Many scenarios of physics beyond the standard model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an e+e- collider, such a leptophilic scalar (φL) would be produced predominantly through radiation from a τ lepton. We report herein a search for e+e-→τ+τ-φL, φL→ℓ+ℓ- (ℓ=e, μ) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the φL coupling to leptons in the range 0.04<7.0 GeV. These bounds significantly improve upon the current constraints, excluding almost entirely the parameter space favored by the observed discrepancy in the muon anomalous magnetic moment below 4 GeV at 90% confidence level.

Lees, J., Poireau, V., Tisserand, V., Grauges, E., Palano, A., Eigen, G., et al. (2020). Search for a Dark Leptophilic Scalar in e+e- Collisions. PHYSICAL REVIEW LETTERS, 125(18) [10.1103/PhysRevLett.125.181801].

Search for a Dark Leptophilic Scalar in e+e- Collisions

Carpinelli M.;
2020

Abstract

Many scenarios of physics beyond the standard model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an e+e- collider, such a leptophilic scalar (φL) would be produced predominantly through radiation from a τ lepton. We report herein a search for e+e-→τ+τ-φL, φL→ℓ+ℓ- (ℓ=e, μ) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the φL coupling to leptons in the range 0.04<7.0 GeV. These bounds significantly improve upon the current constraints, excluding almost entirely the parameter space favored by the observed discrepancy in the muon anomalous magnetic moment below 4 GeV at 90% confidence level.
Articolo in rivista - Articolo scientifico
Elementary particles; Magnetic moments; Anomalous magnetic moments; BABAR experiment; Confidence levels; E+e- collider; Parameter spaces; The standard model
English
2020
125
18
181801
none
Lees, J., Poireau, V., Tisserand, V., Grauges, E., Palano, A., Eigen, G., et al. (2020). Search for a Dark Leptophilic Scalar in e+e- Collisions. PHYSICAL REVIEW LETTERS, 125(18) [10.1103/PhysRevLett.125.181801].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/395235
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