Near Threshold Structures and Hadronic Molecules

The $X(3960)$ seen in $D_{s}^{+} D_{s}^{-}$ as the $X(3930)$ state seen in $ D^{+} D^{-} $

“…The peak is remarkably close to the D + s D − s threshold, 3937 MeV, which makes one wonder where it could not be a signal for a resonance just below threshold 1 . This is actually a well known feature of reactions as discussed in [2] and found in some specific reactions [3,4].…”

Heavy Flavour Physics and CP Violation at LHCb: a Ten-Year Review

“…Many theoretical efforts have been placed to understand how quarks are combined to form a multi-body system [309][310][311][312]. At the same time, more and more new states are observed experimentally which cannot fit into the conventional hadron spectra [46].…”

$J/ψ$ decay to $ ϕ,ω, K^{*0}$ plus $f_0(1370)$, $f_0(1710)$, $K_0^*(1430)$, $f_2(1270)$, $f'_2(1525)$ and $K_2^*(1430)$: role of the $D$-wave for tensor production

“…The generation of resonances from the interaction of elementary hadrons occupies today a special place in Hadron Physics, from the pioneering work on meson-baryon interaction [1] and on meson-meson interaction [2] till now, when the unprecedented large amount of new states found experimentally has spurred a wave of research showing that many of the states found can be explained from this molecular hadron-hadron perspective (see reviews on the subject [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]).…”