Search results for "140"
showing 10 items of 140 documents
The radiative decay of the Lambda(1405) and its two-pole structure
2007
We evaluate theoretically the radiative decay widths into $\gamma\Lambda$ and $\gamma\Sigma^0$ of the two poles of the $\Lambda(1405)$ found in chiral unitary theories and we find quite different results for each of the two poles. We show that, depending on which reaction is used to measure the $\Lambda(1405)$ radiative decays, one gives more weight to one or the other pole, resulting in quite different shapes in the $\gamma\Lambda(\Sigma^0)$ invariant mass distributions. Our results for the high-energy pole agree with those of the empirical determination of the $\gamma\Lambda$ and $\gamma\Sigma^0$ radiative widths (based on an isobar model fitting of the $K^-p$ atom data), which are someti…
Kotoutumiskoulutuksen opetussuunnitelman perusteet kuvaa tavoitettaan osallisuutta epämääräisesti ja kapeasti
2023
Kotoutumiskoulutuksen uudessa perusteasiakirjassa korostuu osallisuuden käsite. Se jää kuitenkin määrittelemättä: osallisuuteen viitataan sekä kapearajaisesti työmarkkinaosallisuutena että epäsuorasti niin, että käsitteen varsinainen merkitys jää avoimeksi. Tutkimuskirjallisuudessa osallisuus edellyttää laaja-alaista sosiaalis-yhteiskunnallista kuulumista ja yhdenvertaisuutta. nonPeerReviewed
Emergence of extreme events in fiber-based parametric processes driven by a partially incoherent pump wave
2009
Modulation instability (MI) generated by a picosecond coherent pulse has been recently identified as the key element of the generation of optical rogue-waves in supercontinuum-based systems [1]. Similar rare but highly energetic pulse structures can also appear in non-solitonic configurations such as Raman amplifiers driven by a partially incoherent pump wave propagating in fibres with low group velocity dispersion [2]. Therefore, one may wonder whether optical rogue-like event can also occur in MI-based amplifier because both Raman and parametric amplifiers benefit from a quasi-instantaneous gain. We provide here experimental evidence of rare optical events in a parametric amplifier in pre…
Generation of localized pulses from incoherent wave in optical fiber lines made of concatenated Mamyshev regenerators
2008
International audience; We investigate the novel properties of optical fiber lines made of Mamyshev regenerators (MRs) based on self-phase modulation and subsequent spectral filtering. In particular, we show that such a regenerator line can be used to generate random sequences of optical pulses from an incoherent wave. This behavior is related to the existence of stable eigenpulses that can propagate unchanged through the regenerator line and act as attractors for incoming pulses. By changing the regenerator parameters, we also report the existence of multiple eigenpulses and limit cycles. Finally, we demonstrate that MRs could be used as efficient nonlinear gates in fiber laser cavities.
Ultraviolet-induced paramagnetic centers and absorption changes in singlemode Ge-doped optical fibers
2009
We investigated the laser-energy-density dependence of absorption changes and paramagnetic centers induced by a cw Ar+ laser operating at 5.1 eV, in both unloaded and H-2-loaded single mode Ge-doped optical fibers. The induced absorption is measured in the blue and near ultraviolet spectral range by using the 3.1 eV photoluminescence, ascribed to Ge lone pair center (GLPC), as an in situ probe source. We find that the Ge (1) center (GeO4-) is induced upon UV exposure by electron trapping on GeO4 precursors, where the free electrons are most likely produced by ionization of GLPC. Ge (1) is responsible of optical transmission loss of the fiber in the investigated range. Hydrogen loading stron…
Evolution of Photo-induced defects in Ge-doped fiber/preform: influence of the drawing
2011
International audience; We have studied the generation mechanisms of two different radiation-induced point defects, the Ge(1) and Ge(2) centers, in a germanosilicate fiber and in its original preform. The samples have been investigated before and after X-ray irradiation using the confocal microscopy luminescence and the electron paramagnetic resonance techniques. Our experimental results show the higher radiation sensitivity of the fiber as compared to the perform and suggest a relation between Ge(1) and Ge(2) generation. To explain our data we have used different models, finding that the destruction probability of the Ge(1) and Ge(2) defects is larger in fiber than in preform, whereas the …
Agritourism, between legislation and marketing: A leading sector for local development the case of the province of Palermo
2018
This work stems from a desire to understand the dynamics of a sector that is of particular interest for the economy and regional development of Sicily. Due to its geographical position, rich history, and natural beauty, Sicily is a year-round attraction for large numbers of tourists from all over the world. In this respect, it is vital to invest in the local area, to try to maintain and increase the potential that the territory itself can offer. With this work, we consider the agritourism sector to specifically assess its potential interest for business people and consumers, both actual and potential. Indeed, if on one side modern tourism was born from a desire to visit faraway places, it i…
Dynamics and Limits of Regulatory Privatization: Reorganizing audit oversight in Russia
2019
Accounting and auditing are often cited as key sites where business regulation has been privatized, globalized and neoliberalized. Yet, these sites have also undergone a legitimacy crisis in recent years, marked by a shift from self-regulation to increased public oversight. This paper investigates these developments by reference to the evolution of a public/private audit oversight regime (audit of the auditors) in Russia. We show how, in the early stages of post-Soviet reforms, old state-administered forms of financial oversight were replaced with market-oriented arrangements (peer reviews) offered by newly founded private professional accountancy associations as a service to their members.…
Zvaigžņotā Debess: 2013, Vasara (220)
2013
Saturs: Pēdējā "Apollo" ekspedīcija uz Mēnesi ; Vissavienības Astronomijas un ģeodēzijas biedrības Latvijas nodaļa ; M.Gills. ESON – astronomijas popularizēšanas tīkls ; S.Kropa. Dvēsele Atakamas tuksnesī ; M.G. Īsumā: ESO Astro Camp Eiropas vidusskolēniem 2013.gada decembrī ; A.Alksnis. Atklāta vēl viena no Saulei vistuvākajām kaimiņzvaigznēm ; A.Alksnis. Tuvēja zvaigzne, kas ir izveidojusies jau drīz pēc Lielā Sprādziena ; A.Alksnis. Čeļabinskas superbolīds – simtgades notikums ; A.Alksnis. Nevis pārsteidzoša nova, bet gan kvazāra uzliesmojums ; I.Eglītis. Orius – Baldones observatorijā atklātais centaurs ; R.Misa. Denisa Tito Marsa iedvesmas fonds ; A.A. Īsumā: Ap zvaigzni Gleznotāja Bet…
Photoproduction of K∗ for the study of Λ(1405)
2004
Abstract The photo-induced K ∗ vector meson production is investigated for the study of the Λ(1405) resonance. This reaction is particularly suited to the isolation of the second pole in the Λ(1405) region which couples dominantly to the K N channel. We obtain the mass distribution of the Λ(1405) which peaks at 1420 MeV, and differs from the nominal one. Combined with several other reactions, like the π−p→K0πΣ which favours the first pole, this detailed study will reveal a novel structure of the Λ(1405) state.