Title of article :
Muon and tau anomalies updated
Author/Authors :
Stephan Narison، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2001
Pages :
18
From page :
53
To page :
70
Abstract :
We present a new independent evaluation of the hadronic vacuum polarization contributions alhad(l.o.)≡12(g−2)lhad(l.o.) to the anomalous magnetic moment (anomaly) of the muon and tau leptons using τ-decays and e+e− data. The alone theoretical input used for describing the high-energy region not accessible experimentally is perturbative QCD plus (negligible) additional effects due to the QCD vacuum condensates. We obtain: aμhad(l.o.)=7020.6(75.6)×10−11 and aτhad(l.o.)=353.6(3.8)×10−8, which we compare with previous determinations. Confronting the theoretical Standard Model (SM) predictions of aμ with the recent BNL measurement leads to aμnew≡aμexp−aμSM=333(173)×10−11. Combined with existing determinations, this leads to the conservative range: 112⩽aμnew×1011⩽573 at 90% CL, from which we derive lower bounds on the scales of some new physics. We also update our old and first predictions of the SM contributions to aτ. Including QED to sixth order, higher order hadronic and electroweak contributions, we obtain aτSM=117 711(12)×10−8, waiting for a future precise measurement of aτ.
Journal title :
PHYSICS LETTERS B
Serial Year :
2001
Journal title :
PHYSICS LETTERS B
Record number :
914475
Link To Document :
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