The CP violation phase phi_s and charge asymmetries in B^0_s decays have been measured by the D0 experiment in Run II of the Fermilab Tevatron Collider where proton anti-proton collisions take place at a center of mass energy of sqrt{s}=1.96 TeV. The measurements are based on integrated luminosities between 1.0 fb^-1 and 2.8 fb^-1. A 1.8 sigma deviation from the Standard Model is observed in the measurement of the CP violation phase phi_s=-0.57^{+0.24}_{-0.30} (stat) ^{+0.07}_{-0.02} (syst) rad in the decay channel B^0_s -> J/psi phi. A combination with CDF results yields a 2.2 sigma deviation from the Standard Model.
Using 1fb^{-1} of pp collision data collected at center of mass energy sqrt{s} = 7 TeV during 2011 by the LHCb detector. Measurements of the triple product asymmetries, polarisation amplitudes and strong phase difference in the decay B_s^0 to phi phi are presented.
We present branching fraction and CP asymmetry measurements as well as angular studies of B to phi phi K decays using 464 x 10^6 BBbar events collected by the BaBar experiment. The branching fractions are measured in the phi phi invariant mass range below the eta_c resonance (m_phiphi <2.85 GeV). We find B(B+ to phi phi K+) = (5.6 +/- 0.5 +/- 0.3) x 10^-6 and B(B0 to phi phi K0) = (4.5 +/- 0.8 +/- 0.3) x 10^-6, where the first uncertaintiy is statistical and the second systematic. The measured direct CP asymmetries for the B+- decays are A_CP = -0.10 +/- 0.08 +/- 0.02 below the eta_c threshold…
Rates, Polarizations, and Asymmetries in Charmless Vector-Vector B Decays
With a sample of approximately 89 million BBbar pairs collected with the BABAR detector, we measure branching fractions, determine the degree of longitudinal polarization, and search for direct CP violation in the decays B0=>phiK*0 and B+=>phiK*+. We perform a search for other charmless vector-vector B decays involving rho and K*(892) resonances and observe the decays B+=>rho0K*+ and B+=>rho0rho+. The branching fractions are measured to be BR(phiK*0)=(11.1^{+1.3}_{-1.2} \pm 1.1)10^{-6}, BR(phiK*+)=(12.1^{+2.1}_{-1.9} \pm 1.5)10^{-6}, BR(rho0K*+)=(7.7^{+2.1}_{-2.0} \pm 1.4)10^{-6}, and BR(rho0r…
Observation of Time-Dependent CP Violation in B0 -> eta' K0 Decays and Improved Measurements of CP Asymmetries in B0 -> phiK0, KsKsKs and B0 -> J/psi K0 Decays
Azimuthal asymmetries in semi-inclusive production of positive (h^+) and negative hadrons (h^-) have been measured by scattering 160 GeV muons off longitudinally polarised deuterons at CERN. The asymmetries were decomposed in several terms according to their expected modulation in the azimuthal angle phi of the outgoing hadron. Each term receives contributions from one or several spin and transverse-momentum-dependent parton distribution and fragmentation functions. The amplitudes of all phi-modulation terms of the hadron asymmetries integrated over the kinematic variables are found to be cons…
Recent results using B_s -> J/Psi phi decays for measuring the CP violating phase, phi_s, and the decay width difference for the two mass eigenstates, Delta Gamma_s, are presented from the CDF and D0 experiments at the Fermilab Tevatron collider.
Measurement of CP Asymmetries and Branching Fractions in a Time-Dependent Dalitz Analysis of B^0-->(rho pi)^0 and a Constraint on the Quark Mixing Angle phi_2
We briefly discuss measurements of CP violation in Bs --> J/psi phi decay. Both the phenomenology of Bs mixing and the importance of the measurement to searches for new physics, as well as technical details and issues with the analysis are included. While current results are consistent with the standard model, even large contributions from new physics cannot be excluded.
Hadrons containing b-quarks represent a great opportunity to investigate the flavor sector of the Standard Model (SM) and to look for New Physics effects (NP). In this report we review the most up-to-date results on b-hadron decay rates and CP violating asymmetries: among other results, we report Branching Ratio (BR) and CP Violation (CPV) of B0, B0s and Lambda0b decay modes into pairs of charmless charged hadrons (pions, kaons and protons), the first search for CPV in B0s to phiphi decays and the first observation of bs to K0starK0star decay. Two new results from the CDF collaboration are rep…
We present measurements of the branching fractions, longitudinal polarization, and direct CP-violation asymmetries for the decays B+ -> rho0 K*+ and B+ -> f0(980) K*+ with a sample of 467+/-5 million BBbar pairs collected with the BaBar detector at the PEP-II asymmetric-energy e^+e^- collider at the SLAC National Accelerator Laboratory. We observe B+ -> rho0 K*+ with a significance of 5.3 sigma and measure the branching fraction Br(B+ -> rho0 K*+) = (4.6+/-1.0+/-0.4) x 10^{-6}, the longitudinal polarization fL = 0.78+/-0.12+/-0.03, and the CP-violation asymmetry ACP = 0.31+/-0.13+/-0.03. We ob…
We measure the inclusive single muon charge asymmetry and the like-sign dimuon charge asymmetry in $p \bar{p}$ collisions using the full data set of 10.4 fb$^{-1}$ collected with the D0 detector at the Fermilab Tevatron. The standard model predictions of the charge asymmetries induced by CP violation are small in magnitude compared to the current experimental precision, so non-zero measurements could indicate new sources of CP violation. The measurements differ from the standard model predictions of CP violation in these asymmetries with a significance of 3.6 standard deviations. These results…
Recent analyses of single $W$ and $Z$ boson production properties and asymmetries from the CDF and DØ experiments at the Fermilab Tevatron are reported. For $W$ boson production, measurements of the production and lepton charge asymmetries are presented. For $Z/γ^*$ production, the following measurements are presented: $dσ/dy$, $(1/σ) (dσ/dp_T)$, $(1/σ) (dσ/d\phistar)$, lepton angular coefficients, and $A_{FB}$ with extraction of $\sin^2θ_W$ and the light quark couplings to the $Z$. Most of these measurements are in good agreement with QCD predictions.
We present a new measurement of the unitarity triangle angle phi3 using a Dalitz plot analysis of the KsPi+Pi- decay of the neutral D meson produced in B->D(*)K decays. The method exploits the interference between D0 and D0bar to extract the angle phi3, strong phase delta and the ratio r of suppressed and allowed amplitudes. We apply this method to a 605 fb-1 data sample collected by the Belle experiment. The analysis uses three decays: B->DK, and B->D*K with D*->DPi0 and D*->Dgamma, as well as the corresponding charge-conjugate modes. From a combined maximum likelihood fit to the three modes,…
Study of CP violation in the decay channel Bs->J/psi phi is essential to exploring and constraining physics beyond the Standard Model in the quark flavour sector. The experimental progress in this area of activity at the LHC and Tevatron is discussed.
$CP$ violation asymmetry is expected to be very small within the Standard Model. Observation of $CP$ violation in charm sector would hint towards New Physics. Time-reversal asymmetry is sensitive to $CPV$ via the $CPT$ Theorem, and is a clean and alternative way to search for CP violation in charm decays. This is achieved by the use of triple-product correlations in 4-body charm meson decays. The results from previous searches at BaBar and LHCb Collaborations and the latest results from Belle are reported. The most recent result from Belle performed in $D^{0} \to K^{+}K^{-}π^{+}π^{-}$ decays u…
I report some recent results on direct CP violation measurements in hadronic decays collected by the upgraded Collider Detector (CDF II) at the Fermilab Tevatron: CP-violating asymmetries in the two-body non-leptonic charmless decays of $b$-hadrons, the first reconstruction in hadron collisions of the suppressed decays $B^- \to D(\to K^+π^-)K^-$ and $B^- \to D(\to K^+π^-)π^-$, and the measurement of TP asymmetries in the $B^{0}_{s} \to ϕϕ$ decays.
We present world-leading results on CP-violating asymmetries and branching fractions of several decay modes of B0, B0s, and Λb hadrons into charmless two-body, and of B\pm into charm, final states collected by the CDF detector. We also report a new measurement of CP-violating asymmetries in D\ast\pm-tagged D0 \rightarrow h+h- (h = K or π) decays, where any enhancement from the Standard Model prediction would be unambiguous evidence for New Physics.
The knowledge of charm production asymmetries is an important prerequisite for many of the possible searches for CP violation in charm. Measurements of these asymmetries at hadron colliders can also help to improve our understanding of QCD. These proceedings review existing measurements and discuss some of the experimental challenges of determining charge asymmetries at the per-mille level.
New Measurements of Time-Dependent CP-Violating Asymmetries in b --> s Transitions at Belle
我们基于在KEKB能量非对称e+e-对撞机的Belle探测器上的Upperion（4S）共振处收集的275 x 10^6个BBbar对的样本，对B 0--> phi K 0，K+ K-Ks，f0（980）Ks，eta' Ks，omega Ks，Ks pi 0和K*0 gamma（K*0 --> Ks pi 0）衰变中CP破坏参数进行了新的测量。一个中性B介子在一个特定的衰变通道中被完全重建，伴随的B介子的味道从它的衰变产物中被识别。从两个B衰变之间的适当的时间间隔的分布中的不对称性获得每个衰变模式的CP-违反参数。所有结果都是初步的。
Azimuthal asymmetries in exclusive electroproduction of a real photon from an unpolarized deuterium target are measured with respect to beam helicity and charge. They appear in the distribution of these photons in the azimuthal angle phi around the virtual-photon direction, relative to the lepton scattering plane. The extracted asymmetries are attributed to either the deeply virtual Compton scattering process or its interference with the Bethe-Heitler process. They are compared with earlier results on the proton target. In the measured kinematic region, the beam-charge asymmetry amplitudes and…
Using data collected by LHCb experiment in 2011 we report the measurements of charge asymmetries in charmless decays of B mesons in two or three charged kaons or pions. We find positive charge asymmetries in the channels Bs->K-pi+(3.3 sigmas), B+->K+pi+pi- (2.8 sigmas), and B+->pi+pi+pi- (4.2 sigmas) and negative in B0->K+pi-(6 sigmas),B+->K+K+K- (3.7 sigma), B+->K+K-pi+ (3.0 sigma).
A first measurement of time-reversal (T) asymmetries that are not also CP asymmetries has been recently achieved by the BaBar collaboration. We analyze the measured asymmetries in the presence of direct CP violation, CPT violation, wrong strangeness decays and wrong sign semileptonic decays. We note that the commonly used S_{ψK} and C_{ψK} parameters are CP-odd, but have a T-odd CPT-even part and a T-even CPT-odd part. We introduce parameters that have well-defined transformation properties under CP, T and CPT. We identify contributions to the measured asymmetries that are T conserving. We exp…
Prospects in CP violation measurements at the Tevatron Collider
费米实验室的Tevatron对撞机是目前最丰富的b-强子来源，这要归功于1.96 TeV ppbar碰撞中的大b-bbar产生截面。最近的探测器升级允许广泛的CP破坏和味道混合测量，完全竞争（自标记模式的不对称性）或互补（B_s和b-重子衰变的不对称性）与B-工厂。在本文中，我们回顾了一些最近的CP破坏的结果，从DO和CDF合作，我们讨论了未来的测量前景。
We revisit the topic of triple-product asymmetries which probe CP violation through differential distributions. We construct distributions with well-defined discrete symmetry properties and characterize the asymmetries formed upon them. It is stressed that the simplest asymmetries may not be optimal. We explore systematic generalizations having limited reliance on the process dynamics and phase-space parametrization. They exploit larger fractions of the information contained in differential distributions and may lead to increased sensitivities to CP violation. Our detailed treatment of the cas…
