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1.
Phys Rev Lett ; 108(4): 042501, 2012 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-22400828

RESUMO

Evidence for the neutron-rich hypernucleus (Λ)(6)H is presented from the FINUDA experiment at DAΦNE, Frascati, studying (π+,π-) pairs in coincidence from the K(stop)(-) + (6)Li →(Λ)(6)H + π+ production reaction followed by (Λ)(6)H → (6)He + π- weak decay. The production rate of (Λ)(6) undergoing this two-body π- decay is determined to be (2.9 ± 2.0) × 10(-6)/K(stop)(-). Its binding energy, evaluated jointly from production and decay, is BΛ((Λ)(6)H) = (4.0 ± 1.1) MeV with respect to (5)H+Λ. A systematic difference of (0.98 ± 0.74) MeV between BΛ values derived separately from decay and from production is tentatively assigned to the (Λ)(6)H 0(g.s.)(+) → 1+ excitation.

2.
Electromagn Biol Med ; 27(3): 241-53, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18821200

RESUMO

Current peaks have been observed and measured in electrolytic ionic current of L-glutamic acid aqueous solutions at room temperature, in static magnetic fields of 20, 40, and 60 muT flux densities, with a superimposed extremely low-frequency, (1/10) Hz, alternating magnetic field flux density of 40 nT. The distributions of the peaks have mean values centered at the cyclotron resonance frequency of the singly charged L-glutamic acid ion molecular mass in the corresponding static field. Amplitudes and widths of the peaks are compared and analyzed to extract their correlation. The results can be considered a contribution to the understanding of the experimental phenomenology in low-frequency electromagnetic fields on ionic currents of L-glutamic amino acid aqueous solutions. The results can be of interest in the studies on the interaction of the electromagnetic fields with some structural neurotransmitters in cellular medium.


Assuntos
Ácido Glutâmico/química , Magnetismo , Água/química , Eletrólitos/química , Concentração de Íons de Hidrogênio , Soluções
3.
Electromagn Biol Med ; 27(1): 25-39, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18327712

RESUMO

A current peak has been observed and measured in ionic electrolytic current of a glutamic acid aqueous solution, placed in a static magnetic field of flux density of 40 microT, with a superimposed low-frequency alternating magnetic field of flux density of 40 nT. The peak occurs at the frequency of the cyclotronic resonance of the molecular mass of a single charged glutamic acid ion, placed in a magnetic flux density equal to that of the static field. The amplitude of the current peak is about 30% of the background electrolytic current. Qualitative considerations and a listing of unsolved problems related to the phenomenology are given. The result is the first contribution to the study we have undertaken on the effects of low-frequency alternating electromagnetic fields on the ionic current of amino acid aqueous solutions which are the basic structural units of the proteins.


Assuntos
Eletrólitos/química , Campos Eletromagnéticos , Ácido Glutâmico/química , Água/química , Concentração de Íons de Hidrogênio , Soluções , Fatores de Tempo
4.
Phys Rev Lett ; 94(21): 212303, 2005 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-16090313

RESUMO

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively.

5.
Phys Rev Lett ; 89(18): 183201, 2002 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-12398596

RESUMO

We report the stopping power of molecular hydrogen for antiprotons of kinetic energy above the maximum (approximately 100 keV) with the purpose of comparing with the proton one. Our result is consistent with a positive difference in antiproton-proton stopping powers above approximately 250 keV and with a maximum difference between the stopping powers of 21%+/-3% at around 600 keV.

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