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Search for invisible decays of the Upsilon(1S)
B Aubert1, Y Karyotakis, J P Lees
1Laboratoire d'Annecy-le-Vieux de Physique des Particules (LAPP), Université de Savoie, CNRS/IN2P3, F-74941 Annecy-Le-Vieux, France.
Physical Review Letters
|April 7, 2010
Summary
Researchers searched for invisible decays of the Upsilon(1S) meson, finding no evidence. An upper limit was set on the branching fraction for Upsilon(1S) invisible decays, contributing to particle physics research.
Area of Science:
- Particle Physics
- High-Energy Physics
- Experimental Physics
Background:
- The Upsilon(1S) meson is a key state in quarkonium physics.
- Understanding meson decays is crucial for testing the Standard Model.
- Invisible decays, where the Upsilon(1S) decays into undetected particles, are of theoretical interest.
Purpose of the Study:
- To search for evidence of invisible decays of the Upsilon(1S) meson.
- To set an upper limit on the branching fraction of Upsilon(1S) invisible decays.
- To constrain new physics models that predict such decays.
Main Methods:
- Utilized a data sample of 91.4 x 10^6 Upsilon(3S) mesons collected at the BABAR/PEP-II B factory.
- Selected events consistent with the decay Upsilon(3S) --> pi(+)pi(-)Upsilon(1S).
- Searched for the Upsilon(1S) meson decaying invisibly, identified by the recoiling dipion system.
Main Results:
- No significant signal for invisible Upsilon(1S) decays was observed.
- An upper limit on the branching fraction was established: B(Upsilon(1S) --> invisible) < 3.0 x 10^-4.
- This limit is set at the 90% confidence level.
Conclusions:
- The study places constraints on the rate of invisible Upsilon(1S) decays.
- The findings contribute to the ongoing search for physics beyond the Standard Model.
- Further experimental and theoretical investigations are warranted.
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