Jun 5 – 9, 2023
Genova, Italy
Europe/Rome timezone

The LHCb state PΛ_{psi s} (4338) as a triangle singularity

Jun 7, 2023, 3:36 PM
DAD - Room 5H (Genova, Italy)

DAD - Room 5H

Genova, Italy

Contributed Hadron decays, production and interactions Hadron decays, production and interaction


Eric Swanson (University of Pittsburgh)


We present a model for the J/ψ Λ spectrum in B− → J/ψ Λ p ̄ decays, including the PΛ_{psi s} (4338)
baryon recently observed by the LHCb collaboration. We assume production via triangle diagrams
which couple to the final state via non-perturbative interactions which are constrained by heavy-
quark and SU3-flavor symmetry. The bulk of the distribution is described by a triangle diagram
with a color-favored electroweak vertex, while the sharp PΛ (4338) enhancement is due to the ψs
triangle singularity in another diagram featuring a 1/2− baryon consistent with Σc(2800).

Primary author

Eric Swanson (University of Pittsburgh)

Presentation materials