scholarly journals Irreducible Cartesian Tensor Analysis of Harmonic Scattering from Chiral Fluids

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1466
Author(s):  
David L. Andrews
Keyword(s):  
Time Reversal ◽  
Media Analysis ◽  
Boundary Values ◽  
Cpt Symmetry ◽  
Chiral Media ◽  
Third Harmonic ◽  
Symmetry Principles ◽  
Charge Parity ◽  
Chiral Fluids ◽  
A Current

Symmetry principles of several distinct kinds are revealingly engaged in an analysis focussing on third harmonic scattering, a current focus of research on nonlinear optics in chiral media. Analysis in terms of irreducible Cartesian tensors elucidates the detailed electrodynamical origin and character of the corresponding material properties. Considerations of fundamental charge, parity and time reversal (CPT) symmetry reveal the conditions for an interplay of transition multipoles to elicit a chiral response using circularly polarised pump radiation, and the symmetry of quantised angular momentum underpins the associated selection rules and angular distribution. The intrinsic structural symmetry of chiral scatterers determines their capacity to exhibit differential response. Exploiting permutational index symmetry in the response tensors enables quantitative assessment of the boundary values for experimentally measurable properties, including circular intensity differentials.

Imaging Cracks in Bones Using Acoustic Nonlinearity: A Simulation Study

2011 ◽  
Vol 97 (5) ◽  
pp. 728-733
Author(s):  
Yang Liu ◽  
Xiasheng Guo ◽  
Zhao Da ◽  
Dong Zhang ◽  
Xiufen Gong
Keyword(s):  
Time Reversal ◽  
Three Dimensional ◽  
Harmonic Component ◽  
Ultrasonic Signal ◽  
Long Bone ◽  
Third Harmonic ◽  
Acoustic Nonlinearity ◽  
The Third ◽  
Nonlinear Approach ◽  
Radial Depth

This article proposes an acoustic nonlinear approach combined with the time reversal technique to image cracks in long bones. In this method, the scattered ultrasound generated from the crack is recorded, and the third harmonic nonlinear component of the ultrasonic signal is used to reconstruct an image of the crack by the time reversal process. Numerical simulations are performed to examine the validity of this approach. The fatigue long bone is modeled as a hollow cylinder with a crack of 1, 0.1, and 0.225 mm in axial, radial and circumferential directions respectively. A broadband 500 kHz ultrasonic signal is used as the exciting signal, and the extended three-dimensional Preisach-Mayergoyz model is used to describe the nonclassical nonlinear dynamics of the crack. Time reversal is carried out by using the filtered third harmonic component. The localization capability depends on the radial depth of the crack.

scholarly journals The Particle as a Statistical Ensemble of Events in Stueckelberg-Horwitz-Piron Electrodynamics †

2017 ◽  
Author(s):  
Martin Land
Keyword(s):  
Time Reversal ◽  
Lorentz Invariance ◽  
Pair Creation ◽  
Statistical Ensemble ◽  
Field Equations ◽  
Maxwell Theory ◽  
Classical Level ◽  
Equilibrium Limit ◽  
First Order ◽  
A Current

Stueckelberg-Horwitz-Piron (SHP) electrodynamics formalizes the distinction between coordinate time (measured by laboratory clocks) and chronology (temporal ordering) by defining 4D spacetime events xμ as functions of an external evolution parameter τ. Classical spacetime events xμ (τ) evolve as τ grows monotonically, tracing out particle worldlines dynamically and inducing the five U(1) gauge potentials through which events interact. Since Lorentz invariance imposes time reversal symmetry on x0 but not τ, the formalism resolves grandfather paradoxes and related problems of irreversibility. The action involves standard first order field derivatives but includes a higher order τ derivative that while preserving gauge and Lorentz invariance removes certain singularities and makes the related QFT super-renormalizable. The resulting field equations are Maxwell-like but τ-dependent and sourced by a current that represents a statistical ensemble of instantaneous events distributed along the worldline. The width λ of this distribution defines a correlation time for the interactions and a mass spectrum for the photons that carry the interaction. As λ becomes very large, the photon mass goes to zero and the field equations become τ-independent Maxwell’s equations. Maxwell theory thus emerges as an equilibrium limit of SHP, in which λ is larger than any other relevant time scale. Particles and fields are not constrained to mass shells in SHP theory, and by exchanging mass may produce pair creation/annihilation processes at the classical level. On-shell evolution with fixed particle masses is restored through a self-interaction associated with the 5D wave equation.

scholarly journals Searches for Violation of CPT Symmetry and Lorentz Invariance with Astrophysical Neutrinos

Universe ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 42
Author(s):  
Celio A. Moura ◽  
Fernando Rossi-Torres
Keyword(s):  
Gamma Ray ◽  
Lorentz Invariance ◽  
New Physics ◽  
Time Signal ◽  
Cpt Symmetry ◽  
Symmetry Violation ◽  
Oscillation Phase ◽  
Astrophysical Neutrinos ◽  
Charge Parity ◽  
Violation Of Lorentz Invariance

Neutrinos are a powerful tool for searching physics beyond the standard model of elementary particles. In this review, we present the status of the research on charge-parity-time (CPT) symmetry and Lorentz invariance violations using neutrinos emitted from the collapse of stars such as supernovae and other astrophysical environments, such as gamma-ray bursts. Particularly, supernova neutrino fluxes may provide precious information because all neutrino and antineutrino flavors are emitted during a burst of tens of seconds. Models of quantum gravity may allow the violation of Lorentz invariance and possibly of CPT symmetry. Violation of Lorentz invariance may cause a modification of the dispersion relation and, therefore, in the neutrino group velocity as well in the neutrino wave packet. These changes can affect the arrival time signal registered in astrophysical neutrino detectors. Direction or time-dependent oscillation probabilities and anisotropy of the neutrino velocity are manifestations of the same kind of new physics. CPT violation, on the other hand, may be responsible for different oscillation patterns for neutrino and antineutrino and unconventional energy dependency of the oscillation phase or of the mixing angles. Future perspectives for possible CPT and Lorentz violating systems are also presented.

PENGARUH ARUS DAN WAKTU TERHADAP LAPISAN ZINC PLATING PADA MATERIAL SGD400-D DENGAN MENGGUNAKAN PROSES ELEKTROPLATING

2020 ◽  
Vol 7 (1) ◽  
pp. 32-39
Author(s):  
Ari Setiawan ◽  
Novi Laura Indrayani ◽  
Budi Herawan
Keyword(s):  
Salt Spray ◽  
Thickness Measurement ◽  
Media Analysis ◽  
White Rust ◽  
Zinc Plating ◽  
Weight Loss Method ◽  
Loss Method ◽  
Good Coating ◽  
A Current ◽  
The Ideal

This research was conducted to find the ideal current and time used during the plating process, because in every industry the most frequent problems are the thickness that coats the material and the corrosion rate of the material that causes the material to become damaged or no good. This study uses SGD400 carbon steel and zinc as a coating. The research was carried out on a tank containing various kinds of chemical liquids and using electric current as conductivity for the coating media. Analysis using layer thickness measurement using vernier caliper measuring instrument and weight loss method. The results obtained from searching the current and the ideal time using a current of 900 A and a time of 60 minutes is 0.015 mm or 15 μm thick and the SST test (Salt Spray Test) at 72 hours No White Rust and 168 Hours No Red Rust. And good coating results can be seen in microstructure testing using keyence microscope media

scholarly journals Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography

2021 ◽  
Author(s):  
Pawel Moskal ◽  
Aleksander Gajos ◽  
Muhsin Mohammed ◽  
Jyoti Chhokar ◽  
Neha Chug ◽  
...  
Keyword(s):  
Angular Correlation ◽  
Imaging Techniques ◽  
Tomographic Reconstruction ◽  
Bound State ◽  
Cpt Symmetry ◽  
Final State ◽  
Positron Emission Tomography Scanner ◽  
Fundamental Symmetry ◽  
Positron Emission ◽  
Charge Parity

Abstract Charged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remains scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron–positron bound state (positronium atom) motivate further investigation, including fundamental symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner as a high-acceptance photon detector to study CPT-prohibited angular correlation in ortho-positronium (o-Ps) annihilations. We record an unprecedented range of kinematical configurations of o-Ps annihilations into three photons. Tomographic reconstruction of the annihilation points in a large medium allows single-event estimation of positronium spin orientation and, consequently, determination of the complete spectrum of angular correlation between the annihilation plane orientation and positronium spin, the non-vanishing expectation value of which would manifest CPT-violating effects. We find no violation at the precision level of 10^{−4}, with a fourfold improvement on the previous measurement. This work enables application of positronium-imaging techniques to study discrete symmetries in positronium decays.

scholarly journals Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
P. Moskal ◽  
A. Gajos ◽  
M. Mohammed ◽  
J. Chhokar ◽  
N. Chug ◽  
...  
Keyword(s):  
Tomographic Reconstruction ◽  
Bound State ◽  
Cpt Symmetry ◽  
Final State ◽  
Positron Emission Tomography Scanner ◽  
Correlation Operator ◽  
Angular Correlations ◽  
Fundamental Symmetry ◽  
Positron Emission ◽  
Charge Parity

AbstractCharged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remains scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron–positron bound state (positronium atom) motivate further investigation, including fundamental symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner to record ortho-positronium (o-Ps) annihilations with single-event estimation of o-Ps spin and determine the complete spectrum of an angular correlation operator sensitive to CPT-violating effects. We find no violation at the precision level of 10−4, with an over threefold improvement on the previous measurement.

The CPT Theorem

2011 ◽  
Author(s):  
Frank Arntzenius
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Time Reversal ◽  
Charge Conjugation ◽  
Temporal Orientation ◽  
Quantum Field ◽  
Cpt Symmetry ◽  
Combined Operation ◽  
Cpt Theorem ◽  
Invariant Quantum

The CPT theorem says that any Lorentz invariant quantum field theory must also be invariant under the combined operation of charge conjugation C, parity P, and time reversal T, even though none of those individual invariances need hold. It is quite strange. Why should a quantum field theory be invariant under the combination of two spatiotemporal discrete transformations, and then a quite different type of transformation (matter–anti-matter transformation)? In one of the first attacks on these and related questions by a philosopher, this chapter argues that CPT symmetry is better understood as PT symmetry. If the author is right, CPT symmetry is really saying that quantum field theory does not care about temporal orientation or spatial handedness.

scholarly journals Gravity, entanglement and CPT-symmetry violation in particle mixing

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
K. Simonov ◽  
A. Capolupo ◽  
S. M. Giampaolo
Keyword(s):  
Time Reversal ◽  
Gravitational Interaction ◽  
Cpt Symmetry ◽  
Many Body ◽  
Symmetry Violation ◽  
Body Effect ◽  
Particle Mixing ◽  
Relevant Role ◽  
Cp Symmetry ◽  
The Universe

Abstract We study the probability oscillations of mixed particles in the presence of self gravitational interaction. We show that the presence of the parity leads to the violation of the time-reversal symmetry while the CP-symmetry is preserved hence inducing a CPT-symmetry violation. This violation is directly associated to the rising of the entanglement among the elements of the system that can be seen as a pure many-body effect scaling with the number of the elements in the system. This effect could have played a relevant role in the first stages of the universe or in core of very dense systems. Experiments based on Rydberg atoms confined in microtraps can simulate the mixing and the mutual interaction, and could allow to test the mechanism here presented.

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