2,205 research outputs found

    Right eigenvalue equation in quaternionic quantum mechanics

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    We study the right eigenvalue equation for quaternionic and complex linear matrix operators defined in n-dimensional quaternionic vector spaces. For quaternionic linear operators the eigenvalue spectrum consists of n complex values. For these operators we give a necessary and sufficient condition for the diagonalization of their quaternionic matrix representations. Our discussion is also extended to complex linear operators, whose spectrum is characterized by 2n complex eigenvalues. We show that a consistent analysis of the eigenvalue problem for complex linear operators requires the choice of a complex geometry in defining inner products. Finally, we introduce some examples of the left eigenvalue equations and highlight the main difficulties in their solution.Comment: 24 pages, AMS-Te

    Transition Rates between Mixed Symmetry States: First Measurement in 94Mo

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    The nucleus 94Mo was investigated using a powerful combination of gamma-singles photon scattering experiments and gamma-gamma-coincidence studies following the beta-decay of 94mTc. The data survey short-lived J^pi=1+,2+ states and include branching ratios, E2/M1 mixing ratios, lifetimes, and transition strengths. The mixed-symmetry (MS) 1+ scissors mode and the 2+ MS state are identified from M1 strengths. A gamma transition between MS states was observed and its rate was measured. Nine M1 and E2 strengths involving MS states agree with the O(6) limit of the interacting boson model-2 using the proton boson E2 charge as the only free parameter.Comment: 9 pages, 3 PostScript figures included, ReVTeX, accepted for publication in Physical Review Letters, tentatively scheduled for August 9, 199

    Extrapyramidal side effects and suicidal ideation under fluoxetine treatment: a case report

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    <p>Abstract</p> <p>Background</p> <p>We present the case of a 52-year-old woman with depression who developed extrapyramidal symptoms (mainly parkinsonism) and suicidal ideation while on fluoxetine.</p> <p>Methods</p> <p>The patient underwent neurological and neuroimaging examination.</p> <p>Results</p> <p>The patient's neurological and neuroimaging examinations were normal and there was no other cause of extrapyramidal symptoms. The patient showed remission of the aforementioned symptomatology when fluoxetine was discontinued.</p> <p>Conclusions</p> <p>This case shows that fluoxetine can be associated with extrapyramidal symptoms, and this may have an aggravating affect on clinical depression progress and the emergence of suicidal ideation.</p

    Extended M1 sum rule for excited symmetric and mixed-symmetry states in nuclei

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    A generalized M1 sum rule for orbital magnetic dipole strength from excited symmetric states to mixed-symmetry states is considered within the proton-neutron interacting boson model of even-even nuclei. Analytic expressions for the dominant terms in the B(M1) transition rates from the first and second 2+2^+ states are derived in the U(5) and SO(6) dynamic symmetry limits of the model, and the applicability of a sum rule approach is examined at and in-between these limits. Lastly, the sum rule is applied to the new data on mixed-symmetry states of 94Mo and a quadrupole d-boson ratio nd(01+)/nd(22+)0.6nd(0^+_1)/nd(2^+_2) \approx 0.6 is obtained in a largely parameter-independent wayComment: 19 pages, 3 figures, Revte

    Single Spin Asymmetries of Inclusive Hadrons Produced in Electron Scattering from a Transversely Polarized 3^3He Target

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    We report the first measurement of target single-spin asymmetries (AN_N) in the inclusive hadron production reaction, e e~+ 3Heh+X~^3\text{He}^{\uparrow}\rightarrow h+X, using a transversely polarized 3^3He target. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons (π±\pi^{\pm}, K±\text{K}^{\pm} and proton) were detected in the transverse hadron momentum range 0.54 <pT<<p_T< 0.74 GeV/c. The range of xFx_F for pions was -0.29 <xF<<x_F< -0.23 and for kaons -0.25 <xF<<x_F<-0.18. The observed asymmetry strongly depends on the type of hadron. A positive asymmetry is observed for π+\pi^+ and K+\text{K}^+. A negative asymmetry is observed for π\pi^{-}. The magnitudes of the asymmetries follow Aπ<Aπ+<AK+|A^{\pi^-}| < |A^{\pi^+}| < |A^{K^+}|. The K^{-} and proton asymmetries are consistent with zero within the experimental uncertainties. The π+\pi^{+} and π\pi^{-} asymmetries measured for the 3^3He target and extracted for neutrons are opposite in sign with a small increase observed as a function of pTp_T.Comment: Updated version, submitted to Phys. Rev.

    Measurement of pretzelosity asymmetry of charged pion production in Semi-Inclusive Deep Inelastic Scattering on a polarized 3^3He target

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    An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized 3^3He target was performed at Jefferson Lab in the kinematic region of 0.16<x<0.350.16<x<0.35 and 1.4<Q2<2.71.4<Q^2<2.7 GeV2{\rm GeV^2}. The pretzelosity asymmetries on 3^3He, which can be expressed as the convolution of the h1Th^\perp_{1T} transverse momentum dependent distribution functions and the Collins fragmentation functions in the leading order, were measured for the first time. Using the effective polarization approximation, we extracted the corresponding neutron asymmetries from the measured 3^3He asymmetries and cross-section ratios between the proton and 3^3He. Our results show that for both π±\pi^{\pm} on 3^3He and on the neutron the pretzelosity asymmetries are consistent with zero within experimental uncertainties.Comment: 6 pages, 3 figures; enlarged the legends in Fig.3; added 3 citation

    Double Spin Asymmetries of Inclusive Hadron Electroproductions from a Transversely Polarized 3He^3\rm{He} Target

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    We report the measurement of beam-target double-spin asymmetries (ALTA_\text{LT}) in the inclusive production of identified hadrons, e \vec{e}~+ 3Heh+X~^3\text{He}^{\uparrow}\rightarrow h+X, using a longitudinally polarized 5.9 GeV electron beam and a transversely polarized 3He^3\rm{He} target. Hadrons (π±\pi^{\pm}, K±K^{\pm} and proton) were detected at 16^{\circ} with an average momentum =2.35 GeV/c and a transverse momentum (pTp_{T}) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the 3He^3\text{He} target were observed to be non-zero for π±\pi^{\pm} production when the target was polarized transversely in the horizontal plane. The π+\pi^{+} and π\pi^{-} asymmetries have opposite signs, analogous to the behavior of ALTA_\text{LT} in semi-inclusive deep-inelastic scattering.Comment: Published in PRC (92.015207), nuclear experiment, high-energy experimen

    Single Spin Asymmetries in Charged Kaon Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized 3He^3{\rm{He}} Target

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    We report the first measurement of target single spin asymmetries of charged kaons produced in semi-inclusive deep inelastic scattering of electrons off a transversely polarized 3He^3{\rm{He}} target. Both the Collins and Sivers moments, which are related to the nucleon transversity and Sivers distributions, respectively, are extracted over the kinematic range of 0.1<<xbjx_{bj}<<0.4 for K+K^{+} and KK^{-} production. While the Collins and Sivers moments for K+K^{+} are consistent with zero within the experimental uncertainties, both moments for KK^{-} favor negative values. The Sivers moments are compared to the theoretical prediction from a phenomenological fit to the world data. While the K+K^{+} Sivers moments are consistent with the prediction, the KK^{-} results differ from the prediction at the 2-sigma level.Comment: 6 pages, 3 figure

    Electroexcitation of the Δ+(1232)\Delta^{+}(1232) at low momentum transfer

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    We report on new p(e,ep)π(e,e^\prime p)\pi^\circ measurements at the Δ+(1232)\Delta^{+}(1232) resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low Q2Q^2 dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements

    Translocation detection in lymphoma diagnosis by split-signal FISH: a standardised approach

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    Lymphomas originating from the lymphatic system comprise about 30 entities classified according to the World Health Organization (WHO). The histopathological diagnosis is generally considered difficult and prone to mistakes. Since non-random chromosomal translocations are specifically involved in different lymphoma entities, their detection will be increasingly important. Hence, a split-signal fluorescence in situ hybridisation (FISH) procedure would be helpful in discriminating the most difficult classifications. The Euro-FISH programme, a concerted action of nine European laboratories, has validated a robust, standardised protocol to improve the diagnostic approach on lymphoma entities. Therefore, 16 fluorescent probes and 10 WHO entities, supplemented with reactive cases, were selected. The results of the Euro-FISH programme show that all probes were correctly cytogenetically located, that the standardised protocol is robust, resulting in reliable results in approximately 90% of cases, and that the procedure could be implemented in every laboratory, bringing the relatively easy interpretation of split-signal probes within the reach of many pathology laboratories
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