Quarks and antiquarks

The following equation represents a strong interaction between particle X and a proton.

What is the quark configuration of X ?

State the names of the four fundamental interactions.

State the products of the decay of a free neutron.

Explain which of the fundamental interactions is responsible for the decay of the neutron.

The forces between two moving electrons cause their paths to change.

Explain, using the concept of exchange particles, why the electron paths change.

The neutral lambda particle Λ⁰ is a baryon with a strangeness of −1

One possible decay for a Λ⁰ is

Deduce the quark structure of a Λ⁰.

State and explain which interaction is involved in this decay.

An antiparticle of the neutral lambda particle decays into a neutral pion and particle X

Identify X.

The rest energy of a Λ⁰ is equal to the energy of a photon with a frequency

Determine, in MeV, the rest energy of a Λ⁰.

The discovery of particles such as the Λ⁰ is made by large international research teams.

Suggest one reason for this.

Which combination of quarks is possible?

The quark combination of a particle is .

Which is true for this particle?

Determine whether the following reaction is a possible decay for the neutral pion π⁰.

State the two possible quark configurations of a π⁰.

^{0 0} A student suggests that the kaon K and the anti-kaon K are the same particle.

Discuss whether this suggestion is correct.

The nucleus is held together by a force. It was predicted that a particle exists that is responsible for this force. The particle itself must experience this force.

The particle would have a rest energy between that of an electron and half that of a nucleon.

Discuss whether a kaon, a muon and a pion each have the properties of the predicted particle.

Information about these three particles is in the Data and Formulae Booklet.

The ⁰ baryon, composed of the quark combination uds, is produced through the strong interaction between a ⁺ meson and a neutron.

What is the quark composition of X ?