Popping out the Higgs boson off vacuum at Tevatron and LHC

In the prospect of diffractive Higgs production at the LHC collider, we give an extensive study of Higgs boson, dijet, diphoton and dilepton production at hadronic colliders via diffraction at both hadron vertices. Our model, based on non factorizable Pomeron exchange, describes well the observed dijet rate observed at Tevatron Run I. Taking the absolute normalization from data, our predictions are given for diffractive processes at Tevatron and LHC. Stringent tests of our model and of its parameters using data being taken now at Tevatron Run II are suggested. These measurements will also allow to discriminate between various models and finally to give precise predictions on diffractive Higgs boson production cross-section at the LHC. 1 Double Diffractive Hard Production through non-factorizable Vacuum Exchange The discovery of the Higgs boson is one of the main goals of searches at the present and next hadronic colliders, the Tevatron and the LHC. The standard, non-diffractive production mechanisms are being studied extensively. The main decay modes of a low-mass Higgs boson are b-quark pairs and τ -leptons, which are difficult to extract from the standard model background processes. A promising channel is the γγ decay mode; however, due to the small branching fraction (about 10−3), a luminosity of the order of 50 fb−1 is needed to establish the existence of the Higgs boson in the mass range below 135 GeV. It is thus important to investigate other, complementary ways to produce and detect the Higgs boson in this mass range. One promising production mode, the exclusive double diffractive production, was proposed some time ago in Ref. [1, 2]. In this case, the Higgs boson is diffractively produced in the central region resulting in a final state composed of the two protons scattered at very small angles and detected in the roman pot detectors, the decay products of the Higgs boson in the main detector, and nothing else. It is thus a very clean signal. The kinematic constraints coming from the proton detection in the roman pot detectors allow a very precise determination of the Higgs boson mass [3], hence improving the signal to background ratio. Contrary to non-diffractive production, the main Higgs boson decay modes, like bb̄ or ττ are thus promising channels. However, the exclusive cross-sections may be very low, and thus put strong limitations to the potentialities of double diffractive production. CERN, CH-1211, Geneva 23, Switzerland and CEA/DSM/DAPNIA/SPP, CE-Saclay, F-91191 Gif-sur-Yvette Cedex, France CEA/DSM/SPhT, Unité de recherche associée au CNRS, CE-Saclay, F-91191 Gif-sur-Yvette Cedex, France CEA/DSM/DAPNIA/SPP, F-91191 Gif-sur-Yvette Cedex, France