Charmlets

Abstract

We discuss the possibility, that multiply charmed exotics are produced in ultrarelativistic heavy ion collisions. Production probabilities at RHIC are estimated and found to be large enough to allow for the possible detection of single and double charmed exotics. We demonstrate that charm matter is bound due to an attractive one-gluon exchange potential. Furthermore, we study the color magnetic and color electric potential separately, as well as the group structure of such exotics and estimate their masses.

Heavy hadron spectroscopy and the bag model

“…We see from Table 2 that the original MIT results are in serious conflict with experimental data and discrepancies seem to be of systematic character. The improved variants [37], [38], and [45] give evidently more reasonable predictions. The agreement of our predictions with available experimental data is rather good, although there are some discrepancies.…”

“…In Ref. [45] the quark-quark interaction is treated perturbatively. Moreover, in this work the nonphysical self-energy term (which was present in the original MIT version of the model) is omitted.…”

Strange exotic states and compact stars

“…for the charmonium states, it is essential to include explicitly the colour-electric interaction terms. This modified bag model can describe reasonably well both, light nonstrange and strange hadrons as well as charmed hadrons with a slightly larger bag constant [15] compared to the standard MIT bag model [16]. A shell-model calculation of multiply charmed and strange quark states, however, does not give bound candidates.…”

“…Those exotic objects can be produced in collisions of heavy-ions at relativistic bombarding energies. The production rates at RHIC amount to 10 −3 to 10 −2 per event within a simple coalescence model [15]. Direct charm measurements will be possible with the PHENIX and STAR detectors at RHIC with their upgrade in the near future using e.g.…”

“…Bulk charmed strange quark matter turns out to be deeply bound within the MIT bag model when including effects from single-gluon exchange [15] even for large values of the MIT bag constant. Therefore, charmed strange quark matter can form bound objects even for the case when ordinary strange quark matter (without charm quarks) is unbound.…”