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Results for “PAULI PRINCIPLE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Entangled Pauli principles: The DNA of quantum Hall fluids

A formalism is developed for the rigorous study of solvable fractional quantum Hall parent Hamiltonians with Landau-level mixing. The idea of organization through “generalized Pauli principles” is expanded to allow for root-level entanglement, giving rise to “entangled Pauli principles.” Through the latter, aspects of the effective field theory description become ingrained in exact microscopic solutions for a great wealth of phases for which no similar single Landau-level description is known. We discuss in detail braiding statistic, edge theory, and rigorous zero-mode counting for the Jain-221 state as derived from a microscopic Hamiltonian. As a result, the relevant root-level entanglement is found to feature an Affleck-Kennedy-Lieb-Tasaki (AKLT)-type matrix-product ground states structure associated with an emergent SU(2) symmetry.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

New Limits on Bosonic Dark Matter, Solar Axions, Pauli Exclusion Principle Violation, and Electron Decay from the Majorana Demonstrator

Here, we present new limits on exotic keV-scale physics based on 478 kg d of Majorana Demonstrator commissioning data. Constraints at the 90% confidence level are derived on bosonic dark matter (DM) and solar axion couplings, Pauli exclusion principle violating (PEPV) decay, and electron decay using monoenergetic peak signal limits above our background. We set our most stringent DM constraints for 11.8 keV mass particles, limiting g A e < 4.5 × 10 -13 for pseudoscalars and ( α ' / α ) < 9.7 × 10 -28 for vectors. We also report a 14.4 keV solar axion coupling limit of g$eff\atop{AN}$ × g A e < 3.8 × 10 -17 , a 1/2 β 2 < 8.5 × 10 - 48 limit on the strength of PEPV electron transitions, and a lower limit on the electron lifetime of τ e > 1.2 × 1 0 24 yr for e - → invisible.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

How the Pauli exclusion principle affects fusion of atomic nuclei

The Pauli exclusion principle induces a repulsion between composite systems of identical fermions such as colliding atomic nuclei. Our goal is to study how heavy-ion fusion is impacted by this “Pauli repulsion.” Here we propose a new microscopic approach, the density-constrained frozen Hartree-Fock method, to compute the bare potential including the Pauli exclusion principle exactly. Pauli repulsion is shown to be important inside the barrier radius and increases with the charge product of the nuclei. Its main effect is to reduce tunneling probability. Pauli repulsion is part of the solution to the long-standing deep sub-barrier fusion hindrance problem.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Search for charge non-conservation and Pauli exclusion principle violation with the M AJORANA D EMONSTRATOR

Charge conservation and the Pauli exclusion principle result from fundamental symmetries in the standard model of particle physics, and are typically taken as axiomatic. High-precision tests for small violations of these symmetries could point to new physics. Here we consider three models for violation of these processes, which would produce detectable ionization in the high-purity germanium detectors of the M AJORANA D EMONSTRATOR experiment. Using a 37.5 kg yr exposure, we report a lower limit on the electron mean lifetime, improving the previous best limit for the e → v e $\overline{v_e}$ v e decay channel by more than an order of magnitude. Here, we also present searches for two types of violation of the Pauli exclusion principle, setting limits on the probability of an electron to be found in a symmetric quantum state.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Experimental data from a quantum computer verifies the generalized Pauli exclusion principle

“What are the consequences… that Fermi particles cannot get into the same state…” R. P. Feynman wrote of the Pauli exclusion principle, “In fact, almost all the peculiarities of the material world hinge on this wonderful fact.” In 1972 Borland and Dennis showed that there exist powerful constraints beyond the Pauli exclusion principle on the orbital occupations of Fermi particles, providing important restrictions on quantum correlation and entanglement. Here we use computations on quantum computers to experimentally verify the existence of these additional constraints. Quantum many-fermion states are randomly prepared on the quantum computer and tested for constraint violations. Measurements show no violation and confirm the generalized Pauli exclusion principle with an error of one part in one quintillion.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

Effect of the Pauli exclusion principle and the polarization of nuclei on the potential of their interaction for the example of the {sup 16}O+{sup 16}O system

On the basis of the energy-density method, the effect of simultaneously taking into account the Pauli exclusion principle and the monopole and quadrupole polarizations of interacting nuclei on their interaction potential is considered for the example of the {sup 16}O + {sup 16}O system by using the wave function for the two-center shell model. The calculations performed in the adiabatic approximation reveal that the inclusion of the Pauli exclusion principle and the polarization of interacting nuclei, especially their quadrupole polarization, has a substantial effect on the potential of the nucleus-nucleus interaction.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2017

Ternary generalization of Pauli’s principle and the Z{sub 6}-graded algebras

We show how the discrete symmetries Z{sub 2} and Z{sub 3} combined with the superposition principle result in the SL(2,C) symmetry of quantum states. The role of Pauli’s exclusion principle in the derivation of the SL(2,C) symmetry is put forward as the source of the macroscopically observed Lorentz symmetry; then it is generalized for the case of the Z{sub 3} grading replacing the usual Z{sub 2} grading, leading to ternary commutation relations. We discuss the cubic and ternary generalizations of Grassmann algebra. Invariant cubic forms on such algebras are introduced, and it is shown how the SL(2,C) group arises naturally in the case of two generators only, as the symmetry group preserving these forms. The wave equation generalizing the Dirac operator to the Z{sub 3}-graded case is introduced, whose diagonalization leads to a sixthorder equation. The solutions of this equation cannot propagate because their exponents always contain non-oscillating real damping factor. We show how certain cubic products can propagate nevertheless. The model suggests the origin of the color SU(3) symmetry.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2016

Search for Pauli exclusion principle violating atomic transitions and electron decay with a p-type point contact germanium detector

Here, a search for Pauli-exclusion-principle-violating K α electron transitions was performed using 89.5 kg-d of data collected with a p-type point contact high-purity germanium detector operated at the Kimballton Underground Research Facility. A lower limit on the transition lifetime of 5.8 × 10 30 s at 90% C.L. was set by looking for a peak at 10.6 keV resulting from the X-ray and Auger electrons present following the transition. A similar analysis was done to look for the decay of atomic K-shell electrons into neutrinos, resulting in a lower limit of 6.8 × 10 30 s at 90% C.L. It is estimated that the Majorana Demonstrator, a 44 kg array of p-type point contact detectors that will search for the neutrinoless double-beta decay of 76 Ge, could improve upon these exclusion limits by an order of magnitude after three years of operation.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

The forces of symmetry and the physical meaning of the Pauli exclusion principle

A mathematically strict analysis of the consequences of the requirement of wave function antisymmetry is presented. It is shown that the probability density for symmetric electron configurations is zero, i.e., these electron configurations in atoms are inaccessible owing to the action of fundamental forces termed by the author “the forces of symmetry”. As a consequence, a fundamentally new, in computational aspect, quantum chemistry can be developed. A previously reported hypothesis that forbids two electrons with the same spins to have equal potentials is confirmed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Multi-level coupled cluster theory

We present a general formalism where different levels of coupled cluster theory can be applied to different parts of the molecular system. The system is partitioned into subsystems by Cholesky decomposition of the one-electron Hartree-Fock density matrix. In this way the system can be divided across chemical bonds without discontinuities arising. The coupled cluster wave function is defined in terms of cluster operators for each part and these are determined from a set of coupled equations. The total wave function fulfills the Pauli-principle across all borders and levels of electron correlation. We develop the associated response theory for this multi-level coupled cluster theory and present proof of principle applications. The formalism is an essential tool in order to obtain size-intensive complexity in the calculation of local molecular properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

A New Approach to Calculating the Potential Energy of Interaction between Two Atoms

A Fourier component of the potential energy of interaction between two atoms has been presented as a polynomial of the biquadratic atomic form factor. A numerical calculation has been performed in the screened Coulomb potential approximation. It is demonstrated that the account for the Pauli principle leads to the occurrence of a potential barrier and an additional region of attraction of two atoms. This model is shown to agree qualitatively with the results of the density-functional-theory calculation.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2015

Systematic muon capture rates in PQRPA

In this work we performed a systematic study of the inclusive muon capture rates for several nuclei with A < 60 using the Projected Random Quasi-particle Phase Approximation (PQRPA) as nuclear model, because it is the only RPA model that treats the Pauli Principle correctly. We reckon that the comparison between theory and data for the inclusive muon capture is not a fully satisfactory test on the nuclear model that is used. The exclusive muon transitions are more robust for such a purpose.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Systematics of the α-decay fine structure in even–even nuclei

We describe α-transitions to low-lying states in even–even nuclei with Z>50,N>82 using the Coherent State Model (CSM). We reproduce the energy levels and electromagnetic transition rates between the states of the ground band employing two parameters, namely the deformation parameter and the strength of the harmonic CSM Hamiltonian. The B(E2) values are described in terms of an effective charge which depends linearly on the deformation parameter. The treatment of the α-emission process is based on an α–daughter interaction containing a monopole component, calculated through a double folding procedure with a M3Y interaction plus a repulsive core simulating the Pauli principle, and a quadrupole–quadrupole (QQ) interaction. The decaying states are identified with the lowest narrow outgoing resonances obtained through the coupled channels method. The α-branching ratios to 2{sup +} states are reproduced by means of the QQ strength. This interaction strength can be fitted with a linear dependence on the deformation parameter, as predicted by the CSM. The theoretical intensities to 4{sup +} and 6{sup +} states are in reasonable agreement with available experimental data. Predictions are made for spherical, transitional and well deformed even–even α-emitters.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Review of the fermionic dark matter model applied to galactic structures

Baryonic components (e.g. bulge and disk) of galactic structures are assumed to be embedded in an isothermal dark matter halo of fermionic nature. Besides the Pauli principle only gravitational interaction is considered. Using the underlying Fermi-Dirac phase space distribution, typical of collisionless relaxation processes, it yields an one-parameter family of scaled solutions which reproduces the observed flat rotation curves in galaxies, and additionally predicts a degenerate core through their centers. In order to provide the right DM halo properties of galaxies a set of four parameters (particle mass, degeneracy parameter at the galactic center, central density and the velocity dispersion) is necessary. The more general density profile shows three regimes depending on radius: an almost uniform very dense quantum core followed by a steep fall, a plateau in the diluted regime and a Boltzmannian tail representing the halo. In contrast to purely Boltzmannian configurations the fermionic DM model containing a quantum core allows to determine the particle mass. We show that the quantum core can be well approximated by a polytrope of index n = 3/2, while the halo can be perfectly described by an isothermal sphere with a halo scale length radius equal to approximately 3/4 of the King-radius.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2019

Does the Excited Cluster {sup 14}N{sup *} Exist in the {sup 15}O Nucleus?

On the basis of the modified potential two-cluster model with forbidden state which effectively take the Pauli principle into account, calculations have been performed of the astrophysical S-factor of radiative p{sup 14}N capture to the ground state of the {sup 15}O nucleus at proton energies up to 5 MeV in the center-of-mass system (c.m.s.) with allowance for wide resonances up to 3.4 MeV in the c.m.s. For an acceptable explanation of the available experimental data it is necessary to allow the existence of the {sup 14}N cluster in the excited state {sup 14}N{sup *} at an excitation energy of 5.69 MeV and angular momentum J{sup π} = 1{sup –}. It is assumed that in such a case it is possible to use the wave function of the {sup 4}D{sub 1/2} state with respect to the relative motion of the p{sup 14}N{sup *} clusters. It is also shown that a description of the S-factor of p{sup 14}N capture in the resonance region is possible only under the assumption that all of the low-lying resonances at 260(1/2{sup +}), 987(3/2{sup +}), 1447(1/2{sup +}), 2187(3/2{sup +}), and 3211(3/2{sup +}) keV in the c.m.s. are {sup 4}D{sub 1/2} and {sup 4}D{sub 3/2} scattering waves.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2019

The role of the Heisenberg principle in constrained molecular dynamics model

In this study, we implement the Heisenberg principle into the Constrained Molecular Dynamics model with a similar approach to the Pauli principle using the one-body occupation probability $\bar{f}_i$. Results of the modified and the original model with comparisons to data are given. The binding energies and the radii of light nuclei obtained with the modified model are more consistent with the experimental data than the original one. The collision term and the density distribution are tested through a comparison to p+ 12 C elastic scattering data. Some simulations for fragmentation and superheavy nuclei production are also discussed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

Baryon Anticorrelations in PYTHIA

Abstract We present a computational investigation of a problem of hadron collisions from recent years, that of baryon anticorrelations. This is an experimental dearth of baryons near other baryons in phase space, not seen upon examining numerical Monte Carlo simulations. We have addressed one of the best known Monte Carlo codes, , to see what baryon (anti)correlations it produces, where they are originated at the string-fragmentation level in the underlying Lund model, and what simple modifications could lead to better agreement with data. We propose two ad-hoc alterations of the fragmentation code, a “one-baryon” and an “always-baryon” policies that qualitatively reproduce the data behaviour, i.e anticorrelation, and suggest that lacking Pauli-principle induced corrections at the quark level could be the culprit behind the current disagreement between computations and experiment.

Physics↗