11,421 research outputs found
Assessing the role of nuclear effects in the interpretation of the MiniBooNE low-energy anomaly
We study the impact of the effect of multinucleon interactions in the
reconstruction of the neutrino energy on the fit of the MiniBooNE data in terms
of neutrino oscillations. We obtain some improvement of the fit of the
MiniBooNE low-energy excess in the framework of two-neutrino oscillations and a
shift of the allowed region in the -- plane
towards smaller values of and larger values of
. However this effect is not enough to solve the problem of the
appearance-disappearance tension in the global fit of short-baseline neutrino
oscillation data.Comment: 14 pages; to be published in PR
Muon capture in the front end of the IDS neutrino factory
We discuss the design of the muon capture front end of the neutrino factory
International Design Study. In the front end, a proton bunch on a target
creates secondary pions that drift into a capture transport channel, decaying
into muons. A sequence of rf cavities forms the resulting muon beams into
strings of bunches of differing energies, aligns the bunches to (nearly) equal
central energies, and initiates ionization cooling. The muons are then
accelerated to high energy where their decays provide neutrino beams. For the
International Design Study (IDS), a baseline design must be developed and
optimized for an engineering and cost study. We present a baseline design that
can be used to establish the scope of a future neutrino Factory facility.Comment: 3 pp. 1st International Particle Accelerator Conference: IPAC'10,
23-28 May 2010: Kyoto, Japa
Generation of polarization entangled photon pairs by a single crystal interferometric source pumped by femtosecond laser pulses
Photon pairs, highly entangled in polarization have been generated under
femtosecond laser pulse excitation by a type I crystal source, operating in a
single arm interferometric scheme. The relevant effects of temporal walk-off
existing in these conditions between the ordinary and extraordinary photons
were experimentally investigated. By introducing a suitable temporal
compensation between the two orthogonal polarization components highly
entangled pulsed states were obtained
Realization of Universal Optimal Quantum Machines by Projective Operators and Stochastic Maps
Optimal quantum machines can be implemented by linear projective operations.
In the present work a general qubit symmetrization theory is presented by
investigating the close links to the qubit purification process and to the
programmable teleportation of any generic optimal anti-unitary map. In
addition, the contextual realization of the N ->M cloning map and of the
teleportation of the N->(M-N) universal NOT gate is analyzed by a novel and
very general angular momentum theory. An extended set of experimental
realizations by state symmetrization linear optical procedures is reported.
These include the 1->2 cloning process, the UNOT gate and the quantum
tomographic characterization of the optimal partial transpose map of
polarization encoded qubits.Comment: 11 pages, 7 figure
Multiparticle Quantum Superposition and Stimulated Entanglement by Parity Selective Amplification of Entangled States
A multiparticle quantum superposition state has been generated by a novel
phase-selective parametric amplifier of an entangled two-photon state. This
realization is expected to open a new field of investigations on the
persistence of the validity of the standard quantum theory for systems of
increasing complexity, in a quasi decoherence-free environment. Because of its
nonlocal structure the new system is expected to play a relevant role in the
modern endeavor on quantum information and in the basic physics of
entanglement.Comment: 13 pages and 3 figure
Teleportation scheme implementing contextually the Universal Optimal Quantum Cloning Machine and the Universal Not Gate. Complete experimental realization
By a significant modification of the standard protocol of quantum state
Teleportation two processes ''forbidden'' by quantum mechanics in their exact
form, the Universal NOT gate and the Universal Optimal Quantum Cloning Machine,
have been implemented contextually and optimally by a fully linear method. In
particular, the first experimental demonstration of the Tele-UNOT Gate, a novel
quantum information protocol has been reported (cfr. quant-ph/0304070). A
complete experimental realization of the protocol is presented here.Comment: 11 pages, 3 figure
Continuous variable cloning via network of parametric gates
We propose an experimental scheme for the cloning machine of continuous
quantum variables through a network of parametric amplifiers working as
input-output four-port gates.Comment: 4 pages, 2 figures. To appear on Phys. Rev. Let
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