I. Øverbø

Norwegian University of Science and Technology

Polarization (waves)Linear polarizationParticle physicsWave functionPhysicsGluonMagnetic monopolePhotonFlavourBound stateAtomic physicsNuclear physicsScatteringMesonAnnihilationQuantum electrodynamicsFermionBremsstrahlungNeutral currentBinding energy

16Publications

9H-index

248Citations

Publications 16

Newest

#1Asif Mushtaq (NTNU: Norwegian University of Science and Technology)H-Index: 4

#2Amna Noreen (NTNU: Norwegian University of Science and Technology)H-Index: 3

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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Abstract We investigate a method to solve a class of Schrodinger type equation eigenvalue problems numerically to very high precision P (from thousands to a million of decimals). The memory requirement, and the number of high-precision algebraic operations, of the method scale essentially linearly with P when only eigenvalues are computed. However, since the algorithms for multiplying high-precision numbers scale at a rate between P 1.6 and P log P log log P , the time requirement of our method ...

#1R. Solberg (NTNU: Norwegian University of Science and Technology)H-Index: 1

#2K. Mork (NTNU: Norwegian University of Science and Technology)H-Index: 1

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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Coulomb and screening corrections to the amplitude for Delbr\"uck scattering in the forward direction are calculated.

#1Kåre Olaussen (NTNU: Norwegian University of Science and Technology)H-Index: 13

#2Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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We evaluate the cross section for the radiative capture of spin-12 fermions by monopoles, using wave functions derived from the Kazama-Yang hamiltonian, valid in the limit of low incident relative velocities, β⪡1, and weakly bound states, with binding energies much smaller than the fermion mass, EB⪡M. The cross sections obtained are generally of the order of (Z2αM2)(EB12Mβ2). The formulae obtained can be used to estimate cross sections for the capture of spin-12 nuclei.

#1Kåre Olaussen (NTNU: Norwegian University of Science and Technology)H-Index: 13

#2Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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Abstract Scattering states of definite helicity are constructed - in terms of partial-wave expansions - for a point fermion with spin 1 2 and an extra magnetic moment in the field of an infinitely heavy Dirac monopole, i.e., with the Kazama-Yang hamiltonian. The approximate solutions thus obtained, which are valid for small velocities, β ⪡1, are useful for evaluating capture cross sections.

#1Kåre OlaussenH-Index: 13

#2Haakon A. OlsenH-Index: 12

Last. I. ØverbøH-Index: 9

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The cross section for radiative capture of protons by monopoles is calculated by the use of bound-state and scattering wave functions obtained with the Kazama-Yang Hamiltonian, i.e., with a pointlike proton. For proton velocities ..beta.. = 10/sup -5/--10/sup -3/, the cross sections for capture into the lowest bound states, with binding energies of 938 MeV, 263 keV, and 105 eV, are found to be of the order of 10/sup -28/--10/sup -26/ cm/sup 2/. For the state with binding energy of 263 keV, the c...

#1Kåre Olaussen (NTNU: Norwegian University of Science and Technology)H-Index: 13

#2Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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Abstract We present explicit, approximate, remarkably precise results for the Kazama-Yang monopole-fermion binding energies and wave functions. The results are valid for the states of lowest angular momentum and for the binding energy M − E ⪡ M . They agree very well with the numerically calculated values.

#1Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

#2Per OslandH-Index: 10

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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The linear and circular polarizations of gluons emitted in electron-positron annihilation, e+e−→qqg, are evaluated, including neutral current and beam polarization effects. For the lower part of the gluon bremsstrahlung spectrum, the linear polarization is found to be large and the plane of polarization to be almost parallel to the qqg event plane. The neutral current induced circular polarization is in the upper part of the gluon spectrum of the order of 10–15% at 40 GeV total energy and reache...

Polarization-Induced Azimuthal Flavour Asymmetries in e+e- Annihilation as a Signature of Neutral Currents

#1Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

#2Per OslandH-Index: 10

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

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At high energies, transverse beam polarization leads in e+e- annihilation to an azimuthal variation in the composition of the produced particles. This effect has its origin in the flavour dependence of the ratio between the right- and left-handed components of the neutral current. The detection and identification of particles which are dominantly produced by quarks of one or a few specific flavours, would allow for an observation of this neutral-current effect. We estimate the resulting azimutha...

#1Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

#2Per OslandH-Index: 10

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

view all 3 authors...

According to perturbative QCD, gluons radiated in electron-positron annihilation are linearly polarized in the (qqg) event plane. In large parts of phase space this polarization is close to complete. We point out that this offers a possibility for direct observation of the vector nature of the gluon, by a measurement of the linear polarization of leading isoscalar vector mesons originating in the gluon jets.

#1Haakon A. Olsen (NTNU: Norwegian University of Science and Technology)H-Index: 12

#2Per OslandH-Index: 10

Last. I. Øverbø (NTNU: Norwegian University of Science and Technology)H-Index: 9

view all 3 authors...

Abstract Transverse beam polarization is in e + e - annihilation at high energies shown to lead to a strong azimuthal variation in the flavour composition of the produced quark-antiquark pairs. We describe, in the SU(2) × U(1) model, a way in which this could be used to obtain flavour-specific information on the quark fragmentation functions. In inclusive charged particle rates the effect might be much reduced, but still observable.

Close Researchers

Per Osland

H-index : 9

Haakon A. Olsen

H-index : 12

Kåre Olaussen

H-index : 13

Kjell J. Mork

H-index : 7

Haakon A. Olsen

H-index : 11

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