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Unformatted text preview: – 1– TESTS OF CONSERVATION LAWS Updated May 2010 by L. Wolfenstein (Carnegie-Mellon Uni- versity), T.G. Trippe (LBNL), and C.-J. Lin (LBNL). In keeping with the current interest in tests of conservation laws, we collect together a Table of experimental limits on all weak and electromagnetic decays, mass differences, and moments, and on a few reactions, whose observation would violate conservation laws. The Table is given only in the full Review of Particle Physics , not in the Particle Physics Booklet. For the benefit of Booklet readers, we include the best limits from the Table in the following text. Limits in this text are for CL=90% unless otherwise specified. The Table is in two parts: “Discrete Space-Time Symmetries,” i.e. , C , P , T , CP , and CP T ; and “Number Conservation Laws,” i.e. , lepton, baryon, hadronic ﬂavor, and charge conservation. The references for these data can be found in the the Particle Listings in the Review . A discussion of these tests follows. CP T INVARIANCE General principles of relativistic field theory require invari- ance under the combined transformation CP T . The simplest tests of CP T invariance are the equality of the masses and lifetimes of a particle and its antiparticle. The best test comes from the limit on the mass difference between K and K . Any such difference contributes to the CP-violating parameter . Assuming CP T invariance, φ , the phase of should be very close to 44 ◦ . (See the review “ CP Violation in K L decay” in this edition.) In contrast, if the entire source of CP violation in K decays were a K − K mass difference, φ would be 44 ◦ + 90 ◦ . Assuming that there is no other source of CP T violation than this mass difference, it is possible to deduce that m K − m K ≈ 2( m K L − m K S ) | η | ( 2 3 φ + − + 1 3 φ 00 − φ SW ) sin φ SW , where φ SW = (43 . 51 ± . 05) ◦ , the superweak angle. Using our best values of the CP-violation parameters, we get | ( m K − m K ) /m K | ≤ . 8 × 10 − 18 at CL=90%. Limits can also be CITATION: K. Nakamura et al. (Particle Data Group), JPG 37 , 075021 (2010) (URL: http://pdg.lbl.gov) July 30, 2010 14:34 – 2– placed on specific CP T-violating decay amplitudes. Given the small value of (1 − | η 00 /η + − | ), the value of φ 00 − φ + − provides a measure of CP T violation in K L → 2 π decay. Results from CERN  and Fermilab  indicate no CP T-violating effect....
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This note was uploaded on 06/07/2011 for the course PHYS 4132 taught by Professor Kutter during the Spring '11 term at University of Florida.
- Spring '11