Hadrons

    Particles that interact by the strong interaction are called hadrons. This general classification includes mesons and baryons but specifically excludes leptons, which do not interact by the strong force. The weak interaction acts on both hadrons and leptons.

     Hadrons are viewed as being composed of quarks, either as quark-antiquark pairs (mesons) or as three quarks (baryons). There is much more to the picture than this, however, because the constituent quarks are surrounded by a cloud of gluons, the exchange particles for the color force.  

 Definition provided by Hyperphysics

Baryons 

Neutrons 


Proton 

     Baryons are massive particles which are made up of three quarks in the standard model. This class of particles includes the proton and neutron  Other baryons are the lambda, sigma, xi, and omega particles. Baryons are distinct from mesons in that mesons are composed of only two quarks. Baryons and mesons are included in the overall class known as hadrons, the particles which interact by the strong force.  

Definition provided by Hyperphysics 

Mesons

Pion 

    Mesons are intermediate (tend to be short lived) mass particles which are made up of a quark-antiquark pair. Three quark combinations are called baryons.

Definition provided by Hyperphysics 

White and Anti-White  

      All hadrons are either white or anti-white, when "adding" all the quarks together.  Mesons, which is composed of a quark or and a anti-quark, are always anti-white.  In the picture of the pion the quark, and up quark, is blue; the anti-quark, an anti-down, is anti-blue (in the picture the anti-blue quark is yellow). 

     The baryons are allowed to be both white and anti-white because of it they are composed of three quarks.  The neutron in the picture above is made of up, down, down quarks, and with all three colors represented.  The anti-white neutrons, an anti-neutron, is composed of anti-up, anti-down, anti-down anti-quarks.  

Properties of Mesons and Baryons 

Color Confinement  

    Color confinement, often simply called confinement, is the phenomenon that color charged quarks cannot be isolated singularly, and therefore cannot be directly observed. Quarks, by default, clump together to form groups, or hadrons. The two types of hadrons are the mesons (one quark, one antiquark) and the baryons (three quarks). The constituent quarks in a group cannot be separated from their parent hadron, and this is why quarks can never be studied or observed in any more direct way than at a hadron level.

Definition provided by Wikipedia

Color Change 

   A quark can change its color if it undergoes a Nuclear Strong Interaction. The quark emits a gluon that changes  its color, the gluon is absorbed by a neighboring quark changes its color, and emits its own gluon. 

Strangeness

The New Conservation Law.

     The number of strange (and top, bottom and charmed) quarks in a particle must be conserved.  The conservation law is refereed to as strangeness because the strange quark is the third (and strangest at the time) quark discovered. 

     During the electromagnetic and nuclear strong interactions the number of these second and third generation quarks must be conserved. 

Nuclear Weak reactions and strangeness

    When a quark undergoes a Nuclear weak interaction the type of quarks in a particle changes therefor violating the strangeness of the particle. 

 Baryon Octet

      S is the "strangeness" of the particle.  The strangeness of the particle is away of determine the "stability" of the particle.  S = 0 are the most stable particles (even the anti-particle)

             S = 0 has no strange quarks.proton

             S = -2 has two strange quarks

     Q is the charge of the particle 

 Q = -1  negative one fundametal charge

Q = +1 positive one fundametal charge 

    The fundametal charge is 1.602 x 10^-19 C

Meson Octet 

  S is the "strangeness" of the particle.  The strangeness of the particle is away of determine the "stability" of the particle.  S = 0 are the most stable particles (even the anti-particle)

             S = 0 has no strange quarks.proton

             S = -2 has two strange quarks

     Q is the charge of the particle 

             Q = -1  negative one fundametal charge

             Q = +1 positive one fundametal charge 

    The fundametal charge is 1.602 x 10^-19 C