{pi}-{eta} mixing from QCD sum rules

Chan, Chuan-Tsung; Henley, E.M.; Meißner, Thomas

doi:10.2172/10155840

Cited by 5 publications

(14 citation statements)

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“…We also consider the relation of this result to the estimate (3) obtained within chiral perturbation theory, and compare it with the outcome of an independent calculation of d n (θ) reported recently in Ref. [26]. We begin in Section II by studying the phenomenological structure of the neutron correlator, and in particular addressing the issue of how to ensure chiral invariance of the result.…”

Section: Introductionmentioning

confidence: 76%

Theta vacua, QCD sum rules, and the neutron electric dipole moment

2000

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We present a detailed study of the electric dipole moment of the neutron induced by a vacuum theta angle within the framework of QCD sum rules. At next-to-next-to leading order in the operator product expansion, we find the result d n (θ) = 2.4 × 10 −16θ e · cm, to approximately 40% precision. With the current experimental bound this translates into a limit on the theta parameter of |θ| < 3 × 10 −10 . We compare this result with the long-standing estimates obtained within chiral perturbation theory, and observe a numerical similarity, but also significant differences in the source of the dominant contribution.

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Section: Introductionmentioning

confidence: 76%

Theta vacua, QCD sum rules, and the neutron electric dipole moment

2000

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“…0|η n |0 = λe iαγ 5 /2 v. It turns out that of the terms contributing to the neutron EDM, there is a unique structure which is invariant under chiral rotations, namely LS={F σγ 5 , / p}, thus this is the natural quantity on which to focus in constructing a sum rule for the EDM (for alternatives, see [71,72]). Correspondingly, LS=/ p is the relevant chiral-invariant structure for theḡ πN N sum rule.…”

Section: Qcd Sum-rules Techniquesmentioning

confidence: 99%

“…The correlator (3.46) exhibits various Lorentz structures (LS) in its OPE and, in selecting one to consider, one needs to be aware that in a CP -violating background the coupling of the current to the neutron state, described by a spinor v, is not invariant under chiral rotations, i.e. 0|η n |0 = λe iαγ 5 /2 v. It turns out that of the terms contributing to the neutron EDM, there is a unique structure which is invariant under chiral rotations, namely LS={F σγ 5 , / p}, thus this is the natural quantity on which to focus in constructing a sum rule for the EDM (for alternatives, see [71,72]). Correspondingly, LS=/ p is the relevant chiral-invariant structure for the ḡπNN sum rule.…”

Section: Qcd Sum-rules Techniquesmentioning

confidence: 99%

Electric dipole moments as probes of new physics

2005

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We review several aspects of flavour-diagonal CP violation, focussing on the role played by the electric dipole moments (EDMs) of leptons, nucleons, atoms and molecules, which consitute the source of several stringent constraints on new CPviolating physics. We dwell specifically on the calculational aspects of applying the hadronic EDM constraints, reviewing in detail the application of QCD sum-rules to the calculation of nucleon EDMs and CP-odd pion-nucleon couplings. We also consider the current status of EDMs in the Standard Model, and on the ensuing constraints on the underlying sources of CP-violation in physics beyond the Standard Model, focussing on weak-scale supersymmetry.

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Section: Introductionmentioning

confidence: 99%

“…In the case of the neutron EDM, d n ( θ) has been calculated using various different techniques: (1) making use of the dominance of a pion loop-induced logarithm in the chiral limit [7]; (2) in the Skyrme model [8]; and finally using QCD sum rules [9,10]; and all have produced similar results. For the calculation of d EDM n (d u , d d , d s ), the quark tensor charges over the nucleon are required, and various techniques [11,12] have produced results consistent with the predictions of a naive SU(6) quark model.…”

Section: Introductionmentioning

confidence: 99%

Hadron electric dipole moments from CP-odd operators of dimension five via QCD sum rules: the vector meson

Pospelov

Ritz

2000

Physics Letters B

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We present a complete analysis of the electric dipole moment (EDM) of the ρ-meson induced by CP violating operators of dimension 4 and 5 within the QCD sum rules approach. The set of CP-odd operators includes the theta term and the electric and chromoelectric dipole moments of the three light quarks. We find that the ρ-meson EDM induced purely by the EDMs of quarks is smaller, but still in reasonable agreement, with the predictions of a naive constituent quark model. However, the chromoelectric dipole moments, including that of the strange quark, give comparable and sometimes larger contributions. We also consider the effect on the hadronic EDM of the existence of Peccei-Quinn symmetry. When this symmetry is active, chromoelectric dipole moments induce a linear term in the axion potential which leads to a numerically important vacuum contribution to the hadronic EDM. * pospelov@mnhepw.hep.umn.edu † a.ritz@damtp.cam.ac.uk ‡ Present address 1

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{pi}-{eta} mixing from QCD sum rules

Cited by 5 publications

References 0 publications

Theta vacua, QCD sum rules, and the neutron electric dipole moment

Theta vacua, QCD sum rules, and the neutron electric dipole moment

Electric dipole moments as probes of new physics

Hadron electric dipole moments from CP-odd operators of dimension five via QCD sum rules: the vector meson

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