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Published November 21, 2012 | Version Supplemental Material + Published
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Observation of Time-Reversal Violation in the B^0 Meson System

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Abstract

Although CP violation in the B meson system has been well established by the B factories, there has been no direct observation of time-reversal violation. The decays of entangled neutral B mesons into definite flavor states (B^0 or B^0), and J/ψK_L^0 or cc K_S^0 final states (referred to as B_+ or B_-), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, B^0→B_- and B_-→B^0, as a function of the time difference between the two B decays. Using 468×10^6 BB pairs produced in Υ(4S) decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding ΔS_T^+=-1.37±0.14(stat)±0.06(syst) and ΔS_T^-=1.17±0.18(stat)±0.11(syst). These nonzero results represent the first direct observation of T violation through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.

Additional Information

© 2012 American Physical Society. Received 24 July 2012; published 19 November 2012. We are grateful for the excellent luminosity and machine conditions provided by our PEP-II colleagues, and for the substantial dedicated effort from the computing organizations that support BABAR. The collaborating institutions wish to thank SLAC for its support and kind hospitality. This work is supported by DOE and NSF (USA), NSERC (Canada), CEA and CNRS-IN2P3 (France), BMBF and DFG(Germany), INFN (Italy), FOM (The Netherlands), NFR (Norway), MES (Russia), MINECO (Spain), STFC (United Kingdom). Individuals have received support from the Marie Curie EIF (European Union), the A. P. Sloan Foundation (USA) and the Binational Science Foundation (USA-Israel).

Attached Files

Published - PhysRevLett.109.211801.pdf

Supplemental Material - README.TXT

Supplemental Material - epaps.pdf

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Additional details

Identifiers

Eprint ID
35973
Resolver ID
CaltechAUTHORS:20121213-095940056

Funding

Department of Energy (DOE)
NSF
Natural Sciences and Engineering Research Council of Canada (NSERC)
Commissariat à l'Energie Atomique (CEA)
BMBF
Istituto Nazionale di Fisica Nucleare (INFN)
Stichting voor Fundamenteel Onderzoek der Materie (FOM)
Norwegian Research Council
Ministry of Education and Science of the Russian Federation
MINECO (Spain)
Science and Technology Facilities Council (STFC)
Marie Curie Fellowship
Alfred P. Sloan Foundation
Binational Science Foundation (USA-Israel)
Centre National de la Recherche Scientifique (CNRS)
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)
Deutsche Forschungsgemeinschaft (DFG)

Dates

Created
2012-12-13
Created from EPrint's datestamp field
Updated
2023-10-20
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