MATRIX

(MUNICH Automates qT-subtraction and Resummation to Integrate X-sections)

Massimiliano Grazzini, Stefan Kallweit and Marius Wiesemann (e-Print: arXiv:1711.06631)

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| Munich -- the MUlti-chaNnel Integrator at swiss (CH) precision -- |
| Automates qT-subtraction and Resummation to Integrate X-sections  |
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The computational framework Matrix allows the user to evaluate fully differential cross sections for a wide class of processes at hadron colliders in NNLO QCD, NLO EW and NLO QCD for the loop-induced gg contribution. The processes are 2 → 1, 2 → 2 and 2 → 3 hadronic reactions involving Higgs, vector bosons and top quarks in the final state. All possible leptonic decay channels of the vector bosons are included in the calculations, by consistently accounting for all resonant and non-resonant diagrams, off-shell effects and spin correlations. As a consequence the full lepton kinematics is accessible to define realistic cuts and distributions in the fiducial volume. This facilitates direct comparisons with experimental data of rates and unfolded distributions.

MATRIX is based on the Monte Carlo integrator MUNICH, which provides a fully automated computation of arbitrary SM NLO processes, including an efficient phase-space integration and an implementation of Catani-Seymour dipole subtraction. In combination with the a general implementation of the transverse-momentum subtraction method MATRIX achieves NNLO accuracy on the fully differential cross sections. Matrix features an automatic extrapolation procedure that allows the systematic uncertainties inherent to the applied NNLO subtraction procedure to be controlled at the few permille level (or better).

MATRIX has been used for numerous state-of-the-art computations of vector-boson pair production. Below you find the complete list of available processes with the relevant phenomenological references. MATRIX is based on a number of different computations and tools from various people and groups. Please acknowledge their efforts by citing the list of references which is created with every run. In particular, we rely on OpenLoops for all amplitudes up to the one-loop level, and on dedicated calculations for the two-loops amplitudes, such as VVamp for diboson processes and FivePointAmplitudes for triphoton production.

Processes available in MATRIX (fully leptonic final states from vector-boson decays are implicit):

Processes/features to be included in upcoming MATRIX releases (already available upon request):