Measurement of the polarization of the Xi(0) ((Xi(0))over-bar) hyperon beam by the NA48/1 experiment

Batley, J. R.; Kalmus, G. E.; Lazzeroni, C.; Munday, D. J.; Patel, M.; Slater, M. W.; Wotton, S. A.; Arcidiacono, R.; Bocquet, G.; Ceccucci, A.; Cundy, D.; Doble, N.; Falaleev, V.; Gatignon, L.; Gonidec, A.; Grafstrom, P.; Kubischta, W.; Mikulec, I.; Norton, A.; Panzer Steindel, B.; Rubin, P.; Wahl, H.; Goudzovski, E.; Hristov, R.; Kekelidze, V.; Litov, L.; Madigozhin, D.; Molokanova, N.; Potrebenikov, Y.; Stoynev, S.; Zinchenko, A.; Monnier, E.; Swallow, E.; Winston, R.; Sacco, R.; Walker, A.; Baldini, W.; Gianoli, A.; Dalpiaz, P.; Frabetti, P. L.; Martini, M.; Petrucci, F.; Savrie, M.; Scarpa, M.; Calvetti, M.; Collazuol, Gianmaria; Iacopini, E.; Ruggiero, G.; Bizzeti, A.; Lenti, M.; Veltri, M.; Behler, M.; Eppard, K.; Eppard, M.; Hirstius, A.; Kleinknecht, K.; Koch, U.; Marouelli, P.; Masetti, L.; Moosbrugger, U.; Morales, C. M.; Peters, A.; Wanke, R.; Winhart, A.; Dabrowski, A.; Martin, T. F.; Velasco, M.; Cenci, P.; Lubrano, P.; Pepe, M.; Anzivino, G.; Imbergamo, E.; Lamanna, G.; Michetti, A.; Nappi, A.; Petrucci, M. C.; Piccini, M.; Valdata, M.; Cerri, C.; Fantechi, R.; Costantini, F.; Fiorini, L.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Mannelli, I.; Cheshkov, C.; Cheze, J. B.; Beer, M. D.; Debu, P.; Gouge, G.; Marel, G.; Mazzucato, E.; Peyaud, B.; Vallage, B.; Holder, M.; Maier, A.; Ziolkowski, M.; Biino, C.; Cartiglia, N.; Marchetto, F.; Pastrone, N.; Clemencic, M.; Lopez, S. G.; Menichetti, E.; Wislicki, W.; Dibon, H.; Jeitler, M.; Markytan, M.; Neuhofer, G.; Widhalm, L.

doi:10.1016/j.physletb.2009.10.054

A total of 368415 Xi(0) --> Lambda Xi(0) and 31 171 (Xi(0)) over bar --> (Lambda) over bar pi(0) were selected from data recorded in the NA48/1 experiment during 2002 data taking. From this sample, the polarization of Xi(0) and (Xi(0)) over bar hyperons was measured to be P-Xi 0 = -0.102 +/- 0.012(stat) +/- 0.008(syst) and P-(Xi 0) over bar = -0.01 +/- 0.04(stat) 0.008(syst). The dependence of P-Xi 0 on the Xi(0) transverse momentum with respect to the primary proton beam is also presented. With the same data sample. the ratio of (Xi(0)) over bar and Xi(0) fluxes in proton collisions at 400 GeV/c oil a beryllium target was measured. (C) 2009 Elsevier B.V. All rights reserved.