<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi></mml:math> near threshold in holographic QCD: <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>A</mml:mi></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>D</mml:mi></mml:math> gravitational form factors
Kiminad A. Mamo, Ismaïl Zahed
Abstract
The diffractive photoproduction of $J/\mathrm{\ensuremath{\Psi}}$ on a nucleon is mostly due to gluonic exchanges at all $\sqrt{s}$. In holographic QCD (large number of colors and strong ${\text{ }}^{\ensuremath{'}}\mathrm{t}$ Hooft coupling), these exchanges are captured by gravitons near threshold, and their reggeized form (Pomeron) asymptotically. We revisit our holographic analysis of the $A$ and $D$ gravitational form factors in light of the new lattice data, and use them to refine our predictions for the photoproduction of $J/\mathrm{\ensuremath{\Psi}}$ near threshold, and the comparison to the GlueX data. We use these results to estimate the scalar and mass radii of the nucleon, and describe the gravitational pressure and shear across a nucleon.