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Kim, Y.*; Oka, Makoto; Suenaga, Daiki*; Suzuki, Kei
Physical Review D, 107(7), p.074015_1 - 074015_15, 2023/04
Times Cited Count：1 Percentile：54.75(Astronomy & Astrophysics)A chiral effective theory of scalar and vector diquarks is formulated, which is based on 
chiral symmetry and includes interactions between scalar and vector diquarks with one or two mesons. We find that the diquark interaction term with two mesons breaks the 
and flavor 
symmetries. To determine the coupling constants of the interaction Lagrangians, we investigate one-pion emission decays of singly heavy baryons 
(
, 
and 
, 
, 
), where baryons are regarded as diquark-heavy-quark two-body systems. Using this model, we present predictions of the unobserved decay widths of singly heavy baryons. We also study the change of masses and strong decay widths of singly heavy baryons under partial restoration of chiral symmetry.
Kim, Y.*; Oka, Makoto; Suzuki, Kei
Physical Review D, 105(7), p.074021_1 - 074021_17, 2022/04
Times Cited Count：15 Percentile：93.15(Astronomy & Astrophysics)Energy spectrum of doubly heavy tetraquarks, 
(
with 
and 
), is studied in the potential chiral-diquark model. Using the chiral effective theory of diquarks and the quark-diquark-based potential model, the 
, 
, and 
tetraquarks are described as a three-body system composed of two heavy quarks and an antidiquark. We find several bound states, while no and (deep) bound state is seen. We also study the change of the tetraquark masses under restoration of chiral symmetry.
Irie, Yoya*; Oka, Makoto; Yasui, Shigehiro*
Physical Review D, 97(3), p.034006_1 - 034006_12, 2018/02
Times Cited Count：13 Percentile：56.75(Astronomy & Astrophysics)One type of hidden charm pentaquark 
with quark content 
in light-flavor singlet state is studied in the quark model. This state is analogous to the 
with 
in light-flavor octet, which was observed in LHC in 2015. Considering various combinations of color, spin, and light flavor as internal quantum numbers in , we investigate the mass ordering of the 's by adopting both the one-gluon exchange interaction and the instanton-induced interaction in the quark model. The most stable configuration of is identified to be total spin 1/2 in which the 
is combined to be color octet and spin 1, while the uds cluster is in a color octet state. The other color octet configurations, the total spin 
state with the spin 0, and the state with total spin 
and spin 1, are found as excited states. We also discuss possible decay modes of these hidden charm pentaquarks.
Suzuki, Kei
no journal, ,
The Kondo effect is a well-known phenomenon in metal including localized impurities, which leads to drastic modification of electric/thermal/transportproperties of metal. In high-density quark matter, a similar effect can be induced by interaction between a light quark and a "colored" impurity like heavy quarks, which is the so-called QCD Kondo effect. In this talk, I will review a novel phase with condensates consisting of a light quark and a heavy quark, that is the Kondo phase predicted in Refs.[1,2]. In particular, recently, we found that several exciton modes can be excited in this phase, by using an improved analysis [3]. Such modes could affect the transport properties of high-density quark matter. [1] S. Yasui, K. Suzuki, and K. Itakura, Nucl. Phys. A983 (2019) 90. [2] S. Yasui, K. Suzuki, and K. Itakura, Phys. Rev. D96 (2017) 014016. [3] D. Suenaga, K. Suzuki, and S. Yasui, arXiv:1909.07573.
