A5019081841- Neutrino Physics Research
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Cosmology and Gravitation Theories
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Galaxies: Formation, Evolution, Phenomena
- Quantum, superfluid, helium dynamics
- Pulsars and Gravitational Waves Research
- Particle accelerators and beam dynamics
- Scientific Research and Discoveries
- History and Developments in Astronomy
- Computational Physics and Python Applications
- Relativity and Gravitational Theory
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Advanced Thermodynamics and Statistical Mechanics
- Black Holes and Theoretical Physics
- Molecular Spectroscopy and Structure
- Advanced X-ray Imaging Techniques
Max Planck Institute for Physics
2015-2024
European Organization for Nuclear Research
2024
University of California, Los Angeles
2020
Max Planck Society
2006-2019
Lawrence Livermore National Security
2016
CEA Paris-Saclay
2015
Institut de Recherche sur les Lois Fondamentales de l'Univers
2015
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015
Universidad de Zaragoza
2015
Ludwig-Maximilians-Universität München
2013
Hypothetical low-mass particles, such as axions, provide a compelling explanation for the dark matter in universe. Such particles are expected to emerge abundantly from hot interior of stars. To test this prediction, CERN Axion Solar Telescope (CAST) uses 9 T refurbished Large Hadron Collider magnet directed towards Sun. In strong magnetic field, solar axions can be converted X-ray photons which recorded by detectors. 2013–2015 run, thanks low-background detectors and new telescope,...
Photons can mix with low-mass bosons in the presence of external electromagnetic fields if these particles---not necessarily spin 1---couple by a two-photon vertex. Important examples are hypothetical axion (spin 0) and graviton 2). We develop formalism which is adapted to study evolution photon (axion, graviton) beam fields. apply our results discuss possibility detecting axions measurement magnetically induced birefringence vacuum. also photon-axion (graviton) transitions pulsar magnetic...
Preface Acknowledgments 1: The Energy-Loss Argument 2: Anomalous Stellar Energy Losses Bounded by Observations 3: Particles Interacting with Electrons and Baryons 4: Processes in a Nuclear Medium 5: Two-Photon Coupling of Low-Mass Bosons 6: Particle Dispersion Decays Media 7: Nonstandard Neutrinos 8: Neutrino Oscillations 9: Trapped 10: Solar 11: Supernova 12: Radiative from Distant Sources 13: What Have We Learned SN 1987A? 14: Axions 15: Miscellaneous Exotica 16: Neutrinos: Bottom Line...
The neutrino flux and spectra formation in a supernova core is studied by using Monte Carlo code. dominant opacity contribution for νμ elastic scattering on nucleons νμN → Nνμ, where always stands either or ντ. In addition, we switch off variety of processes that allow the exchange energy creation destruction pairs, notably nucleon bremsstrahlung NN NNνμμ, pair annihilation e+e- νμμ νee νμμ, recoil weak magnetism scattering, electrons νμe± e±νμ, electron neutrinos antineutrinos νμνe νeνμ νμe...
The observation of a neutrino pulse from the supernova SN1987A constrains production light exotic particles in proto neutron star. We derive new bound on axion decay constant, ${f}_{a}$\ensuremath{\gtrsim}${10}^{10}$ GeV. If right-handed (RH) neutrinos exist, ``RH Fermi constant'' is ${G}_{\mathrm{RH}\ensuremath{\lesssim}{10}^{\mathrm{\ensuremath{-}}4}{G}_{\mathrm{F}}}$, 2 orders magnitude below laboratory bounds. Dirac mass ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ can be constrained limits.
An 8.8M{⊙} electron-capture supernova was simulated in spherical symmetry consistently from collapse through explosion to essentially complete deleptonization of the forming neutron star. The evolution time (∼9 s) is short because high-density effects suppress our neutrino opacities. After a phase accretion-enhanced luminosities (∼200 ms), luminosity equipartition among all species becomes almost perfect and spectra ν{e} ν{μ,τ} very similar, ruling out neutrino-driven wind as r-process site....
We have searched for solar axions or similar particles that couple to two photons by using the CERN Axion Solar Telescope (CAST) setup with improved conditions in all detectors. From absence of excess X-rays when magnet was pointing Sun, we set an upper limit on axion-photon coupling 8.8 x 10^{-11} GeV^{-1} at 95% CL m_a <~ 0.02 eV. This result is best experimental over a broad range axion masses and eV also supersedes previous derived from energy-loss arguments globular-cluster stars.
We propose a new strategy to search for dark matter axions in the mass range of $40--400\text{ }\ensuremath{\mu}\mathrm{eV}$ by introducing dielectric haloscopes, which consist disks placed magnetic field. The changing media cause discontinuities axion-induced electric field, leading generation propagating electromagnetic waves satisfy continuity requirements at interfaces. Large-area with adjustable distances boost microwave signal (10--100 GHz) an observable level and allow one scan over...
The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....
The red-giant branch (RGB) in globular clusters is extended to larger brightness if the degenerate helium core loses too much energy ``dark channels.'' Based on a large set of archival observations, we provide high-precision photometry for Galactic cluster M5 (NGC 5904), allowing detailed comparison between observed tip RGB with predictions based contemporary stellar evolution theory. In particular, derive 95% confidence limits...
Neutrino flavor evolution in core-collapse supernovae, neutron-star mergers, or the early universe is dominated by neutrino-neutrino refraction, often spawning "self-induced conversion", i.e., shuffling of among momentum modes. This effect driven collective run-away modes coupled "flavor oscillators" and can spontaneously break initial symmetries such as axial symmetry, homogeneity, isotropy, even stationarity. Moreover, growth rates unstable be order interaction energy instead much smaller...
Collective pair conversion ${\ensuremath{\nu}}_{e}{\overline{\ensuremath{\nu}}}_{e}\ensuremath{\leftrightarrow}{\ensuremath{\nu}}_{x}{\overline{\ensuremath{\nu}}}_{x}$ by forward scattering, where $x=\ensuremath{\mu}$ or $\ensuremath{\tau}$, may be generic for supernova neutrino transport. Depending on the local angular intensity of electron lepton number carried neutrinos, rate can ``fast,'' i.e., order...
The brightness of the tip red-giant branch (TRGB) allows one to constrain novel energy losses that would lead a larger core mass at helium ignition and thus brighter TRGB than expected by standard stellar models. required absolute calibrations strongly improve with reliable geometric distances have become available for galaxy NGC 4258 hosts water megamaser Large Magellanic Cloud based on 20 detached eclipsing binaries. Moreover, we revise previous calibration in globular cluster $\omega$...
We derive supernova (SN) bounds on muon-philic bosons, taking advantage of the recent emergence muonic SN models. Our main innovations are to consider scalars $ϕ$ in addition pseudoscalars $a$ and include systematically generic two-photon coupling $G_{γγ}$ implied by a muon triangle loop. This interaction allows for Primakoff scattering radiative boson decays. The globular-cluster bound $G_{γγ}<0.67\times10^{-10}~{\rm GeV}^{-1}$ derived axion-like particles carries over Yukawa couplings...
The hot and dense core formed in the collapse of a massive star is powerful source hypothetical feebly interacting particles such as sterile neutrinos, dark photons, axionlike (ALPs), others. Radiative decays a→2γ deposit this energy surrounding material if mean free path less than radius progenitor star. For first time, we use supernova (SN) population with particularly low explosion energies most sensitive calorimeters to constrain possibility. These SNe are observationally identified...
Neutrino fast flavor conversion (FFC) typically occurs in extremely dense neutrino environments such as those of core-collapse supernovae (CCNe). The typical distance and time scales at which FFCs take place are much smaller than accessible to hydrodynamic simulations CCSNe. In this paper, schematically taken into account spherically symmetric CCSN their distinctive effects delineated.
We present the first simulations of core-collapse supernovae in axial symmetry with feedback from fast neutrino flavor conversion (FFC). Our schematic treatment FFCs assumes instantaneous equilibration under constraint lepton-number conservation individually for each flavor. Systematically varying spatial domain where are assumed to occur, we find that they facilitate SN explosions low-mass (9-12M_{⊙}) progenitors otherwise explode longer time delays, whereas weaken tendency higher-mass...
We review the current status of astrophysical bounds on QCD axions, primarily based observational effects nonstandard energy losses stars, including black-hole superradiance. Over past few years, many traditional arguments have been reexamined both theoretically and using modern data new ideas put forth. This compact updates similar Lecture Notes written by one us in 2006 [Lect. Phys. 741 (2008) 51–71].