Composite asymmetric dark matter (ADM) is the framework that naturally explains the coincidence of the baryon density and the dark matter density of the Universe. Through a portal interaction sharing particle-antiparticle asymmetries in the Standard Model and dark sectors, dark matter particles, which are dark-sector counterparts of baryons, can decay into antineutrinos and dark-sector counterparts of mesons (dark mesons) or dark photon. Subsequent cascade decay of the dark mesons and the dark photon can also provide electromagnetic fluxes at late times of the Universe. The cosmic-ray constraints on the decaying dark matter with the mass of 1–10 GeV has not been well studied. We perform comprehensive studies on the decay of the composite ADM by combining the astrophysical constraints from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>e</mi><mo>±</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi></math> ray. The constraints from cosmic-ray positron measurements by AMS-02 are the most stringent at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≳</mo><mn>2</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>: a lifetime should be larger than the order of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>26</mn></msup><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">s</mi></math>, corresponding to the cutoff scale of the portal interaction of about <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>8</mn></msup><mi>–</mi><msup><mn>10</mn><mn>9</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. We also perform the dedicated analysis for the neutrino monoenergetic signals at Super-Kamiokande and Hyper-Kamiokande due to the atmospheric neutrino background in the energy range of our interest.

Japan

United States

Saikat Das

Poland

Ayuki Kamada

China

Takumi Kuwahara

Kohta Murase

Deheng Song

Composite asymmetric dark matter with a dark photon portal: Multimessenger tests

We study the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>1</mn><mo>+</mo><mn>1</mn></math> flat spacetime dynamics of a classical field configuration corresponding to an ensemble of sine-Gordon kinks and antikinks, semiclassically coupled to a quantum field. This coupling breaks the integrability of the sine-Gordon model resulting in the background’s decay into quantum radiation as kink-antikink pairs annihilate. We find evidence that, on average, the energy of the ensemble scales as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>t</mi><mrow><mo>−</mo><mi>α</mi></mrow></msup></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi><mo>&lt;</mo><mn>1</mn></math> and independent of the coupling strength or the mass of the quantum field. The generalization of this result to domain wall networks in higher spacetime dimensions could be relevant to particle production in the early universe.

Mainak Mukhopadhyay

South Korea

Atsushi Naruko

George Zahariade

Evolution of a kink-antikink ensemble in a quantum vacuum

We present a novel way to probe inelastic dark matter using cosmic-ray (CR) cooling in active galactic nuclei (AGNs). Dark matter (DM) in the vicinity of supermassive black holes may scatter off CRs, resulting in the rapid cooling of CRs for sufficiently large cross sections. This in turn can alter the high-energy neutrino and gamma-ray fluxes detected from these sources. We show that AGN cooling bounds obtained through the multimessenger data of NGC 1068 and TXS <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0506</mn><mo>+</mo><mn>056</mn></mrow></math> allows us to reach unprecedently large mass splittings for inelastic DM (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≳</mo><mi>TeV</mi></math>), orders of magnitude larger than those probed by direct detection experiments and DM capture in neutron stars. Furthermore, we demonstrate that cooling bounds from AGNs can probe thermal light DM with small mass splittings. This provides novel and complementary constraints in parts of a parameter space accessible solely by colliders and beam-dump experiments.

R. Andrew Gustafson

Gonzalo Herrera

Ian M. Shoemaker

Cosmic-ray cooling in active galactic nuclei as a new probe of inelastic dark matter

Ultrahigh-energy neutrinos (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>UHE</mi><mi>ν</mi></mrow></math>s) can be used as a valuable probe of superheavy dark matter above <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>∼</mo><msup><mn>10</mn><mn>9</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, the latter being difficult to probe with collider and direct detection experiments due to the feebly interacting nature. Searching for radio emissions originating from the interaction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>UHE</mi><mi>ν</mi></math>s with the lunar regolith enables us to explore energies beyond <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>10</mn><mn>12</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, which astrophysical accelerators cannot achieve. Taking into account the interaction of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>UHE</mi><mi>ν</mi></math>s with the cosmic neutrino background and resulting standard neutrino cascades to calculate the neutrino flux on Earth, for the first time, we investigate sensitivities of such lunar radio observations to very heavy dark matter. We also examine the impacts of cosmogenic neutrinos that have the astrophysical origin. We show that the proposed ultralong wavelength lunar radio telescope, as well as the existing low-frequency array, can provide the most stringent constraints on decaying or annihilating superheavy dark matter with masses at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>≳</mo><msup><mn>10</mn><mn>12</mn></msup><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. The limits are complementary to or even stronger than those from other <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>UHE</mi><mi>ν</mi></math> detectors, such as the IceCube-Gen2 radio array and the Giant Radio Array for Neutrino Detection.

Jose Alonso Carpio

Probing superheavy dark matter through lunar radio observations of ultrahigh-energy neutrinos and the impacts of neutrino cascades

Recent observations of high-energy neutrinos from active galactic nuclei (AGN), NGC 1068 and TXS <math><mrow><mn>0506</mn><mo>+</mo><mn>056</mn></mrow></math>, suggest that cosmic rays (CRs) are accelerated in the vicinity of the central supermassive black hole and high-energy protons and electrons can cool efficiently via interactions with ambient photons and gas. The dark matter density may be significantly enhanced near the black hole, and CRs could lose energies predominantly due to scatterings with the ambient dark matter particles. We propose CR cooling in AGN as a new probe of dark matter-proton and dark matter-electron scatterings. Under plausible astrophysical assumptions, our constraints on sub-GeV dark matter can be the strongest derived to date. Some of the parameter space favored by thermal light dark matter models might already be probed with current multimessenger observations of AGN.

Germany

Probing light dark matter through cosmic-ray cooling in active galactic nuclei

We show that ATLAS, a collider detector, can measure the flux of high-energy supernova neutrinos, which can be produced from days to months after the explosion. Using Monte Carlo simulations for predicted fluxes, we find at most <math><mrow><mi>O</mi><mo>(</mo><mn>0.1</mn><mi>–</mi><mn>1</mn><mo>)</mo></mrow></math> starting events and <math><mrow><mi>O</mi><mo>(</mo><mn>10</mn><mi>–</mi><mn>100</mn><mo>)</mo></mrow></math> throughgoing events from a supernova 10 kpc away. Possible Galactic supernovae from Betelgeuse and Eta Carinae are further analyzed as demonstrative examples. We argue that, even with limited statistics, ATLAS has the ability to discriminate among flavors and between neutrinos and antineutrinos, making it a unique neutrino observatory so far unmatched in this capability.

Alex Y. Wen

Carlos A. Argüelles

Ali Kheirandish

Detecting High-Energy Neutrinos from Galactic Supernovae with ATLAS

The core-collapse of massive stars and the merger of neutron star binaries are among the most promising candidate sites for the production of high-energy cosmic neutrinos. We demonstrate that the high-energy neutrinos produced in such extreme environments can experience efficient flavor conversions on scales much shorter than those expected in vacuum, due to their coherent forward scatterings with the bath of decohered low-energy neutrinos emitted from the central engine. These low-energy neutrinos, which exist as mass eigenstates, provide a very special and peculiar dominant background for the propagation of the high-energy ones. We point out that the high-energy neutrino flavor ratio is modified to a value independent of neutrinos energies, which is distinct from the conventional prediction with the matter effect. We also suggest that the signals can be used as a novel probe of new neutrino interactions beyond the Standard Model. This is yet another context where neutrino-neutrino interactions can play a crucial role in their flavor evolution.

Sajad Abbar

Oscillations of high-energy cosmic neutrinos in the copious MeV neutrino background

In light of the recent muon <math><mi>g</mi><mo>−</mo><mn>2</mn></math> experiment data from Fermilab, we investigate the implications of a gauged <math><msub><mi>L</mi><mi>μ</mi></msub><mo>−</mo><msub><mi>L</mi><mi>τ</mi></msub></math> model for high energy neutrino telescopes. It has been suggested that a new gauge boson at the MeV scale can both account for the muon <math><mi>g</mi><mo>−</mo><mn>2</mn></math> data and alleviate the tension in the Hubble parameter measurements. It also strikes signals at IceCube from the predicted resonance scattering between high-energy neutrinos and the cosmic neutrino background. We revisit this model based on the latest IceCube shower data, and perform a four-parameter fit to find a preferred region. We do not find evidence for secret interactions. The best-fit points of <math><msub><mi>m</mi><msup><mi>Z</mi><mo>′</mo></msup></msub></math> and <math><msub><mi>g</mi><mrow><mi>μ</mi><mi>τ</mi></mrow></msub></math> are <math><mo>∼</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi></math> and <math><mo>∼</mo><mn>0.1</mn></math>, respectively, depending on assumptions regarding the absolute neutrino masses, and the secret interaction parameter space allowed by the observed IceCube data overlaps with the regions of the parameter space that can explain the muon <math><mi>g</mi><mo>−</mo><mn>2</mn></math> anomaly and Hubble tension as well. We demonstrate that future neutrino telescopes such as IceCube-Gen2 can probe this unique parameter space, and point out that successful measurements would infer the neutrino mass with <math><mn>0.06</mn><mtext> </mtext><mtext> </mtext><mi>eV</mi><mo>≲</mo><mi>Σ</mi><msub><mi>m</mi><mi>ν</mi></msub><mo>≲</mo><mn>0.3</mn><mtext> </mtext><mtext> </mtext><mi>eV</mi></math>.

Zahra Tabrizi

High-energy cosmic neutrinos as a probe of the vector mediator scenario in light of the muon <math><mi>g</mi><mo>−</mo><mn>2</mn></math> anomaly and Hubble tension

High-energy neutrinos from astrophysical transients serve as a probe of neutrino physics beyond the Standard Model. In particular, nonstandard interaction of neutrinos with the cosmic neutrino background or dark matter (DM) may have imprints on not only their spectra but also the arrival and time-delay distributions. Assuming that the interaction occurs at most once during the neutrino propagation, we provide general analytic formulas for light curves of the neutrino echoes induced by BSM. The formulas can be used for constraining neutrino-neutrino scattering, neutrino-DM scattering, and other scattering processes experienced by relativistic particles.

Ryan Eskenasy

Light curves of BSM-induced neutrino echoes in the optically thin limit

The recent IceCube publication claims the observation of cosmic neutrinos with energies down to <math><mo>∼</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, reinforcing the growing evidence that the neutrino flux in the 10–100 TeV range is unexpectedly large. Any conceivable source of these neutrinos must also produce a <math><mi>γ</mi></math>-ray flux which degrades in energy en route to the Earth and contributes to the extragalactic <math><mi>γ</mi></math>-ray background measured by the Fermi satellite. In a quantitative multimessenger analysis, featuring minimalistic assumptions, we find a <math><mo>≳</mo><mn>3</mn><mi>σ</mi></math> tension in the data, reaching <math><mo>∼</mo><mn>5</mn><mi>σ</mi></math> for cosmic neutrinos extended down to <math><mo>∼</mo><mn>1</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi></math>, interpreted as evidence for a population of hidden cosmic-ray accelerators.