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MN Harakeh

Publications and source records attributed to MN Harakeh.

At least 19 recordsLinked to original sources

Gamow-teller strengths of the inverse beta transition 176Yb-->176Lu for spectroscopy of proton-proton and other sub-MeV solar neutrinos

Discrete Gamow-Teller (GT) transitions 176Yb-->176Lu at low excitation energies have been measured via the ( 3He,t) reaction at 450 MeV and at 0 degrees. For 176Yb, two low-lying states are observed, setting low thresholds Q(nu) = 301 and 445 keV for neutrino ( nu) capture. Capture rates estimated from the measured GT strengths, the simple two-state excitation structure, and the low Q(nu) in Yb-Lu indicate that Yb-based nu detectors are well suited for a direct measurement of the sub-MeV solar electron-neutrino ( nu(e)) spectrum including pp neutrinos.

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Search for isovector giant monopole resonances via the Pb(3He,tp) reaction

The (nat)Pb(3He,tp) reaction at E(3He) = 177 MeV was studied to identify 2Planck's over 2piomega isovector monopole strength in Bi isotopes. Monopole strength was found in the region -45<Q<-30 MeV in the coincidence data. The cross section is compared with distorted-wave Born approximation calculations for non-spin-flip and spin-flip isovector monopole resonances. The observed spin-flip and non-spin-flip monopole strengths in the proton-decay channel amount to 20% of the respective non-energy-weighted sum rule.

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Three-nucleon force and the A(y) puzzle in intermediate energy p--> + d and d--> + p elastic scattering

New vector analyzing-power data on p-->+d elastic scattering at E(p) = 150 and 190 MeV have been measured. These are presented together with existing data and with recent d-->+p vector and tensor analyzing power data at E(d) = 270 MeV. The strong negative extremum of both vector analyzing powers A(p)(y) and A(d)(y) at straight theta(c.m.) approximately 80 degrees -120 degrees is underestimated by Faddeev calculations using modern NN forces. Inclusion of the Tucson-Melbourne 3N force shifts the minima upwards, but with conflicting results for A(p)(y), and leading to a good description for A(d)(y). An A(p)(y) puzzle, previously thought to exist at energies E(N)</=30 MeV only, appears to exist also at intermediate energies.

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