Model-Independent Evidence for J/ψp Contributions to Λ_{b}^{0}→J/ψpK^{-} Decays

Area of Science:

• Particle Physics
• High Energy Physics
• Quantum Chromodynamics

Background:

• The study investigates Lambda_b0 decays, a process studied in particle physics.
• Previous research suggested the existence of exotic pentaquark states, specifically Pc+ states, observed in J/psi p invariant mass spectra.

Purpose of the Study:

• To analyze the contributions of J/psi p and J/psi K- within Lambda_b0 decays.
• To provide model-independent evidence supporting the existence of Pc+ pentaquark states.

Main Methods:

• Utilizing a large dataset of Lambda_b0 -> J/psi p K- decays from LHCb.
• Performing a data-driven analysis with minimal assumptions on K- p contributions.
• Employing statistical significance (more than nine standard deviations) to evaluate model compatibility.

Main Results:

• Demonstrated that Lambda_b0 -> J/psi p K- decays cannot be solely described by K- p contributions.
• Established that J/psi p contributions are dominant and necessary for describing the decay.
• Achieved a statistical significance exceeding nine standard deviations for the incompatibility with K- p alone.

Conclusions:

• The findings provide robust, model-independent support for the existence of Pc+ pentaquark states.
• The dominant role of J/psi p contributions in Lambda_b0 decays is confirmed.
• This research strengthens the evidence for exotic hadrons beyond the conventional quark model.