Neutrinos
With no electric charge and interacting primarily by the feeble “weak” force, neutrinos are will-o’-the-wisps that can pass through Earth as easily as a bullet through a bank of fog. ~ Frank Close
A neutrino is electrically neutral, with scant mass. The Standard Model predicted that neutrinos had no mass. Having been proven wrong, the Model was revised.
Neutrinos interacts gravitationally with other particles and can travel close to the speed of light through ordinary matter with almost no effect. While neutrinos are nearly massless and faster than lightning, they pack tremendous mystery.
There is a surfeit of neutrinos. On Earth every second, through every square centimeter, there are 65 billion solar neutrinos flashing by. Most of the neutrinos passing through the Earth come from the Sun.
Wolfgang Pauli theorized neutrinos in 1930 to explain an observed gap in radioactive decay, specifically beta decay, which is mediated by weak interactions. To hold to the law of energy conservation, the matter-energy equation must balance between what existed before the decay and after.
Pauli proposed the missing bit being carried off by a hypothetical neutrino. The neutrino was so minuscule and fleeting that Pauli wagered a case of champagne that the little bugger would never be spotted. He lost the bet in 1956.
According to the Standard Model, as neutrinos have mass, there must be 2 varieties, defined by spin. Only the left-handed variety experience beta decay. The right-handed ones may be the Majorana fermion.
Neutrinos come in at least 3 flavors: electron, muon, and tau; all of which can oscillate between flavors spontaneously. That neutrinos can morph into different flavors indicates that they experience change, and thus are subject to time.
Neutrino oscillations in a vacuum are different from those that interact with matter. This matter effect occurs because electron neutrinos interact with electrons, which changes the effective mass of the neutrinos.
More than electrons are affected. Neutrinos colliding into an atomic nucleus ricochet away, leaving the nucleus recoiling in response.
Neutrino interactions are born in the shade of high-energy nuclear decay, such as reactions that occur in stars, in nuclear reactors, or when cosmic rays slam into atoms. As they are born of decay, neutrinos are mediated (affected) by the weak force.
According to the Standard Model, all fermions have an antithetical twin. By this reckoning, there are equivalent anti-neutrinos. None have been spotted.
Data suggests the existence of additional flavors of neutrinos. Neutrino flavors were determined from measurements of the width of the Z0 boson, which mediates the weak force. Z0 is filled out, so any additional neutrinos that exist would have to be sterile neutrinos: not interacting with the weak force, thereby not affecting the width of Z0.
A non-participant in any 4d particle interactions, sterile neutrinos arise only from non-sterile flavors oscillating into sterile form. 2 sterile neutrino flavors are predicted. There is skepticism about the existence of sterile neutrinos.
You’re trying to prove the existence of something with no interactions. It’s like trying to prove the existence of God.
~ American particle physicist Patrick Huber
Indirect evidence of sterile neutrinos has been found by observing supernovae, and from a nearby dwarf galaxy, as well as in lab experiments.
The sterile neutrino is not something bizarre or exotic. ~ American particle physicist Paul Langacker
Theoretically, sterile neutrino flavors would help explain why the cosmos is dominated by matter rather than a balance of matter and antimatter. Such insignificant particles, hardly interacting with any matter whatsoever, could go a long way in explaining the most fundamental nature of the universe, at least mathematically from a quantum view.
