Heavy Quark Fluorescence

Abstract

Heavy hadrons containing heavy quarks (for example, Upsilon-mesons) feature a scale separation between the heavy quark mass (about 4.5 GeV for the b-quark) and the QCD scale (about 0.3 GeV}) that controls effective masses of lighter constituents. Therefore, as in ordinary molecules, the de-excitation of the lighter, faster degrees of freedom leaves the velocity distribution of the heavy quarks unchanged, populating the available decay channels in qualitatively predictable ways. Automatically an application of the Franck-Condon principle of molecular physics explains several puzzling results of Upsilon(5S) decays as measured by the Belle collaboration, such as the high rate of Bs*-anti Bs* versus Bs*-anti Bs production, the strength of three-body B-anti B + pion decays, or the dip in B momentum shown in these decays. We argue that the data is showing the first Sturm-Liouville zero of the Upsilon(5S) quantum mechanical squared wavefunction, and providing evidence for a largely b-anti b composition of this meson.

4 pages, 4 figures, Figure 2 updated and some typos corrected. To be published in Physical Review Letters

References in corpus (7)

• The quark-gluon vertex in Landau gauge QCD: Its role in dynamical chiral symmetry breaking and quark confinement
• Hadron Loops: General Theorems and Application to Charmonium
• Channel coupling in heavy quarkonia: energy levels, mixing, widths and new states
• QCD Coulomb gauge approach to hybrid mesons
• Measurement of Y(5S) decays to B^0 and B^+ mesons
• Υ(5S) decays into BB and BBπ
• Boost operators in Coulomb-gauge QCD: the pion form factor and Fock expansions in phi radiative decays

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• Mixing and $m_q$ dependence of axial vector mesons in the Coulomb gauge QCD model
• Fock space expansion of sigma meson in leading-Nc
• The lightest flavor--singlet qqq baryons as witnesses to color