758 articles – 2773 Notices  [english version]
 HAL : in2p3-00720925, version 1
 arXiv : 1207.5832
 Physical Review Letters 109 (2012) 211801
 Observation of Time-Reversal Violation in the B0 Meson System
 BABAR Collaboration(s)
 (2012)
 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 $\bar{B}^0$), and $J/\psi K_S^0$ or $c\bar{c} K_S^0$ final states (referred to as $B_+$ or $B_-$), allow comparisons between the probabilities of four pairs of T-conjugated transitions, for example, $\bar{B}^0 \rightarrow B_-$ and $B_- \rightarrow \bar{B}^0$, as a function of the time difference between the two B decays. Using 468 million $B\bar{B}$ pairs produced in $\Upsilon(4S)$ decays collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral B mesons, yielding $\Delta S_T^+ = -1.37 \pm 0.14 (stat.) \pm 0.06 (syst.)$ and $\Delta S_T^- = 1.17 \pm 0.18 (stat.) \pm 0.11 (syst.)$. These nonzero results represent the first direct observation of T violation in the B meson system, through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.
 Thème(s) : Physique/Physique des Hautes Energies - Expérience
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1207.5832
 in2p3-00720925, version 1 http://hal.in2p3.fr/in2p3-00720925 oai:hal.in2p3.fr:in2p3-00720925 Contributeur : Françoise Marechal <> Soumis le : Jeudi 26 Juillet 2012, 10:57:08 Dernière modification le : Jeudi 13 Décembre 2012, 15:11:57