Neutrino Telescope Research Articles

Prospects for detecting proto-neutron star rotation and spin-down using supernova neutrinos

ABSTRACT After a successful supernova, a proto-neutron star (PNS) cools by emitting neutrinos on ∼1–100 s time-scales. Provided that there are neutrino emission ‘hotspots’ or ‘cold-spots’ on the surface of the rotating PNS, we can expect a periodic modulation in the number of neutrinos observable by detectors. We show that Fourier transform techniques can be used to determine the PNS rotation rate from the neutrino arrival times. Provided there is no spin-down, a 1-parameter Discrete Fourier Transform (DFT) is sufficient to determine the spin period of the PNS. If the PNS is born as a magnetar with polar magnetic field strength B0 ≳ 1015 G and is ‘slowly’ rotating with an initial spin period ≳100 ms, then it can spin-down to periods of the order of seconds during the cooling phase. We propose a modified DFT technique with three frequency parameters to detect spin-down. Due to lack of neutrino data from a nearby supernova except the ∼20 neutrinos detected from SN1987A, we use toy models and one physically motivated modulating function to generate neutrino arrival times. We use the false alarm rate (FAR) to quantify the significance of the Fourier power spectrum peaks. We show that PNS rotation and spin-down are detected with $\rm FAR\,\lt\, 2~{{\ \rm per\ cent}}$ (2σ) for periodic signal content $\rm M\gtrsim 13-15~{{\ \rm per\ cent}}$ if 5 × 103 neutrinos are detected in ∼3 s and with $\rm FAR\,\lt\, 1{{\ \rm per\ cent}}$ for $\rm M\,\ge 5{{\ \rm per\ cent}}$ if 5 × 104 neutrinos are detected in ∼3 s. Since we can expect ∼104−105 neutrino detections from a supernova at 10 kpc, detection of PNS rotation and spin-down is possible using the neutrinos from the next Galactic supernova.

VLBI Analysis of a Potential High-Energy Neutrino Emitter Blazar

Recent studies suggest that high-energy neutrinos can be produced in the jets of blazars, radio-loud active galactic nuclei (AGN) with jets pointing close to the line of sight. Due to the relatively poor angular resolution of current neutrino detectors, several sources can be regarded as the possible counterpart of a given neutrino event. Therefore, follow-up observations of counterpart candidates in the electromagnetic regime are essential. Since the Very Long Baseline Interferometry (VLBI) technique provides the highest angular resolution to study the radio jets of blazars, a growing number of investigations are being conducted to connect individual blazars to given high-energy neutrino events. We analyzed more than 20 years of available archival VLBI data of the blazar CTD 74, which has been listed as a possible counterpart of a neutrino event. Using cm-wavelength data, we investigated the jet structure, determined the apparent speed of jet components, and the core flux density before and after the neutrino event. Our results indicate stationary jet features and a significant brightening of the core after the neutrino event.

Environmental radon control in the 700 m underground laboratory at JUNO

The Jiangmen Underground Neutrino Observatory is constructing the world’s largest liquid scintillator detector, with a 20 kt target mass and approximately 700 m of overburden. The total underground space of civil construction is around 300,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}, with the main hall comprising about 120,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}, making it the largest experimental hall in the world. Maintaining a low radon concentration in the underground air is crucial for both human health and the accuracy of experiments involving rare decay detection, such as neutrino and dark matter experiments. To ensure human health and the integrity of neutrino physics experiments, the nominal radon concentration in the main hall must be kept below 200 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document} with a maximum value below 400 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}. Introduction of fresh air from above ground can significantly lower radon concentration. A benchmark experiment conducted in the refuge room near the main hall revealed that the radon emanating from underground water is a significant source of radon in the underground air. The total underground ventilation rate is approximately 160,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}/h of fresh air with about 30 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}222\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{222}$$\\end{document}Rn from the bottom of the vertical tunnel after the installation of powerful fans. Of this, 55,000 m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document}/h is used for ventilation in the main hall. As a result of these measures, the radon concentration inside the main hall has decreased from 1600 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document} to below 200 Bq/m3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^3$$\\end{document} under stable working conditions, with exceptions during rare adverse weather events or fan failures. The employed strategies to control radon concentration in the underground air are described in this paper.

Prospects for combined analyses of hadronic emission from γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray sources in the Milky Way with CTA and KM3NeT

The Cherenkov Telescope Array and the KM3NeT neutrino telescopes are major upcoming facilities in the fields of γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray and neutrino astronomy, respectively. Possible simultaneous production of γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document} rays and neutrinos in astrophysical accelerators of cosmic-ray nuclei motivates a combination of their data. We assess the potential of a combined analysis of CTA and KM3NeT data to determine the contribution of hadronic emission processes in known Galactic γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray emitters, comparing this result to the cases of two separate analyses. In doing so, we demonstrate the capability of Gammapy, an open-source software package for the analysis of γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray data, to also process data from neutrino telescopes. For a selection of prototypical γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray sources within our Galaxy, we obtain models for primary proton and electron spectra in the hadronic and leptonic emission scenario, respectively, by fitting published γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray spectra. Using these models and instrument response functions for both detectors, we employ the Gammapy package to generate pseudo data sets, where we assume 200 h of CTA observations and 10 years of KM3NeT detector operation. We then apply a three-dimensional binned likelihood analysis to these data sets, separately for each instrument and jointly for both. We find that the largest benefit of the combined analysis lies in the possibility of a consistent modelling of the γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray and neutrino emission. Assuming a purely leptonic scenario as input, we obtain, for the most favourable source, an average expected 68% credible interval that constrains the contribution of hadronic processes to the observed γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\gamma $$\\end{document}-ray emission to below 15%.

Searching for dark matter annihilation with IceCube and P-ONE

We present a new search for weakly interacting massive particles utilizing ten years of public IceCube data, setting more stringent bounds than previous IceCube analysis on massive dark matter to neutrino annihilation. We also predict the future potential of the new neutrino observatory, P-ONE, showing that it may even exceed the sensitivities of Fermi-LAT gamma-ray searches by about 1–2 orders of magnitude in 1–10 TeV regions. This analysis considers the diffuse dark matter self-annihilation to neutrinos via direct and indirect channels, from the galactic dark matter halo and extra-galactic sources. We also predict that P-ONE will be capable of pushing these bounds further than IceCube, even reaching the thermal relic abundance utilizing a galactic center search for extended run-time.

Constraints on the proton fraction of cosmic rays at the highest energies and the consequences for cosmogenic neutrinos and photons

Over the last decade, observations have shown that the mean mass of ultra-high-energy cosmic rays (UHECRs) increases progressively toward the highest energies. However, the precise composition is still unknown and several theoretical studies hint at the existence of a subdominant proton component up to the highest energies. Motivated by the exciting prospect of performing charged-particle astronomy with ultra-high-energy (UHE) protons we quantify the level of UHE-proton flux that is compatible with present multimessenger observations and the associated fluxes of neutral messengers produced in the interactions of the protons. We study this scenario with numerical simulations of two independent populations of extragalactic sources and perform a fit to the combined UHECR energy spectrum and composition observables, constrained by diffuse gamma-ray and neutrino observations. We find that up to of order 10% of the cosmic rays at the highest energies can be UHE protons, although the result depends critically on the selected hadronic interaction model for the air showers. Depending on the maximum proton energy (E max p) and the redshift evolution of sources, the associated flux of cosmogenic neutrinos and UHE gamma rays can significantly exceed the multimessenger signal of the mixed-mass cosmic rays. Moreover, if E max p is above the GZK limit, we predict a large flux of UHE neutrinos above EeV energies that is absent in alternate scenarios for the origin of UHECRs. We present the implications and opportunities afforded by these UHE proton, neutrino and photon fluxes for future multimessenger observations.

Non-thermal WIMPy baryogenesis with primordial black hole

We consider the possibility that the weakly interacting massive particles produced from the evaporation of primordial black hole can explain both the relic density of dark matter and the baryon asymmetry of the Universe, through their annihilation which violate B and CP-symmetry. We find that the primordial black hole with mass less than 107g is a good candidate as an source of TeV dark matter with the total annihilation cross section 〈σaυ〉 ≲ 10-7 GeV-2 and the B-violating scattering cross section 〈σaυ〉 ≲ 2 × 10-9 GeV-2. This large annihilation cross section of dark matter in this model would make it available to search them in the indirect search for dark matter such as gamma-ray or neutrino observations.

Prospects for realtime characterization of core-collapse supernova and neutrino properties

Core-collapse supernovae (CCSNe) offer extremely valuable insights into the dynamics of galaxies. Neutrino time profiles from CCSNe, in particular, could reveal unique details about collapsing stars and particle behavior in dense environments. However, CCSNe in our galaxy and the Large Magellanic Cloud are rare and only one supernova neutrino observation has been made so far. To maximize the information obtained from the next Galactic CCSN, it is essential to combine analyses from multiple neutrino experiments in real time and transmit any relevant information to electromagnetic facilities within minutes. Locating the CCSN, in particular, is challenging, requiring disentangling CCSN localization information from observational features associated with the properties of the supernova progenitor and the physics of the neutrinos. Yet, being able to estimate the progenitor distance from the neutrino signal would be of great help for the optimisation of the electromagnetic follow-up campaign that will start soon after the propagation of the neutrino alert. Existing CCSN distance measurement algorithms based on neutrino observations hence rely on the assumption that neutrino properties can be described by the Standard Model. This paper presents a swift and robust approach to extract CCSN and neutrino physics information, leveraging diverse next-generation neutrino detectors to counteract potential measurement biases from Beyond the Standard Model effects.

Characterization of the Hamamatsu 8-inch R14688-100 PMT

Large-scale optical neutrino and dark-matter detectors rely on large-area photomultiplier tubes (PMTs) for cost-effective light detection. The new R14688-100 8-inch PMT developed by Hamamatsu provides state-of-the-art timing resolution of around 1 ns (FWHM), which can help improve vertex reconstruction and enable Cherenkov and scintillation light separation in scintillation-based detectors. This PMT also provides excellent charge resolution, allowing for precision photoelectron counting and improved energy reconstruction. The Eos experiment is the first large-scale optical detector to utilize these PMTs. In this manuscript we present a characterization of the R14688-100 single photoelectron response, such as the transit-time spreads, the dark-rates, and the afterpulsing. The single photoelectron response measurements are performed for the 206 PMTs that will be used in Eos.

Constraining Annihilating Dark Matter Using the Multifrequency Radio Flux Profiles of the M33 Galaxy

Radio data can give stringent constraints for annihilating dark matter. In general, radio observations can detect very accurate radio flux density with high resolution and different frequencies for nearby galaxies. We are able to obtain the radio flux density as a function of distance from the galactic center and frequencies S(r, ν). In this article, we demonstrate a comprehensive radio analysis of the M33 galaxy, combining the radio flux density profile S(r) and the frequency spectrum S(ν) to get the constraints of dark matter annihilation parameters. By analyzing the archival radio data obtained from the Effelsberg telescope, we show that the dark matter annihilation contributing to the radio flux density might be insignificant in the disk region of the M33 galaxy. Moreover, by including the baryonic radio contribution, we constrain the 2σ conservative upper limits of the annihilation cross section, which can be complementary to the existing constraints based on neutrino, cosmic-ray, and gamma-ray observations. Our results indicate that analyzing the galactic multifrequency radio flux profiles can give useful and authentic constraints on dark matter for the leptophilic annihilation channels.

Astrophysical approach to search for heavy neutrino decay

AbstractCosmic rays are a very valuable tool of multi‐messenger astrophysics, as they provide a very different picture of the sky. During the past decades, a large number of active astrophysical objects in our Galaxy and beyond have been discovered through the detection of gamma‐rays with Cherenkov telescopes. Cosmic rays, neutrinos have been successfully supplementing the astronomical view. Also, cosmic rays may offer to investigation of the elementary particle properties. Neutrino telescope detects the Cherenkov radiation generated in water or ice by the passage of relativistic charged particles produced by neutrino collisions with nucleons in the detector volume. Some alternative approaches have been proposed. One of them is using earth matter or mountains as a target volume for the conversion of neutrinos to leptons which then initiate extensive air showers (EAS) in the atmosphere, then showers can be detected by the Cherenkov telescope. Investigations with SHALON Cherenkov telescope have included observations of EAS from the sub‐horizontal direction . Five EAS of ∼10 TeV energies were detected with SHALON from the sub‐horizontal directions in the conditions with the zero expected number of showers. These events may be caused by the decay of a long‐lived penetrating particle entering the atmosphere from the ground and decaying in front of the telescope. As a possible explanation, two scenarios with an unstable neutrino of mass GeV and m is discussed. Remarkably, one of these models has been proposed to explain an excess of electron‐like neutrino events at MiniBooNE.

Shedding light on neutrino self-interactions with solar antineutrino searches

Solar antineutrinos are absent in the standard solar model prediction. Consequently, solar antineutrino searches emerge as a powerful tool to probe new physics capable of converting neutrinos into antineutrinos. In this study, we highlight that neutrino self-interactions, recently gaining considerable attention due to their cosmological and astrophysical implications, can lead to significant solar antineutrino production. We systematically explore various types of four-fermion effective operators and light scalar mediators for neutrino self-interactions. By estimating the energy spectra and event rates of solar antineutrinos at prospective neutrino detectors such as JUNO, Hyper-Kamiokande, and THEIA, we reveal that solar antineutrino searches can impose stringent constraints on neutrino self-interactions and probe the parameter space favored by the Hubble tension.

Measurement of radon emanation and impurity adsorption from argon gas using ultralow radioactive zeolite

The amount of radioactive impurities contaminated in the detector gases is required to be kept at a very low level for rare event particle physics such as dark matter and neutrino observation experiments. Zeolite is a well-known class of materials and is one of the possible candidates for removing impurities from gases. At the same time, the amount of radioactive impurities released from the adsorbent material needs to be sufficiently small. In this paper, a development of a new ultralow radioactive zeolite as a product of the selection of ultralow radioactive materials is reported. Results on the radon emanation and impurity adsorption from argon gas measurements are also described.

Determining the Origin of Very-high-energy Gamma Rays from Galactic Sources by Future Neutrino Observations

Recently, the Large High Altitude Air Shower Observatory (LHAASO) identified 12 gamma-ray sources emitting gamma rays with energies above 100 TeV, making them potential PeV cosmic-ray accelerators (PeVatrons). Neutrino observations are crucial in determining whether the gamma-ray radiation process is of hadronic or leptonic origin. In this paper, we study three detected sources, LHAASO J1908+0621, LHAASO J2018+3651, and LHAASO J2032+4102, which are also the most promising Galactic high-energy neutrino candidate sources with the lowest pretrial p-value based on the stacking searches testing for excess neutrino emission by the IceCube Neutrino Observatory. We study the lepto-hadronic scenario for the observed multiband spectra of these LHAASO sources considering the possible counterpart source of the LHAASO sources. The very-high-energy gamma rays are entirely attributed to the hadronic contribution; therefore, the most optimistic neutrino flux can be derived. Then, we evaluate the statistical significance (p-value) as a function of the observation time of IceCube and the next-generation IceCube-Gen2 neutrino observatory, respectively. Our results tend to disfavor that all gamma rays above 100 GeV from LHAASO J1908+0621 are of purely hadronic origin based on current IceCube observations, but the purely hadronic origin of gamma rays above 100 TeV is still possible. By IceCube-Gen2, the origin of gamma rays above 100 TeV from LHAASO J1908+0621 can be further determined at a 5σ significance level within a running time of ∼3 yr. For LHAASO J2018+3651 and LHAASO J2032+4102, the required running time of IceCube-Gen2 is ∼10 yr (3σ) and ∼10 yr (5σ), respectively. Future observations by the next-generation neutrino telescope will be crucial to understanding the particle acceleration and radiation processes inside the sources.

Sub-GeV Gamma Rays from Nearby Seyfert Galaxies and Implications for Coronal Neutrino Emission

Recent observations of high-energy neutrinos by IceCube and gamma rays by the Fermi Large Area Telescope (LAT) and the MAGIC telescope have suggested that neutrinos are produced in gamma-ray opaque environments in the vicinity of supermassive black holes. In this work, we present 20 MeV–1 TeV spectra of three Seyfert galaxies whose nuclei are predicted to be active in neutrinos, NGC 4151, NGC 4945, and the Circinus galaxy, using 14.4 yr of Fermi LAT data. In particular, we find evidence of sub-GeV excess emission that can be attributed to gamma rays from NGC 4945, as was also seen in NGC 1068. These spectral features are consistent with predictions of the magnetically powered corona model, and we argue that NGC 4945 is among the brightest neutrino active galaxies detectable for KM3Net and Baikal-GVD. On the other hand, in contrast to other reported results, we do not detect gamma rays from NGC 4151, which constrains neutrino emission from the accretion shock model. Future neutrino detectors such as IceCube-Gen2 and MeV gamma-ray telescopes such as AMEGO-X will be crucial for discriminating among the theoretical models.

Multiwavelength spectral modelling of the candidate neutrino blazar PKS 0735+178

ABSTRACT The BL Lac object PKS 0735+178 was in its historic γ-ray brightness state during 2021 December. This period also coincides with the detection of a neutrino event IC 211208A, which was localized close to the vicinity of PKS 0735+178. We carried out detailed γ-ray timing and spectral analysis of the source in three epochs: (a) quiescent state (E1), (b) moderate-activity state (E2), and (c) high-activity state (E3) coincident with the epoch of neutrino detection. During the epoch of neutrino detection (E3), we found the largest variability amplitude of 95 per cent. The γ-ray spectra corresponding to these three epochs are well fit by the power-law model and the source is found to show spectral variations with a softer when brighter trend. In epoch E3, we found the shortest flux doubling/halving time of 5.75 h. Even though the spectral energy distribution in the moderate-activity state and in the high-activity state could be modelled by the one-zone leptonic emission model, the spectral energy distribution in the quiescent state required an additional component of radiation over and above the leptonic component. Here, we show that a photomeson process was needed to explain the excess γ-ray emission in the hundreds of GeV that could not be accounted for by the synchrotron self-Compton process.

Measurement of the muon flux at the SND@LHC experiment

The Scattering and Neutrino Detector at the LHC (SND@LHC) started taking data at the beginning of Run 3 of the LHC. The experiment is designed to perform measurements with neutrinos produced in proton-proton collisions at the LHC in an energy range between 100 GeV and 1 TeV. It covers a previously unexplored pseudo-rapidity range of 7.2<η<8.4\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$7.2<\\eta <8.4$$\\end{document}. The detector is located 480 m downstream of the ATLAS interaction point in the TI18 tunnel. It comprises a veto system, a target consisting of tungsten plates interleaved with nuclear emulsion and scintillating fiber (SciFi) trackers, followed by a muon detector (UpStream, US and DownStream, DS). In this article we report the measurement of the muon flux in three subdetectors: the emulsion, the SciFi trackers and the DownStream Muon detector. The muon flux per integrated luminosity through an 18×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document}18 cm2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{2}$$\\end{document} area in the emulsion is: 1.5±0.1(stat)×104fb/cm2.\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} 1.5 \\pm 0.1(\ ext {stat}) \ imes 10^4\\,\ ext {fb/cm}^{2}. \\end{aligned}$$\\end{document}The muon flux per integrated luminosity through a 31×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document}31 cm2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{2}$$\\end{document} area in the centre of the SciFi is: 2.06±0.01(stat)±0.12(sys)×104fb/cm2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} 2.06\\pm 0.01(\ ext {stat})\\pm 0.12(\ ext {sys}) \ imes 10^{4} \ ext {fb/cm}^{2} \\end{aligned}$$\\end{document}The muon flux per integrated luminosity through a 52×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document}52 cm2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{2}$$\\end{document} area in the centre of the downstream muon system is: 2.35±0.01(stat)±0.10(sys)×104fb/cm2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\begin{aligned} 2.35\\pm 0.01(\ ext {stat})\\pm 0.10(\ ext {sys}) \ imes 10^{4}\\,\ ext {fb/cm}^{2} \\end{aligned}$$\\end{document}The total relative uncertainty of the measurements by the electronic detectors is 6%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document} for the SciFi and 4%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document} for the DS measurement. The Monte Carlo simulation prediction of these fluxes is 20–25%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\%$$\\end{document} lower than the measured values.

Pacific Ocean Neutrino Experiment

Following the breakthrough discoveries of very-high-energy neutrinos of astrophysical origin by IceCube, a new field of research, neutrino astronomy, was established in the previous decade. Even though two extragalactic point sources of such neutrinos have been identified by now, TXS 0506+056 and NGC 1068, the origin and processes of the creation of astrophysical neutrinos are still mostly unexplored. To advance quickly in this new field, more neutrino telescopes are needed. This article describes the current status and plans for the development of the Pacific Ocean Neutrino Experiment (P-ONE), which is under construction in the Pacific Ocean near Vancouver Island. The deployment of P-ONE is expected to start in 2025, exploiting the already available deep-sea infrastructure provided by Ocean Networks Canada. P-ONE will complement the existing IceCube, Baikal-GVD, and KM3NeT neutrino telescopes not only with its large detection volume, but also by providing insight into the southern celestial hemisphere, where the central region of the Galactic Plane is located.

Dissecting the γ-Ray Emissions of the Nearby Galaxies NGC 1068 and NGC 253

Intrigued by recent high-energy study results for nearby galaxies with γ-ray emission and in particular NGC 1068 that has been detected as a neutrino-emitting source by the IceCube Neutrino Observatory, we conduct a detailed analysis of the γ-ray data of the galaxies NGC 1068 and NGC 253, obtained with the Large Area Telescope on board the Fermi γ-ray Space Telescope. By checking their possible spectral features and then constructing light curves in the corresponding energy ranges, we identify spectral-change activity from NGC 1068 in the ≥2 GeV energy range and long-term, statistically significant changes for NGC 253 in the ≥5 GeV energy range. In the former, the emission appears harder in two half-year periods than in the otherwise “quiescent” state. In the latter, an ∼two-fold decrease in the detection significance after MJD = 57023 is clearly revealed by the test-statistic maps we obtain. Considering the previous studies carried out and the various models proposed for the γ-ray emissions of the two sources, we discuss the implications of our findings. We suspect that a jet (or outflow) in NGC 1068 might contribute to the γ-ray emission. The nature of the long-term statistically significant changes for NGC 253 is not clear, but since the part of the GeV emission may be connected to the very-high-energy (VHE) emission from the center of the galaxy, it could be further probed with VHE observations.

Monitoring the Baric Modulation of Gas Concentration in the Baksan Neutrino Observatory Tunnel in the Elbrus Region Using Differential Absorption Lidar

Monitoring the Baric Modulation of Gas Concentration in the Baksan Neutrino Observatory Tunnel in the Elbrus Region Using Differential Absorption Lidar