Atsushi Hosaka

Spectrum of heavy baryons in the quark model

Single- and double- heavy baryons are studied in the constituent quark model. The model Hamiltonian is chosen as a standard one with two exceptions : (1) The color-Coulomb term depend on quark masses, and (2) an antisymmetric

P-wave charmed baryons from QCD sum rules

LS

Exotic hadrons with heavy flavors: X, Y, Z, and related states

force is introduced. Model parameters are fixed by the strange baryon spectra,

D-wave charmed and bottomed baryons from QCD sum rules

Lambda

QCD sum rule calculation for P-wave bottom baryons

and

Decay properties of

Sigma

P

baryons. The masses of the observed charmed and bottomed baryons are, then, fairly well reproduced. Our focus is on the low-lying negative-parity states, in which the heavy baryons show specific excitation modes reflecting the mass differences of heavy and light quarks. By changing quark masses from the SU(3) limit to the strange quark mass, further to the charm and bottom quark masses, we demonstrate that the spectra change from the SU(3) symmetry patterns to the heavy quark symmetry ones.

-wave charmed baryons from light-cone QCD sum rules

We study the P-wave charmed baryons using the method of QCD sum rule in the framework of heavy quark effective theory. We consider systematically all possible baryon currents with a derivative for internal ρ- and λ-mode excitations. We have found a good working window for the currents corresponding to the ρ-mode excitations for Λc(2595), Λc(2625), Ξc(2790), and Ξc(2815) that complete two SU(3) 3¯F multiplets of JP=1/2- and 3/2-, while the currents corresponding to the λ-mode excitations seem also consistent with the data. Our results also suggest that there are two Σc(2800) states of JP=1/2- and 3/2- whose mass splitting is 14±7u2009u2009MeV, and two Ξc(2980) states whose mass splitting is 12±7u2009u2009MeV. They have two Ωc partners of JP=1/2- and 3/2-, whose masses are around 3.25±0.20u2009u2009GeV with mass splitting 10±6u2009u2009MeV. All of them together complete two SU(3) 6F multiplets of JP=1/2- and 3/2-. They may also have JP=5/2- partners. Ξc(3080) may be one of them, and the other two are Σc(5/2-) and Ωc(5/2-), whose masses are 85±23u2009u2009MeV and 50±27u2009u2009MeV larger.

Heavy quark symmetry in multihadron systems

In the past decade, exotic hadrons with charm and bottom flavors have been extensively studied both in experiments and in theories. In this review, we provide topical discussions by selecting

Production of strange and charmed baryons in pion induced reactions

X,Y,Z