224 research outputs found
KamLAND Bounds on Solar Antineutrinos and neutrino transition magnetic moments
We investigate the possibility of detecting solar electron antineutrinos with
the KamLAND experiment. These electron antineutrinos are predicted by
spin-flavor oscillations at a significant rate even if this mechanism is not
the leading solution to the SNP. KamLAND is sensitive to antineutrinos
originated from solar B neutrinos. From KamLAND negative results after
145 days of data taking, we obtain model independent limits on the total flux
of solar electron antineutrinos $\Phi({}^8 B)< 1.1-3.5\times 10^4 cm^{-2}\
s^{-1}P<0.15%\mu B< 2.3\times 10^{-21}(\Delta m^2, \tan^2\theta)\mu\lsim 3.9\times 10^{-12} \mu_BB= 50\mu\lsim 9.0\times 10^{-13} \mu_BB= 200\mu\lsim 2.0\times 10^{-13} \mu_BB= 1000$ kG at the same
statistical significance.Comment: 13 pages, 2 figure
Large Spatial Scale Variability in Bathyal Macrobenthos Abundance, Biomass, a- and b-Diversity along the Mediterranean Continental Margin
The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can beseen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project (‘‘Biodiversity andEcosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna’’), weinvestigated the large spatial scale variability (over .1,000 km) of the bathyal macrofauna communities that inhabit theMediterranean basin, and their relationships with the environmental variables. The macrofauna abundance, biomass,community structure and functional diversity were analysed and the a-diversity and b-diversity were estimated across sixselected slope areas at different longitudes and along three main depths. The macrobenthic standing stock and a-diversitywere lower in the deep-sea sediments of the eastern Mediterranean basin, compared to the western and central basins. Themacrofaunal standing stock and diversity decreased significantly from the upper bathyal to the lower bathyal slope stations.The major changes in the community composition of the higher taxa and in the trophic (functional) structure occurred atdifferent longitudes, rather than at increasing water depth. For the b-diversity, very high dissimilarities emerged at all levels:(i) between basins; (ii) between slopes within the same basin; and (iii) between stations at different depths; this thereforedemonstrates the high macrofaunal diversity of the Mediterranean basins at large spatial scales. Overall, the food sources(i.e., quantity and quality) that characterised the west, central and eastern Mediterranean basins, as well as sediment grainsize, appear to influence the macrobenthic standing stock and the biodiversity along the different slope areas
KamLAND, solar antineutrinos and the solar magnetic field
In this work the possibility of detecting solar electron antineutrinos
produced by a solar core magnetic field from the KamLAND recent observations is
investigated. We find a scaling of the antineutrino probability with respect to
the magnetic field profile in the sense that the same probability function can
be reproduced by any profile with a suitable peak field value. In this way the
solar electron antineutrino spectrum can be unambiguosly predicted. We use this
scaling and the negative results indicated by the KamLAND experiment to obtain
upper bounds on the solar electron antineutrino flux. We get
at 95% CL. For 90% CL this becomes
, an improvement by a factor of 3-5
with respect to existing bounds. These limits are independent of the detailed
structure of the magnetic field in the solar interior. We also derive upper
bounds on the peak field value which are uniquely determined for a fixed solar
field profile. In the most efficient antineutrino producing case, we get (95%
CL) an upper limit on the product of the neutrino magnetic moment by the solar
field MeV or for
.Comment: 15 pages. References corrected. Minor changes in the tex
Shallow-water gaseohydrothermal plume studies after massive eruption at Panarea, Aeolian Islands, Italy
Copyright © 2013 Elsevier. NOTICE: This is the author’s version of a work accepted for publication by Elsevier. Changes resulting from the publishing process, including peer review, editing, corrections, structural formatting and other quality control mechanisms, may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Marine Systems, 2014, Vol.131, pp. 1-9 DOI: http://dx.doi.org/10.1016/j.jmarsys.2013.10.001Marine water dynamics in the near field of a massive gas eruption near Panarea (Aeolian Islands volcanic arc, SE Tyrrhenian Sea)
is described. ADCP current-meters were deployed during the paroxysmal phase in 2002 and 2003 a few meters from the degassing
vent, recording day-long timeseries. Datasets were sorted to remove errors and select good quality ensembles over the entire water
column. Standard deviation of error velocity was considered a proxy for inhomogeneous velocity fields over beams. Time series
intervals had been selected when the basic ADCP assumptions were fulfilled and random errors minimized. Backscatter data were
also processed to identify bubbles in the water column with the aim of locating bubble-free ensembles. Reliable timeseries are
selected combining these data. Two possible scenarios have been described: firstly, a high dynamic situation with visible surface
diverging rings of waves, entrainment on the lower part of the gas column, detrainment in the upper part and a stagnation line (SL)
at mid depth where currents were close to zero and most of the gas bubbles spread laterally; secondly, a lower dynamic situation
with water entraining into the gas plume at all depths and no surface rings of diverging waves. Reasons for these different dynamics
may be ascribed to changes in gas fluxes (one order of magnitude higher in 2002). Description of SL is important to quantify its
position in the water column and timing for entrainment-detrainment, and it can be measured by ADCP and calculated from models.Italian ISMAR-CNR, La Spezia. http://www.ismar.cnr.it/organization/geographic-units/ismar-la-spezi
Predictions from non trivial Quark-Lepton complementarity
The complementarity between the quark and lepton mixing matrices is shown to
provide robust predictions. We obtain these predictions by first showing that
the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices,
may have a zero (1,3) entry which is favored by experimental data.
We obtain that any theoretical model with a vanishing (1,3) entry of V_M that
is in agreement with quark data, solar, and atmospheric mixing angle leads to
. This value is consistent with the
present 90% CL experimental upper limit. We also investigate the prediction on
the lepton phases. We show that the actual evidence, under the only assumption
that the correlation matrix V_M product of CKM and PMNS has a zero in the entry
(1,3), gives us a prediction for the three CP-violating invariants J, S_1, and
S_2. A better determination of the lepton mixing angles will give stronger
prediction for the CP-violating invariants in the lepton sector. These will be
tested in the next generation experiments. Finally we compute the effect of non
diagonal neutrino mass in "l_i -> l_j gamma" in SUSY theories with non trivial
Quark-Lepton complementarity and a flavor symmetry. The Quark-Lepton
complementarity and the flavor symmetry strongly constrain the theory and we
obtain a clear prediction for the contribution to "mu -> e gamma" and the "tau"
decays "tau -> e gamma" and "tau -> mu gamma". If the Dirac neutrino Yukawa
couplings are degenerate but the low energy neutrino masses are not degenerate,
then the lepton decays are related among them by the V_M entries. On the other
hand, if the Dirac neutrino Yukawa couplings are hierarchical or the low energy
neutrino masses are degenerate, then the prediction for the lepton decays comes
from the CKM hierarchy.Comment: 15 pages, 5 figures, ws-ijmpa class included, Proceedings of the CTP
Symposium on Sypersymmetry at LH
Testing the solar LMA region with KamLAND data
We investigate the potential of 3 kiloTon-years(kTy) of KamLAND data to
further constrain the and values compared to those
presently allowed by existing KamLAND and global solar data. We study the
extent, dependence and characteristics of this sensitivity in and around the
two parts of the LMA region that are currently allowed. Our analysis with 3 kTy
simulated spectra shows that KamLAND spectrum data by itself can constrain
with high precision. Combining the spectrum with global solar data
further tightens the constraints on allowed values of and
. We also study the effects of future neutral current data with a
total error of 7% from the Sudbury Neutrino Observatory. We find that these
future measurements offer the potential of considerable precision in
determining the oscillation parameters (specially the mass parameter).Comment: 16 pages, to appear in J Phys.
Perbandingan Kekuatan Ikan Lemon (Lubia Caeruleus) dengan Ikan Lele (Clarias Batrachus) pada Tegangan 18 Volt
Ikan sebagai hewan air memiliki mekanisme fisiologis yang tidak dimiliki hewan darat. Ikan dapat merespon arus listrik karena memiliki organ elektroreseptor. Secara umum, elektroreseptor merupakan pengembangan dan modifikasi gurat sisi atau lateral line. Untuk mengetahui bahwa ikan dapat merespon arus listrik dilakukan penelitian dengan melakukan perbandingan ketahanan ikan lemon (Lubia caeruleus) dengan ikan lele pada tegangan 18 volt. Digunakan plat PCB sebagai pengantar arus listrik antara katoda dengan anoda pada dengan tegangan 18 volt, dengan medan listrik yang dihasilkan sebesar 171 v/m. Dari hasil pengamatan respon ikan terhadap medan listrik mempengaruhi perilaku ikan karena terinduksi oleh arus tersebut dan ikan menuju wilayah yang efektif dari elektroda. Ikan lele (Clarias batrachus) lebih kuat ketahanan tubuhnya dalam merespon arus listrik dibandingkan ikan lemon (Lubia caeruleus)
Deep-sea polychaetes (Annelida) from the Malta Escarpment (western Ionian Sea)
AbstractThe polychaete assemblages from an escarpment area in the western Ionian Sea are characterised in terms of species richness, evenness and trophic composition. Moreover, the first occurrence of the genus Barantolla in the Mediterranean Sea, and of Lumbrinerides carpinei and Exogone (Parexogone) campoyi in Italian waters, is reported. Aricidea trilobata Laubier and Ramos, 1974 is redescribed on the basis of new material with the new name Aricidea (Acmira) jeaneteae, together with a brief description of two deep-water species belonging to the genus Levinsenia
- …
