Enhanced and tunable electric dipole-dipole interactions near a planar metal film

Science.gov (United States)

Zhou, Lei-Ming; Yao, Pei-Jun; Zhao, Nan; Sun, Fang-Wen

2017-08-01

We investigate the enhanced electric dipole-dipole interaction of surface plasmon polaritons (SPPs) supported by a planar metal film waveguide. By taking two nitrogen-vacancy (NV) center electric dipoles in diamond as an example, both the coupling strength and collective relaxation of two dipoles are studied with the numerical Green Function method. Compared to two-dipole coupling on a planar surface, metal film provides stronger and tunable coupling coefficients. Enhancement of the interaction between coupled NV center dipoles could have applications in both quantum information and energy transfer investigation. Our investigation provides systematic results for experimental applications based on a dipole-dipole interaction mediated with SPPs on a planar metal film.

Dipole-dipole interaction of dust grains in plasmas

International Nuclear Information System (INIS)

Tskhakaya, D.D.; Shukla, P.K.

2005-01-01

Complete screening of the negative dust grain charge by a cloud of trapped ions in plasmas is investigated. In the external electric field, the compound dust particle - 'dust grain + ion cloud' acquires a dipole moment due to displacement of the centers of positive and negative charges in the opposite directions. By analogy to the Van der Waals potential, the dipole-dipole interaction of the compound dust particles can have an attractive behavior. It is shown that the dipole-dipole attractive force can exceed the shadowing force that is connected with the reciprocal interception of ions by the neighboring dust grains

Permanent dipole moments and damping in nonlinear optics. A quantum electrodynamic description

International Nuclear Information System (INIS)

Davila-Smith, L.C.

1999-01-01

Based on the well-known transformation of the electric-dipole interaction, different nonlinear optical processes are analysed. The transformation provides a convenient means for ascertaining the effects of permanent dipoles on the optical behaviour of systems with a response dominated by two energy levels. By establishing the general validity of the procedure for parametric and non-parametric processes, it is shown how the detailed structure of the optical nonlinearity can be ascertained, based on a novel interpretation of the relevant quantum electrodynamical Feynman diagrams. This transformation is used to analysed a novel five-wave mixing process, which is also developed in this thesis. This process is of considerable interest for its involvement in the generation of even harmonics in isotropic media. Also, the flexibility in the beam geometry affords considerable scope for the study of the polarisation and angular dependence. Finally, a general study of the effects of resonance in matter-radiation interactions is given, justifying the phenomenological incorporation of the damping addenda. The two alternative convention used when the damping is introduced are discussed, showing that both conventions lead to different physical results. Based on these studies the resonance effects are considered in relation to different multiphoton processes. (author)

Inhibition of two-photon absorption due to dipole-dipole interaction in nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London, N6A 3K7 (Canada)], E-mail: msingh@uwo.ca

2008-07-21

We have investigated the inhibition of two-photon absorption in photonic crystals doped with an ensemble of four-level nanoparticles. The particles are interacting with one another by the dipole-dipole interaction. Dipoles in nanoparticles are induced by a selected transition. Numerical simulations have been performed for an isotropic photonic crystal. Interesting phenomena have been predicted such as the inhibition of the two-photon absorption due to the dipole-dipole interaction. It has also been found that the inhibition effect can be switched on and off by tuning a decay resonance energy within the energy band of the crystal. A theory of dressed states has been used to explain the results.

Dipole-dipole van der Waals interaction in alkali halides

International Nuclear Information System (INIS)

Thakur, B.N.; Thakur, K.P.

1978-01-01

Values of van der Waals dipole-dipole constants and interaction energetics of alkali halides are reported using the recent data. The values obtained are somewhat larger than those of earlier workers. (orig.) [de

Ab initio study of the RbSr electronic structure: Potential energy curves, transition dipole moments, and permanent electric dipole moments

Energy Technology Data Exchange (ETDEWEB)

Pototschnig, Johann V., E-mail: johann.pototschnig@tugraz.at; Krois, Günter; Lackner, Florian; Ernst, Wolfgang E., E-mail: wolfgang.ernst@tugraz.at [Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz (Austria)

2014-12-21

Excited states and the ground state of the diatomic molecule RbSr were calculated by post Hartree-Fock molecular orbital theory up to 22 000 cm{sup −1}. We applied a multireference configuration interaction calculation based on multiconfigurational self-consistent field wave functions. Both methods made use of effective core potentials and core polarization potentials. Potential energy curves, transition dipole moments, and permanent electric dipole moments were determined for RbSr and could be compared with other recent calculations. We found a good agreement with experimental spectra, which have been obtained recently by helium nanodroplet isolation spectroscopy. For the lowest two asymptotes (Rb (5s {sup 2}S) + Sr (5s4d {sup 3}P°) and Rb (5p {sup 2}P°) + Sr (5s{sup 2} {sup 1}S)), which exhibit a significant spin-orbit coupling, we included relativistic effects by two approaches, one applying the Breit-Pauli Hamiltonian to the multireference configuration interaction wave functions, the other combining a spin-orbit Hamiltonian and multireference configuration interaction potential energy curves. Using the results for the relativistic potential energy curves that correspond to the Rb (5s {sup 2}S) + Sr (5s4d {sup 3}P°) asymptote, we have simulated dispersed fluorescence spectra as they were recently measured in our lab. The comparison with experimental data allows to benchmark both methods and demonstrate that spin-orbit coupling has to be included for the lowest states of RbSr.

Ab initio study of the RbSr electronic structure: potential energy curves, transition dipole moments, and permanent electric dipole moments.

Science.gov (United States)

Pototschnig, Johann V; Krois, Günter; Lackner, Florian; Ernst, Wolfgang E

2014-12-21

Excited states and the ground state of the diatomic molecule RbSr were calculated by post Hartree-Fock molecular orbital theory up to 22 000 cm(-1). We applied a multireference configuration interaction calculation based on multiconfigurational self-consistent field wave functions. Both methods made use of effective core potentials and core polarization potentials. Potential energy curves, transition dipole moments, and permanent electric dipole moments were determined for RbSr and could be compared with other recent calculations. We found a good agreement with experimental spectra, which have been obtained recently by helium nanodroplet isolation spectroscopy. For the lowest two asymptotes (Rb (5s (2)S) + Sr (5s4d (3)P°) and Rb (5p (2)P°) + Sr (5s(2) (1)S)), which exhibit a significant spin-orbit coupling, we included relativistic effects by two approaches, one applying the Breit-Pauli Hamiltonian to the multireference configuration interaction wave functions, the other combining a spin-orbit Hamiltonian and multireference configuration interaction potential energy curves. Using the results for the relativistic potential energy curves that correspond to the Rb (5s (2)S) + Sr (5s4d (3)P°) asymptote, we have simulated dispersed fluorescence spectra as they were recently measured in our lab. The comparison with experimental data allows to benchmark both methods and demonstrate that spin-orbit coupling has to be included for the lowest states of RbSr.

Collisional transfer of coherence by electric dipole-dipole interaction

OpenAIRE

Gough , W.

1983-01-01

An expression is derived for the contribution from dipole-dipole interaction to the intensity of sensitized fluorescence, from the results of a theory by Chiu. Tensor operator methods are used. The degree of polarization is deduced for certain particular cases.

Electronic properties of graphene nano-flakes: Energy gap, permanent dipole, termination effect, and Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Singh, Sandeep Kumar, E-mail: SandeepKumar.Singh@uantwerpen.be; Peeters, F. M., E-mail: Francois.Peeters@uantwerpen.be [Department of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Neek-Amal, M., E-mail: neekamal@srttu.edu [Department of Physics, University of Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Department of Physics, Shahid Rajaee Teacher Training University, Lavizan, Tehran 16788 (Iran, Islamic Republic of)

2014-02-21

The electronic properties of graphene nano-flakes (GNFs) with different edge passivation are investigated by using density functional theory. Passivation with F and H atoms is considered: C{sub N{sub c}} X{sub N{sub x}} (X = F or H). We studied GNFs with 10 < N{sub c} < 56 and limit ourselves to the lowest energy configurations. We found that: (i) the energy difference Δ between the highest occupied molecular orbital and the lowest unoccupied molecular orbital decreases with N{sub c}, (ii) topological defects (pentagon and heptagon) break the symmetry of the GNFs and enhance the electric polarization, (iii) the mutual interaction of bilayer GNFs can be understood by dipole-dipole interaction which were found sensitive to the relative orientation of the GNFs, (iv) the permanent dipoles depend on the edge terminated atom, while the energy gap is independent of it, and (v) the presence of heptagon and pentagon defects in the GNFs results in the largest difference between the energy of the spin-up and spin-down electrons which is larger for the H-passivated GNFs as compared to F-passivated GNFs. Our study shows clearly the effect of geometry, size, termination, and bilayer on the electronic properties of small GNFs. This study reveals important features of graphene nano-flakes which can be detected using Raman spectroscopy.

Looking for permanent electric dipole moment

International Nuclear Information System (INIS)

Sakemi, Yasuhiro

2007-01-01

Exploration of the permanent electric dipole moment (EDM) is one of the important ways to promote the research of fundamental symmetries and interactions. In this paper the progress of the exploration up to the present is overviewed and then the present status and expectation in future of the experiment using cooled unstable atoms which is the hopeful method to measure electron EDM is presented. At first the physical meaning of the CPT symmetry breaking is introduced and the upper limit of EDM of electron, muon, tau, proton, neutron, Λ hyperon and 199 Hg are tabulated. It is explained how EDM appears in the theory beyond the standard model, the supersymmetry model e.g. The on-going experiments of EDM exploration of neutrons, nuclei, electrons, molecules and charged particles are briefly reviewed. Finally the experiment to use the Bose-Einstein condensation (BEC) to produce ultra low temperature of nK range by using the laser to cool down radioactive element is presented. Since the amplification of EDM is expected to be large in heavy unstable atoms, francium isotopes which are obtained by heavy ion fusion of 197 Au target bombarded with 18 O beam are chosen in this experiment. It has been confirmed that Rb can be kept in the instrument for 20 minutes up to the present. Progress toward trapping Fr is under way by optimizing numbers of experimental parameters. Experiments by the groups in foreign countries are overviewed briefly. (S. Funahashi)

Search for a permanent electric-dipole moment using atomic indium

International Nuclear Information System (INIS)

Sahoo, B. K.; Pandey, R.; Das, B. P.

2011-01-01

We propose indium (In) as a possible candidate for observing the permanent electric dipole moment (EDM) arising from violations of parity (P) and time-reversal (T) symmetries. This atom has been laser cooled and therefore the measurement of its EDM has the potential of improving on the current best EDM limit for a paramagnetic atom, which comes from thallium. We report the results of our calculations of the EDM enhancement factor due to the electron EDM and the ratio of the atomic EDM to the electron-nucleus scalar-pseudoscalar (S-PS) interaction coupling constant in In within the framework of the relativistic coupled cluster theory. It might be possible to get new limits for the electron EDM and the S-PS CP-violating coupling constant by combining the results of our calculations with the measured value of the EDM of In when it is available. These limits could have important implications for the standard model (SM) of particle physics.

Solitary excitations in discrete two-dimensional nonlinear Schrodinger models with dispersive dipole-dipole interactions

DEFF Research Database (Denmark)

Christiansen, Peter Leth; Gaididei, Yuri Borisovich; Johansson, M.

1998-01-01

The dynamics of discrete two-dimensional nonlinear Schrodinger models with long-range dispersive interactions is investigated. In particular, we focus on the cases where the dispersion arises from a dipole-dipole interaction, assuming the dipole moments at each lattice site to be aligned either...

Communication: Permanent dipoles contribute to electric polarization in chiral NMR spectra

International Nuclear Information System (INIS)

Buckingham, A. David

2014-01-01

Nuclear magnetic resonance spectroscopy is blind to chirality because the spectra of a molecule and its mirror image are identical unless the environment is chiral. However, precessing nuclear magnetic moments in chiral molecules in a strong magnetic field induce an electric polarization through the nuclear magnetic shielding polarizability. This effect is equal and opposite for a molecule and its mirror image but is small and has not yet been observed. It is shown that the permanent electric dipole moment of a chiral molecule is partially oriented through the antisymmetric part of the nuclear magnetic shielding tensor, causing the electric dipole to precess with the nuclear magnetic moment and producing a much larger temperature-dependent electric polarization with better prospects of detection

Search for a permanent Xe-electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Zimmer, Stefan [Institut fuer Physik, Universitaet Mainz (Germany); Collaboration: MIXed-Collaboration

2016-07-01

A permanent electric dipole moment (EDM) of the isotope {sup 129}Xe would imply a breakdown of both parity P and time-reversal symmetry T and, through the CPT theorem, a breakdown in CP, the combined symmetries of charge conjugation C and parity P. Our goal is to improve the present experimental limit (d{sub Xe}<3.10{sup -27} ecm) by about three orders of magnitude. The most precise EDM limit on diamagnetic atoms was measured on {sup 199}Hg (d{sub Hg}<3.1.10{sup -29} ecm). To get more stringent limits, we perform a {sup 3}He/{sup 129}Xe clock comparison experiment with the detection of free spin precession of gaseous, nuclear polarized {sup 3}He or {sup 129}Xe samples with a SQUID as magnetic flux detector. The precession of co-located {sup 3}He/{sup 129}Xe nuclear spins are used as an ultra-sensitive probe for non-magnetic spin interactions of type δν∝ d{sub Xe}.E. With our experimental setup at the research center Juelich we are able to observe spin coherence times T{sub 2}{sup *} of several hours for both species. We report on first experimental results achieved within the MIXed-collaboration.

Magnetisation of magnetite nanoparticles medium with dipol-dipol interaction

International Nuclear Information System (INIS)

Ali-zade, R. A.

2005-01-01

Full text: Magnetisation expression for magnetite nanoparticles medium with dipo-dipol interaction has been obtained. We suggested, that energy magnetic dipol-dipol interaction of magnetite nanopaticles is determined by: E d-d = - m 2 /4πμ 0 r 3 (cth x -1/x) 2 where x=mH/kT. This expression has been substituted in statistical sum of magnetite nanoparticles medium. Obtained statistical sum consists the production of two statistical sums. The first statistical sum described non-interacting magnetite nanoparticle medium and from this is obtained Langevan equation. Second statistical sum is: Z 2 -∫exp(Σm 2 /4π 0 r 3 (cth x -1/x) 2 ) dΩ 2 . The second statistical sum has been expanded in Taylor's set and taken into consideration first two terms. Integration has been carried out over all volume. In this case take into account that, number twice interactions of magnetite nanoparticles in unit volume is equal to N(N-1)/2 at N>>1 to N 2 /2. We obtain expressions for magnetisation and initial magnetic susceptibility of interacting magnetite nanoparticles medium take into account that Φ=-kT ln Z, M=-dΦ/dH, χ=dM/dH: M=M Sφm (cth x -1/x)+ 1/3 M S 2 φ m 2 (1μ 0 H) ln(VM S /kT).(cth x -1/x)(-xcsch 2 x+1/x) χ 0 =1/3 (m/kT)+ 1/27 M S 2 φ m 2 (1μ 0 )ln(VM S /kT).(m/kT) 2 . Second term in the magnetisation is sufficient at weak and middle magnetic fields. At large magnetic fields, it leads to zero. The second term of magnetisation has maximum at x=1.566. The values of experimental and calculated magnetic field corresponding to magnetisation maximum for magnetite nanoparticles medium (mean diameter of nanoparticle is 9.4 nm) are 1.19 10 4 A/m and 1.25 10 4 A/m respectively. Magnetic dipol-dipol interaction influence to magnetisation of magnetite nanoparticles. Magnetite nanoparticles lined along external magnetic fields line and formatted chains. Magnetisation of medium occurs by the 'parallel' mechanism method magnetisation of chains

Magnetization reversal processes of isotropic permanent magnets with various inter-grain exchange interactions

Directory of Open Access Journals (Sweden)

Hiroshi Tsukahara

2017-05-01

Full Text Available We performed a large-scale micromagnetics simulation on a supercomputing system to investigate the properties of isotropic nanocrystalline permanent magnets consisting of cubic grains. In the simulation, we solved the Landau–Lifshitz–Gilbert equation under a periodic boundary condition for accurate calculation of the magnetization dynamics inside the nanocrystalline isotropic magnet. We reduced the inter-grain exchange interaction perpendicular and parallel to the external field independently. Propagation of the magnetization reversal process is inhibited by reducing the inter-grain exchange interaction perpendicular to the external field, and the coercivity is enhanced by this restraint. In contrast, when we reduce the inter-grain exchange interaction parallel to the external field, the coercivity decreases because the magnetization reversal process propagates owing to dipole interaction. These behaviors show that the coercivity of an isotropic permanent magnet depends on the direction of the inter-grain exchange interaction.

Charge trapping and de-trapping in isolated CdSe/ZnS nanocrystals under an external electric field: indirect evidence for a permanent dipole moment.

Science.gov (United States)

Zang, Huidong; Cristea, Mihail; Shen, Xuan; Liu, Mingzhao; Camino, Fernando; Cotlet, Mircea

2015-09-28

Single nanoparticle studies of charge trapping and de-trapping in core/shell CdSe/ZnS nanocrystals incorporated into an insulating matrix and subjected to an external electric field demonstrate the ability to reversibly modulate the exciton dynamics and photoluminescence blinking while providing indirect evidence for the existence of a permanent ground state dipole moment in such nanocrystals. A model assuming the presence of energetically deep charge traps physically aligned along the direction of the permanent dipole is proposed in order to explain the dynamics of nanocrystal blinking in the presence of a permanent dipole moment.

Permanent electric dipole moments of PtX (X = H, F, Cl, Br, and I) by the composite approach

Science.gov (United States)

Deng, Dan; Lian, Yongqin; Zou, Wenli

2017-11-01

Using the FPD composite approach of Peterson et. al. we calculate the permanent electric dipole moments of PtX (X = H, F, Cl, Br, and I) at the equilibrium geometries of their ground states. The dipole moment of PtF is estimated to be 3.421 Debye, being very close to the experimental value of 3.42(6) Debye. This research also suggests the ordering of dipole moments of PtX being proportional to the electronegativity of X.

Effect of intermolecular dipole-dipole interactions on interfacial supramolecular structures of C3-symmetric hexa-peri-hexabenzocoronene derivatives.

Science.gov (United States)

Mu, Zhongcheng; Shao, Qi; Ye, Jun; Zeng, Zebing; Zhao, Yang; Hng, Huey Hoon; Boey, Freddy Yin Chiang; Wu, Jishan; Chen, Xiaodong

2011-02-15

Two-dimensional (2D) supramolecular assemblies of a series of novel C(3)-symmetric hexa-peri-hexabenzocoronene (HBC) derivatives bearing different substituents adsorbed on highly oriented pyrolytic graphite were studied by using scanning tunneling microscopy at a solid-liquid interface. It was found that the intermolecular dipole-dipole interactions play a critical role in controlling the interfacial supramolecular assembly of these C(3)-symmetric HBC derivatives at the solid-liquid interface. The HBC molecule bearing three -CF(3) groups could form 2D honeycomb structures because of antiparallel dipole-dipole interactions, whereas HBC molecules bearing three -CN or -NO(2) groups could form hexagonal superstructures because of a special trimeric arrangement induced by dipole-dipole interactions and weak hydrogen bonding interactions ([C-H···NC-] or [C-H···O(2)N-]). Molecular mechanics and dynamics simulations were performed to reveal the physics behind the 2D structures as well as detailed functional group interactions. This work provides an example of how intermolecular dipole-dipole interactions could enable fine control over the self-assembly of disklike π-conjugated molecules.

Dynamic Dipole-Dipole Interactions between Excitons in Quantum Dots of Different Sizes

DEFF Research Database (Denmark)

Matsueda, Hideaki; Leosson, Kristjan; Xu, Zhangcheng

2005-01-01

Micro-photoluminescence spectra of GaAs/AlGaAs coupled quantum dots (QDs) are given, and proposed to be analyzed by our resonance dynamic dipole-dipole interaction (RDDDI) model, based on parity inheritance and exchange of virtual photons among QDs of different sizes....

Translational Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

OpenAIRE

Opatrny, T.; Deb, B.; Kurizki, G.

2003-01-01

We propose and investigate a realization of the position- and momentum-correlated Einstein-Podolsky-Rosen (EPR) states [Phys. Rev. 47, 777 (1935)] that have hitherto eluded detection. The realization involves atom pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The EPR "paradox" with translational variables is then modified by lattice-diffraction effects, and can be verified to a high degree of ...

Dynamic dipole-dipole interactions between excitons in quantum dots of different sizes

DEFF Research Database (Denmark)

Matsueda, Hideaki; Leosson, Kristjan; Xu, Zhangcheng

2004-01-01

A model of the resonance dynamic dipole-dipole interaction between excitons confined in quantum dots (QDs) of different sizes at close enough distance is given in terms of parity inheritance and exchange of virtual photons. Microphotoluminescence spectra of GaAs-AlGaAs coupled QDs are proposed to...

Using permanent magnets to boost the dipole field for the High-Energy LHC

CERN Document Server

Zimmermann, Frank

2012-01-01

The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb- Ti, Nb$_{3}$Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability in principle.

Scattering properties of point dipole interactions

DEFF Research Database (Denmark)

Zolotaryuk, Alexander; Christiansen, Peter Leth; Iermakova, S.V.

2006-01-01

dipole interactions with a renormalized coupling constant are analysed. Depending on the parameter values, all these interactions being self-adjoint extensions of the one-dimensional Schrodinger operator are shown to be divided into four types: (i) interactions will full transparency, (ii) non...

Dipole-dipole dispersion interactions between neutrons

OpenAIRE

Babb, James F.; Higa, Renato; Hussein, Mahir S.

2016-01-01

We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the $\\Delta$-resonance ($J^{\\pi}$ = + 3/2, I = 3/2). We found b...

Induced dipole-dipole coupling between two atoms at a migration resonance

Science.gov (United States)

Kaur, Maninder; Mian, Mahmood

2018-05-01

Results of numerical simulations for the resonant energy exchange phenomenon called Migration reaction between two cold Rydberg atoms are presented. The effect of spatial interatomic distance on the onset of peculiar coherent mechanism is investigated. Observation of Rabi-like population inversion oscillation at the resonance provides a clear signature of dipole induced exchange of electronic excitations between the atoms. Further we present the results for the dependence of expectation value of the interaction hamiltonian on the interatomic distance, which is responsible for energy exchange process. The results of this observation endorse the range of inter atomic distance within which the excitation exchange process occurs completely or partially. Migration process enhance the Rydberg-Rydberg interaction in the absence of an external field, under the condition of the zero permanent dipole moments. Our next observation sheds light on the fundamental mechanism of induced electric fields initiated by the oscillating dipoles in such energy exchange processes. We explore the dependence of induced electric field on the interatomic distance and angle between the dipoles highlighting the inverse power law dependence and anisotropic property of the field. We put forward an idea to utilise the coherent energy exchange process to build efficient and fast energy transfer channels by incorporating more atoms organised at successive distances with decreasing distance gradient.

Position and Momentum Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

Science.gov (United States)

Opatrný, T.; Kolář, M.; Kurizki, G.

We consider a possible realization of the position- and momentum-correlated atomic pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The Einstein-Podolsky-Rosen (EPR) "paradox" [Einstein 1935] with translational variables is then modified by lattice-diffraction effects. We study a possible mechanism of creating such diatom entangled states by varying the effective mass of the atoms.

The permanent electric dipole moment of thorium sulfide, ThS.

Science.gov (United States)

Le, Anh; Heaven, Michael C; Steimle, Timothy C

2014-01-14

Numerous rotational lines of the {18.26}1-X(1)Σ(+) band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and Λ-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, μ⃗el, of 4.58(10) D and 6.72(5) D for the X(1)Σ(+) (v = 0) and {18.26}1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO.

Search for the permanent electric dipole moment of 129Xe

Science.gov (United States)

Sachdeva, Natasha; Chupp, Timothy; Gong, Fei; Babcock, Earl; Salhi, Zahir; Burghoff, Martin; Fan, Isaac; Killian, Wolfgang; Knappe-Grüneberg, Silvia; Schabel, Allard; Seifert, Frank; Trahms, Lutz; Voigt, Jens; Degenkolb, Skyler; Fierlinger, Peter; Krägeloh, Eva; Lins, Tobias; Marino, Michael; Meinel, Jonas; Niessen, Benjamin; Stuiber, Stefan; Terrano, William; Kuchler, Florian; Singh, Jaideep

2017-09-01

CP-violation in Beyond-the-Standard-Model physics, necessary to explain the baryon asymmetry, gives rise to permanent electric dipole moments (EDMs). EDM measurements of the neutron, electron, paramagnetic and diamagnetic atoms constrain CP-violating parameters. The current limit for the 129Xe EDM is 6 ×10-27 e . cm (95 % CL). The HeXeEDM experiment at FRM-II (Munich Research Reactor) and BMSR-2 (Berlin Magnetically Shielded Room) uses a stable magnetic field in a magnetically shielded room and 3He comagnetometer with potential to improve the limit by two orders of magnitude. Polarized 3He and 129Xe free precession is detected with SQUID magnetometers in the presence of applied electric and magnetic fields. Conclusions from recent measurements will be presented.

Dipole-dipole interactions in a hot atomic vapor and in an ultracold gas of Rydberg atoms

Science.gov (United States)

Sautenkov, V. A.; Saakyan, S. A.; Bronin, S. Ya; Klyarfeld, A. B.; Zelener, B. B.; Zelener, B. V.

2018-01-01

In our paper ideal and non-ideal gas media of neutral atoms are analyzed. The first we discuss a dipole broadening of atomic transitions in excited dilute and dense metal vapors. Then the theoretical studies of the dipole-dipole interactions in dense ultracold gas of Rydberg atoms are considered. Possible future experiments on a base of our experimental arrangement are suggested.

The permanent electric dipole moment of thorium sulfide, ThS

Energy Technology Data Exchange (ETDEWEB)

Le, Anh; Steimle, Timothy C., E-mail: Tsteimle@ASU.edu [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Heaven, Michael C. [Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

2014-01-14

Numerous rotational lines of the (18.26)1-X{sup 1}Σ{sup +} band system of thorium sulfide, ThS, were recorded near 547.6 nm at a resolution of approximately 30 MHz. Measurements were made under field-free conditions, and in the presence of a static electric field. The field-free spectrum was analyzed to produce rotational and Λ-doubling parameters. The Stark shifts induced by the electric field were analyzed to determine permanent electric dipole moments, μ{sup -vector}{sub el}, of 4.58(10) D and 6.72(5) D for the X{sup 1}Σ{sup +} (v = 0) and (18.26)1 states, respectively. The results are compared with the predictions of previous and new electronic structure calculations for ThS, and the properties of isovalent ThO.

Proposal for Translational Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices

Science.gov (United States)

Opatrný, Tomáš; Deb, Bimalendu; Kurizki, Gershon

2003-06-01

We propose and investigate a realization of the position- and momentum-correlated Einstein-Podolsky-Rosen (EPR) states [Phys. Rev. 47, 777 (1935)] that have hitherto eluded detection. The realization involves atom pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The EPR “paradox” with translational variables is then modified by lattice-diffraction effects and can be verified to a high degree of accuracy in this scheme.

Interaction of counter-streaming plasma flows in dipole magnetic field

OpenAIRE

Shaikhislamov, I F; Posukh, V G; Melekhov, A V; Prokopov, P A; Boyarintsev, E L; Zakharov, Yu P; Ponomarenko, A G

2017-01-01

Transient interaction of counter-streaming super-sonic plasma flows in dipole magnetic dipole is studied in laboratory experiment. First quasi-stationary flow is produced by teta-pinch and forms a magnetosphere around the magnetic dipole while laser beams focused at the surface of the dipole cover launch second explosive plasma expanding from inner dipole region outward. Laser plasma is energetic enough to disrupt magnetic field and to sweep through the background plasma for large distances. ...

Impact of a permanent El Niño (El Padre) and Indian Ocean Dipole in warm Pliocene climates

Science.gov (United States)

Shukla, Sonali P.; Chandler, Mark A.; Jonas, Jeff; Sohl, Linda E.; Mankoff, Ken; Dowsett, Harry J.

2009-01-01

 Pliocene sea surface temperature data, as well as terrestrial precipitation and temperature proxies, indicate warmer than modern conditions in the eastern equatorial Pacific and imply permanent El Niño–like conditions with impacts similar to those of the 1997/1998 El Niño event. Here we use a general circulation model to examine the global-scale effects that result from imposing warm tropical sea surface temperature (SST) anomalies in both modern and Pliocene simulations. Observed SSTs from the 1997/1998 El Niño event were used for the anomalies and incorporate Pacific warming as well as a prominent Indian Ocean Dipole event. Both the permanent El Niño (also called El Padre) and Indian Ocean Dipole (IOD) conditions are necessary to reproduce temperature and precipitation patterns consistent with the global distribution of Pliocene proxy data. These patterns may result from the poleward propagation of planetary waves from the strong convection centers associated with the El Niño and IOD.

Collapse instability of solitons in the nonpolynomial Schroedinger equation with dipole-dipole interactions

International Nuclear Information System (INIS)

Gligoric, G; Hadzievski, Lj; Maluckov, A; Malomed, B A

2009-01-01

A model of the Bose-Einstein condensate (BEC) of dipolar atoms, confined in a combination of a cigar-shaped trap and optical lattice acting in the axial direction, is studied in the framework of the one-dimensional (1D) nonpolynomial Schroedinger equation (NPSE) with additional terms describing long-range dipole-dipole (DD) interactions. The NPSE makes it possible to describe the collapse of localized modes, which was experimentally observed in the self-attractive BEC confined in tight traps, in the framework of the 1D description. We study the influence of the DD interactions on the dynamics of bright solitons, especially concerning their collapse-induced instability. Both attractive and repulsive contact and DD interactions are considered. The results are summarized in the form of stability/collapse diagrams in a respective parametric space. In particular, it is shown that the attractive DD interactions may prevent the collapse instability in the condensate with attractive contact interactions.

Permanent and induced dipole requirements in ab initio calculations of electron affinities of polar molecules

International Nuclear Information System (INIS)

Garrett, W.R.

1979-01-01

Through the use of a molecular pseudopotential method, we determine the a approximate magnitudes of errors that result when electron affinity determinations of polar negative ions are made through ab initio calculations in which the use of a given basis set yields inappropriate values for permanent and induced dipole moments of the neutral molecule. These results should prove useful in assessing the adequacy of basis sets in ab initio calculations of molecular electron affinities for simple linear polar molecules

New all-optical method for measuring molecular permanent dipole moment difference using two-photon absorption spectroscopy

International Nuclear Information System (INIS)

Rebane, A.; Drobizhev, M.; Makarov, N.S.; Beuerman, E.; Tillo, S.; Hughes, T.

2010-01-01

Stark effect, in combination with spectral hole burning and single-molecule spectroscopy, has been a fruitful technique to study permanent electric dipole moment of molecules in condensed phase. However, because measuring Stark shifts relies on external fields and narrow line- or hole-widths, the applicability of this method at ambient conditions required by most biological systems has remained limited. Here we demonstrate a new all-optical method for measuring the molecular dipole moment difference between ground and excited states using two-photon absorption (2PA) spectroscopy. We show that the value and orientation of the static dipole moment difference can be determined from the corresponding absolute 2PA cross-section. We use this new method to determine for the first time the strength of local electric field E loc =0.1-1.0x10 8 V/cm inside beta-barrel of Fruit series of red fluorescent proteins. Because our method does not rely on external field and is applicable in liquid solutions, it is well suited for the study of biological systems.

On the effects on a Landau-type system for an atom with no permanent electric dipole moment due to a Coulomb-type potential

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Abinael B.; Bakke, Knut, E-mail: kbakke@fisica.ufpb.br

2016-02-15

We analyse the bound states for a Landau-type system for an atom with no permanent electric dipole moment subject to a Coulomb-type potential. By comparing the energy levels for bound states of the system with the Landau quantization for an atom with no permanent electric dipole moment (Furtado et al., 2006), we show that the energy levels of the Landau-type system are modified, where the degeneracy of the energy levels is broken. Another quantum effect investigated is a dependence of the angular frequency of the system on the quantum numbers associated with the radial modes and the angular momentum. As examples, we obtain the angular frequency and the energy levels associated with the ground state and the first excited state of the system.

On the effects on a Landau-type system for an atom with no permanent electric dipole moment due to a Coulomb-type potential

International Nuclear Information System (INIS)

Oliveira, Abinael B.; Bakke, Knut

2016-01-01

We analyse the bound states for a Landau-type system for an atom with no permanent electric dipole moment subject to a Coulomb-type potential. By comparing the energy levels for bound states of the system with the Landau quantization for an atom with no permanent electric dipole moment (Furtado et al., 2006), we show that the energy levels of the Landau-type system are modified, where the degeneracy of the energy levels is broken. Another quantum effect investigated is a dependence of the angular frequency of the system on the quantum numbers associated with the radial modes and the angular momentum. As examples, we obtain the angular frequency and the energy levels associated with the ground state and the first excited state of the system.

Measurements of vacuum magnetic birefringence using permanent dipole magnets: the PVLAS experiment

Science.gov (United States)

Della Valle, F.; Gastaldi, U.; Messineo, G.; Milotti, E.; Pengo, R.; Piemontese, L.; Ruoso, G.; Zavattini, G.

2013-05-01

The PVLAS collaboration is presently assembling a new apparatus (at the INFN section of Ferrara, Italy) to detect vacuum magnetic birefringence (VMB). VMB is related to the structure of the quantum electrodynamics (QED) vacuum and is predicted by the Euler-Heisenberg-Weisskopf effective Lagrangian. It can be detected by measuring the ellipticity acquired by a linearly polarized light beam propagating through a strong magnetic field. Using the very same optical technique it is also possible to search for hypothetical low-mass particles interacting with two photons, such as axion-like (ALP) or millicharged particles. Here we report the results of a scaled-down test setup and describe the new PVLAS apparatus. This latter is in construction and is based on a high-sensitivity ellipsometer with a high-finesse Fabry-Perot cavity (>4 × 105) and two 0.8 m long 2.5 T rotating permanent dipole magnets. Measurements with the test setup have improved, by a factor 2, the previous upper bound on the parameter Ae, which determines the strength of the nonlinear terms in the QED Lagrangian: A(PVLAS)e < 3.3 × 10-21 T-2 at 95% c.l. Furthermore, new laboratory limits have been put on the inverse coupling constant of ALPs to two photons and confirmation of previous limits on the fractional charge of millicharged particles is given.

Vortical structures for nanomagnetic memory induced by dipole-dipole interaction in monolayer disks

Science.gov (United States)

Liu, Zhaosen; Ciftja, Orion; Zhang, Xichao; Zhou, Yan; Ian, Hou

2018-05-01

It is well known that magnetic domains in nanodisks can be used as storage units for computer memory. Using two quantum simulation approaches, we show here that spin vortices on magnetic monolayer nanodisks, which are chirality-free, can be induced by dipole-dipole interaction (DDI) on the disk-plane. When DDI is sufficiently strong, vortical and anti-vortical multi-domain textures can be generated simultaneously. Especially, a spin vortex can be easily created and deleted through either external magnetic or electrical signals, making them ideal to be used in nanomagnetic memory and logical devices. We demonstrate these properties in our simulations.

Two-leg ladder systems with dipole–dipole Fermion interactions

Science.gov (United States)

Mosadeq, Hamid; Asgari, Reza

2018-05-01

The ground-state phase diagram of a two-leg fermionic dipolar ladder with inter-site interactions is studied using density matrix renormalization group (DMRG) techniques. We use a state-of-the-art implementation of the DMRG algorithm and finite size scaling to simulate large system sizes with high accuracy. We also consider two different model systems and explore stable phases in half and quarter filling factors. We find that in the half filling, the charge and spin gaps emerge in a finite value of the dipole–dipole and on-site interactions. In the quarter filling case, s-wave superconducting state, charge density wave, homogenous insulating and phase separation phases occur depend on the interaction values. Moreover, in the dipole–dipole interaction, the D-Mott phase emerges when the hopping terms along the chain and rung are the same, whereas, this phase has been only proposed for the anisotropic Hubbard model. In the half filling case, on the other hand, there is either charge-density wave or charged Mott order phase depends on the orientation of the dipole moments of the particles with respect to the ladder geometry.

Dipole-dipole dispersion interactions between neutrons

Energy Technology Data Exchange (ETDEWEB)

Babb, James F. [Harvard-Smithsonian Center for Astrophysics, ITAMP, Cambridge, MA (United States); Higa, Renato [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo (Brazil); Hussein, Mahir S. [Universidade de Sao Paulo, Instituto de Fisica, Sao Paulo (Brazil); Universidade de Sao Paulo, Instituto de Estudos Avancados, Sao Paulo (Brazil); Departamento de Fisica, Instituto Tecnologico de Aeronautica, CTA, Sao Jose dos Campos (Brazil)

2017-06-15

We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the Δ-resonance (J{sup π} = +3/2, I = 3/2). We found both dynamical effects to be quite relevant for distances r between ∝ 50 fm up to ∝ 10{sup 3} fm in the nn system, the neutron-wall system and in the wall-neutron-wall system, reaching the expected asymptotic limit beyond that. Relevance of our findings to the confinement of ultra cold neutrons inside bottles is discussed. (orig.)

Zeroth order regular approximation approach to electric dipole moment interactions of the electron

Science.gov (United States)

Gaul, Konstantin; Berger, Robert

2017-07-01

A quasi-relativistic two-component approach for an efficient calculation of P ,T -odd interactions caused by a permanent electric dipole moment of the electron (eEDM) is presented. The approach uses a (two-component) complex generalized Hartree-Fock and a complex generalized Kohn-Sham scheme within the zeroth order regular approximation. In applications to select heavy-elemental polar diatomic molecular radicals, which are promising candidates for an eEDM experiment, the method is compared to relativistic four-component electron-correlation calculations and confirms values for the effective electric field acting on the unpaired electron for RaF, BaF, YbF, and HgF. The calculations show that purely relativistic effects, involving only the lower component of the Dirac bi-spinor, are well described by treating only the upper component explicitly.

First Measurement of the Atomic Electric Dipole Moment of (225)Ra.

Science.gov (United States)

Parker, R H; Dietrich, M R; Kalita, M R; Lemke, N D; Bailey, K G; Bishof, M; Greene, J P; Holt, R J; Korsch, W; Lu, Z-T; Mueller, P; O'Connor, T P; Singh, J T

2015-06-12

The radioactive radium-225 ((225)Ra) atom is a favorable case to search for a permanent electric dipole moment. Because of its strong nuclear octupole deformation and large atomic mass, (225)Ra is particularly sensitive to interactions in the nuclear medium that violate both time-reversal symmetry and parity. We have developed a cold-atom technique to study the spin precession of (225)Ra atoms held in an optical dipole trap, and demonstrated the principle of this method by completing the first measurement of its atomic electric dipole moment, reaching an upper limit of |d((225)Ra)|<5.0×10(-22)  e cm (95% confidence).

Quantum transfer energy in the framework of time-dependent dipole-dipole interaction

Science.gov (United States)

El-Shishtawy, Reda M.; Haddon, Robert C.; Al-Heniti, Saleh H.; Raffah, Bahaaudin M.; Berrada, K.; Abdel-Khalek, S.; Al-Hadeethi, Yas F.

2018-03-01

In this work, we examine the process of the quantum transfer of energy considering time-dependent dipole-dipole interaction in a dimer system characterized by two-level atom systems. By taking into account the effect of the acceleration and speed of the atoms in the dimer coupling, we demonstrate that the improvement of the probability for a single-excitation transfer energy extremely benefits from the incorporation of atomic motion effectiveness and the energy detuning. We explore the relevance between the population and entanglement during the time-evolution and show that this kind of nonlocal correlation may be generated during the process of the transfer of energy. Our work may provide optimal conditions to implement realistic experimental scenario in the transfer of the quantum energy.

Lepton dipole moments

CERN Document Server

Marciano, William J

2010-01-01

This book provides a self-contained description of the measurements of the magnetic dipole moments of the electron and muon, along with a discussion of the measurements of the fine structure constant, and the theory associated with magnetic and electric dipole moments. Also included are the searches for a permanent electric dipole moment of the electron, muon, neutron and atomic nuclei. The related topic of the transition moment for lepton flavor violating processes, such as neutrinoless muon or tauon decays, and the search for such processes are included as well. The papers, written by many o

Micromagnetic simulation for the magnetization reversal process of Nd-Fe-B hot-deformed nanocrystalline permanent magnets

Directory of Open Access Journals (Sweden)

Hiroshi Tsukahara

2017-05-01

Full Text Available We numerically demonstrated the magnetization reversal process inside a hot-deformed nanocrystalline permanent magnet. We performed large-scale micromagnetics simulation based on the Landau–Lifshitz–Gilbert equation with 0.1 billion calculation cells. The simulation model for the hot-deformed nanocrystalline permanent magnet consists of 2622 tabular grains that interact with each other by inter-grain exchange and dipole interactions. When the strength of the external field approached a coercive force, nucleation cores were created at the grain surface. The magnetization reversal was propagated by the inter-grain and dipole interactions. When the grains had overlapping regions parallel to the external field, the magnetization reversal propagated quickly between the grains due to the dipole interaction. In contrast, the motion of the magnetic domain wall was inhibited at interfaces between the grains perpendicular to the external field. Reversal magnetic domains had a pillar-shaped structure that is parallel to the external field. In the perpendicular direction, the reversal magnetic domain expanded gradually because of the inhibition of the domain wall motion.

Compensation of the magnetization current induced sextupole error at LHC injection field by short lumped permanent sextupole magnets, incorporated into the end configuration of superconducting dipoles

CERN Document Server

Asner, A

1985-01-01

Compensation of the magnetization current induced sextupole error at LHC injection field by short lumped permanent sextupole magnets, incorporated into the end configuration of superconducting dipoles

Vacuum fluctuations and radiation reaction contributions to the resonance dipole-dipole interaction between two atoms near a reflecting boundary

Science.gov (United States)

Zhou, Wenting; Rizzuto, Lucia; Passante, Roberto

2018-04-01

We investigate the resonance dipole-dipole interaction energy between two identical atoms, one in the ground state and the other in the excited state, interacting with the electromagnetic field in the presence of a perfectly reflecting plane boundary. The atoms are prepared in a correlated (symmetric or antisymmetric) Bell-type state. Following a procedure due to Dalibard et al. [J. Dalibard et al., J. Phys. (Paris) 43, 1617 (1982);, 10.1051/jphys:0198200430110161700 J. Phys. (Paris) 45, 637 (1984), 10.1051/jphys:01984004504063700], we separate the contributions of vacuum fluctuations and radiation reaction (source) field to the resonance interaction energy between the two atoms and show that only the source field contributes to the interatomic interaction, while vacuum field fluctuations do not. By considering specific geometric configurations of the two-atom system with respect to the mirror and specific choices of dipole orientations, we show that the presence of the mirror significantly affects the resonance interaction energy and that different features appear with respect to the case of atoms in free space, for example, a change in the spatial dependence of the interaction. Our findings also suggest that the presence of a boundary can be exploited to tailor and control the resonance interaction between two atoms, as well as the related energy transfer process. The possibility of observing these phenomena is also discussed.

Theoretical study on the ground state of the polar alkali-metal-barium molecules: Potential energy curve and permanent dipole moment

International Nuclear Information System (INIS)

Gou, Dezhi; Kuang, Xiaoyu; Gao, Yufeng; Huo, Dongming

2015-01-01

In this paper, we systematically investigate the electronic structure for the 2 Σ + ground state of the polar alkali-metal-alkaline-earth-metal molecules BaAlk (Alk = Li, Na, K, Rb, and Cs). Potential energy curves and permanent dipole moments (PDMs) are determined using power quantum chemistry complete active space self-consistent field and multi-reference configuration interaction methods. Basic spectroscopic constants are derived from ro-vibrational bound state calculation. From the calculations, it is shown that BaK, BaRb, and BaCs molecules have moderate values of PDM at the equilibrium bond distance (BaK:1.62 D, BaRb:3.32 D, and BaCs:4.02 D). Besides, the equilibrium bond length (4.93 Å and 5.19 Å) and dissociation energy (0.1825 eV and 0.1817 eV) for the BaRb and BaCs are also obtained

Search for the permanent electric dipole moment of {sup 129}Xe

Energy Technology Data Exchange (ETDEWEB)

Grasdijk, Olivier; Jungmann, Klaus; Willmann, Lorenz [KVI, University of Groningen (Netherlands); Heil, Werner; Karpuk, Sergei; Scharth, Anja; Sobolev, Yuri; Tullney, Kathlynne [Institut fuer Physik, Universitaet Mainz (Germany); Allmendinger, Fabian; Schmidt, Ulrich [Physikalisches Institut, Universitaet Heidelberg (Germany); Burghoff, Martin; Kilian, Wolfgang; Schnabel, Allard; Seifert, Frank; Trahms, Lutz [PTB Berlin (Germany)

2013-07-01

Permanent electric dipole moments (EDMs) violate parity and time reversal symmetry at the same time. Assuming CPT invariance a non-zero EDM would also violate CP symmetry, which could provide an explanation for the observed matter-antimatter asymmetry in the universe. An EDM at the present limit of experimental sensitivity would provide unambiguous evidence for physics beyond the Standard Model. Our approach is to observe the coherent spin-precession of co-located {sup 3}He/{sup 129}Xe polarized samples over extended periods of 1 day, typically. Based on results of measurements on Lorentz-invariance, we intend to reach a measurement sensitivity that will improve the present upper limit d{sub Xe} = 3 . 10{sup -27} ecm significantly. Phase I of this experiment will be performed in the magnetically shielded room BMSR-2 of the PTB Berlin using very sensitive SQUID gradiometers as magnetic flux detectors and electric fields of 2 kV/cm. The experimental setup, in particular the implementation of the electric field, and current status of work are presented.

Reduced Limit on the Permanent Electric Dipole Moment of ^{199}Hg.

Science.gov (United States)

Graner, B; Chen, Y; Lindahl, E G; Heckel, B R

2016-04-22

This Letter describes the results of the most recent measurement of the permanent electric dipole moment (EDM) of neutral ^{199}Hg atoms. Fused silica vapor cells containing enriched ^{199}Hg are arranged in a stack in a common magnetic field. Optical pumping is used to spin polarize the atoms orthogonal to the applied magnetic field, and the Faraday rotation of near-resonant light is observed to determine an electric-field-induced perturbation to the Larmor precession frequency. Our results for this frequency shift are consistent with zero; we find the corresponding ^{199}Hg EDM d_{Hg}=(-2.20±2.75_{stat}±1.48_{syst})×10^{-30}e cm. We use this result to place a new upper limit on the ^{199}Hg EDM |d_{Hg}|<7.4×10^{-30}e cm (95% C.L.), improving our previous limit by a factor of 4. We also discuss the implications of this result for various CP-violating observables as they relate to theories of physics beyond the standard model.

Constraints on exotic dipole-dipole couplings between electrons at the micron scale

Science.gov (United States)

Kotler, Shlomi; Ozeri, Roee; Jackson Kimball, Derek

2015-05-01

Until recently, the magnetic dipole-dipole coupling between electrons had not been directly observed experimentally. This is because at the atomic scale dipole-dipole coupling is dominated by the exchange interaction and at larger distances the dipole-dipole coupling is overwhelmed by ambient magnetic field noise. In spite of these challenges, the magnetic dipole-dipole interaction between two electron spins separated by 2.4 microns was recently measured using the valence electrons of trapped Strontium ions [S. Kotler, N. Akerman, N. Navon, Y. Glickman, and R. Ozeri, Nature 510, 376 (2014)]. We have used this measurement to directly constrain exotic dipole-dipole interactions between electrons at the micron scale. For light bosons (mass 0.1 eV), we find that coupling constants describing pseudoscalar and axial-vector mediated interactions must be | gPegPe/4 πℏc | <= 1 . 5 × 10-3 and | gAegAe/4 πℏc | <= 1 . 2 × 10-17 , respectively, at the 90% confidence level. These bounds significantly improve on previous constraints in this mass range: for example, the constraints on axial-vector interactions are six orders of magnitude stronger than electron-positron constraints based on positronium spectroscopy. Supported by the National Science Foundation, I-Core: the Israeli excellence center, and the European Research Council.

A simulation assessment of the thermodynamics of dense ion-dipole mixtures with polarization

International Nuclear Information System (INIS)

Bastea, Sorin

2014-01-01

Molecular dynamics (MD) simulations are employed to ascertain the relative importance of various electrostatic interaction contributions, including induction interactions, to the thermodynamics of dense, hot ion-dipole mixtures. In the absence of polarization, we find that an MD-constrained free energy term accounting for the ion-dipole interactions, combined with well tested ionic and dipolar contributions, yields a simple, fairly accurate free energy form that may be a better option for describing the thermodynamics of such mixtures than the mean spherical approximation (MSA). Polarization contributions induced by the presence of permanent dipoles and ions are found to be additive to a good approximation, simplifying the thermodynamic modeling. We suggest simple free energy corrections that account for these two effects, based in part on standard perturbative treatments and partly on comparisons with MD simulation. Even though the proposed approximations likely need further study, they provide a first quantitative assessment of polarization contributions at high densities and temperatures and may serve as a guide for future modeling efforts

Energy harvesting from the interaction of a Lamb dipole with a flexible cantilever

Science.gov (United States)

Tang, Hui; Wang, Chenglei

2017-11-01

Energy harvesting from interactions of coherent flow structures with flexible solid structures can be used for powering miniature electronic devices. Although effective, the fundamental mechanism of such an energy extraction process has not been fully understood. Therefore, this study aims to provide more physical insights into this problem. The coherent flow structure is represented by a Lamb dipole, and the solid structure is assumed as a two-dimensional flexible cantilever. The cantilever is placed along the propagation direction of the dipole, with its fixed end initially towards or away from the dipole and its lateral distance from the dipole center varied. As the dipole passes through the cantilever, the latter can extract energy from the former through effective interactions. Such a two-dimensional fluid-structure interaction problem is numerically studied at a low Reynolds number of 200 using a lattice Boltzmann method (LBM) based numerical framework. The simulation results reveal that the flexible cantilever with a moderate stiffness is more beneficial to the energy harvesting, and it can scavenge more energy from the ambient vortices when its fixed end is initially away from the dipole with a relatively small lateral distance. The authors gratefully acknowledge the financial support for this study from the Research Grants Council of Hong Kong under General Research Fund (Project No. PolyU 152493/16E).

Effect of pairwise dipole–dipole interaction among three-atom systems

Indian Academy of Sciences (India)

2014-07-18

Jul 18, 2014 ... We present an analysis of a system of three two-level atoms interacting with one another through dipole–dipole interaction. The interaction manifests between the excited state of one of the atoms and the ground state of its nearest neighbour. Steady-state populations of the density matrix elements are ...

Carrier-envelope phase-dependent transmitted spectra in inversion-asymmetric media with permanent dipole moments

International Nuclear Information System (INIS)

Yang Weifeng; Song Xiaohong; Zhang Chaojin; Xu Zhizhan

2009-01-01

We investigate the transmitted spectra of a few-cycle ultrashort pulse in an inversion-asymmetric medium with a permanent dipole moment (PDM). Our results show that even-order harmonics can be generated in this medium. Moreover, the generated even-order harmonics depend strongly on the carrier-envelope phase (CEP) of initial incident few-cycle ultrashort pulses. Physical analysis of the re-emitted spectra of the medium reveals that the CEP-dependent spectral effect is originated from the inversion-asymmetric structure and the corresponding PDM effects: two-photon transition dominates in the nonlinear process and further induces the generations of the even-order harmonics. Furthermore, the orientation relation between the electric field peak of the pulse and the PDM results in even-order harmonic generations depending on the CEP.

The Röntgen interaction and forces on dipoles in time-modulated optical fields

Science.gov (United States)

Sonnleitner, Matthias; Barnett, Stephen M.

2017-12-01

The Röntgen term is an often neglected contribution to the interaction between an atom and an electromagnetic field in the electric dipole approximation. In this work we discuss how this interaction term leads to a difference between the kinetic and canonical momentum of an atom which, in turn, leads to surprising radiation forces acting on the atom. We use a number of examples to explore the main features of this interaction, namely forces acting against the expected dipole force or accelerations perpendicular to the beam propagation axis.

Mercury monohalides: suitability for electron electric dipole moment searches.

Science.gov (United States)

Prasannaa, V S; Vutha, A C; Abe, M; Das, B P

2015-05-08

Heavy polar diatomic molecules are the primary tools for searching for the T-violating permanent electric dipole moment of the electron (eEDM). Valence electrons in some molecules experience extremely large effective electric fields due to relativistic interactions. These large effective electric fields are crucial to the success of polar-molecule-based eEDM search experiments. Here we report on the results of relativistic ab initio calculations of the effective electric fields in a series of molecules that are highly sensitive to an eEDM, the mercury monohalides (HgF, HgCl, HgBr, and HgI). We study the influence of the halide anions on E_{eff}, and identify HgBr and HgI as attractive candidates for future electric dipole moment search experiments.

Position and Momentum Entanglement of Dipole-Dipole Interacting Atoms in Optical Lattices: The Einstein-Podolsky-Rosen Paradox on a Lattice

OpenAIRE

Opatrny, T.; Kolar, M.; Kurizki, G.; Deb, B.

2004-01-01

We study a possible realization of the position- and momentum-correlated atomic pairs that are confined to adjacent sites of two mutually shifted optical lattices and are entangled via laser-induced dipole-dipole interactions. The Einstein-Podolsky-Rosen (EPR) ``paradox'' [Phys. Rev. 47, 777 (1935)] with translational variables is then modified by lattice-diffraction effects. This ``paradox'' can be verified to a high degree of accuracy in this scheme.

On the Effect of Dipole-Dipole Interactions on the Quantum Statistics of Surface Plasmons in Multiparticle Spaser Systems

Science.gov (United States)

Shesterikov, A. V.; Gubin, M. Yu.; Karpov, S. N.; Prokhorov, A. V.

2018-04-01

The problem of controlling the quantum dynamics of localized plasmons has been considered in the model of a four-particle spaser composed of metallic nanoparticles and semiconductor quantum dots. Conditions for the observation of stable steady-state regimes of the formation of surface plasmons in this model have been determined in the mean-field approximation. It has been shown that the presence of strong dipole-dipole interactions between metallic nanoparticles of the spaser system leads to a considerable change in the quantum statistics of plasmons generated on the nanoparticles.

Elementary quantum mechanics of the neutron with an electric dipole moment.

Science.gov (United States)

Baym, Gordon; Beck, D H

2016-07-05

The neutron, in addition to possibly having a permanent electric dipole moment as a consequence of violation of time-reversal invariance, develops an induced electric dipole moment in the presence of an external electric field. We present here a unified nonrelativistic description of these two phenomena, in which the dipole moment operator, [Formula: see text], is not constrained to lie along the spin operator. Although the expectation value of [Formula: see text] in the neutron is less than [Formula: see text] of the neutron radius, [Formula: see text], the expectation value of [Formula: see text] is of order [Formula: see text] We determine the spin motion in external electric and magnetic fields, as used in past and future searches for a permanent dipole moment, and show that the neutron electric polarizability, although entering the neutron energy in an external electric field, does not affect the spin motion. In a simple nonrelativistic model we show that the expectation value of the permanent dipole is, to lowest order, proportional to the product of the time-reversal-violating coupling strength and the electric polarizability of the neutron.

Effects of dipole—dipole interaction on entanglement transfer

International Nuclear Information System (INIS)

Guo Hong; Xiong Hengna

2008-01-01

A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered. The effects of dipole—dipole (dd) interaction between two atoms on the atom-atom entanglement and mode-mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled

Dipole moments of molecules solvated in helium nanodroplets

International Nuclear Information System (INIS)

Stiles, Paul L.; Nauta, Klaas; Miller, Roger E.

2003-01-01

Stark spectra are reported for hydrogen cyanide and cyanoacetylene solvated in helium nanodroplets. The goal of this study is to understand the influence of the helium solvent on measurements of the permanent electric dipole moment of a molecule. We find that the dipole moments of the helium solvated molecules, calculated assuming the electric field is the same as in vacuum, are slightly smaller than the well-known gas-phase dipole moments of HCN and HCCCN. A simple elliptical cavity model quantitatively accounts for this difference, which arises from the dipole-induced polarization of the helium

Calculation of the dispersion-dipole coefficients for interactions between H, He, and H2

International Nuclear Information System (INIS)

Bishop, D.M.; Pipin, J.

1993-01-01

Collisions between atoms and molecules create an induced dipole moment which, at long range separations, stems, in part, from the van der Waals interactions between the colliding species. This contribution is known as the dispersion dipole moment and is of the order R -7 , where R is the separation between particles. Although there have been several approximate calculations of the dispersion-dipole coefficients which govern this contribution, and are the counterparts to the van der Waals dispersion-energy coefficients, there have been few ab initio calculations. In this article we present highly accurate results, based on explicitly electron-correlated wave functions, for the dispersion-dipole coefficients pertaining to interactions between pairs chosen from H, He, and H 2 . We also obtain values with some of the currently used approximate formulas. A comparison shows that these values differ, in general, by a significant amount (∼20--∼40 %) from the accurate ones. We also tabulate values of the dipole--dipole-quadrupole polarizability tensor (B) for imaginary frequency (iω) for a range of frequencies appropriate to a 64-point Gauss--Legendre quadrature for H, He, and H 2 . These values were used in certain numerical integrations we made to verify our original results which had been obtained by analytic integration---they may, however, be useful in other contexts. For H--H 2 and H 2 --H 2 , these are the only ab initio calculations of the dispersion-dipole coefficients of which we are aware

Multipole resonance in the interaction of a spherical Ag nanoparticle with an emitting dipole

International Nuclear Information System (INIS)

Liu Jia-Dong; Song Feng; Zhang Jun; Wang Feng-Xiao; Wang Li-Chao; Liu Shu-Jing

2014-01-01

The effect of multipole resonance in the interaction between a spherical metallic nanoparticle (MNP) and an emitting dipole is studied with the Mie theory. The results show that the absorption peak of the MNP with respect to the field of the emitting dipole is blue-shifted with the decrease of the spacing between MNP and emitting dipole due to the enhanced multipole resonance. At a short distance, the enhanced multipole terms of scattering are not obvious compared with the dipole term. For the decay rate of the emitting dipole, multipole resonance brings about the enhancement of it largely at short spacing. For the radiative decay rate, the behavior is quite different. The dipole term is dominant at a short spacing, and the multipole term is dominant at a larger spacing. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Permanent magnets including undulators and wigglers

CERN Document Server

Bahrdt, J

2010-01-01

After a few historic remarks on magnetic materials we introduce the basic definitions related to permanent magnets. The magnetic properties of the most common materials are reviewed and the production processes are described. Measurement techniques for the characterization of macroscopic and microscopic properties of permanent magnets are presented. Field simulation techniques for permanent magnet devices are discussed. Today, permanent magnets are used in many fields. This article concentrates on the applications of permanent magnets in accelerators starting from dipoles and quadrupoles on to wigglers and undulators.

Electric-dipole-moment enhancement factor for the thallium atom, and a new upper limit on the electric dipole moment of the electron

International Nuclear Information System (INIS)

Sandars, P.G.H.; Sternheimer, R.M.

1975-01-01

Some time ago, an accurate upper limit on a possible permanent electric dipole moment of the thallium atom in the 6 2 P 1 / 2 ground state was obtained by Gould. The result was D/sub Tl/ = [(1.3 +- 2.4) x 10 -21 cm]e. In connection with this value, a calculation of the electric dipole enhancement factor R/sub Tl/, which is defined as the ratio D/sub Tl//D/sub e/, where D/sub e/is the corresponding upper limit on a possible electric dipole moment of the (valence) electron was carried out. A value R/subTl/ = 700 was obtained, which leads to an upper limit D/sub e/ = [(1.9 +- 3.4) x 10 -24 cm]e. This result is comparable with the value D/sub e/ -24 cm)e previously obtained by Weisskopf et al. from measurements on the cesium atom, and with the result of Player and Sandars of [(0.7 +- 2.2) x 10 -24 cm]e obtained from the search for an electric dipole moment in the 3 P 2 metastable state of xenon. All three results set a stringent upper limit on the amount of a possible violation of T and P invariance in electromagnetic interactions. (U.S.)

Effect of pairwise dipole–dipole interaction among three-atom systems

Indian Academy of Sciences (India)

The excitement to study dynamics of dipole–dipole interaction stems from the fact that ... As the detailed results for the two-atom case are published in [13], only .... state are |gee〉, |ege〉 and |eeg〉 and are denoted as |5〉, |6〉 and |7〉. Finally, the ...

Dilution effects on combined magnetic and electric dipole interactions: A study of ferromagnetic cobalt nanoparticles with tuneable interactions

Science.gov (United States)

Hod, M.; Dobroserdova, A.; Samin, S.; Dobbrow, C.; Schmidt, A. M.; Gottlieb, M.; Kantorovich, S.

2017-08-01

Improved understanding of complex interactions between nanoparticles will facilitate the control over the ensuing self-assembled structures. In this work, we consider the dynamic changes occurring upon dilution in the self-assembly of a system of ferromagnetic cobalt nanoparticles that combine magnetic, electric, and steric interactions. The systems examined here vary in the strength of the magnetic dipole interactions and the amount of point charges per particle. Scattering techniques are employed for the characterization of the self-assembly aggregates, and zeta-potential measurements are employed for the estimation of surface charges. Our experiments show that for particles with relatively small initial number of surface electric dipoles, an increase in particle concentration results in an increase in diffusion coefficients; whereas for particles with relatively high number of surface dipoles, no effect is observed upon concentration changes. We attribute these changes to a shift in the adsorption/desorption equilibrium of the tri-n-octylphosphine oxide (TOPO) molecules on the particle surface. We put forward an explanation, based on the combination of two theoretical models. One predicts that the growing concentration of electric dipoles, stemming from the addition of tri-n-octylphosphine oxide (TOPO) as co-surfactant during particle synthesis, on the surface of the particles results in the overall repulsive interaction. Secondly, using density functional theory, we explain that the observed behaviour of the diffusion coefficient can be treated as a result of the concentration dependent nanoparticle self-assembly: additional repulsion leads to the reduction in self-assembled aggregate size despite the shorter average interparticle distances, and as such provides the growth of the diffusion coefficient.

Many particle magnetic dipole-dipole and hydrodynamic interactions in magnetizable stent assisted magnetic drug targeting

International Nuclear Information System (INIS)

Cregg, P.J.; Murphy, Kieran; Mardinoglu, Adil; Prina-Mello, Adriele

2010-01-01

The implant assisted magnetic targeted drug delivery system of Aviles, Ebner and Ritter is considered both experimentally (in vitro) and theoretically. The results of a 2D mathematical model are compared with 3D experimental results for a magnetizable wire stent. In this experiment a ferromagnetic, coiled wire stent is implanted to aid collection of particles which consist of single domain magnetic nanoparticles (radius ∼10nm). In order to model the agglomeration of particles known to occur in this system, the magnetic dipole-dipole and hydrodynamic interactions for multiple particles are included. Simulations based on this mathematical model were performed using open source C++ code. Different initial positions are considered and the system performance is assessed in terms of collection efficiency. The results of this model show closer agreement with the measured in vitro experimental results and with the literature. The implications in nanotechnology and nanomedicine are based on the prediction of the particle efficiency, in conjunction with the magnetizable stent, for targeted drug delivery.

Spontaneous Formation of Anti-ferromagnetic Vortex Lattice in a Fast Rotating BEC with Dipole Interactions

International Nuclear Information System (INIS)

Yang Shijie; Feng Shiping; Wen Yuchuan; Yu Yue

2007-01-01

When a Bose-Einstein condensate is set to rotate, superfluid vortices will be formed, which finally condense into a vortex lattice as the rotation frequency further increases. We show that the dipole-dipole interactions renormalize the short-range interaction strength and result in a distinction between interactions of parallel-polarized atoms and interactions of antiparallel-polarized atoms. This effect may lead to a spontaneous breakdown of the rapidly rotating Bose condensate into a novel anti-ferromagnetic-like vortex lattice. The upward-polarized Bose condensate forms a vortex lattice, which is staggered against a downward-polarized vortex lattice. A phase diagram related to the coupling strength is obtained.

The search for permanent electric dipole moments, in particular for the one of the neutron

CERN Document Server

CERN. Geneva

2010-01-01

Nonzero permanent electric dipole moments (EDM) of fundamental systems like particles, nuclei, atoms or molecules violate parity and time reversal invariance. Invoking the CPT theorem, time reversal violation implies CP violation. Although CP-violation is implemented in the standard electro-weak theory, EDM generated this way remain undetectably small. However, this CP-violation also appears to fail explaining the observed baryon asymmetry of our universe. Extensions of the standard theory usually include new CP violating phases which often lead to the prediciton of larger EDM. EDM searches in different systems are complementary and various efforts worldwide are underway, but no finite value could be established yet. An improved search for the EDM of the neutron requires, among other things, much better statistics. At PSI, we are presently commissioning a new high intensity source of ultracold neutrons. At the same time, with an international collaboration, we are setting up for a new measurement of the ...

Dynamically fluctuating electric dipole moments in fullerene-based magnets.

Science.gov (United States)

Kambe, Takashi; Oshima, Kokichi

2014-09-19

We report here the direct evidence of the existence of a permanent electric dipole moment in both crystal phases of a fullerene-based magnet--the ferromagnetic α-phase and the antiferromagnetic α'-phase of tetra-kis-(dimethylamino)-ethylene-C60 (TDAE-C60)--as determined by dielectric measurements. We propose that the permanent electric dipole originates from the pairing of a TDAE molecule with surrounding C60 molecules. The two polymorphs exhibit clear differences in their dielectric responses at room temperature and during the freezing process with dynamically fluctuating electric dipole moments, although no difference in their room-temperature structures has been previously observed. This result implies that two polymorphs have different local environment around the molecules. In particular, the ferromagnetism of the α-phase is founded on the homogeneous molecule displacement and orientational ordering. The formation of the different phases with respect to the different rotational states in the Jahn-Teller distorted C60s is also discussed.

Measurement of permanent electric dipole moments of charged hadrons in storage rings

Energy Technology Data Exchange (ETDEWEB)

Pretz, Joerg, E-mail: pretz@physik.rwth-aachen.de [III. Physikalisches Institut (Germany); Collaboration: JEDI Collaboration

2013-03-15

Permanent Electric Dipole Moments (EDMs) of elementary particles violate two fundamental symmetries: time reversal invariance ( T ) and parity ( P ). Assuming the CPT theorem this implies CP violation. The CP violation of the Standard Model is orders of magnitude too small to be observed experimentally in EDMs in the foreseeable future. It is also way too small to explain the asymmetry in abundance of matter and anti-matter in our universe. Hence, other mechanisms of CP violation outside the realm of the Standard Model are searched for and could result in measurable EDMs. Up to now most of the EDM measurements were done with neutral particles. With new techniques it is now possible to perform dedicated EDM experiments with charged hadrons at storage rings where polarized particles are exposed to an electric field. If an EDM exists the spin vector will experience a torque resulting in change of the original spin direction which can be determined with the help of a polarimeter. Although the principle of the measurement is simple, the smallness of the expected effect makes this a challenging experiment requiring new developments in various experimental areas. Complementary efforts to measure EDMs of proton, deuteron and light nuclei are pursued at Brookhaven National Laboratory and at Forschungszentrum Juelich with an ultimate goal to reach a sensitivity of 10{sup - 29}e{center_dot}cm.

Effect of the magnetic dipole interaction on a spin-1 system

Science.gov (United States)

Hu, Fangqi; Jia, Wei; Zhao, Qing

2018-05-01

We consider a hybrid system composed of a spin-1 triplet coupled to a nuclear spin. We study the effect of the axisymmetric and the quadrupole term of the magnetic dipole interaction between the two electrons forming the triplet on the energy spectrum in a static magnetic field. The energy spectrum obtained by directly diagonalizing the Hamiltonian of the system shows that these two terms not only remove the special crossings that appear in the absence of the magnetic dipole interaction, but also produce new (avoided) crossings by lifting the relevant levels. Specially, the gaps between the avoided crossing levels increase with the strength of the quadrupole term. In order to accurately illustrate these effects, we present the results for the discriminant and von Neumann entropy of one electron interacting with the rest of the whole system. Finally, by numerically solving the time-dependent Schrödinger equations of the system, we discover that the polarization oscillation of electron and nuclear spin is in-phase and the total average longitudinal spin is not conserved at location of avoided crossing, but the two results are opposite beyond that.

Electron paramagnetic resonance line shifts and line shape changes due to heisenberg spin exchange and dipole-dipole interactions of nitroxide free radicals in liquids 8. Further experimental and theoretical efforts to separate the effects of the two interactions.

Science.gov (United States)

Peric, Mirna; Bales, Barney L; Peric, Miroslav

2012-03-22

The work in part 6 of this series (J. Phys. Chem. A 2009, 113, 4930), addressing the task of separating the effects of Heisenberg spin exchange (HSE) and dipole-dipole interactions (DD) on electron paramagnetic resonance (EPR) spectra of nitroxide spin probes in solution, is extended experimentally and theoretically. Comprehensive measurements of perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDT) in squalane, a viscous alkane, paying special attention to lower temperatures and lower concentrations, were carried out in an attempt to focus on DD, the lesser understood of the two interactions. Theoretically, the analysis has been extended to include the recent comprehensive treatment by Salikhov (Appl. Magn. Reson. 2010, 38, 237). In dilute solutions, both interactions (1) introduce a dispersion component, (2) broaden the lines, and (3) shift the lines. DD introduces a dispersion component proportional to the concentration and of opposite sign to that of HSE. Equations relating the EPR spectral parameters to the rate constants due to HSE and DD have been derived. By employing nonlinear least-squares fitting of theoretical spectra to a simple analytical function and the proposed equations, the contributions of the two interactions to items 1-3 may be quantified and compared with the same parameters obtained by fitting experimental spectra. This comparison supports the theory in its broad predictions; however, at low temperatures, the DD contribution to the experimental dispersion amplitude does not increase linearly with concentration. We are unable to deduce whether this discrepancy is due to inadequate analysis of the experimental data or an incomplete theory. A new key aspect of the more comprehensive theory is that there is enough information in the experimental spectra to find items 1-3 due to both interactions; however, in principle, appeal must be made to a model of molecular diffusion to separate the two. The permanent diffusion model is used to

Electric dipole moments and chemical bonding of diatomic alkali-alkaline earth molecules.

Science.gov (United States)

Pototschnig, Johann V; Hauser, Andreas W; Ernst, Wolfgang E

2016-02-17

We investigate the properties of alkali-alkaline earth diatomic molecules in the lowest Σ(+) states of the doublet and quartet multiplicity by ab initio calculations. In all sixteen cases studied, the permanent electric dipole moment points in opposite directions for the two spin states. This peculiarity can be explained by molecular orbital theory. We further discuss dissociation energies and bond distances. We analyze trends and provide an empirically motivated model for the prediction of the permanent electric dipole moment for combinations of alkali and alkaline earth atoms not studied in this work.

Limits on CP nonconserving interactions from electric dipole moments

International Nuclear Information System (INIS)

Haxton, W.C.

1994-01-01

I discuss bounds on CP-nonconserving (CPNC) and parity-nonconserving (PNC) hadronic interactions that result from measurements of atomic electric dipole moments. In most models of hadronic CPNC, the nuclear edm arises primarily from the polarization of the ground state by the CPNC PNC NN interaction, rather than from the edms of valence nucleons. When the atom is placed in an external field, the nucleus is fully shielded apart from nuclear finite size effects and relativistic corrections arising from hyperfine interactions, so that careful atomic calculations must be performed to deduce the residual sensitivity to the nuclear edm. I describe these shielding effects qualitatively, and present results from more detailed calculations. Atomic limits, when translated into effective bounds on the neutron edm, have now reached sensitivities that are comparable to direct neutron edm limits. I also discuss limits that can be extracted on CPNC parity-conserving (PC) hadronic interactions. Such interactions can generate atomic edms when combined with weak radiative corrections

Dipoles on a Two-leg Ladder

DEFF Research Database (Denmark)

Gammelmark, Søren; Zinner, Nikolaj Thomas

2013-01-01

We study polar molecules with long-range dipole-dipole interactions confined to move on a two-leg ladder for different orientations of the molecular dipole moments with respect to the ladder. Matrix product states are employed to calculate the many-body ground state of the system as function...... that there is a critical angle at which ordering disappears. This angle is slightly larger than the angle at which the dipoles are non-interacting along a single leg. This behavior should be observable using current experimental techniques....

Study of dipole interaction in micron-width NiFe/Cu/NiFe/NiO wire using exchange anisotropy

International Nuclear Information System (INIS)

Kimura, Takashi; Itagaki, Yoshio; Wakaya, Fujio; Gamo, Kenji

2001-01-01

The dipole interaction between a NiFe layer pinned by a NiO and a free NiFe layer in a micron-wide NiFe/Cu/NiFe/NiO wire was studied by changing the direction of the exchange bias from the NiO layer. The effect of the dipole interaction when the exchange bias was perpendicular to the wire axis was larger than that when the exchange bias was parallel to the wire axis, and was consistently explained by the stray field caused by the magnetic charges of the pinned layer. It was demonstrated that this method, using exchange anisotropy, is useful for investigating the dipole interaction between ferromagnetic materials separated by a nonmagnetic material in small-scale magnetic multilayers. [copyright] 2001 American Institute of Physics

Effect of finite detection efficiency on the observation of the dipole-dipole interaction of a few Rydberg atoms

International Nuclear Information System (INIS)

Ryabtsev, I. I.; Tretyakov, D. B.; Beterov, I. I.; Entin, V. M.

2007-01-01

We have developed a simple analytical model describing multiatom signals that are measured in experiments on dipole-dipole interaction at resonant collisions of a few Rydberg atoms. It has been shown that finite efficiency of the selective field-ionization detector leads to the mixing up of the spectra of resonant collisions registered for various numbers of Rydberg atoms. The formulas which help to estimate an appropriate mean Rydberg atom number for a given detection efficiency are presented. We have found that a measurement of the relation between the amplitudes of collisional resonances observed in the one- and two-atom signals provides a straightforward determination of the absolute detection efficiency and mean Rydberg atom number. We also performed a testing experiment on resonant collisions in a small excitation volume of a sodium atomic beam. The resonances observed for 1-4 detected Rydberg atoms have been analyzed and compared with theory

On dipole interaction of the oxcillator with a scalar field

International Nuclear Information System (INIS)

Razumov, A.V.; Taranov, A.Yu.

1979-01-01

Dipole interaction of the oscillator with scalar field in one-dimensional case is studied. Solutions of the classical equations of motion are found and the conditions of the boundedness of the classical Hamiltonian from below are obtained. In the quantum theory the problem of choosing the zeroth approximation of perturbation theory in the case when the spectra of the free and complete Hamiltonian do not coincide with each other, is analysed

Study of dipole-dipole interactions between iron and spin labelled centre in cytochrome C by means of ESR; Badanie oddzialywan dipolowo-dipolowych pomiedzy zelazem a znacznikiem spinowym w cytochromie C metoda SF EPR

Energy Technology Data Exchange (ETDEWEB)

Blicharski, W; Froncisz, W; Kostrzewa, A; Osyczka, A; Turyna, B [Inst. Biologii Molekularnej, Uniwersytet Jagiellonski, Cracow (Poland)

1994-12-31

The influence of dipole-dipole interactions between two different spins localized in the same molecule on spin-lattice relaxation time have been discussed on the base of measured spectra by means of pulsed ESR. The structural conclusions, the distance between interacting paramagnetic centers, for molecules of three derivatives of cytochrome C have been presented. 8 refs, 2 figs, 1 tab.

The permanent electric dipole moment of the neutron and atomic 129Xe

International Nuclear Information System (INIS)

Heckel, B.

1984-01-01

Recently the Seattle group has measured the permanent edm of atomic 129 Xe to be d /sub Xe/ = (-0.3 + or - 1.1) x 10 -26 cm. This measurement provides an improvement by a factor of 10 4 over the best previous measurement of an atomic edm. The edm of Xe is most sensitive to a T-violating electron-nucleon interaction, but can also be generated by an intrinsic electron edm or an edm of the Xe nucleus. In the second half of this presentation, each of these mechanisms will be briefly discussed and a description of the experiment will be given

Electric dipole moment of diatomic molecules by configuration interaction. IV.

Science.gov (United States)

Green, S.

1972-01-01

The theory of basis set dependence in configuration interaction calculations is discussed, taking into account a perturbation model which is valid for small changes in the self-consistent field orbitals. It is found that basis set corrections are essentially additive through first order. It is shown that an error found in a previously published dipole moment calculation by Green (1972) for the metastable first excited state of CO was indeed due to an inadequate basis set as claimed.

Magnetic dipolar interaction in two-dimensional complex plasmas

International Nuclear Information System (INIS)

Feldmann, J D; Kalman, G J; Rosenberg, M

2006-01-01

Various interactions can play a role between the mesoscopic dust grains of a complex plasma. We study a system composed of dust grains that have both an electric charge and a permanent magnetic dipole moment. It is assumed that the grains occupy lattice sites, as dictated by their Coulomb interaction. In addition, they possess a spin degree of freedom (orientation of magnetic dipole moment) that is not constrained by the Coulomb interaction, thus allowing for the possibility of equilibrium orientational ordering and 'wobbling' about the equilibrium orientations. As a result, collective modes develop. We identify in-plane and out-of-plane wobbling modes and discuss their dispersion characteristics both in the ferromagnetic and in the anti-ferromagnetic ground state

Interaction of a supersonic plasma jet with a coaxial dipole magnetic field

International Nuclear Information System (INIS)

Landes, K.

1975-01-01

A low pressure plasma jet of considerable conductivity can be influenced by a magnetic field. On the other hand the influencing magnetic field is changed by currents induced in the plasma jet. New astrophysical examples of suchlike interaction have been found in the investigation of the moon, where the partially not currentfree solar wind is influenced by locally confined magnetic fields. In the experiment reported, the interaction of a supersonic plasma jet with a coaxial, dipole-shaped magnetic field is investigated. A current is superimposed to the plasma jet. (Auth.)

Electric dipole moments reconsidered

International Nuclear Information System (INIS)

Rupertsberger, H.

1989-01-01

The electric dipole moments of elementary particles, atoms, molecules and their connection to the electric susceptibility are discussed for stationary states. Assuming rotational invariance it is emphasized that for such states only in the case of a parity and time reversal violating interaction the considered particles can obtain a nonvanishing expectation value for the electric dipole moment. 1 fig., 13 refs. (Author)

Electric dipole moment of 3He

International Nuclear Information System (INIS)

Avishai, Y.; Fabre de la Ripelle, M.

1987-01-01

The contribution of CP violating nucleon-nucleon interaction to the electric dipole moment of 3 He is evaluated following a recent proposal for its experimental detection. Two models of CP violating interactions are used, namely, the Kobayashi-Maskawa mechanism and the occurrence of the Θ term in the QCD lagrangian. These CP violating interactions are combined with realistic strong nucleon-nucleon interactions to induce a CP forbidden component of the 3 He wave function. The matrix element of the electric dipole operator is then evaluated between CP allowed and CP forbidden components yielding the observable electric dipole moment. Using the parameters emerging from the penguin terms in the Kobaysashi-Maskawa model we obtain a result much larger than the electric dipole moment of the neutron in the same model. On the other hand, no enhancement is found for the Θ-term mechanism. A possible explanation for this difference is discussed. Numerical estimates can be given only in the Kobayashi-Maskawa model, giving d( 3 He) ≅ 10 30 e . cm. In the second mechanism, the estimate give d ( 3 He) ≅ 10 16 anti Θ. (orig.)

Molecular near-field antenna effect in resonance hyper-Raman scattering: Intermolecular vibronic intensity borrowing of solvent from solute through dipole-dipole and dipole-quadrupole interactions

Energy Technology Data Exchange (ETDEWEB)

Shimada, Rintaro; Hamaguchi, Hiro-o, E-mail: hhama@nctu.edu.tw [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan (China)

2014-05-28

We quantitatively interpret the recently discovered intriguing phenomenon related to resonance Hyper-Raman (HR) scattering. In resonance HR spectra of all-trans-β-carotene (β-carotene) in solution, vibrations of proximate solvent molecules are observed concomitantly with the solute β-carotene HR bands. It has been shown that these solvent bands are subject to marked intensity enhancements by more than 5 orders of magnitude under the presence of β-carotene. We have called this phenomenon the molecular-near field effect. Resonance HR spectra of β-carotene in benzene, deuterated benzene, cyclohexane, and deuterated cyclohexane have been measured precisely for a quantitative analysis of this effect. The assignments of the observed peaks are made by referring to the infrared, Raman, and HR spectra of neat solvents. It has been revealed that infrared active and some Raman active vibrations are active in the HR molecular near-field effect. The observed spectra in the form of difference spectra (between benzene/deuterated benzene and cyclohexane/deuterated cyclohexane) are quantitatively analyzed on the basis of the extended vibronic theory of resonance HR scattering. The theory incorporates the coupling of excited electronic states of β-carotene with the vibrations of a proximate solvent molecule through solute–solvent dipole–dipole and dipole–quadrupole interactions. It is shown that the infrared active modes arise from the dipole–dipole interaction, whereas Raman active modes from the dipole–quadrupole interaction. It is also shown that vibrations that give strongly polarized Raman bands are weak in the HR molecular near-field effect. The observed solvent HR spectra are simulated with the help of quantum chemical calculations for various orientations and distances of a solvent molecule with respect to the solute. The observed spectra are best simulated with random orientations of the solvent molecule at an intermolecular distance of 10 Å.

Energy dissipation of rigid dipoles in a viscous fluid under the action of a time-periodic field: The influence of thermal bath and dipole interaction

Science.gov (United States)

Lyutyy, T. V.; Reva, V. V.

2018-05-01

Ferrofluid heating by an external alternating field is studied based on the rigid dipole model, where the magnetization of each particle in a fluid is supposed to be firmly fixed in the crystal lattice. Equations of motion, employing Newton's second law for rotational motion, the condition of rigid body rotation, and the assumption that the friction torque is proportional to angular velocity are used. This oversimplification permits us to expand the model easily: to take into account the thermal noise and interparticle interaction that allows us to estimate from unified positions the role of thermal activation and dipole interaction in the heating process. Our studies are conducted in three stages. The exact expressions for the average power loss of a single particle are obtained within the dynamical approximation. Then, in the stochastic case, the power loss of a single particle is estimated analytically using the Fokker-Planck equation and numerically using the effective Langevin equation. Finally, the power loss for the particle ensemble is obtained using the molecular dynamics method. Here, the local dipole fields are calculated approximately based on the Barnes-Hut algorithm. The revealed trends in the behavior of both a single particle and the particle ensemble suggest the way of choosing the conditions for obtaining the maximum heating efficiency. The competitiveness character of the interparticle interaction and thermal noise is investigated in detail. Two situations, when the thermal noise rectifies the power loss reduction caused by the interaction, are described. The first of them is related to the complete destruction of dense clusters at high noise intensity. The second one originates from the rare switching of the particles in clusters due to thermal activation, when the noise intensity is relatively weak. In this way, the constructive role of noise appears in the system.

Electric Dipole Moments of Hadrons

OpenAIRE

Wirzba, Andreas

2016-01-01

A nonzero electric dipole moment (EDM) of the neutron, proton, deuteron, helion or any finite system necessarily involves the breaking of a symmetry, either by the presence of external fields (leading to the case of induced EDMs) or explicitly by the breaking of the discrete parity and time-reflection symmetries in the case of permanent EDMs. Recent - and in the case of the deuteron even unpublished - results for the relevant matrix elements of nuclear EDM operators are presented and the rel...

Constraints on Exotic Dipole-Dipole Couplings between Electrons at the Micrometer Scale.

Science.gov (United States)

Kotler, Shlomi; Ozeri, Roee; Kimball, Derek F Jackson

2015-08-21

New constraints on exotic dipole-dipole interactions between electrons at the micrometer scale are established, based on a recent measurement of the magnetic interaction between two trapped 88Sr(+) ions. For light bosons (mass≤0.1  eV) we obtain a 90% confidence interval for an axial-vector-mediated interaction strength of |g(A)(e)g(A)(e)/4πℏc|≤1.2×10(-17). Assuming CPT invariance, this constraint is compared to that on anomalous electron-positron interactions, derived from positronium hyperfine spectroscopy. We find that the electron-electron constraint is 6 orders of magnitude more stringent than the electron-positron counterpart. Bounds on pseudoscalar-mediated interaction as well as on torsion gravity are also derived and compared with previous work performed at different length scales. Our constraints benefit from the high controllability of the experimental system which contained only two trapped particles. It therefore suggests a useful new platform for exotic particle searches, complementing other experimental efforts.

Giant Primeval Magnetic Dipoles

Science.gov (United States)

Thompson, Christopher

2017-07-01

Macroscopic magnetic dipoles are considered cosmic dark matter. Permanent magnetism in relativistic field structures can involve some form of superconductivity, one example being current-carrying string loops (“springs”) with vanishing net tension. We derive the cross-section for free classical dipoles to collide, finding it depends weakly on orientation when mutual precession is rapid. The collision rate of “spring” loops with tension { T }˜ {10}-8{c}4/G in galactic halos approaches the measured rate of fast radio bursts (FRBs) if the loops compose most of the dark matter. A large superconducting dipole (LSD) with mass ˜1020 g and size ˜1 mm will form a ˜100 km magnetosphere moving through interstellar plasma. Although hydromagnetic drag is generally weak, it is strong enough to capture some LSDs into long-lived rings orbiting supermassive black holes (SMBHs) that form by the direct collapse of massive gas clouds. Repeated collisions near young SMBHs could dominate the global collision rate, thereby broadening the dipole mass spectrum. Colliding LSDs produce tiny, hot electromagnetic explosions. The accompanying paper shows that these explosions couple effectively to propagating low-frequency electromagnetic modes, with output peaking at 0.01-1 THz. We describe several constraints on, and predictions of, LSDs as cosmic dark matter. The shock formed by an infalling LSD triggers self-sustained thermonuclear burning in a C/O (ONeMg) white dwarf (WD) of mass ≳1 M ⊙ (1.3 M ⊙). The spark is generally located off the center of the WD. The rate of LSD-induced explosions matches the observed rate of Type Ia supernovae.

Angle-dependent quantum Otto heat engine based on coherent dipole-dipole coupling

Science.gov (United States)

Su, Shan-He; Luo, Xiao-Qing; Chen, Jin-Can; Sun, Chang-Pu

2016-08-01

Electromagnetic interactions between molecules or within a molecule have been widely observed in biological systems and exhibit broad application for molecular structural studies. Quantum delocalization of molecular dipole moments has inspired researchers to explore new avenues to utilize this physical effect for energy harvesting devices. Herein, we propose a simple model of the angle-dependent quantum Otto heat engine which seeks to facilitate the conversion of heat to work. Unlike previous studies, the adiabatic processes are accomplished by varying only the directions of the magnetic field. We show that the heat engine continues to generate power when the angle relative to the vector r joining the centres of coupled dipoles departs from the magic angle θm where the static coupling vanishes. A significant improvement in the device performance has to be attributed to the presence of the quantum delocalized levels associated with the coherent dipole-dipole coupling. These results obtained may provide a promising model for the biomimetic design and fabrication of quantum energy generators.

Electric dipole polarizability from first principles calculations

International Nuclear Information System (INIS)

Miorelli, M.; University of British Columbia, Vancouver, BC; Bacca, S.; University of Manitoba; Barnea, N.

2016-01-01

The electric dipole polarizability quantifies the low-energy behavior of the dipole strength and is related to critical observables such as the radii of the proton and neutron distributions. Its computation is challenging because most of the dipole strength lies in the scattering continuum. In our paper we combine integral transforms with the coupled-cluster method and compute the dipole polarizability using bound-state techniques. Furthermore, employing different interactions from chiral effective field theory, we confirm the strong correlation between the dipole polarizability and the charge radius, and study its dependence on three-nucleon forces. Finally, we find good agreement with data for the 4 He, 40 Ca, and 16 O nuclei, and predict the dipole polarizability for the rare nucleus 22 O.

Influence of magnetic dipole and magnetoelastic interactions on the phase states of 2D non-Heisenberg ferromagnetic with complex exchange interactions

International Nuclear Information System (INIS)

Fridman, Yu.A.; Matunin, D.A.; Klevets, Ph.N.; Kosmachev, O.A.

2009-01-01

The phase states of the 2D non-Heisenberg ferromagnetic with anisotropic bilinear and biquadratic exchange interactions are investigated. The limiting cases of the system under consideration are the two-dimensional XY-model with biquadratic exchange interaction and the isotropic Heisenberg ferromagnetic. The account of the magnetic dipole interaction leads to the realization of spatially inhomogeneous quadrupolar phase. The stability regions of various phase transitions for different values of the material parameters are studied. The phase diagram is built. Besides, the temperature phase transitions are investigated. The influence of the magnetoelastic interaction on the formation of the long-range quadrupolar order is determined.

The dipole moment of the electron carrier adrenodoxin is not critical for redox partner interaction and electron transfer.

Science.gov (United States)

Hannemann, Frank; Guyot, Arnaud; Zöllner, Andy; Müller, Jürgen J; Heinemann, Udo; Bernhardt, Rita

2009-07-01

Dipole moments of proteins arise from helical dipoles, hydrogen bond networks and charged groups at the protein surface. High protein dipole moments were suggested to contribute to the electrostatic steering between redox partners in electron transport chains of respiration, photosynthesis and steroid biosynthesis, although so far experimental evidence for this hypothesis was missing. In order to probe this assumption, we changed the dipole moment of the electron transfer protein adrenodoxin and investigated the influence of this on protein-protein interactions and electron transfer. In bovine adrenodoxin, the [2Fe-2S] ferredoxin of the adrenal glands, a dipole moment of 803 Debye was calculated for a full-length adrenodoxin model based on the Adx(4-108) and the wild type adrenodoxin crystal structures. Large distances and asymmetric distribution of the charged residues in the molecule mainly determine the observed high value. In order to analyse the influence of the resulting inhomogeneous electric field on the biological function of this electron carrier the molecular dipole moment was systematically changed. Five recombinant adrenodoxin mutants with successively reduced dipole moment (from 600 to 200 Debye) were analysed for their redox properties, their binding affinities to the redox partner proteins and for their function during electron transfer-dependent steroid hydroxylation. None of the mutants, not even the quadruple mutant K6E/K22Q/K24Q/K98E with a dipole moment reduced by about 70% showed significant changes in the protein function as compared with the unmodified adrenodoxin demonstrating that neither the formation of the transient complex nor the biological activity of the electron transfer chain of the endocrine glands was affected. This is the first experimental evidence that the high dipole moment observed in electron transfer proteins is not involved in electrostatic steering among the proteins in the redox chain.

Dipole-induced exchange bias.

Science.gov (United States)

Torres, Felipe; Morales, Rafael; Schuller, Ivan K; Kiwi, Miguel

2017-11-09

The discovery of dipole-induced exchange bias (EB), switching from negative to positive sign, is reported in systems where the antiferromagnet and the ferromagnet are separated by a paramagnetic spacer (AFM-PM-FM). The magnitude and sign of the EB is determined by the cooling field strength and the PM thickness. The same cooling field yields negative EB for thin spacers, and positive EB for thicker ones. The EB decay profile as a function of the spacer thickness, and the change of sign, are attributed to long-ranged dipole coupling. Our model, which accounts quantitatively for the experimental results, ignores the short range interfacial exchange interactions of the usual EB theories. Instead, it retains solely the long range dipole field that allows for the coupling of the FM and AFM across the PM spacer. The experiments allow for novel switching capabilities of long range EB systems, while the theory allows description of the structures where the FM and AFM are not in atomic contact. The results provide a new approach to design novel interacting heterostructures.

Extreme enhancement of blocking temperature by strong magnetic dipoles interaction of α-Fe nanoparticle-based high-density agglomerate

International Nuclear Information System (INIS)

Kura, H; Takahashi, M; Ogawa, T

2011-01-01

High-volume fraction α-Fe nanoparticle (NP) agglomerates were prepared using chemically synthesized NPs. In the agglomerate, NPs are separated by surfactant and NP superlattice with a hexagonal close-packed structure is locally realized. Volume fractions of NPs at 20% and 42% were obtained in agglomerates consisting of 2.9 nm and 8.2 nm diameter NPs, respectively. The high saturation magnetization of α-Fe NPs and high volume fraction of NPs in the agglomerate provide strong magnetic dipole-dipole interaction. The interaction energy of the agglomerate became much larger than the anisotropic energy of individual NPs. As a result, the blocking temperature of the 8.2 nm NP agglomerate was significantly enhanced from 52.2 K to around 500 K. (fast track communication)

Photoelectron spectroscopy and the dipole approximation

Energy Technology Data Exchange (ETDEWEB)

Hemmers, O.; Hansen, D.L.; Wang, H. [Univ. of Nevada, Las Vegas, NV (United States)] [and others

1997-04-01

Photoelectron spectroscopy is a powerful technique because it directly probes, via the measurement of photoelectron kinetic energies, orbital and band structure in valence and core levels in a wide variety of samples. The technique becomes even more powerful when it is performed in an angle-resolved mode, where photoelectrons are distinguished not only by their kinetic energy, but by their direction of emission as well. Determining the probability of electron ejection as a function of angle probes the different quantum-mechanical channels available to a photoemission process, because it is sensitive to phase differences among the channels. As a result, angle-resolved photoemission has been used successfully for many years to provide stringent tests of the understanding of basic physical processes underlying gas-phase and solid-state interactions with radiation. One mainstay in the application of angle-resolved photoelectron spectroscopy is the well-known electric-dipole approximation for photon interactions. In this simplification, all higher-order terms, such as those due to electric-quadrupole and magnetic-dipole interactions, are neglected. As the photon energy increases, however, effects beyond the dipole approximation become important. To best determine the range of validity of the dipole approximation, photoemission measurements on a simple atomic system, neon, where extra-atomic effects cannot play a role, were performed at BL 8.0. The measurements show that deviations from {open_quotes}dipole{close_quotes} expectations in angle-resolved valence photoemission are observable for photon energies down to at least 0.25 keV, and are quite significant at energies around 1 keV. From these results, it is clear that non-dipole angular-distribution effects may need to be considered in any application of angle-resolved photoelectron spectroscopy that uses x-ray photons of energies as low as a few hundred eV.

Manipulation of positron orbits in a dipole magnetic field with fluctuating electric fields

Science.gov (United States)

Saitoh, H.; Horn-Stanja, J.; Nißl, S.; Stenson, E. V.; Hergenhahn, U.; Pedersen, T. Sunn; Singer, M.; Dickmann, M.; Hugenschmidt, C.; Stoneking, M. R.; Danielson, J. R.; Surko, C. M.

2018-01-01

We report the manipulation of positron orbits in a toroidal dipole magnetic field configuration realized with electric fields generated by segmented electrodes. When the toroidal circulation motion of positrons in the dipole field is coupled with time-varying electric fields generated by azimuthally segmented outer electrodes, positrons undergo oscillations of their radial positions. This enables quick manipulation of the spatial profiles of positrons in a dipole field trap by choosing appropriate frequency, amplitude, phase, and gating time of the electric fields. According to numerical orbit analysis, we applied these electric fields to positrons injected from the NEPOMUC slow positron facility into a prototype dipole field trap experiment with a permanent magnet. Measurements with annihilation γ-rays clearly demonstrated the efficient compression effects of positrons into the strong magnetic field region of the dipole field configuration. This positron manipulation technique can be used as one of essential tools for future experiments on the formation of electron-positron plasmas.

C6H6/Au(111): Interface dipoles, band alignment, charging energy, and van der Waals interaction

International Nuclear Information System (INIS)

Abad, E.; Martinez, J. I.; Flores, F.; Ortega, J.; Dappe, Y. J.

2011-01-01

We analyze the benzene/Au(111) interface taking into account charging energy effects to properly describe the electronic structure of the interface and van der Waals interactions to obtain the adsorption energy and geometry. We also analyze the interface dipoles and discuss the barrier formation as a function of the metal work-function. We interpret our DFT calculations within the induced density of interface states (IDIS) model. Our results compare well with experimental and other theoretical results, showing that the dipole formation of these interfaces is due to the charge transfer between the metal and benzene, as described in the IDIS model.

Torque for electron spin induced by electron permanent electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Senami, Masato, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Fukuda, Masahiro, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Ogiso, Yoji, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp; Tachibana, Akitomo, E-mail: senami@me.kyoto-u.ac.jp, E-mail: akitomo@scl.kyoto-u.ac.jp [Department of Micro Engineering, Kyoto University, Kyoto 615-8540 (Japan)

2014-10-06

The spin torque of the electron is studied in relation to the electric dipole moment (EDM) of the electron. The spin dynamics is known to be given by the spin torque and the zeta force in quantum field theory. The effect of the EDM on the torque of the spin brings a new term in the equation of motion of the spin. We study this effect for a solution of the Dirac equation with electromagnetic field.

The BFKL pomeron calculus in the dipole approach

International Nuclear Information System (INIS)

Kozlov, M.; Levin, E.; Prygarin, A.

2007-01-01

In this paper we continue to pursue a goal of finding an effective theory for high energy interaction in QCD based on the colour dipole approach, for which the BFKL pomeron calculus gives a low energy limit. The key problem, that we try to solve in this paper is the probabilistic interpretation of the BFKL pomeron calculus in terms of the colourless dipoles and their interactions. We demonstrate that the BFKL pomeron calculus has two equivalent descriptions: (i) one is the generating functional which gives a clear probabilistic interpretation of the processes of high energy scattering and also provides a Hamiltonian-like description of the system of interacting dipoles; (ii) the second is the Langevin equation with a specific noise term which is rather complicated. We found that at high energies this Langevin equation can be reduced to the Langevin equation for directed percolation in the momentum space if the impact parameter is large, namely, b1/k, where k is the transverse momentum of a dipole. Unfortunately, this simplified form of Langevin equation is not applicable for summation of pomeron loops, where one integrates over all possible values of impact parameter. We show that the BFKL pomeron calculus with two vertices (splitting P->P+P and merging P+P->P of pomerons) can be interpreted as a system of colourless dipoles with two processes: the decay of one dipole into two and the merging of two dipoles into one dipole. However, a number of assumptions we have to make on the way to simplify the noise term in the Langevin equation and/or to apply the probabilistic interpretation, therefore, we can consider both of these approaches in the present form only as the QCD motivated models

Microscopic evaluation of the nuclear dipole polarizability

Energy Technology Data Exchange (ETDEWEB)

Lipparini, E; Orlandini, G; Stringari, S; Traini, M [Trento Univ. (Italy). Dept. di Matematica e Fisica

1977-12-01

The dipole polarizability sum rule has been evaluated by means of a restricted Hartree-Fock approach. The method leads to a simple and analytical expression for the dipole polarizability. Explicit calculations have been performed in /sup 16/O and /sup 40/Ca with different types of interaction.

Optimal control of orientation and entanglement for two dipole-dipole coupled quantum planar rotors.

Science.gov (United States)

Yu, Hongling; Ho, Tak-San; Rabitz, Herschel

2018-05-09

Optimal control simulations are performed for orientation and entanglement of two dipole-dipole coupled identical quantum rotors. The rotors at various fixed separations lie on a model non-interacting plane with an applied control field. It is shown that optimal control of orientation or entanglement represents two contrasting control scenarios. In particular, the maximally oriented state (MOS) of the two rotors has a zero entanglement entropy and is readily attainable at all rotor separations. Whereas, the contrasting maximally entangled state (MES) has a zero orientation expectation value and is most conveniently attainable at small separations where the dipole-dipole coupling is strong. It is demonstrated that the peak orientation expectation value attained by the MOS at large separations exhibits a long time revival pattern due to the small energy splittings arising form the extremely weak dipole-dipole coupling between the degenerate product states of the two free rotors. Moreover, it is found that the peak entanglement entropy value attained by the MES remains largely unchanged as the two rotors are transported to large separations after turning off the control field. Finally, optimal control simulations of transition dynamics between the MOS and the MES reveal the intricate interplay between orientation and entanglement.

Effect of dipole interaction on collective modes in 3He-A

International Nuclear Information System (INIS)

Tewordt, L.; Schopohl, N.; Vollhardt, D.

1977-01-01

A general theory for the correlation functions of superfluid 3 He which takes into account rigorously the magnetic dipole interaction is developed. The resulting equations are solved for the Anderson--Brinkman--Morel (ABM) state and for wave vectors q oriented parallel to the energy gap axis. Then the dispersion relations of low-frequency modes, including Fermi liquid corrections and damping due to pair breaking, are calculated in the zero-temperature and zero-field limit. There are two real frequency modes arising from each of the longitudinal and transverse spin density correlation functions: a spin wave and an orbit wave, both exhibiting a frequency gap where that of the spin wave is somewhat modified in comparison to the unperturbed longitudinal nuclear magnetic resonance frequency Ω/sup ABM//sub L/. The orbit wave is damped much more strongly than the spin wave. Further, there are two real frequency modes arising from the density correlation function: the sound wave, having a frequency gap of the order Ω/sup ABM//sub L/, and an orbit wave, exhibiting a gap in wave number of order Ω/sup ABM//sub L//v/sub F/.: The NMR frequency undergoes a small splitting, which is the result of the splitting of the energy gap due to the dipole interaction. One of the two gaps still has nodes.: In addition to these low-frequency modes our equations yield resonances at frequencies of the order of the gap frequency Δ 0 /h, i.e., at ω=1.22Δ 0 /h and at ω=1.58 Δ 0 /h. The damping and the oscillator strengths of these resonances are calculated

Point interactions of the dipole type defined through a three-parametric power regularization

International Nuclear Information System (INIS)

Zolotaryuk, A V

2010-01-01

A family of point interactions of the dipole type is studied in one dimension using a regularization by rectangles in the form of a barrier and a well separated by a finite distance. The rectangles and the distance are parametrized by a squeezing parameter ε → 0 with three powers μ, ν and τ describing the squeezing rates for the barrier, the well and the distance, respectively. This parametrization allows us to construct a whole family of point potentials of the dipole type including some other point interactions, such as e.g. δ-potentials. Varying the power τ, it is possible to obtain in the zero-range limit the following two cases: (i) the limiting δ'-potential is opaque (the conventional result obtained earlier by some authors) or (ii) this potential admits a resonant tunneling (the opposite result obtained recently by other authors). The structure of resonances (if any) also depends on a regularizing sequence. The sets of the {μ, ν, τ}-space where a non-zero (resonant or non-resonant) transmission occurs are found. For all these cases in the zero-range limit the transfer matrix is shown to be with real parameters χ and g depending on a regularizing sequence. Those cases when χ ≠ 1 and g ≠ 0 mean that the corresponding δ'-potential is accompanied by an effective δ-potential.

Constraints on T-odd and P-even hadronic interactions from nucleon, nuclear, and atomic electric dipole moments

International Nuclear Information System (INIS)

Haxton, W.C.; Hoering, A.; Musolf, M.J.; Old Dominion Univ., Norfolk, VA

1994-01-01

We deduce constraints on time-reversal-noninvariant (TRNI), parity-conserving (PC) hadronic interactions from nucleon, nuclear, and atomic electric dipole moment (edm) limits. Such interactions generate edm's through weak radiative corrections. We consider long-ranged mechanisms, i.e., those mediated by meson exchanges in contrast to short-range two-loop mechanisms. We find that the ratio of typical TRNI. PC nuclear matrix elements to those of the strong interaction are approx-lt 10 -5 , a limit about two orders of magnitude more stringent than those from direct detailed balance studies of such interactions

Permanent magnets in accelerators can save energy, space and cost

DEFF Research Database (Denmark)

Bødker, F.; Baandrup, L.O.; Hauge, N.

2013-01-01

coils permit fine tuning of the magnetic field. Magnetic field measurements and thermal stability tests show that the Green Magnet fully meets the magnetic requirements of the previously used electromagnet. A permanent 30° bending dipole is currently being development to demonstrate the use of Green...

Calculation of helium-like ion dipole susceptibility with account for electron interaction

International Nuclear Information System (INIS)

Pal'chikov, V.G.; Tkachev, A.N.

1989-01-01

Numerical estimations of electron interaction effects are carried out for helium-like ions inserted in a homogeneous electric field. Statistical dipole polarizations and hyperpolarizations are calculated for the main state taking into account corrections of the first order to approximation of noninteracting electrons. Summation according to the full spectrum of intermediate states is carried out by the method of Coulomb-Green functions (CGF), that permitted to use analytical methods to calculate matrix elements of correlation diagrams. When calculating polarizations, relativistic corrections ∼(αZ) 2 , where α - the constant of a fine structure, Z-nucleus charge, are taken into account

The neutron electric dipole moments as a test of the superweak interaction theory

CERN Document Server

Wolfenstein, Lincoln

1974-01-01

Theoretical calculations of the neutron electric dipole moment D/sub n / are reviewed for various theories of CP violation. It is shown that for the superweak interaction theory D/sub n/ is less than 10/sup -29/ e.cm in contrast to values of 10/sup -23/ to 10/sup -24/ predicted by many but not all milliweak theories. It is concluded that prospective measurements of D/sub n/ may provide decisive evidence against or significant evidence in favour of the superweak theory. (26 refs).

Description of the giant dipole mode in states of high angular momentum

International Nuclear Information System (INIS)

Hilton, R.R.

1982-01-01

The effects of the Coriolis interaction on the giant dipole mode is discussed within the framework of a cranked deformed oscillator in which dipole-dipole two body forces are taken into account. Energy splittings of the dipole mode in addition to those attributable to the shape are found. (orig.)

Dipole moments of the rho meson

International Nuclear Information System (INIS)

Hecht, M.B.; McKellar, B.H.P.

1997-04-01

The electric and magnetic dipole moments (EDM) of the rho meson are calculated using the propagators and vertices derived from the quantum chromodynamics Dyson-Schwinger equations. Results obtained from using the Bethe-Salpeter amplitude studied by Chappell, Mitchell et. al., and Pichowsky and Lee, are compared. The rho meson EDM is generated through the inclusion of a quark electric dipole moment, which is left as a free variable. These results are compared to the perturbative results to obtain a measure of the effects of quark interactions and confinement. The two dipole moments are also calculated using the phenomenological MIT bag model to provide a further basis for comparison

Modeling molecular boiling points using computed interaction energies.

Science.gov (United States)

Peterangelo, Stephen C; Seybold, Paul G

2017-12-20

The noncovalent van der Waals interactions between molecules in liquids are typically described in textbooks as occurring between the total molecular dipoles (permanent, induced, or transient) of the molecules. This notion was tested by examining the boiling points of 67 halogenated hydrocarbon liquids using quantum chemically calculated molecular dipole moments, ionization potentials, and polarizabilities obtained from semi-empirical (AM1 and PM3) and ab initio Hartree-Fock [HF 6-31G(d), HF 6-311G(d,p)], and density functional theory [B3LYP/6-311G(d,p)] methods. The calculated interaction energies and an empirical measure of hydrogen bonding were employed to model the boiling points of the halocarbons. It was found that only terms related to London dispersion energies and hydrogen bonding proved significant in the regression analyses, and the performances of the models generally improved at higher levels of quantum chemical computation. An empirical estimate for the molecular polarizabilities was also tested, and the best models for the boiling points were obtained using either this empirical polarizability itself or the polarizabilities calculated at the B3LYP/6-311G(d,p) level, along with the hydrogen-bonding parameter. The results suggest that the cohesive forces are more appropriately described as resulting from highly localized interactions rather than interactions between the global molecular dipoles.

Topology optimization for design of segmented permanent magnet arrays with ferromagnetic materials

Science.gov (United States)

Lee, Jaewook; Yoon, Minho; Nomura, Tsuyoshi; Dede, Ercan M.

2018-03-01

This paper presents multi-material topology optimization for the co-design of permanent magnet segments and iron material. Specifically, a co-design methodology is proposed to find an optimal border of permanent magnet segments, a pattern of magnetization directions, and an iron shape. A material interpolation scheme is proposed for material property representation among air, permanent magnet, and iron materials. In this scheme, the permanent magnet strength and permeability are controlled by density design variables, and permanent magnet magnetization directions are controlled by angle design variables. In addition, a scheme to penalize intermediate magnetization direction is proposed to achieve segmented permanent magnet arrays with discrete magnetization directions. In this scheme, permanent magnet strength is controlled depending on magnetization direction, and consequently the final permanent magnet design converges into permanent magnet segments having target discrete directions. To validate the effectiveness of the proposed approach, three design examples are provided. The examples include the design of a dipole Halbach cylinder, magnetic system with arbitrarily-shaped cavity, and multi-objective problem resembling a magnetic refrigeration device.

Study of top quark dipole interactions in t t \\xAF production associated with two heavy gauge bosons at the LHC

Science.gov (United States)

Etesami, Seyed Mohsen; Khatibi, Sara; Mohammadi Najafabadi, Mojtaba

2018-04-01

In this paper, we investigate the prospects of measuring the strong and weak dipole moments of the top quark at the Large Hadron Collider (LHC). Measurements of these couplings provide an excellent opportunity to probe new physics interactions as they have quite small magnitudes in the standard model. Our analyses are performed using the production cross sections of t t ¯W W and t t ¯Z Z processes in the same sign dilepton and four-lepton final states, respectively. The sensitivities to strong and weak top quark dipole interactions at the 95% confidence level for various integrated luminosity scenarios are derived and compared with other studies. To estimate the constraints, the main source of backgrounds and a realistic simulation of the detector response are considered.

The nucleon electric dipole form factor from dimension-six time-reversal violation

NARCIS (Netherlands)

de Vries, J.; Mereghetti, E.; Timmermans, R. G. E.; van Kolck, U.

2011-01-01

We calculate the electric dipole form factor of the nucleon that arises as a low-energy manifestation of time-reversal violation in quark-gluon interactions of effective dimension 6: the quark electric and chromoelectric dipole moments, and the gluon chromoelectric dipole moment. We use the

Adsorption of hydrophobin on different self-assembled monolayers: the role of the hydrophobic dipole and the electric dipole.

Science.gov (United States)

Peng, Chunwang; Liu, Jie; Zhao, Daohui; Zhou, Jian

2014-09-30

In this work, the adsorptions of hydrophobin (HFBI) on four different self-assembled monolayers (SAMs) (i.e., CH3-SAM, OH-SAM, COOH-SAM, and NH2-SAM) were investigated by parallel tempering Monte Carlo and molecular dynamics simulations. Simulation results indicate that the orientation of HFBI adsorbed on neutral surfaces is dominated by a hydrophobic dipole. HFBI adsorbs on the hydrophobic CH3-SAM through its hydrophobic patch and adopts a nearly vertical hydrophobic dipole relative to the surface, while it is nearly horizontal when adsorbed on the hydrophilic OH-SAM. For charged SAM surfaces, HFBI adopts a nearly vertical electric dipole relative to the surface. HFBI has the narrowest orientation distribution on the CH3-SAM, and thus can form an ordered monolayer and reverse the wettability of the surface. For HFBI adsorption on charged SAMs, the adsorption strength weakens as the surface charge density increases. Compared with those on other SAMs, a larger area of the hydrophobic patch is exposed to the solution when HFBI adsorbs on the NH2-SAM. This leads to an increase of the hydrophobicity of the surface, which is consistent with the experimental results. The binding of HFBI to the CH3-SAM is mainly through hydrophobic interactions, while it is mediated through a hydration water layer near the surface for the OH-SAM. For the charged SAM surfaces, the adsorption is mainly induced by electrostatic interactions between the charged surfaces and the oppositely charged residues. The effect of a hydrophobic dipole on protein adsorption onto hydrophobic surfaces is similar to that of an electric dipole for charged surfaces. Therefore, the hydrophobic dipole may be applied to predict the probable orientations of protein adsorbed on hydrophobic surfaces.

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

International Nuclear Information System (INIS)

Wang, Yimin; Bowman, Joel M.; Kamarchik, Eugene

2016-01-01

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na + H 2 O, F − H 2 O, and Cl − H 2 O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H 2 O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na + and aVTZ basis for Cl − and F − ), over a large range of distances and H 2 O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

Interaction between propulsion and levitation system in the HTSC-permanent magnet conveyance system

International Nuclear Information System (INIS)

Ohashi, S.; Nishio, R.; Hashikawa, T.

2010-01-01

The magnetically levitated conveyance system has been developed. Pinning force of high temperature bulk superconductors (HTSC) are used for the levitation and the guidance of the carrier. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs on the carrier body. To increase the load weight, the repulsive force of the permanent magnet is introduced. The hybrid levitation system is composed. The repulsive force by the permanent magnet between the load stage on the carrier and the magnetic rail on the ground is used to support the load weight. As the load stage is connected to the carrier body by the linear sliders, the mass of the load weight does not act on the carrier body. The interaction between the electromagnet and the permanent magnet under the load stage generates the propulsion force. The electromagnet is constructed by the air core coils, and excited only when the load stage passes. The interaction between the propulsion and the levitation system is investigated. Disturbance of the propulsion system on the levitation and the guidance force is measured. The results show the influence of the propulsion electromagnet on the pinning force is little, and this propulsion system works effectively.

Interaction between propulsion and levitation system in the HTSC-permanent magnet conveyance system

Energy Technology Data Exchange (ETDEWEB)

Ohashi, S., E-mail: ohashi@ipcku.kanasi-u.ac.j [Kansai University 3-3-35, Yamate-cho, Suita, Osaka 564-8680 (Japan); Nishio, R.; Hashikawa, T. [Kansai University 3-3-35, Yamate-cho, Suita, Osaka 564-8680 (Japan)

2010-11-01

The magnetically levitated conveyance system has been developed. Pinning force of high temperature bulk superconductors (HTSC) are used for the levitation and the guidance of the carrier. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs on the carrier body. To increase the load weight, the repulsive force of the permanent magnet is introduced. The hybrid levitation system is composed. The repulsive force by the permanent magnet between the load stage on the carrier and the magnetic rail on the ground is used to support the load weight. As the load stage is connected to the carrier body by the linear sliders, the mass of the load weight does not act on the carrier body. The interaction between the electromagnet and the permanent magnet under the load stage generates the propulsion force. The electromagnet is constructed by the air core coils, and excited only when the load stage passes. The interaction between the propulsion and the levitation system is investigated. Disturbance of the propulsion system on the levitation and the guidance force is measured. The results show the influence of the propulsion electromagnet on the pinning force is little, and this propulsion system works effectively.

Elastic fields, dipole tensors, and interaction between self-interstitial atom defects in bcc transition metals

Science.gov (United States)

Dudarev, S. L.; Ma, Pui-Wai

2018-03-01

Density functional theory (DFT) calculations show that self-interstitial atom (SIA) defects in nonmagnetic body-centered-cubic (bcc) metals adopt strongly anisotropic configurations, elongated in the direction [S. Han et al., Phys. Rev. B 66, 220101 (2002), 10.1103/PhysRevB.66.220101; D. Nguyen-Manh et al., Phys. Rev. B 73, 020101 (2006), 10.1103/PhysRevB.73.020101; P. M. Derlet et al., Phys. Rev. B 76, 054107 (2007), 10.1103/PhysRevB.76.054107; S. L. Dudarev, Annu. Rev. Mater. Res. 43, 35 (2013), 10.1146/annurev-matsci-071312-121626]. Elastic distortions, associated with such anisotropic atomic structures, appear similar to distortions around small prismatic dislocation loops, although the extent of this similarity has never been quantified. We derive analytical formulas for the dipole tensors of SIA defects, which show that, in addition to the prismatic dislocation looplike character, the elastic field of a SIA defect also has a significant isotropic dilatation component. Using empirical potentials and DFT calculations, we parametrize dipole tensors of defects for all the nonmagnetic bcc transition metals. This enables a quantitative evaluation of the energy of elastic interaction between the defects, which also shows that in a periodic three-dimensional simple cubic arrangement of crowdions, long-range elastic interactions between a defect and all its images favor a orientation of the defect.

ALICE dipole and decoration

CERN Multimedia

Maximilien Brice

2004-01-01

The ALICE cavern receives a painting made specially to mark the 50th anniversary of CERN that is mounted on the L3 solenoid magnet, reused from the LEP experiment that ran from 1989 to 2000. The dipole, which is cooled by demineralised water, will bend the path of muons that leave the huge rectangular solenoid. These muons are heavy electrons that interact less with matter allowing them to be studied at large distances from the interaction point.

CONSTRAINT ON LIGHT DIPOLE DARK MATTER FROM HELIOSEISMOLOGY

Energy Technology Data Exchange (ETDEWEB)

Lopes, Ilídio [Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Kadota, Kenji [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Silk, Joseph, E-mail: ilidio.lopes@ist.utl.pt, E-mail: ilopes@uevora.pt, E-mail: kadota.kenji@f.nagoya-u.jp, E-mail: silk@astro.ox.ac.uk [Institut d' Astrophysique de Paris, UMR 7095 CNRS, Université Pierre et Marie Curie, 98 bis Boulevard Arago, F-75014 Paris (France)

2014-01-10

We investigate the effects of a magnetic dipole moment of asymmetric dark matter (DM) in the evolution of the Sun. The dipole interaction can lead to a sizable DM scattering cross section even for light DM, and asymmetric DM can lead to a large DM number density in the Sun. We find that solar model precision tests, using as diagnostic the sound speed profile obtained from helioseismology data, exclude dipolar DM particles with a mass larger than 4.3 GeV and magnetic dipole moment larger than 1.6 × 10{sup –17} e cm.

A multiferroic material to search for the permanent electric dipole moment of the electron

Czech Academy of Sciences Publication Activity Database

Rushchanskii, K.Z.; Kamba, Stanislav; Goian, Veronica; Vaněk, Přemysl; Savinov, Maxim; Prokleška, J.; Nuzhnyy, Dmitry; Knížek, Karel; Laufek, F.; Eckel, S.; Lamoreaux, S.K.; Sushkov, A.; Ležaič, M.; Spaldin, N.A.

2010-01-01

Roč. 9, č. 8 (2010), s. 649-654 ISSN 1476-1122 R&D Projects: GA ČR(CZ) GA202/09/0682 Institutional research plan: CEZ:AV0Z10100520 Keywords : multiferroics * electric dipole moment of the electron * dielectric and magnetic properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 29.897, year: 2010

Electric dipole moment of diatomic molecules by configuration interaction. V - Two states of /2/Sigma/+/ symmetry in CN.

Science.gov (United States)

Green, S.

1972-01-01

Previous accurate dipole moment calculation techniques are modified to be applicable to higher excited states of symmetry. The self-consistent fields and configuration interactions are calculated for the X(2)Sigma(+) and B(2)Sigma(+) states of CN. Spin hyperfine constants and spin density at the nucleus are considered in the context of one-electron operator properties. The values of the self-consistent field and configuration interaction for the spin density are compared with experimental values for several diatomic molecules.

ACOL dipoles

International Nuclear Information System (INIS)

Vlogaert, J.

1987-01-01

This paper describes the general design of ACOL dipoles, including the special injection area dipole. A list of mechanical, electrical and magnetic parameters and results of magnetic measurements are presented. Particular attention is paid to the proximity effects between quadrupoles and dipoles

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

Energy Technology Data Exchange (ETDEWEB)

Wang, Yimin, E-mail: yimin.wang@emory.edu; Bowman, Joel M., E-mail: jmbowma@emory.edu [Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States); Kamarchik, Eugene, E-mail: eugene.kamarchik@gmail.com [Quantum Pomegranate, LLC, 2604 Kings Lake Court NE, Atlanta, Georgia 30345 (United States)

2016-03-21

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na{sup +}H{sub 2}O, F{sup −}H{sub 2}O, and Cl{sup −}H{sub 2}O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H{sub 2}O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na{sup +} and aVTZ basis for Cl{sup −} and F{sup −}), over a large range of distances and H{sub 2}O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

Tuning permanent magnets with adjustable field clamps

International Nuclear Information System (INIS)

Schermer, R.I.

1987-01-01

The effective length of a permanent-magnet assembly can be varied by adjusting the geometrical parameters of a field clamp. This paper presents measurements on a representative dipole and quadrupole as the field clamp is withdrawn axially or radially. The detailed behavior depends upon the magnet multipolarity and geometry. As a rule-of-thumb, a 3-mm-thick iron plate placed at one end plane of the magnet will shorten the length by one-third of the magnet bore radius

Lack of screening in the continuous dipole systems

International Nuclear Information System (INIS)

Park, Y.M.; Princeton Univ., NJ

1979-01-01

We study continuos statistical systems interacting via a regularized dipole potential in the grand canonical ensemble. In the explicity given region of high temperature (or low density) we show that the effective potential between two parallel dipoles is not absolutely integrable (it is, however, square integrable), which implies that the effective potential does not fall faster than /x/ -3 in some directions. (orig.) 891 HJ/orig. 892 MKO

Giant dipole modes in heavy-ion reactions

International Nuclear Information System (INIS)

Suraud, E.; Schuck, P.

1988-07-01

A detailed study of the excitation of giant dipole modes (GDR) in intermediate energy heavy-ion collisions is presented in the framework of a full (non linearized) Landau-Vlasov equation. After having recalled the basic inputs of this dynamical formalism, within insisting upon the limitations of the Uehling-Uhlenbeck collision integral and upon the introduction of a realistic (isospin dependant) effective interaction, we present our tools for analysing the GDR in the simple case of isolated nuclei. We then pass on to simulations of collisions and discuss in some detail isospin modes in the model 12 Be + 12 C reaction. Results obtained for the energy of the excited dipole mode are in agreement with what is expected for excited, rotating, giant dipole oscillations in deformed nuclei

A storage ring experiment to detect a proton electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Anastassopoulos, V. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece; Andrianov, S. [Faculty of Applied Mathematics and Control Processes, Saint-Petersburg State University, Saint-Petersburg, Russia; Baartman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T2A3, Canada; Baessler, S. [Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA; Bai, M. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Benante, J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Berz, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA; Blaskiewicz, M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Bowcock, T. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Brown, K. [Brookhaven National Laboratory, Upton, New York 11973, USA; Casey, B. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Conte, M. [Physics Department and INFN Section of Genoa, 16146 Genoa, Italy; Crnkovic, J. D. [Brookhaven National Laboratory, Upton, New York 11973, USA; D’Imperio, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Fanourakis, G. [Institute of Nuclear and Particle Physics NCSR Demokritos, GR-15310 Aghia Paraskevi Athens, Greece; Fedotov, A. [Brookhaven National Laboratory, Upton, New York 11973, USA; Fierlinger, P. [Technical University München, Physikdepartment and Excellence-Cluster “Universe,” Garching, Germany; Fischer, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Gaisser, M. O. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Giomataris, Y. [CEA/Saclay, DAPNIA, 91191 Gif-sur-Yvette Cedex, France; Grosse-Perdekamp, M. [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA; Guidoboni, G. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Hacıömeroğlu, S. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Hoffstaetter, G. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Huang, H. [Brookhaven National Laboratory, Upton, New York 11973, USA; Incagli, M. [Physics Department, University and INFN Pisa, Pisa, Italy; Ivanov, A. [Faculty of Applied Mathematics and Control Processes, Saint-Petersburg State University, Saint-Petersburg, Russia; Kawall, D. [Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA; Kim, Y. I. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; King, B. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Koop, I. A. [Budker Institute of Nuclear Physics, 630090 Novosibirsk, Russia; Lazarus, D. M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Lebedev, V. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Lee, M. J. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Lee, S. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Lee, Y. H. [Korea Research Institute of Standards and Science, Daejeon 34141, South Korea; Lehrach, A. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Lenisa, P. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Levi Sandri, P. [Laboratori Nazionali di Frascati, INFN, I-00044 Frascati, Rome, Italy; Luccio, A. U. [Brookhaven National Laboratory, Upton, New York 11973, USA; Lyapin, A. [Royal Holloway, University of London, Egham, Surrey, United Kingdom; MacKay, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Maier, R. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Makino, K. [Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA; Malitsky, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Marciano, W. J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Meng, W. [Brookhaven National Laboratory, Upton, New York 11973, USA; Meot, F. [Brookhaven National Laboratory, Upton, New York 11973, USA; Metodiev, E. M. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Harvard College, Harvard University, Cambridge, Massachusetts 02138, USA; Miceli, L. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Moricciani, D. [Dipartimento di Fisica dell’Univ. di Roma “Tor Vergata” and INFN Sezione di Roma Tor Vergata, Rome, Italy; Morse, W. M. [Brookhaven National Laboratory, Upton, New York 11973, USA; Nagaitsev, S. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Nayak, S. K. [Brookhaven National Laboratory, Upton, New York 11973, USA; Orlov, Y. F. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Ozben, C. S. [Istanbul Technical University, Istanbul 34469, Turkey; Park, S. T. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Pesce, A. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Petrakou, E. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Pile, P. [Brookhaven National Laboratory, Upton, New York 11973, USA; Podobedov, B. [Brookhaven National Laboratory, Upton, New York 11973, USA; Polychronakos, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Pretz, J. [RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Ptitsyn, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Ramberg, E. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Raparia, D. [Brookhaven National Laboratory, Upton, New York 11973, USA; Rathmann, F. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Rescia, S. [Brookhaven National Laboratory, Upton, New York 11973, USA; Roser, T. [Brookhaven National Laboratory, Upton, New York 11973, USA; Kamal Sayed, H. [Brookhaven National Laboratory, Upton, New York 11973, USA; Semertzidis, Y. K. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea; Senichev, Y. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Sidorin, A. [Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; Silenko, A. [Joint Institute for Nuclear Research, Dubna, Moscow region, Russia; Research Institute for Nuclear Problems of Belarusian State University, Minsk, Belarus; Simos, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Stahl, A. [RWTH Aachen University and JARA-Fame, III. Physikalisches Institut B, Physikzentrum, 52056 Aachen, Germany; Stephenson, E. J. [Indiana University Center for Spacetime Symmetries, Bloomington, Indiana 47405, USA; Ströher, H. [Institut für Kernphysik and JARA-Fame, Forschungszentrum Jülich, 52425 Jülich, Germany; Syphers, M. J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA; Department of Physics, Northern Illinois University, DeKalb, Illinois 60115, USA; Talman, J. [Brookhaven National Laboratory, Upton, New York 11973, USA; Talman, R. M. [Laboratory for Elementary-Particle Physics, Cornell University, Ithaca, New York 14853, USA; Tishchenko, V. [Brookhaven National Laboratory, Upton, New York 11973, USA; Touramanis, C. [Department of Physics, University of Liverpool, Liverpool, United Kingdom; Tsoupas, N. [Brookhaven National Laboratory, Upton, New York 11973, USA; Venanzoni, G. [Laboratori Nazionali di Frascati, INFN, I-00044 Frascati, Rome, Italy; Vetter, K. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA; Vlassis, S. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece; Won, E. [Center for Axion and Precision Physics Research, Institute for Basic Science (IBS), Daejeon 34141, South Korea; Physics Department, Korea University, Seoul 02841, South Korea; Zavattini, G. [University of Ferrara, INFN of Ferrara, Ferrara, Italy; Zelenski, A. [Brookhaven National Laboratory, Upton, New York 11973, USA; Zioutas, K. [Department of Physics, University of Patras, 26500 Rio-Patras, Greece

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of $10^{-29}e\\cdot$cm by using polarized "magic" momentum $0.7$~GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the Standard Model at the scale of 3000~TeV.

A storage ring experiment to detect a proton electric dipole moment.

Science.gov (United States)

Anastassopoulos, V; Andrianov, S; Baartman, R; Baessler, S; Bai, M; Benante, J; Berz, M; Blaskiewicz, M; Bowcock, T; Brown, K; Casey, B; Conte, M; Crnkovic, J D; D'Imperio, N; Fanourakis, G; Fedotov, A; Fierlinger, P; Fischer, W; Gaisser, M O; Giomataris, Y; Grosse-Perdekamp, M; Guidoboni, G; Hacıömeroğlu, S; Hoffstaetter, G; Huang, H; Incagli, M; Ivanov, A; Kawall, D; Kim, Y I; King, B; Koop, I A; Lazarus, D M; Lebedev, V; Lee, M J; Lee, S; Lee, Y H; Lehrach, A; Lenisa, P; Levi Sandri, P; Luccio, A U; Lyapin, A; MacKay, W; Maier, R; Makino, K; Malitsky, N; Marciano, W J; Meng, W; Meot, F; Metodiev, E M; Miceli, L; Moricciani, D; Morse, W M; Nagaitsev, S; Nayak, S K; Orlov, Y F; Ozben, C S; Park, S T; Pesce, A; Petrakou, E; Pile, P; Podobedov, B; Polychronakos, V; Pretz, J; Ptitsyn, V; Ramberg, E; Raparia, D; Rathmann, F; Rescia, S; Roser, T; Kamal Sayed, H; Semertzidis, Y K; Senichev, Y; Sidorin, A; Silenko, A; Simos, N; Stahl, A; Stephenson, E J; Ströher, H; Syphers, M J; Talman, J; Talman, R M; Tishchenko, V; Touramanis, C; Tsoupas, N; Venanzoni, G; Vetter, K; Vlassis, S; Won, E; Zavattini, G; Zelenski, A; Zioutas, K

2016-11-01

A new experiment is described to detect a permanent electric dipole moment of the proton with a sensitivity of 10 -29 e ⋅ cm by using polarized "magic" momentum 0.7 GeV/c protons in an all-electric storage ring. Systematic errors relevant to the experiment are discussed and techniques to address them are presented. The measurement is sensitive to new physics beyond the standard model at the scale of 3000 TeV.

An Insightful Problem Involving the Electromagnetic Radiation from a Pair of Dipoles

Science.gov (United States)

Smith, Glenn S.

2010-01-01

The time-average power radiated by a pair of infinitesimal dipoles is examined as their spacing is varied. The results elucidate the effect of the interaction of the dipoles on their radiation. (Contains 4 figures.)

Electric dipole moment of the neutron in gauge theory

International Nuclear Information System (INIS)

Shabalin, E.P.

1983-01-01

One of the consequences of violation of CP invariance of the physical world is the existence of an electric dipole moment of elementary particles. The renormalization gauge theory of the electroweak and strong interactions developed during the past decade has revealed several possible sources of violation of CP invariance: direct violation of CP invariance in the Lagrangian of the electroweak interactions, spontaneous violation of CP invariance, and violation of CP invariance in the strong interactions described by quantum chromodynamics. The present review is devoted to a discussion of the predictions for the electric dipole moment of the neutron which follow from the various sources of violation of CP invariance in the theory. It includes the theoretical results obtained in the framework of gauge theory during the past decade up to the beginning of 1982. A comparison of the prediction of various gauge models with the experimental measurements of the electric dipole moment will make it possible to gain a better understanding of the nature of violation of CP invariance

Quantum Phase Shift of a Moving Dipole under a Magnetic Field at a Distance

Science.gov (United States)

Lee, Kang-Ho; Kim, Young-Wan; Kang, Kicheon

2018-03-01

We predict a quantum phase shift of a moving electric dipole in the presence of an external magnetic field at a distance. On the basis of the Lorentz-covariant field interaction approach, we show that a phase shift appears in the internal dipole state under the condition that the dipole is moving in the field-free region, which is distinct from the topological He-McKellar-Wilkens phase generated by a direct overlap of the dipole and the field. We discuss the experimental feasibility of detecting this phase with atomic interferometry and argue that detection of this phase will resolve the question of the locality in quantum electromagnetic interaction.

Search for electric dipole moments at storage rings

Energy Technology Data Exchange (ETDEWEB)

Onderwater, C. J. G., E-mail: onderwater@kvi.nl [University of Groningen, KVI (Netherlands)

2012-05-15

Permanent electric dipole moments (EDMs) violate parity and time-reversal symmetry. Within the Standard Model (SM) they are many orders of magnitude below present experimental sensitivity. Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of 'new physics'. Until recently it was believed that only electrically neutral systems could be used for sensitive searches of EDMs. With the introduction of a novel experimental method, high precision for charged systems will be within reach as well. The features of this method and its possibilities are discussed.

Self-force on an electric dipole in the spacetime of a cosmic string

Energy Technology Data Exchange (ETDEWEB)

Muniz, C.R., E-mail: celiomuniz@yahoo.com [Grupo de Física Teórica (GFT), Universidade Estadual do Ceará, UECE-FECLI, Iguatu, Ceará (Brazil); Bezerra, V.B., E-mail: valdir@ufpb.br [Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, CEP 58051-970, João Pessoa, PB (Brazil)

2014-01-15

We calculate the electrostatic self-force on an electric dipole in the spacetime generated by a static, thin, infinite and straight cosmic string. The electric dipole is held fixed in different configurations, namely, parallel, perpendicular to the cosmic string and oriented along the azimuthal direction around this topological defect, which is stretched along the z axis. We show that the self-force is equivalent to an interaction of the electric dipole with an effective dipole moment which depends on the linear mass density of the cosmic string and on the configuration. The plots of the self-forces as functions of the parameter which determines the angular deficit of the cosmic string are shown for those different configurations. -- Highlights: •Review of regularized Green’s function applied to the problem. •Self-force on an electric dipole in the string spacetime for some orientations. •Representation via graphs of the self-forces versus angular parameter of the cosmic string. •Self-force induced by the string seen as an interaction between two dipoles. •Discussion about the superposition principle in this non-trivial background.

Magnetic and electric dipole moments of the H 3Δ1 state in ThO

International Nuclear Information System (INIS)

Vutha, A. C.; Kirilov, E.; DeMille, D.; Spaun, B.; Gurevich, Y. V.; Hutzler, N. R.; Doyle, J. M.; Gabrielse, G.

2011-01-01

The metastable H 3 Δ 1 state in the thorium monoxide (ThO) molecule is highly sensitive to the presence of a CP-violating permanent electric dipole moment of the electron (eEDM) [E. R. Meyer and J. L. Bohn, Phys. Rev. A 78, 010502 (2008)]. The magnetic dipole moment μ H and the molecule-fixed electric dipole moment D H of this state are measured in preparation for a search for the eEDM. The small magnetic moment μ H =8.5(5)x10 -3 μ B displays the predicted cancellation of spin and orbital contributions in a 3 Δ 1 paramagnetic molecular state, providing a significant advantage for the suppression of magnetic field noise and related systematic effects in the eEDM search. In addition, the induced electric dipole moment is shown to be fully saturated in very modest electric fields (<10 V/cm). This feature is favorable for the suppression of many other potential systematic errors in the ThO eEDM search experiment.

AutoDipole - Automated generation of dipole subtraction terms

International Nuclear Information System (INIS)

Hasegawa, K.; Uwer, P.

2009-11-01

We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for bothmassless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. (orig.)

AutoDipole - Automated generation of dipole subtraction terms

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, K.; Uwer, P. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2009-11-15

We present an automated generation of the subtraction terms for next-to-leading order QCD calculations in the Catani-Seymour dipole formalism. For a given scattering process with n external particles our Mathematica package generates all dipole terms, allowing for bothmassless and massive dipoles. The numerical evaluation of the subtraction terms proceeds with MadGraph, which provides Fortran code for the necessary scattering amplitudes. Checks of the numerical stability are discussed. (orig.)

Exploring the Dipole Polarizability of $^{11}$Li at REX-ISOLDE

CERN Multimedia

2002-01-01

Dipole polarizability refers to the effect of the excitation to negative parity states through the electric dipole interaction. In nuclear physics dipole polarizability has not yet played a major role. For nuclei close to the drip lines where the separation energies of neutrons (or protons) are small, a substantial part of the dipole strength function occurs at low excitation energies. We here propose to investigate this effect by measuring elastic scattering at energies close to the Coulomb barrier. REX-ISOLDE together with the new improved yields of $^{11}$Li provides the ideal setting for this experiment. We ask for a total of 24 shifts with proton beam plus 3 shifts of stable beam from a Ta-foil target.

Electric dipole polarizability: from few- to many-body systems

Directory of Open Access Journals (Sweden)

Miorelli Mirko

2016-01-01

Full Text Available We review the Lorentz integral transform coupled-cluster method for the calculation of the electric dipole polarizability. We benchmark our results with exact hyperspherical harmonics calculations for 4He and then we move to a heavier nucleus studying 16O. We observe that the implemented chiral nucleon-nucleon interaction at next-to-next-to-next-to-leading order underestimates the electric dipole polarizability.

Iterative Dipole Moment Method for the Dielectrophoretic Particle-Particle Interaction in a DC Electric Field

Directory of Open Access Journals (Sweden)

Qing Zhang

2018-01-01

Full Text Available Electric force is the most popular technique for bioparticle transportation and manipulation in microfluidic systems. In this paper, the iterative dipole moment (IDM method was used to calculate the dielectrophoretic (DEP forces of particle-particle interactions in a two-dimensional DC electric field, and the Lagrangian method was used to solve the transportation of particles. It was found that the DEP properties and whether the connection line between initial positions of particles perpendicular or parallel to the electric field greatly affect the chain patterns. In addition, the dependence of the DEP particle interaction upon the particle diameters, initial particle positions, and the DEP properties have been studied in detail. The conclusions are advantageous in elelctrokinetic microfluidic systems where it may be desirable to control, manipulate, and assemble bioparticles.

On the dipole approximation with error estimates

Science.gov (United States)

Boßmann, Lea; Grummt, Robert; Kolb, Martin

2018-01-01

The dipole approximation is employed to describe interactions between atoms and radiation. It essentially consists of neglecting the spatial variation of the external field over the atom. Heuristically, this is justified by arguing that the wavelength is considerably larger than the atomic length scale, which holds under usual experimental conditions. We prove the dipole approximation in the limit of infinite wavelengths compared to the atomic length scale and estimate the rate of convergence. Our results include N-body Coulomb potentials and experimentally relevant electromagnetic fields such as plane waves and laser pulses.

Iron free permanent magnet systems for charged particle beam optics

International Nuclear Information System (INIS)

Lund, S.M.; Halbach, K.

1995-01-01

The strength and astounding simplicity of certain permanent magnet materials allow a wide variety of simple, compact configurations of high field strength and quality multipole magnets. Here we analyze the important class of iron-free permanent magnet systems for charged particle beam optics. The theory of conventional segmented multipole magnets formed from uniformly magnetized block magnets placed in regular arrays about a circular magnet aperture is reviewed. Practical multipole configurations resulting are presented that are capable of high and intermediate aperture field strengths. A new class of elliptical aperture magnets is presented within a model with continuously varying magnetization angle. Segmented versions of these magnets promise practical high field dipole and quadrupole magnets with an increased range of applicability

Radiative Decay Rates for Electric Dipole, Magnetic Dipole and Electric Quadrupole Transitions in Triply Ionized Thulium (Tm IV

Directory of Open Access Journals (Sweden)

Saturnin Enzonga Yoca

2017-09-01

Full Text Available A new set of radiative decay parameters (oscillator strengths, transition probabilities for spectral lines in triply ionized thulium (Tm IV has been obtained within the framework of the pseudo-relativistic Hartree-Fock (HFR approach. The effects of configuration interaction and core-polarization have been investigated in detail and the quality of the results has been assessed through a comparison between different HFR physical models. The spectroscopic data listed in the present paper cover electric dipole as well as magnetic dipole and electric quadrupole transitions in a wide range of wavelengths from extreme ultraviolet to near infrared.

Hyperfine interaction mediated electric-dipole spin resonance: the role of frequency modulation

International Nuclear Information System (INIS)

Li, Rui

2016-01-01

The electron spin in a semiconductor quantum dot can be coherently controlled by an external electric field, an effect called electric-dipole spin resonance (EDSR). Several mechanisms can give rise to the EDSR effect, among which there is a hyperfine mechanism, where the spin-electric coupling is mediated by the electron–nucleus hyperfine interaction. Here, we investigate the influence of frequency modulation (FM) on the spin-flip efficiency. Our results reveal that FM plays an important role in the hyperfine mechanism. Without FM, the electric field almost cannot flip the electron spin; the spin-flip probability is only about 20%. While under FM, the spin-flip probability can be improved to approximately 70%. In particular, we find that the modulation amplitude has a lower bound, which is related to the width of the fluctuated hyperfine field. (paper)

Experimental search for the electron electric dipole moment with laser cooled francium atoms

Energy Technology Data Exchange (ETDEWEB)

Inoue, T., E-mail: inoue-t@cyric.tohoku.ac.jp [Tohoku University, Frontier Research Institute of Interdisciplinary Sciences (Japan); Ando, S.; Aoki, T.; Arikawa, H.; Ezure, S.; Harada, K.; Hayamizu, T.; Ishikawa, T.; Itoh, M.; Kato, K.; Kawamura, H.; Uchiyama, A. [Tohoku University, Cyclotron and Radioisotope Center (Japan); Aoki, T. [University of Tokyo, Graduate School of Arts and Sciences (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Hatakeyama, A. [Tokyo University of Agriculture and Technology, Department of Applied Physics (Japan); Hatanaka, K. [Osaka University, Research Center for Nuclear Physics (Japan); Imai, K. [Advanced Science Research Center, Japan Atomic Energy Agency (Japan); Murakami, T. [Kyoto University, Department of Physics (Japan); Nataraj, H. S. [Indian Institute of Technology Roorkee (India); and others

2015-04-15

A laser cooled heavy atom is one of the candidates to search for the permanent electric dipole moment (EDM) of the electron due to the enhancement mechanism and its long coherence time. The laser cooled francium (Fr) factory has been constructed to perform the electron EDM search at the Cyclotron and Radioisotope Center, Tohoku University. The present status of Fr production and the EDM measurement system is presented.

Electric dipole moment of 3He

International Nuclear Information System (INIS)

Avishai, Y.; Fabre de la Ripelle, M.

1986-01-01

The contribution of a CP-nonconserving nucleon-nucleon interaction to the electric dipole moment of 3 He is evaluated in view of a recent proposal for its experimental detection. We use two models of CP-nonconserving interactions in combination with a Reid soft-core strong nucleon-nucleon interaction. In the Kobayashi-Maskawa model of CP nonconservation the order of magnitude is 10 -30 eX while the presence of the theta term in the QCD Langrangian contributes an order of magnitude 10 -16 theta-bar e cm

Bosonic and fermionic dipoles on a ring

DEFF Research Database (Denmark)

Zöllner, Sascha; Pethick, C. J.; Bruun, Georg Morten

2011-01-01

We show that dipolar bosons and fermions confined in a quasi-one-dimensional ring trap exhibit a rich variety of states because their interaction is inhomogeneous. For purely repulsive interactions, with increasing strength of the dipolar coupling there is a crossover from a gaslike state...... to an inhomogeneous crystal-like one. For small enough angles between the dipoles and the plane of the ring, there are regions with attractive interactions, and clustered states can form....

The inter-adsorbate interaction mediated by Shockley-type surface state electrons and dipole moment: Cs and Ba atoms absorbed on Ag (1 1 1) films

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shuyuan [College of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Zhang, Hong, E-mail: hongzhang@scu.edu.cn [College of Physical Science and Technology, Sichuan University, Chengdu 610065 (China); Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, Sichuan University, Chengdu 610064 (China); Miyamoto, Yoshiyuki [Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, 1-1-1 Umezono, Tsukuba 305-8568 (Japan)

2014-01-15

Through first-principles investigation, we display the formation process of Shockley-type surface states which emerges on silver thin films along Ag (1 1 1) orientation with increasing thicknesses from 6 to 21 layers. We look at the surface state band for various adatoms adsorbed on 6, 12, 18 layers strained Ag (1 1 1) films with different coverage, and discuss the long range interaction mediated by surface state electrons. We discovered that film's thickness can modulate the surface state mediated interaction drastically, but the dipole–dipole repulsive interaction is not affected by slab thickness. This factor had never been discussed in detail. Therefore, adatoms adsorbed on thin films have strong attractive interaction which leads to small adsorption separation and the tendency of island formation. For different coverage or different adsorbate types, both surface states and dipole moment are modulated. The three factors, film's thickness, adsorbate coverage and adatoms types, could help us learn more about the interactions between adatoms and exploit advanced ways to control surface geometry structures of self-assembly.

The inter-adsorbate interaction mediated by Shockley-type surface state electrons and dipole moment: Cs and Ba atoms absorbed on Ag (1 1 1) films

International Nuclear Information System (INIS)

Zhang, Shuyuan; Zhang, Hong; Miyamoto, Yoshiyuki

2014-01-01

Through first-principles investigation, we display the formation process of Shockley-type surface states which emerges on silver thin films along Ag (1 1 1) orientation with increasing thicknesses from 6 to 21 layers. We look at the surface state band for various adatoms adsorbed on 6, 12, 18 layers strained Ag (1 1 1) films with different coverage, and discuss the long range interaction mediated by surface state electrons. We discovered that film's thickness can modulate the surface state mediated interaction drastically, but the dipole–dipole repulsive interaction is not affected by slab thickness. This factor had never been discussed in detail. Therefore, adatoms adsorbed on thin films have strong attractive interaction which leads to small adsorption separation and the tendency of island formation. For different coverage or different adsorbate types, both surface states and dipole moment are modulated. The three factors, film's thickness, adsorbate coverage and adatoms types, could help us learn more about the interactions between adatoms and exploit advanced ways to control surface geometry structures of self-assembly.

Theory of tunneling ionization of molecules: Weak-field asymptotics including dipole effects

DEFF Research Database (Denmark)

Tolstikhin, Oleg I.; Morishita, Toru; Madsen, Lars Bojer

2011-01-01

The formulation of the parabolic adiabatic expansion approach to the problem of ionization of atomic systems in a static electric field, originally developed for the axially symmetric case [ Phys. Rev. A 82 023416 (2010)], is generalized to arbitrary potentials. This approach is used to rederive...... the asymptotic theory of tunneling ionization in the weak-field limit. In the atomic case, the resulting formulas for the ionization rate coincide with previously known results. In addition, the present theory accounts for the possible existence of a permanent dipole moment of the unperturbed system and, hence......, applies to polar molecules. Accounting for dipole effects constitutes an important difference of the present theory from the so-called molecular Ammosov-Delone-Krainov theory. The theory is illustrated by comparing exact and asymptotic results for a set of model polar molecules and a realistic molecular...

Fermion electric dipole moments induced by P- and T-odd WWγ interactions in the minimal supersymmetric standard model and multi-Higgs-boson model

International Nuclear Information System (INIS)

West, T.H.

1994-01-01

We calculate fermion electric dipole moments generated by P- and T-odd WWγ interactions in the supersymmetry and multi-Higgs-boson models without using an approximation first introduced by Marciano and Queijeiro. In essence, this approximation consists of ignoring the details of the high energy physics responsible for the W electric dipole moment. For the minimal supersymmetry model, our more exact results are roughly three times those obtained from the simplest application of the above-mentioned approximation for gaugino masses larger than m W . However, if the gaugino masses are approx-lt m W , our results are less than would be expected from the Marciano-Queijeiro estimate. In part, because of this suppression, we discover that the experimental bounds on d n place no restrictions on either the allowed values of d W or on the permitted masses of the minimal supersymmetry model. This contradicts the findings of Vendramin who used the Marciano-Queijeiro results to deduce such prohibited regions of parameter space and mildly improves the prospects of observing a nonzero W-boson electric dipole moment in accelerator experiments. In the case of the multi-Higgs-boson model, we again find fermion electric dipole moments that are three times those expected from a simple application of the Marciano-Queijeiro technique. In addition, when this result is combined with a complete two-loop calculation of the W electric dipole moment, we find that the fermion electric dipole moments generated in this way are approximately 30 times those expected from a previous calculation by He and McKellar

Dual Shapiro-Virasoro amplitudes in the dipole picture of QCD at small x

Science.gov (United States)

Peschanski, R.

1997-02-01

Using the dipole picture describing the 1/(NC) limit of QCD at small x and the conformal invariance properties of the BFKL kernel in transverse coordinate space, we show that the 1 ==> p dipole densities can be expressed in terms of dual Shapiro-Virasoro amplitudes B2p+2 and their generalization including non-zero conformal spins. We discuss the possibility of an effective closed string theory of interacting QCD dipoles.

Dipole-sheet multipole magnets for accelerators

International Nuclear Information System (INIS)

Walstrom, P.L.

1993-01-01

The dipole-sheet formalism can be used to describe both cylindrical current-sheet multipole magnets and cylindrical-bore magnets made up of permanent magnet blocks. For current sheets, the formalism provides a natural way of finding a finite set of turns that approximate a continuous distribution. The formalism is especially useful In accelerator applications where large-bore, short, high-field-quality magnets that are dominated by fringe fields are needed. A further advantage of the approach is that in systems with either open or cylindrically symmetric magnetic boundaries, analytical expressions for the three-dimensional fields that are suitable for rapid numerical evaluation can be derived. This development is described in some detail. Also, recent developments in higher-order particle-beam optics codes based on the formalism are described briefly

Magnetic dipole moment of a moving electric dipole

OpenAIRE

Hnizdo, V.

2012-01-01

The current density of a moving electric dipole is expressed as the sum of polarization and magnetization currents. The magnetic field due to the latter current is that of a magnetic dipole moment that is consistent with the relativistic transformations of the polarization and magnetization of macroscopic electrodynamics.

Installation of the ALICE dipole magnet

CERN Multimedia

Maximilien Brice

2005-01-01

The large dipole magnet is installed on the ALICE detector at CERN. This magnet, which is cooled by demineralised water, will bend the path of muons that leave the huge rectangular solenoid (in the background). These muons are heavy electrons that interact less with matter, allowing them to traverse the main section of the detector.

Multiple transparency windows and Fano interferences induced by dipole-dipole couplings

Science.gov (United States)

Diniz, E. C.; Borges, H. S.; Villas-Boas, C. J.

2018-04-01

We investigate the optical properties of a two-level system (TLS) coupled to a one-dimensional array of N other TLSs with dipole-dipole coupling between the first neighbors. The first TLS is probed by a weak field, and we assume that it has a decay rate much greater than the decay rates of the other TLSs. For N =1 and in the limit of a Rabi frequency of a probe field much smaller than the dipole-dipole coupling, the optical response of the first TLS, i.e., its absorption and dispersion, is equivalent to that of a three-level atomic system in the configuration which allows one to observe the electromagnetically induced transparency (EIT) phenomenon. Thus, here we investigate an induced transparency phenomenon where the dipole-dipole coupling plays the same role as the control field in EIT in three-level atoms. We describe this physical phenomenon, named a dipole-induced transparency (DIT), and investigate how it scales with the number of coupled TLSs. In particular, we have shown that the number of TLSs coupled to the main TLS is exactly equal to the number of transparency windows. The ideas presented here are very general and can be implemented in different physical systems, such as an array of superconducting qubits, or an array of quantum dots, spin chains, optical lattices, etc.

Electromagnetic core-mantle coupling associated with changes in the geomagnetic dipole field

International Nuclear Information System (INIS)

Watanabe, Hidehumi; Yukutake, Takesi.

1975-01-01

On a shelluar earth model electromagnetic coupling between the mantle and the core is investigated when the geomagnetic dipole field changes its intensity. Besides electromagnetic interaction between the dipole change and the relative slip of the mantle to the core, coupling of the dipole change with shear motions within the core is considered. If, in the core, the dipole change is limited within a surface layer shallower than a few hundred kilometers, the electromagnetic interaction gives the same order of magnitudes and phases of mantle oscillation as suggested from observation for three different periods, 8000, 400 and 65 years, provided that the electrical conductivity of the bottom part of the mantle is 10 -9 to 10 -8 emu. It is shown that mean motion of the surface shells of the core thus calculated is compatible with the observed variations in the drift velocity of the geomagnetic secular change. Except for surface shells, those in the deep interior is confirmed to oscillate almost with the same angular velocity, like a rigid rotation, for all the periods. (auth.)

Electric dipole moment searches using the isotope 129-xenon

Energy Technology Data Exchange (ETDEWEB)

Kuchler, Florian

2014-11-13

Two new complementary experiments searching for a permanent electric dipole moment (EDM) of 129-xenon are presented. Besides demonstration of a sensitivity improvement by employing established methods and a highly sensitive SQUID detection system the progress towards a novel measurement approach is discussed. The new method introduces time-varying electric fields and a liquid hyper-polarized xenon sample with a potential improvement in sensitivity of three orders of magnitude. The search for EDMs is motivated by their symmetry-breaking nature. A non-zero EDM provides a new source of CP violation to solve the mystery of the huge excess of matter over anti-matter in our Universe.

A simple stochastic model for dipole moment fluctuations in numerical dynamo simulations

Directory of Open Access Journals (Sweden)

Domenico G. eMeduri

2016-04-01

Full Text Available Earth's axial dipole field changes in a complex fashion on many differenttime scales ranging from less than a year to tens of million years.Documenting, analysing, and replicating this intricate signalis a challenge for data acquisition, theoretical interpretation,and dynamo modelling alike. Here we explore whether axial dipole variationscan be described by the superposition of a slow deterministic driftand fast stochastic fluctuations, i.e. by a Langevin-type system.The drift term describes the time averaged behaviour of the axial dipole variations,whereas the stochastic part mimics complex flow interactions over convective time scales.The statistical behaviour of the system is described by a Fokker-Planck equation whichallows useful predictions, including the average rates of dipole reversals and excursions.We analyse several numerical dynamo simulations, most of which havebeen integrated particularly long in time, and also the palaeomagneticmodel PADM2M which covers the past 2 Myr.The results show that the Langevin description provides a viable statistical modelof the axial dipole variations on time scales longer than about 1 kyr.For example, the axial dipole probability distribution and the average reversalrate are successfully predicted.The exception is PADM2M where the stochastic model reversal rate seems too low.The dependence of the drift on the axial dipolemoment reveals the nonlinear interactions that establish thedynamo balance. A separate analysis of inductive and diffusive magnetic effectsin three dynamo simulations suggests that the classical quadraticquenching of induction predicted by mean-field theory seems at work.

Degree of Response to Homeopathic Potencies Correlates with Dipole Moment Size in Molecular Detectors: Implications for Understanding the Fundamental Nature of Serially Diluted and Succussed Solutions.

Science.gov (United States)

Cartwright, Steven J

2018-02-01

 The use of solvatochromic dyes to investigate homeopathic potencies holds out the promise of understanding the nature of serially succussed and diluted solutions at a fundamental physicochemical level. Recent studies have shown that a range of different dyes interact with potencies and, moreover, the nature of the interaction is beginning to allow certain specific characteristics of potencies to be delineated.  The study reported in this article takes previous investigations further and aims to understand more about the nature of the interaction between potencies and solvatochromic dyes. To this end, the UV-visible spectra of a wide range of potential detectors of potencies have been examined using methodologies previously described.  Results presented demonstrate that solvatochromic dyes are a sub-group of a larger class of compounds capable of demonstrating interactions with potencies. In particular, amino acids containing an aromatic bridge also show marked optical changes in the presence of potencies. Several specific features of molecular detectors can now be shown to be necessary for significant interactions with homeopathic potencies. These include systems with a large dipole moment, electron delocalisation, polarizability and molecular rigidity.  Analysis of the optical changes occurring on interaction with potencies suggests that in all cases potencies increase the polarity of molecular detectors to a degree that correlates with the size of the compound's permanent or ground dipole moment. These results can be explained by inferring that potencies themselves have polarity. Possible candidates for the identity of potencies, based on these and previously reported results, are discussed. The Faculty of Homeopathy.

Photoswitchable molecular dipole antennas with tailored coherent coupling in glassy composite

DEFF Research Database (Denmark)

Elbahri, Mady; Zillohu, Ahnaf Usman; Gothe, Bastian

2015-01-01

. We also introduce the concept of 'tailored molecular photonic coupling' while highlighting the role of interferences for the design of optically active media by adjusting the photonic response of the medium with the real and imaginary refractive index of photoswitchable molecules in the 'ON' state...... alteration of photochromic molecular dipole antennas. We successfully demonstrate the concept of Brewster wavelength, which is based on the dipolar interaction between radiating dipoles and the surrounding matrix possessing a net dipole moment, as a key tool for highly localized sensing of matrix polarity....... Our results enhance our fundamental understanding of coherent dipole radiation and open a new vein of research based on glassy disordered dipolar composites that act as macroscopic antenna with cooperative action; furthermore, these results have important implications for new design rules of tailored...

Physical Realization of von Neumann Lattices in Rotating Bose Gases with Dipole Interatomic Interactions.

Science.gov (United States)

Cheng, Szu-Cheng; Jheng, Shih-Da

2016-08-22

This paper reports a novel type of vortex lattice, referred to as a bubble crystal, which was discovered in rapidly rotating Bose gases with long-range interactions. Bubble crystals differ from vortex lattices which possess a single quantum flux per unit cell, while atoms in bubble crystals are clustered periodically and surrounded by vortices. No existing model is able to describe the vortex structure of bubble crystals; however, we identified a mathematical lattice, which is a subset of coherent states and exists periodically in the physical space. This lattice is called a von Neumann lattice, and when it possesses a single vortex per unit cell, it presents the same geometrical structure as an Abrikosov lattice. In this report, we extend the von Neumann lattice to one with an integral number of flux quanta per unit cell and demonstrate that von Neumann lattices well reproduce the translational properties of bubble crystals. Numerical simulations confirm that, as a generalized vortex, a von Neumann lattice can be physically realized using vortex lattices in rapidly rotating Bose gases with dipole interatomic interactions.

The dipole representation of vector meson electroproduction beyond leading twist

International Nuclear Information System (INIS)

Besse, A.; Szymanowski, L.; Wallon, S.

2013-01-01

We link the recent computation beyond leading twist of the impact factor of the transition γ T ⁎ →ρ T performed in the light-cone collinear approach, to the dipole picture by expressing the hard part of the process through its Fourier transform in coordinate space. We show that in the Wandzura–Wilczek approximation the impact factor up to twist 3 factorises in the wave function of the photon combined with the distribution amplitudes of the ρ-meson and the colour dipole scattering amplitude with the t-channel gluons. We show also that beyond the Wandzura–Wilczek approximation, the hard contribution of the amplitude still exhibits the signature of the interaction of a single colour dipole with the t-channel gluons. This result allows a phenomenological approach of the helicity amplitudes of the leptoproduction of vector meson, by combining our results to a dipole/target scattering amplitude model.

Contribution of relativistic quantum chemistry to electron’s electric dipole moment for CP violation

Energy Technology Data Exchange (ETDEWEB)

Abe, M., E-mail: minoria@tmu.ac.jp; Gopakumar, G., E-mail: gopakumargeetha@gmail.com; Hada, M., E-mail: hada@tmu.ac.jp [Tokyo Metropolitan University, 1-1, Minami-Osawa, Hachioji-city, Tokyo 192-0397 (Japan); JST, CREST, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Das, B. P., E-mail: das@iiap.ernet.in [Indian Institute of Astrophysics, Bangalore 560 034 (India); Tatewaki, H., E-mail: htatewak@nsc.nagoya-cu.ac.jp [Graduate School of Natural Sciences, Nagoya City University, Nagoya, Aichi 467-8501 (Japan); Mukherjee, D., E-mail: pcdm@iacs.res.in [Raman Center of Atomic, Molecular and Optical Sciences, IACS, Kolkata 700 032 (India)

2015-12-31

The search for the electric dipole moment of the electron (eEDM) is important because it is a probe of Charge Conjugation-Parity (CP) violation. It can also shed light on new physics beyond the standard model. It is not possible to measure the eEDM directly. However, the interaction energy involving the effective electric field (E{sub eff}) acting on an electron in a molecule and the eEDM can be measured. This quantity can be combined with E{sub eff}, which is calculated by relativistic molecular orbital theory to determine eEDM. Previous calculations of E{sub eff} were not sufficiently accurate in the treatment of relativistic or electron correlation effects. We therefore developed a new method to calculate E{sub eff} based on a four-component relativistic coupled-cluster theory. We demonstrated our method for YbF molecule, one of the promising candidates for the eEDM search. Using very large basis set and without freezing any core orbitals, we obtain a value of 23.1 GV/cm for E{sub eff} in YbF with an estimated error of less than 10%. The error is assessed by comparison of our calculations and experiments for two properties relevant for E{sub eff}, permanent dipole moment and hyperfine coupling constant. Our method paves the way to calculate properties of various kinds of molecules which can be described by a single-reference wave function.

Magnetostatic interactions and forces between cylindrical permanent magnets

International Nuclear Information System (INIS)

Vokoun, David; Beleggia, Marco; Heller, Ludek; Sittner, Petr

2009-01-01

Permanent magnets of various shapes are often utilized in magnetic actuators, sensors or releasable magnetic fasteners. Knowledge of the magnetic force is required to control devices reliably. Here, we introduce an analytical expression for calculating the attraction force between two cylindrical permanent magnets on the assumption of uniform magnetization. Although the assumption is not fulfilled exactly in cylindrical magnets, we obtain a very good agreement between the calculated and measured forces between two identical cylindrical magnets and within an array of NdFeB cylindrical magnets.

Dynamics of nonstationary dipole vortices

DEFF Research Database (Denmark)

Hesthaven, J.S.; Lynov, Jens-Peter; Nycander, J.

1993-01-01

The dynamics of tilted dipole vortices in the equivalent barotropic vorticity (or Hasegawa-Mima) equation is studied. A recent theory is compared with numerical simulations and found to describe the short time behavior of dipole vortices well. In the long time limit the dipoles are found to eithe...... disintegrate or relax toward a steady eastward propagating dipole vortex. This relaxation is a consequence of nonviscous enstrophy loss by the dipole vortex....

The electric dipole moment of cobalt monoxide, CoO.

Science.gov (United States)

Zhuang, Xiujuan; Steimle, Timothy C

2014-03-28

A number of low-rotational lines of the E(4)Δ7/2 ← X(4)Δ7/2 (1,0) band system of cobalt monoxide, CoO, were recorded field free and in the presence of a static electric field. The magnetic hyperfine parameter, h7/2, and the electron quadrupole parameter, eQq0, for the E(4)Δ7/2(υ = 1) state were optimized from the analysis of the field-free spectrum. The permanent electric dipole moment, μ(→)(el), for the X(4)Δ7/2 (υ = 0) and E(4)Δ7/2 (υ = 1) states were determined to be 4.18 ± 0.05 D and 3.28 ± 0.05 D, respectively, from the analysis of the observed Stark spectra of F' = 7 ← F″ = 6 branch feature in the Q(7/2) line and the F' = 8 ← F″ = 7 branch feature in the R(7/2) line. The measured dipole moments of CoO are compared to those from theoretical predictions and the trend across the 3d-metal monoxide series discussed.

The 11 T Dipole for HL-LHC: Status and Plan

CERN Document Server

Savary, F; Bordini, B; Bottura, L; Chlachidze, G; Ramos, D; Izquierdo Bermudez, S; Karppinen, M; Lackner, F; Loffler, C H; Moron-Ballester, R; Nobrega, A; Perez, J C; Prin, H; Smekens, D; de Rijk, G; Redaelli, S; Rossi, L; Willering, G; Zlobin, A V; Giovannozzi, M

2016-01-01

The upgrade of the Large Hadron Collider (LHC) collimation system includes additional collimators in the LHC lattice. The longitudinal space for these collimators will be created by replacing some of the LHC main dipoles with shorter but stronger dipoles compatible with the LHC lattice and main systems. The project plan comprises the construction of two cryoassemblies containing each of the two 11-T dipoles of 5.5-m length for possible installation on either side of interaction point 2 of LHC in the years 2018-2019 for ion operation, and the installation of two cryoassemblies on either side of interaction point 7 of LHC in the years 2023-2024 for proton operation. The development program conducted in conjunction between the Fermilab and CERN magnet groups is progressing well. The development activities carried out on the side of Fermilab were concluded in the middle of 2015 with the fabrication and test of a 1-m-long two-in-one model and those on the CERN side are ramping up with the construction of 2-m-long ...

MODELES ET CALCUL DES SYSTEMES DE SUSPENSION MAGNETIQUE PASSIVE -DEVELOPPEMENTS ET CALCULS ANALYTIQUES EN 2D ET 3D DES INTERACTIONS ENTRE AIMANTS PERMANENTS-

OpenAIRE

Allag , Hicham

2010-01-01

The passive magnetic suspensions operate using attractive or repulsive forces exerted between permanent magnets. After giving an overview of different possible configurations of magnetic suspensions, the calculation of interactions between permanent magnets was developed. The calculations are realised for parallelepipeds magnets, where the magnetization is represented by distributions of charges or poles (Coulombian approach). All interactions (energy, forces, torques, etc ....) was calculate...

Levitation force on a permanent magnet over a superconducting plane: Modified critical-state model

International Nuclear Information System (INIS)

Yang, Z.J.

1997-01-01

The authors consider a model system of a permanent magnet above a semi-infinite superconductor. They introduce a modified critical-state model, and carry out derivations of the levitation force acting on the magnet. A key feature of the modification allows the current density to be less than the critical value. The theoretical results show an exponential relationship between the force and the distance. Analytical expressions are developed for permanent magnets in the form of a point dipole, a tip of a magnetic force microscope, and a cylindrical magnet. In the latter case, the exponential relationship has been observed in numerous experiments but without previous interpretation

The dipole representation of vector meson electroproduction beyond leading twist

Energy Technology Data Exchange (ETDEWEB)

Besse, A. [LPT, Universite Paris-Sud, CNRS, 91405, Orsay (France); Szymanowski, L. [National Center for Nuclear Research (NCBJ), Warsaw (Poland); Wallon, S., E-mail: wallon@th.u-psud.fr [LPT, Universite Paris-Sud, CNRS, 91405, Orsay (France); UPMC Univ. Paris 06, Faculte de Physique, 4 place Jussieu, 75252 Paris Cedex 05 (France)

2013-02-01

We link the recent computation beyond leading twist of the impact factor of the transition {gamma}{sub T}{sup Low-Asterisk }{yields}{rho}{sub T} performed in the light-cone collinear approach, to the dipole picture by expressing the hard part of the process through its Fourier transform in coordinate space. We show that in the Wandzura-Wilczek approximation the impact factor up to twist 3 factorises in the wave function of the photon combined with the distribution amplitudes of the {rho}-meson and the colour dipole scattering amplitude with the t-channel gluons. We show also that beyond the Wandzura-Wilczek approximation, the hard contribution of the amplitude still exhibits the signature of the interaction of a single colour dipole with the t-channel gluons. This result allows a phenomenological approach of the helicity amplitudes of the leptoproduction of vector meson, by combining our results to a dipole/target scattering amplitude model.

The dipole-dipole dispersion forces for small, intermediate and large distances

International Nuclear Information System (INIS)

Antonio, J.C.

1986-10-01

An improved expression is obtained for the dipole-dipole London dispersion force between closed shell atoms for small, intermediate and large distances compared with their linear dimensions. (Author) [pt

On the electric dipole moments of small sodium clusters from different theoretical approaches

Energy Technology Data Exchange (ETDEWEB)

Aguado, Andres, E-mail: aguado@metodos.fam.cie.uva.es [Departamento de Fisica Teorica, Atomica, y Optica, Universidad de Valladolid (Spain); Largo, Antonio, E-mail: alargo@qf.uva.es [Departamento de Quimica Fisica y Quimica Inorganica, Universidad de Valladolid (Spain); Vega, Andres, E-mail: vega@fta.uva.es [Departamento de Fisica Teorica, Atomica, y Optica, Universidad de Valladolid (Spain); Balbas, Luis Carlos, E-mail: balbas@fta.uva.es [Departamento de Fisica Teorica, Atomica, y Optica, Universidad de Valladolid (Spain)

2012-05-03

Graphical abstract: The dipole moments and polarizabilities of a few isomers of sodium clusters of selected sizes (n = 13, 14, 16) are calculated using density functional theory methods as well as ab initio MP2, CASSCF, and MR-CI methods. Among the density functional approaches, we consider the usual local density and generalized gradient approximations, as well as a recent van der Waals self-consistent functional accounting for non-local dispersion interactions. Highlights: Black-Right-Pointing-Pointer Dipole moment and polarizability of sodium clusters from DFT and ab initio methods. Black-Right-Pointing-Pointer New van der Waals selfconsistent implementation of non-local dispersion interactions. Black-Right-Pointing-Pointer New starting isomeric geometries from extensive search of global minimum structures. Black-Right-Pointing-Pointer Good agreement with recent experiments at cryogenic temperatures. - Abstract: The dipole moments of Na{sub n} clusters in the size range 10 < n < 20, recently measured at very low temperature (20 K), are much smaller than predicted by standard density functional methods. On the other hand, the calculated static dipole polarizabilities in that range of sizes deviate non-systematically from the measured ones, depending on the employed first principles approach. In this work we calculate the dipole moments and polarizabilities of a few isomers of Na{sub n} clusters of selected sizes (n = 13, 14, 16), obtained recently through an extensive unbiased search of the global minimum structures, and using density functional theory methods as well as ab initio MP2, CASSCF, and MR-CI methods. Among the density functional approaches, we consider the usual local density and generalized gradient approximations, as well as a recent van der Waals self-consistent functional accounting for non-local dispersion interactions. Both non-local pseudopotentials and all-electron implementations are employed and compared in order to assess the possible

On the electric dipole moments of small sodium clusters from different theoretical approaches

International Nuclear Information System (INIS)

Aguado, Andrés; Largo, Antonio; Vega, Andrés; Balbás, Luis Carlos

2012-01-01

Graphical abstract: The dipole moments and polarizabilities of a few isomers of sodium clusters of selected sizes (n = 13, 14, 16) are calculated using density functional theory methods as well as ab initio MP2, CASSCF, and MR-CI methods. Among the density functional approaches, we consider the usual local density and generalized gradient approximations, as well as a recent van der Waals self-consistent functional accounting for non-local dispersion interactions. Highlights: ► Dipole moment and polarizability of sodium clusters from DFT and ab initio methods. ► New van der Waals selfconsistent implementation of non-local dispersion interactions. ► New starting isomeric geometries from extensive search of global minimum structures. ► Good agreement with recent experiments at cryogenic temperatures. - Abstract: The dipole moments of Na n clusters in the size range 10 n clusters of selected sizes (n = 13, 14, 16), obtained recently through an extensive unbiased search of the global minimum structures, and using density functional theory methods as well as ab initio MP2, CASSCF, and MR-CI methods. Among the density functional approaches, we consider the usual local density and generalized gradient approximations, as well as a recent van der Waals self-consistent functional accounting for non-local dispersion interactions. Both non-local pseudopotentials and all-electron implementations are employed and compared in order to assess the possible contribution of the core electrons to the electric dipole moments. Our new geometries possess significantly smaller electric dipole moments than previous density functional results, mostly when combined with the van der Waals exchange–correlation functional. However, although the agreement with experiment clearly improves upon previous calculations, the theoretical dipole moments are still about one order of magnitude larger than the experimental values, suggesting that the correct global minimum structures have not been

Cooperative behavior of qutrits with dipole-dipole interactions

OpenAIRE

Mandilara, A.; Akulin, V. M.

2006-01-01

We have identified a class of many body problems with analytic solution beyond the mean-field approximation. This is the case where each body can be considered as an element of an assembly of interacting particles that are translationally frozen multi-level quantum systems and that do not change significantly their initial quantum states during the evolution. In contrast, the entangled collective state of the assembly experiences an appreciable change. We apply this approach to interacting th...

Dipole polarizability of neutron rich nuclei and the symmetry energy

Energy Technology Data Exchange (ETDEWEB)

Horvat, Andrea; Johansen, Jacob; Miki, Kenjiro; Schindler, Fabia; Schrock, Philipp [IKP, TU Darmstadt (Germany); Aumann, Thomas [IKP, TU Darmstadt (Germany); GSI, Darmstadt (Germany); Boretzky, Konstanze [GSI, Darmstadt (Germany); Collaboration: R3B-Collaboration

2015-07-01

As a part of a systematic investigation of the dipole response of stable up to very neutron rich tin isotopes, nuclear and electromagnetic excitation of {sup 124}Sn-{sup 134}Sn has been investigated at relativistic energies in inverse kinematics induced by carbon and lead targets at the LAND-R3B setup at GSI in Darmstadt. The electric dipole response and the nuclear reaction cross section, total and charge-changing, are obtained from the kinematically complete determination of momenta of all particles on an event by event basis. The dipole polarizability is extracted from the Coulomb excitation interaction channel, in order to make use of relevant correlations of this observable with nuclear matter properties such as the symmetry energy at saturation density (J) and it's slope (L). The systematics of the low-lying ''pygmy'' dipole strength, the giant dipole resonance (GDR) and the neutron skin thickness are determined with respect to increasing isospin asymmetry. This talk also discusses the correlations and sensitivities of these variables and observables obtained within the framework of nuclear energy density functional theory.

The pygmy dipole resonance in neutron-rich nuclei

International Nuclear Information System (INIS)

Hung, Nguyen Quang; Kiet, Hoang Anh Tuan; Duc, Huynh Ngoc; Chuong, Nguyen Thi

2016-01-01

The pygmy dipole resonance (PDR), which has been observed via the enhancement of the electric dipole strength E 1 of atomic nuclei, is studied within a microscopic collective model. The latter employs the Hartree-Fock (HF) method with effective nucleon-nucleon interactions of the Skyrme types plus the random-phase approximation (RPA). The results of the calculations obtained for various even-even nuclei such as "1"6"-"2"8O, "4"0"-"5"8Ca, "1"0"0"-"1"2"0Sn, and "1"8"2"-"2"1"8Pb show that the PDR is significantly enhanced when the number of neutrons outside the stable core of the nucleus is increased, that is, in the neutron-rich nuclei. As the result, the relative ratio between the energy weighted sum of the strength of the PDR and that of the GDR (giant dipole resonance) does not exceed 4%. The collectivity of the PDR and GDR states will be also discussed. (paper)

A sensitive search for a muon electric dipole moment

International Nuclear Information System (INIS)

Semertzidis, Yannis K.; Carey, R.M.; Miller, J.P.; Rind, O.; Roberts, B.L.; Sulak, L.R.; Brown, H.; Danby, G.T.; Jackson, J.W.; Larsen, R.; Lazarus, D.M.; Meng, W.; Morse, W.M.; Ozben, C.S.; Prigl, R.; Semertzidis, Y.K.; Balakin, V.; Bazhan, A.; Dudnikov, A.; Khazin, B. I.

2001-01-01

We are proposing a new method to carry out a dedicated search for a permanent electric dipole moment (EDM) of the muon with a sensitivity at a level of 10 -24 e·cm. The experiment will be sensitive to non-standard physics like SUSY. The experimental design exploits the strong motional electric field sensed by relativistic particles in a magnetic storage ring. As a key feature, a novel technique has been invented in which the g-2 precession is compensated with a radial electric field. The EDM signature will be an out of plane muon spin precession as a function of time. The rate of this precession will be proportional to the EDM amplitude of the muon

UNK superconducting dipole development

International Nuclear Information System (INIS)

Ageev, A.I.; Andreev, N.I.; Balbekov, V.I.

1987-01-01

For choozing the design of superconducting dipoles (SCD) for the IHEP UNK the test results for SCD with warm and cold iron are given. The main parameters of dipoles are presented. The SCD designs are described. At present works on SP magnet simulation for UNK are carried out in two directions. Tests are conducted on a rig with a chain of series dipoles with a warm magnetic screen. The purpose of these tests is to study heat exchange and hydraulics in magnets, energy and helium evacuation in emergency magnet transition into normal conditions, simulation of possible cooling and heating schemes. Another direction involves production of short and full-scale dipole models with cold iron and their testing on rigs. The final choice of the dipole design for commercial production is planned for 1987

Relativistic quasiparticle time blocking approximation: Dipole response of open-shell nuclei

International Nuclear Information System (INIS)

Litvinova, E.; Ring, P.; Tselyaev, V.

2008-01-01

The self-consistent relativistic quasiparticle random-phase approximation (RQRPA) is extended by the quasiparticle-phonon coupling (QPC) model using the quasiparticle time blocking approximation (QTBA). The method is formulated in terms of the Bethe-Salpeter equation (BSE) in the two-quasiparticle space with an energy-dependent two-quasiparticle residual interaction. This equation is solved either in the basis of Dirac states forming the self-consistent solution of the ground state or in the momentum representation. Pairing correlations are treated within the Bardeen-Cooper-Schrieffer (BCS) model with a monopole-monopole interaction. The same NL3 set of the coupling constants generates the Dirac-Hartree-BCS single-quasiparticle spectrum, the static part of the residual two-quasiparticle interaction and the quasiparticle-phonon coupling amplitudes. A quantitative description of electric dipole excitations in the chain of tin isotopes (Z=50) with the mass numbers A=100,106,114,116,120, and 130 and in the chain of isotones with (N=50) 88 Sr, 90 Zr, 92 Mo is performed within this framework. The RQRPA extended by the coupling to collective vibrations generates spectra with a multitude of 2q x phonon (two quasiparticles plus phonon) states providing a noticeable fragmentation of the giant dipole resonance as well as of the soft dipole mode (pygmy resonance) in the nuclei under investigation. The results obtained for the photo absorption cross sections and for the integrated contributions of the low-lying strength to the calculated dipole spectra agree very well with the available experimental data

Magnetic properties of high temperature superconductors and their interaction with high energy permanent magnets

International Nuclear Information System (INIS)

Agarwala, A.K.

1990-01-01

Magnetic properties of sintered samples of YBCO ceramic superconductors at various temperatures were measured using a vibrating sample magnetometer (VSM). Also, measurements of forces experienced by a well characterized rare earth-transition metal (RE-TM) permanent magnet (PM) interacting with the superconducting YBCO sample cooled in liquid nitrogen, were performed. Based upon the observed hysteretic magnetization properties of these high temperature superconductors (HTS), the HTS-PM interaction force at liquid nitrogen temperature was calculated from first principle, and finally correlated to the force measurement results. With this analysis, magnetic forces between the same HTS and PM system including the levitation as well as suspension effects at liquid-helium temperature are predicted

Changes in earth's dipole.

Science.gov (United States)

Olson, Peter; Amit, Hagay

2006-11-01

The dipole moment of Earth's magnetic field has decreased by nearly 9% over the past 150 years and by about 30% over the past 2,000 years according to archeomagnetic measurements. Here, we explore the causes and the implications of this rapid change. Maps of the geomagnetic field on the core-mantle boundary derived from ground-based and satellite measurements reveal that most of the present episode of dipole moment decrease originates in the southern hemisphere. Weakening and equatorward advection of normal polarity magnetic field by the core flow, combined with proliferation and growth of regions where the magnetic polarity is reversed, are reducing the dipole moment on the core-mantle boundary. Growth of these reversed flux regions has occurred over the past century or longer and is associated with the expansion of the South Atlantic Anomaly, a low-intensity region in the geomagnetic field that presents a radiation hazard at satellite altitudes. We address the speculation that the present episode of dipole moment decrease is a precursor to the next geomagnetic polarity reversal. The paleomagnetic record contains a broad spectrum of dipole moment fluctuations with polarity reversals typically occurring during dipole moment lows. However, the dipole moment is stronger today than its long time average, indicating that polarity reversal is not likely unless the current episode of moment decrease continues for a thousand years or more.

The electric dipole moment of cobalt monoxide, CoO

Energy Technology Data Exchange (ETDEWEB)

Zhuang, Xiujuan, E-mail: zhuangxj@hnu.edu.cn [College of Physics and Microelectronics Science, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, Hunan University, Changsha 410082 (China); Steimle, Timothy C. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States)

2014-03-28

A number of low-rotational lines of the E{sup 4}Δ{sub 7/2} ← X{sup 4}Δ{sub 7/2} (1,0) band system of cobalt monoxide, CoO, were recorded field free and in the presence of a static electric field. The magnetic hyperfine parameter, h{sub 7/2}, and the electron quadrupole parameter, eQq{sub 0}, for the E{sup 4}Δ{sub 7/2}(υ = 1) state were optimized from the analysis of the field-free spectrum. The permanent electric dipole moment, μ{sup -vector}{sub el}, for the X{sup 4}Δ{sub 7/2} (υ = 0) and E{sup 4}Δ{sub 7/2} (υ = 1) states were determined to be 4.18 ± 0.05 D and 3.28 ± 0.05 D, respectively, from the analysis of the observed Stark spectra of F′ = 7 ← F″ = 6 branch feature in the Q(7/2) line and the F′ = 8 ← F″ = 7 branch feature in the R(7/2) line. The measured dipole moments of CoO are compared to those from theoretical predictions and the trend across the 3d-metal monoxide series discussed.

Isovector giant dipole resonance in hot rotating light nuclei in the calcium region

International Nuclear Information System (INIS)

Shanmugam, G.; Thiagasundaram, M.

1989-01-01

The isovector giant dipole resonances in hot rotating light nuclei in the calcium region are studied using a rotating anisotropic harmonic oscillator potential and a separable dipole-dipole residual interaction. The influence of temperature on the isovector giant dipole resonance is assumed to occur through the change of deformation of the average field only. Calculations are performed for the three nuclei /sup 40,42/Ca and /sup 46/Ti which have spherical, oblate, and prolate ground states, respectively, to see how their shape transitions at higher excited states affect the isovector giant resonance frequencies built on them. It is seen that, while the width fluctuations present at T = 0 vanish at T = 0.5 MeV in /sup 40,42/Ca, they persist up to T = 1.5 MeV in the case of /sup 46/Ti. This behavior brings out the role of temperature on shell effects which in turn affects the isovector giant dipole resonance widths

Accurate quantum calculations of translation-rotation eigenstates in electric-dipole-coupled H2O@C60 assemblies

Science.gov (United States)

Felker, Peter M.; Bačić, Zlatko

2017-09-01

We present methodology for variational calculation of the 6 n -dimensional translation-rotation (TR) eigenstates of assemblies of n H2O@C60 moieties coupled by dipole-dipole interactions. We show that the TR Hamiltonian matrix for any n can be constructed from dipole-dipole matrix elements computed for n = 2 . We present results for linear H2O@C60 assemblies. Two classes of eigenstates are revealed. One class comprises excitations of the 111 rotational level of H2O. The lowest-energy 111 -derived eigenstate for each assembly exhibits significant dipole ordering and shifts down in energy with the assembly size.

RHIC spin flipper AC dipole controller

Energy Technology Data Exchange (ETDEWEB)

Oddo, P.; Bai, M.; Dawson, C.; Gassner, D.; Harvey, M.; Hayes, T.; Mernick, K.; Minty, M.; Roser, T.; Severino, F.; Smith, K.

2011-03-28

The RHIC Spin Flipper's five high-Q AC dipoles which are driven by a swept frequency waveform require precise control of phase and amplitude during the sweep. This control is achieved using FPGA based feedback controllers. Multiple feedback loops are used to and dynamically tune the magnets. The current implementation and results will be presented. Work on a new spin flipper for RHIC (Relativistic Heavy Ion Collider) incorporating multiple dynamically tuned high-Q AC-dipoles has been developed for RHIC spin-physics experiments. A spin flipper is needed to cancel systematic errors by reversing the spin direction of the two colliding beams multiple times during a store. The spin flipper system consists of four DC-dipole magnets (spin rotators) and five AC-dipole magnets. Multiple AC-dipoles are needed to localize the driven coherent betatron oscillation inside the spin flipper. Operationally the AC-dipoles form two swept frequency bumps that minimize the effect of the AC-dipole dipoles outside of the spin flipper. Both AC bumps operate at the same frequency, but are phase shifted from each other. The AC-dipoles therefore require precise control over amplitude and phase making the implementation of the AC-dipole controller the central challenge.

Electric dipole moment of magnetoexciton in concentric quantum rings

Science.gov (United States)

García, L. F.; Mikhailov, I. D.; Revinova, S. Yu

2017-12-01

We study properties of exciton in a weakly coupled concentric quantum rings, penetrated by an axially directed magnetic flux and subjected to an electric field in the ring’s plane. To this end, we adopt a simple model of quasi-one-dimensional rotator, for which the wave functions and the corresponding energies we found by using the double Fourier series expansion method. Revealed multiple intersections of the energy levels provide conditions for abrupt changes of the radial and the angular quantum numbers, making possible the tunnelling of carriers between rings and allowing the formation of a permanent large dipole moment. We show that the electric and magnetic polarizability of concentric quantum rings with a trapped exciton are very sensible to external electric and magnetic fields.

Relativistic configuration-interaction calculations of electric dipole n=2−n=3 transitions for medium-charge Li-like ions

Energy Technology Data Exchange (ETDEWEB)

Deng, Banglin, E-mail: banglindeng@yahoo.cn [Department of Applied Physics, Chengdu University of Technology, Chengdu 610059, Sichuan (China); Jiang, Gang [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, Sichuan (China); Zhang, Chuanyu [Department of Applied Physics, Chengdu University of Technology, Chengdu 610059, Sichuan (China)

2014-09-15

In this work, the multi-configuration Dirac–Fock and relativistic configuration-interaction methods have been used to calculate the transition wavelengths, electric dipole transition probabilities, line strengths, and absorption oscillator strengths for the 2s–3p, 2p–3s, and 2p–3d transitions in Li-like ions with nuclear charge Z=7–30. Our calculated values are in good agreement with previous experimental and theoretical results. We took the contributions from Breit interaction, finite nuclear mass corrections, and quantum electrodynamics corrections to the initial and final levels into account, and also found that the contributions from Breit interaction, self-energy, and vacuum polarization grow fast with increasing nuclear charge for a fixed configuration. The ratio of the velocity to length form of the transition rate (A{sub v}/A{sub l}) was used to estimate the accuracy of our calculations.

Hybrid permanent magnet gradient dipoles for the recycler ring at Fermilab

International Nuclear Information System (INIS)

Brown, B.C.; Dimarco, J.; Foster, G.W.; Glass, H.D.; Haggard, J.E.; Harding, D.J.; Jackson, G.R.; May, M.R.; Nicol, T.H.; Ostiguy, J.-F.; Schlabach, R.; Volk, J.T.

1997-11-01

Hybrid permanent magnets provide the magnetic fields for an anti- proton storage ring which is under construction at Fermilab. Using a combined function lattice, gradient magnets provide the bending, focusing and sextupole correction for the regular cells. Shorter magnets without sextupole are used in dispersion suppressor cells. These magnets use a 4.7 m ( 3 m) long iron shell for flux return, bricks of 25.4 mm thick strontium ferrite supply the flux and transversely tapered iron poles separated by aluminum spacers set the shape of the magnetic field. Central fields of 0.14 T with gradients of ∼6%/inch (∼13%/inch) are required. Field errors are expected to be less than 10 -4 of the bend field over an aperture of ±40 mm (horizontal) x ±20 mm (vertical). Design, procurement, fabrication, pole potential adjustment, field shape trimming and measured fields will be reported

Elastic dipoles of point defects from atomistic simulations

Science.gov (United States)

Varvenne, Céline; Clouet, Emmanuel

2017-12-01

The interaction of point defects with an external stress field or with other structural defects is usually well described within continuum elasticity by the elastic dipole approximation. Extraction of the elastic dipoles from atomistic simulations is therefore a fundamental step to connect an atomistic description of the defect with continuum models. This can be done either by a fitting of the point-defect displacement field, by a summation of the Kanzaki forces, or by a linking equation to the residual stress. We perform here a detailed comparison of these different available methods to extract elastic dipoles, and show that they all lead to the same values when the supercell of the atomistic simulations is large enough and when the anharmonic region around the point defect is correctly handled. But, for small simulation cells compatible with ab initio calculations, only the definition through the residual stress appears tractable. The approach is illustrated by considering various point defects (vacancy, self-interstitial, and hydrogen solute atom) in zirconium, using both empirical potentials and ab initio calculations.

Dipole modes of a superfluid Bose–Fermi mixture in the BCS-BEC crossover

International Nuclear Information System (INIS)

Wen, Wen; Chen, Bingyan; Zhang, Xuewu

2017-01-01

Motivated by the first experimental realization by the Ecole Normale Supérieure (ENS) group of a mixture of a Bose–Einstein condensate with a Fermi superfluid continuously changing from a Bardeen–Cooper–Schrieffer (BCS) superfluid to a Bose–Einstein condensate (BEC) (Ferrier-Barbut et al 2014 Science 345 1035), we analytically study the dipole modes of the superfluid Bose–Fermi mixture in the BCS-BEC crossover. The analytical approach can explicitly reveal relationships between the frequencies of the dipole modes and the microscopic properties of the novel system. We start from coupled hydrodynamic equations, where the equation of state for the Fermi superfluid in the crossover is an analytical fitting formula based on experimental data, and by using a scaling approach we analytically study eigenfrequencies of the dipole modes for the coupled system in the ENS experimental parameters. Without the boson–fermion interaction in the equilibrium density profiles, our theoretical results can be reduced to the mean-field model and is consistent with the experimental data. However, by further taking into account the boson–fermion interaction numerically and analytically, we find that the results disagree with the experiment, especially in the parameter regime where the boson interaction is smaller than the boson–fermion interaction. (paper)

A Note on the Dipole Coordinates

OpenAIRE

Kageyama, Akira; Sugiyama, Tooru; Watanabe, Kunihiko; Sato, Tetsuya

2004-01-01

A couple of orthogonal coordinates for dipole geometry are proposed for numerical simulations of plasma geophysics in the Earth's dipole magnetic field. These coordinates have proper metric profiles along field lines in contrast to the standard dipole coordinate system that is commonly used in analytical studies for dipole geometry.

Operador dipolo-dipolo na base de momento angular: um complemento ao estudo de ressonância magnética nuclear Dipole-dipole operator in angular momentum basis: a complementary study in nuclear magnetic resonance

Directory of Open Access Journals (Sweden)

Rita de Cássia de Oliveira Sebastião

2008-01-01

Full Text Available The relationship between the magnetic dipole-dipole potential energy function and its quantum analogue is presented in this work. It is assumed the reader is familiar with the classical expression of the dipolar interaction and has basic knowledge of the quantum mechanics of angular momentum. Except for these two points only elementary steps are involved.

Electron-selective contacts via ultra-thin organic interface dipoles for silicon organic heterojunction solar cells

Science.gov (United States)

Reichel, Christian; Würfel, Uli; Winkler, Kristina; Schleiermacher, Hans-Frieder; Kohlstädt, Markus; Unmüssig, Moritz; Messmer, Christoph A.; Hermle, Martin; Glunz, Stefan W.

2018-01-01

In the last years, novel materials for the formation of electron-selective contacts on n-type crystalline silicon (c-Si) heterojunction solar cells were explored as an interfacial layer between the metal electrode and the c-Si wafer. Besides inorganic materials like transition metal oxides or alkali metal fluorides, also interfacial layers based on organic molecules with a permanent dipole moment are promising candidates to improve the contact properties. Here, the dipole effect plays an essential role in the modification of the interface and effective work function of the contact. The amino acids L-histidine, L-tryptophan, L-phenylalanine, glycine, and sarcosine, the nucleobase adenine, and the heterocycle 4-hydroxypyridine were investigated as dipole materials for an electron-selective contact on the back of p- and n-type c-Si with a metal electrode based on aluminum (Al). Furthermore, the effect of an added fluorosurfactant on the resulting contact properties was examined. The performance of n-type c-Si solar cells with a boron diffusion on the front was significantly increased when L-histidine and/or the fluorosurfactant was applied as a full-area back surface field. This improvement was attributed to the modification of the interface and the effective work function of the contact by the dipole material which was corroborated by numerical device simulations. For these solar cells, conversion efficiencies of 17.5% were obtained with open-circuit voltages (Voc) of 625 mV and fill factors of 76.3%, showing the potential of organic interface dipoles for silicon organic heterojunction solar cells due to their simple formation by solution processing and their low thermal budget requirements.

Constraints on long-range spin-gravity and monopole-dipole couplings of the proton

Science.gov (United States)

Jackson Kimball, Derek F.; Dudley, Jordan; Li, Yan; Patel, Dilan; Valdez, Julian

2017-10-01

Results of a search for a long-range monopole-dipole coupling between the mass of the Earth and rubidium (Rb) nuclear spins are reported. The experiment simultaneously measures the spin precession frequencies of overlapping ensembles of 85Rb and 87Rb atoms contained within an evacuated, antirelaxation-coated vapor cell. The nuclear structure of the Rb isotopes makes the experiment particularly sensitive to spin-dependent interactions of the proton. The spin-dependent component of the gravitational energy of the proton in the Earth's field is found to be smaller than 3 ×10-18 eV , improving laboratory constraints on long-range monopole-dipole interactions by over 3 orders of magnitude.

Testing of a Single 11 T $Nb_3Sn$ Dipole Coil Using a Dipole Mirror Structure

Energy Technology Data Exchange (ETDEWEB)

Zlobin, Alexander [Fermilab; Andreev, Nicolai [Fermilab; Barzi, Emanuela [Fermilab; Chlachidze, Guram [Fermilab; Kashikhin, Vadim [Fermilab; Nobrega, Alfred [Fermilab; Novitski, Igor [Fermilab; Turrioni, Daniele [Fermilab; Karppinen, Mikko [CERN; Smekens, David [CERN

2014-07-01

FNAL and CERN are developing an 11 T Nb3Sn dipole suitable for installation in the LHC. To optimize coil design parameters and fabrication process and study coil performance, a series of 1 m long dipole coils is being fabricated. One of the short coils has been tested using a dipole mirror structure. This paper describes the dipole mirror magnetic and mechanical designs, and reports coil parameters and test results.

Self-induced dipole force and filamentation instability of a matter wave

DEFF Research Database (Denmark)

Saffman, M.

1998-01-01

The interaction of copropagating electromagnetic and matter waves is described with a set of coupled higher-order nonlinear Schrodinger equations. Optical self-focusing modulates an initially planar wave leading to the generation of dipole forces on the atoms. Atomic channeling due to the dipole...... forces leads, in the nonlinear regime, to filamentation of the atomic beam. Instability growth rates are calculated for atomic beams with both low and high phase space densities. In one transverse dimension an exact solution is found that describes a coupled optical and atomic soliton....

On the He-McKellar-Wilkens phase of an electric dipole

Science.gov (United States)

Rai, Yam P.; Rai, Dhurba

2017-08-01

The He-McKellar-Wilkens (HMW) phase of an electric dipole moving in a static magnetic field is derived by explicitly considering the interaction between the currents associated with the moving dipole and the magnetic vector potential. Conditions for the observation of the HMW phase in different field configurations are investigated. A practical setup is proposed that provides essentially a radial magnetic field with inverse radial dependence for the observation of the HMW phase with magnetic field alone. Possible magnetic field control of exciton current in an open ring setup is discussed.

The consequences of improperly describing oscillator strengths beyond the electric dipole approximation

Energy Technology Data Exchange (ETDEWEB)

Lestrange, Patrick J.; Egidi, Franco; Li, Xiaosong, E-mail: xsli@uw.edu [Department of Chemistry, University of Washington, Seattle, Washington 98195 (United States)

2015-12-21

The interaction between a quantum mechanical system and plane wave light is usually modeled within the electric dipole approximation. This assumes that the intensity of the incident field is constant over the length of the system and transition probabilities are described in terms of the electric dipole transition moment. For short wavelength spectroscopies, such as X-ray absorption, the electric dipole approximation often breaks down. Higher order multipoles are then included to describe transition probabilities. The square of the magnetic dipole and electric quadrupole are often included, but this results in an origin-dependent expression for the oscillator strength. The oscillator strength can be made origin-independent if all terms through the same order in the wave vector are retained. We will show the consequences and potential pitfalls of using either of these two expressions. It is shown that the origin-dependent expression may violate the Thomas-Reiche-Kuhn sum rule and the origin-independent expression can result in negative transition probabilities.

The consequences of improperly describing oscillator strengths beyond the electric dipole approximation.

Science.gov (United States)

Lestrange, Patrick J; Egidi, Franco; Li, Xiaosong

2015-12-21

The interaction between a quantum mechanical system and plane wave light is usually modeled within the electric dipole approximation. This assumes that the intensity of the incident field is constant over the length of the system and transition probabilities are described in terms of the electric dipole transition moment. For short wavelength spectroscopies, such as X-ray absorption, the electric dipole approximation often breaks down. Higher order multipoles are then included to describe transition probabilities. The square of the magnetic dipole and electric quadrupole are often included, but this results in an origin-dependent expression for the oscillator strength. The oscillator strength can be made origin-independent if all terms through the same order in the wave vector are retained. We will show the consequences and potential pitfalls of using either of these two expressions. It is shown that the origin-dependent expression may violate the Thomas-Reiche-Kuhn sum rule and the origin-independent expression can result in negative transition probabilities.

Possible displacement of mercury's dipole

International Nuclear Information System (INIS)

Ng, K.H.; Beard, D.B.

1979-01-01

Earlier attempts to model the Hermean magnetospheric field based on a planet-centered magnetic multipole field have required the addition of a quadrupole moment to obtain a good fit to space vehicle observations. In this work we obtain an equally satisfactory fit by assuming a null quadrupole moment and least squares fitting of the displacement of the planetary dipole from the center of the planet. We find a best fit for a dipole displacement from the planet center of 0.033 R/sub m/ away from the solar direction, 0.025 R/sub m/ toward dawn in the magnetic equatorial plane, and 0.189 R/sub m/ northward along the magnetic dipole axis, where R/sub m/ is the planet radius. Therefore the presence of a magnetic quadrupole moment is not ruled out. The compressed dipole field more completely represents the field in the present work than in previous work where the intrinsic quadrupole field was not included in the magnetopause surface and field calculations. Moreover, we have corrected a programing error in previous work in the computation of dipole tilt lambda away from the sun. We find a slight increase for the planet dipole moment of 190γR/sub m/ 3 and a dipole tilt angle lambda away from the sun. We find a slight increase for the planet moment of 190γR/sub m/ 3 and a dipole tilt angle lambda of only 1.2 0 away from the sun. All other parameters are essentially unchanged

Electric Dipole Polarizability of ^{48}Ca and Implications for the Neutron Skin.

Science.gov (United States)

Birkhan, J; Miorelli, M; Bacca, S; Bassauer, S; Bertulani, C A; Hagen, G; Matsubara, H; von Neumann-Cosel, P; Papenbrock, T; Pietralla, N; Ponomarev, V Yu; Richter, A; Schwenk, A; Tamii, A

2017-06-23

The electric dipole strength distribution in ^{48}Ca between 5 and 25 MeV has been determined at RCNP, Osaka from proton inelastic scattering experiments at forward angles. Combined with photoabsorption data at higher excitation energy, this enables the first extraction of the electric dipole polarizability α_{D}(^{48}Ca)=2.07(22)  fm^{3}. Remarkably, the dipole response of ^{48}Ca is found to be very similar to that of ^{40}Ca, consistent with a small neutron skin in ^{48}Ca. The experimental results are in good agreement with ab initio calculations based on chiral effective field theory interactions and with state-of-the-art density-functional calculations, implying a neutron skin in ^{48}Ca of 0.14-0.20 fm.

Dipoles at rest

International Nuclear Information System (INIS)

Griffiths, D.J.

1992-01-01

In a world populated by magnetic monopoles (as well as ordinary electric charges), there are two kinds of electric dipoles: those due to separated electric charges, and those due to current loops of magnetic charge. Similarly, there are two kinds of magnetic dipoles: those due to separated magnetic monopoles, and those due to electric current loops. This paper derives the potentials and fields of each of the four dipole species, and calculates the force, torque, energy, momentum, and angular momentum of each type, when placed (at rest) in a static external field (which may itself be produced by electric charges and currents, magnetic charges and currents, or all of these). Some implications and applications of the various results are discussed

Some dipole shower studies

Science.gov (United States)

Cabouat, Baptiste; Sjöstrand, Torbjörn

2018-03-01

Parton showers have become a standard component in the description of high-energy collisions. Nowadays most final-state ones are of the dipole character, wherein a pair of partons branches into three, with energy and momentum preserved inside this subsystem. For initial-state showers a dipole picture is also possible and commonly used, but the older global-recoil strategy remains a valid alternative, wherein larger groups of partons share the energy-momentum preservation task. In this article we introduce and implement a dipole picture also for initial-state radiation in Pythia, and compare with the existing global-recoil one, and with data. For the case of Deeply Inelastic Scattering we can directly compare with matrix element expressions and show that the dipole picture gives a very good description over the whole phase space, at least for the first branching.

Ionization of Rb Rydberg atoms in the attractive nsnp dipole-dipole potential

International Nuclear Information System (INIS)

Park, Hyunwook; Shuman, E. S.; Gallagher, T. F.

2011-01-01

We have observed the ionization of a cold gas of Rb Rydberg atoms which occurs when nsns van der Waals pairs of ns atoms of n≅ 40 on a weakly repulsive potential are transferred to an attractive dipole-dipole nsnp potential by a microwave transition. Comparing the measurements to a simple model shows that the initial 300-μK thermal velocity of the atoms plays an important role. Excitation to a repulsive dipole-dipole potential does not lead to more ionization on a 15-μs time scale than leaving the atoms in the weakly repulsive nsns state. This observation is slightly surprising since a radiative transition must occur to allow ionization in the latter case. Finally, by power broadening of the microwave transition, to allow transitions from the initial nsns state to the nsnp state over a broad range of internuclear spacings, it is possible to accelerate markedly the evolution to a plasma.

W-boson electric dipole moment

International Nuclear Information System (INIS)

He, X.; McKellar, B.H.J.

1990-01-01

The W-boson electric dipole moment is calculated in the SU(3) C xSU(2) L xU(1) Y model with several Higgs-boson doublets. Using the constraint on the CP-violating parameters from the experimental upper bound of the neutron electric dipole moment, we find that the W-boson electric dipole moment is constrained to be less than 10 -4

Electroabsorption spectra of carotenoid isomers: Conformational modulation of polarizability vs. induced dipole moments

International Nuclear Information System (INIS)

Krawczyk, Stanislaw; Jazurek, Beata; Luchowski, Rafal; Wiacek, Dariusz

2006-01-01

Electroabsorption spectra of all-trans, 13-cis and 15-cis isomers of carotenoids violaxanthin and β-carotene frozen in organic solvents were analysed in terms of changes in permanent dipole moment, Δμ, and in the linear polarizability, Δα, on electronic excitation. The spectral range investigated covered the two carotenoid absorption bands in the VIS and UV, known to originate from differently oriented transition dipole moments. In contrast with the collinearity of the apparent Δμ with Δα in the lowest-energy allowed (VIS) transition 1A g - ->1B u + , the axis of the largest polarizability change in the UV transition 1A g - ->1A g + (''cis band'') was found to make a large angle with the transition moment, while the direction of Δμ appears to be much closer to it. These data support the view that Δμ's inferred from electrochromic spectra of carotenoids are apparent and are not induced by the local matrix field in the solvent cavity, but merely result from conformational modulation of molecular polarizability

Electric dipole moments of charged leptons and lepton flavor violating interactions in the general two Higgs doublet model

International Nuclear Information System (INIS)

Iltan, E. O.

2001-01-01

We calculate the electric dipole moment of the electron using the experimental result of the muon electric dipole moment and upper limit of the BR(μ->eγ) in the framework of the general two Higgs doublet model. Our prediction is 10 -32 ecm, which lies in the experimental current limits. Further, we obtain constraints for the Yukawa couplings {bar ξ} N,τe D and {bar ξ} N,τμ D . Finally, we present an expression which connects the BR(τ->μγ) and the electric dipole moment of the τ lepton and study the relation between these physical quantities

Elementary isovector spin and orbital magnetic dipole modes revisited in the shell model

International Nuclear Information System (INIS)

Richter, A.

1988-08-01

A review is given on the status of mainly spin magnetic dipole modes in some sd- and fp-shell nuclei studied with inelastic electron and proton scattering, and by β + -decay. Particular emphasis is also placed on a fairly new, mainly orbital magnetic dipole mode investigated by high-resolution (e,e') and (p,p') scattering experiments on a series of fp-shell nuclei. Both modes are discussed in terms of the shell model with various effective interactions. (orig.)

Dipole and quadrupole forces exerted on atoms in laser fields: The nonperturbative approach

International Nuclear Information System (INIS)

Sindelka, Milan; Moiseyev, Nimrod; Cederbaum, Lorenz S.

2006-01-01

Manipulation of cold atoms by lasers has so far been studied solely within the framework of the conventional dipole approximation, and the atom-light interaction has been treated using low order perturbation theory. Laser control of atomic motions has been ascribed exclusively to the corresponding light-induced dipole forces. In this work, we present a general theory to derive the potential experienced by an atom in a monochromatic laser field in a context analogous to the Born-Oppenheimer approximation for molecules in the field-free case. The formulation goes beyond the dipole approximation and gives rise to the field-atom coupling potential terms which so far have not been taken into consideration in theoretical or experimental studies. Contrary to conventional approaches, our method is based upon the many electron Floquet theory and remains valid also for high intensity laser fields (i.e., for a strongly nonperturbative atom-light interaction). As an illustration of the developed theory, we investigate the trapping of cold atoms in optical lattices. We find that for some atoms for specific laser parameters, despite the absence of the dipole force, the laser trapping is still possible due to the electric quadrupole forces. Namely, we show that by using realistic laser parameters one can form a quadrupole optical lattice which is sufficiently strong to trap Ca and Na atoms

Dynamics of a nonlinear dipole vortex

DEFF Research Database (Denmark)

Hesthaven, J.S.; Lynov, Jens-Peter; Nielsen, A.H.

1995-01-01

A localized stationary dipole solution to the Euler equations with a relationship between the vorticity and streamfunction given as omega=-psi+psi(3) is presented. By numerical integration of the Euler equations this dipole is shown to be unstable. However, the initially unstable dipole reorganiz...

Electrostatic-Dipole (ED) Fusion Confinement Studies

Science.gov (United States)

Miley, George H.; Shrestha, Prajakti J.; Yang, Yang; Thomas, Robert

2004-11-01

The Electrostatic-Dipole (ED) concept significantly differs from a "pure" dipole confinement device [1] in that the charged particles are preferentially confined to the high-pressure region interior of the dipole coil by the assistance of a surrounding spherical electrostatic grid. In present ED experiments, a current carrying coil is embedded inside the grid of an IEC such as to produce a magnetic dipole field. Charged particles are injected axisymmetrically from an ion gun (or duo-plasmatron) into the center of the ED confinement grid/dipole ring where they oscillate along the magnetic field lines and pass the peak field region at the center of the dipole region. As particles begin accelerating away from the center region towards the outer electrostatic grid region, they encounter a strong electrostatic potential (order of 10's of kilovolts) retarding force. The particles then decelerate, reverse direction and re-enter the dipole field region where again magnetic confinement dominates. This process continues, emulating a complex harmonic oscillator motion. The resulting pressure profile averaged over the field curvature offers good plasma stability in the ED configuration. The basic concept and results from preliminary experiments will be described. [1] M.E. Mauel, et al. "Dipole Equilibrium and Stability," 18th IAEA Conference of Plasma Phys. and Control. Nuclear Fusion, Varenna, Italy 2000, IAEA-F1-CN-70/TH

Superconducting dipole magnet for the CBM experiment at FAIR

Directory of Open Access Journals (Sweden)

Kurilkin P.

2017-01-01

Full Text Available The scientific goal of the CBM (Compressed Baryonic Matter experiment at FAIR (Darmstadt is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The 5.15 MJ superconducting dipole magnet will be used in the silicon tracking system of the CBM detector. The magnet will provide a magnetic field integral of 1 Tm which is required to obtain a momentum resolution of 1% for the track reconstruction. The results of the development of dipole magnet of the CBM experiment are presented.

The interaction between the permanent magnet and ceramic superconductor with organic filler

International Nuclear Information System (INIS)

Woźny, L; Kisiel, A; Garbera, A

2016-01-01

The aim of the study was to examine the phenomenon of magnetic levitation for YBaCuO superconducting samples in pure form and with epoxy resin content of 40%. Samples of superconductors were prepared by the standard reaction in the solid state. The forces of interaction between the superconductor and neodymium permanent magnet were measured. Samples with epoxy resin fillers had significantly smaller levitation force than the sample of the sintered superconductors. This is due to a much lower content of pure superconducting material in the sample volume (about 60% of the YBaCuO). However, the obvious advantage of such samples is the possibility of preparation superconductors with complicated shapes, eg. for use in a superconducting bearings or other devices. (paper)

Temperature compensation of NdFeB permanent magnets

International Nuclear Information System (INIS)

Kim, S.H.; Doose, C.

1997-01-01

Permanent magnet blocks of NdFeB have a relatively high maximum energy product. Because of its relatively low Curie temperature, however, NdFeB has a large temperature coefficient for its residual induction. The temperature coefficients of the relative magnetic fields (ΔB/B)/ΔT in the air gap of NdFeB dipole magnets were reduced from -1.1 x 10 -3 /c to less than 2 x 10 -5 /degree C under operating temperatures of ± 6 C. This was achieved passively by using 1.25-mm-thick strips of 30%-Ni-Fe alloy as flux shunts for the NdFeB blocks. The magnets with soft-steel poles and flux-return yokes were assembled and measured in a temperature-controlled environment

CALCULATION OF PHYSISORPTION ENERGIES OF

African Journals Online (AJOL)

but it may naturally arise through semi-quantum mechanical treatment of the admolecule - surface electrostatic interaction. For the physisorption of molecules with permanent dipole moment it is reasonable, in our opinion, to represent the admolecule by a classical dipole so as to avoid overlap of the admolecule and solid ...

Magnetic field modification of optical magnetic dipoles.

Science.gov (United States)

Armelles, Gaspar; Caballero, Blanca; Cebollada, Alfonso; Garcia-Martin, Antonio; Meneses-Rodríguez, David

2015-03-11

Acting on optical magnetic dipoles opens novel routes to govern light-matter interaction. We demonstrate magnetic field modification of the magnetic dipolar moment characteristic of resonant nanoholes in thin magnetoplasmonic films. This is experimentally shown through the demonstration of the magneto-optical analogue of Babinet's principle, where mirror imaged MO spectral dependencies are obtained for two complementary magnetoplasmonic systems: holes in a perforated metallic layer and a layer of disks on a substrate.

Magnetostatic interactions and forces between cylindrical permanent magnets

Czech Academy of Sciences Publication Activity Database

Vokoun, David; Beleggia, M.; Heller, Luděk; Šittner, Petr

2009-01-01

Roč. 321, č. 22 (2009), s. 3758-3763 ISSN 0304-8853 EU Projects: European Commission(XE) 46559 - CERINKA Institutional research plan: CEZ:AV0Z10100520 Keywords : cylinder * force measurement * magnetostatic * permanent magnet Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.204, year: 2009

Effect of electromagnetic dipole dark matter on energy transport in the solar interior

Energy Technology Data Exchange (ETDEWEB)

Geytenbeek, Ben; Rao, Soumya; White, Martin; Williams, Anthony G. [ARC Centre of Excellence for Particle Physics at the Terascale and CSSM, Department of Physics, University of Adelaide, Adelaide, South Australia 5005 (Australia); Scott, Pat; Vincent, Aaron C. [Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Serenelli, Aldo, E-mail: bg364@cam.ac.uk, E-mail: soumya.rao@ncbj.gov.pl, E-mail: p.scott@imperial.ac.uk, E-mail: aldos@ice.csic.es, E-mail: aaron.vincent@imperial.ac.uk, E-mail: martin.white@adelaide.edu.au, E-mail: anthony.williams@adelaide.edu.au [Institute of Space Sciences (IEEC-CSIC), Campus UAB, Carrer de Can Magrans s/n, 08193, Barcelona (Spain)

2017-03-01

In recent years, a revised set of solar abundances has led to a discrepancy in the sound-speed profile between helioseismology and theoretical solar models. Conventional solutions require additional mechanisms for energy transport within the Sun. Vincent et al. have recently suggested that dark matter with a momentum or velocity dependent cross section could provide a solution. In this work, we consider three models of dark matter with such cross sections and their effect on the stellar structure. In particular, the three models incorporate dark matter particles interacting through an electromagnetic dipole moment: an electric dipole, a magnetic dipole or an anapole. Each model is implemented in the DarkStec stellar evolution program, which incorporates the effects of dark matter capture and heat transport within the solar interior. We show that dark matter with an anapole moment of ∼ 1 GeV{sup −2} or magnetic dipole moment of ∼ 10{sup −3}μ {sub p} can improve the sound-speed profile, small frequency separations and convective zone radius with respect to the Standard Solar Model. However, the required dipole moments are strongly excluded by direct detection experiments.

Field - dipole interactions in L-cysteine-thiolate self assembled at p- and n-GaAs(100) electrodes

International Nuclear Information System (INIS)

Lazarescu, Valentina; Toader, Ana-Maria; Enache, Mirela; Preda, Loredana; Anastasescu, Mihai; Dobrescu, Gianina; Negrila, Catalin; Lazarescu, Mihai Florin

2015-01-01

L-cysteine-thiolate monolayers spontaneously self-assembled on p- and n-GaAs(100) electrodes have been investigated by electrochemical impedance spectroscopy in H 2 SO 4 solutions. On p-doped samples a potential-induced reversible proton transfer occurs within the L-cysteine-thiolate layer during both forward and backward potential scans; in contrast, on n-doped samples it is observed only in the reverse scan. The XPS data and the fractal analysis of the AFM images point to the field - dipole interactions operating distinctively in the L-cysteine-thiolate layer formed at p- and n-doped semiconducting substrates as the origin of the observed difference. The interaction of this small but highly polar molecule with the electrostatic field driven by the diffuse distribution of the excess charge in the semiconductor subsurface region both in equilibrium and under polarization conditions turned out to play a key role in determining the optimal orientation of the two polar groups. The latter one seems to be a prerequisite for the potential-induced internal proton transfer

Intrinsic electric dipole moments of paramagnetic atoms : Rubidium and cesium

NARCIS (Netherlands)

Nataraj, H. S.; Sahoo, B. K.; Das, B. P.; Mukherjee, D.

2008-01-01

The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that of its constituent electrons and a scalar-pseudoscalar (S-PS) electron-nucleus interaction. The electron EDM and the S-PS contributions to the EDMs of these atoms scale as approximate to

Density-functional approach to the three-body dispersion interaction based on the exchange dipole moment

Energy Technology Data Exchange (ETDEWEB)

Proynov, Emil; Wang, Matthew; Kong, Jing, E-mail: jing.kong@mtsu.edu [Department of Chemistry and Center for Computational Sciences, Middle Tennessee State University, Murfreesboro, Tennessee 37132 (United States); Liu, Fenglai [Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, New York 14260 (United States); Gan, Zhengting [Q-Chem Inc., 5001 Baum Boulevard, Pittsburgh, Pennsylvania 15213 (United States)

2015-08-28

We implement and compute the density functional nonadditive three-body dispersion interaction using a combination of Tang-Karplus formalism and the exchange-dipole moment model of Becke and Johnson. The computation of the C{sub 9} dispersion coefficients is done in a non-empirical fashion. The obtained C{sub 9} values of a series of noble atom triplets agree well with highly accurate values in the literature. We also calculate the C{sub 9} values for a series of benzene trimers and find a good agreement with high-level ab initio values reported recently in the literature. For the question of damping of the three-body dispersion at short distances, we propose two damping schemes and optimize them based on the benzene trimers data, and the fitted analytic potentials of He{sub 3} and Ar{sub 3} trimers fitted to the results of high-level wavefunction theories available from the literature. Both damping schemes respond well to the optimization of two parameters.

Influence of silver nanoparticles on relaxation processes and efficiency of dipole – dipole energy transfer between dye molecules in polymethylmethacrylate films

Energy Technology Data Exchange (ETDEWEB)

Bryukhanov, V V; Borkunov, R Yu; Tsarkov, M V [Immanuel Kant Baltic Federal University, Kaliningrad (Russian Federation); Konstantinova, E I; Slezhkin, V A [Kaliningrad State Technical University, Kaliningrad (Russian Federation)

2015-10-31

The fluorescence and phosphorescence of dyes in thin polymethylmethacrylate (PMMA) films in the presence of ablated silver nanoparticles has been investigated in a wide temperature range by methods of femtosecond and picosecond laser photoexcitation. The fluorescence and phosphorescence times, as well as spectral and kinetic characteristics of rhodamine 6G (R6G) molecules in PMMA films are measured in a temperature range of 80 – 330 K. The temperature quenching activation energy of the fluorescence of R6G molecules in the presence of ablated silver nanoparticles is found. The vibrational relaxation rate of R6G in PMMA films is estimated, the efficiency of the dipole – dipole electron energy transfer between R6G and brilliant green molecules (enhanced by plasmonic interaction with ablated silver nanoparticles) is analysed, and the constants of this energy transfer are determined. (nanophotonics)

Influence of silver nanoparticles on relaxation processes and efficiency of dipole – dipole energy transfer between dye molecules in polymethylmethacrylate films

International Nuclear Information System (INIS)

Bryukhanov, V V; Borkunov, R Yu; Tsarkov, M V; Konstantinova, E I; Slezhkin, V A

2015-01-01

The fluorescence and phosphorescence of dyes in thin polymethylmethacrylate (PMMA) films in the presence of ablated silver nanoparticles has been investigated in a wide temperature range by methods of femtosecond and picosecond laser photoexcitation. The fluorescence and phosphorescence times, as well as spectral and kinetic characteristics of rhodamine 6G (R6G) molecules in PMMA films are measured in a temperature range of 80 – 330 K. The temperature quenching activation energy of the fluorescence of R6G molecules in the presence of ablated silver nanoparticles is found. The vibrational relaxation rate of R6G in PMMA films is estimated, the efficiency of the dipole – dipole electron energy transfer between R6G and brilliant green molecules (enhanced by plasmonic interaction with ablated silver nanoparticles) is analysed, and the constants of this energy transfer are determined. (nanophotonics)

Electric dipole strength and dipole polarizability in 48Ca within a fully self-consistent second random–phase approximation

Directory of Open Access Journals (Sweden)

D. Gambacurta

2018-02-01

Full Text Available The second random–phase–approximation model corrected by a subtraction procedure designed to cure double counting, instabilities, and ultraviolet divergences, is employed for the first time to analyze the dipole strength and polarizability in 48Ca. All the terms of the residual interaction are included, leading to a fully self-consistent scheme. Results are illustrated with two Skyrme parametrizations, SGII and SLy4. Those obtained with the SGII interaction are particularly satisfactory. In this case, the low-lying strength below the neutron threshold is well reproduced and the giant dipole resonance is described in a very satisfactory way especially in its spreading and fragmentation. Spreading and fragmentation are produced in a natural way within such a theoretical model by the coupling of 1 particle-1 hole and 2 particle-2 hole configurations. Owing to this feature, we may provide for the electric polarizability as a function of the excitation energy a curve with a similar slope around the centroid energy of the giant resonance compared to the corresponding experimental results. This represents a considerable improvement with respect to previous theoretical predictions obtained with the random–phase approximation or with several ab-initio models. In such cases, the spreading width of the excitation cannot be reproduced and the polarizability as a function of the excitation energy displays a stiff increase around the predicted centroid energy of the giant resonance.

Electric dipole strength and dipole polarizability in 48Ca within a fully self-consistent second random-phase approximation

Science.gov (United States)

Gambacurta, D.; Grasso, M.; Vasseur, O.

2018-02-01

The second random-phase-approximation model corrected by a subtraction procedure designed to cure double counting, instabilities, and ultraviolet divergences, is employed for the first time to analyze the dipole strength and polarizability in 48Ca. All the terms of the residual interaction are included, leading to a fully self-consistent scheme. Results are illustrated with two Skyrme parametrizations, SGII and SLy4. Those obtained with the SGII interaction are particularly satisfactory. In this case, the low-lying strength below the neutron threshold is well reproduced and the giant dipole resonance is described in a very satisfactory way especially in its spreading and fragmentation. Spreading and fragmentation are produced in a natural way within such a theoretical model by the coupling of 1 particle-1 hole and 2 particle-2 hole configurations. Owing to this feature, we may provide for the electric polarizability as a function of the excitation energy a curve with a similar slope around the centroid energy of the giant resonance compared to the corresponding experimental results. This represents a considerable improvement with respect to previous theoretical predictions obtained with the random-phase approximation or with several ab-initio models. In such cases, the spreading width of the excitation cannot be reproduced and the polarizability as a function of the excitation energy displays a stiff increase around the predicted centroid energy of the giant resonance.

On the Interface Dipole at the Pentacene−Fullerene Heterojunction: A Theoretical Study

KAUST Repository

Linares, Mathieu

2010-02-25

The electronic structure at organic/organic interfaces plays a key role, among others, in defining the quantum efficiency of organics-based photovoltaic cells. Here, we perform quantum-chemical and microelectrostatic calculations on molecular aggregates of various sizes and shapes to characterize the interfacial dipole moment at pentacene/C60 heterojunctions. The results show that the interfacial dipole mostly originates in polarization effects due to the asymmetry in the multipolar expansion of the electronic density distribution between the interacting molecules, rather than in a charge transfer from donor to acceptor. The local dipole is found to fluctuate in sign and magnitude over the interface and appears as a sensitive probe of the relative arrangements of the pentacene and C60 molecules (and of the resulting local electrical fields sensed by the molecular units). © 2010 American Chemical Society.

On the Interface Dipole at the Pentacene−Fullerene Heterojunction: A Theoretical Study

KAUST Repository

Linares, Mathieu; Beljonne, David; Cornil, Jérôme; Lancaster, Kelly; Brédas, Jean-Luc; Verlaak, Stijn; Mityashin, Alexander; Heremans, Paul; Fuchs, Andreas; Lennartz, Christian; Idé, Julien; Méreau, Raphaël; Aurel, Philippe; Ducasse, Laurent; Castet, Frédéric

2010-01-01

The electronic structure at organic/organic interfaces plays a key role, among others, in defining the quantum efficiency of organics-based photovoltaic cells. Here, we perform quantum-chemical and microelectrostatic calculations on molecular aggregates of various sizes and shapes to characterize the interfacial dipole moment at pentacene/C60 heterojunctions. The results show that the interfacial dipole mostly originates in polarization effects due to the asymmetry in the multipolar expansion of the electronic density distribution between the interacting molecules, rather than in a charge transfer from donor to acceptor. The local dipole is found to fluctuate in sign and magnitude over the interface and appears as a sensitive probe of the relative arrangements of the pentacene and C60 molecules (and of the resulting local electrical fields sensed by the molecular units). © 2010 American Chemical Society.

Self-consistent description of dipole states taking into account the one-particle continuum

International Nuclear Information System (INIS)

Gareev, F.A.; Ershov, S.N.; Pyatov, N.I.; Fayans, S.A.; Salamov, D.I.

1981-01-01

A self-consistent translationally invariant model with separable effective interactions is used to describe the dipole excitations of spherical nuclei. The equations for the effective field are solved in the coordinate representation, taking the one-particle continuum into account exactly. This makes it possible to obtain the escape widths of excitations with energy above the nucleon-emission threshold. We calculate the energies, B(E1), strength functions, escape widths, and transition densities of the dipole states for a number of light and heavy nuclei

Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish

Science.gov (United States)

Jun, James Jaeyoon; Longtin, André; Maler, Leonard

2013-01-01

In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI) and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT) to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF) requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal’s positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole source

Real-Time Localization of Moving Dipole Sources for Tracking Multiple Free-Swimming Weakly Electric Fish.

Directory of Open Access Journals (Sweden)

James Jaeyoon Jun

Full Text Available In order to survive, animals must quickly and accurately locate prey, predators, and conspecifics using the signals they generate. The signal source location can be estimated using multiple detectors and the inverse relationship between the received signal intensity (RSI and the distance, but difficulty of the source localization increases if there is an additional dependence on the orientation of a signal source. In such cases, the signal source could be approximated as an ideal dipole for simplification. Based on a theoretical model, the RSI can be directly predicted from a known dipole location; but estimating a dipole location from RSIs has no direct analytical solution. Here, we propose an efficient solution to the dipole localization problem by using a lookup table (LUT to store RSIs predicted by our theoretically derived dipole model at many possible dipole positions and orientations. For a given set of RSIs measured at multiple detectors, our algorithm found a dipole location having the closest matching normalized RSIs from the LUT, and further refined the location at higher resolution. Studying the natural behavior of weakly electric fish (WEF requires efficiently computing their location and the temporal pattern of their electric signals over extended periods. Our dipole localization method was successfully applied to track single or multiple freely swimming WEF in shallow water in real-time, as each fish could be closely approximated by an ideal current dipole in two dimensions. Our optimized search algorithm found the animal's positions, orientations, and tail-bending angles quickly and accurately under various conditions, without the need for calibrating individual-specific parameters. Our dipole localization method is directly applicable to studying the role of active sensing during spatial navigation, or social interactions between multiple WEF. Furthermore, our method could be extended to other application areas involving dipole

Object permanence in lemurs.

Science.gov (United States)

Deppe, Anja M; Wright, Patricia C; Szelistowski, William A

2009-03-01

Object permanence, the ability to mentally represent objects that have disappeared from view, should be advantageous to animals in their interaction with the natural world. The objective of this study was to examine whether lemurs possess object permanence. Thirteen adult subjects representing four species of diurnal lemur (Eulemur fulvus rufus, Eulemur mongoz, Lemur catta and Hapalemur griseus) were presented with seven standard Piagetian visible and invisible object displacement tests, plus one single visible test where the subject had to wait predetermined times before allowed to search, and two invisible tests where each hiding place was made visually unique. In all visible tests lemurs were able to find an object that had been in clear view before being hidden. However, when lemurs were not allowed to search for up to 25-s, performance declined with increasing time-delay. Subjects did not outperform chance on any invisible displacements regardless of whether hiding places were visually uniform or unique, therefore the upper limit of object permanence observed was Stage 5b. Lemur species in this study eat stationary foods and are not subject to stalking predators, thus Stage 5 object permanence is probably sufficient to solve most problems encountered in the wild.

Hyperfine interactions and electric dipole moments in the [16.0]1.5(v = 6), [16.0]3.5(v = 7), and X2Δ(5/2) states of iridium monosilicide, IrSi.

Science.gov (United States)

Le, Anh; Steimle, Timothy C; Morse, Michael D; Garcia, Maria A; Cheng, Lan; Stanton, John F

2013-12-19

The (6,0)[16.0]1.5-X(2)Δ(5/2) and (7,0)[16.0]3.5-X(2)Δ(5/2) bands of IrSi have been recorded using high-resolution laser-induced fluorescence spectroscopy. The field-free spectra of the (191)IrSi and (193)IrSi isotopologues were modeled to generate a set of fine, magnetic hyperfine, and nuclear quadrupole hyperfine parameters for the X(2)Δ(5/2)(v = 0), [16.0]1.5(v = 6), and [16.0]3.5 (v = 7) states. The observed optical Stark shifts for the (193)IrSi and (191)IrSi isotopologues were analyzed to produce the permanent electric dipole moments, μ(el), of -0.414(6) D and 0.782(6) D for the X(2)Δ(5/2) and [16.0]1.5 (v = 6) states, respectively. Properties of the X(2)Δ(5/2) state computed using relativistic coupled-cluster methods clearly indicate that electron correlation plays an essential role. Specifically, inclusion of correlation changes the sign of the dipole moment and is essential for achieving good accuracy for the nuclear quadrupole coupling parameter eQq0.

Quantum states with topological properties via dipolar interactions

Energy Technology Data Exchange (ETDEWEB)

Peter, David

2015-06-25

This thesis proposes conceptually new ways to realize materials with topological properties by using dipole-dipole interactions. First, we study a system of ultracold dipolar fermions, where the relaxation mechanism of dipolar spins can be used to reach the quantum Hall regime. Second, in a system of polar molecules in an optical lattice, dipole-dipole interactions induce spin-orbit coupling terms for the rotational excitations. In combination with time-reversal symmetry breaking this leads to topological bands with Chern numbers greater than one.

A sum rule calculation of the neutron electric dipole moment from a quark chromoelectric dipole coupling

International Nuclear Information System (INIS)

Kogan, I.I.; Wyler, D.

1992-01-01

The neutron electric dipole moment (NEDM) from a quark chromoelectric dipole moment is calculated using a QCD sumrule approach. We demonstrate that leading contributions to the NEDM come from induced condensates (quark and quark-gluon condensate magnetic susceptibilities) which are also determined. Other possible contributions to the NEDM such as a quark electric dipole moment or a triple gluon operator are briefly discussed. (orig.)

Development of a SQUID-based 3He Co-magnetometer Readout for a Neutron Electric Dipole Moment Experiment

OpenAIRE

Kim, Young Jin; Clayton, Steven M.

2012-01-01

A discovery of a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new search of neutron EDM, to be conducted at the spallation neutron source (SNS) at ORNL, is designed to improve the present experimental limit of ~10^-26 e-cm by two orders of magnitude. The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the L...

Automating dipole subtraction

Energy Technology Data Exchange (ETDEWEB)

Hasegawa, K.; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Uwer, P. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Theoretische Teilchenphysik

2008-07-15

We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg{yields}t anti tggg. (orig.)

Automating dipole subtraction

International Nuclear Information System (INIS)

Hasegawa, K.; Moch, S.; Uwer, P.

2008-07-01

We report on automating the Catani-Seymour dipole subtraction which is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. The automatization rests on three essential steps: the creation of the dipole terms, the calculation of the color linked squared Born matrix elements, and the evaluation of different helicity amplitudes. The routines have been tested for a number of complex processes, such as the real emission process gg→t anti tggg. (orig.)

Automatic dipole subtraction

International Nuclear Information System (INIS)

Hasegawa, K.

2008-01-01

The Catani-Seymour dipole subtraction is a general procedure to treat infrared divergences in real emission processes at next-to-leading order in QCD. We automatized the procedure in a computer code. The code is useful especially for the processes with many parton legs. In this talk, we first explain the algorithm of the dipole subtraction and the whole structure of our code. After that we show the results for some processes where the infrared divergences of real emission processes are subtracted. (author)

A study of interaction effect theoretical with combination size grain on magnetics in of permanent magnet

International Nuclear Information System (INIS)

Tarihoran, Doansi; Manaf, Azwar

2002-01-01

Stoner-Wohlfarth theory, SW shows a deviation around 30-40% to the measurement result of a permanent magnetic material with nanometer-sized grains. This is caused by this theory neglecting the interacting grain factor. This research modifies SW theory by calculating the grain interacting effect. The modification is made by assuming the interacting energy of a mono-domain grain has ellipsoidal shaped focused at the edge of the grain. SW grain in this calculation model is a box-shaped in a grain with edges of the box placed in the skin's grain. The result shows that interacting effect make remanent polarization increasing drastically and coercive field value decreasing when grain's size reaches 20% of size of the first mono-domain grain. For material with ND 2 Fe 14 B phase, the optimum coercive field value and remanent polarization that producing maximum product energy, (BH) m ax obtained in a material with 5 nanometer-size grains. Qualitatively there is as appropriate result between the calculation and measurement

The electrostatic interaction between interfacial colloidal particles

Science.gov (United States)

Hurd, A. J.

1985-11-01

The electrostatic interaction between charged, colloidal particles trapped at an air-water interface is considered using linearised Poisson-Boltzmann results for point particles. In addition to the expected screened-Coulomb contribution, which decays exponentially, an algebraic dipole-dipole interaction occurs that may account for long-range interactions in interfacial colloidal systems.

Electric-dipole-coupled H2O@C60 dimer: Translation-rotation eigenstates from twelve-dimensional quantum calculations.

Science.gov (United States)

Felker, Peter M; Bačić, Zlatko

2017-02-28

We report on variational solutions to the twelve-dimensional (12D) Schrödinger equation appertaining to the translation-rotation (TR) eigenstates of H 2 O@C 60 dimer, associated with the quantized "rattling" motions of the two encapsulated H 2 O molecules. Both H 2 O and C 60 moieties are treated as rigid and the cage-cage geometry is taken to be fixed. We consider the TR eigenstates of H 2 O@C 60 monomers in the dimer to be coupled by the electric dipole-dipole interaction between water moieties and develop expressions for computing the matrix elements of that interaction in a dimer basis composed of products of monomer 6D TR eigenstates reported by us recently [P. M. Felker and Z. Bačić, J. Chem. Phys. 144, 201101 (2016)]. We use these expressions to compute TR Hamiltonian matrices of H 2 O@C 60 dimer for two values of the water dipole moment and for various dimer geometries. 12D TR eigenstates of the dimer are then obtained by filter diagonalization. The results reveal two classes of eigenstates, distinguished by the leading order (first or second) at which dipole-dipole coupling contributes to them. The two types of eigenstates differ in the general magnitude of their dipole-induced energy shifts and in the dependence of those shifts on the value of the water dipole moment and on the distance between the H 2 O@C 60 monomers. The dimer results are also found to be markedly insensitive to any change in the orientations of the C 60 cages. Finally, the results lend some support for the interpretation that electric dipole-dipole coupling is at least partially responsible for the apparent reduced-symmetry environment experienced by H 2 O in the powder samples of H 2 O@C 60 [K. S. K. Goh et al., Phys. Chem. Chem. Phys. 16, 21330 (2014)], but only if the water dipole is taken to have a magnitude close to that of free water. The methodology developed in the paper is transferable directly to the calculation of TR eigenstates of larger H 2 O@C 60 assemblies, that will

Constraints on CP violating four-fermion interactions

International Nuclear Information System (INIS)

He, X.G.; McKellar, B.

1996-04-01

It has been shown that CP violating electron-nucleon and nucleon-nucleon interactions can induce atomic electric dipole moments and are therefore constrained from experimental data. We show that using the experimental upper bounds on neutron and electron electric dipole moments, one can also obtain constraints, in some cases better ones, on these interactions. In addition stringent constraints can also be obtained for muon-quark and tauon-quark four-fermion CP violating interactions, which cannot be constrained from atomic electric dipole moment experiments. 12 refs., 2 tabs., 1 fig

Effects of an electric field on interaction of aromatic systems.

Science.gov (United States)

Youn, Il Seung; Cho, Woo Jong; Kim, Kwang S

2016-04-30

The effect of uniform external electric field on the interactions between small aromatic compounds and an argon atom is investigated using post-HF (MP2, SCS-MP2, and CCSD(T)) and density functional (PBE0-D3, PBE0-TS, and vdW-DF2) methods. The electric field effect is quantified by the difference of interaction energy calculated in the presence and absence of the electric field. All the post-HF methods describe electric field effects accurately although the interaction energy itself is overestimated by MP2. The electric field effect is explained by classical electrostatic models, where the permanent dipole moment from mutual polarization mainly determines its sign. The size of π-conjugated system does not have significant effect on the electric field dependence. We found out that PBE0-based methods give reasonable interaction energies and electric field response in every case, while vdW-DF2 sometimes shows spurious artifact owing to its sensitivity toward the real space electron density. © 2015 Wiley Periodicals, Inc.

High-field dipoles for future accelerators

International Nuclear Information System (INIS)

Wipf, S.L.

1984-09-01

This report presents the concept for building superconducting accelerator dipoles with record high fields. Economic considerations favor the highest possible current density in the windings. Further discussion indicates that there is an optimal range of pinning strength for a superconducting material and that it is not likely for multifilamentary conductors to ever equal the potential performance of tape conductors. A dipole design with a tape-wound, inner high-field winding is suggested. Methods are detailed to avoid degradation caused by flux jumps and to overcome problems with the dipole ends. Concerns for force support structure and field precision are also addressed. An R and D program leading to a prototype 11-T dipole is outlined. Past and future importance of superconductivity to high-energy physics is evident from a short historical survey. Successful dipoles in the 10- to 20-T range will allow interesting options for upgrading present largest accelerators

On the search for the electric dipole moment of strange and charm baryons at LHC

Energy Technology Data Exchange (ETDEWEB)

Botella, F.J.; Garcia Martin, L.M.; Martinez Vidal, F.; Oyanguren, A.; Ruiz Vidal, J. [Universitat de Valencia-CSIC, Instituto de Fisica Corpuscular (IFIC), Valencia (Spain); Marangotto, D.; Merli, A.; Neri, N. [INFN Sezione di Milano, Milan (Italy); Milano Univ., Milan (Italy)

2017-03-15

Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange Λ baryons, selected from weak decays of charm baryons produced in pp collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of CPT symmetry can be performed by measuring the magnetic dipole moment of Λ and anti Λ baryons. For short-lived Λ{sup +}{sub c} and Ξ{sup +}{sub c} baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed. (orig.)

Magnetic monopoles and dipoles in quantum mechanics

International Nuclear Information System (INIS)

Lipkin, H.J.; Peshkin, M.

1986-01-01

The force on and the energy of a ''di-monopole'', which is the limiting case of a dipole made from two monopoles at zero separation and finite magnetic moment, interacting with an externally fixed magnetic field resulting from an electric current, is considered. A model involving only a monopole is used to illustrate the physical principles involved when magnetic sources move in a solenoidal field whose source is an electric current. The problems encountered in Hamiltonian theory are discussed. 5 refs., 3 figs

The electric dipole moment of magnesium deuteride, MgD.

Science.gov (United States)

Steimle, Timothy C; Zhang, Ruohan; Wang, Hailing

2014-06-14

The (0,0) A(2)Π-X (2)Σ(+) band of a cold molecular beam sample of magnesium monodeuteride, MgD, has been recorded field-free and in the presence of a static electric field of up to 11 kV/cm. The lines associated with the lowest rotational levels are detected for the first time. The field-free spectrum was analyzed to produce an improved set of fine structure parameters for the A(2)Π (v = 0) state. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments, μ(el) of 2.567(10)D and 1.31(8)D for A(2)Π (v = 0) and X(2)Σ(+)(v = 0) states, respectively. The recommended value for μ(el)(X(2)Σ(+) (v = 0)) for MgH, based upon the measured value for MgD, is 1.32(8)D.

Molecular dynamics of polarizable point dipole models for molten NaI. Comparison with first principles simulations

Directory of Open Access Journals (Sweden)

Trullàs J.

2011-05-01

Full Text Available Molecular dynamics simulations of molten NaI at 995 K have been carried out using polarizable ion models based on rigid ion pair potentials to which the anion induced dipole polarization is added. The polarization is added in such a way that point dipoles are induced on the anions by both local electric field and deformation short-range damping interactions that oppose the electrically induced dipole moments. The structure and self-diffusion results are compared with those obtained by Galamba and Costa Cabral using first principles Hellmann-Feynman molecular dynamics simulations and using classical molecular dynamics of a shell model which allows only the iodide polarization

Asymmetry of neoclassical transport by dipole electric field

International Nuclear Information System (INIS)

Wang Zhongtian; Wang Long

2004-01-01

Effects of dipole electric fields on neoclassical transport are studied. Large asymmetry in transport is created. The dipole fields, which are in a negative R-direction, reduce the ion drift, increase electron drift, and change the steps of excursion due to collisions. It is found that different levels of dipole field intensities have different types of transport. For the lowest level of the dipole field, the transport returns to the neoclassical one. For the highest level of the dipole field, the transport is turned to be the turbulence transport similar to the pseudo-classical transport. Experimental data may be corresponded to a large level of the dipole field intensity. (authors)

Hadronic electric dipole moments in R-parity violating supersymmetry

International Nuclear Information System (INIS)

Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery E.; Kovalenko, Sergey

2006-01-01

We calculate the electric dipole moments (EDM) of the neutral 199 Hg atom, neutron and deuteron within a generic R-parity violating SUSY model (Re p SUSY) on the basis of a one-pion-exchange model with CP-odd pion-nucleon interactions. We consider two types of the Re p SUSY contributions to the above hadronic EDMs: via the quark chromoelectric dipole moments (CEDM) and CP-violating 4-quark interactions. We demonstrate that the former contributes to all the three studied EDMs while the latter appears only in the nuclear EDMs via the CP-odd nuclear forces. We find that the Re p SUSY induced 4-quark interactions arise at tree level through the sneutrino exchange and involve only s and b quarks. Therefore, their effect in hadronic EDMs is determined by the strange and bottom-quark sea of the nucleon. From the null experimental results on the hadronic EDMs we derive the limits on the imaginary parts of certain products Im(λ ' λ ' *) of the trilinear Re p -couplings and show that the currently best limits come from the 199 Hg EDM experiments. We demonstrate that some of these limits are better than those existing in the literature. We argue that future storage ring experiments on the deuteron EDM are able to improve these limits by several orders of magnitude

Polarization electric dipole moment in nonaxial nuclei

International Nuclear Information System (INIS)

Denisov, V.Yu.; Davidovskaya, O.I.

1996-01-01

An expression for the macroscopic polarization electric dipole moment is obtained for nonaxial nuclei whose radii of the proton and neutron surfaces are related by a linear equation. Dipole transitions associated with the polarization electric dipole moment are analyzed for static and dynamical multipole deformations

Time reversal violating nuclear polarizability and atomic electric dipole moment

International Nuclear Information System (INIS)

Ginges, J.S.M.; Flambaum, V.V.; Mititelu, G.

2000-01-01

Full text: We propose a nuclear mechanism which can induce an atomic electric dipole moment (EDM). The interaction of external electric E and magnetic H fields with nuclear electric and magnetic dipole moments, d and ,u, gives rise to an energy shift, U= -β ik E i H k , where β ik is the nuclear polarizability. Parity and time invariance violating (P,T-odd) nuclear forces generate a mixed P,T-odd nuclear polarizability, whereψ 0 and ψ n are P,T-odd perturbed ground and excited nuclear states, respectively. In the case of a heavy spherical nucleus with a single unpaired nucleon, the perturbed wavefunctions are U = -β ik E i H k , where ξis a constant proportional to the strength of the nuclear P,T-odd interaction, σ is the nuclear spin operator, and ψ n is an unperturbed wavefunction. There are both scalar and tensor contributions to the nuclear P,T-odd polarizability. An atomic EDM is induced by the interaction of the fields of an unpaired electron in an atom with the P,T-odd perturbed atomic nucleus. An estimate for the value of this EDM has been made. The measurements of atomic EDMs can provide information about P,T-odd nuclear forces and test models of CP-violation

Dephasing due to Nuclear Spins in Large-Amplitude Electric Dipole Spin Resonance.

Science.gov (United States)

Chesi, Stefano; Yang, Li-Ping; Loss, Daniel

2016-02-12

We analyze effects of the hyperfine interaction on electric dipole spin resonance when the amplitude of the quantum-dot motion becomes comparable or larger than the quantum dot's size. Away from the well-known small-drive regime, the important role played by transverse nuclear fluctuations leads to a Gaussian decay with characteristic dependence on drive strength and detuning. A characterization of spin-flip gate fidelity, in the presence of such additional drive-dependent dephasing, shows that vanishingly small errors can still be achieved at sufficiently large amplitudes. Based on our theory, we analyze recent electric dipole spin resonance experiments relying on spin-orbit interactions or the slanting field of a micromagnet. We find that such experiments are already in a regime with significant effects of transverse nuclear fluctuations and the form of decay of the Rabi oscillations can be reproduced well by our theory.

Formation of dislocation dipoles in irradiated graphite

International Nuclear Information System (INIS)

Niwase, Keisuke

2005-01-01

Recently, we have proposed a dislocation dipole accumulation model to explain the irradiation-induced amorphization of graphite. However, the structure of dislocation dipole in the hexagonal networks is still an open question at the atomic-level. In this paper, we propose a possible formation process of the dislocation dipole

The dipole response of {sup 132}Sn

Energy Technology Data Exchange (ETDEWEB)

Schrock, Philipp; Aumann, Thomas; Johansen, Jacob; Schindler, Fabia [IKP, TU Darmstadt (Germany); Boretzky, Konstanze [GSI Helmholtzzentrum (Germany); Rossi, Dominic [Michigan State University (United States); Collaboration: R3B-Collaboration

2015-07-01

The Isovector Giant Dipole Resonance (IVGDR) is a well-known collective excitation in which all protons oscillate against all neutrons of a nucleus. In neutron-rich nuclei an additional low-lying dipole excitation occurs, often denoted as Pygmy Dipole Resonance (PDR). To study the PDR in exotic Sn-isotopes, an experiment has been successfully performed with the upgraded R{sup 3}B-LAND setup at GSI. The complete-kinematics measurement of all reaction participants allows for the reconstuction of the excitation energy and, hence, the extraction of the dipole strength. Presented are the main features of the experiment, the analysis concept and the current status of the analysis of the dipole response of the doubly-magic isotope {sup 132}Sn.

Statistical and computer analysis for the solvent effect on the elctronis adsorption spectra of monoethanolamine complexes

International Nuclear Information System (INIS)

Masoud, M.S.; Motaweh, H.A.; Ali, A.E.

1999-01-01

Full text.the electronic absorption spectra of the octahedral complexes containing monoethanolamine were recorded in different solvents (dioxine, chlororm, ethanol, dimethylformamide, dimethylsulfoxide and water). The data analyzed based on multiple linear regression technique using the equation: ya (a is the regression intercept) are various empirical solvent polarytiparameters; constants are calculated using micro statistic program on pc computer. The solvent spectral data of the complexes are compared to that of nugot, the solvent assists the spectral data to be red shifts. In case of Mn (MEA) CL complex, numerous bands are appeared in presence of CHCI DMF and DMSO solvents probably due to the numerous oxidation states. The solvent parameters: E (solvent-solute hydrogen bond and dipolar interaction); (dipolar interaction related to the dielectric constant); M (solute permanent dipole-solvent induced ipole) and N (solute permanent dipole-solvent permanent dipole) are correlated with the structure of the complexes, in hydrogen bonding solvents (Band in case of complexes as the dielectric constant increases, blue shift occurs in due to conjugation with high stability, the data in DMF and DMSO solvents are nearly the same probably due to their similarity

One-Dimensional Rydberg Gas in a Magnetoelectric Trap

International Nuclear Information System (INIS)

Mayle, Michael; Hezel, Bernd; Lesanovsky, Igor; Schmelcher, Peter

2007-01-01

We study the quantum properties of Rydberg atoms in a magnetic Ioffe-Pritchard trap which is superimposed by a homogeneous electric field. Trapped Rydberg atoms can be created in long-lived electronic states exhibiting a permanent electric dipole moment of several hundred Debye. The resulting dipole-dipole interaction in conjunction with the radial confinement is demonstrated to give rise to an effectively one-dimensional ultracold Rydberg gas with a macroscopic interparticle distance. We derive analytical expressions for the electric dipole moment and the required linear density of Rydberg atoms

Backfire antennas with dipole elements

DEFF Research Database (Denmark)

Nielsen, Erik Dragø; Pontoppidan, Knud

1970-01-01

A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating...

Super-Coulombic atom-atom interactions in hyperbolic media

Science.gov (United States)

Cortes, Cristian L.; Jacob, Zubin

2017-01-01

Dipole-dipole interactions, which govern phenomena such as cooperative Lamb shifts, superradiant decay rates, Van der Waals forces and resonance energy transfer rates, are conventionally limited to the Coulombic near-field. Here we reveal a class of real-photon and virtual-photon long-range quantum electrodynamic interactions that have a singularity in media with hyperbolic dispersion. The singularity in the dipole-dipole coupling, referred to as a super-Coulombic interaction, is a result of an effective interaction distance that goes to zero in the ideal limit irrespective of the physical distance. We investigate the entire landscape of atom-atom interactions in hyperbolic media confirming the giant long-range enhancement. We also propose multiple experimental platforms to verify our predicted effect with phonon-polaritonic hexagonal boron nitride, plasmonic super-lattices and hyperbolic meta-surfaces as well. Our work paves the way for the control of cold atoms above hyperbolic meta-surfaces and the study of many-body physics with hyperbolic media.

Electric dipole moment of diatomic molecules

International Nuclear Information System (INIS)

Rosato, A.

1983-01-01

The electric dipole moment of some diatomic molecules is calculated using the Variational Cellular Method. The results obtained for the CO, HB, HF and LiH molecules are compared with other calculations and with experimental data. It is shown that there is strong dependence of the electric dipole moment with respect to the geometry of the cells. The possibility of fixing the geometry of the problem by giving the experimental value of the dipole moment is discussed. (Author) [pt

Dipole plasma in molecular crystals

International Nuclear Information System (INIS)

Kotel'nikov, Yu.E.; Kochelaev, B.I.

1976-01-01

Collective oscillations in a system of electric dipoles of molecular crystals are investigated. It has been proved in the exciton approximation that in an elementary cell of a molecular crystal with one molecule there may exist energy fluctuations of the ''dipole'' plasma, analogous to plasma oscillations in the charged Fermi liquid

Droplet-model electric dipole moments

International Nuclear Information System (INIS)

Myers, W.D.; Swiatecki, W.J.

1991-01-01

Denisov's recent criticism of the droplet-model formula for the dipole moment of a deformed nucleus as derived by Dorso et al., it shown to be invalid. This helps to clarify the relation of theory to the measured dipole moments, as discussed in the review article by Aberg et al. (orig.)

LHC dipoles: the countdown has begun

CERN Document Server

Patrice Loiez

2002-01-01

At the entrance to the fourth floor corridor of the LHC-MMS (Main Magnets and Superconductors) Group in building 30, the Director-General has unveiled an electronic information panel indicating the number of LHC dipoles still to be delivered and the days remaining to the deadline (30 June 2006). The panel was the idea of Lucio Rossi, leader of the MMS Group, which is responsible for the construction of the dipole magnets. The unveiling ceremony took place on the morning of Friday 11 October 2002, at the end of a drink held to celebrate with MMS group and the LHC top management the exceptional performance of the latest dipoles, built by the French consortium Alstom-Jeumont. They are the first dipoles to achieve a magnetic field of 9 tesla in one go without quenching, thus exceeding the nominal operating field of 8.3 tesla. The challenge is now to increase the production rate from 2 to 35 dipoles per month by 2004 in order to meet the deadline, while maintaining this quality. Photo 01: The Director-General Luci...

Comparison of electric dipole and magnetic dipole models for electromagnetic pulse generated by nuclear detonation in space

International Nuclear Information System (INIS)

Zhu Meng; Zhou Hui; Cheng Yinhui; Li Baozhong; Wu Wei; Li Jinxi; Ma Liang; Zhao Mo

2013-01-01

Electromagnetic pulse can be generated by the nuclear detonation in space via two radiation mechanisms. The electric dipole and magnetic dipole models were analyzed. The electric radiation in the far field generated by two models was calculated as well. Investigations show that in the case of one hundred TNT yield detonations, when electrons are emitted according to the Gaussian shape, two radiation models can give rise to the electric field in great distances with amplitudes of kV/m and tens of V/m, independently. Because the geomagnetic field in space is not strong and the electrons' angular motion is much weaker than the motion in the original direction, radiations from the magnetic dipole model are much weaker than those from the electric dipole model. (authors)

Hydrogen atom excitation in intense attosecond laser field: Gauge dependence of dipole approximation

Energy Technology Data Exchange (ETDEWEB)

Aldarmaa, Ch., E-mail: aldaraa2004@yahoo.com, E-mail: l-xemee@yahoo.com; Khenmedekh, L., E-mail: aldaraa2004@yahoo.com, E-mail: l-xemee@yahoo.com [Theoretical Physics and Simulation Group, School of Materials Technology, MUST (Mongolia); Lkhagva, O. [School of Physics and Electronics, NUM (Mongolia)

2014-03-24

It is assumed that, the atomic excitations probability can be calculated using first order perturbation theory and dipole approximations. The validity of the dipole approximations had been examined by comparing the results with the results obtained by exact calculations within the first order perturbation theory[2]. Figure 1 shows the time dependence of the transition probability in the dipole approximation. From these plots it is obvious that, the probabilities obtained in the length gauge are higher than that in the velocity gauge, in the interaction period (−τ/2dipole approximation) calculations results. (Figure 2) Though the time evolution of the same transition probabilities are different for these cases, the final results are the same for all three cases, excluding the 6s-6p{sub 0} transition. For the later case, only the length gauge give a false results, but the velocity gauge give the same result as the exact one, for the final value of the transition probability.

Neutron Electric Dipole Moment Experiments

OpenAIRE

Peng, Jen-Chieh

2008-01-01

The neutron electric dipole moment (EDM) provides unique information on CP violation and physics beyond the Standard Model. We first review the history of experimental searches for neutron electric dipole moment. The status of future neutron EDM experiments, including experiments using ultra-cold neutrons produced in superfluid helium, will then be presented.

Electric dipole moment of diatomic molecules

International Nuclear Information System (INIS)

Rosato, A.

1983-01-01

The electric dipole moment of some diatomic molecules is calculated using the Variational Cellular Method. The results obtained for the molecules CO, HB, HF and LiH are compared with other calculations and with experimental data. It is shown that there is strong dependence of the electric dipole moment with respect to the geometry of the cells. It is discussed the possibility of fixing the geometry of the problem by giving the experimental value of the dipole moment. (Author) [pt

Polar and low polar solvents media effect on dipole moments of some diazo Sudan dyes

Science.gov (United States)

Zakerhamidi, M. S.; Golghasemi Sorkhabi, Sh.; Shamkhali, A. N.

2014-06-01

Absorption and fluorescence spectra of three Sudan dyes (SudanIII, SudanIV and Sudan black B) were recorded in various solvents with different polarity in the range of 300-800 nm, at room temperature. The solvatochromic method was used to investigate dipole moments of these dyes in ground and excited states, in different media. The solvatochromic behavior of these substances and their solvent-solute interactions were analyzed via solvent polarity parameters. Obtained results express the effects of solvation on tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media with different polarity. Furthermore, analyze of solvent-solute interactions and value of ground and excited states dipole moments suggests different forms of resonance structures for Sudan dyes in polar and low-polar solvents.

The neutron electric dipole moment in the cloudy bag model

International Nuclear Information System (INIS)

Morgan, M.A.; Miller, G.A.

1986-01-01

An evaluation of the neutron electric dipole moment (NEDM), using the cloudy bag model (CBM) shows that two CP-violating effects (a quark mass term and a pion-quark interaction) have contributions that are about equal in magnitude, but opposite in sign. This cancellation allows the upper limit on the θ parameter to increase by about an order of magnitude. (orig.)

Magnetic guns with cylindrical permanent magnets

DEFF Research Database (Denmark)

Vokoun, David; Beleggia, Marco; Heller, Luděk

2012-01-01

The motion of a cylindrical permanent magnet (projectile) inside a tubular permanent magnet, with both magnets magnetized axially, illustrates nicely the physical principles behind the operation of magnetic guns. The force acting upon the projectile is expressed semi-analytically as derivative...... of the magnetostatic interaction energy. For comparison, the forces involved are also calculated numerically using finite elements methods. Based on the conservation of the magnetostatic and kinetic energies, the exit and asymptotic velocities are determined. The derived formulas can be used to optimize the generated...... forces and motion of the inner cylindrical magnet....

The electric dipole moment of magnesium deuteride, MgD

Energy Technology Data Exchange (ETDEWEB)

Steimle, Timothy C., E-mail: TSteimle@asu.edu; Zhang, Ruohan [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604 (United States); Wang, Hailing [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200062 (China)

2014-06-14

The (0,0) A{sup 2}Π–X {sup 2}Σ{sup +} band of a cold molecular beam sample of magnesium monodeuteride, MgD, has been recorded field-free and in the presence of a static electric field of up to 11 kV/cm. The lines associated with the lowest rotational levels are detected for the first time. The field-free spectrum was analyzed to produce an improved set of fine structure parameters for the A{sup 2}Π (v = 0) state. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments, μ{sup -vector}{sub el} of 2.567(10)D and 1.31(8)D for A{sup 2}Π (v = 0) and X{sup 2}Σ{sup +}(v = 0) states, respectively. The recommended value for μ{sup -vector}{sub el}(X{sup 2}Σ{sup +} (v = 0)) for MgH, based upon the measured value for MgD, is 1.32(8)D.

Electric Dipole Transition Moments and Solvent-Dependent Interactions of Fluorescent Boron-Nitrogen Substituted Indole Derivatives.

Science.gov (United States)

Saif, Mari; Widom, Julia R; Xu, Senmiao; Abbey, Eric R; Liu, Shih-Yuan; Marcus, Andrew H

2015-06-25

Fluorescent analogues of the indole side chain of tryptophan can be useful spectroscopic probes of protein-protein and protein-DNA interactions. Here we present linear dichroism and solvent-dependent spectroscopic studies of two fluorescent analogues of indole, in which the organic C═C unit is substituted with the isosteric inorganic B-N unit. We studied the so-called "external" BN indole, which has C2v symmetry, and the "fused" BN indole with Cs symmetry. We performed a combination of absorption and fluorescence spectroscopy, ultraviolet linear dichroism (UV-LD) in stretched poly(ethylene) (PE) films, and quantum chemical calculations on both BN indole compounds. Our measurements allowed us to characterize the degree of alignment for both molecules in stretched PE films. We thus determined the orientations and magnitudes of the two lowest energy electric dipole transition moments (EDTMs) for external BN indole, and the two lowest energy EDTMs for fused BN indole within the 30 000-45 000 cm(-1) spectral range. We compared our experimental results to those of quantum chemical calculations using standard density functional theory (DFT). Our theoretical predictions for the low-energy EDTMs are in good agreement with our experimental data. The absorption and fluorescence spectra of the external and the fused BN indoles are sensitive to solvent polarity. Our results indicate that the fused BN indole experiences much greater solvation interactions with polar solvents than does the external BN indole.

Dual Aharonov-Casher effect and persistent dipole current

International Nuclear Information System (INIS)

Yi, J.; Jeon, G.S.; Choi, M.Y.

1995-01-01

An electric dipole moving in a magnetic field acquires a nontrivial quantum phase in the appropriate configuration. It is shown that this phase is manifested by the persistent dipole current induced on a ring pierced by a line of magnetic monopoles. Such a current depends on the statistics of the dipoles, which may have interesting implications for experiments. It is also pointed out that the dipole current cannot be self-sustained

Particle electric dipole moments

CERN Document Server

Pendlebury, J M

2000-01-01

Measurements of particle electric dipole moments (EDMs) continue to put powerful constraints on theories of T-symmetry and CP-symmetry violation, which form currently one of the most prominent fields in particle physics. EDM measurements have been concentrated on neutral systems such as the neutron and atoms and molecules. These measurements allow one to deduce, in turn, the electric dipole moments of the fundamental fermions, that is, the lighter leptons and quarks and also those of some heavy nuclei.

Spinodal Theory: A Common Rupturing Mechanism in Spinodal Dewetting and Surface Directed Phase Separation (Some Technological Aspects: Spatial Correlations and the Significance of Dipole-Quadrupole Interaction in Spinodal Dewetting)

International Nuclear Information System (INIS)

Singh, S.P.; Singh, S.P.

2011-01-01

The emerging structures in spinodal dewetting of thin nano films and spinodal decomposition of binary mixtures are found to be similar with certain differences attributed to the nonlinearities inherent in the wetting forces. This paper deals with the technological aspects of the spinodal processes by giving a brief account of the theory and to correlate the two phenomena termed as spinodal dewetting of thin nano films and surface-directed phase separation. The MC simulation micrographs at early stage of spinodal dewetting of a (linear) polymer film confined between two hard walls (using FENE potential between the beads on same chain and Morse potential between inter and intra chain beads) show similarities with surface-directed phase separation (using metropolis algorithm) in creation of holes. The spinodal dewetting is also criticized on the basis of global minimization of free energy emerging from dipole-quadrupole interactions. A novel molecular scale-driving mechanism coming from asymmetric interface formation in spinodal processes is also proposed. It can be believed that the modeling done with the films under confinement of two walls works as a classical mathematical Ansatz to the dipole-quadrupole interaction coming from quantum origins and giving rise to lateral interactions in the process reflecting a colossal behavior in thin nano films though weak in nature

Spinodal Theory: A Common Rupturing Mechanism in Spinodal Dewetting and Surface Directed Phase Separation (Some Technological Aspects: Spatial Correlations and the Significance of Dipole-Quadrupole Interaction in Spinodal Dewetting

Directory of Open Access Journals (Sweden)

Satya Pal Singh

2011-01-01

Full Text Available The emerging structures in spinodal dewetting of thin nano films and spinodal decomposition of binary mixtures are found to be similar with certain differences attributed to the nonlinearities inherent in the wetting forces. This paper deals with the technological aspects of the spinodal processes by giving a brief account of the theory and to correlate the two phenomena termed as spinodal dewetting of thin nanofilms and surface-directed phase separation. The MC simulation micrographs at early stage of spinodal dewetting of a (linear polymer film confined between two hard walls (using FENE potential between the beads on same chain and Morse potential between inter and intra chain beads show similarities with surface-directed phase separation (using metropolis algorithm in creation of holes. The spinodal dewetting is also criticized on the basis of global minimization of free energy emerging from dipole-quadrupole interactions. A novel molecular scale-driving mechanism coming from asymmetric interface formation in spinodal processes is also proposed. It can be believed that the modeling done with the films under confinement of two walls works as a classical mathematical ansatz to the dipole-quadrupole interaction coming from quantum origins and giving rise to lateral interactions in the process reflecting a colossal behavior in thin nano films though weak in nature.

Visualizing dipole radiation

International Nuclear Information System (INIS)

Girwidz, Raimund V

2016-01-01

The Hertzian dipole is fundamental to the understanding of dipole radiation. It provides basic insights into the genesis of electromagnetic waves and lays the groundwork for an understanding of half-wave antennae and other types. Equations for the electric and magnetic fields of such a dipole can be derived mathematically. However these are very abstract descriptions. Interpreting these equations and understanding travelling electromagnetic waves are highly limited in that sense. Visualizations can be a valuable supplement that vividly present properties of electromagnetic fields and their propagation. The computer simulation presented below provides additional instructive illustrations for university lectures on electrodynamics, broadening the experience well beyond what is possible with abstract equations. This paper refers to a multimedia program for PCs, tablets and smartphones, and introduces and discusses several animated illustrations. Special features of multiple representations and combined illustrations will be used to provide insight into spatial and temporal characteristics of field distributions—which also draw attention to the flow of energy. These visualizations offer additional information, including the relationships between different representations that promote deeper understanding. Finally, some aspects are also illustrated that often remain unclear in lectures. (paper)

QCD corrections to neutron electric dipole moment from dimension-six four-quark operators

Energy Technology Data Exchange (ETDEWEB)

Hisano, Junji, E-mail: hisano@eken.phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); IPMU, TODIAS, University of Tokyo, Kashiwa 277-8568 (Japan); Tsumura, Koji, E-mail: ko2@eken.phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Yang, Masaki J.S., E-mail: yang@eken.phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)

2012-07-18

In this Letter, the renormalization-group equations for the (flavor-conserving) CP-violating interaction are derived up to the dimension six, including all the four-quark operators, at one-loop level. We apply them to the models with the neutral scalar boson or the color-octet scalar boson which have CP-violating Yukawa interactions with quarks, and discuss the neutron electric dipole moment in these models.

Is the 2MASS dipole convergent?

OpenAIRE

Chodorowski, Michał; Bilicki, Maciej; Mamon, Gary A.; Jarrett, Thomas

2010-01-01

We study the growth of the clustering dipole of galaxies from the Two Micron All Sky Survey (2MASS). We find that the dipole does not converge before the completeness limit of the 2MASS Extended Source Catalog, i.e. up to about 300 Mpc/h. We compare the observed growth of the dipole with the theoretically expected, conditional growth for the LambdaCDM power spectrum and cosmological parameters constrained by WMAP. The observed growth turns out to be within 1-sigma confidence level of the theo...

Plasma confinement in a magnetic dipole

International Nuclear Information System (INIS)

Kesner, J.; Bromberg, L.; Garnier, D.; Mauel, M.

1999-01-01

A dipole fusion confinement device is stable to MHD interchange and ballooning modes when the pressure profile is sufficiently gentle. The plasma can be confined at high beta, is steady state and disruption free. Theory indicates that when the pressure gradient is sufficiently gentle to satisfy MHD requirements drift waves will also be stable. The dipole approach is particularly applicable for advanced fuels. A new experimental facility is presently being built to test the stability and transport properties of a dipole-confined plasma. (author)

Plasma confinement in a magnetic dipole

International Nuclear Information System (INIS)

Kesner, J.; Bromberg, L.; Garnier, D.; Mauel, M.

2001-01-01

A dipole fusion confinement device is stable to MHD interchange and ballooning modes when the pressure profile is sufficiently gentle. The plasma can be confined at high beta, is steady state and disruption free. Theory indicates that when the pressure gradient is sufficiently gentle to satisfy MHD requirements drift waves will also be stable. The dipole approach is particularly applicable for advanced fuels. A new experimental facility is presently being built to test the stability and transport properties of a dipole-confined plasma. (author)

Multiscale dipole relaxation in dielectric materials

DEFF Research Database (Denmark)

Hansen, Jesper Schmidt

2016-01-01

Dipole relaxation from thermally induced perturbations is investigated on different length scales for dielectric materials. From the continuum dynamical equations for the polarisation, expressions for the transverse and longitudinal dipole autocorrelation functions are derived in the limit where ...

Measurement of net electric charge and dipole moment of dust aggregates in a complex plasma.

Science.gov (United States)

Yousefi, Razieh; Davis, Allen B; Carmona-Reyes, Jorge; Matthews, Lorin S; Hyde, Truell W

2014-09-01

Understanding the agglomeration of dust particles in complex plasmas requires knowledge of basic properties such as the net electrostatic charge and dipole moment of the dust. In this study, dust aggregates are formed from gold-coated mono-disperse spherical melamine-formaldehyde monomers in a radiofrequency (rf) argon discharge plasma. The behavior of observed dust aggregates is analyzed both by studying the particle trajectories and by employing computer models examining three-dimensional structures of aggregates and their interactions and rotations as induced by torques arising from their dipole moments. These allow the basic characteristics of the dust aggregates, such as the electrostatic charge and dipole moment, as well as the external electric field, to be determined. It is shown that the experimental results support the predicted values from computer models for aggregates in these environments.

How to introduce the magnetic dipole moment

International Nuclear Information System (INIS)

Bezerra, M; Kort-Kamp, W J M; Cougo-Pinto, M V; Farina, C

2012-01-01

We show how the concept of the magnetic dipole moment can be introduced in the same way as the concept of the electric dipole moment in introductory courses on electromagnetism. Considering a localized steady current distribution, we make a Taylor expansion directly in the Biot-Savart law to obtain, explicitly, the dominant contribution of the magnetic field at distant points, identifying the magnetic dipole moment of the distribution. We also present a simple but general demonstration of the torque exerted by a uniform magnetic field on a current loop of general form, not necessarily planar. For pedagogical reasons we start by reviewing briefly the concept of the electric dipole moment. (paper)

Progress on the Development of the $Nb_3Sn$ 11T Dipole for the High Luminosity Upgrade of LHC

CERN Document Server

Savary, Frederic; Bordini, Bernardo; Bottura, Luca; Fiscarelli, Lucio; Fleiter, Jerome; Foussat, Arnaud; Izquierdo Bermudez, Susana; Karppinen, Mikko; Lackner, Friedrich; Loffler, Christian H; Nilsson, Emelie; Perez, Juan Carlos; Prin, Herve; Principe, Rosario; Ramos, Delio; de Rijk, Gijs; Rossi, Lucio; Smekens, David; Sequeira Tavares, Sandra; Willering, Gerard; Zlobin, Alexander V

2017-01-01

The high-luminosity large hadron collider (LHC) project at CERN entered into the production phase in October 2015 after the completion of the design study phase. In the meantime, the development of the 11 T dipole needed for the upgrade of the collimation system of the machine made significant progress with very good performance of the first two-in-one magnet model of 2-m length made at CERN. The 11 T dipole, which is more powerful than the current main dipoles of LHC, can be made shorter with an equivalent integrated field. This will allow creating space for the installation of additional collimators in specific locations of the dispersion suppressor regions. Following tests carried out during heavy ions runs of LHC in the end of 2015, and a more recent review of the project budget, the installation plan for the 11 T dipole was revised. Consequently, one 11 T dipole full assembly containing two 11 T dipoles of 5.5-m length will be installed on either side of interaction point 7. These two units shall be inst...

A table top experiment to investigate production and properties of a plasma confined by a dipole magnet.

Science.gov (United States)

Baitha, Anuj Ram; Kumar, Ashwani; Bhattacharjee, Sudeep

2018-02-01

We report a table top experiment to investigate production and properties of a plasma confined by a dipole magnet. A water cooled, strong, cylindrical permanent magnet (NdFeB) magnetized along the axial direction and having a surface magnetic field of ∼0.5 T is employed to create a dipole magnetic field. The plasma is created by electron cyclotron resonance heating. Visual observations of the plasma indicate that radiation belts appear due to trapped particles, similar to the earth's magnetosphere. The electron temperature lies in the range 2-13 eV and is hotter near the magnets and in a downstream region. It is found that the plasma (ion) density reaches a value close to 2 × 10 11 cm -3 and peaks at a radial distance about 3 cm from the magnet. The plasma beta β (β = plasma pressure/magnetic pressure) increases radially outward, and the maximum β for the present experimental system is ∼2%. It is also found that the singly charged ions are dominant in the discharge.

A table top experiment to investigate production and properties of a plasma confined by a dipole magnet

Science.gov (United States)

Baitha, Anuj Ram; Kumar, Ashwani; Bhattacharjee, Sudeep

2018-02-01

We report a table top experiment to investigate production and properties of a plasma confined by a dipole magnet. A water cooled, strong, cylindrical permanent magnet (NdFeB) magnetized along the axial direction and having a surface magnetic field of ˜0.5 T is employed to create a dipole magnetic field. The plasma is created by electron cyclotron resonance heating. Visual observations of the plasma indicate that radiation belts appear due to trapped particles, similar to the earth's magnetosphere. The electron temperature lies in the range 2-13 eV and is hotter near the magnets and in a downstream region. It is found that the plasma (ion) density reaches a value close to 2 × 1011 cm-3 and peaks at a radial distance about 3 cm from the magnet. The plasma beta β (β = plasma pressure/magnetic pressure) increases radially outward, and the maximum β for the present experimental system is ˜2%. It is also found that the singly charged ions are dominant in the discharge.

Cryogenics in CEBAF HMS dipole

International Nuclear Information System (INIS)

Bogensberger, P.; Ramsauer, F.; Brindza, P.; Wines, R.; Koefler, H.

1994-01-01

The paper will report upon the final design, manufacturing and tests of CEBAF's HMS Dipole cryogenic equipment. The liquid nitrogen circuits, the helium circuits and thermal insulation of the magnet will be addressed. The cryogenic reservoir and control module as an integral part of the HMS Dipole magnet will be presented. The construction, manufacturing, tests and final performance of the HMS Dipole cryogenic system will be reported. The LN 2 circuit and the He circuit are tied together by the control system for cool down, normal operation and standby. This system monitors proper temperature differences between both circuits and controls the cryogenic supply to meet the constraints. Implementation of the control features for the cryogenic system into the control system will be reported

A simple model for the magnetoelectric interaction in multiferroics

International Nuclear Information System (INIS)

Filho, Cesar J Calderon; Barberis, Gaston E

2011-01-01

The (anti)ferromagnetic and ferroelectric transitions in some multiferroic compounds seem to be strongly correlated. Even for systems that do not show spontaneous ferroelectricity such as the LiMPO 4 (M = Mn, Fe, Co, Ni) compounds, the coupling between magnetic and electric degrees of freedom is evident experimentally. Here, we present a simple numerical calculation to simulate this coupling that leads to the two transitions. We assume a magnetic sublattice consisting of classical magnetic moments coupled to a separated nonmagnetic sublattice consisting of classical electric dipoles. The coupling between them is realized through a phenomenological spin-lattice Hamiltonian, and the solution is obtained using the Monte Carlo technique. In the simplest version, the magnetic system is 2D Ising (anti)ferromagnetic lattice, with nearest neighbors interactions only, and the electric moments are permanent moments, coupled electrically. Within this approximation, the second order magnetic transition induces ferroelectricity in the electric dipoles. We show that these calculations can be extended to other magnetic systems, (x-y model and 3D Heisenberg) and to systems where the electric moments are created by strains, generated via spin-lattice coupling, so the model can be applied to model realistic systems such as the olivines mentioned above.

Field of a dipole in charged black-hole electrostatics

International Nuclear Information System (INIS)

Souza, J.A.

1979-01-01

By using the solution of Adler and Das for Maxwell's equations in a Reissner-Nordstroem optimally charged background metric, the field of a static electric dipole is found and then, by a duality rotation, the field of a static magnetic dipole is obtained. A generalization of the concept of electric-dipole moment is proposed for static dipoles in curved manifolds, and the behaviour of the fields both for the dipole very near and very far from the singular surface of the Reissner-Nordstroem geometry is studied. (author)

Nonlocal excitonic–mechanical interaction in a nanosystem

Energy Technology Data Exchange (ETDEWEB)

Zabolotskii, A. A., E-mail: zabolotskii@iae.nsk.su [Russian Academy of Sciences, Institute of Automatics and Electrometry, Siberian Branch (Russian Federation)

2016-11-15

The dynamics of a nanoparticle during its dipole interaction with an excitonic excitation in an extended quasi-one-dimensional polarizable medium is investigated. Bundles of J-aggregates of dye molecules are considered as an example of the latter. The nonlocal excitonic–mechanical interaction between the field of an amplifying or absorbing nanoparticle and excitons in a bundle has been simulated numerically. It has been found that the interaction between the field of the induced nanoparticle dipole and the fields of the molecular dipoles in an aggregate can lead to a change in the particle trajectory and excitonic pulse shape. The possibility of controlling the nanoparticle by excitonic pulses and the reverse effect of the nanoparticle field on the dynamics of excitons due to the nonlocal excitonic–mechanical interaction has been demonstrated.

Magnetic dipole excitations of the 163Dy nucleus

Science.gov (United States)

Zenginerler, Zemine; Tabar, Emre; Yakut, Hakan; Kuliev, Ali Akbar; Guliyev, Ekber

2014-03-01

In this study some properties of the magnetic dipole excitations of the deformed odd mass 163Dy nucleus were studied by using Quasiparticle-phonon nuclear model (QPNM). The several of the ground-state and low-lying magnetic dipole (M1) mode characteristics were calculated for deformed odd-mass nuclei using a separable Hamiltonian within the QPNM. The M1 excited states, reduced transition probabilities B(M1), the ground-state magnetic properties such as magnetic moment (μ), intrinsic magnetic moment (gK) , effective spin factor (gseff.) are the fundamental characteristics of the odd-mass nucleus and provide key information to understand nuclear structure. The theoretical results were compared with the available experimental data and other theoretical approaches. Calculations show that the spin-spin interaction in this isotopes leads to polarization effect influencing the magnetic moments. Furthermore we found a strong fragmentation of the M1 strength in 163Dy nucleus which was in qualitative agreement with the experimental data. Sakarya University, Project Number: 2012-50-02-007 and Z.Zenginerler acknowledge to TUBITAK-TURKEY 2013, fellowship No: 2219.

Special-Purpose High-Torque Permanent-Magnet Motors

Science.gov (United States)

Doane, George B., III

1995-01-01

Permanent-magnet brushless motors that must provide high commanded torques and satisfy unusual heat-removal requirement are developed. Intended for use as thrust-vector-control actuators in large rocket engines. Techniques and concepts used to design improved motors for special terrestrial applications. Conceptual motor design calls for use of rotor containing latest high-energy-product rare-earth permanent magnets so that motor produces required torque while drawing smallest possible currents from power supply. Torque generated by electromagnetic interaction between stator and permanent magnets in rotor when associated electronic circuits applied appropriately temporally and spatially phased currents to stator windings. Phase relationships needed to produce commanded torque computed in response to torque command and to electronically sensed angular position of rotor relative to stator.

Simulation study on the structural properties of colloidal particles with offset dipoles.

Science.gov (United States)

Rutkowski, David M; Velev, Orlin D; Klapp, Sabine H L; Hall, Carol K

2017-05-03

A major research theme in materials science is determining how the self-assembly of new generations of colloidal particles of complex shape and surface charge is guided by their interparticle interactions. In this paper, we describe results from quasi-2D Monte Carlo simulations of systems of colloidal particles with offset transversely-oriented extended dipole-like charge distributions interacting via an intermediate-ranged Yukawa potential. The systems are cooled slowly through an annealing procedure during which the temperature is lowered in discrete steps, allowing the system to equilibrate. We perform ground state calculations for two, three and four particles at several shifts of the dipole vector from the particle center. We create state diagrams in the plane spanned by the temperature and the area fraction outlining the boundaries between fluid, string-fluid and percolated states at various values of the shift. Remarkably we find that the effective cooling rate in our simulations has an impact on the structures formed, with chains being more prevalent if the system is cooled quickly and cyclic structures more prevalent if the system is cooled slowly. As the dipole is further shifted from the center, there is an increased tendency to assemble into small cyclic structures at intermediate temperatures. These systems further self-assemble into open lattice-like arrangements at very low temperatures. The novel structures identified might be useful for photonic applications, new types of porous media for filtration and catalysis, and gel matrices with unusual properties.

Engineering electric and magnetic dipole coupling in arrays of dielectric nanoparticles

Science.gov (United States)

Li, Jiaqi; Verellen, Niels; Van Dorpe, Pol

2018-02-01

Dielectric nanoparticles with both strong electric and magnetic dipole (ED and MD) resonances offer unique opportunities for efficient manipulation of light-matter interactions. Here, based on numerical simulations, we show far-field diffractive coupling of the ED and MD modes in a periodic rectangular array. By using unequal periodicities in the orthogonal directions, each dipole mode is separately coupled and strongly tuned. With this method, the electric and magnetic response of the dielectric nanoparticles can be deliberately engineered to accomplish various optical functionalities. Remarkably, an ultra-sharp MD resonance with sub-10 nm linewidth is achieved with a large enhancement factor for the magnetic field intensity on the order of ˜103. Our results will find useful applications for the detection of chemical and biological molecules as well as the design of novel photonic metadevices.

Formation and temporal evolution of the Lamb-dipole

DEFF Research Database (Denmark)

Nielsen, A.H.; Juul Rasmussen, J.

1997-01-01

of the evolving dipoles depend on the initial condition. However, the gross properties of their evolution are only weakly dependent on the detailed structure and can be well-described by the so-called Lamb-dipole solution. The viscous decay of the Lamb-dipole, leading to an expansion and a decreasing velocity...

Stacks of SPS Dipole Magnets

CERN Multimedia

1974-01-01

Stacks of SPS Dipole Magnets ready for installation in the tunnel. The SPS uses a separated function lattice with dipoles for bending and quadrupoles for focusing. The 6.2 m long normal conducting dipoles are of H-type with coils that are bent-up at the ends. There are two types, B1 (total of 360) and B2 (384). Both are for a maximum field of 1.8 Tesla and have the same outer dimensions (450x800 mm2 vxh) but with different gaps (B1: 39x129 mm2, B2: 52x92 mm2) tailored to the beam size. The yoke, made of 1.5 mm thick laminations, consists of an upper and a lower half joined together in the median plane once the coils have been inserted.

Enhanced terahertz magnetic dipole response by subwavelength fiber

DEFF Research Database (Denmark)

Atakaramians, Shaghik; Shadrivov, Ilya V.; Miroshnichenko, Andrey E.

2018-01-01

Dielectric sub-wavelength particles have opened up a new platform for realization of magnetic light. Recently, we have demonstrated that a dipole emitter by a sub-wavelength fiber leads to an enhanced magnetic response. Here, we experimentally demonstrate an enhanced magnetic dipole source......-fiber system excited by a magnetic source. This coupled magnetic dipole and optical fiber system can be considered a unit cell of metasurfaces for manipulation of terahertz radiation and is a proof-of-concept of a possibility to achieve enhanced radiation of a dipole source in proximity of a sub...

Supersymmetric relations among electromagnetic dipole operators

International Nuclear Information System (INIS)

Graesser, Michael; Thomas, Scott

2002-01-01

Supersymmetric contributions to all leptonic electromagnetic dipole operators have essentially identical diagrammatic structure. With approximate slepton universality this allows the muon anomalous magnetic moment to be related to the electron electric dipole moment in terms of supersymmetric phases, and to radiative flavor changing lepton decays in terms of small violations of slepton universality. If the current discrepancy between the measured and standard model values of the muon anomalous magnetic moment is due to supersymmetry, the current bound on the electron electric dipole moment then implies that the phase of the electric dipole operator is less than 2x10 -3 . Likewise the current bound on μ→eγ decay implies that the fractional selectron-smuon mixing in the left-left mass squared matrix, δm μ-tildee-tilde) 2 /m l-tilde) 2 , is less than 10 -4 . These relations and constraints are fairly insensitive to details of the superpartner spectrum for moderate to large tan β

Image tuning techniques for enhancing the performance of pure permanent magnet undulators with small gap/period ratios

Energy Technology Data Exchange (ETDEWEB)

Tatchyn, R. [Stanford Univ., CA (United States)

1995-12-31

The on-axis field of a small-gap undulator constricted out of pure permanent magnet (PM) blocks arranged in an alternating-dipole (i.e., 2 dipoles/period) array can be substantially varied by positioning monolithic permeable plates above and below the undulator jaws. This simple technique, which can be used to control the 1st harmonic energy in conventional synchrotron radiation (SR) or Free Electron Laser (FEL) applications requiring sub-octave tuning, can also be shown to suppress magnetic inhomogeneities that can contribute to the undulator`s on-axis field errors. If a standard 4 block/period Halbach undulator, composed of PM blocks with square cross sections, is rearranged into an alternating-dipole array with the same period, the peak field that can be generated with superimposed image plates can substantially exceed that of the pure-PM Halbach array. This design technique, which can be viewed as intermediate between the {open_quotes}pure-PM{close_quotes} and standard {open_quotes}hybrid/PM{close_quotes} configurations, provides a potentially cost-effective method of enhancing the performance of small-gap, pure-PM insertion devices. In this paper we report on the analysis and recent characterization of pure-PM undulator structures with superimposed image plates, and discuss possible applications to FEL research.

Permanently reconfigured metamaterials due to terahertz induced mass transfer of gold

DEFF Research Database (Denmark)

Strikwerda, Andrew; Zalkovskij, Maksim; Iwaszczuk, Krzysztof

2015-01-01

We present a new technique for permanent metamaterial reconfiguration via optically induced mass transfer of gold. This mass transfer, which can be explained by field-emission induced electromigration, causes a geometric change in the metamaterial sample. Since a metamaterial's electromagnetic...... response is dictated by its geometry, this structural change massively alters the metamaterial's behavior. We show this by optically forming a conducting pathway between two closely spaced dipole antennas, thereby changing the resonance frequency by a factor of two. After discussing the physics...... of the process, we conclude by presenting an optical fuse that can be used as a sacrificial element to protect sensitive components, demonstrating the applicability of optically induced mass transfer for device design. (C)2015 Optical Society of America...

Fourier-positivity constraints on QCD dipole models

Directory of Open Access Journals (Sweden)

Bertrand G. Giraud

2016-09-01

Full Text Available Fourier-positivity (F-positivity, i.e. the mathematical property that a function has a positive Fourier transform, can be used as a constraint on the parametrization of QCD dipole-target cross-sections or Wilson line correlators in transverse position space r. They are Bessel transforms of positive transverse momentum dependent gluon distributions. Using mathematical F-positivity constraints on the limit r→0 behavior of the dipole amplitudes, we identify the common origin of the violation of F-positivity for various, however phenomenologically convenient, dipole models. It is due to the behavior r2+ϵ, ϵ>0 softer, even slightly, than color transparency. F-positivity seems thus to conflict with the present dipole formalism when it includes a QCD running coupling constant α(r.

Dipole moments of the τ lepton as a sensitive probe for physics beyond the standard model

International Nuclear Information System (INIS)

Mahanta, U.

1996-01-01

CP-violating dipole moments of leptons vanish at least to three loop order and are estimated to be (m l /MeV)x1.6x10 -40 ecm in the standard model (SM), where m l is the mass of the lepton. However, they can receive potentially large contributions in some beyond the SM scenarios and this makes them very sensitive probes of new physics. In this article we show that a nonuniversal interaction, involving leptoquarks to the quark-lepton pair of the third generation through helicity-unsuppressed couplings of the order of ordinary gauge couplings, can generate electric and weak dipole moments of the order of 10 -19 ecm for the τ lepton. This is greater than pure supersymmetric (SUSY) and left-right (LR) contributions by almost three orders of magnitude. It is also greater than the mirror fermionic contribution by an order of magnitude. The measurements of d τ z and d τ γ at CERN LEP, SLC, and TCF are expected to reach sensitivities of 10 -18 ecm and 10 -19 ecm, respectively, in the near future. The observation of a nonvanishing dipole moment of τ at these facilities would, therefore, strongly favor superstring-inspired light leptoquark-mediated interactions, over pure SUSY or LR interactions and perhaps also mirror-generated mixings without some sort of quark-lepton unification as its origin. copyright 1996 The American Physical Society

Electric dipoles on the Bloch sphere

OpenAIRE

Vutha, Amar C.

2014-01-01

The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic & molecular physics.

Dipole Bands in 196Hg

International Nuclear Information System (INIS)

Lawrie, J. J.; Lawrie, E. A.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D.; Msezane, B.; Benatar, M.; Mabala, G. K.; Mutshena, K. P.; Federke, M.; Mullins, S. M.; Ncapayi, N. J.; Vymers, P.

2011-01-01

High spin states in 196 Hg have been populated in the 198 Pt(α,6n) reaction at 65 MeV and the level scheme has been extended. A new dipole band has been observed and a previously observed dipole has been confirmed. Excitation energies, spins and parities of these bands were determined from DCO ratio and linear polarization measurements. Possible quasiparticle excitations responsible for these structures are discussed.

Magneto-Electric Dipole Antenna Arrays

OpenAIRE

Gupta, Shulabh; Jiang, Li Jun; Caloz, Christophe

2014-01-01

A planar magneto-electric (ME) dipole antenna array is proposed and demonstrated by both full-wave analysis and experiments. The proposed structure leverages the infinite wavelength propagation characteristic of composite right/left-handed (CRLH) transmission lines to form high-gain magnetic radiators combined with radial conventional electric radiators, where the overall structure is excited by a single differential feed. The traveling-wave type nature of the proposed ME-dipole antenna enabl...

Constraining the neutrino magnetic dipole moment from white dwarf pulsations

International Nuclear Information System (INIS)

Córsico, A.H.; Althaus, L.G.; Bertolami, M.M. Miller; Kepler, S.O.; García-Berro, E.

2014-01-01

Pulsating white dwarf stars can be used as astrophysical laboratories to constrain the properties of weakly interacting particles. Comparing the cooling rates of these stars with the expected values from theoretical models allows us to search for additional sources of cooling due to the emission of axions, neutralinos, or neutrinos with magnetic dipole moment. In this work, we derive an upper bound to the neutrino magnetic dipole moment (μ ν ) using an estimate of the rate of period change of the pulsating DB white dwarf star PG 1351+489. We employ state-of-the-art evolutionary and pulsational codes which allow us to perform a detailed asteroseismological period fit based on fully DB white dwarf evolutionary sequences. Plasmon neutrino emission is the dominant cooling mechanism for this class of hot pulsating white dwarfs, and so it is the main contributor to the rate of change of period with time (Pidot) for the DBV class. Thus, the inclusion of an anomalous neutrino emission through a non-vanishing magnetic dipole moment in these sequences notably influences the evolutionary timescales, and also the expected pulsational properties of the DBV stars. By comparing the theoretical Pidot value with the rate of change of period with time of PG 1351+489, we assess the possible existence of additional cooling by neutrinos with magnetic dipole moment. Our models suggest the existence of some additional cooling in this pulsating DB white dwarf, consistent with a non-zero magnetic dipole moment with an upper limit of μ ν  ∼< 10 -11  μ B . This bound is somewhat less restrictive than, but still compatible with, other limits inferred from the white dwarf luminosity function or from the color-magnitude diagram of the Globular cluster M5. Further improvements of the measurement of the rate of period change of the dominant pulsation mode of PG 1351+489 will be necessary to confirm our bound

The dipoles reach the half-way mark

CERN Multimedia

2006-01-01

With the positioning of the 616th magnet, installation of the LHC dipoles has reached the half-way mark. Only half the dipoles remain to be installed! The 616th dipole out of a total of 1232 was installed at 3 a.m on Wednesday 12 July. Night and day, the tunnel is the setting for a never-ending series of carefully choreographed installation operations. At a rate of around twenty per week, there has been a steady underground flow of dipole magnets, each measuring 15 metres in length and weighing 34 tonnes. 'In order to recover the accumulated delays, installation is proceeding three times faster than planned', confides Claude Hauviller, who is supervising LHC installation. Four dipoles can be transported underground at the same time. It is a real challenge, which the 65-man team responsible for this difficult task faces on a daily basis. This is because there is very little space in the tunnel and there are no passing places for the magnet transport vehicles. The room for manoeuvre can sometimes be measured ...

Coulomb couplings in solubilised light harvesting complex II (LHCII): challenging the ideal dipole approximation from TDDFT calculations.

Science.gov (United States)

López-Tarifa, P; Liguori, Nicoletta; van den Heuvel, Naudin; Croce, Roberta; Visscher, Lucas

2017-07-19

The light harvesting complex II (LHCII), is a pigment-protein complex responsible for most of the light harvesting in plants. LHCII harvests sunlight and transfers excitation energy to the reaction centre of the photo-system, where the water oxidation process takes place. The energetics of LHCII can be modulated by means of conformational changes allowing a switch from a harvesting to a quenched state. In this state, the excitation energy is no longer transferred but converted into thermal energy to prevent photooxidation. Based on molecular dynamics simulations at the microsecond time scale, we have recently proposed that the switch between different fluorescent states can be probed by correlating shifts in the chromophore-chromophore Coulomb interactions to particular protein movements. However, these findings are based upon calculations in the ideal point dipole approximation (IDA) where the Coulomb couplings are simplified as first order dipole-dipole interactions, also assuming that the chromophore transition dipole moments lay in particular directions of space with constant moduli (FIX-IDA). In this work, we challenge this approximation using the time-dependent density functional theory (TDDFT) combined with the frozen density embedding (FDE) approach. Our aim is to establish up to which limit FIX-IDA can be applied and which chromophore types are better described under this approximation. For that purpose, we use the classical trajectories of solubilised light harvesting complex II (LHCII) we have recently reported [Liguori et al., Sci. Rep., 2015, 5, 15661] and selected three pairs of chromophores containing chlorophyll and carotenoids (Chl and Car): Chla611-Chla612, Chlb606-Chlb607 and Chla612-Lut620. Using the FDE in the Tamm-Dancoff approximation (FDEc-TDA), we show that IDA is accurate enough for predicting Chl-Chl Coulomb couplings. However, the FIX-IDA largely overestimates Chl-Car interactions mainly because the transition dipole for the Cars is not

Electric dipoles on the Bloch sphere

International Nuclear Information System (INIS)

Vutha, Amar C

2015-01-01

The time evolution of a two-level quantum mechanical system can be geometrically described using the Bloch sphere. By mapping the Bloch sphere evolution onto the dynamics of oscillating electric dipoles, we provide a physically intuitive link between classical electromagnetism and the electric dipole transitions of atomic and molecular physics. (paper)

Exclusive vector meson production with leading neutrons in a saturation model for the dipole amplitude in mixed space

Science.gov (United States)

Amaral, J. T.; Becker, V. M.

2018-05-01

We investigate ρ vector meson production in e p collisions at HERA with leading neutrons in the dipole formalism. The interaction of the dipole and the pion is described in a mixed-space approach, in which the dipole-pion scattering amplitude is given by the Marquet-Peschanski-Soyez saturation model, which is based on the traveling wave solutions of the nonlinear Balitsky-Kovchegov equation. We estimate the magnitude of the absorption effects and compare our results with a previous analysis of the same process in full coordinate space. In contrast with this approach, the present study leads to absorption K factors in the range of those predicted by previous theoretical studies on semi-inclusive processes.

The effect of the dust’s electric dipole moment on transverse oscillations of the one dimensional dusty crystals

Directory of Open Access Journals (Sweden)

S Karimi

2013-10-01

Full Text Available In this paper, we investigated the effect of dipole-dipole interaction between the dust particles on the transverse oscillation of one dimensional dusty crystal. We used the Boltzmann distribution for the electrons and ions density and assumed that dust particles are negatively charged. The equation of motion for dust particles in this one dimensional chain was obtained. It is shown that the direction of dipoles plays an important role in the motion of dusts and significantly changes the oscillation frequency. Also, in the long wavelength approximation, a nonlinear Schrödinger equation for the evolution of the amplitude of the nonlinear oscillations was derived, showing that both the bright solitons and the dark solitons could exist.

Reiterated inclusions of dipoles in a dense plasma

International Nuclear Information System (INIS)

Naouri, Gerard

1983-01-01

This thesis introduces a simple model made up for the calculation of pressure effects in dense and partially ionized 3 D two component plasma. The technic used is the description of the overlapping of atomic orbitals by means of interacting dipoles incased in one another. By iteration of this procedure we get an effective two-body potential which allows us to calculate line shifts of hydrogenic ions. In conclusion we suggest a possible improvement of the method by substituting a self consistent potential to the Debye one for the calculation of the wave functions. [fr

SSC collider dipole magnet end mechanical design

International Nuclear Information System (INIS)

Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, M.; Leung, K.K.

1991-01-01

This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described

Dovetail spoke internal permanent magnet machine

Science.gov (United States)

Alexander, James Pellegrino [Ballston Lake, NY; EL-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Lokhandwalla, Murtuza [Clifton Park, NY; Shah, Manoj Ramprasad [Latham, NY; VanDam, Jeremy Daniel [West Coxsackie, NY

2011-08-23

An internal permanent magnet (IPM) machine is provided. The IPM machine includes a stator assembly and a stator core. The stator core also includes multiple stator teeth. The stator assembly is further configured with stator windings to generate a stator magnetic field when excited with alternating currents and extends along a longitudinal axis with an inner surface defining a cavity. The IPM machine also includes a rotor assembly and a rotor core. The rotor core is disposed inside the cavity and configured to rotate about the longitudinal axis. The rotor assembly further includes a shaft. The shaft further includes multiple protrusions alternately arranged relative to multiple bottom structures provided on the shaft. The rotor assembly also includes multiple stacks of laminations disposed on the protrusions and dovetailed circumferentially around the shaft. The rotor assembly further includes multiple pair of permanent magnets for generating a magnetic field, which magnetic field interacts with the stator magnetic field to produce a torque. The multiple pair of permanent magnets are disposed between the stacks. The rotor assembly also includes multiple middle wedges mounted between each pair of the multiple permanent magnets.

Energy flow of electric dipole radiation in between parallel mirrors

Science.gov (United States)

Xu, Zhangjin; Arnoldus, Henk F.

2017-11-01

We have studied the energy flow patterns of the radiation emitted by an electric dipole located in between parallel mirrors. It appears that the field lines of the Poynting vector (the flow lines of energy) can have very intricate structures, including many singularities and vortices. The flow line patterns depend on the distance between the mirrors, the distance of the dipole to one of the mirrors and the angle of oscillation of the dipole moment with respect to the normal of the mirror surfaces. Already for the simplest case of a dipole moment oscillating perpendicular to the mirrors, singularities appear at regular intervals along the direction of propagation (parallel to the mirrors). For a parallel dipole, vortices appear in the neighbourhood of the dipole. For a dipole oscillating under a finite angle with the surface normal, the radiating tends to swirl around the dipole before travelling off parallel to the mirrors. For relatively large mirror separations, vortices appear in the pattern. When the dipole is off-centred with respect to the midway point between the mirrors, the flow line structure becomes even more complicated, with numerous vortices in the pattern, and tiny loops near the dipole. We have also investigated the locations of the vortices and singularities, and these can be found without any specific knowledge about the flow lines. This provides an independent means of studying the propagation of dipole radiation between mirrors.

On the state space of the dipole ghost

International Nuclear Information System (INIS)

Binegar, B.

1984-01-01

A particular representation of SO(4, 2) is identified with the state space of the free dipole ghost. This representation is then given an explicit realization as the solution space of a 4th-order wave equation on a spacetime locally isomorphic to Minkowski space. A discrete basis for this solution space is given, as well as an explicit expression for its SO(4, 2) invariant inner product. The connection between the modes of dipole field and those of the massless scalar field is clarified, and a recent conjecture concerning the restriction of the dipole representation to the Poincare subgroup is confirmed. A particular coordinate transformation then reveals the theory of the dipole ghost in Minkowski space. Finally, it is shown that the solution space of the dipole equation is not unitarizable in a Poincare invariant manner. (orig.)

Electric dipole moments of the fluorescent probes Prodan and Laurdan: experimental and theoretical evaluations.

Science.gov (United States)

Vequi-Suplicy, Cíntia C; Coutinho, Kaline; Lamy, M Teresa

2014-03-01

Several experimental and theoretical approaches can be used for a comprehensive understanding of solvent effects on the electronic structure of solutes. In this review, we revisit the influence of solvents on the electronic structure of the fluorescent probes Prodan and Laurdan, focusing on their electric dipole moments. These biologically used probes were synthesized to be sensitive to the environment polarity. However, their solvent-dependent electronic structures are still a matter of discussion in the literature. The absorption and emission spectra of Prodan and Laurdan in different solvents indicate that the two probes have very similar electronic structures in both the ground and excited states. Theoretical calculations confirm that their electronic ground states are very much alike. In this review, we discuss the electric dipole moments of the ground and excited states calculated using the widely applied Lippert-Mataga equation, using both spherical and spheroid prolate cavities for the solute. The dimensions of the cavity were found to be crucial for the calculated dipole moments. These values are compared to those obtained by quantum mechanics calculations, considering Prodan in vacuum, in a polarizable continuum solvent, and using a hybrid quantum mechanics-molecular mechanics methodology. Based on the theoretical approaches it is evident that the Prodan dipole moment can change even in the absence of solute-solvent-specific interactions, which is not taken into consideration with the experimental Lippert-Mataga method. Moreover, in water, for electric dipole moment calculations, it is fundamental to consider hydrogen-bonded molecules.

SSC collider dipole magnet end mechanical design

International Nuclear Information System (INIS)

Delchamps, S.W.; Bossert, R.C.; Carson, J.; Ewald, K.; Fulton, H.; Kerby, J.; Koska, W.; Strait, J.; Wake, S.M.; Leung, K.K.

1991-05-01

This paper describes the mechanical design of the ends of Superconducting Super Collider dipole magnets to be constructed and tested at Fermilab. Coil end clamps, end yoke configuration, and end plate design are discussed. Loading of the end plate by axial Lorentz forces is discussed. Relevant data from 40 mm and 50 mm aperture model dipole magnets built and tested at Fermilab are presented. In particular, the apparent influence of end clamp design on the quench behavior of model SSC dipoles is described. 8 refs., 3 figs

Long-range interactions among three alkali-metal atoms

International Nuclear Information System (INIS)

Marinescu, M.; Starace, A.F.

1996-01-01

The long-range asymptotic form of the interaction potential surface for three neutral alkali-metal atoms in their ground states may be expressed as an expansion in inverse powers of inter-nuclear distances. The first leading powers are proportional to the dispersion coefficients for pairwise atomic interactions. They are followed by a term responsible for a three body dipole interaction. The authors results consist in evaluation of the three body dipole interaction coefficient between three alkali-metal atoms. The generalization to long-range n atom interaction terms will be discussed qualitatively

Relaxed geometries and dipole moments of positron complexes with diatomic molecules

Energy Technology Data Exchange (ETDEWEB)

Assafrao, Denise; Mohallem, Jose R, E-mail: rachid@fisica.ufmg.b [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, CP 702, 30123-970, Belo Horizonte, MG (Brazil)

2010-01-01

Relaxed geometries and dipole moments of diatomic molecules interacting with a slow positron are reported as functions of the positron distance to the more electronegative atom. A molecular model for the complex that allows applications to large systems is used. The electron population on the positron is proposed as a weighting function to calculate the average quantities. Results show Self-Consistent-Field quality or better.

The dipole moments of the linear polycarbon monosulfides

International Nuclear Information System (INIS)

Murakami, Akinori

1989-01-01

The dipole moments of the linear polycarbon monosulfides, CS, C 2 S and C 3 S molecule (radical)s were calculated by ab initio SCF-CI method. The equilibrium geometries of the C n S molecules were obtained by MP3 method using the 6-31G** basis set. From the split balencetype (MIDI-4) to the Huzinaga's well tempered extended type(WT) were used to evaluate dipole moments. Final results were obtained using the WT+2d basis set and CI calculation. The calculated dipole moment of the CS molecule, 1.96 debye, is in good agreement with experimental one. The dipole moment of the C 2 S radical is calculated to be 2.81 debye and 3.66 debye for C 3 S molecule. The calculated dipole moments of the C n S will be accurate with in 0.1 debye(5%)

Dipole Resonances of 76Ge

Science.gov (United States)

Ilieva, R. S.; Cooper, N.; Werner, V.; Rusev, G.; Pietralla, N.; Kelly, J. H.; Tornow, W.; Yates, S. W.; Crider, B. P.; Peters, E.

2013-10-01

Dipole resonances in 76Ge have been studied using the method of Nuclear Resonance Fluorescence (NRF). The experiment was performed using the Free Electron Laser facility at HI γS/TUNL, which produced linearly polarised quasi-monoenergetic photons in the 4-9 MeV energy range. Photon strength, in particular dipole strength, is an important ingredient in nuclear reaction calculations, and recent interest in its study has been stimulated by observations of a pygmy dipole resonance near the neutron separation energy Sn of certain nuclei. Furthermore, 76Ge is a candidate for 0 ν 2 β -decay. The results are complimentary to a relevant experiment done at TU Darmstadt using Bremsstrahlung beams. Single-resonance parities and a preliminary estimate of the total photo-excitation cross section will be presented. This work was supported by the U.S. DOE under grant no. DE-FG02-91ER40609.

Derivation of the dipole map

International Nuclear Information System (INIS)

Ali, Halima; Punjabi, Alkesh; Boozer, Allen

2004-01-01

In our method of maps [Punjabi et al., Phy. Rev. Lett. 69, 3322 (1992), and Punjabi et al., J. Plasma Phys. 52, 91 (1994)], symplectic maps are used to calculate the trajectories of magnetic field lines in divertor tokamaks. Effects of the magnetic perturbations are calculated using the low MN map [Ali et al., Phys. Plasmas 11, 1908 (2004)] and the dipole map [Punjabi et al., Phys. Plasmas 10, 3992 (2003)]. The dipole map is used to calculate the effects of externally located current carrying coils on the trajectories of the field lines, the stochastic layer, the magnetic footprint, and the heat load distribution on the collector plates in divertor tokamaks [Punjabi et al., Phys. Plasmas 10, 3992 (2003)]. Symplectic maps are general, efficient, and preserve and respect the Hamiltonian nature of the dynamics. In this brief communication, a rigorous mathematical derivation of the dipole map is given

Effects of dipole magnet inhomogeneities on the beam ellipsoid

International Nuclear Information System (INIS)

Tsoupas, N.; Colman, J.; Levine, M.; McKenzie-Wilson, R.; Ward, T.; Grand, P.

1986-01-01

The RAYTRACE computer code has been modified to accept magnetic fields measured in the median plane of a dipole magnet. This modification allows one to study the effects of a non-ideal dipole magnet on the beam ellipsoid (as defined by the TRANSPORT code manual). The effects on the beam ellipsoid are due to: field inhomogeneities in the interior region of the dipole, and discrepancies from design conditions of the magnetic field values in the fringe field region. The results of the RAYTRACE code calculations based on experimentally measured fields will be compared with the results derived using both an ideal (no inhomogeneities) dipole with SCOFF boundaries and an ideal dipole with perfect (according to design) fringe fields

Diagnostics of the Fermilab Tevatron using an AC dipole

Energy Technology Data Exchange (ETDEWEB)

Miyamoto, Ryoichi [Univ. of Texas, Austin, TX (United States)

2008-08-01

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f ~ 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

Improved Limits on Axionlike-Particle-Mediated P , T -Violating Interactions between Electrons and Nucleons from Electric Dipole Moments of Atoms and Molecules

Science.gov (United States)

Stadnik, Y. V.; Dzuba, V. A.; Flambaum, V. V.

2018-01-01

In the presence of P , T -violating interactions, the exchange of axionlike particles between electrons and nucleons in atoms and molecules induces electric dipole moments (EDMs) of atoms and molecules. We perform calculations of such axion-exchange-induced atomic EDMs using the relativistic Hartree-Fock-Dirac method including electron core polarization corrections. We present analytical estimates to explain the dependence of these induced atomic EDMs on the axion mass and atomic parameters. From the experimental bounds on the EDMs of atoms and molecules, including Cs 133 , Tl 205 , Xe 129 , Hg 199 , Yb 171 F 19 , Hf 180 F+ 19 , and Th 232 O 16 , we constrain the P , T -violating scalar-pseudoscalar nucleon-electron and electron-electron interactions mediated by a generic axionlike particle of arbitrary mass. Our limits improve on existing laboratory bounds from other experiments by many orders of magnitude for ma≳10-2 eV . We also place constraints on C P violation in certain types of relaxion models.

The Collider dipole magnet program

International Nuclear Information System (INIS)

Baldi, R.W.; Bailey, R.; Bever, D.; Bogart, L.; Gigg, G.; Packer, M.; Page, L.; Stranberg, N.

1991-01-01

The Superconducting Super Collider will consist of more large superconducting magnets than have been built to date. Over 12,000 superconducting magnets are required and more than 8,000 will be Collider dipoles. The dipole magnet program is on the critical path of the project and requires the optimized utilization of the Nation's resources - National Laboratories, Universities and Industry. General Dynamics and Westinghouse Electric Corporation have been chosen as the Leader and Follower companies for the design of producible magnets and the manufacturing of the SSC dipoles. Industry has the necessary experience, skills and facilities required to produce reliable and cost effective dipole magnets. At peak production, 10 CDMs per day, very large quantities (nearly 130 metric tonnes/day) of materials will have to be procured from companies nationwide and fabricated into defect-free magnets. A key element of the SSCL's strategy to produce the most efficient CDM program is to employ the Leader-Follower approach, with the Leader transferring technology from the laboratories to the Leader's facility, fully integrating the Follower in the producibility and tooling/factory design efforts, and assisting the Follower in magnet qualification tests. General Dynamics is ready to help build America's most powerful research tool. Management is in place, the facilities are ready for activation and resources are available for immediate assignment

Dipole rescattering and the nuclear structure function

Energy Technology Data Exchange (ETDEWEB)

Carvalho, F. [Depto de Ciencias Exatas e da Terra, Universidade Federal de Sao Paulo, SP (Brazil); Goncalves, V. P. [Instituto de Fisica e Matematica, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Navarra, F. S.; Oliveira, E. G. [Instituto de Fisica, Universidade de Sao Paulo Rua do Matao, Travessa R, 187, 05508-090 Sao Paulo, SP (Brazil)

2013-03-25

In the framework of the dipole model, we study the effects of the dipole multiple scatterings in a nuclear target and compute the nuclear structure function. We compare different unitarization schemes and confront our results with the E665 data.

A new formulation of the relativistic many-body theory of electric dipole moments of closed shell atoms

International Nuclear Information System (INIS)

Latha, K V P; Angom, Dilip; Chaudhuri, Rajat K; Das, B P; Mukherjee, Debashis

2007-01-01

The electric dipole moments of closed-shell atoms are sensitive to the parity and time-reversal violating phenomena in the nucleus. The nuclear Schiff moment is one such property, it arises from the parity and time reversal violating quark-quark interactions and the quark-chromo electric dipole moments. We calculate the electric dipole moment of atomic 199 Hg arising from the nuclear Schiff moment using the relativistic coupled-cluster theory. This is the most accurate calculation of the quantity to date. Our calculations in combination with the experiment data provide important insights to the P and T violating coupling constants at the elementary particle level. In addition, a new limit on the tensor-pseudo tensor induced atomic EDM, calculated using the relativistic coupled-cluster theory is also presented

Nanoscale shift of the intensity distribution of dipole radiation.

Science.gov (United States)

Shu, Jie; Li, Xin; Arnoldus, Henk F

2009-02-01

The energy flow lines (field lines of the Poynting vector) for radiation emitted by a dipole are in general curves, rather than straight lines. For a linear dipole the field lines are straight, but when the dipole moment of a source rotates, the field lines wind numerous times around an axis, which is perpendicular to the plane of rotation, before asymptotically approaching a straight line. We consider an elliptical dipole moment, representing the most general state of oscillation, and this includes the linear dipole as a special case. Due to the spiraling near the source, for the case of a rotating dipole moment, the field lines in the far field are displaced with respect to the outward radial direction, and this leads to a shift of the intensity distribution of the radiation in the far field. This shift is shown to be independent of the distance to the source and, although of nanoscale dimension, should be experimentally observable.

Beam orbit control in TESLA superconducting cavities from dipole mode measurements

International Nuclear Information System (INIS)

Paparella, R.

2006-09-01

The knowledge of the electromagnetic interaction between a beam and the surrounding vacuum chamber is necessary in order to optimize the accelerator performance in terms of stored current. Many instability phenomena may occur in the machine because of the fields produced by the beam and acting back on itself. Basically, these fields, wake-fields, produce an extra voltage, affecting the longitudinal dynamics, and a transverse kick which deflects the beam. In this thesis we present the results of theoretical and experimental investigations to demonstrate the possibility of using the dipolar wake fields of the superconducting accelerating to measure the beam transverse position. After an introduction to the ILC project and to the TESLA technology, of superconducting RF cavities, we will approach the problem from an analytical point of view in chapter 2. The expression of the wake fields in a cylindrical cavity will be investigated and the electromagnetic field modes derived from Maxwell equations in an original way. Graphical solutions of a Matlab program simulating the fields due to a particle passing through a pill-box cavity along a generic path will be shown. The interaction of the beam with higher order modes (HOM) in the TESLA cavities has been studied in the past at the TESLA Test Facility (TTF) in order to determine whether the modes with the highest loss factor are sufficiently damped. Starting from the results obtained before 2003, HOM signals has been better observed and examined in order to use dipole modes to find the electric center of each cavity in the first TTF accelerating module. The results presented in chapter 3 will show that by monitoring the HOM signal amplitude for two polarizations of a dipole mode, one can measure electrical center of the modes with a resolution of 50 μm. Moreover, a misalignment of the first TTF module with respect to the gun axis has been predicted using cavity dipole modes. Alternatives to this method are described in

Dislocation dipole annihilation in diamond and silicon

Energy Technology Data Exchange (ETDEWEB)

Rabier, J; Pizzagalli, L, E-mail: jacques.rabier@univ-poitiers.fr [Institut PPRIMME, Departement de Physique et Mecanique des Materiaux - UPR 3346 CNRS, Universite de Poitiers, ENSMA - SP2MI, BP 30179, F-86962 Chasseneuil Futuroscope Cedex (France)

2011-02-01

The mechanism of dislocation dipole annihilation has been investigated in C and Si using atomistic calculations with the aim of studying their annihilation by-products. It is shown, in C as well as in Si, that dipole annihilation yields debris that can be depicted as a cluster of vacancies, or alternately by two internal free surfaces. These defects have no strain field and can hardly be seen using usual TEM techniques. This suggests that the brown colouration of diamond could be due to microstructures resulting from deformation mechanisms associated with dipole formation and their annihilation rather than to a climb mechanism and vacancy aggregation. In silicon where a number of dipoles have been evidenced by TEM when dislocation trails are found, such debris could be the missing link responsible for the observation of strong chemical reactivity and electrical activity in the wake of moving dislocations.

Communication: theoretical study of ThO for the electron electric dipole moment search.

Science.gov (United States)

Skripnikov, L V; Petrov, A N; Titov, A V

2013-12-14

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H(3)Δ1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [http://www.electronedm.org]. To interpret the experiment in terms of eEDM and dimensionless constant kT, P characterizing the strength of the T,P-odd pseudoscalar-scalar electron-nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, Eeff, and a parameter of the T,P-odd pseudoscalar-scalar interaction, WT, P, in ThO is required. We report our results for Eeff (84 GV/cm) and WT, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H(3)Δ1 → X(1)Σ(+) transition energy, which can serve as a measure of reliability of the obtained Eeff and WT, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the Ω-doublets of H(3)Δ1.

Communication: Theoretical study of ThO for the electron electric dipole moment search

International Nuclear Information System (INIS)

Skripnikov, L. V.; Petrov, A. N.; Titov, A. V.

2013-01-01

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H 3 Δ 1 state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k T, P characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E eff , and a parameter of the T,P-odd pseudoscalar–scalar interaction, W T, P , in ThO is required. We report our results for E eff (84 GV/cm) and W T, P (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H 3 Δ 1 → X 1 Σ + transition energy, which can serve as a measure of reliability of the obtained E eff and W T, P values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the Ω-doublets of H 3 Δ 1

The neutron electric dipole moment and the Weinberg's operator

International Nuclear Information System (INIS)

Li Chongsheng; Hu Bingquan

1992-01-01

After a summary of the predictions for the neutron electric dipole moment in a number of models of CP violation, the authors review mainly the recent developments associated with Weimberg's purely gluonic CP violation operator. Its implications on the neutron electric dipole moment in various models of CP violation are discussed. Inspired by Weimberg's work, several new mechanisms of generating large electric dipole moments of charged leptons and large electric and chromo-electric dipole moments of light quarks are recently proposed. Brief discussions on these new developments are also given

Electric Dipole Antenna: A Source of Gravitational Radiation

Directory of Open Access Journals (Sweden)

Chifu E. N.

2013-07-01

Full Text Available In this article, the gravitational scalar potential due to an oscillating electric dipole antenna placed in empty space is derived. The gravitational potential obtained propagates as a wave. The gravitational waves have phase velocity equal to the speed of light in vacuum (c at the equatorial plane of the electric dipole antenna, unlike electromagnetic waves from the dipole antenna that cancel out at the equatorial plane due to charge symmetry.

GenLocDip: A Generalized Program to Calculate and Visualize Local Electric Dipole Moments.

Science.gov (United States)

Groß, Lynn; Herrmann, Carmen

2016-09-30

Local dipole moments (i.e., dipole moments of atomic or molecular subsystems) are essential for understanding various phenomena in nanoscience, such as solvent effects on the conductance of single molecules in break junctions or the interaction between the tip and the adsorbate in atomic force microscopy. We introduce GenLocDip, a program for calculating and visualizing local dipole moments of molecular subsystems. GenLocDip currently uses the Atoms-In-Molecules (AIM) partitioning scheme and is interfaced to various AIM programs. This enables postprocessing of a variety of electronic structure output formats including cube and wavefunction files, and, in general, output from any other code capable of writing the electron density on a three-dimensional grid. It uses a modified version of Bader's and Laidig's approach for achieving origin-independence of local dipoles by referring to internal reference points which can (but do not need to be) bond critical points (BCPs). Furthermore, the code allows the export of critical points and local dipole moments into a POVray readable input format. It is particularly designed for fragments of large systems, for which no BCPs have been calculated for computational efficiency reasons, because large interfragment distances prevent their identification, or because a local partitioning scheme different from AIM was used. The program requires only minimal user input and is written in the Fortran90 programming language. To demonstrate the capabilities of the program, examples are given for covalently and non-covalently bound systems, in particular molecular adsorbates. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A novel approach to measure the electric dipole moment of the isotope 129-Xe

Directory of Open Access Journals (Sweden)

Kuchler F.

2014-03-01

Full Text Available Permanent electric dipole moments (EDM of fundamental systems are promising systems to find new CP violation beyond the Standard Model. Our EDM experiment is based on hyper-polarized liquid xenon droplets of sub-millimeter size on a micro-fabricated structure, placed in a low-field NMR setup. Implementation of rotating electric fields enables a conceptually new EDM measurement technique, allowing thorough investigation of systematic effects. Still, a Ramsey-type spin precession experiment with static electric field can be realized at similar sensitivity within the same setup. Employing superconducting pick-up coils and highly sensitive LTc-SQUIDs, a large array of independent measurements can be performed simultaneously. With our approach we aim to finally increase the sensitivity on the EDM of 129Xe by more than three orders of magnitude.

On the magnitude of electric dipole moment of a neutron in the Weinberg CP-violation model

International Nuclear Information System (INIS)

Ansel'm, A.A.; Bunakov, V.E.; Gudkov, V.P.; Ural'tsev, N.G.

1984-01-01

It is shown, that the magnitude of the electric dipole moment of an neutron in the Weinberg CP-violation model is determined by the interaction with neutral Higgs bosons and it exceeds the existing experimental limit by two or three orders

Dipole response of 76Se above 4 MeV

Science.gov (United States)

Goddard, P. M.; Cooper, N.; Werner, V.; Rusev, G.; Stevenson, P. D.; Rios, A.; Bernards, C.; Chakraborty, A.; Crider, B. P.; Glorius, J.; Ilieva, R. S.; Kelley, J. H.; Kwan, E.; Peters, E. E.; Pietralla, N.; Raut, R.; Romig, C.; Savran, D.; Schnorrenberger, L.; Smith, M. K.; Sonnabend, K.; Tonchev, A. P.; Tornow, W.; Yates, S. W.

2013-12-01

The dipole response of 3476Se in the energy range from 4 to 9 MeV has been analyzed using a (γ⃗,γ') polarized photon scattering technique, performed at the High Intensity γ-Ray Source facility at Triangle Universities Nuclear Laboratory, to complement previous work performed using unpolarized photons. The results of this work offer both an enhanced sensitivity scan of the dipole response and an unambiguous determination of the parities of the observed J=1 states. The dipole response is found to be dominated by E1 excitations, and can reasonably be attributed to a pygmy dipole resonance. Evidence is presented to suggest that a significant amount of directly unobserved excitation strength is present in the region, due to unobserved branching transitions in the decays of resonantly excited states. The dipole response of the region is underestimated when considering only ground state decay branches. We investigate the electric dipole response theoretically, performing calculations in a three-dimensional (3D) Cartesian-basis time-dependent Skyrme-Hartree-Fock framework.

Continuous millennial decrease of the Earth's magnetic axial dipole

Science.gov (United States)

Poletti, Wilbor; Biggin, Andrew J.; Trindade, Ricardo I. F.; Hartmann, Gelvam A.; Terra-Nova, Filipe

2018-01-01

Since the establishment of direct estimations of the Earth's magnetic field intensity in the first half of the nineteenth century, a continuous decay of the axial dipole component has been observed and variously speculated to be linked to an imminent reversal of the geomagnetic field. Furthermore, indirect estimations from anthropologically made materials and volcanic derivatives suggest that this decrease began significantly earlier than direct measurements have been available. Here, we carefully reassess the available archaeointensity dataset for the last two millennia, and show a good correspondence between direct (observatory/satellite) and indirect (archaeomagnetic) estimates of the axial dipole moment creating, in effect, a proxy to expand our analysis back in time. Our results suggest a continuous linear decay as the most parsimonious long-term description of the axial dipole variation for the last millennium. We thus suggest that a break in the symmetry of axial dipole moment advective sources occurred approximately 1100 years earlier than previously described. In addition, based on the observed dipole secular variation timescale, we speculate that the weakening of the axial dipole may end soon.

Short chain molecular junctions: Charge transport versus dipole moment

International Nuclear Information System (INIS)

Ikram, I. Mohamed; Rabinal, M.K.

2015-01-01

Graphical abstract: - Highlights: • The role of dipole moment of organic molecules on molecular junctions has been studied. • Molecular junctions constituted using propargyl molecules of different dipole moments. • The electronic properties of the molecules were calculated using Gaussian software. • Junctions show varying rectification due to their varying dipole moment and orientation. - Abstract: The investigation of the influence of dipole moment of short chain organic molecules having three carbon atoms varying in end group on silicon surface was carried on. Here, we use three different molecules of propargyl series varying in dipole moment and its orientation to constitute molecular junctions. The charge transport mechanism in metal–molecules–semiconductor (MMS) junction obtained from current–voltage (I–V) characteristics shows the rectification behavior for two junctions whereas the other junction shows a weak rectification. The electronic properties of the molecules were calculated using Gaussian software package. The observed rectification behavior of these junctions is examined and found to be accounted to the orientation of dipole moment and electron cloud density distribution inside the molecules

5cm aperture dipole studies

International Nuclear Information System (INIS)

McInturff, A.D.; Bossert, R.; Carson, J.; Fisk, H.E.; Hanft, R.; Kuchnir, M.; Lundy, R.; Mantech, P.; Strait, J.

1986-01-01

The results obtained during the evolution of the design, construction, and testing program of the design ''B'' dipole are presented here. Design ''B'' is one of the original three competing designs for the Superconducting Super Collider ''SSC'' arc dipoles. The final design parameters were as follows: air cored (less than a few percent of the magnetic field derived from any iron present), aluminum collared, two layered winding, 5.5T maximum operating field, and a 5 cm cold aperture. There have been fourteen 64 cm long 5 cm aperture model dipoles cold tested (at 4.3K and less) in this program so far. There was a half length full size (6m) mechanical analog (M-10) built and tested to check the cryostat's mechanical design under ramping and quench conditions. Several deviations from the ''Tevatron'' dipole fabrication technique were incorporated, for example the use of aluminum collars instead of stainless steel. The winding technique variations explored were ''dry welding,'' a technique with the cable covered with Kapton insulation only and ''wet winding'' where the Kapton was covered with a light coat of ''B'' stage epoxy. Test data include quench currents, field quality (Fourier multipole co-efficients), coil magnetization, conductor current performance, and coil loading. Quench current, loss per cycle, and harmonics were measured as a function of the magnitude and rate of change of the magnetic field, and helium bath temperature

Dissecting an LHC dipole

CERN Multimedia

2004-01-01

The cold mass of a 15-metre main dipole magnet has some fifteen different components. All the main components are manufactured under CERN's direct responsibility. Four of them transit through CERN before being shipped to the dipole assembly contractors, namely the cable, which constitutes the magnet's superconducting core (see Bulletin 14/2004), the beam screens, the heat exchanger tubes and the cold bore beam tubes. The two latter components transit via Building 927 where they undergo part of the production process. The 58-mm diameter heat exchanger tubes will remove heat from the magnets using superfluid helium. The 53-mm diameter cold bore tubes will be placed under vacuum to allow the twin beams to circulate around the LHC.

Electric dipole moments with and beyond flavor invariants

Science.gov (United States)

Smith, Christopher; Touati, Selim

2017-11-01

In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino masses. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. Finally, the formalism is adapted to deal with a third class of flavor structures, sensitive to the flavored U (1) phases, and used to study the impact of the strong CP-violating interaction and the interplay between the neutrino Majorana phases and possible baryon and/or lepton number violating interactions.

Electric dipole moments with and beyond flavor invariants

Directory of Open Access Journals (Sweden)

Christopher Smith

2017-11-01

Full Text Available In this paper, the flavor structure of quark and lepton electric dipole moments in the SM and beyond is investigated using tools inspired from Minimal Flavor Violation. While Jarlskog-like flavor invariants are adequate for estimating CP-violation from closed fermion loops, non-invariant structures arise from rainbow-like processes. Our goal is to systematically construct these latter flavor structures in the quark and lepton sectors, assuming different mechanisms for generating neutrino masses. Numerically, they are found typically much larger, and not necessarily correlated with, Jarlskog-like invariants. Finally, the formalism is adapted to deal with a third class of flavor structures, sensitive to the flavored U(1 phases, and used to study the impact of the strong CP-violating interaction and the interplay between the neutrino Majorana phases and possible baryon and/or lepton number violating interactions.

Colour dipoles and virtual Compton scattering

International Nuclear Information System (INIS)

McDermott, M.

2002-01-01

An analysis of Deeply Virtual Compton Scattering (DVCS) is made within the colour dipole model. We compare and contrast two models for the dipole cross-section which have been successful in describing structure function data. Both models agree with the available cross section data on DVCS from HERA. We give predictions for various azimuthal angle asymmetries in HERA kinematics and for the DVCS cross section in the THERA region. (orig.)

High field dipole magnet design concepts

International Nuclear Information System (INIS)

Nicol, T.H.

1988-12-01

High field dipole magnets will play a crucial role in the development of future accelerators whether at Fermilab or elsewhere. This paper presents conceptual designs for two such dipoles; 6.6 and 8.8 Tesla, with special focus on their suitability for upgrades to the Fermilab Tevatron. Descriptions and cross-sectional views will be presented as will preliminary estimates of heat loads and costs. 3 refs., 2 figs., 2 tabs

Manipulation and control of the interfacial polarization in organic light-emitting diodes by dipolar doping

Directory of Open Access Journals (Sweden)

Lars Jäger

2016-09-01

Full Text Available Most of the commonly used electron transporting materials in organic light-emitting diodes exhibit interfacial polarization resulting from partially aligned permanent dipole moments of the molecules. This property modifies the internal electric field distribution of the device and therefore enables an earlier flat band condition for the hole transporting side, leading to improved charge carrier injection. Recently, this phenomenon was studied with regard to different materials and degradation effects, however, so far the influence of dilution has not been investigated. In this paper we focus on dipolar doping of the hole transporting material 4,4-bis[N-(1-naphthyl-N-phenylamino]-biphenyl (NPB with the polar electron transporting material tris-(8-hydroxyquinolate aluminum (Alq3. Impedance spectroscopy reveals that changes of the hole injection voltage do not scale in a simple linear fashion with the effective thickness of the doped layer. In fact, the measured interfacial polarization reaches a maximum value for a 1:1 blend. Taking the permanent dipole moment of Alq3 into account, an increasing degree of dipole alignment is found for decreasing Alq3 concentration. This observation can be explained by the competition between dipole-dipole interactions leading to dimerization and the driving force for vertical orientation of Alq3 dipoles at the surface of the NPB layer.

Manipulation and control of the interfacial polarization in organic light-emitting diodes by dipolar doping

Science.gov (United States)

Jäger, Lars; Schmidt, Tobias D.; Brütting, Wolfgang

2016-09-01

Most of the commonly used electron transporting materials in organic light-emitting diodes exhibit interfacial polarization resulting from partially aligned permanent dipole moments of the molecules. This property modifies the internal electric field distribution of the device and therefore enables an earlier flat band condition for the hole transporting side, leading to improved charge carrier injection. Recently, this phenomenon was studied with regard to different materials and degradation effects, however, so far the influence of dilution has not been investigated. In this paper we focus on dipolar doping of the hole transporting material 4,4-bis[N-(1-naphthyl)-N-phenylamino]-biphenyl (NPB) with the polar electron transporting material tris-(8-hydroxyquinolate) aluminum (Alq3). Impedance spectroscopy reveals that changes of the hole injection voltage do not scale in a simple linear fashion with the effective thickness of the doped layer. In fact, the measured interfacial polarization reaches a maximum value for a 1:1 blend. Taking the permanent dipole moment of Alq3 into account, an increasing degree of dipole alignment is found for decreasing Alq3 concentration. This observation can be explained by the competition between dipole-dipole interactions leading to dimerization and the driving force for vertical orientation of Alq3 dipoles at the surface of the NPB layer.

Collisionless scattering of plasma cloud in a dipole magnetic field

International Nuclear Information System (INIS)

Osipyan, D.A.

2006-01-01

Results of numerical simulation of dense plasma cloud scattering dynamics in a magnetized background and MHD indignations generation are presented. The magnetic field has dipole structure. The initial system of equations includes the Vlasov equations for ionic components of plasma, hydrodynamic approach for electrons and Maxwell's system of equations. The method of solution is based on the use of the method of particles in cells and finite difference splitting schemes. Quantitative characteristics of dependence of scattering cloud parameters from the Mach-Alfven number and parameter of magnetic laminar interaction are observed. In particular, a condition of more effective deformation of a cloud is large values of the Mach-Alfven numbers and small parameters of the magnetic laminar interaction

Elastic interactions between hydrogen atoms in metals. II. Elastic interaction energies

International Nuclear Information System (INIS)

Shirley, A.I.; Hall, C.K.

1986-01-01

The fully harmonic lattice approximation derived in a previous paper is used to calculate the elastic interaction energies in the niobium-hydrogen system. The permanent-direct, permanent-indirect, induced-direct, and induced-indirect forces calculated previously each give rise to a corresponding elastic interaction between hydrogen atoms. The latter three interactions have three- and four-body terms in addition to the usual two-body terms. These quantities are calculated and compared with the corresponding two-body permanent elastic interactions obtained in the harmonic-approximation treatment of Horner and Wagner. The results show that the total induced elastic energy is approximately (1/3) the size of the total permanent elastic energy and opposite to it in sign. The total elastic energy due to three-body interactions is approximately (1/4) the size of the total two-body elastic energy, while the total four-body elastic energy is approximately 5% of the total two-body energy. These additional elastic energies are expected to have a profound effect on the thermodynamic and phase-change behavior of a metal hydride

Intrinsic Electric Dipole Moments of Paramagnetic Atoms: Rubidium and Cesium

OpenAIRE

Nataraj, H. S.; Sahoo, B. K.; Das, B. P.; Mukherjee, D.

2008-01-01

The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that of its constituent electrons and a scalar--pseudo-scalar (S-PS) electron-nucleus interactions. The electron EDM and the S-PS EDM contribution to atomic EDM scales as Z^3. Thus, the heavy paramagnetic atomic systems will exhibit large enhancement factors. However, the nature of the coupling is so small that it becomes an interest of high precision atomic experiments. In this work, we...

Investigation of the influence of intermolecular interactions on the electronic stopping cross sections

International Nuclear Information System (INIS)

Krotz, R.; Neuwirth, W.; Pietsch, W.

1980-01-01

The electronic stopping cross sections for Li projectiles have been measured in various kinds of targets. They are analyzed here with respect to the different types of interactions between the constituents of the target: interactions between the atoms in a compound (chemical bonding), the ion-dipole interaction, if the target is an electrolytic solution, and the dipole-dipole interaction among polar molecules. The influence on the stopping cross section depends on the strength of these interactions; it varies from a few percent in the latter case up to 20% and more in a compound. These influences are the largest, if the velocity of the projectile is of the order of the average orbital velocity of the target atoms. (author)

Perturbative odderon in the dipole model

International Nuclear Information System (INIS)

Kovchegov, Yuri V.; Szymanowski, Lech; Wallon, Samuel

2004-01-01

We show that, in the framework of Mueller's dipole model, the perturbative QCD odderon is described by the dipole model equivalent of the BFKL equation with a C-odd initial condition. The eigenfunctions and eigenvalues of the odderon solution are the same as for the dipole BFKL equation and are given by the functions E n,ν and χ(n,ν) correspondingly, where the C-odd initial condition allows only for odd values of n. The leading high-energy odderon intercept is given by α odd -1=((2α s N c )/(π))χ(n=1,ν=0)=0 in agreement with the solution found by Bartels, Lipatov and Vacca. We proceed by writing down an evolution equation for the odderon including the effects of parton saturation. We argue that saturation makes the odderon solution a decreasing function of energy

The Influence of Train Leakage Currents on the LEP Dipole Field

CERN Document Server

Bravin, Enrico; Dehning, Bernd; Drees, A; Galbraith, Peter; Geitz, M A; Henrichsen, K N; Koratzinos, M; Mugnai, G

1998-01-01

The determination of the mass and the width of the Z boson at CERN's LEP accelerator, an e+e- storage ring with a circumference of approximately 27 kilometres, imposes heavy demands on the knowledge of the LEP counter-rotating electron and positron beam energies. The precision required is of the order of 1 MeV or »20 ppm frequency. Due to its size the LEP collider is influenced by various macroscopic and regional factors such as the position of the moon or seasonal changes of the rainfall in the area, as reported earlier. A new and not less surprising effect of the LEP energy was observed in 1995: railroad trains in the Geneva region perturb the dipole field. A parasitic flow of electricity, originating from the trains, travels along the LEP ground cable and the vacuum chamber, interacting with the dipole field. An account of the phenomenon with its explanation substantiated by dedicated measurements is presented.

First Investigations on the Energy Deposited in a D0 early separation scheme Dipole for the LHC upgrade

CERN Document Server

Hoa, C

2007-01-01

This note gives the first results of energy deposition calculation on a simplified model for an early scheme separation dipole D0, located at 3.5 m from the IP. The Monte Carlo code FLUKA version 2006.3 has been used for modelling the multi-particle interactions and energy transport. After a short introduction to particle interaction with matter and power deposition processes, the FLUKA modelling is described with bench marked power deposition calculation on the TAS, the absorber located in front of the triplet quadrupoles. The power deposition results for the D0 early scheme are then discussed in details, with the averaged and peak power density, and the variations of the total heat load in the dipole with the longitudinal position and with the aperture diameter.

Concentration dependence of the wings of a dipole-broadened magnetic resonance line in magnetically diluted lattices

Energy Technology Data Exchange (ETDEWEB)

Zobov, V. E., E-mail: rsa@iph.krasn.ru [Russian Academy of Sciences, Kirenskii Institute of Physics, Siberian Branch (Russian Federation); Kucherov, M. M. [Siberian Federal University, Institute of Space and Information Technologies (Russian Federation)

2017-01-15

The singularities of the time autocorrelation functions (ACFs) of magnetically diluted spin systems with dipole–dipole interaction (DDI), which determine the high-frequency asymptotics of autocorrelation functions and the wings of a magnetic resonance line, are studied. Using the self-consistent fluctuating local field approximation, nonlinear equations are derived for autocorrelation functions averaged over the independent random arrangement of spins (magnetic atoms) in a diamagnetic lattice with different spin concentrations. The equations take into account the specificity of the dipole–dipole interaction. First, due to its axial symmetry in a strong static magnetic field, the autocorrelation functions of longitudinal and transverse spin components are described by different equations. Second, the long-range type of the dipole–dipole interaction is taken into account by separating contributions into the local field from distant and near spins. The recurrent equations are obtained for the expansion coefficients of autocorrelation functions in power series in time. From them, the numerical value of the coordinate of the nearest singularity of the autocorrelation function is found on the imaginary time axis, which is equal to the radius of convergence of these expansions. It is shown that in the strong dilution case, the logarithmic concentration dependence of the coordinate of the singularity is observed, which is caused by the presence of a cluster of near spins whose fraction is small but contribution to the modulation frequency is large. As an example a silicon crystal with different {sup 29}Si concentrations in magnetic fields directed along three crystallographic axes is considered.

Noncommutative QED and anomalous dipole moments

International Nuclear Information System (INIS)

Riad, I.F.; Sheikh-Jabbari, M.M.

2000-09-01

We study QED on noncommutative spaces, NCQED. In particular we present the detailed calculation for the noncommutative electron-photon vertex and show that the Ward identity is satisfied. We discuss that in the noncommutative case moving electron will show electric dipole effects. In addition, we work out the electric and magnetic dipole moments up to one loop level. For the magnetic moment we show that noncommutative electron has an intrinsic (spin independent) magnetic moment. (author)

Dislocation self-organization under single slip straining and dipole properties

International Nuclear Information System (INIS)

Chiu, Y.-L.; Veyssiere, Patrick

2008-01-01

Spontaneous microstructural organization under single slip is investigated by transmission electron microscopy. The formation and the structure of dislocation entanglements are analyzed on three types of fcc-based systems, Al, Cu and TiAl, all deformed by {1 1 1} slip. Differences are found that depend on stacking fault energy and lattice friction. The importance of dipolar configurations is outlined. Selected properties of dipoles are analyzed theoretically under isotropic and anisotropic elasticity in cubic systems. At variance from screw and near-screw dipoles, the stress-free equilibrium angle of an edge dipole is little dependent on the material's elastic anisotropy. In Cu, for instance, a screw dipole is at equilibrium at around 59 deg. from the slip plane, and this angle is unchanged over a range of dislocation characters of approximately ±20 deg. On the other hand, given a dipole height, the passing stress is a maximum in the screw orientation. It is, however, not a minimum in the edge orientation. Static and dynamic dipole properties are but little affected by dissociation down to a dipole height of the order of a few times the dissociation distance

Positron-electron annihilation in a field of a fixed electric dipole

International Nuclear Information System (INIS)

Butkevich, E.R.; Sabirov, R.Kh.

1989-01-01

Positron annihilation from dipole Ps state conditioned by simultaneous localization of positron and electron in the field of fixed electric dipole is considered. Calculation of annihilation γ-quantum angular correlation curve is performed. For the fixed value of the dipole moment the correlation curve half-width is reduced with the reduction of dipole charges. Correlation curve narrowing takes place with the growth of dipole moment. It is stressed that when interpreting the narrow component one should be careful when choosing the appropriate annihilation mechanism. Experimental result analysis is given

Open-Midplane Dipoles for a Muon Collider

International Nuclear Information System (INIS)

Weggel, R.; Gupta, R.; Kolonko, J.; Scanlan, R.; Cline, D.; Ding, X.; Anerella, M.; Kirk, H.; Palmer, B.; Schmalzle, J.

2011-01-01

For a muon collider with copious decay particles in the plane of the storage ring, open-midplane dipoles (OMD) may be preferable to tungsten-shielded cosine-theta dipoles of large aperture. The OMD should have its midplane completely free of material, so as to dodge the radiation from decaying muons. Analysis funded by a Phase I SBIR suggests that a field of 10-20 T should be feasible, with homogeneity of 1 x 10 -4 and energy deposition low enough for conduction cooling to 4.2 K helium. If funded, a Phase II SBIR would refine the analysis and build and test a proof-of-principle magnet. A Phase I SBIR has advanced the feasibility of open-midplane dipoles for the storage ring of a muon collider. A proposed Phase II SBIR would refine these predictions of stresses, deformations, field quality and energy deposition. Design optimizations would continue, leading to the fabrication and test, for the first time, of a proof-of-principle dipole of truly open-midplane design.

Properties of the superconductor in accelerator dipole magnets

Science.gov (United States)

Teravest, Derk

Several aspects of the application of superconductors to high field dipole magnets for particle accelerators are discussed. The attention is focused on the 10 tesla (1 m model) magnet that is envisaged for the future Large Hadron Collider (LHC) accelerator. The basic motivation behind the study is the intention of employing superconductors to their utmost performance. An overview of practical supercomputers, their applications and their impact on high field dipole magnets used for particle accelerators, is presented. The LHC reference design for the dipole magnets is outlined. Several models were used to study the influence of a number of factors in the shape and in particular, the deviation from the shape that is due to the flux flow state. For the investigated extrinsic and intrinsic factors, a classification can be made with respect to the effect on the shape of the characteristic of a multifilamentary wire. The optimization of the coil structure for high field dipole magnets, with respect to the field quality is described. An analytical model for solid and hollow filaments, to calculate the effect of filament magnetization in the quality of the dipole field, is presented.

Neutron Electric Dipole Moment from Gauge-String Duality.

Science.gov (United States)

Bartolini, Lorenzo; Bigazzi, Francesco; Bolognesi, Stefano; Cotrone, Aldo L; Manenti, Andrea

2017-03-03

We compute the electric dipole moment of nucleons in the large N_{c} QCD model by Witten, Sakai, and Sugimoto with N_{f}=2 degenerate massive flavors. Baryons in the model are instantonic solitons of an effective five-dimensional action describing the whole tower of mesonic fields. We find that the dipole electromagnetic form factor of the nucleons, induced by a finite topological θ angle, exhibits complete vector meson dominance. We are able to evaluate the contribution of each vector meson to the final result-a small number of modes are relevant to obtain an accurate estimate. Extrapolating the model parameters to real QCD data, the neutron electric dipole moment is evaluated to be d_{n}=1.8×10^{-16}θ e cm. The electric dipole moment of the proton is exactly the opposite.

Photoinduced electric dipole in CuCl quantum dots

International Nuclear Information System (INIS)

Masumoto, Yasuaki; Naruse, Fumitaka; Kanno, Atsushi

2003-01-01

Electromodulated absorption spectra of CuCl quantum dots modulated at twice the modulation frequency of electric field, 2f, show prominent structure around persistently burned hole. It grows in proportion to square of the electric field in the same manner as the 2f component of electromodulated absorption spectra of the dots without the laser exposure. Even the f component of electromodulated signal was observed around the burned hole position. These observations are explained by considering electric dipole formed in hole burned and photoionized quantum dots. Photoionization not only produces persistent spectral hole burning but also the local built-in electric field and photoinduced dipole moment in quantum dots. The dipole moment is estimated to be about 5 debye for 3.2-nm-radius quantum dots. The dipole moments are randomly oriented but 1% anisotropy is deduced from the electromodulated signal at f

Self-organised aggregation of a pair of particles with different resonant frequencies and electric dipole moments of transitions, controlled by an external quasi-resonant field

Energy Technology Data Exchange (ETDEWEB)

Slabko, V V; Tsipotan, A S; Aleksandrovsky, A S [Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk (Russian Federation)

2013-05-31

The influence of the oscillation phases of the dipole moments induced in metal nanoparticles and quantum dots by an external laser field on their interaction energy is considered. It is shown that a difference in resonant frequencies leads to the formation of additional minima and maxima, which are absent in the spectral dependence of the interaction energy of identical particles at similar orientations of the pair of particles with respect to the plane of polarisation of radiation. These features are due to the fact that the oscillation phase difference of the induced dipole moments of particles reaches values close to {pi}. (interaction of laser radiation with matter. laser plasma)

Electric-dipole-induced universality for Dirac fermions in graphene.

Science.gov (United States)

De Martino, Alessandro; Klöpfer, Denis; Matrasulov, Davron; Egger, Reinhold

2014-05-09

We study electric dipole effects for massive Dirac fermions in graphene and related materials. The dipole potential accommodates towers of infinitely many bound states exhibiting a universal Efimov-like scaling hierarchy. The dipole moment determines the number of towers, but there is always at least one tower. The corresponding eigenstates show a characteristic angular asymmetry, observable in tunnel spectroscopy. However, charge transport properties inferred from scattering states are highly isotropic.

Dipole defects in beryl

International Nuclear Information System (INIS)

Holanda, B A; Cordeiro, R C; Blak, A R

2010-01-01

Dipole defects in gamma irradiated and thermally treated beryl (Be 3 Al 2 Si 6 O 18 ) samples have been studied using the Thermally Stimulated Depolarization Currents (TSDC) technique. TSDC experiments were performed in pink (morganite), green (emerald), blue (aquamarine) and colourless (goshenite) natural beryl. TSDC spectra present dipole peaks at 190K, 220K, 280K and 310K that change after gamma irradiation and thermal treatments. In morganite samples, for thermal treatments between 700K and 1100K, the 280K peak increase in intensity and the band at 220K disappears. An increase of the 280K peak and a decrease of the 190K peak were observed in the TSDC spectra of morganite after a gamma irradiation of 25kGy performed after the thermal treatments. In the case of emerald samples, thermal treatments enhanced the 280K peak and gamma irradiation partially destroyed this band. The goshenite TSDC spectra present only one band at 280K that is not affected either by thermal treatments or by gamma irradiation. All the observed peaks are of dipolar origin because the intensity of the bands is linearly dependent on the polarization field, behaviour of dipole defects. The systematic study, by means of TSDC measurements, of ionizing irradiation effects and thermal treatments in these crystals makes possible a better understanding of the role played by the impurities in beryl crystals.

Electric Dipole Echoes in Rydberg Atoms

International Nuclear Information System (INIS)

Yoshida, S.; Reinhold, C. O.; Burgdoerfer, J.; Zhao, W.; Mestayer, J. J.; Lancaster, J. C.; Dunning, F. B.

2007-01-01

We report the first observation of echoes in the electric dipole moment of an ensemble of Rydberg atoms precessing in an external electric field F. Rapid reversal of the field direction is shown to play a role similar to that of a π pulse in NMR in rephasing a dephased ensemble of electric dipoles resulting in the buildup of an echo. The mechanisms responsible for this are discussed with the aid of classical trajectory Monte Carlo simulations

Perturbative odderon in the dipole model

Energy Technology Data Exchange (ETDEWEB)

Kovchegov, Yuri V.; Szymanowski, Lech; Wallon, Samuel

2004-04-29

We show that, in the framework of Mueller's dipole model, the perturbative QCD odderon is described by the dipole model equivalent of the BFKL equation with a C-odd initial condition. The eigenfunctions and eigenvalues of the odderon solution are the same as for the dipole BFKL equation and are given by the functions E{sup n,{nu}} and {chi}(n,{nu}) correspondingly, where the C-odd initial condition allows only for odd values of n. The leading high-energy odderon intercept is given by {alpha}{sub odd}-1=((2{alpha}{sub s}N{sub c})/({pi})){chi}(n=1,{nu}=0)=0 in agreement with the solution found by Bartels, Lipatov and Vacca. We proceed by writing down an evolution equation for the odderon including the effects of parton saturation. We argue that saturation makes the odderon solution a decreasing function of energy.

On the radiation of electric, magnetic and toroidal dipoles

International Nuclear Information System (INIS)

Afanas'ev, G.N.; Stepanovskij, Yu.P.

2002-01-01

We consider the radiation of electric, magnetic and toroidal dipoles uniformly moving in unbounded medium (this corresponds to the Tamm-Frank problem). The densities of these dipoles are obtained from the corresponding charge-current densities in an infinitesimal limit. The behaviour of radiation intensities in the neighbourhood of the Cherenkov threshold β = 1/n is investigated. The frequency and velocity regions are defined where radiation intensities are maximal. The comparison with previous attempts is given. We consider also the radiation of electric, magnetic and toroidal dipoles uniformly moving in medium, in a finite space interval (this corresponds to the Tamm problem). The properties of radiation arising from the precession of a magnetic dipole are studied

On the Radiation of Electric, Magnetic and Toroidal Dipoles

CERN Document Server

Afanasiev, G N

2002-01-01

We consider the radiation of electric, magnetic and toroidal dipoles uniformly moving in unbounded medium (this corresponds to the Tamm-Frank problem). The densities of these dipoles are obtained from the corresponding charge-current densities in an infinitesimal limit. The behaviour of radiation intensities in the neighbourhood of the Cherenkov threshold beta=1/n is investigated. The frequency and velocity regions are defined where radiation intensities are maximal. The comparison with previous attempts is given. We consider also the radiation of electric, magnetic and toroidal dipoles uniformly moving in medium, in a finite space interval (this corresponds to the Tamm problem). The properties of radiation arising from the precession of a magnetic dipole are studied.

Nuclear electric dipole moments in chiral effective field theory

Energy Technology Data Exchange (ETDEWEB)

Bsaisou, J.; Vries, J. de [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Hanhart, C. [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); JARA - Forces and Matter Experiments,Forschungszentrum Jülich, D-52425 Jülich (Germany); Liebig, S. [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Meißner, Ulf-G. [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); JARA - Forces and Matter Experiments,Forschungszentrum Jülich, D-52425 Jülich (Germany); JARA - High Performance Computing,Forschungszentrum Jülich, D-52425 Jülich (Germany); Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics,Universität Bonn,D-53115 Bonn (Germany); Minossi, D. [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Nogga, A.; Wirzba, A. [Institute for Advanced Simulation, Institut für Kernphysik, and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); JARA - Forces and Matter Experiments,Forschungszentrum Jülich, D-52425 Jülich (Germany)

2015-03-19

We provide a consistent and complete calculation of the electric dipole moments of the deuteron, helion, and triton in the framework of chiral effective field theory. The CP-conserving and CP-violating interactions are treated on equal footing and we consider CP-violating one-, two-, and three-nucleon operators up to next-to-leading-order in the chiral power counting. In particular, we calculate for the first time EDM contributions induced by the CP-violating three-pion operator. We find that effects of CP-violating nucleon-nucleon contact interactions are larger than those found in previous studies based on phenomenological models for the CP-conserving nucleon-nucleon interactions. Our results which apply to any model of CP violation in the hadronic sector can be used to test various scenarios of CP violation. As examples, we study the implications of our results on the QCD θ-term and the minimal left-right symmetric model.

Effective field theory, electric dipole moments and electroweak baryogenesis

International Nuclear Information System (INIS)

Balazs, Csaba; White, Graham; Yue, Jason

2017-01-01

Negative searches for permanent electric dipole moments (EDMs) heavily constrain models of baryogenesis utilising various higher dimensional charge and parity violating (CPV) operators. Using effective field theory, we create a model independent connection between these EDM constraints and the baryon asymmetry of the universe (BAU) produced during a strongly first order electroweak phase transition. The thermal aspects of the high scale physics driving the phase transition are paramaterised by the usual kink solution for the bubble wall profile. We find that operators involving derivatives of the Higgs field yield CPV contributions to the BAU containing derivatives of the Higgs vacuum expectation value (vev), while non-derivative operators lack such contributions. Consequently, derivative operators cannot be eliminated in terms of non-derivative operators (via the equations of motion) if one is agnostic to the new physics that leads to the phase transition. Thus, we re-classify the independent dimension six operators, restricting ourselves to third generation quarks, gauge bosons and the Higgs. Finally, we calculate the BAU (as a function of the bubble wall width and the cutoff) for a derivative and a non-derivative operator, and relate it to the EDM constraints.

Effective field theory, electric dipole moments and electroweak baryogenesis

Energy Technology Data Exchange (ETDEWEB)

Balazs, Csaba; White, Graham [ARC Centre of Excellence for Particle Physics at the Terascale School of Physics and Astronomy,Monash University,Victoria 3800 (Australia); Yue, Jason [Department of Physics, National Taiwan Normal University,Taipei 116, Taiwan (China); ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics,The University of Sydney,NSW 2006 (Australia)

2017-03-07

Negative searches for permanent electric dipole moments (EDMs) heavily constrain models of baryogenesis utilising various higher dimensional charge and parity violating (CPV) operators. Using effective field theory, we create a model independent connection between these EDM constraints and the baryon asymmetry of the universe (BAU) produced during a strongly first order electroweak phase transition. The thermal aspects of the high scale physics driving the phase transition are paramaterised by the usual kink solution for the bubble wall profile. We find that operators involving derivatives of the Higgs field yield CPV contributions to the BAU containing derivatives of the Higgs vacuum expectation value (vev), while non-derivative operators lack such contributions. Consequently, derivative operators cannot be eliminated in terms of non-derivative operators (via the equations of motion) if one is agnostic to the new physics that leads to the phase transition. Thus, we re-classify the independent dimension six operators, restricting ourselves to third generation quarks, gauge bosons and the Higgs. Finally, we calculate the BAU (as a function of the bubble wall width and the cutoff) for a derivative and a non-derivative operator, and relate it to the EDM constraints.

Neutral dipole-dipole dimers: A new field in science

Science.gov (United States)

Kosower, Edward M.; Borz, Galina

2018-03-01

Dimer formation with dipole neutralization produces species such as low polarity water (LPW) compatible with hydrophobic surfaces (Phys. Chem. Chem. Phys. 2015, 17, 24895-24900) Dimerization and dipole neutralization occurs for N-methylacetamide on polyethylene, a behavior drastically different from its contortions in acetonitrile on AgBr:AgCl planar crystals (AgX) (ChemPhysChem 2014, 15, 3598-3607). The weak infrared absorption of the amide dimer on polyethylene is shown experimentally. Dimerization of palmitic acid is shown along with some of the many ramifications for intracellular systems. Polyoligomers of water are present on polyethylene surfaces. Some high resolution spectra of three of the polyoligomers of water are shown along with a mechanistic scheme for polyoligomer formation and dissolution. The structures of some of the oligomers are known from spectroscopic studies of water on AgX. The scope of the article begins with PE, generally accepted as hydrophobic. The IR of PE revealed not only that water was present but that it appeared in two forms, oligomers (O) and polyoligomers (PO). How did we recognize what they were? These species had been observed as especially strong "marker" peaks in the spectra1 of water placed on planar AgX, a platform developed by Katzir and his coworkers [6]. But there was a problem: the proximity to PE of oligomers with substantial (calculated) dipole moments and thus polarity, including cyclic hexamers of water (chair and boat forms), the cyclic pentamer, the books I and II, and the cyclic trimer [7a]. Another link was needed, a role perfectly fit by the already cited low polarity water (LPW). The choice was experimentally supported by the detection of low intensity absorption in the bending region.Some important generalities flow from these results. What other dimers might be present in the biological or chemical world? Palmitic acid dimer (PAD) would be a candidate for decreasing the polarity of the acid (PA). Another

Measurement of the b hadron lifetime with the dipole method

Science.gov (United States)

Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Levinthal, D.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Zimmermann, A.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barbeiro, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Sau Lan Wu; Wu, X.; Zheng, M.; Zobernig, G.; Aleph Collaboration

1993-09-01

A measurement of the average lifetime of b hadrons has been performed with dipole method on a sample of 260 000 hadronic Z decays recorded with the ALEPH detector during 1991. The dipole is the distance between the vertices built in the opposite hemispheres. The mean dipole is extracted from all the events without attempting b enrichment. Comparing the average of the data dipole distribution with a Monte Carlo calibration curve obtained with different b lifetimes, an average b hadron lifetime of 1.51±0.08 ps is extracted.

Anisotropic and long-range vortex interactions in two-dimensional dipolar bose gases

NARCIS (Netherlands)

Mulkerin, B.C.; Bijnen, van R.M.W.; O'Dell, D.H.J.; Martin, A.M.; Parker, N.G.

2013-01-01

We perform a theoretical study into how dipole-dipole interactions modify the properties of superfluid vortices within the context of a two-dimensional atomic Bose gas of co-oriented dipoles. The reduced density at a vortex acts like a giant antidipole, changing the density profile and generating an

Calculation of the atomic electric dipole moment of Pb2+ induced by nuclear Schiff moment

Science.gov (United States)

Ramachandran, S. M.; Latha, K. V. P.; Meenakshisundaram, N.

2017-07-01

We report the atomic electric dipole moment induced by the P, T violating interactions in the nuclear/sub-nuclear level, for 207Pb2+ and 207Pb, owing to the recent interest in the ferroelectric crystal PbTiO3 as one of the candidates for investigating macroscopic P, T-odd effects. In this paper, we calculate the atomic electric dipole moments of 207Pb and Pb2+, parametrized in terms of the P, T-odd coupling parameter, the nuclear Schiff moment (NSM), S, in the frame-work of the coupled-perturbed Hartree-Fock theory. We estimate the Schiff moment of Pb2+ using the experimental result of a system, which is electronically similar to the Pb2+ ion. We present the dominant contributions of the electric dipole moment (EDM) matrix elements and the important correlation effects contributing to the atomic EDM of Pb2+. Our results provide the first ever calculated EDM of the Pb2+ ion, and an estimate of its NSM from which the P, T-odd energy shift in a PbTiO3 crystal can be evaluated.

Iron saturation control in RHIC dipole magnets

International Nuclear Information System (INIS)

Thompson, P.A.; Gupta, R.C.; Kahn, S.A.; Hahn, H.; Morgan, G.H.; Wanderer, P.J.; Willen, E.

1991-01-01

The Relativistic Heavy Ion Collider (RHIC) will require 360 dipoles of 80 mm bore. This paper discusses the field perturbations produced by the saturation of the yoke iron. Changes have been made to the yoke to reduce these perturbations, in particular, decapole -4 . Measurements and calculations for 6 series of dipole magnets are presented. 2 refs., 2 figs., 1 tab

Giant dipole resonance by many levels theory

International Nuclear Information System (INIS)

Mondaini, R.P.

1977-01-01

The many levels theory is applied to photonuclear effect, in particular, in giant dipole resonance. A review about photonuclear dipole absorption, comparing with atomic case is done. The derivation of sum rules; their modifications by introduction of the concepts of effective charges and mass and the Siegert theorem. The experimental distributions are compared with results obtained by curve adjustment. (M.C.K.) [pt

Neutron Electric Dipole Moment from colored scalars⋆

Directory of Open Access Journals (Sweden)

Fajfer Svjetlana

2014-01-01

Full Text Available We present new contributions to the neutron electric dipole moment induced by a color octet, weak doublet scalar, accommodated within a modified Minimal Flavor Violating framework. These flavor non-diagonal couplings of the color octet scalar might account for an assymmetry of order 3 × 10−3 for aCP(D0 → K−K+ − aCP(D0 → π+π− at tree level. The same couplings constrained by this assymmetry also induce two-loop contributions to the neutron electric dipole moment. We find that the direct CP violating asymmetry in neutral D-meson decays is more constraining on the allowed parameter space than the current experimental bound on neutron electric dipole moment.

Relaxed electric dipole moments of polar molecules interacting with a slow positron: H{sub 2}O and CH{sub 3}X (X=F, Cl, Br)

Energy Technology Data Exchange (ETDEWEB)

Assafrao, Denise; Mohallem, Jose R, E-mail: rachid@fisica.ufmg.b [Laboratorio de Atomos e Moleculas Especiais, Departamento de FIsica, ICEx, Universidade Federal de Minas Gerais, PO Box 702, 30123-970, Belo Horizonte, MG (Brazil)

2010-08-14

The variation in the electric dipole moments of H{sub 2}O, CH{sub 3}F, CH{sub 3}Cl and CH{sub 3}Br as their geometries relax due to interaction with a positron is evaluated. The results are in good agreement with a recently observed empirical dependence of the positron binding energy on molecular properties (Danielson et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 235203). For binding energies larger than 100 meV relaxation could alter significantly the analysis of the binding, but it is in the prospect of generating effective potentials for positron scattering by molecules that the effect can be more important.

Probing CP Violation with the Deuteron Electric Dipole Moment

CERN Document Server

Lebedev, Oleg; Pospelov, Maxim; Ritz, Adam; Lebedev, Oleg; Olive, Keith A.; Pospelov, Maxim; Ritz, Adam

2004-01-01

We present an analysis of the electric dipole moment (EDM) of the deuteron as induced by CP-violating operators of dimension 4, 5 and 6 including theta QCD, the EDMs and color EDMs of quarks, four-quark interactions and the Weinberg operator. We demonstrate that the precision goal of the EDM Collaboration's proposal to search for the deuteron EDM, (1-3)\\times 10^{-27} e cm, will provide an improvement in sensitivity to these sources of one-two orders of magnitude relative to the existing bounds. We consider in detail the level to which CP-odd phases can be probed within the MSSM.

Study on the dipole moment of asphaltene molecules through dielectric measuring

KAUST Repository

Zhang, Long Li; Yang, Chao He; Wang, Ji Qian; Yang, Guo Hua; Li, Li; Li, Yan Vivian; Cathles, Lawrence

2015-01-01

The polarity of asphaltenes influences production, transportation, and refining of heavy oils. However, the dipole moment of asphaltene molecules is difficult to measure due to their complex composition and electromagnetic opaqueness. In this work, we present a convenient and efficient way to determine the dipole moment of asphaltene in solution by dielectric measurements alone without measurement of the refractive index. The dipole moment of n-heptane asphaltenes of Middle East atmospheric residue (MEAR) and Ta-He atmospheric residue (THAR) are measured within the temperature range of -60°C to 20°C. There is one dielectric loss peak in the measured solutions of the two types of asphaltene at the temperatures of -60°C or -40°C, indicating there is one type of dipole in the solution. Furthermore, there are two dielectric loss peaks in the measured solutions of the two kinds of asphaltene when the temperature rises above -5°C, indicating there are two types of dipoles corresponding to the two peaks. This phenomenon indicates that as the temperature increases above -5°C, the asphaltene molecules aggregate and present larger dipole moment values. The dipole moments of MEAR C7-asphaltene aggregates are up to 5 times larger than those before aggregation. On the other hand, the dipole moments of the THAR C7-asphaltene aggregates are only 3 times larger than those before aggregation. It will be demonstrated that this method is capable of simultaneously measuring multi dipoles in one solution, instead of obtaining only the mean dipole moment. In addition, this method can be used with a wide range of concentrations and temperatures.

Conceptual design of Dipole Research Experiment (DREX)

Science.gov (United States)

Xiao, Qingmei; Wang, Zhibin; Wang, Xiaogang; Xiao, Chijie; Yang, Xiaoyi; Zheng, Jinxing

2017-03-01

A new terrella-like device for laboratory simulation of inner magnetosphere plasmas, Dipole Research Experiment, is scheduled to be built at the Harbin Institute of Technology (HIT), China, as a major state scientific research facility for space physics studies. It is designed to provide a ground experimental platform to reproduce the inner magnetosphere to simulate the processes of trapping, acceleration, and transport of energetic charged particles restrained in a dipole magnetic field configuration. The scaling relation of hydromagnetism between the laboratory plasma of the device and the geomagnetosphere plasma is applied to resemble geospace processes in the Dipole Research Experiment plasma. Multiple plasma sources, different kinds of coils with specific functions, and advanced diagnostics are designed to be equipped in the facility for multi-functions. The motivation, design criteria for the Dipole Research Experiment experiments and the means applied to generate the plasma of desired parameters in the laboratory are also described. Supported by National Natural Science Foundation of China (Nos. 11505040, 11261140326 and 11405038), China Postdoctoral Science Foundation (Nos. 2016M591518, 2015M570283) and Project Supported by Natural Scientific Research Innovation Foundation in Harbin Institute of Technology (No. 2017008).

Critical dynamics of an interacting magnetic nanoparticle system

DEFF Research Database (Denmark)

Hansen, Mikkel Fougt; Jonsson, P.E.; Nordblad, P.

2002-01-01

Effects of dipole-dipole interactions on the magnetic relaxation have been investigated for three Fe-C nanoparticle samples with volume concentrations of 0.06, 5 and 17 vol%. While both the 5 and 17 vol% samples exhibit collective behaviour due to dipolar interactions, only the 17 vol% sample dis...... displays critical behaviour close to its transition temperature. The behaviour of the 5 vol% sample can be attributed to a mixture of collective and single-particle dynamics....

LHC dipoles flood into CERN : the dipole nr 154 crowns the efforts of the LHC teams for increasing the fabrication rate of the magnets.

CERN Multimedia

Maximilien Brice

2003-01-01

On 3 December the "tableau" on the 4th floor in building 30 indicated 1078 dipoles to completion - or in other words, 154 dipoles had by this day been delivered to CERN, enough to complete the first octant of the machine. CERN has also now received enough superconducting cable - the "heart" of the magnets - for 600 dipoles, nearly half the total number of 1232.

Gyre-driven decay of the Earth's magnetic dipole

Science.gov (United States)

Finlay, Christopher C.; Aubert, Julien; Gillet, Nicolas

2016-01-01

Direct observations indicate that the magnitude of the Earth's magnetic axial dipole has decreased over the past 175 years; it is now 9% weaker than it was in 1840. Here we show how the rate of dipole decay may be controlled by a planetary-scale gyre in the liquid metal outer core. The gyre's meridional limbs on average transport normal polarity magnetic flux equatorward and reverse polarity flux poleward. Asymmetry in the geomagnetic field, due to the South Atlantic Anomaly, is essential to the proposed mechanism. We find that meridional flux advection accounts for the majority of the dipole decay since 1840, especially during times of rapid decline, with magnetic diffusion making an almost steady contribution generally of smaller magnitude. Based on the morphology of the present field, and the persistent nature of the gyre, the current episode of dipole decay looks set to continue, at least for the next few decades. PMID:26814368

arXiv Dipole portal to heavy neutral leptons

CERN Document Server

Magill, Gabriel; Pospelov, Maxim; Tsai, Yu-Dai

We consider generic neutrino dipole portals between left-handed neutrinos, photons, and right-handed heavy neutral leptons (HNL) with Dirac masses. The dominance of this portal significantly alters the conventional phenomenology of HNLs. We derive a comprehensive set of constraints on the dipole portal to HNLs by utilizing data from LEP, LHC, MiniBooNE, LSND as well as observations of Supernova 1987A and consistency of the standard Big Bang Nucleosynthesis. We calculate projected sensitivities from the proposed high-intensity SHiP beam dump experiment, and the ongoing experiments at the Short-Baseline Neutrino facility at Fermilab. Dipole mediated Primakoff neutrino upscattering and Dalitz-like meson decays are found to be the main production mechanisms in most of the parametric regime under consideration. Proposed explanations of LSND and MiniBooNE anomalies based on HNLs with dipole-induced decays are found to be severely constrained, or to be tested in the future experiments.

Quantum electric-dipole liquid on a triangular lattice.

Science.gov (United States)

Shen, Shi-Peng; Wu, Jia-Chuan; Song, Jun-Da; Sun, Xue-Feng; Yang, Yi-Feng; Chai, Yi-Sheng; Shang, Da-Shan; Wang, Shou-Guo; Scott, James F; Sun, Young

2016-02-04

Geometric frustration and quantum fluctuations may prohibit the formation of long-range ordering even at the lowest temperature, and therefore liquid-like ground states could be expected. A good example is the quantum spin liquid in frustrated magnets. Geometric frustration and quantum fluctuations can happen beyond magnetic systems. Here we propose that quantum electric-dipole liquids, analogues of quantum spin liquids, could emerge in frustrated dielectrics where antiferroelectrically coupled electric dipoles reside on a triangular lattice. The quantum paraelectric hexaferrite BaFe12O19 with geometric frustration represents a promising candidate for the proposed electric-dipole liquid. We present a series of experimental lines of evidence, including dielectric permittivity, heat capacity and thermal conductivity measured down to 66 mK, to reveal the existence of an unusual liquid-like quantum phase in BaFe12O19, characterized by itinerant low-energy excitations with a small gap. The possible quantum liquids of electric dipoles in frustrated dielectrics open up a fresh playground for fundamental physics.

Hyperfine-mediated static polarizabilities of monovalent atoms and ions

International Nuclear Information System (INIS)

Dzuba, V. A.; Flambaum, V. V.; Beloy, K.; Derevianko, A.

2010-01-01

We apply relativistic many-body methods to compute static differential polarizabilities for transitions inside the ground-state hyperfine manifolds of monovalent atoms and ions. Knowledge of this transition polarizability is required in a number of high-precision experiments, such as microwave atomic clocks and searches for CP-violating permanent electric dipole moments. While the traditional polarizability arises in the second order of interaction with the externally applied electric field, the differential polarizability involves an additional contribution from the hyperfine interaction of atomic electrons with nuclear moments. We derive formulas for the scalar and tensor polarizabilities including contributions from magnetic dipole and electric quadrupole hyperfine interactions. Numerical results are presented for Al, Rb, Cs, Yb + , Hg + , and Fr.

Dipole strength distributions from HIGS Experiments

Directory of Open Access Journals (Sweden)

Werner V.

2015-01-01

76Ge and 76Se, in order to investigate their dipole response up to the neutron separation threshold. Gamma-ray beams from bremsstrahlung at the S-DALINAC and from Compton-backscattering at HIGS have been used to measure absolute cross sections and parities of dipole excited states, respectively. The HIGS data allows for indirect measurement of averaged branching ratios, which leads to significant corrections in the observed excitation cross sections. Results are compared to statistical calculations, to test photon strength functions and the Axel-Brink hypothesis

Rabi Oscillations between Ground and Rydberg States with Dipole-Dipole Atomic Interactions

International Nuclear Information System (INIS)

Johnson, T. A.; Urban, E.; Henage, T.; Isenhower, L.; Yavuz, D. D.; Walker, T. G.; Saffman, M.

2008-01-01

We demonstrate Rabi oscillations of small numbers of 87 Rb atoms between ground and Rydberg states with n≤43. Coherent population oscillations are observed for single atoms, while the presence of two or more atoms decoheres the oscillations. We show that these observations are consistent with van der Waals interactions of Rydberg atoms

Pressure profiles of plasmas confined in the field of a magnetic dipole

International Nuclear Information System (INIS)

Davis, Matthew S; Mauel, M E; Garnier, Darren T; Kesner, Jay

2014-01-01

Equilibrium pressure profiles of plasmas confined in the field of a dipole magnet are reconstructed using magnetic and x-ray measurements on the levitated dipole experiment (LDX). LDX operates in two distinct modes: with the dipole mechanically supported and with the dipole magnetically levitated. When the dipole is mechanically supported, thermal particles are lost along the field to the supports, and the plasma pressure is highly peaked and consists of energetic, mirror-trapped electrons that are created by electron cyclotron resonance heating. By contrast, when the dipole is magnetically levitated losses to the supports are eliminated and particles are lost via slower cross-field transport that results in broader, but still peaked, plasma pressure profiles. (paper)

Lattice calculation of electric dipole moments and form factors of the nucleon

Science.gov (United States)

Abramczyk, M.; Aoki, S.; Blum, T.; Izubuchi, T.; Ohki, H.; Syritsyn, S.

2017-07-01

We analyze commonly used expressions for computing the nucleon electric dipole form factors (EDFF) F3 and moments (EDM) on a lattice and find that they lead to spurious contributions from the Pauli form factor F2 due to inadequate definition of these form factors when parity mixing of lattice nucleon fields is involved. Using chirally symmetric domain wall fermions, we calculate the proton and the neutron EDFF induced by the C P -violating quark chromo-EDM interaction using the corrected expression. In addition, we calculate the electric dipole moment of the neutron using a background electric field that respects time translation invariance and boundary conditions, and we find that it decidedly agrees with the new formula but not the old formula for F3. Finally, we analyze some selected lattice results for the nucleon EDM and observe that after the correction is applied, they either agree with zero or are substantially reduced in magnitude, thus reconciling their difference from phenomenological estimates of the nucleon EDM.

Installation Strategy for the LHC Main Dipoles

CERN Multimedia

Fartoukh, Stephane David

2004-01-01

All positions in the LHC machine are not equivalent in terms of beam requirements on the geometry and the field quality of the main dipoles. In the presence of slightly or strongly out-of tolerance magnets, a well-defined installation strategy will therefore contribute to preserve or even optimize the performance of the machine. Based on the present status of the production, we have anticipated a list of potential issues (geometry, transfer function, field direction and random b3) which, combined by order of priority, have been taken into account to define a simple but efficient installation algorithm for the LHC main dipoles. Its output is a prescription for installing the available dipoles in sequence while reducing to an absolute minimum the number of holes required by geometry or FQ issues.

The permanent process

DEFF Research Database (Denmark)

Møller, Jesper; McCullagh, Peter

We extend the boson process first to a large class of Cox processes and second an even larger class of infinitely divisible point processes. Density and moment results are studied in detail. These results are obtained in closed form as weighted permanents, so the extension is called a permanent...... process. Temporal extensions and a particularly tractable case of the permanent process are also studied. Extensions of the ferminon process along similar lines, leading to so-called determinant processes, are discussed at the end. While the permanent process is attractive, the determinant process...

Effects of gastrointestinal tissue structure on computed dipole vectors

Directory of Open Access Journals (Sweden)

Pullan Andrew J

2007-10-01

Full Text Available Abstract Background Digestive diseases are difficult to assess without using invasive measurements. Non-invasive measurements of body surface electrical and magnetic activity resulting from underlying gastro-intestinal activity are not widely used, in large due to their difficulty in interpretation. Mathematical modelling of the underlying processes may help provide additional information. When modelling myoelectrical activity, it is common for the electrical field to be represented by equivalent dipole sources. The gastrointestinal system is comprised of alternating layers of smooth muscle (SM cells and Interstitial Cells of Cajal (ICC. In addition the small intestine has regions of high curvature as the intestine bends back upon itself. To eventually use modelling diagnostically, we must improve our understanding of the effect that intestinal structure has on dipole vector behaviour. Methods Normal intestine electrical behaviour was simulated on simple geometries using a monodomain formulation. The myoelectrical fields were then represented by their dipole vectors and an examination on the effect of structure was undertaken. The 3D intestine model was compared to a more computationally efficient 1D representation to determine the differences on the resultant dipole vectors. In addition, the conductivity values and the thickness of the different muscle layers were varied in the 3D model and the effects on the dipole vectors were investigated. Results The dipole vector orientations were largely affected by the curvature and by a transmural gradient in the electrical wavefront caused by the different properties of the SM and ICC layers. This gradient caused the dipoles to be oriented at an angle to the principal direction of electrical propagation. This angle increased when the ratio of the longitudinal and circular muscle was increased or when the the conductivity along and across the layers was increased. The 1D model was able to represent the

Effect of the repulsive force in the HTSC-permanent magnet hybrid bearing system

International Nuclear Information System (INIS)

Ohashi, S.; Kobayashi, S.

2009-01-01

Magnetic levitation using the pinning force of the YBaCuO high-T c bulk superconductor (HTSC) materials has an advantage to achieve stable levitation without control. To increase levitation force, the HTSC-permanent magnet hybrid magnetic bearing system is introduced. A circular shaped three phase Nd-Fe-B permanent magnet is installed on the rotor, and HTSC bulk superconductor is set on the stator. The additional permanent magnet is installed under the HTSC. Repulsive force of the permanent magnet is used for levitation, and pinning force between the HTSC and permanent magnet is used for guidance force of the bearing. In this system, relationship between permanent magnet and the HTSC is important. When repulsive force of the permanent magnet is large, pinning force of superconductor is used to keep the rotor position. As a result, stability for the lateral direction is decreased with hybrid system. For levitation force, effect of the hybrid system is not observed with column HTSC. Compared with the ring HTSC results, the following thing is considered. Because there is no space that flux of one permanent magnet acts on the other one with the column HTSC configuration, interaction between two permanent magnets becomes small.

Laser-induced interactions

International Nuclear Information System (INIS)

Green, W.R.

1979-01-01

This dissertation discusses some of the new ways that lasers can be used to control the energy flow in a medium. Experimental and theoretical considerations of the laser-induced collision are discussed. The laser-induced collision is a process in which a laser is used to selectively transfer energy from a state in one atomic or molecular species to another state in a different species. The first experimental demonstration of this process is described, along with later experiments in which lasers were used to create collisional cross sections as large as 10 - 13 cm 2 . Laser-induced collisions utilizing both a dipole-dipole interaction and dipole-quadrupole interaction have been experimentally demonstrated. The theoretical aspects of other related processes such as laser-induced spin-exchange, collision induced Raman emission, and laser-induced charge transfer are discussed. Experimental systems that could be used to demonstrate these various processes are presented. An experiment which produced an inversion of the resonance line of an ion by optical pumping of the neutral atom is described. This type of scheme has been proposed as a possible method for constructing VUV and x-ray lasers

Hadron production at LHC in dipole momentum space

Energy Technology Data Exchange (ETDEWEB)

Basso, E. A.; Gay Ducati, M. B. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970 - Porto Alegre, RS (Brazil); De Oliveira, E. G. [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05314-970 Sao Paulo, SP (Brazil)

2013-03-25

The dipole color approach is the framework that considers the quark-antiquark pair scattering off the target. The rapidity evolution of color dipoles is given by the nonlinear Balitsky-Kovchegov (BK) equation, for which analytical solutions are not yet known. A good way to explore the asymptotic BK solutions is through the traveling wave method of QCD, that uses a correspondence between the BK evolution equation in momentum space and reaction-diffusion physics. Using the traveling wave based AGBS model for the dipole amplitude in momentum space, and within the k{sub t}-factorization formalism, we describe the LHC data on single inclusive hadron yield for p-p collisions.

Hadron production at LHC in dipole momentum space

International Nuclear Information System (INIS)

Basso, E. A.; Gay Ducati, M. B.; De Oliveira, E. G.

2013-01-01

The dipole color approach is the framework that considers the quark-antiquark pair scattering off the target. The rapidity evolution of color dipoles is given by the nonlinear Balitsky-Kovchegov (BK) equation, for which analytical solutions are not yet known. A good way to explore the asymptotic BK solutions is through the traveling wave method of QCD, that uses a correspondence between the BK evolution equation in momentum space and reaction-diffusion physics. Using the traveling wave based AGBS model for the dipole amplitude in momentum space, and within the k t -factorization formalism, we describe the LHC data on single inclusive hadron yield for p–p collisions.

Search for electric dipole moments in storage rings

Directory of Open Access Journals (Sweden)

Lenisa Paolo

2016-01-01

Full Text Available The JEDI collaboration aims at making use of storage ring to provide the most precise measurement of the electric dipole moments of hadrons. The method makes exploits a longitudinal polarized beam. The existence an electric dipole moment would generate a torque slowly twisting the particle spin out of plan of the storage ring into the vertical direction. The observation of non zero electric dipole moment would represent a clear sign of new physics beyond the Standard Model. Feasiblity tests are presently undergoing at the COSY storage ring Forschungszentrum Jülich (Germany, to develop the novel techniques to be implemented in a future dedicated storage ring.

Spontaneous transition rates for electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions for He-like calcium and sulfur ions

International Nuclear Information System (INIS)

Kingston, A.E.; Norrington, P.H.; Boone, A.W.

2002-01-01

The spontaneous decay rates for the electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1) and magnetic quadrupole (M2) transitions between all of the 1s 2 , 1s2 l and 1s3 l states have been obtained for helium-like calcium and sulfur ions. To assess the accuracy of the calculations, the transition probabilities were calculated using two sets of configuration interaction wavefunctions. One set of wavefunctions was generated using the fully relativistic GRASP code and the other was obtained using CIV3, in which relativistic effects are introduced using the Breit-Pauli approximation. The transition rates, A values, oscillator strengths and line strengths from our two calculations are found to be similar and to compare very well with other recent results for Δn=1 or 2 transitions. For Δn=0 transitions the agreement is much less good; this is mainly due to differences in the calculated excitation energies. (author)

Broadband electromagnetic dipole scattering by coupled multiple nanospheres

Science.gov (United States)

Jing, Xufeng; Ye, Qiufeng; Hong, Zhi; Zhu, Dongshuo; Shi, Guohua

2017-11-01

With the development of nanotechnology, the ability to manipulate light at the nanoscale is critical to future optical functional devices. The use of high refractive index dielectric single silicon nanoparticle can achieve electromagnetic dipole resonant properties. Compared with single nanosphere, the use of dimer and trimer introduces an additional dimension (gap size) for improving the performance of dielectric optical devices through the coupling between closely connected silicon nanospheres. When changing the gap size between the nanospheres, the interaction between the particles can be from weak to strong. Compared with single nanospheres, dimerized or trimeric nanospheres exhibit more pronounced broadband scattering properties. In addition, by introducing more complex interaction, the trimericed silicon nanospheres exhibit a more significant increase in bandwidth than expected. In addition, the presence of the substrate will also contribute to the increase in the bandwidth of the nanospheres. The broadband response in dielectric nanostructures can be effectively applied to broadband applications such as dielectric nanoantennas or solar cells.

Effect of grain boundary phase on the magnetization reversal process of nanocrystalline magnet using large-scale micromagnetic simulation

Directory of Open Access Journals (Sweden)

Hiroshi Tsukahara

2018-05-01

Full Text Available We investigated the effects of grain boundary phases on magnetization reversal in permanent magnets by performing large-scale micromagnetic simulations based on Landau–Lifshitz–Gilbert equation under a periodic boundary. We considered planar grain boundary phases parallel and perpendicular to an easy axis of the permanent magnet and assumed the saturation magnetization and exchange stiffness constant of the grain boundary phase to be 10% and 1%, respectively, for Nd2Fe14B grains. The grain boundary phase parallel to the easy axis effectively inhibits propagation of magnetization reversal. In contrast, the domain wall moves across the grain boundary perpendicular to the easy axis. These properties of the domain wall motion are explained by dipole interaction, which stabilizes the antiparallel magnetic configuration in the direction perpendicular to the magnetization orientation. On the other hand, the magnetization is aligned in the same direction by the dipole interaction parallel to the magnetization orientation. This anisotropy of the effect of the grain boundary phase shows that improvement of the grain boundary phase perpendicular to the easy axis effectively enhances the coercivity of permanent magnets.

Ion solvation in polymer blends and block copolymer melts: effects of chain length and connectivity on the reorganization of dipoles.

Science.gov (United States)

Nakamura, Issei

2014-05-29

We studied the thermodynamic properties of ion solvation in polymer blends and block copolymer melts and developed a dipolar self-consistent field theory for polymer mixtures. Our theory accounts for the chain connectivity of polymerized monomers, the compressibility of the liquid mixtures under electrostriction, the permanent and induced dipole moments of monomers, and the resultant dielectric contrast among species. In our coarse-grained model, dipoles are attached to the monomers and allowed to rotate freely in response to electrostatic fields. We demonstrate that a strong electrostatic field near an ion reorganizes dipolar monomers, resulting in nonmonotonic changes in the volume fraction profile and the dielectric function of the polymers with respect to those of simple liquid mixtures. For the parameter sets used, the spatial variations near an ion can be in the range of 1 nm or larger, producing significant differences in the solvation energy among simple liquid mixtures, polymer blends, and block copolymers. The solvation energy of an ion depends substantially on the chain length in block copolymers; thus, our theory predicts the preferential solvation of ions arising from differences in chain length.

Analysis and design of short, iron-free dipole magnets

International Nuclear Information System (INIS)

Harvey, A.R.

1981-01-01

Iron-free, dipole magnets are used extensively as steering magnets to correct for the bending, induced by extraneous magnetic fields, of particle beams that are being transported in vacuum. Generally, the dipoles are long enough that the space occupied by the end conductors is small compared to the overall magnet length. In a recent application, however, this criteria did not apply. This has motivated a reanalysis of the characteristics of a system of small aspect ratio (length/diameter) dipoles that are spaced at relatively large axial distances

Using the DDA (Discrete Dipole Approximation Method in Determining the Extinction Cross Section of Black Carbon

Directory of Open Access Journals (Sweden)

Skorupski Krzysztof

2015-03-01

Full Text Available BC (Black Carbon, which can be found in the atmosphere, is characterized by a large value of the imaginary part of the complex refractive index and, therefore, might have an impact on the global warming effect. To study the interaction of BC with light often computer simulations are used. One of the methods, which are capable of performing light scattering simulations by any shape, is DDA (Discrete Dipole Approximation. In this work its accuracy was estimated in respect to BC structures using the latest stable version of the ADDA (vr. 1.2 algorithm. As the reference algorithm the GMM (Generalized Multiparticle Mie-Solution code was used. The study shows that the number of volume elements (dipoles is the main parameter that defines the quality of results. However, they can be improved by a proper polarizability expression. The most accurate, and least time consuming, simulations were observed for IGT_SO. When an aggregate consists of particles composed of ca. 750 volume elements (dipoles, the averaged relative extinction error should not exceed ca. 4.5%.

The electromagnetic design of a permanent magnet based separator

International Nuclear Information System (INIS)

Nedelcu, S.

2002-08-01

The aim of this work was to design a permanent magnet based device that can selectively transport paramagnetic particles. Using specialised electromagnetic design software various arrangements of permanent magnets have been investigated. Each test geometry had to be constructively simple and able to produce highly non-uniform magnetic fields before being considered further in any more detail. The main parameter to indicate that the test geometry might be a suitable device has been ascribed to the ratio η between the highest (ON) and lowest (OFF) magnetic fields that were measured. A linear arrangement of permanent magnets has been considered first. This device produced a ratio η ∼ 2. Further, the cylindrical and the tubular arrangements may be considered as substantial improvements over the first geometry. The OFF magnetic fields have been substantially reduced by the method of magnetic shielding. Intensive research and modelling has been spent on addressing the problem of finding the optimal geometry for such arrangements. An experimental system has been also built, and the experimental values were compared against the theory. However, the results produced evidence that the manufacturing of any improved geometry (an estimated η ∼ 100) in this direction might be very difficult, for the tolerances involved were very strict. The disk arrangement was the latest device to be investigated. Particularly, a magnetic dipole model developed earlier for the ring arrangement suggested the way in which to arrange the magnets in the ON position. Moreover, the use of the magnetic symmetry of the device forced the OFF magnetic fields to negligible values. Detailed computer simulations of the dynamics of the particles in the applied magnetic field of the tubular and disk arrangements have been earned out. The adopted models could show realistic phenomena, e.g. particle clustering, chaining, block movement, etc. The separation efficiency proved to be nearly 100%. For the

Dipole-Oriented Molecular Solids Can Undergo a Phase Change and Still Maintain Electrical Polarization

Energy Technology Data Exchange (ETDEWEB)

Glavic, Artur G [ORNL; Cassidy, Andrew M [ORNL; Jorgensen, Mads Ry Ry [University of Aarhus, Denmark; Lauter, Valeria [ORNL; Rosu-Finsen, Alexander [Heriot-Watt University, Edinburgh, UK; Lasne, Jérôme [Heriot-Watt University, Edinburgh, UK; Jorgensen, Jakob [Aarhus University, Denmark; Iversen, Bo [ORNL; McCoustra, Martin [Heriot-Watt University, Edinburgh, UK; Field, David [University of Aarhus, Denmark

2016-10-02

It has recently been demonstrated that nanoscale molecular films can spontaneously assemble to self-generate intrinsic electric fields that can exceed 10⁸ V/m. These electric fields originate from polarization charges in the material that arise because the films self-assemble to orient molecular dipole moments. This has been called the spontelectric effect. Such growth of spontaneously polarized layers of molecular solids has implications for our understanding of how intermolecular interactions dictate the structure of molecular materials used in a range of applications, for example, molecular semiconductors, sensors, and catalysts. In this paper, we present the first in situ structural characterization of a representative spontelectric solid, nitrous oxide. Infrared spectroscopy, temperature-programmed desorption, and neutron reflectivity measurements demonstrate that polarized films of nitrous oxide undergo a structural phase transformation upon heating above 48 K. A mean-field model can be used to describe quantitatively the magnitude of the spontaneously generated field as a function of film-growth temperature, and this model also recreates the phase change. Finally, this reinforces the spontelectric model as a means of describing long-range dipole–dipole interactions and points to a new type of ordering in molecular thin films.

Forced flow cooling of ISABELLE dipole magnets

International Nuclear Information System (INIS)

Bamberger, J.A.; Aggus, J.; Brown, D.P.; Kassner, D.A.; Sondericker, J.H.; Strobridge, T.R.

1976-01-01

The superconducting magnets for ISABELLE will use a forced flow supercritical helium cooling system. In order to evaluate this cooling scheme, two individual dipole magnets were first tested in conventional dewars using pool boiling helium. These magnets were then modified for forced flow cooling and retested with the identical magnet coils. The first evaluation test used a l m-long ISA model dipole magnet whose pool boiling performance had been established. The same magnet was then retested with forced flow cooling, energizing it at various operating temperatures until quench occurred. The magnet performance with forced flow cooling was consistent with data from the previous pool boiling tests. The next step in the program was a full-scale ISABELLE dipole ring magnet, 4.25 m long, whose performance was first evaluated with pool boiling. For the forced flow test the magnet was shrunk-fit into an unsplit laminated core encased in a stainless steel cylinder. The high pressure gas is cooled below 4 K by a helium bath which is pumped below atmospheric pressure with an ejector nozzle. The performance of the full-scale dipole magnet in the new configuration with forced flow cooling, showed a 10 percent increase in the attainable maximum current as compared to the pool boiling data

Magnetic guns with cylindrical permanent magnets

Czech Academy of Sciences Publication Activity Database

Vokoun, David; Beleggia, M.; Heller, Luděk

2012-01-01

Roč. 324, č. 9 (2012), s. 1715-1719 ISSN 0304-8853 R&D Projects: GA ČR(CZ) GAP107/11/0391; GA AV ČR IAA100100920 Institutional research plan: CEZ:AV0Z10100520 Keywords : permanent magnet * cylindrical magnet * Earnshaw's theorem * magnetic gun * magnetostatic interaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.826, year: 2012 http://www.sciencedirect.com/science/article/pii/S0304885311008997

Hyperpolarizabilities for the one-dimensional infinite single-electron periodic systems: I. Analytical solutions under dipole-dipole correlations

OpenAIRE

Jiang, Shidong; Xu, Minzhong

2005-01-01

The analytical solutions for the general-four-wave-mixing hyperpolarizabilities $\\chi^{(3)}(-(w_1+w_2+w_3);w_1,w_2,w_3)$ on infinite chains under both Su-Shrieffer-Heeger and Takayama-Lin-Liu-Maki models of trans-polyacetylene are obtained through the scheme of dipole-dipole correlation. Analytical expressions of DC Kerr effect $\\chi^{(3)}(-w;0,0,w)$, DC-induced second harmonic generation $\\chi^{(3)}(-2w;0,w,w)$, optical Kerr effect $\\chi^{(3)}(-w;w,-w,w)$ and DC-electric-field-induced optica...

Transportation studies: 40-MM collider dipole magnets

International Nuclear Information System (INIS)

Daly, E.

1992-01-01

Several fully functional 40-mm Collider Dipole Magnets (CDM) were instrumented with accelerometers to monitor shock and vibration loads during transport. The magnets were measured with optical tooling telescopes before and after transport. Changes in mechanical alignment due to shipping and handling were determined. The mechanical stability of the cryogen lines were checked using the same method. Field quality and dipole angle were measured warm before and after transport to determine changes in these parameters. Power spectra were calculated for accelerometers located on the cold mass, vacuum vessel, and trailer bed. Where available, plots of field quality and dipole roll both before and after were created. Shipping loads measured were largest in the vertical direction, where most of the structural deformation of the magnet was evident. It was not clear that magnetic performance was affected by the shipping and handling environment

Parallel-fed planar dipole antenna arrays for low-observable platforms

CERN Document Server

Singh, Hema; Jha, Rakesh Mohan

2016-01-01

This book focuses on determination of scattering of parallel-fed planar dipole arrays in terms of reflection and transmission coefficients at different levels of the array system. In aerospace vehicles, the phased arrays are often in planar configuration. The radar cross section (RCS) of the vehicle is mainly due to its structure and the antennas mounted over it. There can be situation when the signatures due to antennas dominate over the structural RCS of the platform. This necessitates the study towards the reduction and control of antenna/ array RCS. The planar dipole array is considered as a stacked linear dipole array. A systematic, step-by-step approach is used to determine the RCS pattern including the finite dimensions of dipole antenna elements. The mutual impedance between the dipole elements for planar configuration is determined. The scattering till second-level of couplers in parallel feed network is taken into account. The phase shifters are modelled as delay line. All the couplers in the feed n...

Systematics of the electric dipole response in stable tin isotopes

Science.gov (United States)

Bassauer, Sergej; von Neumann-Cosel, Peter; Tamii, Atsushi

2018-05-01

The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP), Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

Systematics of the electric dipole response in stable tin isotopes

Directory of Open Access Journals (Sweden)

Bassauer Sergej

2018-01-01

Full Text Available The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP, Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

Enhanced terahertz magnetic dipole response by subwavelength fiber

Directory of Open Access Journals (Sweden)

Shaghik Atakaramians

2018-05-01

Full Text Available Dielectric sub-wavelength particles have opened up a new platform for realization of magnetic light. Recently, we have demonstrated that a dipole emitter by a sub-wavelength fiber leads to an enhanced magnetic response. Here, we experimentally demonstrate an enhanced magnetic dipole source in the terahertz frequency range. By placing the fiber next to the hole in a metal screen, we find that the radiation power can be enhanced more than one order of magnitude. The enhancement is due to the excitation of the Mie-type resonances in the fiber. We demonstrate that such a system is equivalent to a double-fiber system excited by a magnetic source. This coupled magnetic dipole and optical fiber system can be considered a unit cell of metasurfaces for manipulation of terahertz radiation and is a proof-of-concept of a possibility to achieve enhanced radiation of a dipole source in proximity of a sub-wavelength fiber. It can also be scaled down to optical frequencies opening up promising avenues for developing integrated nanophotonic devices such as nanoantennas or lasers on fibers.

Collectivity of dipole bands in {sup 196}Pb

Energy Technology Data Exchange (ETDEWEB)

Carpenter, M.P.; Liang, Y.; Janssens, R.V.F. [and others

1995-08-01

The region of nuclei with mass {approximately} 190 was studied extensively over the last few years following the discovery of superdeformation in {sup 190}Hg. More recently, considerable interest in the neutron-deficient Pb isotopes developed with the discover of a number of bands at high spin connected by dipole transitions in both even {sup 192-200}Pb and odd {sup 197-201}Pb nuclei. The majority of the dipole bands are regular in character (i.e. transition energies increase smoothly with spin) while the remaining bands are referred to as irregular in character, due to the fact that the transition energies do not increase smoothly with spin. The properties of the dipole bands were interpreted in terms of high-K, moderately-deformed oblate states built on configurations involving high-J, shape-driving quasiproton excitations coupled to rotation-aligned quasineutrons. It was suggested that the difference between the regular and irregular dipole sequences is related to the deformation where the irregular sequences are thought to be less collective than their regular counterparts.

Transmission of electric dipole radiation through an interface

Energy Technology Data Exchange (ETDEWEB)

Arnoldus, Henk F., E-mail: hfa1@msstate.edu [Department of Physics and Astronomy, Mississippi State University, P.O. Drawer 5167, Mississippi State, MS 39762-5167 (United States); Berg, Matthew J., E-mail: matt.berg@msstate.edu [Department of Physics and Astronomy, Mississippi State University, P.O. Drawer 5167, Mississippi State, MS 39762-5167 (United States); Li, Xin, E-mail: Xin.Li@millersville.edu [Department of Physics, P.O. Box 1002, Millersville University, Millersville, PA 17551 (United States)

2014-02-07

We consider the transmission of electric dipole radiation through an interface between two dielectrics, for the case of a vertical dipole. Energy flows along the field lines of the Poynting vector, and in the optical near field these field lines are curves (as opposed to optical rays). When the radiation passes through the interface into a thicker medium, the field lines bend to the normal (as rays do), but the transmission angle is not related to the angle of incidence. The redirection of the radiation at the interface is determined by the angle dependence of the transmission coefficient. This near-field redistribution is responsible for the far-field angular power pattern. When the transmission medium is thinner than the embedding medium of the dipole, some energy flows back and forth through the interface in an oscillating fashion. In each area where field lines dip below the interface, an optical vortex appears just above the interface. The centers of these vortices are concentric singular circles around the dipole axis.

Analyzing the Anomalous Dipole Moment Type Couplings of Heavy Quarks with FCNC Interactions at the CLIC

International Nuclear Information System (INIS)

Senol, A.; Tasci, A. T.; Verep, C.

2014-01-01

We examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant standard model decay modes at the compact linear collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities for 3σ observation limit

Polarized electric dipole moment of well-deformed reflection asymmetric nuclei

International Nuclear Information System (INIS)

Denisov, V.Yu.

2012-01-01

The expression for polarized electric dipole moment of well-deformed reflection asymmetric nuclei is obtained in the framework of liquid-drop model in the case of geometrically similar proton and neutron surfaces. The expression for polarized electric dipole moment consists of the first and second orders terms. It is shown that the second-order correction terms of the polarized electric dipole moment are important for well-deformed nuclei

Strong CP violation and the neutron electric dipole form factor

International Nuclear Information System (INIS)

Kuckei, J.; Dib, C.; Faessler, A.; Gutsche, T.; Kovalenko, S. G.; Lyubovitskij, V. E.; Pumsa-ard, K.

2007-01-01

We calculate the neutron electric dipole form factor induced by the CP-violating θ term of QCD within a perturbative chiral quark model which includes pion and kaon clouds. On this basis, we derive the neutron electric dipole moment and the electron-neutron Schiff moment. From the existing experimental upper limits on the neutron electric dipole moment, we extract constraints on the θ parameter and compare our results with other approaches

A differential dielectric spectroscopy setup to measure the electric dipole moment and net charge of colloidal quantum dots.

Science.gov (United States)

Kortschot, R J; Bakelaar, I A; Erné, B H; Kuipers, B W M

2014-03-01

A sensitive dielectric spectroscopy setup is built to measure the response of nanoparticles dispersed in a liquid to an alternating electric field over a frequency range from 10(-2) to 10(7) Hz. The measured complex permittivity spectrum records both the rotational dynamics due to a permanent electric dipole moment and the translational dynamics due to net charges. The setup consists of a half-transparent capacitor connected in a bridge circuit, which is balanced on pure solvent only, using a software-controlled compensating voltage. In this way, the measured signal is dominated by the contributions of the nanoparticles rather than by the solvent. We demonstrate the performance of the setup with measurements on a dispersion of colloidal CdSe quantum dots in the apolar liquid decalin.

Avoiding bias effects in NMR experiments for heteronuclear dipole-dipole coupling determinations: principles and application to organic semiconductor materials.

Science.gov (United States)

Kurz, Ricardo; Cobo, Marcio Fernando; de Azevedo, Eduardo Ribeiro; Sommer, Michael; Wicklein, André; Thelakkat, Mukundan; Hempel, Günter; Saalwächter, Kay

2013-09-16

Carbon-proton dipole-dipole couplings between bonded atoms represent a popular probe of molecular dynamics in soft materials or biomolecules. Their site-resolved determination, for example, by using the popular DIPSHIFT experiment, can be challenged by spectral overlap with nonbonded carbon atoms. The problem can be solved by using very short cross-polarization (CP) contact times, however, the measured modulation curves then deviate strongly from the theoretically predicted shape, which is caused by the dependence of the CP efficiency on the orientation of the CH vector, leading to an anisotropic magnetization distribution even for isotropic samples. Herein, we present a detailed demonstration and explanation of this problem, as well as providing a solution. We combine DIPSHIFT experiments with the rotor-directed exchange of orientations (RODEO) method, and modifications of it, to redistribute the magnetization and obtain undistorted modulation curves. Our strategy is general in that it can also be applied to other types of experiments for heteronuclear dipole-dipole coupling determinations that rely on dipolar polarization transfer. It is demonstrated with perylene-bisimide-based organic semiconductor materials, as an example, in which measurements of dynamic order parameters reveal correlations of the molecular dynamics with the phase structure and functional properties. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pulse interactions in a quantum dot waveguide in the regime of electromagnetically Induced transparency

DEFF Research Database (Denmark)

Nielsen, Per; Nielsen, Henri; Mørk, Jesper

2006-01-01

The interaction of optical pulses in a quantum dot waveguide in the slow-light regime is investigated. Dipole oscillations lead to strong interactions between the two pulses, implying a minimum pulse separation for optical buffer applications.......The interaction of optical pulses in a quantum dot waveguide in the slow-light regime is investigated. Dipole oscillations lead to strong interactions between the two pulses, implying a minimum pulse separation for optical buffer applications....

Communication: Theoretical study of ThO for the electron electric dipole moment search

Energy Technology Data Exchange (ETDEWEB)

Skripnikov, L. V., E-mail: leonidos239@gmail.com; Petrov, A. N.; Titov, A. V. [Federal State Budgetary Institute “Petersburg Nuclear Physics Institute,” Gatchina, Leningrad district 188300 (Russian Federation); Department of Physics, Saint Petersburg State University, Saint Petersburg, Petrodvoretz 198904 (Russian Federation)

2013-12-14

An experiment to search for the electron electric dipole moment (eEDM) on the metastable H{sup 3}Δ{sub 1} state of ThO molecule was proposed and now prepared by the ACME Collaboration [ http://www.electronedm.org ]. To interpret the experiment in terms of eEDM and dimensionless constant k{sub T,} {sub P} characterizing the strength of the T,P-odd pseudoscalar–scalar electron–nucleus neutral current interaction, an accurate theoretical study of an effective electric field on electron, E{sub eff}, and a parameter of the T,P-odd pseudoscalar–scalar interaction, W{sub T,} {sub P}, in ThO is required. We report our results for E{sub eff} (84 GV/cm) and W{sub T,} {sub P} (116 kHz) together with the hyperfine structure constant, molecule frame dipole moment, and H{sup 3}Δ{sub 1} → X{sup 1}Σ{sup +} transition energy, which can serve as a measure of reliability of the obtained E{sub eff} and W{sub T,} {sub P} values. Besides, our results include a parity assignment and evaluation of the electric-field dependence for the magnetic g factors in the Ω-doublets of H{sup 3}Δ{sub 1}.

Quantum calculation of dipole excitation in fusion reaction

International Nuclear Information System (INIS)

Simenel, C.; Chomaz, Ph.; De France, G.

2000-01-01

The excitation of the giant dipole resonance by fusion is studied with N/Z asymmetry in the entrance channel. The TDHF solution exhibits a strong dipole vibration which can be associated with a giant vibration along the main axis of a fluctuating prolate shape. The consequences on the gamma-ray emission from hot compound nuclei are discussed. (author)

Interaction mechanism for energy transfer from Ce to Tb ions in silica

International Nuclear Information System (INIS)

Seed Ahmed, H.A.A.; Chae, W.S.; Ntwaeaborwa, O.M.; Kroon, R.E.

2016-01-01

Energy transfer phenomena can play an important role in the development of luminescent materials. In this study, numerical simulations based on theoretical models of non-radiative energy transfer are compared to experimental results for Ce, Tb co-doped silica. Energy transfer from the donor (Ce) to the acceptor (Tb) resulted in a decrease in the Ce luminescence intensity and lifetime. The decrease in intensity corresponded best with the energy transfer models based on the exchange interaction and the dipole-dipole interaction. The critical transfer distance obtained from the fitting using both these models is around 2 nm. Since the exchange interaction requires a distance shorter than 1 nm to occur, the mechanism most likely to account for the energy transfer is concluded to be the dipole–dipole interaction. This is supported by an analysis of the lifetime data.

Field quality issues in iron-dominated dipoles at low fields

International Nuclear Information System (INIS)

Brown, B.C.

1996-10-01

In order to help assess the usable dynamic range of iron-dominated dipoles, field shape data at low field on several Fermi-lab accelerator dipole designs are presented. Emphasis is placed on the systematic and random values of the low field sextupole since it is the first ''allowed'' field error. The Main Injector dipoles provide four times smaller sextupole and more than 20 times less sextupole hysteresis than earlier designs for the Main Ring

Toward verification of electroweak baryogenesis by electric dipole moments

International Nuclear Information System (INIS)

Fuyuto, Kaori; Hisano, Junji; Senaha, Eibun

2016-01-01

We study general aspects of the CP-violating effects on the baryon asymmetry of the Universe (BAU) and electric dipole moments (EDMs) in models extended by an extra Higgs doublet and a singlet, together with electroweak-interacting fermions. In particular, the emphasis is on the structure of the CP-violating interactions and dependences of the BAU and EDMs on masses of the relevant particles. In a concrete mode, we investigate a relationship between the BAU and the electron EDM for a typical parameter set. As long as the BAU-related CP violation predominantly exists, the electron EDM has a strong power in probing electroweak baryogenesis. However, once a BAU-unrelated CP violation comes into play, the direct correlation between the BAU and electron EDM can be lost. Even in such a case, we point out that verifiability of the scenario still remains with the help of Higgs physics.

Toward verification of electroweak baryogenesis by electric dipole moments

Energy Technology Data Exchange (ETDEWEB)

Fuyuto, Kaori, E-mail: fuyuto@th.phys.nagoya-u.ac.jp [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Hisano, Junji, E-mail: hisano@eken.phys.nagoya-u.ac.jp [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Department of Physics, Nagoya University, Nagoya 464-8602 (Japan); Kavli IPMU (WPI), University of Tokyo, Kashiwa, Chiba 277-8584 (Japan); Senaha, Eibun, E-mail: senaha@ncu.edu.tw [Department of Physics and Center for Mathematics and Theoretical Physics, National Central University, Taoyuan, 32001, Taiwan (China)

2016-04-10

We study general aspects of the CP-violating effects on the baryon asymmetry of the Universe (BAU) and electric dipole moments (EDMs) in models extended by an extra Higgs doublet and a singlet, together with electroweak-interacting fermions. In particular, the emphasis is on the structure of the CP-violating interactions and dependences of the BAU and EDMs on masses of the relevant particles. In a concrete mode, we investigate a relationship between the BAU and the electron EDM for a typical parameter set. As long as the BAU-related CP violation predominantly exists, the electron EDM has a strong power in probing electroweak baryogenesis. However, once a BAU-unrelated CP violation comes into play, the direct correlation between the BAU and electron EDM can be lost. Even in such a case, we point out that verifiability of the scenario still remains with the help of Higgs physics.

Structure of the pygmy dipole resonance in Sn-124

NARCIS (Netherlands)

Endres, J.; Savran, D.; Butler, P. A.; Harakeh, M. N.; Harissopulos, S.; Herzberg, R. -D.; Kruecken, R.; Lagoyannis, A.; Litvinova, E.; Pietralla, N.; Ponomarev, V. Yu.; Popescu, L.; Ring, P.; Scheck, M.; Schlueter, F.; Sonnabend, K.; Stoica, V. I.; Zilges, A.; Wortche, Heinrich

2012-01-01

Background: In atomic nuclei, a concentration of electric dipole strength around the particle threshold, commonly denoted as pygmy dipole resonance, may have a significant impact on nuclear structure properties and astrophysical scenarios. A clear identification of these states and the structure of

Dipole strength distributions from HIGS Experiments

Science.gov (United States)

Werner, V.; Cooper, N.; Goddard, P. M.; Humby, P.; Ilieva, R. S.; Rusev, G.; Beller, J.; Bernards, C.; Crider, B. P.; Isaak, J.; Kelley, J. H.; Kwan, E.; Löher, B.; Peters, E. E.; Pietralla, N.; Romig, C.; Savran, D.; Scheck, M.; Tonchev, A. P.; Tornow, W.; Yates, S. W.; Zweidinger, M.

2015-05-01

A series of photon scattering experiments has been performed on the double-beta decay partners 76Ge and 76Se, in order to investigate their dipole response up to the neutron separation threshold. Gamma-ray beams from bremsstrahlung at the S-DALINAC and from Compton-backscattering at HIGS have been used to measure absolute cross sections and parities of dipole excited states, respectively. The HIGS data allows for indirect measurement of averaged branching ratios, which leads to significant corrections in the observed excitation cross sections. Results are compared to statistical calculations, to test photon strength functions and the Axel-Brink hypothesis

Prototype and proposed ISABELLE dipoles

International Nuclear Information System (INIS)

McInturff, A.D.; Sampson, W.B.; Robins, K.E.; Dahl, P.F.; Damm, R.

1977-01-01

Data are presented on the latest dipole prototypes to update the operational parameters possible for ISABELLE. This data base will constantly expand until the start of construction of the storage rings. The data will include field quality, stray field magnitudes, quench temperature and propagation times, protection capabilities singly and in multiple units, maximum central fields obtained and training behavior. Performance of the dipoles versus temperature and mode of refrigeration will be discussed. The single layer cosine theta turns distribution coils' parameters are better than those required for the operation of the 200 x 200 GeV version of ISABELLE. The double layer prototype has exceeded the magnetic field performance and two dimensional quality of field needed for the 400 x 400 GeV version of ISABELLE

He leak testing of Indus-2 dipole vacuum chambers

International Nuclear Information System (INIS)

Sindal, B.K.; Bhavsar, S.T.; Shukla, S.K.

2003-01-01

Full text: Centre for Advanced Technology is developing its second synchrotron radiation source INDUS-2 which is a 2.5 GeV electron storage ring. Dipole vacuum chambers are the vital components of Indus-2 vacuum system. Each of these chambers is approx. 3.6 m long and 0.67 m wide with 24 nos. of ports of various sizes. The dipole chambers were made by machining two halves and they are then lip welded together. The dipole chamber has approx. 14 m of total weld length and it was leak tested for leak tightness of the order of 10 -10 mbar 1/s. Helium mass spectrometer leak detector (HMSLD) was utilized for the leak testing. Subsequently the leaks of various orders in welding joints were repaired and leak tightness achieved. This paper describes the experiences during leak testing of 20 nos. of aluminum dipole chambers for INDUS-2

The Question of Decalage Between Object Permanence and Person Permanence

Science.gov (United States)

And Others; Jackson, Elaine

1978-01-01

Presents a study of decalage between object permanence and person permanence. Decalage was influenced by environmental as well as stimulus factors with infants tested between 6- and 81/4-months/of-age. (BD)

Quench Performance of the First Twin-aperture 11 T Dipole for LHC upgrades

CERN Document Server

Zlobin, A V; Apollinari, G; Barzi, E; Chlachidze, G; Nobrega, A; Novitski, I; Stoynev, S; Turrioni, D; Auchmann, B; Izquierdo Bermudez, S; Karppinen, M; Rossi, L; Savary, F; Smekens, D

2015-01-01

FNAL and CERN are developing a twin-aperture 11 T Nb$_{3}$Sn dipole suitable for installation in the LHC. A single-aperture 2-m long dipole demonstrator and two 1-m long dipole models have been fabricated and tested at FNAL in 2012-2014. The two 1 m long collared coils were then assembled into the first twin-aperture Nb$_{3}$Sn demonstrator dipole and tested. Test results of this twin-aperture Nb$_{3}$Sn dipole model are reported and discussed.

Essure Permanent Birth Control

Science.gov (United States)

... Prosthetics Essure Permanent Birth Control Essure Permanent Birth Control Share Tweet Linkedin Pin it More sharing options ... Print Essure is a a permanently implanted birth control device for women (female sterilization). Implantation of Essure ...

An interdecadal climate dipole between Northeast Asia and Antarctica over the past five centuries

Science.gov (United States)

Fang, Keyan; Chen, Deliang; Guo, Zhengtang; Zhao, Yan; Frank, David; He, Maosheng; Zhou, Feifei; Shi, Feng; Seppä, Heikki; Zhang, Peng; Neukom, Raphael

2018-03-01

Climate models emphasize the need to investigate inter-hemispheric climatic interactions. However, these models often underestimate the inter-hemispheric differences in climate change. With the wide application of reanalysis data since 1948, we identified a dipole pattern between the geopotential heights (GPHs) in Northeast Asia and Antarctica on the interdecadal scale in boreal summer. This Northeast Asia/Antarctica (NAA) dipole pattern is not conspicuous on the interannual scale, probably in that the interannual inter-hemispheric climate interaction is masked by strong interannual signals in the tropics associated with the El Niño-Southern Oscillation (ENSO). Unfortunately, the instrumental records are not sufficiently long-lasting to detect the interdecadal variability of the NAA. We thus reconstructed GPHs since 1565, making using the proxy records mostly from tree rings in Northeast Asia and ice cores from Antarctica. The strength of the NAA is time-varying and it is most conspicuous in the eighteenth century and after the late twentieth century. The strength of the NAA matches well with the variations of the solar radiation and tends to increase in along with its enhancement. In boreal summer, enhanced heating associated with high solar radiation in the Northern Hemisphere drives more air masses from the South to the North. This inter-hemispheric interaction is particularly strong in East Asia as a result of the Asian summer monsoon. Northeast Asia and Antarctica appear to be the key regions responsible for inter-hemispheric interactions on the interdecadal scale in boreal summer since they are respectively located at the front and the end of this inter-hemispheric trajectory.

Printed board dipole trim magnet design for 20 MeV LIA

Energy Technology Data Exchange (ETDEWEB)

Liu, Chengjun; Zhu, Wenjun; Zhang, Kaizhi; Zhang, Wenwei; Yu, Haijun [China Academy of Engineering Physics., Chengdu (China). Inst. of Fluid Physics

1997-12-31

The printed board dipole trim magnet design for a 20 MeV LIA is presented. The prototype dipole magnet with the sin/cos distributed windings has demonstrated more than 650 Gs-cm integrated dipole field and 1% integrated dipole field homogeneity within 5 cm in radius, which is about 40% of the magnet radius. Numerical modeling of two prototype magnet designs using the 3D magnetic field code SCMAG is presented as well as data from magnetic field measurements of the two magnets. The agreement between the calculations and measurements is accurate to 2-3%. (author). 3 figs., 4 refs.

Electron electric dipole moment in Inverse Seesaw models

Energy Technology Data Exchange (ETDEWEB)

Abada, Asmaa; Toma, Takashi [Laboratoire de Physique Théorique, CNRS, University Paris-Sud, Université Paris-Saclay,91405 Orsay (France)

2016-08-11

We consider the contribution of sterile neutrinos to the electric dipole moment of charged leptons in the most minimal realisation of the Inverse Seesaw mechanism, in which the Standard Model is extended by two right-handed neutrinos and two sterile fermion states. Our study shows that the two pairs of (heavy) pseudo-Dirac mass eigenstates can give significant contributions to the electron electric dipole moment, lying close to future experimental sensitivity if their masses are above the electroweak scale. The major contribution comes from two-loop diagrams with pseudo-Dirac neutrino states running in the loops. In our analysis we further discuss the possibility of having a successful leptogenesis in this framework, compatible with a large electron electric dipole moment.

Electron electric dipole moment in Inverse Seesaw models

International Nuclear Information System (INIS)

Abada, Asmaa; Toma, Takashi

2016-01-01

We consider the contribution of sterile neutrinos to the electric dipole moment of charged leptons in the most minimal realisation of the Inverse Seesaw mechanism, in which the Standard Model is extended by two right-handed neutrinos and two sterile fermion states. Our study shows that the two pairs of (heavy) pseudo-Dirac mass eigenstates can give significant contributions to the electron electric dipole moment, lying close to future experimental sensitivity if their masses are above the electroweak scale. The major contribution comes from two-loop diagrams with pseudo-Dirac neutrino states running in the loops. In our analysis we further discuss the possibility of having a successful leptogenesis in this framework, compatible with a large electron electric dipole moment.

An effective field theory for the neutron electric dipole moment

International Nuclear Information System (INIS)

Chang, D.; Kephart, T.W.; Keung, W.Y.; Yuan, T.C.

1992-01-01

We derive a CP-odd effective field theory involving the field strengths of the gluon and the photon and their duals as a result of integrating out a heavy quark which carries both the chromo-electric dipole moment and electric dipole moment. The coefficients of the induced gluonic, photonic, and mixed gluon-photon operators with dimension ≤ 8 are determined. Implications of some of these operators on the neutron electric dipole moment are also discussed. (orig.)

Continuous atom laser with Bose-Einstein condensates involving three-body interactions

Energy Technology Data Exchange (ETDEWEB)

Carpentier, A V; Michinel, H; Novoa, D [Area de Optica, Facultade de Ciencias de Ourense, Universidade de Vigo, As Lagoas s/n, Ourense, ES-32004 (Spain); Olivieri, D N, E-mail: avcarpentier@uvigo.e [Area de Linguaxes e sistemas informaticos, Escola Superior de EnxenerIa Informatica, Universidade de Vigo, As Lagoas s/n, Ourense, ES-32004 (Spain)

2010-05-28

We demonstrate, through numerical simulations, the emission of a coherent continuous matter wave of constant amplitude from a Bose-Einstein condensate in a shallow optical dipole trap. The process is achieved by spatial control of the variations of the scattering length along the trapping axis, including elastic three-body interactions due to dipole interactions. In our approach, the outcoupling mechanism is atomic interactions, and thus, the trap remains unaltered. We calculate analytically the parameters for the experimental implementation of this continuous wave atom laser.

Modification of the CEBAF transport dipoles for energy upgrade considerations

International Nuclear Information System (INIS)

D. Bullard; L. Harwood; T. Hiatt; J. Karn; E. Martin; W. Oren; C. Rode; K. Sullivan; R. Wines; M. Wiseman

1999-01-01

The CEBAF accelerator at the Thomas Jefferson National Accelerator Facility contains 415 resistive dipoles in the recirculation arcs and transport lines. These dipoles were originally designed and magnetically mapped to support the operation of the accelerator at 6 GeV. Recent interests in upgrading the CEBAF energy beyond 6 GeV prompted a study into operating the dipoles beyond their design limits. Finite element modeling was performed to quantify saturation effects at higher currents and to test simple modifications to improve magnetic performance. For confirmation, various steps were prototyped and magnetically measured. Measurement results agreed with finite element models and showed that saturation could be reduced to manageable levels. It was found that the most populous dipole families could be modified to reach twice their design field with minimal cost and effort. At these higher fields, the magnets operate at a reasonable thermal state with minimal saturation losses a nd little degradation in field quality. Work continues on studying the smaller population of dipoles to determine their performance at higher fields

ARIADNE - A Monte Carlo for QCD cascades in the colour dipole formulation

International Nuclear Information System (INIS)

Pettersson, U.

1988-04-01

We present a Monte Carlo program for generating QCD cascades, based on the colour dipole approximation. In this formulation the gluons are radiated from dipoles that are stretched from one colour charge to the corresponding anti-charge. The subsequent emission of gluons thus corresponds to the dipoles being split into smaller and smaller dipoles. This formulation automatically takes into account the angular ordering and the ordering in transverse momenta, and it also gives some nontrivial azimuthal effects. (author)

Application of the finite-field coupled-cluster method to calculate molecular properties relevant to electron electric-dipole-moment searches

Science.gov (United States)

Abe, M.; Prasannaa, V. S.; Das, B. P.

2018-03-01

Heavy polar diatomic molecules are currently among the most promising probes of fundamental physics. Constraining the electric dipole moment of the electron (e EDM ), in order to explore physics beyond the standard model, requires a synergy of molecular experiment and theory. Recent advances in experiment in this field have motivated us to implement a finite-field coupled-cluster (FFCC) approach. This work has distinct advantages over the theoretical methods that we had used earlier in the analysis of e EDM searches. We used relativistic FFCC to calculate molecular properties of interest to e EDM experiments, that is, the effective electric field (Eeff) and the permanent electric dipole moment (PDM). We theoretically determine these quantities for the alkaline-earth monofluorides (AEMs), the mercury monohalides (Hg X ), and PbF. The latter two systems, as well as BaF from the AEMs, are of interest to e EDM searches. We also report the calculation of the properties using a relativistic finite-field coupled-cluster approach with single, double, and partial triples' excitations, which is considered to be the gold standard of electronic structure calculations. We also present a detailed error estimate, including errors that stem from our choice of basis sets, and higher-order correlation effects.

Evaluation of the transfer of heat from the coil of the LHC dipole magnet to Helium II

International Nuclear Information System (INIS)

Richter, D.; Sevred, A.; Fleiter, J.; Baudouy, B.; Devred, A.

2007-01-01

During operation of the Large Hadron Collider at CERN, heat will be generated inside the coils of its superconducting magnets as a consequence of ramping of magnetic field, and of the interaction of lost beam particles with the magnet mass. Heat has to be transferred from the conductor into the He II coolant and removed from the magnet environment. During the LHC R and D stage, this transfer has been extensively studied on simulated coil segments at CEA/Saclay, and by analyzing dynamic behavior of short model magnets at CERN. Owing to the importance of efficient cooling for the design of future superconducting accelerator magnets, study of heat transfer has been restored at CERN and in frame of the Next European Dipole Collaboration. The article features two recently performed works: 1) Attempt to analyse archived high ramp rate quench data of 1-m-long LHC model dipole magnets of the 2. generation. 2) Development of a method for direct measurement of heat transfer on segments of production LHC dipole magnet coils. (authors)

Statistical decay of dipole-excited states of Zr isotopes

Energy Technology Data Exchange (ETDEWEB)

Gayer, Udo; Zweidinger, Markus; Beck, Tobias; Mertes, Laura; Pai, Haridas; Pietralla, Norbert; Ries, Philipp; Romig, Christopher; Werner, Volker [IKP, TU Darmstadt (Germany); Cooper, Nathan [University of Richmond, Richmond (United States); Isaak, Johann [EMMI, GSI, Darmstadt (Germany); FIAS, Frankfurt (Germany); Loeher, Bastian; Savran, Deniz [GSI, Darmstadt (Germany); Scheck, Marcus [School of Engineering, UWS, Paisley (United Kingdom); SUPA, Glasgow (United Kingdom); Tornow, Werner [Duke University, Durham (United States)

2016-07-01

Decay properties of electric dipole excitations below the neutron separation threshold of {sup 92,94,96}Zr have been determined in several (γ,γ') and (vector γ,γ') experiments at the Darmstadt High Intensity Photon Setup and the High-Intensity Gamma-Ray Source in Durham, USA. The model of statistical decay is used to guide an interpretation of this low-lying dipole strength which is frequently discussed to arise from the low-energy tail of the giant dipole resonance and potentially an additional resonance structure often referred to as the pygmy dipole resonance. The availability of three complete data sets in the Zr isotopic chain allowed for a precise test of these extrapolations to low energies using different models for the level density and the photon strength function. In the talk, data and calculations are presented, and the suitability of photon scattering data for this kind of analysis is discussed.

Anomalous Magnetic and Electric Dipole Moments of the $\\tau$

CERN Document Server

Taylor, L

1998-01-01

This paper reviews the theoretical predictions for and the experimental measurements of the anomalous magnetic and electric dipole moments of the tau lepton. In particular, recent analyses of the e/sup +/e/sup -/ to tau /sup +/ tau /sup -/ gamma process from the L3 and OPAL collaborations are described. The most precise results, from L3, for the anomalous magnetic and electric dipole moments respectively are: a/sub tau /=0.004+or-0.027+or-0.023 and d /sub tau /=(0.0+or-1.5+or-1.3)*10/sup -16/ e.cm. (22 refs). This paper reviews the theoretical predictions for and the experimental measurements of the anomalous magnetic and electric dipole moments of the tau lepton. In particular, recent analyses of the $\\eettg$ process from the L3 and OPAL collaborations are described. The most precise results, from L3, for the anomalous magnetic and electric dipole moments respectively are: $\\atau = 0.004 10^{-16}{e{\\cdot}\\mathrm{cm}}$.

Rotation and oscillation of nonlinear dipole vortex in the drift-unstable plasma

International Nuclear Information System (INIS)

Orito, Kohtaro; Hatori, Tadatsugu.

1997-10-01

The behaviors of the nonlinear dipole vortex in the drift unstable plasma are studied by numerical approaches. Model equations used in numerical simulation are derived from two-fluid model and are composed of two equations with respect to the electrostatic potential and the density perturbation. When the initial dipole vortex is inclined at some angle with respect to the direction of the drift velocity, the dipole vortex oscillates or rotates in the first stage. These phenomenon also happen in the stable system. In the second stage, one part of the dipole vortex grows and another decays because of the destabilization. The shrunk vortex rotates around the enlarged vortex. Consequently, a monopole vortex appears out of the dipole vortex. (author)

Tracking single dynamic MEG dipole sources using the projected Extended Kalman Filter.

Science.gov (United States)

Yao, Yuchen; Swindlehurst, A Lee

2011-01-01

This paper presents two new algorithms based on the Extended Kalman Filter (EKF) for tracking the parameters of single dynamic magnetoencephalography (MEG) dipole sources. We assume a dynamic MEG dipole source with possibly both time-varying location and dipole orientation. The standard EKF-based tracking algorithm performs well under the assumption that the dipole source components vary in time as a Gauss-Markov process, provided that the background noise is temporally stationary. We propose a Projected-EKF algorithm that is adapted to a more forgiving condition where the background noise is temporally nonstationary, as well as a Projected-GLS-EKF algorithm that works even more universally, when the dipole components vary arbitrarily from one sample to the next.

Applicability of the dipole-dipole method for structural studies: examples from the Northern Apennines

Directory of Open Access Journals (Sweden)

L. Alfano

1998-06-01

Full Text Available We present some results of a geoelectrical investigation program conducted in the Northern Apennines, namely in the Val d'Aveto and Bobbio window and surrounding areas. Field activity included the execution of more than 50 vertical electrical soundings with continuous polar dipole-dipole spread. We image the geometries of some deep geological structures; in particular we found a resistive background, whose resistivity is different along the geoelectrical profiles. In our interpretation the resistive background consists of subligurid and tuscan units underlying the alloctone Ligurid units in the area surrounding the Val d'Aveto and Bobbio window. The resistive background was not found, at least at the same depths, toward north-east. Therefore, the geoelectrical survey revealed the position of the front of the subligurid and Tuscan nappes toward the plain for a depth of about one kilometer.

Dipole polarizability and neutron skin in {sup 68}Ni