In the framework of the Born-Oppenheimer Effective Field Theory, the hyperfine structure of heavy quarkonium hybrids at leading order in the $1/m_Q$ expansion is determined by two potentials. We estimate those potentials by interpolating between the known short distance behavior and the long distance behavior calculated in the QCD Effective String Theory. The long distance behavior depends, at...
Glueballs are elusive states. These unique particles, arising directly from the non-Abelian nature of the QCD gauge symmetry, were theoretically predicted in the early 1970s. Yet, their experimental observation remains a matter of debate within the community. The existing signals are difficult to interpret, partly due to the lack of theoretical consensus on their expected...
Baryons can be described within several theoretical frameworks. Among them, the constituent approach is widely used. In this context, we aim to evaluate the accuracy of an approached model of baryons: the quark-diquark approximation. It consists in separating the three-body system into two subsequent two-body ones: a pair of two quarks (the diquark) and a subsystem consisting of the diquark...
Over the past two decades, a new class of exotic states, commonly referred to as XYZ states, has been identified. These states are incompatible with the conventional quark–antiquark picture and are therefore considered candidates for tetraquarks, mesonic molecules, or hybrids. Since the BESIII experiment began colliding e⁺e⁻ beams in the center-of-mass energy range between 2.0 and 4.9 GeV, it...
We have generated an updated version of the pΩ potential for low-energy interactions based on an effective field theory approach. This potential, together with other potentials based either on different parametrizations or lattice QCD, have been used to solve the Schrödinger equation, obtaining the scattering wave functions. Using these wave functions, we have computed the pΩ femtoscopic...
The existence of the nucleonic pentaquark resonances $P_{c\bar{c}}(4312)^+$, $P_{c\bar{c}}(4380)^+$, $P_{c\bar{c}}(4440)^+$, $P_{c\bar{c}}(4457)^+$, $P_{c\bar{c}s}(4338)^0$ and $P_{c\bar{c}s}(4459)^0$, established by the LHCb collaboration, has been one of the major discoveries in hadron physics in the latest years. Most of these states (5 out of 6) can be understood as hadronic molecules,...
One of the main issues posed by the presence of hadrons in any reaction is their final-state interactions, which are formally expressed in terms of the unitarity of the amplitude. In two-body scattering, unitarity is usually imposed in the direct channel only, as one is not sensitive to the details of the crossed channels. This is certainly not the case for a three-body decay, where the three...
S-matrix theory is one of the most powerful framework to study the unstable states
that populate QCD spectrum. In particular, it is very useful to extract physical properties
of the "exotics" candidates - particles that cannot be described by ordinary quark model -
in a non perturbative, phenomenological way. In this talk, I will introduce some 3-body formalisms we are developing to...
The study of hadronic scattering processes remains fundamental for understanding the dynamics of strong interactions across energy scales. Finite-Energy Sum Rules (FESR) provide a powerful framework for connecting low-energy resonance behavior with the high-energy regime described by Regge theory, offering valuable constraints on phenomenological amplitudes. Motivated by the COMPASS...
Lattice QCD and models predict the lightest hybrid meson with explicit gluonic degrees of freedom to have spin-exotic quantum numbers $J^{PC}=1^{-+}$ and a mass below $2\,\text{GeV}$. Experiments have reported two candidates with such exotic quantum numbers, the $\pi_1(1400)$ in the $\eta\pi$ channel and the $\pi_1(1600)$, which has been observed in various final states, including...
