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A Method to Quantify the Radiation Characteristics of an Unknown Interference Source

Description: From introduction: A new method for determining the radiation characteristics of leakage from electronic equipment for interference studies is described in this report. Basically, an unintentional leakage source is considered to be electrically small, and may be characterized by three equivalent orthogonal electric dipole moments and three equivalent orthogonal magnetic dipole moments. When an unknown source object is placed at the center of a transverse electromagnetic (TEM) cell, its radiated energy couples into the fundamental transmission mode and propagates toward the two output ports of the TEM cell. With a hybrid junction inserted into a loop connecting the cell output ports, one is able to measure the sum and difference powers and the relative phase between the sum and difference outputs. Systematic measurements of these powers and phases at six different source object positions, based on a well-developed theory, are sufficient to determine the amplitudes and phases of the unknown component dipole moments, from which the detailed free-space radiation pattern of the unknown source and the total radiated power can be determined. Results of simulated theoretical examples and an experiment using a spherical dipole radiator are given to illustrate the theory and measurement procedure.
Date: October 1982
Creator: Ma, Mark T. & Koepke, Galen H.
Partner: UNT Libraries Government Documents Department

Dipole Moments of Diphenyl Compounds with Conjugated Double Bonds

Description: This thesis is a continuation of a study of molecular moments begun by Joseph T. Fielder. In his paper he discussed the theory and the equipment necessary for such a study. It is the purpose of this paper to set forth modifications of his equipment, to present data obtained with this modified equipment, and to interpret this data.
Date: 1950
Creator: Spalding, Dan W.
Partner: UNT Libraries

Direct Measurement of the Neutral Weak Dipole Moments of the tau Lepton

Description: We present direct measurements of the neutral weak anomalous magnetic dipole moment, a{sub {tau}}{sup w}, and neutral weak electric dipole moment, d{sub {tau}}{sup w}, of the tau lepton. The dipole moments are measured by analyzing the decays of {tau} leptons produced in the annihilation of positrons and longitudinally polarized electrons on the Z boson resonance at the SLC. Using 6736 Z decays to {tau}{sup +} {tau}{sup {minus}} pairs elected from our 1993-1998 data sample we obtain Re(a{sub {tau}}{sup w}) = (0.26 {+-} 1.24) x 10{sup {minus}3}, Im(a{sub {tau}}{sup w}) = ({minus}0.02 {+-} 0.66) x 10{sup {minus}3}, Re(d{sub {tau}}{sup w}) = (0.18 {+-} 0.67) x 10 {sup {minus}17} e {center_dot} cm, and Im(D{sub {tau}}{sup w}) = ({minus}0.26 {+-} 0.37) x 10{sup {minus}17} e {center_dot} cm.
Date: July 16, 1999
Creator: Barklow, Tim
Partner: UNT Libraries Government Documents Department

Search for anomalous couplings in the decay of polarized Z bosons to tau lepton pairs

Description: Using a sample of 4,500 polarized Z decays to {tau} lepton pairs accumulated with the SLD detector at the SLAC Linear Collider (SLC) in 1993-95, a search has been made for anomalous couplings in the neutral current reaction e{sup +}e{sup {minus}}{yields}{tau}{sup +}{tau}{sup {minus}}. A measurement of the CP violating Weak Electric Dipole Moment (WEDM) and the CP conserving Weak Magnetic Dipole Moment (WMDM) of the {tau} lepton has been performed by considering the transverse spin polarization of {tau} leptons produced at the Z pole. Using a maximum likelihood technique, the observed {tau} decay spectra in the e, {mu}, {pi}, and {rho} decay channels are used to infer the net transverse polarization of the underlying tau leptons, and a fit for the anomalous dipole moments is performed. No evidence for these dipole movements is observed, and limits are placed on both the real and imaginary parts of the WEDM and WMDM.
Date: June 1, 1997
Creator: Torrence, E.C.
Partner: UNT Libraries Government Documents Department

MUON G-2 AND ELECTRIC DIPOLE MOMENTS IN STORAGE RINGS: POWERFUL PROBES OF PHYSICS BEYOND THE STANDARD MODEL.

Description: We have shown that the study of dipole moments, both magnetic and electric, in storage rings offer unique opportunities in probing physics beyond the Standard Model (SM). Both methods use similar techniques (particle and spin precession in magnetic storage rings). We are currently investigating the systematic errors associated with the resonance electric dipole moment (EDM) method. So far it looks very promising.
Date: May 23, 2005
Creator: SEMERTZIDIS, Y.K.
Partner: UNT Libraries Government Documents Department

Anisotropy in CdSe quantum rods

Description: The size-dependent optical and electronic properties of semiconductor nanocrystals have drawn much attention in the past decade, and have been very well understood for spherical ones. The advent of the synthetic methods to make rod-like CdSe nanocrystals with wurtzite structure has offered us a new opportunity to study their properties as functions of their shape. This dissertation includes three main parts: synthesis of CdSe nanorods with tightly controlled widths and lengths, their optical and dielectric properties, and their large-scale assembly, all of which are either directly or indirectly caused by the uniaxial crystallographic structure of wurtzite CdSe. The hexagonal wurtzite structure is believed to be the primary reason for the growth of CdSe nanorods. It represents itself in the kinetic stabilization of the rod-like particles over the spherical ones in the presence of phosphonic acids. By varying the composition of the surfactant mixture used for synthesis we have achieved tight control of the widths and lengths of the nanorods. The synthesis of monodisperse CdSe nanorods enables us to systematically study their size-dependent properties. For example, room temperature single particle fluorescence spectroscopy has shown that nanorods emit linearly polarized photoluminescence. Theoretical calculations have shown that it is due to the crossing between the two highest occupied electronic levels with increasing aspect ratio. We also measured the permanent electric dipole moment of the nanorods with transient electric birefringence technique. Experimental results on nanorods with different sizes show that the dipole moment is linear to the particle volume, indicating that it originates from the non-centrosymmetric hexagonal lattice. The elongation of the nanocrystals also results in the anisotropic inter-particle interaction. One of the consequences is the formation of liquid crystalline phases when the nanorods are dispersed in solvent to a high enough concentration. The preparation of the stable liquid crystalline solution of CdSe nanorods ...
Date: September 1, 2003
Creator: Li, Liang-shi
Partner: UNT Libraries Government Documents Department

Possible mechanism of formation and stability of anomalous states of water

Description: The authors examine the physical processes which are involved in the formation and stability of the anomalous states of water reported recently. The initial step of adding a small amount of ionic compound X{sup +}Y{sup {minus}} to pure water leads t the formation of water clusters X{sup +} (H{sub 2}O){sub n} and Y{sup {minus}} (H{sub 2}O){sub n} with n {much_gt} 1. The structure of the cluster around the ion depends sensitively on the equation of state. The authors explore the consequences of possible polymorphic states of H{sub 2}O in the liquid phase at room temperature. If there are low-lying polymorphic states, the local dipole moment and the local density will change discontinuously as a function of the radial distance from the ion, and regions of different polymorphic states will be found at different separations from the ion. Fragmentation of the cluster by vigorous shaking may break up the cluster into small domains to allow subsequent coalescence of these domains or the growth of the domains as seeds to form greater domains of polymorphic states. Further experimental and theoretical analyses are needed to study these pictures.
Date: January 1, 1998
Creator: Wong, C.Y. & Lo, S.Y.
Partner: UNT Libraries Government Documents Department

Flavor Structure of Warped Extra Dimension Models

Description: We recently showed, in hep-ph/0406101, that warped extra dimensional models with bulk custodial symmetry and few TeV KK masses lead to striking signals at B-factories. In this paper, using a spurion analysis, we systematically study the flavor structure of models that belong to the above class. In particular we find that the profiles of the zero modes, which are similar in all these models, essentially control the underlying flavor structure. This implies that our results are robust and model independent in this class of models. We discuss in detail the origin of the signals in B-physics. We also briefly study other NP signatures that arise in rare K decays (K {yields} {pi}{nu}{nu}), in rare top decays [t {yields} c{gamma}(Z, gluon)] and the possibility of CP asymmetries in D{sup 0} decays to CP eigenstates such as K{sub s}{pi}{sup 0} and others. Finally we demonstrate that with light KK masses, {approx} 3 TeV, the above class of models with anarchic 5D Yukawas has a ''CP problem'' since contributions to the neutron electric dipole moment are roughly 20 times larger than the current experimental bound. Using AdS/CFT correspondence, these extra-dimensional models are dual to a purely 4D strongly coupled conformal Higgs sector thus enhancing their appeal.
Date: August 10, 2004
Creator: Agashe, Kaustubh; Perez, Gilad & Soni, Amarjit
Partner: UNT Libraries Government Documents Department

B-factory signals for a warped extra dimension

Description: We study predictions for B-physics in a class of models, recently introduced, with a non-supersymmetric warped extra dimension. In these models few ({approx} 3) TeV Kaluza-Klein masses are consistent with electroweak data due to bulk custodial symmetry. Furthermore, there is an analog of GIM mechanism which is violated by the heavy top quark (just as in SM) leading to striking signals at B-factories: (1) New Physics (NP) contributions to {Delta}F = 2 transitions are comparable to SM. This implies that, within this NP framework, the success of the SM unitarity triangle fit is a ''coincidence''. Thus, clean extractions of unitarity angles via e.g. B {yields} {pi}{pi}, {rho}{pi}, {rho}{rho}, DK are likely to be affected, in addition to O(1) deviation from SM prediction in Bs mixing. (2) O(1) deviation from SM predictions for B {yields} X{sub s}{ell}{sup +}{ell}{sup -} in rate as well as in forward-backward and direct CP asymmetry. (3) Large mixing-induced CP asymmetry in radiative B decays, wherein the SM unambiguously predicts very small asymmetries. Also, with KK masses 3 TeV or less, and with anarchic Yukawa masses, contributions to electric dipole moments of the neutron are roughly 20 times larger than the current experimental bound so that this framework has a ''CP problem''.
Date: August 24, 2004
Creator: Agashe, Kaustubh; Perez, Gilad & Soni, Amarjit
Partner: UNT Libraries Government Documents Department

A new-generation EM system for the detection and classification of buried metallic objects

Description: A prime requirement in discrimination between UXO and non-UXO metallic fragments (clutter) is to determine accurately the response parameters that characterize a metallic object in the ground. Lawrence Berkeley National Laboratory has been involved in assessing and comparing existing systems, and designing an optimum system for UXO detection. A prototype of a new electromagnetic system will be built based on the results of this study. The detection and characterization of metallic objects can be considered a two-step process: location and identification. A multi-component transmitter-receiver system is essential for the identifying of the principal dipole moments of a target. The ground response imposes an early time limit on the time window available for target discrimination. Once the target response falls below the ground response, it will be poorly resolved, especially since the ground response itself will be variable due to the inhomogeneous nature of the near surface. For a given range of targets and given ambient noise characteristics, one can optimize system bandwidth so as to maximize the observable signal-to-noise ratio. A sensor with four or more decades of flat frequency response is needed to record the secondary magnetic fields associated with the target.
Date: June 1, 2003
Creator: Gasperikova, Erika
Partner: UNT Libraries Government Documents Department

Spacetime geodesy and the LAGEOS-3 satellite experiment

Description: This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). LAGEOS-1 is a dense spherical satellite whose tracking accuracy is such as to yield a medium-term inertial reference frame and that is used as an adjunct to more difficult and more data-intensive absolute frame measurements. LAGEOS-3, an identical satellite to be launched into an orbit complementary to that of LAGEOS-1, would experience an equal and opposite classical precession to that of LAGEOS- 1. Besides providing a more accurate real-time measurement of the earth`s length of day and polar wobble, this paired-satellite system would provide the first direct measurement of the general relativistic frame-dragging effect. Of the five dominant error sources in this experiment, the largest one involves surface forces on the satellite and their consequent impact on the orbital nodal precession. The surface forces are a function of the spin dynamics of the satellite. We have modeled the spin dynamics of a LAGEOS-type satellite and used this spin model to estimate the impact of the thermal rocketing effect on the LAGEOS-3 experiment. We have also performed an analytic tensor expansion of Synge`s world function to better reveal the nature of the predicted frame-dragging effect. We showed that this effect is not due to the Riemann curvature tensor, but rather is a ``potential effect`` arising from the acceleration of the world lines in the Kerr spacetime geometry.
Date: April 1, 1996
Creator: Miller, W.A.; Chen, Kaiyou; Habib, S.; Kheyfets, A. & Holz, D.E.
Partner: UNT Libraries Government Documents Department

Constraints on anomalous top quark couplings at the LHC

Description: Measurements of distributions associated with the pair production of top quarks at the LHC can be used to constrain (or observe) the anomalous chromomagnetic dipole moment(k) of the top. For example, using either the tt(bar) invariant mass or the Pt distribution of top we find that sensitivities to ; k; of order 0.05 are obtainable with 100 /fb of integrated luminosity. This is similar in magnitude to what can be obtained at a 500 GeV NLC with an integrated luminosity of 50 /fb through an examination of the e(+)e(-) right arrow tt(bar)g process.
Date: September 1, 1996
Creator: Rizzo, T.G.
Partner: UNT Libraries Government Documents Department

Fermion masses and anomalous dipole moments

Description: Fermion mass generation via quantum loops is briefly described. The potential for large anomalous dipole moments, {delta}a{sub f} {approx_equal} m{sub f}{sup 2}/M{sup 2}, in such schemes is demonstrated. Implications for the muon`s anomalous magnetic moment as well as the top quark`s chromo and electroweak moments are discussed.
Date: August 1, 1995
Creator: Marciano, W.J.
Partner: UNT Libraries Government Documents Department

Intermolecular potential functions and high resolution molecular spectroscopy of weakly bound complexes. Final progress report

Description: This report describes accomplishments over the past year in research supported by this grant. Two papers published in this period are briefly discussed. The general goal of the work is to consolidate the understanding of experimental results through a theoretical model of intermolecular potential energy surfaces. Progress in the experimental and theoretical phases of the program are presented and immediate goals outlined. The ability to construct analytic intermolecular potential functions that accurately predict the energy of interaction between small molecules will have great impact in many areas of chemistry, biochemistry, and biology.
Date: April 1, 1997
Creator: Muenter, J.S.
Partner: UNT Libraries Government Documents Department

Low scale seesaw, electron EDM and leptogenesis in a model with spontaneous CP violation

Description: Strong correlations between leptogenesis and low energy CP violating leptonic processes have been shown by us to exist fin the minimal left-right symmetric model with spontaneous CP violation. In this note, they investigate the implications of this model for the electric dipole moment of the electron. With an additional broken U(1){sub H} symmetry, the seesaw scale can be lowered to close to the electroweak scale. This additional symmetry also makes the connection between CP violation in quark sector to that in the lepton sector possible.
Date: September 1, 2006
Creator: Chen, Mu-Chun; /Fermilab /UC, Irvine; Mahanthappa, K.T. & U., /Colorado
Partner: UNT Libraries Government Documents Department

New search for the neutron electric dipole moment

Description: We report on a new experiment to search for the neutron electric dipole moment which has the potential ta lower the current limit by a factor of 50 to 100. A unique approach to this measurement is described including the results of recent measurements at LANSCE of the mass diffusion coefficient for 3He in superfluid 4He.
Date: January 1, 2002
Creator: Barnes, Peter D.
Partner: UNT Libraries Government Documents Department

RESONANCE METHOD OF ELECTRIC-DIPOLE-MOMENT MEASUREMENTS IN STORAGE RINGS.

Description: A ''resonance method'' of measuring the electric dipole moment (EDM) of nuclei in storage rings is described, based on two new ideas: (1) Oscillating particles velocities in resonance with spin precession, and (2) alternately producing two sub-beams with different betatron tunes--one sub-beam to amplify and thus make it easier to correct ring imperfections that produce false signals imitating EDM signals, and the other to make the EDM measurement.
Date: May 10, 2006
Creator: ORLOV, Y.F.; MORSE, W.M. & SEMERTZIDIS, Y.K.
Partner: UNT Libraries Government Documents Department

THE PROTOTYPE ALUMINUM - CARBON SINGLE, DOUBLE, AND TRIPLE BONDS: Al - CH3, Al = CH2, AND Al. = CH

Description: Nonempirical quantum mechanical methods have been used to investigate the A{ell}CH{sub 3}, A{ell}CH{sub 2}, and A{ell}CH molecules, which may be considered to represent the simplest aluminum-carbon single, double, and triple bonds. Equilibrium geometries and vibrational frequencies were determined at the self-consistent-field level of theory using double zeta basis set: A{ell}(11s7p/6s4p), C(9s5p/4s2p), H(4s/2s). The {sup 1}A{sub 1} ground state of A{ell}CH{sub 3} has a reasonably conventional A{ell}-C single bond of length 2.013 {angstrom}, compared to 1.96 {angstrom} in the known molecule A{ell}(CH{sub 3}){sub 3}. The CH equilibrium distance is 1.093 {angstrom} and the A{ell}-C-H angle 111.9{sup o}. The structures of three electron states each of A{ell}CH{sub 2} and A{ell}CH were similarly predicted, The interesting result is that the ground state of A{ell}CH{sub 2} does not contain an A{ell}-C double bond, and the ground state of A{ell}CH is not characterized by an A{ell}{triple_bond}C bond. The multiply-bonded electronic states do exist but they lie 21 kcal (A{ell}CH{sub 2}) and 86 kcal (A{ell}CH) above the respective ground states. The dissociation energies of the three ground electronic states are predicted to be 68 kcal (A{ell}CH{sub 3}), 77 kcal (A{ell}CH{sub 2}), and 88 kcal (A{ell}CH), Vibrational frequencies are also predicted for the three molecules, and their electronic structures are discussed with reference to Mulliken populations and dipole moments.
Date: June 1, 1980
Creator: Fox, Douglas J.; Ray, Douglas; Rubesin, Philip C. & Schaefer III, Henry F.
Partner: UNT Libraries Government Documents Department

Detection of bacteria in suspension using a superconducting Quantum interference device

Description: We demonstrate a technique for detecting magnetically-labeled Listeria monocytogenes and for measuring the binding rate between antibody-linked magnetic particles and bacteria. This assay, which is both sensitive and straightforward to perform, can quantify specific bacteria in a sample without the need to immobilize the bacteria or wash away unbound magnetic particles. In the measurement, we add 50 nm diameter superparamagnetic particles, coated with antibodies, to a liquid sample containing L. monocytogenes. We apply a pulsed magnetic field to align the magnetic dipole moments and use a high transition temperature Superconducting Quantum Interference Device (SQUID), an extremely sensitive detector of magnetic flux, to measure the magnetic relaxation signal when the field is turned off. Unbound particles randomize direction by Brownian rotation too quickly to be detected. In contrast, particles bound to L. monocytogenes are effectively immobilized and relax in about 1 s by rotation of the internal dipole moment. This Neel relaxation process is detected by the SQUID. The measurements indicate a detection limit of (5.6 {+-} 1.1) x 10{sup 6} L. monocytogenes for a 20 {micro}L sample volume. If the sample volume were reduced to 1 nL, we estimate that the detection limit could be improved to 230 {+-} 40 L. monocytogenes cells. Time-resolved measurements yield the binding rate between the particles and bacteria.
Date: June 9, 2003
Creator: Grossman, H.L.; Myers, W.R.; Vreeland, V.J.; Alper, J.D.; Bertozzi, C.R. & Clarke, J.
Partner: UNT Libraries Government Documents Department

The Astromag Superconducting Magnet Facility Configured for a FreeFlying Satellite

Description: ASTROMAG is a particle astrophysics facility that was originally configured for the Space Station. The heart of the ASTROMAG facility is a large superconducting magnet which is cooled using superfluid helium. The task of resizing the facility so that it will fly in a satellite in. a high angle of inclination orbit is driven by the launch weight capability of the launch rocket and the desire to be able to do nearly the same physics as the Space Station version of ASTROMAG. In order to reduce the launch weight, the magnet and its cryogenic system had to be downsized, yet the integrated field generated by the magnet in the particle detectors has to match the Space Station version of the magnet. The use of aluminum matrix superconductor and oriented composite materials in the magnet insulation permits one to achieve this goal. The net magnetic dipole moment from the ASTROMAG magnet must be small to minimize the torque due to interaction with the earth's magnetic field. The ASTROMAG magnet consists of identical two coils 1.67 meters apart. The two coils are connected in series in persistent mode. Each coil is designed to carry 2.34 million ampere turns. Both coils are mounted on the same magnetic axis and they operate at opposite polarity. This reduces the dipole moment by a factor of more than 1000. This is tolerable for the Space Station version of the magnet. A magnet operating on a free flying satellite requires additional compensation. This report presents the magnet parameters of a free flying version of ASTROMAG and the parameters of the space cryogenic system for the magnet.
Date: June 1, 1991
Creator: Green, M.A. & Smoot, George F.
Partner: UNT Libraries Government Documents Department

The effect of microhydration on ionization energies of thymine

Description: A combined theoretical and experimental study of the effect of microhydration on ionization energies (IEs) of thymine is presented. The experimental IEs are derived from photoionization efficiency curves recorded using tunable synchrotron VUV radiation. The onsets of the PIE curves are 8.85+-0.05, 8.60+-0.05, 8.55+-0.05, and 8.40+-0.05 eV for thymine, thymine mono-, di-, and tri-hydrates, respectively. The computed (EOM-IP-CCSD/cc-pVTZ) AIEs are 8.90, 8.51, 8.52, and 8.35 eV for thymine and the lowest isomers of thymine mono-, di-, and tri-hydrates. Due to large structural relaxation, the Franck-Condon factors for the 0<-- 0 transitions are very small shifting the apparent PIE onsets to higher energies. Microsolvation strongly affects IEs of thymine -- addition of each water molecule reduces the first vertical IE by 0.10-0.15 eV. The adiabatic IE decreases even more (up to 0.4 eV). The magnitude of the effect varies for different ionized states and for different isomers. For the ionized states that are localized on thymine the dominant contribution to the IE reduction is the electrostatic interaction between the delocalized positive charge on thymine and the dipole moment of the water molecule.
Date: January 3, 2011
Creator: Khistyev, Kirill; Bravaya, Ksenia B.; Kamarchik, Eugene; Kostko, Oleg; Ahmed, Musahid & Krylov, Anna I.
Partner: UNT Libraries Government Documents Department