Related papers: Two-body Pion Absorption on $^3He$ at Threshold
Recently, deeply bound pionic states were found experimentally in (d, $^3$He) reactions on $^{208}$Pb. They found an isolated peak structure in the bound region below the pion production threshold. We study theoretically these excitation…
In this talk we cover several issues concerning pion production. The first one is the p p ----> p p pi^0 reaction where an alternative explanation based on the off shell extrapolation of the pi N amplitude is offered. A recent model for the…
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…
We present realistic models of pion-exchange three-nucleon interactions obtained by fitting the energies of all the 17 bound or narrow states of 3 <= A <= 8 nucleons, calculated with less than 2% error using the Green's function Monte Carlo…
Based on a counting scheme that explicitly takes into account the large momentum sqrt(M m_pi) characteristic for pion production in nucleon-nucleon collisions we calculate all diagrams for the reaction NN --> NN pi at threshold up to…
The double differential production cross sections, $d^2\sigma/d\Omega dE$, for hydrogen isotopes and charged pions in the reaction of p + Nb at 3.5 GeV proton beam energy have been measured by the High Acceptance DiElectron Spectrometer…
Recently, the n$^3$He collaboration reported a measurement of the parity-violating (PV) proton directional asymmetry $A_{\mathrm {PV}} = (1.55\pm 0.97~\mathrm {(st\ at)} \pm 0.24~\mathrm {(sys)})\times 10^{-8}$ in the capture reaction of…
The 2H(p,n) charge exchange reaction at T_p=790 MeV is used to study the Delta(1232)-nucleon interaction in the Delta resonance excitation energy region. For the Delta-N potential, a meson exchange model is adopted where pi, rho, omega, and…
The amplitude of subthreshold phi-meson production is calculated using dominant tree-level diagrams for three-body collisions. It is shown that the production can overwhelmingly be described by two-step processes. The effect of the genuine…
We present results on the nucleon scalar, axial and tensor charges as well as on the momentum fraction, and the helicity and transversity moments. The pion momentum fraction is also presented. The computation of these key observables is…
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…
The impulse approximation (one-body operator) in the n p --> d pi^0 reaction is reexamined with emphasis on the issues of reducibility and recoil corrections. An inconsistency when one pion exchange is included in the production operator is…
In this talk I review the main features of the coherent/diffractive pion production by neutrinos on nuclei. The method is based on PCAC and relates the reaction $\textbf{boson} + \textbf{nucleus} \to \textbf{pion} + \textbf{nucleus}$ to…
{ {\bf Background:} Knowing the difference between the neutron and proton densities of nuclei is a significant topic because of its importance for understanding neutron star structures and cooling mechanisms. The coherent-nuclear…
We investigate the formation cross sections of the deeply bound pionic atoms on halo nuclei theoretically. We consider one-neutron pick-up (d,3He) reaction for the pionic atom formation and find that the formation rate is significantly…
We calculate the muon capture rate on the deuteron to next-to-next-to-leading order in the pionless effective field theory. The result can be used to constrain the two-nucleon isovector axial coupling L_{1,A} to +/- 2 fm^3 if the muon…
Production of leading neutrons in DIS is usually considered as a tool to measure the pion structure function at small x accessible at HERA. The main obstacle is the lack of reliable evaluations of the absorption corrections, which…
A hypothesis is proposed herein, suggesting that a pion-nuclear resonance may be observed in the $\alpha+d\to{}^6\mathrm{Li}(3.563)+\pi^0$ reaction. The resonance has a $\pi NN\alpha$ structure, containing $\alpha NN$ and $\pi NN$…
We have calculated the effect of the inclusion of final state interactions on pion production from nuclei with incident pion beams. We find that the effect of absorption, along with geometric considerations, explains much of the enhancement…
The first data from MAX-lab in Lund, Sweden on pion production in photonuclear reactions at threshold energies, is presented. The decrease of the total yield of pi+ in gamma + 12C, 27Al reactions below 200 MeV as well as differential,…