Inadequacy of zerowidth approximation for a light Higgs boson signal
Abstract
In the Higgs search at the LHC, a light Higgs boson ( {{115} {{GeV}} lesssim {M_{{H}}} lesssim {13}0 {{GeV}}} ) is not excluded by experimental data. In this mass range, the width of the Standard Model Higgs boson is more than four orders of magnitude smaller than its mass. The zerowidth approximation is hence expected to be an excellent approximation. We show that this is not always the case. The inclusion of offshell contributions is essential to obtain an accurate Higgs signal normalisation at the 1% precision level. For gg (→ H) → VV, V = W,Z, {O} (10 %) corrections occur due to an enhanced Higgs signal in the region M _{ V V } > 2 M _{ V }, where also sizable Higgscontinuum interference occurs. We discuss how experimental selection cuts can be used to exclude this region in search channels where the Higgs invariant mass cannot be reconstructed. We note that the H → V V decay modes in weak boson fusion are similarly affected.
 Publication:

Journal of High Energy Physics
 Pub Date:
 August 2012
 DOI:
 10.1007/JHEP08(2012)116
 arXiv:
 arXiv:1206.4803
 Bibcode:
 2012JHEP...08..116K
 Keywords:

 Higgs Physics;
 Standard Model;
 QCD;
 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment
 EPrint:
 26 pages, 18 figures, 6 tables