37,649 research outputs found
Possible trace of neutrino nonstandard interactions in the supernova
Neutrino non-standard interactions (NSI), previously introduced for the sun,
are studied in the supernova context. For normal hierarchy the probability for
electron neutrinos and antineutrinos at low energy () is
substantially increased with respect to the non-NSI case and joins its value
for inverse hierarchy which is constant with energy. Also for inverse hierarchy
the NSI and non-NSI probabilities are the same for each neutrino and
antineutrino species. These are the possible visible effects of NSI in the
supernova. The decay into antineutrinos, which has been previously shown to be
implied by dense matter, cannot be seen experimentally, owing to the smallness
of the antineutrino production probability.Comment: 5 pages, 3 eps figures. Acknowledgements include
Muon anomaly and a lower bound on higgs mass due to a light stabilized radion in the Randall-Sundrum model
We investigate the Randall-Sundrum model with a light stabilized radion
(required to fix the size of the extra dimension) in the light of muon
anomalous magnetic moment . Using the recent data
(obtained from the E821 experiment of the BNL collaboration) which differs by
from the Standard Model result, we obtain constraints on radion
mass \mphi and radion vev \vphi. In the presence of a radion the beta
functions \beta(\l) and of higgs quartic coupling (\l) and
top-Yukawa coupling () gets modified. We find these modified beta
functions. Using these beta functions together with the anomaly constrained
\mphi and \vphi, we obtain lower bound on higgs mass . We compare our
result with the present LEP2 bound on .Comment: Version to be appeared in IJMP
A Study on Performance and Power Efficiency of Dense Non-Volatile Caches in Multi-Core Systems
In this paper, we present a novel cache design based on Multi-Level Cell
Spin-Transfer Torque RAM (MLC STTRAM) that can dynamically adapt the set
capacity and associativity to use efficiently the full potential of MLC STTRAM.
We exploit the asymmetric nature of the MLC storage scheme to build cache lines
featuring heterogeneous performances, that is, half of the cache lines are
read-friendly, while the other is write-friendly. Furthermore, we propose to
opportunistically deactivate ways in underutilized sets to convert MLC to
Single-Level Cell (SLC) mode, which features overall better performance and
lifetime. Our ultimate goal is to build a cache architecture that combines the
capacity advantages of MLC and performance/energy advantages of SLC. Our
experiments show an improvement of 43% in total numbers of conflict misses, 27%
in memory access latency, 12% in system performance, and 26% in LLC access
energy, with a slight degradation in cache lifetime (about 7%) compared to an
SLC cache
Distributed photovoltaic systems: Utility interface issues and their present status. Intermediate/three-phase systems
The interface issues between the intermediate-size Power Conditioning Subsystem (PCS) and the utility are considered. A literature review yielded facts about the status of identified issues
Electric Field Effect in Diluted Magnetic Insulator Anatase Co:TiO2
An external electric field induced reversible modulation of room temperature
magnetic moment is achieved in an epitaxial and insulating thin film of
dilutely cobalt-doped anatase TiO2. This first demonstration of electric field
effect in any oxide based diluted ferromagnet is realized in a high quality
epitaxial heterostructure of PbZr0.2Ti0.8O3/Co:TiO2/SrRuO3 grown on (001)
LaAlO3. The observed effect, which is about 15% in strength in a given
heterostructure, can be modulated over several cycles. Possible mechanisms for
electric field induced modulation of insulating ferromagnetism are discussed.Comment: 14 pages, 4 figure
On CP Violation in Minimal Renormalizable SUSY SO(10) and Beyond
We investigate the role of CP phases within the renormalizable SUSY SO(10)
GUT with one 10_H, one 126bar_H one 126_H and one 210_H Higgs representations
and type II seesaw dominating the neutrino mass matrix. This framework is non
trivially predictive in the fermionic sector and connects in a natural way the
GUT unification of b and tau Yukawa couplings with the bi-large mixing scenario
for neutrinos. On the other hand, existing numerical analysis claim that
consistency with quark and charged lepton data prevents the minimal setup from
reproducing the observed CP violation via the Cabibbo-Kobayashi-Maskawa (CKM)
matrix. We re-examine the issue and find by inspection of the fermion mass sum
rules and a detailed numerical scan that, even though the CKM phase takes
preferentially values in the second quadrant, the agreement of the minimal
model with the data is actually obtained in a non negligible fraction of the
parameter space. We then consider a recently proposed renormalizable extension
of the minimal model, obtained by adding one chiral 120-dimensional Higgs
supermultiplet. We show that within such a setup the CKM phase falls naturally
in the observed range. We emphazise the robust predictivity of both models here
considered for neutrino parameters that are in the reach of ongoing and future
experiments.Comment: 9 pages, 6 figures. Two refs added, discussion expanded. To appear on
Phys. Rev.
Ultimate intrinsic coercivity samarian-cobalt magnet. An Earth based feasibility study for Space Shuttle missions
Techniques for the electromagnetic containerless reaction of samarium with cobalt for the formation of samarium-cobalt alloys are summarized. The effort expended to reduce and instrument the oxygen partial pressure in the reaction chamber and coolant gas system are described as well as the experiments in which these improvements were shown to be partially effective. A stainless steel glove box capable of being evacuated to low 10 to the -6th torr pressure and refilled with ultra-pure argon was built and installed. Necessary accessories to perform SmCo5 powder preparation, compaction and subsequent encapsulation of the powder inside a hot isostatic pressing cannister were designed, built, and incorporated into the chamber. All accessories were tested for proper functioning inside the chamber. Using the facility, the first batch of densified SmCo5 powder was fabricated to near total density. Analysis of the densified compacts shows that oxygen contamination during fabrication was near zero
Spin-polarized transport in inhomogeneous magnetic semiconductors: theory of magnetic/nonmagnetic p-n junctions
A theory of spin-polarized transport in inhomogeneous magnetic semiconductors
is developed and applied to magnetic/nonmagnetic p-n junctions. Several
phenomena with possible spintronic applications are predicted, including
spinvoltaic effect, spin valve effect, and giant magnetoresistance. It is
demonstrated that only nonequilibrium spin can be injected across the
space-charge region of a p-n junction, so that there is no spin injection (or
extraction) at low bias.Comment: Minor Revisions. To appear in Phys. Rev. Let
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