Transverse polarization of Λ and Λ¯ hyperons in quasireal photoproduction

Airapetian, A. et al. (2007) Transverse polarization of Λ and Λ¯ hyperons in quasireal photoproduction. Physical Review D, 76(9), Art. 092008. (doi: 10.1103/PhysRevD.76.092008)

Abstract

The HERMES experiment has measured the transverse polarization of Λ and Λ̅ hyperons produced inclusively in quasireal photoproduction at a positron beam energy of 27.6 GeV. The transverse polarization PnΛ of the Λ hyperon is found to be positive while the observed Λ̅ polarization is compatible with zero. The values averaged over the kinematic acceptance of HERMES are PnΛ=0.078±0.006(stat)±0.012(syst) and PnΛ̅ =-0.025±0.015(stat)±0.018(syst) for Λ and Λ̅ , respectively. The dependences of PnΛ and PnΛ̅ on the fraction ζ of the beam’s light-cone momentum carried by the hyperon and on the hyperon’s transverse momentum pT were investigated. The measured Λ polarization rises linearly with pT and exhibits a different behavior for low and high values of ζ, which approximately correspond to the backward and forward regions in the center-of-mass frame of the γ*N reaction.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kaiser, Professor Ralf and Seitz, Dr Bjoern and Rosner, Professor Guenther
• Authors: Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V., Andrus, A., Aschenauer, E., Augustyniak, W., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Baturin, V., Baumgarten, C., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Blok, H., Böttcher, H., Borissov, A., Bouwhuis, M., Brack, J., Brüll, A., Brunn, I., Capitani, G., Chiang, H., Ciullo, G., Contalbrigo, M., Court, G., Dalpiaz, P., De Leo, R., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Düren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Ely, J., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Fox, B., Franz, J., Frullani, S., Gärber, Y., Gapienko, G., Gapienko, V., Garibaldi, F., Garutti, E., Gaskell, D., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Greeniaus, L., Haeberli, W., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W., Hillenbrand, A., Holler, Y., Hommez, B., Iarygin, G., Izotov, A., Jackson, H., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Königsmann, K., Kolster, H., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V., Lagamba, L., Lapikás, L., Laziev, A., Lenisa, P., Liebing, P., Lindemann, T., Lipka, K., Lorenzon, W., Makins, N., Marukyan, H., Masoli, F., Menden, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Nowak, W.-D., Oganessyan, K., Ohsuga, H., Orlandi, G., Potashov, S., Potterveld, D., Raithel, M., Reggiani, D., Reimer, P., Reischl, A., Reolon, A., Rith, K., Rosner, G., Rostomyan, A., Ryckbosch, D., Sanjiev, I., Savin, I., Scarlett, C., Schäfer, A., Schill, C., Schnell, G., Schüler, K., Schwind, A., Seibert, J., Seitz, B., Shanidze, R., Shibata, T.-A., Shutov, V., Simani, M., Sinram, K., Stancari, M., Statera, M., Steffens, E., Steijger, J., Stewart, J., Stösslein, U., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tessarin, S., Thomas, E., Tkabladze, A., Trzcinski, A., Tytgat, M., Urciuoli, G., van der Nat, P., van der Steenhoven, G., van de Vyver, R., Veretennikov, D., Vetterli, M., Vikhrov, V., Vincter, M., Visser, J., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Wise, T., Yen, S., Yoneyama, S., Zihlmann, B., Zohrabian, H., and Zupranski, P.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review D
• Publisher: American Physical Society
• ISSN: 1550-7998
• ISSN (Online): 1550-2368