ± 0.388 0.122 ± 0.280 0.219 ± 0.280 0.004 ± 0.267 -0.106 ± 0.267
0.20 - 0.30 -0.037 ± 0.226 -0.490 ± 0.225 -0.044 ± 0.169 -0.013 ± 0.169 -0.245 ± 0.160 0.041 ± 0.161
0.30 - 0.40 0.008 ± 0.168 -0.157 ± 0.168 0.073 ± 0.122 0.004 ± 0.122 -0.099 ± 0.115 0.016 ± 0.115
0.40 - 0.50 0.120 ± 0.137 0.139 ± 0.137 -0.048 ± 0.096 -0.105 ± 0.096 -0.055 ± 0.088 0.044 ± 0.088
0.50 - 0.60 0.021 ± 0.116 0.008 ± 0.116 -0.008 ± 0.080 -0.008 ± 0.080 0.007 ± 0.073 -0.003 ± 0.073
0.60 - 0.70 0.094 ± 0.099 0.021 ± 0.099 0.034 ± 0.070 0.016 ± 0.070 -0.019 ± 0.061 0.074 ± 0.061
0.70 - 0.80 0.161 ± 0.086 -0.075 ± 0.086 -0.068 ± 0.062 -0.114 ± 0.062 -0.012 ± 0.053 0.017 ± 0.053
0.80 - 0.90 -0.078 ± 0.077 0.125 ± 0.077 -0.007 ± 0.055 0.023 ± 0.055 -0.001 ± 0.036 0.024 ± 0.036
0.90 - 1.00 0.063 ± 0.071 0.063 ± 0.071 0.075 ± 0.052 0.028 ± 0.052 0.014 ± 0.043 -0.049 ± 0.043

Figure 3: Comparison of spin transfer $D_{LL}$ for for positive and negative $\eta$ versus $p_T$ for differently triggered samples in the present analysis, together with previously published results in the region of kinematic overlap.

1) Λ η < 0
‹pT› JP1 L2JetHigh Run 5
2.5 -0.001±0.019±0.019 0.007±0.027±0.008 0.013±0.110±0.032
3.5 0.029±0.029±0.006 0.007±0.037±0.005 0.107±0.143±0.038
4.5 -0.026±0.050±0.006 0.005±0.057±0.005 -
6.0 -0.033±0.068±0.009 -0.005±0.067±0.006 -

2) Λ η > 0
‹pT› JP1 L2JetHigh Run 5
2.5 -0.031±0.019±0.020 0.040±0.027±0.008 0.125±0.102±0.031
3.5 0.006±0.029±0.006 -0.015±0.037±0.007 -0.031±0.133±0.035
4.5 -0.024±0.050±0.008 0.008±0.057±0.011 -
6.0 -0.080±0.068±0.012 0.006±0.067±0.014 -

3) anti-Λ η < 0
‹pT› JP1 L2JetHigh Run 5
2.5 0.022±0.013±0.019 -0.047±0.024±0.009 -0.040±0.066±0.023
3.5 -0.021±0.020±0.006 -0.023±0.032±0.005 -0.109±0.085±0.026
4.5 0.007±0.037±0.005 -0.083±0.049±0.007 -
6.0 0.133±0.060±0.011 0.137±0.063±0.010 -

4) anti-Λ η > 0
‹pT› JP1 L2JetHigh Run 5
2.5 -0.005±0.013±0.019 0.002±0.024±0.008 -0.034±0.061±0.020
3.5 0.000±0.020±0.006 0.033±0.032±0.006 -0.120±0.080±0.026
4.5 -0.019±0.037±0.007 -0.061±0.049±0.010 -
6.0 0.082±0.060±0.012 -0.023±0.063±0.014 -

Figure 4: Comparison of spin transfer $D_{LL}$ with model predictions for positive $\eta$ versus $p_T$. The vertical bars and boxes indicate the sizes of the statistical and systematic uncertainties, respectively.

‹pT› Λ anti-Λ
2.5 -0.008±0.015±0.016 -0.003±0.011±0.017
3.5 -0.002±0.022±0.006 0.010±0.016±0.006
4.5 -0.010±0.036±0.009 -0.034±0.028±0.008
6.0 -0.036±0.048±0.013 0.032±0.043±0.013