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.

scholarly journals TESTS OF LORENTZ AND CPT VIOLATION WITH MiniBooNE NEUTRINO OSCILLATION EXCESSES

2012 ◽  
Vol 27 (25) ◽  
pp. 1230024 ◽  
Author(s):  
TEPPEI KATORI
Keyword(s):  
Standard Model ◽  
Neutrino Oscillation ◽  
Lorentz Invariance ◽  
Planck Scale ◽  
Lorentz Violation ◽  
New Physics ◽  
Cpt Symmetry ◽  
Standard Model Extension ◽  
Sidereal Time ◽  
Short Baseline

Violation of Lorentz invariance and CPT symmetry is a predicted phenomenon of Planck-scale physics. Various types of data are analyzed to search for Lorentz violation under the Standard Model Extension (SME) framework, including neutrino oscillation data. MiniBooNE is a short-baseline neutrino oscillation experiment at Fermilab. The measured excesses from MiniBooNE cannot be reconciled within the neutrino Standard Model (νSM); thus it might be a signal of new physics, such as Lorentz violation. We have analyzed the sidereal time-dependence of MiniBooNE data for signals of the possible breakdown of Lorentz invariance in neutrinos. In this brief review, we introduce Lorentz violation, the neutrino sector of the SME and the analysis of short-baseline neutrino oscillation experiments. We then present the results of the search for Lorentz violation in MiniBooNE data. This review is based on the published result.

scholarly journals MIXING IN THE D0 SYSTEM RESULTS FROM COLLIDER EXPERIMENTS

2003 ◽  
Vol 18 (01) ◽  
pp. 1-22 ◽  
Author(s):  
MONIKA GROTHE
Keyword(s):  
Standard Model ◽  
Experimental Observation ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Symmetry Violation ◽  
Mixing Parameters ◽  
Statistical Precision ◽  
The Standard Model ◽  
Charge Parity ◽  
Cp Symmetry

Mixing in the D0 system may provide a sensitive probe for new physics beyond the Standard Model (SM) but has so far eluded experimental observation. The SM predictions are typically small (< 10-3) for the mixing parameters x, y which, in the absence of charge-parity (CP) symmetry violation, measure the mass (x = Δ m/Γ) and lifetime (y = ΔΓ/2Γ) difference of the CP eigenstates in the D0 system. The asymmetric B-factory experiments BABAR and Belle open up the opportunity of measuring x, y with unprecedented statistical precision and sample purities. Results from BABAR and Belle, and from CLEO are reviewed.

scholarly journals Astroparticle Physics with H.E.S.S.: recents results and nearfuture prospects

2019 ◽  
Vol 209 ◽  
pp. 01054
Author(s):  
Emmanuel Moulin
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Lorentz Invariance ◽  
Cosmic Ray ◽  
High Energy ◽  
New Physics ◽  
Galactic Centre ◽  
Astroparticle Physics ◽  
Dark Matter Search ◽  
Physics Program

H.E.S.S. is an array of five Imaging Atmospheric Cherenkov Telescopes located in Namibia. It is designed for observations of astrophysical sources emitting very-high-energy (VHE) gamma rays in the energy range from a few ten GeVs to several ten TeVs. The H.E.S.S. instrument consists of four identical 12 m diameter telescopes and a 28 m diameter telescope placed at the center of the array. An ambitious Astroparticle Physics program is being carried out by the H.E.S.S. collaboration searching for New Physics in the VHE gamma-ray sky. The program includes the search for WIMP dark matter and axion-like particles, tests of Lorentz invariance, cosmic-ray electron measurements, and search for intergalactic magnetic fields. I will present the latest results on dark matter search from the observations of the Galactic Centre region, the search for Lorentz invariance violation with the 2014 flare observation of Markarian 501, and the first measurement of the cosmic-ray electron spectrum up to 20 TeV. The future of the H.E.S.S. Astroparticle Physics program will be discussed.

scholarly journals Fundamental physics with blazar spectra: a critical appraisal

2019 ◽  
Vol 491 (4) ◽  
pp. 5268-5276 ◽  
Author(s):  
Giorgio Galanti ◽  
Fabrizio Tavecchio ◽  
Marco Landoni
Keyword(s):  
Gamma Ray ◽  
Lorentz Invariance ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
New Physics ◽  
Spectral Energy ◽  
Bl Lac ◽  
Very High Energy ◽  
Emission Models ◽  
Hadron Beam

ABSTRACT Very-high-energy (VHE) BL Lacertae (BL Lac) spectra extending above $10 \, \rm TeV$ provide a unique opportunity for testing physics beyond the standard model of elementary particle and alternative blazar emission models. We consider the hadron beam scenario, the conversion of photons to axion-like particles (ALPs) and the Lorentz invariance violation (LIV) by analysing their consequences and induced modifications to BL Lac spectra. In particular, we consider how different processes can provide similar spectral features (e.g. hard tails) and we discuss the ways they can be disentangled. We use data from High-Energy Gamma-Ray Astronomy (HEGRA) of a high state of Markarian 501 and the High-Energy Stereoscopic System (H.E.S.S.) spectrum of the extreme BL Lac (EHBL) 1ES 0229+200. In addition, we consider two hypothetical EHBLs similar to 1ES 0229+200 located at redshifts z = 0.3 and z = 0.5. We observe that both the hadron beam and the photon–ALP oscillations predict a hard tail extending to energies larger than those possible in the standard scenario. Photon–ALP interaction predicts a peak in the spectra of distant BL Lacs at about $20\rm {-}30 \, \rm TeV$, while LIV produces a strong peak in all BL Lac spectra around $\sim 100 \, \rm TeV$. The peculiar feature of the photon–ALP conversion model is the production of oscillations in the spectral energy distribution, so that its detection/absence can be exploited to distinguish between the considered models. The above-mentioned features of the three models might be detected by the upcoming Cherenkov Telescope Array. Thus, future observations of BL Lac spectra could eventually shed light on new physics and alternative blazar emission models, driving fundamental research towards a specific direction.

Real-time signal processing in field programmable gate array based digital gamma-ray spectrometer

2020 ◽  
Vol 91 (10) ◽  
pp. 104707
Author(s):  
Yinyu Liu ◽  
Hao Xiong ◽  
Chunhui Dong ◽  
Chaoyang Zhao ◽  
Quanfeng Zhou ◽  
...  
Keyword(s):  
Signal Processing ◽  
Real Time ◽  
Field Programmable Gate Array ◽  
Gamma Ray ◽  
Time Signal ◽  
Gamma Ray Spectrometer ◽  
Field Programmable ◽  
Gate Array ◽  
Real Time Signal Processing

scholarly journals Neutrino Astronomy with IceCube

2016 ◽  
Vol 12 (S324) ◽  
pp. 322-329
Author(s):  
Kevin J. Meagher
Keyword(s):  
Real Time ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Galactic Nuclei ◽  
High Energy ◽  
Glacial Ice ◽  
Astrophysical Neutrinos ◽  
Charged Secondary ◽  
Neutrino Astronomy ◽  
The Antarctic

AbstractThe IceCube Neutrino Observatory is a cubic kilometer neutrino telescope located at the Geographic South Pole. Cherenkov radiation emitted by charged secondary particles from neutrino interactions is observed by IceCube using an array of 5160 photomultiplier tubes embedded between a depth of 1.5 km to 2.5 km in the Antarctic glacial ice. The detection of astrophysical neutrinos is a primary goal of IceCube and has now been realized with the discovery of a diffuse, high-energy flux consisting of neutrino events from tens of TeV up to several PeV. Many analyses have been performed to identify the source of these neutrinos: correlations with active galactic nuclei, gamma-ray bursts, and the galactic plane. IceCube also conducts multi-messenger campaigns to alert other observatories of possible neutrino transients in real-time. However, the source of these neutrinos remains elusive as no corresponding electromagnetic counterparts have been identified. This proceeding will give an overview of the detection principles of IceCube, the properties of the observed astrophysical neutrinos, the search for corresponding sources (including real-time searches), and plans for a next-generation neutrino detector, IceCube–Gen2.

scholarly journals Limits on quantum gravity effects from Swift short gamma-ray bursts

2017 ◽  
Vol 607 ◽  
pp. A121 ◽  
Author(s):  
M. G. Bernardini ◽  
G. Ghirlanda ◽  
S. Campana ◽  
P. D’Avanzo ◽  
J.-L. Atteia ◽  
...  
Keyword(s):  
Quantum Gravity ◽  
Gamma Ray ◽  
Lorentz Invariance ◽  
Spectral Energy Distribution ◽  
Gamma Ray Bursts ◽  
Low Energy ◽  
Energy Separation ◽  
Spectral Energy ◽  
Spectral Evolution ◽  
Short Grbs

The delay in arrival times between high and low energy photons from cosmic sources can be used to test the violation of the Lorentz invariance (LIV), predicted by some quantum gravity theories, and to constrain its characteristic energy scale EQG that is of the order of the Planck energy. Gamma-ray bursts (GRBs) and blazars are ideal for this purpose thanks to their broad spectral energy distribution and cosmological distances: at first order approximation, the constraints on EQG are proportional to the photon energy separation and the distance of the source. However, the LIV tiny contribution to the total time delay can be dominated by intrinsic delays related to the physics of the sources: long GRBs typically show a delay between high and low energy photons related to their spectral evolution (spectral lag). Short GRBs have null intrinsic spectral lags and are therefore an ideal tool to measure any LIV effect. We considered a sample of 15 short GRBs with known redshift observed by Swift and we estimate a limit on EQG ≳ 1.5 × 1016 GeV. Our estimate represents an improvement with respect to the limit obtained with a larger (double) sample of long GRBs and is more robust than the estimates on single events because it accounts for the intrinsic delay in a statistical sense.

scholarly journals Constraints on Lorentz Invariance Violation with Multiwavelength Polarized Astrophysical Sources

Galaxies ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 44
Author(s):  
Qi-Qi Zhou ◽  
Shuang-Xi Yi ◽  
Jun-Jie Wei ◽  
Xue-Feng Wu
Keyword(s):  
Gamma Ray ◽  
Lorentz Invariance ◽  
Polarized Light ◽  
Polarization Plane ◽  
Polarization Angle ◽  
Intrinsic Polarization ◽  
Frequency Dependent ◽  
Invariance Violation ◽  
Linearly Polarized ◽  
Order Of Magnitude

Possible violations of Lorentz invariance (LIV) can produce vacuum birefringence, which results in a frequency-dependent rotation of the polarization plane of linearly polarized light from distant sources. In this paper, we try to search for a frequency-dependent change of the linear polarization angle arising from vacuum birefringence in the spectropolarimetric data of astrophysical sources. We collect five blazars with multiwavelength polarization measurements in different optical bands (UBVRI). Taking into account the observed polarization angle contributions from both the intrinsic polarization angle and the rotation angle induced by LIV, and assuming that the intrinsic polarization angle is an unknown constant, we obtain new constraints on LIV by directly fitting the multiwavelength polarimetric data of the five blazars. Here, we show that the birefringence parameter η quantifying the broken degree of Lorentz invariance is limited to be in the range of −9.63×10−8<η<6.55×10−6 at the 2σ confidence level, which is as good as or represents one order of magnitude improvement over the results previously obtained from ultraviolet/optical polarization observations. Much stronger limits can be obtained by future multiwavelength observations in the gamma-ray energy band.

scholarly journals Testing Lorentz symmetry violation with an invariant minimum speed

2018 ◽  
Vol 33 (23) ◽  
pp. 1850148 ◽  
Author(s):  
Cláudio Nassif ◽  
A. C. Amaro de Faria ◽  
Rodrigo Francisco dos Santos
Keyword(s):  
Decay Rate ◽  
Special Relativity ◽  
Proper Time ◽  
Lorentz Invariance ◽  
Atomic Clock ◽  
Life Time ◽  
Single Atom ◽  
Symmetry Violation ◽  
Minimum Speed ◽  
Radioactive Sample

This work presents an experimental test of Lorentz invariance violation in the infrared (IR) regime by means of an invariant minimum speed in spacetime and its effects on the time when an atomic clock given by a certain radioactive single-atom (e.g. isotope Na[Formula: see text]) is a thermometer for an ultracold gas like the dipolar gas Na[Formula: see text]K[Formula: see text]. So, according to a Deformed Special Relativity (DSR) so-called Symmetrical Special Relativity (SSR), where there emerges an invariant minimum speed V in the subatomic world, one expects that the proper time of such a clock moving close to V in thermal equilibrium with the ultracold gas is dilated with respect to the improper time given in lab, i.e. the proper time at ultracold systems elapses faster than the improper one for an observer in the lab, thus leading to the so-called proper time dilation so that the atomic decay rate of an ultracold radioactive sample (e.g. Na[Formula: see text]) becomes larger than the decay rate of the same sample at room temperature. This means a suppression of the half-life time of a radioactive sample thermalized with an ultracold cloud of dipolar gas to be investigated by NASA in the Cold Atom Lab (CAL).

scholarly journals Searching for VHE gamma-ray emission associated with IceCube astrophysical neutrinos using FACT, H.E.S.S., MAGIC, and VERITAS

2017 ◽  
Author(s):  
Marcos Santander ◽  
Daniela Dorner ◽  
Jonathan Dumm ◽  
Konstancja Satalecka ◽  
Fabian Schüssler ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Astrophysical Neutrinos ◽  
Gamma Ray Emission
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