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Recent SND results on the study of the process e+e−→ π0γ are presented. The study is based on data collected with the SND detector on the VEPP-2M and VEPP-2000 e+e− colliders with an integrated luminosity of 25 and 46 pb−1, respectively. The VEPP-2M data used in this analysis are recorded in the center-of-mass energy range 0.60-1.38 GeV, while the VEPP-2000 data in the range 1.05-2.00 GeV.

Regular data taking with the CMD-3 at the electron-positron collider VEPP-2000 is under way since 2010. The collected data sample corresponds to about 200 inverse picobarns of integrated luminosity per detector in the energy range from 0.32 up to 2 GeV, with a goal to collect about 1 fb −1 during next five years. Some of the recent results from the CMD-3 detector are discussed.

Recent results of the SND detector experiments are presented. Data were taken at the VEPP-2000 and the VEPP-2M e+e− colliders in the Novosibirsk in the c.m. energy ranges from 0.3 to 2.00 GeV. Integrated luminosity used are 70pb-1 and 25pb-1 respectively. The cross sections of the e+e− → π0γ, K+K−, ωπ0, π+π−π0η, ωη, ωηπ0 processes has been measured.

A new scenario for the first operational run of the High Luminoisty LHC (HL–LHC) era (Run 4) has recently been developed to accommodate a period of performance ramp-up to achieve an annual integrated luminosity close to the nominal HL–LHC design target. The operational scenario in terms of beam parameters and machine settings, as well as the different phases to reach optimal performance, are described here along with the impact of potential delays to key hardware components.

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image).A combination is presented of all inclusive deep inelastic cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current ... scattering for zero beam polarisation. The data were taken at proton beam energies of 920, 820, 575 and 460 GeV and an electron beam energy of 27.5 GeV. The data correspond to an integrated luminosity of about 1 fb... and span six orders of magnitude in negative four-momentum-transfer squared, ..., and Bjorken x. The correlations of the systematic uncertainties were evaluated and taken into account for the combination. The combined cross sections were input to QCD analyses at leading order, next-to-leading order and at next-to-next-to-leading order, providing a new set of parton distribution functions, called HERAPDF2.0. In addition to the experimental uncertainties, model and parameterisation uncertainties were assessed for these parton distribution functions. Variants of HERAPDF2.0 with an alternative gluon parameterisation, HERAPDF2.0AG, and using fixed-flavour-number schemes, HERAPDF2.0FF, are presented. The analysis was extended by including HERA data on charm and jet production, resulting in the variant HERAPDF2.0Jets. The inclusion of jet-production cross sections made a simultaneous determination of these parton distributions and the strong coupling constant possible, resulting in ... An extraction of ... and results on electroweak unification and scaling violations are also presented.

The super τ-charm facility (STCF) is an electron−positron collider proposed by the Chinese particle physics community. It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5 × 10 35 cm −2·s −1 or higher. The STCF will produce a data sample about a factor of 100 larger than that of the present τ-charm factory - the BEPCII, providing a unique platform for exploring the asymmetry of matter-antimatter (charge-parity violation), in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions, as well as searching for exotic hadrons and physics beyond the Standard Model. The STCF project in China is under development with an extensive R&D program. This document presents the physics opportunities at the STCF, describes conceptual designs of the STCF detector system, and discusses future plans for detector R&D and physics case studies.

The process e+e-→K+K-π0 is studied with the SND detector at the VEPP-2000 e+e- collider. Basing on data with an integrated luminosity of 26.4 pb-1 we measure the e+e-→K+K-π0 cross section in the center-of-mass energy range from 1.28 up to 2 GeV. The measured mass spectrum of the Kπ system indicates that the dominant mechanism of this reaction is the transition through the K∗(892)K intermediate state. The cross section for the ϕπ0 intermediate state is measured separately. The SND results are consistent with previous measurements in the BABAR experiment and have comparable accuracy. We study the effect of the interference between the ϕπ0 and K∗K amplitudes. It is found that the interference gives sizable contribution to the measured e+e-→ϕπ0→K+K-π0 cross section below 1.7 GeV.

Observations of an event (several energetic eruptions leading to a terminal explosion that is surprisingly hydrogen-rich) with the spectrum of a supernova do not match with other observations of supernovae. A very unusual supernova Thousands of 'core-collapse' supernovae have been observed over the past 15 years, with common observational elements such as hydrogen absorption lines that slow over time and a single light-curve peak or luminosity that plateaus for around 100 days before declining. Iair Arcavi and colleagues report observations of the supernova iPTF14hls, which does not display the usual elements. Its light curve has multiple peaks and extends over 600 days. They conclude that the properties could be explained by ejection of several tens of solar masses of gas a few hundred days before the explosion, but there is no viable explanation for how this occurred. Although multiple pre-supernova eruptions are predicted by the pulsational pair instability, that model is inconsistent with the energetics involved here and the continued presence of hydrogen absorption lines with no decrease in velocity. Every supernova so far observed has been considered to be the terminal explosion of a star. Moreover, all supernovae with absorption lines in their spectra show those lines decreasing in velocity over time, as the ejecta expand and thin, revealing slower-moving material that was previously hidden. In addition, every supernova that exhibits the absorption lines of hydrogen has one main light-curve peak, or a plateau in luminosity, lasting approximately 100 days before declining 1 . Here we report observations of iPTF14hls, an event that has spectra identical to a hydrogen-rich core-collapse supernova, but characteristics that differ extensively from those of known supernovae. The light curve has at least five peaks and remains bright for more than 600 days; the absorption lines show little to no decrease in velocity; and the radius of the line-forming region is more than an order of magnitude bigger than the radius of the photosphere derived from the continuum emission. These characteristics are consistent with a shell of several tens of solar masses ejected by the progenitor star at supernova-level energies a few hundred days before a terminal explosion. Another possible eruption was recorded at the same position in 1954. Multiple energetic pre-supernova eruptions are expected to occur in stars of 95 to 130 solar masses, which experience the pulsational pair instability 2 , 3 , 4 , 5 . That model, however, does not account for the continued presence of hydrogen, or the energetics observed here. Another mechanism for the violent ejection of mass in massive stars may be required.

Infrared (IR) luminosity of lightning channel in the 3–5 μm range usually persisted throughout the entire interstroke interval, which is in contrast to the simultaneously recorded visible (0.4–0.8 μm) luminosity that always decayed to an undetectable level prior to a subsequent return stroke pulse. A longer visible luminosity period at the end of flash tended to be associated with a longer IR afterglow period following the decay of visible luminosity (and by inference current) to an undetectable level. At the end of flash, the IR luminosity persisted up to about 1 s, and the median IR afterglow duration was a factor of 10 longer than the median visible luminosity duration. The IR luminosity often exhibited a hump when the visible luminosity was monotonically decaying or undetectable, with the corresponding channel temperature being likely around 3400 K. Plain Language Summary Lightning is usually imaged in the visible (0.4–0.8 μm) range, although it also produces significant infrared (IR) emission. In this study, we compare, for the first time, the medium‐to‐far (3–5 μm) IR luminosity of lightning channels with the simultaneously recorded visible luminosity. The key findings include the persistent nature of IR luminosity throughout interstroke intervals, which is in contrast to visible luminosity that always decayed to an undetectable level before the following return‐stroke onset. After the last stroke, IR luminosity persisted much longer than visible luminosity. The IR luminosity often exhibited a hump when visible luminosity was monotonically decreasing or already undetectable. We inferred that the IR hump, occurring when the channel temperature decreases to a few thousand Kelvin, is associated with enhanced IR emission from nitric oxide molecules whose concentration is expected to be maximum around 3400 K. We also examined a number of factors influencing IR afterglow duration, such as the number of preceding strokes, return‐stroke peak current, and the occurrence of M‐components. This study contributes to the very limited literature on the IR emission from lightning and provides new insights into the dynamics of lightning channel cooling process. Key Points In contrast to the visible, infrared (IR) channel luminosity between strokes usually persisted through the following return‐stroke onset IR luminosity profile often exhibited an increase (hump) when the visible luminosity was monotonically decaying or undetectable At the end of flash, IR luminosity persisted up to ∼1 s and its median duration was a factor of 10 longer than its visible counterpart

The European Space Agency has invested heavily in two cornerstones missions: Herschel and Planck. The legacy data from these missions provides an unprecedented opportunity to study cosmic dust in galaxies so that we can, for example, answer fundamental questions about the origin of the chemical elements, physical processes in the interstellar medium (ISM), its effect on stellar radiation, its relation to star formation and how this relates to the cosmic far-infrared background. In this paper we describe the DustPedia project, which enables us to develop tools and computer models that will help us relate observed cosmic dust emission to its physical properties (chemical composition, size distribution, and temperature), its origins (evolved stars, supernovae, and growth in the ISM), and the processes that destroy it (high-energy collisions and shock heated gas). To carry out this research, we combine the Herschel/Planck data with that from other sources of data, and provide observations at numerous wavelengths ( ≤ 41 ) across the spectral energy distribution, thus creating the DustPedia database. To maximize our spatial resolution and sensitivity to cosmic dust, we limit our analysis to 4231 local galaxies ( v < 3000 km s−1) selected via their near-infrared luminosity (stellar mass). To help us interpret this data, we developed a new physical model for dust (THEMIS), a new Bayesian method of fitting and interpreting spectral energy distributions (HerBIE) and a state-of-the-art Monte Carlo photon-tracing radiative transfer model (SKIRT). In this, the first of the DustPedia papers, we describe the project objectives, data sets used, and provide an insight into the new scientific methods we plan to implement.