Coulomb dissociation of N-20,N-21

Neutron-rich light nuclei and their reactions play an important role in the creation of chemical elements. Here, data from a Coulomb dissociation experiment on N-20,N-21 are reported. Relativistic N-20,N-21 ions impinged on a lead target and the Coulomb dissociation cross section was determined in a kinematically complete experiment. Using the detailed balance theorem, the N-19(n,gamma)N-20 and N-20(n,gamma)N-21 excitation functions and thermonuclear reaction rates have been determined. The N-19(n,gamma)N-20 rate is up to a factor of 5 higher at T < 1 GK with respect to previous theoretical calculations, leading to a 10% decrease in the predicted fluorine abundance.

El pensamiento religioso de Fernando Sánchez Dragó

Fernando Sánchez Dragó pertenece por edad a la generación de 1956, aunque por afinidad está más cerca de la siguiente, la de 1968, una generación iconoclasta, nihilista y anarquista. Hay a su alrededor un grupo de intelectuales muy conocidos situados dentro de la contracultura (Salvador Pániker, Luis Racionero, Antonio Escohotado, Ramiro Calle, Pepa Roma y Fernando Díez), que sufren por primera vez una influencia directa de las religiones orientales al tiempo que experimentan con drogas visionarias. Un día de marzo de 1967 sufre una experiencia de conversión en Benarés mientras contempla el Ganges, que hará que sienta lo sagrado a partir de entonces a la manera oriental. Descubre el mundo de los hippies y se inicia en la “ebriedad sagrada” de las drogas enteogénicas, que le abren las puertas de la percepción. La lectura de de Carl Gustav Jung hace surgir en él la idea de escribir el libro que le hará famoso, Gárgoris y Habidis. Una historia mágica de España, que indaga en el inconsciente colectivo de los españoles mediante la búsqueda de sus arquetipos. Frente a los demás compañeros de la generación de 1968, que rompen con la tradición española, él decide emprender un viaje de signo contrario en dirección al pasado en busca de un sentido religioso del mundo y de la vida en la España antigua, hasta descubrir una tradición que además es esotérica y heterodoxa, pero que con el paso del tiempo terminará por imaginar como una invención suya que nunca existió...

Direct experimental evidence for a multiparticle-hole ground state configuration of deformed Mg-33

The first direct experimental evidence of a multiparticle-hole ground state configuration of the neutron-rich Mg-33 isotope has been obtained via intermediate energy (400 A MeV) Coulomb dissociation measurement. The major part similar to(70 +/- 13)% of the cross section is observed to populate the excited states of Mg-32 after the Coulomb breakup of Mg-33. The shapes of the differential Coulomb dissociation cross sections in coincidence with different core excited states favor that the valence neutron occupies both the s(1/2) and p(3/2) orbitals. These experimental findings suggest a significant reduction and merging of sd-pf shell gaps at N similar to 20 and 28. The ground state configuration of Mg-33 is predominantly a combination of Mg-32(3.0,3.5MeV; 2(-), 1(-)) circle times nu(s1/2), Mg-32(2.5MeV; 2(+)) circle times nu(p3/2), and Mg-32(0; 0(+)) circle times nu(p3/2). The experimentally obtained quantitative spectroscopic information for the valence neutron occupation of the s and p orbitals, coupled with different core states, is in agreement with Monte Carlo shell model (MCSM) calculation using 3 MeV as the shell gap at N = 20.

Mapping chiral symmetry breaking in the excited baryon spectrum

We study the conjectured “insensitivity to chiral symmetry breaking” in the highly excited light baryon spectrum. While the experimental spectrum is being measured at JLab and CBELSA/TAPS, this insensitivity remains to be computed theoretically in detail. As the only existing option to have both confinement, highly excited states, and chiral symmetry, we adopt the truncated Coulomb-gauge formulation of QCD, considering a linearly confining Coulomb term. Adopting a systematic and numerically intensive variational treatment up to 12 harmonic oscillator shells we are able to access several angular and radial excitations. We compute both the excited spectra of I=1/2 and I=3/2 baryons, up to large spin J=13/2, and study in detail the proposed chiral multiplets. While the static-light and light-light spectra clearly show chiral symmetry restoration high in the spectrum, the realization of chiral symmetry is more complicated in the baryon spectrum than earlier expected.