In this talk I will consider signal-background interference effects in Higgs-mediated diphoton production at the LHC.
>The inclusion of such effects results in a shift of the diphoton invariant mass distribution and in a destructive contribution to the total cross section.
As pointed out in earlier works, one can exploit interference studies to put bounds on the Higgs boson decay width.
Given the current and future prospects on the precision achievable in Higgs-related measurements, these effects could offer valuable complementary information on such bounds.
After reviewing the Higgs interferometry framework I will present an extension of this analysis up to NNLO QCD in the so-called soft-virtual approximation.
I will finally discuss the impact of higher-order corrections on those observables pertinent to Higgs boson width studies.