Related papers: Extracting the sigma-term from low-energy pion-nuc…
A microscopic model for the $N\bar N\to\pi\pi$ process is presented in the meson exchange framework, which in the pseudophysical region agrees with available quasiempirical information. The scalar ($\sigma$) and vector ($\rho$) piece of…
We highlight some of the recent advances in the application of chiral effective field theory (chiral EFT) with baryons to the $\pi N$ scattering process. We recall some problems that cast doubt on the applicability of chiral EFT to $\pi N$…
A description of low-energy scattering of pions and nuclei within a BUU transport model is presented. Implementing different scenarios of medium modifications, the mean free path of pions in nuclear matter at low momenta and pion absorption…
We present a light-front determination of the pionic contribution to the nucleon self-energy, $\Sigma_\pi$, to second-order in pion-baryon coupling constants that allows the pion-nucleon vertex function to be treated in a model-independent…
A novel extrapolation method has been used to deduce the charged Pion-Nucleon coupling constant from backward $np$ differential scattering cross sections. We applied it to new measurements performed at 162 MeV at the The Svedberg Laboratory…
This work provides a brief history of determinations of the pion-nucleon ($\pi N$) coupling constant from $\pi N$ and $N N$ data. From robust analyses of twenty reported values of the charged-pion coupling constant, exhibiting sizeable…
The scattering lengths of the pi Sigma systems are key quantities in understanding the structure of the Lambda(1405) resonance and the subthreshold extrapolation of the barK N interaction. We demonstrate that the pi Sigma scattering lengths…
We calculate the chiral corrections to Weinberg's prediction for the S--wave $\pi N$ scattering lengths up--to--and--including order ${\cal O}(M_\pi^3)$ making use of heavy baryon chiral perturbation theory. For the isospin--odd scattering…
We perform a detailed Regge analysis of NN, pion-N and pion-pion scattering. From it, we find expressions that represent the pion-pion scattering amplitudes with an accuracy of a few percent, for exchange of isospin zero, and $\sim15%$ for…
A comprehensive analysis of $\pi K\rightarrow \pi K$ and $\pi\pi\rightarrow K\bar K$ amplitudes at large unphysical pion mass for all important partial waves is presented. A set of crossing-symmetric partial-wave hyperbolic dispersion…
The scattering amplitude of the photoproduction of $\pi^{+}$ is calculated using the helicity formalism. The pseudovector coupling $\pi$-N interaction with the non-perturbative term is applied to the perturbative expansion. The parameters…
Low energy proton-proton scattering is studied in pionless effective field theory. Employing the dimensional regularization and MS-bar and power divergence subtraction schemes for loop calculation, we calculate the scattering amplitude in…
In recent years, high-accuracy data for pionic hydrogen and deuterium have become the primary source of information on the pion-nucleon scattering lengths. Matching the experimental precision requires, in particular, the study of…
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…
In this work, we develop an updated model for pion-nucleus scattering in the framework of the distorted wave impulse approximation in momentum space. We construct the second-order pion-nucleus potential, which involves analysis of…
We review two manifestations of chiral symmetry breaking in the pion sector. First, we examine the $\pi\pi$ scattering amplitude at threshold, which is completely determined by the chiral symmetry breaking part of the strong interaction,…
The nuclear sigma term is calculated including the nuclear matrix element of the derivative of the NN interaction with respect to the quark mass, $m_q\frac{\partial V_{NN}}{\partial m_q}$. The NN potential is evaluated in the…
The DIRAC experiment at CERN has achieved a sizeable production of $\pi^+\pi^-$ atoms and has significantly improved the precision on its lifetime determination. From a sample of 21227 atomic pairs, a 4% measurement of the S-wave $\pi\pi$…
We have considered the holographic large $N_c$ QCD model proposed by Sakai and Sugimoto and evaluated the non-Abelian DBI-action on the D8-brane upto $(\alpha')^4$ terms. Restricting to the pion sector, these corrections give rise to four…
We present technical details of the evaluation of the elastic pi-pi scattering amplitude to two loops in chiral perturbation theory. In particular, we elaborate on the renormalization procedure at the two-loop order and on the evaluation of…