Recent years have seen rapid developments in our knowledge and understanding of meson spectroscopy, especially in the charm quark sectors. In my invited overview I discussed some of these recent new developments, including theoretical developments, n
ew production mechanisms such as B decays and double charmonium production, and the discovery of several of the many new candidates for excited charmonia, charm meson molecules, and hybrid (excited glue) mesons, in both charmonium and light quark sectors. In this writeup, due to length constraints I will restrict my discussion to a few examples of these new states, some of their broader theoretical implications, and future prospects.
In this invited talk I discuss two recent applications of charmonium (Psi) decays to N Nbar m final states, where N is a nucleon and m is a light meson. There are several motivations for studying these decays: 1) They are useful for the study of N* s
pectroscopy; 2) they can be used to estimate cross sections for the associated charmonium production processes p pbar to Psi m, which PANDA plans to exploit in searches for charmonium hybrid exotics; and 3) they may allow the direct experimental measurement of NNm (meson-nucleon) strong couplings, which provide crucial input information for meson exchange models of the NN force. The latter two topics are considered in this talk, which will also compare results from a simple hadron pole model of these decays to recent experimental data.
This invited summary gives some concluding remarks regarding theoretical aspects of the research presented at Charm2010. I will specialize to the role of theory and the relative reach of theory and experiment in three of the major areas of charm phys
ics address at this conference, specifically 1) charm production, 2) charm weak decays, and 3) charm hadron spectroscopy. After a discussion of the status of progress on representative topics in each of these areas I will conclude with a previously unrelated Feynman story from a conference in the early days of charm.
Exitation of atomic levels due to interaction with electromagnetic waves has been the subject of numerous works, both experimental and theoretical. This topic became of interest in accelerator physics in relation to high efficiency charge exchange in
jection into rings for high beam power applications. Taking equations of resonant atom-wave interaction equations as a basis, this paper shows that there exist some interesting phenomena which lead to the existence of trapped electomagnetic waves (photon traps) in a medium that consists of atoms with transition frequencies in proximity to the wave frequency. These traps may exist in random and periodic lattices, and may have very low loss rate. The atomic medium can serve as an excellent wavegiude or tool to form and transmit electromagnetic waves for applications to accelerators and to electromagnetic devices in general, where high pressure gas use is acceptable. In addition, such traps in gases may accumulate substantial energy for a long period of time, leading to the possibility of creating objects similar (or equivalent) to ball lightning.
