We present the two-loop virtual amplitudes for heavy-quark pair production in light quark-antiquark annihilation and gluon fusion channels, including full spin and color dependence. We use expansions around kinematical limits and numerical integration to obtain results for the involved master integrals. From these, we determine the renormalised infrared finite remainders of the coefficients of amplitude decompositions in terms of color and spin structures. The remainders are given in form of numerical interpolation grids supported by expansions around the production threshold and the high energy limit. Finally, we provide the spin density matrix, which encodes the heavy-quark spin correlations and is sufficient for phenomenological applications. Our results are necessary for the derivation of top-quark pair production cross sections in hadron collisions in the narrow width approximation with next-to-next-to-leading order accuracy in QCD.
We explore polarized heavy quarkonium production using the color evaporation model at leading order. We present the polarized to total yield ratio as a function of center of mass energy and rapidity in $p+p$ collisions. At energies far above the $Q \overline Q$ production threshold, we find charmonium and bottomonium production to be longitudinally polarized ($J_z=0$). The quarkonium states are also longitudinally polarized at central rapidity, becoming transversely polarized ($J_z=\pm1$) at the most forward rapidities.
We provide a first calculation of the complete next-to-leading order QCD corrections for heavy flavor contributions to the inclusive structure function $g_1$ in longitudinally polarized deep-inelastic scattering. The results are derived with largely analytical methods and retain the full dependence on the heavy quark's mass. We discuss all relevant technical details of the calculation and present numerical results for the heavy quark scaling functions. We perform important crosschecks to verify our results in the known limit of photoproduction and for the unpolarized electroproduction of heavy…
We report on a recently completed, first calculation of the full next-to-leading order QCD corrections for heavy flavor contributions to the inclusive structure function $g_1$ in longitudinally polarized deep-inelastic scattering. All results are derived with largely analytical methods and retain the full dependence on the heavy quark's mass. As a first phenomenological application, inclusive charm production at a future electron-ion collider and its sensitivity to the polarized gluon distribution is studied. Theoretical uncertainties due to the residual dependence on unphysical factorization …
Heavy-quark contributions to the polarized DIS structure functions at NLO in the ACOT scheme
Universität Münster(明斯特大学);Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes,CNRS/IN2P3(亚原子物理与宇宙学实验室,格勒诺布尔阿尔卑斯大学,法国国家科学研究中心/法国国家核子和粒子物理研究所)
We present a first calculation of the heavy flavor contribution to the longitudinally polarized DIS structure function $g_1$, differential in the transverse momentum or the rapidity of the observed heavy antiquark $\overline{Q}$. All results are obtained at next-to-leading order accuracy with a newly developed parton-level Monte Carlo generator that also allows one to study observables associated with the heavy quark pair such as its invariant mass distribution or its correlation in azimuthal angle. First phenomenological studies are presented in a kinematic regime relevant for a future Electr…
We present a first calculation of the heavy flavor contribution to the longitudinally polarized deep-inelastic scattering structure function $g_1^{Q}$, differential in the transverse momentum or the rapidity of the observed heavy quark $Q$ or antiquark $\overline Q$. All results are obtained at next-to-leading order accuracy in QCD within the framework of a newly developed parton-level Monte Carlo generator that also allows one to study observables associated with the produced heavy quark pair such as its invariant mass distribution or its correlation in azimuthal angle. First phenomenological…