Production of excited ${\Lambda }_c^{+}$ baryons through ${\Lambda }_b$ hadronic weak decays

Abstract

In this work, to establish a more abundant ${\Lambda }_c$ baryon spectrum, we discuss the production potentials of the excited ${\Lambda }_c$ baryons through ${\Lambda }_b$ hadronic weak decays within a constituent quark model. Based on our successful explanations of the existing experimental data for the ${\Lambda }_b\to {\Lambda }_c({\pi }^{-},K^{-},D^{-},D_s^{-},D_s^{\ast -})$ processes, we further calculate the decay rates of the ${\Lambda }_b$ baryon into the $1P$-, $1D$-, $2S$-, $3S$-, $2P$-, $1F$-, and $2D$-wave ${\Lambda }_c$ excited states. It is found that these ${\Lambda }_c$ excitations have a large production rate in the ${\Lambda }_b$ hadronic weak decay process associated ${\pi }^{-}$ meson emitting, i.e., ${\Lambda }_b\to {\Lambda }_c^{\ast }{\pi }^{-}$, their branching fractions can reach up to $\mathcal{O}(10^{-3})$. To search for the higher $3S$-, $2P$-, $1F$-, and $2D$-wave ${\Lambda }_c$ states, the ${\Lambda }_b\to {\Lambda }_c(3S){\pi }^{-}\to D^{\ast 0}p{\pi }^{-}$, and ${\Lambda }_b\to {\Lambda }_c(2P,2D,1F){\pi }^{-}\to D^{(\ast )0}p{\pi }^{-}$ decays are worth observing in future experiments.

14 pages, 1 figure