The element V ub of the CKM mixing matrix is the smallest of the quark couplings and is crucial in understanding CP violation in the B system. In this review, we discuss the present status of the determination of its magnitude, which involves a significant effort both experimentally and theoretically. Decisive progress has been achieved in recent years, thanks in part to the large data sets tha...

Written by Ernst Zinner Washington University, St. Louis, MO Our solar system formed 4.6 billion years ago. Primitive meteorites provide samples that were formed in its earliest days and thus can give us information about this period. To establish the sequence of events during solar system formation on a time scale of a million years radioactive isotopes that decay with half-lives comparable to...

The subunit composition of the GABAA receptor determines the decay time of the GABAergic inhibitory postsynaptic current (IPSC). In mice in which the 1 subunit is deleted, the decay time is longer than in wild-type mice, while the spatial spread of activity in the visual cortex following local stimulation is reduced. Using a simple network model of the visual cortex, we show that this reduced s...

The one-level B-matrix approach is used to calculate alpha decay widths for several low-lying 0+, 2+, and 4+ excited states of the 0 nucleus, The interior wave functions are calculated within the ZBM (pqy2, d5rq, sq12) shell-model space with various effective interactions. The exterior wave functions are calculated from an n+ C folding model potential obtained with the M3Y interaction. A new me...

Abstract. In this paper we consider the transmission problem of a material composed of three components; one of them is a Kelvin–Voigt viscoelastic material, the second is an elastic material (no dissipation), and the third is an elastic material inserted with a frictional damping mechanism. The main result of this paper is that the rate of decay will depend on the position of each component. W...

PURPOSE To investigate previous, current, or planned participation in, and perceptions toward, multifactorial fall prevention programs such as those delivered through a falls clinic in the community setting, and to identify factors influencing older people's intent to undertake these interventions. DESIGN AND METHODS Community-dwelling people aged >70 years completed a telephone survey. Parti...

I consider constraints on a phenomenological decaying dark matter model, in which two weakly interacting massive particle species have a small mass splitting, and in which the heavier particle decays to the lighter particle and a massless particle on cosmological time scales. The decay parameter space is parametrized by vk, the speed of the lighter particle in the center-of-mass frame of the he...

The 3 862.5 cm−1 vibration of oxygen in crystalline germanium is shown to decay into one 1 local mode of the oxygen center plus two lattice modes. This description predicts increases in the linewidths in O-doped germanium, and decreases in the linewidths in O-doped germanium, as the Ge mass in the Ge-O-Ge complex increases, in agreement with observation. The decay time is expected to vary only ...

The feasibility of exciting a localized X-wave pulse from a finite aperture is addressed. Also, the possibility of using a finite-time excitation of a dynamic aperture to generate a finite-energy approximation to an X-wave pulse is explored. The analysis is carried out by using a Gaussian time window to time limit the infinite X-wave initial excitation. Huygens’ construction is used to calculat...

In this paper we present an effective technique for compacting a large sequence of input vectors into a much shorter one so as to reduce the circuit-level simulation time by orders of magnitude and maintain the accuracy of the power estimates. In particular, we model the effects of complex spatiotemporal correlations and rise/fall time slopes on total power dissipation. As the results demonstra...