Related papers: Phenomenological study of the pp -> pi+ pn reactio…
The proton-proton fusion process p p->d e^+ nu_e is calculated at threshold to fifth order in pionless effective field theory. There are two unknown two-body currents contributing at the second and fourth orders. Combined with the previous…
Pion Compton scattering is studied in perturbative QCD for real and space--like initial photons. Different methods for the convolution of the hard amplitude with the pion wave--functions, which have in the past led to conflicting results,…
Low-energy Compton scattering off the proton is used for determination of the proton polarizabilities. However, the present empirical determinations rely heavily on the theoretical description(s) of the experimental cross sections in terms…
Low energy theorems have been derived for the coefficients of the effective range expansion in s-wave nucleon-nucleon scattering valid to leading nontrivial order in an expansion based $Q$ counting, a scheme in which both $m_\pi$ and $1/a$…
Data on the total cross sections for the pp -> pp eta, pn -> pn eta, and pn -> d eta reactions and the pp -> pp eta differential cross section near threshold are analysed in a one-meson-exchange model. After including initial and…
We obtain reliable $\pi\pi$ scattering amplitudes consistent with experimental data, both at low and high energies, and fulfilling appropriate analyticity properties. We do this by first fitting experimental low energy ($s^{1/2}\leq1.42…
We have analyzed pion-nucleon scattering using the manifestly relativistic covariant framework of Infrared Regularization up to {\cal O}(q^3) in the chiral expansion, where q is a generic small momentum. We describe the low-energy phase…
The proton analyzing power Ay0 and the deuteron tensor analyzing power T20 are evaluated for the pd <-> pi+ t process, in the energy region around and above the Delta resonance. These calculations extend a previous analysis of the…
Near threshold pion production experiments have been recently carried out and used to extract S--wave $\pi\pi$ scattering lengths. We emphasize here that at present these processes are related only at the tree level (and its first…
The analysing power measurements for the p(pol)p -> pp eta reaction studied in this dissertation are used in the determination of the reaction mechanism of the eta meson production in nucleon-nucleon collisions. Measurements have been…
From recent charge exchange measurements in the extreme forward direction, an independent and precise determination of the pion nucleon coupling constant is possible. This determination has reopened the debate on the value of this…
We review recent progress in our understanding of elastic and inelastic pion reactions on two nucleon systems from the point of view of effective field theory. The discussion includes pion-deuteron scattering, gamma d to pi-nn, and NN to…
A study of the reaction pi+ + d --> p + p has been performed in the energy range of 18 - 44 MeV. Total cross sections and differential cross sections at six angles have been measured at 15 energies with an energy increment of 1 - 2 MeV.…
The Compton scattering on a charged pion is studied using the dispersion relations. Unknown mass, full width and decay width into \gamma \gamma of the sigma meson are found from a fit to the experimental data for the process \gamma+\gamma…
Using newly calculated electromagnetic corrections, we have made a phase shift analysis of experimental data on pi+/- p elastic scattering up to 100 MeV, assuming the effective hadronic interaction to be isospin invariant. The output…
We investigate the $pp \to pK^{+}\Lambda$ reaction within an effective Lagrangian model where the contributions to the amplitudes are taken into account within the tree level. The initial interaction between the two nucleons is modeled by…
We consider interference effects between p-wave resonance scattering amplitude and background s-wave amplitude in low-energy neutron scattering from a heavy nucleus which goes through the compound nucleus stage. The first effect is in the…
The scaling of pion multiplicities with system size in proton-nucleus and nucleus-nucleus reactions at 200 A GeV is investigated. A nuclear geometry calculation of incoherent multiple scattering including effects of deceleration of the…
The saturation properties of the nuclear matter taking pion correlations into account is studied. We construct a Bogoliubov transformations for the pion pair operators and calculate the energy associated with the pion pairs. The pion…
Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni and Zr have been measured as part of a study of the pion-nucleus potential across threshold. The `anomalous' repulsion in the s-wave…