Nuclear Physics Flashcards
What is the strong force?
Holds the nucleus together, so particles are at specific distances from one another.
When is the strong force attractive?
Between 0.5-3fm, to overcome electrostatic repulsion between protons
When is the strong force repulsive?
Below 0.5fm
What is spin?
property of a particle related to its intrinsic angular momentum
What is a lepton?
fundamental particle that doesn’t experience the nuclear strong force
What are hadrons?
particles that experience nuclear strong force and decay by weak nuclear force
What happens when a particle finds its antiparticle?
They undergo annihilation, destroying each other and emitting two equal photons as energy
What is charge on an up quark?
+2/3
What is the Baryon number on a quark
1/3
What’s the strangeness of a strange quark?
-1
What is the charge on a down quark?
-1/3
What is the quark composition of a proton
pud-u-like, uud
What is the quark composition of a neutron?
dunderhead, ddu
What field does a photon mediate?
Electromagnetic field
What field does the gluon mediate?
Nuclear strong force
What field does the W+ boson mediate and what charge?
Weak nuclear field, +1
What field does the W- boson mediate and what charge?
Weak nuclear field, -1
What field does the Z boson mediate and what charge?
Weak nuclear field, 0
What is the spin on a lepton?
±1/2
What is the spin on a quark?
±1/2
What is the spin on a boson?
integer
What is the spin on a meson?
0
What is the charge on a neutrino?
0
What is pair production?
When energy is converted into mass, and new particles are made, each particle has its corresponding antiparticle
What is quark confinement?
You can never have a free quark - they always come in pairs or triplets or quintets
What happens in beta-minus decay?
Neutron changes into a proton, d quark into u quark, electron and antineutrino emitted
What happens in beta-plus decay?
Proton changes into a neutron, u quark changes to d quark, positron and neutrino emitted
What is spin on an up quark?
±1/2
What is the typical half life of a free neutron?
15 minutes
How to find size of nucleus in experiment?
alpha particle scattering, use coulomb’s law, in a vacuum
How to deduce whether reaction can take place?
If it can, then mass reactants > mass of products
