Related papers: $\chi_{c1}$ and $\chi_{c2}$ production at $e^+e^-$…
Associated selectron-neutralino production in the process $e^-\gamma\to\tilde e^-\tilde\chi^0$ provides a striking supersymmetric signal: events with a single high $p_\perp$ electron and otherwise only invisible particles. For $e^-\gamma$…
Recent data from the Tevatron has revealed that the production rate of prompt charmonium at large transverse momentum is orders of magnitude larger than the best theoretical predictions of a few years ago. These surprising results can be…
In Supersymmetry with large $\tan\beta$ values, the lighter stau ($\tilde{\tau}_{1}$) may be lighter than the lightest chargino ($\tilde{\chi}^{\pm}_{1}$). The decay $\tilde{\chi}^{\pm}_{1} \to \tilde{\tau}^{\pm}_{1} \nu_{\tau}$, followed…
We calculate cross sections of a pair $B_c$ meson production on the basis of two-photon mechanism from electron-positron annihilation. We investigate the production cross sections in nonrelativistic approximation and with the account of…
One of the hot topics in hadron physics is the study of the new exotic charmonium states and the determination of their internal structure. Another important topic is the search for effects of the magnetic field created in high energy…
We study, at leading order in the large number of colours expansion and within the Resonance Chiral Theory framework, the odd-intrinsic-parity $e^+ e^- \rightarrow \pi^+ \pi^- (\pi^0, \eta)$ cross-sections in the energy regime populated by…
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…
A selection of results from electron-positron collisions at BESIII are reviewed. The results presented here illustrate the wide range of physics topics that can be studied using the Beijing Electron Positron Collider~(BEPC). At low…
We calculate the next-to-leading order QCD corrections to the excited charmonium $\chi_{cJ}$ associated with $ W^+ b $ production from top-quark decay. Our results show that detecting the $\chi_{c0}$ production from top-quark decay is very…
Classical and semi-classical energy states of relativistic electrons bounded by a massive and charged core with the charge-mass-radio Q/M and macroscopic radius R_c are discussed. We show that the energies of semi-classical (bound) states…
It is shown that $BR(\chi_{b1}(1P)\rightarrow Z\rightarrow e^+e^-)\simeq 3.3\cdot 10^{-7}$, $BR(\chi_{b1}(2P)\rightarrow Z\rightarrow e^+e^-)\simeq 4.1\cdot 10^{-7}$ and $BR(\chi_{c1}(1P)\rightarrow Z\rightarrow e^+e^-)\simeq 10^{-8}$ that…
In the present paper, we discuss the $P$-wave bottomonium production within the both color octet and color singlet models in NLO at LHC energies. We calculate the production and the transverse momentum distributions of the $\chi_{1,2b}$…
The first results of a project in progress for the validation of the simulation of electron-positron pair production are presented. They concern the pair production cross section in a low energy range close to the production threshold. The…
The ALICE Collaboration studies the production of J/psi meson in pp collisions at the center-of-mass energies of 2.76 and 7 TeV at mid- and forward-rapidity. Inclusive production cross-sections are presented as a function of the collision…
Belle and BaBar experiments at the KEKB and PEP-II B-factories provide also an excellent environment for spectroscopy studies. In this report we present recent results in the field of charmonium spectroscopy, focusing on new charmonium-like…
We analyze the production in $e^+e^-$ collisions of new heavy fermions stemming from extensions of the Standard Model. We write down the most general expression for the production of two heavy fermions and their subsequent decays, allowing…
We discuss bounds to strong gravity arising from annihilation of electron and positrons and the corresponding enhancement of the cross section for the production of massive particles. Two complementary examples are discussed, the case of…
We report the first observation of $e^+e^-$ annihilations into states of positive $C$-parity, namely $\rho^0 \rho^0$ and $\phi\rho^0$. The two states are observed in the $\pip\pim\pip\pim$ and $K^+K^-\pip\pim$ final states, respectively, in…
The advent of back-scattered laser beams for electron-positron colliders will allow detailed studies of a large array of high energy photon-photon and photon-electron collision processes with polarized beams. These include tests of…
We study the production of the lightest neutralinos in the radiative process $e^+e^- \to \tilde\chi^0_1 \tilde\chi^0_1\gamma$ in low energy supersymmetric models for the International Linear Collider energies with longitudinally polarized…