Conveners
4; Thu-IIIb
- Akira Ohnishi
Light quarks form diquark clusters in hadrons and hadronic matter. We construct a chiral effective theory of spin 0 (scalar-pseudo-scalar) and 1 (axial-vector and vector) diquarks. The masses of the diquarks contain chiral invariant and non-invariant terms. The latter is given in terms of chiral condensate and thus variant in finite temperature and/or density. The parameters of the effective...
Because the $\Lambda(1405)$ cannot be explained by the $qqq$ picture in the constituent quark model, it is expected to have an internal structure of, for instance, the $\bar{K}N$ molecular state. In recent experiments, many candidates for exotic hadrons have been discovered in the heavy quark sector such as $XYZ$ mesons, for which hadronic molecular states and tetraquark states are proposed....
The SU(3) flavor symmetry in the quark model for baryons allows as many $\Xi$ resonances as $N^{*}$ and $\Delta^{*}$ combined. Only a handful of these states have been identified experimentally and among these states, only six states have three and four-star status according to PDG. The GlueX experiment, in Jefferson Lab's Hall D using a photon beam of energies up to 12 GeV allows us to study...
While various theoretical studies have been performed for the excited $\Xi(1620)$ and $\Xi(1690)$ states, their nature was not well understood due to the lack of experimental data. Recently, the invariant mass distribution of the $\Xi_c\rightarrow\pi\pi\Xi$ decay was observed by the Belle collaboration [1].
By fitting the invariant mass distribution with the Breit-Wigner distribution, the...
The recent discoveries of the pentaquark, $P_C$, states and $XYZ$ mesons in the charmed quark sector has initiated a new epoch in hadron physics. The existence of exotic multi-quark states beyond the conventional three and two quark systems has obviously been realised. Such states could manifest as single colour bound objects, or evolve from meson-baryon and meson-meson interactions,...