Measurement ofAy(θ) forn+208Pb from 6 to 10 MeV and the neutron-nucleus interaction over the energy range from bound states at -17 MeV up to scattering at 40 MeV

The idea that the η meson could form a bound system with nucleus was put forward long ago by Q.Haider and L.C.Liu and was based on the observation that the low energy η-nucleon interaction was attractive. Since then a number of theoretical calculations have been performed to the predict eta-nucleus bound states. Such bound states-the so called "eta-mesic nuclei" - are predicted to have finite widths and will eventually decay. The experimental confirmation of such a quasi-bound system would be a very useful tool for investigation of interaction between a short lived eta-meson and the nucleus. Since the eta-mesons can not be produced as a secondary beam, the eta-meson particles are available for investigations only as products of certain nuclear reactions where they appear as final state particles. The final state interaction(FSI) effects are the only source of information about the eta-meson interaction with the nucleus. Experiments were performed at the cooler synchrotron accelerator, COSY, Juelich using dedicated detection systems to study the eta-nucleus interaction. The present talk summarizes the status of previous experimental searches. Some preliminary results of the experiments performed at COSY on the eta-nucleus FSI studies are also presented here. The details of the experiments done at COSY, Juelich on eta-mesic nuclei searches along with recent results are reported in an another communication in this proceedings.

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Graphene nanoribbons in criss-crossed electric and magnetic fields

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0215 ◽

2010 ◽

Vol 368 (1932) ◽

pp. 5431-5443 ◽

Cited By ~ 11

Author(s):

Oleksiy Roslyak ◽

Godfrey Gumbs ◽

Danhong Huang

Keyword(s):

Magnetic Fields ◽

Energy Range ◽

Bound States ◽

Graphene Nanoribbons ◽

Strong Electric Field ◽

Polarized Light ◽

Circularly Polarized Light ◽

Electric And Magnetic Fields ◽

Electron Transport Properties ◽

Electrically Enhanced

Graphene nanoribbons (GNRs) in mutually perpendicular electric and magnetic fields are shown to exhibit dramatic changes in their band structure and electron-transport properties. A strong electric field across the ribbon induces multiple chiral Dirac points, closing the semiconducting gap in armchair GNRs. A perpendicular magnetic field induces partially formed Landau levels as well as dispersive surface-bound states. Each of the applied fields on its own preserves the even symmetry E k = E − k of the sub-band dispersion. When applied together, they reverse the dispersion parity to be odd, which gives E e, k =− E h,− k , and mix the electron and hole sub-bands within the energy range corresponding to the change in potential across the ribbon. This leads to oscillations of the ballistic conductance within this energy range. The broken time-reversal symmetry provides dichroism in the absorption of the circularly polarized light. As a consequence, one can observe electrically enhanced Faraday rotation, since the edges of the ribbon provide formation of the substantial density of states.

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Solar Flare Energetic Neutral Emission Measurements in the Project Coronas-I

International Astronomical Union Colloquium ◽

10.1017/s0252921100026208 ◽

1994 ◽

Vol 144 ◽

pp. 635-639

Author(s):

J. Baláž ◽

A. V. Dmitriev ◽

M. A. Kovalevskaya ◽

K. Kudela ◽

S. N. Kuznetsov ◽

...

Keyword(s):

Solar Flare ◽

Energy Range ◽

Gamma Rays ◽

Pulse Shape ◽

Gamma Ray ◽

Pulse Shape Discrimination ◽

Shape Discrimination ◽

Solar Neutron ◽

Low Altitude

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.

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Recent Radiative and Collisional Atomic Data of Astrophysical Interest

International Astronomical Union Colloquium ◽

10.1017/s0252921100107596 ◽

1988 ◽

Vol 102 ◽

pp. 129-132

Author(s):

K.L. Baluja ◽

K. Butler ◽

J. Le Bourlot ◽

C.J. Zeippen

Keyword(s):

Mass Production ◽

Bound States ◽

Physical Models ◽

Impact Excitation ◽

Electron Impact Excitation ◽

Atomic Data ◽

Isoelectronic Sequence ◽

Astrophysical Interest ◽

Radiative Transitions ◽

Forbidden Transitions

SummaryUsing sophisticated computer programs and elaborate physical models, accurate radiative and collisional atomic data of astrophysical interest have been or are being calculated. The cases treated include radiative transitions between bound states in the 2p4and 2s2p5configurations of many ions in the oxygen isoelectronic sequence, the photoionisation of the ground state of neutral iron, the electron impact excitation of the fine-structure forbidden transitions within the 3p3ground configuration of CℓIII, Ar IV and K V, and the mass-production of radiative data for ions in the oxygen and fluorine isoelectronic sequences, as part of the international Opacity Project.

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