97 research outputs found

    Three bit mass spectral search program

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    Computer program is developed to interpret spectral data in order to assist chemist in identifying low resolution mass spectra. Two versions of program, using approximately same amount of core are available. In both programs, core requirements are roughly proportional to maximum number of unknowns to be handled on each pass through tape

    An α2(Zα)5m\alpha^{2}(Z \alpha)^{5}m Contribution to the Hydrogen Lamb Shift from Virtual Light by Light Scattering

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    The radiative correction to the Lamb shift of order α2(Zα)5m\alpha^{2}(Z\alpha)^5m induced by the light by light scattering insertion in external photons is obtained. The new contribution turns out to be equal to −0.122(2)α2(Zα)5/(πn3)(mr/m)3m-0.122(2)\alpha^2(Z\alpha)^5/(\pi n^3)(m_r/m)^3m. Combining this contribution with our previous results we obtain the complete correction of order α2(Zα)5m\alpha^{2}(Z\alpha)^5m induced by all diagrams with closed electron loops. This correction is 37.3(1)37.3(1) kHz and 4.67(1)4.67(1) kHz for the 1S1S- and 2S2S-states in hydrogen, respectively.Comment: pages, Penn State Preprint PSU/TH/142, February 199

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

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    We have formulated the quasipotential method for the calculation of the relativistic and radiative corrections to the magnetic moment of the two-particle bound state in the case of particles with arbitrary spin. It is shown that the g-factors of bound particles contain O(α2)O(\alpha^2) terms depending on the particle spin. Numerical values for the g-factors of the electron in the hydrogen atom and deuterium are obtained.Comment: Talk presented at Nuclear Physics Department Conference "Physics of Fundamental Interactions" Russian Academy of Sciences, ITEP, Moscow, 27 November-1 December 2000. 11 pages, 1 figure uses linedraw.st

    Two-Loop Polarization Contributions to Radiative-Recoil Corrections to Hyperfine Splitting in Muonium

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    We calculate radiative-recoil corrections of order α2(Zα)(m/M)EF\alpha^2(Z\alpha)(m/M)E_F to hyperfine splitting in muonium generated by the diagrams with electron and muon polarization loops. These corrections are enhanced by the large logarithm of the electron-muon mass ratio. The leading logarithm cubed and logarithm squared contributions were obtained a long time ago. The single-logarithmic and nonlogarithmic contributions calculated here improve the theory of hyperfine splitting, and affect the value of the electron-muon mass ratio extracted from the experimental data on the muonium hyperfine splitting.Comment: 15 pages, 11 figure

    Leptonic ÎŒ \mu - and τ \tau -decays: mass effects, polarization effects and O(α) O(\alpha) radiative corrections

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    We calculate the radiative corrections to the unpolarized and the four polarized spectrum and rate functions in the leptonic decay of a polarized ÎŒ \mu into a polarized electron. The new feature of our calculation is that we keep the mass of the final state electron finite which is mandatory if one wants to investigate the threshold region of the decay. Analytical results are given for the energy spectrum and the polar angle distribution of the final state electron whose longitudinal and transverse polarization is calculated. We also provide analytical results on the integrated spectrum functions. We analyze the me→0 m_e \to 0 limit of our general results and investigate the quality of the me→0 m_e \to 0 approximation. In the me→0 m_e \to 0 case we discuss in some detail the role of the O(α) O(\alpha) anomalous helicity flip contribution of the final electron which survives the me→0 m_e \to 0 limit. The results presented in this 0203048 also apply to the leptonic decays of polarized τ \tau -leptons for which we provide numerical results.Comment: 39 pages, 11 postscript figures added. Updated version. Four references added. A few text improvements. Final version to appear in Phys.Rev.

    Radiative Correction to the Nuclear-Size Effect and Hydrogen-Deuterium Isotopic Shift

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    The radiative correction to the nuclear charge radius contribution to the Lamb shift of order α(Zα)5mr3\alpha(Z\alpha)^5m_r^3 is calculated. In view of the recent high precision experimental data, this theoretical correction produces a significant contribution to the hydrogen-deuterium isotopic shift.Comment: 5 pages, REVTEX, replaced with the final version, to be published in Phys.Rev. A, two references adde

    Eight-component two-fermion equations

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    An eight-component formalism is proposed for the relativistic two-fermion problem. In QED, it extends the applicability of the Dirac equation with hyperfine interaction to the positronium case. The use of exact relativistic two-body kinematics entails a CP-invariant spectrum which is symmetric in the total cms energy. It allows the extension of recent \alpha^6 recoil corrections to the positronium case, and implies new recoil corrections to the fine and hyperfine structures and to the Bethe logarithm.Comment: Revtex, accepted for publication in Phys. Rev.

    Heavy quarkonium: progress, puzzles, and opportunities

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    A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the BB-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

    Production of singlet P-wave ccˉc \bar c and bbˉb \bar b states

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    No spin-singlet bbˉb \bar b quarkonium state has yet been observed. In this paper we discuss the production of the singlet P-wave bbˉb\bar{b} and ccˉc\bar{c} 1P1^1P_1 states hbh_b and hch_c. We consider two possibilities. In the first the 1P1^1P_1 states are produced via the electromagnetic cascades \ups(3S) \to \eta_b(2S) + \gamma \to h_b + \gamma \gamma \to \eta_b +\gamma\gamma\gamma and ψâ€Č→ηcâ€Č+γ→hc+γγ→ηc+γγγ\psi'\to \eta_c' + \gamma \to h_c + \gamma \gamma \to \eta_c + \gamma\gamma\gamma. A more promising process consists of single pion transition to the 1P1^1P_1 state followed by the radiative transition to the 11S01^1S_0 state: \ups(3S)\to h_b + \pi^0 \to \eta_b + \pi^0 +\gamma and ψâ€Č→hc+π0→ηc+π0+Îł\psi' \to h_c + \pi^0 \to \eta_c + \pi^0 +\gamma. For a million \ups(3S) or ψâ€Č\psi''s produced we expect these processes to produce several hundred events.Comment: 13 pages, LaTeX, 1 figure, to be published Phys. Rev. D. Some equation numbers and one table number correcte
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