Related papers: Test of final state approximations using threshold…
We report studies of the response of a massless particle confined by a potential. At large momentum transfer q it exhibits \tilde{y} or equivalently Nachtmann \xi scaling, and acquires a constant width independent of q. This width has a…
We perform a momentum-space calculation of the reaction $pp \rightarrow pp\pi ^0$ near threshold. Direct production and pion rescattering are taken into account. For the latter a T-matrix obtained from a microscopic model of the $\pi N$…
Final-state interactions in the response of a many-body system to an external probe delivering large momentum are normally described using the eikonal approximation, for the trajectory of the struck particle, and the frozen approximation,…
Final state interactions in the $S$--wave $\pi\pi$ system (I=0,2) are re-examined on the basis of the Omn\`es-Mus\-khe\-li\-shvili equation and the coupled channel formalism. The contributions to the pion scalar form factor from $\rho$ and…
A procedure is proposed which accounts for final state interaction corrections for near threshold meson production in nucleon-nucleon scattering. In analogy with the Watson-Migdal approximation, it is shown that in the limit of extremely…
A more reasonable trial ground state wave function is constructed for the relative motion of an interacting two-fermion system in a 1D harmonic potential. At the boundaries both the wave function and its first derivative are continuous and…
We evaluate the threshold matrix-element for the reaction $pp \to pp\pi^0$ in a fully relativistic Feynman diagrammatic approach. We employ a simple effective range approximation to take care of the S-wave $pp$ final-state interaction. The…
We analyse the experimental data on near threshold $\pi$, $\eta$, $\omega$, $\eta'$ and $K^+$ production from $pp$ collisions and show that all information gained so far is compatible with approximately constant production matrix elements…
The final-state interaction in multichannel decay processes is sytematically studied with application to B decay in mind. Since the final-state inteaction is intrinsically interwoven with the decay interaction in this case, no simple phase…
We investigate the nature of the near-threshold enhancement in the ppbar invariant mass spectrum of the reaction J/Psi -> gamma ppbar reported recently by the BES Collaboration. Using the Juelich NNbar model we show that the mass dependence…
Model independent formulae are derived for the polarizations and spin correlations of protons in the final state of $pp \to pp\omega $, taking into consideration all the six threshold partial wave amplitudes $f_1, ..., f_6$ covering $Ss,…
In this paper, we construct a type of interacting particle systems to approximate a class of stochastic different equations whose coefficients depend on the conditional probability distributions of the processes given partial observations.…
Near-threshold $\Lambda\bar\Lambda$ mass spectra for the reactions $e^+e^- \to \eta\Lambda\bar\Lambda$ and $e^+e^- \to \phi\Lambda\bar\Lambda$ are investigated with an emphasis on the role played by the interaction in the…
Recent results on particle momentum and spin correlations are discussed, particularly, in view of the role played by the effect of final state interaction. It is demonstrated that this effect allows for (i) correlation femtoscopy with…
It is shown that most of the available data on the $pp\to pp\eta$ reaction, including the invariant mass distributions in the $pp\to pp\eta$ reaction recently measured at COSY, can be understood in terms of the partial-wave amplitudes…
Beam dump experiments have been used to search for new particles with null results interpreted in terms of limits on masses $m_\phi$ and coupling constants $\epsilon$. However these limits have been obtained by using approximations…
We study the effects of a possible strong final state interaction among longitudinal W's in gamma.gamma --> W+W-. The relevant partial wave amplitudes are modified by an Omn\`es function approximated by a Breit-Wigner form factor. We study…
We quantify the important effect of strong final state interactions in the weak $K\to2\pi$ amplitudes, using the measured $\pi$--$\pi$ phase shifts with J=0 and $I=0,2$. The final rescattering of the two pions provides a strong enhancement…
The numerically exact evaluation of the van der Waals interaction, also known as Casimir interaction when including retardation effects, constitutes a challenging task. We present a new approach based on the plane-wave basis and demonstrate…
Calculations of two-step rescattering and pion emission for the 12C(e,e'p) reaction at very large missing energies and momenta are compared with recent data from TJNAF. For parallel kinematics, final state interactions are strongly reduced…