Differential cross sections and recoil polarizations for the reaction $\gamma p\to K^{+}{\Sigma }^0$

Journal Article · Fri Aug 06 04:00:00 UTC 2010 · Physical Review C, Nuclear Physics

DOI: https://doi.org/10.1103/PhysRevC.82.025202 · OSTI ID:986375

Dey, B.; Meyer, C. A.; Bellis, M.; McCracken, M. E.; Williams, M.; Adhikari, K. P.; Aghasyan, M.; Anghinolfi, M.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Berman, B. L.; Biselli, A. S.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Crede, V. ; D’Angelo, A.; Daniel, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Dhamija, S.; Dickson, R.; Djalali, C.; Doughty, D.; Dugger, M.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Eugenio, P.; Fegan, S.; Fradi, A.; Gabrielyan, M. Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Hassall, N.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Jawalkar, S. S.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Konczykowski, P.; Kubarovsky, V.; Kuleshov, S. V.; Kuznetsov, V.; Livingston, K.; MacGregor, I. J. D.; Martinez, D.; McAndrew, J.; McKinnon, B.; Mikhailov, K.; Mirazita, M.; Mokeev, V.; Moreno, B.; Moriya, K.; Morrison, B.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Nasseripour, R.; Nepali, C. S.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niroula, M. R.; Osipenko, M.; Ostrovidov, A. I.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Pereira, S. Anefalos; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Salamanca, J.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Strakovsky, I. I.; Strauch, S.; Tang, W.; Taylor, C. E.; Tedeschi, D. J.; Tkachenko, S.; Ungaro, M.; Watts, D. P.; Vernarsky, B.; Vineyard, M. F.; Voutier, E.; Weinstein, L. B.; Wood, M. H.; Yegneswaran, A.; Zhang, J.; Zhao, B.; Zhao, Z. W.

Here, high-statistics measurements of differential cross sections and recoil polarizations for the reaction $$\gamma p \rightarrow K^+ \Sigma^0$$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($$\sqrt{s}$$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K^+$ production angle. Independent measurements were made using the $$K^{+}p\pi^{-}$$($$\gamma$$) and $$K^{+}p$$($$\pi^-,\gamma$$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $$\sqrt{s}$$ coverage. Above $$\sqrt{s} \approx 2.5$$ GeV, $$t$$- and $$u$$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($$P_\Sigma$$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $$P_\Sigma$$ is of the same magnitude but opposite sign as $$P_\Lambda$$, in agreement with the static SU(6) quark model prediction of $$P_\Sigma \approx -P_\Lambda$$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $$P_\Sigma$$ and $$P_\Lambda$$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
• Grant/Contract Number: AC05-06OR23177
• OSTI ID: 986375
• Report Number(s): JLAB-PHY--10-1183; DOE/OR/23177--1223; arXiv:1006.0374
• Journal Information: Physical Review C, Nuclear Physics, Journal Name: Physical Review C, Nuclear Physics Journal Issue: 2 Vol. 82; ISSN 0556-2813; ISSN PRVCAN
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English