Speaker
Description
Exclusive $\chi_c$ production is sensitive to the C-odd colorless tri-gluon correlation in the $t$-channel - the long sought Odderon. While a non-perturbative C-odd compound has been recently discovered through elastic $pp$ collisions [1], however, Odderon escaped the direct detections at HERA. At the EIC and the EIcC, the high luminosity can counteract the feeble Odderon amplitude. Using the high energy light-cone approach we compute the amplitude and the cross section for $\chi_{c0}$, $\chi_{c1}$ and $\chi_{c2}$ production. We find an excess above the Primakoff background as well as the characteristically slow falling t-distribution, predicting about a dozen events per month should be seen at the EIC. In the low-$t$ region a contribution from the spin dependent Odderon is revealed that is closely related to the gluon Sivers function [3]: one of the main targets at the future EIC and EIcC. Focusing on axial vector $\chi_{c1}$, where the Coulomb tail (~1/|t|) of the Primakoff process is screened (Landau-Yang theorem), the spin dependent Odderon can be directly probed in unpolarized $\gamma+p$ collisions. The two contributions (spin dependent Odderon and photon) can be disentangled by accessing the $\chi_{c1}$ polarization via the angular distribution of its decay products revealing another potential signature for the Odderon at the EIC.
