The Structure of Matter (DP IB Physics: HL)

The decay of a  baryon is given by the equation

Which row, A to D in the table, correctly identifies the charge, baryon number and lepton number of particle X?

Which row in the table gives the correct quark combination for the particle?

	particle	category	quark combination
A.	proton	baryon
B.	positive pion	meson
C.	neutron	meson
D.	negative pion	meson

This Feynman diagram shows particles interacting via a W^– boson.

Which of the following particle choices are correct?

The decay of a neutral kaon  is given by the equation

What must particles X and Y be?

A pion can decay to produce two leptons.

Which of the following reactions is possible?

This Feynman diagram shows particles interacting leading to the production of a β⁺ particle.

Which of the following particle choices are correct?

Which row in the table, A to D, includes a valid particle for every column?

The following Feynman diagram shows the baryons and leptons in a nuclear decay.

Which of the four Feynman diagrams, A to D, is physically equivalent to the diagram given for this decay?

In the Geiger–Marsden experiment, alpha particles are used to investigate scattering by gold atoms.

What do the results of the experiment provide evidence for?

Which of the following statements correctly describes why quarks were first hypothesised?

The diagram is an example of a ‘baryon decuplet’. Baryons are organised along horizontal and diagonal axes, as shown in the diagram below.

What is the quark structure of the  bayron?

A collision between particles creates 4 mesons:

The overall charge and strangeness of the 4 mesons is zero.

What are possible quark combinations for X and Y?

	X	Y
A
B
C
D

The baryon has strangeness of −1 and is produced through the strong interaction between a meson and a neutron.

What is the quark composition of particle X?

Particles can be organised in a plot known as the ‘eightfold way’, as shown in the diagram below. 

What are the quark compositions of Σ⁺, Σ^–, Ξ⁰ and Ξ^–?

	Σ+	Σ–	Ξ0	Ξ–
A
B
C
D

The K^– is an example of a meson with strangeness –1.

Which of the following combinations of particles could the K^– particle decay to?

Which of the four hadrons shown could be Ξ⁰?

None of the following decay equations for baryons are permitted. 

Equation 1: 

Equation 2: 

Equation 3: 

Equation 4:

Which property is not conserved in each equation?

The charmed sigma particle,  decays through the following equation:

Both  and  contain one charm quark and have strangeness of 0.

Which of the following could be the quark structure of the  and the ?

A
B
C
D

The following Feynman diagram shows the baryons and leptons in a nuclear decay

Which of the four Feynman diagrams, A to D, is physically equivalent to the diagram given for this decay?

The Higgs Boson was discovered at CERN in 2012. It is not stable and decays into other particles.

Which of the following could not be a possible decay pathway for the Higgs Boson?