Hard exclusive electroproduction of π⁺π^-pairs

Airapetian, A. et al. (2004) Hard exclusive electroproduction of π⁺π^-pairs. Physics Letters B, 599(3-4), pp. 212-222. (doi: 10.1016/j.physletb.2004.08.059)

Abstract

Hard exclusive electroproduction of pi(+) pi(-) pairs off hydrogen and deuterium targets has been studied by the HERMES experiment at DESY Legendre moments (P-1) and (P-3) of the angular distributions of pi(+) mesons in the center-of-mass frame of the pair have been measured for the first time. Their dependence on the pi(+) pi(-) invariant mass can be understood as being due to the interference between relative P-wave (isovector) and S-, D-wave (isoscalar) states of the two pions. The increase in magnitude of (P-1) as Bjorken x increases is interpreted in the framework of generalized parton distributions as an enhancement of flavour non-singlet qq exchange for larger values of x, which leads to a sizable admixture of isoscalar and isovector pion pairs. In addition, the interference between P-wave and D-wave states separately for transverse and longitudinal pion pairs has been studied. The data indicate that in the f(2)(1270) region at [Q(2)] = 3 GeV2 higher-twist effects can be as large as the leading-twist longitudinal component.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Shearer, Dr Craig and Rosner, Professor Guenther
• Authors: Airapetian, A., Akopov, N., Akopov, Z., Amarian, M., Ammosov, V.V., Andrus, A., Aschenauer, E.C., Augustyniak, W., Avakian, R., Avetissian, A., Avetissian, E., Bailey, P., Balin, D., Baturin, V., Beckmann, M., Belostotski, S., Bernreuther, S., Bianchi, N., Blok, H.P., Bottcher, H., Borissov, A., Borysenko, A., Bouwhuis, M., Brack, J., Brull, A., Bryzgalov, V., Capitani, G.P., Chen, T., Ciullo, G., Contalbrigo, M., Dalpiaz, P.F., De Leo, R., Demey, M., De Nardo, L., De Sanctis, E., Devitsin, E., Di Nezza, P., Duren, M., Ehrenfried, M., Elalaoui-Moulay, A., Elbakian, G., Ellinghaus, F., Elschenbroich, U., Fabbri, R., Fantoni, A., Fechtchenko, A., Felawka, L., Frullani, S., Gapienko, G., Gapienko, V., Garibaldi, F., Garrow, K., Garutti, E., Gavrilov, G., Gharibyan, V., Graw, G., Grebeniouk, O., Greeniaus, L.G., Gregor, I.M., Griffioen, K.A., Hafidi, K., Hartig, M., Hasch, D., Heesbeen, D., Henoch, M., Hertenberger, R., Hesselink, W.H.A., Hillenbrand, A., Hoek, M., Holler, Y., Hommez, B., Iarygin, G., Ivanilov, A., Izotov, A., Jackson, H.E., Jgoun, A., Kaiser, R., Kinney, E., Kisselev, A., Kopytin, M., Korotkov, V., Kozlov, V., Krauss, B., Krivokhijine, V.G., Lagamba, L., Lapikas, L., Laziev, A., Lenisa, P., Liebing, P., Linden-Levy, L.A., Lipka, K., Lorenzon, W., Lu, H., Lu, J., Lu, S., Ma, B.Q., Maiheu, B., Makins, N.C.R., Mao, Y., Marianski, B., Marukyan, H., Masoli, F., Mexner, V., Meyners, N., Mikloukho, O., Miller, C.A., Miyachi, Y., Muccifora, V., Nagaitsev, A., Nappi, E., Naryshkin, Y., Nass, A., Negodaev, M., Nowak, W.D., Oganessyan, K., Ohsuga, H., Osborne, A., Pickert, N., Potashov, S., Potterveld, D.H., Raithel, M., Reggiani, D., Reimer, P.E., Reischl, A., Reolon, A.R., Riedl, C., Rith, K., Rosner, G., Rostomyan, A., Rubacek, L., Rubin, J., Ryckbosch, D., Salomatin, Y., Sanjiev, I., Savin, I., Schafer, A., Schill, C., Schnell, G., Schuler, K., Seele, J., Seidl, R., Seitz, B., Shanidze, R., Shearer, C., Shibata, T., Shutov, V., Sinram, K., Sommer, W., Stancari, M., Statera, M., Steffens, E., Steijger, J.J., Stenzel, H., Stewart, J., Stinzing, F., Tait, P., Tanaka, H., Taroian, S., Tchuiko, B., Terkulov, A., Tkabladze, A., Trzcinski, A., Tytgat, M., Vandenbroucke, A., van der Nat, P., van der Steenhoven, G., van Haarlem, Y., Vetterli, M., Vikhrov, V., Vincter, M., Vogel, C., Vogt, M., Volmer, J., Weiskopf, C., Wendland, J., Wilbert, J., Smit, G., Ye, Y., Ye, Z., Yen, S., Zihlmann, B., and Zupranski, P.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physics Letters B
• Publisher: Elsevier BV
• ISSN: 0370-2693
• ISSN (Online): 1873-2445