Related papers: No Sommerfeld resummation factor in e+e- -> ppbar …
Unexpected features of the BaBar data on e+e- in baryon-antibaryon cross sections are discussed. These data have been collected, with unprecedented accuracy, by means of the initial state radiation technique, which is particularly suitable…
A peculiar feature, observed in the BaBar data on e+e- -> baryon-antibaryon cross sections, is the non-vanishing cross section at threshold for all these processes. This is the expectation due to the Coulomb enhancement factor acting on a…
Contrary to the longtime and widely conceived belief, we proved that the specific heat coefficient $\gamma$ --also called Sommerfeld coefficient -- of the interacting Fermion system is not renormalized by the wave-function renormalization…
The reactions ppbar -> e+e- and e+e- -> ppbar are analyzed in the near-threshold region. Specific emphasis is put on the role played by the interaction in the initial- or final antinucleon-nucleon state which is taken into account…
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 investigate two exclusive processes, e+ e- -> eta_c + gamma and e+ e- -> J/psi + J/psi, at the center-of-momentum energy sqrt{s}=10.58 GeV within the framework of the nonrelativistic QCD factorization approach. A class of relativistic…
A new mechanism of baryon-antibaryon production via nonperturbative double pair creation in intermediate mesons is proposed and the theory contains no fitting parameters. It is shown, that near-threshold resonances are responsible for…
The Coulomb corrections to the cross section of $e^+e^-$ pair production in ultrarelativistic nuclear collisions are calculated in the next-to-leading approximation with respect to the parameter $L=\ln \gamma_A\gamma_B$ ($\gamma_{A,B}$ are…
We study the observed enhancement of a $p\bar p$ system near the threshold in the process $J/\psi \to \gamma p\bar p$ and $e^+ e^- \to p\bar p$. From early studies the enhancement can be explained by final state interactions, which are in…
The reaction $e^+e^- \to \bar \Lambda \Lambda$ is investigated for energies close to the threshold. Specific emphasis is put on the role played by the interaction in the final $\bar \Lambda \Lambda$ system which is taken into account…
In the reaction of the antiproton-deuteron electromagnetic annihilation pbar + d --> e+e-n the value of the invariant mass M of the (e+e-) pair can be near or below the (pbar p) mass even for enough high momentum of incident antiproton.…
We discuss the QCD constraints on e+e- --> baryon-anti-baryon close to threshold, in light of the puzzling experimental data which indicate that close to threshold sigma (e+e- --> n n-bar) > sigma (e+e- --> p p-bar). We focus on the process…
We employ a recent resummation method to deal with divergent series, based on the Meijer G-function, which gives access to the non-perturbative regime of any QFT from the first few known coefficients in the perturbative expansion. Using…
We have performed numerical simulations of the unpolarized e+e- --> p pbar process in kinematic conditions under discussion for a possible upgrade of the existing DAFNE facility. By fitting the cross section angular distribution with a…
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…
We improve the description of pion-photon interactions in the radiative return process $e^+e^-\to \pi^+\pi^-\gamma$ at the next-to-leading order by including the pion form factor in the Feynman rules. We present a general calculation of the…
Using recent BABAR, CMD-3 and SND data, the sum of $e^+e^- \to 3(\pi^+\pi^-), 2(\pi^+\pi^-\pi^0), p\bar{p}, n\bar{n}$ cross sections is obtained. Unlike $e^+e^- \to 3(\pi^+\pi^-)$ and $e^+e^- \to 2(\pi^+\pi^-\pi^0)$ processes, no structures…
Two-loop contributions to the electromagnetic form factors are calculated in the kinematic regime close to the fermion-antifermion threshold. The results are presented in an expansion in the velocity $\beta$ of the fermions in the c.m.…
We present a new calculation, in the nonrelativistic QCD (NRQCD) factorization formalism, of the relativistic corrections to the double-charmonium cross section sigma[e+ e- -> J/psi+eta_c] at the energy of the Belle and BABAR experiments.…
Numerical results on non-factorizable corrections to e+e- --> WW --> 4fermions with semi-leptonic and hadronic final states, as well as to e+e- --> ZZ --> 4fermions, are presented. The corrections turn out to be small in comparison to the…