ABSTRACT
The atomic nucleus is composed of two different kinds of fermions: protons and neutrons. If the protons and neutrons did not interact, the Pauli exclusion principle would force the majority of fermions (usually neutrons) to have a higher average momentum. Our high-energy electron-scattering measurements using (12)C, (27)Al, (56)Fe, and (208)Pb targets show that even in heavy, neutron-rich nuclei, short-range interactions between the fermions form correlated high-momentum neutron-proton pairs. Thus, in neutron-rich nuclei, protons have a greater probability than neutrons to have momentum greater than the Fermi momentum. This finding has implications ranging from nuclear few-body systems to neutron stars and may also be observable experimentally in two-spin-state, ultracold atomic gas systems.
ABSTRACT
A measurement of beam helicity asymmetries in the reaction 3He[over â](e[over â],e'n)pp is performed at the Mainz Microtron in quasielastic kinematics to determine the electric to magnetic form factor ratio of the neutron GEn/GMn at a four-momentum transfer Q2=1.58 GeV2. Longitudinally polarized electrons are scattered on a highly polarized 3He gas target. The scattered electrons are detected with a high-resolution magnetic spectrometer, and the ejected neutrons are detected with a dedicated neutron detector composed of scintillator bars. To reduce systematic errors, data are taken for four different target polarization orientations allowing the determination of GEn/GMn from a double ratio. We find µnGEn/GMn=0.250±0.058(stat)±0.017(syst).
ABSTRACT
Cor pulmonary is a partial complication of majority chronic light diseases and despite its prolonged study many questions of this problem still remain unsolved and disputable, complicated diagnosis of diseases at early stages, its development, treatment is of little efficiency and the rate of deaths is high. Working-out the algorithm of the diagnosis of cor pulmonary on the grounds of mathematical modeling and analysis of laboratory indices. Worked-out dimensionless parameters of more informational indices of aggregate particularities of formal elements of blood, lipid spectrum, the level human interleukin 1beta irrespective each other with the record of permissible diapason permit diagnosing the early stages of disease, estimate its dynamics and make provisions against its further development.
Subject(s)
Blood Viscosity , Interleukin-1beta/blood , Lipids/blood , Pulmonary Heart Disease/diagnosis , Algorithms , Chronic Disease , Humans , Pulmonary Heart Disease/blood , Severity of Illness IndexABSTRACT
Cor pulmonary remains one of the actual tasks of modern pulmonogy, cardiology. The aim of the investigation is working-out algorithm diagnoses of cor pulmonary on the grounds of mathematical modeling and analyses of the results of several instrumental indices. The results of the investigation indices showed that worked-out by means of mathematical analyses the dimensionless coefficients permit find out the necessary instrumental indices for CP diagnose. Dimensionless coefficients promote control over the efficiency of treatment and also enable the development of new optimal scheme CP therapy.
Subject(s)
Pulmonary Heart Disease/diagnosis , Pulmonary Heart Disease/physiopathology , Severity of Illness Index , Adolescent , Adult , Aged , Algorithms , Blood Pressure , Blood Pressure Determination , Female , Humans , Male , Middle Aged , Models, Theoretical , Pulmonary Circulation , Vital Capacity , Young AdultABSTRACT
We analyze recent data from high-momentum-transfer (p, pp) and (p, ppn) reactions on carbon. For this analysis, the two-nucleon short-range correlation (NN-SRC) model for backward nucleon emission is extended to include the motion of the NN pair in the mean field. The model is found to describe major characteristics of the data. Our analysis demonstrates that the removal of a proton from the nucleus with initial momentum 275-550 MeV/c is 92(+8/-18) % of the time accompanied by the emission of a correlated neutron that carries momentum roughly equal and opposite to the initial proton momentum. This indicates that the probabilities of pp or nn SRCs in the nucleus are at least a factor of 6 smaller than that of pn SRCs. Our result is the first estimate of the isospin structure of NN-SRCs in nuclei, and may have important implication for modeling the equation of state of asymmetric nuclear matter.
ABSTRACT
The ratios of inclusive electron scattering cross sections of 4He, 12C, and 56Fe to 3He have been measured at 1 < xB <. At Q2 > 1.4 GeV2, the ratios exhibit two separate plateaus, at 1.5 < xB < 2 and at xB > 2.25. This pattern is predicted by models that include 2- and 3-nucleon short-range correlations (SRC). Relative to A = 3, the per-nucleon probabilities of 3-nucleon SRC are 2.3, 3.1, and 4.4 times larger for A = 4, 12, and 56. This is the first measurement of 3-nucleon SRC probabilities in nuclei.
