309 research outputs found

    The two-dimensional hydrogen atom revisited

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    The bound state energy eigenvalues for the two-dimensional Kepler problem are found to be degenerate. This "accidental" degeneracy is due to the existence of a two-dimensional analogue of the quantum-mechanical Runge-Lenz vector. Reformulating the problem in momentum space leads to an integral form of the Schroedinger equation. This equation is solved by projecting the two-dimensional momentum space onto the surface of a three-dimensional sphere. The eigenfunctions are then expanded in terms of spherical harmonics, and this leads to an integral relation in terms of special functions which has not previously been tabulated. The dynamical symmetry of the problem is also considered, and it is shown that the two components of the Runge-Lenz vector in real space correspond to the generators of infinitesimal rotations about the respective coordinate axes in momentum space.Comment: 10 pages, no figures, RevTex

    The Influence of Leadership Style and Organizational Citizenship Behaviour (OCB) on Organizational Performance: A Case of ICT Firm in Saudi Arabia

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    The purpose of this quantitative study was to examine the influence of leadership style and organizational citizenship behaviour (OCB) on organizational behaviour. This study arises from the need to know the factors that can increase the organizational performance in the MOBAILI telecommunication company which located in Saudi Arabia. It is argued in this thesis that very limited number of studies have been conducted on the relationship between leadership style and OCB in the perspective of developing countries in general, so this study aimed at investigating whether leadership style and OCB have a positive impact on organizational performance in one of telecommunication company called MOBAILI located in Saudi Arabia. To this end, 86 respondents working in MOBAILI telecommunication company located in Saudi Arabia were selected to participate in the study. Organizational performance was measured by the 10-item developed by Steele (1987). Leadership style was measured by the 20-items and OCB was measured by 12-items developed by Podsakoff and Mackenzie(as cited in Niehoff & Moorman, 1993). The instruments for in this study were measured by using the 5-item questionnaire. The findings revealed that leadership style and organizational citizenship behaviour (OCB) were statistically and significantly related to organizational performance. OCB was found to be the best predictor of organizational performance. The limitations of this study and the recommendations for future research are also discussed

    Noncommutative Coordinates Invariant under Rotations and Lorentz Transformations

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    Dynamics with noncommutative coordinates invariant under three dimensional rotations or, if time is included, under Lorentz transformations is developed. These coordinates turn out to be the boost operators in SO(1,3) or in SO(2,3) respectively. The noncommutativity is governed by a mass parameter MM. The principal results are: (i) a modification of the Heisenberg algebra for distances smaller than 1/M, (ii) a lower limit, 1/M, on the localizability of wave packets, (iii) discrete eigenvalues of coordinate operator in timelike directions, and (iv) an upper limit, MM, on the mass for which free field equations have solutions. Possible restrictions on small black holes is discussed.Comment: 14 pages; LaTex using JHEP3.cl

    Noncommuting spherical coordinates

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    Restricting the states of a charged particle to the lowest Landau level introduces a noncommutativity between Cartesian coordinate operators. This idea is extended to the motion of a charged particle on a sphere in the presence of a magnetic monopole. Restricting the dynamics to the lowest energy level results in noncommutativity for angular variables and to a definition of a noncommuting spherical product. The values of the commutators of various angular variables are not arbitrary but are restricted by the discrete magnitude of the magnetic monopole charge. An algebra, isomorphic to angular momentum, appears. This algebra is used to define a spherical star product. Solutions are obtained for dynamics in the presence of additional angular dependent potentials.Comment: 5 pages, RevTex4 fil

    Spin content of constituent quarks and one-spin asymmetries in inclusive processes

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    We consider mechanism for one-spin asymmetries observed in inclusive hadron production. The main role belongs to the orbital angular momentum of the quark-antiquark cloud in the internal structure of constituent quarks. We argue that the origin of the asymmetries in pion production is a result of retaining of this internal angular orbital momentum by the perturbative phase of QCD under transition from the non-perturbative phase. The non-perturbative hadron structure is based on the results of chiral quark models. PACS number(s): 11.30.Qc, 12.40.Pp, 13.75.Ni, 13.88.+eComment: 21 pages LaTeX + 8 figures (not included

    Anomalous Chromomagnetic Moments of Quarks and Large Transverse Energy Jets

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    We consider the jet cross sections for gluons coupling to quarks with an anomalous chromomagnetic moment. We then apply this to the deviation and bounds from QCD found in the CDF and D0 Fermilab data, respectively, to find a range of possible values for the anomalous moments. The quadratic and quartic terms in the anomalous moments can fit to the rise of a deviation with transverse energy. Since previous analyses have been done on the top quark total cross section, here we assume the same moment on all quarks except the top and find the range κκ/(2mq)=1.0±0.3|\kappa'| \equiv |\kappa/(2 m_q)| = 1.0\pm 0.3 TeV1^{-1} for the CDF data. Assuming the anomalous moment is present only on a charm or bottom quark which is pair produced results in a range κb,c=3.5±1.0|\kappa'_{b,c}| = 3.5 \pm 1.0 TeV1^{-1}. The magnitudes here are compared with anomalous magnetic moments that could account for RbR_b and found to be in the same general range, as well as not inconsistent with LEP and SLD bounds on ΔΓhad\Delta \Gamma_{\text{had}}.Comment: REVTeX, 11 pages, 2 postscript figure

    Variational Principle in the Algebra of Asymptotic Fields

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    This paper proposes a variational principle for the solutions of quantum field theories in which the ``trial functions'' are chosen from the algebra of asymptotic fields, and illustrates this variational principle in simple cases.Comment: 15 pages, Latex, no figure

    Coherent States and N Dimensional Coordinate Noncommutativity

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    Considering coordinates as operators whose measured values are expectations between generalized coherent states based on the group SO(N,1) leads to coordinate noncommutativity together with full NN dimensional rotation invariance. Through the introduction of a gauge potential this theory can additionally be made invariant under NN dimensional translations. Fluctuations in coordinate measurements are determined by two scales. For small distances these fluctuations are fixed at the noncommutativity parameter while for larger distances they are proportional to the distance itself divided by a {\em very} large number. Limits on this number will lbe available from LIGO measurements.Comment: 16 pqges. LaTeX with JHEP.cl
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