Physicists have observed evidence of a new subatomic particle. Further research will try to determine if it is the elusive Higgs boson, thought to be responsible for giving matter its property of mass.
In the Standard Model of physics, matter is made up of small particles called fermions (quarks and leptons). Forces such as electromagnetism are carried by bosons.
“Atom Smashers” Reveal Hints of Higgs
Physicists use electromagnetic fields to whip beam of protons around and around, accelerating them to nearly speed of light. This gives the protons enormous kinetic energy. Finally, the beams are allowed to intersect, and where protons collide, their energy is related. New particles – some of them very short-lived – are formed from this energy.
Higgs is Big (Mass is Equivalent to Energy)
As Albert Einstein discovered, mass can be defined as a quantity of energy. Subatomic particle masses are given as amounts of electron volts (the energy of a single electron accelerated by a potential difference of one volt). The newly discovered particle (possibly the Higgs boson) is found to have a mass of about 125 billion electron volts. Other particles, such as photons, have no mass at all.
Higgs is the Key to Why Matter has Mass
Imagine a party where guests are evenly spaced around the room. The room of guests represents the Higgs field, which is everywhere in the universe. Each guest represents Higgs boson. Suddenly a celebrity enters (the celebrity is a particle of ordinary matter).
Guests notice the celebrity and rush in closer to be near her. As the celebrity moves through the room, the clump of guests surrounding her gives the group additional momentum. The clump is harder to stop than one guest alone would be. The clump has acquired mass.
A different celebrity enters and passes quickly through without attracting any attention from the guests. This is a weakly interacting particle, and it has no mass (it has not gotten any from the Higgs field). It may be a photon or other massless particles.