Particle Physics

What is a general description of a baryon?

Options

A   It consists of three quarks that must all be the same flavour.
B   It consists of three quarks that do not need to be the same flavour.
C   It consists of two quarks that must both be the same flavour.
D   It consists of two quarks that do not need to be the same flavour.

A stationary nucleus has nucleon number $A$.
The nucleus decays by emitting a proton with speed $v$ to form a new nucleus with speed $u$. The new nucleus and the proton move away from one another in opposite directions.
Which equation gives $v$ in terms of $A$ and $u$?

Options

A   $v = \left(\frac{A}{4} - 1\right)u$
B   $v = (A - 1)u$
C   $v = Au$
D   $v = (A + 1)u$

What is the change to the quark composition of a nucleus that takes place during $\beta^{+}$ decay?

Options

A   down to antiup
B   down to up
C   up to antidown
D   up to down

What is the charge, in terms of the elementary charge $e$, on a charm quark?

Options

A   $-\frac{2}{3}e$
B   $-\frac{1}{3}e$
C   $+\frac{1}{3}e$
D   $+\frac{2}{3}e$

Which list contains only fundamental particles?

Options

A   antineutrinos, baryons, neutrons, electrons
B   mesons, electrons, neutrinos, protons
C   positrons, quarks, hadrons, protons
D   quarks, positrons, neutrinos, leptons

Which statement explains why alpha-particles have discrete energies, but beta-particles have a continuous range of energies?

Options

A   Beta-particles have a much smaller mass than alpha-particles which means beta-particles can be emitted with a larger range of velocities.
B   Only alpha-particles experience repulsion from the nucleus which is dependent on the number of protons in the nucleus.
C   Only beta-particles are emitted with another lepton and some energy is transferred to the other lepton.
D   Only the energy of alpha-particles is discrete because the composition of alpha-particles is always the same.

A hadron consists of antiquarks that are all identical.

What is a possible value, in terms of the elementary charge $e$, for the charge on the hadron?

Options

A   $0e$
B   $+1e$
C   $+2e$
D   $+3e$

Two neutral atoms are isotopes of the same element.

Which statement about the atoms is correct?

Options

A   They have a different number of neutrons and a different number of electrons.
B   They have a different number of neutrons and the same number of protons.
C   They have the same number of neutrons and a different number of electrons.
D   They have the same number of neutrons and the same number of protons.

What is the composition of a meson?

Options

A   $1$ quark and $1$ antiquark
B   $1$ quark and $2$ antiquarks
C   $2$ quarks and $1$ antiquark
D   $3$ quarks

A nucleus of carbon-11 contains $6$ protons and $5$ neutrons.

The nucleus of carbon-11 decays by $\beta^+$ emission.

What is the total number of up and down quarks in the product of the decay of this nucleus?

Options