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444 - M. H. Zhao , S. Kun , O. Merlo 2013
The present discussion rises a number of the questions. For example, is rotational coherence of large molecules necessarily destroyed in the conventionally statistical limit of structureless non-selective continuum (for fixed total spin and parity va lues) under the conditions of complete intramolecular energy redistribution and vibrational dephasing in the regime of strong ro-vibrational coupling? For the slow cross-symmetry phase relaxation, quantum coherent superpositions of a large number of complex configurations with, e.g., many different total angular momenta produce image of a rotation of macroscopic object with classically fixed (single) total angular momentum. Suppose that the quantum coherent superpositions involving a very large number of different good quantum numbers play a role, in a hidden form, in a formation of macroscopic world. Then why these quantum superpositions are so stable against quick aging/decay of ordered complex structures preventing or slowing down tendencies towards uniform occupation of the available phase space as prescribed by the random matrix theory? And what kind of complex macroscopic phenomena may reveal traces of partially coherent quantum superpositions involving a huge number of quantum-mechanically different integrals of motion behind of what is referred to as conservation laws in classical physics employed for the description of the macroscopic world?
139 - S. Kun , Y. Li , M. H. Zhao 2013
The idea of a thermalized non-equilibrated state of matter offers a conceptually new understanding of the strong angular asymmetry. In this compact review we present some clarifications, corrections and further developments of the approach, and provi de a brief account of results previously discussed but not reported in the literature. The cross symmetry compound nucleus $S$-matrix correlations are obtained (i) starting from the unitary $S$-matrix representation, (ii) by explicitly taking into account a process of energy equilibration, and (iii) without taking the thermodynamic limit of an infinite number of particles in the thermalized system. It is conjectured that the long phase memory is due to the exponentially small total spin off-diagonal resonance intensity correlations. This manifestly implies that the strong angular asymmetry intimately relates to extremely small deviations of the eigenfunction distribution from Gaussian law. The spin diagonal resonance intensity correlations determine a new time/energy scale for a validity of random matrix theory. Its definition does not involve overlaps of the many-body interacting configurations with shell model non-interacting states and thus is conceptually different from the physical meaning (inverse energy relaxation time) of the spreading widths introduced by Wigner. Exact Gaussian distribution of the resonance wave functions corresponds to the instantaneous phase relaxation. We invite the nuclear reaction community for the competition to describe, as the first challenge, the strong forward peaking in the typically evaporation part of the proton spectra. This is necessary to initiate revealing long-term misconduct in the heavily cross-disciplinary field, also important for nuclear industry applications.
313 - M. Huang , F. Zhou , R. Wada 2012
Subbarrier fusion of the 7Li + 12C reaction is studied using an antisymmetrized molecular dynamics model (AMD) with an after burner, GEMINI. In AMD, 7Li shows an alpha + t structure at its ground state and it is significantly deformed. Simulations ar e made near the Coulomb barrier energies, i.e., E_{cm} = 3 - 8 MeV. The total fusion cross section of the AMD + GEMINI calculations as a function of incident energy is compared to the experimental results and both are in good agreement at E_{cm} > 3 MeV. The cross section for the different residue channels of the AMD + GEMINI at E_{cm} = 5 MeV is also compared to the experimental results.
572 - M. Huang , R. Wada , Z. Chen 2010
Isotope yields have been analyzed within the framework of a Modified Fisher Model to study the power law yield distribution of isotopes in the multifragmentation regime. Using the ratio of the mass dependent symmetry energy coefficient relative to th e temperature, $a_{sym}/T$, extracted in previous work and that of the pairing term, $a_{p}/T$, extracted from this work, and assuming that both reflect secondary decay processes, the experimentally observed isotope yields have been corrected for these effects. For a given I = N - Z value, the corrected yields of isotopes relative to the yield of $^{12}C$ show a power law distribution, $Y(N,Z)/Y(^{12}C) sim A^{-tau}$, in the mass range of $1 le A le 30$ and the distributions are almost identical for the different reactions studied. The observed power law distributions change systematically when I of the isotopes changes and the extracted $tau$ value decreases from 3.9 to 1.0 as I increases from -1 to 3. These observations are well reproduced by a simple de-excitation model, which the power law distribution of the primary isotopes is determined to $tau^{prim} = 2.4 pm 0.2$, suggesting that the disassembling system at the time of the fragment formation is indeed at or very near the critical point.
103 - M. Huang , A. Bonasera , Z. Chen 2010
We discuss experimental evidence for a nuclear phase transition driven by the different concentration of neutrons to protons. Different ratios of the neutron to proton concentrations lead to different critical points for the phase transition. This is analogous to the phase transitions occurring in 4He-3He liquid mixtures. We present experimental results which reveal the N/A (or Z/A) dependence of the phase transition and discuss possible implications of these observations in terms of the Landau Free Energy description of critical phenomena.
59 - M. Huang , Z. Chen , S. Kowalski 2010
Isoscaling is derived within a recently proposed modified Fisher model where the free energy near the critical point is described by the Landau O(m^6) theory. In this model m = (N-Z)/A is the order parameter, a consequence of (one of) the symmetries of the nuclear Hamiltonian. Within this framework we show that isoscaling depends mainly on this order parameter through the external (conjugate) field H. The external field is just given by the difference in chemical potentials of the neutrons and protons of the two sources. To distinguish from previously employed isoscaling relationships, this approach is dubbed: m - scaling. We discuss the relationship between this framework and the standard isoscaling formalism and point out some substantial differences in interpretation of experimental results which might result. These should be investigated further both theoretically and experimentally.
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