Nuclear Theory·nucl-th
9 papers—5 primary·4 cross-listed
Waseem Bashir🇮🇳 · Saeed Uddin🇮🇳 · Hamid Nanda🇮🇳
We calculate the particle ratios for a strongly interacting hadronic matter matter using non-linear Walecka model (NLWM) in relativistic mean-field approximation. A comparison with Hadron Resonance Gas Model is made.
Y. K. Tanaka🇯🇵 · K. Itahashi🇯🇵 · H. Fujioka🇯🇵 · Y. Ayyad🇯🇵 · J. Benlliure🇪🇸 · K.-T. Brinkmann🇩🇪 · S. Friedrich🇩🇪 · H. Geissel🇩🇪 · J. Gellanki🇳🇱 · C. Guo🇨🇳 · E. Gutz🇩🇪 · E. Haettner🇩🇪 and 42 other authors
Excitation-energy spectra of C nuclei near the -meson production threshold have been measured by missing-mass spectroscopy using the C(,) reaction. A carbon target has been irradiated with a 2.5 GeV proton beam supplied by the synchrotron SIS-18 at GSI to produce meson bound states in C nuclei. Deuterons emitted at in the reaction have been momentum-analyzed by the fragment separator (FRS) used as a high-resolution spectrometer. No distinct structure due to the formation of -mesic states is observed although a high statistical sensitivity is achieved in the experimental spectra. Upper limits on the formation cross sections of -mesic states are determined, and thereby a constraint imposed on the -nucleus interaction is discussed.
Context. Monte Carlo methods have enabled nuclear reaction rates from uncertain inputs to be presented in a statistically meaningful manner. However, these uncertainties are currently computed assuming no correlations between the physical quantities that enter those calculations. This is not always an appropriate assumption. Astrophysically important reactions are often dominated by resonances, whose properties are usually normalized to a well-known reference resonance. This insight provides a basis from which to develop a flexible framework for including correlations in Monte Carlo reaction rate calculations. Aims. The aim of this work is to develop and test a method for including correlations in Monte Carlo reaction rate calculations when the input has been normalized to a common reference. Methods. A mathematical framework is developed for including correlations between input parameters in Monte Carlo reaction rate calculations. The magnitude of those correlations is calculated from the uncertainties typically reported in experimental papers, where full correlation information is not available. The method is applied to four illustrative examples: a fictional 3-resonance reaction, Al(p,)Si, Na(p,)Ne, and Na(,p)Al. Results. Reaction rates at low temperatures that are dominated by a few isolated resonances are found to minimally impacted by correlation effects. However, reaction rates determined from many overlapping resonances can be significantly affected. Uncertainties in the Na(,p)Al reaction, for example, increase by up to a factor of 5. This highlights the need to take correlation effects into account in reaction rate calculations, and provide insight into which cases are expected to be most affected by them. The impact of correlation effects on nucleosynthesis is also investigated.
The impact parameter (b) dependence on the saturation scale, in the framework of the Color Glass Condensate (b-CGC) dipole model, is investigated from the configurational point of view. During the calculations and analysis of the quantum nuclear states, the critical points of stability in the configurational entropy setup are computed, matching the experimental parameters that define the onset of the quantum regime in the b-CGC in the literature with very good accuracy. This new approach is crucial and important for understanding the stability of quantum systems in study of deep inelastic scattering processes.
first authorsco-authorsvia INSPIRE