Measurement of the lifetime difference in D0 meson decays

We report a measurement of the D0-D macro(0) mixing parameter y(CP) using 23.4 fb(-1) of data collected near the Upsilon(4S) resonance with the Belle detector at KEKB. y(CP) is measured from the lifetime difference of D0 mesons decaying into the K(-)pi(+) state and the CP-even eigenstate K(-)K(+). We find y(CP) = (-0.5+/-1.0(+0.7)(-0.8))x10(-2), where the first error is statistical and the second is systematic, corresponding to a 95% confidence interval -0.030相似文献   

Limits on D0-D0 mixing and bottom particle production cross section from hadronically produced same-sign dimuon events

The rates for same-sign and opposite-sign dimuon events with missing energy (indicative of final-state neutrinos) have been measured in 278 GeV π^?-Fe and 350 GeV proton-Fe collisions. The main source of opposite-sign events is two semi-leptonic decays of hadronically produced charm states. The same-sign events are consistent with background from pion and kaon decays. We obtain a limit of 0.044 (90% CL) on the fraction of D⁰ semileptonic decays that result in the wrong-sign muon and conclude that less than 9% (90% CL) of same-sign dimuon events produced in neutrino interactions can be attributed to D⁰-$\text{D}$⁰ mixing. The data imply δm < 6.5 × 10^?4 eV and $\text{δλ}\text{λ}\text{< 0.55}$ for the difference in mass and inverse lifetime of the CP eigenstates of the D⁰. Limits on diffractive bottom production cross sections in proton and pion collisions are also presented.     

A new triterpene glucosyl ester from the fruit of the blackberry (Rubus allegheniensis)

A new triterpene glucosyl ester, rubusside A, has been isolated from the fruit of the blackberry (Rubus allegheniensis PORT.) along with a known triterpene glucosyl ester, niga-ichigoside F1. The chemical structure of rubusside A was determined on the basis of spectroscopic data as well as chemical evidence.     

Unconstrained Optimization Reformulations of Variational Inequality Problems

Recently, Peng considered a merit function for the variational inequality problem (VIP), which constitutes an unconstrained differentiable optimization reformulation of VIP. In this paper, we generalize the merit function proposed by Peng and study various properties of the generalized function. We call this function the D-gap function. We give conditions under which any stationary point of the D-gap function is a solution of VIP and conditions under which it provides a global error bound for VIP. We also present a descent method for solving VIP based on the D-gap function.