The Physics Case for the New Muon (g-2) Experiment

Abstract

This White Paper briefly reviews the present status of the muon (g-2) experiment and the physics motivation for a new effort. The present comparison between experiment and theory indicates a tantalizing $3.4\sigma$ deviation. An improvement in precision on this comparison by a factor of 2--with the central value remaining unchanged--will exceed the ``discovery'' threshold, with a sensitivity above $6\sigma$. The 2.5-fold reduction improvement goal of the new Brookhaven E969 experiment, along with continued steady reduction of the standard model theory uncertainty, will achieve this more definitive test. Already, the (g-2) result is arguably the most compelling indicator of physics beyond the standard model and, at the very least, it represents a major constraint for speculative new theories such as supersymmetry or extra dimensions. In this report, we summarize the present experimental status and provide an up-to-date accounting of the standard model theory, including the expectations for improvement in the hadronic contributions, which dominate the overall uncertainty. Our primary focus is on the physics case that motivates improved experimental and theoretical efforts. Accordingly, we give examples of specific new-physics implications in the context of direct searches at the LHC as well as general arguments about the role of an improved (g-2) measurement. A brief summary of the plans for an upgraded effort complete the report.

18 pages, 7 figures

References in corpus (5)

• Distinguishing Spins in Supersymmetric and Universal Extra Dimension Models at the Large Hadron Collider
• Constraints on Supersymmetric Models from the Muon Anomalous Magnetic Moment
• The $e^{+}{e}^{-}\to K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}$, $K^{+}{K}^{-}{\pi }^0{\pi }^0$ and $K^{+}{K}^{-}{K}^{+}{K}^{-}$ Cross Sections Measured with Initial-State Radiation
• Universal Extra Dimensions and the Muon Magnetic Moment
• SFITTER: SUSY Parameter Analysis at LHC and LC

Cited by in corpus (17)

• The Next-to-Minimal Supersymmetric extension of the Standard Model reviewed
• Physics at a future Neutrino Factory and super-beam facility
• Fitting the Phenomenological MSSM
• Likelihood Functions for Supersymmetric Observables in Frequentist Analyses of the CMSSM and NUHM1
• GM2Calc: Precise MSSM prediction for $(g-2)$ of the muon
• Prediction for the Lightest Higgs Boson Mass in the CMSSM using Indirect Experimental Constraints
• Muon Anomaly from Lepton Vacuum Polarization and The Mellin--Barnes Representation
• Photonic SUSY Two-Loop Corrections to the Muon Magnetic Moment
• CP Violation in the SUSY Seesaw: Leptogenesis and Low Energy
• Physics Beyond the Standard Model: Supersymmetry
• Particle Physics at the LHC Start
• (g-2)_mu and supersymmetry: status and prospects
• Large tan(beta) effects in flavour physics
• Hadronic Light-by-Light Contribution to Muon g-2
• Particle Physics in the LHC Era and beyond
• The Hadronic Light-by-Light Contribution to Muon g-2: A Short Review
• Theory of the Hadronic Light-by-Light Contribution to Muon g-2