Speaker
Dr
Sachiko Takeuchi
(Japan College of Social Work)
Description
The recent experiments by LHCb indicates that the $NJ/\psi$-$\Lambda_c \bar D$-$\Sigma_c \bar D$ or $q^3c\bar c$ systems have a rich spectrum [1].
Theoretically also, it has been found that a quark cluster model, or a hadron model which includes the five-quark mode, gives narrow resonances or cusps in the $Y_c \bar D$ scattering [2,3].
Such a structure appears because the three light quarks in the system can take a color-octet isospin-1/2 spin-3/2 configuration, in which the color-magnetic interaction becomes attractive comparing to the relevant threshold.
Here we discuss the strange pentaquark systems with the hidden heavy quark pair. The three light quarks now can also form a color-octet flavor-singlet spin-1/2 configuration. Then, the color magnetic interaction is more attractive than the isospin-1/2 case and causes a baryon-meson bound state. We argue that the pentaquarks with strangeness can be candidates of the exotic baryons.
[1] R.Aaij et al., [LHCb Collaboration], arXiv:1904.03947 [hep-ex].
[2] S.Takeuchi and M.Takizawa, Phys.Lett.B764, 254 (2017)
[3] Y.Yamaguchi, A.Giachino, et.al., Phys.Rev.D96,114031 (2017)
Primary author
Dr
Sachiko Takeuchi
(Japan College of Social Work)
Co-authors
Mr
Alessandro Giachino
(Istituto Nazionale di Fisica Nucleare (INFN))
Dr
Elena Santopinto
(Istituto Nazionale di Fisica Nucleare (INFN))
Dr
Makoto Oka
(Advanced Science Research Center, Japan Atomic Energy Agency)
Dr
Makoto Takizawa
(Showa Pharmaceutical University, J-PARC Branch, KEK Theory Center, IPNS, KEK)
