Related papers: I=2 pion scattering length with the parametrized f…
We conduct a two-flavor ($N_f=2$) lattice QCD calculation of the elastic phase-shifts for pion-pion scattering in the scalar, isoscalar channel (the $\sigma$-meson). The calculation is performed for two quark masses corresponding to a pion…
High statistics sample of kaon decays collected by NA48-CERN experiment allowed two independent measurements of the pion scattering length. Methods and Results are discussed
In this work we present the analysis of the energy spectrum from a recent two-flavor ($N_f=2$) lattice QCD calculation for pion-pion scattering in the scalar, isoscalar channel (the $\sigma$-meson). The lattice simulation was performed for…
Elastic nucleon-pion scattering amplitudes are computed using lattice QCD on a single ensemble of gauge field configurations with $N_{\rm f} = 2+1$ dynamical quark flavors and $m_{\pi} = 200~{\rm MeV}$. The $s$-wave scattering lengths with…
We present a lattice QCD calculation of the scattering phase shift for the I=2 $S$-wave two-pion system using the finite size method proposed by L\"uscher. We work in the quenched approximation employing the standard plaquette action at…
A new evaluation of the universal $\pi\pi$ scattering length relation is used to extract the $\pi\pi$ $s$-wave scattering lengths from threshold pion production data. Previous work has shown that the chiral perturbation series relating…
Our study on the cut-off effects in quenched light hadron spectroscopy and pion scattering length with the fixed point action is extended by results obtained at a lattice spacing a=0.102 fm in a box of size L=1.8 fm. The cut-off effects are…
We present results for the isospin-0 $\pi\pi$ s-wave scattering length calculated with Osterwalder-Seiler valence quarks on Wilson twisted mass gauge configurations. We use three $N_f = 2$ ensembles with unitary (valence) pion mass at its…
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…
A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon scattering length, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge…
Chiral Ward identities lead to consistent accounting for the sigma's width in the linear sigma model's Feynman rules. Reanalysis of pion scattering data at threshold imply a mass for the sigma of 600+ 200 - 100 MeV.
A complete calculation of the corrections to pion-deuteron scattering length up to order $\chi^{3/2}$ with $\chi=m_{\pi}/M_{N}$ is performed. The calculation includes the dispersive contributions and corrections due to the explicit…
We present the first-ever lattice computation of pi pi-scattering in the I=1 channel with Nf=2 dynamical quark flavours obtained including an ensemble with physical value of the pion mass. Employing a global fit to data at three values of…
The scattering lengths of a two pion system are the {\it golden magnitudes} to test the QCD predictions in the low energy sector. The DIRAC (PS-212) experiment at CERN will obtain a particular combination of the S-wave isospin 0 and 2…
We study pion-pion scattering in partially-quenched twisted-mass lattice QCD using chiral perturbation theory. The specific partially-quenched setup corresponds to that used in numerical lattice QCD calculations of the $I=0$ scattering…
The multichannel S- and P-wave amplitudes for the pion-pion scattering, constructed requiring analyticity and unitarity of the S-matrix and using the uniformization procedure, are elaborated using the dispersion relations with imposed…
Scattering lengths for two pseudoscalar meson systems, $\pi\pi(I=2)$, $KK(I=1)$ and $\pi K(I=3/2,\ 1/2)$, are calculated from lattice QCD by using the finite size formula. We perform the calculation with $N_f=2+1$ gauge configurations…
We perform a non-perturbative lattice calculation of the P-wave pion-pion scattering phase in the rho-meson decay channel using two flavors of maximally twisted mass fermions at pion masses ranging from 480 MeV to 290 MeV. Making use of…
We use the framework of effective field theories to discuss the determination of the S-wave \pi N scattering lengths from the recent high-precision measurements of pionic deuterium observables. The theoretical analysis proceeds in several…
We investigate how L\"uscher's relation between the finite-volume energy of two pions at rest and pion scattering lengths has to be modified in quenched QCD. We find that this relation changes drastically, and in particular, that ``enhanced…