Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S)
We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy e +e - collider at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb -1 recorded at the γ(4S) resonance and 3.9 fb...
| প্রধান লেখক: | , , , , , , , , , , , , , , , , , , , , , , , , |
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| বিন্যাস: | Journal article |
| ভাষা: | English |
| প্রকাশিত: |
2002
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| _version_ | 1826286845981360128 |
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| author | Aubert, B Boutigny, D Gaillard, J Hicheur, A Karyotakis, Y Lees, J Robbe, P Tisserand, V Palano, A Pompili, A Chen, G Chen, J Qi, N Rong, G Wang, P Zhu, Y Eigen, G Stugu, B Abrams, G Borgland, A Breon, AB Brown, D Button-Shafer, J Cahn, R Clark, A |
| author_facet | Aubert, B Boutigny, D Gaillard, J Hicheur, A Karyotakis, Y Lees, J Robbe, P Tisserand, V Palano, A Pompili, A Chen, G Chen, J Qi, N Rong, G Wang, P Zhu, Y Eigen, G Stugu, B Abrams, G Borgland, A Breon, AB Brown, D Button-Shafer, J Cahn, R Clark, A |
| author_sort | Aubert, B |
| collection | OXFORD |
| description | We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy e +e - collider at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb -1 recorded at the γ(4S) resonance and 3.9 fb -1 off resonance. One of the neutral B mesons, which are produced in pairs at the γ(4S), is fully reconstructed in the CP decay modes J/ ψK S0, ψ(2S)K S0, χ c1K S0, J/ψK* 0 (K* 0→K S0π 0) and J/ψK L0, or in flavor-eigenstate modes involving D (*)π/p/a 1 and J/ψK* 0 (K* 0→K +π -). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural netsvork tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B 0-B̄ 0 oscillation frequency Δm d are measured with a sample of about 6350 fully-reconstructed B 0 decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds Δm d=0.516±0.016(stat)±0.010(syst) ps -1. The value of the asymmetry amplitude sin 2β is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B 0 decays in the CP-eigenstate modes. We find sin 2β=0.59 ±0.14(stat)±0. 05(syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter |λ|=0. 93±0.09(stat)±0.03(syst), which is consistent with the expectation of |λ|=1 for no direct CP violation. © 2002 The American Physical Society. |
| first_indexed | 2024-03-07T01:49:46Z |
| format | Journal article |
| id | oxford-uuid:99aef5ed-176e-4f0f-9696-f15dd4571a2c |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:49:46Z |
| publishDate | 2002 |
| record_format | dspace |
| spelling | oxford-uuid:99aef5ed-176e-4f0f-9696-f15dd4571a2c2022-03-27T00:16:07ZStudy of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S)Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:99aef5ed-176e-4f0f-9696-f15dd4571a2cEnglishSymplectic Elements at Oxford2002Aubert, BBoutigny, DGaillard, JHicheur, AKaryotakis, YLees, JRobbe, PTisserand, VPalano, APompili, AChen, GChen, JQi, NRong, GWang, PZhu, YEigen, GStugu, BAbrams, GBorgland, ABreon, ABBrown, DButton-Shafer, JCahn, RClark, AWe present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at the PEP-II asymmetric-energy e +e - collider at the Stanford Linear Accelerator Center. The data sample consists of 29.7 fb -1 recorded at the γ(4S) resonance and 3.9 fb -1 off resonance. One of the neutral B mesons, which are produced in pairs at the γ(4S), is fully reconstructed in the CP decay modes J/ ψK S0, ψ(2S)K S0, χ c1K S0, J/ψK* 0 (K* 0→K S0π 0) and J/ψK L0, or in flavor-eigenstate modes involving D (*)π/p/a 1 and J/ψK* 0 (K* 0→K +π -). The flavor of the other neutral B meson is tagged at the time of its decay, mainly with the charge of identified leptons and kaons. A neural netsvork tagging algorithm is used to recover events without a clear lepton or kaon tag. The proper time elapsed between the decays is determined by measuring the distance between the decay vertices. Wrong-tag probabilities, the time-difference resolution function, and the B 0-B̄ 0 oscillation frequency Δm d are measured with a sample of about 6350 fully-reconstructed B 0 decays in hadronic flavor-eigenstate modes. A maximum-likelihood fit to this flavor eigenstate sample finds Δm d=0.516±0.016(stat)±0.010(syst) ps -1. The value of the asymmetry amplitude sin 2β is determined from a simultaneous maximum-likelihood fit to the time-difference distribution of the flavor-eigenstate sample and about 642 tagged B 0 decays in the CP-eigenstate modes. We find sin 2β=0.59 ±0.14(stat)±0. 05(syst), demonstrating that CP violation exists in the neutral B meson system. We also determine the value of the CP violation parameter |λ|=0. 93±0.09(stat)±0.03(syst), which is consistent with the expectation of |λ|=1 for no direct CP violation. © 2002 The American Physical Society. |
| spellingShingle | Aubert, B Boutigny, D Gaillard, J Hicheur, A Karyotakis, Y Lees, J Robbe, P Tisserand, V Palano, A Pompili, A Chen, G Chen, J Qi, N Rong, G Wang, P Zhu, Y Eigen, G Stugu, B Abrams, G Borgland, A Breon, AB Brown, D Button-Shafer, J Cahn, R Clark, A Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S) |
| title | Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S) |
| title_full | Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S) |
| title_fullStr | Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S) |
| title_full_unstemmed | Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S) |
| title_short | Study of time-dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the γ (4S) |
| title_sort | study of time dependent cp violating asymmetries and flavor oscillations in neutral b decays at the γ 4s |
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