Zobrazeno 1 - 10
of 2 889
pro vyhledávání: '"Weidenmüller, H. A."'
Autor:
Weidenmüller, H. A.
Publikováno v:
Phys. Rev. E 105 (2022) 044143
To model a complex system intrinsically separated by a barrier, we use two random Hamiltonians, coupled to each other either by a tunneling matrix element or by an intermediate transition state. We study that model in the universal limit of large mat
Externí odkaz:
http://arxiv.org/abs/2202.04914
Autor:
Harney, H. -L., Weidenmüller, H. A.
Given N data points drawn from a chi-square distribution, we use Bayesian inference to determine most likely values and N-dependent confidence intervals for the width sigma and the number k of degrees of freedom of that distribution. Using reduced pa
Externí odkaz:
http://arxiv.org/abs/2106.06311
Autor:
Papenbrock, T., Weidenmüller, H. A.
Publikováno v:
Phys. Rev. C 102, 044324 (2020)
We develop an effective field theory (EFT) for deformed odd-mass nuclei. These are described as an axially symmetric core to which a nucleon is coupled. In the coordinate system fixed to the core the nucleon is subject to an axially symmetric potenti
Externí odkaz:
http://arxiv.org/abs/2005.11865
Publikováno v:
Phys. Rev. C 101, 014607 (2020)
The statistical model of compound-nucleus reactions predicts that the fluctuations of the partial $\gamma$-decay widths for a compound-nucleus resonance are governed by the Porter-Thomas distribution (PTD), and that consequently the distribution of t
Externí odkaz:
http://arxiv.org/abs/1909.06250
Several experiments [1-3] show significant deviations from predictions of the statistical model of nuclear reactions. We summarize unsuccessful recent theoretical efforts to account for such disagreement in terms of a violation of orthogonal invarian
Externí odkaz:
http://arxiv.org/abs/1810.13385
Autor:
Papenbrock, T., Weidenmüller, H. A.
Publikováno v:
Phys. Scr. 91, 053004 (2016)
We present an effective field theory (EFT) for a model-independent description of deformed atomic nuclei. In leading order this approach recovers the well-known results from the collective model by Bohr and Mottelson. When higher-order corrections ar
Externí odkaz:
http://arxiv.org/abs/1511.09373
Using a random-matrix approach and Monte-Carlo simulations, we generate scattering matrices and cross sections for compound-nucleus reactions. In the absence of direct reactions we compare the average cross sections with the analytic solution given b
Externí odkaz:
http://arxiv.org/abs/1509.00510
Autor:
Papenbrock, T., Weidenmüller, H. A.
Publikováno v:
J. Phys. G: Nucl. Part. Phys. 42, 105103 (2015)
Spontaneous symmetry breaking in non-relativistic quantum systems has previously been addressed in the framework of effective field theory. Low-lying excitations are constructed from Nambu-Goldstone modes using symmetry arguments only. We extend that
Externí odkaz:
http://arxiv.org/abs/1505.01703
By coupling a doorway state to a see of random background states, we develop the theory of doorway states in the framework of the random-phase approximation (RPA). Because of the symmetry of the RPA equations, that theory is radically different from
Externí odkaz:
http://arxiv.org/abs/1407.3626
Autor:
Pluhar, Z., Weidenmüller, H. A.
For simple connected graphs with incommensurate bond lengths and with unitary symmetry we prove the Bohigas-Giannoni-Schmit conjecture in its most general form. Using supersymmetry and taking the limit of infinite graph size, we show that the generat
Externí odkaz:
http://arxiv.org/abs/1407.1148