Dear All,

We have the pleasure of inviting you to the Particle Theory Seminar on Tuesday, November 21  at 12:15, which will be given by

Sanjin Benić (University of Zagreb)

entitled

„ Odderon at the EIC from exclusive production of C-even charmonia".

Abstact:

Recently, TOTEM and D0 collaborations announced the discovery of the odderon in the pp vs ppbar elastic cross section difference [1,2]. Our main goal here is to investigate the  potential  for  the  odderon  detection  at  the  future  EIC.  This  talk  is  focused  on  our recent  computation  [3,4]  of  exclusive  C-even  charmonia  productions  in  high-energy electron-proton collisions. The C-even charmonia states serve as a probe of the odderon amplitude  in  the  proton  which  is  an  off-forward  generalized  transverse  momentum distribution formed by at least three gluons in a C-odd state. The computation is based on the Color Glass Condensate framework, where we numerically solve the Balitsky- Kovchegov evolution equation for coupled pomeron-odderon system. Our initial conditions are based on a microscopic quark model computation [5] that is an essential ingredient  for  a  proper  account  of  the  so-called  Donnachie-Landshoff  mechanism according to which even a large-|t| scattering would not break up the proton if it involves a three-gluon exchange. Our comprehensive  results cover the exclusive production of the eta_c meson [4] and the chi_cJ family (J = 0, 1, 2) [3]. While eta_c was originally suggested already long time ago [6], chi_c was not discussed so far. Due to the large branching ratio to J\Psi+gamma we argue that chi_c should be a more suitable channel for  the  potential  odderon  detection  at  the  EIC.  In  our  computation  we  pay  special attention to the interference with the Primakoff process where our model computation fixes  the  relative  phase  between  the  two  contributions.  We  demonstrate  how  the deviations from the purely Primakoff contribution can be used as a probe of the odderon amplitude in the proton at the EIC.

[1] TOTEM collaboration, Eur. Phys. J. C 80, 91 (2020) [2] D0 collaboration, Phys. Rev. D 86, 012009 (2012) [3] SB, A. Dumitru, A. Kaushik, L. Motyka, T. Stebel, in preparation [4] SB, D. Horvatic, A. Kaushik, E. A. Vivoda, Phys. Rev. D 108 (2023) 7, 074005 [5] A. Dumitru, H. Mantysaari, R. Paatelainen, Phys. Rev. D 107, L011501 (2023) [6]  J.  Czyzewski,  J.  Kwiecinski,  L.  Motyka,  and  M.  Sadzikowski,  Phys.  Lett.  B  398, 400 (1997)

The speaker will be on-site, local participants are invited to meet in the seminar room D-2-02.