Study of $$qqq{\bar{q}}Q$$ pentaquark system in the chiral quark model

Abstract

AbstractWith the discovery of some hidden-charm pentaquark resonances by the LHCb Collaboration, investigations of pentaquark states containing heavy quarks have aroused the interest of theorists. We study herein $$qqq{\bar{q}}Q$$ q q q q ¯ Q ($$q = u$$ q = u or d, $$Q=c$$ Q = c or b) pentaquark system, in the framework of the chiral quark model. In consequence, some charmed and bottomed pentaquarks are considered to exist by five-body dynamical calculations. In the charm sector, $$\Sigma _c\pi (IJ^P=0\frac{1}{2}^-)$$ Σ c π ( I J P = 0 1 2 - ) and $$\Sigma _c^*\pi (IJ^P=0\frac{3}{2}^-)$$ Σ c ∗ π ( I J P = 0 3 2 - ) are possible candidates of $$\Lambda _c(2595)$$ Λ c ( 2595 ) and $$\Lambda _c(2625)$$ Λ c ( 2625 ) , respectively. Besides, two high-spin states, $$\Sigma _c^*\rho (IJ^P=0\frac{5}{2}^-)$$ Σ c ∗ ρ ( I J P = 0 5 2 - ) and $$\Delta D^*(IJ^P=1\frac{5}{2}^-)$$ Δ D ∗ ( I J P = 1 5 2 - ) , are also found in the energy region of $$3.2 \sim 3.3$$ 3.2 ∼ 3.3 GeV. In the bottom sector, $$\Sigma _b\pi (IJ^P=0\frac{1}{2}^-)$$ Σ b π ( I J P = 0 1 2 - ) , $$\Sigma _b^*\pi (IJ^P=0\frac{3}{2}^-)$$ Σ b ∗ π ( I J P = 0 3 2 - ) could be candidates of $$\Lambda _b(5912)$$ Λ b ( 5912 ) and $$\Lambda _b(5920)$$ Λ b ( 5920 ) , respectively. And $$\Sigma _b^*\rho (IJ^P=0\frac{5}{2}^-)$$ Σ b ∗ ρ ( I J P = 0 5 2 - ) and $$\Delta B^*(IJ^P=1\frac{5}{2}^-)$$ Δ B ∗ ( I J P = 1 5 2 - ) are found in the energy region of $$6.5 \sim 6.6$$ 6.5 ∼ 6.6 GeV. $$\Sigma _c^{(*)}\pi $$ Σ c ( ∗ ) π and $$\Sigma _b^{(*)}\pi $$ Σ b ( ∗ ) π are expected as compact states, while $$\Sigma _c^*\rho $$ Σ c ∗ ρ , $$\Sigma _b^*\rho $$ Σ b ∗ ρ , $$\Delta D^*$$ Δ D ∗ and $$\Delta B^*$$ Δ B ∗ are expected as molecular states.