相关论文: Leptonic decay of the Upsilon(1S) meson at third o…

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…

We present a calculation of the hindered M$1$ $\Upsilon(2S) \to \eta_b(1S) \gamma$ decay rate using lattice non-relativistic QCD. The calculation includes spin-dependent relativistic corrections to the NRQCD action through…

In the paper, we study the $\Upsilon(1S)$ leptonic decay width $\Gamma(\Upsilon(1S)\to \ell^+\ell^-)$ by using the principle of maximum conformality (PMC) scale-setting approach. The PMC adopts the renormalization group equation to set the…

We address the long-standing problem of negative decay and production rates in perturbative QCD for exclusive processes by proposing amplitude-level NRQCD factorization as a systematic prescription. Building on this, we present the first…

We determine the leading-order nonrelativistic quantum chromodynamics (NRQCD) matrix element < O_1 >_Upsilon and the ratio < q^2>_Upsilon, for Upsilon=Upsilon(nS) with n=1, 2, and 3 by comparing the measured values for Gamma[Upsilon -> e^+…

We examine the electronic width ratios of Upsilon resonances below the BBbar threshold by means of an effective (Cornell-type) QCD potential incorporating 1/m_b corrections obtained from a prior fit to the bottomonium spectrum. From our…

Using data obtained with the CLEO~III detector, running at the Cornell Electron Storage Ring (CESR), we report on a new study of exclusive radiative Upsilon(1S) decays into the final states gamma pi^+ pi^-, gamma K^+ K^-, and gamma p pbar..…

The decays of $\Upsilon(1s)\to\gamma(\eta',\eta)$ are studied by an approach which has successfully predicted the ratio $\frac{\Gamma(J/\psi\to\gamma\eta')}{\Gamma(J/\psi\to\gamma\eta)}$. Strong dependence on quark mass has been found in…

We report on a search for the radiative decay of Upsilon(1S) to the pseudoscalar mesons eta and etaprime in 21.2 +/- 0.2 times 10^6 Upsilon(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring (CESR). The eta…

In this paper, we calculate the decay widths and branching fractions for the decays $Z \to J/\psi+\Upsilon(nS)$ ($n=1,2,3$) at future super $Z$ factory and at the CEPC/FCC-ee, including both the relativistic and QCD corrections within the…

The CLEO Collaboration has observed the first hadronic transition among bottomonium (b bbar) states other than the dipion transitions among vector states, Upsilon(nS) -> pi pi Upsilon(mS). In our study of Upsilon(3S) decays, we find a…

In this work, we investigate the characteristics of the spin-singlet state $\eta_b$ of the bottomonia family via the radiative decays of $\Upsilon(nS)\to \eta_b+\gamma$. The theoretical estimation of the decay widths is carried out in terms…

We report on a study of exclusive radiative decays of the Upsilon(1S) resonance collected with the CLEO-II detector operating at CESR. We present the first observation of the radiative decays Upsilon(1S)->gamma pi+pi- and Upsilon(1S)->gamma…

In the framework of the nonrelativistic quantum chromodynamics factorization formalism, we study the processes of $\psi(nS)$ and $\Upsilon(nS)$ decay into a lepton pair or a charm pair associated with two jets up to the next-to-leading…

We report on a search for the radiative decay U(1S) -> gamma + eta' in 61.3 pb^-1 of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Three decay chains were investigated, all involving eta' -> pi+ pi- + eta,…

Using data taken with the CLEO II detector at the Cornell Electron Storage Ring, we have determined the ratio of branching fractions: $R_{\gamma} \equiv \Gamma(\Upsilon(1S) \rightarrow \gamma gg)/\Gamma(\Upsilon(1S) \rightarrow ggg) = (2.75…

Using the CLEO III detector we report on a new study of exclusive radiative Upsilon(1S) decays into the final states gamma pi^+ pi^-, gamma K^+ K^- and gamma p anti-p. We present branching ratios for the decay modes Upsilon(1S) to gamma…

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 study the $\Upsilon(1S)$ radiative decays to $\gamma \pi^+ \pi^-$ and $\gamma K^+ K^-$ using data recorded with the BaBar detector operating at the SLAC PEP-II asymmetric-energy $e^+ e^-$ collider at center-of-mass energies at the…

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…