6,831 research outputs found
The flavor of neutrinos in muon decays at a neutrino factory and the LSND puzzle
The accurate prediction of the neutrino beam produced in muon decays and the
absence of opposite helicity contamination for a particular neutrino flavor
make a future neutrino factory the ideal place to look for the lepton flavor
violating (LFV) decays of the kind \mu^+\ra e^+\nuebar\numu and lepton number
violating (LNV) processes like \mu^-\ra e^-\nue\numu. Excellent sensitivities
can be achieved using a detector capable of muon and/or electron identification
with charge discrimination. This would allow to set experimental limits that
improve current ones by more than two orders of magnitude and test the
hypothesis that the LSND excess is due to such anomalous decays, rather than
neutrino flavor oscillations in vacuum.Comment: 19 pages, 4 figure
Fine-grained entanglement loss along renormalization group flows
We explore entanglement loss along renormalization group trajectories as a
basic quantum information property underlying their irreversibility. This
analysis is carried out for the quantum Ising chain as a transverse magnetic
field is changed. We consider the ground-state entanglement between a large
block of spins and the rest of the chain. Entanglement loss is seen to follow
from a rigid reordering, satisfying the majorization relation, of the
eigenvalues of the reduced density matrix for the spin block. More generally,
our results indicate that it may be possible to prove the irreversibility along
RG trajectories from the properties of the vacuum only, without need to study
the whole hamiltonian.Comment: 5 pages, 3 figures; minor change
Results of MAGIC on Galactic sources
MAGIC is a single-dish Cherenkov telescope located on La Palma (Spain), hence
with an optimal view on the Northern sky. Sensitive in the 30 GeV-30 TeV energy
band, it is nowadays the only ground-based instrument being able to measure
high-energy gamma-rays below 100 GeV. We review the most recent experimental
results on Galactic sources obtained using MAGIC. These include pulsars, binary
systems, supernova remnants and unidentified sources.Comment: 4 pages, 8 figures, to appear in the proceedings of "4th Heidelberg
International Symposium on High Energy Gamma-Ray Astronomy 2008
Results of MAGIC on Galactic sources
MAGIC is a single-dish Cherenkov telescope located on La Palma (Spain), hence
with an optimal view on the Northern sky. Sensitive in the 30 GeV-30 TeV energy
band, it is nowadays the only ground-based instrument being able to measure
high-energy gamma-rays below 100 GeV. We review the most recent experimental
results on Galactic sources obtained using MAGIC. These include pulsars, binary
systems, supernova remnants and unidentified sources.Comment: 4 pages, 8 figures, to appear in the proceedings of "4th Heidelberg
International Symposium on High Energy Gamma-Ray Astronomy 2008
Quantum-enhanced gyroscopy with rotating anisotropic Bose–Einstein condensates
High-precision gyroscopes are a key component of inertial navigation systems. By considering matter wave gyroscopes that make use of entanglement it should be possible to gain some advantages in terms of sensitivity, size, and resources used over unentangled optical systems. In this paper we consider the details of such a quantum-enhanced atom interferometry scheme based on atoms trapped in a carefully-chosen rotating trap. We consider all the steps: entanglement generation, phase imprinting, and read-out of the signal and show that quantum enhancement should be possible in principle. While the improvement in performance over equivalent unentangled schemes is small, our feasibility study opens the door to further developments and improvements
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