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- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/09%3A_Relativistic_Kinematics/9.01%3A_Lorentz_Transformations_of_Energy_and_MomentumFrom the Lorentz transformation property of time and position, for a change of velocity along the \(x\)-axis from a coordinate system at rest to one that is moving with velocity \({\vec{v}} = (v_x,0,0...From the Lorentz transformation property of time and position, for a change of velocity along the \(x\)-axis from a coordinate system at rest to one that is moving with velocity \({\vec{v}} = (v_x,0,0)\) we have We know however that the full four-momentum is conserved, i.e., if we have two particles coming into a collision and two coming out, the sum of four-momenta before and after is equal,
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/04%3A_Nuclear_Models/4.01%3A_Nuclear_Shell_ModelThe simplest of the single particle models is the nuclear shell model. It is based on the observation that the nuclear mass formula, which describes the nuclear masses quite well on average, fails for...The simplest of the single particle models is the nuclear shell model. It is based on the observation that the nuclear mass formula, which describes the nuclear masses quite well on average, fails for certain “magic numbers”, i.e., for neutron number N=20, 28, 50, 82, 126 and proton number Z=20, 28, 50, 82.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/09%3A_Relativistic_Kinematics/9.02%3A_Invariant_MassOne of the key numbers we can extract from mass and momentum is the invariant mass, a number independent of the Lorentz frame we are in.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/08%3A_Symmetries_of_the_theory_of_strong_interactions/8.04%3A__SU(4)%2C_SU(5)%2C_and_SU(6)_flavor_symmetriesOnce we have three flavors of quarks, we can ask the question whether more flavors exists. At the moment we know of three generations of quarks, corresponding to three generations (pairs).
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/07%3A_Symmetries_and_Particle_Physics/7.06%3A_CP_ViolationThe first experimental confirmation of symmetry breaking was found when studying the β− decay of Co-60.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/01%3A_A_History_of_Particle_Physics/1.11%3A_GUTS_Supersymmetry_and_SupergravityIt might already be getting some signals: researchers at DESY see a new signal in a region of particle that are 200 GeV heavy – it might be noise, but it could well be significant! There are several i...It might already be getting some signals: researchers at DESY see a new signal in a region of particle that are 200 GeV heavy – it might be noise, but it could well be significant! There are several ideas floating around: one is the grand-unified theory, where we try to combine all the disparate forces in nature in one big theoretical frame.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/09%3A_Relativistic_KinematicsEinstein’s idea of the equivalence between mass and energy plays an extremely fundamental role in this field of physics. In order for this to be possible we typically need processes that occur at veloc...Einstein’s idea of the equivalence between mass and energy plays an extremely fundamental role in this field of physics. In order for this to be possible we typically need processes that occur at velocities near the light velocity c , so that the kinematics of these processes requires relativity. In this chapter we shall succinctly introduce the few necessary concepts of relativistic kinematics.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/08%3A_Symmetries_of_the_theory_of_strong_interactions/8.06%3A_The_Feynman_Diagrams_of_Quantum_Chromodynamics_(QCD)Quarks interact more strongly the further they are apart, and more weakly as they are close by – asymptotic freedom. It means that free quarks can’t be seen, but at high energies quarks look more and ...Quarks interact more strongly the further they are apart, and more weakly as they are close by – asymptotic freedom. It means that free quarks can’t be seen, but at high energies quarks look more and more like free particles. The gluon comes in 8 colour combinations (since it carries a colour and anti-colour index, minus the scalar combination). The relevant diagrams are sketches in Figure \(\PageIndex{1}\). Figure \(\PageIndex{1}\): The basic building blocks for QCD Feynman diagrams
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/01%3A_A_History_of_Particle_Physics/1.12%3A_Extraterrestrial_Particle_PhysicsOne of the problems is that it is difficult to see how e can actually build a microscope that can look a a small enough scale, i.e., how we can build an accelerator that will be able to accelerate par...One of the problems is that it is difficult to see how e can actually build a microscope that can look a a small enough scale, i.e., how we can build an accelerator that will be able to accelerate particles to high enough energies? The answer is simple – and has been more or less the same through the years: Look at the cosmos. Processes on an astrophysical scale can have amazing energies.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/03%3A_Nuclear_Masses/3.01%3A_Experimental_FactsEach nucleus has a (positive) charge Ze , and integer number times the elementary charge e . This follows from the fact that atoms are neutral! Nuclei of identical charge come in different masses, a...Each nucleus has a (positive) charge Ze , and integer number times the elementary charge e . This follows from the fact that atoms are neutral! Nuclei of identical charge come in different masses, all approximate multiples of the “nucleon mass”. Nuclei of identical charge (chemical type) but different mass are called isotopes. Nuclei of approximately the same mass, but different chemical type, are called isobars.
- https://phys.libretexts.org/Bookshelves/Nuclear_and_Particle_Physics/Nuclear_and_Particle_Physics_(Walet)/07%3A_Symmetries_and_Particle_PhysicsSymmetries in physics provide a great fascination to us – one of the hang-ups of mankind. We can recognize a symmetry easily, and they provide a great tool to classify shapes and patterns. There is an...Symmetries in physics provide a great fascination to us – one of the hang-ups of mankind. We can recognize a symmetry easily, and they provide a great tool to classify shapes and patterns. There is an important area of mathematics called group theory, where one studies the transformations under which an object is symmetric.
