scholarly journals Analysis of Birefringence and Dispersion Effects from Spacetime-Symmetry Breaking in Gravitational Waves

Universe ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 380
Author(s):  
Kellie O’Neal-Ault ◽  
Quentin G. Bailey ◽  
Tyann Dumerchat  ◽  
Leïla Haegel ◽  
Jay Tasson
Keyword(s):  
Symmetry Breaking ◽  
Gravitational Wave ◽  
Gravitational Waves ◽  
New Physics ◽  
Effective Field ◽  
Cpt Violation ◽  
Cpt Symmetry ◽  
Spacetime Symmetry ◽  
Sensitivity Studies ◽  
Theory Framework

In this work, we review the effective field theory framework to search for Lorentz and CPT symmetry breaking during the propagation of gravitational waves. The article is written so as to bridge the gap between the theory of spacetime-symmetry breaking and the analysis of gravitational-wave signals detected by ground-based interferometers. The primary physical effects beyond General Relativity that we explore here are dispersion and birefringence of gravitational waves. We discuss their implementation in the open-source LIGO-Virgo algorithm library suite, and we discuss the statistical method used to perform a Bayesian inference of the posterior probability of the coefficients for symmetry-breaking. We present preliminary results of this work in the form of simulations of modified gravitational waveforms, together with sensitivity studies of the measurements of the coefficients for Lorentz and CPT violation. The findings show the high potential of gravitational wave sources across the sky to sensitively probe for these signals of new physics.

scholarly journals Gravitational waves: where we are, where we go

2019 ◽  
Vol 209 ◽  
pp. 01045
Author(s):  
Fulvio Ricci
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Present Status ◽  
New Physics ◽  
Third Generation ◽  
The Third ◽  
The Earth ◽  
Gravitational Wave Detectors

We review the present status of the Gravitational wave detectors on the Earth, focusing the attention on the present innovations and the longer term perspectives to improve their sensitivity. Then we conclude mentioning few potential searches of new Physics phenomena to be performed with these detectors and those of the third generation.

scholarly journals Probing the nonunitarity of the leptonic mixing matrix at the CEPC

2016 ◽  
Vol 31 (33) ◽  
pp. 1644006 ◽  
Author(s):  
Stefan Antusch ◽  
Oliver Fischer
Keyword(s):  
Field Theory ◽  
Standard Model ◽  
Effective Field Theory ◽  
New Physics ◽  
Effective Field ◽  
Neutrino Masses ◽  
Performance Parameters ◽  
The Standard Model ◽  
Mixing Matrix ◽  
Theory Framework

The nonunitarity of the leptonic mixing matrix is a generic signal of new physics aiming at the generation of the observed neutrino masses. We discuss the Minimal Unitarity Violation (MUV) scheme, an effective field theory framework which represents the class of extensions of the Standard Model (SM) by heavy neutral leptons, and discuss the present bounds on the nonunitarity parameters as well as estimates for the sensitivity of the CEPC, based on the performance parameters from the preCDR.

scholarly journals Is SMEFT enough?

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Timothy Cohen ◽  
Nathaniel Craig ◽  
Xiaochuan Lu ◽  
Dave Sutherland
Keyword(s):  
Standard Model ◽  
Symmetry Breaking ◽  
Independent Set ◽  
Higgs Doublet ◽  
New Physics ◽  
Effective Field ◽  
Electroweak Symmetry Breaking ◽  
Electroweak Symmetry ◽  
Goldstone Bosons ◽  
The Standard Model

Abstract There are two canonical approaches to treating the Standard Model as an Effective Field Theory (EFT): Standard Model EFT (SMEFT), expressed in the electroweak symmetric phase utilizing the Higgs doublet, and Higgs EFT (HEFT), expressed in the broken phase utilizing the physical Higgs boson and an independent set of Goldstone bosons. HEFT encompasses SMEFT, so understanding whether SMEFT is sufficient motivates identifying UV theories that require HEFT as their low energy limit. This distinction is complicated by field redefinitions that obscure the naive differences between the two EFTs. By reformulating the question in a geometric language, we derive concrete criteria that can be used to distinguish SMEFT from HEFT independent of the chosen field basis. We highlight two cases where perturbative new physics must be matched onto HEFT: (i) the new particles derive all of their mass from electroweak symmetry breaking, and (ii) there are additional sources of electroweak symmetry breaking. Additionally, HEFT has a broader practical application: it can provide a more convergent parametrization when new physics lies near the weak scale. The ubiquity of models requiring HEFT suggests that SMEFT is not enough.

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 Consistent QFT description of non-standard neutrino interactions

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Adam Falkowski ◽  
Martín González-Alonso ◽  
Zahra Tabrizi
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
New Physics ◽  
Effective Field ◽  
Quantum Field ◽  
The Standard Model ◽  
Mechanical Approach ◽  
Theory Result ◽  
Quantum Mechanical Approach ◽  
Theory Framework

Abstract Neutrino oscillations are precision probes of new physics. Apart from neutrino masses and mixings, they are also sensitive to possible deviations of low-energy interactions between quarks and leptons from the Standard Model predictions. In this paper we develop a systematic description of such non-standard interactions (NSI) in oscillation experiments within the quantum field theory framework. We calculate the event rate and oscillation probability in the presence of general NSI, starting from the effective field theory (EFT) in which new physics modifies the flavor or Lorentz structure of charged-current interactions between leptons and quarks. We also provide the matching between the EFT Wilson coefficients and the widely used simplified quantum-mechanical approach, where new physics is encoded in a set of production and detection NSI parameters. Finally, we discuss the consistency conditions for the standard NSI approach to correctly reproduce the quantum field theory result.

scholarly journals Parametrized classifiers for optimal EFT sensitivity

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Siyu Chen ◽  
Alfredo Glioti ◽  
Giuliano Panico ◽  
Andrea Wulzer
Keyword(s):  
Statistical Learning ◽  
High Energy ◽  
New Physics ◽  
Effective Field ◽  
Analytic Description ◽  
Leptonic Decays ◽  
Learning Classifier ◽  
The Standard Model ◽  
Standard Model Amplitude ◽  
Theory Framework

Abstract We study unbinned multivariate analysis techniques, based on Statistical Learning, for indirect new physics searches at the LHC in the Effective Field Theory framework. We focus in particular on high-energy ZW production with fully leptonic decays, modeled at different degrees of refinement up to NLO in QCD. We show that a considerable gain in sensitivity is possible compared with current projections based on binned analyses. As expected, the gain is particularly significant for those operators that display a complex pattern of interference with the Standard Model amplitude. The most effective method is found to be the “Quadratic Classifier” approach, an improvement of the standard Statistical Learning classifier where the quadratic dependence of the differential cross section on the EFT Wilson coefficients is built-in and incorporated in the loss function. We argue that the Quadratic Classifier performances are nearly statistically optimal, based on a rigorous notion of optimality that we can establish for an approximate analytic description of the ZW process.

scholarly journals Gravitational Waves from Inflation

2020 ◽  
Author(s):  
◽  
Maria Mylova
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Parity Violation ◽  
Background Radiation ◽  
Effective Field ◽  
Energy Scale ◽  
Mode Analysis ◽  
Strongly Coupled ◽  
Short Period ◽  
Microwave Background Radiation

The focus of this work is on the topic of gravitational wave cosmology. We look for new observational signatures for primordial gravitational waves and especially for frameworks that can produce an enhanced tensor spectrum. In such cases, the gravitational wave energy density can enter within the sensitivity curves of gravi-tational wave detectors or it could leave a measurable imprint in the polarization pattern of the Cosmic Microwave Background radiation. This is very important as more sensitive, next generation experiments are expected to make indirect and direct measurements of the primordial stochastic gravitational wave background.Our investigation showed that an enhanced tensor amplitude can be achieved, within the framework of the Horndeski theory, if there is a short period where slow-roll inflation is violated. We considered a model of kinetically driven inflation where for a short time the scalar field velocity is heavily time-dependent. During that time the would-be decaying tensor mode becomes a growing mode. Analysis of the bispectrum showed that this can lead to sizeable tensor non-Gaussianities.We also considered possible realizations of the effective field theory of Scalar-Tensor gravity. In particular, we looked for a setup up of operators that could lead to the enhancement of parity violating effects for tensors. We introduced modifications to gravity which enabled us to parametrically approach the scale at which maximal parity violation occurs. Using the mathematical machinery for effective field theories we showed that sub-leading quadratic operators can become important signalling the presence of the Chern Simons instability. This inevitably implies the existence of non-trivial cubic interactions which could stand the theory strongly coupled at energies not far above the energy scale of inflation. Consequently, this can lead to large parity violation in tensor non-Gaussianity.

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.

DETECTION OF GRAVITATIONAL WAVES FROM INFLATION

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 116-128 ◽  
Author(s):  
MARC KAMIONKOWSKI ◽  
ANDREW H. JAFFE
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Large Scale ◽  
Planck Scale ◽  
New Physics ◽  
Energy Scale ◽  
Grand Unification ◽  
Microwave Background ◽  
The Right ◽  
Gravitational Wave Background

Recent measurements of temperature fluctuations in the cosmic microwave background (CMB) indicate that the Universe is flat and that large-scale structure grew via gravitational infall from primordial adiabatic perturbations. Both od these observations seem to indicate that we are on the right track with inflation. But what is the new physics responsible for inflation? This question can be answered with observations of the polarization of the CMB. Inflation predicts robustly the existence of a stochastic background of cosmological gravitational waves with an amplitude proportional to the square of the energy scale of inflation. This gravitational-wave background induces a unique signature in the polarization of the CMB. If inflation took place at an energy scale much smaller than that of grand unification, then the signal will be too small to be detectable. However, if inflation had something to do with grand unification or Planck-scale physics, then the signal is conceivably detectable in the optimistic case by the Planck satellite, or if not, then by a dedicated post-Planck CMB polarization experiment. Realistic developments in dector technology as well as a proper scan strategy could produce such a post-Planck experiment that would improve on Planck's sensitivity to the gravitational-wave background by several orders of magnitude in a decade timescale.

Sign in / Sign up

Export Citation Format

Share Document