61 research outputs found
Fauna kopnenih jednakonožaca (Isopoda: Oniscidea) Baranje (Hrvatska)
Pitfall samples were taken during summer 2003 in 25 habitats of the Baranya triangle (Croatia) to describe the isopod fauna. The 125 traps caught a total of 2,808 isopods belonging to 11 species: Haplophthalmus danicus, Hyloniscus riparius, Platyarthrus hoffmannseggii, Cylisticus convexus, Porcellium collicola, Protracheoniscus politus, Trachelipus ratzeburgii, Trachelipus nodulosus, Trachelipus rathkii, Armadillidium vulgare and Armadillidium zenckeri. The most characteristic species of the area are A. vulgare, T. rathkii, P. collicola and H. riparius. The composition of the isopod assemblage proved to be similar to that in the Hungarian part of the Drava lowland.Tijekom ljeta 2003. godine na 25 postaja u hrvatskom dijelu Baranje uzorkovana je fauna kopnenih Isopoda metodom lovnih posuda. Uzorkovano je 2808 jednakonožaca uporabom 125 lovnih posuda. Uzorkovane jedinke svrstane su u 11 vrsta: Haplophthalmus danicus, Hyloniscus riparius, Platyarthrus hoffmannseggii, Cylisticus convexus, Porcellium collicola, Protracheoniscus politus, Trachelipus ratzeburgii, Trachelipus nodulosus, Trachelipus rathkii, Armadillidium vulgare i Armadillidium zenckeri. S obzirom na učestalost i lokalno rasprostranjenje za područje Baranje su najkarakterističnije vrste: A. vulgare, T. rathkii, P. collicola i H. riparius. Kvalitativni sastav faune jednakonožaca hrvatskog djela Baranje vrlo je sličan, te se poklapa s većinom vrsta faune jednakonožaca nizinskog područja Drave u Mađarskoj
Prilog poznavanju faune ušara Hrvatske (Diptera: Hippoboscidae)
Faunistic research into louse flies (Hippoboscidae) in Croatia during the last two decades has increased the total number of louse flies known from this country to 11 species, of which Ornithoica turdi, Ornithophila metallica, Ornithomya avicularia, Ornithomya biloba, Ornithomya chloropus, Ornithomya fringillina, Crataerina melbae, Stenepteryx hirundinis and Icosta minor are new to Croatia.Faunistička istraživanja ušara (Hippoboscidae) tijekom posljednjih dvadeset godina u Hrvatskoj rezultirala su utvrđivanjem 11 vrsta, od kojih su drozdova ušara (Ornithoica turdi), sjajna ušara (Ornithophila metallica), velika ptičja ušara (Ornithomya avicularia), lastavičja ušara (Ornithomya biloba), tamna ptičja ušara (Ornithomya chloropus), mala ptičja ušara (Ornithomya fringillina), velika čiopina ušara (Crataerina melbae), piljkova ušara (Stenepteryx hirundinis) i mala čapljina ušara (Icosta minor) nove u fauni Hrvatske. Ukupni broj vrsta iz porodice ušara u Hrvatskoj fauni povećan je na 11 vrsta
Search for solar axions using Li-7
We describe a novel approach to the search for solar, near-monochromatic
hadronic axions, the latter being suggested to be created in the solar core
during M1 transitions between the first excited level of Li-7, at 478 keV, and
the ground state. As a result of Doppler broadening, in principle these axions
can be detected via resonant absorption by the same nuclide on the Earth.
Excited nuclei of Li-7 are produced in the solar interior by Be-7 electron
capture and thus the axions are accompanied by emission of Be-7 solar neutrinos
of energy 384 keV. An experiment was made which has yielded an upper limit on
hadronic axion mass of 32 keV at the 95% confidence level.Comment: revtex, 4 pages with 2 figures, title revised, minor changes, matches
version to appear in Phys. Rev.
Recent searches for solar axions and large extra dimensions
We analyze the data from two recent experiments designed to search for solar
axions within the context of multidimensional theories of the Kaluza-Klein
type. In these experiments, axions were supposed to be emitted from the solar
core, in M1 transitions between the first excited state and the ground state of
57Fe and 7Li. Because of the high multiplicity of axionic Kaluza-Klein states
which couple with the strength of ordinary QCD axions, we obtain much more
stringent experimental limits on the four-dimensional Peccei-Quinn breaking
scale f_{PQ}, compared with the solar QCD axion limit. Specifically, for the
57Fe experiment, f_{PQ}>1x10^6 GeV in theories with two extra dimensions and a
higher-dimensional gravitational scale M_H of order 100 TeV, and f_{PQ}>1x10^6
GeV in theories with three extra dimensions and M_H of order 1 TeV (to be
compared with the QCD axion limit, f_{PQ}>8x10^3 GeV). For the 7Li experiment,
f_{PQ}>1.4x10^5 GeV and 3.4x10^5 GeV, respectively (to be compared with the QCD
axion limit, f_{PQ}>1.9x10^2 GeV). It is an interesting feature of our results
that, in most cases, the obtained limit on f_{PQ} cannot be coupled with the
mass of the axion, which is essentially set by the (common) radius of the extra
dimensions.Comment: 4 pages, revtex 4, minor changes, version accepted by PR
Prospects for the CERN Axion Solar Telescope Sensitivity to 14.4 keV Axions
The CERN Axion Solar Telescope (CAST) is searching for solar axions using the
9.0 T strong and 9.26 m long transverse magnetic field of a twin aperture LHC
test magnet, where axions could be converted into X-rays via reverse Primakoff
process. Here we explore the potential of CAST to search for 14.4 keV axions
that could be emitted from the Sun in M1 nuclear transition between the first,
thermally excited state, and the ground state of 57Fe nuclide. Calculations of
the expected signals, with respect to the axion-photon coupling, axion-nucleon
coupling and axion mass, are presented in comparison with the experimental
sensitivity.Comment: 4 pages, 1 figure. Submitted to Nucl. Instr. and Meth.
Results and perspectives of the solar axion search with the CAST experiment
The status of the solar axion search with the CERN Axion Solar Telescope
(CAST) will be presented. Recent results obtained by the use of He as a
buffer gas has allowed us to extend our sensitivity to higher axion masses than
our previous measurements with He. With about 1 h of data taking at each of
252 different pressure settings we have scanned the axion mass range 0.39 eV 0.64 eV. From the absence of an excess of x rays when the
magnet was pointing to the Sun we set a typical upper limit on the axion-photon
coupling of g GeV at 95% C.L., the
exact value depending on the pressure setting. CAST published results represent
the best experimental limit on the photon couplings to axions and other similar
exotic particles dubbed WISPs (Weakly Interacting Slim Particles) in the
considered mass range and for the first time the limit enters the region
favored by QCD axion models. Preliminary sensitivities for axion masses up to
1.16 eV will also be shown reaching mean upper limits on the axion-photon
coupling of g GeV at 95% C.L.
Expected sensibilities for the extension of the CAST program up to 2014 will be
presented. Moreover long term options for a new helioscope experiment will be
evoked.Comment: 4 pages, 2 pages, to appear in the proceedings of the 24th Rencontres
de Blois V2 A few affiliations were not corrected in previous version V3
Author adde
New solar axion search in CAST with He filling
The CERN Axion Solar Telescope (CAST) searches for conversion in
the 9 T magnetic field of a refurbished LHC test magnet that can be directed
toward the Sun. Two parallel magnet bores can be filled with helium of
adjustable pressure to match the X-ray refractive mass to the axion
search mass . After the vacuum phase (2003--2004), which is optimal for
eV, we used He in 2005--2007 to cover the mass range of
0.02--0.39 eV and He in 2009--2011 to scan from 0.39--1.17 eV. After
improving the detectors and shielding, we returned to He in 2012 to
investigate a narrow range around 0.2 eV ("candidate setting" of our
earlier search) and 0.39--0.42 eV, the upper axion mass range reachable with
He, to "cross the axion line" for the KSVZ model. We have improved the
limit on the axion-photon coupling to (95% C.L.), depending on the pressure settings. Since 2013, we
have returned to vacuum and aim for a significant increase in sensitivity.Comment: CAST Collaboration 6 pages 3 figure
Solar axion search with the CAST experiment
The CAST (CERN Axion Solar Telescope) experiment is searching for solar
axions by their conversion into photons inside the magnet pipe of an LHC
dipole. The analysis of the data recorded during the first phase of the
experiment with vacuum in the magnet pipes has resulted in the most restrictive
experimental limit on the coupling constant of axions to photons. In the second
phase, CAST is operating with a buffer gas inside the magnet pipes in order to
extent the sensitivity of the experiment to higher axion masses. We will
present the first results on the data taking as well as the
system upgrades that have been operated in the last year in order to adapt the
experiment for the data taking. Expected sensitivities on the
coupling constant of axions to photons will be given for the recent run just started in March 2008.Comment: Proceedings of the ICHEP 2008 conferenc
Search for chameleons with CAST
In this work we present a search for (solar) chameleons with the CERN Axion
Solar Telescope (CAST). This novel experimental technique, in the field of dark
energy research, exploits both the chameleon coupling to matter () and to photons () via the Primakoff effect. By reducing
the X-ray detection energy threshold used for axions from 1keV to 400eV
CAST became sensitive to the converted solar chameleon spectrum which peaks
around 600eV. Even though we have not observed any excess above background,
we can provide a 95% C.L. limit for the coupling strength of chameleons to
photons of for .Comment: 8 pages, 12 figure
Search for low Energy solar Axions with CAST
We have started the development of a detector system, sensitive to single
photons in the eV energy range, to be suitably coupled to one of the CAST
magnet ports. This system should open to CAST a window on possible detection of
low energy Axion Like Particles emitted by the sun. Preliminary tests have
involved a cooled photomultiplier tube coupled to the CAST magnet via a
Galileian telescope and a switched 40 m long optical fiber. This system has
reached the limit background level of the detector alone in ideal conditions,
and two solar tracking runs have been performed with it at CAST. Such a
measurement has never been done before with an axion helioscope. We will
present results from these runs and briefly discuss future detector
developments.Comment: Paper submitted to the proceedings of the "4th Patras Workshop on
Axions, WIMPs and WISPs", DESY, Hamburg Site - Germany, 18-21 June 2008.
Author affiliations are reported on the title page of the paper. In version
2: 1 affiliation change, 3 references adde
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