Investigation of $$\varXi _c^0$$ in a chiral quark model

Abstract

Recently, three new states of $$\varXi _c^0$$ Ξ c 0 were observed in the invariant mass spectrum of $$\varLambda ^+_cK^-$$ Λ c + K - by LHCb collaboration. In this work, we use a chiral quark model to investigate these three exited states with the help of Gaussian expansion method both in three-quark structure and in five-quark structure with all possible quantum numbers $$IJ^P=\frac{1}{2}(\frac{1}{2})^-$$ I J P = 1 2 ( 1 2 ) - , $$\frac{1}{2}(\frac{3}{2})^-$$ 1 2 ( 3 2 ) - , $$\frac{1}{2}(\frac{5}{2})^-$$ 1 2 ( 5 2 ) - , $$\frac{3}{2}(\frac{1}{2})^-$$ 3 2 ( 1 2 ) - , $$\frac{3}{2}(\frac{3}{2})^-$$ 3 2 ( 3 2 ) - and $$\frac{3}{2}(\frac{5}{2})^-$$ 3 2 ( 5 2 ) - . The calculations shows that the masses of 2S and 1D states of $$\varXi _c$$ Ξ c are comparable to experimental results; In addition, the resonance states of five-quark configuration are possible candidates of these new states with negative parity by using the real scaling method and their decay width is also given.

An updated review of the new hadron states

“…) We briefly review several possible explanations for the Ξ c (2923), Ξ c (2939), and Ξ c (2965) as follows, and refer interested readers to Refs. [322,274,323] for more discussions. We shall notice that all these explanations are not (exactly) the same, partly because the heavy quark effective theory does not work quite well for these charmed baryons.…”

Toward discovering low-lying P-wave excited Σ c baryon states *

“…Additionally, the and resonances are good candidates for the -wave -mode singly bottom baryons [16, 41-44, 48-51, 53, 62]. Finally, some unconventional interpretations, such as molecular or pentaquark, were also proposed in the literature for the newly observed resonances, [63][64][65][66][67][68][69][70][71][72][73][74], [75], [76,77], and [78][79][80][81]. As a whole, a fairly complete -mode -wave spectrum in the , , , , and families may be established with discovery of the series of heavy baryons at the LHC.…”