2.1.13
Application of Conservation Laws
Changing Quark Type
Changing Quark Type
Quarks can only change type via the weak nuclear force. Beta-minus and beta-plus decay are two examples of this.
![Illustrative background for Beta-minus decay](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/5.1.1.1a - Nucleus structure, protons, neutrons-min,h_400,q_80,w_640.png)
![Illustrative background for Beta-minus decay ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/5.1.1.1a - Nucleus structure, protons, neutrons-min,h_400,q_80,w_640.png)
Beta-minus decay
Beta-minus decay
- When a neutron decays into a proton, its constituent quarks need to change from udd to uud.
- So one down quark changes into an up quark.
- Only the weak interaction can result in quarks changing type, so the decay of a neutron into a proton (beta-minus decay) must be governed by the weak nuclear force.
![Illustrative background for Beta-plus decay](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/5.2.1 Radioactivity/beta-min,h_400,q_80,w_640.jpg)
![Illustrative background for Beta-plus decay ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/5.2.1 Radioactivity/beta-min,h_400,q_80,w_640.jpg)
Beta-plus decay
Beta-plus decay
- When a proton decays into a neutron, its constituent quarks need to change from uud to udd.
- So one up quark changes into a down quark.
- Only the weak interaction can result in quarks changing type. So the decay of a proton into a neutron (beta-plus decay) must be governed by the weak nuclear force.
Conservation Laws in Particle Physics
Conservation Laws in Particle Physics
When solving problems in particle physics, you need to remember the following rules:
![Illustrative background for Charge](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/Edexcel/7 electricity/sparking,h_400,q_80,w_640.jpg)
![Illustrative background for Charge ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/Edexcel/7 electricity/sparking,h_400,q_80,w_640.jpg)
Charge
Charge
- Charge is always conserved.
![Illustrative background for Baryon number](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/10.3.1 Using materials/marbles-1659398_640-min,h_400,q_80,w_640.jpg)
![Illustrative background for Baryon number ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/chemistry/10.3.1 Using materials/marbles-1659398_640-min,h_400,q_80,w_640.jpg)
Baryon number
Baryon number
- Baryon number is always conserved.
![Illustrative background for Energy](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.1 Energy Changes/blow-torch-min,h_400,q_80,w_640.jpg)
![Illustrative background for Energy ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.1 Energy Changes/blow-torch-min,h_400,q_80,w_640.jpg)
Energy
Energy
- Energy is always conserved.
![Illustrative background for Lepton numbers](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.1 Energy Changes/light-bulbs-min,h_400,q_80,w_640.jpg)
![Illustrative background for Lepton numbers ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/1.5.1 Energy Changes/light-bulbs-min,h_400,q_80,w_640.jpg)
Lepton numbers
Lepton numbers
- Each lepton number is conserved separately.
- Both the muon lepton number, Lμ, and the electron lepton number, Le, are always conserved.
![Illustrative background for Strangeness](https://image-v2.cdn.app.senecalearning.com/2018-09/bee3b772-a56b-48d1-82f2-260df4d0be8e/emotions-funny-face-,h_400,q_80,w_640.jpg)
![Illustrative background for Strangeness ?? "content](https://image-v2.cdn.app.senecalearning.com/2018-09/bee3b772-a56b-48d1-82f2-260df4d0be8e/emotions-funny-face-,h_400,q_80,w_640.jpg)
Strangeness
Strangeness
- Strangeness is always conserved for strong interactions.
- Strangeness is sometimes not conserved for weak interactions because this interaction can result in a change of quark type.
- For example, in weak interactions an 's' quark can change to a 'u' quark.
- In weak interactions, only one quark can change at a time so strangeness can change by either +1, 0 or -1.
![Illustrative background for Momentum](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/2.2.1 Thermal expansion/train-1728537_640-min,h_400,q_80,w_640.jpg)
![Illustrative background for Momentum ?? "content](https://image-v2.cdn.app.senecalearning.com/courseImages/physics/2.2.1 Thermal expansion/train-1728537_640-min,h_400,q_80,w_640.jpg)
Momentum
Momentum
- Momentum is always conserved.
Working in Particle Physics
Working in Particle Physics
Large teams of scientists are needed to confirm new knowledge.
![Illustrative background for Validation of new knowledge](https://image-v2.cdn.app.senecalearning.com/2018-08/09543ee4-a509-4f8f-9bdc-78289d9c2a4b/Work-office-discussion-,h_400,q_80,w_640.jpg)
![Illustrative background for Validation of new knowledge ?? "content](https://image-v2.cdn.app.senecalearning.com/2018-08/09543ee4-a509-4f8f-9bdc-78289d9c2a4b/Work-office-discussion-,h_400,q_80,w_640.jpg)
Validation of new knowledge
Validation of new knowledge
- Validating new knowledge means confirming that the new knowledge is correct.
- Particle physics experiments create massive amounts of data.
- Particle physics experiments are also very expensive to run.
- These two reasons are why scientists need to work collaboratively to pool resources and expertise.
- Large teams working collaboratively are needed to validate new knowledge in particle physics.
1Measurements & Errors
2Particles & Radiation
2.1Particles
2.1.1Atomic Model
2.1.2Specific Charge, Protons & Neutron Numbers
2.1.3End of Topic Test - Atomic Model
2.1.4Isotopes
2.1.5Stable & Unstable Nuclei
2.1.6End of Topic Test - Isotopes & Nuclei
2.1.7A-A* (AO3/4) - Stable & Unstable Nuclei
2.1.8Particles, Antiparticles & Photons
2.1.9Particle Interactions
2.1.10Classification of Particles
2.1.11End of Topic Test - Particles & Interactions
2.1.12Quarks & Antiquarks
2.1.13Application of Conservation Laws
2.1.14End of Topic Test - Leptons & Quarks
2.1.15Exam-Style Question - Radioactive Decay
2.2Electromagnetic Radiation & Quantum Phenomena
3Waves
3.1Progressive & Stationary Waves
3.2Refraction, Diffraction & Interference
4Mechanics & Materials
4.1Force, Energy & Momentum
4.1.1Scalars & Vectors
4.1.2Vector Problems
4.1.3End of Topic Test - Scalars & Vectors
4.1.4Moments
4.1.5Centre of Mass
4.1.6End of Topic Test - Moments & Centre of Mass
4.1.7Motion in a Straight Line
4.1.8Graphs of Motion
4.1.9Bouncing Ball Example
4.1.10End of Topic Test - Motion in a Straight Line
4.1.11Acceleration Due to Gravity
4.1.12Projectile Motion
4.1.13Friction
4.1.14Terminal Speed
4.1.15End of Topic Test - Acceleration Due to Gravity
4.1.16Newton's Laws
4.1.17Momentum
4.1.18Momentum 2
4.1.19End of Topic Test - Newton's Laws & Momentum
4.1.20A-A* (AO3/4) - Newton's Third Law
4.1.21Work & Energy
4.1.22Power & Efficiency
4.1.23Conservation of Energy
4.1.24End of Topic Test - Work, Energy & Power
4.1.25Exam-Style Question - Forces
5Electricity
5.1Current Electricity
5.1.1Basics of Electricity
5.1.2Current-Voltage Characteristics
5.1.3End of Topic Test - Basics of Electricity
5.1.4Resistivity
5.1.5Superconductivity
5.1.6A-A* (AO3/4) - Superconductivity
5.1.7End of Topic Test - Resistivity & Superconductors
5.1.8Circuits
5.1.9Power and Conservation
5.1.10Potential Divider
5.1.11Emf & Internal Resistance
5.1.12End of Topic Test - Power & Potential
5.1.13Exam-Style Question - Resistance
6Further Mechanics & Thermal Physics (A2 only)
6.1Periodic Motion (A2 only)
6.2Thermal Physics (A2 only)
7Fields & Their Consequences (A2 only)
7.1Fields (A2 only)
7.2Gravitational Fields (A2 only)
7.3Electric Fields (A2 only)
7.4Capacitance (A2 only)
7.5Magnetic Fields (A2 only)
7.5.1Magnetic Flux Density
7.5.2End of Topic Test - Capacitance & Flux Density
7.5.3Moving Charges in a Magnetic Field
7.5.4Magnetic Flux & Flux Linkage
7.5.5Electromagnetic Induction
7.5.6Electromagnetic Induction 2
7.5.7Alternating Currents
7.5.8Operation of a Transformer
7.5.9Magnetic Flux Density
7.5.10End of Topic Test - Electromagnetic Induction
8Nuclear Physics (A2 only)
8.1Radioactivity (A2 only)
8.1.1Rutherford Scattering
8.1.2Alpha & Beta Radiation
8.1.3Gamma Radiation
8.1.4Radioactive Decay
8.1.5Half Life
8.1.6End of Topic Test - Radioactivity
8.1.7Nuclear Instability
8.1.8Nuclear Radius
8.1.9Mass & Energy
8.1.10Binding Energy
8.1.11Induced Fission
8.1.12Safety Aspects of Nuclear Reactors
8.1.13End of Topic Test - Nuclear Physics
8.1.14A-A* (AO3/4) - Nuclear Fusion
9Option: Astrophysics (A2 only)
9.1Telescopes (A2 only)
9.2Classification of Stars (A2 only)
9.3Cosmology (A2 only)
10Option: Medical Physics (A2 only)
10.1Physics of the Eye (A2 only)
10.2Physics of the Ear (A2 only)
10.3Biological Measurement (A2 only)
10.4Non-Ionising Imaging (A2 only)
10.5X-Ray Imaging (A2 only)
10.6Radionuclide Imaging & Therapy (A2 only)
11Option: Engineering Physics (A2 only)
11.1Rotational Dynamics (A2 only)
11.2Thermodynamics & Engines (A2 only)
12Option: Turning Points in Physics (A2 only)
12.1Discovery of the Electron (A2 only)
12.2Wave-Particle Duality (A2 only)
Jump to other topics
1Measurements & Errors
2Particles & Radiation
2.1Particles
2.1.1Atomic Model
2.1.2Specific Charge, Protons & Neutron Numbers
2.1.3End of Topic Test - Atomic Model
2.1.4Isotopes
2.1.5Stable & Unstable Nuclei
2.1.6End of Topic Test - Isotopes & Nuclei
2.1.7A-A* (AO3/4) - Stable & Unstable Nuclei
2.1.8Particles, Antiparticles & Photons
2.1.9Particle Interactions
2.1.10Classification of Particles
2.1.11End of Topic Test - Particles & Interactions
2.1.12Quarks & Antiquarks
2.1.13Application of Conservation Laws
2.1.14End of Topic Test - Leptons & Quarks
2.1.15Exam-Style Question - Radioactive Decay
2.2Electromagnetic Radiation & Quantum Phenomena
3Waves
3.1Progressive & Stationary Waves
3.2Refraction, Diffraction & Interference
4Mechanics & Materials
4.1Force, Energy & Momentum
4.1.1Scalars & Vectors
4.1.2Vector Problems
4.1.3End of Topic Test - Scalars & Vectors
4.1.4Moments
4.1.5Centre of Mass
4.1.6End of Topic Test - Moments & Centre of Mass
4.1.7Motion in a Straight Line
4.1.8Graphs of Motion
4.1.9Bouncing Ball Example
4.1.10End of Topic Test - Motion in a Straight Line
4.1.11Acceleration Due to Gravity
4.1.12Projectile Motion
4.1.13Friction
4.1.14Terminal Speed
4.1.15End of Topic Test - Acceleration Due to Gravity
4.1.16Newton's Laws
4.1.17Momentum
4.1.18Momentum 2
4.1.19End of Topic Test - Newton's Laws & Momentum
4.1.20A-A* (AO3/4) - Newton's Third Law
4.1.21Work & Energy
4.1.22Power & Efficiency
4.1.23Conservation of Energy
4.1.24End of Topic Test - Work, Energy & Power
4.1.25Exam-Style Question - Forces
5Electricity
5.1Current Electricity
5.1.1Basics of Electricity
5.1.2Current-Voltage Characteristics
5.1.3End of Topic Test - Basics of Electricity
5.1.4Resistivity
5.1.5Superconductivity
5.1.6A-A* (AO3/4) - Superconductivity
5.1.7End of Topic Test - Resistivity & Superconductors
5.1.8Circuits
5.1.9Power and Conservation
5.1.10Potential Divider
5.1.11Emf & Internal Resistance
5.1.12End of Topic Test - Power & Potential
5.1.13Exam-Style Question - Resistance
6Further Mechanics & Thermal Physics (A2 only)
6.1Periodic Motion (A2 only)
6.2Thermal Physics (A2 only)
7Fields & Their Consequences (A2 only)
7.1Fields (A2 only)
7.2Gravitational Fields (A2 only)
7.3Electric Fields (A2 only)
7.4Capacitance (A2 only)
7.5Magnetic Fields (A2 only)
7.5.1Magnetic Flux Density
7.5.2End of Topic Test - Capacitance & Flux Density
7.5.3Moving Charges in a Magnetic Field
7.5.4Magnetic Flux & Flux Linkage
7.5.5Electromagnetic Induction
7.5.6Electromagnetic Induction 2
7.5.7Alternating Currents
7.5.8Operation of a Transformer
7.5.9Magnetic Flux Density
7.5.10End of Topic Test - Electromagnetic Induction
8Nuclear Physics (A2 only)
8.1Radioactivity (A2 only)
8.1.1Rutherford Scattering
8.1.2Alpha & Beta Radiation
8.1.3Gamma Radiation
8.1.4Radioactive Decay
8.1.5Half Life
8.1.6End of Topic Test - Radioactivity
8.1.7Nuclear Instability
8.1.8Nuclear Radius
8.1.9Mass & Energy
8.1.10Binding Energy
8.1.11Induced Fission
8.1.12Safety Aspects of Nuclear Reactors
8.1.13End of Topic Test - Nuclear Physics
8.1.14A-A* (AO3/4) - Nuclear Fusion
9Option: Astrophysics (A2 only)
9.1Telescopes (A2 only)
9.2Classification of Stars (A2 only)
9.3Cosmology (A2 only)
10Option: Medical Physics (A2 only)
10.1Physics of the Eye (A2 only)
10.2Physics of the Ear (A2 only)
10.3Biological Measurement (A2 only)
10.4Non-Ionising Imaging (A2 only)
10.5X-Ray Imaging (A2 only)
10.6Radionuclide Imaging & Therapy (A2 only)
11Option: Engineering Physics (A2 only)
11.1Rotational Dynamics (A2 only)
11.2Thermodynamics & Engines (A2 only)
12Option: Turning Points in Physics (A2 only)
12.1Discovery of the Electron (A2 only)
12.2Wave-Particle Duality (A2 only)
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