Question What is a Neutrino?

[Harry Costas]

The importance of Neutrinos is becoming one of the points researched by scientists.

[Submitted on 18 Jun 2025]

Shimmering Darkness: Mapping the Evolution of Supernova-Neutrino-Boosted Dark Matter within the Milky Way​

Yen-Hsun Lin, Meng-Ru Wu

Supernova-neutrino-boosted dark matter (SNν BDM) has emerged as a promising portal for probing sub-GeV dark matter. In this work, we investigate the behavior of BDM signatures originating from core-collapse supernovae (CCSNe) within the Milky Way (MW) over the past one hundred thousand years, examining both their temporal evolution and present-day spatial distributions. We show that while the MW BDM signature is approximately diffuse in the nonrelativistic regime, it exhibits significant temporal variation and spatial localization when the BDM is relativistic. Importantly, we compare these local MW signatures with the previously proposed diffuse SNν BDM (DBDM), which arises from the accumulated flux of all past SNe in the Universe [Y.-H. Lin and M.-R. Wu, Phys. Rev. Lett. 133, 111004 (2024)]. In the nonrelativistic limit, DBDM consistently dominates over the local diffuse MW BDM signature. Only when the MW BDM becomes ultrarelativistic and transitions into a transient, highly-localized signal, it can potentially surpass the DBDM background. This work thus reinforces the importance of DBDM for SNν BDM searches until the next galactic SN offers new opportunities.

 

[Harry Costas]

[Submitted on 18 Jun 2025]

Supernova-Boosted Dark Matter at Large-Volume Neutrino Detectors​

Badal Bhalla, Fazlollah Hajkarim, Doojin Kim, Kuver Sinha

Core-collapse supernovae, among the universe's most energetic events, offer a novel window into the dark sector by potentially producing a flux of boosted dark matter (BDM). We explore the potential to detect the BDM produced by supernovae with a focus on fermionic dark matter that interacts with the visible sector through a dark gauge boson. We consider the expected BDM flux at Earth, originating from both the diffuse background of all galactic supernovae and potentially strong signals from individual nearby events. Focusing on BDM-electron scattering, we project the sensitivity of major current and future large-volume neutrino detectors - DUNE, Hyper-Kamiokande, and JUNO - to this elusive signal. Our results indicate that these experiments can significantly constrain or discover BDM within compelling parameter spaces, with sensitivity notably enhanced during nearby supernova occurrences. We further emphasize the unique multi-messenger opportunity presented by a galactic supernova, where the characteristic time delay between the neutrino burst and the BDM signal arrival could provide powerful evidence and enable probes of dark matter properties.

 

[jhixon]

Neutrinos actually works like this; matter is held together by electrons and the proton contains 2 up charms and 1 down. Antimatter is held together by neutrinos and the antiproton contains 2 down charms and 1 up charm. Matter has electrons in the outer orbit, so when neutrinos come close they pass through matter because the "Law of Charges" says that a negative energy (electrons) and negative energy (neutrinos) repel each other thus neutrinos don't bond with any matter and pass right through. They are researching them because they do not understand how neutrinos work in our universe. Hope this helps..

 

[Harry Costas]

Hell jhixon
I agree

 

[Harry Costas]

[Submitted on 25 Jun 2025]

Analytic formulation of Leptogenesis with neutrino oscillation data employing the general parametrization for neutrino mass matrix​

Nobuchika Okada, Digesh Raut

The observed neutrino oscillations and baryon asymmetry, unexplained by the Standard Model (SM), can both be accounted for by extending the SM to include Majorana right-handed neutrinos (RHNs). Tiny neutrino masses naturally arise through the Type-I seesaw mechanism, which involves lepton number violation. Meanwhile, the baryon asymmetry can be generated via leptogenesis, where the out-of-equilibrium decay of RHNs produces a lepton asymmetry that is partially converted into a baryon asymmetry through sphaleron processes. The Dirac Yukawa couplings play the crucial role for both Type-I seesaw and leptogenesis. In this work, we derive an analytic expression for the CP asymmetry parameter in a general parametrization. Focusing on a hierarchical RHN mass spectrum, we evaluate the lowest mass of the lightest RHN that reproduce both neutrino oscillation data and the observed baryon asymmetry. We study the case with two and three generations of RHNs for both thermal and non-thermal leptogenesis scenarios. Besides the standard Type-I seesaw involving SM Higgs doublet, we also examine the Type-I seesaw with a new neutrinophillic Higgs doublet. In this case for non-thermal leptogenesis, the minimum value for the lightest RHN mass can be as low as sphaleron decoupling temperature.

 

[Harry Costas]

[Submitted on 25 Jun 2025]

Diagnosing electron-neutrino lepton number crossings in core-collapse supernovae: a comparison of methods​

Marie Cornelius (NBIA and DARK, Niels Bohr Institute), Irene Tamborra (NBIA and DARK, Niels Bohr Institute), Malte Heinlein (MPI Astrophysics, Garching and TUM, Garching), Hans-Thomas Janka (MPI Astrophysics, Garching)

Fast neutrino flavor conversion may impact the explosion mechanism and nucleosynthesis in core-collapse supernovae. A necessary condition for fast flavor conversion is the presence of crossings in the angular distribution of the electron-neutrino lepton number (ELN crossing). Because of the computational costs, flavor-dependent angular distributions are not computed by the vast majority of state-of-the-art hydrodynamical simulations; instead, angular distributions are reconstructed employing approximate methods in post-processing. In this work, we evaluate the performance of four methods adopted to diagnose the existence of ELN crossings. For selected post-bounce times, we extract the fluid and thermodynamic properties from spherically symmetric supernova simulations for an 18.6 M_\odot progenitor, testing cases with and without muons as well as with and without mixing-length treatment of proto-neutron star convection. We compare the occurrence of crossings in the angular distributions obtained by solving the Boltzmann equations with those in distributions reconstructed from angular moments of our Boltzmann solutions by using the maximum entropy and Minerbo schemes, and also with crossings identified via a polynomial weighting function applied to the angular moments. Our results show that the polynomial method and the Minerbo closure scheme have severe limitations. The maximum entropy approach captures most of the forward crossings, although it fails to reproduce or misidentifies crossings in a subset of our models. These findings highlight the need for robust modeling of the neutrino angular properties in order to assess the impact of flavor conversion on the supernova mechanism.

 

[jhixon]

Since neutrinos pass right through matter and violate the Pauli Exclusion Principle, this shows that they are not part of matter at all. They can't be weighed like matter, so because neutrinos have inverse function, the scale would need to be inverted or mounted upside down to accurately measure it. This is how you see new physics. Life is Beautiful...

 

[Harry Costas]

Neutrinos, Higginson, etc, are the finest particles and maybe confined by Partonic matter, which can be confined by Quark composites, which Neutron Matter can confine.

Neutrino matter core.
Chiral Supersymmetry Dipolar Electromagnetic vector fields create jets that may go for 100,000 Lt/Yrs

 

[Harry Costas]

Neutrinos' importance has been on the rise in recent years, as scientists seek to understand their properties and their role in Nucleosynthesis.

[Submitted on 18 Jun 2025]

Shimmering Darkness: Mapping the Evolution of Supernova-Neutrino-Boosted Dark Matter within the Milky Way​

Yen-Hsun Lin, Meng-Ru Wu

Supernova-neutrino-boosted dark matter (SN\nu BDM) has emerged as a promising portal for probing sub-GeV dark matter. In this work, we investigate the behavior of BDM signatures originating from core-collapse supernovae (CCSNe) within the Milky Way (MW) over the past one hundred thousand years, examining both their temporal evolution and present-day spatial distributions. We show that while the MW BDM signature is approximately diffuse in the nonrelativistic regime, it exhibits significant temporal variation and spatial localization when the BDM is relativistic. Importantly, we compare these local MW signatures with the previously proposed diffuse SN\nu BDM (DBDM), which arises from the accumulated flux of all past SNe in the Universe [Y.-H. Lin and M.-R. Wu, Phys. Rev. Lett. 133, 111004 (2024)]. In the nonrelativistic limit, DBDM consistently dominates over the local diffuse MW BDM signature. Only when the MW BDM becomes ultrarelativistic and transitions into a transient, highly-localized signal, it can potentially surpass the DBDM background. This work thus reinforces the importance of DBDM for SN\nu BDM searches until the next galactic SN offers new opportunities.

 

[Harry Costas]

[Submitted on 18 Jun 2025]

Supernova-Boosted Dark Matter at Large-Volume Neutrino Detectors​

Badal Bhalla, Fazlollah Hajkarim, Doojin Kim, Kuver Sinha

Core-collapse supernovae, among the universe's most energetic events, offer a novel window into the dark sector by potentially producing a flux of boosted dark matter (BDM). We explore the potential to detect the BDM produced by supernovae with a focus on fermionic dark matter that interacts with the visible sector through a dark gauge boson. We consider the expected BDM flux at Earth, originating from both the diffuse background of all galactic supernovae and potentially strong signals from individual nearby events. Focusing on BDM-electron scattering, we project the sensitivity of major current and future large-volume neutrino detectors - DUNE, Hyper-Kamiokande, and JUNO - to this elusive signal. Our results indicate that these experiments can significantly constrain or discover BDM within compelling parameter spaces, with sensitivity notably enhanced during nearby supernova occurrences. We further emphasize the unique multi-messenger opportunity presented by a galactic supernova, where the characteristic time delay between the neutrino burst and the BDM signal arrival could provide powerful evidence and enable probes of dark matter properties.

 

[Harry Costas]

Looks like the Space forum is closing