Related papers: Colour Octet Contribution in Exclusive P-Wave Char…
We show that although there is no infrared divergence in exclusive P-wave quarkonium decays, the colour octet contribution is no less important than in the inclusive decay. Results from more proper calculations with only colour singlet…
In the last years, the need of the colour octet state in inclusive P-wave charmonium decay has been firmly established. However, the implications of this in the corresponding exclusive reactions have not been fully recognized. We argue for…
It is argued that colour octet contribution in exclusive charmonium decays is very important even though the same infrared divergence found in P-wave colour singlet inclusive decay is absent. This comes about because of the suppression at…
Recent advances in our understanding of the higher-wave quarkonia have generated much interests in quarkonium physics. However most are devoted to inclusive decays and productions. Experimental data of several two-body exclusive decay…
The importance of the color octet component in P-wave charmonia is discussed in the context of exclusive decay processes. It is vital to include this contribution already at the level of the two-body decay channels. The \pi \pi and…
We investigate the theoretical uncertainties of $P$-wave charmonium decays into two pions, $\chi_{\c J}\rightarrow \pi^+\pi^-$, $\pi^0\pi^0$. Constraining the pion distribution-amplitude from the recent precise data on $F_{\pi\gamma}(Q^2)$,…
We demonstrate that exclusive B decays to P-wave charmonium factorize in the non-relativistic limit provided that colour-octet contributions are taken into account, and estimate the branching fractions. Although there are very large…
We compute the decay rates and $H$-energy distributions of $B$ mesons into the final state $H+X$, where $H$ can be any one of the $S$-wave or $P$-wave charmonia, at next-to-leading order in the strong coupling. We find that a significant…
In the framework of QCD factorization, we study the $B$ meson exclusive decays $B\to \chi_{cJ}K$ where the spin-triplet P-wave charmonium states $\chi_{cJ}(J=0,1,2)$ are described by the color-singlet non-relativistic wave functions. We…
Calculations for inclusive J/psi production in Upsilon decay through the color-octet mechanisms b\bar b[^3S_1, 1] -> c \bar c[^{2s+1}L_J, 8] + g are presented. It is shown that these O(alpha^5_sv^4_c) contributions compete with other…
In Z^0 decay into prompt charmonium, ie. charmonium not originating from B-meson decays, the most important contribution is expected to come from colour-octet mechanisms. However, previous fixed-order calculations of the colour-octet…
The importance of including colour octet contributions in describing decay and production of quarkonium states is briefly discussed for two cases : the radiative decays of the $\Upsilon$ and the production of $J/\psi$ in the inclusive $B$…
We study hadronic decays $\chi_{cJ}\rightarrow K^*(892)\bar{K} $ within the effective field theory framework. We consider the colour-singlet and colour-octet contributions and study their properties using (p)NRQCD effective theory. We show…
We present a discussion of radiative decays $\chi_{cJ}\rightarrow\gamma \rho (\omega, \phi)$. The decay amplitudes are computed within the QCD factorisation framework. NRQCD has been used in the heavy meson sector as well as a collinear…
The proton form factor, two-photon annihilations into $p\bar{p}$ as well as exclusive charmonium decays are critically examined. It will be argued that the standard perturbative QCD analysis of these reactions fails, i.e. the need for…
The contributions from the color-octet components $|(c\bar b)_{\bf 8}(^{1}S_{0}) g>$ and $|(c\bar b)_{\bf 8}(^{3}S_{1}) g>$ to the $h_{B_c}$ or $\chi_{B_c}^J$ (the $P$-wave $B_c$ meson) hadroproduction are estimated in terms of the complete…
In this paper we present a complete next-to-leading order QCD calculation of the $\chi_J$ ($^3P_J\; ;J=0,1,2$) hadronic decay width. We include the NLO colour-octet contribution, as defined in the Bodwin, Braaten and Lepage formalism. We…
The role of power corrections and higher Fock-state contributions to exclusive charmonium decays will be discussed. It will be argued that the J/Psi (Psi') decays into baryon-antibaryon pairs are dominated by the valence Fock-state…
We show that the colour-singlet contributions to the hadroproduction of J/psi in association with a W boson are sizable, if not dominant over the colour-octet contributions. They are of two kinds, sg -> J/psi + c + W at alpha^3_S alpha and…
We calculate the inclusive decay rate of the spin-triplet bottomonium states chi_{bJ} into charm hadrons, including the leading-order color-singlet and color-octet bb-bar annihilation mechanisms. We also calculate the momentum distribution…