Search results for "Mixing"

Neutrino Gas in Equilibrium with Self-Interaction

2005

We study a neutrino gas in equilibrium both at T = 0 and at finite temperature. The neutrinos are assumed to be massive Dirac particles with two generations interacting with each other via neutral currents and with a background of matter. We analyze the main properties of the neutrino eigenmodes in the medium, such as effective masses and mixing angle.

Present Knowledge of the Lepton Mixing Matrix from Neutrino Oscillation Experiments

1986

An analysis of experimental results in the framework of simultaneous oscillations of three neutrino flavours is used, in a combined fit, to constrain the elements of the 3 × 3 unitary lepton mixing matrix and to obtain limits on the three lepton mixing angles αeμ, αe τ and αμτ.

Proton-Neutron QRPA

2007

We discussed proton—neutron two-quasiparticle excitations and their electromagnetic and beta decays in Chap. 15. In Chap. 17 we introduced the pn-QTDA, the simplest configuration mixing scheme of these excitations. The vacuum of the pnQTDA is the BCS vacuum, and the solutions of the pn-QTDA satisfy a variational principle.1

10.7 Weak quark mixing and the CKM matrix

2008

Lifetimes of intruder states in 186Pb, 188Pb and 194Po

2008

Abstract Lifetimes of prolate intruder states in 186Pb and 188Pb and oblate intruder states in 194Po have been determined through recoil distance Doppler-shift lifetime measurements. Deformation parameters of | β 2 | = 0.29 ( 5 ) and | β 2 | = 0.17(3) have been extracted from experimental B ( E 2 ) values for the prolate and the oblate bands, respectively. The present study addresses the phenomenon of shape coexistence typical for the nuclei near Z = 82 and N = 104 , providing information on configuration mixing of intrinsic structures of the nuclei of interest. The results are compared with the available lifetime data and theoretical results for neutron-deficient Po, Pb, Hg and Pt nuclei. …

Cooling and crystallization recorded in trachytic enclaves hosted in pantelleritic magmas (Pantelleria, Italy): Implications for pantellerite petroge…

2015

Abstract This study focuses on the comenditic trachyte enclaves hosted in pantelleritic lava and pumices emplaced during one of the most recent eruptive events at Pantelleria (~ 6 ka). Enclaves range from mm-sized fragments to dm-sized blocks with spheroidal to amoeboid shapes and characteristic globular surfaces; they are crystal-rich with ~ 30 vol% large anorthoclase, less abundant Fe-rich olivine, clinopyroxene and Fe–Ti oxides. Vesicles ranging from a few mm to 1–2 cm in size are distributed throughout the enclave and are commonly filled with microlite-free vesicular glass. The groundmass presents spectacular textures, including fine to coarse spherulites and hopper and skeletal microli…

Backward frequency doubling of near infrared picosecond pulses.

2014

We report on backward second-harmonic generation using ps laser pulses in congruent lithium niobate with 3.2 µm periodic poling. Three resonant peaks were measured between 1530 and 1730 nm, corresponding to 16th, 17th and 18th quasi-phase-matching orders in the backward configuration, with a conversion efficiency of 4.75 x 10(-5%)/W for the 16th order. We could also discriminate the contributions from inverted domains randomized in duty-cycle.

Control processes for stimulated Raman scattering in optical fibers by dual-frequency pumping

1998

We pointed out that with nondegenerate frequency, and orthogonally polarized pump waves, the SRS may be suppressed in one of the axes of a highly birefringent fiber either via a four wave mixing (FWM) parametric process, or through the orthogonal component of the Raman nonlinearity.

On-chip quantum optical frequency comb sources

2018

Integrated optical frequency comb sources, based on nonlinear microring resonators, can be used to generate complex quantum states. In particular, we achieved multi-photon and high-dimensional entangled quantum states, as well as their coherent control.

Simultaneous achievement of polarization attraction and Raman amplification in optical fibers

2004

We present a theoretical analysis and experimental demonstration of the combined effects of polarization attraction and Raman amplification in isotropic optical fibers. The polarization attraction is based on four-wave mixing interaction of counterpropagating waves.