Quarks Flashcards
What are the conservation laws associated with quarks?
Quarks have conservation laws for flavors such as strangeness (S), charm (C), beauty (B), and truth (T). These conservation laws govern the balance of quark flavors in particle interactions.
Describe the concept of lepton-quark symmetry.
Lepton-quark symmetry suggests that quarks and leptons have similar weak interactions. For example, replacing νe with u quark, e^- with d quark, νµ with c quark, and µ^- with s quark in Feynman diagrams demonstrates this symmetry. However, quark mixing introduces deviations from strict symmetry.
What is the Cabibbo angle, and how does it relate to quark mixing?
The Cabibbo angle (θc) quantifies the degree of mixing between quark states. It determines the strength of previously allowed weak interaction vertices and allows previously forbidden interactions. The measured value of the Cabibbo angle is approximately 13.1 degrees.
What is the CKM matrix, and why is it important in particle physics?
The Cabibbo-Kobayashi-Maskawa (CKM) matrix describes the mixing between different quark generations. It contains parameters that govern the strength of flavor-changing weak interactions. The CKM matrix’s complex nature is crucial for understanding CP violation, which is essential for explaining the matter-antimatter imbalance in the universe.
What are neutral current interactions, and how do they differ from charged current interactions?
Neutral current interactions involve the exchange of Z^0 bosons and do not involve flavor-changing interactions. Unlike charged current interactions, neutral current interactions do not alter the flavor of the participating particles.
