Related papers: The electromagnetic effects in $K_{e4}$ decay
We discuss charge symmetry breaking in the $\Lambda N$ interaction. In order to investigate the $\Lambda p$ and $\Lambda n$ interactions at low energies, we propose to utilize the $K^-d\to \pi^-\Lambda p$ and $K^-d\to \pi^0\Lambda n$…
A simple Regge pole model for $K\pi$ scattering explains the large $e^{i \delta}$ between isospin amplitudes which is observed at the D meson mass ($\delta \approx \pi/2$). It predicts $\delta \approx 14^{\circ}- 20^{\circ}$ at the B mass.…
The strong interaction shift $\epsilon$ and broadening {\Gamma} in pionic deuterium have been determined in a high statistics study of the {\pi}D(3p - 1s) X-ray transition using a high-resolution crystal spectrometer. The pionic deuterium…
We consider strong and electromagnetic isospin violation in near-threshold pion-kaon scattering. At tree level, such effects are small for all physical channels. We work out the complete one-loop corrections to the process pi^- K^+ -> pi^0…
Dipolar interaction between the magnetic moments of electrons is studied as a source for electron spin decay in quantum dots or arrays of quantum dots. This magnetic interaction will govern spin decay, after other sources, such as the…
Using results from the chiral perturbation theory for the s-wave interaction and the delta-resonance model for the p-wave interaction of pions with nucleons, we have evaluated the spectral functions of pions in asymmetric nuclear matter…
The isoscalar and isovector scattering lengths (b_0,b_1) are determined using a unitarized coupled channel approach based on chiral Lagrangians. Using experimental values of pionic hydrogen and deuterium as well as low energy pi N…
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…
We recently considered $K_{\ell 4}$ decays in the framework of chiral perturbation theory based on the effective Lagrangian including mesons, photons, and leptons. There, we published analytic one-loop-level expressions for form factors $f$…
We argue that due to isospin and U-spin invariance of strong low-energy interactions the S-wave scattering lengths a^0_0 and a^1_0 of bar-KN scattering with isospin I=0 and I = 1 satisfy the low-energy theorem a^0_0 + 3 a^1_0 = 0 valid to…
We present calculations of the $S$-wave isospin-zero and isospin-two pion-pion scattering lengths within a nucleon-meson model with parity doubling. Both scattering lengths are computed in various approximations, ranging from a mean-field…
We investigate the low-energy interactions between the charmonium state $J/\psi$ and the light pseudoscalar mesons ($\pi$ and $K$) within the framework of dispersion relations.We demonstrate that the symmetry-breaking terms in the chiral…
Inelastic neutron scattering (INS) experiments were performed to investigate the spin dynamics in magnetoelectric effect (ME) LiCoPO$_4$ single crystals. Weak dispersion was detected in the magnetic excitation spectra along the three…
Recent results from the NA48/2 experiment are presented. The $\pi\pi$ scattering lengths $a_0^0$ and $a_0^2$ have been extracted from the cusp in the $M_{00}^2$ distribution of $K^\pm \to \pi^\pm \pi^0 \pi^0$ decays and from the $K^\pm \to…
We study the effect of isospin degree of freedom on the balance energy (E$_{bal}$) as well as its mass dependence throughout the mass range for two different sets of isobaric systems with N/Z = 1 and 1.4 at different colliding geometries…
The S wave pion deuteron scattering length is presented at NLO in the Effective Field Theory formulation of the two nucleon system with perturbative pions. At this order, this observable is determined by the iso-scalar S wave pion nucleon…
We consider pion-nucleon scattering in heavy-baryon chiral perturbation theory to third order. All electromagnetic corrections appearing to this order are included. We thus have a consistent description of strong and electromagnetic…
The pion-deuteron scattering length is computed to next-to-next-to-leading order in baryon chiral perturbation theory. A modified power-counting is then formulated which properly accounts for infrared enhancements engendered by the large…
In the last few years it has become possible to study low energy pi pi scattering in kaon decays to three pions, thanks to the high statistics measurement of K+- -> pi+- pi0 pi0 decays performed by the NA48/2 experiment at the CERN SPS. At…
The four-body decays $D^+ \to K^-\pi^+e^+\nu_e$ ($D_{e4}^+$) and $D^0\to \overline{K^0}\pi^-e^+\nu_e$ ($D^0_{e4}$) are studied in a model where the momentum-dependence of the hadronic matrix elements are described in terms of $K^*(892)$ and…