PoS(LL2014)031 PoS(LL2014)031 Precision tools for Higgs physics * Maria Vittoria Garzelli and Adam Kardos MTA-DE Particle Physics Research Group, University of Debrecen, H-4010 Debrecen P.O.Box 105, Hungary Zoltán Trócsányi † Institute of Physics and MTA-DE Particle Physics Research Group, University of Debrecen, H-4010 Debrecen P.O.Box 105, Hungary E-mail: Z.Trocsanyi@atomki.hu We present theoretical predictions for the hadroproduction of t ¯ t + b ¯ b final state matching nu- merical computations at NLO accuracy in QCD with shower Monte Carlo programs. We propose to use half of the sum of transverse masses as renormalization and factorization scales, which gives small NLO K-factor and scale dependence. The events stored according to the Les Houches accord can be used as input in shower Monte Carlo programs to simulate parton showering and hadronization. We show that the decay of the heavy particles may affect the kinematic distribu- tions most, while the changes due to PS and hadronization are small except in regions dominated by Sudakov suppression. Loops and Legs in Quantum Field Theory 27 April 2014 - 02 May 2014 Weimar, Germany * This research was supported by the Hungarian Scientific Research Fund grant K-101482, the European Union and the European Social Fund through Supercomputer, the national virtual lab TAMOP-4.2.2.C-11/1/KONV-2012-0010 and the LHCPhenoNet network PITN-GA-2010-264564 projects . † Speaker. c  Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/