Particle physics | CEE Academy

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PARTICLE PHYSICS

▢ Basic Idea:

❖ Definition: Study of most fundamental particles of nature + forces acting between them

❖ Modern Classification: Standard Model of Particle Physics

Table 1: Standard Model Main Groups

Group	Meaning
Fermions	Matter-forming particles
Bosons	Force-carrying particles
Higgs boson	Mass-related particle

▢ Fundamental Particle Classification:

Table 1: Main Classification

Fundamental particles	Subtypes	Spin	Function
Fermions	Quarks + leptons	\\(\\frac{1}{2}\\)	Matter formation
Bosons	Gauge bosons + Higgs	Integer spin	Force / mass-related

❖ Memory:

•
•
Force particles = bosons = integer spin
•
Higgs boson = spin 0 = scalar boson

▢ Fermions:

❖ Definition: Matter particles having half-integral spin

❖ Spin: \\(\\frac{1}{2}\\)

❖ Principle: Obey Pauli exclusion principle

❖ Pauli Exclusion Principle: Two identical fermions cannot occupy same quantum state

Table 1: Types of Fermions

Type	Examples
Quarks	up, down, charm, strange, top, bottom
Leptons	electron, muon, tau, neutrinos

▢ Bosons:

❖ Definition: Particles having integral spin

❖ Main Role: Force carriers

❖ Spin: 0, 1, 2, ...

Table 1: Types of Bosons

Type	Examples	Function
Gauge bosons	photon, gluon, W, Z	Carry forces
Scalar boson	Higgs boson	Mass-related mechanism

▢ Spin:

❖ Definition: Intrinsic quantum angular momentum; not ordinary physical spinning

Table 1: Spin Table

Spin	Particle type	Examples
\\(\\frac{1}{2}\\)	Fermions	electron, quarks, neutrinos
1	Gauge bosons	photon, gluon, W, Z
0	Scalar boson	Higgs boson
2	Hypothetical graviton	gravity carrier; not confirmed

❖ Exam Memory: Half spin → fermion → matter; integer spin → boson → force

▢ Electric Charge:

❖ Meaning: Determines interaction with electromagnetic force

❖ Unit: \\(e\\)

Table 1: Common Charges

Particle	Charge
Electron	−1
Proton	+1
Neutron	0
Photon	0

▢ Quarks:

❖ Definition: Fundamental fermions forming hadrons

❖ Important Point: Quarks are normally not found freely due to color confinement

Table 1: Six Quarks

Generation	Quark	Symbol	Charge	Spin
1st	Up	u	+\\(\\frac{2}{3}\\)	\\(\\frac{1}{2}\\)
1st	Down	d	−\\(\\frac{1}{3}\\)	\\(\\frac{1}{2}\\)
2nd	Charm	c	+\\(\\frac{2}{3}\\)	\\(\\frac{1}{2}\\)
2nd	Strange	s	−\\(\\frac{1}{3}\\)	\\(\\frac{1}{2}\\)
3rd	Top	t	+\\(\\frac{2}{3}\\)	\\(\\frac{1}{2}\\)
3rd	Bottom	b	−\\(\\frac{1}{3}\\)	\\(\\frac{1}{2}\\)

❖ Memory:

•
\\(u,c,t=+\\frac{2}{3}\\)
•
\\(d,s,b=-\\frac{1}{3}\\)
•
All quarks → spin \\(\\frac{1}{2}\\)

▢ Proton and Neutron Charge:

Table 1: Quark Composition

Particle	Composition	Charge calculation	Total charge
Proton	uud		+1
Neutron	udd		0

❖ Exam Trap: Neutron is neutral but contains charged quarks; charge cancels

▢ Hadrons:

❖ Definition: Particles made of quarks

❖ Nature: Composite, not fundamental

❖ **table:

◈ caption: Important Baryons

◈ data:

Baryon
Composition
Charge

Proton
uud
+1

Neutron
udd
0

▢ Leptons:

❖ Definition: Fundamental fermions that do not participate in strong nuclear force

❖ **table:

❖ Charged Leptons: \\(e,\\mu,\\tau=-1\\)

❖ Neutral Leptons: \\(\\nu_e,\\nu*\\mu,\\nu*\\tau=0\\)

❖ Neutrino:

•
Electrically neutral
•
Weak interaction
•
Very difficult to detect

▢ Generations of Matter:

Table 1: Three Generations

Generation	Quarks	Leptons
1st	up, down	electron, electron neutrino
2nd	charm, strange	muon, muon neutrino
3rd	top, bottom	tau, tau neutrino

❖ Ordinary Matter: Mainly first-generation particles: up quark + down quark + electron

❖ Atoms:

Table 1: Atomic Parts

Atomic part	Main particles
Proton	up + down quarks
Neutron	up + down quarks
Electron	electron lepton

▢ Gauge Bosons:

❖ Definition: Force-carrying bosons

Table 1: Gauge Bosons

Boson	Symbol	Force carried	Charge	Spin
Photon	\\(\\gamma\\)	Electromagnetic force	0	1
Gluon	g	Strong nuclear force	0 electric charge	1
W plus	\\(W^+\\)	Weak nuclear force	+1	1
W minus	\\(W^-\\)	Weak nuclear force	−1	1
Z boson	\\(Z^0\\)	Weak nuclear force	0	1

❖ Memory:

•
\\(\\gamma\\) → electromagnetic force
•
g → strong force
•
\\(W^+,W^-,Z^0\\) → weak force

▢ Fundamental Forces:

Table 1: Forces and Carriers

Force	Carrier	Acts on	Important role
Strong force	Gluon	Quarks	Binds quarks inside protons and neutrons
Electromagnetic force	Photon	Charged particles	Electricity, magnetism, light
Weak force	\\(W^+,W^-,Z^0\\)	Quarks and leptons	Beta decay, neutrino interactions
Gravity	Hypothetical graviton	Mass-energy	Not included fully in Standard Model

▢ Higgs Boson:

Table 1: Higgs Boson

Property	Answer
Symbol	H
Charge	0
Spin	0
Type	Scalar boson
Function	Related to mass generation

❖ Exam Point: Only elementary scalar boson in Standard Model

❖ Scalar: Spin = 0

❖ Trap: Higgs boson is not a gauge boson like photon

▢ Antiparticles:

❖ Definition: Corresponding particle with same mass and spin but opposite charge / quantum numbers

Table 1: Particle vs Antiparticle

Property	Antiparticle compared to particle
Mass	Same
Spin	Same
Charge	Opposite
Other quantum numbers	Opposite

Table 2: Examples

Particle	Antiparticle
Electron \\(e^-\\)	Positron \\(e^+\\)
Proton \\(p^+\\)	Antiproton \\(p^-\\)
Neutrino \\(\\nu\\)	Antineutrino \\(\\bar\\nu\\)
Quark q	Antiquark \\(\\bar q\\)
\\(W^+\\)	\\(W^-\\)

▢ Important Particle Charges and Spins:

Table 1: Charge + Spin + Type

Particle	Charge	Spin	Type
Up quark	+\\(\\frac{2}{3}\\)	\\(\\frac{1}{2}\\)	Fermion
Down quark	−\\(\\frac{1}{3}\\)	\\(\\frac{1}{2}\\)	Fermion
Charm quark	+\\(\\frac{2}{3}\\)	\\(\\frac{1}{2}\\)	Fermion
Strange quark	−\\(\\frac{1}{3}\\)	\\(\\frac{1}{2}\\)	Fermion
Top quark	+\\(\\frac{2}{3}\\)	\\(\\frac{1}{2}\\)	Fermion
Bottom quark	−\\(\\frac{1}{3}\\)	\\(\\frac{1}{2}\\)	Fermion
Electron	−1	\\(\\frac{1}{2}\\)	Fermion
Muon	−1	\\(\\frac{1}{2}\\)	Fermion
Tau	−1	\\(\\frac{1}{2}\\)	Fermion
Neutrino	0	\\(\\frac{1}{2}\\)	Fermion
Photon	0	1	Boson
Gluon	0 electric	1	Boson
\\(W^+\\)	+1	1	Boson
\\(W^-\\)	−1	1	Boson
\\(Z^0\\)	0	1	Boson
Higgs boson	0	0	Boson

▢ Fundamental vs Composite Particles:

Table 1: Fundamental Particles

Category	Particles
Quarks	u, d, c, s, t, b
Leptons	electron, muon, tau, neutrinos
Gauge bosons	photon, gluon, W, Z
Scalar boson	Higgs boson

Table 2: Composite Particles

Composite particle	Made of
Proton	3 quarks
Neutron	3 quarks
Meson	quark + antiquark
Atom	proton + neutron + electron
Nucleus	proton + neutron

❖ Exam Trap: Proton is composite, not elementary

▢ Important Differences:

Table 1: Fermions vs Bosons

Feature	Fermions	Bosons
Spin	Half-integer	Integer
Main role	Matter formation	Force mediation
Examples	quarks, leptons	photon, gluon, W, Z, Higgs
Pauli exclusion	Follow	Do not follow
Occupancy	One state cannot have identical fermions	Many bosons can occupy same state

Table 2: Quarks vs Leptons

Feature	Quarks	Leptons
Strong force	Yes	No
Electric charge	Fractional	Integral or zero
Found alone	No; due to confinement	Yes
Examples	up, down, charm	electron, muon, neutrino
Form	Hadrons	Do not form hadrons

Table 3: Baryons vs Mesons

Feature	Baryons	Mesons
Composition	3 quarks	quark + antiquark
Spin type	Half-integer	Integer
Particle type	Fermion	Boson
Examples	proton, neutron	pion, kaon

▢ Common Exam Traps:

Table 1: Traps

Trap	Correct concept
Proton fundamental?	No; proton = uud = composite
Neutron charge zero means no charged parts?	Wrong; neutron = udd; charges cancel
Gluon has electric charge?	No electric charge but carries color charge
Neutrino = photon?
Higgs = gauge boson?	No; Higgs is scalar boson with spin 0

▢ Most Probable MCQ Facts:

Table 1: High-Yield Clues

Question clue	Answer
Matter particles	Fermions
Force carriers	Bosons
Spin of fermions	\\(\\frac{1}{2}\\)
Spin of photon	1
Spin of gluon	1
Spin of W and Z bosons	1
Spin of Higgs boson	0
Charge of up quark	+\\(\\frac{2}{3}\\)
Charge of down quark	−\\(\\frac{1}{3}\\)
Charge of electron	−1
Charge of neutrino	0
Proton composition	uud
Neutron composition	udd
Meson composition	quark + antiquark
Baryon composition	3 quarks
Electromagnetic carrier	Photon
Strong force carrier	Gluon
Weak force carriers	\\(W^+,W^-,Z^0\\)
Scalar boson	Higgs boson
Ordinary matter mainly	up quark + down quark + electron
Leptons do not take part in	Strong force
Quarks never found freely due to	Color confinement
Antiparticle of electron	Positron
Antiparticle of \\(W^+\\)	\\(W^-\\)
Neutral weak boson	\\(Z^0\\)

▢ Final Exam Memory:

Table 1: Ultra-High-Yield Summary

Concept	Memory
Standard Model	12 fermions + bosons
12 fermions	6 quarks + 6 leptons
Quarks
Leptons	\\(e,\\mu,\\tau=-1\\); \\(\\nu=0\\)
Bosons	\\(\\gamma\\)=EM, g=strong, W/Z=weak
Higgs	H, spin 0, mass generation
Proton	uud = +1
Neutron	udd = 0

Q1.

When particle-antiparticle pair is annihilated, energy liberated is

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Q2.

Quark combination of neutron is:

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Q3.

According to standard Model spin half particles are known as:

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Q4.

Quark combination of proton is:

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Q5.

The elementary particle responsible for fundamental interaction is:

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Q6.

What is the quark combination of an antineutron?

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Q7.

Antiparticle of electron is:

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Q8.

The quark composition of a proton is:

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Q9.

If a neutron, composed of up and down quarks, decays, it gives an electron, a neutrino and:

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Q10.

The quark combination that makes up a neutron is:

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Q11.

udd is:

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Q12.

Which of the following has the smallest mass?

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Q13.

Quark combination of neutron is:

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Q14.

Fundamental particles that constitute matter in the Standard Model are classified as:

Q15.

The fundamental particles that mediate the electromagnetic, weak and strong interactions in the Standard Model are:

Q16.

What is the intrinsic spin of the fundamental matter fermions in the Standard Model?

Q17.

What is the intrinsic spin quantum number of a photon?

Q18.

What is the intrinsic spin of the Higgs boson?

Q19.

Which of the following is an up-type quark?

Q20.

What is the electric charge of an up quark in units of the elementary charge \(e\)?

Q21.

What is the electric charge of a down quark in units of \(e\)?

Q22.

What is the valence-quark composition of a proton?

Q23.

What is the valence-quark composition of a neutron?

Q24.

What is the total electric charge of a proton, expressed in units of \(e\)?

Q25.

What is the total electric charge of a neutron, expressed in units of \(e\)?

Q26.

Conventional baryons such as protons and neutrons are described as having how many valence quarks?

Q27.

Conventional mesons have which valence-quark composition?

Q28.

Which of the following is a lepton?

Q29.

Which of the following leptons has zero electric charge?

Q30.

Which list contains only the three charged lepton types?

Q31.

Which class of fundamental Standard Model matter particles does not participate in the strong interaction?

Q32.

Which particle mediates the electromagnetic interaction?

Q33.

Which particle mediates the fundamental strong interaction between quarks?

Q34.

Which bosons mediate the weak interaction?

Q35.

Which boson carries positive electric charge?

Q36.

Which of these particles is electrically neutral?

Q37.

Which of the following is not an elementary particle in the Standard Model?

Q38.

Which fundamental particles are the main building blocks of ordinary atoms?

56Particle physics

Table 1: Standard Model Main Groups

Table 1: Main Classification

Table 1: Types of Fermions

Table 1: Types of Bosons

Table 1: Spin Table

Table 1: Common Charges

Table 1: Six Quarks

Table 1: Quark Composition

Table 1: Three Generations

Table 1: Atomic Parts

Table 1: Gauge Bosons

Table 1: Forces and Carriers

Table 1: Higgs Boson

Table 1: Particle vs Antiparticle

Table 2: Examples

Table 1: Charge + Spin + Type

Table 1: Fundamental Particles

Table 2: Composite Particles

Table 1: Fermions vs Bosons

Table 2: Quarks vs Leptons

Table 3: Baryons vs Mesons

Table 1: Traps

Table 1: High-Yield Clues

Table 1: Ultra-High-Yield Summary

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