The Experts below are selected from a list of 17502 Experts worldwide ranked by ideXlab platform
Walter Winter - One of the best experts on this subject based on the ideXlab platform.
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Effects of random Matter Density fluctuations on the neutrino oscillation transition probabilities in the Earth
Physics Letters B, 2020Co-Authors: Björn Jacobsson, Tommy Ohlsson, Håkan Snellman, Walter WinterAbstract:In this Letter, we investigate the effects of random fluctuations of the Earth Matter Density for long baselines on the neutrino oscillation transition probabilities. We especially identify relevant parameters characterizing the Matter Density noise and calculate their effects by averaging over statistical ensembles of a large number of Matter Density profiles. For energies and baselines appropriate to neutrino factories, absolute errors on the relevant appearance probabilities are at the level of \DeltaP(alphabeta)\ similar to 10(-4) (with perhaps \P-mue similar to 1% for neutrinos), whereby a modest improvement in understanding of the geophysical data should render such effects unimportant.QC 2010052
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Reconstruction of the Earth's Matter Density profile using a single neutrino baseline
Physics Letters B, 2020Co-Authors: Tommy Ohlsson, Walter WinterAbstract:In this Letter, we show numerically that a symmetric Earth Matter Density profile can, in principle, be reconstructed from a single baseline energy spectrum up to a certain precision. For the numerical evaluations in the high-dimensional parameter space we use a genetic algorithm.QC 2010052
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The Role of Matter Density uncertainties in the analysis of future neutrino factory experiments
Physical Review D, 2003Co-Authors: Tommy Ohlsson, Walter WinterAbstract:Matter Density uncertainties can affect the measurements of the neutrino oscillation parameters at future neutrino factory experiments, such as the measurements of the mixing parameters theta(13) and delta(CP). We compare different Matter Density uncertainty models and discuss the possibility to include the Matter Density uncertainties in a complete statistical analysis. Furthermore, we systematically study in which measurements and where in the parameter space Matter Density uncertainties are most relevant. We illustrate this discussion with examples that show the effects as functions of different magnitudes of the Matter Density uncertainties. We find that Matter Density uncertainties are especially relevant for large sin(2)2theta(13)greater than or similar to10(-3). Within the KamLAND-allowed range, they are most relevant for the precision measurements of sin(2)2theta(13) and delta(CP), but less relevant for binary measurements, such as for the sign of Deltam(31)(2), the sensitivity to sin(2)2theta(13), or the sensitivity to maximal CP violation. In addition, we demonstrate that knowing the Matter Density along a specific baseline better than to about 1% precision means that all measurements will become almost independent of the Matter Density uncertainties.
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The Effects of Matter Density uncertainties on neutrino oscillations in the earth
arXiv: High Energy Physics - Phenomenology, 2003Co-Authors: Björn Jacobsson, Tommy Ohlsson, Walter Winter, Håkan SnellmanAbstract:We compare three different methods to evaluate uncertainties in the Earth's Matter Density profile, which are relevant to long baseline experiments, such as neutrino factories.
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Effects of random Matter Density fluctuations on the neutrino oscillation transition probabilities in the Earth
Physics Letters B, 2002Co-Authors: Björn Jacobsson, Tommy Ohlsson, Håkan Snellman, Walter WinterAbstract:Abstract In this Letter, we investigate the effects of random fluctuations of the Earth Matter Density for long baselines on the neutrino oscillation transition probabilities. We especially identify relevant parameters characterizing the Matter Density noise and calculate their effects by averaging over statistical ensembles of a large number of Matter Density profiles. For energies and baselines appropriate to neutrino factories, absolute errors on the relevant appearance probabilities are at the level of | ΔP αβ |∼10 −4 (with perhaps | ΔP μe |/ P μe ∼1% for neutrinos), whereby a modest improvement in understanding of the geophysical data should render such effects unimportant.
R Kanungo - One of the best experts on this subject based on the ideXlab platform.
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nuclear Matter Density distribution in the neutron rich nuclei 12 14be from proton elastic scattering in inverse kinematics
Nuclear Physics, 2012Co-Authors: S Ilieva, F Aksouh, G D Alkhazov, L V Chulkov, A V Dobrovolsky, P Egelhof, H Geissel, M Gorska, A G Inglessi, R KanungoAbstract:Abstract In the present work, the differential cross sections for small-angle proton elastic scattering on the 12,14 Be nuclei were measured in inverse kinematics, using secondary radioactive beams with energies near 700 MeV/u produced with the fragment separator FRS at GSI. The main part of the experimental setup was the active target IKAR, which was used simultaneously as a target and a detector for the recoil protons. Auxiliary detectors for projectile tracking and isotope identification completed the setup. The measured differential cross sections were analyzed using the Glauber multiple-scattering theory. For the evaluation of the data several phenomenological nuclear-Matter Density parametrizations and a sum of Gaussian parametrization were used. The nuclear-Matter radii and radial Density distributions of the isotopes 12,14 Be were deduced. Extended nuclear-Matter Density distributions were observed in both isotopes, and the halo structure of 14 Be was confirmed. The results were also compared with microscopic few-body and fermionic molecular dynamics model calculations concerning the structure of these neutron-rich nuclei.
Tommy Ohlsson - One of the best experts on this subject based on the ideXlab platform.
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Effects of random Matter Density fluctuations on the neutrino oscillation transition probabilities in the Earth
Physics Letters B, 2020Co-Authors: Björn Jacobsson, Tommy Ohlsson, Håkan Snellman, Walter WinterAbstract:In this Letter, we investigate the effects of random fluctuations of the Earth Matter Density for long baselines on the neutrino oscillation transition probabilities. We especially identify relevant parameters characterizing the Matter Density noise and calculate their effects by averaging over statistical ensembles of a large number of Matter Density profiles. For energies and baselines appropriate to neutrino factories, absolute errors on the relevant appearance probabilities are at the level of \DeltaP(alphabeta)\ similar to 10(-4) (with perhaps \P-mue similar to 1% for neutrinos), whereby a modest improvement in understanding of the geophysical data should render such effects unimportant.QC 2010052
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Reconstruction of the Earth's Matter Density profile using a single neutrino baseline
Physics Letters B, 2020Co-Authors: Tommy Ohlsson, Walter WinterAbstract:In this Letter, we show numerically that a symmetric Earth Matter Density profile can, in principle, be reconstructed from a single baseline energy spectrum up to a certain precision. For the numerical evaluations in the high-dimensional parameter space we use a genetic algorithm.QC 2010052
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Effects and influences on neutrino oscillations due to a thin Density layer perturbation added to a Matter Density profile
Physics Letters B, 2020Co-Authors: Tommy OhlssonAbstract:In this Letter, we show the effects on the transition probabilities for neutrino oscillations due to a thin constant Density layer perturbation added to an arbitrary Matter Density profile, In the case of two neutrino flavors, we calculate the effects both analytically and numerically, whereas in the case of three neutrino flavors, we perform the studies purely numerically. As an realistic example we consider the effects of the Earth's atmosphere when added to the Earth's Matter Density profile on the neutrino oscillation transition probabilities for atmospheric neutrinos.QC 2010052
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The Role of Matter Density uncertainties in the analysis of future neutrino factory experiments
Physical Review D, 2003Co-Authors: Tommy Ohlsson, Walter WinterAbstract:Matter Density uncertainties can affect the measurements of the neutrino oscillation parameters at future neutrino factory experiments, such as the measurements of the mixing parameters theta(13) and delta(CP). We compare different Matter Density uncertainty models and discuss the possibility to include the Matter Density uncertainties in a complete statistical analysis. Furthermore, we systematically study in which measurements and where in the parameter space Matter Density uncertainties are most relevant. We illustrate this discussion with examples that show the effects as functions of different magnitudes of the Matter Density uncertainties. We find that Matter Density uncertainties are especially relevant for large sin(2)2theta(13)greater than or similar to10(-3). Within the KamLAND-allowed range, they are most relevant for the precision measurements of sin(2)2theta(13) and delta(CP), but less relevant for binary measurements, such as for the sign of Deltam(31)(2), the sensitivity to sin(2)2theta(13), or the sensitivity to maximal CP violation. In addition, we demonstrate that knowing the Matter Density along a specific baseline better than to about 1% precision means that all measurements will become almost independent of the Matter Density uncertainties.
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The Effects of Matter Density uncertainties on neutrino oscillations in the earth
arXiv: High Energy Physics - Phenomenology, 2003Co-Authors: Björn Jacobsson, Tommy Ohlsson, Walter Winter, Håkan SnellmanAbstract:We compare three different methods to evaluate uncertainties in the Earth's Matter Density profile, which are relevant to long baseline experiments, such as neutrino factories.
Paul M Thompson - One of the best experts on this subject based on the ideXlab platform.
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greater cortical gray Matter Density in lithium treated patients with bipolar disorder
Biological Psychiatry, 2007Co-Authors: Carrie E Bearden, Paul M Thompson, Manish Dalwani, Kiralee M Hayashi, Mark Nicoletti, Michael Trakhtenbroit, David C Glahn, Paolo Brambilla, Roberto B Sassi, Alan G MallingerAbstract:Background The neurobiological underpinnings of bipolar disorder are not well understood. Previous neuroimaging findings have been inconsistent; however, new methods for three-dimensional (3-D) computational image analysis may better characterize neuroanatomic changes than standard volumetric measures. Methods We used high-resolution magnetic resonance imaging and cortical pattern matching methods to map gray Matter differences in 28 adults with bipolar disorder, 70% of whom were lithium-treated (mean age = 36.1 ± 10.5; 13 female subject), and 28 healthy control subjects (mean age = 35.9 ± 8.5; 11 female subjects). Detailed spatial analyses of gray Matter Density (GMD) were conducted by measuring local proportions of gray Matter at thousands of homologous cortical locations. Results Gray Matter Density was significantly greater in bipolar patients relative to control subjects in diffuse cortical regions. Greatest differences were found in bilateral cingulate and paralimbic cortices, brain regions critical for attentional, motivational, and emotional modulation. Secondary region of interest (ROI) analyses indicated significantly greater GMD in the right anterior cingulate among lithium-treated bipolar patients (n = 20) relative to those not taking lithium (n = 8). Conclusions These brain maps are consistent with previous voxel-based morphometry reports of greater GMD in portions of the anterior limbic network in bipolar patients and suggest neurotrophic effects of lithium as a possible etiology of these neuroanatomic differences.
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mapping continued brain growth and gray Matter Density reduction in dorsal frontal cortex inverse relationships during postadolescent brain maturation
The Journal of Neuroscience, 2001Co-Authors: Elizabeth R Sowell, Paul M Thompson, Kevin D Tessner, Arthur W TogaAbstract:Recent in vivo structural imaging studies have shown spatial and temporal patterns of brain maturation between childhood, adolescence, and young adulthood that are generally consistent with postmortem studies of cellular maturational events such as increased myelination and synaptic pruning. In this study, we conducted detailed spatial and temporal analyses of growth and gray Matter Density at the cortical surface of the brain in a group of 35 normally developing children, adolescents, and young adults. To accomplish this, we used high-resolution magnetic resonance imaging and novel computational image analysis techniques. For the first time, in this report we have mapped the continued postadolescent brain growth that occurs primarily in the dorsal aspects of the frontal lobe bilaterally and in the posterior temporo-occipital junction bilaterally. Notably, maps of the spatial distribution of postadolescent cortical gray Matter Density reduction are highly consistent with maps of the spatial distribution of postadolescent brain growth, showing an inverse relationship between cortical gray Matter Density reduction and brain growth primarily in the superior frontal regions that control executive cognitive functioning. Inverse relationships are not as robust in the posterior temporo-occipital junction where gray Matter Density reduction is much less prominent despite late brain growth in these regions between adolescence and adulthood. Overall brain growth is not significant between childhood and adolescence, but close spatial relationships between gray Matter Density reduction and brain growth are observed in the dorsal parietal and frontal cortex. These results suggest that progressive cellular maturational events, such as increased myelination, may play as prominent a role during the postadolescent years as regressive events, such as synaptic pruning, in determining the ultimate Density of mature frontal lobe cortical gray Matter.
In Kyoon Lyoo - One of the best experts on this subject based on the ideXlab platform.
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frontal lobe gray Matter Density decreases in bipolar i disorder
Biological Psychiatry, 2004Co-Authors: In Kyoon Lyoo, Andrew L Stoll, Christina M Demopulos, Aimee Parow, Stephen R Dager, Seth D Friedman, David L Dunner, Perry F RenshawAbstract:Abstract Background This study was conducted to explore differences in gray and white Matter Density between bipolar and healthy comparison groups using voxel-based morphometry (VBM). Methods Brain magnetic resonance imaging was performed for 39 subjects with bipolar I disorder and 43 comparison subjects. Images were registered into a proportional stereotaxic space and segmented into gray Matter, white mater, and cerebrospinal fluid. Statistical parametric mapping was used to calculate differences in gray and white Matter Density between groups. Results Bipolar subjects had decreased gray Matter Density in left anterior cingulate gyrus (Brodmann’s area [BA] 32, 7.3% decrease), an adjacent left medial frontal gyrus (BA 10, 6.9% decrease), right inferior frontal gyrus (BA 47, 9.2% decrease), and right precentral gyrus (BA 44, 6.2% decrease), relative to comparison subjects. Conclusions The observation of a gray Matter Density decrease in the left anterior cingulate, which processes emotions, in bipolar subjects is consistent with prior reports that used region-of-interest analytic methods. Decreased gray Matter Density in the right inferior frontal gyrus, which processes nonverbal and intrinsic functions, supports nondominant hemisphere dysfunction as a component of bipolar disorder.
