Large Penguin effects in the CP Asymmetry of B0d ->pi+pi-

Penguin effects in the CP asymmetries of $B^0_d\rightarrow \pi^+\pi^-$ , \bd\rightarrow\rho^{\pm}\pi^{\mp} and \bd\rightarrow a^{\pm}_1 \pi^{\mp} are studied as function of the CKM unitarity triangle $\alpha$. Despite a fairly small penguin amplitude, it leads to quite sizable uncertainties in the determination of $\sin(2\alpha)$ from all but very large asymmetries. This effect is maximal for vanishing final state interaction phases, for which it can cause, for instance, an asymmetry of 40\%\ if $\alpha=\pi/2$.Comment: (14 pages, PHYZZX, 1 figure, available upon request), SLAC-PUB-591

T-Violating Triple-Product Correlations in Charmless Lambda_b Decays

Using factorization, we compute, within the standard model, the T-violating triple-product correlations in the charmless decays Lambda_b -> F_1 F_2, where F_1 is a light spin-1/2 baryon and F_2 is a pseudoscalar (P) or vector (V) meson. We find a large triple-product asymmetry of 18% for the decay Lambda_b -> p K^-. However, for other classes of Lambda_b -> F_1 P decays, the asymmetry is found to be at most at the percent level. For Lambda_b -> F_1 V decays, we find that all triple-product asymmetries are small (at most O(1%)) for a transversely-polarized V, and are even smaller for longitudinal polarization. Our estimates of the nonfactorizable contributions to these decays show them to be negligible, and we describe ways of testing this.Comment: 15 pages, LaTeX, no figure

On Measuring CPCP Violation in Neutral BB-meson Decays at the Υ(4S)\Upsilon (4S) Resonance

Within the standard model we carry out an analysis of $CP$-violating observables in neutral $B$-meson decays at the $\Upsilon (4S)$ resonance. Both time-dependent and time-integrated $CP$ asymmetries are calculated, without special approximations, to meet various possible measurements at symmetric and asymmetric $e^{+}e^{-}$ $B$ factories. We show two ways to distinguish between direct and indirect $CP$-violating effects in the $CP$-eigenstate channels such as $B^{0}_{d}/\bar{B}^{0}_{d}\rightarrow \pi^{+}\pi^{-}$ and $\pi^{0} K_{S}$. Reliable knowledge of the Cabibbo-Kobayashi-Maskawa phase and angles can in principle be extracted from measurements of some non-$CP$-eigenstate channels, e.g. $B^{0}_{d}/\bar{B}^{0}_{d}\rightarrow D^{\pm}\pi^{\mp}$ and $\stackrel{(-)}{D}$$^{(*)0}K_{S}$, even in the presence of significant final-state interactions.Comment: Latex file 13 pages, CERN-TH.7194/94 and PVAMU-HEP-94-2 (Phys. Lett. B328 (1994) 477). (A few minor typing errors have been corrected.

The Renormalization Group and Quantum Hall Edge States

The role of edge states in phenomena like the quantum Hall effect is well known. In this paper we show how the choice of boundary conditions for a one-particle Schr\"odinger equation can give rise to states localized at the edge of the system. We consider both the example of a free particle and the more involved example of a particle in a magnetic field. In each case, edge states arise from a non-trivial scaling limit involving the boundary conditions. Second quantization of these quantum mechanical systems leads to a multi-particle ground state carrying a persistent current at the edge. We show that the theory quantized with this vacuum displays an ``anomaly'' at the edge which is the mark of a quantized Hall conductivity in the presence of an external magnetic field. We also offer interpretations for the physics of such boundary conditions which may have a bearing on the nature of the excitations of these systems.Comment: 21 pages; submitted as uuencoded, compressed postscrip

CP asymmetries in B0 decays in the left-right model

We study time dependent CP asymmetries in B^0_{d,s} decays in the left-right model with spontaneous breakdown of CP. Due to the new contributions to B^0-\bar B^0 mixing the CP asymmetries can be substantially modified. Moreover, there can be significant new contributions to the $B$-meson decay amplitudes from the magnetic penguins. Most promising for detection of the new physics in the planned $B$ factories is that the CP asymmetries in the decays B--> J/\psi K_S and B--> \phi K_S which are supposed to be equal in the standard model can differ significantly in this class of models independently of the results in the measurements of B--> X_s \gamma.Comment: Revised version, to appear in PR

SUSY GUTs contributions and model independent extractions of CP phases

We consider the origin of new phases in supersymmetric grand unification model, and show how significant new contributions arise from the gluino mediated diagram. We then present a more general model independent analysis of various modes of B-decays suggested previously for measurement of the CKM phases and point out what they really measure. It is in principle possible to separate out all the phases.Comment: 13 pages (Latex), 2 PS figures, a few remarks are added and a typo is corrected. To appear in Phys. Rev. Let

Weak phases from topological-amplitude parametrization

We propose a parametrization for two-body nonleptonic $B$ meson decays, in which the various topologies of amplitudes are counted in terms of powers of the Wolfenstein parameter $\lambda\sim 0.22$. The weak phases and the amplitudes are determined by comparing this parametrization with available measurements. It is possible to obtain the phase $\phi_3$ from the $B\to K\pi$ data up to theoretical uncertainty of $O(\lambda^3)\sim 1$. The recently measured $B_d^0\to\pi^0\pi^0$ branching ratio implies a large color-suppressed or penguin amplitude, and that the extraction of the phase $\phi_2$ from the $B\to\pi\pi$ data may suffer theoretical uncertainty more than the expected one of $O(\lambda^2)\sim 5$.Comment: 11 pages, 4 figure

CP-Violating Asymmetries in Charmless Non-Leptonic Decays B→PP,PV,VVB \to PP, PV, VV in the Factorization Approach

We present estimates of the direct (in decay amplitudes) and indirect (mixing- induced) CP-violating asymmetries in the non-leptonic charmless two-body decay rates for $B \to PP$, $B \to PV$ and $B \to VV$ decays and their charged conjugates, where P(V) is a light pseudoscalar (vector) meson. These estimates are based on a generalized factorization approach making use of next-to-leading order perturbative QCD contributions which generate the required strong phases. No soft final state interactions are included. We study the dependence of the asymmetries on a number of input parameters and show that there are at least two (possibly three) classes of decays in which the asymmetries are parametrically stable in this approach. The decay modes of particular interest are: \optbar{B^0} \to \pi^+ \pi^-, \optbar{B^0} \to K_S^0 \pi^0, \optbar{B^0} \to K_S^0 \eta^\prime, \optbar{B^0} \to K_S^0 \eta and \optbar{B^0} \to \rho^+ \rho^-. Likewise, the CP-violating asymmetry in the decays \optbar{B^0} \to K_S^0 h^0 with $h^0=\pi^0,K_S^0, \eta,\eta^\prime$ is found to be parametrically stable and large. Measurements of these asymmetries will lead to a determination of the phases $\sin 2\alpha$ and $\sin 2 \beta$ and we work out the relationships in these modes in the present theoretical framework. We also show the extent of the so-called "penguin pollution" in the rate asymmetry $A_{CP}(\pi^+ \pi^-)$ and of the "tree shadow" in the asymmetry $A_{CP}(K_S^0\eta^\prime)$ which will effect the determination of $\sin 2 \alpha$ and $\sin 2 \beta$ from the respective measurements. CP-violating asymmetries in $B^\pm \to \pi^\pm \eta^\prime$, $B^\pm \to K^{*\pm} \eta$, $B^\pm \to K^{*\pm} \eta^\prime$ and $B^\pm \to K^{*\pm}\rho^0$ are potentially interesting and are studied here.Comment: 42 pages (LaTex) including 19 figures, requires epsfig.sty; submitted to Phys. Rev.

Comparative Study of CP Asymmetries in Supersymmetric Models

We systematically analyze the supersymmetric contributions to the mixing CP asymmetries and branching ratios of B -> Phi K(S) and B -> eta(prime) K(S) processes. We consider both gluino and chargino exchanges in a model independent way by using the mass insertion approximation method. While we adopt the QCD factorization approach for evaluating the corresponding hadronic matrix elements, a critical comparison with predictions in naive factorization one is also provided. We find that pure chargino contributions cannot accommodate the current experimental results on CP asymmetries, mainly due to b -> s gamma constraints. We show that charged Higgs contributions can relax these constraints making chargino responsible for large asymmetries. On the other hand, gluino exchanges can easily saturate both the constraints on B -> Phi K(S) and B -> eta(prime) K(S) CP asymmetries. Moreover, we also find that the simultaneous contributions from gluino and chargino exchanges could easily account for the present experimental results on the mentioned asymmetries. Remarkably, large experimentally allowed enhancements of B -> eta(prime) K(S) branching ratio can easily be achieved by the contribution of two mass insertions in gluino exchanges. Finally, we analyze the correlations between the CP asymmetries of these processes and the direct CP asymmetry in b -> s gamma decay. When all experimental constraints are satisfied, supersymmetry favors large and positive values of b -> s gamma asymmetry.Comment: New figures and references added, version to appear on Nucl. Phys. B, 57 pages, LaTeX, 21 eps figure

Survival with low- and high-flux dialysis

FUNDING COSMOS is sponsored by the Bone and Mineral Research Unit (Hospital Universitario Central de Asturias), SAFIM (Sociedad Asturiana Fomento Investigaciones O´ seas), the European Renal Association–European Dialysis and Transplant Association, the National Program of I þ D þ I 2008–2011 and Instituto de Salud Carlos III (ISCIII), the ISCIII Retic REDinREN (RD06/0016/1013, RD12/0021/0023 and RD16/ 0009/0017), the ISCIII (ICI14/00107, PI17/00384 and PI20/ 00633), Fondo Europeo de Desarrollo Regional (FEDER), Plan Estatal de I þ D þ I 2013–2016, Plan de Ciencia, Tecnologia e Innovacion 2013–2017 y 2018–2022 del Principado de Asturias (GRUPIN14-028, IDI-2018-000152), Fundacio´n Renal I ´nigo A ~ ´ lvarez de Toledo (FRIAT) and the Spanish Society of Nephrology (Estudio Estrate´gico de la SEN). Logistics (meetings, secretarial help, printing of materials, development of website for data entry, etc.) have been financially supported by AMGEN Europe and FRIAT. The authors are not aware of any additional relationships, funding or financial holdings that might be perceived as affecting the objectivity of this study. COSMOS participating centres: see Supplementary Appendix.Background. Besides advances in haemodialysis (HD), mortality rates are still high. The effect of the different types of HD membranes on survival is still a controversial issue. The aim of this COSMOS (Current management Of Secondary hyperparathyroidism: a Multicentre Observational Study) analysis was to survey, in HD patients, the relationship between the use of conventional low- or high-flux membranes and all-cause and cardiovascular mortality. Methods. COSMOS is a multicentre, open-cohort, 3-year prospective study, designed to evaluate mineral and bone disorders in the European HD population. The present analysis included 5138 HD patients from 20 European countries, 3502 randomly selected at baseline (68.2%), plus 1636 new patients with <1 year on HD (31.8%) recruited to replace patients who died, were transplanted, switched to peritoneal dialysis or lost to follow-up by other reasons. Cox-regression analysis with timedependent variables, propensity score matching and the use of an instrumental variable (facility-level analysis) were used. Results. After adjustments using three different multivariate models, patients treated with high-flux membranes showed a lower all-cause and cardiovascular mortality risks fhazard ratio (HR) = 0.76 [95% confidence interval (CI) 0.61-0.96] and HR = 0.61 (95% CI 0.42-0.87), respectivelyg, that remained significant after matching by propensity score for all-cause mortality (HR = 0.69, 95% CI 0.52-0.93). However, a facility-level analysis showed no association between the case-mix-adjusted facility percentage of patients dialysed with high-flux membranes and all-cause and cardiovascular mortality. Conclusions. High-flux dialysis was associated with a lower relative risk of all-cause and cardiovascular mortality. However, dialysis facilities using these dialysis membranes to a greater extent did not show better survival.publishersversionpublishe