9,509 research outputs found
CP Violation in B Decays within QCD Factorization
We analyze the extraction of weak phases from CP violation in
decays. By combining the information on mixing induced CP
violation in , namely , with the precision
observable obtained from the ``gold-plated''mode ,
we propose the determination of the unitarity triangle. We also discuss
alternative ways to analyze which can be useful if new physics
affects -- mixing. Predictions and uncertainties for and
in QCD factorization are examined in detail. It is pointed out that a
simultaneous expansion in and leads to interesting
simplifications. At first order infrared divergences are absent, while the most
important effects are retained. Independent experimental tests of the
factorization framework are briefly discussed.Comment: 3 pages; 2 figures; To appear in the proceedings of International
Europhysics Conference on High-Energy Physics (HEP 2003), Aachen, Germany,
17-23 Jul 200
CKM matrix from non-leptonic B-decays
We analyze the impact of the forthcoming CP-violating observables in the
system, combined with the precise measurement of
, in the extraction of the CKM matrix. Computing the penguin parameters within QCD factorization yields a precise determination of , reflected by a weak dependence on , which is shown to be a
second order effect. Using the SU(3)-flavour symmetry argument and the current
-factories data provided by the modes, we complement
the CP-violating observables in a variety of ways, in
particular we find that . Finally, we investigate systematically the
SU(3)-symmetry breaking factor within QCD factorization.Comment: 4 pages; 4 figures (requires epsfig, psfrag); To appear in the
proceedings of 32nd International Conference on High-Energy Physics (ICHEP
04), Beijing, China, 16-22 Aug 200
Phenomenological study of the double radiative decay
Using the operator product expansion (OPE) technique, we study the rare
double radiative decay in the Standard Model (SM) and
beyond. We estimate the short-distance (SD) contribution to the decay amplitude
in a region of the phase space which is around the point where all decay
products have energy in the rest frame of the -meson. At lowest
order in , the matrix element is then expressed in
terms of the usual form factors known from semileptonic rare decays.
The integrated SD branching ratio in the SM in the OPE region turns out to be
.
We work out the di-photon invariant mass distribution with and without the
resonant background through . In
the SM, the resonance contribution is dominant in the region of phase space
where the OPE is valid. On the other hand, the present experimental upper limit
on decays, leaves considerable room for New Physics
(NP) in the one-particle-irreducible contribution to
decays. In this case, we find that the SD branching
ratio can be enhanced by one order of magnitude with respect to its SM value
and the SD contribution can lie outside of the resonance peaks.Comment: 4 pages, 2 figures (requires epsfig, psfrag), To appear in the
proceedings of the International Europhysics Conference on High Energy
Physics, 21-27 July 2005, Lisboa, Portuga
Effects of Low pH on Lactate Dehydrogenase Kinetics of Diving and Nondiving Reptiles
The properties of lactate dehydrogenase were examined in two snake species, Nerodia rhombifera and Elaphe obsoleta, and a turtle species, Pseudemys scripta. Our purpose was to compare the LDH activity of reptiles with limited anaerobic capabilities with that of the well established diver Pseudemys. The Michaelis-Menten kinetics of LDH and its susceptibility to inhibition by elevated pyruvate concentrations were investigated in the brain and heart of the three species. All tissue incubations and enzyme activity determinations were done at a pH of 7.0 in order to stimulate a diving blood pH in the three species. In both tissues the LDH activity of the snakes was higher than that of Pseudemys at pyruvate concentrations ranging between .03 mM and .50 mM. The Km values of the snakes were lower than those of Pseudemys, suggesting a greater enzyme-substrate affinity in the snake tissues. The Vmax values were higher in the snake tissues indicating a faster conversion of substrate to product. Heart LDH activity was reduced to an equal extent by high pyruvate concentrations in each of the three species. Elaphe brain LDH was most susceptible to pyruvate inhibition, but Nerodia and Pseudemys brain LDH were inhibited to an equal extent. The results indicate that the kinetic behavior of brain and heart LDH of the three species is similar at a pH of 7.4 and a pH of 7.0. The results also suggest that the LDH of Pseudemys is no better adapted to withstand anaerobic conditions than that of Nerodia or Elaphe at a pH of 7.0
Behaviours of natural organic matter in membrane filtration for surface water treatment : a review
Membrane application in surface water treatment provides many advantages over conventional treatment. However, this effort is hampered by the fouling issue, which restricts its widespread application due to increases in hydraulic resistances, operational and maintenance costs, deterioration of productivity and frequency of membrane regeneration problems. This paper discusses natural organic matter (NOM) and its components as the major membrane foulants that occur during the water filtration process, possible fouling mechanisms relating to reversible and irreversible of NOM fouling, current techniques used to characterize fouling mechanisms and methods to control fouling. Feed properties, membrane characteristics, operational conditions and solution chemistry were also found to strongly influence the nature and extent of NOM fouling. Findings of such studies are highlighted. The understanding of the combined roles of controlling factors and the methods used is very important in order to choose and optimize the best technique and conditions during surface water treatment. The future potential of membrane application for NOM removal is also discussed
Model Independent Bound on the Unitarity Triangle from CP Violation in B-> pi+ pi- and B-> psi K_S
We derive model independent lower bounds on the CKM parameters (1-rhobar) and
etabar as functions of the mixing-induced CP asymmetry S in B-> pi+ pi- and
sin(2 beta) from B->psi K_S. The bounds do not depend on specific results of
theoretical calculations for the penguin contribution to B-> pi+ pi-. They
require only the very conservative condition that a hadronic phase, which
vanishes in the heavy-quark limit, does not exceed 90 degrees in magnitude. The
bounds are effective if -sin(2 beta) < S < 1. Dynamical calculations indicate
that the limits on rhobar and etabar are close to their actual values.Comment: 5 pages, 2 figure
Finding of coefficients and oxidizable nitrogen from palm oil mill effluent (POME) for activated sludge models(ASMs)
Activated Sludge Models (ASMs) have been widely used as a basis for further model development in wastewater treatment processes. Values for parameters to be used are vital for the accuracy of the modeling approach. The objective of this study is to determine coefficients of the system, and oxidizable nitrogen of palm oil mill effluent (POME). A continuous stirred tank reactor (CSTR), with continuous flow for 20 hours, was used in this study. The DO profile for 11 days was monitored. The total, soluble, insoluble COD and soluble ammonia nitrogen were measured at the beginning and end of the experiment. Also, the coefficients and oxidizable nitrogen fractions are determined
Is there any Link Between Commodity Price and Monetary Policy? Evidence from Australia
The aim of this paper is to examine whether the commodity prices predict inflation, unemployment and short term interest rate in Australia. Advanced time series econometric modeling such as vector autoregressive model, cointegration and granger causality are used for this purpose. The empirical results show that three commodity prices (COMRL, COMNRL and COMBSMTL) precede inflation. However, no evidence of reverse causation is found. These findings have important implication for monetary authority. Inflation targeting experience has so far been hit by positive supply shocks. In case of negative supply shock, commodity price may be useful in singling out the likely direction of inflation.Commodity price; monetary policy; Cointegration; Error correction model; Granger causality test
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