21. |
22. |
23. |
24. |
25. |
26. |
27. |
28. Dark matter line searches with the Cherenkov Telescope ArrayS. Abe, Saptashwa Bhattacharyya, Christopher Eckner, Judit Pérez Romero, Samo Stanič, Veronika Vodeb, Serguei Vorobiov, Gabrijela Zaharijas, Danilo Zavrtanik, Marko Zavrtanik, Miha Živec, 2024, izvirni znanstveni članek Opis: Monochromatic gamma-ray signals constitute a potential smoking gun signature for annihilating
or decaying dark matter particles that could relatively easily be distinguished from astrophysical
or instrumental backgrounds. We provide an updated assessment of the sensitivity of
the Cherenkov Telescope Array (CTA) to such signals, based on observations of the Galactic
centre region as well as of selected dwarf spheroidal galaxies. We find that current limits
and detection prospects for dark matter masses above 300 GeV will be significantly improved,
by up to an order of magnitude in the multi-TeV range.
This demonstrates that CTA will set a new standard for gamma-ray astronomy also in this respect, as the world's largest and most sensitive high-energy gamma-ray observatory, in particular due to its exquisite energy resolution at TeV energies and the adopted observational strategy focussing
on regions with large dark matter densities.
Throughout our analysis, we use up-to-date instrument response functions, and we thoroughly
model the effect of instrumental systematic uncertainties in our statistical treatment. We further present results for other potential signatures with sharp spectral features, e.g. box-shaped spectra, that would likewise very clearly point to a particle dark matter origin. Ključne besede: dark matter experiments, dark matter theory, gamma ray experiments, Cherenkov Telescope Array Observatory Objavljeno v RUNG: 24.09.2024; Ogledov: 191; Prenosov: 0
Celotno besedilo (2,04 MB) Gradivo ima več datotek! Več... |
29. Impact of the magnetic horizon on the interpretation of the Pierre Auger Observatory spectrum and composition dataA. Abdul Halim, Andrej Filipčič, Jon Paul Lundquist, Shima Ujjani Shivashankara, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, 2024, izvirni znanstveni članek Opis: The flux of ultra-high energy cosmic rays reaching Earth above the ankle energy (5 EeV) can be described as a mixture of nuclei injected by extragalactic sources with very hard spectra and a low rigidity cutoff.
Extragalactic magnetic fields existing between the Earth and the closest sources can affect the observed CR spectrum by reducing the flux of low-rigidity particles reaching Earth. We perform a combined fit of the spectrum and distributions of depth of shower maximum measured with the Pierre Auger Observatory including the effect of this magnetic horizon in the propagation of UHECRs in the intergalactic space.
We find that, within a specific range of the various experimental and phenomenological systematics, the magnetic horizon effect can be relevant for turbulent magnetic field strengths in the local neighbourhood in which the closest sources lie
of order Brms ≃ (50–100) nG (20 Mpc/ds)( 100 kpc/Lcoh)1/2, with ds the typical intersource separation and Lcoh the magnetic field coherence length. When this is the case,
the inferred slope of the source spectrum becomes softer and can be closer to the expectations of diffusive shock acceleration, i.e., ∝ E-2.
An additional cosmic-ray population with higher source density and softer spectra, presumably also extragalactic and dominating the cosmic-ray flux at EeV energies, is also required to reproduce the overall spectrum and composition results for all energies down to 0.6 EeV. Ključne besede: ultra high energy cosmic rays, UHECR propagation, magnetic horizon effect, Pierre Auger Observatory Objavljeno v RUNG: 24.09.2024; Ogledov: 160; Prenosov: 0
Celotno besedilo (3,65 MB) Gradivo ima več datotek! Več... |
30. Optimiziranje materialnega toka v procesu logistike podjetja ETA Cerkno : diplomsko deloŽan Slabe, 2024, diplomsko delo Opis: V diplomskem delu je obravnavan problem notranje sledljivosti pakirne embalaže in ulitkov ter obročev v podjetju. Motivacija za delo je bilo izboljšanje natančnosti zalog in sledljivosti materialov, kar je ključnega pomena za učinkovito delovanje podjetja. Namen dela je bil analizirati obstoječe procese in predlagati rešitve za boljšo notranjo sledljivost. Pri raziskavi smo uporabili metode opazovanja in analize trenutnega stanja z izvedbo inventur in sodelovanja z različnimi oddelki. Predlagali smo postavitev skenirnih tabel, opremljenih s črtnimi kodami materialov, kar omogoča boljšo sledljivost med skladišči in proizvodnimi obrati. Predlagali smo tudi optimizacijo proizvodnih kosovnic in s tem izboljšali točnost zalog v sistemu SAP, kar predstavlja originalno rešitev problema. Ugotovitve kažejo, da bodo skenirne table in optimizirane proizvodne kosovnice močno izboljšale sledljivost materialov in zmanjšale napake pri zalogah. Praktična vrednost diplomskega dela se odraža v optimiziranem upravljanju zalog, kar prispeva k večji učinkovitosti in zmanjšanju stroškov v podjetju. Ključne besede: diplomske naloge, pakirna embalaža, ulitki, proizvodna kosovnica, črtna koda Objavljeno v RUNG: 24.09.2024; Ogledov: 121; Prenosov: 0
Celotno besedilo (1,65 MB) |