相关论文: Quarkonium Production and Decay
Recent results in studies of bottomonium especially relevant to charmonium are reviewed. This report covers dipion transition matrix elements, $\eta$ production in $\Upsilon$ transitions, $\Upsilon$ decays to invisible particles, a search…
By analyzing existing data on pseudoscalar charmonium decays, we obtain the ratio of the branching fractions of $\eta_c(2S)$ and $\eta_c$ decays into ten different final states with light hadrons. For the first time, we test the two…
The interpretation of the J/psi suppression patterns observed in nuclear collisions, at CERN and RHIC, as a signature of the formation of a deconfined phase of QCD matter, requires knowing which fractions of the measured J/psi yields, in pp…
I introduce an entirely new dynamical description for exotic charmoniumlike hadrons, based upon the competing effects of the strong attraction between quarks in a diquark, and the inability of the diquark to hadronize on its own due to…
About 40-50 % of the quarkonium ground states J/psi(1S) and Upsilon(1S) produced in hadronic collisions originate from the decay of higher excitations. In a hot medium, these higher states are dissociated at lower temperatures than the more…
We reconsider quarkonium production in a field-theoretical setting and we show that the lowest-order mechanism for heavy-quarkonium production receives in general contributions from two different cuts. The first one corresponds to the usual…
Recent results on charmonia decays at BESII/BEPC are reported, including the observation of psi'-->K_S K_L, psi'--> Vector + Tensor and psi'--> Vector + Pseudoscalar for the measurement of the relative phase between the strong and…
We calculate the direct production rate of $J/\psi$ in top quark decays. The color-octet $J/\psi$ production via $t\rightarrow W^+ b J/\psi$ is shown to have a large branching ratio of order $1.5\times 10^{-4}$, which is over an order of…
Quarkonium has been proposed as a sensitive probe of quark-gluon plasma (QGP) more than thirty years ago. Since then, lots of experimental efforts have been devoted to study its production in heavy-ion collisions to search for QGP and study…
In this paper we analyze the photoproduction of heavy quarkonia pairs which include $b$-quarks, such as $B_{c}^{+}B_{c}^{-}$-mesons or charmonium-bottomonium pairs. Compared to charmonia pair production, these channels get contributions…
The phase between three-gluon and one-photon amplitudes in psi(2S) and psi(3770) decays is analyzed.
We review heavy quark and quarkonium production in high energy hadronic collisions. We discuss the status of the theoretical calculations and their uncertainties. We then compare the current theoretical results with the most recent…
The suppression of quarkonium production in nucleus-nucleus collisions was originally proposed as a signal of colour deconfinement. Strong ``anomalous" J/\psi suppression in Pb-Pb collisions has been reported at this Conference by the NA50…
I briefly review Non-Relativistic QCD and related effective theories, and discuss applications to heavy quarkonium decay, and production in electron-positron colliders.
In recent years the B-factories and other machines have found evidence for a large number of new states with hidden charm: candidate h_c(1P), eta_c(2S), and chi_{c2}(2P) states; the well-established X(3872); enhancements called X(3940),…
The relation between the hyperfine structure and leptonic decay rates of heavy quarkonia is considered with the account of relativistic and radiative corrections. The calculated decay rates agree well with the available experimental data,…
We review recent progress made in the theory of quarkonium production in hadronic collisions.
Recent developments in heavy quarknoium physics are reviewed in brief, including (i) nonrelativistic QCD(NRQCD), (ii) the importance of color-octet $(Q\bar{Q})$ components in the decay and the production of a physical heavy quarkonium…
Production mechanisms for quarkonium states in hadronic collisions remain difficult to understand. The decay angular distributions of J/$\psi$ or $\Upsilon(nS)$ states into $\mu^+ \mu^-$ final states are sensitive to the matrix elements in…
The goal of this section is to assess the possibility that quarkonium production rates may be enhanced in nucleus-nucleus interactions at the LHC relative to that predicted by extrapolation of processes thought to be dominant at lower…