Structure of the final states in Higgs production at Hadronic Colliders

We quantify the rate and the signal-to-background ratio for Higgs $\to b\bar{b}$ detection in double-diffractive events at the Tevatron and the LHC. The signal is predicted to be very small at the Tevatron, but observable at the LHC. We exemplify the diagnostic power of hadronic antenna pattern by considering the topology of hadronic flow corresponding to Higgs $\to b\bar{b}$ events.Comment: 4 pages, talk given at XXXI International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL http://ismd31.ccnu.edu.cn

Rapidity Gap Higgs Signal at the Tevatron and the LHC

We quantify the rate and the signal-to-background ratio for Higgs --> b anti-b detection in double-diffractive events at the Tevatron and the LHC. The signal is predicted to be very small at the Tevatron, but observable at the LHC. We show that the double-diffractive dijet production may serve as a unique gluon factory. This process can be used also as a Pomeron-Pomeron luminosity monitor.Comment: 12 pages, 1 figure, Late

Hunting a light CP-violating Higgs via diffraction at the LHC

We study the central diffractive production of the (three neutral) Higgs bosons, with a rapidity gap on either side, in an MSSM scenario with CP-violation. We consider the bb-bar and tautau-bar decay for the light H_1 boson and the four b-jet final state for the heavy H_2 and H_3 bosons, and discuss the corresponding backgrounds. A direct indication of the existence of CP-violation can come from the observation of either an azimuthal asymmetry in the angular distribution of the tagged forward protons (for the exclusive pp -> p+H+p process) or of a sin(2phi) contribution in the azimuthal correlation between the transverse energy flows in the proton fragmentation regions for the process with the diffractive dissociation of both incoming protons (pp -> X+H+Y). We emphasise the advantage of reactions with the rapidity gaps (that is production by the pomeron-pomeron fusion) to probe CP parity and to determine the quantum numbers of the produced central object.Comment: 11 pages, 3 figure

Scattering amplitudes of fermions on monopoles

We consider scattering processes involving massless fermions and ’t Hooft-Polyakov magnetic monopoles in a minimal SU(2) model and in the Grand Unified SU(5) theory. We construct expressions for on-shell amplitudes for these processes in the J = 0 partial wave using the spinor helicity basis consisting of single-particle and pairwise helicities. These processes are unsuppressed and are relevant for the monopole catalysis of proton decay. The amplitudes for the minimal processes involving a single fermion scattering on a monopole in the initial state and half-fermion solitons in the final state are presented for the first time and are used to obtain the amplitudes for processes involving more fermions in the initial state and integer fermion numbers in the final state. A number of such anomalous and non-anomalous processes, along with their amplitude expressions, are written down for the SU(5) GUT model

Diffractive gamma-gamma production at hadron colliders

We compute the cross section for exclusive double-diffractive gamma-gamma production at the Tevatron, $p{\bar p} \to p + \gamma\gamma + {\bar p}$, and the LHC. We evaluate both the gluon-gluon and quark-antiquark t-channel exchange contributions to the process. The observation of exclusive gamma-gamma production at the Tevatron will provide a check on the model predictions, and offer an opportunity to confirm the expectations for exclusive double-diffractive Higgs production at the LHC.Comment: 16 pages, 7 figure