English
Related papers

Related papers: Is the generalized Brink-Axel hypothesis valid?

200 papers

We have analyzed primary $\gamma$-ray spectra of the odd-odd $^{238}$Np nucleus extracted from $^{237}$Np($d,p\gamma$)$^{238}$Np coincidence data measured at the Oslo Cyclotron Laboratory. The primary $\gamma$ spectra cover an…

Nuclear Experiment · Physics 2016-01-13 M. Guttormsen , A. C. Larsen , A. Görgen , T. Renstrøm , S. Siem , T. G. Tornyi , G. M. Tveten

The gamma strength function and level density of 1- states in 96Mo have been extracted from a high-resolution study of the (p,p') reaction at 295 MeV and extreme forward angles. By comparison with compound nucleus $\gamma$ decay…

The validity of the Brink-Axel hypothesis, which is especially important for numerous astrophysical calculations, is addressed for 116,120,124Sn below the neutron separation energy by means of three independent experimental methods. The…

The knowledge of beta decay transitional probabilities and GamowTeller (GT) strength functions from highly excited states of nuclides is of particular importance for applications to astrophysical network calculations of nucleosynthesis in…

Nuclear Theory · Physics 2024-11-21 Fakeha Farooq , Jameel-Un Nabi , Ramoona Shehzadi

Weak interaction charged current transition strengths from highly excited nuclear states are fundamental ingredients for accurate modeling of compact object composition and dynamics, but are difficult to obtain either from experiment or…

Nuclear Theory · Physics 2022-02-09 Raul A. Herrera , Calvin W. Johnson , George M. Fuller

Key nuclear inputs for the astrophysical r process simulations are the weak interaction rates. Consequently, the accuracy of these inputs directly affects the reliability of nucleosynthesis modeling. Majority of the stellar rates, used in…

Solar and Stellar Astrophysics · Physics 2024-11-05 Fakeha Farooq , Jameel-Un Nabi , Ramoona Shehzadi

The authors of the letter "Test of the Brink-Axel Hypothesis for the Pygmy Dipole Resonance" [Phys. Rev. Lett. 119, 182503 (2017)] claim a violation of the Brink-Axel hypothesis by (gamma,gamma') data from gELBE for 96Mo [Phys. Rev. C 79,…

Nuclear Experiment · Physics 2018-07-06 Gencho Rusev , Ronald Schwengner , Arnd R. Junghans

Sum rules provide useful insights into transition strength functions and are often expressed as expectation values of an operator. In this letter I demonstrate that non-energy-weighted transition sum rules have strong secular dependences on…

Nuclear Theory · Physics 2015-09-02 Calvin W. Johnson

Partial cross sections of the $^{89}$Y(p,$\gamma$)$^{90}$Zr reaction have been measured to investigate the $\gamma$-ray strength function in the neutron-magic nucleus $^{90}$Zr. For five proton energies between $E_p=3.65$ MeV and $E_p=4.70$…

Nuclear Experiment · Physics 2015-04-21 L. Netterdon , A. Endres , S. Goriely , J. Mayer , P. Scholz , M. Spieker , A. Zilges

We study the fluctuation-dissipation theorem for a Brownian particle driven into a nonequilibrium steady state experimentally. We validate two different theoretical variants of a generalized fluctuation-dissipation theorem. Furthermore, we…

Soft Condensed Matter · Physics 2015-05-18 Jakob Mehl , Valentin Blickle , Udo Seifert , Clemens Bechinger

Fluctuations associated with stretched E2 transitions from high spin levels in nuclei around $^{168}$Yb are investigated by a cranked shell model extended to include residual two-body interactions. It is found that the gamma-ray energies…

Nuclear Theory · Physics 2009-10-22 M. Matsuo , T. Døssing , B. Herskind , S. Frauendorf

Fluctuation theorems have a very special place in the study of non equilibrium dynamics of physical systems. The form in which it is used most extensively is the Gallavoti-Cohen Fluctuation Theorem which is in terms of the distribution of…

Classical Physics · Physics 2015-12-01 G. S. Agarwal , Sushanta Dattagupta

For a minimal Hubbard-type system at different interaction strengths U, we investigate the density-response for an excitation beyond the linear regime using the generalized Kadanoff-Baym ansatz (GKBA) and the second Born (2B) approximation.…

Strongly Correlated Electrons · Physics 2015-06-12 K. Balzer , S. Hermanns , M. Bonitz

We investigate the reliability of transition strengths computed in the random-phase approximation (RPA), comparing with exact results from diagonalization in full $0\hbar\omega$ shell-model spaces. The RPA and shell-model results are in…

Nuclear Theory · Physics 2009-11-07 Ionel Stetcu , Calvin W. Johnson

We employ the phenomenological theory of the quasiparticle relaxation based on the simplified two-band description and the spin-fluctuation induced interband coupling to analyze recent normal-state transport data in electron-doped iron…

Strongly Correlated Electrons · Physics 2010-03-18 P. Prelovsek , I. Sega

We study the effects of random fluctuations on quantum phase transitions by the energy gap analysis. For the infinite-ranged spin-glass models with a transverse field, we find that a strong sample-to-sample fluctuation effect leads to broad…

Disordered Systems and Neural Networks · Physics 2010-04-13 Kazutaka Takahashi , Yoshiki Matsuda

Generalized oscillator strengths (GOS's) for the Na $3s -3p$ transition have been investigated using the spin-polarized technique of the random phase approximation with exchange (RPAE) and the first Born approximation (FBA), focussing our…

Atomic Physics · Physics 2009-11-06 Zhifan Chen , Alfred Z Msezane

The Gamma-Ray Burst (GRB) prompt emission is believed to be from highly relativistic electrons accelerated in relativistic shocks. From the GRB high-energy power-law spectral indices $\beta$ observed by the Burst and Transient Source…

Astrophysics · Physics 2009-11-11 R. -F. Shen , P. Kumar , E. L. Robinson

Recent theoretical work has not led to a consensus regarding the nature of the low-energy E1 strength in the 40,44,48Ca isotopes, for which high-resolution (gamma,gamma') data exist. Here we revisit this problem using the first-order…

Nuclear Theory · Physics 2012-03-21 P. Papakonstantinou , H. Hergert , V. Yu. Ponomarev , R. Roth

We derive fluctuation relations for a many-body quantum system prepared in a Generalised Gibbs Ensemble subject to a general nonequilibrium protocol. By considering isolated integrable systems, we find generalisations to the Tasaki-Crooks…

Statistical Mechanics · Physics 2015-06-19 James M. Hickey , Sam Genway
‹ Prev 1 2 3 10 Next ›