Related papers: Exclusive meson production at HERMES
The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized HERA positron beam scattering off an unpolarized hydrogen target is measured at HERMES. The asymmetry arises from deeply virtual…
This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0…
High transverse momentum pi0-mesons have been measured with the H1 detector at HERA in deep-inelastic ep scattering events at low Bjorken-x, down to x <~ 4.10^{-5}. The measurement is performed in a region of small angles with respect to…
The study of {\rho}0 meson helicity amplitude ratios at HERMES shows that the amplitude hierarchy expected from pQCD is confirmed. The contribution of Unnatural Parity Exchange in the production of {\rho}0 mesons is significant at HERMES…
A search for single top production in ep collisions using the complete high energy data from HERA is presented. This search is based on the analysis of events containing isolated leptons (electrons or muons) and missing transverse momentum…
Continuing our previous study of Deeply Virtual Meson Production (DVMP) at twist-3 accuracy, we derive compact expressions for all helicity amplitudes. We perform a phenomenological analysis of the helicity-amplitude ratio…
The analysis of $W$ production and the search for anomalous single top production is performed with the H1 detector at HERA with an integrated luminosity of 0.5 fb$^{-1}$, consisting of the complete high energy data from the HERA programme.…
The electroproduction of rho mesons is studied at HERA with the H1 detector at high Q^2 and high |t|. Cross sections are measured as a function of Q^2, W and t. The W dependence of the gamma*-p cross section is observed to increase with Q^2…
We evaluate the leading order amplitude for the deep exclusive electroproduction of an exotic hybrid meson in the Bjorken regime. We show that, contrary to naive expectation, this amplitude factorizes at the twist 2 level and thus scales…
We consider pion production in parity-violating electron scattering (PVES) in the presence of nucleon strangeness in the framework of partial wave analysis with unitarity. Using the experimental bounds on the strange form factors obtained…
Background: Measurements of exclusive meson production are a useful tool in the study of hadronic structure. In particular, one can discern the relevant degrees of freedom at different distance scales through these studies. Purpose: To…
A successful interpretation of the cross sections for elastic and inelastic vector meson production can be made if one assumes the underlying dynamics to be governed by hard partonic subprocesses. Extending these partonic approaches to…
Exclusive coherent and incoherent electroproduction of the $\rho^0$ meson from $^1$H and $^{14}$N targets has been studied at the HERMES experiment as a function of coherence length ($l_c$), corresponding to the lifetime of hadronic…
Hybrid/exotic meson spectroscopy searches at Jefferson Lab require the accurate theoretical description of the production mechanism in peripheral photoproduction. We develop a model for $\pi\Delta$ photoproduction at high energies ($5 \leq…
The photoproduction of isolated photons has been measured in diffractive events recorded by the ZEUS detector at HERA. Cross sections are evaluated in the photon-proton transverse-energy and pseudorapidity ranges 5<ET(gamma)<15 GeV and…
Results of inclusive measurements of inelastic electron and positron scattering from unpolarized protons and deuterons at the HERMES experiment are presented. The structure functions $F_2^p$ and $F_2^d$ are determined using a…
Central exclusive production (CEP) processes in high-energy hadron-hadron collisions provide an especially clean environment in which to measure the nature and quantum numbers (in particular, the spin and parity) of new resonance states.…
We consider photoproduction of $\omega$ mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for interactions of the transversely polarized…
The helicity structure of the diffractive electroproduction of rho mesons, e + p -> e + rho + Y, is studied in a previously unexplored region of large four-momentum transfer squared at the proton vertex, t: 0 < t' < 3 GeV^2, where t' = |t|…
Protons and antiprotons at collider energies are a source of high energy Weizsaecker--Williams photons. This opens up a possibility to study at the LHC exclusive photoproduction of heavy vector mesons at energies much larger than possible…