scholarly journals Construction of Higher-Order Metric Fluctuation Terms in Spacetime Symmetry-Breaking Effective Field Theory

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 834
Author(s):  
Quentin G. Bailey
Keyword(s):  
Symmetry Breaking ◽  
Conservation Laws ◽  
Effective Field Theory ◽  
Effective Field ◽  
Flat Background ◽  
Special Cases ◽  
Field Fluctuations ◽  
Lorentz Symmetry Breaking ◽  
Diffeomorphism Symmetry ◽  
Metric Fluctuations

We examined the basic conservation laws for diffeomorphism symmetry in the context of spontaneous diffeomorphism and local Lorentz-symmetry breaking. The conservation laws were used as constraints on a generic series of terms in an expansion around a flat background. We found all such terms for a two-tensor coupling to cubic order in the metric and tensor field fluctuations. The results are presented in a form that can be used for phenomenological calculations. One key result is that if we preserve the underlying diffeomorphism symmetry in a spontaneous-symmetry breaking scenario, one cannot decouple the two-tensor fluctuations from the metric fluctuations at the level of the action, except in special cases of the quadratic actions.

scholarly journals Effective field theory for spacetime symmetry breaking

2015 ◽  
Vol 92 (4) ◽  
Author(s):  
Yoshimasa Hidaka ◽  
Toshifumi Noumi ◽  
Gary Shiu
Keyword(s):  
Field Theory ◽  
Symmetry Breaking ◽  
Effective Field Theory ◽  
Effective Field ◽  
Spacetime Symmetry

scholarly journals SPECTRUM AND DECAYS OF HADRONIC ATOMS

2005 ◽  
Vol 20 (02n03) ◽  
pp. 358-364 ◽  
Author(s):  
JULIA SCHWEIZER
Keyword(s):  
Field Theory ◽  
Symmetry Breaking ◽  
Effective Field Theory ◽  
Ground State ◽  
Effective Field ◽  
Isospin Symmetry ◽  
Leading Order ◽  
Isospin Symmetry Breaking ◽  
Hadronic Atoms

We describe the spectra and decays of π+π-and π±K∓atoms within a non-relativistic effective field theory. The evaluations of the energy shifts and widths are performed at next-to-leading order in isospin symmetry breaking. The prediction for the lifetime of the π±K∓atom in its ground-state yields τ10=(3.7±0.4)·10-15s .

COMMENTS ON HIERARCHICAL SYMMETRY BREAKING IN EFFECTTVE THEORY OF CALABI-YAU COMPACTIFIED SUPERSTRING

1990 ◽  
Vol 05 (23) ◽  
pp. 1901-1908
Author(s):  
DAIJIRO SUEMATSU
Keyword(s):  
Field Theory ◽  
Symmetry Breaking ◽  
Effective Field Theory ◽  
Radiative Correction ◽  
Effective Field ◽  
Large Hierarchy ◽  
Chiral Superfields

We re-examine the possibility of large hierarchical symmetry breaking in the effective field theory of Calabi-Yau compactified superstring. We introduce the general superpotential containing the allowed moduli couplings. In certain manifolds one-loop radiative correction gives the non-trivial minimum and that solution suggests the possibility of large hierarchical symmetry breaking. To realize such a large hierarchy, it seems to require that 27(h2,1 + h1,1) > 48π2 and H1 ( End T) chiral superfields should have certain types of couplings to moduli fields.

scholarly journals Consequences of chirally enhanced explanations of (g − 2)μ for h → μμ and Z → μμ

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Andreas Crivellin ◽  
Martin Hoferichter
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Symmetry Breaking ◽  
Effective Field Theory ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
New Physics ◽  
Effective Field ◽  
Point Of View ◽  
New Particles

Abstract With the long-standing tension between experiment and Standard-Model (SM) prediction in the anomalous magnetic moment of the muon aμ recently reaffirmed by the Fermilab experiment, the crucial question becomes which other observables could be sensitive to the underlying physics beyond the SM to which aμ may be pointing. While from the effective field theory (EFT) point of view no direct correlations exist, this changes in specific new physics models. In particular, in the case of explanations involving heavy new particles above the electroweak (EW) scale with chiral enhancement, which are preferred to evade exclusion limits from direct searches, correlations with other observables sensitive to EW symmetry breaking are expected. Such scenarios can be classified according to the SU(2)L representations and the hypercharges of the new particles. We match the resulting class of models with heavy new scalars and fermions onto SMEFT and study the resulting correlations with h → μμ and Z → μμ decays, where, via SU(2)L symmetry, the latter process is related to Z → νν and modified W-μ-ν couplings.

scholarly journals Leading logs in QCD axion effective field theory

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Gonzalo Alonso-Álvarez ◽  
Fatih Ertas ◽  
Joerg Jaeckel ◽  
Felix Kahlhoefer ◽  
Lennert J. Thormaehlen
Keyword(s):  
Field Theory ◽  
Symmetry Breaking ◽  
Effective Field Theory ◽  
Degrees Of Freedom ◽  
Explicit Construction ◽  
Effective Field ◽  
Electroweak Scale ◽  
Ultraviolet Cutoff ◽  
Breaking Scale

Abstract The axion is much lighter than all other degrees of freedom introduced by the Peccei-Quinn mechanism to solve the strong CP problem. It is therefore natural to use an effective field theory (EFT) to describe its interactions. Loop processes calculated in the EFT may however explicitly depend on the ultraviolet cutoff. In general, the UV cutoff is not uniquely defined, but the dimensionful couplings suggest to identify it with the Peccei-Quinn symmetry-breaking scale. An example are K+ → π+ + a decays that will soon be tested to improved precision in NA62 and KOTO and whose amplitude is dominated by the term logarithmically dependent on the cutoff. In this paper, we critically examine the adequacy of using such a naive EFT approach to study loop processes by comparing EFT calculations with ones performed in complete QCD axion models. In DFSZ models, for example, the cutoff is found to be set by additional Higgs degrees of freedom and to therefore be much closer to the electroweak scale than to the Peccei-Quinn scale. In fact, there are non-trivial requirements on axion models where the cutoff scale of loop processes is close to the Peccei-Quinn scale, such that the naive EFT result is reproduced. This suggests that the existence of a suitable UV embedding may impose restrictions on axion EFTs. We provide an explicit construction of a model with suitable fermion couplings and find promising prospects for NA62 and IAXO.

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