Measurement of the longitudinal spin transfer to and $\bar{\varLambda}$ hyperons in polarised muon DIS

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2009-11, Vol.64 (2), p.171-179
• Main Authors: Alexakhin, VYu, Alexandrov, Yu, Austregesilo, A, Baum, G, Bedfer, Y, Bernhard, J, Bertini, R, Bettinelli, M, Bordalo, P, Bravar, A, Brona, G, Burtin, E, Chiosso, M, Colantoni, M, Crespo, M L, Das, S, Dhara, L, Dinkelbach, A M, Donskov, S V, Doshita, N, Duic, V, Duennweber, W, Efremov, A, Eversheim, P D, Finger, M, Gautheron, F, Gazda, R, Gerassimov, S, Geyer, R, Giorgi, M, Gobbo, B, Grabmueller, S, Guskov, A, Harrach, Dvon, Hoeppner, Ch, Ishimoto, S, Jahn, R, Jasinski, P, Kang, D, Ketzer, B, Kisselev, Yu, Klein, F, Kolosov, V N, Koenigsmann, K, Kotzinian, A M, Kraemer, M, Kroumchtein, Z V, Kurek, K, Le Goff, JM, Lednev, A A, Lichtenstadt, J, Liska, T, Maggiora, M, Mallot, G K, Marzec, J, Matsuda, T, Moinester, MA, Nagaytsev, A, Nagel, T, Nassalski, J, Neubert, S, Neyret, D, Padee, A, Paul, S, Pesaro, G, Peshekhonov, D V, Piragino, G, Platchkov, S, Pochodzalla, J, Pretz, J, Rapatsky, V, Reicherz, G, Reggiani, D, Richter, A, Rondio, E, Sapozhnikov, M G, Sarkar, S, Schiavon, P, Schmitt, L, Schroeder, W, Siebert, H-W, Sinha, L, Smirnov, GI, Sozzi, F, Srnka, A, Stolarski, M, Sulc, M, Takekawa, S, Tessaro, S, Tessarotto, F, Teufel, A, Virius, M, Vlassov, N V, Vossen, A, Weitzel, Q, Zaremba, K, Ziembicki, M, Zhao, J, Zhuravlev, N, Zvyagin, A
• Format: Article
• Language: English
• Subjects: CERN; Compatibility; Frames; Hyperons; Magnetic properties; Mathematical models; Muons; Particle spin
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-009-1143-7

The longitudinal polarisation transfer from muons to and $\bar{\varLambda}$ hyperons, $D_{\varLambda(\bar{\varLambda})}$ , has been studied in deep-inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The spin transfers to and $\bar{\varLambda}$ produced in the current fragmentation region exhibit different behaviours as a function of x and x sub(F ). The measured x and x sub(F )dependences of D sub(LL ) super( )are compatible with zero, while $D_{\bar{\varLambda}}$ tends to increase with x sub(F ), reaching values of 0.4-0.5. The resulting average values are D sub(LL ) super( )= -0.012c0.047c0.024 and $D_{\bar{\varLambda}}$ = 0.249c0.056c0.049. These results are discussed in the frame of recent model calculations.