1.5 Particle Interactions Flashcards
what happens when a single force acts on an object
it changes the momentum of the object
what is the momentum of the object of equal to
mass multiplied by velocity
what happens to the momentum when 2 objects interact
they exert equal and opposite forces on each other and momentum is transferred through these forces if no other forces act on them
Richard Feynmans detailed idea on wy protons repel each other
the electromagnetic force between 2 charged particles is due to the exchange of virtual photons
why are the photons described as virtual
we can’t detect them directly
if we intercepted them via a detector it would stop the force acting
what force can cause a neutron to change into a proton in b- decay and a proton to change into a neutron in b+ decay
weak nuclear force
why can’t it be the electromagnetic force changing them
because the neutron isn’t charged
why must the force doing this be weaker than the strong nuclear force
it would effect stable nuclei
neutrinos and antineutrinos hardly react with other particles but when might they
a neutrino can interact with a neutron and make it change into a proton. a b- particle is emitted as a result of the change
an antineutrino can interact with a proton and make it change into a neutron. a b+ particle is emitted as the result of this change
what’re the interactions between anti/neutrinos and other particles due to
W bosons that exchange the particles
facts about W bosons
have a non zero rest mass
very short range of no more than 0.001 fm
can be positively charged irnegatively charged
when and where were W bosons first detected
1983 by scientists using 2km diameter super proton synchrotron at the CERN in Geneva
how were the W bosons produced
protons and antiprotons at very high energies were made to collide and annihilate with each other and at sufficiently high energies produce W bosons as well as photons
what happens if no neutrino or antineutrino are present
the w- boson decays into a beta - particle and an antineutrino
a w+ decays into a beta + particle and an neutrino
what is electron capture
when a proton in a proton rich nucleus turns into an electron due to a weak interaction with an inner shell electron
what must happen for an electron capture to have a w- boson
an electron with sufficient energy
what are photons and W Bosons known as
force carriers as they are exchanged when the electromagnetic force and the weak nuclear force act representatively
what are the four fundamental interactions in nature
gravitational attraction between any 2 objects due to there mass
electromagnetic force which acts between objects due to there electric charge and explains all electric and magnetic effects
strong nuclear force which holds protons and neutrons together in stable nuclei
weak nuclear force causes b- decay
Facts about W boson
charged
non zero rest mass
exchanges particles via weak nuclear force
Facts about virtual photon
uncharged
zero rest mass
exchanges particles via electromagnetic force
