Related papers: Mixing of partial waves near $B^* \bar B^*$ thresh…
The s-channel annihilation of proton and antiproton into a neutral pion and a real or virtual photon followed by lepton pair emission is studied. Such mechanism is expected to play a role at moderate values of the total energy $\sqrt{s}$,…
The production of heavy meson-antimeson pairs of the type $S\,V$ and $P \, A$ in $e^+e^-$ annihilation is considered, with $P$ and $V$ being the ground-state $J^P=0^-$ and $J^P=1^-$ (anti)mesons from the $(1/2)^-$ doublet, and $S$ and $A$…
We consider the process of annihilation of e^+ e^- to three pion final state for the case of moderately high energies. The final state emission of virtual and real photon is considered explicitly. The calculations are performed in frames of…
Short range meson-exchange mechanisms such as $\rho\to\omega\pi^0$ contribute significantly to the amplitude for $pp\rightarrow pp\pi^0$ near threshold in addition to pion rescattering. The uncertainty of the latter contribution, which…
We compute the mass shifts and mixing of the Omega and Phi mesons at finite temperature due to scattering from thermal pions. The Rho and b_1 mesons are important intermediate states. Up to a temperature of 140 MeV the Omega mass increases…
The large set of accurate data on differential cross section and analyzing power from the CERN LEAR experiment on $\bar pp \to \pi^+\pi^-$ in the range from 360 to 1550 MeV/c is well reproduced within a distorted wave approximation…
A partial wave analysis of the of the $\pi ^0\pi ^0$ system produced in the charge exchange reaction: $\pi ^-p\to \pi ^0\pi ^0n$ at an incident momentum of $18.3 GeV/c$ is presented as a function of ${\pi ^0\pi ^0}$ invariant mass,…
We evaluate the threshold matrix-element for the reaction $pp \to pp\pi^0$ in a fully relativistic Feynman diagrammatic approach. We employ a simple effective range approximation to take care of the S-wave $pp$ final-state interaction. The…
The energy dependence of the cross sections of $p\bar p$, $n\bar n$, and meson production in $e^+e^-$ annihilation in the vicinity of the $p\bar p$ and $n\bar n$ thresholds is studied. The proton-neutron mass difference and the $p\bar p$…
We study CP violation and the contribution of the strong pion-pion interactions in the three-body B+- --> pi+- pi-+ pi+- decays within a quasi two-body QCD factorization approach. The short distance interaction amplitude is calculated in…
The electron positron annihilation reaction into four pion production has been studied, through the channel $e^++e^-\to \bar \rho+\rho $. The differential (and total) cross sections and various polarization observables for this reaction…
We study the energy dependence of the e^+e^- to ppbar cross section close to the two-nucleon threshold, recently reported by the BaBar collaboration. Our analysis also includes the pbarp to e^+e^- data collected by PS170 collaboration and…
In the first Born approximation we study the reactions $K\phi\to\pi K$, $\rho K$, $\pi K^*$, and $\rho K^*$ with quark-antiquark annihilation and creation. Transition amplitudes are derived with the development in spherical harmonics of the…
Based on 12.0 $\mathrm{fb^{-1}}$ of $e^{+}e^{-}$ collision data samples collected by the BESIII detector at center-of-mass energies from 4.1271 to 4.3583 GeV, a partial wave analysis is performed for the process $e^{+}e^{-} \rightarrow…
In this work, we provide a simultaneous and accurate description of the $\pi^+\pi^-$ and $\pi^{\pm} J/\psi$ invariant mass distributions of the recent BESIII data on $e^+ e^- \to J/\psi \; \pi^+ \pi^-$ together with the $e^+ e^- \to J/\psi…
The cross section of the $p(e,e'\pi^+)n$ reaction has been measured for five kinematic settings at an invariant mass of $W = 1094$ MeV and for a four-momentum transfer of $Q^2 = 0.078$ (GeV/$c$)$^2$. The measurement has been performed at…
We calculate the pion self-energies in asymmetric nuclear matter in the two-loop approximation of chiral perturbation theory. We find three types of corrections beyond the well-known linear density approximation. The resulting s-wave…
The process of $e^+ e^-$ annihilation into $\pi^+ \pi^-$ pair with radiation of the photon is considered. The amplitude of the reaction $e^+ e^- \to \pi^+ \pi^- \gamma$ consists of the model independent initial-state radiation (ISR) and…
The charge asymmetry in the process $e^+e^-\to \pi^+\pi^-\pi^0$ is studied taking into account a longitudinal polarization of electrons (positrons). The asymmetry arises due to interference of amplitudes corresponding to production of pions…
The $K^+$ and $K^0$ meson mass difference induces the mixing of the $a^0_0(980)$ and $f_0(980)$ resonances, the amplitude of which, between the $K^+K^-$ and $K^0\bar K^0$ thresholds, is large in magnitude, of the order of $…