University of Birmingham Master class,23rd April 2008 Ravjeet Kour Journey into the heart of matter Introducing Particle Physics

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Topics  Fundamental particle Leptons & quarks Properties  Antiparticles  Forces in nature  Carrier of the forces Properties

University of Birmingham Master class,23rd April 2008 Ravjeet Kour So what is particle physics?  Everything in the universe is made of Particle of matter: called fundamental Particles  Particle Physics : Study these Particle  Work out how they interact to make the Universe look and behave the way it does Fundamental elements

University of Birmingham Master class,23rd April 2008 Ravjeet Kour What is fundamental

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Standard model 6 quarks, 6 leptons Every particle is associated with the antiparticle

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Anti particles

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour  Quarks have fractional charge  Each quark has its anti particle  Carry another type of charge: colour charge (P = uud = 2/3+2/3-1/3=1)

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour colour charge o Quarks & gluons are colour charge particles oTwo close quark exchange gluons colour force field 3 colour charges

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Properties  Each quark has one of the colour  Red + blue +green = colour neutral (baryon)  Gluon (emission + absorption) changes colour  Colour is conserved

University of Birmingham Master class,23rd April 2008 Ravjeet Kour What holds it Murray Gell-Mann (b. 1929) together

University of Birmingham Master class,23rd April 2008 Ravjeet Kour what hold it Together Four fundamental forces Electromagnetism Strong Weak Gravity

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Electromagnetism Force between the two charges unlike charge attract like charge repel Carrier particle are photons Photons has zero mass & travel with speed of light

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Strong forces  Attractive force between the nucleons  This force overcome the repulsive force within an nucleus  Hold the quarks together to form hadrons  Carrier particles are called Gluons (8 gluons)

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Weak forces  Causes massive quarks & leptons to decay into lighter ones  Force carriers are W+,W- & Z  Responsible for flavour change ( when quark or lepton changes type)

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Gravity Acts between all particles with mass Carrier are the Gravitons ??

University of Birmingham Master class,23rd April 2008 Ravjeet Kour conclusion

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Need for accelerators & detectors

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Any questions ?

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Leptons Six type which come in three pair without color Tau and muon heavier than electron Spin ½ particles

University of Birmingham Master class,23rd April 2008 Ravjeet Kour

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Gluons gluon animation (a). As the quark propagates through nuclear matter, it loses energy by emitting gluons (b) and creating pairs of quarks and anti-quarks (c). As the system begins to return to equilibrium, two-quark systems (pions) are formed

University of Birmingham Master class,23rd April 2008 Ravjeet Kour Gluons Carry colour / anticolour pair 8 gluons

University of Birmingham Master class,23rd April 2008 Ravjeet Kour