### Conveners

#### Heavy meson spectroscopy: Session 1

- Gianluigi Cibinetto (Istituto Nazionale di Fisica Nucleare)

#### Heavy meson spectroscopy: Session 4

- Eric Swanson (University of Pittsburgh)

#### Heavy meson spectroscopy: Joint session with Exotic hadrons and candidates

- Roberta Cardinale (Istituto Nazionale di Fisica Nucleare)

#### Heavy meson spectroscopy: Session 2

- Gianluigi Cibinetto (Istituto Nazionale di Fisica Nucleare)
- Roberta Cardinale (Istituto Nazionale di Fisica Nucleare)

Recent results on B_c production and decays from the proton-proton collision data taken by the ATLAS and CMS experiments will be presented.

Ds0*(2317) and Ds1(2460) have long been conjectured to be DK and D*K bound states. In this talk, we show that their productions in B decays can be well explained with the triangle mechanism in the molecular picture. Furthermore, we show for the first time that their prompt production yields in electron-positron collisions can be explained in the coalescence model. The comparison with the...

We predict the correlation functions relevant in femtoscopy studies for $S$-wave $D_{(s)}\phi$ pairs, with $D_{(s)}$ a pseudoscalar open charm meson and $\phi$ a Goldstone boson, describing their interactions with next-to-leading order unitarized heavy-meson chiral perturbation theory amplitudes.

In the $(S,I)=(0,1/2)$ sector, the effect of the two-state structure around $2300\,\text{MeV}$...

We study the time evolution of the number of charm mesons after the kinetic freeze-out of the hadron gas produced by a central heavy-ion collision. The $\pi D^*\to \pi D^*$ reaction rates have t-channel singularities that give contributions inversely proportional to the thermal width of the $D$. The ratio of the $D^0$ and $D^+$ production rate can differ significantly from those predicted...

We study the interaction of two $ D^* $ and a $\bar{K}^{*}$ by using the Fixed Center Approximation to the Faddeev equations to search for bound states of the three body system. Since the $ D^* D^* $ interaction is attractive and gives a bound state, and so is the case of the $D^* \bar{K}^{*}$ interaction, where the $J^{P}=0^{+}$ bound state is identified with the $X_0 (2900)$, the $ D^* D^*...

The increasing number of discovered heavy quark exotic hadrons call for immediate theoretical investigations based on first principles. Our study focuses on tetra-quark states made up of a bottom and charm quark in the axial-vector ($1^+$) channel with isospin I=0, using Lattice Quantum Chromodynamics.

These computations were conducted on the state-of-the-art MILC ensembles using dynamical...

We have studied the contribution of the state $X(3930)$, coming from the interaction of the $D \overline{D}$ and $D^{+}_s D^{-}_s$ channels, to the $B^- \to K^- J/\psi \omega $ decay. The purpose of this work is to offer a complementary tool to see if the $X(3930)$ state observed in the $D^+ D^-$ channel is the same or not as the $X(3960)$ resonance claimed by the LHCb collaboration from a...

We calculate the total cross section and transverse momentum distributions for the production of the enigmatic $\chi_{c1}(3872)$ (or X(3872)) (see [1]) assuming different scenarios:

$c \bar c$ state and $D^{0*} {\bar D}^0 + D^0 {\bar D}^{0*}$ molecule.

The derivative of the $c \bar c$ wave function needed in the first

scenario is taken from a potential $c \bar c$ model...

The Born-Oppenheimer approximation for QCD provides an intuitive yet rigorous framework for the study of mesons containing two heavy quarks. The energy levels of QCD with two static color sources, numerically accessible on the lattice, are translated into potentials for the nonrelativistic motion of the heavy quarks. The mass spectrum is then determined simply by integrating a multichannel...

The approach to exotic hadrons with heavy quarks based on the Effective Field Theory is overviewed and its application to particular near-threshold exotic states in the spectrum of charmonium and bottomonium is discussed.

We perform the first global and unitary analysis of e+e− → b ̄b cross sections. We analyze exclusive cross sections in the BB ̄, B∗B ̄(+c.c.), B∗B ̄∗, Bs∗B ̄s∗, Υ(nS)π+π− and hb(nP)π+π− channels as well as the total inclusive cross section for b ̄b production. Pole positions and residues are determined for four vector states, which we associate with the Υ(4S), Υ(10750), Υ(5S) (or Υ(10860)),...

In this talk, I will discuss our efforts to explain the mass gaps and decay constants of the ground state and radially excited state heavy mesons in the light-front quark model. We highlight the importance of mixing 1S and 2S harmonic oscillator basis as the trial wave function in the variational analysis. A small mixture is needed to explain available experimental and lattice data. The...

Belle II offers unique possibilities for discovering and interpreting exotic multiquark bound states to probe the fundamentals of QCD. This talk presents recent results on a unique data set collected at energies above the $\Upsilon$(4S), including searches for the hidden bottom transition between Y(10750) and $\chi_{bJ}$ and measurements of the energy dependence of the $e^+e^- \to B^{(*)} \bar...

Although the charmonium spectrum seems well investigated, charmonia can still be used as benchmarks to test our QCD predictions, as these states lay in the transition region between perturbative and non-perturbative QCD. Despite the need for experimental confirmations, setbacks arise from limited statistics due to the production of non-vector states. Some charmonium states' properties and...

The LHCb experiment has collected a unique sample of data from high-energy proton proton collisions, that enables a range of studies of heavy meson spectroscopy. As well as high-profile results on exotic states, many of which are covered in other talks, these studies also provide crucial information about conventional mesons. Latest results on charmonia, charm, and beauty mesons are...