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A Correction to this paper has been published: 10.1140/epjc/s10052-018-6364-1

We studied the feasibility of observing light-by-light scattering in a photon–photon collider based on an existing accelerator complex and a commercially available laser system. We investigated the statistical significance of the signal over the QED backgrounds through a Monte Carlo simulation with a detector model. The study showed that light-by-light scattering can be observed with a statistical significance of eight to ten sigma in a year of operation, depending on the operating conditions.

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.

A bstract Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays τ ± → ℓ ± γ ( ℓ = e, μ ) are predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via τ ± → ℓ ± γ using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb − 1 , is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions, B ( τ ± → μ ± γ ) ≤ 4 . 2 × 10 − 8 and B ( τ ± → e ± γ ) ≤ 5 . 6 × 10 − 8 , are set at 90% confidence level.

Tumor cells often produce high levels of reactive oxygen species (ROS) and display an increased ROS scavenging system. However, the molecular mechanism that balances antioxidative and oxidative stress in cancer cells is unclear. Here, we determined that oncogenic multiple copies in T-cell malignancy 1 (MCT-1) activity promotes the generation of intracellular ROS and mitochondrial superoxide. Overexpression of MCT-1 suppresses p53 accumulation but elevates the manganese-dependent superoxide dismutase (MnSOD) level via the YY1-EGFR signaling cascade, which protects cells against oxidative damage. Conversely, restricting ROS generation and/or targeting YY1 in lung cancer cells effectively inhibits the EGFR-MnSOD signaling pathway and cell invasiveness induced by MCT-1. Significantly, MCT-1 overexpression in lung cancer cells promotes tumor progression, necrosis and angiogenesis, and increases the number of tumor-promoting M2 macrophages and cancer-associated fibroblasts in the microenvironment. Clinical evidence further confirms that high expression of MCT-1 is associated with an increase in YY1, EGFR and MnSOD expression, accompanied by tumor recurrence, poor overall survival and EGFR mutation status in patients with lung cancers. Together, these data indicate that the MCT-1 oncogenic pathway is implicated in oxidative metabolism and lung carcinogenesis.

A bstract We report a new measurement of the e + e − → ϒ( nS ) π + π − ( n = 1 , 2 , 3) cross sections at energies from 10 . 52 to 11 . 02 GeV using data collected with the Belle detector at the KEKB asymmetric-energy e + e − collider. We observe a new structure in the energy dependence of the cross sections; if described by a Breit-Wigner function its mass and width are found to be M = 10752.7 ± 5.9 − 1.1 + 0.7 MeV / c 2 and Γ = 35.5 − 11.3 − 3.3 + 17.6 + 3.9 MeV, where the first error is statistical and the second is systematic. The global significance of the new structure including systematic uncertainty is 5.2 standard deviations. We also find evidence for the e + e − → ϒ (1 S ) π + π − process at the energy 10 . 52 GeV, which is below the B B ¯ threshold.

We present the achievements of the last years of the experimental and theoretical groups working on hadronic cross section measurements at the low-energy e + e − colliders in Beijing, Frascati, Ithaca, Novosibirsk, Stanford and Tsukuba and on τ decays. We sketch the prospects in these fields for the years to come. We emphasise the status and the precision of the Monte Carlo generators used to analyse the hadronic cross section measurements obtained as well with energy scans as with radiative return, to determine luminosities and τ decays. The radiative corrections fully or approximately implemented in the various codes and the contribution of the vacuum polarisation are discussed.

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 Using a total of 5 . 25 fb − 1 of e + e − collision data with center-of-mass energies from 4.236 to 4.600 GeV, we report the first observation of the process e + e − → ηψ (2 S ) with a statistical significance of 4.9 standard deviations. The data sets were collected by the BESIII detector operating at the BEPCII storage ring. We measure the yield of events integrated over center-of-mass energies and also present the energy dependence of the measured cross section.

This work investigated effect of glass fibre fabric structures, feedstock feed rate and screen size on specific shredding energy of glass fibre reinforced plastics (GFRP) waste via a two-level factorial design of experiment study. Four types of fabric structure, i.e. unidirectional (UD), biaxial (BIAX), triaxial (TRIAX) and chopped strand mat (CSM), were impregnated separately with unsaturated polyester resin to manufacture GFRP plates. The shredding energy was measured using a two-wattmeter approach. During shredding, CSM demonstrated a relatively flat power consumption curve compared to other fabric types. It was also noticed that the GFRP plate reinforced with more complex woven structure, i.e. TRIAX, required higher energy for shredding, especially with a combination of high feed rate and small screen size. It was found that mechanical efficiency was only around 8.2-15.7% and 0.8-2.2% for shredding at feed rate of 60 kg/hr and 10 kg/hr respectively. It was also found that adopting a larger screen size and lower feed rate could reduce the specific shredding energy.