Scientists May Have Discovered a New Fundamental Particle: Sterile Neutrino (theregister.co.uk)

Artem Tashkinov writes: It needs more sigmas, but Fermilab boffins in America are carefully speculating that they may have seen evidence of a new fundamental particle: the sterile neutrino. The suggestion follows tests conducted by the MiniBooNE (Mini Booster Neutrino Experiment) instrument, located near Chicago. Its mission is to detect neutrino mass through their oscillations. In the Standard Model of physics, neutrinos, like all particles, are initially assumed to be massless, but some observations, like neutrino oscillation, suggest there's mass there. The experiment that possibly detected sterile neutrinos collected 15 years of data from its commissioning in 2002, and the results have only now reached pre-press outlet arXiv.

Over 15 years, MiniBooNE detected a few hundred more electron neutrinos than were predicted in Standard Model theory. The extra particles suggests there is a fourth, heavier flavor. The findings bring the MiniBooNE team tantalizingly close to a "result" -- it's a 4.8 sigma result, when "discovery" demands 5 sigma.

Comments

Re:Straight from wikipedia

[slack_justyb]

from where does its mass come

Well ask yourself this, where does the majority of mass of a proton come from? A proton is an imbalance in a sea of gluons of exactly two up quarks and one down quarks. That is 2 * 2.3 MeV/c**2 + 4.8 MeV/c**2 = 9.4 MeV/c**2 but the Proton is 938 and some change MeV/c**2, that's a roughly 930 MeV/c**2 difference. Where does the extra energy come from?

Potential energy, thermal energy, and so on all contribute to the mass of an object. Indeed, even particles that interact via the Higgs mechanism do so via a potential difference. The leading idea for potential energy difference in neutrinos is via the seesaw mechanism. but the point is that differences between any two things creates a potential and the energy of that potential contributes to mass and in the case of the proton, is pretty much the majority of the mass.

Re:Straight from wikipedia

[Baloroth]

Higgs interactions do not count, as the Higgs is not a fundamental force. The sterile neutrino is actually a solution to the problem of the neutrino mass: neutrinos are massless in the Standard Model, but not in reality, so we know there must be some mechanism to produce their observed mass. A coupling of the neutrino to its sterile counterpart (through the Higgs) could give it mass in the same way as all the other fermions, but that requires sterile neutrinos (or very very heavy non-sterile neutrinos), which are heavily dis-favored by theoreticians. The alternative, the Majorana mechanism, would make the neutrino and anti-neutrino the same particle and give them mass by coupling them together. This measurement, if true (it's possible there's unknown systematics) would probably prove the sterile neutrino theory correct, though it's possible there is another explanation. Neutrinos are tricky beasts.