Related papers: Exclusive Backward-Angle Omega Meson Electroproduc…
In this talk it is reported on an analysis of hard exclusive electroproduction of pseudoscalar mesons within the handbag approach. It is argued that recent measurements of pion electroproduction performed by HERMES and CLAS clearly indicate…
The electroproduction of $\eta '$ mesons from a $\mathrm{^{1}H}$ target at $W=2.13~\text{GeV}$, $Q^{2} = 0.46~\left( \text{GeV}/c\right)^{2}$ and $\cos \theta^{\text{CM}}_{\gamma^{*}\eta'} \approx -1$ has been experimentally measured. The…
Differential cross sections for eta photoproduction off protons have been measured at E_gamma = 1.6 - 2.4 GeV in the backward direction. A bump structure has been observed above 2.0 GeV in the total energy. No such bump is observed in cross…
The study of exclusive $\pi^{\pm}$ electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio $R_L=\sigma_L^{\pi^-}/\sigma_L^{\pi^+}$ is sensitive to…
In 2018, the E12-17-003 experiment was conducted at the Thomas Jefferson National Accelerator Facility (JLab) to explore the possible existence of an nnLambda state in the reconstructed missing mass distribution from a tritium gas target…
The PHENIX experiment at RHIC has measured the invariant cross section for omega-meson production at mid-rapidity in the transverse momentum range 2.5 < p_T < 9.25 GeV/c in p+p and d+Au collisions at sqrt(s_NN) = 200 GeV. Measurements in…
We report the measurement of differential cross sections for $\omega$ and $\eta'$ photoproduction from protons at backward angles ($-1.0<\cos\Theta_{C.M}^{X}<-0.8$) using linearly polarized photons at $E_{\gamma}=$$1.5-3.0$ GeV.…
The cross section of the exclusive $\pi^0$ and $\eta$ electroproduction reaction $ep\to e^\prime p^\prime \pi^0/\eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections…
Differential cross sections and photon beam asymmetries for $\pi^0$ photoproduction have been measured at $E_\gamma$ = 1.5--2.4 GeV and at the $\pi^0$ scattering angles, --1 $<$ cos$\Theta_{c.m.} <$ --0.6. The energy-dependent slope of…
We apply the light-cone technique to electroproduction reaction $ep\to e\pi^+n$ long considered as a means of measuring the electromagnetic form factor of the pion. We show that the interpretation of the long-standing puzzle of large…
We investigate photoproduction of $\omega$ off a nucleon target $\gamma N\to\omega N$ by using a Reggeized model where $\pi(135)+\sigma(500)+f_1(1285)+f_2(1270)$+Pomeron exchanges are included in the $t$-channel for the reaction at forward…
The exclusive electroproduction of $\pi^+$ above the resonance region was studied using the $\rm{CEBAF}$ Large Acceptance Spectrometer ($\rm{CLAS}$) at Jefferson Laboratory by scattering a 6 GeV continuous electron beam off a hydrogen…
Within the meson exchange model we study $\omega$ meson photoproduction at energies above the s channel resonance region. Different model prescriptions for the $\omega{NN}$ vertex function are investigated imposing gauge invariance as well…
The recent exclusive backward-angle electroproduction of omega from Jefferson Lab Hall C electron-proton fixed-target scattering experiments above the resonance region hints at a new domain of applicability of QCD factorization in a unique…
An experimental study of $\omega$ photoproduction on the proton was conducted by using the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. The $\gamma p\to\omega p$…
Cross section measurements of the exclusive p(e,e'K+)Lambda,Sigma^0 electroproduction reactions have been performed at the Mainz Microtron MAMI in the A1 spectrometer facility using for the first time the Kaos spectrometer for kaon…
Photoproduction of pi0 mesons was studied with the Crystal-Barrel detector at ELSA for incident energies from 300 MeV to 3 GeV. Differential cross sections d sigma /d Omega, d sigma/d t, and the total cross section are presented. For…
We review the potentialities offered by the study of backward exclusive processes in a new scaling regime, i.e. involving a large -timelike or spacelike- Q2 photon and a baryonic exchange in the t-channel. We recall the concept of…
Photoproduction cross sections are reported for the reaction $\gamma p\to p\eta$ using energy-tagged photons and the CLAS spectrometer at Jefferson Laboratory. The $\eta$ mesons are detected in their dominant charged decay mode, $\eta\to…
We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, $e p \to e^\prime n \pi^+$, above the resonance region at backward pion center-of-mass angles. The…