Measurement of the N ->Delta (+)(1232) transition at high-momentum transfer by pi(0) electroproduction

Ungaro, M. et al. (2006) Measurement of the N ->Delta (+)(1232) transition at high-momentum transfer by pi(0) electroproduction. Physical Review Letters, 97(11), (doi: 10.1103/PhysRevLett.97.112003)

Abstract

We report a new measurement of the exclusive electroproduction reaction gamma(*)p ->pi(0)p to explore the evolution from soft nonperturbative physics to hard processes via the Q(2) dependence of the magnetic (M1+), electric (E1+), and scalar (S1+) multipoles in the N ->Delta transition. 9000 differential cross section data points cover W from threshold to 1.4 GeV/c(2), 4 pi center-of-mass solid angle, and Q(2) from 3 to 6 GeV2/c(2), the highest yet achieved. It is found that the magnetic form factor G(M)(*) decreases with Q(2) more steeply than the proton magnetic form factor, the ratio E1+/M1+ is small and negative, indicating strong helicity nonconservation, and the ratio S1+/M1+ is negative, while its magnitude increases with Q(2).

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Protopopescu, Dr Dan
• Authors: Ungaro, M., Stoler, P., Aznauryan, I., Burkert, V. D., Joo, K., Smith, L. C., Adams, G., Amarian, M., Ambrozewicz, P., Anghinolfi, M., Asryan, G., Audit, G., Avakian, H., Bagdasaryan, H., Ball, J. P., Baltzell, N. A., Barrow, S., Batourine, V., Battaglieri, M., Bedliski, I., Bektasoglu, M., Bellis, M., Benmouna, N., Berman, B. L., Biselli, A. S., Bonner, B. E., Bouchigny, S., Boiarinov, S., Bradford, R., Branford, D., Briscoe, W. J., Brooks, W. K., Bultmann, S., Butuceanu, C., Calarco, J. R., Careccia, S. L., Carman, D. S., Cazes, A., Chen, S., Cole, P. L., Coltharp, P., Cords, D., Corvisiero, P., Crabb, D., Cummings, J. P., De Sanctis, E., DeVita, R., Degtyarenko, P. V., Denizli, H., Dennis, L., Deur, A., Dharmawardane, K. V., Djalali, C., Dodge, G. E., Donnelly, J., Doughty, D., Dugger, M., Dytman, S., Dzyubak, O. P., Egiyan, H., Egiyan, K. S., Elouadrhiri, L., Eugenio, P., Fatemi, R., Fedotov, G., Feldman, G., Feuerbach, R. J., Funsten, H., Garcon, M., Gavalian, G., Gilfoyle, G. P., Giovanetti, K. L., Girod, F. X., Goetz, J., Gordon, C. I. O., Gothe, R. W., Griffioen, K. A., Guidal, M., Guillo, M., Guler, N., Guo, L., Gyurjyan, V., Hadjidakis, C., Hakobyan, R. S., Hardie, J., Heddle, D., Hersman, F. W., Hleiqawi, I., Holtrop, M., Hicks, K., Hyde-Wright, C. E., Ilieva, Y., Ireland, D. G., Ishkhanov, B. S., Ito, M. M., Jenkins, D., Jo, H. S., Juengst, H. G., Kellie, J. D., Khandaker, M., Kim, W., Klein, A., Klein, F. J., Klimenko, A. V., Kossov, M., Kramer, L. H., Kubarovsky, V., Kuhn, J., Kuhn, S. E., Lachniet, J., Laget, J. M., Langheinrich, J., Lawrence, D., Lee, T., Li, J., Livingston, K., Marchand, C., Markov, N., McAleer, S., McKinnon, B., McNabb, J. W. C., Mecking, B. A., Mehrabyan, S., Melone, J. J., Mestayer, M. D., Meyer, C. A., Mikhailov, K., Minehart, R., Mirazita, M., Miskimen, R., Mokeev, V., Morand, L., Morrow, S. A., Mueller, J., Mutchler, G. S., Napolitano, J., Nasseripour, R., Niccolai, S., Niculescu, G., Niculescu, I., Niczyporuk, B. B., Niroula, M., Niyazov, R. A., Nozar, M., O'Rielly, G. V., Osipenko, M., Ostrovidov, A. I., Park, K., Pasyuk, E., Philips, S. A., Pivnyuk, N., Pocanic, D., Pogorelko, O., Polli, E., Pozdniakov, S., Preedom, B. M., Price, J. W., Prok, Y., Protopopescu, D., Qin, L. M., Raue, B. A., Riccardi, G., Ricco, G., Ripani, M., Ritchie, B. G., Ronchetti, F., Rosner, G., Rossi, P., Rubin, P. D., Sabatie, F., Salgado, C., Santoro, J. P., Sapunenko, V., Schumacher, R. A., Serov, V. S., Sharabian, Y. G., Skabelin, A. V., Smith, E. S., Sober, D. I., Stavinsky, A., Stepanyan, S. S., Stepanyan, S., Stokes, B. E., Strakovsky, I. I., Strauch, S., Taiuti, M., Tedeschi, D. J., Thoma, U., Tkabladze, A., Todor, L., Tkachenko, S., Tur, C., Vineyard, M. F., Vlassov, A. V., Weinstein, L. B., Weygand, D. P., Williams, M., Wolin, E., Wood, M. H., Yegneswaran, A., Zana, L., Zhang, B., Zhang, J., and Zhao, B.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114