Elementary particles and their properties

what are elementary particle made of and basic forces of nature

1. Elementary Particles A nd T heir P roperties M.Zeeshan Khalid 09050610-039

2. Elementary particles Introduction The most fundamental constituents of our universe are the elementary, or fundamental particles. They are the "building blocks" that make up everything in the universe. Though their most basic nature is still being debated, most of these particles have well-documented, experimentally verified properties. Listed here are the most important of those properties. However, many aspects of cosmology are still being developed, and additional elementary particles of higher mass may be discovered in the near future with the next generation of particle accelerators.

3. The Structure of Matter The Structure of Matter The elementary particles known today are divided into three families. All "everyday" matter is made up of atoms, once thought to be the smallest division of matter. atoms have a substructure in their own right - they are made of a negatively charged electron cloud surrounding a positively-charged nucleus. The nucleus in turn can be divided still further into positively charged protons and neutral neutrons. A proton is made of two up-quarks and a down-quark, and a neutron is made of two down-quarks and an up-quark.

4. Cont… e. Protons are made of two up-quarks of electric charge 2/3 each, and one down-quark of electric charge -1/3; these charges add together to produce an overall charge of 1. Neutrons consist of two down-quarks of -1/3 each and one up-quark of 2/3; these cancel out to an overall charge of 0. Thus, the atom itself is neutral.

5. The Family Tables The following tables summarize most of the properties of the various particles belonging to the three families of subatomic particles. The properties listed here, along with the name of the particle, are: mass, electric charge, strong charge, weak charge. The strong charges of quarks have been creatively designated red, green, and blue by physicists; they do not, however, actually have color - they are too small for light waves to bounce off. A particle's mass determines how it responds to gravity, the electric charge determines its response to electromagnetism, its strong charge determines its response to the strong force, and its weak charge determines its response to the strong force.

6. Family 1 Particle Mass Electric Charge Strong Charge Weak Charge Electron .0054 -1 -1/2 Electron-Neutrino <10 -8 1/2 Up Quark .0047 2/3 red, green, blue 1/2 Down Quark .0074 -1/3 red, green, blue -1/2

7. Family 2 Particle Mass Electric Charge Strong Charge Weak Charge Muon .11 -1 -1/2 Muon -Neutrino <.0003 1/2 Charm Quark 1.6 2/3 red, green, blue 1/2 Strange Quark .16 -1/3 red, green, blue -1/2

8. Family 3 Particle Mass Electric Charge Strong Charge Weak Charge Tau 1.9 -1 -1/2 Tau-Neutrino <.033 1/2 Top Quark 189 2/3 red, green, blue 1/2 Bottom Quark 5.2 -1/3 red, green, blue - 1/2

9. Fundamental Forces: There are four fundamental forces in the Universe: gravitation (between particles with mass) electromagnetic (between particles with charge/magnetism) strong nuclear force (between quarks) weak nuclear force (operates between neutrinos and electrons)