Search for evidence of two photon contribution in elastic electron proton data

We reanalyze the most recent data on elastic electron proton scattering. We look for a deviation from linearity of the Rosenbluth fit to the differential cross section, which would be the signature of the presence of two photon exchange. The two photon contribution is parametrized by a one parameter formula, based on symmetry arguments. The present data do not show evidence for such deviation.Comment: 15 pages 3 figures More details on the fitting procedure, more explicit explanation

Polarization effects in the reaction e++e−→ρ++ρ−e^++e^-\to \rho^+ +\rho^- and determination of the ρ−\rho - meson form factors in the time--like region

The electron positron annihilation reaction into four pion production has been studied, through the channel $e^++e^-\to \bar \rho+\rho$. The differential (and total) cross sections and various polarization observables for this reaction have been calculated in terms of the electromagnetic form factors of the corresponding $\gamma^*\rho\rho$ current. The elements of the spin--density matrix of the $\rho -$meson were also calculated. Numerical estimations have been done, with the help of phenomenological form factors obtained in the space--like region of the momentum transfer squared and analytically extended to the time-like region.Comment: 19 pages, 2 figures, to appear in Phys Rev

Право экспертной инициативы с позиции юридической герменевтики

The article is devoted to the analysis of one of the rights forming the procedural status of a forensic expert, that is the right of expert initiative. The right is considered not only from a procedural point of view, but also in the context of professional, moral and ethical standards that should guide a forensic expert in his activities. The right of expert initiative is considered as a professional responsibility of an expert. From the perspective of legal hermeneutics an attempt is made to identify its direct recipient and more importantly - the form of realization of this right by the expert. The norm in question is examined within the context of regulatory legal acts and in this connection, we try to understand the content of this norm considering the basic principle of forensic expert activity - the objectivity principle and the complementary principles of comprehensiveness and completeness of a research. The question is raised of the mandatory nature of the norm for the expert regardless of the procedural form of its implementation.Анализируется одно из прав, составляющих процессуальный статус судебного эксперта, а именно – право экспертной инициативы. Данное право рассмотрено не только с процессуальной точки зрения, но и в контексте профессиональных и морально-этических норм, которыми должен руководствоваться в своей деятельности судебный эксперт. Право экспертной инициативы рассматривается как профессиональная обязанность эксперта. Сделана попытка с позиций юридической герменевтики установить непосредственного адресата нормы и, самое главное, форму реализации данного права экспертом. Исследуемая норма рассматривается в контексте нормативно-правовых актов, в связи с чем сделана попытка уяснить содержание данной нормы с учетом основного принципа судебно-экспертной деятельности – принципа объективности – и дополняющих его принципов всесторонности и полноты исследований. Автор поднимает вопрос об обязательном характере исследуемой нормы для эксперта независимо от того, какова ее процессуальная форма реализации

K^- ^3He and K^+K^- interactions in the pd -> ^3He K^+K^- reaction

We investigate the K^- ^3He and K^+ K^- interactions in the reaction pd -> ^3He K^+ K^- near threshold and compare our model calculations with data from the MOMO experiment at COSY-Juelich. A large attractive effective K^- p amplitude would give a significant K^- ^3He final-state interaction effect which is not supported by the experimental data. We also estimate upper limits for the a_0(980) and f_0(980) contributions to the produced K^+ K^- pairs.Comment: 5 pages, 2 figures, accepted for publication in PR

The elastic electron-deuteron scattering beyond one-photon exchange

We discuss the elastic ed scattering beyond Born approximation. It is shown that the reaction amplitude contains six generalized form factors, but only three linearly independent combinations of them (we call them generalized charge, quadrupole and magnetic form factors) contribute to the reaction cross section in the second order perturbation theory. We examine two-photon exchange and find that it includes two types of diagrams, when two virtual photons interact with the same nucleon and when the photons interact with different nucleons. Estimations based on nonrelativistic calculations with the deuteron wave function for realistic NN potential show that the main contribution to the generalized charge, quadrupole and magnetic form factors comes from diagrams of the first type.Comment: v2, published version in PR

COMBINED ANTIHYPERTENSIVE THERAPY: ACE INHIBITOR PLUS CALCIUM CHANNEL BLOCKER. NEW ADVANTAGES OF THE KNOWN COMBINATION

Advantages of combined therapy of patients with arterial hypertension are considered. Special attention is paid to usage of ACE inhibitor and calcium antagonist combination

Analysis of polarization observables and radiative effects for the reaction pˉ+p→e++e−\bar p+p\rightarrow e^++e^-

The expressions for the differential cross section and of the polarization observables for the reaction $\bar p+p\rightarrow e^++e^-$ are given in terms of the nucleon electromagnetic form factors in the laboratory system. Radiative corrections due to the emission of virtual and real soft photons from the leptons are also calculated. Unlike the center-of- mass system case, they depend on the scattering angle. Polarization effects are derived in the case when the antiproton beam, the target and the electron in the final state are polarized. Numerical estimations have been done for all observables for the PANDA experimental conditions using models for the nucleon electromagnetic form factors in the time-like region. The radiative corrections to the differential cross section are calculated as function of the beam energy and of the electron angle.Comment: 18 pages, 8 figure

Cross section and polarization observables for the reaction e++e−→a1(1260)+πe^++e^-\to a_1(1260)+\pi

A model independent formalism for the electron positron annihilation reaction $e^++e^-\to a_1(1260)+\pi$ has been derived. The differential and total cross sections and the elements of the spin--density matrix of the $a_1$-meson were calculated in terms of the electromagnetic form factors of the corresponding $\gamma^*a_1\pi$ current. Simple models of $a_1$ form factors have been fitted to the available cross section data and they allow to give numerical predictions for the different observables.Comment: 19 pages, 6 figures Added formulas for axial meson decay in 3 pions Modified version to appear in PR

Polarization effects in e++e−→dˉ+de^+ +e^-\to \bar d+d and determination of time like deuteron form factors

Polarization effects in the reaction $e^++e^-\to \bar d+d$ have been investigated for the case of longitudinally polarized electron beam and arbitrary polarization of the produced deuteron, with the aim of a determination of the time-like complex deuteron electromagnetic form factors. General expressions of polarization observables are derived and numerical estimations have been carried out by means of various models of deuteron electromagnetic form factors, for kinematical conditions near threshold.Comment: 19 pages, 3 figure

Petroleum-related hydrocarbons in deep and subsurface sediments from South-Western Barents Sea

Subsurface sediments from a pockmark area in South-Western Barents Sea have been earlier found to contain elevated levels of petroleum-related polycyclic aromatic hydrocarbons. This work describes a comprehensive analysis of various biomarkers, including the highly source-specific hopanes, in a 4.5 m long gravity core from the same area, together with subsurface sediment samples from other areas in the region without pockmarks present (“background samples”). A clear difference between the pockmark gravity core and the background sediment cores was found, both with regard to genesis and the level of transformation of organic matter. A number of indicator parameters, such as methylphenanthrene index (MPI-1), point towards a significantly higher maturity of hydrocarbons in the pockmark core throughout its length as compared to the other sampled locations. Higher contents of microbial hopanoids (hopenes) may indicate the former presence of petroleum. These findings confirm the hypothesis of a natural hydrocarbon source in the deeper strata present in the studied location with pockmarks