Related papers: The back-to-back region in e^+e^- energy--energy c…
In this talk, we consider the computation of D and B fragmentation functions in e+e- annihilation. We present an improved differential cross section that merges together the O(alpha_s^2) fixed-order calculation and the…
We calculate the second-order QCD corrections to the forward-backward asymmetry in $e^+e^-$ annihilation. Using the quark axis definition, we do not agree with either existing calculation, but the difference relative to one of them is small…
We update a previous N$^3$LL$^\prime$+${\cal O}(\alpha_s^3)$ determination of the strong coupling from a global fit to thrust data by including newly available perturbative ingredients, upgrading the renormalization scales to include a…
The cross section for different processes induced by $e^+e^-$ annihilation, in the kinematical limit $\beta_{\mu}\approx\beta_{\pi}=(1-m_{\pi}^2/\epsilon^2)^{1/2}\sim 1$, is calculated taking into account first order corrections to the…
The recently proposed participant dissipating effective-energy approach is applied to describe the dependence on centrality of the multiplicity of charged particles measured in heavy-ion collisions at the collision energies up to the…
Fully relativistic approach to evaluate the correlation effects in highly charged ions is presented. The interelectronic-interaction contributions of first and second orders in $1/Z$ are treated rigorously within the framework of…
We present a detailed description of our calculation of next-to-leading order QCD corrections to heavy quark production in e^+ e^- collisions including mass effects. In particular, we study the observables $R_3^{b\ql}$ and $D_2^{b\ql}$ in…
Double logarithms of $Q^2/m_c^2$ that appear in the cross section for $e^+e^-\to J/\psi + \eta_c$ at next-to-leading order (NLO) in the strong coupling $\alpha_s$ account for the bulk of the NLO correction at $B$-factory energies. (Here,…
We study the azimuthal correlation of hadron pairs produced in hadron-hadron collisions in the framework of perturbative QCD. We concentrate our attention on the `almost back-to-back' region where resummation of large logarithms due to soft…
Next-to-Leading-Order(NLO) QCD corrections to J/jpsi plus eta_c production in e+e- annihilation at sqrt{s}=10.6 GeV is calculated in this paper, and an analytic result is obtained. By choosing proper physical parameters, a K factor (ratio…
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…
We present the analysis of two-particle angular correlations using coordinate systems defined with the conventional beam axis and the event thrust axis, and propose the latter to be a useful representation for the correlation structure…
A generator with $\alpha^2$ order radiative correction effects, including both the initial state radiative corrections and the photon vacuum polarization corrections, is built for the full simulation of $e^+e^- \to hadrons $ in cross…
The production of identified hadrons inside jets in $e^+ e^-$ annihilation allows for detailed studies of parton-to-hadron fragmentation functions in a clean environment. We compute hadron-in-jets production cross sections for $e^+e^- \to…
We explore the correspondence between the final state in e^+e^- annihilation and the small-x hadronic wavefunction in the transverse plane both in weakly coupled QCD and strongly coupled N=4 SYM. At strong coupling, the virtual and static…
The observed suppression of high-$p_T$ hadron spectra, finite azimuthal anisotropy, disappearance of jet-like back-to-back correlations, and their centrality dependence in $Au+Au$ collisions at RHIC are shown to be quantitatively described…
The energy-energy correlator (EEC) is an observable of wide interest for collider physics and Standard Model measurements, due to both its simple theoretical description in terms of the energy-momentum tensor and its novel features for…
Current and future colliders will provide high precision experimental data. In order to use the high experimental precision it has to be matched with theoretical predictions at the same level of accuracy or better. This involves the…
In this talk I will review the experimental status and the prospects for the future of $\sigma(e^+ e^- \to hadrons)$ at low energy. The recent preliminary results obtained by KLOE and BABAR collaborations using the radiative return will be…
A study of the energy dependence of event shape observables is presented. The strong coupling constant \alpha_s has been determined from the mean values of six event shape observables. Power corrections, employed for the measurement of…