PT Journal
AU Xie, JJ
   Oset, E
TI Search for the Sigma* state in Lambda(+)(c) -> pi(+)pi(0)pi(-)Sigma(+) decay by triangle singularity
SO Physics Letters B
JI Phys. Lett. B
PY 2019
BP 450
EP 453
VL 792
DI 10.1016/j.physletb.2019.04.011
LA English
AB A Sigma* resonance with spin-parity J(P) = 1/2(-) and mass in the vicinity of the (K) over barN threshold has been predicted in the unitary chiral approach and inferred from the analysis of CLAS data on the gamma p -> K+pi(0)Sigma(0) reaction. In this work, based on the dominant Cabibbo favored weak decay mechanism, we perform a study of Lambda(+)(c) -> pi(+)pi(0)Sigma* with the possible Sigma* state decaying into pi(-)Sigma(+) through a triangle diagram. This process is initiated by Lambda(+)(c) -> pi(+)(K) over bar *N, then the (K) over bar* decays into (K) over bar pi and (K) over barN produce the Sigma* through a triangle loop containing (K) over bar *N (K) over bar which develops a triangle singularity. We show that the pi(-)Sigma(+) state is generated from final state interaction of (K) over barN in S-wave and isospin I = 1, and the Lambda(+)(c) -> pi(+)pi(0)pi(-)Sigma(+) decay can be used to study the possible Sigma* state around the (K) over barN threshold. The proposed decay mechanism can provide valuable information on the nature of the Sigma* resonance and can in principle be tested by facilities such as LHCb, BelleII and BESIII.
ER