In-medium covariant propagator of baryons under a strong magnetic field: Effect of the intrinsic magnetic moments

Energy Technology Data Exchange (ETDEWEB)

Aguirre, R.M.; Paoli, A.L. de [Universidad Nacional de La Plata, and IFLP, Departamento de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina)

2016-11-15

We obtain the covariant propagator at finite temperature for interacting baryons immersed in a strong magnetic field. The effect of the intrinsic magnetic moments on the Green function are fully taken into account. We make an expansion in terms of eigenfunctions of a Dirac field, which leads us to a compact form of its propagator. We present some simple applications of these propagators, where the statistical averages of nuclear currents and energy density are evaluated. (orig.)

Fits combining hyperon semileptonic decays and magnetic moments and CVC

International Nuclear Information System (INIS)

Bohm, A.; Kielanowski, P.

1982-10-01

We have performed a test of CVC by determining the baryon charges and magnetic moments from the hyperon semileptonic data. Then CVC was applied in order to make a joint fit of all baryon semileptonic decay data and baryon magnetic moments for the spectrum generating group (SG) model as well as for the conventional (cabibbo and magnetic moments in nuclear magnetons) model. The SG model gives a very good fit with chi 2 /n/sub D/ = 25/20 approximately equals 21% C.L. whereas the conventional model gives a fit with chi 2 /n/sub D/ = 244/20

Magnetic moments of hyperons

International Nuclear Information System (INIS)

Overseth, O.E.

1981-01-01

The Fermilab Neutral Hyperon Beam Collaboration has measured the magnetic moments of Λ 0 , XI-neutral and XI-minus hyperons. With a recently published result for the Σ + hyperon, we now have precision measurements on the magnetic moments of six baryons. This allows a sensitive test of the quark model. The data are in qualitative agreement with the simple additive static quark model. Quantitatively however the data disagree with theoretical predictions by typically 15%. Several theoretical attempts to understand or remedy this discrepancy will be mentioned

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.)

Sum rules and systematics for baryon magnetic moments

International Nuclear Information System (INIS)

Lipkin, H.J.

1983-11-01

The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties encountered are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks; e.g. from a pion cloud. The large magnitude of the THETA - moment may indicate that the strange quark contribution to the THETA moments is considerably larger than the value μ(Λ) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the Σ - moment include a value very close to -(1/2)μ(Σ + ) which would indicate that strange quarks do not contribute at all to the Σ moments. (author)

Sum rules and systematics for baryon magnetic moments

International Nuclear Information System (INIS)

Lipkin, H.J.

1984-01-01

The new experimental values of hyperon magnetic moments are compared with sum rules predicted from general quark models. Three difficulties encountered are not easily explained by simple models. The isovector contributions of nonstrange quarks to hyperon moments are smaller than the corresponding contribution to nucleon moments, indicating either appreciable configuration mixing in hyperon wave functions and absent in nucleons or an additional isovector contribution beyond that of valence quarks, e.g. from a pion cloud. The large magnitude of the Ψ - moment may indicate that the strange quark contribution to the Ψ moments is considerably larger than the value μ(Λ) predicted by simple models which have otherwise been very successful. The set of controversial values from different experiments of the Σ - moment include a value very close to -1/2μ(Σ + ) which would indicate that strange quarks do not contribute at all to the Σ moments. (orig.)

Radiative decays of single heavy flavour baryons

International Nuclear Information System (INIS)

Majethiya, Ajay; Patel, Bhavin; Vinodkumar, P.C.

2009-01-01

The electromagnetic transitions between (J P =(3)/(2) + ) and (J P =(1)/(2) + ) baryons are important decay modes to observe new hadronic states experimentally. For the estimation of these transitions widths, we employ a non-relativistic quark potential model description with color Coulomb plus linear confinement potential. Such a description has been employed to compute the ground-state masses and magnetic moments of the single heavy flavor baryons. The magnetic moments of the baryons are obtained using the spin-flavor structure of the constituting quark composition of the baryon. Here, we also define an effective constituent mass of the quarks (ecqm) by taking into account the binding effects of the quarks within the baryon. The radiative transition widths are computed in terms of the magnetic moments of the baryon and the photon energy. Our results are compared with other theoretical models. (orig.)

Electromagnetic dipole moments of charged baryons with bent crystals at the LHC

Energy Technology Data Exchange (ETDEWEB)

Bagli, E.; Bandiera, L.; Guidi, V.; Mazzolari, A. [Universita di Ferrara, Ferrara (Italy); INFN, Sezione di Ferrara (Italy); Cavoto, G. [' ' Sapienza' ' Universita di Roma, Rome (Italy); INFN, Sezione di Roma (Italy); Henry, L.; Martinez Vidal, F.; Ruiz Vidal, J. [IFIC, Universitat de Valencia-CSIC, Valencia (Spain); Marangotto, D. [Universita di Milano, Milan (Italy); INFN, Sezione di Milano (Italy); Merli, A.; Neri, N. [Universita di Milano, Milan (Italy); CERN, Geneva (Switzerland); INFN, Sezione di Milano (Italy)

2017-12-15

We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector. (orig.)

Fits of the baryon magnetic moments to the quark model and spectrum-generating SU(3)

International Nuclear Information System (INIS)

Bohm, A.; Teese, R.B.

1982-01-01

We show that for theoretical as well as phenomenological reasons the baryon magnetic moments that fulfill simple group transformation properties should be taken in intrinsic rather than nuclear magnetons. A fit of the recent experimental data to the reduced matrix elements of the usual octet electromagnetic current is still not good, and in order to obtain acceptable agreement, one has to add correction terms to the octet current. We have texted two kinds of corrections: U-spin-scalar terms, which are singles out by the model-independent algebraic properties of the hadron electromagnetic current, and octet U-spin vectors, which could come from quark-mass breaking in a nonrelativistic quark model. We find that the U-spin-scalar terms are more important than the U-spin vectors for various levels of demanded theoretical accuracy

Magnetic dipole moment of the Δ(1232) in chiral perturbation theory

International Nuclear Information System (INIS)

Hacker, C.; Wies, N.; Scherer, S.; Gegelia, J.

2006-01-01

The magnetic dipole moment of the Δ(1232) is calculated in the framework of manifestly Lorentz-invariant baryon chiral perturbation theory in combination with the extended on-mass-shell renormalization scheme. As in the case of the nucleon, at leading order both isoscalar and isovector anomalous magnetic moments are given in terms of two low-energy constants. In contrast to the nucleon case, at next-to-leading order the isoscalar anomalous magnetic moment receives a (real) loop contribution. Moreover, due to the unstable nature of the Δ(1232), at next-to-leading order the isovector anomalous magnetic moment not only receives a real but also an imaginary loop contribution. (orig.)

Magnetic moments of triply heavy baryons in quark-diquark model

International Nuclear Information System (INIS)

Thakkar, Kaushal; Majethiya, Ajay; Vinodkumar, P.C.

2016-01-01

Along with the well-established triply flavoured (uuu) and strange (sss) baryons, QCD predicts similar states made up of charm quarks, the triply-charmed baryon, ccc and bottom quarks, the triply-bottom baryon, bbb. Such a state has yet to be observed experimentally. After the observation of the doubly charmed baryon by the SELEX group, it is expected that the triply heavy flavour baryonic state may be in the offing very soon. Though considerable amount of data on the properties of the singly-heavy baryons are available in literature, only sparse attention has been paid to the spectroscopy of double and triple-heavy flavour baryons, perhaps mainly due to the lack of experimental incentives

arXiv Electromagnetic dipole moments of charged baryons with bent crystals at the LHC

CERN Document Server

Bagli, E.; Cavoto, G.; Guidi, V.; Henry, L.; Marangotto, D.; Martinez Vidal, F.; Mazzolari, A.; Merli, A.; Neri, N.; Ruiz Vidal, J.

2017-12-05

We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.

Quadrupole moments of low-lying baryons with spin

Indian Academy of Sciences (India)

The chiral constituent quark model ( CQM) with general parametrization (GP) method has been formulated to calculate the quadrupole moments of the spin − 3 2 + decuplet baryons and spin − 3 2 + → 1 2 + transitions. The implications of such a model have been investigated in detail for the effects of symmetry breaking ...

Properties of light flavour baryons in hypercentral quark model

Indian Academy of Sciences (India)

Light baryons; magnetic moments; transition magnetic moment; radiative decay width. ... particles are produced by scattering the pion, photon, or electron ... and decuplet) for testing any model hypothesis and understanding the dynamics of ...

On the electromagnetic properties of the baryon octet

International Nuclear Information System (INIS)

Leinweber, D.B.; Woloshyn, R.M.; Draper, T.

1990-11-01

A numerical simulation of quenched QCD on a 24x12x12x24 lattice at β=5.9 is used to calculate the electric and magnetic form factors of the baryon octet. Magnetic moments, electric radii, magnetic radii, and magnetic transition moments are extracted from the form factors. (Author) (4 refs., 4 figs.)

Magnetic moments of octet baryons in a chiral potential model

International Nuclear Information System (INIS)

Barik, N.

1986-01-01

Incorporating the lowest-order pionic correction, the magnetic moments of the nucleon octet have been calculated in a chiral potential model. The potential, representing phenomenologically the nonperturbative gluon self-couplings, is chosen with equally mixed scalar and vector parts in a power-law form. The results are in reasonable agreement with experiment. (author)

Magnetic moments of octet baryons in a chiral potential model

Energy Technology Data Exchange (ETDEWEB)

Barik, N; Das, M

1986-12-01

Incorporating the lowest-order pionic correction, the magnetic moments of the nucleon octet have been calculated in a chiral potential model. The potential, representing phenomenologically the nonperturbative gluon self-couplings, is chosen with equally mixed scalar and vector parts in a power-law form. The results are in reasonable agreement with experiment. 32 refs., 2 tables.

Electromagnetic properties of baryons

Energy Technology Data Exchange (ETDEWEB)

Haupt, C.

2006-07-01

Static observables of bound state systems in field theoretic descriptions are usually extracted from form factors in the limit of vanishing squared four-momentum transfer of the probing exchange particle. On the other hand, static properties in nonrelativistic quantum mechanics can be formulated by means of expectation values involving essentially scalar products of wave functions. The main objective of this work is to show that a synthesis of both approaches is indeed possible - at least if certain restrictions are made to the kind of interactions between the constituents of the bound system - leading to new insights into the structure of static properties. The focus lies especially on the charge radii and magnetic moments of baryons described within a covariant constituent quark model having its field theoretic foundations in the Bethe-Salpeter equation. The current matrix element in the Breit frame between the vertex functions is derived. The charge radius and magnetic moment of a bound three-fermion system is then derived by starting from their usual definition from form factors and in case of the charge radius also from the well-known radius of a charge distribution in classical electrodynamics. In both cases the static limit at the photon point is taken analytically and subsequently the integration over the relative energy variables is done. Finally the vertex functions are replaced by Salpeter amplitudes and the expression is symmetrized over the three fermions. The final results express the charge radius and magnetic moment of the three-fermion system as expectation values with respect to Salpeter amplitudes. The numerical implementation of the analytic results is done within a covariant constituent quark model with quark confinement and a residual instanton interaction accounting for the fine structure of the observed mass spectra. The Salpeter amplitudes which where obtained by solving the Salpeter equation are used to compute the expectation values of

Hyperons: Insights into baryon structures

International Nuclear Information System (INIS)

Lach, J.

1991-08-01

The baryon octet is composed mainly of hyperons. Modern high energy hyperon beams provide a tool for the study of hyperon static properties and interactions. Experiments with these beams have provided new insights into hyperon rare decays, magnetic moments, and interactions. These experiments provide us with insights into the strong, weak, and electromagnetic structure of the baryons. 65 refs., 45 figs., 5 tabs

Erratum to: Quadrupole moments of low-lying baryons with spin ...

Indian Academy of Sciences (India)

physics pp. 1083. Erratum to: Quadrupole moments of low-lying baryons with spin-. 1. 2. +. , spin-. 3. 2. +. , and spin-. 3. 2. +. → 1. 2. + transitions. NEETIKA SHARMA and HARLEEN DAHIYA. ∗. Department of Physics, Dr. B.R. Ambedkar National Institute of Technology,. Jalandhar 144 011, India. ∗. Corresponding author.

Magnetic moment for the negative parity Λ→Σ0 transition in light cone QCD sum rules

Directory of Open Access Journals (Sweden)

T.M. Aliev

2016-07-01

Full Text Available The magnetic moment of the Λ→Σ0 transition between negative parity baryons is calculated in framework of the QCD sum rules approach by using the general form of the interpolating currents. The pollution arising from the positive-to-positive, and positive-to-negative parity baryons is eliminated by constructing the sum rules for different Lorentz structures. A comparison of our result with the predictions of the results of other approaches for the positive parity baryons is presented.

Photoproduction of hermaphrodite baryons

International Nuclear Information System (INIS)

Barnes, T.; Close, F.E.

1983-02-01

It is shown that photoexcitation of the lightest hermaphrodite baryons is strongly suppressed from proton targets but allowed from neutrons, a result that is reminiscent of a quark model selection rule due to Moorhouse (Phys. Rev. Lett.; 16:772 (1966)). This is consistent with suggestions that the P 11 (1710) is the lightest q 3 G baryon and eliminates the possibility that the Roper resonance is dominantly an hermaphrodite state. Magnetic moments do not constrain the possibility of considerable mixing of q 3 G into the nucleon and delta's Fock space wavefunctions. (author)

Masses and magnetic moments of triple heavy flavour baryons in ...

Indian Academy of Sciences (India)

The vital properties of these heaviest baryons in nature are their masses and ..... in bringing out a possible saturation property of the basic interactions within the ... forward to the experimental support to our predictions, from different future ...

A parts-per-billion measurement of the antiproton magnetic moment

CERN Document Server

Smorra, C; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-01-01

Precise comparisons of the fundamental properties of matter–antimatter conjugates provide sensitive tests of charge–parity–time (CPT) invariance1, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons2, leptons3, 4 and baryons5, 6 have compared different properties of matter–antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level7, 8: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron3. Here we report a high-precision measurement of in units of the nuclear magneton μN with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic ...

Single heavy flavour baryons using Coulomb plus a power law interquark potential

International Nuclear Information System (INIS)

Majethiya, A.; Patel, B.; Vinodkumar, P.C.

2008-01-01

Properties of single heavy flavor baryons in a non-relativistic potential model with colour Coulomb plus a power law confinement potential have been studied using a simple variational method. The ground-state masses of single heavy baryons and the mass difference between the J P =3/2 + and J P =1/2 + states are computed using a spin-dependent two-body potential. Using the spin-flavour structure of the constituting quarks and by defining an effective confined mass of the constituent quarks within the baryons, the magnetic moments are computed. The masses and magnetic moments of the single heavy baryons are found to be in accordance with the existing experimental values and with other theoretical predictions. It is found that an additional attractive interaction of the order of -200 MeV is required for the antisymmetric states of Λ Q (Q element of c,b). It is also found that the spin-hyperfine interaction parameters play a decisive role in hadron spectroscopy. (orig.)

A parts-per-billion measurement of the antiproton magnetic moment.

Science.gov (United States)

Smorra, C; Sellner, S; Borchert, M J; Harrington, J A; Higuchi, T; Nagahama, H; Tanaka, T; Mooser, A; Schneider, G; Bohman, M; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-10-18

Precise comparisons of the fundamental properties of matter-antimatter conjugates provide sensitive tests of charge-parity-time (CPT) invariance, which is an important symmetry that rests on basic assumptions of the standard model of particle physics. Experiments on mesons, leptons and baryons have compared different properties of matter-antimatter conjugates with fractional uncertainties at the parts-per-billion level or better. One specific quantity, however, has so far only been known to a fractional uncertainty at the parts-per-million level: the magnetic moment of the antiproton, . The extraordinary difficulty in measuring with high precision is caused by its intrinsic smallness; for example, it is 660 times smaller than the magnetic moment of the positron. Here we report a high-precision measurement of in units of the nuclear magneton μ N with a fractional precision of 1.5 parts per billion (68% confidence level). We use a two-particle spectroscopy method in an advanced cryogenic multi-Penning trap system. Our result  = -2.7928473441(42)μ N (where the number in parentheses represents the 68% confidence interval on the last digits of the value) improves the precision of the previous best measurement by a factor of approximately 350. The measured value is consistent with the proton magnetic moment, μ p  = 2.792847350(9)μ N , and is in agreement with CPT invariance. Consequently, this measurement constrains the magnitude of certain CPT-violating effects to below 1.8 × 10 -24 gigaelectronvolts, and a possible splitting of the proton-antiproton magnetic moments by CPT-odd dimension-five interactions to below 6 × 10 -12 Bohr magnetons.

Magnetic monopole interactions: shell structure of meson and baryon states

International Nuclear Information System (INIS)

Akers, D.

1986-01-01

It is suggested that a low-mass magnetic monopole of Dirac charge g = (137/2)e may be interacting with a c-quark's magnetic dipole moment to produce Zeeman splitting of meson states. The mass M 0 = 2397 MeV of the monopole is in contrast to the 10 16 -GeV monopoles of grand unification theories (GUT). It is shown that shell structure of energy E/sub n/ = M 0 + 1/4nM 0 ... exists for meson states. The presence of symmetric meson states leads to the identification of the shell structure. The possible existence of the 2397-MeV magnetic monopole is shown to quantize quark masses in agreement with calculations of quantum chromodynamics (QCD). From the shell structure of meson states, the existence of two new mesons is predicted: eta(1814 +/- 50 MeV) with I/sup G/(J/sup PC/) = 0 + (0 -+ ) and eta/sub c/ (3907 +/- 100 MeV) with J/sup PC/ = 0 -+ . The presence of shell structure for baryon states is shown

Baryons in the unquenched quark model

Energy Technology Data Exchange (ETDEWEB)

Bijker, R.; Díaz-Gómez, S. [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, AP 70-543, 04510 Mexico DF (Mexico); Lopez-Ruiz, M. A. [Physics Department and Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN 47408 (United States); Santopinto, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, via Dodecaneso 33, I-16146 Italy (Italy)

2016-07-07

In this contribution, we present the unquenched quark model as an extension of the constituent quark model that includes the effects of sea quarks via a {sup 3}P{sub 0} quark-antiquark pair-creation mechanism. Particular attention is paid to the spin and flavor content of the proton, magnetic moments and β decays of octet baryons.

Electromagnetic corrections to baryon masses

International Nuclear Information System (INIS)

Durand, Loyal; Ha, Phuoc

2005-01-01

We analyze the electromagnetic contributions to the octet and decuplet baryon masses using the heavy-baryon approximation in chiral effective field theory and methods we developed in earlier analyses of the baryon masses and magnetic moments. Our methods connect simply to Morpurgo's general parametrization of the electromagnetic contributions and to semirelativistic quark models. Our calculations are carried out including the one-loop mesonic corrections to the basic electromagnetic interactions, so to two loops overall. We find that to this order in the chiral loop expansion there are no three-body contributions. The Coleman-Glashow relation and other sum rules derived in quark models with only two-body terms therefore continue to hold, and violations involve at least three-loop processes and can be expected to be quite small. We present the complete formal results and some estimates of the matrix elements here. Numerical calculations will be presented separately

Magnetic Moment of $^{59}$Cu

CERN Multimedia

2002-01-01

Experiment IS358 uses the intense and pure beams of copper isotopes provided by the ISOLDE RILIS (resonance ionization laser ion source). The isotopes are implanted and oriented in the low temperature nuclear orientation set-up NICOLE. Magnetic moments are measured by $\\beta$-NMR. Copper (Z=29), with a single proton above the proton-magic nickel isotopes provides an ideal testground for precise shell model calculations of magnetic moments and their experimental verification. In the course of our experiments we already determined the magnetic moments of $^{67}$Ni, $^{67}$Cu, $^{68g}$Cu, $^{69}$Cu and $^{71}$Cu which provide important information on the magicity of the N=40 subshell closure. In 2001 we plan to conclude our systematic investigations by measuring the magnetic moment of the neutron-deficient isotope $^{59}$Cu. This will pave the way for a subsequent study of the magnetic moment of $^{57}$Cu with a complementary method.

Double-trap measurement of the proton magnetic moment at 0.3 parts per billion precision.

Science.gov (United States)

Schneider, Georg; Mooser, Andreas; Bohman, Matthew; Schön, Natalie; Harrington, James; Higuchi, Takashi; Nagahama, Hiroki; Sellner, Stefan; Smorra, Christian; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Ulmer, Stefan

2017-11-24

Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct high-precision measurement of the magnetic moment μ p of the proton in units of the nuclear magneton μ N The result, μ p = 2.79284734462 (±0.00000000082) μ N , has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double-Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10 -10 level. Copyright © 2017, American Association for the Advancement of Science.

Magnetic moment of 33Cl

International Nuclear Information System (INIS)

Matsuta, K.; Arimura, K.; Nagatomo, T.; Akutsu, K.; Iwakoshi, T.; Kudo, S.; Ogura, M.; Takechi, M.; Tanaka, K.; Sumikama, T.; Minamisono, K.; Miyake, T.; Minamisono, T.; Fukuda, M.; Mihara, M.; Kitagawa, A.; Sasaki, M.; Kanazawa, M.; Torikoshi, M.; Suda, M.; Hirai, M.; Momota, S.; Nojiri, Y.; Sakamoto, A.; Saihara, M.; Ohtsubo, T.; Alonso, J.R.; Krebs, G.F.; Symons, T.J.M.

2004-01-01

The magnetic moment of 33 Cl (Iπ=3/2+, T1/2=2.51s) has been re-measured precisely by β-NMR method. The obtained magnetic moment |μ|=0.7549(3)μN is consistent with the old value 0.7523(16)μN, but is 5 times more accurate. The value is well reproduced by the shell model calculation, μSM=0.70μN. Combined with the magnetic moment of the mirror partner 33 S, the nuclear matrix elements , , , and were derived

Magnetic moments revisited

International Nuclear Information System (INIS)

Towner, I.S.; Khanna, F.C.

1984-01-01

Consideration of core polarization, isobar currents and meson-exchange processes gives a satisfactory understanding of the ground-state magnetic moments in closed-shell-plus (or minus)-one nuclei, A = 3, 15, 17, 39 and 41. Ever since the earliest days of the nuclear shell model the understanding of magnetic moments of nuclear states of supposedly simple configurations, such as doubly closed LS shells +-1 nucleon, has been a challenge for theorists. The experimental moments, which in most cases are known with extraordinary precision, show a small yet significant departure from the single-particle Schmidt values. The departure, however, is difficult to evaluate precisely since, as will be seen, it results from a sensitive cancellation between several competing corrections each of which can be as large as the observed discrepancy. This, then, is the continuing fascination of magnetic moments. In this contribution, we revisit the subjet principally to identify the role played by isobar currents, which are of much concern at this conference. But in so doing we warn quite strongly of the dangers of considering just isobar currents in isolation; equal consideration must be given to competing processes which in this context are the mundane nuclear structure effects, such as core polarization, and the more popular meson-exchange currents

Electromagnetic moments of hadrons and quarks in a hybrid model

International Nuclear Information System (INIS)

Gerasimov, S.B.

1989-01-01

Magnetic moments of baryons are analyzed on the basis of general sum rules following from the theory of broken symmetries and quark models including the relativistic effects and hadronic corrections due to the meson exchange currents. A new sum rule is proposed for the hyperon magnetic moments, which is in accord with the most precise new data and also with a theory of the electromagnetic ΛΣ 0 mixing. The numerical values of the quark electromagnetic moments are obtained within a hybrid model treating the pion cloud effects through the local coupling of the pion field with the constituent massive quarks. Possible sensitivity of the weak neutral current magnetic moments to violation of the Okubo-Zweig-Izuki rule is emphasized nand discussed. 39 refs.; 1 fig

Effective magnetic moment of neutrinos in strong magnetic fields

International Nuclear Information System (INIS)

Perez M, A.; Perez R, H.; Masood, S.S.; Gaitan, R.; Rodriguez R, S.

2002-01-01

In this paper we compute the effective magnetic moment of neutrinos propagating in dense high magnetized medium. Taking typical values of magnetic field and densities of astrophysical objects (such as the cores of supernovae and neutron stars) we obtain an effective type of dipole magnetic moment in agreement with astrophysical and cosmological bounds. (Author)

Excited state mass spectra of doubly heavy Ξ baryons

Energy Technology Data Exchange (ETDEWEB)

Shah, Zalak; Rai, Ajay Kumar [Sardar Vallabhbhai National Institute of Technology, Department of Applied Physics, Surat, Gujarat (India)

2017-02-15

In this paper, the mass spectra are obtained for doubly heavy Ξ baryons, namely, Ξ{sub cc}{sup +}, Ξ{sub cc}{sup ++}, Ξ{sub bb}{sup -}, Ξ{sub bb}{sup 0}, Ξ{sub bc}{sup 0} and Ξ{sub bc}{sup +}. These baryons consist of two heavy quarks (cc, bb, and bc) with a light (d or u) quark. The ground, radial, and orbital states are calculated in the framework of the hypercentral constituent quark model with Coulomb plus linear potential. Our results are also compared with other predictions, thus, the average possible range of excited states masses of these Ξ baryons can be determined. The study of the Regge trajectories is performed in (n, M{sup 2}) and (J, M{sup 2}) planes and their slopes and intercepts are also determined. Lastly, the ground state magnetic moments of these doubly heavy baryons are also calculated. (orig.)

Magnetic moment of {sup 48}Sc

Energy Technology Data Exchange (ETDEWEB)

Ohtsubo, T., E-mail: tohtsubo@np.gs.niigata-u.ac.jp; Kawamura, Y.; Ohya, S. [Niigata University, Department of Physics (Japan); Izumikawa, T. [Niigata University, Radioisotope Center (Japan); Nishimura, K. [Toyama University, Faculty of Engineering (Japan); Muto, S. [Neutron Science Laboratory, KEK (Japan); Shinozuka, T. [Tohoku University, Cyclotron and Radioisotope Center (Japan)

2007-11-15

Nuclear magnetic resonances were measured for {sup 48}Sc and {sup 44m}Sc oriented at 8 mK in an Fe host metal. The magnetic hyperfine splitting frequencies at an external magnetic field of 0.2 T were determined to be 63.22(11) MHz and 64.81(1) MHz for {sup 48}Sc and {sup 44m}Sc, respectively. With the known magnetic moment of {mu}({sup 44m}Sc)=+3.88 (1) {mu}{sub N}, the magnetic moment of {sup 48}Sc is deduced as {mu}({sup 44}Sc)=+3.785(12) {mu}{sub N}. The measured magnetic moment of {sup 48}Sc is discussed in terms of the shell model using the effective interactions.

Quark-diquark approximation of the three-quark structure of baryons in the quark confinement model

International Nuclear Information System (INIS)

Efimov, G.V.; Ivanov, M.A.; Lyubovitskij, V.E.

1990-01-01

Octet (1 + /2) and decuplet (3 + /2) of baryons as relativistic three-quark states are investigated in the quark confinement model (QCM), the relativistic quark model, based on some assumptions about hadronization and quark confinement. The quark-diquark approximation of the three-quark structure of baryons is proposed. In the framework of this approach the description of the main low-energy characteristics of baryons as magnetic moments, electromagnetic radii and form factors, ratio of axial and vector constants in semileptonic baryon octet decays, strong form factors and decay widths is given. The obtained results are in agreement with experimental data. 31 refs.; 4 figs.; 5 tabs

On verifying magnetic dipole moment of a magnetic torquer by experiments

Science.gov (United States)

Kuyyakanont, Aekjira; Kuntanapreeda, Suwat; Fuengwarodsakul, Nisai H.

2018-01-01

Magnetic torquers are used for the attitude control of small satellites, such as CubeSats with Low Earth Orbit (LEO). During the design of magnetic torquers, it is necessary to confirm if its magnetic dipole moment is enough to control the satellite attitude. The magnetic dipole moment can affect the detumbling time and the satellite rotation time. In addition, it is also necessary to understand how to design the magnetic torquer for operation in a CubeSat under the space environment at LEO. This paper reports an investigation of the magnetic dipole moment and the magnetic field generated by a circular air-coil magnetic torquer using experimental measurements. The experiment testbed was built on an air-bearing under a magnetic field generated by a Helmholtz coil. This paper also describes the procedure to determine and verify the magnetic dipole moment value of the designed circular air-core magnetic torquer. The experimental results are compared with the design calculations. According to the comparison results, the designed magnetic torquer reaches the required magnetic dipole moment. This designed magnetic torquer will be applied to the attitude control systems of a 1U CubeSat satellite in the project “KNACKSAT.”

Variational approach to magnetic moments

Energy Technology Data Exchange (ETDEWEB)

Lipparini, E; Stringari, S; Traini, M [Dipartimento di Matematica e Fisica, Libera Universita di Trento, Italy

1977-11-07

Magnetic moments in nuclei with a spin unsaturated core plus or minus an extra nucleon have been studied using a restricted Hartree-Fock approach. The method yields simple explicit expressions for the deformed ground state and for magnetic moments. Different projection techniques of the HF scheme have been discussed and compared with perturbation theory.

On a model for baryons based on a Dirac equation with confining potentials

International Nuclear Information System (INIS)

Ferreira, P.L.

1977-06-01

An independent particle model for baryons is studied in which the quarks obey a Dirac equation with an average potential of the form V(r) = 1/2 (1 + β)(V 0 + lambda r - γ/r). A numerical solution is obtained for S-waves. Several properties of the 1/2 + baryons such as the ratio (G sub(A)/G sub(V)) sub (N) for nucleons and baryon magnetic moments are analysed in terms of the model. A comparison with the case of a pure linear potential and with a pure harmonic oscillator is made, showing that it is possible to obtain a better agreement with the data in the present case

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)

Magnetic moment measurement of magnetic nanoparticles using atomic force microscopy

International Nuclear Information System (INIS)

Park, J-W; Lee, E-C; Ju, H; Yoo, I S; Chang, W-S; Chung, B H; Kim, B S

2008-01-01

Magnetic moment per unit mass of magnetic nanoparticles was found by using the atomic force microscope (AFM). The mass of the nanoparticles was acquired from the resonance frequency shift of the particle-attached AFM probe and magnetic force measurement was also carried out with the AFM. Combining with magnetic field strength, the magnetic moment per unit mass of the nanoparticles was determined as a function of magnetic field strength. (technical design note)

Theory of nuclear magnetic moments - LT-35

Energy Technology Data Exchange (ETDEWEB)

Kerman, A. K.

1952-09-15

The purpose of these notes is to give an account of some attempts at interpreting the observed values of nuclear magnetic moments. There is no attempt at a complete summary of the field as that would take much more space than is used here. In many cases the arguments are only outlined and references are given for those interested in further details. A discussion of the theory of nuclear magnetic moments necessitates many excursions into the details of the nuclear models because the magnetic moments have a direct bearing on the validity of these models. However the main emphasis here is on those features which tend to explain the magnetic moments and other evidence is not discussed unless it has a direct bearing on the problem. In the first part of the discussion the Shell Model of the nucleus is used, as this model seems to correlate a large body of data relating to the heavier nuclei. Included here are the modifications proposed to explain the fact that the experimental magnetic moments do not fit quantitatively with the exact predictions of the Shell Model. The next sections deal with some of the more drastic modifications introduced to explain the large nuclear quadrupole moments and the effect of these modifications on the magnetic moments. Finally we turn to more detailed investigations of the light nuclei, in particular the - Conjugate nuclei. (author)

Relativistic dynamics of point magnetic moment

Science.gov (United States)

Rafelski, Johann; Formanek, Martin; Steinmetz, Andrew

2018-01-01

The covariant motion of a classical point particle with magnetic moment in the presence of (external) electromagnetic fields is revisited. We are interested in understanding extensions to the Lorentz force involving point particle magnetic moment (Stern-Gerlach force) and how the spin precession dynamics is modified for consistency. We introduce spin as a classical particle property inherent to Poincaré symmetry of space-time. We propose a covariant formulation of the magnetic force based on a `magnetic' 4-potential and show how the point particle magnetic moment relates to the Amperian (current loop) and Gilbertian (magnetic monopole) descriptions. We show that covariant spin precession lacks a unique form and discuss the connection to g-2 anomaly. We consider the variational action principle and find that a consistent extension of the Lorentz force to include magnetic spin force is not straightforward. We look at non-covariant particle dynamics, and present a short introduction to the dynamics of (neutral) particles hit by a laser pulse of arbitrary shape.

Passive axial magnetic bearing with Halbach magnetized array in magnetically suspended control moment gyro application

International Nuclear Information System (INIS)

Sun Jinji; Ren Yuan; Fang Jiancheng

2011-01-01

The paper presents a special configuration of passive axial magnetic bearing with segmented Halbach magnetized array in magnetically suspended control moment gyro (MSCMG). Peculiarity of presented passive axial magnetic bearing is its ability to provide angular stiffness so that it can produce gyro moment when it is used in MSCMG. The MSCMG with this passive axial magnetic bearing can efficiently reduce the power loss when it supplies gyro moment compared with the five degrees of freedom (5-DOF) MSCMG. The characteristics of the suspension force and stiffness of the passive axial magnetic bearing are studied using finite element method (FEM). The performance of the presented passive axial magnetic bearing with Halbach magnetized array is verified by a prototyped MSCMG. - Research highlights: → Passive axial magnetic bearing is used to provide angular stiffness. → Passive axial magnetic bearing is based on repulsion. → Layers Halbach magnetized array realizes higher stiffness per bearing volume. → Passive axial magnetic bearing can provide gyro moment in CMG. → Power loss of MSCMG with PMB does not increase when it provides gyro moment.

Effective field theories of baryons and mesons, or, what do quarks do?

International Nuclear Information System (INIS)

Keaton, G.L.

1995-01-01

This thesis is an attempt to understand the properties of the protons, pions and other hadrons in terms of their fundamental building blocks. In the first chapter the author reviews several of the approaches that have already been developed. The Nambu-Jona-Lasinio model offers the classic example of a derivation of meson properties from a quark Lagrangian. The chiral quark model encodes much of the intuition acquired in recent decades. The author also discusses the non-linear sigma model, the Skyrme model, and the constituent quark model, which is one of the oldest and most successful models. In the constituent quark model, the constituent quark appears to be different from the current quark that appears in the fundamental QCD Lagrangian. Recently it was proposed that the constituent quark is a topological soliton. In chapter 2 the author investigates this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. In chapter 3 the author uses a different plan of attack. Rather than trying to model the constituents of the baryon, he begins with an effective field theory of baryons and mesons, with couplings and masses that are simply determined phenomenologically. Meson loop corrections to baryon axial currents are then computed in the 1/N expansion. It is already known that the one-loop corrections are suppressed by a factor 1/N; here it is shown that the two-loop corrections are suppressed by 1/N 2 . To leading order, these corrections are exactly the same as would be calculated in the constituent quark model. This method therefore offers a different approach to the constituent quark

Electromagnetic properties of light and heavy baryons in the relativistic quark model

International Nuclear Information System (INIS)

Nicmorus Marinescu, Diana

2007-01-01

One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N→Δγ transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit within this

Electromagnetic properties of light and heavy baryons in the relativistic quark model

Energy Technology Data Exchange (ETDEWEB)

Nicmorus Marinescu, Diana

2007-06-14

One of the main challenges of nowadays low-energy physics remains the description of the internal structure of hadrons, strongly connected to the electromagnetic properties of matter. In this vein, the success of the relativistic quark model in the analysis of the hadron structure constitutes a solid motivation for the study carried out throughout this work. The relativistic quark model is extended to the investigation of static electromagnetic properties of both heavy and light baryons. The bare contributions to the magnetic moments of the single-, double- and triple-heavy baryons are calculated. Moreover, the relativistic quark model allows the study of the electromagnetic properties of the light baryon octet incorporating meson cloud contributions in a perturbative manner. The long disputed values of the multipole ratios E2/M1 and C2/M1 and the electromagnetic form factors of the N{yields}{delta}{gamma} transition are successfully reproduced. The relativistic quark model can be viewed as a quantum field theory approach based on a phenomenological Lagrangian coupling light and heavy baryons to their constituent quarks. In our approach the baryon is a composite object of three constituent quarks, at least in leading order. The effective interaction Lagrangian is written in terms of baryon and constituent quark fields. The effective action preserves Lorentz covariance and gauge invariance. The main ingredients of the model are already introduced at the level of the interaction Lagrangian: the three-quark baryon currents, the Gaussian distribution of the constituent quarks inside the baryon and the compositeness condition which sets an upper limit for the baryon-quark vertex. The S-matrix elements are expressed by a set of Feynman quark-diagrams. The model contains only few parameters, namely, the cut-off parameter of the Gaussian quark distribution and the free quark propagator, which are unambiguously determined from the best fit to the data. The heavy quark limit

Magnetic moment of single layer graphene rings

Science.gov (United States)

Margulis, V. A.; Karpunin, V. V.; Mironova, K. I.

2018-01-01

Magnetic moment of single layer graphene rings is investigated. An analytical expression for the magnetic moment as a function of the magnetic field flux through the one-dimensional quantum rings is obtained. This expression has the oscillation character. The oscillation period is equal to one flux quanta.

Exchange currents for hypernuclear magnetic moments

International Nuclear Information System (INIS)

Saito, K.; Oka, M.; Suzuki, T.

1997-01-01

The meson (K and π) exchange currents for the hypernuclear magnetic moments are calculated using the effective Lagrangian method. The seagull diagram, the mesonic diagram and the Σ 0 -excitation diagram are considered. The Λ-N exchange magnetic moments for 5 Λ He and A=6 hypernuclei are calculated employing the harmonic oscillator shell model. It is found that the two-body correction is about -9% of the single particle value for 5 Λ He. The π exchange current, induced only in the Σ 0 -excitation diagram, is found to give dominant contribution for the isovector magnetic moments of hypernuclei with A=6. (orig.)

SU(3) flavour breaking and baryon structure

Energy Technology Data Exchange (ETDEWEB)

Cooke, A.N.; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich GmbH (Germany). Juelich Supercomputing Centre (JSC); Regensburg Univ. (Germany). Institut fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Shanahan, P.; Zanotti, J.M. [Adelaide Univ., SA (Australia). CSSM, School of Chemistry and Physics; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: QCDSF/UKQCD Collaboration

2013-11-15

We present results from the QCDSF/UKQCD collaboration for hyperon electromagnetic form factors and axial charges obtained from simulations using N{sub f}=2+1 flavours of O(a)-improved Wilson fermions. We also consider matrix elements relevant for hyperon semileptonic decays. We find flavour-breaking effects in hyperon magnetic moments which are consistent with experiment, while our results for the connected quark spin content indicates that quarks contribute more to the spin of the {Xi} baryon than they do to the proton.

Relativistic dynamics of point magnetic moment

Energy Technology Data Exchange (ETDEWEB)

Rafelski, Johann; Formanek, Martin; Steinmetz, Andrew [The University of Arizona, Department of Physics, Tucson, AZ (United States)

2018-01-15

The covariant motion of a classical point particle with magnetic moment in the presence of (external) electromagnetic fields is revisited. We are interested in understanding extensions to the Lorentz force involving point particle magnetic moment (Stern-Gerlach force) and how the spin precession dynamics is modified for consistency. We introduce spin as a classical particle property inherent to Poincare symmetry of space-time. We propose a covariant formulation of the magnetic force based on a 'magnetic' 4-potential and show how the point particle magnetic moment relates to the Amperian (current loop) and Gilbertian (magnetic monopole) descriptions. We show that covariant spin precession lacks a unique form and discuss the connection to g - 2 anomaly. We consider the variational action principle and find that a consistent extension of the Lorentz force to include magnetic spin force is not straightforward. We look at non-covariant particle dynamics, and present a short introduction to the dynamics of (neutral) particles hit by a laser pulse of arbitrary shape. (orig.)

Search for strange baryon electric dipole moment at LHCb

CERN Document Server

Lewis, Daniel James

2017-01-01

A search for the EDM of $\\Lambda$ baryons using the LHCb detector is proposed. In order to perform this search, the reconstruction of $\\Lambda$ baryons using T tracks must be possible. This note presents the reconstruction techniques and resolution studies that demonstrate that this is indeed feasible.

Heavy quark and magnetic moment

International Nuclear Information System (INIS)

Mubarak, Ahmad; Jallu, M.S.

1979-01-01

The magnetic moments and transition moments of heavy hadrons including the conventional particles are obtained under the SU(5) truth symmetry scheme. To this end state vectors are defined and the quark additivity principle is taken into account. (author)

Composite quarks and their magnetic moments

International Nuclear Information System (INIS)

Parthasarathy, R.

1980-08-01

A composite quark model based on the symmetry group SU(10)sub(flavour) x SU(10)sub(colour) with the assumption of mass non-degenerate sub-quarks is considered. Magnetic moments of quarks and sub-quarks are obtained from the observed nucleon magnetic moments. Using these quark and sub-quark magnetic moments, a satisfactory agreement for the radiative decays of vector mesons (rho,ω) is obtained. The ratio of the masses of the sub-quarks constituting the u,d,s quarks are found to be Msub(p)/Msub(n) = 0.3953 and Msub(p)/Msub(lambda) = 0.596, indicating a mass hierarchy Msub(p) < Msub(n) < Msub(lambda) for the sub-quarks. (author)

Determination of the neutron magnetic moment

International Nuclear Information System (INIS)

Greene, G.L.; Ramsey, N.F.; Mampe, W.; Pendlebury, J.M.; Smith, K.; Dress, W.B.; Miller, P.D.; Perrin, P.

1981-01-01

The neutron magnetic moment has been measured with an improvement of a factor of 100 over the previous best measurement. Using a magnetic resonance spectrometer of the separated oscillatory field type capable of determining a resonance signal for both neutrons and protons (in flowing H 2 O), we find μ/sub n//μ/sub p/ = 0.68497935(17) (0.25 ppM). The neutron magnetic moment can also be expressed without loss of accuracy in a variety of other units

Induced Magnetic Moment in Defected Single-Walled Carbon Nanotubes

International Nuclear Information System (INIS)

Liu Hong

2006-01-01

The existence of a large induced magnetic moment in defect single-walled carbon nanotube(SWNT) is predicted using the Green's function method. Specific to this magnetic moment of defect SWNT is its magnitude which is several orders of magnitude larger than that of perfect SWNT. The induced magnetic moment also shows certain remarkable features. Therefore, we suggest that two pair-defect orientations in SWNT can be distinguished in experiment through the direction of the induced magnetic moment at some Specific energy points

Quantum tunneling of the magnetic moment in a free nanoparticle

International Nuclear Information System (INIS)

O'Keeffe, M.F.; Chudnovsky, E.M.; Garanin, D.A.

2012-01-01

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. The energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and the quantum phase diagram is obtained. - Highlights: ► We obtain an exact analytical solution of a tunneling spin in a mechanical rotator. ► The quantum phase diagram shows magnetic moment dependence on rotator shape and size. ► Our work explains magnetic properties of free atomic clusters and magnetic molecules.

Can the magnetic moment contribution explain the Ay puzzle?

International Nuclear Information System (INIS)

Stoks, V.G.

1998-01-01

We evaluate the full one-photon-exchange Born amplitude for Nd scattering. We include the contributions due to the magnetic moment of the proton or neutron, and the magnetic moment and quadrupole moment of the deuteron. It is found that the inclusion of the magnetic-moment interaction in the theoretical description of the Nd scattering observables cannot resolve the long-standing A y puzzle. copyright 1998 The American Physical Society

Quantum tunneling of the magnetic moment in a free nanoparticle

Energy Technology Data Exchange (ETDEWEB)

O' Keeffe, M.F. [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States); Chudnovsky, E.M., E-mail: eugene.chudnovsky@lehman.cuny.edu [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States); Garanin, D.A. [Physics Department, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, New York, 10468-1589 (United States)

2012-09-15

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. The energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and the quantum phase diagram is obtained. - Highlights: Black-Right-Pointing-Pointer We obtain an exact analytical solution of a tunneling spin in a mechanical rotator. Black-Right-Pointing-Pointer The quantum phase diagram shows magnetic moment dependence on rotator shape and size. Black-Right-Pointing-Pointer Our work explains magnetic properties of free atomic clusters and magnetic molecules.

Model independent bounds on magnetic moments of Majorana neutrinos

International Nuclear Information System (INIS)

Bell, Nicole F.; Gorchtein, Mikhail; Ramsey-Musolf, Michael J.; Vogel, Petr; Wang, Peng

2006-01-01

We analyze the implications of neutrino masses for the magnitude of neutrino magnetic moments. By considering electroweak radiative corrections to the neutrino mass, we derive model-independent naturalness upper bounds on neutrino magnetic moments, μ ν , generated by physics above the electroweak scale. For Dirac neutrinos, the bound is several orders of magnitude more stringent than present experimental limits. However, for Majorana neutrinos the magnetic moment contribution to the mass is Yukawa suppressed. The bounds we derive for magnetic moments of Majorana neutrinos are weaker than present experimental limits if μ ν is generated by new physics at ∼1 TeV, and surpass current experimental sensitivity only for new physics scales >10-100 TeV. The discovery of a neutrino magnetic moment near present limits would thus signify that neutrinos are Majorana particles

Simple optical measurement of the magnetic moment of magnetically labeled objects

Energy Technology Data Exchange (ETDEWEB)

Heidsieck, Alexandra, E-mail: aheidsieck@tum.de [Zentralinstitut für Medizintechnik, Technische Universität München (Germany); Rudigkeit, Sarah [Physics Department, Technische Universität München (Germany); Rümenapp, Christine; Gleich, Bernhard [Zentralinstitut für Medizintechnik, Technische Universität München (Germany)

2017-04-01

The magnetic moment of magnetically labeled cells, microbubbles or microspheres is an important optimization parameter for many targeting, delivery or separation applications. The quantification of this property is often difficult, since it depends not only on the type of incorporated nanoparticle, but also on the intake capabilities, surface properties and internal distribution. We describe a method to determine the magnetic moment of those carriers using a microscopic set-up and an image processing algorithm. In contrast to other works, we measure the diversion of superparamagnetic nanoparticles in a static fluid. The set-up is optimized to achieve a homogeneous movement of the magnetic carriers inside the magnetic field. The evaluation is automated with a customized algorithm, utilizing a set of basic algorithms, including blob recognition, feature-based shape recognition and a graph algorithm. We present example measurements for the characteristic properties of different types of carriers in combination with different types of nanoparticles. Those properties include velocity in the magnetic field as well as the magnetic moment. The investigated carriers are adherent and suspension cells, while the used nanoparticles have different sizes and coatings to obtain varying behavior of the carriers. - Highlights: • Determination of the magnetic moment of magnetic carriers. • optimized set-up achieve a homogeneous movement. • Automated evaluation with a customized algorithm. • example measurements for the properties of nanoparticle-loaded cells.

Energy of magnetic moment of superconducting current in magnetic field

International Nuclear Information System (INIS)

Gurtovoi, V.L.; Nikulov, A.V.

2015-01-01

Highlights: • Quantization effects observed in superconducting loops are considered. • The energy of magnetic moment in magnetic field can not be deduced from Hamiltonian. • This energy is deduced from a history of the current state in the classical case. • It can not be deduced directly in the quantum case. • Taking this energy into account demolishes agreement between theory and experiment. - Abstract: The energy of magnetic moment of the persistent current circulating in superconducting loop in an externally produced magnetic field is not taken into account in the theory of quantization effects because of identification of the Hamiltonian with the energy. This identification misleads if, in accordance with the conservation law, the energy of a state is the energy expended for its creation. The energy of magnetic moment is deduced from a creation history of the current state in magnetic field both in the classical and quantum case. But taking this energy into account demolishes the agreement between theory and experiment. Impartial consideration of this problem discovers the contradiction both in theory and experiment

Electric and magnetic dipole moments of the neutron

International Nuclear Information System (INIS)

Ramsey, N.F.

1977-01-01

Experiments to measure the electric and magnetic dipole moments of the neutron are described. The apparatus used in this experiment is one to measure with high precision the precessional frequency of the neutron spin in a weak magnetic field with a neutron beam magnetic resonance apparatus similar to that used for measuring the magnetic moment of the neutron. Results of the measurement are presented. 52 references

Spontaneous magnetization in high-density quark matter

DEFF Research Database (Denmark)

Tsue, Yasuhiko; da Providência, João; Providência, Constanca

2015-01-01

It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous magnet...

Macroscopic quantum tunneling of the magnetic moment

Science.gov (United States)

Tejada, J.; Hernandez, J. M.; del Barco, E.

1999-05-01

In this paper we review the work done on magnetic relaxation during the last 10 years on both single-domain particles and magnetic molecules and its contribution to the discovery of quantum tunneling of the magnetic moment (Chudnovsky and Tejada, Macroscopic Quantum tunneling of the Magnetic moment, Cambridge University press, Cambridge, 1998). We present first the theoretical expressions and their connection to quantum relaxation and secondly, we show and discuss the experimental results. Finally, we discuss very recent hysteresis data on Mn 12Ac molecules at extremely large sweeping rate for the external magnetic field which suggest the existence of quantum spin—phonon avalanches.

Ultra-high sensitivity moment magnetometry of geological samples using magnetic microscopy

Science.gov (United States)

Lima, Eduardo A.; Weiss, Benjamin P.

2016-09-01

Useful paleomagnetic information is expected to be recorded by samples with moments up to three orders of magnitude below the detection limit of standard superconducting rock magnetometers. Such samples are now detectable using recently developed magnetic microscopes, which map the magnetic fields above room-temperature samples with unprecedented spatial resolutions and field sensitivities. However, realizing this potential requires the development of techniques for retrieving sample moments from magnetic microscopy data. With this goal, we developed a technique for uniquely obtaining the net magnetic moment of geological samples from magnetic microscopy maps of unresolved or nearly unresolved magnetization. This technique is particularly powerful for analyzing small, weakly magnetized samples such as meteoritic chondrules and terrestrial silicate crystals like zircons. We validated this technique by applying it to field maps generated from synthetic sources and also to field maps measured using a superconducting quantum interference device (SQUID) microscope above geological samples with moments down to 10-15 Am2. For the most magnetic rock samples, the net moments estimated from the SQUID microscope data are within error of independent moment measurements acquired using lower sensitivity standard rock magnetometers. In addition to its superior moment sensitivity, SQUID microscope net moment magnetometry also enables the identification and isolation of magnetic contamination and background sources, which is critical for improving accuracy in paleomagnetic studies of weakly magnetic samples.

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn; Creber, Sarah A.; Vrouwenvelder, Johannes S.; Johns, Michael L.

2015-01-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth's magnetic field system.

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn

2015-03-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth\\'s magnetic field system.

Dynamic interaction between localized magnetic moments in carbon nanotubes

International Nuclear Information System (INIS)

Costa, A T; Muniz, R B; Ferreira, M S

2008-01-01

Magnetic moments dilutely dispersed in a metallic host tend to be coupled through the conduction electrons of the metal. This indirect exchange coupling (IEC), known to occur for a variety of magnetic materials embedded in several different metallic structures, is of rather long range, especially for low-dimensional structures like carbon nanotubes. Motivated by recent claims that the indirect coupling between magnetic moments in precessional motion has a much longer range than its static counterpart, we consider here how magnetic atoms adsorbed to the walls of a metallic nanotube respond to a time-dependent perturbation that induces their magnetic moments to precess. By calculating the frequency-dependent spin susceptibility, we are able to identify resonant peaks whose respective widths provide information about the dynamic aspect of the IEC. We show that by departing from a purely static representation to another in which the moments are allowed to precess, we change from what is already considered a long-range interaction to another whose range is far superior. In other words, localized magnetic moments embedded in a metallic structure can feel each other's presence more easily when they are set in precessional motion. We argue that such an effect can have useful applications leading to large-scale spintronics devices

Meson-exchange-current corrections to magnetic moments in quantum hadrodynamics

International Nuclear Information System (INIS)

Morse, T.M.

1990-01-01

Corrections to the magnetic moments of the non-relativistic shell model (Schmidt lines) have a long history. In the early fifties calculations of pion exchange and core polarization contributions to nuclear magnetic moments were initiated. These calculations matured by the early eighties to include other mesons and the delta isobar. Relativistic nuclear shell model calculations are relatively recent. Meson exchange and the delta isobar current contributions to the magnetic moments of the relativistic shell model have remained largely unexplored. The disagreement between the valence values of spherical relativistic mean-field models and experiment was a major problem with early (1975-1985) quantum hydrodynamics (QHD) calculations of magnetic moments. Core polarization calculations (1986-1988) have been found to resolve the large discrepancy, predicting isoscalar magnetic moments to within typically five percent of experiment. The isovector magnetic moments, however, are about twice as far from experiment with an average discrepancy of about ten percent. The pion, being the lightest of the mesons, has historically been expected to dominate isovector corrections. Because this has been found to be true in non-relativistic calculations, the author calculated the pion corrections in the framework of QHD. The seagull and in-flight pion exchange current diagram corrections to the magnetic moments of eight finite nuclei (plus or minus one valence nucleon from the magic A = 16 and A = 40 doubly closed shell systems) are calculated in the framework of QHD, and compared with earlier non-relativistic calculations and experiment

Quantitative magnetic-moment mapping of a permanent-magnet material by X-ray magnetic circular dichroism nano-spectroscopy

Directory of Open Access Journals (Sweden)

Tetsuro Ueno

2017-05-01

Full Text Available We demonstrate the quantitative mapping of magnetic moments in a permanent-magnet material by X-ray magnetic circular dichroism nano-spectroscopy. An SmCo5 specimen was prepared from the bulk material by using a micro-fabrication technique. Scanning transmission X-ray microscopy images were obtained around the Sm M4,5 absorption edges. By applying the magneto-optical sum rules to these images, we obtained quantitative maps of the orbital and spin magnetic moments as well as their ratio. We found that the magnitudes of the orbital and spin magnetic moments and their ratio do not depend on thickness of the specimen.

Quark-diquark model description for double charm baryons

International Nuclear Information System (INIS)

Majethiya, A.; Patel, B.; Vinodkumar, P. C.

2010-01-01

We report here the mass spectrum and magnetic moments of ccq(q (implied by) u, d, s) systems in the potential model framework by assuming the inter-quark potential as the colour coulomb plus power form with power index ν varying between 0.1 to 2.0. Here the two charm quarks are considered for the diquark states. The conventional one gluon exchange interaction has been employed to get the hyperfine and the fine structure between different states. We have predicted many low-lying states whose experimental verification can exclusively support the quark-diquark structure of the baryons. (authors)

The vector meson with anomalous magnetic moment

International Nuclear Information System (INIS)

Boyarkin, O.M.

1976-01-01

The possibility of introducing an anomalous magnetic moment into the Stuckelberg version of the charged vector meson theory is considered. It is shown that the interference of states with spins equal to one and zero is absent in the presence of an anomalous magnetic moment of a particle. The differential cross section of scattering on the Coulomb field of a nucleus is calculated, and so are the differential and integral cross sections of meson pair production on annihilation of two gamma quanta. The two-photon mechanism of production of a meson pair in colliding electron-positron beams is considered. It is shown that with any value of the anomalous magnetic moment the cross section of the esup(+)esup(-) → esup(+)esup(-)γsup(*)γsup(*) → esup(+)esup(-)Wsup(+)Wsup(-) reaction exceeds that of the esup(+)esup(-) → γsup(*) → Wsup(+)Wsup(-) at sufficiently high energies

Search for Baryon-Number Violating Ξ_{b}^{0} Oscillations.

Science.gov (United States)

Aaij, R; Adeva, B; Adinolfi, M; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Alfonso Albero, A; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Archilli, F; d'Argent, P; Arnau Romeu, J; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Babuschkin, I; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baker, S; Balagura, V; Baldini, W; Baranov, A; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Baryshnikov, F; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Beiter, A; Bel, L J; Beliy, N; Bellee, V; Belloli, N; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Beranek, S; Berezhnoy, A; Bernet, R; Berninghoff, D; Bertholet, E; Bertolin, A; Betancourt, C; Betti, F; Bettler, M-O; van Beuzekom, M; Bezshyiko, Ia; Bifani, S; Billoir, P; Birnkraut, A; Bitadze, A; Bizzeti, A; Bjørn, M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Boettcher, T; Bondar, A; Bondar, N; Bonivento, W; Bordyuzhin, I; Borgheresi, A; Borghi, S; Borisyak, M; Borsato, M; Bossu, F; Boubdir, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britton, T; Brodzicka, J; Brundu, D; Buchanan, E; Burr, C; Bursche, A; Buytaert, J; Byczynski, W; Cadeddu, S; Cai, H; Calabrese, R; Calladine, R; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D H; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cavallero, G; Cenci, R; Chamont, D; Charles, M; Charpentier, Ph; Chatzikonstantinidis, G; Chefdeville, M; Chen, S; Cheung, S F; Chitic, S-G; Chobanova, V; Chrzaszcz, M; Chubykin, A; Ciambrone, P; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collins, P; Colombo, T; Comerma-Montells, A; Contu, A; Cook, A; Coombs, G; Coquereau, S; Corti, G; Corvo, M; Costa Sobral, C M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Currie, R; D'Ambrosio, C; Da Cunha Marinho, F; Dall'Occo, E; Dalseno, J; Davis, A; De Aguiar Francisco, O; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Serio, M; De Simone, P; Dean, C T; Decamp, D; Del Buono, L; Dembinski, H-P; Demmer, M; Dendek, A; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Nezza, P; Dijkstra, H; Dordei, F; Dorigo, M; Dosil Suárez, A; Douglas, L; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Durante, P; Dzhelyadin, R; Dziewiecki, M; Dziurda, A; Dzyuba, A; Easo, S; Ebert, M; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Farley, N; Farry, S; Fazzini, D; Federici, L; Ferguson, D; Fernandez, G; Fernandez Declara, P; Fernandez Prieto, A; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fini, R A; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fleuret, F; Fohl, K; Fontana, M; Fontanelli, F; Forshaw, D C; Forty, R; Franco Lima, V; Frank, M; Frei, C; Fu, J; Funk, W; Furfaro, E; Färber, C; Gabriel, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; Garcia Martin, L M; García Pardiñas, J; Garra Tico, J; Garrido, L; Garsed, P J; Gascon, D; Gaspar, C; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gizdov, K; Gligorov, V V; Golubkov, D; Golutvin, A; Gomes, A; Gorelov, I V; Gotti, C; Govorkova, E; Grabowski, J P; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greim, R; Griffith, P; Grillo, L; Gruber, L; Gruberg Cazon, B R; Grünberg, O; Gushchin, E; Guz, Yu; Gys, T; Göbel, C; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hamilton, B; Han, X; Hancock, T H; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hasse, C; Hatch, M; He, J; Hecker, M; Heinicke, K; Heister, A; Hennessy, K; Henrard, P; Henry, L; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hombach, C; Hopchev, P H; Huard, Z C; Hulsbergen, W; Humair, T; Hushchyn, M; Hutchcroft, D; Ibis, P; Idzik, M; Ilten, P; Jacobsson, R; Jalocha, J; Jans, E; Jawahery, A; Jiang, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Karacson, M; Kariuki, J M; Karodia, S; Kazeev, N; Kecke, M; Kelsey, M; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Klimkovich, T; Koliiev, S; Kolpin, M; Komarov, I; Kopecna, R; Koppenburg, P; Kosmyntseva, A; Kotriakhova, S; Kozeiha, M; Kravchuk, L; Kreps, M; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; Leflat, A; Lefrançois, J; Lefèvre, R; Lemaitre, F; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, P-R; Li, T; Li, Y; Li, Z; Likhomanenko, T; Lindner, R; Lionetto, F; Lisovskyi, V; Liu, X; Loh, D; Loi, A; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Lyu, X; Machefert, F; Maciuc, F; Macko, V; Mackowiak, P; Maddrell-Mander, S; Maev, O; Maguire, K; Maisuzenko, D; Majewski, M W; Malde, S; Malinin, A; Maltsev, T; Manca, G; Mancinelli, G; Manning, P; Marangotto, D; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marinangeli, M; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massacrier, L M; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurice, E; Maurin, B; Mazurov, A; McCann, M; McNab, A; McNulty, R; Mead, J V; Meadows, B; Meaux, C; Meier, F; Meinert, N; Melnychuk, D; Merk, M; Merli, A; Michielin, E; Milanes, D A; Millard, E; Minard, M-N; Minzoni, L; Mitzel, D S; Mogini, A; Molina Rodriguez, J; Mombacher, T; Monroy, I A; Monteil, S; Morandin, M; Morello, M J; Morgunova, O; Moron, J; Morris, A B; Mountain, R; Muheim, F; Mulder, M; Müller, D; Müller, J; Müller, K; Müller, V; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, T D; Nguyen-Mau, C; Nieswand, S; Niet, R; Nikitin, N; Nikodem, T; Nogay, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Oldeman, R; Onderwater, C J G; Ossowska, A; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pais, P R; Palano, A; Palutan, M; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parker, W; Parkes, C; Passaleva, G; Pastore, A; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petrov, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pikies, M; Pinci, D; Pistone, A; Piucci, A; Placinta, V; Playfer, S; Plo Casasus, M; Polci, F; Poli Lener, M; Poluektov, A; Polyakov, I; Polycarpo, E; Pomery, G J; Ponce, S; Popov, A; Popov, D; Poslavskii, S; Potterat, C; Price, E; Prisciandaro, J; Prouve, C; Pugatch, V; Puig Navarro, A; Pullen, H; Punzi, G; Qian, W; Quagliani, R; Quintana, B; Rachwal, B; Rademacker, J H; Rama, M; Ramos Pernas, M; Rangel, M S; Raniuk, I; Ratnikov, F; Raven, G; Ravonel Salzgeber, M; Reboud, M; Redi, F; Reichert, S; Dos Reis, A C; Remon Alepuz, C; Renaudin, V; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Robert, A; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Rogozhnikov, A; Roiser, S; Rollings, A; Romanovskiy, V; Romero Vidal, A; Ronayne, J W; Rotondo, M; Rudolph, M S; Ruf, T; Ruiz Valls, P; Ruiz Vidal, J; Saborido Silva, J J; Sadykhov, E; Sagidova, N; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarpis, G; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schellenberg, M; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schreiner, H F; Schubert, K; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sepulveda, E S; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Simone, S; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, I T; Smith, J; Smith, M; Soares Lavra, L; Sokoloff, M D; Soler, F J P; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefko, P; Stefkova, S; Steinkamp, O; Stemmle, S; Stenyakin, O; Stepanova, M; Stevens, H; Stone, S; Storaci, B; Stracka, S; Stramaglia, M E; Straticiuc, M; Straumann, U; Sun, J; Sun, L; Sutcliffe, W; Swientek, K; Syropoulos, V; Szczekowski, M; Szumlak, T; Szymanski, M; T'Jampens, S; Tayduganov, A; Tekampe, T; Tellarini, G; Teubert, F; Thomas, E; van Tilburg, J; Tilley, M J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Toriello, F; Tourinho Jadallah Aoude, R; Tournefier, E; Traill, M; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tully, A; Tuning, N; Ukleja, A; Usachov, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagner, A; Vagnoni, V; Valassi, A; Valat, S; Valenti, G; Vazquez Gomez, R; Vazquez Regueiro, P; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Venkateswaran, A; Verlage, T A; Vernet, M; Vesterinen, M; Viana Barbosa, J V; Viaud, B; Vieira, D; Vieites Diaz, M; Viemann, H; Vilasis-Cardona, X; Vitti, M; Volkov, V; Vollhardt, A; Voneki, B; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Vázquez Sierra, C; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wang, J; Ward, D R; Wark, H M; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wicht, J; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Winn, M; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wraight, K; Wyllie, K; Xie, Y; Xu, Z; Yang, Z; Yang, Z; Yao, Y; Yin, H; Yu, J; Yuan, X; Yushchenko, O; Zarebski, K A; Zavertyaev, M; Zhang, L; Zhang, Y; Zhelezov, A; Zheng, Y; Zhu, X; Zhukov, V; Zonneveld, J B; Zucchelli, S

2017-11-03

A search for baryon-number violating Ξ_{b}^{0} oscillations is performed with a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3  fb^{-1}. The baryon number at the moment of production is identified by requiring that the Ξ_{b}^{0} come from the decay of a resonance Ξ_{b}^{*-}→Ξ_{b}^{0}π^{-} or Ξ_{b}^{'-}→Ξ_{b}^{0}π^{-}, and the baryon number at the moment of decay is identified from the final state using the decays Ξ_{b}^{0}→Ξ_{c}^{+}π^{-},Ξ_{c}^{+}→pK^{-}π^{+}. No evidence of baryon-number violation is found, and an upper limit at the 95% confidence level is set on the oscillation rate of ω<0.08  ps^{-1}, where ω is the associated angular frequency.

Direct evidence of Ni magnetic moment in TbNi{sub 2}Mn—X-ray magnetic circular dichroism

Energy Technology Data Exchange (ETDEWEB)

Yu, D.H., E-mail: dyu@ansto.gov.au [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, NSW 2234 (Australia); Huang, Meng-Jie [National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Wang, J.L. [Bragg Institute, Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, NSW 2234 (Australia); School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Canberra at the Australian Defense Force Academy, Sydney, ACT 2600 (Australia); Institute for Superconductivity and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); Su, Hui-Chia; Lin, Hong-Ji; Chen, Chien-Te [National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan (China); Campbell, S.J. [School of Physical, Environmental and Mathematical Sciences, University of New South Wales, Canberra at the Australian Defense Force Academy, Sydney, ACT 2600 (Australia)

2014-12-15

We have investigated the individual magnetic moments of Ni, Mn and Tb atoms in the intermetallic compound TbNi{sub 2}Mn in the Laves phase (magnetic phase transition temperature T{sub C} ∼131 K) by X-ray magnetic circular dichroism (XMCD) studies at 300 K, 80 K and 20 K. Analyses of the experimental results reveal that Ni atoms at 20 K in an applied magnetic field of 1 T carry an intrinsic magnetic moment of spin and orbital magnetic moment contributions 0.53±0.01 μ{sub B} and 0.05±0.01 μ{sub B}, respectively. These moment values are similar to those of the maximum saturated moment of Ni element. A very small magnetic moment of order <0.1 μ{sub B} has been measured for Mn. This suggests that Mn is antiferromagnetically ordered across the two nearly equally occupied sites of 16d and 8a. A magnetic moment of up to ∼0.3 μ{sub B} has been observed for the Tb atoms. Identification of a magnetic moment on the Ni atoms has provided further evidence for the mechanism of enhancement of the magnetic phase transition temperature in TbNi{sub 2}Mn compared with TbNi{sub 2} (T{sub C}∼37.5 K) and TbMn{sub 2} (T{sub C}∼54 K) due to rare earth–transition metal (R–T) and transition metal–transition metal (T–T) interactions. The behaviour of the X-ray magnetic circular dichroism spectra of TbNi{sub 2}Mn at 300 K, 80 K and 20 K – above and below the magnetic ordering temperature T{sub C} ∼131 K – is discussed. - Highlights: • We study the magnetic moment of TbNi{sub 2}Mn with XMCD. • We observe directly the Ni intrinsic magnetic moment in TbNi{sub 2}Mn. • We find that Mn ordered antiferromagnetically across the 16d and 8a sites. • We confirm the mechanism for increasing the magnetic phase transition temperature.

The anomalous magnetic moment of the muon

CERN Document Server

Jegerlehner, Friedrich

2017-01-01

This research monograph covers extensively the theory of the muon anomalous magnetic moment and provides estimates of the theoretical uncertainties. The muon anomalous magnetic moment is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations. This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. Recent experiments at the Brookhaven National Laboratory now reach the unbelievable precision of 0.5 parts per million, improving the accuracy of previous g-2 experiments at CERN by a factor of 14. In addition, quantum electrodynamics and electroweak and hadronic effects are reviewed. Since non-perturbative hadronic effects play a key role for the precision test, their evaluation is described in detail. Perspectives fo...

The Anomalous Magnetic Moment of the Muon

CERN Document Server

Jegerlehner, Friedrich

2008-01-01

This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. The muon anomalous magnetic moment amy is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations. Recent experiments at the Brookhaven National Laboratory now reach the unbelievable precision of 0.5 parts per million, improving the accuracy of previous g-2 experiments at CERN by a factor of 14. A major part of the book is devoted to the theory of the anomalous magnetic moment and to estimates of the theoretical uncertainties. Quantum electrodynamics and electroweak and hadronic effects are reviewed. Since non-perturbative hadronic effects play a key role for the precision test, their evaluation is described in detail. After the overview of theory, the exper...

Extracting the Omega- electric quadrupole moment from lattice QCD data

Energy Technology Data Exchange (ETDEWEB)

G. Ramalho, M.T. Pena

2011-03-01

The Omega- has an extremely long lifetime, and is the most stable of the baryons with spin 3/2. Therefore the Omega- magnetic moment is very accurately known. Nevertheless, its electric quadrupole moment was never measured, although estimates exist in different formalisms. In principle, lattice QCD simulations provide at present the most appropriate way to estimate the Omega- form factors, as function of the square of the transferred four-momentum, Q2, since it describes baryon systems at the physical mass for the strange quark. However, lattice QCD form factors, and in particular GE2, are determined at finite Q2 only, and the extraction of the electric quadrupole moment, Q_Omega= GE2(0) e/(2 M_Omega), involves an extrapolation of the numerical lattice results. In this work we reproduce the lattice QCD data with a covariant spectator quark model for Omega- which includes a mixture of S and two D states for the relative quark-diquark motion. Once the model is calibrated, it is used to determine Q_Omega. Our prediction is Q_Omega= (0.96 +/- 0.02)*10^(-2) efm2 [GE2(0)=0.680 +/- 0.012].

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: $\\atau = 0.004 10^{-16}{e{\\cdot}\\mathrm{cm}}$.

Magnetic moments of composite quarks and leptons: further difficulties

International Nuclear Information System (INIS)

Lipkin, H.J.

1980-05-01

The previously noted difficulty of obtaining Dirac magnetic moments in composite models with two basic building blocks having different charges is combined with the observation by Shaw et al., that a light bound fermion state built from heavy constituents must have the Dirac moment in a renormalizable theory. The new constraint on any model that builds leptons from two fundamental fields bound by non-electromagnetic forces is that the ratio of the magnetic moment to the total charge of the bound state is independent of the values of the charges of the constituents; e.g., such a bound state of a spin-1/2 fermion and a scalar boson will have the same magnetic moment if the fermion is neutral and the boson has charge -e or vice versa

New limits on neutrino magnetic moment through nonvanishing 13-mixing

Science.gov (United States)

Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.

2018-05-01

The relatively large value of the neutrino mixing angle θ13 set by recent measurements allows us to use solar neutrinos to set a limit on the neutrino magnetic moment involving the second and third flavor families, μ23. The existence of a random magnetic field in the solar convective zone can produce a significant antineutrino flux when a nonvanishing neutrino magnetic moment is assumed. Even if we consider a vanishing neutrino magnetic moment involving the first family, electron antineutrinos are indirectly produced through the mixing between the first and third families and μ23≠0 . Using KamLAND limits on the solar flux of electron antineutrino, we set the limit μ23behavior of solar magnetic fields. This is the first time that a limit on μ23 has been established in the literature directly from neutrino interactions with magnetic fields, and, interestingly enough, is comparable with the limits on the neutrino magnetic moment involving the first family and with the ones coming from modifications to the electroweak cross section.

arXiv Search for baryon-number-violating $\\Xi_b^0$ oscillations

CERN Document Server

Aaij, Roel; LHCb Collaboration; Adinolfi, Marco; Ajaltouni, Ziad; Akar, Simon; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Alfonso Albero, Alejandro; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio Augusto; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Andreassi, Guido; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Archilli, Flavio; d'Argent, Philippe; Arnau Romeu, Joan; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Babuschkin, Igor; Bachmann, Sebastian; Back, John; Badalov, Alexey; Baesso, Clarissa; Baker, Sophie; Balagura, Vladislav; Baldini, Wander; Baranov, Alexander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Baryshnikov, Fedor; Batozskaya, Varvara; Battista, Vincenzo; Bay, Aurelio; Beaucourt, Leo; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Beiter, Andrew; Bel, Lennaert; Beliy, Nikita; Bellee, Violaine; Belloli, Nicoletta; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Beranek, Sarah; Berezhnoy, Alexander; Bernet, Roland; Berninghoff, Daniel; Bertholet, Emilie; Bertolin, Alessandro; Betancourt, Christopher; Betti, Federico; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bezshyiko, Iaroslava; Bifani, Simone; Billoir, Pierre; Birnkraut, Alex; Bitadze, Alexander; Bizzeti, Andrea; Bjørn, Mikkel; Blake, Thomas; Blanc, Frederic; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Boettcher, Thomas; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Bordyuzhin, Igor; Borgheresi, Alessio; Borghi, Silvia; Borisyak, Maxim; Borsato, Martino; Bossu, Francesco; Boubdir, Meriem; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Braun, Svende; Britton, Thomas; Brodzicka, Jolanta; Brundu, Davide; Buchanan, Emma; Burr, Christopher; Bursche, Albert; Buytaert, Jan; Byczynski, Wiktor; Cadeddu, Sandro; Cai, Hao; Calabrese, Roberto; Calladine, Ryan; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel Hugo; Capriotti, Lorenzo; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carniti, Paolo; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cavallero, Giovanni; Cenci, Riccardo; Chamont, David; Charles, Matthew; Charpentier, Philippe; Chatzikonstantinidis, Georgios; Chefdeville, Maximilien; Chen, Shanzhen; Cheung, Shu Faye; Chitic, Stefan-Gabriel; Chobanova, Veronika; Chrzaszcz, Marcin; Chubykin, Alexsei; Ciambrone, Paolo; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Cogan, Julien; Cogneras, Eric; Cogoni, Violetta; Cojocariu, Lucian; Collins, Paula; Colombo, Tommaso; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombs, George; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Costa Sobral, Cayo Mar; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Crocombe, Andrew; Cruz Torres, Melissa Maria; Currie, Robert; D'Ambrosio, Carmelo; Da Cunha Marinho, Franciole; Dall'Occo, Elena; Dalseno, Jeremy; Davis, Adam; De Aguiar Francisco, Oscar; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Serio, Marilisa; De Simone, Patrizia; Dean, Cameron Thomas; Decamp, Daniel; Del Buono, Luigi; Dembinski, Hans Peter; Demmer, Moritz; Dendek, Adam; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Dey, Biplab; Di Canto, Angelo; Di Nezza, Pasquale; Dijkstra, Hans; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Douglas, Lauren; Dovbnya, Anatoliy; Dreimanis, Karlis; Dufour, Laurent; Dujany, Giulio; Durante, Paolo; Dzhelyadin, Rustem; Dziewiecki, Michal; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Ebert, Marcus; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; Ely, Scott; Esen, Sevda; Evans, Hannah Mary; Evans, Timothy; Falabella, Antonio; Farley, Nathanael; Farry, Stephen; Fazzini, Davide; Federici, Luca; Ferguson, Dianne; Fernandez, Gerard; Fernandez Declara, Placido; Fernandez Prieto, Antonio; Ferrari, Fabio; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fini, Rosa Anna; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fleuret, Frederic; Fohl, Klaus; Fontana, Marianna; Fontanelli, Flavio; Forshaw, Dean Charles; Forty, Roger; Franco Lima, Vinicius; Frank, Markus; Frei, Christoph; Fu, Jinlin; Funk, Wolfgang; Furfaro, Emiliano; Färber, Christian; Gabriel, Emmy; Gallas Torreira, Abraham; Galli, Domenico; Gallorini, Stefano; Gambetta, Silvia; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garcia Martin, Luis Miguel; García Pardiñas, Julián; Garra Tico, Jordi; Garrido, Lluis; Garsed, Philip John; Gascon, David; Gaspar, Clara; Gavardi, Laura; Gazzoni, Giulio; Gerick, David; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianì, Sebastiana; Gibson, Valerie; Girard, Olivier Göran; Giubega, Lavinia-Helena; Gizdov, Konstantin; Gligorov, Vladimir; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gorelov, Igor Vladimirovich; Gotti, Claudio; Govorkova, Ekaterina; Grabowski, Jascha Peter; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graverini, Elena; Graziani, Giacomo; Grecu, Alexandru; Greim, Roman; Griffith, Peter; Grillo, Lucia; Gruber, Lukas; Gruberg Cazon, Barak Raimond; Grünberg, Oliver; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Göbel, Carla; Hadavizadeh, Thomas; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hamilton, Brian; Han, Xiaoxue; Hancock, Thomas Henry; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hasse, Christoph; Hatch, Mark; He, Jibo; Hecker, Malte; Heinicke, Kevin; Heister, Arno; Hennessy, Karol; Henrard, Pierre; Henry, Louis; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hombach, Christoph; Hopchev, Plamen Hristov; Huard, Zachary; Hulsbergen, Wouter; Humair, Thibaud; Hushchyn, Mikhail; Hutchcroft, David; Ibis, Philipp; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jalocha, Pawel; Jans, Eddy; Jawahery, Abolhassan; Jiang, Feng; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kandybei, Sergii; Karacson, Matthias; Kariuki, James Mwangi; Karodia, Sarah; Kazeev, Nikita; Kecke, Matthieu; Kelsey, Matthew; Kenzie, Matthew; Ketel, Tjeerd; Khairullin, Egor; Khanji, Basem; Khurewathanakul, Chitsanu; Kirn, Thomas; Klaver, Suzanne; Klimaszewski, Konrad; Klimkovich, Tatsiana; Koliiev, Serhii; Kolpin, Michael; Komarov, Ilya; Kopecna, Renata; Koppenburg, Patrick; Kosmyntseva, Alena; Kotriakhova, Sofia; Kozeiha, Mohamad; Kravchuk, Leonid; Kreps, Michal; Krokovny, Pavel; Kruse, Florian; Krzemien, Wojciech; Kucewicz, Wojciech; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kuonen, Axel Kevin; Kurek, Krzysztof; Kvaratskheliya, Tengiz; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; Leflat, Alexander; Lefrançois, Jacques; Lefèvre, Regis; Lemaitre, Florian; Lemos Cid, Edgar; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Pei-Rong; Li, Tenglin; Li, Yiming; Li, Zhuoming; Likhomanenko, Tatiana; Lindner, Rolf; Lionetto, Federica; Lisovskyi, Vitalii; Liu, Xuesong; Loh, David; Loi, Angelo; Longstaff, Iain; Lopes, Jose; Lucchesi, Donatella; Lucio Martinez, Miriam; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Lusiani, Alberto; Lyu, Xiao-Rui; Machefert, Frederic; Maciuc, Florin; Macko, Vladimir; Mackowiak, Patrick; Maddrell-Mander, Samuel; Maev, Oleg; Maguire, Kevin; Maisuzenko, Dmitrii; Majewski, Maciej Witold; Malde, Sneha; Malinin, Alexander; Maltsev, Timofei; Manca, Giulia; Mancinelli, Giampiero; Manning, Peter Michael; Marangotto, Daniele; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marin Benito, Carla; Marinangeli, Matthieu; Marino, Pietro; Marks, Jörg; Martellotti, Giuseppe; Martin, Morgan; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massacrier, Laure Marie; Massafferri, André; Matev, Rosen; Mathad, Abhijit; Mathe, Zoltan; Matteuzzi, Clara; Mauri, Andrea; Maurice, Emilie; Maurin, Brice; Mazurov, Alexander; McCann, Michael; McNab, Andrew; McNulty, Ronan; Mead, James Vincent; Meadows, Brian; Meaux, Cedric; Meier, Frank; Meinert, Nis; Melnychuk, Dmytro; Merk, Marcel; Merli, Andrea; Michielin, Emanuele; Milanes, Diego Alejandro; Millard, Edward James; Minard, Marie-Noelle; Minzoni, Luca; Mitzel, Dominik Stefan; Mogini, Andrea; Molina Rodriguez, Josue; Mombacher, Titus; Monroy, Igancio Alberto; Monteil, Stephane; Morandin, Mauro; Morello, Michael Joseph; Morgunova, Olga; Moron, Jakub; Morris, Adam Benjamin; Mountain, Raymond; Muheim, Franz; Mulder, Mick; Müller, Dominik; Müller, Janine; Müller, Katharina; Müller, Vanessa; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nandi, Anita; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Thi Dung; Nguyen-Mau, Chung; Nieswand, Simon; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Nogay, Alla; O'Hanlon, Daniel Patrick; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Ogilvy, Stephen; Oldeman, Rudolf; Onderwater, Gerco; Ossowska, Anna; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Aranzazu; Pais, Preema Rennee; Palano, Antimo; Palutan, Matteo; Papanestis, Antonios; Pappagallo, Marco; Pappalardo, Luciano; Parker, William; Parkes, Christopher; Passaleva, Giovanni; Pastore, Alessandra; Patel, Mitesh; Patrignani, Claudia; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perret, Pascal; Pescatore, Luca; Petridis, Konstantinos; Petrolini, Alessandro; Petrov, Aleksandr; Petruzzo, Marco; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pikies, Malgorzata; Pinci, Davide; Pistone, Alessandro; Piucci, Alessio; Placinta, Vlad-Mihai; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Poli Lener, Marco; Poluektov, Anton; Polyakov, Ivan; Polycarpo, Erica; Pomery, Gabriela Johanna; Ponce, Sebastien; Popov, Alexander; Popov, Dmitry; Poslavskii, Stanislav; Potterat, Cédric; Price, Eugenia; Prisciandaro, Jessica; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Pullen, Hannah Louise; Punzi, Giovanni; Qian, Wenbin; Quagliani, Renato; Quintana, Boris; Rachwal, Bartlomiej; Rademacker, Jonas; Rama, Matteo; Ramos Pernas, Miguel; Rangel, Murilo; Raniuk, Iurii; Ratnikov, Fedor; Raven, Gerhard; Ravonel Salzgeber, Melody; Reboud, Meril; Redi, Federico; Reichert, Stefanie; dos Reis, Alberto; Remon Alepuz, Clara; Renaudin, Victor; Ricciardi, Stefania; Richards, Sophie; Rihl, Mariana; Rinnert, Kurt; Rives Molina, Vicente; Robbe, Patrick; Robert, Arnaud; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Lopez, Jairo Alexis; Rodriguez Perez, Pablo; Rogozhnikov, Alexey; Roiser, Stefan; Rollings, Alexandra Paige; Romanovskiy, Vladimir; Romero Vidal, Antonio; Ronayne, John William; Rotondo, Marcello; Rudolph, Matthew Scott; Ruf, Thomas; Ruiz Valls, Pablo; Ruiz Vidal, Joan; Saborido Silva, Juan Jose; Sadykhov, Elnur; Sagidova, Naylya; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santimaria, Marco; Santovetti, Emanuele; Sarpis, Gediminas; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Saunders, Daniel Martin; Savrina, Darya; Schael, Stefan; Schellenberg, Margarete; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmelzer, Timon; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schreiner, HF; Schubert, Konstantin; Schubiger, Maxime; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Semennikov, Alexander; Sepulveda, Eduardo Enrique; Sergi, Antonino; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Siddi, Benedetto Gianluca; Silva Coutinho, Rafael; Silva de Oliveira, Luiz Gustavo; Simi, Gabriele; Simone, Saverio; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Eluned; Smith, Iwan Thomas; Smith, Jackson; Smith, Mark; Soares Lavra, Lais; Sokoloff, Michael; Soler, Paul; Souza De Paula, Bruno; Spaan, Bernhard; Spradlin, Patrick; Sridharan, Srikanth; Stagni, Federico; Stahl, Marian; Stahl, Sascha; Stefko, Pavol; Stefkova, Slavomira; Steinkamp, Olaf; Stemmle, Simon; Stenyakin, Oleg; Stepanova, Margarita; Stevens, Holger; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Stramaglia, Maria Elena; Straticiuc, Mihai; Straumann, Ulrich; Sun, Jiayin; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Syropoulos, Vasileios; Szczekowski, Marek; Szumlak, Tomasz; Szymanski, Maciej Pawel; T'Jampens, Stephane; Tayduganov, Andrey; Tekampe, Tobias; Tellarini, Giulia; Teubert, Frederic; Thomas, Eric; van Tilburg, Jeroen; Tilley, Matthew James; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Toriello, Francis; Tourinho Jadallah Aoude, Rafael; Tournefier, Edwige; Traill, Murdo; Tran, Minh Tâm; Tresch, Marco; Trisovic, Ana; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tully, Alison; Tuning, Niels; Ukleja, Artur; Usachov, Andrii; Ustyuzhanin, Andrey; Uwer, Ulrich; Vacca, Claudia; Vagner, Alexander; Vagnoni, Vincenzo; Valassi, Andrea; Valat, Sebastien; Valenti, Giovanni; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vecchi, Stefania; van Veghel, Maarten; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Venkateswaran, Aravindhan; Verlage, Tobias Anton; Vernet, Maxime; Vesterinen, Mika; Viana Barbosa, Joao Vitor; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Viemann, Harald; Vilasis-Cardona, Xavier; Vitti, Marcela; Volkov, Vladimir; Vollhardt, Achim; Voneki, Balazs; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; de Vries, Jacco; Vázquez Sierra, Carlos; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wang, Jianchun; Ward, David; Wark, Heather Mckenzie; Watson, Nigel; Websdale, David; Weiden, Andreas; Whitehead, Mark; Wicht, Jean; Wilkinson, Guy; Wilkinson, Michael; Williams, Mark Richard James; Williams, Matthew; Williams, Mike; Williams, Timothy; Wilson, Fergus; Wimberley, Jack; Winn, Michael Andreas; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wraight, Kenneth; Wyllie, Kenneth; Xie, Yuehong; Xu, Zhirui; Yang, Zhenwei; Yang, Zishuo; Yao, Yuezhe; Yin, Hang; Yu, Jiesheng; Yuan, Xuhao; Yushchenko, Oleg; Zarebski, Kristian Alexander; Zavertyaev, Mikhail; Zhang, Liming; Zhang, Yanxi; Zhelezov, Alexey; Zheng, Yangheng; Zhu, Xianglei; Zhukov, Valery; Zonneveld, Jennifer Brigitta; Zucchelli, Stefano

2017-11-03

A search for baryon-number-violating $\\Xi_b^0$ oscillations is performed with a sample of $pp$ collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb$^{-1}$. The baryon number at the moment of production is identified by requiring that the $\\Xi_b^0$ come from the decay of a resonance $\\Xi_b^{*-} \\to \\Xi_b^0 \\pi^-$ or $\\Xi_b^{\\prime-} \\to \\Xi_b^0 \\pi^-$, and the baryon number at the moment of decay is identified from the final state using the decays $\\Xi_b^0 \\to \\Xi_c^+ \\pi^-, ~ \\Xi_c^+ \\to p K^- \\pi^+$. No evidence of baryon number violation is found, and an upper limit is set on the oscillation rate of $\\omega < 0.08$ ps$^{-1}$, where $\\omega$ is the associated angular frequency.

Restrictions on the neutrino magnetic dipole moment

International Nuclear Information System (INIS)

Duncan, M.J.; Sankar, S.U.; Grifols, J.A.; Mendez, A.

1987-01-01

We examine mechanisms for producing neutrino magnetic moments from a wide class of particle theories which are extensions of the standard model. We show that it is difficult to naturally obtain a moment greater than ≅ 10 -2 electron Bohr magnetons. Thus models of phenomena requiring moments of order ≅ 10 -10 magnetons, such as those proposed as a resolution to the solar neutrino puzzle, are in conflict with current perceptions in particle physics. (orig.)

Baryon form factors in chiral perturbation theory

Energy Technology Data Exchange (ETDEWEB)

Kubis, B.; Meissner, U.G. [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Kernphysik

2001-01-01

We analyze the electromagnetic form factors of the ground state baryon octet to fourth order in relativistic baryon chiral perturbation theory. Predictions for the {sigma}{sup -} charge radius and the {lambda}-{sigma}{sup 0} transition moment are found to be in excellent agreement with the available experimental information. Furthermore, the convergence behavior of the hyperon charge radii is shown to be more than satisfactory. (orig.)

On a neutral particle with permanent magnetic dipole moment in a magnetic medium

Science.gov (United States)

Bakke, K.; Salvador, C.

2018-03-01

We investigate quantum effects that stem from the interaction of a permanent magnetic dipole moment of a neutral particle with an electric field in a magnetic medium. We consider a long non-conductor cylinder that possesses a uniform distribution of electric charges and a non-uniform magnetization. We discuss the possibility of achieving this non-uniform magnetization from the experimental point of view. Besides, due to this non-uniform magnetization, the permanent magnetic dipole moment of the neutral particle also interacts with a non-uniform magnetic field. This interaction gives rise to a linear scalar potential. Then, we show that bound states solutions to the Schrödinger-Pauli equation can be achieved.

The magnetic moment of NiO nanoparticles determined by Moessbauer spectroscopy

International Nuclear Information System (INIS)

Bahl, C R H; Hansen, M F; Pedersen, T; Saadi, S; Nielsen, K H; Lebech, B; Moerup, S

2006-01-01

We have studied the magnetic properties of 57 Fe-doped NiO nanoparticles using Moessbauer spectroscopy and magnetization measurements. Two samples with different degrees of interparticle interaction were studied. In both samples the particles were characterized by high-resolution transmission electron microscopy and x-ray diffraction and found to be plate-shaped. Computer simulations showed that high-field Moessbauer data are very sensitive to the size of the uncompensated magnetic moment. From analyses of the Moessbauer spectra we have estimated that the size of the uncompensated magnetic moment is in accordance with a model based on random occupation of surface sites. The analyses of the magnetization data gave larger magnetic moments, but the difference can be explained by the different sensitivity of the two methods to a particle size distribution and by interactions between the particles, which may have a strong influence on the moments estimated from magnetization data

On the origin of the giant magnetic moment of the Al-Mn quasicrystals

Directory of Open Access Journals (Sweden)

Bocharov P.V.

2011-05-01

Full Text Available Ab initio calculations of magnetic moments for icosahedral clusters contained in crystal structures Al10Mn3, Al5Co2, Al17Mn4 (Al13Cr4Si4-type fulfilled in the framework of Density Functional Theory. The AlMn cluster having the trigonal D3h symmetry with the triangle of Mn ions in the interior has the moment being equal to three magnetic moments of a single manganese ion (4.4 μB, the moment of the tetrahedral Td cluster with the Mn tetrahedron in the interior is equal approximately to twelve magnetic moments of the single manganese ion (15.5 μB. The magnetic moment of icosahedral Al-Co clusters having the same configuration is equal to zero. The magnetic moments of the rod assembled from the icosahedral clusters with the sequence Td D3h - Td was found to be 20.5 μB. This value permits to explain the giant magnetic moment of icosahedral and decagonal Al-Mn quasicrystals and gives the indirect evidence to the hierarchical model of the quasicrystals structure proposed by the authors recently. An arrangement of magnetic moment carriers in the interior of the aluminum shell of icosahedral clusters permits to suggest the interaction between contacting manganese ions as the main origin of the giant magnetic moment of the Al-Mn quasicrystals.

Magnetic moment distribution in Co-V alloys

International Nuclear Information System (INIS)

Cable, J.W.

1982-01-01

Magnetization and neutron scattering measurements were made on Co-V alloys containing 10, 15, and 20 at.% V to determine the local environment effects on the magnetic moment distribution in this system. The magnetization data agree with earlier results and suggest the presence of some hcp phase in the 10% sample. This was confirmed by the neutron data which showed both fcc and hcp phases in an approximate 4:1 volume ratio for this alloy. The other two samples were single phase fcc but the 15% alloy was disordered while the 20% alloy was ordered in the Cu 3 Au-type structure with the maximum order consistent with the concentration. In this ordered alloy, the excess Co occupies the V sites. These ''wrong sited'' Co atoms have 12 Co nearest neighbors and larger magnetic moments than the ''properly sited'' Co atoms which have an average of 8.8 Co nearest neighbors. The average moments associated with these two types of sites were determined from flipping-ratio measurements on the superlattice and fundamental reflections. The values obtained are 0.28 μ/sub B//Co for the proper-site atoms and 1.3 μ/sub B//Co for the wrong-site atoms. Average moments at the Co and V sites were determined from the diffuse scattering for the 10% and 15% alloys. The results are 1.38 μ/sub B//Co and -0.26 μ/sub B//V for the 10% sample and 1.05 μ/sub B//Co and -0.11 μ/sub B//V for the 15% sample

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.

Measurement of the electric dipole moment and magnetic moment anomaly of the muon

NARCIS (Netherlands)

Onderwater, CJG

2005-01-01

The experimental precision of the anomalous magnetic moment of the muon has been improved to 0.5 part-per-million by the Brookhaven E821 experiment, similar to the theoretical uncertainty. In the same experiment, a new limit on the electric dipole moment of 2.8 x 10(-19) e-cm (95% CL) was set. The

Core Polarization and Tensor Coupling Effects on Magnetic Moments of Hypernuclei

International Nuclear Information System (INIS)

Jiang-Ming, Yao; Jie, Meng; Hong-Feng, Lü; Greg, Hillhouse

2008-01-01

Effects of core polarization and tensor coupling on the magnetic moments in Λ 13 C, Λ 17 O, and Λ 41 Ca Λ-hypernuclei are studied by employing the Dirac equation with scalar, vector and tensor potentials. It is found that the effect of core polarization on the magnetic moments is suppressed by Λ tensor coupling. The Λ tensor potential reduces the spin-orbit splitting of p Λ states considerably. However, almost the same magnetic moments are obtained using the hyperon wavefunction obtained via the Dirac equation either with or without the A tensor potential in the electromagnetic current vertex. The deviations of magnetic moments for p Λ states from the Schmidt values are found to increase with nuclear mass number. (nuclear physics)

Determination of the magnetic moment of $^{140}$Pr

CERN Multimedia

Kowalska, M; Kreim, K D; Krieger, A R; Litvinov, Y

We propose to measure the nuclear magnetic moment of the neutron-deficient isotope $^{140}$Pr using collinear laser spectroscopy at the COLLAPS experiment. This nuclide is one of two nuclear systems for which a modulated electron capture decay has been observed in hydrogen-like ions in a storage ring. The firm explanation of the observed phenomenon is still missing but some hypotheses suggest an interaction of the unpaired electron with the surrounding magnetic fields of the ring. In order to verify or discard these hypotheses the magnetic moment of $^{140}$Pr is required since this determines the energy of the 1s hyperfine splitting.

Effective particle magnetic moment of multi-core particles

Energy Technology Data Exchange (ETDEWEB)

Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)

2015-04-15

In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

Effective particle magnetic moment of multi-core particles

International Nuclear Information System (INIS)

Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; IJzendoorn, Leo J. van; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

2015-01-01

In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm

Effective particle magnetic moment of multi-core particles

Science.gov (United States)

Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; van IJzendoorn, Leo J.; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

2015-04-01

In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems - BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm - and one single-core particle system - SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

Field Induced Magnetic Moments in a Metastable Iron-Mercury Alloy

DEFF Research Database (Denmark)

Pedersen, M.S.; Mørup, Steen; Linderoth, Søren

1996-01-01

The magnetic properties of a metastable iron-mercury alloy have been investigated in the temperature range from 5 to 200 K by Mossbauer spectroscopy and magnetization measurements. At low temperature the magnetic moment per iron atom is larger than af alpha-Fe. The effective spontaneous magnetic ....... It was found that the field-induced increase of the magnetic moment in the metastable iron-mecury alloy was about 0.06 Bohr magnetons per iron atom in the temperature range from 5 to 200 K for a field change from 6 to 12 T....

Measurement of the Magnetic Moment of the Negative Muon Bound in Different Atoms

CERN Document Server

Mamedov, T N; Gritsaj, K I; Kormann, O; Major, J V; Stoikov, A V; Zimmermann, U

2001-01-01

Theoretical calculations show that the magnetic moment of the electron and the negative muon in a bound state in an atom should be different from the magnetic moment of the free particle due to their relativistic motion. There are also additional radiative corrections to the magnetic moment of a bound electron (muon) due to the presence of the strong Coulomb field of the atomic nucleus. The results of the measurements of the magnetic moment of the negative muon in carbon, oxygen, magnesium, silicon, sulfur, and zinc are presented. The accuracy of the measurements makes it possible to prove the dependence of the relativistic correction to the magnetic moment of a bound muon on Z of the atom.

The effect of a neutrino magnetic moment on nuclear excitation processes

International Nuclear Information System (INIS)

Dodd, A.C.; Papageorgiu, E.; Ranfone, S.

1991-01-01

It is shown that the MeV-range neutrinos with a magnetic moment of ≅ 10 -11 Bohr magnetons would excite nuclei, like 12 C, with cross sections comparable to those obtained in the Standard Model. This implies the possibility of improving the present experimental bounds on the magnetic moment of any flavour of neutrinos by one order of magnitude. Such a magnetic moment would also enhance the coherent neutrino-nuclear scattering in low-temperature detectors, enabling them to set comparable limits. (author)

6-quark contribution to nuclear magnetic moments

International Nuclear Information System (INIS)

Ito, H.

1985-01-01

The magnetic moments of nuclei with LS closed shell +/-1 particle are calculated. Core polarization and meson exchange current are treated realistically in order to single out the 6-quark contribution. Overall agreement with experimental values is quite good. It is shown that the 6-quark system contributes to the respective iso-vector and iso-scalar moments with reasonable magnitudes

Chiral dynamics of baryons in the perturbative chiral quark model

Energy Technology Data Exchange (ETDEWEB)

Pumsa-ard, K.

2006-07-01

In this work we develop and apply variants of a perturbative chiral quark model (PCQM) to the study of baryonic properties dominantly in the low-energy region. In a first step we consider a noncovariant form of the PCQM, where confinement is modelled by a static, effective potential and chiral corrections are treated to second order, in line with similar chiral quark models. We apply the PCQM to the study of the electromagnetic form factors of the baryon octet. We focus in particular on the low-energy observables such as the magnetic moments, the charge and magnetic radii. In addition, the electromagnetic N-delta transition is also studied in the framework of the PCQM. In the chiral loop calculations we consider a quark propagator, which is restricted to the quark ground state, or in hadronic language to nucleon and delta intermediate states, for simplicity. We furthermore include the low-lying excited states to the quark propagator. In particular, the charge radius of the neutron and the transverse helicity amplitudes of the N-delta transition are considerably improved by this additional effect. In a next step we develop a manifestly Lorentz covariant version of the PCQM, where in addition higher order chiral corrections are included. The full chiral quark Lagrangian is motivated by and in analogy to the one of Chiral Perturbation Theory (ChPT). This Lagrangian contains a set of low energy constants (LECs), which are parameters encoding short distance effects and heavy degrees of freedom. We evaluate the chiral Lagrangian to order O(p{sup 4}) and to one loop to generate the dressing of the bare quark operators by pseudoscalar mesons. In addition we include the vector meson degrees of freedom in our study. Projection of the dressed quark operators on the baryonic level serves to calculate the relevant matrix elements. In a first application of this scheme, we resort to a parameterization of the valence quark form factors in the electromagnetic sector. Constraints

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.

Fluxonium-Based Artificial Molecule with a Tunable Magnetic Moment

Science.gov (United States)

Kou, A.; Smith, W. C.; Vool, U.; Brierley, R. T.; Meier, H.; Frunzio, L.; Girvin, S. M.; Glazman, L. I.; Devoret, M. H.

2017-07-01

Engineered quantum systems allow us to observe phenomena that are not easily accessible naturally. The LEGO®-like nature of superconducting circuits makes them particularly suited for building and coupling artificial atoms. Here, we introduce an artificial molecule, composed of two strongly coupled fluxonium atoms, which possesses a tunable magnetic moment. Using an applied external flux, one can tune the molecule between two regimes: one in which the ground-excited state manifold has a magnetic dipole moment and one in which the ground-excited state manifold has only a magnetic quadrupole moment. By varying the applied external flux, we find the coherence of the molecule to be limited by local flux noise. The ability to engineer and control artificial molecules paves the way for building more complex circuits for quantum simulation and protected qubits.

Cooper pairs' magnetic moment in MCFL color superconductivity

International Nuclear Information System (INIS)

Feng Bo; Ferrer, Efrain J.; Incera, Vivian de la

2011-01-01

We investigate the effect of the alignment of the magnetic moments of Cooper pairs of charged quarks that form at high density in three-flavor quark matter. The high-density phase of this matter in the presence of a magnetic field is known to be the Magnetic Color-Flavor-Locked (MCFL) phase of color superconductivity. We derive the Fierz identities of the theory and show how the explicit breaking of the rotational symmetry by the uniform magnetic field opens new channels of interactions and allows the formation of a new diquark condensate. The new order parameter is a spin-1 condensate proportional to the component in the field direction of the average magnetic moment of the pairs of charged quarks. The magnitude of the spin-1 condensate becomes comparable to the larger of the two scalar gaps in the region of large fields. The existence of the spin-1 condensate is unavoidable, as in the presence of a magnetic field there is no solution of the gap equations with nonzero scalar gaps and zero magnetic moment condensate. This is consistent with the fact that the extra condensate does not break any symmetry that has not already been broken by the known MCFL gaps. The spin-1 condensate enhances the condensation energy of pairs formed by charged quarks and the magnetization of the system. We discuss the possible consequences of the new order parameter on the issue of the chromomagnetic instability that appears in color superconductivity at moderate density.

Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

CERN Document Server

Baryshevsky, V.G.

2015-01-01

We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magnetic moment of negatively-charged particles (e.g., beauty baryons), for which the channeling effect is hampered due to far more rapid dechanneling as compared to that for positively-charged particles. Channeling of particles in either straight or bent crystals with polarized nuclei could be used for polarization and the analysis thereof of high-energy particles.

Magnetic moment densities in selected UTX compounds

Czech Academy of Sciences Publication Activity Database

Javorský, P.; Schweizer, J.; Givord, F.; Boucherle, J.-X.; Andreev, Alexander V.; Diviš, M.; Lelievre-Berna, E.; Sechovský, V.

2004-01-01

Roč. 350, - (2004), e131-e134 ISSN 0921-4526 R&D Projects: GA ČR GA202/03/0550 Institutional research plan: CEZ:AV0Z1010914 Keywords : uranium compound * polarized neutron scattering * magnetic moment Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.679, year: 2004

Gate-dependent orbital magnetic moments in carbon nanotubes

DEFF Research Database (Denmark)

Jespersen, Thomas Sand; Grove-Rasmussen, Kasper; Flensberg, Karsten

2011-01-01

We investigate how the orbital magnetic moments of electron and hole states in a carbon nanotube quantum dot depend on the number of carriers on the dot. Low temperature transport measurements are carried out in a setup where the device can be rotated in an applied magnetic field, thus enabling...... accurate alignment with the nanotube axis. The field dependence of the level structure is measured by excited state spectroscopy and excellent correspondence with a single-particle calculation is found. In agreement with band structure calculations we find a decrease of the orbital magnetic moment...... with increasing electron or hole occupation of the dot, with a scale given by the band gap of the nanotube....

Neutrino magnetic moments and the solar neutrino problem

Energy Technology Data Exchange (ETDEWEB)

Akhmedov, E.Kh. [Washington Univ., Seattle, WA (United States). Inst. for Nuclear Theory]|[Valencia Univ. (Spain). Dept. de Fisica Teorica

1994-08-01

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2{theta}{sub o} {approx_gt} 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar {bar {nu}}{sub e}`s.

Neutrino magnetic moments and the solar neutrino problem

International Nuclear Information System (INIS)

Akhmedov, E.Kh.; Valencia Univ.

1994-01-01

Present status of the neutrino magnetic moment solutions of the solar neutrino problem is reviewed. In particular, we discuss a possibility of reconciling different degrees of suppression and time variation of the signal (or lack of such a variation) observed in different solar neutrino experiments. It is shown that the resonant spin-flavor precession of neutrinos due to the interaction of their transitions magnetic moments with solar magnetic field can account for all the available solar neutrino data. For not too small neutrino mixing angles (sin 2θ o approx-gt 0.2 the combined effect of the resonant spin-flavor precession and neutrino oscillations can result in an observable flux of solar bar ν e 's

Nuclear structure studies by means of magnetic moments of excited states

International Nuclear Information System (INIS)

Kaeubler, L.; Prade, H.; Schneider, L.; Brinckmann, H.F.; Stary, F.

1981-09-01

Experimental arrangements installed at the cyclotron U-120 and the tandem accelerator EGP-10 for the in-beam measurement of magnetic moments of excited nuclear states are discribed. The Perturbed-Angular-Distribution-method (PAD) has been used. A new evaluation method has been developed for the unique determination of the Larmor frequency from spin-procession spectra R(t) with less than half of an oscillation period between consecutive particle pulses. Magnetic moments in transitional nuclei or in nuclei near closed shells ( 103 Pd, 105 Ag, 117 Sb, 117 Te, 121 Te, 121 I, 143 Pm and 207 Bi) were measured. The results are discussed with the aim to get information about the nuclear structure of the corresponding isomeric states in connection with complex spectroscopic investigations. Therefore, the experimental values are compared to the results of model calculations (core-polarization, core-particle-coupling, Nilsson, particle-rotation-coupling or shell-model) or to the estimates on the basis of the additivity of effective magnetic moments. Single-particle aspects are discussed in connection with the magnetic moments of hsub(11/2)-, dsub(5/2)- and gsub(7/2)-neutron (ν) and proton (π) states in the nuclei 103 Pd, 117 Te, 121 Te and 143 Pm, respectively. The configurations of (π) 3 and (π)(ν) 2 -three-particle states in 105 Ag, 117 Sb, 121 I and 207 Bi could be determined using the additivity rule. The experimental magnetic moments of states in 143 Pm agree very well with the results of shell-model calculations, which have firstly been carried out also for negative-parity states in this mass region. Considering magnetic moments in 117 Te and 121 Te we could demonstrate the influence of different nuclear deformations on the magnetic moments in transitional nuclei. (author)

Spin-flavor structure of large Nc baryons

International Nuclear Information System (INIS)

Dashen, R.F.; Jenkins, E.; Manohar, A.V.

1995-01-01

The spin-flavor structure of large N c baryons is described in the 1/N c expansion of QCD using quark operators. The complete set of quark operator identities is obtained, and used to derive an operator reduction rule which simplifies the 1/N c expansion. The operator reduction rule is applied to the axial vector currents, masses, magnetic moments, and hyperon nonleptonic decay amplitudes in the SU(3) limit, to first order in SU(3) breaking, and without assuming SU(3) symmetry. The connection between the Skyrme and quark operator representations is discussed. An explicit formula is given for the quark model operators in terms of the Skyrme model operators to all orders in 1/N c for the two flavor case

The effect of a neutrino magnetic moment on nuclear excitation processes

International Nuclear Information System (INIS)

Dodd, A.C.; Papageorgiu, E.; Ranfone, S.

1991-01-01

We discuss the sensitivity of magnetic transitions in nuclei like 12 C, to a small neutrino magnetic moment, and its implications for current and future experiments. We also point out that coherent neutrino-nuclear elastic scattering in low-temperature detectors, might improve the present laboratory bounds on the neutrino magnetic moment by an order of magnitude. (orig.)

Unstable magnetic moments in Ce compounds

International Nuclear Information System (INIS)

Aarts, J.

1984-01-01

The problems which are connected with the appearance or disappearance of local moments in metals are well reflected in the magnetic behaviour of Ce intermetallic compounds. This work describes experiments on two Ce compounds which are typical examples of unstable moment systems. The first of these is CeAl 2 which at low temperatures, shows coexistence of antiferromagnetic order and the Kondo effect. Measurements are presented of the magnetization and the susceptibility in different magnetic field and temperature regions. An analysis of these measurements, using a model for the crystal field effects, shows the agreement between the measurements and the calculations to be reasonably good for CeAl 2 , but this agreement becomes worse upon decreasing Ce concentration. A phenomenological description of the observations is given. The second compound reported on is CeCu 2 Si 2 , the first 'heavy-fermion' superconductor to be investigated. The superconducting state is possibly formed by the quasi-particles of a non-magnetic many body singlet state, and not simply by the (sd) conduction electrons. This being a novel phenomenon, a number of experiments were performed to test this picture and to obtain a detailed description of the behaviour of CeCu 2 Si 2 . Measurements of the Meissner volume, confirmed the superconductivity to be intrinsic. (Auth.)

Magnitude of localized magnetic moments in metals

International Nuclear Information System (INIS)

Kiwi, M.; Pestana, E.; Ramirez, R.

1979-01-01

The magnitude of the localized magnetic moment of a transition or rare earth element impurity in a metal is evaluated within the framework of the Anderson model. Rotational invariance is preserved throughout. Graphs of the magnitude of the magnetization as a function of the relevant parameters of the model are provided and discussed. (author)

The Analytical Evaluation Of Three-Center Magnetic Multipole Moment Integrals By Using Slater Type Orbitals

International Nuclear Information System (INIS)

Oztekin, E.

2010-01-01

In this study, magnetic multipole moment integrals are calculated by using Slater type orbitals (STOs), Fourier transform and translation formulas. Firstly, multipole moment operators which appear in the three-center magnetic multipole moment integrals are translated to b-center from 0-center. So, three-center magnetic multipole moment integrals have been reduced to the two-center. Then, the obtained analytical expressions have been written in terms of overlap integrals. When the magnetic multipole moment integrals calculated, matrix representations for x-, y- and z-components of multipole moments was composed and every component was separately calculated to analytically. Consequently, magnetic multipole moment integrals are also given in terms of the same and different screening parameters.

Strange baryons in a chiral quark-meson model. Pt. 2

International Nuclear Information System (INIS)

McGovern, J.A.; Birse, M.C.

1990-01-01

The chrial-quark meson model is used to study baryon properties with realistic breaking of SU(3). The symmetry breaking is assumed to be strong, so that a random phase approximation (RPA) can be used. In this the strange baryons are described as excitations built on the hedgehog soliton and have an excitation energy of 315 MeV. Other properties of strange baryons are obtained by an approximate spin-isospin projection from the RPA wave function. The magnetic moments agree reasonably well with experiment, but the deviations from the experimental values suggest that the method is valid for the case of rather stronger symmetry breaking than is realistic. The dependence of the RPA energy on the magnitude of the symmetry breaking is examined, and found to be strongly nonlinear for realistic values. This supports the idea that a large πN sigma commutator need not imply a large strange-quark content in the proton. For reasonable values of the scalar meson masses the strange-quark condensate is found to be less than 5% of the total, at the mean-field level. We also estimate the contribution to the condensate from RPA correlations. Within a one-mode approximation we find these to be very small, ≅ 2%. (orig.)

Magnetic moment of short lived {beta}-emitter {sup 24m}Al

Energy Technology Data Exchange (ETDEWEB)

Nishimura, D., E-mail: daiki@vg.phys.sci.osaka-u.ac.jp; Komurasaki, J.; Matsuta, K.; Mihara, M.; Matsumiya, R. [Osaka University, Department of Physics (Japan); Momota, S. [Kochi University of Technology (Japan); Ohtsubo, T. [Niigata University, Department of Physics (Japan); Izumikawa, T. [Niigata University, RI Center (Japan); Hirano, H. [Niigata University, Department of Physics (Japan); Kitagawa, A.; Kanazawa, M.; Torikoshi, M.; Sato, S. [National Institute of Radiological Sciences (Japan); Fukuda, M.; Ishikawa, D. [Osaka University, Department of Physics (Japan); Minamisono, T. [Fukui University of Technology (Japan); Watanabe, R.; Kubo, T. [Niigata University, Department of Physics (Japan); Nojiri, Y. [Kochi University of Technology (Japan); Alonso, J. R. [Lawrence Berkeley Laboratory (United States)

2007-11-15

The magnetic moment of short lived {beta}-emitter {sup 24m}Al (426 keV, I{sup {pi}} = 1{sup +}, T{sub 1/2} = 131 ms) has been measured by means of {beta}-NMR technique, for the first time. From the {beta}-NMR spectrum, the magnetic moment was determined as |{mu}({sup 24m}Al)|=(2.99{+-}0.09){mu}{sub N}. Combined with the known magnetic moment of the mirror partner {sup 24m}Na, the expectation value of < S{sub z} > is obtained to be (0.08 {+-} 0.12). These values are reproduced well by the shell model calculation.

Two dimensional electron gas confined over a spherical surface: Magnetic moment

International Nuclear Information System (INIS)

Hernando, A; Crespo, P; Garcia, M A

2011-01-01

Magnetism of capped nanoparticles, NPs, of non-magnetic substances as Au and ZnO is briefly reviewed. The source of the magnetization is discussed on the light of recent X-ray magnetic circular dichroism experiments. As magnetic dichroism analysis has pointed out impurity atoms bonded to the surface act as donor or acceptor of electrons that occupy the surface states. It is proposed that mesoscopic collective orbital magnetic moments induced at the surface states can account for the experimental magnetism characteristic of these nanoparticles. The total magnetic moment of the surface originated at the unfilled Fermi level can reach values as large as 10 2 or 10 3 Bohr magnetons.

Exchange current contributions to isoscalar magnetic moments

International Nuclear Information System (INIS)

Arima, A.; Bentz, W.; Ichii, S.

1986-01-01

In this work the authors have investigated two recent suggestions which indicated appreciable exchange current contributions to isoscalar magnetic moments. On account of gauge invariance the authors found that in both treatments certain important terms seem to be omitted. The authors then performed explicit calculations using a one-boson exchange model for the exchange current operator. The authors found that the results are sensitive to the ratio of coupling constants g/sub σNN///g/sub ωNN/. Due to this fact it is difficult to draw quantitative conclusions. In the present model calculation the authors found that both g/sub s/(0) and g/sub 1//sup 0/ are enhanced by about 3% to 4%, resulting in non-negligible corrections to isoscalar magnetic moments

Magnetic Fields at First Order Phase Transition: A Threat to Electroweak Baryogenesis

CERN Document Server

De Simone, Andrea; Quiros, Mariano; Riotto, Antonio

2011-01-01

The generation of the observed baryon asymmetry may have taken place during the electroweak phase transition, thus involving physics testable at LHC, a scenario dubbed electroweak baryogenesis. In this paper we point out that the magnetic field which is produced in the bubbles of a first order phase transition endangers the baryon asymmetry produced in the bubble walls. The reason being that the produced magnetic field couples to the sphaleron magnetic moment and lowers the sphaleron energy; this strengthens the sphaleron transitions inside the bubbles and triggers a more effective wash out of the baryon asymmetry. We apply this scenario to the Minimal Supersymmetric extension of the Standard Model (MSSM) where, in the absence of a magnetic field, successful electroweak baryogenesis requires the lightest CP-even Higgs and the right-handed stop masses to be lighter than about 127 GeV and 120 GeV, respectively. We show that even for moderate values of the magnetic field, the Higgs mass required to preserve the ...

Magnetic moment and beta decay of RaE

International Nuclear Information System (INIS)

Morita, Masato; Ohtsubo, Hisao; Arita, Kozo.

1976-01-01

Asymmetry of the beta-ray angular distribution in polarized RaE is evaluated with the numerical values of nuclear matrix elements, i∫r, ∫α and ∫sigma x r, which are derived by the method of the least chi-square fit to the experimental data on the spectral shape, longitudinal polarization and ft value. The magnetic moment of RaE is known to have a negative sign from this calculation, the measured asymmetry in Tokyo and the knowledge about the internal magnetic field at decaying nucleus. A consistent explanation of i∫r, ∫sigma x r and the magnetic moment of RaE is obtained in a shell model, where the tensor forces in the residual interaction and the core polarization are properly taken into account. (auth.)

Magnetotransport in Layered Dirac Fermion System Coupled with Magnetic Moments

Science.gov (United States)

Iwasaki, Yoshiki; Morinari, Takao

2018-03-01

We theoretically investigate the magnetotransport of Dirac fermions coupled with localized moments to understand the physical properties of the Dirac material EuMnBi2. Using an interlayer hopping form, which simplifies the complicated interaction between the layers of Dirac fermions and the layers of magnetic moments in EuMnBi2, the theory reproduces most of the features observed in this system. The hysteresis observed in EuMnBi2 can be caused by the valley splitting that is induced by the spin-orbit coupling and the external magnetic field with the molecular field created by localized moments. Our theory suggests that the magnetotransport in EuMnBi2 is due to the interplay among Dirac fermions, localized moments, and spin-orbit coupling.

The statistic-thermodynamically calculations of magnetic thermodynamically functions for nuclear magnetic moments

International Nuclear Information System (INIS)

Zhu Zhenghe; Luo Deli; Feng Kaiming

2013-01-01

The present work is to calculate the magnetic thermodynamically functions, i.e. energy, the intensity of magnetization, enthalpy, entropy and Gibbs function for nuclear magnetic moments of T, D and neutron n at 2 T and 1, 50, 100 and 150 K from partition functions. It is shown that magnetic saturation of thermonuclear plasma does not easily occur for nuclear magneton is only of 10 -3 of Bohr magneton. The work done by magnetic field is considerable. (authors)

Two dimensional electron gas confined over a spherical surface: Magnetic moment

Energy Technology Data Exchange (ETDEWEB)

Hernando, A; Crespo, P [Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas. P. O. Box 155, Madrid 28230 (Spain) and Dpto. Fisica de Materiales, Universidad Complutense (Spain); Garcia, M A, E-mail: antonio.hernando@adif.es [Instituto de Ceramica y Vidrio, CSIC c/Kelsen, 5 Madrid 28049 (Spain)

2011-04-01

Magnetism of capped nanoparticles, NPs, of non-magnetic substances as Au and ZnO is briefly reviewed. The source of the magnetization is discussed on the light of recent X-ray magnetic circular dichroism experiments. As magnetic dichroism analysis has pointed out impurity atoms bonded to the surface act as donor or acceptor of electrons that occupy the surface states. It is proposed that mesoscopic collective orbital magnetic moments induced at the surface states can account for the experimental magnetism characteristic of these nanoparticles. The total magnetic moment of the surface originated at the unfilled Fermi level can reach values as large as 10{sup 2} or 10{sup 3} Bohr magnetons.

Top quark amplitudes with an anomalous magnetic moment

International Nuclear Information System (INIS)

Larkoski, Andrew J.; Peskin, Michael E.

2011-01-01

The anomalous magnetic moment of the top quark may be measured during the first run of the LHC at 7 TeV. For these measurements, it will be useful to have available tree amplitudes with tt and arbitrarily many photons and gluons, including both QED and color anomalous magnetic moments. In this paper, we present a method for computing these amplitudes using the Britto-Cachazo-Feng-Witten recursion formula. Because we deal with an effective theory with higher-dimension couplings, there are roadblocks to a direct computation with the Britto-Cachazo-Feng-Witten method. We evade these by using an auxiliary scalar theory to compute a subset of the amplitudes.

Anomalous magnetic moment with heavy virtual leptons

Energy Technology Data Exchange (ETDEWEB)

Kurz, Alexander [Karlsruher Institut fuer Technologie (Germany). Inst. fuer Theoretische Teilchenphysik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Liu, Tao; Steinhauser, Matthias [Karlsruher Institut fuer Technologie (Germany). Inst. fuer Theoretische Teilchenphysik; Marquard, Peter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2013-11-15

We compute the contributions to the electron and muon anomalous magnetic moment induced by heavy leptons up to four-loop order. Asymptotic expansion is applied to obtain three analytic expansion terms which show rapid convergence.

Roles of configuration mixing and exchange currents in nuclear magnetic moments and beta decays. Chapter 17

International Nuclear Information System (INIS)

Arima, A.; Hyuga, H.

1979-01-01

The authors review systematically several important mechanisms which affect magnetic moments, magnetic dipole transitions and allowed beta-decays. They are first order configuration mixing, second order configuration mixing, the Sachs moment and other exchange magnetic moments, the contribution of the Sachs moment and other exchange magnetic moments with first order configuration mixing. It is shown that first order configuration mixing and the Sachs moment are important for heavy nuclei, and that all the effects except first order mixing are important for light nuclei. (Auth.)

Magnetic moments and the Skyrme interaction

Energy Technology Data Exchange (ETDEWEB)

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

1977-12-12

The magnetic properties of the Skyrme interaction have been studied by performing a restricted Hartree-Fock calculation in order to evaluate the magnetic polarizability and the corrections to the Schmidt moments in nuclei with closed jj shells plus or minus one nucleon. Different corrections to the Schmidt values have been evaluated and discussed: the M1 core polarization and the renormalization of the gyromagnetic factors due to exchange and spin-orbit forces. Several variants of the Skyrme interaction have been studied and discussed in detail.

Magnetic dipole moments of deformed odd-A nuclei

Energy Technology Data Exchange (ETDEWEB)

Garg, V P; Sharma, S D; Mahesh, P S [Punjabi Univ., Patiala (India). Dept. of Physics

1976-12-01

Using an extended version of A S Davydov and G F Filippov's model (1958), B E Chi and J P Davidson have calculated magnetic moments of odd-A nuclei in 2s-ld shell, diagonalizing the state matrices for a set of parameters giving the best fit for nuclear spectra (1966). To study the failure of this model in case of nuclear moments, instead of diagonalizing an attempt has been made to simplify the expression for magnetic dipole moment for single nucleonic states without configuration mixing. The model takes care of the proper sign of spin projections. On replacing the total angular momentum j of odd particle (proton or neutron) by its projection ..cap omega.., the expression reduces to that of Mottelson and Nilsson for spin-up nuclei. The Coriolis coupling calculations also have been performed for those odd-A nuclei with K = 1/2. The results are found in better agreement with experimental report in comparison with those of other models.

Top Quark Amplitudes with an Anomolous Magnetic Moment

International Nuclear Information System (INIS)

Larkoski, Andrew

2011-01-01

The anomalous magnetic moment of the top quark may be measured during the first run of the LHC at 7 TeV. For these measurements, it will be useful to have available tree amplitudes with t(bar t) and arbitrarily many photons and gluons, including both QED and color anomalous magnetic moments. In this paper, we present a method for computing these amplitudes using the Britto-Cachazo-Feng-Witten recursion formula. Because we deal with an effective theory with higher-dimension couplings, there are roadblocks to a direct computation with the Britto-Cachazo-Feng-Witten method. We evade these by using an auxiliary scalar theory to compute a subset of the amplitudes.

Phase formation, thermal stability and magnetic moment of cobalt nitride thin films

Directory of Open Access Journals (Sweden)

Rachana Gupta

2015-09-01

Full Text Available Cobalt nitride (Co-N thin films prepared using a reactive magnetron sputtering process are studied in this work. During the thin film deposition process, the relative nitrogen gas flow (RN2 was varied. As RN2 increases, Co(N, Co4N, Co3N and CoN phases are formed. An incremental increase in RN2, after emergence of Co4N phase at RN2 = 10%, results in a linear increase of the lattice constant (a of Co4N. For RN2 = 30%, a maximizes and becomes comparable to its theoretical value. An expansion in a of Co4N, results in an enhancement of the magnetic moment, to the extent that it becomes even larger than pure Co. Such larger than pure metal magnetic moment for tetra-metal nitrides (M4N have been theoretically predicted. Incorporation of N atoms in M4N configuration results in an expansion of a (relative to pure metal and enhances the itinerary of conduction band electrons leading to larger than pure metal magnetic moment for M4N compounds. Though a higher (than pure Fe magnetic moment for Fe4N thin films has been evidenced experimentally, higher (than pure Co magnetic moment is evidenced in this work.

Nucleon magnetic moments and magnetic properties of vacuum in QCD

International Nuclear Information System (INIS)

Ioffe, B.L.; Smilga, A.V.

1983-01-01

Magnetic moments of a proton and a neutron are calculated in the QCD sum rule approach. The substantial role of the external electromagnetic field induced vacuum expectation values, the most important of which is connected with quark condensate magnetic susceptibility, is demonstrated. The results are μsub(p)=3.0, μsub(n)=2.0(+-10%) that is in a perfect agreement with experiment. The invariant amplitudes of Δ→pγ transition are also calculated

Magnetic dipole moments of the heavy tensor mesons in QCD

Energy Technology Data Exchange (ETDEWEB)

Aliev, T. M., E-mail: taliev@metu.edu.tr [Physics Department, Middle East Technical University, 06531, Ankara (Turkey); Institute of Physics, Baku (Azerbaijan); Barakat, T., E-mail: tbarakat@KSU.EDU.SA [Physics Department, Middle East Technical University, 06531, Ankara (Turkey); Physics and Astronomy Department, King Saud University, Riyadh (Saudi Arabia); Savcı, M., E-mail: savci@metu.edu.tr [Physics Department, Middle East Technical University, 06531, Ankara (Turkey)

2015-11-03

The magnetic dipole moments of the D{sub 2}, and D{sub S{sub 2}}, B{sub 2}, and B{sub S{sub 2}} heavy tensor mesons are estimated in framework of the light cone QCD sum rules. It is observed that the magnetic dipole moments for the charged mesons are larger than that of its neutral counterpart. It is found that the SU(3) flavor symmetry violation is about 10 % in both b and c sectors.

Magnetic dipole moments of the heavy tensor mesons in QCD

Energy Technology Data Exchange (ETDEWEB)

Aliev, T.M. [Middle East Technical University, Physics Department, Ankara (Turkey); Institute of Physics, Baku (Azerbaijan); Barakat, T. [Middle East Technical University, Physics Department, Ankara (Turkey); King Saud University, Physics and Astronomy Department, Riyadh (Saudi Arabia); Savci, M. [Middle East Technical University, Physics Department, Ankara (Turkey)

2015-11-15

The magnetic dipole moments of the D{sub 2}, and D{sub S{sub 2}}, B{sub 2}, and B{sub S{sub 2}} heavy tensor mesons are estimated in framework of the light cone QCD sum rules. It is observed that the magnetic dipole moments for the charged mesons are larger than that of its neutral counterpart. It is found that the SU(3) flavor symmetry violation is about 10 % in both b and c sectors. (orig.)

Hyperon magnetic moments and total cross sections

International Nuclear Information System (INIS)

Lipkin, H.J.

1982-06-01

The new data on both total cross sections and magnetic moments are simply described by beginning with the additive quark model in an SU(3) limit where all quarks behave like strange quarks and breaking both additivity and SU(3) simultaneously with an additional non-additive mechanism which affects only nonstrange quark contributions. The suggestion that strange quarks behave more simply than nonstrange may provide clues to underlying structure or dynamics. Small discrepancies in the moments are analyzed and shown to provide serious difficulties for most models if they are statistically significant. (author)

Precise Determination of the Strangeness Magnetic Moment of the Nucleon

Energy Technology Data Exchange (ETDEWEB)

Leinweber, D B; Boinepalli, S; Cloet, I C; Thomas, A W; Williams, A G; Young, R D; Zanotti, J M; Zhang, J B

2005-06-01

By combining the constraints of charge symmetry with new chiral extrapolation techniques and recent low mass lattice QCD simulations of the individual quark contributions to the magnetic moments of the nucleon octet, we obtain a precise determination of the strange magnetic moment of the proton. The result, namely G{sub M}{sup s} = -0.051 +/- 0.021 mu{sub N}, is consistent with the latest experimental measurements but an order of magnitude more precise. This poses a tremendous challenge for future experiments.

Magnetic moment jumps in flat and nanopatterned Nb thin-walled cylinders

Energy Technology Data Exchange (ETDEWEB)

Tsindlekht, M.I., E-mail: mtsindl@vms.huji.ac.il [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Genkin, V.M.; Felner, I.; Zeides, F.; Katz, N. [The Racah Institute of Physics, The Hebrew University of Jerusalem, 91904 Jerusalem (Israel); Gazi, Š.; Chromik, Š. [The Institute of Electrical Engineering SAS, Dúbravská cesta 9, 84104 Bratislava (Slovakia); Dobrovolskiy, O.V. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany); Physics Department, V. Karazin Kharkiv National University, 61077 Kharkiv (Ukraine); Sachser, R.; Huth, M. [Physikalisches Institut, Goethe University, 60438 Frankfurt am Main (Germany)

2017-02-15

Highlights: • Magnetization curves of as-prepared and patterned thin-walled cylinders were measured in magnetic fields applied parallel to cylinders axis. • Magnetic moment jumps were observed in magnetic fields lower and above Hc1. • Critical current density in isthmus between two antidots is higher than in a film itself. - Abstract: Penetration of magnetic flux into hollow superconducting cylinders is investigated by magnetic moment measurements. The magnetization curves of a flat and a nanopatterned thin-walled superconducting Nb cylinders with a rectangular cross section are reported for the axial field geometry. In the nanopatterned sample, a row of micron-sized antidots (holes) was milled in the film along the cylinder axis. Magnetic moment jumps are observed for both samples at low temperatures for magnetic fields not only above H{sub c1}, but also in fields lower than H{sub c1}, i. e., in the vortex-free regime. The positions of the jumps are not reproducible and they change from one experiment to another, resembling vortex lattice instabilities usually observed for magnetic fields larger than H{sub c1}. At temperatures above 0.66T{sub c} and 0.78T{sub c} the magnetization curves become smooth for the patterned and the as-prepared sample, respectively. The magnetization curve of a reference flat Nb film in the parallel field geometry does not exhibit jumps in the entire range of accessible temperatures.

Excited state mass spectra of doubly heavy baryons Ω{sub cc}, Ω{sub bb} and Ω{sub bc}

Energy Technology Data Exchange (ETDEWEB)

Shah, Zalak; Rai, Ajay Kumar [Sardar Vallabhbhai National Institute of Technology, Department of Applied Physics, Surat, Gujarat (India); Thakkar, Kaushal [GIDC Degree Engineering college, Department of Applied Sciences and Humanities, Abrama, Navsari (India)

2016-10-15

We discuss the mass spectrum of Ω baryon with two heavy quarks and one light quark (ccs, bbs, and bcs). The main goal of the paper is to calculate the ground state masses and after that, the positive and negative parity excited states masses are also obtained within a hypercentral constituent quark model, using Coulomb plus linear potential framework. We also added a first order correction to the potential. The mass spectra up to 5S for radial excited states and 1P-5P, 1D-4D, and 1F-2F states for orbital excited states are computed for Ω{sub cc}, Ω{sub bb} and Ω{sub bc} baryons. Our obtained results are compared with other theoretical predictions, which could be a useful complementary tool for the interpretation of experimentally unknown heavy baryon spectra. The Regge trajectory is constructed in both the (n{sub r}, M{sup 2}) and the (J, M{sup 2}) planes for Ω{sub cc}, Ω{sub bb} and Ω{sub bc} baryons and their slopes and intercepts are also determined. Magnetic moments of doubly heavy Ω{sup '}s are also calculated. (orig.) 8.

A cosmological lower bound on the neutron electric dipole moment

International Nuclear Information System (INIS)

Ellis, J.; Nanopoulos, D.V.; Rudaz, S.; Gaillard, M.K.

1980-10-01

We argue that in a wide class of grand unified theories diagrams similar to those generating baryon number in the early universe also contribute to renormalization of the CP-violating theta parameter of QCD and hence to the neutron electric dipole moment dsub(n). We then use the apparent baryon-to-photon ratio (nsub(B)/nsub(γ))>=1.3 x 10 -10 to deduce an order-of-magnitude lower bound on the neutron electric dipole moment: dsub(n) > approximately 3 x 10 -28 e-cm. Conversely the present experimental upper limit on dsub(n) implies (nsub(B)/nsub(γ) -7 . We find as a corollary that there is not much scope for entropy generation after the creation of the baryon-antibaryon asymmetry in the very early universe

A Comparison of Methods to Measure the Magnetic Moment of Magnetotactic Bacteria through Analysis of Their Trajectories in External Magnetic Fields

Science.gov (United States)

Fradin, Cécile

2013-01-01

Magnetotactic bacteria possess organelles called magnetosomes that confer a magnetic moment on the cells, resulting in their partial alignment with external magnetic fields. Here we show that analysis of the trajectories of cells exposed to an external magnetic field can be used to measure the average magnetic dipole moment of a cell population in at least five different ways. We apply this analysis to movies of Magnetospirillum magneticum AMB-1 cells, and compare the values of the magnetic moment obtained in this way to that obtained by direct measurements of magnetosome dimension from electron micrographs. We find that methods relying on the viscous relaxation of the cell orientation give results comparable to that obtained by magnetosome measurements, whereas methods relying on statistical mechanics assumptions give systematically lower values of the magnetic moment. Since the observed distribution of magnetic moments in the population is not sufficient to explain this discrepancy, our results suggest that non-thermal random noise is present in the system, implying that a magnetotactic bacterial population should not be considered as similar to a paramagnetic material. PMID:24349185

Calculation of the electron magnetic moment in Fried-Yennie-gauge QED

International Nuclear Information System (INIS)

Adkins, G.S.

1989-01-01

The two-loop contribution to the electron magnetic moment is calculated in the Fried-Yennie gauge. This is the first treatment of the magnetic moment beyond one-loop order in a gauge other than the Feynman gauge. The Fried-Yennie gauge is infrared safe, and the calculation is done without introducing an infrared cutoff or photon mass. The Fried-Yennie-gauge result agrees with the Feynman-gauge result, as expected

Phase analysis of NK-bar scattering and Λ-hyperon magnetic moment

International Nuclear Information System (INIS)

Nikitiu, F.

1987-01-01

The NK-bar-scattering S matrix is suggested to have the P 01 -channel pole which corresponds to Λ-hyperon. The Λ-hyperon magnetic moment is calculated. Its value ''arises'' only due to nucleon magnetic moments and N and K-bar nontrivial relativistic coupling in the P 01 -channel. This is one more method to the quark model methods. The calculations are in agreement with the experimental value of μΛ

Unusual temperature dependence of the magnetic moment in URu2Si2

International Nuclear Information System (INIS)

Faak, B.; Flouquet, J.; Lejay, P.

1994-01-01

The influence of the sample quality on the magnetic properties of the heavy-fermion superconductor URu 2 Si 2 has been studied by elastic neutron scattering. Two single crystals prepared under identical conditions received different heat treatments. The as-grown crystal shows an unusual temperature dependence of the magnetic Bragg peak intensity. The annealed sample behaves normally. The low-temperature magnetic moment is identical for the two samples, showing that the small moment of 0.023 (3) μ B is intrinsic. By varying the instrumental resolution, we show that the ordered moment as well as the limited correlation length (200-400 A) are of static origin. The finite correlation length appears related to defects. (author). 9 refs., 1 fig

Limits on the scaling of nucleon magnetic moments in nuclei

International Nuclear Information System (INIS)

Ericson, T.E.O.; State Univ. of New York, Stony Brook; Richter, A.; State Univ. of New York, Stony Brook

1987-01-01

In view of the suggestion that nucleon magnetic moments inside nuclei may be modified due to a rescaling of the nucleon size, we investigate empirically how large such an effect can be. The method is based on a nearly model-independent scaling relation between the axial vector matrix element and the main part of the corresponding magnetic dipole matrix element supplemented by a small and well understood contribution from the one-pion exchange current. Taking the mass A = 3 and 12 systems as examples the upper limit, for such a change of the nucleon magnetic moment inside nuclei is found to be about 2%, considerably smaller than previous estimates in the literature. (orig.)

Progress in analytical calculations for the anomalous magnetic moment of the muon

International Nuclear Information System (INIS)

Baikov, P.A.

2013-11-01

We present results for certain classes of diagrams contributing to the anomalous magnetic moment of the muon at five-loop order. Our method is based on first constructing an approximating function for the vacuum polarization function of the photon at four loop order which later can be numerically integrated to obtain the anomalous magnetic moment of the muon.

Progress in analytical calculations for the anomalous magnetic moment of the muon

Energy Technology Data Exchange (ETDEWEB)

Baikov, P.A. [Moscow State Univ. (Russian Federation). Skobeltsyn Inst. of Nuclear Physics; Maier, A. [Technische Univ. Muenchen (Germany). Physik Dept. T31; Marquard, P. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2013-11-15

We present results for certain classes of diagrams contributing to the anomalous magnetic moment of the muon at five-loop order. Our method is based on first constructing an approximating function for the vacuum polarization function of the photon at four loop order which later can be numerically integrated to obtain the anomalous magnetic moment of the muon.

Origin of the net magnetic moment in LaCoO3

Science.gov (United States)

Kaminsky, G. M.; Belanger, D. P.; Ye, F.; Fernandez-Baca, J. A.; Wang, J.; Matsuda, M.; Yan, J.-Q.

2018-01-01

We use polarized neutron scattering to characterize the Bragg scattering intensity below TC=89.5 K at the (1,0,0) pseudocubic nuclear Bragg point of LaCoO3. Upon cooling in a field (FC), a net magnetic moment is apparent in Bragg scattering intensity, just as it was in previous magnetization measurements. Critical behavior associated with the net moment near TC upon cooling in small applied fields rapidly rounds with increasing field strength. We show, using a mean-field calculation, that this net moment can develop in a metastable state that forms upon FC, even when all the interactions in the system are antiferromagnetic.

Planar Hall ring sensor for ultra-low magnetic moment sensing

DEFF Research Database (Denmark)

Hung, Tran Quang; Terki, Ferial; Kamara, Souleymanne

2015-01-01

The field sensitivity of a planar Hall effect (PHE) micro-ring type biosensor has been investigated as a function of magnetizing angle of the sensor material, for the sensing of low magnetic moment superparamagnetic labels. The field sensitivity is maximal at a magnetizing angle of α = 20°. At th...

Non-resonant precession of the neutron magnetic moment in antiferromagnets

International Nuclear Information System (INIS)

Skoblin, A.A.

1995-01-01

It is shown that the magnetic moment of a neutron moving in an antiferromagnet with a spiral-order magnetic field slowly precesses. Precession pitch strongly depends on the value and direction of the neutron velocity. 4 refs

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

Interfacial tuning of perpendicular magnetic anisotropy and spin magnetic moment in CoFe/Pd multilayers

Energy Technology Data Exchange (ETDEWEB)

Ngo, D.-T., E-mail: ndthe82@gmail.com [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Meng, Z.L. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Tahmasebi, T. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Data Storage Institute, A-STAR (Agency for Science Technology and Research), 5 Engineering Drive 1, Singapore 117608 (Singapore); Yu, X. [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Thoeng, E. [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Yeo, L.H. [Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Rusydi, A., E-mail: phyandri@nus.edu.sg [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Han, G.C [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Teo, K.-L., E-mail: eleteokl@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)

2014-01-15

We report on a strong perpendicular magnetic anisotropy in [CoFe 0.4 nm/Pd t]{sub 6} (t=1.0–2.0 nm) multilayers fabricated by DC sputtering in an ultrahigh vacuum chamber. Saturation magnetization, M{sub s}, and uniaxial anisotropy, K{sub u}, of the multilayers decrease with increasing the spacing thickness; with a M{sub s} of 155 emu/cc and a K{sub u} of 1.14×10{sup 5} J/m{sup 3} at a spacing thickness of t=2 nm. X-ray absorption spectroscopy and X-ray magnetic circular dichroism measurements reveal that spin and orbital magnetic moments of Co and Fe in CoFe film decrease as a function of Pd thickness, indicating the major contribution of surface/interfacial magnetism to the magnetic properties of the film. - Highlights: • Strong perpendicular magnetic anisotropy essentially contributed by interfacial anisotropy. • Controllably magnetic properties with low M{sub s}, high K{sub u}, high P. • Interfacial magnetic moments modified by CoFe/Pd interfaces with strong spin–orbit coupling. • Narrow Bloch walls with Néel caps. • Superior magnetic characteristics for spin-torque applications.

Anomalous magnetic nucleon moments in a Bethe-Salpeter model

International Nuclear Information System (INIS)

Chak Wing Chan.

1978-01-01

We investigate the anomalous magnetic moment of the nucleon in a field theoretic many-channel model for the electromagnetic form factors of the N anti N, the ππ, the K anti K, the πω and the πrho systems. Propagator self-energy corrections from the Ward idendity and phenomenological strong vertex corrections are both included. The photon is coupled minimally to pions, kaons and nucleons with power multiplicative renormalization. With solutions in the framework of the Bethe-Salpeter equation we obtain a value 1.84 for the isovector moment and a value -0.02 for the isoscalar moment. (orig.)

Nuclear magnetic and electric dipole moments of neon-19

International Nuclear Information System (INIS)

MacArthur, D.W.

1983-01-01

This thesis presents a detailed discussion of a series of experiments designed to measure the magnetic and electric dipole moments of the β-emitting nucleus 19 Ne. The 19 Ne is generated in the reaction 19 F(p,n) 19 Ne and is polarized by a ''stern-Gerlach'' magnet in a rare gas atomic beams machine. The atoms are stored in a cell for many seconds without depolarizing. The parity violating asymmetry in the β angular distribution is used to monitor the nuclear polarization. The polarized atoms are stored in a cell in a uniform magnetic field. The β-asymmetry is monitored by a pair of β-detectors located on either side of the cell. Transitions between the M/sub J/ = +1/2 and M/sub J/ = -1/2 spin states are induced by an rf field generated by a small Helmholtz coil pair surrounding the cell. Nuclear magnetic resonance lines are observed and the magnetic moment of 19 Ne measured to be μ( 19 Ne) = -1.88542(8)μ/sub N/. A new magnet, cell and detectors were designed to give narrow resonance lines. The equipment is described in detail and several resonance line shapes are discussed. The narrowest resonance line achieved with this system was 0.043 Hz FWHM. This width is primarily due to the 19 Ne lifetime. Pulsed NMR lineshapes were also observed. The narrow NMR lines observed in the previous experiment were then used as a probe to look for an electric dipole moment (EDM) in 19 Ne. Any shift in the resonance frequency correlated with changes in an externally applied electric field would be evidence for an EDM. The EDM of the 19 Ne atom was measured to (7.2 +/- 6.2 X 10 -22 e-cm. This experiment and possible improvements are discussed in detail

Resonances and dipole moments in dielectric, magnetic, and magnetodielectric cylinders

DEFF Research Database (Denmark)

Dirksen, A.; Arslanagic, Samel; Breinbjerg, Olav

2011-01-01

An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis...

Induced magnetic moment in stainless steel components of orthodontic appliances in 1.5 T MRI scanners

Science.gov (United States)

Rollins, Nancy K.; Liang, Hui; Park, Yong Jong

2015-01-01

Purpose: Most orthodontic appliances are made of stainless steel materials and induce severe magnetic susceptibility artifacts in brain MRI. In an effort for correcting these artifacts, it is important to know the value of induced magnetic moments in all parts of orthodontic appliances. In this study, the induced magnetic moment of stainless steel orthodontic brackets, molar bands, and arch-wires from several vendors is measured. Methods: Individual stainless steel brackets, molar bands, and short segments of arch-wire were positioned in the center of spherical flask filled with water through a thin plastic rod. The induced magnetic moment at 1.5 T was determined by fitting the B0 map to the z-component of the magnetic dipole field using a computer routine. Results: The induced magnetic moment at 1.5 T was dominated by the longitudinal component mz, with a small contribution from the transverse components. The mz was insensitive to the orientation of the metal parts. The orthodontic brackets collectively dominated the magnetic dipole moment in orthodontic appliances. In brackets from six vendors, the total induced mz from 20 brackets for nonmolar teeth ranged from 0.108 to 0.158 (median 0.122) A ⋅ m2. The mz in eight molar bands with bracket attachment from two vendors ranged from 0.0004 to 0.0166 (median 0.0035) A ⋅ m2. Several full length arch wires had induced magnetic moment in the range of 0.006–0.025 (median 0.015) A ⋅ m2. Conclusions: Orthodontic brackets collectively contributed most to the total magnetic moment. Different types of brackets, molar bands, and arch wires all exhibit substantial variability in the induced magnetic moment. PMID:26429261

Determination of localized magnetic moments in Fe-Cr-Al alloys and the electron structure

International Nuclear Information System (INIS)

Blau, W.

1977-01-01

The localized magnetic moments of Fe and Cr are determined by combination of saturation magnetization measurements and magnetic diffuse scattering. Power series characterizing the interactions between the different kinds of atoms in the alloys are chosen to describe the concentration dependence of the magnetic moments. The different terms are discussed on the basis of band structure models valid for dilute alloys taking into account their modification by impurity interactions. (author)

Magnetic dipole moments of odd-odd lanthanides

International Nuclear Information System (INIS)

Sharma, S.D.; Gandhi, R.

1988-01-01

Magnetic dipole moments of odd-odd lanthanides. Collective model of odd-odd nuclei is applied to predict the magnetic dipole moments, (μ) of odd-odd lanthanides. A simplified version of expression for μ based on diagonalisation of Hamiltonian (subsequent use of eigenvectors to compute μ) is developed for cases of ground state as well as excited states using no configuration mixing and is applied to the cases of odd-odd lanthanides. The formulae applied to the eleven (11) cases of ground states show significant improvement over the results obtained using shell model. Configuration mixing and coriolis coupling is expected to cause further improvement in the results. On comparing the earlier work in this direction the present analysis has clarified that in the expression μ the projection factors have different signs for the case I=Ωp - Ωn and I=Ωn - Ωp, and sign of μ is negative in general in the second case while it is positive in all others of spin projection alignments. Although the general expression holds for excited states as well but in lanthanide region, the experimental reports of magnetic dipole moments of excite states (band heads of higher rational sequences) are not available except in case of five (5) neutron resonance states which cannot be handled on the basis of the present approach with no configuration mixing. Although in the present discussion, the model could not be applied to excited states but the systematics of change in its magnitude with increasing spin at higher rational states is very well understood. The particle part supressed under faster rotation of the nuclear core and thus finally at higher spin I, the value μ is given by μ=g c I (same as in case of even-even nuclei). These systematics are to be verified whenever enough data for higher excited states are available. (author). 11 refs

Solar and atmospheric neutrinos in three generations with a magnetic moment

International Nuclear Information System (INIS)

Pulido, J.; Tao, Z.

1995-01-01

A solution to the solar and atomospheric neutrino problems in three generations in the joint context of matter oscillations and the magnetic moment is investigated. An appropriate rotation of the evolution Hamiltonian reduces the three generation case to a two generation one. A convenient background for such a scenario with small neutrino masses and large magnetic moments is given by the Zee-type models, in which the mass generation mechanism leads to a pair of separate orders of magnitude for the mass square differences between neutrino species. We obtain a ratio var-epsilon congruent 10 -2 --10 -3 between these orders of magnitude, so that one of them [(0.3--3)x10 -2 eV 2 ] is suitable for the atmospheric neutrino solution and the other (∼10 -5 eV 2 ) for the solar neutrino solution. The magnetic moment leads to a decrease of the survival probability with solar neutrino energy. Such a decrease is consistent with the experimental situation

The magnetic moments of the proton and the antiproton

CERN Document Server

Ulmer, S.; Blaum, K.; Braeuninger, S.; Franke, K.; Kracke, H.; Leiteritz, C.; Matsuda, Y.; Nagahama, H.; Ospelkaus, C.; Rodegheri, C.C.; Quint, W.; Schneider, G.; Smorra, C.; Van Gorp, S.; Walz, J.; Yamazaki, Y.

2014-01-01

Recent exciting progress in the preparation and manipulation of the motional quantum states of a single trapped proton enabled the first direct detection of the particle's spin state. Based on this success the proton magnetic moment $\\mu_p$ was measured with ppm precision in a Penning trap with a superimposed magnetic field inhomogeneity. An improvement by an additional factor of 1000 in precision is possible by application of the so-called double Penning trap technique. In a recent paper we reported the first demonstration of this method with a single trapped proton, which is a major step towards the first direct high-precision measurement of $\\mu_p$. The techniques required for the proton can be directly applied to measure the antiproton magnetic moment $\\mu_{\\bar{p}}$. An improvement in precision of $\\mu_{\\bar{p}}$ by more than three orders of magnitude becomes possible, which will provide one of the most sensitive tests of CPT invariance. To achieve this research goal we are currently setting up the Baryo...

Polarization of spin-1 particles without an anomalous magnetic moment in a uniform magnetic field

OpenAIRE

Silenko, Alexander J.

2008-01-01

The polarization operator projections onto four directions remain unchanged for spin-1 particles without an anomalous magnetic moment in a uniform magnetic field. The approximate conservation of the polarization operator projections onto the horizontal axes of the cylindrical coordinate system takes place.

Correct use of the Gordon decomposition in the calculation of nucleon magnetic dipole moments

International Nuclear Information System (INIS)

Mekhfi, Mustapha

2008-01-01

We perform the calculation of the nucleon dipole magnetic moment in full detail using the Gordon decomposition of the free quark current. This calculation has become necessary because of frequent misuse of the Gordon decomposition by some authors in computing the nucleon dipole magnetic moment

Octet baryons in the independent-quark-model approach based on the Dirac equation with a power-law potential

Energy Technology Data Exchange (ETDEWEB)

Barik, N; Das, M [Utkal Univ., Bhubaneswar (India). Dept. of Physics

1983-01-13

Several properties of octet baryons such as (i) the magnetic moment, (ii) (Gsub(A)/Gsub(v))sub(n) for neutron ..beta..-decay and (iii) the charge radius of the proton have been calculated in a simple independent-quark model under the assumption that the individual constituent quarks are confined, in first approximation, by a relativistic power-law potential Vsub(q)(r)=(1+..beta..) (asup(..nu..+1)rsup(..nu..)+V/sub 0/) with a, ..nu..>0. In view of the simplicity of the model, the results obtained are quite encouraging.

Octet baryons in the independent-quark-model approach based on the Dirac equation with a power-law potential

International Nuclear Information System (INIS)

Barik, N.; Das, M.

1983-01-01

Several properties of octet baryons such as (i) the magnetic moment, (ii) (Gsub(A)/Gsub(v))sub(n) for neutron #betta#-decay and (iii) the charge radius of the proton have been calculated in a simple independent-quark model under the assumption that the individual constituent quarks are confined, in first approximation, by a relativistic power-law potential Vsub(q)(r)=(1+#betta#) (asup(#betta#+1)rsup(#betta#)+V 0 ) with a, #betta#>0. In view of the simplicity of the model, the results obtained are quite encouraging. (orig.)

One-pion exchange current corrections for nuclear magnetic moments in relativistic mean field theory

International Nuclear Information System (INIS)

Li Jian; Yao, J.M.; Meng Jie; Arima, Akito

2011-01-01

The one-pion exchange current corrections to isoscalar and isovector magnetic moments of double-closed shell nuclei plus and minus one nucleon with A = 15, 17, 39 and 41 have been studied in the relativistic mean field (RMF) theory and compared with previous relativistic and non-relativistic results. It has been found that the one-pion exchange current gives a negligible contribution to the isoscalar magnetic moments but a significant correction to the isovector ones. However, the one-pion exchange current enhances the isovector magnetic moments further and does not improve the corresponding description for the concerned nuclei in the present work. (author)

Magnetic moments in calcium isotopes via a surface-interaction experiment

International Nuclear Information System (INIS)

Niv, Y.; Hass, M.; Zemel, A.; Goldring, G.

1979-01-01

A rotation of the angular correlation of de-excitation γ-rays from 40 Ca and 44 Ca was observed in a tilted foil geometry. The signs and magnitudes of the magnetic moments of the 2 1 + of 44 Ca and of the 3 1 - level of 40 Ca were determined to be g = -0.28+-0.11 and g = +0.52+-0.18, respectively. This experiment provides further information regarding the polarization of deeply bound electronic configurations produced by a surface-interaction mechanism and demonstrates the feasibility of the present technique for measuring signs and magnitudes of magnetic moments of picosecond nuclear levels. (author)

Composite scalar contributions to the anomalous magnetic moments

International Nuclear Information System (INIS)

Stremnitzer, H.

1984-01-01

It is shown that the composite scalars recently introduced to explain the high Z 0 → e + e - γ rate contribute too much to the lepton anomalous magnetic moments, unless one uses very accurate chiral symmetry or composite models with two preonic scales. (Author)

Magnetic moment measurement of 140Ba nuclei using transient field technique

International Nuclear Information System (INIS)

Saxena, Mansi; Mandal, S.; Siwal, Davinder; Rainovski, G.; Danchev, M.; Damyanova, A.; Gladnishki, K.; Leske, J.; Bauer, C.; Bloch, T.; John, P.; Pietralla, N.; Wollersheim, H.J.; Kojouharov, I.; Pietri, S.; Schaffner, H.

2011-01-01

Mixed symmetry states have been identified in the neutron proton version of the Interacting Boson Model. The motivation of this experiment is to identify uniquely one phonon mixed symmetry states in 140 Ba nuclei by g factor measurement of the states. Magnetic moments measurements provide substantial information on the microscopic structure of the nuclei as the magnetic moment of a nuclei is described by the wave function of one state only. In this present paper we report the preliminary results of the g factor measurement of the first 2 + state of 140 Ba

First observation of magnetic moment precession of channeled particles in bent crystals

International Nuclear Information System (INIS)

Chen, D.; Albuquerque, I.F.; Baublis, V.V.; Bondar, N.F.; Carrigan, R.A. Jr.; Cooper, P.S.; Lisheng, D.; Denisov, A.S.; Dobrovolsky, A.V.; Dubbs, T.; Endler, A.M.F.; Escobar, C.O.; Foucher, M.; Golovtsov, V.L.; Goritchev, P.A.; Gottschalk, H.; Gouffon, P.; Grachev, V.T.; Khanzadeev, A.V.; Kubantsev, M.A.; Kuropatkin, N.P.; Lach, J.; Lang Pengfei; Lebedenko, V.N.; Li Chengze; Li Yunshan; Mahon, J.R.P.; McCliment, E.; Morelos, A.; Newsom, C.; Pommot Maia, M.C.; Samsonov, V.M.; Schegelsky, V.A.; Shi Huanzhang; Smith, V.J.; Sun, C.R.; Tang Fukun; Terentyev, N.K.; Timm, S.; Tkatch, I.I.; Uvarov, L.N.; Vorobyov, A.A.; Yan Jie; Zhao Wenheng; Zheng Shuchen; Zhong Yuanyuan

1992-01-01

Spin precession of channeled particles in bent crystals has been observed for the first time. Polarized Σ + were channeled using bent Si crystals. These crystals provided an effective magnetic field of 45 T which resulted in a measured spin precession of 60±17 degree. This agrees with the prediction of 62±2 degree using the world average of Σ + magnetic moment measurements. This new technique gives a Σ + magnetic moment of (2.40±0.46±0.40)μ N , where the quoted uncertainties are statistical and systematic, respectively. We see no evidence of depolarization in the channeling process

The relation between anomalous magnetic moment and axial anomaly

International Nuclear Information System (INIS)

Teryaev, O.V.

1990-12-01

The conservation of total angular momentum of spinor particle leads to a simple relation between the famous Schwinger and Adler coefficients determining axial anomaly and anomalous magnetic moment, respectively. (author). 8 refs, 1 fig

Puzzle of magnetic moments of Ni clusters revisited using quantum Monte Carlo method.

Science.gov (United States)

Lee, Hung-Wen; Chang, Chun-Ming; Hsing, Cheng-Rong

2017-02-28

The puzzle of the magnetic moments of small nickel clusters arises from the discrepancy between values predicted using density functional theory (DFT) and experimental measurements. Traditional DFT approaches underestimate the magnetic moments of nickel clusters. Two fundamental problems are associated with this puzzle, namely, calculating the exchange-correlation interaction accurately and determining the global minimum structures of the clusters. Theoretically, the two problems can be solved using quantum Monte Carlo (QMC) calculations and the ab initio random structure searching (AIRSS) method correspondingly. Therefore, we combined the fixed-moment AIRSS and QMC methods to investigate the magnetic properties of Ni n (n = 5-9) clusters. The spin moments of the diffusion Monte Carlo (DMC) ground states are higher than those of the Perdew-Burke-Ernzerhof ground states and, in the case of Ni 8-9 , two new ground-state structures have been discovered using the DMC calculations. The predicted results are closer to the experimental findings, unlike the results predicted in previous standard DFT studies.

The muon magnetic moment and new physics

Energy Technology Data Exchange (ETDEWEB)

Stoeckinger, Dominik, E-mail: Dominik.Stoeckinger@tu-dresden.de [Institute for Nuclear and Particle Physics (Germany)

2013-03-15

The impact of the muon magnetic moment measurement on physics beyond the Standard Model is briefly reviewed. Particular emphasis is given on the case of supersymmetry. The sensitivity of g - 2 to supersymmetry parameters and the potential for model discrimination and parameter measurements is described. The interplay between LHC data on the Higgs boson, limits on new particles, and g - 2 is discussed.

Lepton flavour symmetry and the neutrino magnetic moment

International Nuclear Information System (INIS)

Ecker, G.; Grimus, W.

1990-01-01

With the standard model gauge group and the three standard left-handed Weyl neutrinos, two minimal scenarios are investigated where an arbitrary non-abelian lepton flavour symmetry group G H is responsible for a light neutrino with a large magnetic moment. In the first case, with scalar fields carrying lepton flavour, some finetuning is necessary to get a small enough neutrino mass for μ ν = O(10 -11 μ B ). In the second scenario, the introduction of heavy charged gauge singlet fermions with lepton flavour allows for a strictly massless neutrino to one-loop order. In both cases, the interference mechanisms for small m ν and large μ ν is unique, independently of G H . In explicit realizations of the two scenarios, the horizontal groups are found to be non-abelian extensions of a Zeldovich-Konopinski-Mahmoud lepton number symmetry. Only a discrete part of G H is spontaneously broken leading to a light Dirac neutrino with a large magnetic moment. (Authors) 22 refs., 3 figs

Theoretical study on the magnetic moments formation in Ta-doped anatase TiO2

Science.gov (United States)

Bupu, A.; Majidi, M. A.; Rusydi, A.

2017-04-01

We present a theoretical study on Ti-vacancy induced ferromagnetism in Ta-doped anatase TiO2. Experimental study of Ti1-x Ta x O2 thin film has shown that Ti-vacancies (assisted by Ta doping) induce the formation of localized magnetic moment around it, then, the observed ferromagnetism is caused by the alignment of localized magnetic moments through Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. In this study, we focus on the formation of the localized magnetic moments in this system. We hypothesize that on a unit cell, Ti-vacancy has caused four electrons from the surrounding oxygen atoms to become unpaired. These unpaired electrons then arrange themselves into a configuration with a non-zero net magnetic moment. To examine our hypothesis, we construct a Hamiltonian of the four unpaired electrons, incorporating the Coulomb intra- and inter-orbital interactions, in matrix form. Using a set of chosen parameter values, we diagonalize the Hamiltonian to get the eigenstates and eigenvalues, then, with the resulting eigenstates, we calculate the magnetic moment, μ, by obtaining the expectation value of the square of total spin operator. Our calculation results show that in the ground state, provided that the ratio of parameters satisfies some criterion, μ ≈ 4μ B , corresponding to the four electron spins being almost perfectly aligned, can be achieved. Further, as long as we keep the Coulomb intra-orbital interaction between 0.5 and 1 eV, we find that μ ≈ 4μ B is robust up to far above room temperature. Our results demonstrate that Ti vacancies in anatase TiO2 can form very stable localized magnetic moments.

Local moments, exchange interactions, and magnetic order in Mn-doped LaFe2Si2 alloys

International Nuclear Information System (INIS)

Turek, I.; Divis, M.; Niznansky, D.; Vejpravova, J.

2007-01-01

Formation of local magnetic moments in the intermetallic compound LaFe 2 Si 2 due to doping by a few at% of Mn has been investigated by theoretical and experimental tools. While a number of low-temperature experiments prove appearance of non-zero magnetic moments due to the Mn doping, the measured 57 Fe Moessbauer spectra rule out sizable local moments of Fe atoms. This conclusion is in agreement with results of first-principles electronic structure calculations that yield non-vanishing moments only on Mn atoms. The calculated Mn-Mn exchange interactions are of both signs which indicate a magnetically frustrated ground state, probably with a spin-glass-like arrangement of the Mn moments

Unusually large magnetic moments in the normal state and superconducting state of Sn nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Hung, Chi-Hang; Lee, Chi-Hung; Hsu, Chien-Kang; Li, Chi-Yen; Karna, Sunil K.; Wang, Chin-Wei; Wu, Chun-Ming; Li, Wen-Hsien, E-mail: whli@phy.ncu.edu.tw [National Central University, Department of Physics and Center for Neutron Beam Applications (China)

2013-09-15

We report on the observations of spontaneous magnetic moments in the normal as well as in the superconducting states of a 9 nm Sn nanoparticle assembly, through X-ray diffraction, magnetization, ac magnetic susceptibility, and neutron diffraction measurements. The saturation magnetization reaches an unexpectedly large value of 1.04 emu/g at 5 K, with a temperature profile that can be described by Bloch's law with an exponent of b = 1.8. A magnetic moment of Left-Pointing-Angle-Bracket {mu}{sub Z} Right-Pointing-Angle-Bracket = 0.38 {mu}{sub B} develops after cooling from 260 to 4 K. Superconductivity develops below T{sub C} = 3.98 K, which is 7 % higher than the T{sub C} = 3.72 K of bulk Sn. Surprisingly, an addition magnetic moment of Left-Pointing-Angle-Bracket {mu}{sub Z} Right-Pointing-Angle-Bracket = 0.05 {mu}{sub B} develops upon entering the superconducting state.

Nuclear spins, magnetic moments and quadrupole moments of Cu isotopes from N = 28 to N = 46: probes for core polarization effects

CERN Document Server

Vingerhoets, P; Avgoulea, M; Billowes, J; Bissell, M L; Blaum, K; Brown, B A; Cheal, B; De Rydt, M; Forest, D H; Geppert, Ch; Honma, M; Kowalska, M; Kramer, J; Krieger, A; Mane, E; Neugart, R; Neyens, G; Nortershauser, W; Otsuka, T; Schug, M; Stroke, H H; Tungate, G; Yordanov, D T

2010-01-01

Measurements of the ground-state nuclear spins, magnetic and quadrupole moments of the copper isotopes from 61Cu up to 75Cu are reported. The experiments were performed at the ISOLDE facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a 56Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is however strongly reduced at N=40 due to the parity change between the $pf$ and $g$ orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the 56Ni core and weakening of the Z=28 and N=28 shell gaps.

E6-lepton mixing and lepton magnetic moment

International Nuclear Information System (INIS)

Vendramin, I.

1988-01-01

The contributions to the lepton magnetic moment due to the E 6 -exotic fermions and an extra vector boson Z' have been considered. Using the experimental limits on the E 6 -lepton mixing angles, these contributions are at least one order of magnitude smaller than the standard-model ones

Sum rules for baryonic vertex functions and the proton wave function in QCD

International Nuclear Information System (INIS)

Lavelle, M.J.

1985-01-01

We consider light-cone sum rules for vertex functions involving baryon-meson couplings. These sum rules relate the non-perturbative, and experimentally known, coupling constants to the moments of the wave function of the proton state. Our results for these moments are consistent with those obtained from QCD sum rules for two-point functions. (orig.)

Temperature dependence of spin and orbital magnetic moments of Sm 4f electrons in (Sm, Gd)Al2

International Nuclear Information System (INIS)

Qiao, S.; Kimura, A.; Adachi, H.; Iori, K.; Miyamoto, K.; Xie, T.; Namatame, H.; Taniguchi, M.; Tanaka, A.; Muro, T.; Imada, S.; Suga, S.

2005-01-01

X-ray magnetic circular dichroism studies were carried out on (Sm, Gd)Al 2 , a ferromagnet without net magnetization at a certain compensation temperature. For Sm 4f electrons, the following understandings were obtained: the magnitude of expectation value of orbital magnetic moment (m L Sm ) is always larger than that of spin one (m S Sm ), so the cancellation of total spin and orbital magnetic moments cannot be achieved only by Sm 4f electrons and the contributions from Gd ions and conduction electrons are important; when the temperature decreases, the magnitude of both m L Sm and m S Sm increases and the gross magnetic moment due to the Sm 4f electrons monotonically deviates from zero. These results tell us that the temperature dependence of magnetic moments related with the electrons other than Sm 4f ones may play important roles in the subtle adjustment of the total spin and orbital magnetic moments to the zero magnetization at the compensation temperature

Neutrino magnetic moment contribution to the neutrino-deuteron reaction

International Nuclear Information System (INIS)

Tsuji, K.; Nakamura, S.; Sato, T.; Kubodera, K.; Myhrer, F.

2004-01-01

We study the effect of the neutrino magnetic moment on the neutrino-deuteron breakup reaction, using a method called the standard nuclear physics approach, which has already been well tested for several electroweak processes involving the deuteron

Cryogenic magnetic coil and superconducting magnetic shield for neutron electric dipole moment searches

Science.gov (United States)

Slutsky, S.; Swank, C. M.; Biswas, A.; Carr, R.; Escribano, J.; Filippone, B. W.; Griffith, W. C.; Mendenhall, M.; Nouri, N.; Osthelder, C.; Pérez Galván, A.; Picker, R.; Plaster, B.

2017-08-01

A magnetic coil operated at cryogenic temperatures is used to produce spatial, relative field gradients below 6 ppm/cm, stable for several hours. The apparatus is a prototype of the magnetic components for a neutron electric dipole moment (nEDM) search, which will take place at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory using ultra-cold neutrons (UCN). That search requires a uniform magnetic field to mitigate systematic effects and obtain long polarization lifetimes for neutron spin precession measurements. This paper details upgrades to a previously described apparatus [1], particularly the introduction of super-conducting magnetic shielding and the associated cryogenic apparatus. The magnetic gradients observed are sufficiently low for the nEDM search at SNS.

A Bayesian Approach to Magnetic Moment Determination Using μSR

Science.gov (United States)

Blundell, S. J.; Steele, A. J.; Lancaster, T.; Wright, J. D.; Pratt, F. L.

A significant challenge in zero-field μSR experiments arises from the uncertainty in the muon site. It is possible to calculate the dipole field (and hence precession frequency v) at any particular site given the magnetic moment μ and magnetic structure. One can also evaluate f(v), the probability distribution function of v assuming that the muon site can be anywhere within the unit cell with equal probability, excluding physically forbidden sites. Since v is obtained from experiment, what we would like to know is g(μjv), the probability density function of μ given the observed v. This can be obtained from our calculated f(v/μ) using Bayes' theorem. We describe an approach to this problem which we have used to extract information about real systems including a low-moment osmate compound, a family of molecular magnets, and an iron-arsenide compound.

Magnetic moment of inertia within the torque-torque correlation model.

Science.gov (United States)

Thonig, Danny; Eriksson, Olle; Pereiro, Manuel

2017-04-19

An essential property of magnetic devices is the relaxation rate in magnetic switching which strongly depends on the energy dissipation. This is described by the Landau-Lifshitz-Gilbert equation and the well known damping parameter, which has been shown to be reproduced from quantum mechanical calculations. Recently the importance of inertia phenomena have been discussed for magnetisation dynamics. This magnetic counterpart to the well-known inertia of Newtonian mechanics, represents a research field that so far has received only limited attention. We present and elaborate here on a theoretical model for calculating the magnetic moment of inertia based on the torque-torque correlation model. Particularly, the method has been applied to bulk itinerant magnets and we show that numerical values are comparable with recent experimental measurements. The theoretical analysis shows that even though the moment of inertia and damping are produced by the spin-orbit coupling, and the expression for them have common features, they are caused by very different electronic structure mechanisms. We propose ways to utilise this in order to tune the inertia experimentally, and to find materials with significant inertia dynamics.

Magnetic moment oscillation in ammonium perchlorate in a DC SQUID-based magnetic resonance experiment

International Nuclear Information System (INIS)

Montero, V.; Cernicchiaro, G.

2008-01-01

In this work we describe experimental results in which a DC SQUID (superconducting quantum interference device) is used as free induction decay detector. Measurements of a solid ammonium perchlorate (NH 4 ClO 4 ) sample were performed, in zero field, at 4.2 K. Unexpected magnetic moment oscillations were detected at 1.5 kHz. The computation of the magnetic fields suggests that the proton nuclear magnetic resonance may explain the measured resonance, considering reorientation of the ammonium group by quantum tunneling of protons and a magnetic proton dipole-dipole intermolecular interaction model

An experimental magnetic moment determination method based on spatial harmonic analysis of magnetic flux density signatures

Directory of Open Access Journals (Sweden)

A.V. Getman

2013-12-01

Full Text Available Theoretical aspects of an experimental determination method for residual and inductive magnetic moments of a technical object are considered. As input data, the technical object magnetic induction signatures obtained under its linear movement near a pair of three-component sensors are used. A magnetic signature integration technique based on spatial harmonic analysis of the magnetic field represented by twenty-four multipole coefficients is introduced.

SNO results and neutrino magnetic moment solution to the solar ...

Indian Academy of Sciences (India)

that the solar neutrino deficit is due to the interaction of neutrino transition magnetic moment with the solar magnetic ... Another new feature in the analysis is that for the global analysis, we have replaced the spectrum by its centroid. ... rise to mean potentials Va for neutrinos which are proportional to the number density of.

Effects of anomalous magnetic moment and temperature on pair production in an external magnetic field

International Nuclear Information System (INIS)

Dittrich, W.; Bauhoff, W.

1981-01-01

It is re-examined the problem of spontaneous pair creation in an external magnetic field. In contrast to earlier findings, it is shown that pair production does not occur due to the anomalous magnetic moment interaction. However, pairs may be observed in a situation of thermodynamic equilibrium at finite temperatures. (author)

Measurement of time-like baryon electro-magnetic form factors in BESIII

Energy Technology Data Exchange (ETDEWEB)

Morales Morales, Cristina; Dbeyssi, Alaa [Helmholtz-Institut Mainz (Germany); Ahmed, Samer Ali Nasher; Lin, Dexu; Rosner, Christoph; Wang, Yadi [Helmholtz-Institut Mainz (Germany); Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz (Germany); Maas, Frank [Helmholtz-Institut Mainz (Germany); Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz (Germany); PRISMA Cluster of Excellence, Johannes Gutenberg-Universitaet Mainz (Germany); Collaboration: BESIII-Collaboration

2016-07-01

BEPCII is a symmetric electron-positron collider located in Beijing running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows BESIII experiment to measure baryon form factors both from direct electron-positron annihilation and from initial state radiation processes. We present results on direct electron-positron annihilation into proton anti-proton and preliminary results on direct electron-positron annihilation into lambda anti-lambda based on data collected by BESIII in 2011 and 2012. Finally, expectations on the measurement of nucleon and hyperon electro-magnetic form factors from the BESIII high luminosity energy scan in 2015 and from initial state radiation processes at different center-of-mass energies are also shown.

Baryon number fluctuations in quasi-particle model

Energy Technology Data Exchange (ETDEWEB)

Zhao, Ameng [Southeast University Chengxian College, Department of Foundation, Nanjing (China); Luo, Xiaofeng [Central China Normal University, Key Laboratory of Quark and Lepton Physics (MOE), Institute of Particle Physics, Wuhan (China); Zong, Hongshi [Nanjing University, Department of Physics, Nanjing (China); Joint Center for Particle, Nuclear Physics and Cosmology, Nanjing (China); Institute of Theoretical Physics, CAS, State Key Laboratory of Theoretical Physics, Beijing (China)

2017-04-15

Baryon number fluctuations are sensitive to the QCD phase transition and the QCD critical point. According to the Feynman rules of finite-temperature field theory, we calculated various order moments and cumulants of the baryon number distributions in the quasi-particle model of the quark-gluon plasma. Furthermore, we compared our results with the experimental data measured by the STAR experiment at RHIC. It is found that the experimental data can be well described by the model for the colliding energies above 30 GeV and show large discrepancies at low energies. This puts a new constraint on the qQGP model and also provides a baseline for the QCD critical point search in heavy-ion collisions at low energies. (orig.)

Voltage Control of Rare-Earth Magnetic Moments at the Magnetic-Insulator-Metal Interface

Science.gov (United States)

Leon, Alejandro O.; Cahaya, Adam B.; Bauer, Gerrit E. W.

2018-01-01

The large spin-orbit interaction in the lanthanides implies a strong coupling between their internal charge and spin degrees of freedom. We formulate the coupling between the voltage and the local magnetic moments of rare-earth atoms with a partially filled 4 f shell at the interface between an insulator and a metal. The rare-earth-mediated torques allow the power-efficient control of spintronic devices by electric-field-induced ferromagnetic resonance and magnetization switching.

Nuclear moments

CERN Document Server

Kopferman, H; Massey, H S W

1958-01-01

Nuclear Moments focuses on the processes, methodologies, reactions, and transformations of molecules and atoms, including magnetic resonance and nuclear moments. The book first offers information on nuclear moments in free atoms and molecules, including theoretical foundations of hyperfine structure, isotope shift, spectra of diatomic molecules, and vector model of molecules. The manuscript then takes a look at nuclear moments in liquids and crystals. Discussions focus on nuclear paramagnetic and magnetic resonance and nuclear quadrupole resonance. The text discusses nuclear moments and nucl

Strange Quark Magnetic Moment of the Nucleon at the Physical Point.

Science.gov (United States)

Sufian, Raza Sabbir; Yang, Yi-Bo; Alexandru, Andrei; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

2017-01-27

We report a lattice QCD calculation of the strange quark contribution to the nucleon's magnetic moment and charge radius. This analysis presents the first direct determination of strange electromagnetic form factors including at the physical pion mass. We perform a model-independent extraction of the strange magnetic moment and the strange charge radius from the electromagnetic form factors in the momentum transfer range of 0.051  GeV^{2}≲Q^{2}≲1.31  GeV^{2}. The finite lattice spacing and finite volume corrections are included in a global fit with 24 valence quark masses on four lattices with different lattice spacings, different volumes, and four sea quark masses including one at the physical pion mass. We obtain the strange magnetic moment G_{M}^{s}(0)=-0.064(14)(09)μ_{N}. The four-sigma precision in statistics is achieved partly due to low-mode averaging of the quark loop and low-mode substitution to improve the statistics of the nucleon propagator. We also obtain the strange charge radius ⟨r_{s}^{2}⟩_{E}=-0.0043(16)(14)  fm^{2}.

Baryon asymmetry, dark matter and local baryon number

International Nuclear Information System (INIS)

Fileviez Pérez, Pavel; Patel, Hiren H.

2014-01-01

We propose a new mechanism to understand the relation between baryon and dark matter asymmetries in the universe in theories where the baryon number is a local symmetry. In these scenarios the B−L asymmetry generated through a mechanism such as leptogenesis is transferred to the dark matter and baryonic sectors through sphalerons processes which conserve total baryon number. We show that it is possible to have a consistent relation between the dark matter relic density and the baryon asymmetry in the universe even if the baryon number is broken at the low scale through the Higgs mechanism. We also discuss the case where one uses the Stueckelberg mechanism to understand the conservation of baryon number in nature.

Light--light scattering tensor and the anomalous magnetic moment of the muon

International Nuclear Information System (INIS)

Kuraev, E.A.; Silagadze, Z.K.; Cheshel', A.A.; Schiller, A.

1989-01-01

A general expression is obtained for the tensor that describes the effect of light--light scattering on the anomalous magnetic moment of leptons. An explicit expression is derived for the electron-loop contribution, for which an analytic evaluation is carried out of the coefficient in front of the logarithm of the ratio of the muon mass to the electron mass in the anomalous magnetic moment of the muon. Logarithmic contributions due to radiative corrections are shown to originate exclusively from the inclusion of the polarization of the vacuum of virtual photons

Nuclear structure and magnetic moment of the unstable 12B-12N mirror pair

International Nuclear Information System (INIS)

Zheng Yongnan; Zhou Dongmei; Yuan Daqing; Zuo Yi; Fan Ping; Xu Yongjun; Zhu Jiazheng; Wang Zhiqiang; Luo Hailong; Zhang Xizhen; Zhu Shengyun; Mihara, M.; Matsuta, K.; Fukuda, M.; Minamisono, T.; Suzuki, T.

2010-01-01

Magnetic moments of the A=12 unstable mirror pair nuclides 12 B and 12 N have been measured by the β-NMR technique. The experimentally measured magnetic moments are μ( 12 B)=1.00(17)μ N and μ( 12 N)=0.4571(1)μ N . The improved shell model using an SFO Hamiltonian with enhanced spin-isospin monopole proton-neutron interaction and modified single-particle energies is employed to calculate the magnetic moments of 12 B and 12 N. The calculation yields μ( 12 B)=0.929μ N and μ( 12 N)=0.452μ N and has produced a new magic number 6 for the short-lived unstable mirror pair nuclides 12 B and 12 N. (authors)

Baryonic and Non-Baryonic Dark Matter

OpenAIRE

Carr, Bernard

2000-01-01

Cosmological nucleosynthesis calculations imply that there should be both non-baryonic and baryonic dark matter. Recent data suggest that some of the non-baryonic dark matter must be "hot" (i.e. massive neutrinos) and there may also be evidence for "cold" dark matter (i.e. WIMPs). If the baryonic dark matter resides in galactic halos, it is likely to be in the form of compact objects (i.e. MACHOs) and these would probably be the remnants of a first generation of pregalactic or protogalactic P...

About the parametrizations utilized to perform magnetic moments measurements using the transient field technique

Energy Technology Data Exchange (ETDEWEB)

Gómez, A. M., E-mail: amgomezl-1@uqvirtual.edu.co [Programa de Física, Universidad del Quindo (Colombia); Torres, D. A., E-mail: datorresg@unal.edu.co [Physics Department, Universidad Nacional de Colombia, Bogotá (Colombia)

2016-07-07

The experimental study of nuclear magnetic moments, using the Transient Field technique, makes use of spin-orbit hyperfine interactions to generate strong magnetic fields, above the kilo-Tesla regime, capable to create a precession of the nuclear spin. A theoretical description of such magnetic fields is still under theoretical research, and the use of parametrizations is still a common way to address the lack of theoretical information. In this contribution, a review of the main parametrizations utilized in the measurements of Nuclear Magnetic Moments will be presented, the challenges to create a theoretical description from first principles will be discussed.

High-Precision Measurements of the Bound Electron’s Magnetic Moment

Directory of Open Access Journals (Sweden)

Sven Sturm

2017-01-01

Full Text Available Highly charged ions represent environments that allow to study precisely one or more bound electrons subjected to unsurpassed electromagnetic fields. Under such conditions, the magnetic moment (g-factor of a bound electron changes significantly, to a large extent due to contributions from quantum electrodynamics. We present three Penning-trap experiments, which allow to measure magnetic moments with ppb precision and better, serving as stringent tests of corresponding calculations, and also yielding access to fundamental quantities like the fine structure constant α and the atomic mass of the electron. Additionally, the bound electrons can be used as sensitive probes for properties of the ionic nuclei. We summarize the measurements performed so far, discuss their significance, and give a detailed account of the experimental setups, procedures and the foreseen measurements.

Critical Opalescence in Baryonic QCD Matter

OpenAIRE

Antoniou, N. G.; Diakonos, F. K.; Kapoyannis, A. S.; Kousouris, K. S.

2006-01-01

We show that critical opalescence, a clear signature of second-order phase transition in conventional matter, manifests itself as critical intermittency in QCD matter produced in experiments with nuclei. This behaviour is revealed in transverse momentum spectra as a pattern of power laws in factorial moments, to all orders, associated with baryon production. This phenomenon together with a similar effect in the isoscalar sector of pions (sigma mode) provide us with a set of observables associ...

Meson exchange current corrections to magnetic moments in quantum hadro-dynamics

Energy Technology Data Exchange (ETDEWEB)

Morse, T M; Price, C E; Shepard, J R [Colorado Univ., Boulder (USA). Dept. of Physics

1990-11-15

We have calculated pion exchange current corrections to the magnetic moments of closed shell {plus minus}1 particle nuclei near A=16 and 40 within the framework of quantum hadro-dynamics (QHD). We find that the correction is significant and that, in general, the agreement of the QHD isovector moments with experiment is worsened. Comparisons to previous non-relativistic calculations are also made. (orig.).

The effect of baryons in the cosmological lensing PDFs

Science.gov (United States)

Castro, Tiago; Quartin, Miguel; Giocoli, Carlo; Borgani, Stefano; Dolag, Klaus

2018-05-01

Observational cosmology is passing through a unique moment of grandeur with the amount of quality data growing fast. However, in order to better take advantage of this moment, data analysis tools have to keep up the pace. Understanding the effect of baryonic matter on the large-scale structure is one of the challenges to be faced in cosmology. In this work, we have thoroughly studied the effect of baryonic physics on different lensing statistics. Making use of the Magneticum Pathfinder suite of simulations we show that the influence of luminous matter on the 1-point lensing statistics of point sources is significant, enhancing the probability of magnified objects with μ > 3 by a factor of 2 and the occurrence of multiple-images by a factor 5 - 500 depending on the source redshift and size. We also discuss the dependence of the lensing statistics on the angular resolution of sources. Our results and methodology were carefully tested in order to guarantee that our uncertainties are much smaller than the effects here presented.

Magnetic dipole moments of 58Cu and 59Cu by in-source laser spectroscopy

International Nuclear Information System (INIS)

Stone, N. J.; Koester, U.; Stone, J. Rikovska; Fedorov, D. V.; Fedoseyev, V. N.; Flanagan, K. T.; Hass, M.; Lakshmi, S.

2008-01-01

Online measurements of the magnetic dipole moments and isotope shifts of 58 Cu and 59 Cu by the in-source laser spectroscopy method are reported. The results for the magnetic moments are μ ( 58 Cu) =+0.52(8) μ N ,μ( 59 Cu) =+1.84(3) μ N and for the isotope shifts δν 59,65 =1.72(22) GHz and δν 58,65 =1.99(30) GHz in the transition from the 3d 10 4s 2 S 1/2 ground state to the 3d 10 4p 2 P 1/2 state in Cu I. The magnetic moment of 58 Cu is discussed in the context of the strength of the subshell closure at 56 Ni, additivity rules and large-scale shell model calculations

The mean energy loss by neutrino with magnetic moment in strong magnetic field with consideration of positronium contribution to photon dispersion

Science.gov (United States)

Mosichkin, A. F.

2017-11-01

The process of radiative decay of the neutrino with a magnetic moment in a strong magnetic field with consideration of positronium influence on photon dispersion has been studied. Positronium contribution to the photon polarization operator induces significant modifications of the photon dispersion law and neutrino radiative decay amplitude. It has been shown that the mean energy loss of a neutrino with magnetic a moment significantly increases, when the positronium contribution to photon dispersion is taken into account.

Universal Effectiveness of Inducing Magnetic Moments in Graphene by Amino-Type sp3-Defects

Directory of Open Access Journals (Sweden)

Tao Tang

2018-04-01

Full Text Available Inducing magnetic moments in graphene is very important for its potential application in spintronics. Introducing sp3-defects on the graphene basal plane is deemed as the most promising approach to produce magnetic graphene. However, its universal validity has not been very well verified experimentally. By functionalization of approximately pure amino groups on graphene basal plane, a spin-generalization efficiency of ~1 μB/100 NH2 was obtained for the first time, thus providing substantial evidence for the validity of inducing magnetic moments by sp3-defects. As well, amino groups provide another potential sp3-type candidate to prepare magnetic graphene.

High uniformity magnetic coil for search of neutron electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Perez Galvan, A., E-mail: apg@caltech.edu [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Plaster, B. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY, 40506 (United States); Boissevain, J.; Carr, R.; Filippone, B.W.; Mendenhall, M.P.; Schmid, R. [W.K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA, 91125 (United States); Alarcon, R.; Balascuta, S. [Department of Physics, Arizona State University, Tempe, AZ 85287 (United States)

2011-12-21

We present in this article a prototype magnetic coil that has been developed for a new search for the electric dipole moment of the neutron at the Spallation Neutron Source at Oak Ridge National Laboratory. The gradients of the magnetic field generated by the coil have been optimized to reduce known systematic effects and to yield long polarization lifetimes of the trapped particles sampling the highly uniform magnetic field. Measurements of the field uniformity of this prototype magnetic coil are also presented.

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.

The Information Content of Anisotropic Baryon Acoustic Oscillation Scale Measurements

OpenAIRE

Ross, Ashley J.; Percival, Will J.; Manera, Marc

2015-01-01

Anisotropic measurements of the Baryon Acoustic Oscillation (BAO) feature within a galaxy survey enable joint inference about the Hubble parameter $H(z)$ and angular diameter distance $D_A(z)$. These measurements are typically obtained from moments of the measured 2-point clustering statistics, with respect to the cosine of the angle to the line of sight $\\mu$. The position of the BAO features in each moment depends on a combination of $D_A(z)$ and $H(z)$, and measuring the positions in two o...

Is the anomalous magnetic moment the consequence of a non-classical transformation for rotating frames?

International Nuclear Information System (INIS)

Gisin, B V

2002-01-01

We consider the anomalous magnetic moment from an 'optical viewpoint' using an analogy between the motion of a particle with a magnetic moment in a magnetic field and the propagation of an optical pulse through an electro-optical crystal in an electric field. We show that an optical experiment similar to electron magnetic resonance is possible in some electro-optical crystals possessing the Faraday effect. This phenomenon is described by an analogue of the Pauli equation extracted from the Maxwell equation in the slowly varied amplitude approximation. In such an experiment the modulation by rotating fields plays a significant role. From the optical viewpoint the modulation assumes introducing the concept of a point rotation frame with the rotation axis at every point originated from the concept of the optical indicatrix (index ellipsoid). We discuss the connection between the non-classical transformation by transition from one such frame to another and an anomalous magnetic moment

High-energy scattering of particles with anomalous magnetic moments in quantum field theory

International Nuclear Information System (INIS)

Nguen Suan Khan; Pervushin, V.N.

1976-01-01

Eikonal type representations taking into account the anomalous magnetic moments of nucleons are obtained for the amplitude of pion-nucleon and nucleon-nucleon scattering in the asymptotic region s → infinity, (t) (<<) s in the framework of nonrenormalizable quantum field theory. The anomalous magnetic moment leads to additional terms in the amplitude which describe the spin flips in the scattering process. It is shown that the renormalization problem does not arise in the asymptotics s → infinity. As an application the Coulomb interference is considered

Light-cone distribution amplitudes of the ground state bottom baryons in HQET

Energy Technology Data Exchange (ETDEWEB)

Ali, A.; Wang, W. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hambrock, C. [Technische Univ. Dortmund (Germany); Parkhomenko, A.Ya. [P.G. Demidov Yaroslavl State Univ., Yaroslavl (Russian Federation)

2012-12-15

We provide the definition of the complete set of light-cone distribution amplitudes (LCDAs) for the ground state heavy bottom baryons with the spin-parities J{sup P}=1/2{sup +} and J{sup P}=3/2{sup +} in the heavy quark limit. We present the renormalization effects on the twist-2 light-cone distribution amplitudes and use the QCD sum rules to compute the moments of twist-2, twist-3, and twist-4 LCDAs. Simple models for the heavy baryon distribution amplitudes are analyzed with account of their scale dependence.

Big-bang nucleosynthesis and the baryon density of the universe.

Science.gov (United States)

Copi, C J; Schramm, D N; Turner, M S

1995-01-13

For almost 30 years, the predictions of big-bang nucleosynthesis have been used to test the big-bang model to within a fraction of a second of the bang. The agreement between the predicted and observed abundances of deuterium, helium-3, helium-4, and lithium-7 confirms the standard cosmology model and allows accurate determination of the baryon density, between 1.7 x 10(-31) and 4.1 x 10(-31) grams per cubic centimeter (corresponding to about 1 to 15 percent of the critical density). This measurement of the density of ordinary matter is pivotal to the establishment of two dark-matter problems: (i) most of the baryons are dark, and (ii) if the total mass density is greater than about 15 percent of the critical density, as many determinations indicate, the bulk of the dark matter must be "non-baryonic," composed of elementary particles left from the earliest moments.

Heavy baryons

International Nuclear Information System (INIS)

Koerner, J.G.

1994-06-01

We review the experimental and theoretical status of baryons containing one heavy quark. The charm and bottom baryon states are classified and their mass spectra are listed. The appropriate theoretical framework for the description of heavy baryons is the Heavy Quark Effective Theory, whose general ideas and methods are introduced and illustrated in specific examples. We present simple covariant expressions for the spin wave functions of heavy baryons including p-wave baryons. The covariant spin wave functions are used to determine the Heavy Quark Symmetry structure of flavour-changing current-induced transitions between heavy baryons as well as one-pion and one-photon transitions between heavy baryons of the same flavour. We discuss 1/m Q corrections to the current-induced transitions as well as the structure of heavy to light baryon transitions. Whenever possible we attempt to present numbers to compare with experiment by making use of further model-dependent assumptions as e.g. the constituent picture for light quarks. We highlight recent advances in the theoretical understanding of the inclusive decays of hadrons containing one heavy quark including polarization. For exclusive semileptonic decays we discuss rates, angular decay distributions and polarization effects. We provide an update of the experimental and theoretical status of lifetimes of heavy baryons and of exclusive nonleptonic two body decays of charm baryons. (orig.)

Magnetic moments, coupling, and interface interdiffusion in Fe/V(001) superlattices

Science.gov (United States)

Schwickert, M. M.; Coehoorn, R.; Tomaz, M. A.; Mayo, E.; Lederman, D.; O'brien, W. L.; Lin, Tao; Harp, G. R.

1998-06-01

Epitaxial Fe/V(001) multilayers are studied both experimentally and by theoretical calculations. Sputter-deposited epitaxial films are characterized by x-ray diffraction, magneto-optical Kerr effect, and x-ray magnetic circular dichroism. These results are compared with first-principles calculations modeling different amounts of interface interdiffusion. The exchange coupling across the V layers is observed to oscillate, with antiferromagnetic peaks near the V layer thicknesses tV~22, 32, and 42 Å. For all films including superlattices and alloys, the average V magnetic moment is antiparallel to that of Fe. The average V moment increases slightly with increasing interdiffusion at the Fe/V interface. Calculations modeling mixed interface layers and measurements indicate that all V atoms are aligned with one another for tV<~15 Å, although the magnitude of the V moment decays toward the center of the layer. This ``transient ferromagnetic'' state arises from direct (d-d) exchange coupling between V atoms in the layer. It is argued that the transient ferromagnetism suppresses the first antiferromagnetic coupling peak between Fe layers, expected to occur at tV~12 Å.

Magnetic moments of light nuclei within the framework of reduced Hamiltonian method

CERN Document Server

Deveikis, A

1998-01-01

A new procedure for evaluation of magnetic dipole moments of light atomic nuclei has been developed. The procedure presented obeys the principles of antisymmetry and translational invariance and is based on the reduced Hamiltonian method. The theoretical formulation has been illustrated by calculation of magnetic dipole moments for 2 sup H , 3 sup H , 3 sup H e, 4 sup H e, 5 sup H e, 5 sup L i, 11 sup L i, and 6 sup L i nuclei. The calculations were performed in a complete 0(h/2 pi)omega basis. The obtained results are in good agreement with the experimental data. (author)

Summary of static properties of leptons and hadrons

International Nuclear Information System (INIS)

Franklin, J.

1989-01-01

The session on Static Properties of Leptons and Hadrons had six talks on baryon magnetic moments (four experimental and two theoretical) and three talks on other topics (g/2 of the electron, g-2 of the muon, and a search for an electric dipole moment of the neutron). I will first give brief summaries of these last three talks and then present an overview of baryon magnetic moments, updated by the results presented at this symposium

Baryons and baryon resonances in nuclear matter

Science.gov (United States)

Lenske, Horst; Dhar, Madhumita; Gaitanos, Theodoros; Cao, Xu

2018-01-01

Theoretical approaches to the production of hyperons and baryon resonances in elementary hadronic reactions and heavy ion collisions are reviewed. The focus is on the production and interactions of baryons in the lowest SU(3) flavor octet and states from the next higher SU(3) flavor decuplet. Approaches using the SU(3) formalism for interactions of mesons and baryons and effective field theory for hyperons are discussed. An overview of application to free space and in-medium baryon-baryon interactions is given and the relation to a density functional theory is indicated. The intimate connection between baryon resonances and strangeness production is shown first for reactions on the nucleon. Pion-induced hypernuclear reactions are shown to proceed essentially through the excitation of intermediate nucleon resonances. Transport theory in conjunction with a statistical fragmentation model is an appropriate description of hypernuclear production in antiproton and heavy ion induced fragmentation reactions. The excitation of subnuclear degrees of freedom in peripheral heavy ion collisions at relativistic energies is reviewed. The status of in-medium resonance physics is discussed.

Baryon-baryon mixing in hypernuclei

International Nuclear Information System (INIS)

Gibson, B.F.

1998-01-01

Implications of few-body hypernuclei for the understanding of the baryon-baryon interaction are examined. Octet-octet coupling effects not present in conventional, non strange nuclei are the focus. The need to identify strangeness -2 hypernuclei to test model predictions is emphasized

The muon magnetic moment in flipped SU(5)

Energy Technology Data Exchange (ETDEWEB)

Abel, S.A.; Cottingham, W.N. (Bristol Univ. (UK). H.H. Wills Physics Lab.); Whittingham, I.B. (James Cook Univ. of North Queensland, Townsville (Australia). Dept. of Physics)

1991-04-25

The magnetic moment of the muon is examined for the no-scale supersymmetric flipped SU(5) theory, and it is found that supersymmetric contributions to (g-2){sub {mu}} are (-7{+-}2)x10{sup -9} and within this range are predominantly dependent on the scale of supersymmetry breaking. It is therefore suggested that experiments to measure this quantity may serve to limit the parameters of this model. (orig.).

Fen (n=1–6) clusters chemisorbed on vacancy defects in graphene: Stability, spin-dipole moment, and magnetic anisotropy

KAUST Repository

Haldar, Soumyajyoti

2014-05-09

In this work, we have studied the chemical and magnetic interactions of Fen (n=1–6) clusters with vacancy defects (monovacancy to correlated vacancies with six missing C atoms) in a graphene sheet by ab initio density functional calculations combined with Hubbard U corrections for correlated Fe-d electrons. It is found that the vacancy formation energies are lowered in the presence of Fe, indicating an easier destruction of the graphene sheet. Due to strong chemical interactions between Fe clusters and vacancies, a complex distribution of magnetic moments appear on the distorted Fe clusters which results in reduced averaged magnetic moments compared to the free clusters. In addition to that, we have calculated spin-dipole moments and magnetic anisotropy energies. The calculated spin-dipole moments arising from anisotropic spin density distributions vary between positive and negative values, yielding increased or decreased effective moments. Depending on the cluster geometry, the easy axis of magnetization of the Fe clusters shows in-plane or out-of-plane behavior.

Nuclear Magnetic Dipole and Electric Quadrupole Moments: Their Measurement and Tabulation as Accessible Data

Energy Technology Data Exchange (ETDEWEB)

Stone, N. J., E-mail: n.stone@physics.ox.ac.uk [Department of Physics and Astronomy, University of Tennessee, Knoxville Tennessee 37996 (United States)

2015-09-15

The most recent tabulations of nuclear magnetic dipole and electric quadrupole moments have been prepared and published by the Nuclear Data Section of the IAEA, Vienna [N. J. Stone, Report No. INDC(NDS)-0650 (2013); Report No. INDC(NDS)-0658 (2014)]. The first of these is a table of recommended quadrupole moments for all isotopes in which all experimental results are made consistent with a limited number of adopted standards for each element; the second is a combined listing of all measurements of both moments. Both tables cover all isotopes and energy levels. In this paper, the considerations relevant to the preparation of both tables are described, together with observations as to the importance and (where appropriate) application of necessary corrections to achieve the “best” values. Some discussion of experimental methods is included with emphasis on their precision. The aim of the published quadrupole moment table is to provide a standard reference in which the value given for each moment is the best available and for which full provenance is given. A table of recommended magnetic dipole moments is in preparation, with the same objective in view.

Charming baryons

International Nuclear Information System (INIS)

Garcia-Recio, C.; Salcedo, L.L.; Gamermann, D.; Nieves, J.; Romanets, O.; Tolos, L.

2014-01-01

We study odd-parity baryonic resonances with one heavy and three light flavors, dynamically generated by meson-baryon interactions. Special attention is paid to Heavy Quark Spin Symmetry (HQSS), hence pseudoscalar and vector mesons and baryons with J π = 1/2 + and 3/2 + are considered as constituent hadrons. For the hidden-charm sector (N c = N c ¯ = 1), the meson-baryon Lagrangian with Heavy Flavor Symmetry is constructed by a minimal extension of the SU(3) Weinberg-Tomozawa (WT) Lagrangian to fulfill HQSS, such that not new parameters are needed. This interaction can be presented in different formal ways: as a Field Lagrangian, as Hadron creation-annihilation operators, as SU(6)×HQSS group projectors and as multichannel matrices. The multichannel Bethe-Salpeter equation is solved for odd-parity light baryons, hidden-charm N and Δ and Beauty Baryons (Λ b ). Results of calculations with this model are shown in comparison with other models and experimental values for baryonic resonances. (author)

On planar quantum dynamics of a magnetic dipole moment in the presence of electric and magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Silva, Edilberto O. [Universidade Federal do Maranhao, Departamento de Fisica, Sao Luis, MA (Brazil)

2014-10-15

The planar quantum dynamics of a neutral particle with a magnetic dipole moment in the presence of electric and magnetic fields is considered. The criteria to establish the planar dynamics reveal that the resulting nonrelativistic Hamiltonian has a simplified expression without making approximations, and some terms have crucial importance for the system dynamics. (orig.)

Description of magnetic moments of long isotopic chains within the FFS theory

Energy Technology Data Exchange (ETDEWEB)

Borzov, I.N. [IPPE, Obninsk (Russian Federation); Saperstein, E.E.; Tolokonnikov, S.V. [Kurchatov Institute, Moscow (Russian Federation); Neyens, G.; Severijns, N. [Katholieke Universiteit Leuven, Instituut voor Kern- en Stralingsfysica, Leuven (Belgium)

2010-08-15

Dipole magnetic moments of several long isotopic chains are analyzed within the self-consistent finite Fermi system theory with exact account for the pairing and quasiparticle continuum. The momentum dependence of the spin-isospin Landau-Migdal amplitude g' is taken into account. This dependence was introduced previously to describe high-energy electron magnetic scattering. New moment data for nuclei far from the {beta} -stability valley are included in the analysis. For a number of semi-magic isotopes of the tin and lead chains a good description of the data is obtained, with an accuracy of 0.1- 0.2{mu}{sub N}. A chain of non-magic isotopes of copper is also analyzed in detail. (orig.)

The anomalous magnetic moment of the muon

International Nuclear Information System (INIS)

Farley, F.J.M.

1975-01-01

A historical survey of the measurements of the gyromagnetic ratio g of the muon. A brief introduction is given to the theory of the 'anomalous magnetic moment' a equivalent to 1/2(g-2) and its significance is explained. The main part of the review concerns the successive (g-2) experiments to measure a directly, with gradually increasing accuracy. At present experiment and theory agree to (13+-29) parts in 10 9 in g, and the muon still obeys the rules of quantum electrodynamics for a structureless point charge. (author)

The Equivalence Principle and Anomalous Magnetic Moment Experiments

OpenAIRE

Alvarez, C.; Mann, R. B.

1995-01-01

We investigate the possibility of testing of the Einstein Equivalence Principle (EEP) using measurements of anomalous magnetic moments of elementary particles. We compute the one loop correction for the $g-2$ anomaly within the class of non metric theories of gravity described by the \\tmu formalism. We find several novel mechanisms for breaking the EEP whose origin is due purely to radiative corrections. We discuss the possibilities of setting new empirical constraints on these effects.

Shell structure of potassium isotopes deduced from their magnetic moments

CERN Document Server

Papuga, J.; Kreim, K; Barbieri, C; Blaum, K; De Rydt, M; Duguet, T; Garcia Ruiz, R F; Heylen, H; Kowalska, M; Neugart, R; Neyens, G; Nortershauser, W; Rajabali, M M; Sanchez, R; Smirnova, N; Soma, V; Yordanov, D T

2014-09-29

$\\textbf{Background:}$ Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. \\\\ \\\\ $\\textbf{Purpose:}$ Extend our knowledge about the evolution of the $1/2^+$ and $3/2^+$ states for K isotopes beyond the $N = 28$ shell gap. \\\\ \\\\ $\\textbf{Method:}$ High-resolution collinear laser spectroscopy on bunched atomic beams. \\\\ \\\\ $\\textbf{Results:}$ From measured hyperfine structure spectra of K isotopes, nuclear spins and magnetic moments of the ground states were obtained for isotopes from $N = 19$ up to $N = 32$. In order to draw conclusions about the composition of the wave functions and the occupation of the levels, the experimental data were compared to shell-model calculations using SDPF-NR and SDPF-U effective interactions. In addition, a detailed discussion about the evolution of the gap between proton $1d_{3/2}$ and $2s_{1/2}$ in the shell model and $\\textit{ab initio}$ framework is al...

Bimodal distribution of the magnetic dipole moment in nanoparticles with a monomodal distribution of the physical size

International Nuclear Information System (INIS)

Rijssel, Jos van; Kuipers, Bonny W.M.; Erné, Ben H.

2015-01-01

High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal distribution of the magnetic dipole moment. Here, we test this assumption for different types of superparamagnetic iron oxide nanoparticles in the 5–20 nm range, by multimodal fitting of magnetization curves using the MINORIM inversion method. The particles are studied while in dilute colloidal dispersion in a liquid, thereby preventing hysteresis and diminishing the effects of magnetic anisotropy on the interpretation of the magnetization curves. For two different types of well crystallized particles, the magnetic distribution is indeed log-normal, as expected from the physical size distribution. However, two other types of particles, with twinning defects or inhomogeneous oxide phases, are found to have a bimodal magnetic distribution. Our qualitative explanation is that relatively low fields are sufficient to begin aligning the particles in the liquid on the basis of their net dipole moment, whereas higher fields are required to align the smaller domains or less magnetic phases inside the particles. - Highlights: • Multimodal fits of dilute ferrofluids reveal when the particles are multidomain. • No a priori shape of the distribution is assumed by the MINORIM inversion method. • Well crystallized particles have log-normal TEM and magnetic size distributions. • Defective particles can combine a monomodal size and a bimodal dipole moment

Critical opalescence in baryonic QCD matter.

Science.gov (United States)

Antoniou, N G; Diakonos, F K; Kapoyannis, A S; Kousouris, K S

2006-07-21

We show that critical opalescence, a clear signature of second-order phase transition in conventional matter, manifests itself as critical intermittency in QCD matter produced in experiments with nuclei. This behavior is revealed in transverse momentum spectra as a pattern of power laws in factorial moments, to all orders, associated with baryon production. This phenomenon together with a similar effect in the isoscalar sector of pions (sigma mode) provide us with a set of observables associated with the search for the QCD critical point in experiments with nuclei at high energies.

Critical Opalescence in Baryonic QCD Matter

Science.gov (United States)

Antoniou, N. G.; Diakonos, F. K.; Kapoyannis, A. S.; Kousouris, K. S.

2006-07-01

We show that critical opalescence, a clear signature of second-order phase transition in conventional matter, manifests itself as critical intermittency in QCD matter produced in experiments with nuclei. This behavior is revealed in transverse momentum spectra as a pattern of power laws in factorial moments, to all orders, associated with baryon production. This phenomenon together with a similar effect in the isoscalar sector of pions (sigma mode) provide us with a set of observables associated with the search for the QCD critical point in experiments with nuclei at high energies.

Critical Opalescence in Baryonic QCD Matter

International Nuclear Information System (INIS)

Antoniou, N. G.; Diakonos, F. K.; Kapoyannis, A. S.; Kousouris, K. S.

2006-01-01

We show that critical opalescence, a clear signature of second-order phase transition in conventional matter, manifests itself as critical intermittency in QCD matter produced in experiments with nuclei. This behavior is revealed in transverse momentum spectra as a pattern of power laws in factorial moments, to all orders, associated with baryon production. This phenomenon together with a similar effect in the isoscalar sector of pions (sigma mode) provide us with a set of observables associated with the search for the QCD critical point in experiments with nuclei at high energies

The swimming polarity of multicellular magnetotactic prokaryotes can change during an isolation process employing magnets: evidence of a relation between swimming polarity and magnetic moment intensity.

Science.gov (United States)

de Melo, Roger Duarte; Acosta-Avalos, Daniel

2017-09-01

Magnetotactic microorganisms are characterized by swimming in the direction of an applied magnetic field. In nature, two types of swimming polarity have been observed: north-seeking microorganisms that swim in the same direction as the magnetic field, and south-seeking microorganisms that swim in the opposite direction. The present work studies the reversal in the swimming polarity of the multicellular magnetotactic prokaryote Candidatus Magnetoglobus multicellularis following an isolation process using high magnetic fields from magnets. The proportion of north- and south-seeking organisms was counted as a function of the magnetic field intensity used during the isolation of the organisms from sediment. It was observed that the proportion of north-seeking organisms increased when the magnetic field was increased. The magnetic moment for north- and south-seeking populations was estimated using the U-turn method. The average magnetic moment was higher for north- than south-seeking organisms. The results suggest that the reversal of swimming polarity must occur during the isolation process in the presence of high magnetic fields and magnetic field gradients. It is shown for the first time that the swimming polarity reversal depends on the magnetic moment intensity of multicellular magnetotactic prokaryotes, and new studies must be undertaken to understand the role of magnetic moment polarity and oxygen gradients in determination of swimming polarity.

Tilted-foil polarisation and magnetic moments of mirror nuclei at ISOLDE

CERN Multimedia

Bordeanu, C; Thundiyamkulathu Baby, L; Lindroos, M

2002-01-01

We report here on the first measurement in an experimental program initiated at the ISOLDE facility at CERN for the measurement of magnetic moments of short-lived radionuclides. The 60~keV ISOLDE beam from the GPS separator is boosted in energy by a 200~kV high-voltage platform, on which the whole experiment is mounted, in order to achieve sufficiently high energy for transmission through the foils of a tilted-foil setup. The 520~keV $^{23}$Mg(2$^+$) nuclei are polarized by the tilted foil technique and the resulting 0$^o$ - 180$^o$ $\\beta$- asymmetry is monitored as a function of the frequency of an rf-applied perturbing magnetic field in an NMR setup.\\\\ In this experiment, earlier asymmetry measurements were confirmed and an NMR resonance was observed, corresponding to a preliminary value of the magnetic moment of 0.533(6) n.m., in agreement with a previous measurement. The measured asymmetry as function of NMR frequency and the fitted resonance curve are presented in the figure. During the e...

Electric charge quantization and the muon anomalous magnetic moment

International Nuclear Information System (INIS)

Pires, C.A.S. de; Rodrigues da Silva, P.S.

2002-01-01

We investigate some proposals to solve the electric charge quantization puzzle that simultaneously explain the recent measured deviation on the muon anomalous magnetic moment. For this we assess extensions of the electro-weak standard model spanning modifications on the scalar sector only. It is interesting to verify that one can have modest extensions which easily account for the solution for both problems

Study of ψ(3770 decaying to baryon anti-baryon pairs

Directory of Open Access Journals (Sweden)

Li-Gang Xia

2016-05-01

Full Text Available To study the decays of ψ(3770 going to baryon anti-baryon pairs (BB¯, all available experiments of measuring the cross sections of e+e−→BB¯ at center-of-mass energy ranging from 3.0 GeV to 3.9 GeV are combined. To relate the baryon octets, a model based on the SU(3 flavor symmetry is used and the SU(3 breaking effects are also considered. Assuming the electric and magnetic form factors are equal (|GE|=|GM|, a global fit including the interference between the QED process and the resonant process is performed. The branching fraction of ψ(3770→BB¯ is determined to be (2.4±0.8±0.3×10−5, (1.7±0.6±0.1×10−5, (4.5±0.9±0.1×10−5, (4.5±0.9±0.1×10−5, (2.0±0.7±0.1×10−5, and (2.0±0.7±0.1×10−5 for B=p,Λ,Σ+,Σ0,Ξ− and Ξ0, respectively, where the first uncertainty is from the global fit and the second uncertainty is the systematic uncertainty due to the assumption |GE|=|GM|. They are at least one order of magnitude larger than a simple scaling of the branching fraction of J/ψ/ψ(3686→BB¯.

Magnetization, magnetic susceptibility, effective magnetic moment of Fe3+ ions in Bi25FeO39 ferrite

International Nuclear Information System (INIS)

Zatsiupa, A.A.; Bashkirov, L.A.; Troyanchuk, I.O.; Petrov, G.S.; Galyas, A.I.; Lobanovsky, L.S.; Truhanov, S.V.

2014-01-01

Magnetic susceptibility for ferrite Bi 25 FeO 39 is measured at 5–950 K in the magnetic field of 0.86 T. It is shown that Bi 25 FeO 39 is paramagnetic in the temperature range 5−950 K. The saturation magnetization is equal to 5.04μ B per formula unit at 5 K in a magnetic field of 10 T. It is found that at 5−300 K the effective magnetic moment of Fe 3+ ions in Bi 25 FeO 39 is equal to 5.82μ B . - Graphical abstract: The dependence of the magnetization (n, μ B ) on the magnetic field for one formula unit of Bi 25 FeO 39 at 5 K. - Highlights: • Magnetic susceptibility for Bi 25 FeO 39 is measured at 5–950 K in the magnetic field of 0.86 T. • It is shown that Bi 25 FeO 39 is paramagnetic in the temperature range 5−950 K. • The saturation magnetization is equal to 5.04μ B per formula unit at 5 K in a magnetic field of 10 T

Neutrino magnetic moment in a theory with lepton flavor symmetry

International Nuclear Information System (INIS)

Stephanov, M.A.

1987-01-01

A model for generating the neutrino magnetic moment of the order of 10 -10 μ B is proposed, which is based on the SU(3) lepton flavor symmetry. In such a way one can avoid the flavor changing processes. The experimental constraints on the constants of the model are considered

Three types magnetic moment distribution of nonlinear excitations in a Heisenberg helimagnet

Energy Technology Data Exchange (ETDEWEB)

Qi, Jian-Wen [School of Physics, Northwest University, Xi' an 710069 (China); Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Li, Zai-Dong [Department of Applied Physics, Hebei University of Technology, Tianjin 300401 (China); Yang, Zhan-Ying, E-mail: zyyang@nwu.edu.cn [School of Physics, Northwest University, Xi' an 710069 (China); Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Yang, Wen-Li [Shaanxi Key Laboratory for Theoretical Physics Frontiers, Xi' an 710069 (China); Institute of Modern Physics, Northwest University, Xi' an 710069 (China)

2017-06-15

Highlights: • Three different types of soliton excitations under the spin-wave background are demonstrated in spin chain system. • The magnetic moment distributions corresponding to these solitons are characterized in detail. • The formation mechanisms of those excitations are explained by the magnon density distribution. - Abstract: We study the nonlinear spin dynamics of an anisotropic Heisenberg helimagnet in a fourth-order integrable nonlinear Schrödinger equation. We demonstrate that there are three types of nonlinear spin excitations on a spin-wave background in the Heisenberg helimagnet, notably including anti-dark soliton, W-shaped soliton, and multi-peak soliton. The magnetic moment distribution that corresponds to each of these are characterized in detail. Additionally, the formation mechanism is clarified by the magnon density distribution.

Baryon Resonances

International Nuclear Information System (INIS)

Oset, E.; Sarkar, S.; Sun Baoxi; Vicente Vacas, M.J.; Ramos, A.; Gonzalez, P.; Vijande, J.; Martinez Torres, A.; Khemchandani, K.

2010-01-01

In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the Λ(1405) resonance, as well as the prediction of one 1/2 + baryon state around 1920 MeV which might have been seen in the γp→K + Λ reaction.

Large anomalous magnetic moment in three-dimensional Dirac and Weyl semimetals

NARCIS (Netherlands)

Van Der Wurff, E. C I; Stoof, H. T C

2016-01-01

We investigate the effect of Coulomb interactions on the electromagnetic response of three-dimensional Dirac and Weyl semimetals. In a calculation reminiscent of Schwinger's seminal work on quantum electrodynamics, we find three physically distinct effects for the anomalous magnetic moment of the

Spinodal instability of baryon-rich quark matter

International Nuclear Information System (INIS)

Li, Feng; Ko, Che Ming

2017-01-01

The spinodal instabilities of both confined and expanding baryon-rich quark matters are studied in a transport model derived from the Nambu-Jona-Lasino model. Appreciable higher-order density moments are seen as a result of the first-order phase transition in both cases. The skewness of the quark number event-by-event distribution in a small subvolume of the system becomes appreciable for the confined quark matter. For the expanding quark matter, the density fluctuations lead to enhanced anisotropic flows and dilepton yield. (paper)

Baryon structure from lattice QCD

International Nuclear Information System (INIS)

Alexandrou, C.

2009-01-01

We present recent lattice results on the baryon spectrum, nucleon electromagnetic and axial form factors, nucleon to Δ transition form factors as well as the Δ electromagnetic form factors. The masses of the low lying baryons and the nucleon form factors are calculated using two degenerate flavors of twisted mass fermions down to pion mass of about 270 MeV. We compare to the results of other collaborations. The nucleon to Δ transition and Δ form factors are calculated in a hybrid scheme, which uses staggered sea quarks and domain wall valence quarks. The dominant magnetic dipole nucleon to Δ transition form factor is also evaluated using dynamical domain wall fermions. The transverse density distributions of the Δ in the infinite momentum frame are extracted using the form factors determined from lattice QCD. (author)

Lifetimes and magnetic moments in odd-odd 70 As

International Nuclear Information System (INIS)

Pantelica, D.; Negoita, F.; Stanoiu, M.

1998-01-01

The extensive experimental and theoretical work on the structure of N∼Z, A = 60-80 nuclei revealed many interesting features: large prolate deformations (β = 0.4), strong shape variations as a function of particle number, excitation energy, spin and shape coexistence effects. They are related with drastic changes of properties observed in nuclei with Z≥33 when going from spherical nuclei with N = 50 to neutron deficient nuclei with N = 38 or 40. Both the rapid changes in structure and the shape coexistence appear to reflect the competition between the shell gaps which occur at large oblate and prolate deformations near nucleon numbers 36 and 38 for both protons and neutrons. For N∼Z nuclei the same shell gaps appear simultaneously for both protons and neutrons and reinforce each other. The microscopic structure of the nuclei in the mass region A = 60-80 is essentially determined by the 1g 9/2 , 2p 1/2 , 1f 5/2 and 2p 3/2 orbitals. Because no unique interpretation of the unusual features discovered in these nuclei exists, the systematic experimental study of structure of these nuclei is still an interesting subject. As part of a systematic experimental study undertaken to investigate the structure of neutron deficient, odd-odd As nuclei, 68,70,72 As, the level scheme of 70 As was investigated using heavy ion induced reactions and in-beam γ-ray spectroscopy techniques. At energies between 500 and 900 keV a multiplet of negative parity levels has been observed. At higher energies a high-spin positive parity sequence of levels starting with a E x = 1676 keV, J π 8 + level is strongly populated. Additional information is required in order to establish the structure of low and high-spin levels of both parities. The magnetic moments of the 8 + and 9 + levels have been measured using the time-integral perturbed angular distribution technique and the lifetimes of four levels have been determined using the recoil-distance method. From the measured lifetime for the 9

Chiral perturbation theory for generalized parton distributions and baryon distribution amplitudes

Energy Technology Data Exchange (ETDEWEB)

Wein, Philipp

2016-05-06

In this thesis we apply low-energy effective field theory to the first moments of generalized parton distributions and to baryon distribution amplitudes, which are both highly relevant for the parametrization of the nonperturbative part in hard processes. These quantities yield complementary information on hadron structure, since the former treat hadrons as a whole and, thus, give information about the (angular) momentum carried by an entire parton species on average, while the latter parametrize the momentum distribution within an individual Fock state. By performing one-loop calculations within covariant baryon chiral perturbation theory, we obtain sensible parametrizations of the quark mass dependence that are ideally suited for the subsequent analysis of lattice QCD data.

Challenging the Standard Model: High-Precision Comparisons of the Fundamental Properties of Protons and Antiprotons

CERN Multimedia

CERN. Geneva

2018-01-01

The Baryon Antibaryon Symmetry Experiment (BASE-CERN) at CERN’s antiproton decelerator facility is aiming at high-precision comparisons of the fundamental properties of protons and antiprotons, such as charge-to-mass ratios, magnetic moments and lifetimes. Such experiments provide sensitive tests of the fundamental charge-parity-time invariance in the baryon sector. BASE was approved in 2013 and has measured since then, utilizing single-particle multi-Penning-trap techniques, the antiproton-to-proton charge-to-mass ratio with a fractional precision of 69 p.p.t. [1], as well as the antiproton magnetic moment with fractional precisions of 0.8 p.p.m. and 1.5 p.p.b., respectively [2]. At our matter companion experiment BASE-Mainz, we have performed proton magnetic moment measurements with fractional uncertainties of 3.3 p.p.b. [3] and 0.3 p.p.b. [4]. By combining the data of both experiments we provide a baryon-magnetic-moment based CPT test gpbar/gp = 1.000 000 000 2(15), which improves the uncertainty of p...

Fe magnetic moment formation and exchange interaction in Fe{sub 2}P: A first-principles study

Energy Technology Data Exchange (ETDEWEB)

Liu, X.B., E-mail: liuxubo@uta.edu [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Ping Liu, J.; Zhang, Qiming [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Altounian, Z. [Center for the Physics of Materials and Department of Physics, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)

2013-03-15

Electronic structure and magnetic properties of Fe{sub 2}P have been studied by a first-principles density functional theory calculation. The ground state is ferromagnetic and the calculated magnetic moments for Fe{sub 1} (3f) and Fe{sub 2} (3g) are 0.83 and 2.30μ{sub B}, respectively. The nearest neighbor inter-site magnetic exchange coupling parameter at the Fe{sub 1} layer (0.02 mRy) is much smaller than that at the Fe{sub 2} layer (1.29 mRy). The Fe moment at the 3f site is metastable and sensitive to the inter-site exchange interaction with its magnetic neighbors, which is responsible for the first order magnetic transition and large magneto-caloric effect around T{sub C}.

The effect of ions on the magnetic moment of vacancy for ion-implanted 4H-SiC

Science.gov (United States)

Peng, B.; Zhang, Y. M.; Dong, L. P.; Wang, Y. T.; Jia, R. X.

2017-04-01

The structural properties and the spin states of vacancies in ion implanted silicon carbide samples are analyzed by experimental measurements along with first-principles calculations. Different types and dosages of ions (N+, O+, and B+) were implanted in the 4H-silicon carbide single crystal. The Raman spectra, positron annihilation spectroscopy, and magnetization-magnetic field curves of the implanted samples were measured. The fitting results of magnetization-magnetic field curves reveal that samples implanted with 1 × 1016 cm-2 N+ and O+ ions generate paramagnetic centers with various spin states of J = 1 and J = 0.7, respectively. While for other implanted specimens, the spin states of the paramagnetic centers remain unchanged compared with the pristine sample. According to the positron annihilation spectroscopy and first-principles calculations, the change in spin states originates from the silicon vacancy carrying a magnetic moment of 3.0 μB in the high dosage N-implanted system and 2.0 μB in the O-doped system. In addition, the ratio of the concentration of implanted N ions and silicon vacancies will affect the magnetic moment of VSi. The formation of carbon vacancy which does not carry a local magnetic moment in B-implanted SiC can explain the invariability in the spin states of the paramagnetic centers. These results will help to understand the magnetic moments of vacancies in ion implanted 4H-SiC and provide a possible routine to induce vacancies with high spin states in SiC for the application in quantum technologies and spintronics.

Magnetic dipole moments of High-K isomeric states in Hf isotopes

CERN Multimedia

Walters, W; Nishimura, K; Bingham, C R

2007-01-01

It is proposed to make precision measurements of the magnetic moments of 5 multi-quasi-particle K-isomers in Hf nuclei by the Nuclear Magnetic Resonance of Oriented Nuclei (NMR/ON) technique using the NICOLE on-line nuclear orientation facility and exploiting the unique HfF$_{3}$ beams recently available at ISOLDE. Results will be used to extract single-particle and collective g-factors of the isomeric states and their excitations and to shed new light on their structure.

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

Examination of the strangeness contribution to the nucleon magnetic moment

NARCIS (Netherlands)

Chen, XS; Timmermans, RGE; Sun, WM; Zong, HS; Wang, F

We examine the nucleon strangeness magnetic moment mu(s) with a lowest order meson cloud model. We observe that (1) strangeness in the nucleon is a natural requirement of the empirical relation mu(p)/mu(n)similar or equal to-3/2, which favors an SU(3) octet meson cloud instead of merely the SU(2)

Magnetic dipole moments of deformed odd-odd nuclei in 2s-1d and 2p-1f shells

Energy Technology Data Exchange (ETDEWEB)

Verma, A K; Garg, V P; Sharma, S D [Punjabi Univ., Patiala (India). Dept. of Physics

1979-01-01

A simple expression is derived for the computation of the magnetic moments of odd-odd nuclei. The computation of magnetic dipole moments is done with and without quenching factors for the last proton and neutron. The results are found to improve for /sup 22/Na, /sup 24/Na, sup(82m)Rb, /sup 14/N, /sup 68/Gd, /sup 54/Mn and /sup 86/Rb with extreme coupling of angular moments.

Sea quarks contribution to the nucleon magnetic moment and charge radius at the physical point

Science.gov (United States)

Sufian, Raza Sabbir; Yang, Yi-Bo; Liang, Jian; Draper, Terrence; Liu, Keh-Fei; χ QCD Collaboration

2017-12-01

We report a comprehensive analysis of the light and strange disconnected-sea quarks contribution to the nucleon magnetic moment, charge radius, and the electric and magnetic form factors. The lattice QCD calculation includes ensembles across several lattice volumes and lattice spacings with one of the ensembles at the physical pion mass. We adopt a model-independent extrapolation of the nucleon magnetic moment and the charge radius. We have performed a simultaneous chiral, infinite volume, and continuum extrapolation in a global fit to calculate results in the continuum limit. We find that the combined light and strange disconnected-sea quarks contribution to the nucleon magnetic moment is μM(DI )=-0.022 (11 )(09 ) μN and to the nucleon mean square charge radius is ⟨r2⟩E(DI ) =-0.019 (05 )(05 ) fm2 which is about 1 /3 of the difference between the ⟨rp2⟩E of electron-proton scattering and that of a muonic atom and so cannot be ignored in obtaining the proton charge radius in the lattice QCD calculation. The most important outcome of this lattice QCD calculation is that while the combined light-sea and strange quarks contribution to the nucleon magnetic moment is small at about 1%, a negative 2.5(9)% contribution to the proton mean square charge radius and a relatively larger positive 16.3(6.1)% contribution to the neutron mean square charge radius come from the sea quarks in the nucleon. For the first time, by performing global fits, we also give predictions of the light and strange disconnected-sea quarks contributions to the nucleon electric and magnetic form factors at the physical point and in the continuum and infinite volume limits in the momentum transfer range of 0 ≤Q2≤0.5 GeV2 .

Baryons and baryonic matter in the large Nc and heavy quark limits

International Nuclear Information System (INIS)

Cohen, Thomas D.; Kumar, Nilay; Ndousse, Kamal K.

2011-01-01

This paper explores properties of baryons and finite density baryonic matter in an artificial world in which N c , the number of colors, is large and the quarks of all species are degenerate and much larger than Λ QCD . It has long been known that in large N c quantum chromodynamics (QCD), baryons composed entirely of heavy quarks are accurately described in the mean-field approximation. However, the detailed properties of baryons in the combined large N c and heavy-quark limits have not been fully explored. Here some basic properties of baryons are computed using a variational approach. At leading order in both the large N c and heavy-quark expansions the baryon mass is shown to be M baryon ≅N c M Q (1-0.054 26α-tilde s 2 ), where α-tilde s ≡N c α s . The baryon form factor is also computed. Baryonic matter, the analog of nuclear matter in this artificial world, should also be well described in the mean-field approximation. In the special case where all baryons have an identical spin-flavor structure, it is shown that in the formal heavy-quark and large N c limit interactions between baryons are strictly repulsive at low densities. The energy per baryon is computed in this limit and found to be exponentially small. It is shown that when the restriction to baryons with an identical spin-flavor structure is dropped, a phase of baryonic matter exists with a density of 2N f times that for the restricted case but with the same energy (where N f is the number of degenerate flavors). It is shown that this phase is at least metastable.

New Nuclear Magnetic Moment of 209Bi: Resolving the Bismuth Hyperfine Puzzle

Science.gov (United States)

Skripnikov, Leonid V.; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F.; Scheibe, Benjamin; Shabaev, Vladimir M.; Vogel, Michael; Volotka, Andrey V.

2018-03-01

A recent measurement of the hyperfine splitting in the ground state of Li-like 80+208Bi has established a "hyperfine puzzle"—the experimental result exhibits a 7 σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017), 10.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017), 10.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μI) of 209Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μI(209ipts>) and combine it with nuclear magnetic resonance measurements of Bi (NO3 )3 in nitric acid solutions and of the hexafluoridobismuthate(V) BiF6- ion in acetonitrile. The result clearly reveals that μI(209Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

New Nuclear Magnetic Moment of ^{209}Bi: Resolving the Bismuth Hyperfine Puzzle.

Science.gov (United States)

Skripnikov, Leonid V; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F; Scheibe, Benjamin; Shabaev, Vladimir M; Vogel, Michael; Volotka, Andrey V

2018-03-02

A recent measurement of the hyperfine splitting in the ground state of Li-like ^{208}Bi^{80+} has established a "hyperfine puzzle"-the experimental result exhibits a 7σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017)NCAOBW2041-172310.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017)NPAHAX1745-247310.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μ_{I}) of ^{209}Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μ_{I}(^{209}Bi) and combine it with nuclear magnetic resonance measurements of Bi(NO_{3})_{3} in nitric acid solutions and of the hexafluoridobismuthate(V) BiF_{6}^{-} ion in acetonitrile. The result clearly reveals that μ_{I}(^{209}Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

Improving sensitivity to magnetic fields and electric dipole moments by using measurements of individual magnetic sublevels

Science.gov (United States)

Tang, Cheng; Zhang, Teng; Weiss, David S.

2018-03-01

We explore ways to use the ability to measure the populations of individual magnetic sublevels to improve the sensitivity of magnetic field measurements and measurements of atomic electric dipole moments (EDMs). When atoms are initialized in the m =0 magnetic sublevel, the shot-noise-limited uncertainty of these measurements is 1 /√{2 F (F +1 ) } smaller than that of a Larmor precession measurement. When the populations in the even (or odd) magnetic sublevels are combined, we show that these measurements are independent of the tensor Stark shift and the second order Zeeman shift. We discuss the complicating effect of a transverse magnetic field and show that when the ratio of the tensor Stark shift to the transverse magnetic field is sufficiently large, an EDM measurement with atoms initialized in the superposition of the stretched states can reach the optimal sensitivity.

Molecular dynamics simulation for the baryon-quark phase transition at finite baryon density

International Nuclear Information System (INIS)

Akimura, Y.; Maruyama, T.; Chiba, S.; Yoshinaga, N.

2005-01-01

We study the baryon-quark phase transition in the molecular dynamics (MD) of the quark degrees of freedom at finite baryon density. The baryon state at low baryon density, and the deconfined quark state at high baryon density are reproduced. We investigate the equations of state of matters with different u-d-s compositions. It is found that the baryon-quark transition is sensitive to the quark width. (orig.)

Half-metallic ferromagnetism with low magnetic moment in zinc-blende TiBi from first-principles calculations

International Nuclear Information System (INIS)

Chen, Zhi-Yuan; Xu, Bin; Gao, G.Y.

2013-01-01

The structural, electronic and magnetic properties of zinc-blende TiBi are investigated by using the first-principles full-potential linearized augmented plane-wave method. It is found that zinc-blende TiBi exhibits half-metallic ferromagnetism with the energy gap of 1.39 eV in the minority-spin channel. The calculated total magnetic moment of 1.00 µ B per formula unit mainly originates from the Ti atom. We also show that the half-metallicity of zinc-blende TiBi can be maintained up to 3% compression and 5% expansion of lattice constant with respect to the equilibrium lattice, and zinc-blende TiBi is still half-metallic when the spin–orbit coupling is considered. The robust half-metallicity and low magnetic moment make zinc-blende TiBi a potential candidate for spintronic applications. - Highlights: • Half-metallic ferromagnetism in zinc-blende TiBi. • Zinc-blende TiBi has low magnetic moment of 1.00 µ B /f.u. • Spin–orbit coupling does not destroy the half-metallicity of zinc-blende TiBi

Spin, quadrupole moment, and deformation of the magnetic-rotational band head in Pb193

Science.gov (United States)

Balabanski, D. L.; Ionescu-Bujor, M.; Iordachescu, A.; Bazzacco, D.; Brandolini, F.; Bucurescu, D.; Chmel, S.; Danchev, M.; de Poli, M.; Georgiev, G.; Haas, H.; Hübel, H.; Marginean, N.; Menegazzo, R.; Neyens, G.; Pavan, P.; Rossi Alvarez, C.; Ur, C. A.; Vyvey, K.; Frauendorf, S.

2011-01-01

The spectroscopic quadrupole moment of the T1/2=9.4(5) ns isomer in Pb193 at an excitation energy Eex=(2585+x) keV is measured by the time-differential perturbed angular distribution method as |Qs|=2.6(3) e b. Spin and parity Iπ=27/2- are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the 1i13/2 subshell with the (3s1/2-21h9/21i13/2)11- proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation ɛ2=-0.11, similar to that of the 11-proton intruder states, which nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

Potentially large contributions to the muon anomalous magnetic moment from weak-isosinglet squarks in E6 superstring models

International Nuclear Information System (INIS)

Morris, D.A.

1988-01-01

We examine contributions to the anomalous magnetic moment of the muon from weak-isosinglet squarks found in E 6 superstring models. We find that such contributions are up to 2 orders of magnitude larger than those previously calculated and correspondingly require smaller Yukawa couplings in order to maintain agreement with the measured muon anomalous magnetic moment

Lattice QCD results for the HVP contribution to the anomalous magnetic moments of leptons

Directory of Open Access Journals (Sweden)

Borsanyi Szabolcs

2018-01-01

Full Text Available We present lattice QCD results by the Budapest-Marseille-Wuppertal (BMW Collaboration for the leading-order contribution of the hadron vacuum polarization (LOHVP to the anomalous magnetic moments of all charged leptons. Calculations are performed with u, d, s and c quarks at their physical masses, in volumes of linear extent larger than 6 fm, and at six values of the lattice spacing, allowing for controlled continuum extrapolations. All connected and disconnected contributions are calculated for not only the muon but also the electron and tau anomalous magnetic moments. Systematic uncertainties are thoroughly discussed and comparisons with other calculations and phenomenological estimates are made.

Lattice QCD results for the HVP contribution to the anomalous magnetic moments of leptons

Science.gov (United States)

2018-03-01

We present lattice QCD results by the Budapest-Marseille-Wuppertal (BMW) Collaboration for the leading-order contribution of the hadron vacuum polarization (LOHVP) to the anomalous magnetic moments of all charged leptons. Calculations are performed with u, d, s and c quarks at their physical masses, in volumes of linear extent larger than 6 fm, and at six values of the lattice spacing, allowing for controlled continuum extrapolations. All connected and disconnected contributions are calculated for not only the muon but also the electron and tau anomalous magnetic moments. Systematic uncertainties are thoroughly discussed and comparisons with other calculations and phenomenological estimates are made.

Unimodular gravity and the lepton anomalous magnetic moment at one-loop

Energy Technology Data Exchange (ETDEWEB)

Martín, Carmelo P., E-mail: carmelop@fis.ucm.es [Departamento de Física Teórica I, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid (Spain)

2017-07-01

We work out the one-loop contribution to the lepton anomalous magnetic moment coming from Unimodular Gravity. We use Dimensional Regularization and Dimensional Reduction to carry out the computations. In either case, we find that Unimodular Gravity gives rise to the same one-loop correction as that of General Relativity.

Baryons and baryonic matter in four-fermion interaction models

International Nuclear Information System (INIS)

Urlichs, K.

2007-01-01

In this work we discuss baryons and baryonic matter in simple four-fermion interaction theories, the Gross-Neveu model and the Nambu-Jona-Lasinio model in 1+1 and 2+1 space-time dimensions. These models are designed as toy models for dynamical symmetry breaking in strong interaction physics. Pointlike interactions (''four-fermion'' interactions) between quarks replace the full gluon mediated interaction of quantum chromodynamics. We consider the limit of a large number of fermion flavors, where a mean field approach becomes exact. This method is formulated in the language of relativistic many particle theory and is equivalent to the Hartree-Fock approximation. In 1+1 dimensions, we generalize known results on the ground state to the case where chiral symmetry is broken explicitly by a bare mass term. For the Gross-Neveu model, we derive an exact self-consistent solution for the finite density ground state, consisting of a one-dimensional array of equally spaced potential wells, a baryon crystal. For the Nambu- Jona-Lasinio model we apply the derivative expansion technique to calculate the total energy in powers of derivatives of the mean field. In a picture akin to the Skyrme model of nuclear physics, the baryon emerges as a topological soliton. The solution for both the single baryon and dense baryonic matter is given in a systematic expansion in powers of the pion mass. The solution of the Hartree-Fock problem is more complicated in 2+1 dimensions. In the massless Gross-Neveu model we derive an exact self-consistent solution by extending the baryon crystal of the 1+1 dimensional model, maintaining translational invariance in one spatial direction. This one-dimensional configuration is energetically degenerate to the translationally invariant solution, a hint in favor of a possible translational symmetry breakdown by more general geometrical structures. In the Nambu-Jona-Lasinio model, topological soliton configurations induce a finite baryon number. In contrast

Baryons and baryonic matter in four-fermion interaction models

Energy Technology Data Exchange (ETDEWEB)

Urlichs, K.

2007-02-23

In this work we discuss baryons and baryonic matter in simple four-fermion interaction theories, the Gross-Neveu model and the Nambu-Jona-Lasinio model in 1+1 and 2+1 space-time dimensions. These models are designed as toy models for dynamical symmetry breaking in strong interaction physics. Pointlike interactions (''four-fermion'' interactions) between quarks replace the full gluon mediated interaction of quantum chromodynamics. We consider the limit of a large number of fermion flavors, where a mean field approach becomes exact. This method is formulated in the language of relativistic many particle theory and is equivalent to the Hartree-Fock approximation. In 1+1 dimensions, we generalize known results on the ground state to the case where chiral symmetry is broken explicitly by a bare mass term. For the Gross-Neveu model, we derive an exact self-consistent solution for the finite density ground state, consisting of a one-dimensional array of equally spaced potential wells, a baryon crystal. For the Nambu- Jona-Lasinio model we apply the derivative expansion technique to calculate the total energy in powers of derivatives of the mean field. In a picture akin to the Skyrme model of nuclear physics, the baryon emerges as a topological soliton. The solution for both the single baryon and dense baryonic matter is given in a systematic expansion in powers of the pion mass. The solution of the Hartree-Fock problem is more complicated in 2+1 dimensions. In the massless Gross-Neveu model we derive an exact self-consistent solution by extending the baryon crystal of the 1+1 dimensional model, maintaining translational invariance in one spatial direction. This one-dimensional configuration is energetically degenerate to the translationally invariant solution, a hint in favor of a possible translational symmetry breakdown by more general geometrical structures. In the Nambu-Jona-Lasinio model, topological soliton configurations induce a finite baryon

Nuclear orientation experiments on the magnetic moments of europium and gadolinium nuclei

International Nuclear Information System (INIS)

Berg, F.G. van den.

1984-01-01

In this thesis, experimental results on the ground state nuclear magnetic moments of europium and gadolinium isotopes are presented. The nuclear orientation experiments were performed on europium and gadolinium nuclei embedded in several host lattices. Attention is paid to the hyperfine interactions of the ions. Nuclear moments are discussed in the context of nuclear shell model. The theoretical framework is described for nuclear structure and low temperature nuclear orientation. Furthermore, the experimental techniques, the technical arrangement of the orientation apparatus, the methods for radiative detection and the use of nuclear orientation thermometry are described. (Auth.)

Effect of particle-core-vibration coupling near the double closed $^{132}$Sn nucleus from precise magnetic moment measurements

CERN Multimedia

Postma, H; Heyde, K; Walker, P; Grant, I; Veskovic, M; Stone, N; Stone, J

2002-01-01

% IS301 \\\\ \\\\ Low temperature nuclear orientation of isotope-separator implanted short-lived radio-isotopes makes possible the measurements of nuclear magnetic dipole moments of oriented ground and excited states with half-lives longer than a few seconds. Coupling schemes characterizing the odd nucleons and ground-state deformations can be extracted from the nuclear moments. \\\\ We thus propose to measure the magnetic dipole moments of $^{127-133}$Sb to high precision using NMR/ON at the NICOLE facility. With (double magic +1) $^{133}$Sb as the reference, the main aim of this experiment is to examine whether the collective component in the 7/2$^+$ Sb ground state magnetic dipole moment varies as expected according to particle-core coupling calculations carried out for the Sb (Z=51) isotopes. Comparison of the 1-proton-particle excitations in Sb to 1-proton-hole states in In nuclei will shed light on differences between particle and hole excitations as understood within the present model. Comparison of ...

Study of heavy flavored particles

International Nuclear Information System (INIS)

1991-01-01

This report discusses progress on the following topics: time-of- flight system; charmed baryon production and decays; D decays to baryons; measurement of sigma plus particles magnetic moments; and strong interaction coupling

Generalized moment analysis of magnetic field correlations for accumulations of spherical and cylindrical magnetic pertubers

Directory of Open Access Journals (Sweden)

Felix Tobias Kurz

2016-12-01

Full Text Available In biological tissue, an accumulation of similarly shaped objects with a susceptibility difference to the surrounding tissue generates a local distortion of the external magnetic field in magnetic resonance imaging. It induces stochastic field fluctuations that characteristically influence proton spin diffusion in the vicinity of these magnetic perturbers. The magnetic field correlation that is associated with such local magnetic field inhomogeneities can be expressed in the form of a dynamic frequency autocorrelation function that is related to the time evolution of the measured magnetization. Here, an eigenfunction expansion for two simple magnetic perturber shapes, that of spheres and cylinders, is considered for restricted spin diffusion in a simple model geometry. Then, the concept of generalized moment analysis, an approximation technique that is applied in the study of (non-reactive processes that involve Brownian motion, allows to provide analytical expressions for the correlation function for different exponential decay forms. Results for the biexponential decay for both spherical and cylindrical magnetized objects are derived and compared with the frequently used (less accurate monoexponential decay forms. They are in asymptotic agreement with the numerically exact value of the correlation function for long and short times.

The electric dipole moment of the neutron a cosmic seismometer?

CERN Document Server

Nanopoulos, Dimitri V

1981-01-01

One of the most striking successes of Grand Unified Theories is the possibility of understanding, qualitatively and quantitatively the observed baryon asymmetry in the Universe GUTS contain all the basic ingredients for creating the baryon asymmetry, and the expanding Universe provides for free an excellent way to get out of equilibrium at the appropriate times. A very interesting question which is often asked is whether there is some connection between the observed low energy CP-violation in the K-system and the CP-violation operating at superhigh energies and thus responsible for the observed baryon asymmetry. The usual answer is no! Recently, J. Ellis, M.K. Gillard, S.Rudez and the author (Phys. Lett. B, vol.99, p.101, 1981) have done some work towards a connection that may exist between the magnitude of the (still unobserved) electric dipole moment of the neutron (d/sub n /) and the magnitude of the observed baryon asymmetry (n/sub B//n/sub gamma /). This is a review of that work, but with strong emphasis...

On the moment of inertia of a proto neutron star

International Nuclear Information System (INIS)

Zhao Xianfeng; Zhang Hua; Jia Huanyu

2010-01-01

The influences of σ * and Φ mesons,temperature and coupling constants of nucleons on the moment of inertia of the proto neutron star (PNS) are examined in the framework of relativistic mean field theory for the baryon octet {n, p, Λ , Σ - , Σ 0 , Σ + , Ξ - , Ξ 0 } system. It is found that, compared with that without considering σ * and Φ mesons, the moment of inertia decreases. It is also found that the higher the temperature, the larger the incompressibility and symmetry energy coefficient, and the larger the moment of inertia of a PNS. The influence of temperature and coupling constants of the nucleons on the moment of inertia of a PNS is larger than that of the σ * and Φ mesons. (authors)

Electron contribution to the muon anomalous magnetic moment at four loops

International Nuclear Information System (INIS)

Kurz, Alexander; Liu, Tao; Smirnov, Alexander V.; Smirnov, Vladimir A.; Humboldt-Universitaet, Berlin; Humboldt-Universitaet, Berlin; Steinhauser, Matthias

2016-02-01

We present results for the QED contributions to the anomalous magnetic moment of the muon containing closed electron loops. The main focus is on perturbative corrections at four-loop order where the external photon couples to the external muon. Furthermore, all four-loop contributions involving simultaneously a closed electron and tau loop are computed. In combination with our recent results on the light-by-light-type corrections the complete four-loop electron-loop contribution to the anomalous magnetic moment of the muon has been obtained with an independent calculation. Our calculation is based on an asymptotic expansion in the ratio of the electron and the muon mass and shows the importance of higher order terms in this ratio. We perform a detailed comparison with results available in the literature and find good numerical agreement. As a by-product we present analytic results for the on-shell muon mass and wave function renormalization constants at three-loop order including massive closed electron and tau loops, which we also calculated using the method of asymptotic expansion.

Angular distribution in electron-neutrino scattering and the anomalous magnetic moment of the neutrino

International Nuclear Information System (INIS)

Barut, A.O.; Aydin, Z.Z.

1988-08-01

Some implications of the anomalous magnetic moment a υ of the neutrino are discussed, in particular the differential cross-sections of the electron-neutrino (antineutrino) scattering, (υ e and υ μ ), of the magnetic model is compared with the standard model in order to set better limits on a υ . (author). 18 refs, 2 figs

Influence of strain and polycrystalline ordering on magnetic properties of high moment rare earth metals and alloys

International Nuclear Information System (INIS)

Scheunert, G; Ward, C; Hendren, W R; Bowman, R M; Lapicki, A A; Hardeman, R; Mooney, M; Gubbins, M

2014-01-01

Despite being the most suitable candidates for solenoid pole pieces in state-of-the-art superconductor-based electromagnets, the intrinsic magnetic properties of heavy rare earth metals and their alloys have gained comparatively little attention. With the potential of integration in micro and nanoscale devices, thin films of Gd, Dy, Tb, DyGd and DyTb were plasma-sputtered and investigated for their in-plane magnetic properties, with an emphasis on magnetization versus temperature profiles. Based on crystal structure analysis of the polycrystalline rare earth films, which consist of a low magnetic moment fcc layer at the seed interface topped with a higher moment hcp layer, an experimental protocol is introduced which allows the direct magnetic analysis of the individual layers. In line with the general trend of heavy lanthanides, the saturation magnetization was found to drop with increasing unit cell size. In situ annealed rare earth films exceeded the saturation magnetization of a high-moment Fe 65 Co 35 reference film in the cryogenic temperature regime, proving their potential for pole piece applications; however as-deposited rare earth films were found completely unsuitable. In agreement with theoretical predictions, sufficiently strained crystal phases of Tb and Dy did not exhibit an incommensurate magnetic order, unlike their single-crystal counterparts which have a helical phase. DyGd and DyTb alloys followed the trends of the elemental rare earth metals in terms of crystal structure and magnetic properties. Inter-rare-earth alloys hence present a desirable blend of saturation magnetization and operating temperature. (paper)

Study of the baryon-baryon interaction in nucleon-nucleon and pion-deuteron scattering

International Nuclear Information System (INIS)

Fuchs, M.

1993-01-01

After the definition of the Hamiltonian in general form by meson production and absorption the transition to operators pursued, which connect only spaces with definite meson numbers. In this approximation first the self-energy of a single baryon was calculated in its full energy and momentum dependence. Then the formal expressions for the T matrices of nucleon-nucleon and pion-deuteron scattering were derived. The essential components of these expressions are the baryon-baryon T matrix ant transition amplitudes from pion-deuteron channels to baryon-baryon states. The central chapter dealt with the calculation of the baryon-baryon interaction for the general form of the vertices, with the solution of the binding problem and the baryon-baryon T matrix. Finally followed the results on the nucleon-nucleon and pion-deuteron scattering. For this first the transition amplitudes from pion-deuteron states to intermediate baryon-baryon states and the Born graphs of the pion-deuteron scattering had to be calculated. After some remarks to the transition from partial-wave decomposed T matrices to scattering observables an extensive representation of the total, partial, and differential cross sections and a series of spin observables (analyzing powers and spin correlations) for the elastic proton-proton, neutron-proton, and pion-deuteron scattering as well for the fusion reaction pp→πd and the breakup reaction πd→pp follows. Thereby the energies reached from the nucleon-nucleon respectively pion-deuteron threshold up to 100 MeV above the delta resonance

A light Zeldovich-Konopinski-Mahmoud neutrino with a large magnetic moment

International Nuclear Information System (INIS)

Ecker, G.; Grimus, W.; Neufeld, H.

1989-08-01

We propose a non-Abelian extension of a Zeldovich-Konopinski-Mahmoud lepton number symmetry which gives rise to a naturally light Dirac neutrino with a magnetic moment of O(10 -11 μ B ). The neutrino mass appears first at the two-loop level and is well below the experimental upper bound. 13 refs., 3.figs. (Authors)

Magnetic moments and lifetime measurements with a piezoelectrically driven plunger

International Nuclear Information System (INIS)

Rutten, A.J.

1980-01-01

Experiments are described leading to precise values for magnetic dipole moments of excited nuclear states and their mean lifetimes. A plunger system is described especially developed for g-factor and lifetime measurements with the coincidence time-differential recoil-into-vacuum technique. Measurements of the g-factors and lifetimes for the 2 1 + state of 20 O and the 5/2 1 + state of 13 C are described. (Auth.)

Effects of pseudoscalar-baryon channels in the dynamically generated vector-baryon resonances

Energy Technology Data Exchange (ETDEWEB)

Garzon, E.J.; Oset, E. [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica and IFIC, Valencia (Spain)

2012-01-15

We study the interaction of vector mesons with the octet of stable baryons in the framework of the local hidden gauge formalism using a coupled-channels unitary approach, including also the pseudoscalar-baryon channels which couple to the same quantum numbers. We examine the scattering amplitudes and their poles, which can be associated to the known J{sup P}=1/2{sup -}, 3/2{sup -} baryon resonances, and determine the role of the pseudoscalar-baryon channels, changing the width and eventually the mass of the resonances generated with only the basis of vector-baryon states. (orig.)

Bimodal distribution of the magnetic dipole moment in nanoparticles with a monomodal distribution of the physical size

NARCIS (Netherlands)

van Rijssel, Jozef; Kuipers, Bonny W M; Erne, Ben

2015-01-01

High-frequency applications of magnetic nanoparticles, such as therapeutic hyperthermia and magnetic particle imaging, are sensitive to nanoparticle size and dipole moment. Usually, it is assumed that magnetic nanoparticles with a log-normal distribution of the physical size also have a log-normal

The fuzzy bag and baryonic properties with center of mass and recoil corrections

International Nuclear Information System (INIS)

Pilotto, F.

2003-01-01

The fuzzy bag is a hadronic model which has features both of the bag model (energy-momentum conservation, QCD vacuum energy) and of relativistic potential models (confinement achieved through a potential). It is also a chiral model, with the unique property that the pion field is suppressed in the interior of the bag by means of a scalar potential, and yet chiral symmetry is preserved. This scalar potential allows one to control how far the pion field can penetrate in the interior of the bag. We calculate the masses of the fundamental baryon octet taking into account the center of mass, one-gluon exchange and one-pion exchange corrections. We also calculate the nucleon axial charge, charge radii and magnetic moments including center of mass and recoil corrections. The agreement with experiment is excellent, and the results indicate that the pion field is suppressed only very close to the center of the bag. (orig.)

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.

First on-line $\\beta$-NMR on oriented nuclei magnetic dipole moments of the $\

CERN Document Server

Giles, T; Stone, N J; Van Esbroeck, K; White, G; Wöhr, A; Veskovic, M; Towner, I S; Mantica, P F; Prisciandaro, J I; Morrissey, D J; Fedosseev, V; Mishin, V I; Köster, U; Walters, W B

2000-01-01

The first fully on-line use of the angular distribution of $\\beta$ - emission in detection of NMR of nuclei oriented at low temperatures is reported. The magnetic moments of the single valence particle, intermediate mass, isotopes $^{67}$Ni($\

Leading-order hadronic contributions to the electron and tau anomalous magnetic moments

International Nuclear Information System (INIS)

Burger, Florian; Hotzel, Grit

2015-01-01

The leading hadronic contributions to the anomalous magnetic moments of the electron and the τ-lepton are determined by a four-flavour lattice QCD computation with twisted mass fermions. The continuum limit is taken and systematic uncertainties are quantified. Full agreement with results obtained by phenomenological analyses is found.

Baryon stopping and strangeness baryon production in a parton cascade model

International Nuclear Information System (INIS)

Nara, Yasushi

1999-01-01

A parton cascade model which is based on pQCD incorporating hard partonic scattering and dynamical hadronization scheme describes the space-time evolution of parton/hadron system produced by ultra-relativistic nuclear collisions. Hadron yield, baryon stopping and transverse momentum distribution are calculated and compared with experimental data at SPS energies. Using new version of parton cascade code VNI in which baryonic cluster formation is implemented, we calculate the net baryon number distributions and Λ yield. It is found that baryon stopping behavior at SPS energies is well accounted for within the parton cascade picture. As a consequence of the production of the baryon (u and d quark) rich parton matter, parton coalescence naturally explains the enhanced yield of Λ particle which has been observed in experiment. (author)

Spin, quadrupole moment, and deformation of the magnetic-rotational band head in (193)Pb

CERN Document Server

Balabanski, D L; Iordachescu, A; Bazzacco, D; Brandolini, F; Bucurescu, D; Chmel, S; Danchev, M; De Poli, M; Georgiev, G; Haas, H; Hubel, H; Marginean, N; Menegazzo, R; Neyens, G; Pavan, P; Rossi Alvarez, C; Ur, C A; Vyvey, K; Frauendorf, S

2011-01-01

The spectroscopic quadrupole moment of the T(1/2) = 9.4(5) ns isomer in (193)Pb at an excitation energy E(ex) = (2585 + x) keV is measured by the time-differential perturbed angular distribution method as vertical bar Q(s)vertical bar = 2.6(3) e b. Spin and parity I(pi) = 27/2(-) are assigned to it based on angular distribution measurements. This state is the band head of a magnetic-rotational band, described by the coupling of a neutron hole in the 1i(13/2) subshell with the (3s(1/2)(-2)1h(9/2)1i(13/2))(11-) proton excitation. The pairing-plus-quadrupole tilted-axis cranking calculations reproduce the measured quadrupole moment with a moderate oblate deformation epsilon(2) = -0.11, similar to that of the 11(-)proton intruder states, which occur in the even-even Pb nuclei in the region. This is the first direct measurement of a quadrupole moment and thus of the deformation of a magnetic-rotational band head.

Magnetic dipole moment estimation and compensation for an accurate attitude control in nano-satellite missions

Science.gov (United States)

Inamori, Takaya; Sako, Nobutada; Nakasuka, Shinichi

2011-06-01

Nano-satellites provide space access to broader range of satellite developers and attract interests as an application of the space developments. These days several new nano-satellite missions are proposed with sophisticated objectives such as remote-sensing and observation of astronomical objects. In these advanced missions, some nano-satellites must meet strict attitude requirements for obtaining scientific data or images. For LEO nano-satellite, a magnetic attitude disturbance dominates over other environmental disturbances as a result of small moment of inertia, and this effect should be cancelled for a precise attitude control. This research focuses on how to cancel the magnetic disturbance in orbit. This paper presents a unique method to estimate and compensate the residual magnetic moment, which interacts with the geomagnetic field and causes the magnetic disturbance. An extended Kalman filter is used to estimate the magnetic disturbance. For more practical considerations of the magnetic disturbance compensation, this method has been examined in the PRISM (Pico-satellite for Remote-sensing and Innovative Space Missions). This method will be also used for a nano-astrometry satellite mission. This paper concludes that use of the magnetic disturbance estimation and compensation are useful for nano-satellites missions which require a high accurate attitude control.

Neutrino transition magnetic moments and the solar magnetic field on the light of the Kamland evidence

CERN Document Server

Antonelli, V; Picariello, M; Pulido, J; Torrente-Lujan, E

2003-01-01

We present here a recopilation of recent results about the possibility of detecting solar electron antineutrinos produced by solar core and convective magnetic fields. These antineutrinos are predicted by spin-flavor oscillations at a significant rate even if this mechanism is not the leading solution to the SNP. Using the recent Kamland results and assuming a concrete model for antineutrino production by spin-flavor precession in the convective zone based on chaotic magnetic fields,we obtain bounds on the flux of solar antineutrinos, on the average conversion neutrino-antineutrino probability and on intrinsic neutrino magnetic moment. In the most conservative case, $\\mu\\lsim 2.5\\times 10^{-11} \\mu_B$ (95% CL). When studying the effects of a core magnetic field, we find in the weak limit a scaling of the antineutrino probability with respect to the magnetic field profile in the sense that the same probability function can be reproduced by any profile with a suitable peak field value. In this way the solar ele...

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)

Measurement of the negative muon anomalous magnetic moment to 0.7 ppm

NARCIS (Netherlands)

Bennett, GW; Bousquet, B; Brown, HN; Bunce, G; Carey, RM; Cushman, P; Danby, GT; Debevec, PT; Deile, M; Deng, H; Dhawan, SK; Druzhinin, VP; Duong, L; Farley, FJM; Fedotovich, GV; Gray, FE; Grigoriev, D; Grosse-Perdekamp, M; Grossmann, A; Hare, MF; Hertzog, DW; Huang, [No Value; Hughes, VW; Iwasaki, M; Jungmann, K; Kawall, D; Khazin, BI; Krienen, F; Kronkvist, [No Value; Lam, A; Larsen, R; Lee, YY; Logashenko, [No Value; McNabb, R; Meng, W; Miller, JP; Morse, WM; Nikas, D; Onderwater, CJG; Orlov, Y; Ozben, CS; Paley, JM; Peng, Q; Polly, CC; Pretz, J; Prigl, R; Putlitz, GZ; Qian, T; Redin, SI; Rind, O; Roberts, BL; Ryskulov, N; Semertzidis, YK; Shagin, P; Shatunov, YM; Sichtermann, EP; Solodov, E; Sossong, M; Sulak, LR; Trofimov, A; von Walter, P; Yamamoto, A; Huang, X; Kronkvist, I.; Logashenko, I.; Özben, C.S.; Polley, C.C.; Shatunov, Yu.M.; von Walter, R.

2004-01-01

The anomalous magnetic moment of the negative muon has been measured to a precision of 0.7 ppm (ppm) at the Brookhaven Alternating Gradient Synchrotron. This result is based on data collected in 2001, and is over an order of magnitude more precise than the previous measurement for the negative muon.

Classical relativistic spinning particle with anomalous magnetic moment: The precession of spin

International Nuclear Information System (INIS)

Barut, A.O.; Cruz, M.G.

1993-05-01

The theory of classical relativistic spinning particles with c-number internal spinor variables, modelling accurately the Dirac electron, is generalized to particles with anomalous magnetic moments. The equations of motion are derived and the problem of spin precession is discussed and compared with other theories of spin. (author). 32 refs

Lepton anomalous magnetic moments from twisted mass fermions

International Nuclear Information System (INIS)

Burger, Florian; Hotzel, Grit

2014-11-01

We present our results for the leading-order hadronic quark-connected contributions to the electron, the muon, and the tau anomalous magnetic moments obtained with four dynamical quarks. Performing the continuum limit and an analysis of systematic effects, full agreement with phenomenological results is found. To estimate the impact of omitting the quark-disconnected contributions to the hadronic vacuum polarisation we investigate them on one of the four-flavour ensembles. Additionally, the light quark contributions on the four-flavour sea are compared to the values obtained for N f =2 physically light quarks. In the latter case different methods to fit the hadronic vacuum polarisation function are tested.

Magnetic moment and magnetocrystalline anisotropy of 3d-ion subsystem in R2T14B

International Nuclear Information System (INIS)

Bartashevich, M.I.; Kudrevatykh, N.V.; Andreev, A.V.; Rejmer, V.A.

1990-01-01

The effect of substituting cobalt for iron on the magnetic moment, magneto-crystalline anisotropy and thermal expansion of R 2 (Fe 1-x Co x ) 14 B single crystals (R=Y, Gd, 0≤x≤0.3) is investigated. The uniaxial magnetic anisotropy constant K 1 for the 3d-subsystem passes through a maximum at T=4.2 K with increasing Co concentration. For T c the temperature dependence of K 1 does not possess a positive slope. The magnetic moment of the 3d-subsystem at 4.2 K does not exhibit the maximum at intermediate concentrations observed for most R(Fe, Co)-intermetallics. An explanation is presented of the changes in the magnetic properties. It is shown that the variation of the interatomic distances on thermal expansion should not affect the magnitude of the anisotropy constant of the 3d- and R-subsystems

Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments

International Nuclear Information System (INIS)

Stone, N.J.

2011-04-01

This Table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to late 2010. Many of the entries prior to 1988 follow those in Raghavan P., Atomic and Nuclear Data Tables 42, 189 (1989). (author)

Table of Nuclear Magnetic Dipole and Electric Quadrupole Moments

International Nuclear Information System (INIS)

Stone, N.J.

2014-02-01

This Table is a compilation of experimental measurements of static magnetic dipole and electric quadrupole moments of ground states and excited states of atomic nuclei throughout the periodic table. To aid identification of the states, their excitation energy, half-life, spin and parity are given, along with a brief indication of the method and any reference standard used in the particular measurement. The literature search covers the period to early 2014. Many of the entries prior to 1988 follow those in Raghavan P., Atomic and Nuclear Data Tables 42, 189 (1989). (author)

Magnetic moment of extremely proton-rich nucleus 23Al

International Nuclear Information System (INIS)

Nagatomo, T; Matsuta, K; Ozawa, A; Nakashima, Y; Matsumiya, R; Mihara, M; Yasuno, T; Chiba, A; Yamada, K; Momota; Ohtsubo, T; Ohta, M; Shinojima, D; Izumikawa, T; Tanaka, H; Yamaguchi, T; Nakajima, S; Maemura, H; Muranaka, K; Kumashiro, S; Fujiwara, H; Yoshida, K; Sumikama, T; Tanaka, K; Ogura, M; Minamisono, K; Fukuda, M; Minamisono, T; Nojiri, Y; Suzuki, T; Tanihata, I; Alonso, J R; Krebs, G F; Symons, T J M

2005-01-01

The g-factor of the extremely proton-rich nucleus 23 Al (T 1/2 = 0.47 s) has been measured by means of the β-NMR method for the first time. The g-factor were determined as |g| = 1.557(88) from the obtained NMR spectra. From the comparison between the experimental value and the shell model calculation, the spin parity of the ground state of 23 Al was determined as I π = 5/2 + . Thus, the magnetic moment of 23 Al was determined as vertical bar μvertical bar = 3.89(22)μ N

First principles density functional calculation of magnetic moment and hyperfine fields of dilute transition metal impurities in Gd host

International Nuclear Information System (INIS)

Mohanta, S.K.; Mishra, S.N.; Srivastava, S.K.

2014-01-01

We present first principles calculations of electronic structure and magnetic properties of dilute transition metal (3d, 4d and 5d) impurities in a Gd host. The calculations have been performed within the density functional theory using the full potential linearized augmented plane wave technique and the GGA+U method. The spin and orbital contributions to the magnetic moment and the hyperfine fields have been computed. We find large magnetic moments for 3d (Ti–Co), 4d (Nb–Ru) and 5d (Ta–Os) impurities with magnitudes significantly different from the values estimated from earlier mean field calculation [J. Magn. Magn. Mater. 320 (2008) e446–e449]. The exchange interaction between the impurity and host Gd moments is found to be positive for early 3d elements (Sc–V) while in all other cases an anti-ferromagnetic coupling is observed. The trends for the magnetic moment and hyperfine field of d-impurities in Gd show qualitative difference with respect to their behavior in Fe, Co and Ni. The calculated total hyperfine field, in most cases, shows excellent agreement with the experimental results. A detailed analysis of the Fermi contact hyperfine field has been made, revealing striking differences for impurities having less or more than half filled d-shell. The impurity induced perturbations in host moments and the change in the global magnetization of the unit cell have also been computed. The variation within each of the d-series is found to correlate with the d–d hybridization strength between the impurity and host atoms. - Highlights: • Detailed study of transition metal impurities in ferromagnetic Gd has been carried out. • The trends in impurity magnetic moment are qualitatively different from Fe, Co and Ni. • The variation within each of the d-series is found to correlate with the d–d hybridization strength between the impurity and host atoms. • Experimental trend in a hyperfine field has been reproduced successfully

Searching for baryons

International Nuclear Information System (INIS)

Majumdar, Subhabrata

2015-01-01

The current precision cosmological measurements, in agreement with big bang nucleosynthesis studies, tell us that approximately 95 percent of the Universe is 'dark' and only 5 percent of the Universe is 'visible' which comprises of baryons. However, observations reveal only a small fraction of this baryon budget. A key cosmological question arises as to 'where are these missing baryons?'. Simulations and past observations suggest that some of these are in the diffuse cosmic web. Recently, they have been observed, and speculated, to be hiding in the outskirts of massive halos, from Milky Way type galaxies to clusters. Upcoming surveys have the potential to unravel the mystery of the missing baryons. (author)

Precise determination of the magnetic moment of helium in its 23S1 metastable state

International Nuclear Information System (INIS)

Zundell, B.E.

1976-01-01

The electronic magnetic moment of helium was measured by the atomic beam magnetic resonance method using separated oscillating fields. Actually, the magnetic moment of helium relative to that of rubidium was measured. The result was combined with the ratio g/sub J/(Rb)/g/sub J/(H) to get R = g/sub J/(He, 2 3 S 1 )/g/sub J/(H, 2 S/sub 1/2/) = 1 - (23.19 +- 0.1) x 10 -6 . The motivation for this Zeeman measurement was to provide as sensitive a test of the theory of atomic magnetism for a multielectron atom as possible. In particular, the experiment provides a test of the relativistic corrections to the Zeeman effect. The experiment also tests the additivity of the radiative corrections to the magnetic moments of the two electrons. Another motivation concerns the determination of the fine structure constant α from measurements of the 2 3 P fine structure intervals of 4 He; namely, the understanding of the 2 3 S states contributes to the knowledge of the theoretical expressions for the 2 3 P intervals. For the chosen magnetic field of 9.5 kG, the helium resonance frequency was 26.8 GHz, the rubidium frequency, 26.4 GHz. The linewidth associated with the microwave double loop was 25 KHz. Thus it was necessary to pick the resonance line centers to only 1 part in 10 to achieve a 0.1 ppM accuracy. This result is in excellent agreement with the latest theoretical value, R = 1 - 23.21 x 10 -6 ; and with earlier, less precise atomic beam measurements; and with the latest, comparably accurate optical pumping value. Many possible sources of error were investigated. The quoted error is based on analysis of residual systematic effects

Magnetic moments in present relativistic nuclear theories: a mean-field problem

International Nuclear Information System (INIS)

Desplanques, B.

1986-07-01

We show that the magnetic moments of LS closed shell nuclei plus or minus one nucleon derived from non-relativistic Hartree-Fock mean-fields are as bad as those obtained in relativistic approaches of nuclear structure. Deviations with respect to more complete results in both cases are ascribed to the mean-field approximation which neglects some degrees of freedom in the nucleus description. 18 refs

Magnetic moment of a two-particle bound state in quantum electrodynamics

International Nuclear Information System (INIS)

Martynenko, A.P.; Faustov, R.N.

2002-01-01

A quasipotential method for calculating relativistic and radiative corrections to the magnetic moment of a two-particle bound state is formulated for particles of arbitrary spin. It is shown that the expression for the g factors of bound particles involve O(α 2 ) terms depending on the particle spin. Numerical values are obtained for the g factors of the electron in the hydrogen atom and in deuterium

Magnetic moments of ns-isomers in 105Ag and 103Pd

International Nuclear Information System (INIS)

Schneider, L.; Kaeubler, L.; Prade, H.; Hagemann, U.; Story, F.

1979-01-01

In recent years a considerable amount of experimental work has been done in order to study the structure of odd-A transitional nuclei around Z=50. In order to obtain additional experimental information on excited states in 105 Ag and 103 Pd the magnetic moments of the 15/2 + isomer in 105 Ag and the 11/2 - isomer in 103 Pd were determined. (author)

New insights into the neutron electric dipole moment

International Nuclear Information System (INIS)

Ottnad, K.; Kubis, B.; Meissner, U.-G.; Guo, F.-K.

2010-01-01

We analyze the CP-violating electric dipole form factor of the nucleon in the framework of covariant baryon chiral perturbation theory. We give a new upper bound on the vacuum angle, |θ 0 |≤2.5x10 -10 . The quark mass dependence of the electric dipole moment is discussed and compared to lattice QCD data. We also perform the matching between its representations in the three- and two-flavor theories.

Light-cone distribution amplitudes of the baryon octet

International Nuclear Information System (INIS)

Bali, Gunnar S.; Braun, Vladimir M.; Göckeler, Meinulf; Gruber, Michael; Hutzler, Fabian; Schäfer, Andreas; Schiel, Rainer W.; Simeth, Jakob; Söldner, Wolfgang; Sternbeck, Andre; Wein, Philipp

2016-01-01

We present results of the first ab initio lattice QCD calculation of the normalization constants and first moments of the leading twist distribution amplitudes of the full baryon octet, corresponding to the small transverse distance limit of the associated S-wave light-cone wave functions. The P-wave (higher twist) normalization constants are evaluated as well. The calculation is done using N_f=2+1 flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to 222 MeV. Significant SU(3) flavor symmetry violation effects in the shape of the distribution amplitudes are observed.

Light-cone distribution amplitudes of the baryon octet

Energy Technology Data Exchange (ETDEWEB)

Bali, Gunnar S. [Institut für Theoretische Physik, Universität Regensburg,Universitätsstraße 31, D-93040 Regensburg (Germany); Department of Theoretical Physics, Tata Institute of Fundamental Research,Homi Bhabha Road, Mumbai 400005 (India); Braun, Vladimir M.; Göckeler, Meinulf; Gruber, Michael; Hutzler, Fabian; Schäfer, Andreas; Schiel, Rainer W.; Simeth, Jakob; Söldner, Wolfgang [Institut für Theoretische Physik, Universität Regensburg,Universitätsstraße 31, D-93040 Regensburg (Germany); Sternbeck, Andre [Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena,Max-Wien-Platz 1, D-07743 Jena (Germany); Wein, Philipp [Institut für Theoretische Physik, Universität Regensburg,Universitätsstraße 31, D-93040 Regensburg (Germany)

2016-02-10

We present results of the first ab initio lattice QCD calculation of the normalization constants and first moments of the leading twist distribution amplitudes of the full baryon octet, corresponding to the small transverse distance limit of the associated S-wave light-cone wave functions. The P-wave (higher twist) normalization constants are evaluated as well. The calculation is done using N{sub f}=2+1 flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to 222 MeV. Significant SU(3) flavor symmetry violation effects in the shape of the distribution amplitudes are observed.

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.

Baryonic dark matter

International Nuclear Information System (INIS)

Uson, Juan M.

2000-01-01

Many searches for baryonic dark matter have been conducted but, so far, all have been unsuccessful. Indeed, no more than 1% of the dark matter can be in the form of hydrogen burning stars. It has recently been suggested that most of the baryons in the universe are still in the form of ionized gas so that it is possible that there is no baryonic dark matter. Although it is likely that a significant fraction of the dark matter in the Milky Way is in a halo of non-baryonic matter, the data do not exclude the possibility that a considerable amount, perhaps most of it, could be in a tenuous halo of diffuse ionized gas

The exchange of correlated pions and kaons in the baryon-baryon interaction

International Nuclear Information System (INIS)

Reuber, A.G.

1995-09-01

The exchange of two correlated pions or kaons provides the main part of the intermediate-range attraction between two baryons. In this work, a dynamical model for correlated two-pion and two-kaon exchange in the baryon-baryon interaction is presented, both in the scalar-isoscalar (σ) and the vector-isovector (ρ) channel. The contribution of correlated ππ and K anti K exchange is derived from the amplitudes for the transition of a baryon-antibaryon state (B anti B') to a ππ or K anti K state in the pseudophysical region by applying dispersion theory and unitarity. For the B anti B'→ππ, K anti K amplitudes a microscopic model is constructed, which is based on the hadron-exchange picture. The Born terms include contributions from baryon-exchange as well as ρ-pole diagrams. The correlations between the two pseudoscalar mesons are taken into account exactly by means of ππ-K anti K amplitudes derived likewise from a meson-exchange model, which is in line with the empirical ππ data. The parameters of the B anti B'→ππ, K anti K model, which are related to each other by the assumption of SU(3) symmetry, are determined by the adjustment to the quasiempirical N anti N→ππ amplitudes in the pseudophysical region. It is found that correlated K anti K exchange being negligible in the NN interaction plays an important role in the σ-channel for baryon-baryon states with non-vanishing strangeness. The strength of correlated ππ plus K anti K exchange in the σ-channel decreases with the strangeness of the baryon-baryon system becoming more negative. Due to the admixture of baryon-exchange processes to the SU(3)-symmetric ρ-pole contributions the results for correlated ππ-exchange in the vector-isovector channel deviate from what is expected in the naive SU(3) picture for genuine ρ-exchange. (orig.)

Magnetic properties of confined holographic QCD

Science.gov (United States)

Bergman, Oren; Lifschytz, Gilad; Lippert, Matthew

2013-12-01

We investigate the Sakai-Sugimoto model at nonzero baryon chemical potential in a background magnetic field in the confined phase where chiral symmetry is broken. The D8-brane Chern-Simons term holographically encodes the axial anomaly and generates a gradient of the η' meson, which carries a non-vanishing baryon charge. Above a critical value of the chemical potential, there is a second-order phase transition to a mixed phase which includes also ordinary baryonic matter. However, at fixed baryon charge density, the matter is purely η'-gradient above a critical magnetic field.

Neutron-antineutron oscillation and baryonic majoron: low scale spontaneous baryon violation

Energy Technology Data Exchange (ETDEWEB)

Berezhiani, Zurab [Universita dell' Aquila, Dipartimento delle Scienze Fisiche e Chimiche, L' Aquila (Italy); INFN, Laboratori Nazionali Gran Sasso, L' Aquila (Italy)

2016-12-15

We discuss the possibility that baryon number B is spontaneously broken at low scales, of the order of MeV or even smaller, inducing the neutron-antineutron oscillation at the experimentally accessible level. An associated Goldstone particle-baryonic majoron can have observable effects in neutron to antineutron transitions in nuclei or dense nuclear matter. By extending baryon number to an anomaly-free B - L symmetry, the baryo-majoron can be identified with the ordinary majoron associated with the spontaneous breaking of lepton number, and it can have interesting implications for neutrinoless 2β decay with the majoron emission. We also discuss the hypothesis that baryon number can be spontaneously broken by QCD itself via the six-quark condensates. (orig.)

Weak electric and magnetic dipole moments of the τ lepton from azimuthal asymmetries

International Nuclear Information System (INIS)

Sanchez Alvaro, E.

1997-01-01

Measurements of the weak electric dipole moment d τ w and, for the first time, the weak magnetic dipole moment a τ w of the τ lepton using L3 detector at LEP are presented. Azimuthal asymmetries for τ→πν and τ→ρν are used to obtain these measurements. Observed asymmetries are consistent with zero, and the limits set on d τ w and a τ w are vertical stroke d τ w vertical stroke -17 e.cm and vertical stroke a τ w vertical stroke <0.014 at 95% C.L. (orig.)

Magnetic dipole moment of the doubly closed-shell plus one proton nucleus $^{49}$Sc

CERN Multimedia

Gaulard, C V; Walters, W; Nishimura, K; Muto, S; Bingham, C R

It is proposed to measure the magnetic moment of $^{49}$Sc by the Nuclear Magnetic Resonance on Oriented Nuclei (NMR-ON) method using the NICOLE on-line nuclear orientation facility. $^{49}$Sc is the neutron rich, doubly closed-shell, nucleus $^{48}$Ca plus one proton. Results will be used to deduce the effective g-factors in the $^{48}$Ca region with reference to nuclear structure and meson exchange current effects.

Two-flavor QCD correction to lepton magnetic moments at leading-order in the electromagnetic coupling

Energy Technology Data Exchange (ETDEWEB)

Dru Renner, Xu Feng, Karl Jansen, Marcus Petschlies

2011-08-01

We present a reliable nonperturbative calculation of the QCD correction, at leading-order in the electromagnetic coupling, to the anomalous magnetic moment of the electron, muon and tau leptons using two-flavor lattice QCD. We use multiple lattice spacings, multiple volumes and a broad range of quark masses to control the continuum, infinite-volume and chiral limits. We examine the impact of the commonly ignored disconnected diagrams and introduce a modification to the previously used method that results in a well-controlled lattice calculation. We obtain 1.513 (43) 10^-12, 5.72 (16) 10^-8 and 2.650 (54) 10^-6 for the leading-order QCD correction to the anomalous magnetic moment of the electron, muon and tau respectively, each accurate to better than 3%.

Baryons and dual unitarization

International Nuclear Information System (INIS)

Konishi, K.-I.

1977-05-01

Processes involving baryons are discussed in the scheme of dual unitarization. In particular, the topological expansion is generalized to any hadronic S-matrix elements involving baryons and/or mesons. The expansion is based on a model for the baryon propagator, which is a set of three planar Feynman diagrams joined at a junction line. The resulting expansion is a double expansion in 1/N (N = the number of quark flavours) and in the number of baryon loops. Based on this, several new observations are made in phenomenological problems, and a unifying point of view in stressed. The scheme is evidently crossing invariant, and unitarity constraints are imposed order by order in 1/N and in the baryon loop number. (author)

Baryonic dark matter

International Nuclear Information System (INIS)

Lynden-Bell, D.; Gilmore, G.

1990-01-01

Dark matter, first definitely found in the large clusters of galaxies, is now known to be dominant mass in the outer parts of galaxies. All the mass definitely deduced could be made up of baryons, and this would fit well with the requirements of nucleosynthesis in a big bang of small Ω B . However, if inflation is the explanation of the expansion and large scale homogeneity of the universe and of baryon synthesis, and if the universe did not have an infinite extent at the big bang, then Ω should be minutely greater than unity. It is commonly hypothesized that most mass is composed of some unknown, non-baryonic form. This book first discusses the known forms, comets, planets, brown dwarfs, stars, gas, galaxies and Lyman α clouds in which baryons are known to exist. Limits on the amount of dark matter in baryonic form are discussed in the context of the big bang. Inhomogeneities of the right type alleviate the difficulties associated with Ω B = 1 cosmological nucleosynthesis

Baryon structure

International Nuclear Information System (INIS)

Morsch, H.P.; Forschungszentrum Juelich GmbH

1993-01-01

A brief review on the theoretical and experimental situation of baryon spectroscopy is first given. Then, the radial structure of baryons, related to the ground state form factors and the baryonic compressibility, is discussed. An experiment has been performed at Saturne laboratory (France) in which for the first time a compression of the nucleon is observed, exciting the P 11 (1440 MeV) resonance (Roper resonance) by α-particles. The analysis of the data indicates that this excitation covers a large fraction of the available monopole strength in the nucleon. The derived compressibility is discussed as well as the consequence for other fields, as nuclear medium effects on baryon properties, high density phenomena in nuclear collisions as well as colour transparency. In the last point the spin-flip structure of the P 11 (1440 MeV) resonance is discussed. The possibility to determine isoscalar spin-flip strength by polarized deuteron scattering is contrasted with first preliminary results from photon-induced reactions studied at Mainz which indicate a non-negligible M1 excitation of the Roper resonance. (author) 10 figs., 31 refs

Calculation of baryon sum rules and SU(4) mass formulae for mesons and baryons

International Nuclear Information System (INIS)

Bongardt, K.

1976-01-01

Light cone coordinates and field-field anticommutators for the free quark model on the light cone are introduced and light cone charges and light cone currents for the free quark model as well as sum rules for the meson and quark states are derived. The derivation of sum rules for the baryons is attempted. It is seen that it is possible formally to derive the same sum rules for the baryons and for the quarks. The baryon sums were derived through the symmetry properties of the baryon fields. Explicit assumptions about the spatial distribution of the three quarks in the baryons were not utilized. The meson-baryon Σ-terms, Zweig's rules in the SU (4) and a number of properties of the M-matrix are discussed. (BJ) [de

Angle and temperature dependence of the magnetocrystalline anisotropy energy and the microscopic magnetic moments of the ferromagnetic semi-metal CrO{sub 2}; Winkel- und Temperaturabhaengigkeit der magnetokristallinen Anisotropieenergie und der mikroskopischen magnetischen Momente des ferromagnetischen Halbmetalls CrO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Gold, S.

2005-07-01

The aim of this work was to examine, by use of XMCD-effect and additional measurements with SQUID-magnetometer, spin moments and hysteresis loops, but also to clarify the intrinsic properties like magnetocrystalline anisotropy, magnetic dipole term, and the nearly quenched orbital moment. The XMCD-measurements were done at the Cr L{sub 2,3}- and the O K-edge. The results for CrO{sub 2} show a strong dependence of the orbital, the sum of spin moment and magnetic dipole term, and the magnetocrystalline anisotropy energy from the angle between rutile a- and c-axis. Even more than the complete orbital moment, two separable and different spectral features show strong alterations of the different orbital moments. In a second part of this work the temperature dependence was investigated. The aim was to clarify the origin of the orbital moment, dipole term, and MAE in dependence of the spin moment and compare the results to different theoretical models. The extracted orbital moments and the magnetic dipole term show the same temperature dependence as the spin moment. In the following a dependence of the squared measured spin moment could be found for the MAE. For the first time the magnetic dipole term could be identified as the reason of the magnetocrystalline anisotropy energy. A strong Cr-O hybridisation was found, which shows in a similar structure and temperature dependence of the orbital moments for Cr L{sub 2,3} and the XMCD effect at O-K edge. (orig.)

New insights into the neutron electric dipole moment

Energy Technology Data Exchange (ETDEWEB)

Ottnad, K.; Kubis, B. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Meissner, U.-G., E-mail: meissner@hiskp.uni-bonn.d [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universitaet Bonn, D-53115 Bonn (Germany); Institut fuer Kernphysik, Juelich Center for Hadron Physics and Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany); Guo, F.-K. [Institut fuer Kernphysik, Juelich Center for Hadron Physics and Institute for Advanced Simulation, Forschungszentrum Juelich, D-52425 Juelich (Germany)

2010-04-05

We analyze the CP-violating electric dipole form factor of the nucleon in the framework of covariant baryon chiral perturbation theory. We give a new upper bound on the vacuum angle, |theta{sub 0}|<=2.5x10{sup -10}. The quark mass dependence of the electric dipole moment is discussed and compared to lattice QCD data. We also perform the matching between its representations in the three- and two-flavor theories.

Revisiting magnetism of capped Au and ZnO nanoparticles: Surface band structure and atomic orbital with giant magnetic moment

Energy Technology Data Exchange (ETDEWEB)

Hernando, Antonio; Crespo, Patricia [Instituto de Magnetismo Aplicado, UCM-CSIC-ADIF, Las Rozas. P.O. Box 155, 28230 Madrid (Spain); Dept. Fisica de Materiales, Universidad Complutense, Madrid (Spain); Garcia, Miguel Angel [Instituto de Ceramica y Vidrio, CSIC, C/ Kelsen, 5, Madrid 28049 (Spain); Coey, Michael [Trinity College Dublin, Dublin (Ireland); Ayuela, Andres; Echenique, Pedro Miguel [Centro de Fisica de Materiales, CFM-MPC CSIC-UPV/EHU, Donostia International Physics Center (DIPC), 20018 San Sebastian (Spain); Departamento de Fisica de Materiales, Fac. de Quimicas, Universidad del Pais Vasco UPV-EHU, 20018 San Sebastian (Spain)

2011-10-15

In this article we review the exotic magnetism of nanoparticles (NPs) formed by substances that are not magnetic in bulk as described with generality in Section 1. In particular, the intrinsic character of the magnetism observed on capped Au and ZnO NPs is analysed. X-ray magnetic circular dichroism (XMCD) analysis has shown that the magnetic moments are intrinsic and lie in the Au and Zn atoms, respectively, as analysed in Section 2, where the general theoretical ideas are also revisited. Since impurity atoms bonded to the surface act as donor or acceptor of electrons that occupy the surface states, the anomalous magnetic response is analysed in terms of the surface band in Section 3. Finally, Section 4 summarizes our last theoretical proposal. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Holographic Chiral Magnetic Spiral

International Nuclear Information System (INIS)

Kim, Keun-Young; Sahoo, Bindusar; Yee, Ho-Ung

2010-06-01

We study the ground state of baryonic/axial matter at zero temperature chiral-symmetry broken phase under a large magnetic field, in the framework of holographic QCD by Sakai-Sugimoto. Our study is motivated by a recent proposal of chiral magnetic spiral phase that has been argued to be favored against previously studied phase of homogeneous distribution of axial/baryonic currents in terms of meson super-currents dictated by triangle anomalies in QCD. Our results provide an existence proof of chiral magnetic spiral in strong coupling regime via holography, at least for large axial chemical potentials, whereas we don't find the phenomenon in the case of purely baryonic chemical potential. (author)

Hyperfine structure, nuclear spins and magnetic moments of some cesium isotopes

International Nuclear Information System (INIS)

Ekstroem, C.; Ingelman, S.; Wannberg, G.

1977-03-01

Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2 Ssub(1/2) electronic ground state of some cesium isotopes. An on-line oven system which efficiently converts a mass separated ion-beam of alkali isotopes to an atomic beam is described in some detail. Experimentally determined nuclear spins of sup(120, 121, 121m, 122, 122m, 123, 124, 126, 128, 130m, 135m)Cs and magnetic moments of sup(122, 123, 124, 126, 128, 130)Cs are reported and discussed in terms of different nuclear models. The experimental data indicate deformed nuclear shapes of the lightest cesium isotopes. (Auth.)

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Keywords. Hypercentral constituent quark model; charmed and beauty baryons; hyper-Coulomb plus power potential; magnetic moments. Abstract. Triple heavy flavour baryons are studied using the hypercentral description of the three-body system. The confinement potential is assumed as hypercentral Coulomb plus ...

Evidence for a magnetic moment at the Lu site of LuFe2

International Nuclear Information System (INIS)

Kasamatsu, Y.; Armitage, J.G.M.; Lord, J.S.; Riedi, P.C.; Fort, D.

1995-01-01

High pressure 175 Lu NMR measurements of LuFe 2 at 4.2 K suggest that Lu, like Y and Zr, carries a negative magnetic moment, in agreement with self-consistent energy band calculations. The observed spectrum is more complicated than would be expected for a Laves phase compound. ((orig.))

Relativistic two-fermion equations with form factors and anomalous magnetic moment interactions

International Nuclear Information System (INIS)

Ahmed, S.

1977-04-01

Relativistic equations for two-fermion systems are derived from quantum field theory taking into account the form factors of the particles. When the q 2 dependence of the form factors is disregarded, in the static approximation, the two-fermion equations with Coulomb and anomalous magnetic moment interactions are obtained. Separating the angular variables, a sixteen-component relativistic radial equation are finally given

Phase-Transition and Magnetic Moment of the Gd3+ Ion in the Gd2Fe17 Compound

Institute of Scientific and Technical Information of China (English)

HAO Yan-Ming; FU Bin; ZHOU Yan; ZHAO Miao

2009-01-01

The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound: the hexagonal Th2Ni17-type structure at high tem-peratures (above 1243℃), and the rhombohedrai Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.

Two-flavor QCD correction to lepton magnetic moments at leading-order in the electromagnetic coupling

Energy Technology Data Exchange (ETDEWEB)

Feng, Xu [DESY, Zeuthen (Germany). NIC; Muenster Univ. (Germany). Inst. fuer Theoretische Physik; Jansen, Karl; Renner, Dru B. [DESY, Zeuthen (Germany). NIC; Petschlies, Marcus [Humboldt Univ. Berlin (Germany). Inst. fuer Physik

2011-03-15

We present a reliable nonperturbative calculation of the QCD correction, at leading-order in the electromagnetic coupling, to the anomalous magnetic moment of the electron, muon and tau leptons using two-flavor lattice QCD. We use multiple lattice spacings, multiple volumes and a broad range of quark masses to control the continuum, in nite-volume and chiral limits. We examine the impact of the commonly ignored disconnected diagrams and introduce a modi cation to the previously used method that results in a well-controlled lattice calculation. We obtain 1.513(43).10{sup -12}, 5.72(16).10{sup -8} and 2.650(54).10{sup -6} for the leading-order QCD correction to the anomalous magnetic moment of the electron, muon and tau respectively, each accurate to better than 3%. (orig.)

Baryonic Dark Matter

OpenAIRE

Silk, Joseph

1994-01-01

In the first two of these lectures, I present the evidence for baryonic dark matter and describe possible forms that it may take. The final lecture discusses formation of baryonic dark matter, and sets the cosmological context.

X-ray magnetic dichroism: from quantitative determination of magnetic moments to imaging of magnetization dynamics; Dichroisme magnetique des rayons X: de la determination quantitative des moments magnetiques a l'imagerie de la dynamique de l'aimantation

Energy Technology Data Exchange (ETDEWEB)

Vogel, J

2006-03-15

In this document, I use some results of my research activities of the last ten years to show the power of x-ray magnetic dichroism for determining magnetic properties of thin layers, multilayers and nano-structures. The use of sum rules for x-ray dichroism allows a quantitative determination of the spin and orbital contributions to the magnetic moment, for each element of a heterogeneous material separately. Used in a qualitative way, x-ray dichroism allows monitoring the magnetization of the different layers in a multilayer material as a function of applied field. In combination with the temporal structure of synchrotron radiation, it is possible to study fast magnetization reversal with element selectivity, which is important for devices like spin valves and magnetic tunnel junctions. Adding the spatial resolution of a photoelectron emission microscope (PEEM), it becomes possible to study all the details of the fast magnetization reversal in complex magnetic systems. (author)

Electric and magnetic polarizabilities of hadrons via elastic Compton scattering at KAON

International Nuclear Information System (INIS)

Moinester, M.A.; Blecher, M.

1990-08-01

The study of dynamic properties of hadrons presents a challenge. Among the most basic of these are the electric and magnetic polarizabilities describing the electromagnetic structure of hadrons. They characterize the induced transient dipole moments of hadrons in an external electromagnetic field. During gamma-hadron Compton scattering the lowest order scattering is determined by the charge and magnetic moment. The next order scattering is determined by the induced dipole moments. The dipole polarizabilities probe the rigidity of the internal structure of baryons and mesons, the dipole moments being induced by the rearrangement of the hadron constituents driven by the presence of the electric and magnetic fields of the photon during scattering. A sophisticated understanding of hadrons within the framework of QCD will be tested, in part, by the prediction of these quantities. For the light charged pion, chiral symmetry leads to a precise prediction for the polarizabilities. For the heavier charged kaon, chiral perturbation theory can be applied to predict the polarizabilities. For these cases, the experimental polarizabilities subject the underlying chiral symmetry and chiral perturbation techniques of QCD to new and serious tests. Here the physics of electromagnetic polarizabilities is first described, followed by a review of previous experimental and theoretical polarizability results for the proton, neutron, pion, and kaon. A brief description is then given of how polarizabilities for these hadrons can be studied at the proposed TRIUMF KAON facility. (36 refs., 4 figs.)

Meson-baryon components in the states of the baryon decuplet

Energy Technology Data Exchange (ETDEWEB)

Aceti, F.; Oset, E. [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Kavli Institute for Theoretical Physics China, Beijing (China); Dai, L.R. [Liaoning Normal University, Department of Physics, Dalian (China); Kavli Institute for Theoretical Physics China, Beijing (China); Geng, L.S. [Beihang University, School of Physics and Nuclear Energy Engineering and International Research Center for Nuclei and Particles in the Cosmos, Beijing (China); Zhang, Y. [Liaoning Normal University, Department of Physics, Dalian (China)

2014-03-15

We apply an extension of the Weinberg compositeness condition on partial waves of L = 1 and resonant states to determine the weight of the meson-baryon component in the Δ(1232) resonance and the other members of the J{sup P} = (3)/(2){sup +} baryon decuplet. We obtain an appreciable weight of πN in the Δ(1232) wave function, of the order of 60%, which looks more natural when one recalls that experiments on deep inelastic and Drell Yan give a fraction of πN component of 34% for the nucleon. We also show that, as we go to higher energies in the members of the decuplet, the weights of the meson-baryon component decrease and they already show a dominant part for a genuine, non-meson-baryon, component in the wave function. We write a section to interpret the meaning of the Weinberg sum rule when it is extended to complex energies and another one for the case of an energy-dependent potential. (orig.)

Comparison of multi-fluid moment models with particle-in-cell simulations of collisionless magnetic reconnection

International Nuclear Information System (INIS)

Wang, Liang; Germaschewski, K.; Hakim, Ammar H.; Bhattacharjee, A.

2015-01-01

We introduce an extensible multi-fluid moment model in the context of collisionless magnetic reconnection. This model evolves full Maxwell equations and simultaneously moments of the Vlasov-Maxwell equation for each species in the plasma. Effects like electron inertia and pressure gradient are self-consistently embedded in the resulting multi-fluid moment equations, without the need to explicitly solving a generalized Ohm's law. Two limits of the multi-fluid moment model are discussed, namely, the five-moment limit that evolves a scalar pressures for each species and the ten-moment limit that evolves the full anisotropic, non-gyrotropic pressure tensor for each species. We first demonstrate analytically and numerically that the five-moment model reduces to the widely used Hall magnetohydrodynamics (Hall MHD) model under the assumptions of vanishing electron inertia, infinite speed of light, and quasi-neutrality. Then, we compare ten-moment and fully kinetic particle-in-cell (PIC) simulations of a large scale Harris sheet reconnection problem, where the ten-moment equations are closed with a local linear collisionless approximation for the heat flux. The ten-moment simulation gives reasonable agreement with the PIC results regarding the structures and magnitudes of the electron flows, the polarities and magnitudes of elements of the electron pressure tensor, and the decomposition of the generalized Ohm's law. Possible ways to improve the simple local closure towards a nonlocal fully three-dimensional closure are also discussed

Baryon Chiral Dynamics

Energy Technology Data Exchange (ETDEWEB)

Becher,

2002-08-08

After contrasting the low energy effective theory for the baryon sector with one for the Goldstone sector, I use the example of pion nucleon scattering to discuss some of the progress and open issues in baryon chiral perturbation theory.

Measuring baryon-(anti-)baryon interaction cross-sections with femtoscopy in Heavy-Ion Collisions

Energy Technology Data Exchange (ETDEWEB)

Kisiel, A.

2016-12-15

Two-particle correlations at low relative momentum (femtoscopy) are used to study the space-time dynamics of the source created in heavy-ion collisions. The same method can be used in a novel way to study the Final State Interaction potential for various particle pairs. The parameters are also directly related to the relevant interaction cross-sections. Of special interest are correlations of baryons, where the strong interaction often dominates. The femtoscopic technique offers a unique opportunity to study this interaction in such systems. In this work we discuss the similarities and differences of such measurement for baryon-baryon and baryon-antibaryon pairs.

Lifting particle coordinate changes of magnetic moment type to Vlasov-Maxwell Hamiltonian dynamics

International Nuclear Information System (INIS)

Morrison, P. J.; Vittot, M.; Guillebon, L. de

2013-01-01

Techniques for coordinate changes that depend on both dependent and independent variables are developed and applied to the Maxwell-Vlasov Hamiltonian theory. Particle coordinate changes with a new velocity variable dependent on the magnetic field, with spatial coordinates unchanged, are lifted to the field theoretic level, by transforming the noncanonical Poisson bracket and Hamiltonian structure of the Vlasov-Maxwell dynamics. Several examples are given including magnetic coordinates, where the velocity is decomposed into components parallel and perpendicular to the local magnetic field, and the case of spherical velocity coordinates. An example of the lifting procedure is performed to obtain a simplified version of gyrokinetics, where the magnetic moment is used as a coordinate and the dynamics is reduced by elimination of the electric field energy in the Hamiltonian.

Leading-order hadronic contributions to the electron and tau anomalous magnetic moments

Energy Technology Data Exchange (ETDEWEB)

Burger, Florian; Pientka, Grit [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Berlin (Germany); Jansen, Karl [NIC, DESY, Zeuthen (Germany); Petschlies, Marcus [The Cyprus Institute, P.O.Box 27456, Nicosia (Cyprus); Rheinische Friedrich-Wilhelms-Universitaet Bonn, Institut fuer Strahlen- und Kernphysik, Bonn (Germany)

2016-08-15

The leading hadronic contributions to the anomalous magnetic moments of the electron and the τ-lepton are determined by a four-flavour lattice QCD computation with twisted mass fermions. The results presented are based on the quark-connected contribution to the hadronic vacuum polarisation function. The continuum limit is taken and systematic uncertainties are quantified. Full agreement with results obtained by phenomenological analyses is found. (orig.)

The ground state magnetic moment and susceptibility of a two electron Gaussian quantum dot

Science.gov (United States)

Boda, Aalu; Chatterjee, Ashok

2018-04-01

The problem of two interacting electrons moving in a two-dimensional semiconductor quantum dot with Gaussian confinement under the influence of an external magnetic field is studied by using a method of numerical diagonalization of the Hamiltonian matrix with in the effective-mass approximation. The energy spectrum is calculated as a function of the magnetic field. We find the ground state magnetic moment and the magnetic susceptibility show zero temperature diamagnetic peaks due to exchange induced singlet-triplet oscillations. The position and the number of these peaks depend on the size of the quantum dot and also strength of the electro-electron interaction. The theory is applied to a GaAs quantum dot.

Measurement of dipole-moment in atomic transitions under strong external magnetic field

International Nuclear Information System (INIS)

Nittoh, Koichi; Kuwako, Akira; Ikehara, Tadashi; Yoshida, Tadashi; Watanabe, Takasi; Yoguchi, Itaru; Suzuki, Kazuhiro.

1996-01-01

Obtaining an accurate value of the electric dipole moment μ is essential in the fields of laser application technologies. A direct way of measuring the electric dipole moment μ is to observe the Rabi-oscillation which manifests itself in the coherent photo-excitation behavior of atoms. In the case of the elements which have large angular momenta, identifying the Rabi-oscillation in their excitation behavior becomes rather difficult. We proposed an accurate and straightforward method of determining the electric-dipole moment μ between multi-fold degenerate levels. The point is to remove the degeneracy by applying an external magnetic field with the aid of the Zeeman effect and, then, to realize a degeneration free coherent excitation. As a result, we can observe the Rabi-oscillations explicitly in the excitation υs. laser-fluence curves. The present method provides a reliable basis of experimental determination of μ. As an example, we applied the present method to a transition to 0-17,362 cm -1 level in uranium and obtained the value μ=0.86±0.06 (Debye). (author)

Interactions among magnetic moments in the double perovskites Sr2Fe1+xMo1−xO6

International Nuclear Information System (INIS)

Pilo, J.; Carvajal, E.; Oviedo-Roa, R.; Cruz-Irisson, M.; Navarro, O.

2014-01-01

It is well known that every double perovskite shows a characteristic magnetic behavior, as a consequence of the interactions among the magnetic moments associated with the atoms in their cells; at the same time, the electric and magnetic properties of the bulk double perovskite Sr 2 FeMoO 6 are well characterized. In this work we studied the iron rich compounds Sr 2 Fe 1+x Mo 1−x O 6 , using a supercell to model such concentrations that made Fe richer perovskites by ±66.6% and ±200%. Starting from the stoichiometric double perovskite, and modifying the Fe/Mo ratio in the compound, the study of these materials were based on the calculation of the magnetic moment at each atom, as well as the partial density of states

Baryons with chromodynamics

International Nuclear Information System (INIS)

Isgur, N.

1981-01-01

Many of the phenomenological difficulties of the non-relativistic quark model for baryons are overcome when some current prejudices from chromodynamics about quark forces are imposed. The effects of flavour independent confinement, symmetry breaking through quark masses, and colour hyperfine interactions are most prominent, leading to a satisfactory understanding of both the spectroscopy of low-lying baryons and of the signs and magnitudes of baryon couplings. The previously worrisome absence in partial wave analyses of a large number of the states expected in the nonrelativistic quark model is explained in terms of decouplings of the resonances from their elastic channels

Baryon bags in strong coupling QCD

Science.gov (United States)

Gattringer, Christof

2018-04-01

We discuss lattice QCD with one flavor of staggered fermions and show that in the path integral the baryon contributions can be fully separated from quark and diquark contributions. The baryonic degrees of freedom (d.o.f.) are independent of the gauge field, and the corresponding free fermion action describes the baryons through the joint propagation of three quarks. The nonbaryonic dynamics is described by quark and diquark terms that couple to the gauge field. When evaluating the quark and diquark contributions in the strong coupling limit, the partition function completely factorizes into baryon bags and a complementary domain. Baryon bags are regions in space-time where the dynamics is described by a single free fermion made out of three quarks propagating coherently as a baryon. Outside the baryon bags, the relevant d.o.f. are monomers and dimers for quarks and diquarks. The partition sum is a sum over all baryon bag configurations, and for each bag, a free fermion determinant appears as a weight factor.

Calm Multi-Baryon Operators

Directory of Open Access Journals (Sweden)

Berkowitz Evan

2018-01-01

Full Text Available There are many outstanding problems in nuclear physics which require input and guidance from lattice QCD calculations of few baryons systems. However, these calculations suffer from an exponentially bad signal-to-noise problem which has prevented a controlled extrapolation to the physical point. The variational method has been applied very successfully to two-meson systems, allowing for the extraction of the two-meson states very early in Euclidean time through the use of improved single hadron operators. The sheer numerical cost of using the same techniques in two-baryon systems has so far been prohibitive. We present an alternate strategy which offers some of the same advantages as the variational method while being significantly less numerically expensive. We first use the Matrix Prony method to form an optimal linear combination of single baryon interpolating fields generated from the same source and different sink interpolating fields. Very early in Euclidean time this optimal linear combination is numerically free of excited state contamination, so we coin it a calm baryon. This calm baryon operator is then used in the construction of the two-baryon correlation functions.To test this method, we perform calculations on the WM/JLab iso-clover gauge configurations at the SU(3 flavor symmetric point with mπ~ 800 MeV — the same configurations we have previously used for the calculation of two-nucleon correlation functions. We observe the calm baryon significantly removes the excited state contamination from the two-nucleon correlation function to as early a time as the single-nucleon is improved, provided non-local (displaced nucleon sources are used. For the local two-nucleon correlation function (where both nucleons are created from the same space-time location there is still improvement, but there is significant excited state contamination in the region the single calm baryon displays no excited state contamination.

Effect of lattice distortion on uranium magnetic moments in U4Ru7Ge6 studied by polarized neutron diffraction

Science.gov (United States)

Vališka, Michal; Klicpera, Milan; Doležal, Petr; Fabelo, Oscar; Stunault, Anne; Diviš, Martin; Sechovský, Vladimír

2018-03-01

In a cubic ferromagnet, small spontaneous lattice distortions are expected below the Curie temperature, but the phenomenon is usually neglected. This study focuses on such an effect in the U4Ru7Ge6 compound. Based on DFT calculations, we propose a lattice distortion from the cubic I m -3 m space group to a lower, rhombohedral, symmetry described by the R -3 m space group. The strong spin-orbit coupling of the uranium ions plays an essential role in lowering the symmetry, giving rise to two different U sites (U1 and U2). Using polarized neutron diffraction in applied magnetic fields of 1 and 9 T in the ordered state (1.9 K ) and in the paramagnetic state (20 K ), we bring convincing experimental evidence of this splitting of the U sites, with different magnetic moments. The data have been analyzed both by maximum entropy calculations and by a direct fit in the dipolar approximation. In the ordered phase, the μL/μS ratio of the orbital and spin moments on the U2 site is remarkably lower than for the free U3 + or U4 + ion, which points to a strong hybridization of the U 5 f wave functions with the 4 d wave functions of the surrounding Ru. On the U1 site, the μL/μS ratio exhibits an unexpectedly low value: the orbital moment is almost quenched, like in metallic α -uranium. As a further evidence of the 5 f -4 d hybridization in the U4Ru7Ge6 system, we observe the absence of a magnetic moment on the Ru1 site, but a rather large induced moment on the Ru2 site, which is in closer coordination with both U positions. Very similar results are obtained at 20 K in the ferromagnetic regime induced by the magnetic field of 9 T . This shows that applying a strong magnetic field above the Curie temperature also leads to the splitting of the uranium sites, which further demonstrates the intimate coupling of the magnetic ordering and structural distortion. We propose that the difference between the magnetic moment on the U1 and U2 sites results from the strong spin

General classical and quantum-mechanical description of magnetic resonance: an application to electric-dipole-moment experiments

Energy Technology Data Exchange (ETDEWEB)

Silenko, Alexander J. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation)

2017-05-15

A general theoretical description of a magnetic resonance is presented. This description is necessary for a detailed analysis of spin dynamics in electric-dipole-moment experiments in storage rings. General formulas describing a behavior of all components of the polarization vector at the magnetic resonance are obtained for an arbitrary initial polarization. These formulas are exact on condition that the nonresonance rotating field is neglected. The spin dynamics is also calculated at frequencies far from resonance with allowance for both rotating fields. A general quantum-mechanical analysis of the spin evolution at the magnetic resonance is fulfilled and the full agreement between the classical and quantum-mechanical approaches is shown. Quasimagnetic resonances for particles and nuclei moving in noncontinuous perturbing fields of accelerators and storage rings are considered. Distinguishing features of quasimagnetic resonances in storage ring electric-dipole-moment experiments are investigated in detail. The exact formulas for the effect caused by the electric dipole moment are derived. The difference between the resonance effects conditioned by the rf electric-field flipper and the rf Wien filter is found and is calculated for the first time. The existence of this difference is crucial for the establishment of a consent between analytical derivations and computer simulations and for checking spin tracking programs. The main systematical errors are considered. (orig.)

Weak correction to the muon magnetic moment in a gauge model

International Nuclear Information System (INIS)

Darby, D.; Grammer, G. Jr.

1976-01-01

The weak correction, asub(μ)sup(W), to the anomalous magnetic moment of the muon is calculated in an SU(2) x U(1) x U(1) gauge model of weak and electromagnetic interactions. The Rsub(xi) gauge is used and Ward-Takahashi identities are utilized in eliminating all xi-dependence before the loop integration is performed. asub(μ)sup(W,expt) places no constraint on the mass of one of the neutral vector mesons, which may be arbitrarily small. (Auth.)

Anomalous magnetic and weak magnetic dipole moments of the τ lepton in the simplest little Higgs model

Energy Technology Data Exchange (ETDEWEB)

Arroyo-Urena, M.A.; Tavares-Velasco, G. [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Puebla, PUE (Mexico); Hernandez-Tome, G. [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Puebla, PUE (Mexico); Centro de Investigacion y de Estudios Avanzados del Instituto Politecnico Nacional, Departamento de Fisica, Mexico City (Mexico)

2017-04-15

We obtain analytical expressions, both in terms of parametric integrals and Passarino-Veltman scalar functions, for the one-loop contributions to the anomalous weak magnetic dipole moment (AWMDM) of a charged lepton in the framework of the simplest little Higgs model (SLHM). Our results are general and can be useful to compute the weak properties of a charged lepton in other extensions of the standard model (SM). As a by-product we obtain generic contributions to the anomalous magnetic dipole moment (AMDM), which agree with previous results. We then study numerically the potential contributions from this model to the τ lepton AMDM and AWMDM for values of the parameter space consistent with current experimental data. It is found that they depend mainly on the energy scale f at which the global symmetry is broken and the t{sub β} parameter, whereas there is little sensitivity to a mild change in the values of other parameters of the model. While the τ AMDM is of the order of 10{sup -9}, the real (imaginary) part of its AWMDM is of the order of 10{sup -9} (10{sup -10}). These values seem to be out of the reach of the expected experimental sensitivity of future experiments. (orig.)

Modified skyrmion in a baryonic matter

International Nuclear Information System (INIS)

Mishustin, I.N.

1990-01-01

A unified field model describing individual baryons and baryonic matter is developed. The model is based on a chiral-symmetry Lagrangian including the scalar, pion and vector fields interacting with the scalar density and the 4-current of baryons (linear σ-model supplemented by a vector field). Essentially inhomogeneous soliton solutions of the topological type (skirmions) correspond to the individual baryons, whereas homogeneous field configurations correspond to baryonic matter. Estimations show that the model predicts a correct scale of changes of the effective mass (15%) and the radius for the baryon for a normal nuclear matter density. For high baryon densities the model with a massive vector field predicts a phase transition which results in the restoration of chiral symmetry. The new state of the system is characterized by a homogeneous distribution of the meson fields and energy

Strangeness S = -2 baryon-baryon interactions using chiral effective field theory

NARCIS (Netherlands)

Polinder, H.; Haidenbauer, J.; Meissner, U.G.

2007-01-01

We derive the leading order strangeness S =−2 baryon–baryon interactions in chiral effective field theory. The potential consists of contact terms without derivatives and of one-pseudoscalar-meson exchanges. The contact terms and the couplings of the pseudoscalar mesons to the baryons are related

Magnetic moments of multiquark systems and restraints upon the six-quark admixture to the deuteron wave functions

International Nuclear Information System (INIS)

Kondratyuk, L.A.; Krivoruchenko, M.I.; Shchepkin, M.G.

1986-01-01

The magnetic moment of the six-quark bag with the deuteron quantum numbers is calculated in the chiral bag model taking into account the gluonic and the pionic corrections. For the six-quark bag radius R 6q =1.18-1.38 fm (corresponding to the nucleon bag radius R 3q =0.8-1.0 fm) the magnetic moment equals m D 6q =1.17-1.23 nuclear magnetons. This result together with the deuteron magnetic momentum data provides a restraint upon the six-quark bag admixture in the deuteron P B < or approx. 3%. This value is a few times lower than the probability that two nucleons are in the range r < 1.4 fm. Therefore, it may be interpreted as an evidence for a considerable difference between the properties of the effective bag in the deuteron and of the MIT bag

Charged point particles with magnetic moment in general relativity

International Nuclear Information System (INIS)

Amorim, R.; Tiomno, J.

1977-01-01

Halbwachs Lagrangean formalism for the theory of charged point particles with spin (g = 2) is generalized and formulated in General Relativity for particles of arbitrary charge and magnetic moment. Equations are obtained, both corresponding to Frenkel's condition Ssub(μν)Xsup(ν) = 0 and to Nakano's condition Ssub(μν)Psup(ν) = 0. With the later condition the exact equations are highly coupled and non linear. When linearized in the electromagnetic and gravitational fields they coincide with de Groot-Suttorp equations for vanishing gravitational fields and with Dixon-Wald equations in the absence of electromagnetic field. The equations corresponding to Frenkel's condition, when linearized in Ssub(μν), coincide with Papapetrou's and Frenkel's equations in the corresponding limits [pt

X-Ray Magnetic Dichroism of Antiferromagnet Fe2O3 : The Orientation of Magnetic Moments Observed by Fe 2p X-Ray Absorption Spectroscopy

NARCIS (Netherlands)

Kuiper, Pieter; Searle, Barry G.; Rudolf, Petra; Tjeng, L.H.; Chen, C.T.

1993-01-01

We report strong magnetic linear dichroism at the Fe L2,3 edge of the antiferromagnet Fe2O3 (hematite). The relative difference in absorption for light polarized parallel and perpendicular to the magnetic moment is as high as 40% at the Fe L2 edge. The spectra are in excellent agreement with

Theoretical high energy physics research at the University of Chicago: Progress report, April 1, 1987-March 31, 1988

International Nuclear Information System (INIS)

Rosner, J.L.; Sachs, R.G.

1987-12-01

This paper briefly discusses the high energy physics work done at the University of Chicago. Certain topics discussed are: hadron spectroscopy, CP violation, neutral leptons, supersymmetry, magnetic moments of baryons and quarks, low energy effective field theories, electromagnetic properties of baryons and mass mixing of quarks and neutrinos

What can four solar neutrino experiments tell us about the magnetic moment solution to the solar neutrino problem?

International Nuclear Information System (INIS)

Pulido, J.

1993-01-01

The results reported by the four solar neutrino experiments (Homestake, Kamiokande, SAGE, Gallex) are analyzed from the point of view of the magnetic moment solution to the solar neutrino problem. The neutrino deficit reported by the gallium experiments (SAGE, Gallex) is apparently not as large as the one reported by Homestake and Kamiokande, a phenomenon suggesting a greater suppression in the large energy solar neutrino sector but also consistent with a uniform suppression for all neutrinos. Both uniform and nonuniform suppressions are examined for three different variants of the solar magnetic field and the possible parameter ranges for Δ 2 m 21 and μ ν are investigated. Massless neutrinos are not excluded and in all cases Δ 2 m 21 -5 eV 2 . The anticorrelation of the neutrino flux with sunspot activity is possible in any of the experiments but is in no way implied by a sizable magnetic moment and magnetic field

Status of Works on A-40-MCI-Activity Tritium Source for the Measurement of the Antineutrino Magnetic Moment

International Nuclear Information System (INIS)

Yukhimchuk, A.A.; Vinogradov, Yu.I.; Golubkov, A.N.; Grishechkin, S.K.; Il'kaev, R.I.; Kuryakin, A.V.; Lebedev, B.L.; Lobanov, V.N.; Mikhailov, V.N.; Tumkin, D.P.; Bogdanova, L.N.

2005-01-01

For the experiment on the measurement of the electron antineutrino magnetic moment we suggest a new approach to the tritium source design, namely, a configuration of annular cells filled with TiT 2 that are stacked into a hollow cylinder. Detectors are mounted in the hole inside.We present results of the optimization of geometrical and physical parameters of the source with respect to its experimental effectiveness and safety guaranty at all stages of its lifecycle. We discuss the choice of the construction materials and specify technological issues relevant to radiation purity of the source, being of the special concern in the experiment on the electron antineutrino magnetic moment measurement

The search for exotic baryons at the HERMES experiment

International Nuclear Information System (INIS)

Deconinck, Wouter

2008-07-01

One of the interesting questions of Quantum Chromodynamics, the theory that governs the interactions between quarks and gluons, has been whether it is possible to observe hadrons which can not be explained as a combination of only two or three valence quarks. In numerous searches the existence of these exotic hadrons could not be confirmed. Recently, calculations based on the quark soliton model predicted the narrow exotic baryons Θ + and Ξ -- . A narrow resonance identified as the Θ + was observed by several experiments at the predicted mass of 1540 MeV, but later followed by several dedicated experiments that could not confirm these positive results. At the HERMES experiment a search for the quasi-real photoproduction of the exotic baryon Θ + on a deuterium target and the subsequent decay through pK 0 S → pπ + π - revealed a narrow resonance in the pK 0 S invariant mass distribution at 1528 MeV. In the search for the corresponding antiparticle Ξ -- the result is consistent with zero events. In this thesis we present the search for the exotic baryon Ξ -- on a deuterium target in the data sample used for the observation of the Θ + . An upper limit on the cross section of the exotic baryon Ξ -- is determined. The search for the exotic baryon Θ + on hydrogen and deuterium targets at the HERMES experiment is extensively discussed. The event mixing method can be used to estimate the distribution of background events. Several difficulties with this method were addressed, but the background description in the case of the exotic baryon Θ + remains unconvincing. Between the years 2002 and 2005 the HERMES experiment operated with a magnetic holding field around the hydrogen target. A method for the reconstruction of displaced vertices in this field was developed. The data collected during the years 2006 and 2007 offer an integrated luminosity that is several times higher than in previous data sets. After investigating all data sets collected with the HERMES

Magnetic moments of the nucleon octet in a relativistic quark model with chiral symmetry

International Nuclear Information System (INIS)

Barik, N.; Dash, B.K.

1986-01-01

Incorporating the lowest-order pionic correction, the magnetic moments of the nucleon octet have been calculated in a chiral potential model. The potential, representing phenomenologically the nonperturbative gluon interactions including gluon self-couplings, is chosen with equally mixed scalar and vector parts in harmonic form. The results are in reasonable agreement with experiment

Realizing high magnetic moments in fcc Fe nanoparticles through atomic structure stretch

International Nuclear Information System (INIS)

Baker, S H; Roy, M; Thornton, S C; Binns, C

2012-01-01

We describe the realization of a high moment state in fcc Fe nanoparticles through a controlled change in their atomic structure. Embedding Fe nanoparticles in a Cu 1-x Au x matrix causes their atomic structure to switch from bcc to fcc. Extended x-ray absorption fine structure (EXAFS) measurements show that the structure in both the matrix and the Fe nanoparticles expands as the amount of Au in the matrix is increased, with the data indicating a tetragonal stretch in the Fe nanoparticles. The samples were prepared directly from the gas phase by co-deposition, using a gas aggregation source and MBE-type sources respectively for the nanoparticle and matrix materials. The structure change in the Fe nanoparticles is accompanied by a sharp increase in atomic magnetic moment, ultimately to values of ∼2.5 ± 0.3 μ B /atom. (paper)

Chiral Magnetic Spirals

International Nuclear Information System (INIS)

Basar, Goekce; Dunne, Gerald V.; Kharzeev, Dmitri E.

2010-01-01

We argue that the presence of a very strong magnetic field in the chirally broken phase induces inhomogeneous expectation values, of a spiral nature along the magnetic field axis, for the currents of charge and chirality, when there is finite baryon density or an imbalance between left and right chiralities. This 'chiral magnetic spiral' is a gapless excitation transporting the currents of (i) charge (at finite chirality), and (ii) chirality (at finite baryon density) along the direction of the magnetic field. In both cases it also induces in the transverse directions oscillating currents of charge and chirality. In heavy ion collisions, the chiral magnetic spiral possibly provides contributions both to the out-of-plane and the in-plane dynamical charge fluctuations recently observed at BNL RHIC.

Magnetized color flavor locked state and compact stars

CERN Document Server

Felipe, R Gonzalez; Martinez, A Perez

2010-01-01

The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model, taking into account the variation of the strange quark mass, the baryon density, the magnetic field, as well as the bag and gap parameters. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized color flavor locked matter is more stable and could become the ground state inside neutron stars. The mass-radius relation for such stars is also studied.

Corrections for a constant radial magnetic field in the muon g - 2 and electric-dipole-moment experiments in storage rings

Energy Technology Data Exchange (ETDEWEB)

Silenko, Alexander J. [Belarusian State University, Research Institute for Nuclear Problems, Minsk (Belarus); Joint Institute for Nuclear Research, Bogoliubov Laboratory of Theoretical Physics, Dubna (Russian Federation)

2017-10-15

We calculate the corrections for constant radial magnetic field in muon g - 2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of g - 2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab. (orig.)

CEBAF/SURA [Continuous Electron Beam Accelerator Facility]/[Southeastern Universities Research Association] 1987 summer workshop

International Nuclear Information System (INIS)

Gross, F.; Williamson, C.

1987-10-01

This report contains papers from the CEBAF accelerator facility summer workshop. Some topics covered are: baryon-baryon interactions, deuteron form factors; neutron detection; high resolution spectrometers; nuclear strangeness; parity violation; photon-deuteron interactions; chemical reactions in ion sources; quantum chromodynamics; hypernuclear magnetic moments; and photoproduction of π + from 14 N

The QED vacuum polarization function at four loops and the anomalous magnetic moment at five loops

International Nuclear Information System (INIS)

Baikov, P.

2013-07-01

The anomalous moment of the muon is one of the most fundamental observables. It has been measured experimentally with a very high precision and on theory side the contributions from perturbative QED have been calculated up to five-loop level by numerical methods. Contributions to the muon anomalous magnetic moment from certain diagram classes are also accessible by alternative methods. In this paper we present the evaluation of contributions to the QCD corrections due to insertions of the vacuum polarization function at five-loop level.

The QED vacuum polarization function at four loops and the anomalous magnetic moment at five loops

Energy Technology Data Exchange (ETDEWEB)

Baikov, P. [Moscow State Univ. (Russian Federation). D.V. Skobeltsyn Inst. of Nuclear Physics; Maier, A. [Technische Univ. Muenchen, Garching (Germany). Physics Dept. T31; Marquard, P. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2013-07-15

The anomalous moment of the muon is one of the most fundamental observables. It has been measured experimentally with a very high precision and on theory side the contributions from perturbative QED have been calculated up to five-loop level by numerical methods. Contributions to the muon anomalous magnetic moment from certain diagram classes are also accessible by alternative methods. In this paper we present the evaluation of contributions to the QCD corrections due to insertions of the vacuum polarization function at five-loop level.

Electric form factors of the octet baryons from lattice QCD and chiral extrapolation

International Nuclear Information System (INIS)

Shanahan, P.E.; Thomas, A.W.; Young, R.D.; Zanotti, J.M.; Pleiter, D.; Stueben, H.

2014-03-01

We apply a formalism inspired by heavy baryon chiral perturbation theory with finite-range regularization to dynamical 2+1-flavor CSSM/QCDSF/UKQCD Collaboration lattice QCD simulation results for the electric form factors of the octet baryons. The electric form factor of each octet baryon is extrapolated to the physical pseudoscalar masses, after finite-volume corrections have been applied, at six fixed values of Q 2 in the range 0.2-1.3 GeV 2 . The extrapolated lattice results accurately reproduce the experimental form factors of the nucleon at the physical point, indicating that omitted disconnected quark loop contributions are small. Furthermore, using the results of a recent lattice study of the magnetic form factors, we determine the ratio μ p G E p /G M p . This quantity decreases with Q 2 in a way qualitatively consistent with recent experimental results.

Baryonic matter and beyond

OpenAIRE

Fukushima, Kenji

2014-01-01

We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.

Three-generation study of neutrino spin-flavor conversion in supernovae and implication for the neutrino magnetic moment

Science.gov (United States)

Ando, Shin'ichiro; Sato, Katsuhiko

2003-01-01

We investigate resonant spin-flavor (RSF) conversions of supernova neutrinos which are induced by the interaction of neutrino magnetic moment and supernova magnetic fields. From the formulation which includes all three-flavor neutrinos and antineutrinos, we give a new crossing diagram that includes not only ordinary Mikheyev-Smirnov-Wolfenstein (MSW) resonance but also a magnetically induced RSF effect. With the diagram, it is found that four conversions occur in supernovae: two are induced by the RSF effect and two by the pure MSW effect. We also numerically calculate neutrino conversions in supernova matter, using neutrino mixing parameters inferred from recent experimental results and a realistic supernova progenitor model. The results indicate that until 0.5 sec after the core bounce, the RSF-induced ν¯e↔ντ transition occurs efficiently (adiabatic resonance), when μν≳10- 12μB(B0/5×109 G)-1, where B0 is the strength of the magnetic field at the surface of iron core. We also evaluate the energy spectrum as a function of μνB0 at the super-Kamiokande detector and the Sudbury Neutrino Observatory using the calculated conversion probabilities, and find that the spectral deformation might have the possibility to provide useful information on the neutrino magnetic moment as well as the magnetic field strength in supernovae.

Baryon-baryon bound states from first principles in 3+1 lattice QCD with two flavors and strong coupling

International Nuclear Information System (INIS)

Faria da Veiga, Paulo A.; O'Carroll, Michael

2006-01-01

We determine baryon-baryon bound states in (3+1)-dimensional SU(3) lattice QCD with two flavors, 4x4 spin matrices, and in an imaginary time formulation. For small hopping parameter κ>0 and large glueball mass (strong coupling), we show the existence of three-quark isospin 1/2 particles (proton and neutron) and isospin 3/2 baryons (delta particles), with asymptotic masses -3lnκ and isolated dispersion curves. Baryon-baryon bound states of isospin zero are found with binding energy of order κ 2 , using a ladder approximation to a lattice Bethe-Salpeter equation. The dominant baryon-baryon interaction is an energy-independent spatial range-one attractive potential with an O(κ 2 ) strength. There is also attraction arising from gauge field correlations associated with six overlapping bonds, but it is counterbalanced by Pauli repulsion to give a vanishing zero-range potential. The overall range-one potential results from a quark, antiquark exchange with no meson exchange interpretation; the repulsive or attractive nature of the interaction depends on the isospin and spin of the two-baryon state

Corrections for a constant radial magnetic field in the muon \\varvec{g}-2 and electric-dipole-moment experiments in storage rings

Science.gov (United States)

Silenko, Alexander J.

2017-10-01

We calculate the corrections for constant radial magnetic field in muon {g}-2 and electric-dipole-moment experiments in storage rings. While the correction is negligible for the current generation of {g}-2 experiments, it affects the upcoming muon electric-dipole-moment experiment at Fermilab.

Dynamic stabilization of the magnetic field surrounding the neutron electric dipole moment spectrometer at the Paul Scherrer Institute

Energy Technology Data Exchange (ETDEWEB)

Afach, S.; Fertl, M.; Franke, B., E-mail: beatrice.franke@psi.ch, E-mail: bernhard.lauss@psi.ch; Kirch, K. [Paul Scherrer Institute, Villigen (Switzerland); Institute for Particle Physics, Eidgenössische Technische Hochschule, Zürich (Switzerland); Bison, G.; Burri, F.; Chowdhuri, Z.; Daum, M.; Henneck, R.; Lauss, B., E-mail: beatrice.franke@psi.ch, E-mail: bernhard.lauss@psi.ch; Meier, M.; Schmidt-Wellenburg, P.; Zsigmond, G. [Paul Scherrer Institute, Villigen (Switzerland); Bodek, K.; Zejma, J. [Jagellonian University, Cracow (Poland); Grujic, Z.; Kasprzak, M.; Weis, A. [University of Fribourg (Switzerland); Hélaine, V. [Laboratoire de Physique Corpusculaire, Caen (France); Paul Scherrer Institute, Villigen (Switzerland); Koch, H.-C. [Institut für Physik, Johannes-Gutenberg-Universität, Mainz (Germany); University of Fribourg (Switzerland); and others

2014-08-28

The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5 m × 2.5 m × 3 m, disturbances of the magnetic field are attenuated by factors of 5–50 at a bandwidth from 10{sup −3} Hz up to 0.5 Hz, which corresponds to integration times longer than several hundreds of seconds and represent the important timescale for the neutron electric dipole moment measurement. These shielding factors apply to random environmental noise from arbitrary sources. This is achieved via a proportional-integral feedback stabilization system that includes a regularized pseudoinverse matrix of proportionality factors which correlates magnetic field changes at all sensor positions to current changes in the SFC coils.

Weak electric and magnetic form factors for semileptonic baryon decays in an independent-quark model

International Nuclear Information System (INIS)

Barik, N.; Dash, B.K.; Das, M.

1985-01-01

Weak electric and magnetic form factors for semileptonic baryon decays are calculated in a relativistic quark model based on the Dirac equation with the independent-quark confining potential of the form (1+γ 0 )V(r). The values obtained for (g 2 /g 1 ), for various decay modes in a model with V(r) = a'r 2 , are roughly of the same order as those predicted in the MIT bag model. However in a similar model with V(r) = (a/sup nu+1/r/sup ν/+V 0 ), the (g 2 /g 1 ) values agree with the nonrelativistic results of Donoghue and Holstein. Incorporating phenomenologically the effect of nonzero g 2 in the ratio (g 1 /f 1 ), we have estimated the values for (f 2 /f 1 ) for various semileptonic transitions. It is observed that SU(3)-symmetry breaking does not generate significant departures in (f 2 /f 1 ) values from the corresponding Cabibbo values

Determination of baryon-baryon elastic scattering phase shift from finite volume spectra in elongated boxes

Science.gov (United States)

Li, Ning; Wu, Ya-Jie; Liu, Zhan-Wei

2018-01-01

The relations between the baryon-baryon elastic scattering phase shifts and the two-particle energy spectrum in the elongated box are established. We studied the cases with both the periodic boundary condition and twisted boundary condition in the center of mass frame. The framework is also extended to the system of nonzero total momentum with periodic boundary condition in the moving frame. Moreover, we discussed the sensitivity functions σ (q ) that represent the sensitivity of higher scattering phases. Our analytical results will be helpful to extract the baryon-baryon elastic scattering phase shifts in the continuum from lattice QCD data by using elongated boxes.

Compressed baryonic matter experiment at FAIR

Directory of Open Access Journals (Sweden)

Jürgen Eschke

2012-02-01

Full Text Available The Compressed Baryonic Matter (CBM experiment is being planned at the Facility for Antiproton and Ion Research (FAIR, under realization next to the GSI laboratory in Darmstadt, Germany. Its physics programme addresses the QCD phase diagram in the region of highest net baryon densities. Of particular interest are the expected first order phase transition from partonic to hadronic matter, ending in a critical point, and modifcations of hadron properties in the dense medium as a signal of chiral symmetry restoration. Laid out as a fixed-target experiment at the synchrotrons SIS-100/SIS-300, providing magnetic bending power of 100 and 300 T/Fm, the CBM detector will record both proton-nucleus and nucleus-nucleus collisions at beam energies up to 45 AGeV. Hadronic, leptonic and photonic observables will be measured in a large acceptance. The nuclear interaction rates will reach up to 10 MHz to measure extremely rare probes like charm near threshold. This requires the development of novel detector systems, trigger and data acquisition concepts as well as in- novative real-time reconstruction techniques. A key observable of the physics program is a precise measurement of lowmass vector mesons and charmonium in their leptonic decay channel. In CBM, electrons will be identified using a gaseous RICH detector combined with several TRD detectors positioned after a system of silicon tracking stations which are located inside a magnetic dipole field. The concept of the RICH detector, results on R & D as well as feasibility studies and invariant mass distributions of charmonium will be discussed.

Higher-order hadronic and heavy-lepton contributions to the anomalous magnetic moment

International Nuclear Information System (INIS)

Kurz, Alexander; Liu, Tao; Steinhauser, Matthias

2014-07-01

We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result, a μ had,NNLO = 1.24 ± 0.01 x 10 -10 , is of the same order of magnitude as the current uncertainty from the hadronic contributions. For heavy-lepton corrections, analytical results are obtained at four-loop order and compared with the known results.

Density-dependent effective baryon–baryon interaction from chiral three-baryon forces

Energy Technology Data Exchange (ETDEWEB)

Petschauer, Stefan, E-mail: stefan.petschauer@ph.tum.de [Physik Department, Technische Universität München, D-85747 Garching (Germany); Haidenbauer, Johann [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Kaiser, Norbert [Physik Department, Technische Universität München, D-85747 Garching (Germany); Meißner, Ulf-G. [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, D-53115 Bonn (Germany); Bethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn (Germany); Weise, Wolfram [Physik Department, Technische Universität München, D-85747 Garching (Germany)

2017-01-15

A density-dependent effective potential for the baryon–baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon–nucleon interaction. Explicit expressions for the ΛN in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the three-body force in symmetric nuclear matter and pure neutron matter on the ΛN interaction. A moderate repulsion that increases with density is found in comparison to the free ΛN interaction.

Flavour and spin structure of linear baryons

International Nuclear Information System (INIS)

Kawarabayashi, K.; Kitakado, S.; Inami, T.

1979-01-01

Based on the string picture, a phenomenological model for baryons is constructed and their flavour symmetry, exchange degeneracy pattern and spin structure are studied. Baryons on leading trajectories are assumed to have the configuration of two quarks being attached to the ends of a linear string and the third sitting in the middle, called linear baryons. For such linear baryons, a unitarization scheme can be constructed in a manner similar to the dual unitarity scheme for mesons but without recourse to the 1/N expansion. It is found that the interchange interaction of the middle quark with one of the other two quarks at the ends of the string can give rise to a larger exchange degeneracy breaking of the baryon spectrum. With this non-planar correction, the model of linear baryons can account for the observed pattern of leading baryon states. (Auth.)

Electric form factors of the octet baryons from lattice QCD and chiral extrapolation

Energy Technology Data Exchange (ETDEWEB)

Shanahan, P.E.; Thomas, A.W.; Young, R.D.; Zanotti, J.M. [Adelaide Univ., SA (Australia). ARC Centre of Excellence in Particle Physics at the Terascale and CSSM; Horsley, R. [Edinburgh Univ. (United Kingdom). School of Physics and Astronomy; Nakamura, Y. [RIKEN Advanced Institute for Computational Science, Kobe, Hyogo (Japan); Pleiter, D. [Forschungszentrum Juelich (Germany). JSC; Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Stueben, H. [Hamburg Univ. (Germany). Regionales Rechenzentrum; Collaboration: CSSM and QCDSF/UKQCD Collaborations

2014-03-15

We apply a formalism inspired by heavy baryon chiral perturbation theory with finite-range regularization to dynamical 2+1-flavor CSSM/QCDSF/UKQCD Collaboration lattice QCD simulation results for the electric form factors of the octet baryons. The electric form factor of each octet baryon is extrapolated to the physical pseudoscalar masses, after finite-volume corrections have been applied, at six fixed values of Q{sup 2} in the range 0.2-1.3 GeV{sup 2}. The extrapolated lattice results accurately reproduce the experimental form factors of the nucleon at the physical point, indicating that omitted disconnected quark loop contributions are small. Furthermore, using the results of a recent lattice study of the magnetic form factors, we determine the ratio μ{sub p}G{sub E}{sup p}/G{sub M}{sup p}. This quantity decreases with Q{sup 2} in a way qualitatively consistent with recent experimental results.

Production of charmed mesons and charmed baryons at the ISR

International Nuclear Information System (INIS)

Geist, W.M.

1980-01-01

Although many experiments were dedicated to charm search in hadronic interactions no significant signals were found until recently. This is why no consistent picture for charmed particle production could be extracted from the data so far. After the first observation of D + production by the CCHK-Collaboration, the obvious aim is to learn more details about the dominant production mechanisms of this new flavour. The observation of charmed baryon production at the ISR by the CCHK and two other collarborations constitutes another major step forward in this field. Here, the two experiments performed by CCHK with the Split Field Magnet (SFM) will be described, in which charmed meson production and charmed (anti)-baryon production were observed. Cross sections will be presented and consequences of the results will be discussed

On a Neutral Particle with a Magnetic Quadrupole Moment in a Uniform Effective Magnetic Field

International Nuclear Information System (INIS)

Fonseca, I. C.; Bakke, K.

2016-01-01

Quantum effects on a Landau-type system associated with a moving atom with a magnetic quadrupole moment subject to confining potentials are analysed. It is shown that the spectrum of energy of the Landau-type system can be modified, where the degeneracy of the energy levels can be broken. In three particular cases, it is shown that the analogue of the cyclotron frequency is modified, and the possible values of this angular frequency of the system are determined by the quantum numbers associated with the radial modes and the angular momentum and by the parameters associated with confining potentials in order that bound states solutions can be achieved.

The search for exotic baryons at the HERMES experiment

Energy Technology Data Exchange (ETDEWEB)

Deconinck, Wouter

2008-07-15

One of the interesting questions of Quantum Chromodynamics, the theory that governs the interactions between quarks and gluons, has been whether it is possible to observe hadrons which can not be explained as a combination of only two or three valence quarks. In numerous searches the existence of these exotic hadrons could not be confirmed. Recently, calculations based on the quark soliton model predicted the narrow exotic baryons {theta}{sup +} and {xi}{sup --}. A narrow resonance identified as the {theta}{sup +} was observed by several experiments at the predicted mass of 1540 MeV, but later followed by several dedicated experiments that could not confirm these positive results. At the HERMES experiment a search for the quasi-real photoproduction of the exotic baryon {theta}{sup +} on a deuterium target and the subsequent decay through pK{sup 0}{sub S} {yields} p{pi}{sup +}{pi}{sup -} revealed a narrow resonance in the pK{sup 0}{sub S} invariant mass distribution at 1528 MeV. In the search for the corresponding antiparticle {xi}{sup --} the result is consistent with zero events. In this thesis we present the search for the exotic baryon {xi}{sup --} on a deuterium target in the data sample used for the observation of the {theta}{sup +}. An upper limit on the cross section of the exotic baryon {xi}{sup --} is determined. The search for the exotic baryon {theta}{sup +} on hydrogen and deuterium targets at the HERMES experiment is extensively discussed. The event mixing method can be used to estimate the distribution of background events. Several difficulties with this method were addressed, but the background description in the case of the exotic baryon {theta}{sup +} remains unconvincing. Between the years 2002 and 2005 the HERMES experiment operated with a magnetic holding field around the hydrogen target. A method for the reconstruction of displaced vertices in this field was developed. The data collected during the years 2006 and 2007 offer an integrated

B decays to baryons

Indian Academy of Sciences (India)

We note that two-body decays to baryons are suppressed relative to three- and four-body decays. In most of these analyses, the invariant baryon–antibaryon mass shows an enhancement near the threshold. We propose a phenomenological interpretation of this quite common feature of hadronization to baryons.

Study of rare earth local moment magnetism and strongly correlated phenomena in various crystal structures

Energy Technology Data Exchange (ETDEWEB)

Kong, Tai [Iowa State Univ., Ames, IA (United States)

2016-12-17

Benefiting from unique properties of 4f electrons, rare earth based compounds are known for offering a versatile playground for condensed matter physics research as well as industrial applications. This thesis focuses on three specific examples that further explore the rare earth local moment magnetism and strongly correlated phenomena in various crystal structures.

Dynamics of a magnetic monopole in matter, Maxwell equations in dyonic matter and detection of electric dipole moments

International Nuclear Information System (INIS)

Artru, X.; Fayolle, D.

2001-01-01

For a monopole, the analogue of the Lorentz equation in matter is shown to be f = g (H-v centre dot D). Dual-symmetric Maxwell equations, for matter containing hidden magnetic charge in addition to electric ones, are given. They apply as well to ordinary matter if the particles possess T-violating electric dipole moments. Two schemes of experiments for the detection of such moments in macroscopic pieces of matter are proposed

Proximity effects on the local magnetic moments of clusters V{sub 6}-V{sub 9} embedded in a Fe matrix

Energy Technology Data Exchange (ETDEWEB)

Sosa-Hernandez, E.M. [Departamento de Matematicas Aplicadas, Facultad de Contaduria y Administration, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, 78000 San Luis Potosi, S.L.P. (Mexico); Alvarado-Leyva, P.G. [Departamento de Fisica, Facultad de Ciencias, Universidad Autonoma de San Luis Potosi Alvaro Obregon 64, 78000 San Luis Potosi, S.L.P. (Mexico)]. E-mail: pal@galia.fc.uaslp.mx

2006-11-09

The magnetic behavior of clusters V{sub 6}-V{sub 9} in bulk Fe is determined by using an electronic Hamiltonian which includes s, p and d electrons. The spin density distribution is calculated self-consistenly in the unrestricted Hartree-Fock approximation. The local magnetic moments are obtained at V and Fe atoms; the magnetic coupling between Fe and V atoms is antiferromagnetic-like. We consider two cases, the first case correspond to non-interacting clusters, the distance between them is infinity, and the another case, when the clusters are interacting, the separation between them is finite; in the first case, the magnetic order in V{sub 6} is ferromagnetic-like whereas for V{sub 9} the magnetic order is antiferromagnetic-like, in the second case we have found that the magnetic order is not well stablished in V{sub 6}. We have found that the magnetic order in the matrix is not broken by the presence of the V atoms, although the local magnetic moments of Fe atoms at the interface cluster-matrix, are reduced respect to Fe bulk magnetization (2.22{mu} {sub B}) [e.g. {mu} {sub Fe}(5) = 1.98{mu} {sub B} in V{sub 6}; {mu} {sub Fe}(3) 1.89{mu} {sub B} in V{sub 9}].

Quark color-hyperfine interactions in baryons

International Nuclear Information System (INIS)

Anselmino, M.; Lichtenberg, D.B.

1990-01-01

We consider the contribution from the color-hyperfine interaction to the energies of groundstate hadrons, with an emphasis on baryons. We use experimental information about how the color-hyperfine term depends on flavor to make predictions about the masses of baryons containing a heavy quark. We then generalize some relations between color-hyperfine matrix elements in mesons and baryons to obtain a number of additional predictions about the masses of as-yet unobserved baryons. Most of our predictions are in the form of inequalities. (orig.)

Limit on the muon neutrino magnetic moment and a measurement of the CCPIP to CCQE cross section ratio

Energy Technology Data Exchange (ETDEWEB)

Ouedraogo, Serge Aristide [Louisiana State Univ., Baton Rouge, LA (United States)

2008-12-01

A search for the muon neutrino magnetic moment was conducted using the Mini-BooNE low energy neutrino data. The analysis was performed by analyzing the elastic scattering interactions of muon neutrinos on electrons. The analysis looked for an excess of elastic scattering events above the Standard Model prediction from which a limit on the neutrino magnetic could be set. In this thesis, we report an excess of 15.3 ± 6.6(stat)±4.1(syst) v_μe events above the expected background. At 90% C.L., we derived a limit on the muon neutrino magnetic moment of 12.7 x 10^-10 μ_B. The other analysis reported in this thesis is a measurement of charged current single pion production (CCπ⁺) to charged current quasi elastic (CCQE) interactions cross sections ratio. This measurement was performed with two different fitting algorithms and the results from both fitters are consistent with each other.

Meson-baryon-baryon vertex function and the Ward-Takahashi identity

International Nuclear Information System (INIS)

Wang, S.; Banerjee, M.K.

1996-01-01

Ohta proposed a solution for the well-known difficulty of satisfying the Ward-Takahashi identity for a photo-meson-baryon-baryon amplitude (γMBB) when a dressed meson-baryon-baryon (MBB) vertex function is present. He obtained a form for the γMBB amplitude which contained, in addition to the usual pole terms, longitudinal seagull terms which were determined entirely by the MBB vertex function. He arrived at his result by using a Lagrangian which yields the MBB vertex function at tree level. We show that such a Lagrangian can be neither Hermitian nor charge conjugation invariant. We have been able to reproduce Ohta close-quote s result for the γMBB amplitude using the Ward-Takahashi identity and no other assumption, dynamical or otherwise, and the most general form for the MBB and γMBB vertices. However, contrary to Ohta close-quote s finding, we find that the seagull terms are not robust. The seagull terms extracted from the γMBB vertex occur unchanged in tree graphs, such as in an exchange current amplitude. But the seagull terms which appear in a loop graph, as in the calculation of an electromagnetic form factor, are, in general, different. The whole procedure says nothing about the transverse part of the (γMBB) vertex and its contributions to the amplitudes in question. copyright 1996 The American Physical Society

Spins, charge radii and magnetic moments of neutron-rich Mn isotopes measured with bunched beam Collinear Laser Spectroscopy

CERN Document Server

AUTHOR|(CDS)2085887; Heylen, Hanne

In this work, the odd-even $^{51–63}$Mn isotopes have been analyzed using collinear laser spectroscopy, from which the magnetic dipole moment and the change in change in mean square charge radius can be determined. The magnetic moment is very sensitive to the composition of the total nuclear wave function, while the charge radius gives information about the relative size and degree of deformation of the nucleus. An additional advantage of collinear laser spectroscopy is the possibility of direct measurement of the nuclear spin. The main motivation behind the study of these isotopes is to investigate the change in nuclear structure when approaching neutron number N = 40. This region is of interest due to the apparent doubly magic nature of $^{68}$Ni , which is not seen in the N = 40 isotopes of $^{26}$Fe and $^{24}$Cr. Mn, situated between these elements, offers another perspective due to its uncoupled proton. Based on the observed spectra and extracted moments, spins were assigned to $^{59,61,63}$Mn. The ex...

Outlook for baryon spectroscopy

International Nuclear Information System (INIS)

Tripp, R.D.

1976-09-01

The review of baryon spectroscopy includes a number of new generation experiments with greatly improved statistics which have emerged and are enhancing experimental knowledge of baryon resonances. The future research directions are pointed out, and some problems and deficiencies which can be resolved with contemporary techniques are mentioned

Theoretical high energy physics research at the University of Chicago. Technical progress report

International Nuclear Information System (INIS)

Rosner, J.L.

1984-01-01

Research activities are briefly reported in the aras of quarkonium physics, e +- annihilations, neutral heavy leptons, magnetic monopoles, heavy vector bosons beyond the W and Z, supersymmetry, branching ratios in proton decay, and baryon magnetic moments publications are listed. 26 references

Fullerene/layered antiferromagnetic reconstructed spinterface: Subsurface layer dominates molecular orbitals' spin-split and large induced magnetic moment

Science.gov (United States)

Shao, Yangfan; Pang, Rui; Pan, Hui; Shi, Xingqiang

2018-03-01

The interfaces between organic molecules and magnetic metals have gained increasing interest for both fundamental reasons and applications. Among them, the C60/layered antiferromagnetic (AFM) interfaces have been studied only for C60 bonded to the outermost ferromagnetic layer [S. L. Kawahara et al., Nano Lett. 12, 4558 (2012) and D. Li et al., Phys. Rev. B 93, 085425 (2016)]. Here, via density functional theory calculations combined with evidence from the literature, we demonstrate that C60 adsorption can reconstruct the layered-AFM Cr(001) surface at elevated annealing temperatures so that C60 bonds to both the outermost and the subsurface Cr layers in opposite spin directions. Surface reconstruction drastically changes the adsorbed molecule spintronic properties: (1) the spin-split p-d hybridization involves multi-orbitals of C60 and top two layers of Cr with opposite spin-polarization, (2) the subsurface Cr atom dominates the C60 electronic properties, and (3) the reconstruction induces a large magnetic moment of 0.58 μB in C60 as a synergistic effect of the top two Cr layers. The induced magnetic moment in C60 can be explained by the magnetic direct-exchange mechanism, which can be generalized to other C60/magnetic metal systems. Understanding these complex hybridization behaviors is a crucial step for molecular spintronic applications.

Baryon number violation and string topologies

International Nuclear Information System (INIS)

Sjoestrand, T.; Skands, P.Z.

2003-01-01

In supersymmetric scenarios with broken R-parity, baryon number violating sparticle decays become possible. In order to search for such decays, a good understanding of expected event properties is essential. We here develop a complete framework that allows detailed studies. Special attention is given to the hadronization phase, wherein the baryon number violating vertex is associated with the appearance of a junction in the colour confinement field. This allows us to tell where to look for the extra (anti)baryon directly associated with the baryon number violating decay

Reinterpretation of the ''relativistic mass'' correction to the spin magnetic moment of a moving particle

International Nuclear Information System (INIS)

Hegstrom, R.A.; Lhuillier, C.

1977-01-01

Starting from a classical covariant equation of motion for the spin of a particle moving in a homogeneous electromagnetic field (the Bargmann-Michel-Telegdi equation), we show that the ''relativistic mass'' correction to the electron spin magnetic moment, which has been obtained previously from relativistic quantum-mechanical treatments of the Zeeman effect, may be reinterpreted as the combination of three classical effects: (i) the difference in time scales in the electron rest frame vis-a-vis the lab frame, (ii) the Lorentz transformation of the magnetic field between the two frames, and (iii) the Thomas precession of the electron spin due to the acceleration of the electron produced by the magnetic field

Diquark structure of baryons

International Nuclear Information System (INIS)

Silvestre-Brac, B.

1987-01-01

Three body calculations for studying the baryons are performed in a non-relativistic treatment with three quarks interacting via Bhaduri's potential. From the resulting wave functions, it is analysed under which conditions can a diquark structure occurs. Several photos showing quark distributions inside the baryons are presented and discussed in details

Relativistic energy correction of the hydrogen atom with an anomalous magnetic moment

International Nuclear Information System (INIS)

Ambogo, David Otieno

2015-07-01

The electron is known to possess an anomalous magnetic moment, which interacts with the gradient of the electric field. This makes it necessary to compute its effects on the energy spectrum. Even though the Coulomb Dirac equation can be solved in closed form, this is no longer possible when the anomalous magnetic moment is included. In fact the interaction due to this term is so strong that it changes the domain of the Hamiltonian. From a differential equation point of view, the anomalous magnetic moment term is strongly singular near the origin. As usual, one has to resort to perturbation theory. This, however, only makes sense if the eigenvalues are stable. To prove stability is therefore a challenge one has to face before actually computing the energy shifts. The first stability results in this line were shown by Behncke for angular momenta κ≥3, because the eigenfunctions of the unperturbed Hamiltonian decay fast enough near the origin. He achieved this by decoupling the system and then using the techniques available for second order differential equations. Later, Kalf and Schmidt extended Behncke's results basing their analysis on the Pruefer angle technique and a comparison result for first order differential equations. The Pruefer angle method is particularly useful because it shows a better stability and because it obeys a first order differential equation. Nonetheless, Kalf and Schmidt had to exclude some coupling constants for κ>0. This I believe is an artefact of their method. In this study, I make increasing use of asymptotic integration, a method which is rather well adapted to perturbation theory and is known to give stability results to any level of accuracy. Together with the Pruefer angle technique, this lead to a more general stability result and even allows for an energy shifts estimate. Hamiltonians traditionally treated in physics to describe the spin-orbit effect are not self adjoint i.e. they are not proper observables in quantum

Relativistic energy correction of the hydrogen atom with an anomalous magnetic moment

Energy Technology Data Exchange (ETDEWEB)

Ambogo, David Otieno

2015-07-15

The electron is known to possess an anomalous magnetic moment, which interacts with the gradient of the electric field. This makes it necessary to compute its effects on the energy spectrum. Even though the Coulomb Dirac equation can be solved in closed form, this is no longer possible when the anomalous magnetic moment is included. In fact the interaction due to this term is so strong that it changes the domain of the Hamiltonian. From a differential equation point of view, the anomalous magnetic moment term is strongly singular near the origin. As usual, one has to resort to perturbation theory. This, however, only makes sense if the eigenvalues are stable. To prove stability is therefore a challenge one has to face before actually computing the energy shifts. The first stability results in this line were shown by Behncke for angular momenta κ≥3, because the eigenfunctions of the unperturbed Hamiltonian decay fast enough near the origin. He achieved this by decoupling the system and then using the techniques available for second order differential equations. Later, Kalf and Schmidt extended Behncke's results basing their analysis on the Pruefer angle technique and a comparison result for first order differential equations. The Pruefer angle method is particularly useful because it shows a better stability and because it obeys a first order differential equation. Nonetheless, Kalf and Schmidt had to exclude some coupling constants for κ>0. This I believe is an artefact of their method. In this study, I make increasing use of asymptotic integration, a method which is rather well adapted to perturbation theory and is known to give stability results to any level of accuracy. Together with the Pruefer angle technique, this lead to a more general stability result and even allows for an energy shifts estimate. Hamiltonians traditionally treated in physics to describe the spin-orbit effect are not self adjoint i.e. they are not proper observables in quantum

Self-energies of octet and decuplet baryons due to the coupling to the baryon-meson continuum

Energy Technology Data Exchange (ETDEWEB)

Garcia-Tecocoatzi, H. [INFN, Sezione di Genova, Genova (Italy); Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Mexico (Mexico); Bijker, R. [Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Mexico (Mexico); Ferretti, J. [Chinese Academy of Sciences, Institute of Theoretical Physics, Beijing (China); Dipartimento di Fisica, Universita di Roma Sapienza, Roma (Italy); INFN, Roma (Italy); Santopinto, E. [INFN, Sezione di Genova, Genova (Italy)

2017-06-15

We present an unquenched quark model calculation of the mass shifts of ground-state octet and decuplet baryons due to the coupling to the meson-baryon continuum. All ground-state baryons and pseudoscalar mesons are included in our calculation as intermediate states. The q anti q pair creation effects are taken explicitly into account through a microscopic, QCD-inspired, quark-antiquark pair creation mechanism. (orig.)

Search for diquark clustering in baryons

International Nuclear Information System (INIS)

Fleck, S.; Silvestre-Brac, B.; Richard, J.M.

1988-03-01

In the framework of the non-relativistic quark model, we examine to which extent baryons consist of a quark bound to a localized cluster of two quarks simulating a diquark. We consider ground states and orbital excitations for various flavour combinations. A striking clustering shows up sometimes especially for the leading Regge trajectory of the nucleon and single flavoured baryons or for the ground state of baryons bearing two heavy flavours. This is, however, far from being a general pattern and there are clear differences between the three-quark description of baryons and the quark-diquark model

Dynamics of magnetic moments in high-Tc superconductors. Final report

International Nuclear Information System (INIS)

Holland-Moritz, E.; Jostarndt, H.D.

1992-01-01

The central topic of this research project was the question why PrBa 2 Cu 3 O 7 does not become superconducting. For this purpose, Pr specimens were investigated as well as for comparison purposes, specimens of the neighbouring rare earth Nd, by means of inelastic magnetic neutron scattering as a function of temperature and the pulse transmission. As the reason for the suppression of superconductivity, an anomalously large hybridization of 4f electrons of Pr with the p-electrons of oxygen was observed, which causes the magnetic atomic temperatures, which are abnormally high in comparison with other rare earth 1:2:3 systems. The present it is not known whether superconductivity is suppressed spatial correlations of the magnetic 4f-moments. In addition, in this project could be proven successfully for the first time, the high-energy crystal field stimulations in PrBa 2 Cu 3 O 7 as well as in PrBa 2 Cu 3 O 6 . The temperature dependence of the quasielastic line width in NdBa 2 Cu 3 O 7-δ shows a distinctive anomaly at 100 K, which means approximately near to the superconducting transition temperature of the O 7 -systems. It is remarkable that this anomaly occurs in the non-superconducting O 6 -systems as well. This behaviour is not yet completely understood. (orig./UU) [de

Influence of magnetic moment formation on the conductance of coupled quantum wires

International Nuclear Information System (INIS)

Puller, V I; Mourokh, L G; Bird, J P; Ochiai, Y

2005-01-01

In this paper, we develop a model for the resonant interaction between a pair of coupled quantum wires, under conditions where self-consistent effects lead to the formation of a local magnetic moment in one of the wires. Our analysis is motivated by the experimental results of Morimoto et al (2003 Appl. Phys. Lett. 82 3952), who showed that the conductance of one of the quantum wires exhibits a resonant peak at low temperatures, whenever the other wire is swept into the regime where local-moment formation is expected. In order to account for these observations, we develop a theoretical model for the inter-wire interaction that calculated the transmission properties of one (the fixed) wire when the device potential is modified by the presence of an extra scattering term, arising from the presence of the local moment in the swept wire. To determine the transmission coefficients in this system, we derive equations describing the dynamics of electrons in the swept and fixed wires of the coupled-wire geometry. Our analysis clearly shows that the observation of a resonant peak in the conductance of the fixed wire is correlated to the appearance of additional structure (near 0.75 x 2e 2 /h or 0.25 x 2e 2 /h) in the conductance of the swept wire, in agreement with the experimental results of Morimoto et al

Ionospheric plasma escape by high-altitude electric fields: Magnetic moment ''pumping''

International Nuclear Information System (INIS)

Lundin, R.; Hultqvist, B.

1989-01-01

Measurements of electric fields and the composition of upward flowing ionospheric ions by the Viking spacecraft have provided further insight into the mass dependent plasma escape process taking place in the upper ionosphere. The Viking results of the temperature and mass-composition of individual ion beams suggest that upward flowing ion beams can be generated by a magnetic moment ''pumping'' mechanism caused by low-frequency transverse electric field fluctuations, in addition to a field aligned ''quasi-electrostatic'' acceleration process. Magnetic moment ''pumping'' within transverse electric field gradients can be described as a conversion of electric drift velocity to cyclotron velocity by the inertial drift in time-dependent electric field. This gives an equal cyclotron velocity gain for all plasma species, irrespective of mass. Oxygen ions thus gain 16 times as much transverse energy as protons. In addition to a transverse energy gain above the escape energy, a field-aligned quasi-electrostatic acceleration is considered primarily responsible for the collimated upward flow of ions. The field-aligned acceleration adds a constant parallel energy to escaping ionospheric ions. Thus, ion beams at high altitudes can be explained by a bimodal acceleration from both a transverse (equal velocity) and a parallel (equal energy) acceleration process. The Viking observations also show that the thermal energy of ion beams, and the ion beam width are mass dependent. The average O + /H + ''temperature ratio has been found to be 4.0 from the Viking observations. This is less than the factor of 16 anticipated from a coherent transverse electric field acceleration but greater than the factor of 1 (or even less than 1) expected from a turbulent acceleration process. copyright American Geophysical Union 1989

Baryons in the heavy quark effective theory

International Nuclear Information System (INIS)

Mannel, T.; Roberts, W.; Ryzak, Z.

1990-08-01

We show how to incorporate baryons in the heavy quark effective theory. A convenient formalism is exhibited and applied to semileptonic weak decays of heavy baryons and to exclusive production of heavy baryons in e + e - annihilation. (orig.)

Baryonic spectroscopy and its immediate future

International Nuclear Information System (INIS)

Dalitz, R.H.

1975-01-01

The quark model is reviewed briefly for baryons and the various versions of SU(6) symmetry which were proposed and used in connection with baryon spectroscopy are reviewed. A series of basic questions are reviewed which experimental work in this field should aim to settle, as a minimal program. One also heralds the beginning of a new baryon spectroscopy associated with psi physics

Are baryonic galactic halos possible

International Nuclear Information System (INIS)

Olive, K.A.; Hegyi, D.J.

1986-01-01

There is little doubt from the rotation curves of spiral galaxies that galactic halos must contain large amounts of dark matter. In this contribution, the authors review arguments which indicate that it is very unlikely that galactic halos contain substantial amounts of baryonic matter. While the authors would like to be able to present a single argument which would rule out baryonic matter, at the present time they are only able to present a collection of arguments each of which argues against one form of baryonic matter. These include: 1) snowballs; 2) gas; 3) low mass stars and Jupiters; 4) high mass stars; and 5) high metalicity objects such as rooks or dust. Black holes, which do not have a well defined baryon number, are also a possible candidate for halo matter. They briefly discuss black holes

Object representation and magnetic moments in thin alkali films

Science.gov (United States)

Garrett, Douglas C.

2008-10-01

impurities 1/taus and their magnetic cross section sigmas are calculated. We find that single V surface impurities are magnetic while single Mo and Co impurities are non-magnetic. Co surface clusters are magnetic. In chapter 7, thin films of Na, K, Rb and Cs are quench condensed, then covered with 1/100 of a mono-layer of Ti and finally covered with the original host. The magnetization of the films is measured by means of the anomalous Hall effect. An anomalous Hall resistance RAHE is observed for Ti on the surface of K, Rb and Cs and for Ti inside of Cs. Essentially the RAHE varies linearly with the magnetic field and is inversely proportional to the inverse temperature. A small non-linearity of RAHE suggests a Ti moment of about 1microB.

Baryon stopping contribution in net-proton fluctuations measured by STAR experiment

International Nuclear Information System (INIS)

Thakur, Dhananjaya; Jakhar, Sunil; Garg, Prakhar; Sahoo, Raghunath

2016-01-01

The main goal of Beam Energy Scan program by RHIC is to scan the QCD phase diagram i.e temperature (T) versus baryon chemical potential (μB) diagram for strong interaction. At large B existence of QCD critical point (CP) and a first order phase boundary between QGP and hadronic phase is expected. The non-monotonous behavior of higher moment of the distributions of conserved quantity like net-baryon number with √s_N_N are believed to be a good signature of phase transition and CP. A non-monotonous behavior of ĸσ"2 is found around √s_N_N = 19.6 GeV by STAR experiment, which hints for the possible existence of critical point around √s_N_N=19.6 GeV. The proton distributions measured by STAR experiment have the contribution from both production as well as stopping. There may be a significant contribution of stopped protons at RHIC and lower energies which also relate to the softening of the equation of state. In the present work we have estimated the contribution of stopped protons in the protons multiplicity distributions measured by STAR experiment to calculate the higher order fluctuations

Random walk of the baryon number

International Nuclear Information System (INIS)

Kazaryan, A.M.; Khlebnikov, S.Y.; Shaposhnikov, M.E.

1989-01-01

A new approach is suggested for the anomalous nonconservation of baryon number in the electroweak theory at high temperatures. Arguments are presented in support of the idea that the baryon-number changing reactions may be viewed as random Markov processes. Making use of the general theory of Markov processes, the Fokker--Planck equation for the baryon-number distribution density is obtained and kinetic coefficients are calculated

The classical equations of motion for a spinning point particle with charge and magnetic moment

International Nuclear Information System (INIS)

Rowe, E.G.P.; Rowe, G.T.

1987-01-01

The classical, special relativistic equations of motion are derived for a spinning point particle interacting with the electromagnetic field through its charge and magnetic moment. Radiation reaction is included. The energy tensors for the particle and for the field are developed as well-defined distributions; consequently no infinities appear. The magnitude of spin and the rest mass are conserved. (orig.)

Unusual magnetic properties of rare-earth titanium oxides RTiO3: effect of the rare earth on the magnetic moment of titanium in Lasub(x)Ysub(1-x)Ti03 and GdTi03

International Nuclear Information System (INIS)

Greedan, J.E.; MacLean, D.A.

1978-01-01

The rare-earth orthotitanites, RTi0 3 are a relatively new series of materials with properties which are strongly dependent on the identity of the rare-earth ion. Low-temperature magnetization studies on the system Lasub(x)Ysub(1-x)Ti0 3 and the compound GdTi0 3 indicate that the magnitude of the Ti 3+ spontaneous moment depends on the average size of the rare-earth ion and on its magnetic moment. For most of the phases studied except GdTi0 3 the Ti 3+ moment is very much smaller than the 'spin only' value and is non-integral, yet semiconducting behaviour is simultaneously observed. (author)

The Λbaryon as a probe of QCD at LEP

International Nuclear Information System (INIS)

Bruemmer, N.C.

1994-01-01

After a description of the Standard Model, its history, extensions, and the reasons are presented as to why experiments like LEP are important in the quest for the fundamental laws of nature, the models of hadronic decays of the Z 0 are described. Then the way to predict the forward-backward asymmetry and the longitudinal polarisation of the Λ baryon is developed in the context of the quark model for baryons and the JETSET Monte Carlo program. Attention is also given to the shape of the low-momentum part of the spectrum. This has been calculated in the next-to-leading-log approximation, the assuming Local Parton Hadron. Thereafter the experimental setup of the accelerator and the detector and the methods for analysing and selecting the data are briefly described. The kinematic description of Λ decays and its background from K S 0 decays are considered. Different methods to determine the forward-backward asymmetry are discussed, and a method of moments is developed. This leads to analytical expressions for the expected accuracy as a function of the number of events and the angular acceptance. It is shown that this method is equivalent to a log-likelihood method. The method for determining the backgroundd and for measuring the longitudinal Λ polarisation is developed. Finally the experimental results are compared with the theoretical expectations. The first results from the DELPHI detector are given for the forward-backward asymmetry and the longitudinal polarisation of high momentum Λ baryons. The accuracy is not yet sufficient to demonstrate a non-zero value for these quantities, but it is certainly realistic to expect a significant measurement in the near future

Achieving maximum baryon densities

International Nuclear Information System (INIS)

Gyulassy, M.

1984-01-01

In continuing work on nuclear stopping power in the energy range E/sub lab/ approx. 10 GeV/nucleon, calculations were made of the energy and baryon densities that could be achieved in uranium-uranium collisions. Results are shown. The energy density reached could exceed 2 GeV/fm 3 and baryon densities could reach as high as ten times normal nuclear densities

Baryon destruction by asymmetric dark matter

International Nuclear Information System (INIS)

Davoudiasl, Hooman; Morrissey, David E.; Tulin, Sean; Sigurdson, Kris

2011-01-01

We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause induced nucleon decay by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10 29 -10 32 yrs in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter-induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.

Baryon superfluids in AdS/CFT with flavor