相关论文: The ground state of bottomium to two loops and hig…
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…
Recent results on the QCD analysis of bound states of heavy $\bar{q}q$ quarks are reviewed, paying attention to what can be derived from the theory with a reasonable degree of rigour. We report a calculation of $\bar{b}c$ bound states; a…
We include two loop, relativistic one loop and second order relativistic tree level corrections, plus leading nonperturbative contributions, to obtain a calculation of the lower states in the heavy quarkonium spectrum correct up to, and…
The bottom quark pole mass $M_b$ is determined using a sum rule which relates the masses and the electronic decay widths of the $\Upsilon$ mesons to large $n$ moments of the vacuum polarization function calculated from nonrelativistic…
We report evidence for the ground state of bottomonium, eta_b(1S), in the radiative decay Upsilon(3S) --> gamma eta_b in e^+e^- annihilation data taken with the CLEO III detector. Using 6 million Upsilon(3S) decays, and assuming…
The talk presents an update of the bottom quark mass determination from QCD moment sum rules for the Upsilon system by the authors. Employing the MS_bar scheme, we find m_b(m_b) = 4.19 +- 0.06 GeV. The differences to our previous analysis…
We present an evaluation of heavy quarkonium states (bottomium and charmonium) from first principles. We use tree-level QCD (including relativistic corrections) and the full one-loop potential; nonperturbative effects are taken into account…
The mass of the bottom quark (both the pole mass $M_b$ and the $\MSb$ mass $m_b$) and the strong coupling constant $\alpha_s$ have been determined from QCD moment sum rules for the $\Upsilon$ system. In the pole-mass scheme large…
The bottom quark 1S mass, $M_b^{1S}$, is determined using sum rules which relate the masses and the electronic decay widths of the $\Upsilon$ mesons to moments of the vacuum polarization function. The 1S mass is defined as half the…
We study the spectra of the bottomonium and B_c states within perturbative QCD up to order alpha_s^4. The O(Lambda_QCD) renormalon cancellation between the static potential and the pole mass is performed in the epsilon-expansion scheme. We…
The mass of the bottom quark and the strong coupling constant alpha_s are determined from QCD moment sum rules for the Upsilon system. Two analyses are performed using both the pole mass M_b as well as the mass m_b in the $\MSb$ scheme. In…
We determine the bottom $\bar{\rm MS}$ quark mass $\bar{m}_b$ and the quark mass in the potential subtraction scheme from moments of the $b\bar{b}$ production cross section and from the mass of the Upsilon 1S state at…
Using CLEO data, we report on the confirmation of the eta_b(1S0) ground state of bottomonium in the radiative decay Upsilon(3S) -> gamma eta_b. We determine its mass to be M(eta_b) = 9391.8 +- 6.6 +- 2.1 MeV, which corresponds to the…
The renormalized mass of the bottom quark is calculated at the two loop level to order ${\cal O}(\alpha_s G_F M_t^2)$ in the $\msbar$ renormalization scheme. Different strategies for the computation are outlined. The result is applied to…
The bottomonium spectrum is systematically studied within an unquenched quark model. Based on a good description of both the masses and widths for the well-established states, we further give predictions for the higher $S$-, $P$-, and…
Inspired by the newly observed two charged bottomonium-like states, we consider the possible contribution from the intermediate $Z_b(10610)$ and $Z_b(10650)$ states to the $\Upsilon(5S)\to \Upsilon(2S)\pi^+\pi^-$ decay process, which…
We calculate the masses and leptonic decay widths of the bottomonium $b\bar b$ and charmonium $c\bar c$ states in a constituent quark model where the Cornell-like potential and spin-dependent interaction are employed, with all model…
The bottomonium spectrum up to $n = 3$ is studied within Non-Relativistic Quantum Chromodynamics up to N$^3$LO. We consider finite charm quark mass effects both in the QCD potential and the $\overline{\mathrm{MS}}$-pole mass relation up to…
We study the uncertainties in the MSbar bottom quark mass determination using relativistic sum rules to O(alpha_S^2). We include charm mass effects and secondary b bbar production and treat the experimental continuum region more…
We determine the decay rate to leptons of the ground-state $\Upsilon$ meson and its first radial excitation in lattice QCD for the first time. We use radiatively-improved NRQCD for the $b$ quarks and include $u$, $d$, $s$ and $c$ quarks in…