Pages

News: Currently the LaTeX and hidden solutions on this blog do not work on Google Reader.
Email me if you have suggestions on how to improve this blog!

Sunday 21 August 2011

Physics GRE - #20

According to the Standard Model of elementary particles, which of the following is not a composite object?

  • Muon
  • Pi-meson
  • Neutron
  • Deuteron
  • Alpha particle

Solution :

The answer is muon. A muon is an elementary particle (a lepton).

Pi - mesons are a quark with an antiquark.
A neutron is made of two down quarks and an up quark.
A deuteron is a proton and a neutron (a proton is two up quarks and a down quark).
An alpha particle is two protons and two neutrons.

0 comments:

Post a Comment

This webpage is LaTeX enabled. To type in-line formulae, type your stuff between two '$'. To type centred formulae, type '\[' at the beginning of your formula and '\]' at the end.