0000000000066471
AUTHOR
Christoph Hanhart
showing 5 related works from this author
Heavy quarkonium: progress, puzzles, and opportunities
2011
A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flo…
Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
2022
In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molec…
Study of the f(2)(1270) , f(2)'(1525) , f(0)(1370) and f(0)(1710) in the J/psi radiative decays
2009
In this paper we present an approach to study the radiative decay modes of the J/psi into a photon and one of the tensor mesons f (2)(1270) , f' (2)(1525) , as well as the scalar ones f (0)(1370) and f (0)(1710) . Especially, we compare predictions that emerge from a scheme where the states appear dynamically in the solution of vector meson-vector meson scattering amplitudes to those from a (admittedly naive) quark model. We provide evidence that it might be possible to distinguish amongst the two scenarios, once improved data are available.
Direct X(3872) production in e+e- collisions
2014
Direct production of the charmonium-like state $X(3872)$ in $e^+e^-$ collisions is considered in the framework of the vector meson dominance model. An order-of-magnitude estimate for the width $\Gamma(X\to e^+e^-)$ is found to be $\gtrsim$0.03 eV. The same approach applied to the $\chi_{c1}$ charmonium decay predicts the corresponding width of the order 0.1 eV in agreement with earlier estimates. Experimental perspectives for the direct production of the $1^{++}$ charmonia in $e^+e^-$ collisions are briefly discussed.
DirectX(3872)production ine+e−collisions
2014
Abstract Direct production of the charmonium-like state X ( 3872 ) in e + e − collisions is considered in the framework of the vector meson dominance model. An order-of-magnitude estimate for the width Γ ( X → e + e − ) is found to be ≳0.03 eV. The same approach applied to the χ c 1 charmonium decay predicts the corresponding width of the order 0.1 eV in agreement with earlier estimates. Experimental perspectives for the direct production of the 1 + + charmonia in e + e − collisions are briefly discussed.