Branching ratios, CPCP asymmetries and polarizations of B→ψ(2S)VB\rightarrow \psi(2S) V decays

We analyzed the nonleptonic decays $B/B_s\to \psi(2S) V$ with $V=(\rho, \omega, K^{*}, \phi)$ by employing the perturbative QCD (PQCD) factorization approach. Here the branching ratios, the $CP$ asymmetries and the complete set of polarization observables are investigated systematically. Besides the traditional contributions from the factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order (NLO) vertex corrections could also provide considerable contributions. The PQCD predictions for the branching ratios of the $B_{(s)}\to \psi(2S)K^{*}, \psi(2S) \phi$ decays are consistent with the measured values within errors. As for $B\to \psi(2S) \rho, \psi(2S) \omega$ decays, the branching ratios can reach the order of $10^{-5}$ and could be measured in the LHCb and Belle-II experiments. The numerical results show that the direct $CP$ asymmetries of the considered decays are very small. Thus the observation of any large direct $CP$ asymmetry for these decays will be a signal for new physics. The mixing induced $CP$ asymmetries in the neutral modes are very close to $\sin 2\beta_{(s)}$, which suggests that these channels can give a cross-check on the measurement of the Cabbibo-Kobayashi-Maskawa (CKM) angle $\beta$ and $\beta_s$. We found that the longitudinal polarization fractions $f_0$ are suppressed to $\sim 50\%$ due to the large nonfactorizable contributions. The magnitudes and phases of the two transverse amplitudes $\mathcal {A}_{\parallel}$ and $\mathcal {A}_{\perp}$ are roughly equal, which is an indication for the approximate light quark helicity conservation in these decays. The overall polarization observables of $B\to \psi(2S) K^{*0}$ and $B_s\to \psi(2S) \phi$ channels are also in good agreement with the experimental measurements as reported by LHCb and BaBar. Other results can also be tested by the LHCb and Belle-II experiments.Comment: 14 pages, 1 figure, 6 table

Quasi-two-body decays B→ηc(1S,2S) [ρ(770),ρ(1450),ρ(1700)→] ππB \to \eta_c {(1S ,2S)}\;[\rho(770),\rho(1450),\rho(1700) \to ]\; \pi\pi in the perturbative QCD approach

In this paper, we calculated the branching ratios of the quasi-two-body decays $B \to \eta_c (1S ,2S)$ $[\rho(770), \rho(1450),\rho(1700)\to ] \pi\pi$ by employing the perturbative QCD (PQCD) approach. The contributions from the $P$-wave resonances $\rho(770)$, $\rho(1450)$ and $\rho(1700)$ were taken into account. The two-pion distribution amplitude $\Phi_{\pi\pi}^{\rm P}$ is parameterized by the vector current time-like form factor $F_{\pi}$ to study the considered decay modes. We found that (a) the PQCD predictions for the branching ratios of the considered quasi-two-body decays are in the order of $10^{-7} \sim 10^{-6}$, while the two-body decay rates ${\cal B}(B \to \eta_c{(1S,2S)} (\rho(1450),\rho(1700)))$ are extracted from those for the corresponding quasi-two-body decays; (b) the whole pattern of the pion form factor-squared $|F_\pi|^2$ measured by the BABAR Collaboration could be understood based on our theoretical results; (c) the general expectation based on the similarity between $B \to \eta_c \pi\pi$ and $B \to J/\psi \pi\pi$ decays are confirmed: $R_2(\eta_c)\approx 0.45$ is consistent with the measured $R_2(J/\psi)\approx 0.56\pm 0.09$ within errors; and (d) new ratios $R_3(\eta_c(1S))$ and $R_4(\eta_c(2S))$ among the branching ratios of the considered decay modes are defined and could be tested by future experiments.Comment: 10 pages, 3 figure

Semi-Parametric Maximum Likelihood Estimates for ROC Curves of Continuous-Scale Tests

In this paper, we propose a semi-parametric maximum likelihood estimate of an ROC curve that satisfies the property of invariance of the ROC curve. In our simulation studies, we demonstrate that the proposed estimator has the best performance among all the existing semi-parametric estimators considered here. Finally, we illustrate the application of the proposed estimator using a real data set

Critical role for the EB1 and APC interaction in the regulation of microtubule polymerization

AbstractHuman EB1 was originally cloned as a protein that interacts with the COOH terminus of adenomatous polyposis coli (APC) [1]. Interestingly, this interaction is often disrupted in colon cancer, due to mutations in APC. EB1 also interacts with the plus-ends of microtubules and targets APC to microtubule tips [2–6]. Since APC is detected on the kinetochores of chromosomes, it has been hypothesized that the EB1-APC interaction connects microtubule spindles to the kinetochores and regulates microtubule stability [7–9]. In yeast, EB1 regulates microtubule dynamics [6, 10, 11], and its binding domain in APC may be conserved in Kar9, an EB1 binding protein involved in the microtubule-capturing mechanism [12–14]. These results suggest that the interaction of EB1 and APC is important and may be conserved. However, it is largely unknown whether the EB1-APC interaction affects microtubule dynamics. Here, we show that EB1 potently promotes microtubule polymerization in vitro and in permeabilized cells, but, surprisingly, only in the presence of the COOH-terminal EB1 binding domain of APC (C-APC). Significantly, this C-APC activity is abolished by phosphorylation, which also disrupts its ability to bind to EB1. Furthermore, yeast EB1 protein effectively substitutes for the human protein but also requires C-APC in promoting microtubule polymerization. Finally, C-APC is able to promote microtubule polymerization when stably expressed in APC mutant cells, demonstrating the ability of C-APC to promote microtubule assembly in vivo. Thus, the interaction between EB1 and APC plays an essential role in the regulation of microtubule polymerization, and a similar mechanism may be conserved in yeast

Global Dynamics and Applications of an Epidemiological Model for Hepatitis C Virus Transmission in China

An epidemiological model is proposed and studied to understand the transmission dynamics and prevalence of HCV infection in China. Theoretical analysis indicates that the basic reproduction number R0 provides a threshold value determining whether the disease dies out or not. Two Lyapunov functions are constructed to prove the global asymptotic stability of the disease-free and the endemic equilibria, respectively. Based on data reported by the National Health and Family Planning Commission of China, the basic reproduction number is estimated as approximately R0=1.9897, which is much less than that for the model when a treatment strategy is not considered. An ever-increasing HCV infection is predicted in the near future. Numerical simulations, performed to investigate the potential effect of antiviral treatment, show that increasing the treatment cure rate and enlarging the treatment rate for patients at the chronic stage remain effective in reducing the number of new infections and the equilibrium prevalence. The finding suggests that treatment measures are significantly beneficial for disease control in terms of reducing new infections and, in particular, more attention should be paid to treatment for patients at the chronic stage