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At least 163 records · Page 9

POEMMA's Target of Opportunity Sensitivity to Cosmic Neutrino Transient Sources

We calculate the sensitivity of space-based cosmic neutrino detection from transient sources in the context of the Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) mission using Target- of-Opportunity (ToO) observations. POEMMA uses two spacecraft each with a large Schmidt telescope to simultaneously view the optical signals generated by extensive air showers (EASs). POEMMA is designed for both ultrahigh-energy cosmic ray and very-high-energy neutrino measurements. POEMMA has significant neutrino sensitivity starting in the 10 PeV decade via measurements of Cherenkov signals from upward-moving EASs initiated by tau neutrinos interacting in the Earth. For ToO observations, POEMMA uses the ability to quickly repoint (90° in 500 seconds) each of the two spacecraft to the direction of the transient source. POEMMA EAS measurements are performed during astronomical night, leading to different observational constraints for short- and long-duration bursts. For short-bursts of order 10(exp 3) s, POEMMA will increase the sensitivity of existing experiments (e.g., IceCube and the Pierre Auger Observatory) by up to two orders of magnitude. For long-duration bursts on the scale of 10(exp 5−6) s, the full celestial sky is available and the average neutrino sensitivity will be increased by up to a factor of 50, reaching the desired level to probe model predictions of transient neutrino sources (e.g., of blazer flares as well as both black hole-black hole and neutron star-neutron star mergers). POEMMA’s neutrino sensitivity to various models of transient neutrino sources are detailed. Altogether, our results demonstrate better sensitivity to ToO neutrino sources from the space-based POEMMA experiment compared to current ground-based experiments, and more importantly, demonstrate unique full-sky coverage for ToO neutrino sources.

Venters, Tonia M.↗

MeV Emission from Pulsar Wind Nebulae: Understanding Extreme Particle Acceleration in Highly Relativistic Outflows

The Earth is constantly bombarded from outer space by energetic particles. Where and how these "cosmic rays" are produced is poorly understood, with various particle types and energies likely originating from different sources. Particularly mysterious is the source of high-energy e+/- produced in our Galaxy, especially those responsible for both the high fraction of e+ in the GeV cosmic ray lepton spectrum and the e+/- and observed excess of microwaves and gamma-rays detected towards the Galactic center and bulge. While these particles could be evidence for exotic forms of dark matter, they might also be produced by "normal" astrophysical sources such as pulsars the strongly magnetized, rapidly rotating neutron stars whose rotational energy powers an ultra-relativistic outflow (commonly referred to as a "pulsar wind") whose interaction with the surrounding medium creates a pulsar wind nebula .While the detection of TeV emission from numerous PWNe strongly suggest they contain e+/- with PeV or higher energies, how and to what energies these particles are produced is unknown, let alone their dependence on the properties of the pulsar, pulsar wind, and surrounding medium. A major reason for this uncertainty is the lack of information concerning their MeV properties, since the synchrotron emission from the highest energy e+/- peaks in this waveband. Only by combining the MeV spectrum of PWNe measured by proposed missions with that obtained at lower (primarily radio and X-ray) and higher (TeV) photon energies by current and hopefully future facilities is it possible to measure the full spectrum of e+/- in these sources. The resultant insights into the underlying acceleration mechanism would significantly impact many areas of astrophysics from indirect searches for dark matter to the origin of cosmic rays to the physics of relativistic outflows observed from active galactic nuclei, gamma-ray bursts, and some gravitational wave events.

Gelfand, Joseph D.↗

The POEMMA (Probe of Extreme Multi-Messenger Astrophysics) Observatory

The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to accurately observe ultra-high-energy cosmic rays (UHECRs) and cosmic neutrinos from space with sensitivity over the full celestial sky. POEMMA will observe the air fluorescence produced by extensive air showers (EASs) from UHECRs and potentially UHE neutrinos above 20 EeV. Additionally, POEMMA has the ability to observe the Cherenkov signal from upward-moving EASs induced by Earth-interacting tau neutrinos above 20 PeV. The POEMMA spacecraft are designed to quickly re-orientate to follow up transient neutrino sources and obtain currently unparalleled neutrino flux sensitivity. Developed as a NASA Astrophysics Probe-class mission, POEMMA consists of two identical satellites flying in loose formation in 525 km altitude orbits. Each POEMMA instrument incorporates a wide field-of-view (45°) Schmidt telescope with an optical collecting area of over 6 sq. m. The hybrid focal surface of each telescope includes a fast (1 μs) near-ultraviolet camera for EAS fluorescence observations and an ultrafast (10 ns) optical camera for Cherenkov EAS observations. In a 5-year mission, POEMMA will provide measurements that open new multi-messenger windows onto the most energetic events in the universe, enabling the study of new astrophysics and particle physics at these extreme energies.

A. V. Olinto↗

The POEMMA (Probe of Extreme Multi-Messenger Astrophysics)Observatory

The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is designed to accurately observe ultra-high-energy cosmic rays (UHECRs) and cosmic neutrinos from space with sensitivity over the full celestial sky. POEMMA will observe the air fluorescence produced by extensive air showers (EASs) from UHECRs and potentially UHE neutrinos above 20 EeV. Additionally, POEMMA has the ability to observe the Cherenkov signal from upward-moving EASs induced by Earth-interacting tau neutrinos above 20 PeV. The POEMMA spacecraft are designed to quickly re-orientate to follow up transient neutrino sources and obtain currently unparalleled neutrino flux sensitivity. Developed as a NASA Astrophysics Probe-class mission, POEMMA consists of two identical satellites flying in loose formation in 525 km altitude orbits. Each POEMMA instrument incorporates a wide field-of-view (45°) Schmidt telescope with an optical collecting area of over 6 m2. The hybrid focal surface of each telescope includes a fast (1 μs) near-ultraviolet camera for EAS fluorescence observations and an ultrafast (10 ns) optical camera for Cherenkov EAS observations. In a 5-year mission, POEMMA will provide measurements that open new multi-messenger windows onto the most energetic events in the universe, enabling the study of new astrophysics and particle physics at these extreme energies.

A. V. Olinto↗

Modeling of the Tau and Muon Neutrino-induced Optical Cherenkov Signals from Upward-moving Extensive Air Showers

We present a detailed modeling and computation methodology to determine the optical Cherenkovsignals produced by upward-moving extensive air showers (EASs) induced byτ-leptons and muons,sourced from the interaction of high-energy astrophysical neutrinos interacting in the Earth. Fol-lowing and extending the physics modeling and Cherenkov signal simulations performed in [1], thisscheme encompasses a new, state-of-the-art computation of the muon neutrino propagation insidethe Earth and the contribution to theτ-lepton muon decay channel. The modeling takes into ac-count all possibleτ-lepton decay and muon energy loss channels that feed the optical Cherenkovemission, produced by both tau and muon initiated EASs. The EAS modeling uses the electronenergy, angular, and lateral distributions in the EAS and their evolution as well as the wavelengthdependence of the Cherenkov emission and its atmospheric attenuation. The results presented hereare focused on the detection capabilities of sub-orbital (balloon-borne) and orbital (satellite) basedinstruments. The latter case was calculated for POEMMAato compare to that presented in [1],specifically including the muon-decay channel ofτ-leptons and the muonic EAS Cherenkov signalfrom muon neutrino interactions in the Earth. By detailing all these individual contributions tothe optical Cherenkov emission and detection, we show how the ensemble that includes muonicchannels provides a large detection capability for space-based, high-energy cosmic neutrino detec-tion. Specifically, we show that for neutrino energies∼<10 PeV, the upward-EAS sensitivity due tomuon neutrino interactions in the Earth begin to dominate over that for tau neutrino interactions,effectively extending the neutrino sensitivity to lower energies.

A L Cummings↗

A GeV to TeV view of shell-type SNRs

Shock acceleration by the shells of supernova remnants (SNRs) has been hypothesized to be the mechanism that produces the bulk of Galactic Cosmic Rays, possibly up to PeV energies. SomeSNRs have been shown to accelerate cosmic rays to TeV energies and above. But which SNRs are indeed efficient accelerators of protons and nuclei? And what is the maximum energy up to which they can efficiently accelerate particles? Measurements of non-thermal emission, especially in the gamma-ray regime, are essential to answer these questions.

A. U. Abeysekara↗

EAS Optical Cherenkov Signatures of Tau Neutrinos for Space and Suborbital Detectors

Multi-messenger observations of transient astrophysical sources have the potential to characterize the highest energy accelerators and the most extreme environments in the Universe. Detection of neutrinos, in particular tau neutrinos generated by neutrino oscillations in transit from their sources to Earth, is possible for neutrino energies above 10 PeV using optical Cherenkov detectors imaging upward-moving extensive air showers (EAS). These EAS are produced from Earth-interacting tau neutrinos leading to tau leptons that subsequently decay in the atmosphere. We compare neutrino detection sensitivities for generic short- and long-burst transient neutrino sources and sensitivities to the diffuse neutrino flux for the second generation Extreme Universe Space Observatory on a Super-Pressure Balloon (EUSO-SPB2) balloon-borne mission and the proposed space-based Probe of Extreme Multi-Messenger Astrophysics (POEMMA) mission.

Mary Hall Reno↗

Neutrino Target-of-Opportunity Observations with Space-based and Suborbital Optical Cherenkov Detectors

Cosmic-ray accelerators capable of reaching ultra-high energies are expected to also produce very high energy neutrinos via hadronic interactions within the source or its surrounding environment. Many of the candidate astrophysical source classes are either transient in nature or exhibit flaring activity. Using the Earth as a neutrino converter, suborbital and space-based optical Cherenkov detectors, such as POEMMA and EUSO-SPB2, will be able to detect upward-moving extensive air showers induced by decaying tau-leptons generated from cosmic tau neutrinos with energies ∼ 10 PeV and above. Both EUSO-SPB2 and POEMMA will be able to quickly repoint, enabling rapid response to astrophysical transient events. We calculate the transient sensitivity and sky coverage for both EUSO-SPB2 and POEMMA, accounting for constraints imposed by the Sun and the Moon on the observation time. We also calculate both detectors’ neutrino horizons for a variety of modeled astrophysical neutrino fluences. We find that both EUSO-SPB2 and POEMMA will achieve transient sensitivities at the level of modeled neutrino fluences for nearby sources. We conclude with a discussion of the prospects of each mission detecting at least one transient event for various modeled astrophysical neutrino sources.

Tonia M Venters↗

Electric Vehicle Infrastructure Projection Tool (EVI-Pro)

This presentation includes results from the second California installment of EVI-Pro. Pursuant to California Assembly Bill 2127, evolving market and technology conditions warrant updating this statewide infrastructure assessment at least every two years. EVI-Pro has been updated to consider California's 2030 goal to have 5 million zero emission vehicles (ZEVs) on the road by 2030. CEC and NREL with the support of UC Davis and other state agencies, have set out to refine EVI-Pro to reflect increasing PEV market share, evolving vehicle and charging technology, and observed charging behavior.

ADVANCED PROPULSION SYSTEMS,ENERGY STORAGE↗

Testing Lepton Flavor Universality and CKM Unitarity with Rare Pion Decays in the PIONEER experiment

The physics motivation and the conceptual design of the PIONEER experiment, a next-generation rare pion decay experiment testing lepton flavor universality and CKM unitarity, are described. Phase I of the PIONEER experiment, which was proposed and approved at Paul Scherrer Institut, aims at measuring the charged-pion branching ratio to electrons vs. muons, $R_{e/\mu}$, 15 times more precisely than the current experimental result, reaching the precision of the Standard Model (SM) prediction at 1 part in $10^4$. Considering several inconsistencies between the SM predictions and data pointing towards the potential violation of lepton flavor universality, the PIONEER experiment will probe non-SM explanations of these anomalies through sensitivity to quantum effects of new particles up to the PeV mass scale. The later phases of the PIONEER experiment aim at improving the experimental precision of the branching ratio of pion beta decay (BRPB), $\pi^+\to \pi^0 e^+ \nu (\gamma)$, currently at $1.036(6)\times10^{-8}$, by a factor of three (Phase II) and an order of magnitude (Phase III). Such precise measurements of BRPB will allow for tests of CKM unitarity in light of the Cabibbo Angle Anomaly and the theoretically cleanest extraction of $|V_{ud}|$ at the 0.02% level, comparable to the deduction from superallowed beta decays.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

EVI-Equity

EVI-Equity (Electric Vehicle Infrastructure for Equity) is a $200k project, started around in June of 2021, with a funding from the Vehicle Technologies Office (VTO). The motivation was to create a new analytical capability that can enable us to quantify and investigate equitable access to and distribution of existing and future deployment of PEVs and EVSEs in neighborhoods, cities, states, and the nation. EVI-Equity is a bottom-up equity-focused analysis model, built upon individual (synthetic) households, aggregated by census block groups. It consists of four core components - community engagement, environmental profiling, household expenditures, and network design. Although there are some commonalities, EVI-Equity is not a vehicle choice model, charging simulation model, or transportation demand model. EVI-Equity is rather a cross-cutting analysis tool, dedicated for evaluating equitable EV adoption and EVSE deployment, encompassing and bridging a wide variety of related tools, models, and frameworks. Some of the results indicate the importance of used vehicle market for low-income households. The presentation also highlights similarities and variations as to preferred public charging locations. For example, regardless of household income, retail spots are the most preferred location for public charging, followed by curbside/street. However, the results also imply that the importance of workplace charging may vary with income - the lower the income, the less important. Environmental profiling results, with an example of ground-level ozone in Atlanta area, show that the contrast between the haves and the have nots of plug-in electric vehicles depends on location. The assessment of household expenditures illustrates the economic impact of home charging access on an individual household level - the lower the income, the greater the impact is. Lastly, Denver metro area and the state of South Dakota are used to showcase the impact of different network design of charging infrastructure, as well as alternative (vs. baseline/existing) electric vehicle adoption pattern.

ADVANCED PROPULSION SYSTEMS,ENERGY PLANNING, POLIC↗

PIONEER: Studies of Rare Pion Decays

A next-generation rare pion decay experiment, PIONEER, is strongly motivated by several inconsistencies between Standard Model (SM) predictions and data pointing towards the potential violation of lepton flavor universality. It will probe non-SM explanations of these anomalies through sensitivity to quantum effects of new particles even if their masses are at very high scales. Measurement of the charged-pion branching ratio to electrons vs. muons $R_{e/\mu}$ is extremely sensitive to new physics effects. At present, the SM prediction for $R_{e/\mu}$ is known to 1 part in $10^4$, which is 15 times more precise than the current experimental result. An experiment reaching the theoretical accuracy will test lepton flavor universality at an unprecedented level, probing mass scales up to the PeV range. Measurement of pion beta decay, $\pi^+\to \pi^0 e^+ \nu (\gamma)$, with 3 to 10-fold improvement in sensitivity, will determine $V_{ud}$ in a theoretically pristine manner and test CKM unitarity, which is very important in light of the recently emerged tensions. In addition, various exotic rare decays involving sterile neutrinos and axions will be searched for with unprecedented sensitivity. The experiment design benefits from experience with the recent PIENU and PEN experiments at TRIUMF and the Paul Scherrer Institut (PSI). Excellent energy and time resolutions, greatly increased calorimeter depth, high-speed detector and electronics response, large solid angle coverage, and complete event reconstruction are all critical aspects of the approach. The PIONEER experiment design includes a 3$\pi$ sr 25 radiation length calorimeter, a segmented low gain avalanche detector stopping target, a positron tracker, and other detectors. Using intense pion beams, and state-of-the-art instrumentation and computational resources, the experiments can be performed at the PSI ring cyclotron.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Signals of a New Gauge Boson from IceCube and Muon $g-2$

A $Z'$ boson associated with a broken $U(1)_{L_{\mu} - L_{\tau}}$ gauge symmetry offers an economical solution to the long-standing $g_\mu-2$ anomaly, confirmed and strengthened by recent measurements at Fermilab. Here, we revisit the impact of such a $Z'$ on the spectrum of high-energy astrophysical neutrinos, as measured by the IceCube experiment. This spectrum has been observed to exhibit a dip-like feature at $E_{\nu} \sim 0.2-1 \, {\rm PeV}$, which could plausibly arise from the physics of the sources themselves, but could also be the consequence of high-energy neutrinos resonantly scattering with the cosmic neutrino background, mediated by a $Z'$ with a mass on the order of $m_{Z'} \sim 10 \, {\rm MeV}$. In this study, we calculate the impact of such a $Z'$ on the high-energy neutrino spectrum for a variety of model parameters and source distributions. For couplings that can resolve the $g_{\mu}-2$ anomaly, we find that this model could self-consistently produce a spectral feature that is consistent with IceCube's measurement, in particular if the neutrinos observed by IceCube predominantly originate from high-redshift sources.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Ultimate Colliders

Our understanding of the Universe critically depends on the fundamental knowledge of particles and fields, which represents a central endeavor of modern high-energy physics. Energy frontier particle colliders - arguably, among the largest, most complex and advanced scientific instruments of modern times - for many decades have been at the forefront of scientific discoveries in high-energy physics. Due to technology advances and beam physics breakthroughs, the colliding beam facilities have progressed immensely and now operate at energies and luminosities many orders of magnitude greater than the pioneering instruments of the early 1960s. While the Large Hadron Collider and the Super-KEKB factory represent the frontier hadron and lepton colliders of today, respectively, future colliders are an essential component of a strategic vision for particle physics. Conceptual studies and technical developments for several exciting near- and medium-term future collider options are underway internationally. Analysis of numerous proposals and studies for far-future colliders indicate the limits of the collider beam technology due to machine size, cost, and power consumption, and call for a paradigm shift of the particle physics research at ultra-high energy but low luminosity colliders approaching or exceeding 1 PeV center-of-mass energy scale.

43 PARTICLE ACCELERATORS↗

Large Neutrino "Collider"

We propose using current and future large-volume neutrino telescopes as ``Large Neutrino Colliders" (L$ν$Cs) to explore TeV-scale physics beyond the Standard Model. Cosmic neutrinos with energies above 100 PeV colliding with nucleons in the detector reach center-of-mass energies beyond the 14 TeV limit of the Large Hadron Collider (LHC). Using recently predicted and measured high-energy and ultra-high-energy neutrino fluxes from IceCube and KM3NeT, we estimate mass-scale sensitivities for representative new physics scenarios at 1--30 km$^3$ L$ν$Cs. Our results demonstrate that L$ν$Cs provide a novel avenue to probe multi-TeV particles with sensitivities comparable to, or even surpassing, those of the LHC.

Bai, Yang [Wisconsin U., Madison; Argonne]↗

New Tests of Low-Scale Quantum Gravity with Cosmic-Ray Collisions

Cosmic ray collisions at high center of mass energy could enable graviton and black hole production as expected in theories of low-scale quantum gravity, such as extra-dimensions, many species, or some versions of string theory. Here we propose three novel phenomenological tests of these theories. We first consider the collision of cosmic rays with ambient protons, electrons and photons in Active Galactic Nuclei (AGN), finding that high-energy neutrino data from the blazar TXS 0506+056 places a constraint on the fundamental scale of gravity of $M_f \gtrsim 0.3$ TeV, and future high-energy neutrino data could raise this bound to $M_f \gtrsim 200$ TeV. We then point out that collisions of pairs of cosmic rays could occur at a sizable rate in AGN where the accelerated cosmic rays are not collimated, or on supermassive black hole binaries. This consideration could potentially let us test unprecedented large fundamental scales of $M_f \gtrsim 2$ PeV. We further compute the corresponding thermal neutrino emission arising from the Hawking evaporation of black holes produced in cosmic ray collisions, finding a spectrum that clearly differs from that expected in meson decays. Finally, we speculate with an scenario which would produce high-energy neutrino and gamma-ray emission from regions in the sky where no multi-wavelength counterparts would be expected, via graviton propagation from a different brane, which then decays in our Universe.

Ettengruber, Manuel [IPhT, Saclay]↗

High energy neutrinos from pulsar-powered optical transients: LFBOTs as potential origin of the KM3NeT event KM3-230213A

Recently, the KM3NeT Collaboration reported the detection of an ultra-high energy ($\sim 220$ PeV) neutrino event, KM3-230213A. In this work, we perform a detailed investigation into whether this event could originate from the diffuse neutrino flux produced by a class of pulsar-powered optical transients. In particular, we consider populations of ordinary supernovae (SNe), super-luminous supernovae (SLSNe), and luminous fast blue optical transients (LFBOTs) with a newly formed magnetar as the central engine. We discuss both the thermal electromagnetic and non-thermal neutrino emission from such sources. We scan the parameter space of the dipolar magnetic field strength and the initial spin period to determine characteristic optical emission properties and lightcurve timescales of these transients. Additionally, our scan identifies which classes of these transients can reproduce the required diffuse flux level and neutrino energies. Combining our results, we conclude that a diffuse neutrino flux from a population of LFBOTs can explain the KM3NeT event. Therefore, pulsar-powered optical transients may serve as promising sources for the current and upcoming high-energy and ultra-high energy neutrino telescopes.

Mukhopadhyay, Mainak [Fermilab; Chicago U., KICP] ↗

Constraining high-energy neutrinos from tidal disruption events with IceCube high-energy starting events

Tidal disruption events (TDEs) have been proposed as candidate sources of high-energy neutrinos. Successful and choked jets, as well as the accretion disk, corona, wind, and outflow regions in a TDE have been examined and shown to produce TeV - PeV neutrinos. In this work, we use the IceCube 12.5 year high energy starting events (HESE) dataset and perform a maximum likelihood analysis to investigate the spatial and temporal correlations between HESE dataset and a selected sample of 89 TDEs. Our results indicate that the currently observed data do not show any significant correlation and hence is consistent with the background only hypothesis. Using this result, we place constraints on the fraction of TDEs harboring intrinsic jets ($f_{\rm jet}$) and the corresponding isotropic-equivalent cosmic ray (CR) energy ($\mathcal{E}_{\rm CR}$). We note that even with limited statistics, we can constrain the parameter space as $\mathcal{E}_{\rm CR} \lesssim 3 \times 10^{53}$ erg for $f_{\rm jet} \gtrsim 0.6$ at more than 90% C.L. Finally, we discuss the theoretical implications of our results and the limits on the all-sky diffuse neutrino flux from TDEs. With more observational data in the electromagnetic band for TDEs and neutrino observations from IceCube and KM3NeT, our analysis can be used to place stringent constraints on physical parameters associated with TDEs.

Mukhopadhyay, Mainak [Fermilab; Chicago U., KICP; ↗