The prescription for the γ5 matrix within dimensional regularization in multiloop calculations is elaborated. The three-loop anomalous dimension of the singlet axial current is calculated.

The renormalization of the axial anomaly in dimensional regularization

Collider physics at the precision frontier

We present results for the two-loop helicity amplitudes entering the NLO QCD corrections to the production of a Higgs boson in association with a $Z$-boson in gluon fusion. The two-loop integrals, involving massive top quarks, are calculated numerically. Results for the interference of the finite part of the two-loop amplitudes with the Born amplitude are shown as a function of the two kinematic invariants on which the amplitudes depend.

/pdf/zh-production-in-gluon-fusion-two-loop-amplitudes-with-full-1jhckrd3ry.pdf

$ZH$ production in gluon fusion: two-loop amplitudes with full top quark mass dependence

We compute the NLO virtual corrections to the partonic cross section of $gg\to HH$, in the high energy limit. Finite Higgs boson mass effects are taken into account via an expansion which is shown to converge quickly. We obtain analytic results for the next-to-leading order form factors which can be used to compute the cross section. The method used for the calculation of the (non-planar) master integrals is described in detail and explicit results are presented.

/pdf/double-higgs-boson-production-at-nlo-in-the-high-energy-5g67dlafel.pdf

Double Higgs boson production at NLO in the high-energy limit: complete analytic results

We compute the next-to-leading virtual QCD corrections to the partonic cross section of the production of a Higgs boson in association with a $Z$ boson in gluon fusion. The calculation is based on the recently introduced method of evaluating the amplitude via an expansion in terms of a small transverse momentum. We generalize the method to the case of different masses in the final state and of a process not symmetric in the forward-backward direction exchange. Our analytic approach gives a very good approximation (better than percent) of the partonic cross section in the center of mass energy region up to $\sim 750 \,\textrm{GeV}$, where at the LHC $\sim 98\%$ of the total hadronic cross section is concentrated.

/pdf/virtual-corrections-to-gg-zh-via-a-transverse-momentum-dxjt9p7tad.pdf

Virtual corrections to gg → ZH via a transverse momentum expansion

We compute the next-to-leading order virtual corrections to the partonic cross-section of the process gg → ZH, in the high-energy and large-mt limits. We use Pade approximants to increase the radius of convergence of the high-energy expansion in $$ {m}_t^2/s $$
 , $$ {m}_t^2/t $$
 and $$ {m}_t^2/u $$
 and show that precise results can be obtained down to energies which are fairly close to the top quark pair threshold. We present results both for the form factors and the next-to-leading order virtual cross-section.

/pdf/virtual-corrections-to-gg-zh-in-the-high-energy-and-large-mt-2qjybb8mvv.pdf

Go Mishima

Papers

Virtual corrections to gg → ZH in the high-energy and large-mt limits