= Higgs Self Coupling


This page contains the codes for generating events in processes '''p p > VH''', '''VBF''', '''tHj''' and '''ttH''' and '''H > 4l''' including the effect of trilinear Higgs self coupling at one-loop. [[BR]]

Please cite: Fabio Maltoni, Davide Pagani, Ambresh Shivaji and Xiaoran Zhao[http://xxx.lanl.gov/abs/1707.XXXXX arXiv:1707.XXXXX]

'''Authors : Xiaoran Zhao [https://cp3.irmp.ucl.ac.be/Members/xzhao email] and Ambresh Shivaji [https://cp3.irmp.ucl.ac.be/Members/shivaji email] '''


== trilinear-FF (The Form-factor code to run VH, VBF and Hto4l) [attachment:trilinear-FF.tar.gz FF] [[BR]]

In this folder we provide: [[BR]]

a) 'loop_hvv'   : the UFO model folder with modified VVH vertices due to trilinear couplings at one-loop[[BR]]

b) "hvvcoef.cpp": C++ implementation of form factors[[BR]]

c) "Makefile"   : to generate static library (libhvvcoef.a) which is used during event generation[[BR]]

d) "ReadMe.txt" : explains how to use the code step by step and benchmarking for HZ process


== trilinear-RW (The Reweighting code to run VH, VBF, tHj and ttH) [attachment:trilinear-RW.tar.gz RW] [[BR]]

In this folder we provide: [[BR]]

a) 'hhh-model': the UFO model file to be used[[BR]]

b) "gevirt.sh": auxiliary script to generate virtual EW subprocesses[[BR]]

c) "vvh-loop_diagram_generation.py" : to select right set of one-loop diagrams in VH, VBF and tHj[[BR]]

d) "tth-loop_diagram_generation.py" : to select right set of one-loop diagrams in ttH[[BR]]

e) "check_OLP.f": reweighting code[[BR]]

f) "makefile"   : makefile for reweighting code[[BR]]

g) "ReadMe.txt" : explains how to use the code step by step and benchmarking for HZ process[[BR]]

h) we also provide 'example_hz' folder which contains a simple script to build the reweighting code for HZ as an example[[BR]]


(All calculations are done in G_\mu scheme and benchmarking is done with MG5_aMC_v2_5_5)

== ZH diagrams at one-loop due to trilinear coupling

[[Image(loop_k3_hz.png)]]

== ttH diagrams at one-loop due to trilinear coupling [[BR]]
(Not all diagrams are included here.)

[[Image(loop_k3_tth.png)]]