4,728 research outputs found
Composite (pseudo) scalar contributions to muon g-2
We have calculated the composite (pseudo) scalar contributions to the
anomalous magnetic moment of muons in models of walking technicolor. By the
axial or scale anomaly the light scalars such as techni-dilaton, techni-pions
or techni-eta have anomalous couplings to two-photons, which make them natural
candidates for the recent 750 GeV resonance excess, observed at LHC. Due to the
anomalous couplings, their contributions to muon (g-2) are less suppressed and
might explain the current deviation in muon (g-2) measurements from theory.Comment: 9 pages, 2 figures; published versio
Holographic calculation of hadronic contributions to muon g-2
Using the gauge/gravity duality, we compute the leading order hadronic (HLO)
contribution to the anomalous magnetic moment of muon, amu(HLO). Holographic
renormalization is used to obtain a finite vacuum polarization. We find
amu(HLO) =470.5 x 10^{-10} in AdS/QCD with two light flavors, which is compared
with the currently revised BABAR data estimated from e^+ e^- -> pi^+ pi^-
events, amu(HLO)[pipi]=(514.1 +- 3.8) x 10^{-10}.Comment: 12 pages, latex, references adde
Clockwork graviton contributions to muon
The clockwork mechanism for gravity introduces a tower of massive graviton
modes, "clockwork gravitons," with a very compressed mass spectrum, whose
interaction strengths are much stronger than that of massless gravitons. In
this work, we compute the lowest order contributions of the clockwork gravitons
to the anomalous magnetic moment, , of muon in the context of extra
dimensional model with a five dimensional Planck mass, . We find that the
total contributions are rather insensitive to the detailed model parameters,
and determined mostly by the value of . In order to account for the
current muon anomaly, should be around , and the
size of the extra dimension has to be quite large, m.
For , the clockwork graviton contributions are too small
to explain the current muon anomaly. We also compare the clockwork
graviton contributions with other extra dimension models such as
Randall-Sundrum models or large extra dimension models. We find that the
leading contributions in the small curvature limit are universal, but the
cutoff-independent subleading contributions vary for different background
geometries and the clockwork geometry gives the smallest subleading
contributions.Comment: 14 pages, 4 figures: v3 minor corrections, to appear in PR
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