Downloaded from the self-conjugate 4n nuclei which we call a-nuclei are especially stable energetically, therefore the fragmentation (or fission) thresholds of respective nuclei into constituent a-nuclei plus a residual nucleus lie in series starting in the region of quite low excitation energy.Since a-nuclei are strongly bound systems, they are hardly excited even when two a-nuclei are in a close distance. The fact that inter-nucleus forces between spin-isospin saturated nuclei are generally weak promotes further the tendency that a-nuclei preserve their identity in their interaction process. Furthermore the repulsive force of a short range part of the inter-nucleus inter-at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from factorily the low-lying positive-parity excited states, 02 + at 7.66 MeV and 22 + (or 08 + ?) at ,...__,10.3 MeV shown in Fig. 1-1.From these studies, the ground rotational band (consisting of ground 01 +, 2 1 + at 4.44 MeV and 41 + at 14.08 MeV) was regarded as having a strong shellmodel-like character, although a-clustering effect is important. The latter nature (namely the persistency of a-clustering) was investigated in detail by Abe, Hiura and Tanaka 17 l by the use of the molecular orbital method preserving the spatial symmetry of [ 4 8 ]. Takigawa and Arima 18 l investigated the *> Many works were made with various frameworks and a-a potentials. Here, however, we do not mention them in detail. See a review article given by Tamagaki and Fujiwara for the works on the 3a problem.••> at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from 15 0, 15 N, 17 0 and 11 F, the spacing between the centroids of the p and the sd shells is estimated as about 17 MeV. ii) We can deduce a value of fiw = 13.4 MeV corresponding to the harmonic oscillator parameter b = 1.76 fm at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from Another standpoint for incorporating a 4p-4h configuration was the weak coupling model by Arima, Horiuchi and Sebe 58 >• 59 >• 60 > which assumed that the at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from *' The RGM study for the "O+a system was also carried out by Siinkel and Wildermuth."'l **l Similar RGM analysis of the "0-a interaction was made by Ando, Ikeda and Suzuki 106 J by comparing with the a-a and "0-16 0 cases. at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from at Purdue University Libraries ADMN on June 1, 2015 http://ptps.oxfordjournals.org/ Downloaded from *> As for wi'lr(t), harmonic oscillator functions and locally peaked Gaussian functions are also available by the use of fPNLM(J., v, S). Actually, the latter functions were examined and were found to give the same results obtained by the set (2·5) (Ref. 41)). at Purdue University Lib...

No abstract

We present a general strategy to extend quantum cluster algorithms for S = 1 / 2 spin systems, such as the loop algorithm, to those with an arbitrary size of spins. The partition function of a high- S spin system is generally represented by the path integral of a S = 1 / 2 model with special boundary conditions in the imaginary-time direction. We introduce additional graphs for the boundary part and give the labeling probability explicitly, which completes the algorithm together with an existing S = 1 / 2 algorithm. As a demonstration, we simulate the integer-spin antiferromagnetic Heisenberg chains. The magnitude of the first excitation gap is estimated to be 0.41048(6), 0.08917(4), and 0.01002(3) for S = 1, 2, and 3, respectively.

No abstract

We describe the main building blocks of a generic automated package for the calculation of Feynman diagrams. These blocks include the generation and creation of a model file, the graph generation, the symbolic calculation at an intermediate level of the Dirac and tensor algebra, implementation of the loop integrals, the generation of the matrix elements or helicity amplitudes, methods for the phase space integrations and eventually the event generation. The report focuses on the fully automated systems for the calculation of physical processes based on the experience in developing GRACE-loop which is a general purpose code applicable to one-loop corrections in the Standard Model. As such, a detailed description of the renormalisation procedure in the Standard Model is given emphasizing the central role played by the non-linear gauge fixing conditions for the construction of such automated codes. These new gauge-fixing conditions are used as a very efficient means to check the results of large scale automated computations in the Standard Model. Their need is better appreciated when it comes to devising efficient and powerful algorithms for the reduction of the tensorial structures of the loop integrals and the reduction of the N > 4 point-function to lower rank integrals. A new technique for these reduction algorithms is described. Explicit formulae for all two-point functions in a generalised non-linear gauge are given, together with the complete set of counterterms. We also show how infrared divergences are dealt with in the system. We give a comprehensive presentation of some systematic test-runs which have been performed at the one-loop level for a wide variety of two-to-two processes to show the validity of the gauge check. These cover fermion-fermion scattering, gauge boson scattering into fermions, gauge bosons and Higgs bosons scattering processes. Comparisons with existing results on some one-loop computation in the Standard Model show excellent agreement. These include e + e − → tt, W + W − , ZH; γγ → tt, W + W − ; eγ → eZ, νW and W + W − → W + W − . We also briefly recount some recent development concerning the calculation of one-loop corrections to 3 body final states cross sections in e + e − with the help of an automated system.

No abstract

We study the roles of the tensor and pairing correlations on the halo formation in 11 Li with an extended 9 Li+n+n model. We first solve the ground state of 9 Li in the shell model basis by taking 2p-2h states using the Gaussian functions with variational size parameters to take into account the tensor correlation fully. In 11 Li, the tensor and pairing correlations in 9 Li are Pauli-blocked by additional two neutrons, which work coherently to make the configurations containing the 0p 1/2 state pushed up and close to those containing the 1s 1/2 state. Hence, the pairing interaction works efficiently to mix the two configurations by equal amount and develop the halo structure in 11 Li. For 10 Li, the inversion phenomenon of s-and p-states is reproduced in the same framework. Our model furthermore explains the recently observed Coulomb breakup strength and charge radius for 11 Li.

No abstract