Search results for "parametri"
showing 10 items of 1144 documents
Definition of theΔmass and width
2007
In the framework of effective field theory we show that, at two-loop order, the mass and width of the $\ensuremath{\Delta}$ resonance defined via the (relativistic) Breit-Wigner parametrization both depend on the choice of field variables. In contrast, the complex-valued position of the pole of the propagator is independent of this choice.
An improved global analysis of nuclear parton distribution functions including RHIC data
2008
We present an improved leading-order global DGLAP analysis of nuclear parton distribution functions (nPDFs), supplementing the traditionally used data from deep inelastic lepton-nucleus scattering and Drell-Yan dilepton production in proton-nucleus collisions, with inclusive high-$p_T$ hadron production data measured at RHIC in d+Au collisions. With the help of an extended definition of the $\chi^2$ function, we now can more efficiently exploit the constraints the different data sets offer, for gluon shadowing in particular, and account for the overall data normalization uncertainties during the automated $\chi^2$ minimization. The very good simultaneous fit to the nuclear hard process data…
Practical system for the generation of pulsed quantum frequency combs
2017
The on-chip generation of large and complex optical quantum states will enable low-cost and accessible advances for quantum technologies, such as secure communications and quantum computation. Integrated frequency combs are on-chip light sources with a broad spectrum of evenly-spaced frequency modes, commonly generated by four-wave mixing in optically-excited nonlinear micro-cavities, whose recent use for quantum state generation has provided a solution for scalable and multi-mode quantum light sources. Pulsed quantum frequency combs are of particular interest, since they allow the generation of single-frequency-mode photons, required for scaling state complexity towards, e.g., multi-photon…
Novel Narrow-Band Spectral Interference Filter with Very High Transmittance
2011
We report a novel scheme to improve the effective transmission of a standard interference filter, and demonstrate over 97% passband transmission. Such high efficiency is critical for quantum information applications, e.g. high-efficiency single-photon generation utilizing parametric down-conversion. The scheme can also be modified to function with a tilted filter, thereby allowing tuning of the passband frequency. In addition, the tilted configuration creates an infinite number of consecutive reflections from and transmissions through the filter, further improving the net filter transmission. Because spectral interference filters are a key element in optical quantum information experiments …
Type I optical parametric oscillators above threshold are perfect squeezers for empty gauss-hermite modes at any pumping level
2007
A type I optical parametric oscillator pumped by a Gaussian beam above threshold and tuned to its first transverse mode family is shown to yield a perfectly squeezed, empty Gauss-Hermite mode at any pumping level.
Quantum fluctuations in cavity solitons
2005
Quantum fluctuations of degenerate optical parametric oscillators' cavity solitons (CS) are studied. We show that CSs are sources of perfectly squeezed light that exhibit photon fluctuations below the shot-noise level as well.
Quantum noise properties of cavity solitons
2006
General method for studying quantum fluctuations of dissipative structures formed in nonlinear optical cavities is presented. Application to cavity soliton supported by degenerate optical parametric oscillator is presented. Squeezing and intensity fluctuations spectra are discussed.
Generation of multimode squeezing and entanglement in the space and frequency domains : A general “supermode” approach
2009
Optical parametric oscillators (OPO) have been extensively used in the continuous variable quantum optics community as a resource to produce non-classical states of light, including squeezed states or entangled beams. They have been widely studied, theoretically and experimentally, in the single mode case, and have found many applications to quantum information protocols and high sensitivity optical measurements. However, as the complexity of quantum information protocols increases, the need for multiplexed quantum channels has emerged, which require the use of multimode non-classical states of light.
Comment On The Lepton Mixing Matrix
1980
The problem of finding a suitable parametrization for a nontrivial lepton mixing matrix is considered in the framework of the ''sequential'' Weinberg-Salam theory. It is noted that in the case of n lepton generations there are in fact n+1 different theories, corresponding to different numbers m of right-handed neutrino fields present in the Lagrangian. These (n,m) models conserve CP for leptonic couplings naturally only for m=0 or 1 when n > or = 3. These models would seem to be useful as self-consistent approximations for reducing the number of parameters in the experimental analysis of lepton mixing matrices.
Parametric self-trapping in the presence of randomized quasi phase matching
2010
We report on experimental evidence of parametric spatial solitons in a quadratic crystal with randomized periodic ferroelectric poling. Two-color self-focusing via quadratic cascading overcomes the diffractive nature of both fundamental and frequency-doubled beams.