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Inadequacy of zero-width approximation for a light Higgs boson signal

  • Nikolas Kauer
  • Giampiero Passarino
Article

Abstract

In the Higgs search at the LHC, a light Higgs boson \( \left( {{115}\,{\text{GeV}} \lesssim {M_{\text{H}}} \lesssim {13}0\,{\text{GeV}}} \right) \) 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 zero-width approximation is hence expected to be an excellent approximation. We show that this is not always the case. The inclusion of off-shell contributions is essential to obtain an accurate Higgs signal normalisation at the 1% precision level. For gg (→ H) → VV, V = W,Z, \( \mathcal{O} \)(10 %) corrections occur due to an enhanced Higgs signal in the region M V V > 2 M V , where also sizable Higgs-continuum 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 HV V decay modes in weak boson fusion are similarly affected.

Keywords

Higgs Physics Standard Model QCD 

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Copyright information

© SISSA, Trieste, Italy 2012

Authors and Affiliations

  1. 1.Department of Physics, Royal HollowayUniversity of LondonEghamU.K.
  2. 2.Dipartimento di Fisica TeoricaUniversità degli Studi di TorinoTorinoItaly
  3. 3.INFN, Sezione di TorinoTorinoItaly

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