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Lausanne, 8 February 2000 Symmetry and Its Violation-unifying concept of universe- Tatsuya Nakada
- regular pattern - symmetry - … Nature Observation Recognition Concept of Symmetry
- regular pattern - symmetry - … Concept Realisation Creating arts
m1m2 G f = r2 Natural Science Generalising and making physical laws Observation gmngmn Postulating and predicting phenomena Observation Extracting more abstract concept
Geometrical Symmetries Translation Reflection (parity) Rotation R R R R R R R R R R R R R R R R R R R R R R continuous discrete continuous
Spontaneous Breakdown of Rotational Symmetry before dinner once dinner starts
10% 90% World Mirror World (parity violation) Violation of L-R Symmetry World Mirror World 90% 10%
L-R symmetry is fully violated. Even more with DNA
Goal of Elementary Particle Physics To look for 1) the ultimate building blocks of the world 2) forces between them 3) underlying dynamics
Solar System BuildingForceUnderlyingblocksdynamics sun and planets gravitation Newton’s laws of motion Atomic System BuildingForceUnderlyingblocksdynamics electron and electromagnetic Quantum nucleus interaction Mechanics (relativistic) Examples
q q q g g W n e q q q q q e e Elementary Particle System BuildingForceUnderlyingblocksdynamics quarks and electromagnetic Quantum leptons (photon: g) Field + weak Theory anti-quarks and (W, Z0) anti-leptons strong (gluon: g) The Standard Model
can be described by rotation and/or translation symmetries in four-dimensional real space (t, x, y, z) or some “internal” space Properties of building blocks, forces and underlying dynamics
we saw already Parity: (x, y, z) (-x, -y, -z) two more to come Charge conjugation: particle antiparticle Time reversal: t -t What about discrete symmetries? No quantum field theory without CPT symmetry
antineutrino neutrino connected by CP transformation Right-handed Left-handed particle world antiparticle world
CP Violation We know two examples which shows matter world anti-matter world. CP symmetry is violated !!
matter big bang anti-matter amount of matter = amount ofanti-matter our universe only with matter Evolution of Universe CP violation
p+p- K0 Decay Time Weak decay of neutral K mesons
CP violation CPLEAR Experiment (1999) neutral kaon decay time distribution anti-neutral kaon decay time distribution
LHCb experiment will look for CP violation beyond the Standard Model in the particle worldusing B-mesons. Problem!! CP violation in the kaon decays can be explained by the Standard Model. CP violation in the universe cannot be explained by the Standard Model.
Standard Model New Physics q q W X complex coupling constant complex coupling constant q q Mechanism of CP Violation CP transformation containscomplex conjugation: e-iH t eiH*t i.e. H* HCP violation
p 7 TeV=2.710-7 cal1g of those p’s = 20 daysof US energy consumption p 7 TeV 14 TeV mini bang LHCb detector At LHC ~100 times more B mesons then before
USA Brazil Ukraine Finland France UK Switzerland Germany Italy Poland PRC Netherlands Romania Russia Spain The LHCb Experiment Calorimeters LHCb Tracker Shieldingplate Yoke Coil RICH-1 RICH-2 Moun Vertex
LHCb event seen by the vertex detector (Lausanne participation) An Event
Possibly discovering new physics beyond the Standard Model. Primary Goal of LHCb To understand better the origin of CP violation.
No Maxwell, no radio nor TV. No Röntgen, no X ray picture. No Quantum Mechanics, no modern electronics - understanding the most fundamental nature of material is one of the most important cultural activities. - elementary particles are one of the basic concepts of modern physics which should be known by everybody. Everybody knows that the earth is round! FAQ Why do we do basic research? - applied research will achieve “state of art”.- basic research opens new horizon. Why do we do/teach particle physics?
- experiments demands state of art technology: spin-off. - students learn how to work in an international collaboration with a given time scale and still to remain creative. Why do we do experimental particle physics? We are all curious to know how we are here!