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Published on: November 15, 2013
Determination of the X(3872) meson quantum numbers
R Aaij1, C Abellan Beteta, B Adeva
1Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.
Physical Review Letters
|June 18, 2013
Summary
Researchers determined the quantum numbers of the X(3872) meson to be J(PC)=1(++) using LHCb data. This finding excludes previous assignments and supports exotic particle explanations for the X(3872) state.
Area of Science:
- High Energy Physics
- Particle Physics
- Quantum Mechanics
Background:
- The X(3872) is an exotic meson whose quantum numbers have been debated.
- Previous measurements allowed for two possible assignments: J(PC)=1(++) and J(PC)=2(-+).
Purpose of the Study:
- To definitively determine the quantum numbers of the X(3872) meson.
- To distinguish between the J(PC)=1(++) and J(PC)=2(-+) assignments.
Main Methods:
- Analysis of angular correlations in B(+)→X(3872)K(+) decays.
- Utilizing data from 1.0 fb(-1) of proton-proton collisions collected by the LHCb detector.
- Employing a likelihood-ratio test across the full angular phase space.
Main Results:
- The quantum numbers of the X(3872) meson were determined to be J(PC)=1(++).
- The alternative assignment J(PC)=2(-+) was rejected with a statistical significance exceeding 8 standard deviations.
- The decay channels X(3872)→π(+)π(-)J/ψ and J/ψ→μ(+)μ(-) were utilized.
Conclusions:
- The established quantum numbers J(PC)=1(++) strongly favor exotic interpretations of the X(3872) meson.
- This precise determination resolves ambiguity and guides future theoretical models of exotic hadrons.
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