相关论文: Observables in the Decays of B to Two Vector Meson…
For the photoproduction of vector mesons, all single and double spin observables involving vector meson two-body decays are defined consistently in the $\gamma N$ center of mass. These definitions yield a procedure for extracting physically…
We present measurements of B meson decays to the final states omegaK*, omegarho, and omega f_0, where K* indicates a spin 0, 1, or 2 strange meson. The data sample corresponds to 465x10^6 BBbar pairs collected with the BABAR detector at the…
Polarization measurements provide a detailed method to test the Standard Model and to search for new physics. Most previous studies depend on pre-selected coordinates, which blurs the significance of the results. The construction of two…
We discuss the eight independent spin observables for the $W$ boson in terms of its vector and tensor polarizations and identify the angular distributions and asymmetries able to separate them in collider experiments. The results are…
An important experimental effort has been accomplished in recent years in the measurement of rates, polarization and CP observables in $B$ decays into two light vector mesons. On the theoretical side, after a very consistent effort done…
Angular distributions of a B meson decaying into two vector mesons are discussed with emphasis on time evolution effects on the complete set of amplitude bilinears. Time integrated quantities are suggested to observe substantial CP…
An analysis of all possible polarization observables for the case of vector meson photoproduction from a nucleon target is presented. The question of which observables are needed to determine completely the basic photoproduction amplitudes…
The di-fermion angular distribution observed in decays of inclusively produced vector particles is characterized by two frame-independent observables, reflecting the average spin-alignment of the produced particle and the magnitude of…
The joint angular distribution of the decay B \to J/\Psi V, where V is an axial vector or vector resonance, followed by the subsequent decay processes of the J/\Psi and V is calculated using the covariant density method. In particular, the…
We develop polarization observables for the processes $\gamma N\to\pi\pi N$ and $\pi N\to\pi\pi N$, using both a helicity and hybrid helicity-transversity basis. Such observables are crucial if processes that produce final states consisting…
The factorization theorem in Decays of $B_{(s)}$ mesons to two charmed mesons (both pseudoscalar and vector) can still be proved in the leading order in $m_D/m_B$ and $\Lambda_{\rm{QCD}}/m_D$ expansion. Working in the perturbative QCD…
We report studies in polarization in B decay into two vector mesons with data equivalent to $253 {\rm fb^{-1}}$ on $\Upsilon(4S)$ resonance at KEKB. In $B^0 \to \phi K^{*0}$, $B^+ \to \phi K^{*+}$ and $B^+ \to \rho^+ K^{*0}$ decays, we…
We revisit the decay $\Lambda_b^0\to \Lambda_c^+ \ell^-\bar\nu$ ($\ell = e,\mu,\tau$) with a subsequent two-body decay $\Lambda_c^+ \to \Lambda^0 \pi^+$ in the Standard Model and in generic New Physics models. The decay's joint…
A large number of observables can be constructed from differential decay rate based on the polarization of final state while considering decay of a neutral meson $(P^0 \text{ or } \bar P^0)$ to two vector particles. But all of these…
Since the degree of polarization of the vector particle in semileptonic decay strongly influences the decay width of the particles, it can be used as a measure of CKM matrix elements. We show that |V_{cb}| can be determined from the…
When a neutral meson $(P^0 \text{ or } \bar P^0)$ decays to two vector particles, a large number of observables can be constructed from differential decay rate based on the polarization of final state. But, theoretically, all of them are…
The kinematic distributions of the lepton pairs produced in the decay of the Standard Model Higgs to ZZ and WW are related to the polarization fractions of the virtual vector bosons. The full amplitude can be decomposed analytically into a…
In a sample of 6.6 million produced B mesons we have observed decays B -> eta' K, with branching fractions BR(B+ -> eta' K+ = 6.5 +1.5 -1.4 +- 0.9) x $10^{-5}$ and BR(B0 -> eta' K0 = 4.7 +2.7 -2.0 +- 0.9) x $10^{-5}$. We have searched with…
In two meson photoproduction off a nucleon, for the case in which two of the three final state hadrons are products of the decay of an intermediate resonance, general expressions for its decay distribution and for polarization observables…
In a sample of 19 million produced B mesons we have observed decays B -> eta K*, and improved our previous measurements of B -> eta' K. The branching fractions we measure for these decay modes are B(B+ -> eta K*+) = (27.3 +9.6 -8.2 (stat)…