Search for Odderon induced contributions to exclusive Meson Photoproduction at HERA

Abstract

Odderon induced contributions to exclusive photoproduction of ${\pi }^{\circ }$, $f_2(1270)$ and $a_2(1320)$ have been searched for at HERA, using the multiphoton decays of these mesons. No indication for such contributions was found, in a kinematic region defined by the average photon-proton centre-of-mass energy $<W>=200-215$ GeV, photon virtualities $Q^2<0.01$GeV${}^2$ and $0.02$GeV${}^2<|t|<0.3$GeV${}^2$, where t is the squared momentum transfer at the proton vertex. The measured upper limits for the cross sections, $\sigma (\gamma p{\to }^{\mathbb{O}}{\pi }^{\circ }{N}^{\ast })<39$ nb, $\sigma (\gamma p{\to }^{\mathbb{O}}{f}_2(1270)X)<16$ nb and $\sigma (\gamma p{\to }^{\mathbb{O}}{a}_2(1320)X)<96$ nb, all at 95% CL, are lower than the predictions by a theoretical model. Exclusive photoproduction of $\omega$ and $\omega {\pi }^{\circ }$, in the $3\gamma$ and $5\gamma$ decay modes, is observed with the expected cross sections.

9 pages, 7 figures (requires amssymb and epsfig); Talk presented in the Intern. Conference on New Trends in High Energy Physics, 22-29.9.2001, Yalta, Crimea, Ukraine; To appear in the Proceedings

Cited by in corpus (3)

• The Odderon in High Energy Elastic pp Scattering
• Searching for the Odderon in Ultraperipheral Proton--Ion Collisions at the LHC
• The Odderon: Theoretical Status and Experimental Tests