Charm Mixing and D Dalitz Analysis at BESIII

AbstractWe study D0D‾0 pairs produced in e+e− collisions at s=3.773GeV using a data sample of 2.92fb−1 collected with the BESIII detector. Using world-average values of external parameters, we obtain cosδKπ=1.02±0.11±0.06±0.01, δKπ is the strong phase difference between the doubly Cabibbo-suppressed process D‾0→K−π+ and the Cabibbo-favored process D0→K−π+. A measurement of the parameter yCP in D0−D‾0 oscillations is performed by taking advantage of quantum coherence between pair-produced D0 and D‾0 mesons near threshold, the preliminary result is yCP=(−1.6±1.3±0.6)%. An analysis of the D+→KS0π+π0 Dalitz plot is performed, the Dalitz plot is found to be well presented by a combination of six quasi-two-body decay channels [KS0ρ+, KS0ρ(1450)+, K‾⁎0π+, K‾0(1430)0π+, K‾(1680)0π+, κ‾0π+] plus a small nonresonant component. Using the fit fractions from this analysis, partial branching ratios are updated with higher precision than previous measurements

The cosmic ray test of MRPCs for the BESIII ETOF upgrade

In order to improve the particle identification capability of the Beijing Spectrometer III (BESIII),t is proposed to upgrade the current endcap time-of-flight (ETOF) detector with multi-gap resistive plate chamber (MRPC) technology. Aiming at extending ETOF overall time resolution better than 100ps, the whole system including MRPC detectors, new-designed Front End Electronics (FEE), CLOCK module, fast control boards and time to digital modules (TDIG), was built up and operated online 3 months under the cosmic ray. The main purposes of cosmic ray test are checking the detectors' construction quality, testing the joint operation of all instruments and guaranteeing the performance of the system. The results imply MRPC time resolution better than 100$ps$, efficiency is about 98$\%$ and the noise rate of strip is lower than 1$Hz/$($scm^{2}$) at normal threshold range, the details are discussed and analyzed specifically in this paper. The test indicates that the whole ETOF system would work well and satisfy the requirements of upgrade

Disturbance Attenuation and Rejection for a Class of Switched Nonlinear Systems Subject to Input and Sensor Saturations

This paper investigates the problem of disturbance attenuation and rejection for a class of switched nonlinear systems subject to input and sensor saturations, in which exosystem generated disturbances and H2-norm bounded disturbances are considered. The full-order and reduced-order observers are designed according to whether the system states are available or not. Based on the estimating values of the system states and exosystem generated disturbances, the design schemes for the composite controllers are put forward based on the full-order and reduced-order observers, respectively. For a switched system, the input and sensor saturations would influence the effective synthesis of observer and controller. By sector nonlinearity technology, the stability of the augmented closed-loop systems under the proposed composite controllers are analyzed, and the conditions of synthesis of the observers and controllers are further presented to ensure the augmented systems to be robustly asymptotically stable with a weighted H∞ performance level. An example is given to guarantee the effectiveness of the proposed control schemes

Co-transport of Pb (II) and Cd (II) in saturated porous media: effects of colloids, flow rate and grain size

The transport of Pb(II) or Cd(II) in subsurface has been studied in the literature; however; their co-transport in porous media in presence of colloids has not been clearly understood. In this work, a series of column experiments were conducted to study Pb(II) and Cd(II) co-transport in saturated porous media under various experimental conditions with different combination of colloidal solution (montmorillonite colloid, manual loessial soil colloid and humic acid), flow rate (0.1, 0.5 and 1.0 ml min−1) and sand grain size (0.4–0.8mm and 0.8–2.0mm). The results showed that increase of flow rate and grain size promoted the mobility of Pb(II) and Cd(II), furthermore, the presences of mobile colloids also enhanced the mobility of the two heavy metals, meanwhile, Cd(II) showed higher mobility than Pb(II) in the columns. Findings from this work enhanced current understanding of the competitive transport and colloid-facilitated transport of heavy metals in saturated porous media

Portable Dual-Modular Immunosensor Constructed from Bimetallic Metal–Organic Framework Heterostructure Grafted with Enzyme-Mimicking Label for Rosiglitazone Detection

Immunosensor with photoelectrochemistry and fluorescence responsibility is widely used in biomedical detection, health monitoring, and food safety inspection. The cumbersome configuration and low integration of the current immunosensors, however, have brought challenges for their practical applications. To address these challenges, a portable and phone-APP controlled dual-modular immunosensor based on a bimetallic metal–organic framework (MOF) heterostructured photoelectrode, ZnO/NiZn-MOF/CdS, grafted with an enzyme-mimicking Au@CuO/Cu2O label is constructed to achieve simultaneous photoelectrochemistry and fluorescence signage. In the electrode design, the construction of a bimetallic NiZn metal–organic framework (NiZn-MOF) into the common ZnO/CdS photoresponsive structure achieves significant and stable photocurrent output under a very low-power LED light source for not only accelerating the transfer of photogenerated electrons from CdS to ZnO, but also stabilizing the holes of CdS to improve its photocorrosion resistance. After the graft of multifunctional enzyme-mimicking Au@CuO/Cu2O label clusters, a portable dual-modular immunosensor is built for the detection of rosiglitazone, a common antidiabetic drug and strictly restricted food residual, over a range from 10−3 to 1 µg L−1. This MOF-based immunosensor offers insights into highly sensitive dual-modular responsive material innovations and provides miniaturized biomedical detectors with promising commercialization potentials.</p