The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
L B Weinstein - One of the best experts on this subject based on the ideXlab platform.
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center of mass motion of short range correlated Nucleon pairs studied via the a e e pp reaction
Physical Review Letters, 2018Co-Authors: Eliahu Cohen, O Hen, E Piasetzky, L B Weinstein, M Duer, Aaron J Schmidt, I Korover, H Hakobyan, S Adhikari, Z AkbarAbstract:Short-range correlated (SRC) Nucleon pairs are a vital part of the nucleus, accounting for almost all Nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the Nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field Nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field Nucleons in specific quantum states.
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Nucleon Nucleon correlations short lived excitations and the quarks within
Reviews of Modern Physics, 2017Co-Authors: O Hen, Gerald A Miller, E Piasetzky, L B WeinsteinAbstract:This article reviews our current understanding of how the internal quark structure of a Nucleon bound in nuclei differs from that of a free Nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to Nucleon-Nucleon Short-Range Correlations (SRC) in nuclei. Our review and new analysis (involving the amplitudes of non-Nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident. The influence of strongly correlated neutron-proton pairs involving highly virtual Nucleons is responsible for both effects. These correlated pairs are temporary high-density fluctuations in the nucleus in which the internal structure of the Nucleons is briefly modified. This conclusion needs to be solidified by the future experiments and improved theoretical analyses that are discussed herein.
Ulf-g. Meißner - One of the best experts on this subject based on the ideXlab platform.
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Impurity lattice Monte Carlo for hypernuclei
The European Physical Journal A, 2020Co-Authors: Dillon Frame, Timo A. Lähde, Dean Lee, Ulf-g. MeißnerAbstract:We consider the problem of including $$\varLambda $$ Λ hyperons into the ab initio framework of nuclear lattice effective field theory. In order to avoid large sign oscillations in Monte Carlo simulations, we make use of the fact that the number of hyperons is typically small compared to the number of Nucleons in the hypernuclei of interest. This allows us to use the impurity lattice Monte Carlo method, where the minority species of fermions in the full nuclear Hamiltonian is integrated out and treated as a worldline in Euclidean projection time. The majority fermions (Nucleons) are treated as explicit degrees of freedom, with their mutual interactions described by auxiliary fields. This is the first application of the impurity lattice Monte Carlo method to systems where the majority particles are interacting. Here, we show how the impurity Monte Carlo method can be applied to compute the binding energies of the light hypernuclei. In this exploratory work we use spin-independent Nucleon–Nucleon and hyperon–Nucleon interactions to test the computational power of the method. We find that the computational effort scales approximately linearly in the number of Nucleons. The results are very promising for future studies of larger hypernuclear systems using chiral effective field theory and realistic hyperon–Nucleon interactions, as well as applications to other quantum many-body systems.
O Hen - One of the best experts on this subject based on the ideXlab platform.
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center of mass motion of short range correlated Nucleon pairs studied via the a e e pp reaction
Physical Review Letters, 2018Co-Authors: Eliahu Cohen, O Hen, E Piasetzky, L B Weinstein, M Duer, Aaron J Schmidt, I Korover, H Hakobyan, S Adhikari, Z AkbarAbstract:Short-range correlated (SRC) Nucleon pairs are a vital part of the nucleus, accounting for almost all Nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the Nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field Nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field Nucleons in specific quantum states.
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Nucleon Nucleon correlations short lived excitations and the quarks within
Reviews of Modern Physics, 2017Co-Authors: O Hen, Gerald A Miller, E Piasetzky, L B WeinsteinAbstract:This article reviews our current understanding of how the internal quark structure of a Nucleon bound in nuclei differs from that of a free Nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to Nucleon-Nucleon Short-Range Correlations (SRC) in nuclei. Our review and new analysis (involving the amplitudes of non-Nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident. The influence of strongly correlated neutron-proton pairs involving highly virtual Nucleons is responsible for both effects. These correlated pairs are temporary high-density fluctuations in the nucleus in which the internal structure of the Nucleons is briefly modified. This conclusion needs to be solidified by the future experiments and improved theoretical analyses that are discussed herein.
William Detmold - One of the best experts on this subject based on the ideXlab platform.
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hyperon Nucleon interactions from quantum chromodynamics and the composition of dense nuclear matter
Physical Review Letters, 2012Co-Authors: Silas R Beane, Saul D Cohen, William Detmold, Kostas Orginos, Alfredo Parreno, E Chang, Martin J SavageAbstract:eld theory. The interactions determined from QCD are consistent with those extracted from hyperon-Nucleon experimental data within uncertainties, and strengthen theoretical arguments that the strange quark is a crucial component of dense nuclear matter. The interactions between hyperons and Nucleons are important for understanding the composition of dense nuclear matter. In high-density baryonic systems, the large values of the Fermi energies may make it energetically advantageous for some of the Nucleons to transform into hyperons via the weak interactions, with the increase in rest mass being more than compensated for by the decrease in combined Fermi energy of the baryon-lepton system. This is speculated to occur in the interior of neutron stars, but a quantitative understanding of this phenomenon depends on knowledge of the hyperon-Nucleon (YN) interactions in the medium. In this letter we use n scattering phase shifts in the 1 S0 and 3 S1 spinchannels calculated with Lattice QCD (LQCD) to quantify the energy shift of the hyperon in dense neutron matter, as might occur in the interior of a neutron star. Our results strongly suggest an important role for strangeness in such environments. Precise Nucleon-Nucleon (NN) interactions constrained by experiment and chiral symmetry, together with numerically small but important three-Nucleon interactions, have served as input to rened many-body techniques for
E Piasetzky - One of the best experts on this subject based on the ideXlab platform.
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center of mass motion of short range correlated Nucleon pairs studied via the a e e pp reaction
Physical Review Letters, 2018Co-Authors: Eliahu Cohen, O Hen, E Piasetzky, L B Weinstein, M Duer, Aaron J Schmidt, I Korover, H Hakobyan, S Adhikari, Z AkbarAbstract:Short-range correlated (SRC) Nucleon pairs are a vital part of the nucleus, accounting for almost all Nucleons with momentum greater than the Fermi momentum (k_{F}). A fundamental characteristic of SRC pairs is having large relative momenta as compared to k_{F}, and smaller center of mass (c.m.) which indicates a small separation distance between the Nucleons in the pair. Determining the c.m. momentum distribution of SRC pairs is essential for understanding their formation process. We report here on the extraction of the c.m. motion of proton-proton (pp) SRC pairs in carbon and, for the first time in heavier and ansymetric nuclei: aluminum, iron, and lead, from measurements of the A(e,e^{'}pp) reaction. We find that the pair c.m. motion for these nuclei can be described by a three-dimensional Gaussian with a narrow width ranging from 140 to 170 MeV/c, approximately consistent with the sum of two mean-field Nucleon momenta. Comparison with calculations appears to show that the SRC pairs are formed from mean-field Nucleons in specific quantum states.
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Nucleon Nucleon correlations short lived excitations and the quarks within
Reviews of Modern Physics, 2017Co-Authors: O Hen, Gerald A Miller, E Piasetzky, L B WeinsteinAbstract:This article reviews our current understanding of how the internal quark structure of a Nucleon bound in nuclei differs from that of a free Nucleon. We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to Nucleon-Nucleon Short-Range Correlations (SRC) in nuclei. Our review and new analysis (involving the amplitudes of non-Nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident. The influence of strongly correlated neutron-proton pairs involving highly virtual Nucleons is responsible for both effects. These correlated pairs are temporary high-density fluctuations in the nucleus in which the internal structure of the Nucleons is briefly modified. This conclusion needs to be solidified by the future experiments and improved theoretical analyses that are discussed herein.
