The New Era of Multimessenger Astronomy
multimessenger.desy.de
multimessenger.desy.de
13 observatories and 5 satellites contributed to the discovery.
If you are interested in the topic and understand German, check out Episode RZ073 of Raumzeit Podcast, topic: IceCube Neutrino Observatory which covers this (no affilication).
> Neutrinos are the lightest and least interacting of all known particles. They easily fly through planets, stars and whole galaxies, completely unaffected. Because of this, neutrinos can reach us from extreme environments in the cosmos, inaccessible by other messengers.
Two slides later:
> It spies for flashes of light generated when a cosmic neutrino hits an atom of the ice, sparking a cascade of secondary particles that leave their trace in the detector.
So why do neutrinos interact with atoms of ice in detectors but pass through planets and galaxies?
Neutrinos are normally created by beta decay[0]. So when they are detected, are they going through "beta reabsorbtion"? Does the (anti-)neutrino hit an electron, form a W boson, then collide with a proton to form a neutron? Or is there another interaction that causes the light?
But the important point is that it's only via the weak interaction (meaning only via the W^\pm and Z^0 bosons).
On re-reading, it's like the neutrino "bumps" the positive charge out of the proton. Like the neutrino interacting with a down quark will convert them into an up quark and a positron.
Edit: Inverse beta decay, commonly abbreviated to IBD, is a nuclear reaction involving electron antineutrino scattering off a proton, creating a positron and a neutron.
... The IBD reaction can only be initiated when the antineutrino possesses at least 1.806 MeV of kinetic energy (called the threshold energy). This threshold energy is due to a difference in mass between the products ( positron and neutrino ) and the reactants ( antineutrino and proton ) and also slightly due to a relativistic mass effect on the antineutrino. Most of the antineutrino energy is distributed to the positron due to its small mass relative to the neutron.
https://en.wikipedia.org/wiki/Inverse_beta_decay
To state the obvious, since the Neutrino is massless, its energy can only come from momentum. Hence the distribution of the 1.806 MeV from the Wiki article above:
P+ to N: 1.293 MeV
Positron: 0.511 MeV
total: 1.804 MeV (rounding error?)The way this detector works is that is essentially a gigantic swimming pool of water and periodically there will be an interaction someplace in it which produces a tiny flash of light/radiation which we can then observe. If we could somehow 'see' through the earth or sun, we could observe these same interactions at a much larger scale.
Now we get one about a milestone for a particular experiment instead : /