New data concerning neutrino oscillations as obtained in the T2K and NOvA accelerator neutrino experiments are considered. Both collaborations reported on a moderate preference for normal mass ...ordering, but the difference of measured values of CP violating phases δ
CP
amounted to two standard deviations (2σ) and the result of T2K experiment excluded CP invariance conservation with about 2σ confidence. Joint analysis of the data of two experiments can lead to inverted mass hierarchy and δ
CP
≈ 3π/2. In addition, importance of the obtained results for non-oscillation analysis of neutrino experiments is discussed.
The charged-current quasi-elastic scattering of muon neutrinos on a carbon target is analyzed using the relativistic distorted-wave impulse approximation (RDWIA), taking into account the contribution ...of the two-particle and two-hole meson exchange current (MEC) to the weak response functions. A fit the RDWIA + MEC model to the MiniBooNE neutrino data is performed, and the best-fit value of nucleon axial mass MA≈1.20 GeV is obtained. We also extract the values of the axial form factor FA(Q2) as a function of the squared momentum transfer Q2 from the measured dσ/dQ2 cross section. The flux-integrated charged-current quasi-elastic–like differential cross sections for neutrino scattering at energies of the NOvA experiment are estimated within the RDWIA + MEC approach.
Relative Astrometry in an Annular Field Gai, M.; Vecchiato, A.; Riva, A. ...
Publications of the Astronomical Society of the Pacific,
03/2022, Letnik:
134, Številka:
1033
Journal Article
Recenzirano
Odprti dostop
Abstract
Background.
Relative astrometry at or below the microarcsec level with a 1 m class space telescope has been repeatedly proposed as a tool for exo-planet detection and characterization, as ...well as for several topics at the forefront of Astrophysics and Fundamental Physics.
Aim.
This paper investigates the potential benefits of an instrument concept based on an annular field of view, as compared to a traditional focal plane imaging a contiguous area close to the telescope optical axis.
Method.
Basic aspects of relative astrometry are reviewed as a function of the distribution on the sky of reference stars brighter than
G
= 12 mag (from Gaia EDR3). Statistics of field stars for targets down to
G
= 8 mag is evaluated by analysis and simulation.
Results.
Observation efficiency benefits from prior knowledge on individual targets, since source model is improved with few measurements. Dedicated observations (10–20 hr) can constrain the orbital inclination of exoplanets to a few degrees. Observing strategy can be tailored to include a sample of stars, materialising the reference frame, sufficiently large to average down the residual catalog errors to the desired microarcsec level. For most targets, the annular field provides typically more reference stars, by a factor four to seven in our case, than the conventional field. The brightest reference stars for each target are up to 2 mag brighter.
Conclusions.
The proposed annular field telescope concept improves on observation flexibility and/or astrometric performance with respect to conventional designs. It appears therefore as an appealing contribution to optimization of future relative astrometry missions.
Using data of the Baksan Underground Scintillation Telescope we have searched for muon neutrinos and antineutrinos with energies above 1 GeV coinciding with the gravitational wave (GW) event GW170817 ...that was recorded on August 17, 2017, by the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) and Advanced Virgo observatories. This is the first detection of the new type of events occurring as a result of a merger of two neutron stars in a binary system. A short gamma-ray burst (GRB) GRB170817A accompanying this event is evidence of particle acceleration in the source whose precise position was determined by detection of the subsequent optical signal. No neutrino signals were found with the Baksan Underground Scintillation Telescope in the interval ±500 s around the moment of the gravitational wave event GW170817, as well as during the next 14 days. The upper limits on integral fluxes of muon neutrino and antineutrino from the source are derived.
Background. The term “paraduodenal pancreatitis” (PP) was proposed as a synonym for duodenal dystrophy (DD) and groove pancreatitis, but it is still unclear what organ PP originates from and how to ...treat it properly. Objective. To assess the results of different types of treatment for PP. Method. Prospective analysis of 62 cases of PP (2004–2013) with histopathology of 40 specimens was performed; clinical presentation was assessed and the results of treatment were recorded. Results. Preoperative diagnosis was correct in all the cases except one (1.9%). Patients presented with abdominal pain (100%), weight loss (76%), vomiting (30%), and jaundice (18%). CT, MRI, and endoUS were the most useful diagnostic modalities. Ten patients were treated conservatively, 24 underwent pancreaticoduodenectomies (PD), pancreatico- and cystoenterostomies (8), Nakao procedures (5), duodenum-preserving pancreatic head resections (5), and 10 pancreas-preserving duodenal resections (PPDR) without mortality. Full pain control was achieved after PPRDs in 83%, after PDs in 85%, and after PPPH resections and draining procedures in 18% of cases. Diabetes mellitus developed thrice after PD. Conclusions. PD is the main surgical option for PP treatment at present; early diagnosis makes PPDR the treatment of choice for PP; efficacy of PPDR for DD treatment provides proof that so-called PP is an entity of duodenal, but not “paraduodenal,” origin.
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