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Papers by Gayane Karapetyan

EPL (Europhysics Letters), 2017

The impact parameter (b) dependence on the saturation scale, in the framework of the Color Glass ... more 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.

EPL (Europhysics Letters)

The dipole-nucleus forward scattering amplitude rules the onset of the gluon anomalous dimension,... more The dipole-nucleus forward scattering amplitude rules the onset of the gluon anomalous dimension, in the Color-Glass Condensate regime. In this model, the onset of quantum regime is here derived as a critical stable point in the nuclear configurational entropy, matching the fitted experimental data in the literature with accuracy of ∼ 1%. It corroborates with the informational entropy paradigm in high energy nuclear physics.

Journal of Atmospheric and Solar-Terrestrial Physics

<p&amp... more <p>Natural and artificial lakes are able to change the climate of their surroundings. These modifications are collectively known as lake effects and range from microscale to synoptic scale. The presence of the lake can cause negative effect on the local thunderstorm activity in summertime decreasing the convection and precipitation over lakes due to the greater stability created by the lower atmosphere and the colder surfaces of the lake [1, 2]. However, it also can have a positive impact on thundercloud generation when the temperature difference between air in 850 mb height and near earth's surface is more than 13 C causing instability in the atmosphere [3].</p><p> </p><p>The main objective of the present study is to investigate the impact of Lake Fertő (Neusiedler See, located in Hungary and Austria) on local thunderstorm activity by applying statistical analysis on meteorological and lightning data and event studies. Data of the Blitzortung lightning location network, local meteorological data (temperature, precipitation) measured at stations around the lake, water temperature measured at Fertőrákos and temperature measured at 850 mb in Vienna station were used for the analysis. The local thunderstorm activity was investigated during summertime (May - September) in 2015, 2016 and 2017. Lightning distribution maps above and around the lake for the investigated period have been determined based on the Blitzortung data.</p><p> </p><p>According to the lightning distribution maps we can not observe any positive impact of the lake on the lightning activity when water temperature was higher than the air temperature around the lake. Furthermore, we can not conclude that there is a clear negative effect of the lake on the lightning activity based on the lightning distribution maps when the air temperature is higher than the water temperature. Nevertheless, there are some months when it seems a clear border between the lightning activity measured above the lake and at the coast (e. g. in June and July 2015, June 2016). The negative effect also seems to appear in some cases of the investigated local individual thunderstorms, namely the thunderstorm activity is larger above the surrounding surface than directly above the lake. This seems to strengthen the hypothesis that "Deep convection is not often formed in summer above the lakes, and existing storms dissipate significantly when moving above the lakes due to the greater stability created by the lower atmosphere and the colder surfaces of the lake" [1].</p><p> </p><p>[1] Lyons, W. A., Some effects of Lake Michigan upon sqall lines and summertime convention. Proc. 9th Conf. Great Lakes Research, Great Lakes Res. Div. Publ. No. 15, University of Michigan, 259–273, 1966</p><p>[2] Scott, R. W., & Huff, F. A. . Impacts of the Great Lakes on Regional Climate Conditions. Journal of Great Lakes Research, 22(4), 845–863.,…

Journal of Contemporary Physics (Armenian Academy of Sciences), 2007

⎯The isomeric ratios of fragments of photofission of 238 U and 232 Th have been determined experi... more ⎯The isomeric ratios of fragments of photofission of 238 U and 232 Th have been determined experimentally at the bremsstrahlung end-point of 50 and 3500 MeV. Results of measurements enabled us to estimate the mean angular momenta of primary fragments and to compare them with the published data.

EPJ Web of Conferences, 2014

A comprehensive set of 110 radioactive nuclide cross sections with mass numbers 22 ≤ A ≤ 198 amu ... more A comprehensive set of 110 radioactive nuclide cross sections with mass numbers 22 ≤ A ≤ 198 amu in the interaction of 4.4-GeV deuterons with 197 Au have been measured for the first time. The results including charge distributions have been parameterized in term of a 3-parameter equation in order to reproduces the isobaric distributions. Using data from the charge distributions, the total mass-yield distribution was obtained. The new experimental data of the recoil properties of reaction products were also obtained. Kinematical characteristics of the reaction products obtained from measurements of the residuals emitted in the forward and backward directions exhibit different behavior depending on the mass region. The kinematical features of reaction products have been analyzed on the basis of the two-step model of high-energy nuclear reactions and discussed in terms of the different reaction mechanisms.

Exotic Nuclei, 2015

The cross sections for the binary fission of 197 Au, 181 Ta and 209 Bi targets induced by 11 B io... more The cross sections for the binary fission of 197 Au, 181 Ta and 209 Bi targets induced by 11 B ions were measured at intermediate energies. The fission products cross sections were studied by means of activation analysis in off-line regime observed γ-ray spectra. The fission cross section is reconstructed on the basis of charge and mass distribution of the fission products.

Physical Review C, 2015

A study of photofission on 181 Ta induced by bremsstrahlung with endpoint energies of 50 and 3500... more A study of photofission on 181 Ta induced by bremsstrahlung with endpoint energies of 50 and 3500 MeV has been performed. The fission yields have been measured by using the induced-activity method in an off-line analysis. The total photofission yields for the tantalum target at 50 and 3500 MeV are found to be 5.4 ± 1.1 μb/ equivalent quanta per second (eq.q) and 0.77 ± 0.11 mb/eq.q, respectively, and the corresponding deduced fissilities are (0.23 ± 0.05)×10 −3 and (2.9 ± 0.5)×10 −3. Mass-and charge-yield distributions were derived from the data. The results were compared with the simulated results from the CRISP code for multimodal fission by the assuming symmetrical fission mode.

EPL (Europhysics Letters), 2017

The impact parameter (b) dependence on the saturation scale, in the framework of the Color Glass ... more 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.

EPL (Europhysics Letters)

The dipole-nucleus forward scattering amplitude rules the onset of the gluon anomalous dimension,... more The dipole-nucleus forward scattering amplitude rules the onset of the gluon anomalous dimension, in the Color-Glass Condensate regime. In this model, the onset of quantum regime is here derived as a critical stable point in the nuclear configurational entropy, matching the fitted experimental data in the literature with accuracy of ∼ 1%. It corroborates with the informational entropy paradigm in high energy nuclear physics.

Journal of Atmospheric and Solar-Terrestrial Physics

<p&amp... more <p>Natural and artificial lakes are able to change the climate of their surroundings. These modifications are collectively known as lake effects and range from microscale to synoptic scale. The presence of the lake can cause negative effect on the local thunderstorm activity in summertime decreasing the convection and precipitation over lakes due to the greater stability created by the lower atmosphere and the colder surfaces of the lake [1, 2]. However, it also can have a positive impact on thundercloud generation when the temperature difference between air in 850 mb height and near earth's surface is more than 13 C causing instability in the atmosphere [3].</p><p> </p><p>The main objective of the present study is to investigate the impact of Lake Fertő (Neusiedler See, located in Hungary and Austria) on local thunderstorm activity by applying statistical analysis on meteorological and lightning data and event studies. Data of the Blitzortung lightning location network, local meteorological data (temperature, precipitation) measured at stations around the lake, water temperature measured at Fertőrákos and temperature measured at 850 mb in Vienna station were used for the analysis. The local thunderstorm activity was investigated during summertime (May - September) in 2015, 2016 and 2017. Lightning distribution maps above and around the lake for the investigated period have been determined based on the Blitzortung data.</p><p> </p><p>According to the lightning distribution maps we can not observe any positive impact of the lake on the lightning activity when water temperature was higher than the air temperature around the lake. Furthermore, we can not conclude that there is a clear negative effect of the lake on the lightning activity based on the lightning distribution maps when the air temperature is higher than the water temperature. Nevertheless, there are some months when it seems a clear border between the lightning activity measured above the lake and at the coast (e. g. in June and July 2015, June 2016). The negative effect also seems to appear in some cases of the investigated local individual thunderstorms, namely the thunderstorm activity is larger above the surrounding surface than directly above the lake. This seems to strengthen the hypothesis that "Deep convection is not often formed in summer above the lakes, and existing storms dissipate significantly when moving above the lakes due to the greater stability created by the lower atmosphere and the colder surfaces of the lake" [1].</p><p> </p><p>[1] Lyons, W. A., Some effects of Lake Michigan upon sqall lines and summertime convention. Proc. 9th Conf. Great Lakes Research, Great Lakes Res. Div. Publ. No. 15, University of Michigan, 259–273, 1966</p><p>[2] Scott, R. W., & Huff, F. A. . Impacts of the Great Lakes on Regional Climate Conditions. Journal of Great Lakes Research, 22(4), 845–863.,…

Journal of Contemporary Physics (Armenian Academy of Sciences), 2007

⎯The isomeric ratios of fragments of photofission of 238 U and 232 Th have been determined experi... more ⎯The isomeric ratios of fragments of photofission of 238 U and 232 Th have been determined experimentally at the bremsstrahlung end-point of 50 and 3500 MeV. Results of measurements enabled us to estimate the mean angular momenta of primary fragments and to compare them with the published data.

EPJ Web of Conferences, 2014

A comprehensive set of 110 radioactive nuclide cross sections with mass numbers 22 ≤ A ≤ 198 amu ... more A comprehensive set of 110 radioactive nuclide cross sections with mass numbers 22 ≤ A ≤ 198 amu in the interaction of 4.4-GeV deuterons with 197 Au have been measured for the first time. The results including charge distributions have been parameterized in term of a 3-parameter equation in order to reproduces the isobaric distributions. Using data from the charge distributions, the total mass-yield distribution was obtained. The new experimental data of the recoil properties of reaction products were also obtained. Kinematical characteristics of the reaction products obtained from measurements of the residuals emitted in the forward and backward directions exhibit different behavior depending on the mass region. The kinematical features of reaction products have been analyzed on the basis of the two-step model of high-energy nuclear reactions and discussed in terms of the different reaction mechanisms.

Exotic Nuclei, 2015

The cross sections for the binary fission of 197 Au, 181 Ta and 209 Bi targets induced by 11 B io... more The cross sections for the binary fission of 197 Au, 181 Ta and 209 Bi targets induced by 11 B ions were measured at intermediate energies. The fission products cross sections were studied by means of activation analysis in off-line regime observed γ-ray spectra. The fission cross section is reconstructed on the basis of charge and mass distribution of the fission products.

Physical Review C, 2015

A study of photofission on 181 Ta induced by bremsstrahlung with endpoint energies of 50 and 3500... more A study of photofission on 181 Ta induced by bremsstrahlung with endpoint energies of 50 and 3500 MeV has been performed. The fission yields have been measured by using the induced-activity method in an off-line analysis. The total photofission yields for the tantalum target at 50 and 3500 MeV are found to be 5.4 ± 1.1 μb/ equivalent quanta per second (eq.q) and 0.77 ± 0.11 mb/eq.q, respectively, and the corresponding deduced fissilities are (0.23 ± 0.05)×10 −3 and (2.9 ± 0.5)×10 −3. Mass-and charge-yield distributions were derived from the data. The results were compared with the simulated results from the CRISP code for multimodal fission by the assuming symmetrical fission mode.