Spin observables for pion photoproduction on the deuteron in the Δ\Delta(1232)-resonance region

Spin observables for the three charge states of the pion for the pion photoproduction reaction on the deuteron, $\gamma d\to\pi NN$, with polarized photon beam and/or oriented deuteron target are predicted. For the beam-target double-spin asymmetries, it is found that only the longitudinal asymmetries $T_{20}^{\ell}$ and $T_{2\pm 2}^{\ell}$ do not vanish, whereas all the circular and the other longitudinal asymmetries do vanish. The sensitivity of spin observables to the model deuteron wave function is investigated. It has been found that only $T_{21}$ and $T_{22}$ are sensitive to the model deuteron wave function, in particular in the case of $\pi^0$-production above the $\Delta$-region, and that other asymmetries are not.Comment: 16 pages, 8 figures, accepted for publication in J. Phys. G: Nucl. Part. Phy

Polarization observables of the gamma d --> PiNN reaction in the Delta(1232)-resonance region

Polarization observables of the three charge states of the pion for the $\gamma d\to\pi NN$ reaction with polarized photon beam and/or oriented deuteron target are evaluated over the whole $\Delta$(1232)-resonance region adopting a nonrelativistic model based on time-ordered perturbation theory. Results for the $\pi$-meson spectra, linear photon asymmetry, vector and tensor target asymmetries are presented. Particular attention is given, for the first time, to double polarization asymmetries for which we present results for $T_{20}^{\ell}$ and $T_{2\pm 2}^{\ell}$. We found that all other double polarization asymmetries of photon and deuteron target are vanished.Comment: 17 Pages, 8 Figures, accepted for publication in Int. J. Mod. Phys.

Mean parity of single quantum excitation of some optical fields in thermal environments

The mean parity (the Wigner function at the origin) of excited binomial states, excited coherent states and excited thermal states in thermal channel is investigated in details. It is found that the single-photon excited binomial state and the single-photon excited coherent state exhibit certain similarity in the aspect of their mean parity in the thermal channel. We show the negative mean parity can be regarded as an indicator of nonclassicality of single-photon excitation of optical fields with a little coherence, especially for the single-photon excited thermal states.Comment: 4 pages, 4 figures, RevTex4; PACS numbers: 42.50.Dv, 03.65.Yz, 05.40.Ca; Three typo errors have been correcte

EveTAR: Building a Large-Scale Multi-Task Test Collection over Arabic Tweets

This article introduces a new language-independent approach for creating a large-scale high-quality test collection of tweets that supports multiple information retrieval (IR) tasks without running a shared-task campaign. The adopted approach (demonstrated over Arabic tweets) designs the collection around significant (i.e., popular) events, which enables the development of topics that represent frequent information needs of Twitter users for which rich content exists. That inherently facilitates the support of multiple tasks that generally revolve around events, namely event detection, ad-hoc search, timeline generation, and real-time summarization. The key highlights of the approach include diversifying the judgment pool via interactive search and multiple manually-crafted queries per topic, collecting high-quality annotations via crowd-workers for relevancy and in-house annotators for novelty, filtering out low-agreement topics and inaccessible tweets, and providing multiple subsets of the collection for better availability. Applying our methodology on Arabic tweets resulted in EveTAR , the first freely-available tweet test collection for multiple IR tasks. EveTAR includes a crawl of 355M Arabic tweets and covers 50 significant events for which about 62K tweets were judged with substantial average inter-annotator agreement (Kappa value of 0.71). We demonstrate the usability of EveTAR by evaluating existing algorithms in the respective tasks. Results indicate that the new collection can support reliable ranking of IR systems that is comparable to similar TREC collections, while providing strong baseline results for future studies over Arabic tweets

Assessment of magmatic versus post-magmatic processes in the Mueilha rare-metal granite, Eastern Desert of Egypt, Arabian-Nubian Shield

The Mueilha rare-metal granite, exposed in the central Eastern Desert of Egypt, is a post-collisional intrusion that formed in the final magmatic stage of the evolution of the Arabian-Nubian Shield. The Mueilha intrusion was emplaced as a high-level magmatic cupola into metamorphic country rocks. It consists of two cogenetic intrusive bodies: an early phase emplaced at shallow depth and now penetratively altered to white albite granite and a later phase of red granites emplaced at greater depth that better preserve magmatic features. The albite granite is less common and represents the upper margin of the Mueilha intrusion, the apex of the magmatic cupola. The red granites are volumetrically dominant and appears to have crystallized from the margins inward, forming a composite pluton zoned from muscovite granite to alkali feldspar granite. All parts of the Mueilha pluton appear to have been emplaced within a short time interval, before complete crystallization of the earliest phase. The geochemistry of the Mueilha granites is typical of rare-metal granites, characterized by high SiO₂, Na₂O + K₂O, Nb, Rb, Ta, Y, U, Th, Sn, and W with depletion in P, Mg, Ti, Sr and Ba. They are weakly peraluminous and highly fractionated with A-type character. The chondrite-normalized REE patterns have strongly negative Eu anomalies, typical of highly differentiated granites that evolved through a transitional magmatic–hydrothermal stage. The primary magma feeding the Mueilha intrusion was generated by partial melting of the juvenile crust of the Arabian-Nubian Shield; it subsequently underwent extensive fractional crystallization and metasomatism by late- to post-magmatic fluids. Separation of fluids from the oversaturated melt promoted both diffuse greisenization and focused segregation of pegmatite and fluorite and quartz veins. Alkalis liberated from feldspars consumed by greisenization were redeposited during albitization in the uppermost part of the magma chamber. Despite penetration of the intrusion boundary by discrete dikes, veins, and aphophyses, diffuse alteration of the metamorphic country rocks is not apparent. Primary columbite-series minerals crystallized from the melt and were later partly replaced by secondary Nb and Ta minerals (fluorcalciomicrolite and wodginite) during hydrothermal alteration

CMS Software Distribution on the LCG and OSG Grids

The efficient exploitation of worldwide distributed storage and computing resources available in the grids require a robust, transparent and fast deployment of experiment specific software. The approach followed by the CMS experiment at CERN in order to enable Monte-Carlo simulations, data analysis and software development in an international collaboration is presented. The current status and future improvement plans are described.Comment: 4 pages, 1 figure, latex with hyperref

Density reconstruction from biased tracers and its application to primordial non-Gaussianity

Large-scale Fourier modes of the cosmic density field are of great value for learning about cosmology because of their well-understood relationship to fluctuations in the early universe. However, cosmic variance generally limits the statistical precision that can be achieved when constraining model parameters using these modes as measured in galaxy surveys, and moreover, these modes are sometimes inaccessible due to observational systematics or foregrounds. For some applications, both limitations can be circumvented by reconstructing large-scale modes using the correlations they induce between smaller-scale modes of an observed tracer (such as galaxy positions). In this paper, we further develop a formalism for this reconstruction, using a quadratic estimator similar to the one used for lensing of the cosmic microwave background. We incorporate nonlinearities from gravity, nonlinear biasing, and local-type primordial non-Gaussianity, and verify that the estimator gives the expected results when applied to N-body simulations. We then carry out forecasts for several upcoming surveys, demonstrating that, when reconstructed modes are included alongside directly-observed tracer density modes, constraints on local primordial non-Gaussianity are generically tightened by tens of percents compared to standard single-tracer analyses. In certain cases, these improvements arise from cosmic variance cancellation, with reconstructed modes taking the place of modes of a separate tracer, thus enabling an effective "multitracer" approach with single-tracer observations.Comment: 30 pages plus 14 pages appendices, 19 figure

Experimental evidence of photoinduced valence change of Fe<SUP>3+</SUP> in BaTiO<SUB>3</SUB> and mechanism for growth of new grating in depleted pump condition: an EPR investigation

With a view to understanding the role of photo-induced valence changes of impurities in BaTiO3 in the phenomena of photorefraction, EPR experiments were conducted under in situ He-Ne laser illumination. These experiments gave evidence for photoinduced valence change of Fe in BaTiO3 at room temperature. The EPR signal due to trivalent iron was found to reduce in intensity with laser illumination The kinetics of the valence change has been investigated. Under large fringe width condition, the time constant of the decay is identified as the dielectric relaxation time &#932;d. The changes in line shape on laser illumination to Dysonian form, appeared most predominantly in mechanically poled crystal compared to electrically poled single domain crystals. This demonstrated the possible role of domain walls and the defects there, as source or sinks of charge carriers on photo excitation. It is observed, that there is transient growth of Fe3+, when the laser illumination was put on, before its decay. This was attributed to charge transfer between electrons in oxygen vacancies and Fe4+. This predicted the growth of a transient grating under depleted pump condition in a two beam coupling experiment. This was experimentally proved by following the diffracted signal of the reading beam under the depleted pump condition