# Particle Physics Workshop: The World of Particles and their

```Particle Physics Workshop: The World of Particles and their Interactions
This document gives detailed guidelines for teachers on the tasks described in the
accompanying power point presentation of the Particle Physics Workshop.
Resources
One pack of 30 trump cards per group of 5 students maximum (from document “trump
cards”). Each pack contains:
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6 quarks,
6 anti-quarks
6 leptons
6 anti-leptons
6 bosons
How to play [1]
The aim of the game is to collect as many families (groups of 6 cards that belong to the
same family) as possible.
1. Deal out all the cards so that every player gets an almost equal number of cards; this will
depend on the number of players.
2. The dealer starts by asking another player for a card needed to complete a family.
3. If the other player has the card, they must give it to this player.
4. The player may continue asking for cards until they make a mistake.
5. When a mistake is made the player who was asked for their card takes their turn to
request cards.
6. During the game, players can request and retake the cards taken from them in previous
rounds.
7. When a player gathers a family they must put the 6 cards face down on the table in front
of them.
8. The player who collects the most families is the winner.
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
Resources
To make the standard model that includes matter and antimatter:
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30 Plastic coloured balls
o 12 must have the same colour for quarks and anti-quarks
o 12 must have another colour for leptons and anti-leptons
o 6 must have a third colour for bosons
 http://www.theworks.co.uk/p/outdoor-toys/mega-box-ofballs/5021813115458
 http://www.argos.co.uk/static/Product/partNumber/3665514.htm
Coloured pencils for designing the particle before making it (must include the same
variety of colours as the plastic balls available)
Black thin permanent markers (for writing on the particles)
A box of various decorations
o http://www.theworks.co.uk/p/embellishments/bumper-craftpack/5052089001978)
2kg of plasticine
o http://www.easycomposites.co.uk/products/newplast-plasticine-modellingclay.aspx
Scales to measure 5 grams
Sellotape (to close the particle once it is stuffed)
double-sided sellotape (to stick the features on the particle)
Scissors and art knife for cutting the balls open
Black and white card to be used for a feature that distinguishes matter (white) from
antimatter (black)
Top trump cards (30 in total) for designing the particles
Worksheet “The world of particles with mass” for reference
Designing the particles
The whole class must decide what colour balls they will assign for each particle family i.e.
quarks and anti-quarks one colour, leptons and anti-leptons another and finally bosons a
third colour. Each student will make one particle from a total of 30 particles.
1. Teacher distributes trump cards, one per student.
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
2. Students look at the box of decorations to give them an idea of what is available.
3. They read the particle information on the trump card in order to get inspiration for their
design.
4. They decide what they want their particle to look like.
(a) For example: what will a strange particle look like?
(b) What will a charm particle look like?
5. Students working on a particle-antiparticle pair must sit near each other because they
will be making these decisions together, since their particles will be identical with the
exception of one feature (e.g. hat, cape, base stand) which will be made in white card
for the particle and in black card for the antiparticle.
6. Students draw the particle features they chose on the trump card.
Giving mass to the particles
Students take one of the plastic balls (the right colour) and read the information about the
mass of the particle they are making, from the worksheet “The world of particles with
mass”. They will add mass to their particle by filling the ball with plasticine following the
rules below:
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If the particle is “very light” they do not put any plasticine in it;
If the particle is “light”, they cut-open the ball along its waist and put 5 grams of
plasticine inside it. Then they close the ball and stick it with sellotape;
If the particle is “heavy”, they cut-open the ball along its waist and half-fill it with
plasticine (about 100g). Then they close the ball and stick it with sellotape;
If the particle is “very heavy”, they cut-open the ball along its waist and fill it up
entirely with plasticine (about 200g). Then they close the ball and stick it with
sellotape.
1. Students look at the particle trump card and the design they chose.
2. They then take the features they have chosen from the box of decorations and use
double-sided sellotape to stick these features on the ball-particle.
3. They add the final matter-antimatter feature in white or black card, which will
distinguish the particle from its antiparticle.
4. Finally they write the name of the particle at its back (as seen below).
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
Resources
One pack of 36 trump cards per group of 5 students maximum (from document “trump
cards”). Each pack contains:
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6 quarks
6 anti-quarks
6 leptons
6 anti-leptons
6 bosons
6 bosons
How to play [2]
The rules of likes are listed in the trump cards. This game can be run for a limited amount of
time; the winner is the person with the largest number of cards.
1. Anyone may deal.
2. The cards are shuffled and dealt out to the players as equally as possible. Players do not
look at their cards but keep them in a face down stack in front of them.
3. The player to dealer's left begins and the turn to play passes clockwise.
4. At your turn you simply turn the top card of your face-down pile and place it face-up
alongside. In this way each player forms a pile of face-up cards beside their face-down
pile.
5. If at any moment two of the face-up piles have particles that like each other at the top
(for example electron and Z), anyone who notices this shouts "snap!".
6. The first person who shouted "snap!" takes both matching face-up piles and adds them
face-down to the bottom of their face-down pile.
7. The game then continues as before, beginning with the player to the left of the last one
who turned a card.
8. If you have no face-down cards left when it comes to your turn, you simply turn over
your face-up pile to make a new face-down pile and turn over the top card as before.
9. If you have no cards left at all, you are out of the game.
10. The last player in is the winner.
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
11. When turning up cards, you are not allowed to peek at your card before the other
players can see it. To ensure this, cards should be turned over facing away from the
player, so that if it is turned too slowly the turning player will see it last.
12. If a player shouts "snap" in error when there is no match, that player's face-up pile is
taken away and put in the centre of the table, where it becomes a snap pool. If this
happens several times there can be several snap pools.
13. If the top card-particle of any player's pile likes the top card-particle of one of the snap
pools, the first player who calls "snap pool" takes both piles.
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
Theoretical background for the teacher
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When particles meet they interact with each other. During this interaction many events
can happen:
o pairs of matter-antimatter particles can disappear and turn into pure energy
(annihilation);
o pure energy can turn into pairs of matter-antimatter particles (creation);
o pairs of particles can disappear and turn into other particles;
o a particle can disappear and turn into a pair of other particles.
Interactions follow the rules of likes and dislikes:
o Quarks and anti-quarks like gluons and photons
o Leptons and anti-leptons like photons, W and Z
o Gluons like quarks and anti-quarks
o Higgs likes everybody apart from photons, gluons and neutrinos
o W and Z like quarks, anti-quarks, leptons, anti-leptons and Higgs
o Photons like quarks, anti-quarks, leptons, anti-leptons and W
For example:
o a gluon will turn into a pair of particles that it likes, such as quark and anti-quark;
o a gluon will never turn into a pair of particles that it dislikes, such as lepton and antilepton;
o a pair of leptons will turn into a particle that they like, e.g. a Z boson;
o a pair of leptons will never turn into a particle that they dislike, e.g. a gluon.
We can show every interaction using a diagram, called a Feynman diagram which was
introduced by the physicist Richard Feynman. Every Feynman diagram tells a story; you
read the diagram starting from the left and following the lines towards the right. For
example, the diagram below shows that an up quark and an anti-up quark annihilated
and produced a gluon. The gluon then turned into a charm quark and an anti-charm
quark.
up quark
charm quark
anti-charm quark
gluon
anti-up quark
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
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During particle interactions the total charge is conserved. This means that the
combined charge at the start is the same as the combined charge in the middle and
at the end. For example, the total charge of the up (+2/3) and anti-up quark (-2/3)
when added together is zero. The gluon charge is also zero. The total charge of the
charm (+2/3) and anti-charm quark (-2/3) when added together is also zero.
Feynman diagrams use lines of particular shape for specific particles as seen in the
table below:
particle
shape for drawing
pipe cleaner shape
quarks and leptons
photons
gluons
W+ or W- or Z
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
Resources
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Pipe cleaners of various colours (five needed for one diagram)
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A4 card for sticking the diagram on it, once it is made
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Sellotape for sticking the diagram on the A4 card
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Sticky white labels (to create the “broken line” effect on the W and Z particles)
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Black and white paper for creating labels for the diagram. Use the white paper for
particles of matter and the black paper for particles of anti-matter.
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Black and white coloured pencils, for writing on the black and white labels.
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A4 printed card with examples of Feynman diagrams (from document “Feynman
diagrams”)
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Worksheet “The world of particles with charge” for reference
How to make a Feynman diagram
Task overview: Students choose one of the given examples of Feynman diagrams. They
make this Feynman diagram using pipe cleaners. They then add white and black labels with
the names of the particles and anti-particles on the diagram they made.
1. Explain to students that particles interact exactly as people interact. Interaction amongst
people includes talking, playing, fighting, dancing, etc. Interaction amongst particles
includes particles appearing and disappearing.
2. Give each student one A4 printed card, as seen below:
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
The card shows all the possible outcomes of the interaction between a charm and an anticharm quark. The six colours (red, navy-blue, green, yellow, purple and sky-blue) on the
right hand side of the diagram indicate the variety of pairs of quarks a gluon can turn into.
For example a gluon can turn into:
 one anti-up quark and one up quark or
 one anti-down quark and one down quark or
 one anti-strange quark and one strange quark or
 one anti-beauty quark and one beauty quark or
 one anti-top quark and one top quark or
 one anti-charm quark and one charm quark.
3. Each student chooses one interaction out of all the six possible ones on the card. For
example one student might choose:
charm quark
anti-up quark
up quark
gluon
anti-charm quark
where another student might choose:
charm quark
anti-down quark
down quark
gluon
anti-charm quark
4. Students will need to recreate this diagram using pipe cleaners. An example of this is
shown below:
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
charm quark
anti-up quark
gluon
anti-charm quark
up quark
5. Once students have recreated the diagram using pipe cleaners, they should stick their
diagram on an A4 card. It does not matter what colour pipe cleaners they choose to use.
The particle paths (the pipe cleaners) vary depending on the particle:
a. For quarks the particle path must be straight.
b. For photons the particle path must be wavy.
c. For gluons the particle path must be loopy.
d. For “W” or “Z” particles the particle path must be “dash shaped”.
A table with all the path shapes is shown on page 8.
6. Students complete their diagram by adding labels with the names of the particles. They
must use white paper for particles of matter and black paper for particles of anti-matter.
How to write a story based on a particle interaction
Task overview: Students use their imagination to write a story about the interaction they
just made. The particles which participate in the interaction become characters of the story;
the scenery can be anything students choose.
Resources
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A4 printed cards with examples of stories (from document “Feynman diagrams”)
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The completed Feynman diagram they created above with pipe cleaners
A4 lined paper
Pencils/rubber
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
1. Students look at the examples of stories, given on the printed cards. This is only to get
their imagination going. They can then come up with their own story which they write
down.
2. Students present their stories to the rest of the class. They can either read loudly their
story or use the particles the class made in task 2 to act a particle-puppet show of the story.
Low ability students
For pupils that find it difficult to write a story, give them one ready-made story before they
2. Then ask students to draw their diagram using the quark characters that appear in their
story.
3. The students can then make their diagram using pipe cleaners and act out the story that
they were given.
4. Students can add labels to their diagram: white labels for matter and black labels for
antimatter.
the students to write their story as a cartoon.
For example:
Draw
Where
your
might your
particles particles
go on their
What
might
your
particles
do?
Who
might
your
particles
meet?
What
might
happen
when
this
meeting
takes
place?
What
new
particles
do you
have
now?
What
do
these
new
particles
do
next?
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
How
would
you
finish
your
story?
High school students
High school students can use different colour pipe cleaners to correctly complete and draw
a Feynman diagram (see photo below).
orange for quarks
blue for photons
yellow for Z
gold for gluons
silver for Higgs
purple for W minus
green for leptons
red for W plus
For high school students use the incomplete Feynman diagram cards that do not include
information on charge. Students should be asked to first complete the diagram on the card
by adding the charge and ensuring that conservation of charge is applied. They can then
construct their diagram using pipe cleaners.
References
[1] Rules for happy families game taken from
http://www.cartamundi.co.uk/en/spielregeln/gamerules/children
[2] Rules for snap game taken from http://www.pagat.com/war/snap.html
Acknowledgements
We would like to thank Phill Day for his very useful input and guidance on the resources of
the Particle Physics Workshop.
Dr Maria Pavlidou, Ogden Science Officer & Prof Cristina Lazzeroni, STFC Public Engagement Fellow (July 2016)
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