Undergraduate
  1. Classical mechanics  1.1. dynamics  1.1.1. Motion in one dimension  1.1.2. Motion in two dimensions  1.1.3. projectile motion  1.1.4. Relative speed  1.1.5. Uniform circular motion  1.1.6. Non-uniform circular motion  1.1.7. Reference frames and transformations  1.2. Newton's Laws of Motion  1.2.1. First law of motion  1.2.2. Second law of motion  1.2.3. Third Law of Motion  1.2.4. Applications of Newton's Laws  1.2.5. Friction and its types  1.2.6. Free Body Diagram  1.2.7. Constraints and pseudo-forces  1.3. Work and Energy  1.3.1. work done by the force  1.3.2. Work–energy theorem  1.3.3. Kinetic energy  1.3.4. Potential energy in classical mechanics  1.3.5. Conservative and non-conservative forces  1.3.6. Energy Conservation  1.3.7. Power and efficiency  1.4. Speed and collisions  1.4.1. Linear momentum  1.4.2. Conservation of momentum  1.4.3. Impulse and impact force  1.4.4. Elastic and inelastic collision  1.4.5. Center of mass and speed  1.4.6. Rocket Propulsion  1.5. Rotational motion  1.5.1. Torque and Angular Momentum  1.5.2. Moment of inertia  1.5.3. Rotational Kinematics  1.5.4. Rotational Energy  1.5.5. Rolling Motion  1.5.6. Precession and gyroscopic motion  1.6. Gravitational force  1.6.1. Newton's law of universal gravitation  1.6.2. Gravitational potential energy  1.6.3. Orbital mechanics  1.6.4. Kepler's laws of planetary motion  1.6.5. Gravitational field and potential  1.7. Fluid mechanics  1.7.1. Pressure and Pascal's Principle  1.7.2. Buoyancy and Archimedes' principle  1.7.3. Fluid Dynamics and Bernoulli's Principle  1.7.4. Viscosity and Poiseuille's law  1.7.5. Surface tension and capillarity  1.8. Oscillations and waves  1.8.1. Simple Harmonic Motion  1.8.2. Damped and driven oscillations  1.8.3. Coupled oscillations and common modes  1.8.4. Wave properties and types  1.8.5. Sound Waves and the Doppler Effect  1.8.6. Wave interference and superposition
  2. Electromagnetism  2.1. Electrostatics  2.1.1. Electric charge and properties  2.1.2. Coulomb's law  2.1.3. Electric field and electric potential  2.1.4. Gauss's Law  2.1.5. Capacitance and Dielectric  2.1.6. Electric dipole and potential energy  2.2. Electric circuits  2.2.1. Current and Resistance  2.2.2. Ohm's law  2.2.3. Kirchhoff's Laws  2.2.4. RC Circuit  2.2.5. AC Circuits and Reactance  2.2.6. Electric power and energy  2.3. Magnetism  2.3.1. Magnetic Fields and Forces  2.3.2. Ampere's Law  2.3.3. Magnetic dipole moment  2.3.4. Biot-Savart law  2.3.5. Magnetic Materials and Hysteresis  2.4. Electromagnetic induction  2.4.1. Faraday's Law  2.4.2. Lenz's law  2.4.3. Self and mutual induction  2.4.4. Transformers and Inductive Circuits  2.5. Maxwell's equations  2.5.1. Gauss's law for electricity  2.5.2. Gauss's law for magnetism  2.5.3. Faraday's law of induction  2.5.4. Ampere-Maxwell law  2.5.5. Electromagnetic waves
  3. Thermodynamics  3.1. Laws of Thermodynamics  3.1.1. Zeroth law of thermodynamics  3.1.2. First law of thermodynamics  3.1.3. Second Law  3.1.4. Third Law  3.2. Heat and work  3.2.1. Heat transfer (conduction, convection, radiation)  3.2.2. Thermal expansion  3.2.3. Heat engines and refrigerators  3.2.4. Carnot cycle and efficiency  3.3. Statistical mechanics  3.3.1. Maxwell–Boltzmann distribution  3.3.2. Entropy and Probability  3.3.3. Partition function  3.3.4. Fermi–Dirac and Bose–Einstein statistics
  4. Optics  4.1. Geometrical Optics  4.1.1. Reflection and Refraction  4.1.2. Mirrors and lenses  4.1.3. Optical Instruments  4.1.4. Fermat's principle  4.2. Wave optics  4.2.1. Interference in wave optics  4.2.2. Diffraction  4.2.3. Polarization  4.2.4. Coherence and holography
  5. Quantum mechanics  5.1. Wave–particle duality  5.1.1. Blackbody radiation in wave–particle duality in quantum mechanics  5.1.2. Photoelectric effect  5.1.3. Compton scattering  5.1.4. De Broglie wavelength  5.2. Schrödinger Equation  5.2.1. Time-independent Schrödinger equation  5.2.2. Particle in a box  5.2.3. Quantum Tunneling  5.2.4. Potential wells and obstacles  5.3. Quantum States  5.3.1. Wave function  5.3.2. Quantum operators  5.3.3. Heisenberg uncertainty principle  5.3.4. Angular momentum and spin
  6. Relativity  6.1. Special relativity  6.1.1. Lorentz transformations  6.1.2. Time expansion and length contraction  6.1.3. Relativistic energy and momentum  6.2. General relativity  6.2.1. Principle of Equivalence  6.2.2. Schwarzschild metric  6.2.3. Gravitational waves  6.2.4. Black holes and event horizons
  7. Solid state physics  7.1. Crystal structure  7.1.1. Bravais lattices  7.1.2. X-ray diffraction  7.1.3. Band theory  7.1.4. Phonons and lattice vibrations  7.2. Electrical and Magnetic Properties  7.2.1. Conductors, Semiconductors and Insulators  7.2.2. Superconductivity  7.2.3. Hall effect
  8. Nuclear and particle physics  8.1. Atomic Structure  8.1.1. Atomic Model  8.1.2. Nuclear binding energy  8.2. Radioactivity  8.2.1. Alpha, beta, gamma decay  8.2.2. Half life  8.2.3. Nuclear Fission and Fusion  8.3. Particle physics  8.3.1. Standard Model  8.3.2. Quarks and Leptons  8.3.3. antimatter  8.3.4. Fundamental interactions
  9. Astrophysics and cosmology  9.1. Stellar evolution  9.1.1. Star formation  9.1.2. Black holes and neutron stars  9.1.3. White dwarfs and supernovae  9.2. Cosmology  9.2.1. The Big Bang Theory  9.2.2. Dark matter and dark energy  9.2.3. Cosmic microwave background

Undergraduate ↓


Nuclear and particle physics


Nuclear and particle physics is a fascinating branch of physics that delves deep into the world of the smallest structures in the universe. It explores the behavior, interactions, and properties of atomic nuclei and fundamental particles. Let's go on a journey to understand these tiny building blocks that govern the universe.

Basics of atomic structure

Atoms are the basic units of matter, consisting of a nucleus surrounded by electrons. The nucleus is composed of protons and neutrons, collectively called nucleons. Protons have a positive charge, and neutrons are electrically neutral. Electrons, which are negatively charged, orbit the nucleus.

The number of protons in the nucleus determines the atomic number and the identity of the element. For example, hydrogen has one proton, while helium has two. Neutrons contribute to the mass of the atom and play an important role in nuclear stability.

Nuclear forces and stability

In nuclear physics, the main focus is on the forces that hold the nucleus together. Despite the repulsive electrical force between the positively charged protons, the nucleus is tightly bound due to the presence of the strong nuclear force, also known as the strong interaction.

This force is about 100 times more powerful than electromagnetic forces and acts over very short distances of the order of 10^-15 meters. It is responsible for binding protons and neutrons into nuclei.

Radioactivity

Some nuclei are unstable and undergo radioactive decay to change into a more stable configuration. There are three main types of radioactive decay:

  • Alpha decay: The nucleus emits an alpha particle, which is made up of two protons and two neutrons (a helium nucleus).
  • Beta decay: A neutron in the nucleus decays into a proton, emitting a beta particle (an electron or a positron) and an antineutrino or neutrinos.
  • Gamma decay: After alpha or beta decay, the daughter nucleus may be in an excited state and release energy in the form of gamma rays to reach a lower energy state.

Modeling of the nucleus

Scientists use different models to understand the structure and behaviour of the nucleus. The liquid drop model and the shell model are two important theoretical frameworks in nuclear physics.

Fluid droplet model

The liquid drop model compares the nucleus to a drop of incompressible nuclear liquid. It explains nuclear phenomena such as binding energy and fission. The model includes various terms representing volume energy, surface energy, Coulomb energy, symmetry energy and pairing energy.

E_{binding} = a_V A - a_S A^{2/3} - a_C frac{Z(Z-1)}{A^{1/3}} - a_{sym} frac{(A-2Z)^2}{A} + delta

Shell model

The shell model is similar to the electron shell model for atoms. It suggests that nucleons occupy discrete energy levels within the nucleus. Similar to electron configurations, nucleons fill atomic shells, and certain "magic numbers" of nucleons lead to particularly stable nuclei.

Fission and fusion

Nuclear reactions are interactions between two atomic nuclei or between a nucleus and a subatomic particle. Fission and fusion are the two primary types of nuclear reactions.

Fragmentation

Nuclear fission occurs when a heavy nucleus splits into smaller nuclei, releasing a considerable amount of energy. This process is used in nuclear power plants and atomic bombs. The original nucleus absorbs a neutron, becomes unstable, and splits into two or more fission products with the additional neutron.

Merger

Fusion, on the other hand, is the process by which two lighter nuclei combine to form a heavier nucleus, releasing energy in the process. Fusion powers the Sun and other stars. If successfully harnessed on Earth, it promises to provide a virtually unlimited, clean energy source.

Particle physics

Particle physics advances our understanding of the smallest particles of matter, called elementary particles. These include quarks, leptons, bosons, and other particles. The standard model of particle physics is a theory that describes how these particles interact via fundamental forces.

Standard model

The Standard Model classifies all known elementary particles and describes three of the four fundamental forces in the universe: electromagnetic, weak, and strong forces. Gravity is not included in this model. The major particles in the Standard Model are:

  • Quarks: The building blocks of protons and neutrons. Six types of quarks exist: up, down, charm, strange, top, and bottom.
  • Leptons: These include electrons, muons, taos, and their associated neutrinos.
  • Gauge bosons: Force carriers - the photon for the electromagnetic force, the W and Z bosons for the weak force, and the gluon for the strong force.
  • Higgs boson: Provides mass to quarks and leptons via the Higgs mechanism.
,
|Type|Particle|Symbol|
,
| lepton | electron | e^- |
| | Electron Neutrino | ν_e |
| | muon | μ^- |
| | Muon neutrino | ν_μ |
| | tau | τ^- |
| | tau neutrino | ν_τ |
,
| Quarks | Up | U |
| | down | d |
| | Attraction | C |
| | odd |s |
| | top | t |
| | down | b |
,
| gauge boson | photon | γ |
| | W boson | W^± |
| | Z boson | Z^0 |
||Gluon|G|
,

Detection and experimentation

Most knowledge in nuclear and particle physics is obtained through experimentation using particle accelerators and detectors. Particle accelerators, such as the Large Hadron Collider (LHC), accelerate particles to high speeds and make them collide. These collisions can reveal information about subatomic structures and forces.

Detectors are used to identify the particles produced by these collisions, characterizing them based on their energy, momentum, charge, and interactions. Detectors can be large-scale experiments that require international collaboration.

Applications of nuclear and particle physics

Nuclear and particle physics have many applications in various fields of study. Here are some examples:

  • Medical imaging and therapy: Techniques such as positron emission tomography (PET) use the principles of particle physics for medical imaging. Radiotherapy, using radiation to treat cancer, is another application.
  • Energy production: Nuclear reactors use fission reactions to produce energy. Fusion has the potential for clean energy if used effectively.
  • Scientific research: Insights gained from atomic physics advance our understanding of the fundamental forces and matter in the universe.
  • Environmental tracing: Isotopic tracing methods help in dating environmental changes and chronological dating.

Conclusion

Nuclear and particle physics provide an extraordinary view of the fundamental processes that define the universe. From the behavior of atomic nuclei to the interactions of elementary particles, the field combines experimental simplicity with profound theoretical implications. Aspiring physicists who delve into nuclear and particle physics uncover the wonders of the microscopic world, learning about the forces that shape our reality.


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