First measurement of Ξ− polarization in photoproduction

Bono, J. et al. (2018) First measurement of Ξ− polarization in photoproduction. Physics Letters B, 783, pp. 280-286. (doi: 10.1016/j.physletb.2018.07.004)

Abstract

Despite decades of studies of the photoproduction of hyperons, both their production mechanisms and their spectra of excited states are still largely unknown. While the parity-violating weak decay of hyperons offers a means of measuring their polarization, which could help discern their production mechanisms and identify their excitation spectra, no such study has been possible for doubly strange baryons in photoproduction, due to low production cross sections. However, by making use of the reaction γ p → K + K +−, we have measured, for the first time, the induced polarization, P, and the transferred polarization from circularly polarized real photons, characterized by Cx and Cz , to recoiling −s. The data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab for photon energies from just over threshold (2.4 GeV) to 5.45 GeV. These first-time measurements are compared, and are shown to broadly agree, with model predictions in which cascade photoproduction proceeds through the decay of intermediate hyperon resonances that are produced via relativistic meson exchange, offering a new step forward in the understanding of the production and polarization of doublystrange baryons.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sokhan, Dr Daria and Glazier, Dr Derek and Protopopescu, Dr Dan and MacGregor, Professor Douglas and McKinnon, Dr Bryan and Livingston, Dr Kenneth and Montgomery, Dr Rachel and Ireland, Professor David and Rosner, Professor Guenther
• Authors: Bono, J., Guo, L., Raue, B.A., Adhikari, S., Kunkel, M.C., Adhikari, K.P., Akbar, Z., Amaryan, M.J., Ball, J., Barion, L., Bashkanov, M., Battaglieri, M., Batourine, V., Bedlinskiy, I., Biselli, A.S., Brooks, W.K., Burkert, V.D., Cao, F., Carman, D.S., Celentano, A., Charles, G., Chetry, T., Ciullo, G., Clary, B. A., Cole, P.L., Contalbrigo, M., Crede, V., D'Angelo, A., Dashyan, N., De Vita, R., Defurne, M., Deur, A., Diehl, S., Djalali, C., Dugger, M., Egiyan, H., El Alaoui, A., El Fassi, L., Eugenio, P., Fedotov, G., Filippi, A., Fradi, A., Gavalian, G., Gevorgyan, N., Ghandilyan, Y., Girod, F.X., Glazier, D.I., Gohn, W., Golovatch, E., Gothe, R.W., Griffioen, K.A., Hafidi, K., Harrison, N., Hattawy, M., Heddle, D., Hicks, K., Holtrop, M., Ilieva, Y., Ireland, D.G., Isupov, E.L., Jo, H.S., Johnston, S., Kabir, M.L., Keller, D., Khachatryan, G., Khachatryan, M., Khandaker, M., Kim, A., Kim, W., Klein, A., Klein, F.J., Kubarovsky, V., Lenisa, P., Livingston, K., MacGregor, I.J.D., Markov, N., McKinnon, B., Mineeva, T., Montgomery, R.A., Munoz Camacho, C., Niculescu, G., Osipenko, M., Ostrovidov, A.I., Paolone, M., Paremuzyan, R., Park, K., Pasyuk, E., Phelps, W., Pogorelko, O., Price, J.W., Prok, Y., Protopopescu, D., Ripani, M., Rizzo, A., Rosner, G., Sabatié, F., Salgado, C., Schumacher, R.A., Sharabian, Y., Skorodumina, I., Smith, G.D., Sokhan, D., Sparveris, N., Stepanyan, S., Strakovsky, I.I., Strauch, S., Taiuti, M., Tan, J.A., Ungaro, M., Voskanyan, H., Voutier, E., Wang, R., Wei, X., Wood, M.H., Zachariou, N., Zana, L., Zhang, J., and Zhao, Z.W.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Physics Letters B
• Publisher: Elsevier
• ISSN: 0370-2693
• ISSN (Online): 1873-2445
• Published Online: 09 July 2018
• Copyright Holders: Copyright © 2018 The Authors
• First Published: First published in Physics Letters B 783: 280-286
• Publisher Policy: Reproduced under a Creative Commons License