Related papers: Determining alpha_s from the hyperfine splitting m…
We use the available data on e+ e- -> hadrons to determine the value of the QED coupling at the Z pole. The inclusion of recent preliminary BES-II data in the analysis is found to reduce the ambiguity in the determination of the coupling,…
Employing the heavy quark pole mass and static potential that were obtained from resummation of the renormalon-caused large order behavior to all orders, and matching the resummed static potential to the long distance Cornell potential we…
We present two determinations of the strong coupling \(\alpha_s\). The first one is from the static energy at three-loop accuracy, and may be considered an update of earlier determinations by some of us. The new analysis includes new…
We revise the analysis of the bottomonium hyperfine splitting within the lattice nonrelativistic QCD. The Wilson coefficients of the radiatively improved lattice action are evaluated by a semianalytic approach based on the asymptotic…
Theoretical basics and experimental determinations of the coupling parameter of the Strong Interaction, $\alpha_s$, are reviewed. The world average value of $\alpha_s$, expressed at the energy scale of the rest mass of the $Z^0$ boson, is…
We give results for the Upsilon spectrum from lattice QCD using an improved version of the NRQCD action for b quarks which includes radiative corrections to kinetic terms at O(v^4) in the velocity expansion. We also include for the first…
A novel method to extract the QCD coupling alpha_s from the energy evolution of the moments of the parton-to-hadron fragmentation functions at low fractional hadron momentum z, is presented. The evolution of the moments (multiplicity, peak,…
The prediction of the strong coupling assuming (supersymmetric) coupling constant unification is reexamined. We find, using the new electroweak data, $\alpha_{s}(M_{Z}) \approx 0.129 \pm 0.010$. The implications of the large $\alpha_{s}$…
We report the first evidence for the eta_b(2S) using the h_b(2P)->eta_b(2S)gamma transition and the first observation of the h_b(1P)->eta_b(1S)gamma and h_b(2P)->eta_b(1S)gamma transitions. The mass and width of the eta_b(1S) and eta_b(2S)…
The ground state hyperfine splitting of positronium $\Delta_{\mathrm{HFS}}$ is sensitive to high order corrections of quantum electrodynamics (QED) in bound state. The theoretical prediction and the averaged experimental value for…
The precise value of the strong coupling $\alpha_s(m_{Z})$ at the $Z$-boson mass $m_{Z}$ is essential for high-energy phenomenology and precision tests of quantum chromodynamics (QCD). We present the status of a program targeting a $\sim…
We give a brief review of our recent QCD analysis carried out over the deep inelastic scattering data on F2 structure function and in the non-singlet approximation to the accuracy up to next-to-next-to-leading-order. Specifically, analysis…
We determine the strong coupling constant $\alpha_s(M_Z)$ from the static QCD potential by matching a lattice result and a theoretical calculation. We use a new theoretical framework based on operator product expansion (OPE), where…
As tests of QCD in the bottomonium system, we give the most accurate results to date for the ground-state hyperfine splitting and the $\Upsilon$ leptonic width from full lattice QCD. These quantities are both accurately known from…
We calculate the Lamb, fine and hyperfine shifts in $b\bar b$ with $n=2$, $l=0,1$. Radiative corrections as well as leading nonperturbative corrections (known to be due to the gluon condensate) are taken into account. The calculation is…
Using recent CLEO III results for the cross section for $e^+e^- \to {\rm hadrons}$ at seven centre-of-mass energies between 6.964 and 10.538 GeV, we derive a value for the strong coupling constant…
Using the most recent release of the ALEPH $\tau$ decay data, we present a very detailed phenomenological update of the $\alpha_s(m_\tau^2)$ determination. We have exploited the sensitivity to the strong coupling in many different ways,…
By relating fine and hyperfine spittings for l=1 states in bottomium we can factor out the less tractable part of the perturbative and nonperturbative effects. Reliable predictions for one of the fine splittings and the hyperfine splitting…
We report the results of a search for the bottomonium ground state eta_b(1S) in the photon energy spectrum with a sample of (109 +/- 1) million of Upsilon(3S) recorded at the Upsilon(3S) energy with the BABAR detector at the PEP-II B…
Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the $h_b(1P)$ spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential…