Higgs decays into bosons and fermions

“We now know that the Higgs particle can decay into both bosons and fermions, which means we can exclude certain theories predicting that the Higgs particle does not couple to fermions.” As a group of elementary particles, fermions form the matter while bosons act as force carriers between fermions.

Atomic mass: 98% from gluons

When particles pass through this field, their interactions with it imbue them with mass. The Higgs mechanism is often said to account for the origin of mass in the visible universe. This statement, however, is incorrect. The mass of quarks accounts for only 2 percent of the mass of the proton and the neutron, respectively. The other 98 percent, we think, arises largely from the actions of gluons. But how gluons help to generate proton and neutron mass is not evident, because they are themselves massless.

Higgs gives mass to W and Z bosons and to fermions

The Higgs has a “Mexican hat” shaped potential with nonzero strength everywhere (including otherwise empty space), which in its vacuum state breaks the weak isospin symmetry of the electroweak interaction. When this happens, three components of the Higgs field are “absorbed” by the SU(2) and U(1) gauge bosons (the “Higgs mechanism”) to become the longitudinal components of the now-massive W and Z bosons of the weak force. The remaining electrically neutral component separately couples to other particles known as fermions (via Yukawa couplings), causing these to acquire mass as well. Some versions of the theory predict more than one kind of Higgs fields and bosons.

Matter is merely vacuum fluctuations

The apparently substantial stuff is actually no more than fluctuations in the quantum vacuum.

Each proton (or neutron) is made of three quarks, but the individual masses of these quarks only add up to about 1% of the proton’s mass.

The rest of it—99% of material mass—is created by the force that binds quarks together, called the strong nuclear force. In quantum terms, the strong force is carried by a field of virtual particles called gluons, randomly popping into existence and disappearing again. The energy of these vacuum fluctuations has to be included in the total mass of the proton and neutron.