Related papers: Physics in Charm Energy Region
The cross section for the photoproduction of large-p_T J/psi mesons at HERA is calculated at next-to-leading order, adopting a perturbative approach to describe the fragmentation of charm quarks and gluons into J/psi mesons. We treat the…
The predictions are presented for the diagonal and transition form factors of light hadrons in the time-like region up to the production threshold of an open charm quantum number. The comparison with existing data on the decays of J/psi and…
The open charm effects via intermediate hadron loop transitions seem to play a crucial role in the understanding of several existing "puzzles" in charmonium exclusive decays, such as the $\psi(3770)$ non-$D\bar{D}$ decays, and "$\rho\pi$…
New results from charm experiments have led to renewed interest in this physics. The charm sector is now seen as a powerful tool to search for new physics and to advance our understanding of the standard model. We owe much of this progress…
We consider the production of electroweak $Z$ or $W^\pm$ bosons associated with $J/\psi$ mesons at the LHC conditions. Our attention is focused on new partonic subprocesses which yet have never been considered in the literature, namely, the…
Recent measurements in the charm sector are reviewed, concentrating on results which are sensitive to New Physics effects. The scope of the presentation includes D0-D0bar mixing searches, a CPT / Lorentz invariance study, and a range of…
We present a calculation of the charm and gluon fragmentation contributions to inclusive $J/\psi$ and $\psi'$ production at large transverse momentum at the Tevatron. For $\psi$ production, we include both fragmentation directly into $\psi$…
Production of $c\bar c$ pairs in elementary hadron-hadron collisions is introduced in a simulation of relativistic heavy ion collisions. Coalescence of charmed quarks and antiquarks into various charmonium states is performed and the…
Using the results of our recent analysis of e^+e^- annihilation, we plot the curves for the diagonal and transition form factors of light hadrons in the time-like region up to the production threshold of an open charm quantum number. The…
The charmonium system provides an opportunity to explore a wide variety of topics in hadronic physics. Studies of the properties of and transitions among cc-bar states yield insight into relativistic and non-perturbative QCD effects. At the…
Detailed studies of weak charm decays fill an important {\em future} role in high energy physics. Chief among them are: (i) validating the theoretical control achieved over hadronization as a worthwhile goal in its own right; (ii)…
We summarize recent results for charm physics. These results span several categories: charm mixing, indirect (time-dependent) CP violation, direct (time-integrated) CP violation, T violation, semileptonic and leptonic decays, and decays of…
I review possible resolution of the $J/\psi (\psi^{\prime}) \to \rho-\pi$ puzzle based on two inputs: the relative phase between the one- photon and the gluonic decay amplitudes, and a possible hadronic excess in the inclusive…
A slow $J/\psi$ bump exists in the inclusive $B\to J/\psi + X$ spectrum, while the softness of $J/\psi$ spectrum in $\Upsilon(1S) \to J/\psi + X$ decay is in strong contrast with expectations from color octet mechanism. We propose {\it…
We compute the contributions to large-$p_T$ $J/\psi$ production at HERA coming from fragmentation of gluons and charm quarks. We find that the charm quark fragmentation contribution dominates over the direct production of $J/\psi$ via…
Hybrid charmonium with mass ~4 GeV could be produced via a c c.bar color-octet component in b->c c.bar s. These states could be narrow and could have a significant branching ratio to light hadrons, perhaps enhanced by glueballs. Decays to…
Abundance of charm data in the current and future low energy flavor experiments makes it possible to study rare decays of D-mesons with ever increased precision. I discuss theoretical implications of derived constraints on New Physics…
To investigate a recent proposal that J/$\psi$ production in ultra-relativistic nuclear collisions is of thermal origin we have reanalyzed the data from the NA38/50 collaboration within a thermal model including charm. Comparison of the…
New results on properties and decays of open charm and charmonium states are reviewed. The emphasis is on examples that illustrate the various aspects through which studies of charm physics impact the field.
We study the charmonium coherent photoproduction and hadroproduction consistently with modifications from both cold and hot nuclear matters. The strong electromagnetic fields from fast moving nucleus interact with the other target nucleus,…