Related papers: Octet contributions in radiative upsilon decays
The inclusive $\Upsilon(1S,2S,3S)$ photoproduction at the future Circular-Electron-Positron-Collider (CEPC) is studied based on the non-relativistic QCD (NRQCD). Including the contributions from both direct and resolved photons, we present…
The effect of isoscalar S-wave multichannel pi pi -> pi pi, K antiK, eta eta scattering is considered in the analysis of decay data of the Upsilon-mesons. We show that when allowing for the final state interaction contribution to the decays…
Semileptonic decays of doubly heavy baryons are studied in the framework of the relativistic quark model. The doubly heavy baryons are treated in the quark-diquark approximation. The transition amplitudes of heavy diquarks bb and bc going…
We discuss the non-perturbative and the radiative corrections to inclusive B decays from the point of view known from QED corrections to high energy e^+ e^- processes. Here the leading contributions can be implemented through the so called…
We present a non-perturbative lattice calculation of the form factors which contribute to the amplitudes for the radiative decays $P\to \ell \bar \nu_\ell \gamma$, where $P$ is a pseudoscalar meson and $\ell$ is a charged lepton. Together…
Hadronic annihilation rate of $1^{+-}$ heavy quarkonium is given to next-to-leading order in $\alpha_s$ and leading order in $v^2$ using a recently developed factorization formalism which is based on NRQCD. The result includes both the…
We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at $O(m\alpha_s^5)$ in the heavy quarkonium spectrum. These leading logs, when…
Using Nonrelativistic QCD on the lattice we studied the mass spectrum of quarkonium systems nonperturbatively for a range of the bar quark mass. We determined two products of the matrix elements involved in quarkonium decays and studied the…
With the potential prospects of the ${\Upsilon}(nS)$ at high-luminosity dedicated heavy-flavor factories, the color-favored ${\Upsilon}(nS)$ ${\to}$ $B_{c}{\pi}$, $B_{c}K$ weak decays are studied with the pQCD approach. It is found that…
Using the Ogata-Shiba wave function, the spectral functions of the one-dimensional infinite U Hubbard model are calculated for various concentrations. It is shown that the ``shadow band'' feature due to 2k_F fluctuations becomes more…
The recent observation and measurement of the decay $Z_c(3900) \to \rho \eta_c$ provides the data on the relative strength of the pion and $\rho$ coupling in the corresponding transitions between exotic resonances and pure heavy quarkonium.…
The conventional color-singlet model was challenged by the recent data on quarkonium production. Discrepancies in production rates were observed at the Tevatron, at LEP, and in fixed-target experiments. The newly advocated color-octet…
In this talk the ALP production from radiative quarkonium decays is presented. To this purpose, the relevant cross-section is computed from a $d=5$ effective Lagrangian containing simultaneous ALP couplings to $b(c)$-quarks and photons. The…
We calculate the decay rate of bottomonium to two-charm quark jets $\Upsilon \to c \bar c$ at the tree level and one-loop level including color-singlet and color-octet $b \bar b$ annihilations. We find that the short distance coefficient of…
QED gauge invariance, when combined with analyticity, leads to constraints on the low energy end of the emitted photon spectra. This is known as Low's theorem. It is shown that the Ore-Powell result, as well as further developments for the…
The NLO QCD corrections to Upsilon production via S-wave color-octet states Upsilon(^1S_0^8,^3S_1^8) at the Tevatron and LHC is calculated. The K factors of total cross section (ratio of NLO to LO) are 1.313 and 1.379 for Upsilon(^1S_0^8)…
In this article, we study the radiative transitions among the vector and scalar heavy quarkonium states with the covariant light-front quark model. In calculations, we observe that the radiative decay widths are sensitive to the constituent…
We extend an earlier calculation within lattice QCD of excited light meson resonances with $J^{PC}=1^{--}, 2^{--}, 3^{--}$ at the SU(3) flavor point in the singlet representation, by considering the octet representation. In this case the…
We compute the O(\alpha_s^2) contributions to the photon energy spectrum of the inclusive decay \bar{B} -> X_s \gamma associated with the magnetic penguin operator O_7. They are an essential part of the ongoing NNLO calculation of this…
We present a relativistic calculation of two-photon decays for heavy and light mesons in the framework of the Salpeter equation for quark-antiquark states. The meson-photon-photon vertex is computed by reconstructing the Bethe-Salpeter…