Virtual bremsstrahlung in proton-proton scattering

The virtual bremsstrahlung process, in addition to the real photon bremsstrahlung, provides an elaborate tool for studying the nucleon-nucleon interaction. The additional degree of freedom which exists in the virtual bremsstrahlung production, a longitudinal polarization of the virtual photon, allows transversal, longitudinal, and interference terms to be studied. The squared transition amplitude for p + p → p + p + e+ + e− can be written [1, 2]:|A|2∝1M2γ{WT(1−2l2M2γsin2θl)+WL(1−4l2k20cos2θl))+2l2sin2θlM2γ(WTTcos2ϕl+W′TTsin2ϕl+2l2sin2θlk0Mγ(WLTcosϕl+W′LTsinϕl)},(1)where 1 is a relative momentum of dilepton pair and θ ι , φ ι are polar and azimuthal angle of 1 relative to a reaction plane. By measuring the momenta of the outgoing dilepton pair, all kinematic factors in Eq. (1) are determined and in principle the response functions (transversal, longitudinal, and interference terms) W i , i = T, L, TT, TT′, LT, LT′ can be extracted

Vector analyzing powers of deuteron-proton elastic scattering and breakup at 130 MeV

Set of vector analyzing power data of the (d) over barp elastic scattering and H-1((d) over bar, pp)n breakup reactions at 130-MeV deuteron beam energy has been measured in the domain of very forward polar angles. The results are compared with theoretical predictions originating from various approaches: realistic nucleon-nucleon (NN) potentials and the NN potentials combined with a three-nucleon force (3NF) model and with predictions based on the ChPT framework. In case of the breakup process, none of the theoretical calculations reveal sensitivity to any of the dynamical effects such as 3NF or Coulomb interaction and they describe the experimental data equally well. For the elastic scattering, the Coulomb correction appears not negligible at very small theta(c.m.)(d). The effect seems to be confirmed by the data

Proton-proton bremsstrahlung towards the elastic limit

In oder to study proton-proton bremsstrahlung moving towards the elastic limit, a detection system, consisting of Plastic-ball and SALAD, was set up and an experiment at 190 MeV incident beam energy was performed. Here, the experimental setup and the data analysis procedure along with some results obtained in the measurement are discussed