I discuss recent results of inclusive and exclusive electroproduction experiments at Jefferson Lab. They include measurements of the spin response for protons and neutrons in the resonance region, exclusive single pion and multiple pion production to measure resonance transition multipoles, and searches for missing quark model states. A brief outlook to the new domain of Generalized Parton Dist...

We study baryon pair production in two-photon collisions, γγ → BB̄, within perturbative quantum chromodynamics, treating baryons as quark-diquark systems. We extend previous work within the same approach by treating constituent-mass effects systematically by means of an expansion in the small parameter (mass/photon energy). Our approach enables us to give a consistent description of the cross se...

We analyze in detail the size of next-to-leading order corrections to hard exclusive meson production within the collinear factorization approach. Corrections to the cross section are found to be huge at small xB and substantial in typical fixed-target kinematics. With the models we take for nucleon helicity-flip distributions, the transverse target polarization asymmetry in vector meson produc...

We study baryon pair production in two-photon collisions, γγ → BB̄, within perturbative quantum chromodynamics, treating baryons as quark-diquark systems. We extend previous work within the same approach by treating constituent-mass effects systematically by means of an expansion in the small parameter (mass/photon energy). Our approach enables us to give a consistent description of the cross se...

We examine, as a correction to the central exclusive Higgs boson production in pp collisions at the LHC, the rescattering of gluonic ladders off the proton. As usual, at the lowest order the hard part of this process can be described as a fusion of two hard gluonic ladders. We calculate corrections to this hard amplitude which are due to rescattering of these ladders. These corrections, which c...

We study the exclusive, double–diffractive production of the Standard Model Higgs particle in hadronic collisions at LHC and FNAL (upgraded) energies. Such a mechanism would provide an exceptionally clean signal for experimental detection in which the usual penalty for triggering on the rare decays of the Higgs could be avoided. In addition, because of the color singlet nature of the hard inter...

In this talk it is reported on analyses of p → lπn and πp → lln within the handbag approach. It is argued that recent measurements of hard pion production performed by HERMES and CLAS clearly indicate the occurrence of strong contributions from transversely polarized photons. The γ ∗ T → π transitions are described by the transversity GPDs accompanied by twist-3 pion wave functions. The experim...

We show how the early data runs of the LHC can provide valuable checks of the different components of the formalism used to predict the cross sections of central exclusive processes. The ‘soft’ rapidity gap survival factor can be studied in electroweak processes, such as W+gaps events, where the bare amplitude is well known. The generalized gluon distribution, in the appropriate kinematic regio...

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