TY  - GEN
Y1  - 2002///
TI  - Measurement of inclusive Lambda / Antilambda hyperon polarisation in proton nucleus collisions at 920 GeV proton beam energy
N2  - A minimum bias dataset was analysed for transverse hyperon polarisation in p + A -> Lambda / Antilambda + X events. The data were taken in the commissioning phase of the HERA-B detector at HERA, DESY, using the proton beam of 920 GeV energy to collide with fixed target wires of different materials.  A sample of approximately 2900 Lambdas was obtained in a kinematical region  of transverse momentum p_t in [0.2,2.2] GeV/c and Feynman variable x_F in [-0.19,0.03] and roughly 1350 Antilambdas were found in the range of p_t in [0.12,1.64] GeV/c and x_F in [-0.13,0.01].  These samples were analysed for transverse polarisation using extensive Monte Carlo studies for acceptance determination, yielding: Pol(Lambda)    : 0.073 +/- 0.073 (stat) +/-  0.0095 (syst) Pol(Antilambda): 0.006 +/- 0.129 (stat) +/-  0.0381 (syst). The found result is compatible with the only other inclusive measurement that is available at x_F < 0. Concluding, the possible significant contribution to the field of hyperon polarisation physics of the HERA-B spectrometer due to its unique kinematical range and possibility to study A dependencies is pointed out.
AV  - public
A1  - Pleier, Marc-André
ID  - heidok2292
KW  - Hyperon-PolarisationHERA-B detector 
KW  -  proton nucleus collisions 
KW  -  lambda hyperon 
KW  -  hyperon polarisation
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/2292/
ER  -