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 (B0 or B¯0), and J/ψKL0 or cc¯KS0 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 468×106 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 ΔST+=-1.37±0.14(stat)±0.06(syst) and ΔST-=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.

Observation of Time-Reversal Violation in the B^{0} Meson System

LANCERI, LIVIO;VITALE, LORENZO;
2012

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 (B0 or B¯0), and J/ψKL0 or cc¯KS0 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 468×106 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 ΔST+=-1.37±0.14(stat)±0.06(syst) and ΔST-=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.
File in questo prodotto:
File Dimensione Formato  
PhysRevLett.109.211801-accepted.pdf

non disponibili

Tipologia: Documento in Pre-print
Licenza: Digital Rights Management non definito
Dimensione 282.12 kB
Formato Adobe PDF
282.12 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11368/2767934
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 153
  • ???jsp.display-item.citation.isi??? 128
social impact