Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity of e^(+)e^(-)collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm=3.773 GeV.The integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to February 2024 were determined to be 4.995±0.019 fb^(-1),8.157±0.031 fb^(-1),and 4.191±0.016 fb^(-1),respectively,by analyzing large angle Bhabha scattering events.The uncertainties are dominated by systematic effects,and the statistical uncertainties are negligible.Our results provide essential input for future analyses and precision measurements.

Bilirubin adsorption property of mesoporous silica and amine-grafted mesoporous silica

Nephritic, hepatic and immune failures would lead to the overload of endogenous toxic molecules(e.g. bilirubin, cholic acid, uric acid, creatinine etc.) in human bodies. It is fatal in most cases and extracorporeal blood purification(ECBP) is powerful first-aid therapy. Adsorbents are key parts of ECBP apparatus. Mesoporous silicas should be promising candidates for these medical adsorbents, but there is no report about this. Herein, pure and amine-grafted mesoporous silicas have been applied to adsorb bilirubin, cholic acid, uric acid, creatinine and phenobarbital for the first time. These mesoporous materials show high adsorption capacities for bilirubin and uric acid in phosphate buffer solution(PBS). Effects of pore sizes, amine-modification, temperature and ionic strength on their bilirubin adsorption capacities have been studied in detail.

A vacuum nano-casting route to magnetite cores/mesoporous silica shell composites

Hollow mesoporous silica spheres with magnetite cores(HMSMC) have been fabricated by Vacuum Nano-casting Route. The amount of magnetite cores and saturation magnetization value can be easily adjusted by changing the concentration of iron nitrate solution used in the synthesis procedure. Furthermore, the as-prepared HMSMCs still maintain narrow mesopore distribution, high surface area and large pore volume after the hollow cores of hollow mesoporous silica spheres were filled with magnetite particles. Specially, when the saturation magnetization value of as-prepared HMSMCs reaches 22.0 emu/g, the surface area and pore volume of corresponding HMSMCs are 149 m^2/g and 0.19 cm^3/g, respectively, and the pore size is 2.30 nm. The corresponding samples are characterized by X-ray diffraction, N_2 sorption isotherms, transmission electron microscopy and vibrating-sample magnetometer.

Amplitude analysis of the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)

Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BESIII detector,a joint amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(S)are observed in both channels.With the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,respectively.The branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,respectively.The amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.

Determination of the number ofψ(3686)events taken at BESⅢ

The number ofψ(3686)events collected by the BESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic events.The uncertainty is systematic and the statistical uncertainty is negligible.Meanwhile,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,respectively.Both numbers are consistent with the previous measurements within one standard deviation.The total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.