English

Chromoelectric and chromomagnetic matching to scalar and spin-two nucleon structure

High Energy Physics - Phenomenology 2026-07-21 v1 High Energy Physics - Theory

Abstract

Compact heavy quarkonium couples through the multipole interaction to scalar and spin-two gluonic operators. At leading chromoelectric order the corresponding matching coefficients satisfy C2Φ=CSΦC_2^\Phi=-C_S^\Phi; an independent chromomagnetic polarizability lifts this relation within the general CP-even, spin-independent, local two-gluon interaction at dimension four and zero derivative order. We construct an RG-consistent realization in a fixed MSMS convention. The QCD trace identity converts the gluon-only scalar matching condition into an invariant basis and fixes the correlated quark-mass coefficient required when the interaction is re-expressed in the scale-dependent basis away from the matching scale, whereas leading-logarithmic singlet evolution induces a quark spin-two coefficient. In threshold-aligned symmetric kinematics, the canonical-spin non-flip projection contains Ai(t)A_i(t) and the combination 3Bi(t)Di(t)3B_i(t)-D_i(t). An explicit Breit-frame calculation relates this projection to an off-diagonal helicity representation for nonzero spacelike tt; the off-diagonal form is kinematic rather than an additional dynamical spin flip. Linearity of the scalar and spin-two evolution factorizes the chromomagnetic dependence of their ratio as R2/0Φ(t;ρΦ)=[(1+ρΦ)/(1ρΦ)]R2/0Φ(t;0)R_{2/0}^{\Phi}(t;\rho_\Phi)=[(1+\rho_\Phi)/(1-\rho_\Phi)]R_{2/0}^{\Phi}(t;0) within the gluon-only dimension-four matching setup. The result separates state-dependent quarkonium matching from scalar and gravitational nucleon structure and states explicitly the assumptions under which this factorization holds.

Keywords

Cite

@article{arxiv.2607.18831,
  title  = {Chromoelectric and chromomagnetic matching to scalar and spin-two nucleon structure},
  author = {Arkadiy I. Syamtomov},
  journal= {arXiv preprint arXiv:2607.18831},
  year   = {2026}
}

Comments

10 pages, 1 figure