SCI 270: On Nuclear Technology Practice Problems  
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6. High-Energy Particles

  1. Give six gauge bosons please.


    __8 gluon (strong)_
    h v or gamma


    colored g
    W plus (Weak)

    _Z (Weak)

    __W minus (Weak)



  2. What are the functions of guage bosons?

    __Gauge bosons are force carriers for the 4 different types of forces._

    __ Represented by wave lines in Feynmann diagrams. _________________________

  3. Give six mesons
    Pion zero_____

    Pion plus_____

    Pion minus____

    u u* or d d*

    u d*

    d u*
    u* or d* anti quarks
    2 gamma
    muons and
    muons and
    Name Kaon zero
    Kaon plus
    Kaon minus

    d s*

    u s*

    s u*

    Gamma rays
    muons, pions
    and neutrinos
    muons, pions
    and neutrinos

  4. Give five Baryons
    Name Neutron, n Proton, p Sigma plus
    Lumbda Cascade sigmas and charm





    uds,uus,(uus)*, udc

  5. What are the same between a particle and its antiparticle?

    ___ They have the same mass but opposite charge and magnetic momentum____

  6. Dirac combined the theory of relativity with quantum mechanics to get a theory, which predicted a new state for an electron or a particle in general. In this new state, how does the total energy of the particle change as its speed increases?

    __ The total energy becomse more negative ___

    What does this diagram represent in terms of filling of energy states for particles and antiparticles?

    __The positive energy states are all empty but all the negative energy states are occupied ___

  8.   -  
    What does this diagram represent in terms of filling of energy states for particles and antiparticles?

    ___ One of the positive energy state is occupied and one of the negative energy state is empty. This represent a particle-antiparticl pair. ____

  9. The rest mass of an electron is 0.51 MeV.

    What happens to a positron and an electron when they come together?

    __The combine into a positronium for a very short moment and then annihilate themselves. Their mass and energy are converted into two photons, each with a minimum energy of 0.51 MeV __

  10. What did C.D. Anderson observe in 1932 in his cloud chamber that led him to the discovery of positrons?

    __ He observed tracks very similar to those of electron, but these tracks curve opposite compared to those of the electrons in the presence of a magnetic field. ___

  11. The rest mass of an electron is 0.51 MeV
    Gamma photons with what energy is most likely to cause a pair production?

    __ Gamma-ray energies must be 1.02 MeV or greater. However, the probability increases as the photon energy increases. Photons with energy greater than 5 MeV loose their energy most likely by pair production than by Compton scattering or by photo electric effect. __

  12. What are force carriers between charged particles?

    __ Force carriers between charges are photons: radio wave, short radio wave, microwave, IR, light, UV, X-ray, gamma rays etc. ___

  13. What are the four forces and what is the order according to their strengths?

    __ The relative strength of strong, electromagnetic, weak, and gravity forces are 1, 0.0073, 1e-10 and 1e-39 respectively. __

  14. What does this Fynman diagram represent?

    __ This diagram represent two electrons exchanging a photon. Since the states of the electrons change, this represent an inelastic scattering of electrons. __

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