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Observation of Exotic J/ψϕ Resonant Structure in Diffractive Processes in Proton-Proton Collisions.
R Aaij1, A S W Abdelmotteleb2, C Abellan Beteta3
1Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.
Physical Review Letters
|February 10, 2025
Summary
This study presents the first analysis of J/ψϕ production in diffractive proton-proton collisions. Data favors a resonant model, confirming the χ_{c0}(4500) and χ_{c1}(4274) states.
Area of Science:
- High-energy physics
- Particle physics
- Quantum chromodynamics
Background:
- J/ψϕ production in diffractive processes is not well understood.
- Previous studies focused on non-diffractive processes or different final states.
Purpose of the Study:
- To investigate J/ψϕ production in diffractive proton-proton collisions for the first time.
- To test resonant vs. nonresonant production models.
- To search for new exotic states in this channel.
Main Methods:
- Analysis of LHCb data from proton-proton collisions at 13 TeV.
- Integrated luminosity of 5 fb⁻¹.
- Amplitude analysis to determine the production mechanism and resonant contributions.
Main Results:
- The data disfavor a nonresonant J/ψϕ production model.
- The results are consistent with a resonant model.
- Observation of the χ_{c0}(4500) state with a significance > 6σ.
- Confirmation of the χ_{c1}(4274) state with a significance > 4σ.
Conclusions:
- The J/ψϕ system in diffractive processes is dominated by resonant contributions.
- The observed states are consistent with those found in B⁺ decays.
- This study provides new insights into the nature of exotic charmonium states.
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