phi photo-production from Li, C, Al, and Cu nuclei at Egamma=1.5 - 2.4 GeV
arXiv:nucl-ex/0411016 · doi:10.1016/j.physletb.2005.01.023
Abstract
The photo-production of $Ï$ mesons from Li, C, Al, and Cu at forward angles has been measured at $E_gamma$=1.5--2.4 GeV. The number of events for incoherent phi photo-production is found to have a target mass number dependence of $A^{0.72\pm 0.07}$ in the kinematical region of $|t|\le 0.6$ ${\rm GeV}^2/c^2$. The total cross section of the $Ï$-nucleon interaction, $Ï_{ÏN}$, has been estimated as $35^{+17}_{-11}$ mb using the $A$-dependence of the $Ï$ photo-production yield and a Glauber-type multiple scattering theory. This value is much larger than $Ï_{ÏN}$ in free space, suggesting that the $Ï$ properties might change in the nuclear medium.
12 pages 4 figures, submitted to Phys. Lett. B