Neutrinos are allowed to mix and to oscillate among their flavor. Muon and tau in particular oscillate at largest values.Last Minos experiment claimed possible difference among their matter and anti-matter masses, leading to a first violation of the most believed CPT symmetry.Isotropically born atmospheric muon neutrino at 20-80 GeV, while up-going, they might be partially suppressed by mixing in analogy to historical SuperKamiokande muon neutrino disappearance into tau, leading to large scale anisotropy signals. Here we show an independent muon rate foreseen in Deep Core based on observed SK signals extrapolated to DeepCore mass and its surrounding. Our rate prediction partially differ from previous ones. The neutrino muon disappearance into tau is leading to an anisotropy in vertical up-going muon track: in particular along channel 3-5 we expect a huge rate (tens of thousand of events) of neutral current events, charged current electron and inclined crossing muons. Moreover at channel 6-9 we expect a severe suppression of the rate due to muon disappearance (in CPT conserved frame). Such an anisotropy might be partially tested by more than one string detection at E> 45 GeV energy. A CPT violation may induce a more remarkable suppression of vertical up-going tracks because of larger anti-neutrino muon reduction for E> 35 GeV.
A MINOS result seemed to hint a different anti-neutrino mass splitting and mixing angle with respect to the neutrino ones, offering a hint for a CPT violation in lepton sector. However more recent MINOS data reduced the neutrino-antineutrino differences leading to a narrow discrepancy almost compatible with no CPT violation, hard to be disentangled. Moreover last a few years of OPERA activity on tau appearance is still un-probed (one unique event). Both flavor muon-tau mixing, tau appearance and eventual CPT violation disentanglement need more tools to be enhanced. Atmospheric muon neutrino sp…
The 6-year dataset of high-energy starting events (HESE) at IceCube indicates a spectrum of astrophysical neutrinos much softer than expected from the Fermi shock acceleration mechanism. On the other hand, IceCube's up-going muon neutrino dataset and Fermi-LAT's gamma-ray spectrum point to an $E^{-2}$ neutrino spectrum. If the HESE data above 200 TeV are fit with the latter flux, an excess at lower energies ensues, which then suggests a multicomponent spectrum. We show that the HESE dataset can be explained by a single $E^{-2}$ power-law neutrino flux from a muon-damped $pγ$ source if neutrino…
On 2010 MINOS experiment was showing an hint of possible different mass splitting and mixing angles for neutrinos and anti-neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector; last year 2012 a second result from MINOS showed a reduced discrepancy between the two set of parameters, nearly compatible with no CPT violation. We proposed an experiment for more precise estimation of neutrino oscillation parameters being useful not only for a complete discrimination for CPT scenarios, but also for mass hierarchy and theta 13 determination, and mostly for the first oscillat…
Lorentz invariance plays a fundamental role in modern physics. However, tiny violations of the Lorentz invariance may arise in some candidate quantum gravity theories. Prominent signatures of the gravitational Lorentz invariance violation (gLIV) include anisotropy, dispersion, and birefringence in the dispersion relation of gravitational waves (GWs). Using a total of 50 GW events in the GW transient catalogs GWTC-1 and GWTC-2, we perform an analysis on the anisotropic birefringence phenomenon. The use of multiple events allows us to completely break the degeneracy among gLIV coefficients and g…
We analyze the temporal variation of the diurnal anisotropy of sub-TeV cosmic ray intensity observed with the Matsushiro (Japan) underground muon detector over two full solar activity cycles in 1985-2008. The average sidereal amplitude over the entire period is 0.034+-0.003 %, which is roughly one third of the amplitude reported from AS and deep-underground muon experiments monitoring multi-TeV GCR intensity suggesting a significant attenuation of the anisotropy due to the solar modulation. We find, on the other hand, only weak correlations either with the solar activity- or magnetic-cycles. W…
Atmospheric muon neutrino in Deep Core (whose rate and spectra might be soon available) should exhibit a suppression (due to tens GeV up-going muon neutrino converted into tau flavor) that must be imprinted in out-coming rate spectra. We estimate here our independent muon neutrino spectra based on SK and its projected record on Deep Core Channels. Our estimate (based on cosmic rays, muon records and tested Super-Kamiokande (SK) data) differs both in shape and in rate from other previous published spectra. The expected rate might exhibit a minimum near channel 6 of Deep Core strings and it shou…
In this work, we use muon bundles which are formed in extensive air showers and detected at the ground level as a tool for searching anisotropy of high energy cosmic rays. Such choice is explained by the penetrating ability of muons which allows them to retain the direction of primary particles with a good accuracy. In 2012-2022, we performed long-term muon bundle detection with the coordinate-tracking detector DECOR, which is a part of the Experimental complex NEVOD (MEPhI, Moscow). To search for the cosmic rays anisotropy, the muon bundles arriving at zenith angles in the range from 15 to 75…
According to CACTus catalog, during periods of a high solar activity every day up to tens of coronal mass ejections are observed. Such ejections have an impact on the flux of cosmic rays that permeate the space around us. Unlike most ground cosmic ray detectors, muon hodoscope URAGAN (MEPhI) allows to investigate not only the integrated counting rate of registered particles, but also the spatial and angular characteristics of the muon flux at ground level. This approach to particle detection allows fixing changes in the flux of cosmic rays not only for geoeffective CMEs, but also for the eject…
The interaction of high energy cosmic rays with the Earth's atmosphere produces extensive air showers of secondary particles with a large muon component. By exploiting the sensitivity of neutrino telescopes to high energy muons, it is possible to use these detectors for precision cosmic ray studies. The high rate of cosmic-ray muon events provides a high-statistics data sample that can be used to look for anisotropy in the arrival directions of the parent particles at the per-mille level. This paper reports on the observation of anisotropy in the cosmic ray data collected with the IceCube neut…
We analyze the cosmic-ray variations during a significant Forbush decrease observed with world-wide networks of ground-based neutron monitors and muon detectors during November 3-5, 2021. Utilizing the difference between primary cosmic-ray rigidities monitored by neutron monitors and muon detectors, we deduce the rigidity spectra of the cosmic-ray density (or omnidirectional intensity) and the first- and second-order anisotropies separately, for each hour of data. A clear two-step decrease is seen in the cosmic-ray density with the first $\sim2\%$ decrease after the interplanetary shock arriva…
Muon neutrino astronomy is drown within a polluted atmospheric neutrino noise. However at 24 GeV energy atmospheric muon neutrinos, while rising vertically along the terrestrial diameter, should disappear (or be severely depleted) while converting into tau flavor: any rarest vertical 12 GeV muon track at South Pole Deep Core volume, pointing back to North Pole, might be tracing mostly a noise-free astrophysical signal. The corresponding Deep Core 6-7-8-9 channels trigger maybe point in those directions and inside that energy range without much background. Deep Core detector at South Pole, may …
Lorentz invariance is the fundamental symmetry of Einstein's theory of special relativity, and has been tested to great level of detail. However, theories of quantum gravity at the Planck scale indicate that Lorentz symmetry may be broken at that scale motivating further tests. While the Planck energy is currently unreachable by experiment, tiny residual effects at attainable energies can become measurable when photons propagate over sufficiently large distances. The Standard-Model Extension (SME) is an effective field theory approach to describe low-energy effects of quantum gravity theories.…
Recently different experiments mention to have observed a large scale cosmic-ray anisotropy at TeV energies, e.g. Milagro, Tibet and Super-Kamiokande. For these energies the cosmic-rays are expected to be nearly isotropic. Any measurements of cosmic-rays anisotropy could bring some information about propagation and origin of cosmic-rays. Though the primary aim of the ANTARES neutrino telescope is the detection of high energy cosmic neutrinos, the detector measures mainly down-doing muons, which are decay products of cosmic-rays collisions in the Earth's atmosphere. This proceeding describes an…
Spectral and anisotropy properties of IceCube astrophysical neutrino signal reveal an evidence for a significant Galactic contribution to the neutrino flux in Southern hemisphere. We check if the Galactic contribution is detectable in the astrophysical muon neutrino flux observed from a low positive declinations region of the Northern sky. Estimating the Galactic neutrino flux in this part of the sky from gamma-ray and Southern sky neutrino data, we find that the Northern sky astrophysical muon neutrino signal shows an excess over the Galactic flux. This points to the presence of an additional…
The GRAPES-3 muon telescope in Ooty, India had claimed detection of a 2 hour (h) high-energy ($\sim$20 GeV) burst of galactic cosmic-rays (GCRs) through a $>$50$σ$ surge in GeV muons, was caused by reconnection of the interplanetary magnetic field (IMF) in the magnetosphere that led to transient weakening of Earth's magnetic shield. This burst had occurred during a G4-class geomagnetic storm (storm) with a delay of $\frac{1}{2}$h relative to the coronal mass ejection (CME) of 22 June 2015 (Mohanty et al., 2016). However, recently a group interpreted the occurrence of the same burst in a subset…
The behavior of photons in the presence of Lorentz and CPT violation is studied. Allowing for operators of arbitrary mass dimension, we classify all gauge-invariant Lorentz- and CPT-violating terms in the quadratic Lagrange density associated with the effective photon propagator. The covariant dispersion relation is obtained, and conditions for birefringence are discussed. We provide a complete characterization of the coefficients for Lorentz violation for all mass dimensions via a decomposition using spin-weighted spherical harmonics. The resulting nine independent sets of spherical coefficie…
Global analysis of the extended cosmic-ray decreases observed with world-wide networks of neutron monitors and muon detectors; temporal variation of the rigidity spectrum and its implication
IceCube is a cubic-kilometer Cherenkov detector located in the deep ice at the geographic South Pole. The dominant event yield in the deep ice detector consists of penetrating atmospheric muons produced in cosmic ray air showers with energies above several 100 GeV. In addition, the surface array, IceTop, deployed above the IceCube deep ice detector, measures the electromagnetic signal and low-energy muons of the air shower. Hence, IceCube and IceTop yield unique opportunities to study cosmic rays with large statistics in great detail. We discuss the latest results of air shower measurements fr…
Rome University（罗马大学）；INFN Rome（意大利国家核物理研究所罗马分部）；MIFP（马利诺国际前沿物理中心）；APC laboratory（粒子与宇宙学实验室）；National Research Nuclear University ”MEPHI” (Moscow State Engineering Physics Institute)（国立研究核子大学莫斯科工程物理学院）；Niccolò Cusano University（尼古拉·库萨诺大学）；University Roma Tre（罗马三大）；Gubkin Russian State University (National Research University)（古比雪夫俄罗斯国立大学）；Institute of Physics, Southern Federal University（南联邦大学物理研究所）
