Here are the answers to your questions about neutrinos.
1. Are neutrinos part of the Standard Model?
Yes, but it's complicated.
Neutrinos (in their three "flavors": electron, muon, and tau) are fundamental particles included in the Standard Model of particle physics.
However, the Standard Model has a major flaw: it originally predicted that neutrinos are massless. For decades, this was the accepted theory.
We now have definitive experimental evidence (from "neutrino oscillation") that neutrinos do have mass. This discovery means the original Standard Model is incomplete. While neutrinos are listed in the model, their mass is the first major piece of experimental physics that points to a "Beyond the Standard Model" framework.
2. Are neutrinos part of the Higgs field?
No. In the Standard Model, neutrinos do not interact with the Higgs field.
This is directly related to the mass problem:
* How particles get mass: In the Standard Model, particles like electrons and quarks get their mass by interacting with the Higgs field.
* The Neutrino Problem: For a particle to interact with the Higgs field, it must have both a "left-handed" and a "right-handed" version.
* The Missing Particle: Scientists have only ever observed left-handed neutrinos. The Standard Model does not include a right-handed neutrino.
Because neutrinos (in the model) lack a right-handed partner, they cannot interact with the Higgs field to gain mass. This is why the Standard Model incorrectly predicted they were massless.
Since we know neutrinos do have mass, how they get it is one of the biggest unsolved mysteries in physics today. It almost certainly requires a new mechanism that is not part of the Standard Model.