arXiv subjects

Clark Downum

Publications and source records attributed to Clark Downum.

4 recordsLinked to original sources

arXiv2010

Nucleon-Nucleon Interactions from the Quark Model

We report on investigations of the applicability of non-relativistic constituent quark models to the low-energy nucleon-nucleon (NN) interaction. The major innovations of a resulting NN potential are the use of the $^3$P$_0$ decay model and quark model wave functions to derive nucleon-nucleon-meson form-factors, and the use of a colored spin-spin contact hyperfine interaction to model the repulsive core rather than the phenomenological treatment common in other NN potentials. We present the results of the model for experimental free NN scattering phase shifts, S-wave scattering lengths and effective ranges and deuteron properties. Plans for future study are discussed.

nucl-th↗

arXiv2010

Novel Charmonium and Bottomonium Spectroscopies due to Deeply Bound Hadronic Molecules from Single Pion Exchange

Pion exchange in S-wave between hadrons that are themselves in a relative S-wave is shown to shift energies by hundreds of MeV, leading to deeply bound quasi-molecular states. In the case of charmed mesons $D^*,D_1$ a spectroscopy arises consistent with enigmatic charmonium states observed above 4 GeV in $e^+e^-$ annihilation. A possible explanation of $Y(4260)\to ψππ$ and $Y(4360) \to ψ'ππ$ is found. We give results for all isospin and charge-conjugation combinations, and comment on flavor exotic doubly charmed states and bottomonium analogs. A search in $D\bar{D}3π$ is recommended to test this hypothesis. An exotic $1^{-+}$ is predicted to occur in the vicinity of the $Y$(4260).

hep-ph↗

arXiv2009

On the possibility of Deeply Bound Hadronic Molecules from single Pion Exchange

Pion exchange in S-wave between hadrons that are themselves in a relative S-wave can shift energies by hundreds of MeV. In the case of charmed mesons $D,D^*,D_0,D_1$ a spectroscopy of quasi-molecular states may arise consistent with enigmatic charmonium states observed above 4 GeV in $e^+e^-$ annihilation. A possible explanation of $Y(4260)\to ψππ$ and $Y(4360) \to ψ'ππ$ is found. Searches in $D\bar{D}3π$ channels as well as B decays are recommended to test this hypothesis.

hep-ph↗

arXiv2008

Charmonium production in e+e- to ψ+ X(c\bar c) and e+e- to D*D_J

The dominance of chi_0 in the data for e+e- to psi + chi_J(c\bar{c}) is shown to violate OZI factorization. Single gluon exchange gives a non-factorizing effective S.L interaction that generates a large scalar production amplitude. This also has observable effects near threshold in e+e- to D*D_J, where enhancements of D*D_0 and DD_1 channels are predicted. Further tests and implications are discussed.

hep-ph↗