Search results for " Polarization"
showing 10 items of 668 documents
Evolutionary algorithm for fiber laser in ultrashort pulse regime
2016
This thesis deals with the generation of ultrashort pulses within a fiber laser cavity through the automatic optimization of its parameters by an evolutionary algorithm. The interest of this subject comes from the difficulty to systematically explore dynamics in a large domain of experimental parameters. We have shown that it is possible to implement an evolutionary algorithm on fiber laser cavity with appropriate precautions. We have experimentally demonstrated for the first time the mode locking of a laser cavity only using the optimization of polarization controllers through an automatic and self-learning procedure. We also have demonstrated that selecting the mode locking from it radio-…
State of the Art in Alq3-Based Spintronic Devices
2015
Since the first observation of a magnetoresistance signal in a vertical organic spin valve in 2004, tris (8-hydroxyquinoline) aluminium (Alq3) molecule has become a standard material for organic spintronics devices. This chapter will briefly present the state of the art on Alq3-based spintronic devices and the different approaches applied through the years to try to optimize these systems. It will be remarked that, despite extensively investigated, many fundamental questions regarding the spin injection and transport mechanisms through the organic layer are still unclear. The chapter will also present some of the most controversial topics in the organic spintronic area and it will highlight…
Interaction between heterobinuclear molecules and nature of the ground spin state in oximato-bridged [CuIIMII]2 bis-binuclear complexes (M=Cu, Ni, Mn…
1999
[EN] Two new heterobimetallic complexes [Cu(pdmg)Ni(Me-3[12]N-3)(CH3CH2OH)](ClO4)(2)(2) and [Cu(pdmg) Mn(bipy)(2)]-ClO4)(2) . H2O (3) (H(2)pdmg = 3,9-dimethyl-4,8-diazaundeca-3,8-diene-2 10-dione dioxime; Me-3[12]N-3 = 2,4,4-trimethyl-1,5,9-triazacyclododeca-1-ene; bipy = 2,2'-bipyridyl) have been prepared and characterized. The structure of 2 has been determined by single-crystal X-ray diffraction methods. It consists of [Cu(pdmg)Ni(Me-3[12]N-3)(CH3CH2OH)](2+) cations and non-coordinated perchlorate anions. The [Cu(pdmg)(CH3CH2OH)] complex coordinates to the [Ni(Me-3[12]N-3)](2+) fragment to afford the binuclear unit doubly-bridged by oximato groups in cis arrangement. The coordination geo…
The stability and functional properties of proteoliposomes mixed with dextran derivatives bearing hydrophobic anchor groups
1992
Liposomes composed of Escherichia coli phospholipid were coated with polysaccharides bearing hydrophobic palmitoyl anchors. The effect on the stability of liposomes without or with integral membrane proteins was investigated. A high concentration of hydrophobized dextrans protected the liposomes against detergent degradation, decreased the fluidity of the membranes, prevented fusion of the liposomes and enhanced their stability. Proteoliposomes containing beef heart cytochrome-c oxidase and the lactose transport carrier of E. coli were similarly affected by coating with the dextrans. Under these conditions both membrane proteins were still active. Long-term stability of the coated liposomes…
"P_AntiLambda vs. wide centrality bins (2.76 TeV)" of "Global polarization of $\Lambda$ and $\overline{\Lambda}$ hyperons in Pb-Pb collisions at the …
2021
The $\bar\Lambda$ global polarization as function of centrality for Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$~TeV.
"P_AntiLambda vs. pT (2.76TeV, 15-50%)" of "Global polarization of $\Lambda$ and $\overline{\Lambda}$ hyperons in Pb-Pb collisions at the LHC"
2021
The $\bar\Lambda$ global polarization as function of transverse momentum ($p_{\mathrm{T}}$) for 15-50% centrality in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$~TeV.
"P_Lambda vs. pT (2.76TeV, 15-50%)" of "Global polarization of $\Lambda$ and $\overline{\Lambda}$ hyperons in Pb-Pb collisions at the LHC"
2021
The $\Lambda$ global polarization as function of transverse momentum ($p_{\mathrm{T}}$) for 15-50% centrality in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$~TeV.
A Precise Measurement of the $\tau$ Polarisation at LEP-1
2000
The $\tau$ polarisation has been studied with the ${\rm e^+e^-}\to \tau^+\tau^-$ data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the Z resonance firstly through the exclusive decay channels ${\rm e}\nu\bar{\nu}$ , $\mu\nu\bar{\nu}$ , $\pi\nu$ , $\rho\nu$ and ${\rm a}_1\nu$ and secondly with an inclusive hadronic analysis which benefits from a higher efficiency and a better systematic precision. The results have been combined with those previously published on 1990 to 1992 DELPHI data, to produce results which reflect the full LEP-1 statistics. The fit of the $\tau$ polarisation dependence on the production angle yielded the polarisation parameters ${\cal A}_{_{\sc…
Double Polarization Observables in Pentaquark Photoproduction
2019
We investigate the properties of the hidden charm pentaquark-like resonances first observed by LHCb in 2015, by measuring the polarization transfer KLL between the incident photon and the outgoing proton in the exclusive photoproduction of J/psi near threshold. We present a first estimate of the sensitivity of this observable to the pentaquark photocouplings and hadronic branching ratios, and extend our predictions to the case of initial state helicity correlation ALL, using a polarized target. These results serve as a benchmark for the SBS experiment at Jefferson Lab, which proposes to measure for the first time the helicity correlations ALL and KLL in J/psi exclusive photoproduction, in o…
Spin alignment and violation of the OZI rule in exclusive ω and ϕ production in pp collisions
2014
Exclusive production of the isoscalar vector mesons $\omega$ and $\phi$ is measured with a 190 GeV$/c$ proton beam impinging on a liquid hydrogen target. Cross section ratios are determined in three intervals of the Feynman variable $x_{F}$ of the fast proton. A significant violation of the OZI rule is found, confirming earlier findings. Its kinematic dependence on $x_{F}$ and on the invariant mass $M_{p\mathrm{V}}$ of the system formed by fast proton $p_\mathrm{fast}$ and vector meson $V$ is discussed in terms of diffractive production of $p_\mathrm{fast}V$ resonances in competition with central production. The measurement of the spin density matrix element $\rho_{00}$ of the vector mesons…