Related papers: Study of e+e- annihilation at low energies
We sketch some recent ideas proposed as the mechanism behind the puzzling experimental results on baryon-antibaryon production in e+e- annihilation close to threshold. The essential new point in the proposed mechanism is that it is a…
Using the CLEO III detector, we measure absolute cross sections for e+e- -> hadrons at seven center-of-mass energies between 6.964 and 10.538 GeV. R, the ratio of hadronic and muon pair production cross sections, is measured at these…
Elementary particle physics using beams from accelerators and cosmic rays are compared. In particular, recent results on the energy evolution of charged particle multiplicities, the differences between quark and gluon jets, and scaling…
One of the basic motivations of the KLOE and KLOE-2 collaborations is the test of fundamental symmetries and the search for phenomena beyond the Standard Model via the hadronic and leptonic decays of ground-state mesons and via their…
We have updated our evaluation of the hadronic contribution to the running of the QED fine structure constant using the recent precise measurements of the e+e- annihilation at the center-of-mass (c.m.s.) energy region between 2.6 and 3.65…
Studies of hadronic final states of $e^+e^-$ annihilations, observed at the Large Electron Positron Collider LEP at CERN, are reviewed. The topics included cover measurements of $\alpha_s$, hadronic event shapes and hadronisation studies,…
A short review of theoretical and experimental results on fragmentation in e^+e^- annihilation is presented. Starting with an introduction of the concept of fragmentation functions in e^+e^- annihilation, aspects of scaling violation,…
The BABAR collaboration has nearly completed a program of precise measurements of the cross sections for the dominant channels of e+e- --> hadrons from threshold to an energy of 3-5 GeV using the initial-state radiation (ISR) method, i.e.…
We present the NGAMMA Monte Carlo event generator for QED processes of $e^+e^-$ annihilation into a multiphoton final state, $e^+e^-\to N\gamma (N \ge 2)$. These processes are an important source of background in the study of $e^+e^-\to…
Events with tagged photons in the process of electron-positron annihilation into hadrons are considered. The initial state radiation is suggested to scan the hadronic cross section with the energy. QED radiative corrections are taken into…
We present searches for the rare decay modes D0 to e+e-, D0 to mu+mu- and D0 to e mu in continuum e+e- to cbar c events recorded by the BABAR detector in a data sample that corresponds to an integrated luminosity of 468 f^-1. These decays…
This report reviews the achievements of the Crystal Barrel experiment at the Low Energy Antiproton Ring (LEAR) at CERN. During seven years of operation Crystal Barrel has collected very large statistical samples in pbarp annihilation,…
We present the first fully analytic calculation of the Quantum Chromodynamics (QCD) event shape observable Energy-Energy Correlation in electron-positron annihilation at Next-To-Leading Order (NLO). This result sheds light on the analytic…
We consider the computation of D and B fragmentation functions in e+e- annihilation. We compare the results of fitting present data using the next-to-leading-logarithmic resummed approach, versus the O(alpha_s^2) fixed-order calculation,…
The collimation $C$ of a hadronic event in the e^+e^- annihilation is defined as the average of $\cos\theta$, $C=<\cos\theta>$, where $\theta$ is the angle of each hadron measured from the thrust axis, and the average is over all the…
We present a selection of recent results from studies of rare hadronic B decays based on a sample of 232 million BBbar pairs, corresponding to an integrated luminosity of 211/fb, which were recorded with the BaBar detector at the PEP-II…
We argue that the recent CLEO-c data on $e^+e^-$ annihilation into pairs of charmed mesons at c.m. energy around 4.0 GeV are not well described by a single resonance $\psi(4040)$, but can be better understood if there is an additional…
Recent results on charged rare kaon decays from the NA48/2 Collaboration and on neutral kaon decays from the KLOE Collaboration will be reviewed.
Charged particle energy spectra in e+e- annihilation are compared with the analytical predictions from the QCD evolution equation in the Modified Leading Log Approximation. With the nonperturbative initial condition shifted down to…
We have studied hadronic events from e+e- annihilation data at centre-of-mass energies of sqrt{s}=172, 183 and 189 GeV. The total integrated luminosity of the three samples, measured with the OPAL detector, corresponds to 250 pb^-1. We…