相关论文: Polarization States in B -> rho K* and New Physics
It has been observed in B->phiK* and B^{0(+)}->rho^{0(+)}K^{*0} that the fraction of transverse decays, fT, and the fraction of longitudinal decays, fL, are roughly equal, in opposition to the naive expectation, fT/fL << 1. If one requires…
In this paper, we examine B -> VT decays (V is a vector and T is a tensor meson), whose final-state particles can have transverse or longitudinal polarization. Measurements have been made of B -> \phi K_2^*, and it is found that fT/fL is…
We consider the new-physics (NP) solution to the polarization puzzle in B -> phi K* decays. We note that any such solution must reproduce the data in B -> phi Ks, where there are disagreements with the standard model in CP-asymmetry…
We perform an analysis of the K* polarization states in the exclusive B meson decay B0->K*0(-> K- pi+)l+ l- (l=e, mu, tau) in the low dilepton mass region, where the final vector meson has a large energy. Working in the transversity basis,…
B --> K^* \pi and B --> \rho K decays involve the same quark-level processes as B --> \pi K. Analyzing the measurements of the former decays might be able to shed additional light on the new-physics hints in the current B --> \pi K data. We…
With a sample of about 227 million BB pairs recorded with the BABAR detector we perform a full angular analysis of the decay B0->phi K*0(892). Ten measurements include polarization, phases, and five CP asymmetries. We also observe the decay…
The recent observations of sizable transverse fractions of B-> phi K* are strongly contrary to the Standard Model expectation. We analyze all possible new-physics four-quark operators. We find that two classes of new-physics operators could…
$B\to\phi K^*$ ($\btos$) is three separate decays, one for each polarization of the final-state vector mesons (one longitudinal, two transverse). It is observed that the fraction of transverse decays, $\fT$, and the fraction of longitudinal…
We discuss, in detail, the K* polarization states in the exclusive B meson decay B0-> K*0(-> K-pi+)l^+l^- (l=e, \mu, \tau) in the low dilepton mass region. We focus on the study of the angular distribution of this decay that provides…
First observations of the B_s0->D_s*- pi+, B_s0->D_s- rho+ and B_s0->D_s*- rho+ decays are reported together with measurements of their branching fractions: B(B_s0->D_s*- pi+)=(2.4 +0.5-0.4(stat.) +-0.3(syst.) +-0.4(fs))x10^(-3), B(Bs->D_s-…
With the full $\babar$ data sample of 465 million BaBar pairs, we observe the decays B+- ->phi(1020) K_1(1270)+- and B+- ->phi(1020) K_2*(1430) +-. We measure the branching fractions (6.1+-1.6+-1.1)\times 10^{-6} and (8.4+- 1.9+- 0.9)\times…
The pure penguin process $B\to \phi K^*$ is one of the most important probes of physics beyond the Standard Model. Recently BaBar and Belle have measured the unexpectedly large transverse polarization in the decays $B\to \phi K^*$, which…
The rare decay B -> K* (-> K pi) mu+ mu- is regarded as one of the crucial channels for B physics as the polarization of the K* allows a precise angular reconstruction resulting in many observables that offer new important tests of the…
Factorizable amplitudes in B decays to light vector meson pairs give a longitudinal polarization satisfying 1- f_L =O(1/m_b^2). This remains formally true when non-factorizable graphs are included in QCD factorization, and is numerically…
The photon polarization in radiative decays B -> Y gamma is known to be a subtle probe of the effective Lagrangian structure and possible New Physics effects. We discuss exclusive decay mode B -> phi K gamma where the experimentally…
We explore the decays of $B\to V_1V_2$ ($V_{1,2}= (\rho, \omega,K^*, \phi)$ and $B= (B^0, B^+,B_s)$) with transverse polarizations. We explicitly evaluate the eigenstates of T-odd scalar operators involving spins for the first time, which…
In pure-penguin bbar -> sbar B -> V_1 V_2 decays (V_{1,2} are vector mesons), fT/fL ~= 1 has been observed (fT (fL) is the polarization fraction of transverse (longitudinal) decays). Explanations of this unexpectedly large result have been…
The experimental observation of sizable transverse components for B-> phi K^* decay is in strong contrast to all other VV modes, and poses a challenge to our understanding of B decay dynamics. Observing that the gluon emitted from b->…
The decay mode B -> rho pi is currently studied as a channel allowing, in principle, to measure without ambiguities the angle alpha of the unitarity triangle. It is also investigated by the CLEO Collaboration where a branching ratio larger…
We demonstrate that the polarization fractions of most tree-dominated $B\to VV$ decays can be simply understood by means of kinematics in the heavy-quark or large-energy limit. For example, the longitudinal polarization fractions $R_L$ of…