3,236 research outputs found
A search for Z' in muon neutrino associated charm production
In many extensions of the Standard Model the presence of an extra neutral
boson, Z', is invoked. A precision study of weak neutral-current exchange
processes involving only second generation fermions is still missing. We
propose a search for Z' in muon neutrino associated charm production. This
process only involves Z' couplings with fermions from the second generation. An
experimental method is thoroughly described using an ideal detector. As an
application, the accuracy reachable with present and future experiments has
been estimated.Comment: 13 pages, 3 figures, late
Generation of tunable entanglement and violation of a Bell-like inequality between different degrees of freedom of a single photon
We demonstrate a scheme to generate noncoherent and coherent correlations,
i.e., a tunable degree of entanglement, between degrees of freedom of a single
photon. Its nature is analogous to the tuning of the purity (first-order
coherence) of a single photon forming part of a two-photon state by tailoring
the correlations between the paired photons. Therefore, well-known tools such
as the Clauser-Horne-Shimony-Holt (CHSH) Bell-like inequality can also be used
to characterize entanglement between degrees of freedom. More specifically,
CHSH inequality tests are performed, making use of the polarization and the
spatial shape of a single photon. The four modes required are two polarization
modes and two spatial modes with different orbital angular momentum.Comment: 7 pages, 5 figures. Updated to be consistent with published versio
Kaon decay interferometry as meson dynamics probes
We discuss the time dependent interferences between and in the
decays in and , to be studied at interferometry machines
such as the -factory and LEAR. We emphasize the possibilities and the
advantages of using interferences, in comparison with width measurements, to
obtain information both on conserving and violating amplitudes.
Comparison with present data and suggestions for future experiments are made.Comment: 15 pages, in RevTex, Report INFNNA-IV-93-31, UTS-DFT-93-2
Interference of Conversion and Bremsstrahlung Amplitudes in the Decay K_L -> mu^+ mu^- gamma
In the region of large mu^+ mu^- invariant mass, the decay spectrum of K_L ->
mu^+ mu^- gamma deviates from the Dalitz pair spectrum, as a result of
interference between conversion (K_L -> gamma^* gamma -> mu^+ mu^- gamma) and
bremsstrahlung amplitudes. The latter is proportional to the K_L -> mu^+ mu^-
matrix element, whose 2 gamma-absorptive part appears to dominate the observed
K_L -> mu^+ mu^- decay rate. We examine the extent to which a scrutiny of the
K_L -> mu^+ mu^- gamma spectrum in the end-point region could provide evidence
on the real part of the K_L -> mu^+ mu^- amplitude. As a by-product, we obtain
the absorptive part of the K_L -> gamma^* gamma form factor, using data on the
K_L -> pi^+ pi^- gamma spectrum.Comment: 7 pages, 4 figure
Normal metal tunnel junction-based superconducting quantum interference proximity transistor: the N-SQUIPT
We report the fabrication and characterization of an alternative design for a
superconducting quantum interference proximity transistor (SQUIPT) based on a
normal metal (N) probe. The absence of direct Josephson coupling between the
proximized metal nanowire and the N probe allows us to observe the full
modulation of the wire density of states around zero voltage and current
\textit{via} the application of an external magnetic field. This results into a
drastic suppression of power dissipation which can be as low as a few W. In this context the interferometer allows an improvement of up to
four orders of magnitude with respect to earlier SQUIPT designs, and makes it
ideal for extra-low power cryogenic applications. In addition, the N-SQUIPT has
been recently predicted to be the enabling candidate for the implementation of
coherent caloritronic devices based on proximity effect.Comment: 5 pages, 4 color figure
Photonic polarization gears for ultra-sensitive angular measurements
Quantum metrology bears a great promise in enhancing measurement precision,
but is unlikely to become practical in the near future. Its concepts can
nevertheless inspire classical or hybrid methods of immediate value. Here, we
demonstrate NOON-like photonic states of m quanta of angular momentum up to
m=100, in a setup that acts as a "photonic gear", converting, for each photon,
a mechanical rotation of an angle {\theta} into an amplified rotation of the
optical polarization by m{\theta}, corresponding to a "super-resolving" Malus'
law. We show that this effect leads to single-photon angular measurements with
the same precision of polarization-only quantum strategies with m photons, but
robust to photon losses. Moreover, we combine the gear effect with the quantum
enhancement due to entanglement, thus exploiting the advantages of both
approaches. The high "gear ratio" m boosts the current state-of-the-art of
optical non-contact angular measurements by almost two orders of magnitude.Comment: 10 pages, 4 figures, + supplementary information (10 pages, 3
figures
Strong rescattering in K-> 3pi decays and low-energy meson dynamics
We present a consistent analysis of final state interactions in
decays in the framework of Chiral Perturbation Theory.
The result is that the kinematical dependence of the rescattering phases cannot
be neglected. The possibility of extracting the phase shifts from future
interference experiments is also analyzed.Comment: 14 pages in RevTex, 3 figures in postscrip
Potential energy savings from circular economy scenarios based on construction and agri-food waste in Italy
In this study, our aim was to explore the potential energy savings obtainable from the recycling of 1 tonne of Construction and Demolition Waste (C&DW) generated in the Metropolitan City of Naples. The main fraction composing the functional unit are mixed C&DW, soil and stones, concrete, iron, steel and aluminium. The results evidence that the recycling option for the C&DW is better than landfilling as well as that the production of recycled aggregates is environmentally sustainable since the induced energy and environmental impacts are lower than the avoided energy and environmental impacts in the life cycle of recycled aggregates. This LCA study shows that the transition to the Circular Economy offers many opportunities for improving the energy and environmental performances of the construction sector in the life cycle of construction materials by means of internal recycling strategies (recycling C&DW into recycled aggregates, recycled steel, iron and aluminum) as well as external recycling by using input of other sectors (agri-food by-products) for the manufacturing of construction materials. In this way, the C&D sector also contributes to realizing the energy and bioeconomy transition by disentangling itself from fossil fuel dependence
Survey Design to Unravel Freight Transportation Demand of Establishments in Cities
Freight transportation serves the vital role of fulfilling the goods demand of residents in cities, yet little is known about the mechanisms that generate freight movements and their impact on traffic. Even though technology may allow us to better trace real-time movements, establishment surveys are still important to collect data on strategic and tactical freight transportation decisions. Leveraging state-of-art knowledge, a survey was specifically designed to investigate freight travel demand. This paper shows the preparation, execution and data processing of a survey on establishments in Singapore. Analysis of the survey data allows us to explain variations in delivery, such as, the types of supplier, the size and frequency of goods deliveries, and the timing of deliveries
Coating thermal noise for arbitrary shaped beams
Advanced LIGO's sensitivity will be limited by coating noise. Though this
noise depends on beam shape, and though nongaussian beams are being seriously
considered for advanced LIGO, no published analysis exists to compare the
quantitative thermal noise improvement alternate beams offer. In this paper, we
derive and discuss a simple integral which completely characterizes the
dependence of coating thermal noise on shape. The derivation used applies
equally well, with minor modifications, to all other forms of thermal noise in
the low-frequency limit.Comment: 3 pages. Originally performed in August 2004. Submitted to CQG. (v2)
: Corrections from referee and other
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