Speakers
Description
The diabatic approach in QCD [1-3] allows to describe a quarkoniumlike meson in terms of heavy quark-antiquark and open-flavor meson-meson pairs, interacting through a coupled-channel potential inferred from lattice calculations of string breaking [4]. In this talk, we present a systematic analysis of $J^{PC}=1^{++}$ charmoniumlike mesons with energies up to $4.0$ GeV within the diabatic framework. We show that the spectrum contains only two bound states: one conventional, assigned to the $1P$ charmonium state $\chi_{c1}(1P)$, and one unconventional, located very close below the $D^{0}\bar{D}^{\ast 0}$ threshold, which may be naturally identified with $\chi_{c1}(3872)$. The rest of the spectrum consists in a continuum of $D^{0}\bar{D}^{\ast 0}$ and $D^{+}D^{\ast -}$ scattering states, whose analysis indicates the presence of a resonance near $3960$ MeV, with a width of about $70$ MeV. We illustrate how this resonance, called $\chi_{c1}(2P)$ as it may be assigned to a mostly conventional $2P$ charmonium state, is likely overshadowed in its expected main decay channels, $D^{0}\bar{D}^{\ast 0}$ and $D^{+}D^{\ast -}$, by the threshold enhancements due to the loosely bound state, $\chi_{c1}(3872)$. Finally, we discuss alternative discovery channels.
[1] R. Bruschini, P.Gonzalez, Phys.Rev.D 102, 074002 (2020).
[2] R. Bruschini, P.Gonzalez, Phys.Rev.D 104, 074025 (2021).
[3] R. Bruschini, P.Gonzalez, Phys.Rev.D 105, 054028 (2022).
[4] G. S. Bali, H. Neff, T. Düssel, T. Lippert and K. Schilling (SESAM Collaboration), Phys. Rev. D 71, 114513 (2005).
