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The neutron-rich carbon isotopes 19,17C have been investigated via proton inelastic scattering on a liquid hydrogen target at 70 MeV/nucleon. The invariant mass method in inverse kinematics was employed to reconstruct the energy spectrum, in which fast neutrons and charged fragments were detected in coincidence using a neutron hodoscope and a dipole magnet system. A peak has been observed with an excitation energy of 1.46(10) MeV in 19C, while three peaks with energies of 2.20(3), 3.05(3), and 6.13(9) MeV have been observed in 17C. Deduced cross sections are compared with microscopic DWBA calculations based on p-sd shell model wave functions and modern nucleon-nucleus optical potentials. Jpi assignments are made for the four observed states as well as the ground states of both nuclei.Comment: 20 page

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Background-free" spectra of inelastic α-particle scattering have been measured at a beam energy of 385 MeV in 90,92 Zr and 92 Mo at extremely forward angles, including 0 • . The ISGMR strength distributions for the three nuclei coincide with each other, establishing clearly that nuclear incompressibility is not influenced by nuclear shell structure near A ∼90 as was claimed in recent measurements. PACS numbers: 24.30.Cz, 21.65.+f, 25.55.Ci, 27.60.+j Nuclear incompressibility is a fundamental quantity characterizing the equation of state (EOS) of nuclear matter [1]. A number of important phenomena such as the radii of neutron stars, the strength of supernova explosions, transverse flow in relativistic heavy-ion collisions, the nuclear skin thickness, etc. require a good understanding of the EOS of nuclear matter [2,3]. The nuclear incompressibility for infinite nuclear matter, K ∞ , may be determined experimentally from the compressional "breathing mode" of nuclear density oscillation, the isoscalar giant monopole resonance (ISGMR), in finite nuclei [4,5]. In the scaling model, the energy of the ISGMR is directly related to the nuclear incompressibility of the nucleus and is given by [4]:where K A is the incompressibility of a nucleus with mass number A, r 2 0 is the ground state mean square radius, and m is the nucleon mass. The determination of K ∞ from K A is achieved within a framework of self-consistent RPA calculations, using the widely accepted method described by Blaizot et al. [2,6]. The presently accepted value of K ∞ , determined from ISGMR in "standard" nuclei such as 90 Zr and 208 Pb, is 240 ± 20 MeV [7-10]. Because the compressional modes are collective phenomena, the determination of K ∞ should be independent of the choice of the nucleus, provided that approximately 100% of the energy weighted sum rule (EWSR) fraction is exhausted in the ISGMR peak; this condition is satisfied for sufficiently heavy nuclei (A ≥ 90) [2]. The use of the aforementioned "standard nuclei" stems primarily from the relative ease in doing theoretical calculations for the doubly-magic nuclei.In recent work by the Texas A & M group [11][12][13], it has been claimed that the ISGMR strength distributions vary in a rather dramatic manner in nuclei in the A ∼ 90 region. In particular, the A=92 nuclei, 92 Zr and 92 Mo, emerged quite disparate from the others: The ISGMR energies (E ISGMR ) for 92 Zr and 92 Mo were observed to be, respectively, 1.22 and 2.80 MeV higher than that of 90 Zr. Consequently, the K A values determined for 92 Zr and 92 Mo were ∼27 MeV and ∼56 MeV, respectively, higher than that of 90 Zr. These results, if correct, imply significant nuclear structure contribution to the nuclear incompressibility in this mass region. Such nuclear structure effects have not been observed in any of the investigations of ISGMR going back to its first identification in the late 1970's [14,15] and, indeed, would be contrary to the standard hydrodynamical picture associated with this mode of collective oscillation [16]. Further...

The first total synthesis of (+/-)-psychotrimine, a novel trimeric indole alkaloid isolated from Psychotria rostrata, was achieved. In the total synthesis, the copper-mediated intramolecular and intermolecular aminations of halobenzenes, which respectively contributed to the construction of a pyrrolidinoindoline core and the installation of a third tryptamine unit, were used as key steps.