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Proceedings of the Second International Conference on Precision Measurement and Fundamental Constants, June 8-12, 1981

Description: Abstract: This volume presents the Proceedings of the Second International Conference on Precision Measurement and Fundamental Constants, held at the National Bureau of Standards in Gaithersburg, MD, from June 8-12, 1981. Like its 1970 predecessor, the Conference provided an international forum for theoretical, experimental, and applied scientists actively engaged in research on precision measurements relating to the fundamental physical constants, and on the testing of related fundamental theory. More specifically, the purpose of the Conference was to assess the present state of the precision measurement-fundamental constants field, to examine basic limitations, and to explore the prospects for future significant advances. The principal subjects covered were: frequency, wavelength, spectroscopy, quantum electrodynamics, the gas constant, x-ray interferometry, nuclidic masses, uncertainty assignment, gravitational acceleration, mass, electrical quantities, gravity, and relativity. These proceedings contain the vast majority of both the invited review papers and the contributed current research papers presented at the Conference. The new results reported at the Conference were considered for inclusion in the 1983 least-squares adjustment of the constants carried out under the auspices of the Task Group on Fundamental Constants of the Committee on Data for Science and Technology (CODATA).
Date: August 1984
Creator: Taylor, B. N. & Phillips, William D.
Partner: UNT Libraries Government Documents Department

Computerized data base of the fundamental constants of nature

Description: Fifty-seven fundamental constants of nature were computerized from the up-to-date evaluations of E. R. Cohen and B. N. Taylor. The constants are annotated with regard to symbol, value, uncertainty, and scaling factor. This computerization is part of the scientific data base project of the Information Research Group at Lawrence Livermore Laboratory. The MASTER CONTROL data base management system is used. The computerized fundamental constants can be requested from the ERDA Computer Program Exchange and Information Center of the Argonne National Laboratory or from the National Technical Information Service of the U. S. Department of Commerce. This is the first of a series of releases on preparation of computerized scientific and technological data banks. The next release is a data bank of conversion factors for different units of measurements. 3 figures.
Date: December 1, 1975
Creator: Henry, E.A. & Hampel, V.E.
Partner: UNT Libraries Government Documents Department

The fundamental constants of nature from lattice gauge theory simulations

Description: The fundamental laws of nature as we now know them are governed the fundamental parameters of the Standard Model. Some of these, such as the masses of the quarks, have been hidden from direct observation by the confinement of quarks. They are now being revealed through large scale numerical simulation of lattice gauge theory.
Date: January 1, 2005
Creator: Mackenzie, Paul B.
Partner: UNT Libraries Government Documents Department

The fundamental and universal nature of Boltzmann`s constant

Description: The nature of Boltzmann`s constant is very unclear in the physics literature. In the first part of this paper, on general considerations, the authors examine this situation in detail and demonstrate the conclusion that Boltzmann`s constant is indeed both fundamental and universal. As a consequence of their development they find there is an important implication of this work for the problem of the entropy of information. In the second part they discuss, Szilard`s famous construction showing in detail how his result is incompatible with the demonstrations in both parts 1 and 2.
Date: July 1, 1996
Creator: Biedenharn, L.C. & Solem, J.C.
Partner: UNT Libraries Government Documents Department

Topological Quantization in Units of the Fine Structure Constant

Description: Fundamental topological phenomena in condensed matter physics are associated with a quantized electromagnetic response in units of fundamental constants. Recently, it has been predicted theoretically that the time-reversal invariant topological insulator in three dimensions exhibits a topological magnetoelectric effect quantized in units of the fine structure constant {alpha} = e{sup 2}/{h_bar}c. In this Letter, we propose an optical experiment to directly measure this topological quantization phenomenon, independent of material details. Our proposal also provides a way to measure the half-quantized Hall conductances on the two surfaces of the topological insulator independently of each other.
Date: November 11, 2011
Creator: Maciejko, Joseph; /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC; Qi, Xiao-Liang; /Station Q, UCSB /Stanford U., Phys. Dept. /Stanford U., Materials Sci. Dept. /SLAC; Drew, H.Dennis; U., /Maryland et al.
Partner: UNT Libraries Government Documents Department

A Different Look at Dark Energy and the Time Variation of Fundamental Constants

Description: This paper makes the simple observation that a fundamental length, or cutoff, in the context of Friedmann-Lemaitre-Robertson-Walker (FRW) cosmology implies very different things than for a static universe. It is argued that it is reasonable to assume that this cutoff is implemented by fixing the number of quantum degrees of freedom per co-moving volume (as opposed to a Planck volume) and the relationship of the vacuum-energy of all of the fields in the theory to the cosmological constant (or dark energy) is re-examined. The restrictions that need to be satisfied by a generic theory to avoid conflicts with current experiments are discussed, and it is shown that in any theory satisfying these constraints knowing the difference between w and minus one allows one to predict w. It is argued that this is a robust result and if this prediction fails the idea of a fundamental cutoff of the type being discussed can be ruled out. Finally, it is observed that, within the context of a specific theory, a co-moving cutoff implies a predictable time variation of fundamental constants. This is accompanied by a general discussion of why this is so, what are the strongest phenomenological limits upon this predicted variation, and which limits are in tension with the idea of a co-moving cutoff. It is pointed out, however, that a careful comparison of the predicted time variation of fundamental constants is not possible without restricting to a particular model field-theory and that is not done in this paper.
Date: February 7, 2011
Creator: Weinstein, Marvin
Partner: UNT Libraries Government Documents Department

Workshop Summary: Fundamental Neutron Physics in the United States: An Opportunity in Nuclear, Particle, and Astrophysics for the Next Decade

Description: Low-energy neutrons from reactor and spallation neutron sources have been employed in a wide variety of investigations that shed light on important issues in nuclear, particle, and astrophysics; in the elucidation of quantum mechanics; in the determination of fundamental constants; and in the study of fundamental symmetry violation (Appendix A, Glossary). In many cases, these experiments provide important information that is not otherwise available from accelerator-based nuclear physics facilities or high energy accelerators. An energetic research community in the United States is engaged in ''fundamental'' neutron physics. With exciting recent results, the possibility of new and upgraded sources, and a number of new experimental ideas, there is an important opportunity for outstanding science in the next decade. ''Fundamental'' neutron physics experiments are usually intensity limited. Researchers require the highest flux neutron sources available, which are either high-flux reactors (continuous sources) or spallation neutron sources (pulsed sources). The primary mission of these major facilities is neutron scattering for materials science research. Notwithstanding this condensed matter focus, essentially all neutron scattering facilities have accepted the value of an on-site fundamental physics program and have typically allocated 5 to 10% of their capabilities (i.e., beam lines) toward nuclear and particle physics research activities.
Date: August 24, 2001
Creator: Greene, G.
Partner: UNT Libraries Government Documents Department

On the measuremnt of. pi

Description: Inspired by Stillman Drake's definition of Galilean Units as those for which (L/T{sup 2} = ({pi}{sup 2}/8)g) where g is any finite, constant acceleration measured in units of L and T, we construct a kinematical dimensional analysis based only on two universal, dimensionless constants. For the linear relation between L and T we use Einsteinian Units L/ = (1)c. For orbiting masses negligible compared to some mass unit M, we use Keplerian Units based on his second law (L{sup 2}/T = (1/2{pi})h/M). Then the unit for orbital angular momentum is {Dirac h}, independent of the mass scale. This allows us to define dimensionless coupling constants f{sup 2} = {beta} = v/c where v is the orbital velocity. We find that most of relativistic quantum mechanics requires only kinematical units. Dynamical units require a mass scale with universal significance, set by the orbital velocity v = c (or f{sup 2} = 1). In dimensional form this becomes M = (1)({Dirac h}c/G){sup 1/2}. Assuming baryon number conservation, the fact that the proton is the lightest stable baryon allows us to calculate {Dirac h}c/Gm{sub p}{sup 2} {approx} 1.7 {times} 10{sup 38} as the Beckenstein number of the proton--the number of bits of information lost in its formation--and connects our units to the elementary particle mass scale.
Date: February 1, 1992
Creator: Noyes, H.P.
Partner: UNT Libraries Government Documents Department

Comparison of IUPAC k0 Values and Neutron Cross Sections to Determine a Self-consistent Set of Data for Neutron Activation Analysis

Description: Independent databases of nuclear constants for Neutron Activation Analysis (NAA) have been independently maintained by the physics and chemistry communities for many year. They contain thermal neturon cross sections s0, standardization values k0, and transition probabilities Pg. Chemistry databases tend to rely upon direct measurements of the nuclear constants k0 and Pg which are often published in chemistry journals while the physics databases typically include evaluated s0 and Pg data from a variety of experiments published mainly in physics journals. The IAEA/LBNL Evaluated Gamma-ray Activation File (EGAF) also contains prompt and delayed g-ray cross sections sg from Prompt Gamma-ray Activation Analysis (PGAA) measurements that can also be used to determine k0 and s0 values. As a result several independent databases of fundamental constants for NAA have evolved containing slightly different and sometimes discrepant results. An IAEA CRP for a Reference Database for Neutron Activation Analysis was established to compare these databases and investigate the possibilitiy of producing a self-consistent set of s0, k0, sg, and Pg values for NAA and other applications. Preliminary results of this IAEA CRP comparison are given in this paper.
Date: December 1, 2009
Creator: Firestone, Richard B & Revay, Zsolt
Partner: UNT Libraries Government Documents Department

ENAM'04 Fourth International Conference on Exotic Nuclei and Atomic Masses

Description: The conference can trace its origins to the 1950s and 1960s with the Atomic Mass and Fundamental Constants (AMCO) and the Nuclei Far From Stability (NFFS) series of conferences. Held jointly in 1992, the conferences officially merged in 1995 and the fourth conference was held at Callaway Gardens in Pine Mountain, GA and was organized by the Physics Division at Oak Ridge National Laboratory. The conference covered a broad list of topics consisting of a series of invited and contributed presentation highlighting recent research in the following fields: Atomic masses, nuclear moments, and nuclear radii; Forms of radioactivity; Nuclear structure, nuclei at the drip lines, cluster phenomena; Reactions with radioactive ion beams; Nuclear astrophysics; Fundamental symmetries and interactions; Heaviest elements and fission; Radioactive ion beam production and experimental developments; Applications of exotic nuclei
Date: January 1, 2005
Creator: Gross, C. J.; Nazarewicz, W. & Rykaczewski, K. P.
Partner: UNT Libraries Government Documents Department

Nonperturbative estimates of the Standard Model parameters

Description: This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objectives were (1) to develop highly optimized codes for the simulation of lattice Quantum Chromodynamics (QCD) on the Connection Machine CM-5, (2) to use these codes to carry out a comprehensive analysis of Standard Model phenomenology using a large statistical sample, and (3) to combine the results of numerical simulations with experimental data to estimate the unknown parameters of the Standard Model. We were successful in achieving all these goals. Our highly optimized codes were used to debug both the hardware and software of the CM-5. We carried out a comprehensive study of the hadron spectrum, decay constants for mesons, semi- leptonic form factors, form-factors for the rare decay B {r_arrow} K{sup *} {gamma}, {pi}-{pi} scattering amplitude, and matrix elements of a variety of 4-fermion weak operators. From these observables we were able to predict the masses of light quarks, m{sub u} + m{sub d} and m{sub s}, matrix elements of the Cabibbo-Kobayashi-Maskawa mixing matrix, and the CP violating parameters {epsilon} and {epsilon}{prime}. Our new estimates of light-quark masses are roughly half of commonly believed values, and we predict a much larger value for {epsilon}{prime}/{epsilon}, which will be tested experimentally over the next few years. 15 refs.
Date: August 1, 1997
Creator: Gupta, R.; Bhattacharya, T.; Tamayo, P.; Grandy, T.; Kilcup, G. & Sharpe, S.
Partner: UNT Libraries Government Documents Department

Effect of the choice of wave functions on theoretical predictions for symmetry breaking processes: a view from the DKP formalism

Description: When considering an elementary particle matrix element, of necessity one must make an assumption, which often goes unnoticed, as to what formalism should be used for the wave functions. A current or interaction Lagrangian-density matrix-element is of the form V = anti psi/sub out/GAMMA psi/sub in/, where psi/sub in/ and anti psi/sub out/ represent the physical ingoing and outgoing particles, and GAMMA represents the vertex function. A current must have the dimensions of (length)/sup -3/ = (mass)/sup 3/ in units of h = c = 1. psi/sub in/ and anti psi/sub out/ must be described in terms of the physical on-shell masses or else one has no phase space. It is only the vertex function which can be symmetric in the internal symmetry under consideration. The decision as to how much of the matrix element will be taken to be symmetric and how much of the matrix element will be taken to be associated with on-mass-shell wave functions is a fundamental assumption. Depending on how the assumption is made, different results will be predicted. Normally first-order Dirac wave functions, with dimensions (length)/sup -3///sup 2/ and second-order Klein--Gordon wave functions with dimensions (length)/sup -1/ are considered for spin-/sup 1///sub 2/ fermions and spin-O bosons, respectively. The types of new results which are obtained if, on the contrary, one chooses to consider bosons in the first-order Duffin--Kemmer--Petiau formalism are discussed. It is argued that the DKP formalism represents a complementary viewpoint to the spectrum generating approach. Both challenge the standard phenomenology: DKP by changing the wave function, spectrum generating by changing the vertex function.
Date: January 1, 1978
Creator: Nieto, M.M.
Partner: UNT Libraries Government Documents Department