8,017 research outputs found
Nucleon Electric Dipole Moments in High-Scale Supersymmetric Models
The electric dipole moments (EDMs) of electron and nucleons are promising
probes of the new physics. In generic high-scale supersymmetric (SUSY)
scenarios such as models based on mixture of the anomaly and gauge mediations,
gluino has an additional contribution to the nucleon EDMs. In this paper, we
studied the effect of the -violating gluon Weinberg operator induced by the
gluino chromoelectric dipole moment in the high-scale SUSY scenarios, and we
evaluated the nucleon and electron EDMs in the scenarios. We found that in the
generic high-scale SUSY models, the nucleon EDMs may receive the sizable
contribution from the Weinberg operator. Thus, it is important to compare the
nucleon EDMs with the electron one in order to discriminate among the
high-scale SUSY models.Comment: 22 pages, 8 figures, Version accepted for publication in JHE
Electric Dipole Moments as Probes of CPT Invariance
Electric dipole moments (EDMs) of elementary particles and atoms probe
violations of T and P symmetries and consequently of CP if CPT is an exact
symmetry. We point out that EDMs can also serve as sensitive probes of CPT-odd,
CP-even interactions, that are not constrained by any other existing
experiments. Analyzing models with spontaneously broken Lorentz invariance, we
calculate EDMs in terms of the leading CPT-odd operators to show that
experimental sensitivity probes the scale of CPT breaking as high as
10^{12}GeV.Comment: 4 pages, typos correcte
New Two-loop Contributions to Hadronic EDMs in the MSSM
Flavor-changing terms with CP-violating phases in the quark sector may
contribute to the hadronic electric dipole moments (EDMs). However, within the
Standard Model (SM), the source of CP violation comes from the unique CKM
phase, and it turns out that the EDMs are strongly suppressed. This implies
that the EDMs are very sensitive to non-minimal flavor violation structures of
theories beyond the SM. In this paper, we discuss the quark EDMs and CEDMs
(chromoelectric dipole moments) in the MSSM with general flavor-changing terms
in the squark mass matrices. In particular, the charged-Higgs mediated
contributions to the down-quark EDM and CEDM are evaluated at two-loop level.
We point out that these two-loop contributions may dominate over the one-loop
induced gluino or Higgsino contributions even when the squark and gluino masses
are around few TeV and \tan\beta is moderate.Comment: 13 pages, 6 figure
Bs Mixing and Electric Dipole Moments in MFV
We analyze the general structure of four-fermion operators capable of
introducing CP-violation preferentially in Bs mixing within the framework of
Minimal Flavor Violation. The effect requires a minimum of O(Yu^4 Yd^4) Yukawa
insertions, and at this order we find a total of six operators with different
Lorentz, color, and flavor contractions that lead to enhanced Bs mixing. We
then estimate the impact of these operators and of their close relatives on the
possible sizes of electric dipole moments (EDMs) of neutrons and heavy atoms.
We identify two broad classes of such operators: those that give EDMs in the
limit of vanishing CKM angles, and those that require quark mixing for the
existence of non-zero EDMs. The natural value for EDMs from the operators in
the first category is up to an order of magnitude above the experimental upper
bounds, while the second group predicts EDMs well below the current sensitivity
level. Finally, we discuss plausible UV-completions for each type of operator.Comment: 11 pages; v2: references adde
Comparison of electric dipole moments and the Large Hadron Collider for probing CP violation in triple boson vertices
CP violation from physics beyond the Standard Model may reside in triple
boson vertices of the electroweak theory. We review the effective theory
description and discuss how CP violating contributions to these vertices might
be discerned by electric dipole moments (EDM) or diboson production at the
Large Hadron Collider (LHC). Despite triple boson CP violating interactions
entering EDMs only at the two-loop level, we find that EDM experiments are
generally more powerful than the diboson processes. To give example to these
general considerations we perform the comparison between EDMs and collider
observables within supersymmetric theories that have heavy sfermions, such that
substantive EDMs at the one-loop level are disallowed. EDMs generally remain
more powerful probes, and next-generation EDM experiments may surpass even the
most optimistic assumptions for LHC sensitivities.Comment: 26 pages, 14 figures, published version with more argument
Search for electric dipole moments at storage rings
Permanent electric dipole moments (EDMs) violate parity and time reversal
symmetry. Within the Standard Model (SM) they are many orders of magnitude
below present experimental sensitivity. Many extensions of the SM predict much
larger EDMs, which are therefore an excellent probe for the existence of "new
physics". Until recently it was believed that only electrically neutral systems
could be used for sensitive searches of EDMs. With the introduction of a novel
experimental method, high precision for charged systems will be within reach as
well. The features of this method and its possibilities are discussed.Comment: Proc. EXA2011, 6 pages;
http://www.springerlink.com/content/45l35376832vhrg0
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