We calculate the atmospheric flux of prompt neutrinos, produced in decays of the charmed particles at energies beyond 1 TeV. Cross sections of the
D
mesons and
Λ
c
+
baryons production in
pA
and
π
A
...collisions are calculated in the phenomenological quark–gluon string model (QGSM) which is updated using recent measurements of cross sections of the charmed meson production in the LHC experiments. A new estimate of the prompt atmospheric neutrino flux is obtained and compared with the limit from the IceCube experiment, and with predictions of other charm production models.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Baikal Gigaton Volume Detector (Baikal-GVD) is a km
3
-scale neutrino detector currently under construction in Lake Baikal, Russia. The detector consists of several thousand optical sensors ...arranged on vertical strings, with 36 sensors per string. The strings are grouped into clusters of 8 strings each. Each cluster can operate as a stand-alone neutrino detector. The detector layout is optimized for the measurement of astrophysical neutrinos with energies of
∼
100 TeV and above. Events resulting from charged current interactions of muon (anti-)neutrinos will have a track-like topology in Baikal-GVD. A fast
χ
2
-based reconstruction algorithm has been developed to reconstruct such track-like events. The algorithm has been applied to data collected in 2019 from the first five operational clusters of Baikal-GVD, resulting in observations of both downgoing atmospheric muons and upgoing atmospheric neutrinos. This serves as an important milestone towards experimental validation of the Baikal-GVD design. The analysis is limited to single-cluster data, favoring nearly-vertical tracks.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The problem of safe functioning of space vehicles is under investigation. Spacecraft safety is essentially affected by the impact of fragments of space debris and meteorites. Impact of small particle ...can lead to a perforation of the structure of a spacecraft or the Space station. The impact can cause formation of a perforation and gradual loss of atmosphere. Under these conditions, it is crucial detecting the point of perforation and take the measures of precaution for the loss of the internal atmosphere. Practically all known methods for testing the integrity of ground-based structures, aircrafts and other complex technogenic objects are inapplicable for solving similar problems of monitoring the spacecraft condition during a spaceflight. To solve this problem, the integrating fiber-optic sensors (IFOS)-based system for monitoring vibration deformation parameters of spacecraft housings’ surfaces is proposed, which can be developed and implemented in the shortest possible time. Mathematical modeling and laboratory studies have confirmed the possibility of using the Integrating fiber-optic sensors system for assessing the dynamic and static parameters of extended structures.
•The problem of safe functioning of space vehicles is under investigation.•Impact of small particle can lead to a perforation of the structure of a spacecraft or the Space station and gradual loss of atmosphere.•Practically all known methods for testing the integrity of ground-based structures, aircrafts and other complex technogenic objects are inapplicable for solving similar problems of monitoring the spacecraft condition during a spaceflight.•To solve this problem, the integrating fiber-optic sensors (IFOS)-based system for monitoring vibration deformation parameters of spacecraft housings’ surfaces is proposed.•Mathematical modeling and laboratory studies have confirmed the possibility of using the IFOS for assessing the dynamic and static parameters of extended structures.
New calculations are made for the prompt component of atmospheric leptons (muon neutrinos and muons from the decay of charmed particles) in the same hadron cascade model used to calculate the ...characteristics of atmospheric leptons from the decay of π- and
K
-mesons. Spectral zenith-angular distributions of prompt and (π,
K
) leptons are obtained. Cross-energy intervals are found for which the contribution from prompt lepton fluxes is comparable to those of (π,
K
) muons and neutrinos. It is shown that prompt neutrinos can be detected at energies much lower than the cross-energy.
We calculate the high-energy component of the atmospheric neutrino flux which arises from decays of the charmed particles. Cross sections of the D mesons and Λ c + baryons production in pA and πA ...collisions are calculated within the framework of the quark-gluon string model (QGSM). The recent data on the cross sections of charmed meson production at high energies, obtained in experiments at the LHC, allow an improvement of the QGSM free parameters and new estimate of the prompt atmospheric neutrino flux. The newly-calculated flux of the prompt neutrinos is three times smaller than the flux predicted with the previous version of QGSM. We compare our result with the constraint derived from IceCube experiment as well as with predictions obtained with different charm production models.
We have performed a novel calculation of the “prompt” component of atmospheric leptons—muon neutrinos and muons arising in the decays of charmed particles. The same model of the hadron cascade is ...used in our calculation as in the calculation of the characteristics of “conventional” atmospheric neutrinos and muons (from the decays of π,
K
-mesons). The cross sections for the production of the charmed hadrons (
D
, Λ
c
) in pA and πA collisions are calculated within the quark–gluon string model (QGSM), whose parameters have taken into account recent measurements of cross sections of the charmed meson production at high energies. Zenith-angle distributions of the prompt muons and neutrinos have been obtained, the spectra of which are calculated as for certain zenith angles and averaged over zenith angles. The ranges of cross energy where the contribution of prompt leptons is comparable to fluxes of the (π,
K
) muons and neutrinos are found. The possibility is shown to detect the prompt neutrinos from a combined analysis of the spectral characteristics and zenith-angle enhancement of two components of atmospheric neutrinos—(π,
K
) component and prompt (
D
, Λ
c
) neutrinos in experiments at energies much lower than the cross energy.
We propose a method for determining the collimation ratio of a coherent X-ray beam using a planar multilens interferometer. The method is based on the analysis of Talbot images, which are periodic ...patterns of interference fringes formed by the interferometer at corresponding distances. The high sensitivity of the position and period of the interference fringes to the shape of the X-ray beam wavefront enables determination of its collimation degree and evaluation of the coherence properties of the radiation. The effectiveness of the proposed approach is experimentally demonstrated at the ID15B beamline of the European Synchrotron Radiation Facility (ESRF) synchrotron radiation source. A theoretical study is carried out, and the corresponding results of computer simulation are presented. The experimental data obtained correspond fully to the theoretical estimates.
Baikal-GVD: status and prospects Avrorin, A.D.; Avrorin, A.V.; Aynutdinov, V.M. ...
EPJ Web of Conferences,
01/2018, Letnik:
191
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Baikal-GVD is a next generation, kilometer-scale neutrino telescope under construction in Lake Baikal. It is designed to detect astrophysical neutrino fluxes at energies from a few TeV up to 100 PeV. ...GVD is formed by multi-megaton subarrays (clusters). The array construction started in 2015 by deployment of a reduced-size demonstration cluster named "Dubna" . The first cluster in it’s baseline configuration was deployed in 2016, the second in 2017 and the third in 2018. The full-scale GVD will be an array of ~10.000 light sensors with an instrumented volume about of 2 cubic km. The first phase (GVD-1) is planned to be completed by 2020-2021. It will comprise 8 clusters with 2304 light sensors in total. We describe the design of Baikal-GVD and present selected results obtained in 2015 - 2017.
Single-crystal planar compound refractive lenses under diffraction losses (glitches) conditions, when a part of radiation incident on an optical element diffracts from some set of atomic planes, have ...been investigated. A detailed experimental study using synchrotron radiation of the influence of glitches on the focal spot formed by lenses has been performed. An analysis of the data obtained showed that diffraction losses arise on different parts of the parabolic lens profile due to the refraction effect at radiation energies differing by a few electronvolts. As a result, the shape of the focused beam changes with a change in energy near the energy of the glitch.
The experimental study of optical properties of X-ray silicon planar compound refractive lenses at the synchrotron radiation source “KISI–Kurchatov” (Moscow, Russia) are presented. The capability to ...generate a submicron X-ray beam using refractive optics was demonstrated for the first time at this facility. The parameters of the focused beam were determined using the knife-edge technique. The measured minimum lateral focal spot size was 460 ± 70 nm. Additionally, the spatial structure of the beam in the focal spot area was examined. Theoretical estimates of the lenses optical properties and the corresponding computer simulation results are in agreement with the experimental data.
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