Related papers: The pion-pion scattering lengths from DIRAC
We compute the I=2 pi-pi scattering length at pion masses of m_pi ~ 294, 348 and 484 MeV in fully-dynamical lattice QCD using Luscher's finite-volume method. The calculation is performed with domain-wall valence-quark propagators on…
We calculate the leading isospin conserving few-nucleon contributions to pion scattering on $^2$H, $^3$He, and $^4$He. We demonstrate that the strong contributions to the pion-nucleus scattering lengths can be controlled theoretically to an…
The effects of two kinds of coherent lengths, the wave packet length of the emitter and the radius of the coherent source, on pion spectrum distribution are studied. It is shown that both coherent lengths can cause abundant pions at low…
Characteristic properties of pionium $A_{2\pi}$ and associated low energy s--wave cross sections $\sigma(\pi^0\pi^0\to \pi^0\pi^0)$, $\sigma(\pi^+\pi^-\to\pi^0\pi^0)$ and $\sigma(\pi^0\pi^0\to \pi^+\pi^-)$ are investigated with a coupled…
The S-wave scattering length of the strong pion-deuteron (pi D) scattering is calculated in the relativistic field theory model of the deuteron suggested in [1,2].The theoretical result agrees well with the experimental data. The important…
Using newly calculated electromagnetic corrections, we have made a phase shift analysis of experimental data on pi+/- p elastic scattering up to 100 MeV, assuming the effective hadronic interaction to be isospin invariant. The output…
We present a parameter--free calculation of the dispersive and absorptive contributions to the pion--deuteron scattering length based on chiral perturbation theory. We show that once all diagrams contributing to leading order to this…
The properties of QCD matter at finite isospin densities are investigated employing holographic hard-wall and soft-wall AdS/QCD models. It is confirmed that at high enough isospin densities, charged pions start to condense and the pion…
We report on the pion-pion scattering length in the I=2 channel using the parametrized fixed point action. Pion masses of 320 MeV were reached in this quenched calculation of the scattering length.
The next-to-leading order chiral pion-nucleon Lagrangian contains seven finite low-energy constants. Two can be fixed from the nucleon anomalous magnetic moments and another one from the quark mass contribution to the neutron-proton mass…
We present the pion-pion elastic scattering amplitude at finite temperature to one-loop in Chiral Perturbation Theory. The thermal scattering amplitude properly defined allows to generalize the perturbative unitarity relation to the $T\neq…
We apply the perturbative chiral quark model to give predictions for the electromagnetic O(p^2) low-energy couplings of the ChPT effective Lagrangian that define the electromagnetic mass shifts of nucleons and first-order (e^2) radiative…
It is shown that the linear correlation relates the S-wave phase shifts from the threshold up to dipion mass 900 MeV. By using this correlation at the solution of the Roy equations, the accuracy of determination of S-wave lengths is…
We present the results on the relativistic six-pion scattering amplitude at low energy, calculated at $\mathcal{O}(p^4)$ within the framework of the massive $\text{O}(N)$ nonlinear sigma model extended to the next-to-leading order in the…
We consider pion pair production in two-photon collisions, gamma* gamma -> pi+ pi-, at large photon virtuality Q^2 and center-of-mass energy \sqrt{s} in the hard-scattering picture. In the limit where s is large but s << Q^2 we derive an…
We review the cross sections for low-energy $\pi^- \gamma$ reactions in the framework of chiral perturbation theory. Charged pion Compton scattering, $\pi^- \gamma\to \pi^-\gamma$, is considered up to one-loop order where the pion's…
The electric (${\alpha}_{\pi}$) and the magnetic (${\beta}_{\pi}$) polarisabilities are fundamental properties of the pion characterising the rigidity of its internal structure. They have been precisely measured at the COMPASS experiment at…
The elastic pi-N scattering amplitude in the isospin limit is calculated in the framework of heavy baryon chiral perturbation theory, up to the third order. Threshold parameters like scattering lengths, volumes, effective ranges, etc. are…
Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell\le 3$ up to 2 GeV and calculate the low energy $\chi$PT…
We calculate the two-pion wave function for the I=2 $S$-wave two-pion system with a finite scattering momentum and estimate the interaction range between two pions. It allows us to examine the validity of the necessary condition for the…