Related papers: Interference in the reaction $e^+e^-\to\gamma\pi^+…
We show that the final-state interaction explains the nontrivial near-threshold energy dependence of the cross section of the process $e^{+}e^{-}\rightarrow\Lambda_{c}\bar{\Lambda}_{c}$ observed by the Belle and BESIII collaborations. This…
Photon beam asymmetry $\Sigma$ measurements for $\omega$ photoproduction in the reaction $\vec{\gamma} p \to \omega p$ are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam,…
An effective interaction between fermions in a Bose-Fermi mixture is derived. It is induced by density fluctuations of the bosonic background. The contributions from states containing both one and two virtual phonons are taken into account…
The gauge invariant two-photon exchange (TPE) contributions in $e^-\pi^+ \rightarrow e^-\pi^+$ are discussed at hadronic level. The contact term is added to keep the full amplitude gauge invariant by two methods: one is to multiply form…
We propose a general classification of all four fermion final states in $\gamma\gamma$ collisions at a future $e^+e^-$ Linear Collider and discuss the relation of ``signal'' and ``background'' contributions in vector boson production. We…
The final state interactions (FSI) model in which soft rescattering of low mass intermediate states dominates is suggested. It explains why the strong interaction phases are large in the $B_d\to\pi\pi$ channel and are considerably smaller…
The process $e^+e^-\to K^+K^-\pi^0$ is studied with the SND detector at the VEPP-2000 $e^+e^-$ collider. Basing on data with an integrated luminosity of 26.4~pb$^{-1}$ we measure the $e^+e^-\to K^+K^-\pi^0$ cross section in the…
The exclusive reaction $\gamma p \to p \pi^+ \pi^-$ was studied in the photon energy range 3.0 - 3.8 GeV and momentum transfer range $0.4<-t<1.0$ GeV$^2$. Data were collected with the CLAS detector at the Thomas Jefferson National…
Strong final state interaction (FSI) effects can play a central role in the Standard Model prediction of weak $K\to 2\pi$ matrix elements. Here, I discuss how FSI's affect the direct CP violation parameter $\vepp / \vep$ by solving the…
A method parametrizing all inelastic final state interactions (FSI) in $B\to PP$ decays is presented ($P$ - pseudoscalar meson). The method explicitly shows how rescattering leads to the replacement of the short-distance amplitudes with the…
The cross section of reaction e^+e^-\to\pi^+\pi^-\pi^+\pi^- is calculated for energies 0.65\leq \sqrt{s}\leq1 GeV in the framework of the generalized hidden local symmetry model. The calculations are compared with the data of CMD-2 and…
Low-mass (sub-eV) spin-0 dark matter particles, which form a coherently oscillating classical field $\phi = \phi_0 \cos(m_\phi t)$, can induce oscillating variations in the fundamental constants through their interactions with the Standard…
Using ~600 pb-1 collected with the KLOE detector at DAPhiNE, we have studied the production cross section of pi+ pi- pi0 pi0 and p0p0 gamma final states in e+e- collisions at center of mass energies between 1000 and 1030 MeV. By fitting the…
We have studied the e+e- -> omegapi0 cross section in the sqrt(s) interval 1000-1030 MeV using the pi+pi-pi0pi0 and pi0pi0gamma final states with a sample of ~600 pb^-1 collected with the KLOE detector at DAFNE. By fitting the observed…
Fermilab experiment E835 has observed proton-antiproton annihilation production of the charmonium state chi_c0 and its subsequent decay into pi^0 pi^0. Although the resonant amplitude is an order of magnitude smaller than that of the…
In this paper we consider the possibility to test the FSR model in the reaction $e^+e^-\to\pi^+\pi^-\gamma$ at DA$\Phi$NE. We propose to consider the low $Q^2$ region ($Q^2$ is the invariant mass squared of the di-pion system) to study the…
The background due to the direct diffractive dissociation of the photon into the $\pi^+\pi^-$-pair to the "elastic" diffractive $\rho^0$-meson production in electron-proton collisions is calculated. The amplitude for the background process…
We study interference patterns in the phi -> gamma a0 + pi0 rho -> gamma pi eta and phi -> gamma f0 + pi0 rho -> gamma pi0 pi0 reactions. Taking into account the interference, we fit the experimental data and show that the background…
We present a unified picture which studies simultaneously the gamma gamma--> pi^+ pi^-, pi^0 pi^0,K^+ K^-, K^0 bar{K}^0, pi^0 eta reactions up to about sqrt(s)=1.4 GeV reproducing the experimental cross sections. The present work implements…
Unambiguous isospin violation in the strong interaction sector is a key issue in low energy hadronic physics, both experimentally and theoretically. Bernstein has employed the Fermi-Watson theorem to demonstrate that pion photoproduction is…