Related papers: Modified S-wave $\pi\pi$ scattering amplitude for …
We continue the analysis of S-wave production amplitudes for the reaction pi- p -> pi+ pi- n involving the data obtained by the CERN--Cracow-Munich collaboration on a transversely polarized target at 17.2 GeV/c pi- momentum. This study…
We calculate the electromagnetic corrections needed to obtain isospin invariant hadronic pion-pion s-wave scattering lengths a^0, a^2 from the elements a_cc, a_0c of the s-wave scattering matrix for the (\pi^+ \pi^-, \pi^0 \pi^0) system at…
We present the first determination of $\rho \pi$ scattering, incorporating dynamically-coupled partial-waves, using lattice QCD, a first-principles numerical approach to QCD. Considering the case of isospin-2 $\rho \pi$, we calculate…
The determination of the Argonne National Laboratory-Osaka University (ANL-Osaka) Partial-Wave Amplitudes (PWA) of $\pi N$ and $\gamma N$ Reactions is reviewed. The predicted PWA are presented on a web page…
We use a recently developed formalism which generalizes the Weinberg's compositeness condition to partial waves higher than s-wave in order to determine the probability of having a $K \pi$ component in the $K^*$ wave function. A fit is made…
We extend the quark Born diagram formalism for hadron-hadron scattering to processes with valence $q\bar q$ annihilation, specifically $I=0$ and $I=1$ $\pi\pi$ and $I=1/2$ $K\pi$ elastic scattering. This involves the $s$-channel hybrid…
We report on a dispersion relation for the \gamma\gamma\to (\pi\pi)_I S-wave in isospin I emphasizing the low energy region. The f_0(980) signal that emerges in \gamma\gamma\to \pi\pi is also discussed. Our results could be used to…
We comment on a recent paper by Weiser et al. [Phys. Rev. C {\bf 54}, 1930 (1996)]. The authors have performed a single-energy analysis of $\pi^+ p$ scattering data at 68.3 MeV, finding a value for the $S_{31}$ phase shift about 1^o smaller…
A joint analysis of the pi+pi- and pi0pi0 S-wave amplitudes including results of three experiments has been performed. Using our theoretical model of the pion-pion production in which not only the pion exchange but also the a1(1260) meson…
Motivated by the $1/N_c$ expansion, we study a simple model in which the pi-K scattering amplitude is the sum of a current-algebra contact term and resonance pole exchanges. This phenomenological model is crossing symmetric and, when a…
The ``normal'' analysis of $\pbar p$ and $pp$ elastic scattering uses a `spinless' Coulomb amplitude, \ie a Rutherford amplitude ($2\sqrt{\pi}\alpha/t$) multiplied by a Coulomb form factor $G^2(t)$, an {\em ansatz} that pretends that the…
Charge-exchange rescattering $\pi^+\pi^-\to \pi^0\pi^0$ leads to a cusp effect in the $\pi^0\pi^0$ invariant mass spectrum of processes with $\pi^0\pi^0$ in the final state which can be used to measure $\pi\pi$ $S$-wave scattering lengths.…
The results of the analysis of the pi^0 pi^0 scattering amplitudes obtained with pi^- P charge exchange reaction, pi^- P --> pi^0 pi^0 n, data at 9 GeV/c are presented. The pi^0 pi^0 scattering amplitudes show clear f_0(1370) and f_2(1270)…
This paper is focused on two issues: the K\pi spectrum near threshold - the kappa problem -, and the pi\pi spectrum between 1.2 and 1.5 GeV/(c^2) -- the f_0(1370) problem. Both problems will be analysed from the perspective of the $D$ meson…
These lectures treat scattering theory from a non-perturbative point of view. The course begins with a review of formal aspects in scattering theory, discussing the in/out states and the $S$ matrix that connects them. Unitarity relations,…
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 preliminary analysis of $I=1$ $\pi\,\pi$ scattering at the physical point. We make use of the stochastic variant of the distillation framework (also known as sLapH) to compute the relevant two-point correlation matrices using a…
We re-investigate the impact of isospin violation for extracting the s-wave pion pion scattering phase shift difference delta_0(M_K) - delta_2(M_K) from K -> pi pi decays. Compared to our previous analysis in 2003, more precise experimental…
The model-independent analysis of the S- and P-wave pi-pi phase shifts was carried out. This analysis was based on the using of the Roy equations only and all available experimental data from the threshold up to dipion mass 1GeV. The S-wave…
The available experimental information is consistent with the Weinberg predictions for the threshold parameters of pi-pi-scattering. The data, however, only test those relations that are insensitive to the quark masses m_u and m_d. Recent…