Related papers: Subthreshold rho^0 photoproduction on 3He
We discuss the elastic photo- and leptoproduction of rho^0-mesons from nucleons at Q^2 < 1 GeV^2 as studied in recent experiments at HERA and FNAL. We find that the mass distribution of the measured \pi^+\pi^- pairs is determined to a large…
Total cross sections, angular distributions, and invariant-mass distributions have been measured for the photoproduction of $\pi^0\pi^0$ pairs off free protons and off nucleons bound in the deuteron. The experiments were performed at the…
We calculate the modification of a rho meson in nuclear matter through its coupling to resonance-hole states. Starting from a recently proposed model, we include all four star resonances up to 1.9 GeV. In contrast to previous works, we…
A microscopic few-body description of near-threshold coherent photoproduction of the eta meson on tritium and 3He targets is given. The photoproduction cross-section is calculated using the Finite Rank Approximation (FRA) of the nuclear…
Recent results from decay-angle analyses of rho^0 photoproduction are presented and discussed in the context of earlier measurements at lower energy and lower momentum transfer.
The photo-production of $\phi$ mesons from Li, C, Al, and Cu at forward angles has been measured at $E_gamma$=1.5--2.4 GeV. The number of events for incoherent phi photo-production is found to have a target mass number dependence of…
Using 3.07 ${pb}^{-1}$ of data collected in the energy range 0.60-0.97 GeV by CMD-2, about 150 events of the process $\epm \to \pch$ have been selected. The energy dependence of the cross section agrees with the assumption of the $a_1(1260)…
The 4Hep interactions at 2.7 GeV/c and 5 GeV/c initial momenta of alpha-particles are investigated using the 2m liquid hydrogen bubble chamber (the kinetic energies of the initial protons in the nuclear rest frame were Tp = 220 MeV and 620…
Cross sections for the $\pi^+\pi^-$ events arising due to the decay of $\rho^0$ meson have been calculated. This rho meson is considered to produce coherently in the $(p,p^\prime)$ reaction on a nucleus. The distorted wave functions for the…
Threshold enhancements predicted by the Resonance-Spectrum-Expansion (RSE) production amplitude and observed by the BaBaR Collaboration in open-bottom production above the $B\bar{B}$ threshold, as well as by several collaborations in…
We discuss the photoproduction of omega- and rho0-mesons off protons in the particular channel where the target proton is excited to a Roper resonance N*(1440). We propose a simple meson-exchange model for these processes in order to…
The nuclear EMC effect is the observation that quark distributions in bound nucleons experience significant modification at large $x$ relative to free nucleons. Despite decades of measurements verifying the presence of this effect in quarks…
We report on a precision measurement of low-mass muon pairs in 158 AGeV indium-indium collisions at the CERN SPS. A significant excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size of…
The invariant mass spectra of e+e- pairs produced in 12-GeV proton-induced nuclear reactions are measured at the KEK Proton-Synchrotron. On the low-mass side of the omega meson peak, a significant enhancement over the known hadronic sources…
The total cross section for gamma p -> 3pi0 p has been measured for the first time from threshold to 1.4 GeV using the tagged photon beam of the Mainz Microtron. The equipment utilized the Crystal Ball multiphoton spectrometer, the TAPS…
Clear signs of excess dileptons above the known sources were found at the SPS since long. However, a real clarification of these observations was only recently achieved by NA60, measuring dimuons with unprecedented precision in 158A GeV…
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 $\gamma p\to\omega p$…
The low-lying spectra of $^8$He and $^{10}$He nuclei were studied in the $^3$H($^6$He,$p$)$^8$He and $^3$H($^8$He,$p$)$^{10}$He transfer reactions. The $0^+$ ground state (g.s.) of $^8$He and excited states, $2^+$ at $3.6-3.9$ MeV and…
We report the first observation of $e^+e^- \to \rho^+\rho^-$, in a data sample of 379 $fb^{-1}$ collected with the BABAR detector at the {PEP-II} $e^+e^-$ storage ring at center-of-mass energies near $\sqrt{s} = 10.58 GeV. We measure a…
We present a systematic analysis of backward pion photoproduction for the reactions gamma p -> pi0 p and gamma p -> pi+ n. Regge phenomenology is applied at invariant collision energies above 3 GeV in order to fix the reaction amplitude. A…