Related papers: Proton Diffraction Dissociation and Unitarity
We construct diffractive parton distributions in the model of DIS diffraction in which the diffractive state is formed by the $q\bar{q}$ and $q\bar{q}g$ components. The interaction of such systems with the proton is described by the dipole…
Many extensions of the minimal supersymmetric standard model contain superfields for quarks which are singlets under weak isospin with electric charge -1/3. We explore the possibility that such isosinglet quarks have low or intermediate…
In the standard model the proton is protected from decay naturally by gauge symmetries, whereas in the ordinary minimal supersymmetric standard model an ad hoc discrete symmetry is imposed for the proton stability. We present a new…
We assume that the Pomeron is a sum of Regge multipoles, each corresponding to a finite gluon ladder. From a fit to the diffraction cone data of pp- and pbarp- scattering we found that the triple pole is significant for the rise of the…
We investigate contributions to diffractive scattering, which are odd under C- and P-parity. Comparison of p-$\bar p$ and p-p scattering indicates that these odderon contributions are very small and we show how a diquark clustering in the…
Using the QCD dipole picture of the hard BFKL pomeron, we derive the general expressions of the elastic and inelastic components of the proton diffractive structure functions. We obtain a good 7 parameter fit (including a secondary reggeon…
Generic SO(10) GUT models suffer from the problem that Planck scale induced non-renormalizable proton decay operators require extreme suppression of their couplings to be compatible with present experimental upper limits. One way to resolve…
We briefly review the issues of proton decay and fermion masses and mixings in minimal supersymmetric grand unified theories. We argue that minimal SU(5), although tightly constrained by proton decay data, is still not ruled out. However,…
We show that in an $SU(2)\otimes U(1)$ model with a DSF-like invisible axion it is possible to obtain (i) the convergence of the three gauge coupling constants at an energy scale near the Peccei-Quinn scale; (ii) the correct value for…
Large-distance effects, which lead to the spin-flip part of the hadron -pomeron coupling in QCD -models, are discussed. We study spin asymmetries in exclusive reactions and in diffractive $Q \bar Q$ and vector meson production which are…
The value of the important triple-Pomeron coupling is estimated by an unorthodox procedure using the known diffractive parton distribution functions. The result is g_{3P}\simeq 0.2g_N, where g_N is the Pomeron-nucleon coupling. This is in…
We calculate for the first time cross sections for single and central diffractive as well as exclusive diffractive production of dilepton pairs in proton-proton collisions. Several differential distributions are shown. The inclusive…
The Good-Walker mechanism for diffraction is shown to provide a link between total and diffractive structure functions and to be relevant for QCD calculations at small x_{Bj}. For Deep-Inelastic scattering on a small-size target (cf. an…
We perform a NLO QCD analysis of single-diffractive dijet production in proton-antiproton collisions. By comparing the ratio of single- and non-diffractive cross sections to data from the Tevatron, the rapidity-gap survival probability is…
Disagreement percolation connects a Gibbs lattice gas and i.i.d. site percolation on the same lattice such that non-percolation implies uniqueness of the Gibbs measure. This work generalises disagreement percolation to the hard-sphere model…
Results on soft and hard diffraction are briefly reviewed and placed in a QCD perspective using a parton model approach. Issues addressed include factorization, scaling properties, universality of rapidity gap formation, and unitarity.…
Recently, a semiclassical approach to diffraction has been proposed, which treats the proton as a classical colour field. The present paper demonstrates that this approach is consistent with the concept of diffractive parton distributions.…
We extend a perturbative Dyson-type treatment and discrete-symmetry constraints from the Schr\"{o}dinger and von Neumann equations to a dephasing Lindblad framework. This work develops further the odd-symmetric formulation involving dual…
We discuss photon-photon fusion mechanisms of dilepton production in proton-proton collisions with rapidity gap in the main detector and one forward proton in the forward proton detectors. This is relevant for the LHC measurements by…
Background: Time-reversal-invariance violation, or equivalently CP violation, may explain the observed cosmological baryon asymmetry as well as signal physics beyond the Standard Model. In the decay of polarized neutrons, the triple…