Observation of Time Reversal Violation in the B0 Meson System

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 ${\bar{B}}^0$), 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, ${\bar{B}}^0\to B_{-}$ and $B_{-}\to {\bar{B}}^0$, as a function of the time difference between the two B decays. Using 468 million $B\bar{B}$ pairs produced in ${\rm Y}(4S)$ 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 through the exchange of initial and final states in transitions that can only be connected by a T-symmetry transformation.

arXiv comment7 pages, 3 postscript figures, 1 table, appendix with 4 pages containing supplementary material. Accepted by Phys. Rev. Lett

References in corpus (16)

• The BABAR Detector
• An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
• Observation of Large CP Violation in the Neutral B Meson System
• Observation of CP violation in the B^0 meson system
• Evidence for an anomalous like-sign dimuon charge asymmetry
• Direct CP Violating Asymmetry in B0 -> K+pi- Decays
• Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System
• Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays
• Search for T, CP and CPT Violation in B0-B0bar Mixing with Inclusive Dilepton Events
• Studying Indirect Violation of CP, T and CPT in a B-factory
• Time Reversal Violation from the entangled B0-antiB0 system
• CP, T and CPT versus temporal asymmetries for entangled states of the Bd-system
• Charge Asymmetry of Same-Sign Dileptons in $B^0$-${\bar{B}}^0$ Mixing
• Limits on the Decay-Rate Difference of Neutral B Mesons and on CP, T, and CPT Violation in B0-B0bar Oscillations
• Measurement of the charge asymmetry in semileptonic Bs decays
• T and CPT Symmetries in Entangled Neutral Meson Systems

Cited by in corpus (51)

• Direct test of time-reversal symmetry in the entangled neutral kaon system at a $\varphi$-factory
• Entangled baryons: violation of Inequalities based on local realism assuming dependence of decays on hidden variables
• Entanglement entropy in particle decay
• Quantum asymmetry between time and space
• Colloquium: Time-reversal violation with quantum-entangled B mesons
• Symmetry-protected entangling boundary zero modes in crystalline topological insulators
• New Experimental Limit on the Electric Dipole Moment of the Electron in a Paramagnetic Insulator
• Novel T-Violation observable open to any pair of decay channels at meson factories
• Subtleties in the BaBar measurement of time-reversal violation
• Reversing the Arrow of Time
• Status and prospects for $CPT$ and Lorentz invariance violation searches in neutral meson mixing
• One antimatter --- two possible thermodynamics
• Genuine T, CP, CPT asymmetry parameters for the entangled ${\mathbf{B}}_{\mathbf{d}}$ system
• Electric dipole moments of superheavy elements - A case study on copernicium
• Time reversal symmetry violation in entangled pseudoscalar neutral charmed mesons
• Time evolution of cascade decay
• The signal of ill-defined CPT weakening entanglement in the $B_d$ system
• The quantum theory of time, the block universe and human experience
• CP and CPT Violating Parameters Determined from the Joint Decays of $C=+1$ Entangled Neutral Pseudoscalar Mesons
• CP and other Symmetries of Symmetries
• Theory Overview of Testing Fundamental Symmetries
• Constraining dimension-six nonminimal Lorentz-violating electron-nucleon interactions with EDM physics
• T Violation and CPT Tests in Neutral-Meson Systems
• $\mathcal{C}\mathcal{P}$ violation with an unbroken $\mathcal{C}\mathcal{P}$ transformation
• Using time-dependent indirect $CP$ asymmetries to measure $T$ and $CPT$ violation in $B^0$-${\bar{B}}^0$ mixing
• Coherence and decoherence in photon spin-qubit entanglement
• Experimental prospects for C, P, T, CP, and CPT tests
• Novel correlated $D^0\overline{D}{}^0$ systems for $c/b$ physics and tests of $T/CPT$
• T violation and the Unidirectionality of Time: further details of the interference
• Testing Time Reversal Symmetry in Artificial Atoms
• Now, and the Flow of Time
• The KLOE-2 experiment: overview of recent results
• An anomaly in space and time and the origin of dynamics
• The study of NSIs in B and KL rare decays with three generations of quarks and interference effects between the standard model and NSIs
• Trapping Penguins with Entangled B Mesons
• On the group generated by $\mathbf{C}$, $\mathbf{P}$ and $\mathbf{T}$: ${\mathbf{I}}^2={\mathbf{T}}^2={\mathbf{P}}^2=\mathbf{ITP}=-1$, with applications to pseudo-scalar mesons
• Alternative interpretation of relativistic time-reversal and the time arrow
• Laser-assisted kaon decay and CPT symmetry violation
• Three Merry Roads to T-Violation
• A direct test of T symmetry in the neutral K meson system with Ks->pi l nu and Kl->3pi0 at KLOE-2
• Observability of`Cascade Mixing' in B0 --> J/psi K0
• $B^0-{\bar{B}}^0$ entanglement for an ideal experiment on the direct CP violation ${\varphi }_3/\gamma$ phase
• Precise Discussion of Time-Reversal Asymmetries in B-meson decays
• Symmetry violations at BaBar
• Status and Prospects of Discrete Symmetries Tests in Positronium Decays with the J-PET Detector
• Refined Applications of the "Collapse of the Wavefunction"
• Observation of Time-reversal Violation at BABAR
• New constraints on CPT symmetry violation in charm mesons
• Prospects at Future B Factories
• What We've Learned from Heavy Flavour Experiments Since CKM2010
• Recoil electron polarization-dependent T-odd correlations in neutrino elastic scattering on polarized electron target