scholarly journals Hadronic Leading Order Contribution to the Muon g-2

2018 ◽  
Vol 179 ◽  
pp. 01016
Author(s):  
Daisuke Nomura
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Leading Order ◽  
Muon Anomalous Magnetic Moment ◽  
Order Contribution ◽  
Quark Contribution ◽  
The Standard Model ◽  
Vacuum Polarisation

We calculate the Standard Model (SM) prediction for the muon anomalous magnetic moment. By using the latest experimental data for e+e- → hadrons as input to dispersive integrals, we obtain the values of the leading order (LO) and the next-to-leading-order (NLO) hadronic vacuum polarisation contributions as ahad, LO VPμ = (693:27 ± 2:46) × 10-10 and ahad, NLO VP μ = (_9.82 ± 0:04) × 1010-10, respectively. When combined with other contributions to the SM prediction, we obtain aμ(SM) = (11659182:05 ± 3.56) × 10-10; which is deviated from the experimental value by Δaμ(exp) _ aμ(SM) = (27.05 ± 7.26) × 10-10. This means that there is a 3.7 σ discrepancy between the experimental value and the SM prediction. We also discuss another closely related quantity, the running QED coupling at the Z-pole, α(M2 Z). By using the same e+e- → hadrons data as input, our result for the 5-flavour quark contribution to the running QED coupling at the Z pole is Δ(5)had(M2 Z) = (276.11 ± 1.11) × 10-4, from which we obtain Δ(M2 Z) = 128.946 ± 0.015.

Supersymmetric Lepton Flavor Violation, the Muon Anomalous Magnetic Moment, and e- e- Colliders

2003 ◽  
Vol 18 (16) ◽  
pp. 2769-2778
Author(s):  
Graham D. Kribs
Keyword(s):  
Standard Model ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
International Workshop ◽  
Lepton Flavor Violation ◽  
Muon Anomalous Magnetic Moment ◽  
Lepton Flavor ◽  
Flavor Violation ◽  
Central Value ◽  
The Standard Model

I explain the theoretical connection between lepton flavor violation and muon g - 2 in supersymmetry1. Given any central value deviation of muon g - 2 from the standard model that is assumed to be due to weak scale supersymmetry, I show that stringent bounds on lepton flavor violating scalar masses can be extracted. These bounds are essentially independent of supersymmetric parameter space. I then briefly compare this indirect handle on supersymmetric lepton flavor violation with direct observation at a future lepton collider operating in the e- e- mode. This is a summary of a talk given at e- e-01: 4th International Workshop on Electron-Electron Interactions at TeV Energies.

scholarly journals Fermilab muon g-2 experiment

2018 ◽  
Vol 179 ◽  
pp. 01004 ◽  
Author(s):  
Tim Gorringe
Keyword(s):  
Standard Model ◽  
Experimental Technique ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Current Status ◽  
Muon Anomalous Magnetic Moment ◽  
Anomalous Moment ◽  
The Standard Model ◽  
New Interactions ◽  
Future Work

The Fermilab muon g-2 experiment will measure the muon anomalous magnetic moment aμ to 140 ppb – a four-fold improvement over the earlier Brookhaven experiment. The measurement of aμ is well known as a unique test of the standard model with broad sensitivity to new interactions, particles and phenomena. The goal of 140 ppb is commensurate with ongoing improvements in the SM prediction of the anomalous moment and addresses the longstanding 3.5σ discrepancy between the BNL result and the SM prediction. In this article I discuss the physics motivation and experimental technique for measuring aμ, and the current status and the future work for the project.

scholarly journals THEORY OF THE τ LEPTON ANOMALOUS MAGNETIC MOMENT

2007 ◽  
Vol 22 (03) ◽  
pp. 159-179 ◽  
Author(s):  
S. EIDELMAN ◽  
M. PASSERA
Keyword(s):  
Standard Model ◽  
Model Prediction ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Standard Model Prediction ◽  
Low Energy ◽  
Leading Order ◽  
The Standard Model

This paper reviews and updates the Standard Model prediction of the τ lepton g-2. Updated QED and electroweak contributions are presented, together with new values of the leading-order hadronic term, based on the recent low energy e+ e- data from BaBar, CMD-2, KLOE and SND, and hadronic light-by-light contribution. The total prediction is confronted to the available experimental bounds on the τ lepton anomaly, and prospects for its future measurements are briefly discussed.

scholarly journals Status of the Muon g-2 experiment at Fermilab

2019 ◽  
Author(s):  
Anna Driutti
Keyword(s):  
Standard Model ◽  
Magnetic Moment ◽  
Experimental Measurement ◽  
Anomalous Magnetic Moment ◽  
Experimental Result ◽  
Current Status ◽  
Muon Anomalous Magnetic Moment ◽  
Relative Precision ◽  
The Standard Model ◽  
Stringent Test

The aim of the Muon g-2g−2 Experiment at Fermilab (E989) is to measure the muon anomalous magnetic moment (a_\muaμ) with a relative precision of 140 parts-per-billion (ppb). This precision, which is a factor of four improvement from the current experimental result, will allow for a much more stringent test of the Standard Model. This paper present the current status of the experimental measurement of a_\muaμ after the first physics run.

scholarly journals Two and three pseudoscalar production in e+e− annihilation and their contributions to (g − 2)μ

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Wen Qin ◽  
Ling-Yun Dai ◽  
Jorge Portolés
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Pseudoscalar Meson ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Vacuum Polarization ◽  
Meson Production ◽  
The Other ◽  
Joint Analysis ◽  
The Standard Model

Abstract A coherent study of e+e− annihilation into two (π+π−, K+K−) and three (π+π−π0, π+π−η) pseudoscalar meson production is carried out within the framework of resonance chiral theory in energy region E ≲ 2 GeV. The work of [L.Y. Dai, J. Portolés, and O. Shekhovtsova, Phys. Rev. D88 (2013) 056001] is revisited with the latest experimental data and a joint analysis of two pseudoscalar meson production. Hence, we evaluate the lowest order hadronic vacuum polarization contributions of those two and three pseudoscalar processes to the anomalous magnetic moment of the muon. We also estimate some higher-order additions led by the same hadronic vacuum polarization. Combined with the other contributions from the standard model, the theoretical prediction differs still by (21.6 ± 7.4) × 10−10 (2.9σ) from the experimental value.

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