Partial Densities of States, Scattering Matrices, and Green's Functions

The response of an arbitrary scattering problem to quasi-static perturbations in the scattering potential is naturally expressed in terms of a set of local partial densities of states and a set of sensitivities each associated with one element of the scattering matrix. We define the local partial densities of states and the sensitivities in terms of functional derivatives of the scattering matrix and discuss their relation to the Green's function. Certain combinations of the local partial densities of states represent the injectivity of a scattering channel into the system and the emissivity into a scattering channel. It is shown that the injectivities and emissivities are simply related to the absolute square of the scattering wave-function. We discuss also the connection of the partial densities of states and the sensitivities to characteristic times. We apply these concepts to a delta-barrier and to the local Larmor clock.Comment: 13 pages (revtex), 4 figure

Anomalously large critical regions in power-law random matrix ensembles

We investigate numerically the power-law random matrix ensembles. Wavefunctions are fractal up to a characteristic length whose logarithm diverges asymmetrically with different exponents, 1 in the localized phase and 0.5 in the extended phase. The characteristic length is so anomalously large that for macroscopic samples there exists a finite critical region, in which this length is larger than the system size. The Green's functions decrease with distance as a power law with an exponent related to the correlation dimension.Comment: RevTex, 4 pages, 4 eps figures. Final version to be published in Phys. Rev. Let

Comparative evaluation of biochemical parameters and mineral composition of Cucurbita ficifolia, C. maxima and C. moschata fruit, grown in the northern hemisphere

Fruit peel/pulp distribution of biologically active compounds is an important characteristic of plant physiology and the basis of zero waste production in agriculture. Among C. ficifolia, C. maxima and C. moschata the former showed the lowest dry matter content, especially in peel, similar peel and pulp values of antioxidant activity (AOA) and polyphenol content (TP), with the highest levels in fruit placenta. Peel carbohydrate profile of C. ficifolia fruit was characterized by lower levels of disaccharides compared to C. maxima and C. moschata peel and an opposite pattern of monosaccharides accumulation. The analysis of 25 elements content in Cucurbita peel and pulp, using ICP-MS, indicated that C. ficifolia fruit are characterized by significantly high concentrations of Sr, Si and I in pulp compared to the values of C. maxima and C. moschata. On the contrary, C. maxima and C. moschata were characterized by low concentration of pulp Mn. Highly significant positive correlations were recorded between Cr-Sr, Cr-Ca and CaSr (r=0.906; 0.939 and 0.974 respectively) and P-Cu (r=0.968). Despite C. ficifolia, does not contain carotenoids, it is highly valuable due to the high levels of Si, I, Cr and Ca in peel and pulp, which reveals new areas of its application

Сравнительная оценка биохимических показателей и минерального состава плодов Cucurbita ficifolia, C. maxima и C. moschata

Fruit peel/pulp distribution of biologically active compounds is an important characteristic of plant physiology and the basis of zero waste production in agriculture. Among C. ficifolia, C. maxima and C. moschata the former showed the lowest dry matter content, especially in peel, similar peel and pulp values of antioxidant activity (AOA) and polyphenol content (TP), with the highest levels in fruit placenta. Peel carbohydrate profile of C. ficifolia fruit was characterized by lower levels of disaccharides compared to C. maxima and C. moschata peel and an opposite pattern of monosaccharides accumulation. The analysis of 25 elements content in Cucurbita peel and pulp, using ICP-MS, indicated that C. ficifolia fruit are characterized by significantly high concentrations of Sr, Si and I in pulp compared to the values of C. maxima and C. moschata. On the contrary, C. maxima and C. moschata were characterized by low concentration of pulp Mn. Highly significant positive correlations were recorded between Cr-Sr, Cr-Ca and CaSr (r=0.906; 0.939 and 0.974 respectively) and P-Cu (r=0.968). Despite C. ficifolia, does not contain carotenoids, it is highly valuable due to the high levels of Si, I, Cr and Ca in peel and pulp, which reveals new areas of its application. Распределение биологически активных соединений между кожурой и мякотью плодов является важной характеристикой особенности физиологии растения и может служить основой для безотходного производства в сельском хозяйстве.Результаты. Установлено, что среди трех видов тыквы: фиголистной (C. ficifolia), крупноплодной (C. maxima) и мускатной (C. moschata), – фиголистная тыква содержит наименьшее количество сухого вещества, особенно в кожуре плодов, сходные уровни общей антиоксидантной активности (АОА) и содержания полифенолов (ТР) в кожуре и мякоти при максимальных показателях антиоксидантного статуса в плаценте. Углеводный профиль кожуры фиголистной тыквы C. ficifolia характеризовался наименьшими уровнями дисахаридов по сравнению с кожурой крупноплодной C. maxima и мускатной тыквы C. moschata и наибольшими уровнями моносахаров. ИСП-МС анализ содержания 25 элементов в кожуре и мякоти исследованных видов тыквы показал, что фиголистная тыква отличается значительно более высокими уровнями накопления в мякоти Sr, Si, I по сравнению с аналогичными данными для тыквы крупноплодной C. maxima и мускатной C. moschata. Напротив, плоды крупноплодной и мускатной тыквы характеризовались низкими концентрациями Mn в мякоти. Установлены статистически достоверные положительные корреляции между Cr-Sr, Cr-Ca и Ca-Sr (r=0.906; 0.939 и 0.974 соответственно), а также P-Cu (r=0.968). Несмотря на то, что плоды фиголистной тыквы C. ficifolia не содержат каротиноиды, их пищевая ценность в значительной степени связана с высокими уровнями Si, I, Cr и Ca в кожуре плодов и мякоти, что открывает новые горизонты использования этого вида.

Photoproduction of Pseudoscalar Mesons off Nuclei at Forward Angles

With the advent of new photon tagging facilities and novel experimental technologies it has become possible to perform photoproduction cross section measurements of pseudoscalar mesons on nuclei with a percent level accuracy. The extraction of the radiative decay widths from these measurements at forward angles is done by the Primakoff method, which requires theoretical treatment of all processes participating in these reactions at the same percent level. In this work we review the theoretical approach to meson photoproduction amplitudes in the electromagnetic and strong fields of nuclei at forward direction. The most updated description of these processes are presented based on the Glauber theory of multiple scattering. In particular, the effects of final state interactions, corrections for light nuclei, and photon shadowing in nuclei are discussed.Comment: 22 pages, 8 figure

Correlated Strength in Nuclear Spectral Function

We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment confirms by direct measurement the correlated strength predicted by theory.Comment: 4 pages, 2 figures, accepted by Phys. Rev. Let

A New Measurement of the π0\pi^0 Radiative Decay Width

High precision measurements of the differential cross sections for $\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\pi^0 \to \gamma\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ${\pi^0 \to \gamma\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\Gamma{(\pi^0 \to \gamma\gamma)} = 7.82 \pm 0.14 ~({\rm stat.}) \pm 0.17 ~({\rm syst.}) ~{\rm eV}$. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.Comment: 4 pages, 5 figure