arXiv subjects

Kai-Lei Wang

Publications and source records attributed to Kai-Lei Wang.

21 records · Page 2Linked to original sources

arXiv2017

Strong and radiative decays of the doubly charmed baryons

We have systematically studied the strong and radiative decays of the low-lying $1P$-wave doubly charmed baryons. Some interesting observations are: (i) The states $Ξ_{cc}^*$ and $Ω_{cc}^*$ with $J^P=3/2^+$ have a fairly large decay rate into the $Ξ_{cc}γ$ and $Ω_{cc}γ$ channels with a width $\sim 15$ and $\sim7$ keV, respectively. (ii) The lowest lying excited doubly charmed baryons are dominated by the $1P$ $ρ$ mode excitations, which should be quite narrow states. They decay into the ground state with $J^P=1/2^+$ through the radiative transitions with a significant ratio. (iii) The total decay widths of the first orbital excitations of $λ$ mode ($1P_λ$ states with $J^P=1/2^-$, $3/2^-$, $5/2^-$) are about $Γ\sim100$ MeV, and the ratio between the radiative and hadronic decay widths is about $\mathcal{O}(10^{-3})$.

hep-ph↗

arXiv2017

Understanding the newly observed $Ω_c$ states through their decays

The strong and radiative decay properties of the low-lying $Ω_c$ states are studied in a constituent quark model. We find that the newly observed $Ω_c$ states by the LHCb Collaboration can fit in well the decay patterns. Thus, their spin-parity can be possibly assigned as the following: (i) The $Ω_c(3000)$ has $J^P=1/2^-$ and corresponds to the narrow $1P$ mixed state $|1^2P_λ\frac{1}{2}^-\rangle_1$, its partner $|1^2P_λ\frac{1}{2}^-\rangle_2$ should be a broad state with a width of $\sim 100$ MeV. (ii) The $Ω_c(3050)$ and $Ω_c(3066)$ can be assigned to be two $J^P=3/2^-$ states, $|1^4P_λ\frac{3}{2}^-\rangle$ and $|1^2P_λ\frac{3}{2}^-\rangle$, respectively. (iii) The $Ω_c(3090)$ can be assigned as the $|1^4P_λ\frac{5}{2}^-\rangle$ state with $J^P=5/2^-$. (iv) The $Ω_c(3119)$ might correspond to one of the two $2S$ states of the first radial excitations, i.e. $|2^2S_{λλ}\frac{1}{2}^+\rangle$ or $|2^4S_{λλ}\frac{3}{2}^+\rangle$.

hep-ph↗

arXiv2017

Quark model study of the $πN\to πN$ reactions up to the $N(1440)$ resonance region

A combined analysis of the reactions $π^+p\to π^+p$, $π^-p\to π^-p$ and $π^-p\to π^0n$ is carried out with a chiral quark model. The observations are reasonably described from the $Δ(1232)$ resonance region up to the $N(1440)$ resonance region. Besides the $Δ(1232)P_{33}$, a confirmed role of $N(1440)P_{11}$ is found in the polarizations of the $π^-p\to π^-p$ and $π^-p\toπ^0n$ reactions. It is found that the $N(1440)Nπ$ and $Δ(1232)Nπ$ couplings are about $1.7$ and $4.8$ times larger than the expectations from the simple quark model, respectively, which may suggest the unusual property of $N(1440)P_{11}$ and deficiency of the simple quark model in the description of $N(1440)P_{11}$ and $Δ(1232)P_{33}$. The $t$- and $u$-channel backgrounds have notable contributions to the $π^+ p\rightarrowπ^+ p$ reaction, while in the $π^-p\rightarrow π^- p,π^0 n$ reactions, the $s$-channel nucleon and $t$- and $u$-channel backgrounds play crucial roles.

nucl-th↗