We compute the interference between the resonant process $ppto H(rightarrow gammagamma)+2 text{ jets}$ and the corresponding continuum background at leading order in QCD. For the Higgs signal, we include gluon fusion (GF) and vector boson fusion (VBF
) production channels, while for the background we consider all tree-level contributions, including pure EW effects (${cal O}(alpha_{QED}^4)$) and QCD contributions (${cal O}(alpha_{QED}^2 alpha_{s}^2)$), plus the loop-induced gluon-initiated process. After convolution with the experimental mass resolution, the main effect of the interference is to shift the position of the mass peak, as in the inclusive GF case studied previously. The apparent mass shift is small in magnitude but strongly dependent on the Higgs width, potentially allowing for a measurement of, or bound on, the width itself. In the $H(rightarrow gammagamma)+2 text{ jets}$ channel, the VBF and GF contributions generate shifts of opposite signs which largely cancel, depending on the sets of cuts used, to as little as 5 MeV (toward a lower Higgs mass). The small magnitude of the shift makes this channel a good reference mass for measuring the inclusive mass shift of around 60 MeV in the Standard Model.
We consider Standard Model Higgs boson production through gluon--gluon fusion in hadron collisions. We combine the calculation of the next-to-next-to-leading order QCD corrections to the inclusive cross section with the resummation of multiple soft-g
luon emissions at small transverse momenta up to next-to-next-to-leading logarithmic accuracy. The calculation is implemented in the numerical program HRes and allows us to retain the full kinematics of the Higgs boson and of its decay products. We present selected numerical results for the signal cross section at the LHC (sqrt{s}=8 TeV), in the H->2gamma, H->WW->lnu lnu and H->ZZ->4l decay channels by using the nominal cuts applied in current Higgs boson searches by the ATLAS and CMS collaborations.
We consider the transverse-momentum (q_T) distribution of Standard Model Higgs bosons produced by gluon fusion in hadron collisions. At small q_T (q_T<<m_H, m_H being the mass of the Higgs boson), we resum the logarithmically-enhanced contributions d
ue to multiple soft-gluon emission to all order in QCD perturbation theory. At intermediate and large values of q_T (q_T <~m_H), we consistently combine resummation with the known fixed-order results. We use the most advanced perturbative information that is available at present: next-to-next-to-leading logarithmic resummation combined with the next-to-leading fixed-order calculation. We extend previous results including exactly all the perturbative terms up to order alphas^4 in our computation and, after integration over q_T, we recover the known next-to-next-to-leading order result for the total cross section. We present numerical results at the Tevatron and the LHC, together with an estimate of the corresponding uncertainties. Our calculation is implemented in an updated version of the numerical code HqT.
