Momentum sharing in imbalanced Fermi systems Hen, O.; Sargsian, M.; Weinstein, L. B. ...
Science (American Association for the Advancement of Science),
10/2014, Volume:
346, Issue:
6209
Journal Article
Peer reviewed
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 C-12, Al-27, Fe-56, and Pb-208 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.
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We measured the detection efficiency and spatial resolution of multiwire porous dielectric detectors (MWPDDs). Two cases were tested: a CsI-filled MWPDD exposed to a 5.9
keV X-ray flux of 650
/cm
2
...s; and a CsI-filled MWPDD exposed to an α-particle flux of 10
4
cm
2
s. In both cases, the detector operated over several days with no reduction in efficiency or spatial resolution; in fact, these improved slightly with time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aim : to develop a model for predicting preeclampsia (PE) based on the clinically most significant differentially expressed plasma microRNAs. Materials and Methods . A prospective observational ...comparative study was conducted with 62 women, divided into two parallel groups: 32 patients with PE and 30 clinically healthy women with uncomplicated pregnancy. Transcriptomic analysis was performed to identify differentially expressed blood plasma microRNAs using next generation sequencing (NGS). Results . Calculation of risk ratios for PE development allowed to identify 14 plasma microRNAs that influence the development of PE pathology. PE-associated microRNAs hsa-miR-103a-3p, hsa-miR-451a and hsa-miR-516a-5p have a high diagnostic value when combined to assess their blood plasma expression level in early pregnancy stages. Conclusion . The developed prognostic model can be applied to pregnant women at risk for PE development, which may further reduce obstetric complications and improve perinatal outcomes.
We report on the results of the first measurement of exclusive f{sub 0}(980) meson photoproduction on protons for E{sub {gamma}}=3.0-3.8 GeV and -t=0.4-1.0 GeV{sup 2}. Data were collected with the ...CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the {pi}{sup +}{pi}{sup -} channel by performing a partial wave analysis of the reaction {gamma}p{yields}p{pi}{sup +}{pi}{sup -}. Clear evidence of the f{sub 0}(980) meson was found in the interference between P and S waves at M{sub {pi}{sup +}}{sub {pi}{sup -}}{approx}1 GeV. The S-wave differential cross section integrated in the mass range of the f{sub 0}(980) was found to be a factor of about 50 smaller than the cross section for the {rho} meson. This is the first time the f{sub 0}(980) meson has been measured in a photoproduction experiment.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The reaction {sup 2}H(e,e{sup '}p)n has been studied with full kinematic coverage for photon virtuality 1.75<Q{sup 2}<5.5 GeV{sup 2}. Comparisons of experimental data with theory indicate that for ...very low values of neutron recoil momentum (p{sub n}<100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100<p{sub n}<750 MeV/c, proton-neutron rescattering dominates the cross section, while {delta} production followed by the N{delta}{yields}NN transition is the primary contribution at higher momenta.
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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.
Full text
Available for:
BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
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