How to produce elementary particles : (in PARTICLE PHYSICS )

lecture 3-4

How to produce elementary particles :

electrons can be produced by setting up a positively charged plate near a piece of metal .Heat the metallic electrons having enough energy to leave the metal will escape they accelerates to the positively charge plate thus making electron gun . For other particles we have three basic sources to create the elementary particles :-
1.COSMIC RAYS :
High energy particles are bombarding earths outer atmosphere all the time they hit atoms in upper atmosphere and produce shower is of secondary particles (neurons mostly) as source of elementary particles they have a enormous amount of energy as they are free and the rate at which they strike is reasonably low hence they are uncontrollable.

2. NUCLEAR REACTORS :

nuclear reactors radioactive nucleus disintegrates and emits variety of particles like neutron, neutrinos muon ,alpha ,beta and many other particles .

3. PARTICLE ACCELERATORS:

Manmade accelerators start with electron as protons accelerate thus to high energy than smash them into targets separate out the resulting debris to see what has been generated

• these are main three ways to produce elementary particles while mean one is particle accelerators

More explanation :

Producing elementary particles involves high-energy processes typically carried out in particle accelerators or through natural cosmic phenomena. The creation of these particles is governed by Einstein’s famous equation, E=mc², which states that energy can be converted into mass and vice versa. Here are some common methods used to produce elementary particles:

1. Particle Accelerators:
   • Collision Experiments: Particle accelerators like the Large Hadron Collider (LHC) at CERN accelerate particles to nearly the speed of light and then collide them. The high energy from these collisions can produce new particles as a result of the conversion of kinetic energy into mass.
   • Synchrotron Radiation: As charged particles move in circular or spiral paths within an accelerator, they emit synchrotron radiation. This radiation can produce various particles as it interacts with matter.
2. Particle-Decay Processes:
   • Radioactive Decay: Certain radioactive materials undergo decay processes that produce elementary particles as byproducts. For example, beta decay involves the transformation of a neutron into a proton, emitting a beta particle (electron) and an antineutrino.
   • Muon Decay: Muons, heavier relatives of electrons, can decay into electrons, neutrinos, and antineutrinos. Muons are often produced in the upper atmosphere by cosmic rays and can reach the Earth’s surface.
3. High-Energy Astrophysical Processes:
   • Supernovae: During a supernova explosion, extremely high temperatures and pressures can lead to the creation of various elementary particles. Neutrinos, for instance, are abundantly produced in these cataclysmic events.
   • Cosmic Rays: High-energy cosmic rays, originating from various astrophysical sources, constantly bombard the Earth’s atmosphere. When these cosmic rays interact with atmospheric particles, they can produce secondary particles, including elementary ones.
4. Particle Collisions in Space:
   • Cosmic Ray Collisions: In space, high-energy cosmic rays from extragalactic sources can collide with particles, leading to the creation of elementary particles. These collisions occur naturally in the vast cosmic landscape.
5. Experimental Methods:
   • Particle Detectors: Specialized detectors are crucial in identifying and measuring elementary particles. Detectors like the ones at CERN are designed to track the paths, energies, and momenta of particles produced in high-energy collisions.

It’s important to note that the production of elementary particles often involves complex experimental setups and precise control of conditions. Understanding the behavior and characteristics of these particles provides insights into the fundamental nature of matter and the underlying forces governing the universe.

Title:Detection of elementary particles :

Many kinds of particle detectors like Geiger Mullet Counter ,Cbud chamber ,Bubble Chamber ,Photographic Emission

UNITS:-

• Atomic physicist uses eV, where 1eV = 1.6 X 10 ^-19 J
• Nuclear Physicist uses KeV = 10^3eV
• Particle Physicist uses MeV = 10 ^6 eV
• many other units are GeV =10^9 eV , TeV = 10^22

[Momenta are measured in MeV /c , GeV /c ]

weight of protron = 1.67 X 10^-24 g which is equal to 938Mev /c^2

{ fine structure formula = e²/hc = 1/137 }

Title : History of particle physics :

Particle physics, also known as high-energy physics, has a rich history that unfolded over the course of the 20th century. Here is a concise overview of key milestones and developments:

1. Early 20th Century: The Birth of Quantum Mechanics (1900-1920s)

• 1900: Max Planck introduces the concept of quantized energy, laying the groundwork for quantum mechanics.
• 1905: Albert Einstein’s theory of special relativity revolutionizes our understanding of space, time, and energy-mass equivalence (E=mc²).
• 1920s: Quantum mechanics emerges with contributions from Niels Bohr, Louis de Broglie, Erwin Schrödinger, and Werner Heisenberg.

2. Discovery of the Electron and the Atomic Nucleus (1897-1932)

• 1897: J.J. Thomson discovers the electron, challenging the notion that atoms are indivisible.
• 1911: Ernest Rutherford proposes the nuclear model of the atom, identifying a positively charged nucleus at its center.

3. Quantum Field Theory and Quantum Electrodynamics (1920s-1940s)

• 1928: Paul Dirac formulates quantum field theory, unifying quantum mechanics and special relativity.
• 1940s: Quantum Electrodynamics (QED) is developed, successfully describing the electromagnetic interactions of charged particles.

4. Post-WWII Era: Proliferation of Particle Discoveries (1940s-1950s)

• 1947: Discovery of the pion by C.F. Powell, C.M.G. Lattes, and G.P.S. Occhialini opens the era of meson and baryon discoveries.
• 1952: The first muon is discovered in cosmic ray experiments, initially causing confusion due to its unexpected properties.

5. The Birth of the Standard Model (1960s-1970s)

• 1961: Murray Gell-Mann introduces the quark model to explain baryons and mesons.
• 1964: The discovery of the omega-minus baryon supports the quark model.
• 1970s: Development of the Standard Model, incorporating the electromagnetic, weak, and strong nuclear forces.

6. Experimental Confirmations and Higgs Boson Discovery (1980s-2012)

• 1983: Experimental confirmation of the W and Z bosons at CERN supports the electroweak theory.
• 2012: The Large Hadron Collider (LHC) at CERN discovers the long-sought Higgs boson, confirming the mechanism responsible for particle mass.

7. Beyond the Standard Model and Current Frontiers (2000s-Present)

• 2000s-Present: Ongoing experiments explore phenomena beyond the Standard Model, including neutrino oscillations, dark matter searches, and investigations into the properties of antimatter.
• 2020s: Current research includes endeavors such as the High-Luminosity LHC and future colliders, aiming to explore new physics and answer unresolved questions.