Inclusion Of Final State Interactions Research Articles

Pion absorption from the lowest atomic orbital in 2H, 3H and 3He

Abstract. The π− + 2H → n + n, π− + 3H → n + n + n, π− + 3He → n + d and π− + 3He → p + n + n capture reactions from the lowest atomic orbitals are investigated under full inclusion of final state interactions and employing the single-nucleon and two-nucleon transition operators derived at leading order in chiral effective field theory.

Inelastic meson-meson scattering in hadronic matter

We review studies of inelastic meson-meson scattering. In nonperturbative schemes with chiral-perturbation-theory Lagrangians and in models based on effective meson Lagrangians, inelastic meson-meson scattering leads to the successful identification of resonances in meson-meson reactions, adequate inclusion of final state interactions in particle decays, and so on. For mesons of which each consists of a quark and an antiquark, inelastic meson-meson scattering may be caused by quark-antiquark annihilation, quark-antiquark creation, quark interchange, and quark-antiquark annihilation and creation. In transition amplitudes for meson-meson scattering mesonic quark-antiquark relative-motion wave functions depend on hadronic matter, and transition potentials are given in perturbative quantum chromodynamics. Via transition amplitudes the cross sections for inelastic meson-meson scattering depend on the temperature of hadronic matter. Some prominent temperature dependence of the cross sections has been found. Inelastic meson-meson scattering becomes even more significant in proton-proton collisions and lead-lead collisions at the Large Hadron Collider.

Muon Capture on ^3H

The mu ^- + ^3mathrm{H} rightarrow nu _mu + n + n + n capture reaction is studied under full inclusion of final-state interactions with the AV18 nucleon-nucleon potential and the Urbana IX three-nucleon force. We employ the single nucleon weak current operator comprising the dominant relativistic corrections to obtain first estimates of the total capture rates based on realistic forces. Our results are compared with older theoretical predictions.

Muon capture onH3

The muon capture on 3H leading to muonic neutrino and three neutrons in the final state is studied under full inclusion of final state interactions. Predictions for the three-body break-up of 3H are calculated with the AV18 potential, augmented by the Urbana IX three-nucleon force. Our results are based on the single nucleon weak current operator comprising the dominant relativistic corrections. This work is a natural extension of our investigations of the muon capture on 3He leading to 3H or n+d or n+n+p and muonic neutrino in the final state, presented in Phys. Rev. C90, 024001 (2014).

Break-up channels in muon capture on3He

The μ − + 2 H → νμ + n + n, μ − + 3 He → νμ + 3 H, μ − + 3 He → νμ + n + d ,a ndμ − + 3 He → νμ + n + n + p capture reactions are studied with various realistic potentials under full inclusion offinal-state interactions. Our results for the two- and three-body break-up of 3 He are calculated with a variety of nucleon-nucleon potentials, among which is the AV18 potential, augmented by the Urbana IX three-nucleon potential. Most of our results are based on the single-nucleon weak-current operator. As a first step, we tested our calculation in the case of the μ − + 2 H → νμ + n + n and μ − + 3 He → νμ + 3 H reactions, for which theoretical predictions obtained in a comparable framework are available. Additionally, we have been able to obtain for the first time a realistic estimate for the total rates of the muon capture reactions on 3 He in the break-up channels: 544 s −1 and 154 s −1 for the n + d and n + n + p channels, respectively. Our results are compared with the most recent experimental data, finding a rough agreement for the total capture rates, but failing to reproduce the differential capture rates.

Break-up channels in muon capture onHe3

The mu + 2H -> nu + n + n, mu + 3He -> nu + 3H, mu + 3He -> nu + n + d and mu + 3He -> nu + n + n + p capture reactions are studied with various realistic potentials under full inclusion of final state interactions. Our results for the two- and three-body break-up of 3He are calculated with a variety of nucleon-nucleon potentials, among which is the AV18 potential, augmented by the Urbana~IX three-nucleon potential. Most of our results are based on the single nucleon weak current operator. As a first step, we have tested our calculation in the case of the mu + 2H -> nu + n + n and mu + 3He -> nu + 3H reactions, for which theoretical predictions obtained in a comparable framework are available. Additionally, we have been able to obtain for the first time a realistic estimate for the total rates of the muon capture reactions on 3He in the break-up channels: 544 1/s and 154 1/s for the n + d and n + n + p channels, respectively. Our results have also been compared with the most recent experimental data, finding a rough agreement for the total capture rates, but failing to reproduce the differential capture rates.

Electron scattering on two-neutron halo nuclei with full inclusion of final state interactions

Electron scattering on two-neutron halo nuclei with full inclusion of final state interactions

Final state interactions in nonleptonic hyperon decays

We investigate the importance of final state interactions in weak nonleptonic hyperon decays within a relativistic chiral unitary approach based on coupled channels. The effective potentials for meson-baryon scattering are derived from a chiral effective Lagrangian and iterated in a Bethe-Salpeter equation, which generates the low lying baryon resonances dynamically. The inclusion of final state interactions decreases the discrepancy between theory and experiment for both s and p waves. Our study indicates that contributions from higher order terms of the weak effective Lagrangian may play an important role in these decays.

Final state interactions in pion production from nuclei

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 at low invariant mass seen in recent data for invariant mass spectra with increasing atomic number. While the variation among nuclei is well reproduced for all charge states, the enhancement for the ratio for heavy nuclei to deuterium for the pi^+ pi^- final state is only partially understood.

Final state interaction effects inμ-capture induced two-body decay of3He

The $\ensuremath{\mu}$-capture process on ${}^{3}\mathrm{He}$ leading to a neutron, a deuteron, and a $\ensuremath{\mu}$-neutrino in the final state is studied. Three-nucleon Faddeev wave functions for the initial ${}^{3}\mathrm{He}$ bound and the final neutron-deuteron scattering states are calculated using the Bonn B and Paris nucleon-nucleon potentials. The nuclear weak current operator is restricted to the impulse approximation. Large effects on the decay rates of the final state interaction are found. The comparison to recent experimental data shows that the inclusion of final state interactions drastically improves the description of the data.

Polarized 3He and neutron form factors

The transverse-longitudinal response function R TL′ of 3He is studied with full inclusion of final state interaction. Contributions from each nucleon form factor are calculated. Possible relativistic effect is examined in extracting neutron charge form factor from associated spin-dependent asymmetry in inclusive scattering of polarized electrons from polarized 3He.

Lambda flow in heavy-ion collisions: The role of final-state interactions.

Lambda flow in Ni+Ni collisions at SIS energies is studied in the relativistic transport model (RVUU 1.0). It is found that for primordial lambdas the flow is considerably weaker than proton flow. The inclusion of final-state interactions, especially the propagation of lambdas in the mean-field potential, brings the lambda flow close to that of protons. An accurate determination of the lambda flow in heavy-ion experiments is shown to be very useful for studying lambda properties in dense matter. \textcopyright{} 1996 The American Physical Society.

Into two mesons in the quark annihilation model including final state interaction

Annihilation of proton-antiproton (pp) in flight into two mesons is analysed in the non-relativistic A2 quark model including the 3P0 quark-antiquark dynamics. Instead of the previously derived low-energy approximation an exact A2 transition amplitude is used. Applying a full coupled channels formalism we investigate the particular annihilation processes pp → ππ and pp → KK. Total and differential cross sections can be reproduced, assuming an additional strangeness suppression factor in the KK channel. Inclusion of final state interaction only effects polarisation observables and differential cross section in the backward region.

Inclusive electron scattering on 3H and 3He with full inclusion of final state interactions.

Inclusive electron scattering data on $^{3}\mathrm{He}$ and $^{3}\mathrm{H}$ are analyzed under full treatment of the final state interactions (FSI) using realistic nucleon-nucleon forces. The data are well described. We use two different methods, one where we calculate the pd and ppn breakup contributions separately and another one which is related to the optical theorem for Compton scattering. Both rely on precise solutions of Faddeev-like equations and agree perfectly. The importance of FSI and the inclusion of total isospin T=3/2 for the full breakup of $^{3}\mathrm{He}$ is demonstrated. We also comment on the Coulomb sum rule and the extraction of the proton-proton correlation function.

Response functions of three-nucleon systems

We present a formalism to calculate the three-nucleon response functions with full inclusion of final state interactions. Effects of the final state interactions are studied for the longitudinal response functions of 3H and 3He with some realistic NN interactions.

Cabibbo-favored hadronic two-body B decays.

We have analyzed hadronic B decays into \ensuremath{\psi}K, D\ensuremath{\pi}, ${\mathit{D}}^{\mathrm{*}}$\ensuremath{\pi}, and D\ensuremath{\rho} channels with a view to investigate if the uncertainties in the form factors and inclusion of final state interactions and annihilation terms would allow solutions with negative ${\mathit{a}}_{2}$/${\mathit{a}}_{1}$. We have concluded that the new CLEO II data cannot be understood with negative ${\mathit{a}}_{2}$/${\mathit{a}}_{1}$ even after allowing for the effects mentioned above.

Threshold electrodisintegration in the A=3 system.

Inclusive inelastic electron scattering cross sections for {sup 3}H and {sup 3}He were measured for excitation energies below 18 MeV. Longitudinal and transverse response functions were determined from these cross sections for six values of the three-momentum transfer {ital q} in the range 0.88 {lt}{ital q}{lt}2.87 fm{sup {minus}1}. A previously observed {ital C}0 multipole enhancement near threshold in the two-body channel for {sup 3}He is confirmed but is not observed for {sup 3}H. The experimental data are found to be in good agreement with two recent calculations of the longitudinal and transverse response functions. The first uses variational ground-state wave functions and the orthogonal correlated states method to describe the two- and three-body breakup channels. The second uses bound and continuum Faddeev wave functions obtained for a simple central potential. Agreement with the data is good for the first model and better for the second. The inclusion of final-state interactions (FSI) in the Faddeev continuum is found to be very important in these threshold breakup kinematics; in many cases inclusion of FSI changes the response functions by factors of two or three giving excellent agreement with the data. The transverse response functions are well reproduced, even though neither model includesmore » meson exchange currents. Ratios of the response functions for the two nuclei are also well described.« less

Exclusive electron scattering on3He with full inclusion of final-state interactions

Electron-induced proton-deuteron break-up of3 He is calculated using solutions of the 3N Faddeev equations for3He and the final p-d scattering state. The Paris- and Bonn-B two-nucleon interactions are employed. We study the importance of final-state interaction effects. Recent NIKHEF data are fairly well described.

Y scaling and final state interactions in 3He

Two theoretical approaches to y-italic scaling based on different treatments of final state interactions are compared. Experimental data show scaling in both treatments; however, there is strong disagreement between data and the West prediction based on a Faddeev momentum distribution. Partial inclusion of final state interaction by Sick, Day, and McCarthy substantially improves the comparison with data. Dramatic sensitivity to the treatment of final state interaction suggests that existing theoretical analyses are not decisive.

The magnitude of the parity-violating nucleon-pion couplingN 0-, and final-state interactions

The purpose of this letter is to present a new estimate for the magnitude ot the parity-violating amplitude ~ pT:(henceforth denoted by N~ based on the inclusion of final-state interactions. I t is important to know the magnitude of iV ~ because pion exchange contributes to the long-range par t of the weak parity-violating internucleon potential which manifests itself in parity-violating nuclear transitions (~). In a previous paper (2) TROFIMENKOFF and the author showed that the inclusion of final-state interactions in nonleptonic hyperon decay amplitudes led to a good fit of Sand P-wave amplitudes to experiment, in contrast to the mediocre fit obtained in the conventional current-algebra-PCAC method. Our conclusion in this letter is that the inclusion of final-state interactions, which has been shown (2) both to be essential and to lead to a much improved agreement with experiment for nonleptonic hyperon decays, significantly modiiics the older estimate for N ~ based on the current-algebraPCAC method (3.4). We now briefly review our method for including the effect of final-state interactions on parity-violating nonleptonie hyperon decays and the parity-violating AS----0 process j~--~pT:-. Our notation here is identical with that of ref. {2). This paper (2) should be referred to for general orientation and also specific results. The matrix element T for the parity-violating processes a ~ f l + ~(c) (we are t reat ing both AS = 0 and AS : 1 amplitudes here, because we shall later relate the AS = 0 to the AS-----1 amplitudes) with corresponding momenta P~-+P~-~-k and masses M ~ M~ + m can be wri t ten as