Angelo Esposito

Four-quark hadrons: An updated review

The past decade witnessed a remarkable proliferation of exotic charmonium-like resonances discovered at accelerators. In particular, the recently observed charged states are clearly not interpretable as mesons. Notwithstanding the considerable advances on the experimental side, conflicting theoretical descriptions do not seem to provide a definitive picture about the nature of the so-called XYZ particles. We present here a comprehensive review about this intriguing topic, discussing both those experimental and theoretical aspects which we consider relevant to make further progress in the field. At this state of progress, XYZ phenomenology speaks in favor of the existence of compact four-quark particles (tetraquarks) and we believe that realizing this instructs us in the quest for a firm theoretical framework.

Observation of light nuclei at ALICE and the X ( 3872 ) conundrum

The new data reported by ALICE on the production of light nuclei with

Doubly charmed tetraquarks in Bc and Ξbc decays

{p}_{\ensuremath{\perp}}\ensuremath{\lesssim}10\text{ }\text{ }\mathrm{GeV}

Hadronization scheme dependence of long-range azimuthal harmonics in high energy p + A reactions

in Pb-Pb collisions at

Conformal solids and holography

\sqrt{{s}_{\mathrm{NN}}}=2.76\text{ }\text{ }\mathrm{TeV}

Probing the nature of Zc(′) states via the ηcρ decay

are used to compute an order-of-magnitude estimate of the expected production cross sections of light nuclei in proton-proton collisions at high transverse momenta. We compare the hypertriton, helium-3, and deuteron production cross sections to that of

First sound in holographic superuids at zero temperature

X(3872)

Probing the nature of Z_c states via the eta_c rho decay

, measured in prompt

Compact tetraquark interpretation of the XYZ states

pp

Probing the nature of

collisions by CMS. The results we find suggest a different production mechanism for the