Diffractive production of charm quark/antiquark pairs at RHIC and LHC

We have discussed single and central diffractive production of $c \bar c$ pairs in the Ingelman-Schlein model. In these calculations we have included diffractive parton distributions obtained by the H1 collaboration at HERA and absorption effects neglected in some early calculations in the literature. The absorption effects which are responsible for the naive Regge factorization breaking cause that the cross section for diffractive processes is much smaller than that for the fully inclusive case, but could be measured at RHIC and LHC by imposing special condition on rapidity gaps. We discuss also different approaches to diffractive production of heavy quark/antiquark. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the low-mass diffraction, or large $\beta$-region.Comment: 4 pages, 5 figures, talk given by M. Luszczak at International Workshop on Diffraction in High-Energy Physics, DIFFRACTION 2012, Puerto del Carmen, Lanzarote. (Canary Islands), Spain. September 10 - 15, 201

W+W−W^+ W^- pair production in proton-proton collisions: small missing terms

$W^+ W^-$ production is one of the golden channels for testing the Standard Model as well for searches beyond the Standard Model. We discuss many new subleading processes for inclusive production of $W^+ W^-$ pairs generally not included in the litterature so far. We focus mainly on photon-photon induced processes. We include elastic-elastic, elastic-inelastic, inelastic-elastic and inelastic-inelastic contributions. We also calculate the contributions with resolved photons including the partonic substructure of the virtual photon. Predictions for the total cross section and differential distributions in $W$- boson rapidity and transverse momentum as well as $WW$ invariant mass are presented. The $\gamma \gamma$ components only constitute about 1-2 \% of the inclusive $W^+ W^-$ cross section but increases up to about 10 \% at large $W^{\pm}$ transverse momenta, and are even comparable to the dominant $q \bar q$ component at large $M_{WW}$, i.e. are much larger than the $g g \to W^+ W^-$ one.Comment: 26 pages, 17 figure and 1 table. arXiv admin note: substantial text overlap with arXiv:1309.720