Related papers: $\gamma\gamma$ physics with the KLOE experiment
We present a precise measurement of the ratio R_K=B(K\to e\nu(\gamma))/B(K\to \mu\nu(\gamma)) and a study of the radiative process $K\to e\nu\gamma$, performed with the KLOE detector. The results are based on data collected at the Frascati…
The processes $ e^+e^-\rightarrow \Sigma^0\overline{\Sigma}{}^0 $ and $ e^+e^-\rightarrow\Sigma^+\overline{\Sigma}{}^-$ are studied using initial-state-radiation events in a sample of 980 $\,\mbox{fb}^{-1}$ collected with the Belle detector…
We report on the first observation of the decay KL -> pi0 ee gamma by the KTeV E799 experiment at Fermilab. Based upon a sample of 48 events with an estimated background of 3.6 +/- 1.1 events, we measure the KL -> pi0 ee gamma branching…
The cross section of the process $e^+e^- \to \pi^+\pi^-\pi^0\eta$ has been measured using a data sample of 21.8 pb$^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider. 2769$\pm$95 signal events have been selected in…
The ee -> ee+pi0+X and ee -> ee+K0s+X reactions are studied at LEP using data collected with the L3 detector at sqrt{s}=189-202 GeV. Preliminary results for the differential cross section dsigma/dpt in the transverse momentum range 0.2 GeV…
The study of electron-positron collisions at center-of-mass energies corresponding to charmonium production has reached new levels of sensitivity thanks to experiments by the BES and CLEO Collaborations. Final states $\gamma P$, where $P$…
The KLOE detector at DAFNE, the Frascati Phi-factory, has collected about 8 millions phi decays in 1999. Measurements of Phi decays into pi0, eta, eta', f0(980), a0(980) and pi+pi-pi0 have been performed with statistical accuracy better…
We have measured the absolute branching ratio of the K+ -> pi+ pi0 (gamma) decay, using about 20 million tagged K+ mesons collected with the KLOE detector at DAFNE, the Frascati phi-factory. Signal counts are obtained from the fit of the…
The dynamics of the process $ e^+e^- \to \pi^+\pi^-\pi^0 $ is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 $e^+e^-$ collider. The Dalitz plot distribution and $\pi^+\pi^-$…
Using $15.6$ $\rm fb^{-1}$ of $e^+e^-$ collision data collected at twenty-four center-of-mass energies from $4.0$ to $4.6$ GeV with the BESIII detector, the helicity amplitudes of the process $e^+e^-\to \pi^{+}\pi^{-}\omega$ are analyzed…
The $e^+ e^- \to K^0_{S}K^0_{L}$ cross section has been measured in the center-of-mass energy range 1004--1060 MeV at 25 energy points using $6.1 \times 10^5$ events with $K^0_{S}\to \pi^+\pi^-$ decay. The analysis is based on 5.9 pb$^{-1}$…
Photon colliders (gamma-gamma, gamma-e) are based on backward Compton scattering of laser light off the high energy electrons of linear colliders. Recent study has shown that the gamma-gamma luminosity in the high energy peak can reach…
The process $e^+e^- \to \omega\pi^0 \to \pi^+\pi^-\pi^0\pi^0$ is studied in the center-of-mass energy region $1.05-2.00$ GeV using data with an integral luminosity of about 35 pb$^{-1}$ collected with the SND detector at the VEPP-2000…
The cross section of the process $e^+e^- \to K_S^0 K_S^0\pi^+\pi^-$ has been measured using a data sample of 56.7 pb$^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider. 596$\pm$27 and 210$\pm$18 signal events have…
We present a fully differential computation of $e^+\,e^-\to\gamma\,\gamma$ at next-to-next-to-leading order in QED. The process has been implemented into McMule, completing its set of next-to-next-to-leading-order calculations for the most…
A cross section of the process $e^+e^- \to \pipi\pipi$ has been measured using 6798$\pm$93 signal events from a data sample corresponding to an integrated luminosity of 9.8 pb$^{-1}$ collected with the CMD-3 detector in the center-of-mass…
The $e^+e^- \to \pi^+ \pi^- \pi^0 \chi_{bJ}$ ($J=0,~1,~2$) processes are studied using a 118~fb$^{-1}$ data sample collected at a center-of-mass energy of 10.867 GeV, in the $\Upsilon(10860)$ energy range, with the Belle detector. The…
The KLOE experiment at DAPHNE has collected ~ 450 pb-1 of e+e- collisions at center of mass energy W~1.02 GeV. Preliminary results are presented for the most recent measurements: limit on the BR(Ks->3pi0), BR of the Ke3 decay of the Ks and…
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…
The particle production in photon-photon ($\gamma \gamma$) interactions present in electron-ion collisions is investigated. We present calculations for the total cross sections and event rates related to the production of light mesons…