Related papers: Pion reactions on two--nucleon systems
We present results for two-body observables that are sensitive to the parity-violating component of nucleon-nucleon interactions. These interactions are studied using an effective field theory in which the only dynamic degrees of freedom…
We report on recent results obtained by the above collaboration on the collision processes involving three nucleons, where we pay particular attention on the dynamical role of the pion. After discussing the case at intermediate energies,…
We propose a theory which exploits the charge-exchange reactions ($^3$He,$^3$H$\pi^+$) and (p,n$\pi^+$) as effective sources of virtual pions. We consider processes in which the creation of virtual pions is followed by conventional…
We analyse elastic-pion nucleon scattering to fourth order in heavy baryon chiral perturbation theory, extending the third order study published in Nucl. Phys. A640 (1998) 199. We use various partial wave analyses to pin down the low-energy…
We analyse the interplay between nucleon-nucleon potentials deduced from chiral perturbation theory and a coarse grained representation of the short distance interactions by delta-shells potentials below a certain cut-off distance. While we…
After a brief overview of relevant studies on one-nucleon knockout showing the importance of quantitatively understanding the origin of the quenched spectroscopic factors extracted from data, attention is focussed on two-nucleon emission as…
We investigate the reaction pn -> dpipi in the framework of Chiral Perturbation Theory. For the first time a complete calculation of the leading order contributions is presented. We identify various diagrams that are of equal importance as…
The dependence of pion and strangeness production on the number of participant nucleons and collision energy is discussed for central A+A collisions. A possible interpretation of the experimental results assuming transition to QGP is…
We build a relativistic model to perform calculations of exclusive, semi-exclusive and inclusive unpolarized cross sections and various polarization observables in electron and neutrino scattering experiments with deuteron targets. The…
The differential cross section for gamma-deuteron Compton scattering is computed to next-to-leading order (NLO) in an effective field theory that describes nucleon-nucleon interactions below the pion production threshold. Contributions at…
Observables in proton-deuteron scattering are sensitive probes of the nucleon-nucleon interaction and three-nucleon force effects. Several facilities, including the KVI, allow a detailed study of few-nucleon interactions below the…
In neutrino-nucleus interactions, a proton produced with a correlated pion might exhibit a left-right asymmetry relative to the lepton scattering plane even when the pion is absorbed. Absent in other proton production mechanisms, such an…
Elastic pion-nucleon scattering is analyzed in the framework of chiral perturbation theory up to fourth order within the heavy-baryon expansion and a covariant approach based on an extended on-mass-shell renormalization scheme. We discuss…
The inclusive pion double charge exchange process on nuclei is considered in the framework of the Gribov-Glauber approach. It is shown that inelastic rescatterings related to production of two (and more) pions in the intermediate state give…
The origin of the breakdown scale in an effective field theory treatment of nuclear forces is investigated. Different organizational schemes used in the nonperturbative calculation of nucleon-nucleon scattering seem to break down for…
Theoretical uncertainties of various types are discussed for the nucleon-deuteron elastic scattering observables at the incoming nucleon laboratory energies up to 200 MeV. We are especially interested in the statistical errors arising from…
We investigate hard exclusive reactions on the nucleon with soft pion emission. A parametrization of corresponding hadronic matrix elements in terms of parton distributions for final pion-nucleon state is provided. These distributions are…
We present an overview of our efforts to analyze pion-nucleon elastic scattering data, along with data from related photo- and electroproduction reactions, in order to study the baryon spectrum. We then focus on the Delta(1232) resonance.…
Rescattering following a neutrino-nucleus reaction changes the number, energy, and direction of detectable hadrons. In turn, this affects the selection and kinematic distributions of subsamples of neutrino events used for interaction or…
Over twenty-five years ago, two analyses of the pion-nucleon ($\pi N$) data at low energy (i.e., for pion laboratory kinetic energy $T \leq 100$ MeV) reported on the departure of the extracted scattering amplitudes, corresponding to the two…