NPP2 Flashcards
fourier transform is constant at ___ energy no matter the shape of the distribution
low
4 momentum squared is ___
invariant
projection of spin onto direction of motion
helicity
we can conserve helicity and components of momentum by flipping ___
spin
passing a sequence (___) of particles between 1 and 2, exchange causes a force (exchange of ___) between 1 and 2
field/momentum
for a short amount of time we can ___ from nature and create a particle
borrow energy
each ___ contributes to the probability of scattering via its ___
vertex/charge
a ___ contributes to the probability of scattering via exchange of ___
propagator/momentum
particles containing 3 quarks
baryons
particles containing 2 quarks
mesons
strong interaction is independent of ___
quark flavour
pulling quarks apart is equivalent to
adding energy to the system (can create more gluons)
valence quarks determine
quantum number of nucleons
sea quarks are ___. Effective quantum numbers average out to ___
virtual quark-antiquark pairs/zero
c,b,t are ___ so they play a minor role
very heavy
charge q is proportional to
fine structure constant alpha (coupling constant)
total probability of scattering is proportional to
vertices x propagators
strength of gluon/quark interactions is proportional to
strong force constant
gluons carry together
one colour and one anti-colour
photons interact only with
charge
gluons interact only with
colour (quarks and gluons)
weak interacts with almost
almost everything
higgs interacts with
mass
lepton number for each family is ___ conserved
individually