8,061 research outputs found
Branching fraction and CP asymmetry of the decays B+→K0Sπ+ and B+→K0SK+
Full text linkAn analysis of B+ → K0
Sπ+ and B+ → K0
S K+ decays is performed with the LHCb experiment. The pp
collision data used correspond to integrated luminosities of 1 fb−1 and 2 fb−1 collected at centre-ofmass
energies of
√
s = 7 TeV and
√
s = 8 TeV, respectively. The ratio of branching fractions and the
direct CP asymmetries are measured to be B(B+ → K0
S K+
)/B(B+ → K0
Sπ+
) = 0.064 ± 0.009 (stat.) ±
0.004 (syst.), ACP(B+ → K0
Sπ+
) = −0.022 ± 0.025 (stat.) ± 0.010 (syst.) and ACP(B+ → K0
S K+
) =
−0.21 ± 0.14 (stat.) ± 0.01 (syst.). The data sample taken at
√
s = 7 TeV is used to search for
B+
c
→ K0
S K+ decays and results in the upper limit ( fc · B(B+
c
→ K0
S K+
))/( fu · B(B+ → K0
Sπ+
)) <
5.8 × 10−2 at 90% confidence level, where fc and fu denote the hadronisation fractions of a ¯b
quark
into a B+
c or a B+ meson, respectively
The Cerebral Palsy Quality of Life for Children (CP QOL-Child): Evidence of construct validity
No full textThe Cerebral Palsy Quality of Life for Children (CP QOL-Child) is the first health condition-specific questionnaire designed for measuring QOL in children with cerebral palsy (CP). However, its construct validity has not yet been confirmed by confirmatory factor analysis (CFA). Hence, this study assessed the construct validity of the caregiver proxy-report version of the Chinese version of the CP QOL-Child in children with CP using CFA. ;A total of 312 children with CP (mean age: 8.59 years, SD: 2.52 years) and their caregivers participated in this study. The Chinese version of the CP QOL-Child was completed by the caregivers of children with CP. Then, CFA was applied to evaluate the seven-factor measurement structure of the CP QOL-Child. The seven-factor CFA model had an adequate fit to our data as judged by chi(2) statistic and various goodness-of-fit (GOF) indices, including the root mean square error of approximation (RMSEA). This study provided empirical evidence of the construct validity of the CP QOL-Child to support its use with children with CP in the Chinese speaking society. (C) 2012 Elsevier Ltd. All rights reserved
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
Full text linkThis Letter reports a measurement of the CP violation observables SJ/ψK0S and CJ/ψK0S in the decay channel B0→J/ψK0S performed with 1.0 fb−1 of pp collisions at s√=7 TeV collected by the LHCb experiment. The fit to the data yields SJ/ψK0S=0.73±0.07(stat)±0.04(syst) and CJ/ψK0S=0.03±0.09(stat)±0.01(syst). Both values are consistent with the current world averages and within
expectations from the Standard Model
Measurement of the CP-violating phase \phi s in Bs->J/\psi\pi+\pi- decays
Full text linkMeasurement of the mixing-induced CP-violating phase phi_s in Bs decays is of prime importance in probing new physics. Here 7421 +/- 105 signal events from the dominantly CP-odd final state J/\psi pi+ pi- are selected in 1/fb of pp collision data collected at sqrt{s} = 7 TeV with the LHCb detector. A time-dependent fit to the data yields a value of phi_s=-0.019^{+0.173+0.004}_{-0.174-0.003} rad, consistent with the Standard Model expectation. No evidence of direct CP violation is found
Modulation of serum concentrations and hepatic metabolism of 17beta-estradiol and testosterone by amitraz in rats.
No full text
A study of CP violation in B±→DK±B±→DK± and B±→Dπ±B±→Dπ± decays with D→KS0K±π∓ final states
Full text linkA first study of CP violation in the decay modes B± → [K0S K ±π∓]Dh± and B± → [K0S K ∓π±]Dh±, where h labels a K or π meson and D labels a D0 or D0 meson, is performed. The analysis uses the LHCb data set collected in pp collisions, corresponding to an integrated luminosity of 3 fb−1. The analysis is sensitive to the CP-violating CKM phase γ through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of γ using other decay modes
Measurement of mixing and CP violation parameters in two-body charm decays
Full text linkA study of mixing and indirect CP violation in D 0 mesons through the determination of the parameters y CP and A Γ is presented. The parameter y CP is the deviation from unity of the ratio of effective lifetimes measured in D 0 decays to the CP eigenstate K + K − with respect to decays to the Cabibbo favoured mode K −π+. The result measured using data collected by LHCb in 2010, corresponding to an integrated luminosity of 29 pb−1, is y CP = (5.5 ± 6.3stat ± 4.1syst) × 10−3. The parameter A Γ is the asymmetry of effective lifetimes measured in decays of D 0 and D0 mesons to K + K −. The result is A Γ = (−5.9 ± 5.9stat ± 2.1syst) × 10−3. A data-driven technique is used to correct for lifetime-biasing effects
Spontaneous CP Violating Phase and CKM Matrix Phase
No full text在這篇論文我們研究自發性CP破缺相角與Cabibbo-Kobayashi-Maskawa(CKM)矩陣相角的連結。我們先介紹在標準模型中的CP破缺，以及自發性CP破缺，然後提出一類新的模型來連結在CKM混合矩陣中的CP破缺相角和由Higgs位能中自發性CP破缺所產生的CP相角。建立一個多重Higgs伴隨Peccei-Quinn(PQ)對稱的模型來實現這個概念。這個模型有一些有趣的現象學含義。當所有Higgs的質量變大時CP破缺相角並不會消失。一般來說，在樹狀層級時會有中性Higgs傳遞的味變化中性流(FCNC)交互作用。然而，跟一般多重Higgs模型不同的是，FCNC的Yuwaka耦合會被夸克的質量和CKM混合角所確定。我們也詳細研究了關於中性介子的混合與中子的電偶極矩實驗數據所衍生的涵義。In this thesis we study the connection between the spontaneous CP violating phase and the Cabibbo-Kobayashi-Maskawa (CKM) matrix phase. At first an introduction to CP violation in the Standard Model is presented, following by the spontaneous CP violation, and then a new class of models is proposed to connect the CP violating phase in the CKM mixing matrix with the CP phases responsible for the spontaneous CP violation in the Higgs potential. A multi-Higgs model with Peccei-Quinn(PQ) symmetry is constructed to realize this idea. This model has some interesting phenomenological implications. The CP violating phase does not vanish when all Higgs masses become large. In general, there are flavor changing neutral current (FCNC) interactions mediated by neutral Higgs bosons at the tree level. Unlike the general multi-Higgs models, however, the FCNC Yukawa couplings are fixed in terms of the quark masses and CKM mixing angles. Implications from experimental data for neutral meson mixing and the neutron electric dipole moment are well-studied.1. Introduction : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1.1 Standard Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 CP violation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.1 P, C, T transformation . . . . . . . . . . . . . . . . . . . . . . 6.2.2 The Cabibbo-Kobayashi-Maskawa Model . . . . . . . . . . . . 7.2.3 The determination of VCKM parameters . . . . . . . . . . . . . 11.2.4 CP violating experimental data and CKM model . . . . . . . 13. Multi-Higgs models and spontaneous CP violation : : : : : : : : : : : : : : 19.1 Two Higgs Doublet Model . . . . . . . . . . . . . . . . . . . . . . . . 19.2 Weinberg Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 The strong CP problem and Peccei-Quinn symmetry . . . . . . . . . 24. New model building : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 26.1 Making SCPV phase identical to CKM phase . . . . . . . . . . . . . 26.2 Multi-Higgs model building . . . . . . . . . . . . . . . . . . . . . . . 32.2.1 Higgs potential and CP violating phase . . . . . . . . . . . . . 32.2.2 Mass matrices of Higgs . . . . . . . . . . . . . . . . . . . . . . 34.3 The Yukawa couplings . . . . . . . . . . . . . . . . . . . . . . . . . . 40. Some Implications : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 42.1 Neutral meson mixing . . . . . . . . . . . . . . . . . . . . . . . . . . 42.2 Electric dipole moment of neutron . . . . . . . . . . . . . . . . . . . . 46. Conclusion : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 5
A4 and CP symmetry and a model with maximal CP violation
No full textAbstractWe study a second CP symmetry compatible with the A4 flavor group, which interchanges the representations 1′ and 1″. We analyze the lepton mixing patterns arising from the A4 and CP symmetry broken to residual subgroups Z3 and Z2×CP in the charged lepton and neutrino sectors respectively. One phenomenologically viable mixing pattern is found, and it predicts maximal atmospheric mixing angle as well as maximal Dirac CP phase, trivial Majorana phases and the correlation sin2θ12cos2θ13=1/3. We construct a concrete model based on the A4 and CP symmetry, the above interesting mixing pattern is achieved, the observed charged lepton mass hierarchy is reproduced, and the reactor mixing angle θ13 is of the correct order
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