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Al–B–NiO thin films were prepared using the sol–gel process and deposited on Indium tin oxide (ITO)-coated glass substrates via the dip-coating technique for the purpose of developing high performance electrochromic materials. The influence of the anneal on the structural and electrochromic properties of Al–B–NiO films is reported. Thermogravimetry (TG) and differential thermal analysis (DTA), cyclic voltammetry measurements (CV), UV spectrophotometer, atomic force microscopy (AFM) and X-ray diffraction (XRD) have been used to investigate the structural and electrochromic properties. The thickness of the films was determined by spectrophotometric analysis in 350–1,000 nm wavelength. Results showed that the Al–B–NiO thin films treated at high temperature have both the excellent electrochromic properties and good reversibility. The transmittance change (ΔT) of the film treated at 500 °C reaches still ~50% at the wavelength of 550 nm. The microstructure and the surface morphology were considered to play an important role in the electrochromic properties with different temperatures.

The complicated structure of the neutron cannot be calculated using first-principles calculations due to the large colour charge of quarks and the self-interaction of gluons. Its simplest structure observables are the electromagnetic form factors1, which probe our understanding of the strong interaction. Until now, a small amount of data has been available for the determination of the neutron structure from the time-like kinematical range. Here we present measurements of the Born cross section of electron–positron annihilation reactions into a neutron and anti-neutron pair, and determine the neutron’s effective form factor. The data were recorded with the BESIII experiment at centre-of-mass energies between 2.00 and 3.08 GeV using an integrated luminosity of 647.9 pb−1. Our results improve the statistics on the neutron form factor by more than a factor of 60 over previous measurements, demonstrating that the neutron form factor data from annihilation in the time-like regime is on par with that from electron scattering experiments. The effective form factor of the neutron shows a periodic behaviour, similar to earlier observations of the proton form factor. Future works—both theoretical and experimental—will help illuminate the origin of this oscillation of the electromagnetic structure observables of the nucleon.Form factors encode the structure of nucleons. Measurements from electron–positron annihilation at BESIII reveal an oscillating behaviour of the neutron electromagnetic form factor, and clarify a long-standing photon–nucleon interaction puzzle.

This paper considers a reentrant job shop with one hub machine which a job enters K times. Between any two consecutive entries into the hub, the job is processed on other machines. The objective is to minimize the total flow time. Under two key assumptions, the bottleneck assumption and the hereditary order (HO) assumption on the processing times of the entries, it is proved that there is an optimal schedule with the shortest processing time (SPT) job order and a dynamic programming algorithm is derived to find such a schedule. An approximation algorithm based on the shortest path algorithm and the SPT job order is also proposed to solve the problem. The approximation algorithm finds an optimal clustered schedule. In clustered schedules, jobs are scheduled in disjoint clusters; they resemble batch processing and seem to be of practical importance. Worst-case bounds for clustered schedules are proved with the HO assumption relaxed. Two special cases with the restriction that there are only two entries to the hub machine are further analyzed to offer more insight into the structure of optimal solutions.

Though immensely successful, the standard model of particle physics does not offer any explanation as to why our Universe contains so much more matter than antimatter. A key to a dynamically generated matter–antimatter asymmetry is the existence of processes that violate the combined charge conjugation and parity (CP) symmetry 1 . As such, precision tests of CP symmetry may be used to search for physics beyond the standard model. However, hadrons decay through an interplay of strong and weak processes, quantified in terms of relative phases between the amplitudes. Although previous experiments constructed CP observables that depend on both strong and weak phases, we present an approach where sequential two-body decays of entangled multi-strange baryon–antibaryon pairs provide a separation between these phases. Our method, exploiting spin entanglement between the double-strange Ξ − baryon and its antiparticle 2 Ξ ¯ + , has enabled a direct determination of the weak-phase difference, ( ξ P  −  ξ S ) = (1.2 ± 3.4 ± 0.8) × 10 −2  rad. Furthermore, three independent CP observables can be constructed from our measured parameters. The precision in the estimated parameters for a given data sample size is several orders of magnitude greater than achieved with previous methods 3 . Finally, we provide an independent measurement of the recently debated Λ decay parameter α Λ (refs.  4 , 5 ). The Λ Λ ¯ asymmetry is in agreement with and compatible in precision to the most precise previous measurement 4 . Using spin-entangled baryon–antibaryon pairs, the BESIII Collaboration reports on high-precision measurements of potential charge conjugation and parity (CP)-symmetry-violating effects in hadrons.

Particles directly produced at electron–positron colliders, such as the J/ψ meson, decay with relatively high probability into a baryon–antibaryon pair1. For spin-1/2 baryons, the pair can have the same or opposite helicites. A non-vanishing phase ΔΦ between the transition amplitudes to these helicity states results in a transverse polarization of the baryons2–4. From the joint angular distribution of the decay products of the baryons, this phase as well as the parameters characterizing the baryon and the antibaryon decays can be determined. Here, we report the measurement of ΔΦ = 42.4 ± 0.6 ± 0.5° using Λ → pπ− and Λ¯→p¯π+,n¯π0 decays at BESIII. We find a value for the Λ → pπ− decay parameter of α− = 0.750 ± 0.009 ± 0.004, 17 ± 3% higher than the current world average, which has been used as input for all Λ polarization measurements since 19785,6. For Λ¯→p¯π+ we find α+ = −0.758 ± 0.010 ± 0.007, giving ACP = (α− + α+)/(α− − α+) = −0.006 ± 0.012 ± 0.007, a precise direct test of charge–parity symmetry (CP) violation in Λ decays.The decay asymmetry and helicity phase of polarized baryon–antibaryon pairs are measured at the BESIII experiment, testing charge–parity symmetry and revealing a discrepancy of the Λ → pπ− decay asymmetry with respect to the current world average.

We report the first measurement of the absolute branching fraction of the inclusive decay Λc+→KS0X. The analysis is performed using an e+e- collision data sample corresponding to an integrated luminosity of 567 pb-1 taken at s = 4.6 GeV with the BESIII detector. Using eleven Cabibbo-favored Λ¯c- decay modes and the double-tag technique, this absolute branching fraction is measured to be B(Λc+→KS0X)=(9.9±0.6±0.4)%, where the first uncertainty is statistical and the second systematic. The relative deviation between the branching fractions for the inclusive decay and the observed exclusive decays is (18.7±8.3)%, which indicates that there may be some unobserved decay modes with a neutron or excited baryons in the final state.

A bstract Using 1310 . 6 × 10 6 J/ψ and 448 . 1 × 10 6 ψ (3686) events collected with the BESIII detector, the branching fractions of J/ψ decays to Σ + Σ ¯ − is measured to be (10 . 61 ± 0 . 04 ± 0 . 36) × 10 − 4 , which is significantly more precise than the current world average. The branching fractions of ψ (3686) decays to Σ + Σ ¯ − is measured to be (2 . 52 ± 0 . 04 ± 0 . 09) × 10 − 4 , which is consistent with the previous measurements. In addition, the ratio of B ( ψ (3686) → Σ + Σ ¯ − ) / B ( J/ψ → Σ + Σ ¯ − ) is determined to be (23 . 8 ± 1 . 1)% which violates the “12% rule”.

A bstract By using 6.32 fb − 1 of data collected with the BESIII detector at center-of-mass energies between 4.178 and 4.226 GeV, we perform an amplitude analysis of the decay D s + → K S 0 π + π 0 and determine the relative fractions and phase differences of different intermediate processes, which include K S 0 ρ (770) + , K S 0 ρ (1450) + , K * (892) 0 π + , K * (892) + π 0 , and K * (1410) 0 π + . With the detection efficiency based on the amplitude analysis results, the absolute branching fraction is measured to be ℬ D s + → K S 0 π + π 0 = 5.43 ± 0.30 stat ± 0.15 syst × 10 − 3 .

A bstract Using 10 . 1 × 10 9 J/ψ events produced by the Beijing Electron Positron Collider (BEPCII) at a center-of-mass energy s = 3 . 097 GeV and collected with the BESIII detector, we present a search for the rare semi-leptonic decay J/ψ → D − e + ν e + c.c. No excess of signal above background is observed, and an upper limit on the branching fraction ℬ( J / ψ  →  D − e + ν e  +  c . c .) < 7.1 × 10 −8 is obtained at 90% confidence level. This is an improvement of more than two orders of magnitude over the previous best limit.

A bstract By analyzing 4 . 48 × 10 8 ψ (3686) events collected with the BESIII detector, we observe the decays χ cJ → nK S 0 Λ ¯ + c . c . ( J = 0, 1, 2) for the first time, via the radiative transition ψ (3686) → γχ cJ . The branching fractions are determined to be (6 . 65 ± 0 . 26 stat ± 0 . 41 syst ) × 10 − 4 , (1 . 66 ± 0 . 12 stat ± 0 . 12 syst ) × 10 − 4 , and (3 . 58 ± 0 . 16 stat ± 0 . 23 syst ) × 10 − 4 for J = 0, 1, and 2, respectively.