Study of the decays χcJ → Λ Λ̄φ

Based on (2712.4 ± 14.3) × 10⁶ e⁺e⁻→ψ(3686) events collected with the BESIII detector operating at the BEPCII collider, we report the first evidence of χc0→ Λ Λ φ decays and the first observation of χc1,2→ Λ Λ φ decays, with significances of 4.5σ, 11.3σ and 13.0σ, respectively. The decay branching fractions of χc0,1,2→ Λ Λφ are measured to be ( 2.99±1.24±0.19) × 10⁻⁵, (6.01±0.90±0.40 )× 10⁻⁵, and (7.13±0.81±0.36) × 10⁻⁵, where the first uncertainties are statistical and the second systematic. No obvious enhancement near the Λ Λ̄ production threshold or excited Λ state is found in the Λ φ (or Λ̄φ) system.