Probing Lorentz-violating scalar forces and dark matter with precision matter and antimatter experiments

Posted by klaurent This Week: Astrophysics, Tokyo

Kavli Affiliate: Yevgeny Stadnik | Summary:We explore a class of Lorentz-violating scalar-field models where the effects of the scalar field on antimatter can be strongly enhanced compared to matter. Non-trivial differences in phenomenology arise for spectroscopy measurements depending on whether the scalar field changes slowly or rapidly on the atomic scale. We highlight opportunities for […]


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Hunting the Unseen: Deep Learning Analysis for Semi-Visible Jet Tagging

Posted by klaurent Tokyo

Kavli Affiliate: Mihoko Nojiri | Summary:Semi-Visible Jets (SVJs) constitute a distinctive collider signature of strongly interacting dark sectors, embedding Dark Matter candidates, wherein jets contain both visible Standard Model objects and invisible dark hadrons, giving rise to correlated jet activity and missing transverse momentum. In this work, we investigate SVJs produced through a heavy Z’ […]


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Dark Matter as the Z_2 Partner of the Standard Model Higgs Boson

Posted by klaurent Tokyo

Kavli Affiliate: Yasunori Nomura | Summary:A possible gamma-ray excess from the Galactic halo favors dark matter with a mass of several hundred GeV. In previous work, we found that an electroweak scalar doublet is a particularly economical, and nearly uniquely selected, interpretation among simple renormalizable thermal dark-matter models. We point out that its unbroken Z_2 […]


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Improved Threshold for Particle-Induced Magnetic Avalanche in Single-Molecule Magnets Using Fe$_8$ Molecule

Posted by klaurent Tokyo

Kavli Affiliate: Tom Melia | Summary:Extending the original work on the development of a magnetic avalanche detector using Mn$_12$-ac single-molecule magnet (SMM), we report the results on a significantly lower threshold magnetic avalanche detector using Fe$_8$ SMM. Fe$_8$ has an order of magnitude smaller relaxation time that is expected to produce at least 3 orders […]


Continue.. Improved Threshold for Particle-Induced Magnetic Avalanche in Single-Molecule Magnets Using Fe$_8$ Molecule

Little Red Dots as Shock-Powered High-Energy Neutrino Sources

Posted by klaurent Tokyo

Kavli Affiliate: Shunsaku Horiuchi | Summary:Little Red Dots (LRDs) are compact, high-redshift sources whose physical nature remains uncertain. Their optical spectra bear many similarities to Type IIn supernovae (SNe IIn), motivating a scenario in which their emission is powered by shocks interacting with dense surrounding material. We investigate whether such interactions can power LRDs and […]


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PIFFLE: Characterizing the Foreground Contributions from 4 Decades in Halo Mass to the FRB20230907D Dispersion Measure

Posted by klaurent Tokyo

Kavli Affiliate: John Silverman | Summary:We characterize the foreground environment of FRB20230907D, localized to a galaxy at $z=0.464$, which has an observed dispersion measure of $rm DM_rm obs=1031~rm pc~cm^-3$. At its redshift, FRB20230907D lies above the Macquart relation, the expected relation between cosmological dispersion measure and the source redshift, indicating a substantial excess DM along […]


Continue.. PIFFLE: Characterizing the Foreground Contributions from 4 Decades in Halo Mass to the FRB20230907D Dispersion Measure

Resolved Dust in $zapprox1$ Galaxies with JWST/MIRI MRS: Survey Description and First View on PAHs, Mid-IR Atomic Emission, and Warm H$_2$

Posted by klaurent Tokyo

Kavli Affiliate: John Silverman | Summary:Dust is a key component of galaxies that regulates their thermal balance and, consequently, star formation and the build-up of stellar mass. Polycyclic aromatic hydrocarbons (PAHs) are responsible for reprocessing radiative energy of the galaxies thus tracing dust evolution. Using JWST/MIRI MRS, we present the first resolved view of the […]


Continue.. Resolved Dust in $zapprox1$ Galaxies with JWST/MIRI MRS: Survey Description and First View on PAHs, Mid-IR Atomic Emission, and Warm H$_2$

Resolved Dust in $zapprox1$ Galaxies with JWST/MIRI MRS: Survey Description and First View on PAHs, Mid-IR Atomic Emission, and Warm H$_2$

Posted by klaurent Tokyo

Kavli Affiliate: John Silverman | Summary:Dust is a key component of galaxies that regulates their thermal balance and, consequently, star formation and the build-up of stellar mass. Polycyclic aromatic hydrocarbons (PAHs) are responsible for reprocessing radiative energy of the galaxies thus tracing dust evolution. Using JWST/MIRI MRS, we present the first resolved view of the […]


Continue.. Resolved Dust in $zapprox1$ Galaxies with JWST/MIRI MRS: Survey Description and First View on PAHs, Mid-IR Atomic Emission, and Warm H$_2$

The Atacama Cosmology Telescope: Constraints on the anisotropic screening and birefringence effects with DR6

Posted by klaurent Tokyo

Kavli Affiliate: Toshiya Namikawa | Summary:While we have learned much from recent surveys of the mm-wave sky, many secondary anisotropies of the CMB remain under-explored. We consider two of these here: the anisotropic screening induced by Thomson scattering of CMB photons off free electrons, and cosmic birefringence, the rotation of CMB polarization due to parity-violating […]


Continue.. The Atacama Cosmology Telescope: Constraints on the anisotropic screening and birefringence effects with DR6