WorldWideScience

Sample records for bound pionic states

  1. Deeply bound pionic states

    International Nuclear Information System (INIS)

    We discuss the structure and formation of deeply bound π- states in heavy nuclei, which are expected to be narrow due to the repulsive π--nucleus interaction. Possible experiments to produce those states are described. (author)

  2. Deeply bound pionic atom

    International Nuclear Information System (INIS)

    The standard method of pionic atom formation does not produce deeply bound pionic atoms. A study is made on the properties of deeply bound pionic atom states by using the standard pion-nucleus optical potential. Another study is made to estimate the cross sections of the formation of ls pionic atom states by various methods. The pion-nucleus optical potential is determined by weakly bound pionic atom states and pion nucleus scattering. Although this potential may not be valid for deeply bound pionic atoms, it should provide some hint on binding energies and level widths of deeply bound states. The width of the ls state comes out to be 0.3 MeV and is well separated from the rest. The charge dependence of the ls state is investigated. The binding energies and the widths increase linearly with Z azbove a Z of 30. The report then discusses various methods to populate deeply bound pionic atoms. In particular, 'pion exchange' reactions are proposed. (n, pπ) reaction is discussed first. The cross section is calculated by assuming the in- and out-going nucleons on-shell and the produced pion in (n1) pionic atom states. Then, (n, dπ-) cross sections are estimated. (p, 2Heπ-) reaction would have cross sections similar to the cross section of (n, dπ-) reaction. In conclusion, it seems best to do (n, p) experiment on heavy nuclei for deeply bound pionic atom. (Nogami, K.)

  3. Deeply bound pionic atoms: the story of an ongoing race

    International Nuclear Information System (INIS)

    A short review is made of the steps of the Valencia group in the search for suitable reactions to detect deeply bound pionic states and how these steps were influenced by the parallel steps of the Tokyo team. The present situation and future prospects are outlined. (orig.)

  4. Calculations of deeply bound pionic states in heavy and superheavy atoms

    International Nuclear Information System (INIS)

    Binding energies and widths of pions bound in the 1s-state of heavy and superheavy atoms are evaluated. The repulsive strong interaction lowers the Coulomb binding energy by up to 50%. The energy width of the strongest bound state investigated becomes comparable with the binding energy. No drastic consequence on the pion propagation in nuclear matter is expected. (orig.)

  5. The three-nucleon bound state with isobaric and pionic degrees of freedom

    International Nuclear Information System (INIS)

    Wave function components containing a single Δ-isobar are included in the calculation of the three-nucleon bound states. The two-nucleon interaction acts in all partial waves up to total angular momentum I=2. The presence of a Δ-isobar increases the three-nucleon binding energy by about 0.3 MeV, 0.6 MeV repulsion being a dispersive two-body effect, 0.9 MeV attraction arising from the three-nucleon force with intermediate Δ-isobar. The effect of the Δ on the three-nucleon charge and magnetic form factors is investigated. The possibility of treating the Δ-isobar as a dynamic pion-nucleon system in nuclear structure and nuclear-structure corrections beyond single Δ excitation in the coupled channel approach are also discussed

  6. Measurement of the Strong Interaction Shift and Width of the Ground State of Pionic Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Manil, B., E-mail: manil@spectro.jussieu.fr [Universite Pierre et Marie Curie, Laboratoire Kastler-Brossel, Unite Mixte de Recherche du CNRS no C8552 (France); Anagnostopoulos, D. F. [University of Ioannina, Department of Material Science (Greece); Biri, S. [ATOMKI, Hungary Academie of Science (Hungary); Borchert, G. L. [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Breunlich, W. [IMEP, Osterreichisch Akademie der Wissenschaften (Austria); Egger, J. P. [Institut de Physique de l' Universite de Neuchatel (Switzerland); Gotta, D. [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Gruber, A. [IMEP, Osterreichisch Akademie der Wissenschaften (Austria); Hennebach, M.; Indelicato, P. [Institut fuer Kernphysik, Forschungszentrum Juelich (Germany); Jensen, T. [University of Aarhus (Denmark); Liu, Y. W.; Markushin, V. [Paul Scherrer Institut (Switzerland); Nelms, N. [University of Leicester, Department of Physics and Astronomy (United Kingdom); Simons, L. M. [Paul Scherrer Institut (Switzerland); Zmeskal, H. [IMEP, Osterreichisch Akademie der Wissenschaften (Austria)

    2003-03-15

    An experiment to measure the strong interaction width ({Gamma}{sub 1s}) and shift ({epsilon}{sub 1s}) of the ground state of pionic hydrogen ({pi}{sup -}p), in order to determine the isospin separated scattering lengths (a{sup +} and a{sup -}) with a relative accuracy of better than 10{sup -2}, has been undertaken at the Paul Scherrer Institute (PSI). This measurement is based on high-precision X-ray spectroscopy of the np{sup {yields}1}s transitions pionic hydrogen ({pi}{sup -}p). A preliminary analysis of the data taken in December 2000 is presented.

  7. Real-pion states formed by virtual-pion beam

    International Nuclear Information System (INIS)

    Deeply bound pionic states are discussed from various points of view; highly excited nuclear states as a cluster family of pionic bound states, Σ atom/Σ hypernuclei, halo-like density distributions, virtual pion beam to produce pionic states, etc. (author)

  8. Determination of the hadronic width of the ground state in pionic hydrogen

    International Nuclear Information System (INIS)

    In a new high-precision experiment at the Paul Scherrer Institut (PSI), the hadronic shift (ε1s) and width (Γ1s) of the ground state of pionic hydrogen, which are directly connected to the pion-nucleon isospin scattering lengths, were remeasured (PSI-Experiment R-98-01). The results can be confronted with recent work of effective field theories defined in the low-energy limit of quantum chromodynamics (QCD), such as, e. g., chiral perturbation theory (ChPT). In addition, Γ1s is connected to the pion-nucleon coupling constant fπN. A precisely known value for fπN allows an accurate determination of the Goldberger-Treiman discrepancy, which constitutes a measure of chiral symmetry breaking. This contribution is mainly devoted to describe a method for an accurate extraction of the hadronic width from the π-H data.

  9. Pionic deuterium

    CERN Document Server

    Strauch, Th; Anagnostopoulos, D; Bühler, P; Covita, D S; Gorke, H; Gotta, D; Gruber, A; Hirtl, A; Indelicato, P; Bigot, E -O Le; Nekipelov, M; Santos, J M F dos; Schmid, Ph; Schlesser, S; Simons, L M; Trassinelli, M; Veloso, J F C A; Zmeskal, J

    2010-01-01

    The strong interaction shift $\\epsilon$ and broadening {\\Gamma} in pionic deuterium have been determined in a high statistics study of the {\\pi}D(3p - 1s) X-ray transition using a high-resolution crystal spectrometer. The pionic deuterium shift will provide constraints for the pion-nucleon isospin scattering lengths extracted from measurements of shift and broadening in pionic hydrogen. The hadronic broadening is related to pion absorption and production at threshold. The results are \\epsilon = (-2356 {\\pm} 31)meV (repulsive) and {\\Gamma}1s = (1171+23/-49) meV yielding for the complex {\\pi}D scattering length a = [-(24.99 {\\pm} 0.33) + i (6.22+0.12/-0.26 )]x10-3/m{\\pi}. From the imaginary part, the threshold parameter for pion production is obtained to be {\\alpha} = (251 +5/-11) {\\mu}b. This allows, in addition, and by using results from pion absorption in 3He at threshold, the determination of the effective couplings g0 and g1 for s-wave pion absorption on isoscalar and isovector NN pairs.

  10. Pionic deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Strauch, T.; Gotta, D.; Nekipelov, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Amaro, F.D.; Santos, J.M.F. dos [Coimbra University, Department of Physics, Coimbra (Portugal); Anagnostopoulos, D.F. [University of Ioannina, Department of Materials Science and Engineering, Ioannina (Greece); Buehler, P.; Gruber, A.; Hirtl, A.; Schmid, P.; Zmeskal, J. [Austrian Academy of Sciences, Stefan Meyer Institut for Subatomic Physics, Vienna (Austria); Covita, D.S. [Coimbra University, Department of Physics, Coimbra (Portugal); Paul Scherrer Institut, Laboratory for Particle Physics, Villigen (Switzerland); Gorke, H. [Forschungszentrum Juelich GmbH, Zentralinstitut fuer Elektronik, Juelich (Germany); Indelicato, P.; Le Bigot, E.O.; Schlesser, S.; Trassinelli, M. [UPMC-Paris 6, ENS, CNRS, Laboratoire Kastler Brossel, Paris (France); Simons, L.M. [Paul Scherrer Institut, Laboratory for Particle Physics, Villigen (Switzerland); Veloso, J.F.C.A. [Aveiro University, I3N, Department of Physics, Aveiro (Portugal)

    2011-07-15

    The strong-interaction shift {epsilon}{sub 1s}{sup {pi}}{sup D} and broadening {gamma}{sub 1s}{sup {pi}}{sup D} in pionic deuterium have been determined in a high statistics study of the {pi}D(3p-1s) X-ray transition using a high-resolution crystal spectrometer. The pionic deuterium shift will provide constraints for the pion-nucleon isospin scattering lengths extracted from measurements of shift and broadening in pionic hydrogen. The hadronic broadening is related to pion absorption and production at threshold. The results are {epsilon}{sub 1s}{sup {pi}}{sup D}=(-2356 {+-} 31) meV (repulsive) and {gamma}{sub 1s}{sup {pi}}{sup D} meV yielding for the complex {pi}D scattering length a{sub {pi}}{sub D}=[-(24.99 {+-}0.33)+i(6.22{sub -0.26} {sup +0.12}) ]x 10{sup -3} m{sub {pi}}{sup -1}. From the imaginary part, the threshold parameter for pion production is obtained to be {alpha} = (251{sub -11} {sup +5}){mu}b. This allows, in addition, and by using results from pion absorption in {sup 3}He at threshold, the determination of the effective couplings g{sub 0} and g{sub 1} for s-wave pion absorption on isoscalar and isovector NN pairs. (orig.)

  11. Pionic hydrogen and friends

    Energy Technology Data Exchange (ETDEWEB)

    Gotta, D., E-mail: d.gotta@fz-juelich.de [Forschungszentrum Jülich GmbH and JHCP (Germany); Amaro, F. D. [Coimbra University, Department of Physics (Portugal); Anagnostopoulos, D. F. [University of Ioannina, Department of Materials Science and Engineering (Greece); Bühler, P. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Gorke, H. [Forschungszentrum Jülich GmbH and JHCP (Germany); Covita, D. S. [Coimbra University, Department of Physics (Portugal); Fuhrmann, H.; Gruber, A. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Hennebach, M. [Forschungszentrum Jülich GmbH and JHCP (Germany); Hirtl, A.; Ishiwatari, T. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Indelicato, P. [LKB, UPMC-Paris 6, ENS, CNRS (France); Jensen, T. S. [Ringkjøbing Gymnasium (Denmark); Bigot, E.-O. Le [LKB, UPMC-Paris 6, ENS, CNRS (France); Markushin, V. E. [Paul Scherrer Institut (PSI) (Switzerland); Marton, J. [Stefan Meyer Institut, Austrian Academy of Sciences (Austria); Nekipelov, M. [Forschungszentrum Jülich GmbH and JHCP (Germany); Pomerantsev, V. N.; Popov, V. P. [Skobeltsyn Institut of Nuclear Physics, Lomonossov Moscow State University (Russian Federation); Santos, J. M. F. dos [Coimbra University, Department of Physics (Portugal); and others

    2015-08-15

    Pion-nucleon scattering lengths are directly related to the ground-state level shift and broadening in pionic hydrogen as well as to the pionic deuterium level shift. The level broadening in deuterium measures the strength of pion threshold-production in proton-proton reactions. However, collisional processes during the atomic de-excitation cascade considerably complicate the analysis of X-ray line shapes in order to extract the hadronic broadening. Therefore, additionally the purely electromagnetic twin system muonic hydrogen was studied. Results of these experiments performed at PSI by using a high-resolution crystal spectrometer are discussed in the context with a new analysis approach for the hadronic broadening.

  12. Pionic hydrogen and friends

    International Nuclear Information System (INIS)

    Pion-nucleon scattering lengths are directly related to the ground-state level shift and broadening in pionic hydrogen as well as to the pionic deuterium level shift. The level broadening in deuterium measures the strength of pion threshold-production in proton-proton reactions. However, collisional processes during the atomic de-excitation cascade considerably complicate the analysis of X-ray line shapes in order to extract the hadronic broadening. Therefore, additionally the purely electromagnetic twin system muonic hydrogen was studied. Results of these experiments performed at PSI by using a high-resolution crystal spectrometer are discussed in the context with a new analysis approach for the hadronic broadening

  13. Lectures on Bound states

    CERN Document Server

    Hoyer, Paul

    2016-01-01

    Even a first approximation of bound states requires contributions of all powers in the coupling. This means that the concept of "lowest order bound state" needs to be defined. In these lectures I discuss the "Born" (no loop, lowest order in $\\hbar$) approximation. Born level states are bound by gauge fields which satisfy the classical field equations. As a check of the method, Positronium states of any momentum are determined as eigenstates of the QED Hamiltonian, quantized at equal time. Analogously, states bound by a strong external field $A^\\mu(\\xv)$ are found as eigenstates of the Dirac Hamiltonian. Their Fock states have dynamically created $e^+e^-$ pairs, whose distribution is determined by the Dirac wave function. The linear potential of $D=1+1$ dimensions confines electrons but repels positrons. As a result, the mass spectrum is continuous and the wave functions have features of both bound states and plane waves. The classical solutions of Gauss' law are explored for hadrons in QCD. A non-vanishing bo...

  14. Reflecting Magnon Bound States

    CERN Document Server

    Ahn, C; Rey, S J

    2008-01-01

    In N=4 super Yang-Mills spin chain, we compute reflection amplitudes of magnon bound-state off giant graviton. We first compute the reflection amplitude off Y=0 brane boundary and compare it with the scattering amplitude between two magnon bound-states in the bulk. We find that analytic structure of the two amplitudes are intimately related each other: the boundary reflection amplitude is a square-root of the bulk scattering amplitude. Using such relation as a guide and taking known results at weak and strong coupling limits as inputs, we find the reflection amplitude of an elementary magnon off Z=0 giant graviton boundary. The reflection phase factor is shown to solve crossing and unitarity relations. We then compute the reflection amplitude of magnon bound-state off the Z=0 brane boundary and observe that its analytic structures are again intimately related to the bulk scattering and the Y=0 boundary reflection amplitudes. We also take dyonic giant magnon limit of these reflection amplitudes and confirm tha...

  15. Bound states and the Bekenstein bound

    CERN Document Server

    Bousso, R

    2004-01-01

    We explore the validity of the generalized Bekenstein bound, S <= pi M a. We define the entropy S as the logarithm of the number of states which have energy eigenvalue below M and are localized to a flat space region of width a. If boundary conditions that localize field modes are imposed by fiat, then the bound encounters well-known difficulties with negative Casimir energy and large species number, as well as novel problems arising only in the generalized form. In realistic systems, however, finite-size effects contribute additional energy. We study two different models for estimating such contributions. Our analysis suggests that the bound is both valid and nontrivial if interactions are properly included, so that the entropy S counts the bound states of interacting fields.

  16. Regularity of Bound States

    DEFF Research Database (Denmark)

    Faupin, Jeremy; Møller, Jacob Schach; Skibsted, Erik

    2011-01-01

    We study regularity of bound states pertaining to embedded eigenvalues of a self-adjoint operator H, with respect to an auxiliary operator A that is conjugate to H in the sense of Mourre. We work within the framework of singular Mourre theory which enables us to deal with confined massless Pauli......–Fierz models, our primary example, and many-body AC-Stark Hamiltonians. In the simpler context of regular Mourre theory, our results boil down to an improvement of results obtained recently in [8, 9]....

  17. Hadronic shift in pionic hydrogen

    CERN Document Server

    Hennebach, M; Dax, A; Fuhrmann, H; Gotta, D; Gruber, A; Hirtl, A; Indelicato, P; Liu, Y -W; Manil, B; Markushin, V E; Hassani, A J Rusi el; Simons, L M; Trassinelli, M; Zmeskal, J

    2014-01-01

    The hadronic shift in pionic hydrogen has been redetermined to be $\\epsilon_{1s}=7.086\\,\\pm\\,0.007(stat)\\,\\pm\\,0.006(sys)$\\,eV by X-ray spectroscopy of ground state transitions applying various energy calibration schemes. The experiment was performed at the high-intensity low-energy pion beam of the Paul Scherrer Institut by using the cyclotron trap and an ultimate resolution bent crystal Bragg spectrometer.

  18. Precision measurements in pionic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostopoulos, D.F.; Cargnelli, M.; Fuhrmann, H.; Giersch, M.; Gotta, D.; Gruber, A.; Hennebach, M.; Hirtl, A.; Indelicato, P.; Liu, Y.W.; Manil, B.; Markushin, V.E.; Marton, J.; Nelms, N.; Simons, L.M.; Trasinelli, M.; Zmeskal, J

    2003-06-30

    The strong interaction in the pion nucleon system leads to a shift and a broadening of the 1s-ground state in pionic hydrogen. These two quantities are being measured in an experiment at the Paul Scherrer Institute with much improved precision and allow an experimental test of recent calculations in the framework of Chiral Perturbation Theory. The experimental techniques using high resolution crystal spectroscopy are described as well as recent results.

  19. Hadronic shift in pionic hydrogen

    International Nuclear Information System (INIS)

    The hadronic shift in pionic hydrogen has been redetermined to be ε 1s = 7.086 ± 0.007(stat) ± 0.006(sys) eV by X-ray spectroscopy of ground-state transitions applying various energy calibration schemes. The experiment was performed at the high-intensity low-energy pion beam of the Paul Scherrer Institut by using the cyclotron trap and an ultimate-resolution Bragg spectrometer with bent crystals. (orig.)

  20. Hadronic shift in pionic hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hennebach, M.; Gotta, D. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Anagnostopoulos, D.F. [University of Ioannina, Department of Materials Science and Engineering, Ioannina (Greece); Dax, A.; Liu, Y.W.; Markushin, V.E.; Simons, L.M. [Paul Scherrer Institut, Laboratory for Particle Physics, Villigen (Switzerland); Fuhrmann, H.; Gruber, A.; Hirtl, A.; Zmeskal, J. [Austrian Academy of Sciences, Stefan Meyer Institute for Subatomic Physics, Vienna (Austria); Indelicato, P. [UPMC Univ. Paris 06, Laboratoire Kastler Brossel, Sorbonne Universites, Paris (France); CNRS, Laboratoire Kastler Brossel, Paris (France); Departement de Physique de l' Ecole Normale Superieure, Laboratoire Kastler Brossel, Paris (France); Manil, B. [UPMC Univ. Paris 06, Laboratoire Kastler Brossel, Sorbonne Universites, Paris (France); Rusi el Hassani, A.J. [Universite Abdelmalek Essaadi, Faculte des Sciences et Techniques, Tanger (Morocco); Trassinelli, M. [Sorbonne Universites, Institut des NanoSciences de Paris, Paris (France); CNRS, Institut des NanoSciences de Paris, Paris (France)

    2014-12-01

    The hadronic shift in pionic hydrogen has been redetermined to be ε {sub 1s} = 7.086 ± 0.007(stat) ± 0.006(sys) eV by X-ray spectroscopy of ground-state transitions applying various energy calibration schemes. The experiment was performed at the high-intensity low-energy pion beam of the Paul Scherrer Institut by using the cyclotron trap and an ultimate-resolution Bragg spectrometer with bent crystals. (orig.)

  1. Measurement of Pionic 121Sn atoms at the RI beam factory

    International Nuclear Information System (INIS)

    We have measured the energy spectrum of pionic 121Sn atoms by missing-mass spectroscopy of the 122Sn(d, 3He) reaction near the π − emission threshold. The measurement serves as a pilot experiment for high precision systematic spectroscopy of deeply bound pionic atoms in a new pionic Atom Factory project (piAF) at the RI beam factory (RIBF) of RIKEN. The status of the analysis is reported.

  2. Bound states in string nets

    CERN Document Server

    Schulz, M D; Vidal, J

    2016-01-01

    We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.

  3. Bound anionic states of adenine

    OpenAIRE

    Harańczyk, Maciej; Gutowski, Maciej; Li, Xiang; Bowen, Kit H.

    2007-01-01

    Anionic states of nucleic acid bases are involved in DNA damage by low-energy electrons and in charge transfer through DNA. Previous gas phase studies of free, unsolvated nucleic acid base parent anions probed only dipole-bound states, which are not present in condensed phase environments, but did not observe valence anionic states, which for purine bases are thought to be adiabatically unbound. Contrary to this expectation, we have demonstrated that some thus far ignored tautomers of adenine...

  4. Bound states of 'dressed' particles

    International Nuclear Information System (INIS)

    A new approach to the problem of bound states in relativistic quantum field theories is suggested. It uses the creation - destruction operators of 'dresses' particles which have been granted by Faddeev's (1963) 'dressing' formalism. Peculiarities of the proposed approach as compared to the known ones are discussed. 8 refs. (author)

  5. Pionic Fusion in Light-Ion Systems

    International Nuclear Information System (INIS)

    Two pionic fusion experiments have been performed using the AGOR accelerator facility at KVI in order to study the role of pions in the nuclear interaction. Pionic fusion is a highly coherent process in which two nuclei fuse to a united nucleus and the available centre-of-mass energy is emitted in the pion channel. The reactions 4He(3He,π0)7Be and 6Li(4He,π0)10B were performed at beam energies only about 10 MeV above the coherent pion production threshold (256 MeV and 236.4 MeV, respectively). In order to provide sensitivity to the full dynamics and relevant processes involved in the pionic fusion reaction, almost the full angular distributions of neutral pions have been determined. To this end the fusion products have been identified in the focal plane of the magnetic big-bite spectrometer and the photons from neutral pion decay were detected in the spherical Plastic Ball detector. Detailed simulations of the response of the complete experimental setup were performed in order to verify the unique identification of the exclusive final state. Angular distributions are compared to results of a model [1] based on clustering correlations in nuclei. Using a phenomenological analysis of the angular distribution by Legendre Polynomials, the structure of the angular distributions could be analyzed and the extrapolation into missing parts was performed to determine the total cross section. The results of this analysis confirm the importance of the clustering correlations for both reactions. The mass dependence of the total pionic fusion cross sections is in agreement with the results from existing models extrapolated to the reactions studied here.(author)

  6. Bound entangled states invariant under Ux

    Institute of Scientific and Technical Information of China (English)

    Wang Zhen; Wang Zhi-Xi

    2008-01-01

    This paper obtains an entangled condition for isotropic-like states by using an atomic map. It constructs a class of bound entangled states from the entangled condition and shows that the partial transposition of the state from the constructed bound entangled class is an edge bound entangled state by using range criterion.

  7. Antibaryon-nucleus bound states

    CERN Document Server

    Hrtánková, J

    2014-01-01

    We calculated antibaryon ($\\bar{B}$ = $\\bar{p}$, $\\bar{\\Lambda}$, $\\bar{\\Sigma}$, $\\bar{\\Xi}$) bound states in selected nuclei within the relativistic mean-field (RMF) model. The G-parity motivated $\\bar{B}$-meson coupling constants were scaled to yield corresponding potentials consistent with available experimental data. Large polarization of the nuclear core caused by $\\bar{B}$ was confirmed. The $\\bar{p}$ annihilation in the nuclear medium was incorporated by including a phenomenological imaginary part of the optical potential. The calculations using a complex $\\bar{p}$-nucleus potential were performed fully self-consistently. The $\\bar{p}$ widths significantly decrease when the phase space reduction is considered for $\\bar{p}$ annihilation products, but they still remain sizeable for potentials consistent with $\\bar{p}$-atom data.

  8. Instanton bound states in ABJM theory

    Energy Technology Data Exchange (ETDEWEB)

    Hatsuda, Yasuyuki [DESY Hamburg (Germany). Theory Group; Tokyo Institute of Technology (Japan). Dept. of Physics; Moriyama, Sanefumi [Nagoya Univ. (Japan). Kobayashi Maskawa Inst. and Graduate School of Mathematics; Okuyama, Kazumi [Shinshu Univ., Matsumoto, Nagano (Japan). Dept. of Physics

    2013-06-15

    The partition function of the ABJM theory receives non-perturbative corrections due to instanton effects. We study these non-perturbative corrections, including bound states of worldsheet instantons and membrane instantons, in the Fermi-gas approach. We require that the total non-perturbative correction should be always finite for arbitrary Chern-Simons level. This finiteness is realized quite non-trivially because each bound state contribution naively diverges at some levels. The poles of each contribution should be canceled out in total. We use this pole cancellation mechanism to find unknown bound state corrections from known ones. We conjecture a general expression of the bound state contribution. Summing up all the bound state contributions, we find that the effect of bound states is simply incorporated into the worldsheet instanton correction by a redefinition of the chemical potential in the Fermi-gas system. Analytic expressions of the 3- and 4-membrane instanton corrections are also proposed.

  9. Bound States of Double Flavor Hyperons

    CERN Document Server

    Froemel, F; Riska, D O

    2005-01-01

    Several realistic phenomenological nucleon-nucleon interaction models are employed to investigate the possibility of bound deuteron-like states of such heavy flavor hyperons and nucleons, for which the interaction between the light flavor quark components is expected to be the most significant interaction. The results indicate that deuteron-like bound states are likely to form between nucleons and the $\\Xi_c^{'}$ and $\\Xi_{cc}$ charm hyperons as well as between $\\Xi$ hyperons and double-charm hyperons. Bound states between two $\\Sigma_c$ hyperons are also likely. In the case of beauty hyperons the corresponding states are likely to be deeply bound.

  10. Bound states of heavy flavor hyperons

    Science.gov (United States)

    Frömel, F.; Juliá-Díaz, B.; Riska, D. O.

    2005-04-01

    Several realistic phenomenological nucleon-nucleon interaction models are employed to investigate the possibility of bound deuteron-like states of such heavy flavor hyperons and nucleons, for which the interaction between the light flavor quark components is expected to be the most significant interaction. The results indicate that deuteron-like bound states are likely to form between nucleons and the Ξc' and Ξ charm hyperons as well as between Ξ hyperons and double-charm hyperons. Bound states between two Σ hyperons are also likely. In the case of beauty hyperons the corresponding states are likely to be deeply bound.

  11. Quasi-bound states in continuum

    International Nuclear Information System (INIS)

    We report the prediction of quasi-bound states (resonant states with very long lifetimes) that occur in the eigenvalue continuum of propagating states for a wide region of parameter space. These quasi-bound states are generated in a quantum wire with two channels and an adatom, when the energy bands of the two channels overlap. A would-be bound state that lays just below the upper energy band is slightly destabilized by the lower energy band and thereby becomes a resonant state with a very long lifetime (a second QBIC lays above the lower energy band). (author)

  12. Coulomb bound states of strongly interacting photons

    CERN Document Server

    Maghrebi, M F; Bienias, P; Choi, S; Martin, I; Firstenberg, O; Lukin, M D; Büchler, H P; Gorshkov, A V

    2015-01-01

    We show that two photons coupled to Rydberg states via electromagnetically induced transparency can interact via an effective Coulomb potential. This interaction gives rise to a continuum of two-body bound states. Within the continuum, metastable bound states are distinguished in analogy with quasi-bound states tunneling through a potential barrier. We find multiple branches of metastable bound states whose energy spectrum is governed by the Coulomb potential, thus obtaining a photonic analogue of the hydrogen atom. Under certain conditions, the wavefunction resembles that of a diatomic molecule in which the two polaritons are separated by a finite "bond length." These states propagate with a negative group velocity in the medium, allowing for a simple preparation and detection scheme, before they slowly decay to pairs of bound Rydberg atoms.

  13. Bound states of singlet quarks at LHC

    OpenAIRE

    Krasnikov, N. V.

    1996-01-01

    We discuss the discovery potential of the bound states of singlet quarks at LHC. We find that it is possible to discover bound states of singlet quarks at LHC with singlet quark masses up to 300 Gev for $e_{Q} = \\frac{2}{3}$ and up to 200 Gev for $e_{Q} = -\\frac{1}{3}$.

  14. High-Precision Measurement of Strong-Interaction Effects in Pionic Deuterium

    OpenAIRE

    Strauch, Thomas

    2009-01-01

    The hadronic ground state shift and width in pionic deuterium (piD) were measured with high precision at the pion factory of the Paul Scherrer Institut (PSI), Switzerland (PSI-Experiment R-06.03). The shift in pionic deuterium is directly related to the pion-nucleon isospin scattering lengths as measured from the shift and broadening in pionic hydrogen (piH)(PSI-Experiment R-98.01). The combination of the high-precision results from piH with the value from piD will provide a decisive constrai...

  15. Probing bound states of D-branes

    CERN Document Server

    Lifschytz, G

    1996-01-01

    A zero-brane is used to probe non-threshold BPS bound states of ($p$, $p+2$,$p+4$)-branes. At long distances the stringy calculation agrees with the supergravity calculations. The supergravity description is given, using the interpretation of the $D=8$ dyonic membrane as the bound state of a two-brane inside a four-brane. We investigate the short distance structure of these bound states, compute the phase shift of the scattered zero-brane and find the bound states characteristic size. It is found that there should be a supersymmetric solution of type IIa supergravity, describing a bound state of a zero-brane and two orthogonal two-brane, all inside a four-brane , with an additional unbound zero-brane. We comment on the relationship between $p$-branes and $(p-2)$-branes.

  16. Coulomb Bound States of Strongly Interacting Photons

    Science.gov (United States)

    Maghrebi, M. F.; Gullans, M. J.; Bienias, P.; Choi, S.; Martin, I.; Firstenberg, O.; Lukin, M. D.; Büchler, H. P.; Gorshkov, A. V.

    2015-09-01

    We show that two photons coupled to Rydberg states via electromagnetically induced transparency can interact via an effective Coulomb potential. This interaction gives rise to a continuum of two-body bound states. Within the continuum, metastable bound states are distinguished in analogy with quasibound states tunneling through a potential barrier. We find multiple branches of metastable bound states whose energy spectrum is governed by the Coulomb potential, thus obtaining a photonic analogue of the hydrogen atom. Under certain conditions, the wave function resembles that of a diatomic molecule in which the two polaritons are separated by a finite "bond length." These states propagate with a negative group velocity in the medium, allowing for a simple preparation and detection scheme, before they slowly decay to pairs of bound Rydberg atoms.

  17. On the reflection of magnon bound states

    CERN Document Server

    MacKay, Niall

    2010-01-01

    We investigate the reflection of two-particle bound states of a free open string in the light-cone AdS_5 x S^5 string sigma model, for large angular momentum J=J_56 and ending on a D7 brane which wraps the entire AdS_5 and a maximal S^3 of S^5. We use the superspace formalism to analyse fundamental and two-particle bound states in the cases of supersymmetry-preserving and broken-supersymmetry boundaries. We find the boundary S-matrices corresponding to bound states both in the bulk and on the boundary.

  18. Formation spectra of pionic atoms in the Green's function method

    Science.gov (United States)

    Ikeno, Natsumi; Yamagata-Sekihara, Junko; Nagahiro, Hideko; Hirenzaki, Satoru

    2015-03-01

    We study the formation spectra of deeply bound pionic atoms in the (d, ^3He) reactions using the Green's function method, stimulated by recent developments in experimental techniques. The Green's function method is considered to be a better theoretical formalism than the effective number approach to evaluate the formation rate of unstable systems. We compare the calculated results by the Green's function method with those by the effective number approach in various cases. We find that the differences between the results obtained by both methods are reasonably small and we can reaffirm that the effective number approach is a good theoretical method for the analyses of the previous experimental data with typical binding-energy errors of Δ B.E. ≳ 20keV for the deeply bound pionic atoms. On the other hand, we think that theoretical results using the Green's function method will be necessary in the near future to deduce precise information on the pion properties in nuclei from analyses of the pionic atom data with better accuracy than before.

  19. Black Hole Bound State Metamorphosis

    CERN Document Server

    Chowdhury, Abhishek; Saha, Arunabha; Sen, Ashoke

    2012-01-01

    N=4 supersymmetric string theories contain negative discriminant states whose numbers are known precisely from microscopic counting formulae. On the macroscopic side, these results can be reproduced by regarding these states as multi-centered black hole configurations provided we make certain identification of apparently distinct multi-centered black hole configurations according to a precise set of rules. In this paper we provide a physical explanation of such identifications, thereby establishing that multi-centered black hole configurations reproduce correctly the microscopic results for the number of negative discriminant states without any ad hoc assumption.

  20. Introduction to QCD - a bound state perspective

    CERN Document Server

    Hoyer, Paul

    2011-01-01

    These lecture notes focus on the bound state sector of QCD. Motivated by data which suggests that the strong coupling \\alpha_s(Q) freezes at low Q, and by similarities between the spectra of hadrons and atoms, I discuss if and how QCD bound states may be treated perturbatively. I recall the basic principles of perturbative gauge theory bound states at lowest order in the \\hbar expansion. Born level amplitudes are insensitive to the i\\epsilon prescription of propagators, which allows to eliminate the Z-diagrams of relativistic, time-ordered Coulomb interactions. The Dirac wave function thus describes a single electron which propagates forward in time only, even though the bound state has any number of pair constituents when Feynman propagators are used. In the absence of an external potential, states that are bound by the Coulomb attraction of their constituents can be analogously described using only their valence degrees of freedom. The instantaneous A^0 field is determined by Gauss' law for each wave functi...

  1. Bound - states for truncated Coulomb potentials

    OpenAIRE

    Odeh, Maen; Mustafa, Omar

    2000-01-01

    The pseudoperturbative shifted - $l$ expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.

  2. D-Brane Bound States Redux

    CERN Document Server

    Sethi, S K; Sethi, Savdeep; Stern, Mark

    1998-01-01

    We study the existence of D-brane bound states at threshold in Type II string theories. In a number of situations, we can reduce the question of existence to quadrature, and the study of a particular limit of the propagator for the system of D-branes. This involves a derivation of an index theorem for a family of non-Fredholm operators. In support of the conjectured relation between compactified eleven-dimensional supergravity and Type IIA string theory, we show that a bound state exists for two coincident zero-branes. This result also provides support for the conjectured description of M-theory as a matrix model. In addition, we provide further evidence that there are no BPS bound states for two and three-branes twice wrapped on Calabi-Yau vanishing cycles.

  3. Torons and D-Brane Bound States

    OpenAIRE

    Guralnik, Z.; Ramgoolam, S.

    1997-01-01

    We interpret instantons on a torus with twisted boundary conditions, in terms of bound states of branes. The interplay between the SU(N) and U(1) parts of the U(N) theory of N 4-branes allows the construction of a variety of bound states. The SU(N) and U(1) parts can contribute fractional amounts to the total instanton number which is integral. The geometry of non-self intersecting two-cycles in $T^4$ sheds some light on a number of properties of these solutions.

  4. Spin and relativistic motion of bound states

    OpenAIRE

    JÀrvinen, Matti

    2007-01-01

    The wave functions of moving bound states may be expected to contract in the direction of motion, in analogy to a rigid rod in classical special relativity, when the constituents are at equal (ordinary) time. Indeed, the Lorentz contraction of wave functions is often appealed to in qualitative discussions. However, only few field theory studies exist of equal-time wave functions in motion. In this thesis I use the Bethe-Salpeter formalism to study the wave function of a weakly bound state suc...

  5. Do $\\Xi\\Xi$ bound states exist?

    CERN Document Server

    Haidenbauer, J; Petschauer, S

    2014-01-01

    The existence of baryon-baryon bound states in the strangeness sector is examined in the framework of SU(3) chiral effective field theory. Specifically, the role of SU(3) symmetry breaking contact terms that arise at next-to-leading order in the employed Weinberg power counting scheme is explored. We focus on the 1S0 partial wave and on baryon-baryon channels with maximal isospin since in this case there are only two independent SU(3) symmetry breaking contact terms. At the same time, those are the channels where most of the bound states have been predicted in the past. Utilizing $pp$ phase shifts and $\\Sigma^+ p$ cross section data allows us to pin down one of the SU(3) symmetry breaking contact terms and a clear indication for the decrease of attraction when going from the NN system to strangeness S=-2 is found, which rules out a bound state for $\\Sigma\\Sigma$ with isospin I=2. Assuming that the trend observed for S=0 to S=-2 is not reversed when going to $\\Xi\\Sigma$ and $\\Xi\\Xi$ makes also bound states in ...

  6. Scattering theory methods for bound state problems

    International Nuclear Information System (INIS)

    For the analysis of the properties of a bound state system one may use in place of the Schroedinger equation the Lippmann-Schwinger (LS) equation for the wave function or the LS equation for the reactance operator. Use of the LS equation for the reactance operator constrains the solution to have correct asymptotic behaviour, so this approach would appear to be desirable when the bound state wave function is to be used to calculate particle transfer form factors. The Schroedinger equation based N-level analysis of the s-wave bound states of a square well is compared to the ones based on the LS equation. It is found that the LS equation methods work better than the Schroedinger equation method. The method that uses the LS equation for the wave function gives the best results for the wave functions while the method that uses the LS equation for the reactance operator gives the best results for the binding energies. The accuracy of the reactance operator based method is remarkably insensitive to changes in the oscillator constant used for the harmonic oscillator function basis set. It is also remarkably insensitive to the number of nodes in the bound state wave function. (Auth.)

  7. Relativistic bound states at Born level

    CERN Document Server

    Hoyer, Paul

    2012-01-01

    Theoretical and phenomenological studies indicate that the QCD coupling \\alpha_s(Q^2) freezes in the infrared. Hadrons may then be described by a perturbative expansion around "Born" states bound only by a confining potential. A linear potential results from the QCD equations of motion when Gauss' law for A^0 is solved with F_{\\mu\

  8. On the Bound States of Matrix Strings

    OpenAIRE

    Sahakian, Vatche

    1997-01-01

    We investigate excitations in Matrix Theory on T^2 corresponding to bound states of strings. We demonstrate the Dirichlet aspect of R-R charged vacua through a non-trivial connection between the U(1) and SU(n) sectors of the matrix SYM.

  9. Construction of bound entangled states based on permutation operators

    Science.gov (United States)

    Zhao, Hui; Guo, Sha; Jing, Naihuan; Fei, Shaoming

    2016-04-01

    We present a construction of new bound entangled states from given bound entangled states for arbitrary dimensional bipartite systems. One way to construct bound entangled states is to show that these states are positive partial transpose (PPT) and violate the range criterion at the same time. By applying certain operators to given bound entangled states or to one of the subsystems of the given bound entangled states, we obtain a set of new states which are both PPT and violate the range criterion. We show that the derived bound entangled states are not local unitary equivalent to the original bound entangled states by detail examples.

  10. Deeply bound kaonic states in nuclei

    Institute of Scientific and Technical Information of China (English)

    LI Yi-He; WU Shi-Shu

    2009-01-01

    Using a new phenomenological (K)N interaction which reproduces A(1405) as an I = 0 bound state of (K)N, we have investigated K- -3 He(T = 0) and K- -4 He(T = 1/2) within the framework of the Brueckner-Hartree-Fock(BHF) theory. Our calculations show that the above kaonic nuclear systems are both deeply bound. The binding energy BK- is 124.4 MeV(94.1 MeV) and the width Γ is 11.8 MeV(25.8 MeV) for K- -3 He(T = 0)(K- -4 He(T= 1/2)).

  11. Second bound state of PsH

    OpenAIRE

    Mitroy, J.; Bromley, M. W. J.

    2006-01-01

    The existence of a second bound state of PsH that is electronically stable and also stable against positron annihilation by the normal 2gamma and 3gamma processes is demonstrated by explicit calculation. The state can be found in the 2,4So symmetries with the two electrons in a spin triplet state. The binding energy against dissociation into the H(2p) + Ps(2p) channel was 6.06x10-4 Hartree. The dominant decay mode of the states will be radiative decay into a configuration that autoionizes or ...

  12. Quarks as quasiparticles of bound states

    International Nuclear Information System (INIS)

    A treatment of quarks as strongly bound subsystems of the baryon structure is considered, with the baryons assigned to various states with integers G and B. The requirement that the appropriate fractional values of the quantum numbers of the quarks be obtained, and that appropriate integral values be obtained for the whole system of three bound quarks, uniquely determine the three initial states of the quarks, labeled by the set of values of the quantum numbers G, B, and J. In this connection the new color quantum number is interpreted as a quantity which characterizes the presence of the subsystems in different eigenstates. The self- consistency of the changes of color states in the three-quark system is explained on the basis of a generalized Sakata model. (author)

  13. Pionic hydrogen and deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Gotta, Detlev, E-mail: d.gotta@fz-juelich.de [Forschungszentrum Juelich GmbH and JHCP (Germany); Amaro, F. D. [Coimbra University, Department of Physics (Portugal); Anagnostopoulos, D. F. [University of Ioannina, Department of Materials Science and Engineering (Greece); Buehler, P. [Austrian Academy of Sciences, SMI (Austria); Gorke, H. [Forschungszentrum Juelich GmbH and JHCP (Germany); Covita, D. S. [Coimbra University, Department of Physics (Portugal); Fuhrmann, H.; Gruber, A. [Austrian Academy of Sciences, SMI (Austria); Hennebach, M. [Forschungszentrum Juelich GmbH and JHCP (Germany); Hirtl, A.; Ishiwatari, T. [Austrian Academy of Sciences, SMI (Austria); Indelicato, P.; Bigot, E.-O. Le [LKB, UPMC-Paris 6, ENS, CNRS, Case 74 (France); Marton, J. [Austrian Academy of Sciences, SMI (Austria); Nekipelov, M. [Forschungszentrum Juelich GmbH and JHCP (Germany); Santos, J. M. F. dos [Coimbra University, Department of Physics (Portugal); Schlesser, S. [LKB, UPMC-Paris 6, ENS, CNRS, Case 74 (France); Schmid, Ph. [Austrian Academy of Sciences, SMI (Austria); Simons, L. M. [Paul Scherrer Institut (PSI) (Switzerland); Strauch, Th. [Forschungszentrum Juelich GmbH and JHCP (Germany); and others

    2012-05-15

    The ground-state level shifts and broadenings of the hydrogen isotopes caused by the strong interaction have been redetermined by using a high-resolution crystal spectrometer. An additional measurement of muonic hydrogen reveals properties of the de-excitation cascade of such electrically neutral exotic atoms, in particular Coulomb de-excitation, the understanding of which is essential for the analysis of the hadronic-atom data.

  14. Pionic background for nucleon-nucleon observables

    International Nuclear Information System (INIS)

    A method is presented that allows the unambiguous definition of the one pion exchange contribution to nucleon-nucleon scattering observables and then use it to determine those waves where values of phase shifts and mixing parameters may be understood as sums of pionic and non-pionic dynamical effects. This helps the assessment of the explicative power of the various existing phenomenological potentials and may eventually lead to ways of discriminating their effectiveness. (author) 16 refs.; 19 figs.; 2 tabs

  15. Topological edge states of bound photon pairs

    CERN Document Server

    Gorlach, Maxim A

    2016-01-01

    We predict the existence of interaction-driven edge states of bound two-photon quasiparticles in a dimer periodic array of nonlinear optical cavities. Energy spectrum of photon pairs is dramatically richer than in the noninteracting case or in a simple lattice, featuring collapse and revival of multiple edge and bulk modes as well as edge states in continuum. Despite the unexpected breakdown of the Zak phase technique and the edge mixing of internal and center-of-mass motion we link the edge state existence to the two-photon quantum walk graph connectivity, thus uncovering the topological nature of the many-body problem in complex lattices.

  16. Analytic continuation of bound states to solve resonance states

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Norimichi; Arai, Koji [Niigata Univ. (Japan); Suzuki, Yoshiyuki; Varga, K.

    1997-05-01

    As a method to determine the parameters of the resonance state, a method is proposed using analytic continuation on bound constants of correlation. The characteristics of this method consists in probability of prediction of the parameters of the resonance state only by calculation of the bound state. Owing to conducting the analytic continuation on square root of energy in the bound state as a function relating to the bound constant, energy and width in the bound state was determined. Here was reported on a result of application of this method to three systems. Some partial wave on two systems showing correlation at a simple potential and a resonance state of zero of all orbital angular motion quality in three boson system were determined using the analytic continuation method. These results agreed well with one used a method of integrating Schroedinger equation directly and one used the complex scaling method, and this method was found to be much efficient for the study of the resonance state. Under a background of becoming applicable to the method of analytic continuation, there was development of calculating method for the recent small number multi system. As the characteristics of the analytic continuation method is used for only calculation of the bound state, it is convenient at a point applicable to the method to obtain conventional bound state and then is much efficient in a point of applicability of calculus of variations. However, in order to obtain coefficient of Pade approximation correctly, the bound state must be solved correctly, which is difficult for more complex system and is not always applicable to every systems. (G.K.)

  17. Tsirelson's bound and supersymmetric entangled states

    CERN Document Server

    Borsten, L; Duff, M J

    2012-01-01

    In order to see whether superqubits are more nonlocal than ordinary qubits, we construct a class of two-superqubit entangled states as a nonlocal resource in the CHSH game. Since super Hilbert space amplitudes are Grassmann numbers, the result depends on how we extract real probabilities and we examine three choices of map: (1) DeWitt (2) Trigonometric (3) Modified Rogers. In cases (1) and (2) the winning probability reaches the Tsirelson bound p(win) = cos^2 pi/8 \\simeq 0.8536 of standard quantum mechanics. Case (3) crosses Tsirelson's bound with p(win) = 0.9265. Although all states used in the game involve probabilities lying between 0 and 1, case (3) permits other changes of basis inducing negative transition probabilities.

  18. Quantum Bound States Around Black Holes

    OpenAIRE

    Grain, J.; Barrau, A.

    2007-01-01

    Quantum mechanics around black holes has shown to be one of the most fascinating fields of theoretical physics. It involves both general relativity and particle physics, opening new eras to establish the principles of unified theories. In this article, we show that quantum bound states with no classical equivalent -- as it can easily be seen at the dominant monopolar order -- should be formed around black holes for massive scalar particles. We qualitatively investigate some important physical...

  19. Closed form bound-state perturbation theory

    Directory of Open Access Journals (Sweden)

    Ollie J. Rose

    1980-01-01

    Full Text Available The perturbed Schrödinger eigenvalue problem for bound states is cast into integral form using Green's Functions. A systematic algorithm is developed and applied to the resulting equation giving rise to approximate solutions expressed as functions of the given perturbation parameter. As a by-product, convergence radii for the traditional Rayleigh-Schrödinger and Brillouin-Wigner perturbation theories emerge in a natural way.

  20. Weakly bound states in heterogeneous waveguides

    Science.gov (United States)

    Amore, Paolo; Fernández, Francisco M.; Hofmann, Christoph P.

    2016-07-01

    We study the spectrum of the Helmholtz equation in a two-dimensional infinite waveguide, containing a weak heterogeneity localized at an internal point, and obeying Dirichlet boundary conditions at its border. We use the variational theorem to derive the condition for which the lowest eigenvalue of the spectrum falls below the continuum threshold and a bound state appears, localized at the heterogeneity. We devise a rigorous perturbation scheme and derive the exact expression for the energy to third order in the heterogeneity.

  1. Semirelativistic Bound-State Equations: Trivial Considerations

    Directory of Open Access Journals (Sweden)

    Lucha Wolfgang

    2014-01-01

    Full Text Available Observing renewed interest in long-standing (semi- relativistic descriptions of two-body bound states, we would like to make a few comments on the eigenvalue problem posed by the spinless Salpeter equation and, illustrated by the examples of the nonsingular Woods–Saxon potential and the singular Hulthén potential, recall elementary tools that, in their quest, practitioners looking for analytic albeit approximate solutions will find useful.

  2. Andreev bound states. Some quasiclassical reflections

    International Nuclear Information System (INIS)

    We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it

  3. Andreev bound states. Some quasiclassical reflections

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Y., E-mail: yiriolin@illinois.edu; Leggett, A. J. [University of Illinois at Urhana-Champaign, Dept. of Physics (United States)

    2014-12-15

    We discuss a very simple and essentially exactly solvable model problem which illustrates some nice features of Andreev bound states, namely, the trapping of a single Bogoliubov quasiparticle in a neutral s-wave BCS superfluid by a wide and shallow Zeeman trap. In the quasiclassical limit, the ground state is a doublet with a splitting which is proportional to the exponentially small amplitude for “normal” reflection by the edges of the trap. We comment briefly on a prima facie paradox concerning the continuity equation and conjecture a resolution to it.

  4. Unexpected strong attraction in the presence of continuum bound state

    International Nuclear Information System (INIS)

    The result of few-particle ground-state calculation employing a two-particle non-local potential supporting a continuum bound state in addition to a negative-energy bound state has occasionally revealed unexpected large attraction in producing a very strongly bound ground state. In the presence of the continuum bound state the difference of phase shift between zero and infinite energies has an extra jump of φ as in the presence of an additional bound state. The wave function of the continuum bound state is identical with that of a strongly bound negative-energy state, which leads us to postulate a pseudo bound state in the two-particle system in order to explain the unexpected attraction. The role of the Pauli forbidden states is expected to be similar to these pseudo states. (author)

  5. Bound states -- from QED to QCD

    OpenAIRE

    Hoyer, Paul

    2014-01-01

    These lectures are divided into two parts. In Part 1 I discuss bound state topics at the level of a basic course in field theory: The derivation of the Schr\\"odinger and Dirac equations from the QED Lagrangian, by summing Feynman diagrams and in a Hamiltonian framework. Less well known topics include the equal-time wave function of Positronium in motion and the properties of the Dirac wave function for a linear potential. The presentation emphasizes physical aspects and provides the framework...

  6. Is there an quasi-bound state?

    CERN Document Server

    Wilkin, C; Chiladze, D; Dymov, S; Hanhart, C; Hartmann, M; Hejny, V; Kacharava, A K; Keshelashvili, I; Khoukaz, A; Maeda, Y; Mersmann, T; Mielke, M; Mikirtychiants, S; Papenbrock, M; Rathmann, F; Rausmann, T; Schleichert, R; Ströher, H; Täschner, A; Valdau, Yu; Wronska, A

    2007-01-01

    The observed variation of the total cross section for the dp -> 3He eta reaction near threshold means that the magnitude of the s--wave amplitude falls very rapidly with the eta centre--of--mass momentum. It is shown here that recent measurements of the momentum dependence of the angular distribution imply a strong variation also in the phase of this amplitude. Such a behaviour is that expected from a quasi--bound or virtual eta-3He state. The interpretation can be investigated further through measurements of the deuteron or proton analysing powers and/or spin--correlations.

  7. A balance for Dark Matter bound states

    OpenAIRE

    Nozzoli, F.

    2016-01-01

    Massive particles with self interactions of the order of 0.2 barn/GeV are intriguing Dark Matter candidates from an astrophysical point of view. Direct detection searches for very massive particles, with relatively high cross sections with ordinary matter, cannot rule out $\\sigma/M > 0.01$ barn/GeV, due to atmosphere and material shielding. Here, the possibility of the existence of bound states with ordinary matter, for Dark Matter candidates with not negligible interactions, is considered. T...

  8. Novel Bound States in Graphene with Impurities

    CERN Document Server

    Gupta, Kumar S

    2008-01-01

    We obtain a novel bound state spectrum of the low energy excitations near the Fermi points of graphene in the presence of a charge impurity. The effects of possible short range interactions induced by the impurity are modelled by suitable boundary conditions. The spectrum in the subcritical region of the effective Coulomb coupling is labelled by a parameter which characterizes the boundary conditions and determines the inequivalent quantizations of the system. In the supercritical region we obtain a renormalization group flow for the effective Coulomb coupling.

  9. Method for laser spectroscopy of metastable pionic helium atoms

    International Nuclear Information System (INIS)

    The PiHe collaboration is currently attempting to carry out laser spectroscopy of metastable pionic helium atoms using the high-intensity π− beam of the ring cyclotron facility of the Paul Scherrer Institute. These atoms are heretofore hypothetical three-body Coulomb systems each composed of a helium nucleus, a π− occupying a Rydberg state, and an electron occupying the 1s ground state. We briefly review the proposed method by which we intend to detect the laser spectroscopic signal. This complements our experiments on metastable antiprotonic helium atoms at CERN

  10. On Aharonov-Casher bound states

    Energy Technology Data Exchange (ETDEWEB)

    Silva, E.O. [Universidade Federal do Maranhao, Departamento de Fisica, Sao Luis, MA (Brazil); Andrade, F.M. [Universidade Estadual de Ponta Grossa, Departamento de Matematica e Estatistica, Ponta Grossa, PR (Brazil); Filgueiras, C. [Universidade Federal de Campina Grande, Departamento de Fisica, Caixa Postal 10071, Campina Grande, PB (Brazil); Belich, H. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil)

    2013-04-15

    In this work bound states for the Aharonov-Casher problem are considered. According to Hagen's work on the exact equivalence between spin-1/2 Aharonov-Bohm and Aharonov-Casher effects, is known that the {nabla}.E term cannot be neglected in the Hamiltonian if the spin of particle is considered. This term leads to the existence of a singular potential at the origin. By modeling the problem by boundary conditions at the origin which arises by the self-adjoint extension of the Hamiltonian, we derive for the first time an expression for the bound state energy of the Aharonov-Casher problem. As an application, we consider the Aharonov-Casher plus a two-dimensional harmonic oscillator. We derive the expression for the harmonic oscillator energies and compare it with the expression obtained in the case without singularity. At the end, an approach for determination of the self-adjoint extension parameter is given. In our approach, the parameter is obtained essentially in terms of physics of the problem. (orig.)

  11. Hadron QCD (Bound states in gauge theories)

    International Nuclear Information System (INIS)

    The general principles of the description of bound states in QED and QCD are proposed for the aim of construction of the consistent scheme of calculating hadron spectrum and interaction amplitudes. Such principles are the explicit solution of the Gauss equation for time component, the quantization of the minimal set physical variables and the choice of the time-axis of quantization in accordance with the Markov-Yukawa relativistic theory of bilocal fields. QCD constructed by these principles contains new infrared divergences, changing the behaviour of the Coulomb field on large distances. This divergences (like ones in QED) are removed out with the help of phenomenology, in this case, by taking into account the rising potential as the 'nonperturbative background' for a new perturbation theory. It is shown how in such hadron theory the parton model, nonrelativistic potential spectroscopy, chiral Lagrangian and confinement appear. The Dirac quantization method, renormalization group equations and lattice calculations in their conventional formulation are proved to be untenable for the description of bound states. 23 refs

  12. ADMonium: Asymmetric Dark Matter Bound State

    CERN Document Server

    Bi, Xiao-Jun; Ko, P; Li, Jinmian; Li, Tianjun

    2016-01-01

    We propose a novel framework for asymmetric scalar dark matter (ADM), which has interesting collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\\bar b$. Of particular interest, our setup nicely explains the recent di-photon anomaly at 750 GeV via the events from ${\\rm ADMonium}\\ra 2X(\\ra e^+e^-)$, where the electrons are identified as ...

  13. Bound states -- from QED to QCD

    CERN Document Server

    Hoyer, Paul

    2014-01-01

    These lectures are divided into two parts. In Part 1 I discuss bound state topics at the level of a basic course in field theory: The derivation of the Schr\\"odinger and Dirac equations from the QED Lagrangian, by summing Feynman diagrams and in a Hamiltonian framework. Less well known topics include the equal-time wave function of Positronium in motion and the properties of the Dirac wave function for a linear potential. The presentation emphasizes physical aspects and provides the framework for Part 2, which discusses the derivation of relativistic bound states at Born level in QED and QCD. A central aspect is the maintenance of Poincar\\'e invariance. The transformation of the wave function under boosts is studied in detail in D=1+1 dimensions, and its generalization to D=3+1 is indicated. Solving Gauss' law for $A^0$ with a non-vanishing boundary condition leads to a linear potential for QCD mesons, and an analogous confining potential for baryons.

  14. A balance for Dark Matter bound states

    CERN Document Server

    Nozzoli, F

    2016-01-01

    Massive particles with self interactions of the order of 0.2 barn/GeV are intriguing Dark Matter candidates from an astrophysical point of view. Direct detection searches for very massive particles, with relatively high cross sections with ordinary matter, cannot rule out $\\sigma/M > 0.01$ barn/GeV, due to atmosphere and material shielding. Here, the possibility of the existence of bound states with ordinary matter, for Dark Matter candidates with not negligible interactions, is considered. The existence of bound states, with binding energy larger than $\\sim$1 meV, would offer the possibility to test in laboratory capture cross sections of the order of a barn (or larger). The signature of the detection of a mass increasing of cryogenic samples, due to the possible Dark Matter accumulation, would allow the investigation of Dark Matter particles with mass up to the GUT scale. A proof of concept for a possible detection set-up and the evaluation of some noise sources are described.

  15. Exact Entanglement Cost of Multi-Qubit Bound Entangled States

    OpenAIRE

    Bandyopadhyay, Somshubhro; Roychowdhury, Vwani P.

    2005-01-01

    We report the exact entanglement cost of a class of multiqubit bound entangled states, computed in the context of a universal model for multipartite state preparation. The exact amount of entanglement needed to prepare such states are determined by first obtaining lower bounds using a cut-set approach, and then providing explicit local protocols achieving the lower bound.

  16. Calculation of the density shift and broadening of the transition lines in pionic helium: Computational problems

    Energy Technology Data Exchange (ETDEWEB)

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [Bulgarian Academy of Sciences, INRNE (Bulgaria)

    2015-08-15

    The potential energy surface and the computational codes, developed for the evaluation of the density shift and broadening of the spectral lines of laser-induced transitions from metastable states of antiprotonic helium, fail to produce convergent results in the case of pionic helium. We briefly analyze the encountered computational problems and outline possible solutions of the problems.

  17. Bound states and Lorentz-Poincare symmetry

    International Nuclear Information System (INIS)

    A hypothesis of the ''relation-continuum'' C is put forward, closely connected with isolation of physical system, which extends to finite universal constant c the absolute nature of the Galilean relative coordinates and the absolute Newtonian time. Points of C4 continuum are directly unobservable and the relativistic symmetry L4 of directly observable space-time events becomes the limiting case of the C4-symmetry. Consequently, though the possibility of the hypothesis of C4-continuum is due to quantum physics, the modifications it implies come with finite universal constant (h/2π)/c and concern the description of the internal structure of bound states only. The C4-symmetry of relations, as weaker than the Lorentz-Poincare L4-symmetry of events, makes ''more room'' for quantum dynamical models. The Feynman graphs phenomenology with form factors (vertex functions) of non-point particles left for experimental determination can be connected with the C4-framework which determines their analytic structure. The C4-effects then would reveal themselves only in these processes in which composite particles participate. Therefore, the ''good'' quantum electrodynamics of point-particles is left unmodified. Two off-mass-shell effects are analyzed in the relatively low-energy processes which are connected with the mass-dependent localization of the center-of-mass of composite particle ''M''. They seem to be crucial for the hypothesis itself. (author)

  18. Squashed giants: bound states of giant gravitons

    International Nuclear Information System (INIS)

    We consider giant gravitons in the maximally supersymmetric type IIB plane-wave, in the presence of a constant NSNS B-field background. We show that in response to the background B-field the giant graviton would take the shape of a deformed three-sphere, the size and shape of which depend on the B-field, and that the giant becomes classically unstable once the B-field is larger than a critical value Bcr. In particular, for the B-field which is (anti-)self-dual under the SO(4) isometry of the original giant S3, the closed string metric is that of a round S3, while the open string metric is a squashed three-sphere. The squashed giant can be interpreted as a bound state of a spherical three-brane and circular D-strings. We work out the spectrum of geometric fluctuations of the squashed giant and study its stability. We also comment on the gauge theory which lives on the brane (which is generically a noncommutative theory) and a possible dual gauge theory description of the deformed giant. (author)

  19. Real weights, bound states and duality orbits

    CERN Document Server

    Marrani, Alessio; Romano, Luca

    2015-01-01

    We show that the duality orbits of extremal black holes in supergravity theories with symmetric scalar manifolds can be derived by studying the stabilizing subalgebras of suitable representatives, realized as bound states of specific weight vectors of the corresponding representation of the duality symmetry group. The weight vectors always correspond to weights that are real, where the reality properties are derived from the Tits-Satake diagram that identifies the real form of the Lie algebra of the duality symmetry group. Both N=2 magic Maxwell-Einstein supergravities and the semisimple infinite sequences of N=2 and N=4 theories in D=4 and 5 are considered, and various results, obtained over the years in the literature using different methods, are retrieved. In particular, we show that the stratification of the orbits of these theories occurs because of very specific properties of the representations: in the case of the theory based on the real numbers, whose symmetry group is maximally non-compact and there...

  20. Real weights, bound states and duality orbits

    Science.gov (United States)

    Marrani, Alessio; Riccioni, Fabio; Romano, Luca

    2016-01-01

    We show that the duality orbits of extremal black holes in supergravity theories with symmetric scalar manifolds can be derived by studying the stabilizing subalgebras of suitable representatives, realized as bound states of specific weight vectors of the corresponding representation of the duality symmetry group. The weight vectors always correspond to weights that are real, where the reality properties are derived from the Tits-Satake diagram that identifies the real form of the Lie algebra of the duality symmetry group. Both 𝒩 = 2 magic Maxwell-Einstein supergravities and the semisimple infinite sequences of 𝒩 = 2 and 𝒩 = 4 theories in D = 4 and 5 are considered, and various results, obtained over the years in the literature using different methods, are retrieved. In particular, we show that the stratification of the orbits of these theories occurs because of very specific properties of the representations: in the case of the theory based on the real numbers, whose symmetry group is maximally noncompact and therefore all the weights are real, the stratification is due to the presence of weights of different lengths, while in the other cases it is due to the presence of complex weights.

  1. Effects of Bound States on Dark Matter Annihilation

    OpenAIRE

    An, Haipeng; Wise, Mark B.; Zhang, Yue

    2016-01-01

    We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its non-trivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal rates over the rat...

  2. Effects of Bound States on Dark Matter Annihilation

    OpenAIRE

    An, Haipeng; Wise, Mark B.; Zhang, Yue

    2016-01-01

    We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its non-trivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal ...

  3. Microscopic observation of magnon bound states and their dynamics

    OpenAIRE

    Fukuhara, Takeshi; Schauß, Peter; Endres, Manuel; Hild, Sebastian; Cheneau, Marc; Bloch, Immanuel; Gross, Christian

    2013-01-01

    More than eighty years ago, H. Bethe pointed out the existence of bound states of elementary spin waves in one-dimensional quantum magnets. To date, identifying signatures of such magnon bound states has remained a subject of intense theoretical research while their detection has proved challenging for experiments. Ultracold atoms offer an ideal setting to reveal such bound states by tracking the spin dynamics after a local quantum quench with single-spin and single-site resolution. Here we r...

  4. Precision Study of Positronium: Testing Bound State QED Theory

    OpenAIRE

    Karshenboim, Savely G.

    2003-01-01

    As an unstable light pure leptonic system, positronium is a very specific probe atom to test bound state QED. In contrast to ordinary QED for free leptons, the bound state QED theory is not so well understood and bound state approaches deserve highly accurate tests. We present a brief overview of precision studies of positronium paying special attention to uncertainties of theory as well as comparison of theory and experiment. We also consider in detail advantages and disadvantages of positro...

  5. Dark-matter bound states from Feynman diagrams

    NARCIS (Netherlands)

    K. Petraki; M. Postma; M. Wiechers

    2015-01-01

    If dark matter couples directly to a light force mediator, then it may form bound states in the early universe and in the non-relativistic environment of haloes today. In this work, we establish a field-theoretic framework for the computation of bound-state formation cross-sections, de-excitation an

  6. Bound states in a hyperbolic asymmetric double-well

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, R. R., E-mail: richard.hartmann@dlsu.edu.ph [Physics Department, De La Salle University, 2401 Taft Avenue, Manila (Philippines)

    2014-01-15

    We report a new class of hyperbolic asymmetric double-well whose bound state wavefunctions can be expressed in terms of confluent Heun functions. An analytic procedure is used to obtain the energy eigenvalues and the criterion for the potential to support bound states is discussed.

  7. Tauonium tau+tau-, a bound state of heavy leptons

    International Nuclear Information System (INIS)

    Some properties of an electromagnetically bound state of the recently discovered tau heavy lepton are analyzed. This bound state of tau+tau-, has been called tauonium, T. It is found that the process e+e-→T→X has a very high cross section but that it might have escaped observation because of the very narrow width of the T

  8. The representation of bound state wavefunctions by spherical Hankel functions

    International Nuclear Information System (INIS)

    The representation of a nucleon bound state by a single Hankel function is generalised such that the bound state is expanded as a linear combination of Hankel functions of the same l-value. The singularity at the origin due to the use of Hankel functions is removed. The arguments and coefficients of the expansion are determined by a variational method. (orig.)

  9. X-rays from pionic 3He

    International Nuclear Information System (INIS)

    Pionic X-ray energies, lorentzian widths, and relative intensities have been measured for the transitions in liquid 3He. The pion-nucleus interaction is found to result in an attractive shift of the 1s level of 27 +- 5 eV and in a lorentzian width of 65 +- 12 eV. The measured Ksub(β) to Ksub(α) intensity ratio is 1.05 +- 0.07. (Auth.)

  10. The Pionic Hydrogen Experiment at PSI

    Energy Technology Data Exchange (ETDEWEB)

    Anagnostopoulos, D. F. [University of Ioannina, Department of Material Science (Greece); Biri, S. [Hungarian Academy of Science, Institut of Nuclear Research (Hungary); Borchert, G. [Forschungszentrum Juelich, Institut fuer Kernphysik (Germany); Breunlich, W.; Cargnelli, M. [Osterreichische Akademie der Wissenschaften, Institut fuer Mittelenergiephysik (Austria); Egger, J.-P. [Universite de Neuchatel, Institut de Physique (Switzerland); Fuhrmann, H. [Osterreichische Akademie der Wissenschaften, Institut fuer Mittelenergiephysik (Austria); Gotta, D., E-mail: d.gotta@fz-juelich.de [Forschungszentrum Juelich, Institut fuer Kernphysik (Germany); Giersch, M.; Gruber, A. [Osterreichische Akademie der Wissenschaften, Institut fuer Mittelenergiephysik (Austria); Hennebach, M. [Forschungszentrum Juelich, Institut fuer Kernphysik (Germany); Indelicato, P. [Universite Pierre et Marie Curie, Laboratoire Kastler-Brossel (France); Jensen, T. S. [Institut fuer Theoretische Physik (Switzerland); Kottmann, F. [ETHZ, Institut fuer Teilchenphysik (Switzerland); Liu, Y.-W. [Paul-Scherrer-Institut (PSI) (Switzerland); Manil, B. [Universite Pierre et Marie Curie, Laboratoire Kastler-Brossel (France); Markushin, V. M. [Paul-Scherrer-Institut (PSI) (Switzerland); Marton, J. [Osterreichische Akademie der Wissenschaften, Institut fuer Mittelenergiephysik (Austria); Nelms, N. [University of Leicester, Department of Physics and Astronomy (United Kingdom); Oades, G. C. [Aarhus University, Institute of Physics (Denmark)

    2001-12-15

    The measurement of the strong-interaction effects in pionic hydrogen gives access to fundamental properties of the pion-nucleon interaction. Methods developed within the framework of Heavy-Baryon Chiral Perturbation Theory allow calculations with an accuracy of a few per cent, which should be tested by experiment.Techniques advanced for recent experiments on the precision spectroscopy of X-rays from antiprotonic and pionic atoms will be used in a new series of measurements for pionic hydrogen. The aim is to achieve finally an accuracy of 0.2% for the hadronic shift element of {sub 1s} and most important of about 1% for the broadening {Gamma}{sub 1s}.An essential part of the experimental program is an improved understanding of the atomic cascade. At first, the value of element of {sub 1s} has to be proven not to be influenced by molecular formation. Secondly, a more accurate determination of {Gamma}{sub 1s} requires a detailed study of Coulomb deexcitation.

  11. Asymptotic properties of bound states in coupled quantum wave guides

    Energy Technology Data Exchange (ETDEWEB)

    Maglione, Enrico [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy); Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Ferreira, LIdia S [Centro de Fisica das Interaccoes Fundamentais (CFIF), Avenida Rovisco Pais, Lisbon (Portugal); Departamento de Fisica, Instituto Superior Tecnico, Avenida Rovisco Pais, P1049-001 Lisbon (Portugal); Cattapan, Giorgio [Dipartimento di Fisica G Galilei, Via F Marzolo 8, Padova (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Padova (Italy)

    2006-02-03

    We investigate the motion of bound-state poles in two quantum wave guides laterally coupled through a window. The imaginary momentum ik at the bound-state poles is studied as a function of the size a of the window. Both bound and virtual states appear as a spans the whole range from 0 up to +{infinity}. We are able to find simple scaling laws relating the critical value of the window size at which the nth bound state appears to the number n of bound states, in the limit of large n. A similar relation is also provided for the slope and the second derivative of the pole trajectories in the (k, a) plane. These relations are characterized by an extremely high numerical accuracy. We also evaluate the exact value of the first two derivatives for a = 0.

  12. Recent advances in bound state quantum electrodynamics

    International Nuclear Information System (INIS)

    Recent developments are reviewed in four areas of computational quantum electrodynamics: a new relativistic two-body formalism equal in rigor to the Bethe-Salpeter formalism but with strong calculational advantages is discussed; recent work on the computation of the decay rate of bound systems (positronium in particular) is presented; limits on possible composite structure of leptons are discussed; a new multidimensional integration program ('VEGAS') suitable for higher order calculations is presented

  13. Weakly bound states of polar molecules in bilayers

    CERN Document Server

    Fedorov, D V; Zinner, N T; Jensen, A S

    2011-01-01

    We investigate a system of two polarized molecules in a layered trap. The molecules reside in adjacent layers and interact purely via the dipole-dipole interaction. We determine the properties of the ground state of the system as a function of the dipole moment and polarization angle. A bound state is always present in the system and in the weak binding limit the bound state extends to a very large distance and shows universal behavior.

  14. Relativistic bound states: a mass formula for vector mesons

    International Nuclear Information System (INIS)

    In the framework of a relativistic description of two particles bound states, a mass formula for vector mesons considered as quark-antiquark systems bound by harmonic oscillator like forces is proposed. Results in good agreement with experimental values are obtained

  15. Higgs interchange and bound states of superheavy fermions

    Indian Academy of Sciences (India)

    M De Sanctis

    2013-09-01

    Hypothetical superheavy fourth-generation fermions with a very small coupling with the rest of the Standard Model can give rise to long enough lived bound states. The production and the detection of these bound states would be experimentally feasible at the LHC. Extending, in the present study, the analysis of other authors, a semirelativistic wave equation is solved using an accurate numerical method to determine the binding energies of these possible superheavy fermion-bound states. The interaction given by the Yukawa potential of the Higgs boson exchange is considered; the corresponding relativistic corrections are calculated by means of a model based on the covariance properties of the Hamiltonian. We study the effects given by the Coulomb force. Moreover, we calculate the contributions given by the Coulombic and confining terms of the strong interaction in the case of superheavy quark bound states. The results of the model are critically analysed.

  16. Transport Through Andreev Bound States in a Graphene Quantum Dot

    OpenAIRE

    Dirks, Travis; Hughes, Taylor L.; Lal, Siddhartha; Uchoa, Bruno; Chen, Yung-Fu; Chialvo, Cesar; Goldbart, Paul M.; Mason, Nadya

    2010-01-01

    Andreev reflection-where an electron in a normal metal backscatters off a superconductor into a hole-forms the basis of low energy transport through superconducting junctions. Andreev reflection in confined regions gives rise to discrete Andreev bound states (ABS), which can carry a supercurrent and have recently been proposed as the basis of qubits [1-3]. Although signatures of Andreev reflection and bound states in conductance have been widely reported [4], it has been difficult to directly...

  17. Bound States of a Ferromagnetic Wire in a Superconductor

    Science.gov (United States)

    Sau, Jay D.; Brydon, P. M. R.

    2015-09-01

    We consider the problem of bound states in strongly anisotropic ferromagnetic impurities in a superconductor, motivated by recent experiments that claim to observe Majorana modes at the ends of ferromagnetic wires on a superconducting substrate [S. Nadj-Perge et al., Science 346, 602 (2014)]. Generalizing the successful theory of bound states of spherically symmetric impurities, we consider a wirelike potential using both analytical and numerical approaches. We find that away from the ends of the wire the bound states form bands with pronounced van Hove singularities, giving rise to subgap peaks in the local density of states. For sufficiently strong magnetization of the wire, we show that this process generically produces a sharp peak at zero energy in the local density of states near the ends of the wire. This zero-energy peak has qualitative similarities to the claimed signature of a Majorana mode observed in the aforementioned experiment.

  18. Bound States of a Ferromagnetic Wire in a Superconductor.

    Science.gov (United States)

    Sau, Jay D; Brydon, P M R

    2015-09-18

    We consider the problem of bound states in strongly anisotropic ferromagnetic impurities in a superconductor, motivated by recent experiments that claim to observe Majorana modes at the ends of ferromagnetic wires on a superconducting substrate [S. Nadj-Perge et al., Science 346, 602 (2014)]. Generalizing the successful theory of bound states of spherically symmetric impurities, we consider a wirelike potential using both analytical and numerical approaches. We find that away from the ends of the wire the bound states form bands with pronounced van Hove singularities, giving rise to subgap peaks in the local density of states. For sufficiently strong magnetization of the wire, we show that this process generically produces a sharp peak at zero energy in the local density of states near the ends of the wire. This zero-energy peak has qualitative similarities to the claimed signature of a Majorana mode observed in the aforementioned experiment. PMID:26431011

  19. Pionic-decay spectra of few-body Λ-hypernuclei

    International Nuclear Information System (INIS)

    Pionic-decay spectra are discussed in A=4 and 5 Λ-hypernuclei by using wave-functions obtained by the resonating group method. For Λ5He, the π--spectrum shows a sharp peak at 171 MeV with 1.5 MeV FWHM in the total pion energy. For Λ4H and Λ4He, the spectra have broad peaks around 170 MeV with 6-7 MeV FWHM. This difference is caused by resonance structures of the final-state nuclei under the spin-non-flip dominance in the pionic decay. The calculated partial decay widths are in systematically good agreement with all available experimental data. (author)

  20. Graphene in inhomogeneous magnetic fields: bound, quasi-bound and scattering states

    Energy Technology Data Exchange (ETDEWEB)

    Ramezani Masir, M; Peeters, F M [Departement Fysica, Universiteit Antwerpen Groenenborgerlaan 171, B-2020 Antwerpen (Belgium); Vasilopoulos, P, E-mail: mrmphys@gmail.com, E-mail: takis@alcor.concordia.ca, E-mail: francois.peeters@ua.ac.be [Department of Physics, Concordia University, Montreal, Quebec, H4B 1R6 (Canada)

    2011-08-10

    The electron states in graphene-based magnetic dot and magnetic ring structures and combinations of both are investigated. The corresponding spectra are studied as a function of the radii, the strengths of the inhomogeneous magnetic field and of a uniform background field, the strength of an electrostatic barrier and the angular momentum quantum number. In the absence of an external magnetic field we have only long-lived quasi-bound and scattering states and we assess their influence on the density of states. In addition, we consider elastic electron scattering by a magnetic dot, whose average B vanishes, and show that the Hall and longitudinal resistivities, as a function of the Fermi energy, exhibit a pronounced oscillatory structure due to the presence of quasi-bound states. Depending on the dot parameters this oscillatory structure differs substantially for energies below and above the first Landau level.

  1. Boson bound states in the -Fermi–Pasta–Ulam model

    Indian Academy of Sciences (India)

    Xin-Guang Hu; Ju Xiang; Zheng Jiao; Yang Liu; Guo-Qiu Xie; Ke Hu

    2013-11-01

    The bound states of four bosons in the quantum -Fermi–Pasta–Ulam model are investigated and some interesting results are presented using the number conserving approximation combined with the number state method. We find that the relative magnitude of anharmonic coefficient has a significant effect on forming localized energy in the model, and the wave number plays an important role in forming different bound states. The signature of the quantum breather is also set up by the square of the amplitudes of the corresponding eigenvectors in real space.

  2. Effects of Bound States on Dark Matter Annihilation

    CERN Document Server

    An, Haipeng; Zhang, Yue

    2016-01-01

    We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its non-trivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal rates over the rate for direct dark matter annihilation with Sommerfeld enhancement. The effects are strongest for large dark gauge coupling and when the dark photon mass is smaller than the typical momentum of dark matter in the galaxy. As an example, we show that for thermal dark matter the Fermi gamma ray constraint is substantially increased once bound state effects are taken into account. We also find that bound state effects are not important for dark matter annihilation during the freeze out and recombination epochs.

  3. Proximity induced interface bound states in superconductor-graphene junctions

    OpenAIRE

    Burset, P.; Herrera, W.; Yeyati, A. Levy

    2009-01-01

    We show that interface bound states are formed at isolated graphene-superconductor junctions. These states arise due to the interplay of virtual Andreev and normal reflections taking place at these interfaces. Simple analytical expressions for their dispersion are obtained considering interfaces formed along armchair or zig-zag edges. It is shown that the states are sensitive to a supercurrent flowing on the superconducting electrode. The states provide long range superconducting correlations...

  4. Supergiant halos as an integral record of natural pionic radioactivity

    OpenAIRE

    Ion, D. B.; Ion-Mihai, Reveica; Ion, M. L.; Sandru, Adriana I.

    2004-01-01

    In this paper an unified interpretation of the supergiant halos (SGH), discovered by Grady, Walker and Laemmlein, is discussed. So, it is proved that SGH`s can be considered as integral records of the nuclear pionic radioactivity.

  5. Probing Majorana Bound States in T-Shaped Junctions

    Science.gov (United States)

    Wu, Bin-He; Cheng, Xiao; Wang, Chun-Rui; Gong, Wei-Jiang

    2014-03-01

    We investigate the transport properties of a pair of Majorana bound states in a T-shaped junction, where two normal leads are coupled with an identical Majorana bound state. Both the scattering matrix and the recursive Green function method show that the peak value of the differential conductance (Gpeak) in units of e2/h and the shot noise Fano factor in the zero bias limit (F0), which are measured at the same lead and zero temperature, satisfy a linear relation as F0 = 1 + Gpeak/2, independent of the magnitude or symmetry of the coupling strengths to the leads. Therefore, combined measurements of the differential conductance and shot noise in the T-shaped geometry can serve as a characteristic signature in probing Majorana bound states.

  6. Relativistic bound state approach to fundamental forces including gravitation

    Directory of Open Access Journals (Sweden)

    Morsch H.P.

    2012-06-01

    Full Text Available To describe the structure of particle bound states of nature, a relativistic bound state formalism is presented, which requires a Lagrangian including scalar coupling of two boson fields. The underlying mechanisms are quite complex and require an interplay of overlapping boson fields and fermion-antifermion production. This gives rise to two potentials, a boson-exchange potential and one identified with the long sought confinement potential in hadrons. With minimal requirements, two elementary massless fermions (quantons - with and without charge - and one gauge boson, hadrons and leptons but also atoms and gravitational systems are described by bound states with electric and magnetic coupling between the charges and spins of quantons. No need is found for colour, Higgs-coupling and supersymmetry.

  7. A brief review on Majorana bound states in topological superconductors

    Science.gov (United States)

    Lin, Rui; Wang, Zhi

    2016-07-01

    Topological superconductivity has drawn much attention recently, and most interests are focused on the Majorana bound states existing at the edges of one-dimensional topological superconductors. These Majorana bound states are ideal platform for studying non-Abelian statistics. Meanwhile, they are proposed to be useful in quantum computation. In this review, we introduce the basic concepts and models in this area. We begin from the Kitaev model, which is the most concise model for one-dimensional topological superconductivity. Then, we discuss how to realize this model with spin-orbit coupling in realistic materials. Finally, we show some simple methods to detect the Majorana bound states and study their novel properties with the help of adjacent quantum dots.

  8. Bound States at Threshold resulting from Coulomb Repulsion

    CERN Document Server

    Gridnev, Dmitry K

    2011-01-01

    The eigenvalue absorption for a many-particle Hamiltonian depending on a parameter is analyzed in the framework of non-relativistic quantum mechanics. The long-range part of pair potentials is assumed to be pure Coulomb and no restriction on the particle statistics is imposed. It is proved that if the lowest dissociation threshold corresponds to the decay into two likewise non-zero charged clusters then the bound state, which approaches the threshold, does not spread and eventually becomes the bound state at threshold. The obtained results have applications in atomic and nuclear physics. In particular, we prove that atomic ion with atomic critical charge $Z_{cr}$ and $N_e$ electrons has a bound state at threshold given that $Z_{cr} \\in (N_e -2, N_e -1)$, whereby the electrons are treated as fermions and the mass of the nucleus is finite.

  9. Question of η- and K−- Nucleus Bound States

    International Nuclear Information System (INIS)

    Interaction of the η-meson and that of the K−-meson with nucleons is of special interest because both of them are strongly attractive near threshold. This raises the strong possibility that we may find in nature the bound η- and K−-nuclear (quasi) bound states. This led to experimental programs to hunt for the existence of these states and theoretical studies to keep pace with them. The efforts had positive results. The η-meson studies had been there for several years by now, while those with the K−-meson had been relatively recent. The talk gives a brief critical overview of the η-nuclear interaction studies, especially in context with the η-mesic state explorations. For the K−-meson we give a brief summary of the efforts in understanding the basic K−-nucleon interaction and theoretical explorations for the existence of K−-nucleus bound states. We critically examine the FINUDA measurements as a signal for the existence of the K−-nucleus bound states, especially in context with the contribution of the single nucleon knock-out final state interaction in the (K−, pΛ) reaction.

  10. An Upper Bound of Fully Entangled Fraction of Mixed States

    Science.gov (United States)

    Huang, Xiao-Fen; Jing, Nai-Huan; Zhang, Ting-Gui

    2016-06-01

    We study the fully entangled fraction of a quantum state. An upper bound is obtained for arbitrary bipartite system. This upper bound only depends on the Frobenius norm of the state. Supported by the National Natural Science Foundation of China under Grant Nos. 11401032, 11501153, 11271138, and 11531004; the Natural Science Foundation of Hainan Province under Grant Nos. 20151010, 114006 and 20161006; and the Scientific Research Foundation for Colleges of Hainan Province under Grant No. Hnky2015-18 and Simons Foundation under Grant No. 198129

  11. A framework for bounding nonlocality of state discrimination

    OpenAIRE

    Childs, Andrew M.; Leung, Debbie; Mancinska, Laura; Ozols, Maris

    2012-01-01

    We consider the class of protocols that can be implemented by local quantum operations and classical communication (LOCC) between two parties. In particular, we focus on the task of discriminating a known set of quantum states by LOCC. Building on the work in the paper "Quantum nonlocality without entanglement" [BDF+99], we provide a framework for bounding the amount of nonlocality in a given set of bipartite quantum states in terms of a lower bound on the probability of error in any LOCC dis...

  12. Directional detection of dark matter in universal bound states

    Energy Technology Data Exchange (ETDEWEB)

    Laha, Ranjan

    2015-10-01

    It has been suggested that several small-scale structure anomalies in CDM cosmology can be solved by strong self-interaction between dark matter particles. It was shown in Ref. [1] that the presence of a near threshold S-wave resonance can make the scattering cross section at nonrelativistic speeds come close to saturating the unitarity bound. This can result in the formation of a stable bound state of two asymmetric dark matter particles (which we call darkonium). Ref. [2] studied the nuclear recoil energy spectrum in dark matter direct detection experiments due to this incident bound state. Here we study the angular recoil spectrum, and show that it is uniquely determined up to normalization by the S-wave scattering length. Observing this angular recoil spectrum in a dark matter directional detection experiment will uniquely determine many of the low-energy properties of dark matter independent of the underlying dark matter microphysics.

  13. On Deusons or Deuteronlike Meson-Meson Bound States

    CERN Document Server

    Törnqvist, N A

    1994-01-01

    The systematics of deuteronlike two-meson bound states, {\\it deusons}, is discussed. Previous arguments that many of the present non-$q\\bar q$ states are such states are elaborated including, in particular, the tensor potential. For pseudoscalar states the important observation is made that the centrifugal barrier from the P-wave can be overcome by the $1/r^2$ and $1/r^3$ terms of the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like $B\\bar B^*$ and $B^*\\bar B^*$ composites bound by approximately 50 MeV, while $D\\bar D^*$ and $D^*\\bar D^*$ states are expected near the threshold.

  14. A search for unexpected bound states in 15B

    Science.gov (United States)

    Hoffman, Calem R.

    2014-09-01

    Bound states in 15B are to be populated through the one proton removal reaction from a 16C beam produced at the RCNP EN Course through 18O fragmentation. γ-decays from these states will be identified by an array of Compton-suppressed HPGe Clover detectors (CAGRA). The goals consist of i) identifying any previously unobserved and unexpected bound states in 15B and ii) to assign total angular momenta to known excited states for the first time. At present only two bound states have been observed in 15B, neither with firm spin or parity assignments. The present work to be discussed is aimed at determining whether an excited 3 /2- state, a state with identical spin-parity as the ground state, resides below the neutron separation energy in 15B. Such an excited 3 /2- state is not predicted to appear below the 15B Sn by shell-model calculations using various p- sd interactions. However, a robust systematic, probably related to the s-wave trends found in the single-neutron states in this region, has been observed for neutron-rich N=10 nuclei and it suggests that the state may appear lower in excitation energy than expected. Providing some measure of validation for the N=10 prediction is a similar trend noticed in the energy differences between ground (p)2 neutron states and excited (sd)2 neutron states in the N=8 neutron-rich isotones. In addition to a search for this unexpected state, additional spectroscopic information on 15B will better aid in the understanding of the N=10 isotones when transitioning from 16C into sparsely probed 14Be. Details of the experimental procedures and motivation will be presented and discussed. Bound states in 15B are to be populated through the one proton removal reaction from a 16C beam produced at the RCNP EN Course through 18O fragmentation. γ-decays from these states will be identified by an array of Compton-suppressed HPGe Clover detectors (CAGRA). The goals consist of i) identifying any previously unobserved and unexpected bound

  15. Towards flavored bound states beyond rainbows and ladders

    CERN Document Server

    El-Bennich, B; Paracha, M A; de Melo, J P B C

    2013-01-01

    We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.

  16. Towards flavored bound states beyond rainbows and ladders

    Energy Technology Data Exchange (ETDEWEB)

    El-Bennich, B.; Rojas, E.; Melo, J. P. B. C. de [Laboratório de Física Teórica e Computacional, Universidade Cruzeiro do Sul, São Paulo 01506-000 SP (Brazil); Paracha, M. A. [Laboratorio de Fisica Teorica e Computacional, Universidade Cruzeiro do Sul, Sao Paulo 01506-000 SP, Brazil and Centre for Advanced Mathematics and Physics, National University of Science and Technology, Islamabad (Pakistan)

    2014-11-11

    We give a snapshot of recent progress in solving the Dyson-Schwinger equation with a beyond rainbow-ladder ansatz for the dressed quark-gluon vertex which includes ghost contributions. We discuss the motivations for this approach with regard to heavy-flavored bound states and form factors and briefly describe future steps to be taken.

  17. Detection of positron-atom bound states through resonant annihilation

    CERN Document Server

    Dzuba, V A; Gribakin, G F

    2010-01-01

    A method is proposed for detecting positron-atom bound states by observing Feshbach resonances in positron annihilation at electron volt energies. The method is applicable to a range of open-shell transition metal atoms which are likely to bind the positron: Si, Fe, Co, Ni, Ge, Tc, Ru, Rh, Sn, Sb, Ta, W, Os, Ir, and Pt.

  18. Bound States and Supercriticality in Graphene-Based Topological Insulators

    Directory of Open Access Journals (Sweden)

    Reinhold Egger

    2013-01-01

    Full Text Available We study the bound state spectrum and the conditions for entering a supercritical regime in graphene with strong intrinsic and Rashba spin-orbit interactions within the topological insulator phase. Explicit results are provided for a disk-shaped potential well and for the Coulomb center problem.

  19. In-medium antikaon interactions and bound states

    CERN Document Server

    Gal, Avraham; Barnea, Nir; Cieplý, Aleš; Mareš, Jiří; Gazda, Daniel

    2014-01-01

    Correct treatment of subthreshold Kbar-N dynamics is mandatory in kaonic-atom and Kbar-nuclear bound-state calculations, as demonstrated by using in-medium chirally-based models of Kbar-N interactions. Recent studies of kaonic-atom data reveal appreciable multi-nucleon contributions. Kbar-nuclear widths larger than 50 MeV are anticipated.

  20. Dynamics of deeply bound (K) over-bar states

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří; Friedman, E.; Gal, A.

    2007-01-01

    Roč. 22, 2-3 (2007), s. 633-636. ISSN 0217-751X R&D Projects: GA AV ČR IAA100480617 Institutional research plan: CEZ:AV0Z10480505 Keywords : over-bar-nuclear bound states * over-bar-nuclear relativistic mean field calculations Subject RIV: BE - Theoretical Physics Impact factor: 0.764, year: 2007

  1. Approximate solution of bound state problems through continued fractions

    International Nuclear Information System (INIS)

    A method to solve ordinary linear differential equations through continued fractions is applied to several physical systems. In particular, results for the Schroedinger equation give a good accuracy for the eigenvalues of bound states in the S-wave Yukawa potential, and the lowest order approximations provide exact values for the harmonic oscillator and Coulomb potential eigenvalues and eigenfuctions. (orig.)

  2. Effective field theories for non-relativistic bound states

    International Nuclear Information System (INIS)

    I review some of the progress made in the last ten years in providing a solid foundation to the description of non-relativistic bound states in QED and QCD by means of effective field theories. I will discuss some applications. (author)

  3. K-nuclear bound states in a dynamical model

    Czech Academy of Sciences Publication Activity Database

    Mareš, Jiří; Friedman, E.; Gal, A.

    2006-01-01

    Roč. 770, 1/2 (2006), s. 84-105. ISSN 0375-9474 Institutional research plan: CEZ:AV0Z10480505 Keywords : kaonic atoms * K-nuclear bound states * K-nucleus interaction Subject RIV: BE - Theoretical Physics Impact factor: 2.155, year: 2006

  4. Bound states in the continuum in quasiperiodic systems

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, W.J., E-mail: hsuehwj@ntu.edu.t [Department of Engineering Science, National Taiwan University, Taipei 10660, Taiwan (China); Chen, C.H.; Chang, C.H. [Department of Engineering Science, National Taiwan University, Taipei 10660, Taiwan (China)

    2010-11-01

    We first propose the existence of bound states in the continuums (BICs) in quasiperiodic systems. Owing to long-range correlation, destructive interference may occur in quasiperiodic systems with higher generation order. Occurrences of BICs in Fibonacci quantum wells studied by localization analysis and gap map method are proposed.

  5. Polarization control of the bound state of a vector soliton

    International Nuclear Information System (INIS)

    This article demonstrates that the number of pulses in a group of vector bound solitons can be accurately adjusted by polarization control. We could achieve states with up to seven pulses trapped in a group with equally firm pulse separation. The stable relative phase between pulses within the group is manifested as an interference pattern in the soliton spectrum. (letter)

  6. Bound States in the AdS/CFT Correspondence

    CERN Document Server

    Minces, P

    2004-01-01

    We consider a massive scalar field theory in anti-de Sitter space, in both minimally and non-minimally coupled cases. We introduce a relevant double-trace perturbation at the boundary, by carefully identifying the correct source and generating functional for the corresponding conformal operator. We show that such relevant double-trace perturbation introduces changes in the coefficients in the boundary terms of the action, which in turn govern the existence of a bound state in the bulk. For instance, in the minimally coupled case, we show that the usual action, containing no additional boundary terms, gives rise to a bound state, which can be avoided only through the addition of a proper boundary term. Another notorious example is that of a conformally coupled scalar field, for which there is no associated bound state. In general, in both minimally and non-minimally coupled cases, we explicitly compute the boundary terms which give rise to a bound state, and which ones do not. In the non-minimally coupled case...

  7. Gluon mass generation in the massless bound-state formalism

    CERN Document Server

    Ibañez, D

    2012-01-01

    We present a detailed, all-order study of gluon mass generation within the massless bound-state formalism, which constitutes the general framework for the systematic implementation of the Schwinger mechanism in non-Abelian gauge theories. The main ingredient of this formalism is the dynamical formation of bound-states with vanishing mass, which give rise to effective vertices containing massless poles; these latter vertices, in turn, trigger the Schwinger mechanism, and allow for the gauge-invariant generation of an effective gluon mass. This particular approach has the conceptual advantage of relating the gluon mass directly to quantities that are intrinsic to the bound-state formation itself, such as the "transition amplitude" and the corresponding "bound-state wave-function". As a result, the dynamical evolution of the gluon mass is largely determined by a Bethe-Salpeter equation that controls the dynamics of the relevant wave-function, rather than the Schwinger-Dyson equation of the gluon propagator, as h...

  8. Closed string brane-like states, brane bound states and noncommutative branes

    International Nuclear Information System (INIS)

    We study the mass and different RR charge distributions of the BPS (p,p-2)-brane bound states in the closed string brane-like σ-model. We show that such brane bound states can be realized by introducing a constant B field in the closed string theory. In addition we show that the worldvolume coordinates of these brane bound states turn out to be noncommutative. (author)

  9. Effective Hamiltonian for bound states in Yukawa theory

    International Nuclear Information System (INIS)

    A generalization of the Gell-Mann–Low theorem is applied to lowest nontrivial order to determine an effective Hamiltonian for two-fermion states in relativistic Yukawa theory. The consistency of the corresponding effective Schrödinger equation is thoroughly investigated in various aspects, among others the nonrelativistic and one-body limits, and the small-distance or large-momentum regime of the bound state solutions is discussed in detail. -- Highlights: •A generalization of the Gell-Mann–Low theorem is applied to Yukawa theory. •The effective Hamiltonian for two-fermion states is derived to lowest order. •The nonrelativistic and one-body limits are consistent. •The large-momentum behavior of the bound-state solutions is analyzed. •A critical value for the coupling constant is determined

  10. 'Dressing' and bound states in quantum field theory

    International Nuclear Information System (INIS)

    The program of introducing 'dressed' particles (instead of 'bare' ones) was suggested earlier by L. Faddev et al. It is modified here for the case when 'dressed' states can decay. On the basis of this 'dressing' formalism, a new approach is proposed to the problem of bound states in field theories such as the hydrogen atom and the positronium in QED or hadrons in QCD. Peculiarities of this approach as compared to the known ones are discussed. 22 refs

  11. Observation of bound states in Lieb photonic lattices

    CERN Document Server

    Vicencio, Rodrigo A; Morales-Inostroza, Luis; Real, Bastian; Weimann, Steffen; Szameit, Alexander; Molina, Mario I

    2014-01-01

    We present the first experimental demonstration of a new type of bound states in the continuum, namely, compacton-like linear states in flat bands lattices. To this end, photonic Lieb lattices are employed, which exhibit three tight-binding bands, with one being perfectly flat. Our results could be of great importance for fundamental physics as well as for various applications concerning imaging and data transmission.

  12. Monopole-fermion and dyon-fermion bound states II: Weakly bound states for the lowest angular momentum

    International Nuclear Information System (INIS)

    We investigate weakly bound dyon-fermion states of the lowest angular momentum. Both Coulomb attraction and Coulomb repulsion are studied. Binding energies are given by a transcendental equation which is solved explicitly in a number of limiting cases.Normalized wave functions are given in terms of Bessel functions and confluent hypergeometric functions. (orig.)

  13. Schwinger functions, light-quark bound states and sigma terms

    Science.gov (United States)

    Höll, A.; Maris, P.; Roberts, C. D.; Wright, S. V.

    2006-11-01

    We explore the viability of using solely spacelike information about a Schwinger function to extract properties of bound states. In a concrete example it is not possible to determine properties of states with masses ≳1.2 GeV. Modern Dyson-Schwinger equation methods supply a well-constrained tool that provides access to hadron masses and σ-terms. We report values of the latter for a range of hadrons. Of interest is an analysis relating to a u,d scalar meson, which is compatible with a picture of the lightest 0 as a bound state of a dressed-quark and -antiquark supplemented by a material pion cloud. A constituent-quark σ-term is defined, which affords a means for assessing the flavour-dependence of dynamical chiral symmetry breaking.

  14. Bound States in the Continuum in double layer structures

    Science.gov (United States)

    Li, Liangsheng; Yin, Hongcheng

    2016-06-01

    We have theoretically investigated the reflectivity spectrums of single- and double-layer photonic crystal slabs and the dielectric multilayer stack. It is shown that light can be perfectly confined in a single-layer photonic crystal slab at a given incident angle by changing the thickness, permittivity or hole radius of the structure. With a tunable double-layer photonic crystal slab, we demonstrate that the occurrence of tunable bound states in the continuum is dependent on the spacing between two slabs. Moreover, by analytically investigating the Drude lossless multilayer stack model, the spacing dependence of bound states in the continuum is characterized as the phase matching condition that illuminates these states can occur at any nonzero incident angles by adjusting the spacing.

  15. Andreev bound state spectrum in half-metallic ferromagnets

    International Nuclear Information System (INIS)

    Half-metallic ferromagnets are important for potential applications in spintronics and as sources of completely spin-polarized currents. In heterostructures with superconductors they introduce new effects in the interface regions, like spin-mixing and triplet rotation. A triplet supercurrent trough a half metal has been predicted and experimentally verified. Another interesing question regards the question how the density of states is modified in the half-metallic region. Here we present results of the Andreev bound state spectrum in a half-metal/superconductor proximity structure. We discuss the dependence on the interface parameters that enter the interface scattering matrix of the heterostructure. We discuss the role of odd-frequency pairing amplitudes in the proximity structure. We also study the modification of the Andreev bound state spectrum in a superflow

  16. Shooting quasiparticles from Andreev bound states in a superconducting constriction

    Energy Technology Data Exchange (ETDEWEB)

    Riwar, R.-P.; Houzet, M.; Meyer, J. S. [University of Grenoble Alpes, INAC-SPSMS (France); Nazarov, Y. V., E-mail: Y.V.Nazarov@tudelft.nl [Delft University of Technology, Kavli Institute of NanoScience (Netherlands)

    2014-12-15

    A few-channel superconducting constriction provides a set of discrete Andreev bound states that may be populated with quasiparticles. Motivated by recent experimental research, we study the processes in an a.c. driven constriction whereby a quasiparticle is promoted to the delocalized states outside the superconducting gap and flies away. We distinguish two processes of this kind. In the process of ionization, a quasiparticle present in the Andreev bound state is transferred to the delocalized states leaving the constriction. The refill process involves two quasiparticles: one flies away while another one appears in the Andreev bound state. We notice an interesting asymmetry of these processes. The electron-like quasiparticles are predominantly emitted to one side of the constriction while the hole-like ones are emitted to the other side. This produces a charge imbalance of accumulated quasiparticles, that is opposite on opposite sides of the junction. The imbalance may be detected with a tunnel contact to a normal metal lead.

  17. Are there compact heavy four-quark bound states?

    OpenAIRE

    Vijande, Javier; Weissman, E.; Valcarce, A.; Barnea, N.

    2007-01-01

    We present an exact method to study four-quark systems based on the hyperspherical harmonics formalism. We apply it to several physical systems of interest containing two heavy and two light quarks using different quark-quark potentials. Our conclusions mark the boundaries for the possible existence of compact, nonmolecular, four-quark bound states. While QQ (n) over bar(n) over bar states may be stable in nature, the stability of Q (Q) over barn (n) over bar states would imply the existence ...

  18. A variational study of bound states in the Higgs model

    CERN Document Server

    Siringo, F

    2000-01-01

    The possible existence of Higgs-Higgs bound states in the Higgs sector of the Standard Model is explored using the |hh>+|hhh> variational ansatz of Di Leo and Darewych. The resulting integral equations can be decoupled exactly, yielding a one-dimensional integral equation, solved numerically. We thereby avoid the extra approximations employed by Di Leo and Darewych, and we find a qualitatively different mass renormalization. Within the conventional scenario, where a not-too-large cutoff is invoked to avoid "triviality", we find, as usual, an upperbound on the Higgs mass. Bound-state solutions are only found in the very strong coupling regime, but at the same time a relatively small physical mass is required as a consequence of renormalization.

  19. Observation of Andreev bound states at spin-active interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Detlef; Wolf, Michael Johannes [KIT, Institut fuer Nanotechnologie (Germany); Huebler, Florian [KIT, Institut fuer Nanotechnologie (Germany); KIT, Institut fuer Festkoerperphysik (Germany); Loehneysen, Hilbert von [KIT, Institut fuer Festkoerperphysik (Germany); KIT, Physikalisches Institut (Germany)

    2013-07-01

    We report on high-resolution differential conductance experiments on nanoscale superconductor/ferromagnet tunnel junctions with ultra-thin oxide tunnel barriers. We observe subgap conductance features which are symmetric with respect to bias, and shift according to the Zeeman energy with an applied magnetic field. These features can be explained by resonant transport via Andreev bound states induced by spin-active scattering at the interface. From the energy and the Zeeman shift of the bound states, both the magnitude and sign of the spin-dependent interfacial phase shifts between spin-up and spin-down electrons can be determined. These results contribute to the microscopic insight into the triplet proximity effect at spin-active interfaces.

  20. Bound states in coupled guides. II. Three dimensions

    Science.gov (United States)

    Linton, C. M.; Ratcliffe, K.

    2004-04-01

    We compute bound-state energies in two three-dimensional coupled waveguides, each obtained from the two-dimensional configuration considered in paper I [J. Math. Phys. 45, 1359-1379 (2004)] by rotating the geometry about a different axis. The first geometry consists of two concentric circular cylindrical waveguides coupled by a finite length gap along the axis of the inner cylinder, and the second is a pair of planar layers coupled laterally by a circular hole. We have also extended the theory for this latter case to include the possibility of multiple circular windows. Both problems are formulated using a mode-matching technique, and in the cylindrical guide case the same residue calculus theory as used in paper I is employed to find the bound-state energies. For the coupled planar layers we proceed differently, computing the zeros of a matrix derived from the matching analysis directly.

  1. Bound States in Minkowski Space in 2 + 1 Dimensions

    International Nuclear Information System (INIS)

    The Nakanishi perturbative integral representation of the Bethe–Salpeter amplitude in three-dimensions (2 + 1) is used to solve the corresponding homogeneous Bethe–Salpeter equation in Minkowski space. The projection of this equation onto the null-plane, as reported here, leads to a bound-state equation for the Nakanishi weight function. The explicit forms of the integral equation for the Nakanishi weight function are shown in the ladder approximation. In addition, the valence light-front wave function is presented. The formal steps of the formalism are illustrated to some extend, with the resulting equation being applied to a bound state system composed by two identical scalar particles of mass m, interacting through the exchange of another massive scalar particle of mass μ. The results reported in this contribution show quite good agreement between our calculations obtained from the Bethe–Salpeter amplitude with the Nakanishi weight function with direct solutions obtained in the Euclidean space. (author)

  2. Understanding the nucleon as a Borromean bound-state

    Directory of Open Access Journals (Sweden)

    Jorge Segovia

    2015-11-01

    Full Text Available Analyses of the three valence-quark bound-state problem in relativistic quantum field theory predict that the nucleon may be understood primarily as a Borromean bound-state, in which binding arises mainly from two separate effects. One originates in non-Abelian facets of QCD that are expressed in the strong running coupling and generate confined but strongly-correlated colour-antitriplet diquark clusters in both the scalar–isoscalar and pseudovector–isotriplet channels. That attraction is magnified by quark exchange associated with diquark breakup and reformation. Diquark clustering is driven by the same mechanism which dynamically breaks chiral symmetry in the Standard Model. It has numerous observable consequences, the complete elucidation of which requires a framework that also simultaneously expresses the running of the coupling and masses in the strong interaction. Planned experiments are capable of validating this picture.

  3. Pionic decays and saturation of current-algebra sum rules in a nonrelativistic expansion of the quark shell model

    International Nuclear Information System (INIS)

    Pionic decays of hadrons are calculated using a PCAC (partial conservation of axial-vector current) prescription and a quark shell model with quarks bound by a central potential, described by the Dirac equation. The Dirac Hamiltonian and operators are expanded in v/c, the internal quark velocity. Then, one finds an exact saturation of the current-algebra sum rules as defined in the SU(2)xSU(2) symmetry of Gilman-Harari and Weinberg up to order v4/c4. The saturation is obtained without need of exotics, with the usual excitations of the ground state. The relation with the P = infinity approach is clarified. The corrections found with respect to previous quark models in L = 2 decays are discussed. They do not solve the problem of SU(6)/sub W/ coupling signs. Finally, the whole Weinberg scheme of linear SU(2)xSU(2) symmetry is completed by the expression of the chiral-breaking part of the mass operator m4/sup ts2/

  4. Bound States in the Continuum in Nuclear and Hadron Physics

    CERN Document Server

    Lenske, H; Cao, Xu

    2015-01-01

    The population of bound states in the continuum and their spectral properties are studied on the nuclear and hadronic scale. The theoretical approach is presented and realizations in nuclear and charmonium spectroscopy are dis- cussed. The universality of the underlying dynamical principles is pointed out. Applications to nuclear systems at the neutron dripline and for charmonium spectroscopy by $e^- e^+ \\to D\\bar{D}$ production are discussed.

  5. Weakly bound states of neutrons in gravitational fields

    OpenAIRE

    Khugaev, Avas V.; Sultanov, Renat A.; Guster, Dennis

    2010-01-01

    In this paper a quantum-mechanical behaviour of neutrons in gravitational fields is considered. A first estimation is made using the semiclassical approximation, neglecting General Relativity, magnetic and rotation effects, for neutrons in weakly bound states in the weak gravitational field of the Earth. This result was generalized for a case, in which the Randall - Sundrum correction to Newton's gravitational law on the small scales was applied. Application of the results to Neutron Star phy...

  6. Approximate bound Dirac states for pseudoscalar Hulthen potential

    International Nuclear Information System (INIS)

    In this paper, we present approximate analytical solutions of the Dirac equation with the pseudoscalar Hulthen potential under spin and pseudospin (p-spin) symmetry limits in (3+1) dimensions. The energy eigenvalues and corresponding eigenfunctions are given in their closed forms by using the Nikiforov–Uvarov (NU) method. Numerical results of the energy eigenvalue equations are presented to show the effects of the potential parameters on the bound-state energies. (author)

  7. Bound states in weakly deformed waveguides: numerical vs analytical results

    CERN Document Server

    Amore, Paolo; Fernández, Francisco M; Jacobo, Martin; Zhevandrov, Petr

    2016-01-01

    We have studied the emergence of bound states in weakly deformed and/or heterogeneous waveguides, comparing the analytical predictions obtained using a recently developed perturbative method, with precise numerical results, for different configurations (a homogeneous asymmetric waveguide, a heterogenous asymmetric waveguide and a homogeneous broken-strip). In all the examples considered in this paper we have found excellent agreement between analytical and numerical results, thus providing a numerical verification of the analytical approach.

  8. Fermion Bound States Around Skyrmions in Doped Antiferromagnets

    Institute of Scientific and Technical Information of China (English)

    寇谡鹏

    2003-01-01

    We show the skyrmion effects in doped antiferromagnets for the uniform flux phase. The low-energy effective theory of the t′-J model can be mapped onto the massive quantum electrodynamics. There exist Fermion bound states around skyrmions. For each sublattice, there exist induced fractional fermion numbers around the skyrmions. The total induced fermion number is zero due to the "cancelling effect" between two sublattices with opposite charges.

  9. Two-body bound states & the Bethe-Salpeter equation

    Energy Technology Data Exchange (ETDEWEB)

    Pichowsky, M. [Argonne National Lab., IL (United States); Kennedy, M. [Univ. of New Hampshire, Durham, NH (United States). Physics Dept.; Strickland, M. [Duke Univ., Durham, NC (United States)

    1995-01-18

    The Bethe-Salpeter formalism is used to study two-body bound states within a scalar theory: two scalar fields interacting via the exchange of a third massless scalar field. The Schwinger-Dyson equation is derived using functional and diagrammatic techniques, and the Bethe-Salpeter equation is obtained in an analogous way, showing it to be a two-particle generalization of the Schwinger-Dyson equation. The authors also present a numerical method for solving the Bethe-Salpeter equation without three-dimensional reduction. The ground and first excited state masses and wavefunctions are computed within the ladder approximation and space-like form factors are calculated.

  10. Upsilon particles as bound states of new heavy quarks

    International Nuclear Information System (INIS)

    Charmonium spectroscopy (cc) was analysed, recently using a power confining potential and was determined that the energy eigenvalues are in good agreement with experimental values when it was used a power equal to 1/2 (square root potential). Assuming universality of the potential for quark-antiquark (qq) and assuming that the particle γ (9.4 GeV) is the fundamental state of the pair bb (beauty quark). The remaning bound states of this pair and their leptonic and hadronic decay widths are calculated

  11. Three-boson bound states in finite volume with EFT

    International Nuclear Information System (INIS)

    The universal properties of a three-boson system with large scattering length are well understood within the framework of Effective Field Theory. They include a geometric spectrum of shallow three-body bound states called Efimov states and log-periodic dependence of scattering observables on the scattering length. We investigate the modification of this spectrum in a finite cubic box using a partial wave expansion. The dependence of the binding energies on the box size is calculated and the renormalization of the Effective Field Theory in finite volume is verified explicitly.

  12. Bound states in continuum: Quantum dots in a quantum well

    International Nuclear Information System (INIS)

    We report on the existence of a bound state in the continuum (BIC) of quantum rods (QR). QRs are novel elongated InGaAs quantum dot nanostructures embedded in the shallower InGaAs quantum well. BIC appears as an excited confined dot state and energetically above the bottom of a well subband continuum. We prove that high height-to-diameter QR aspect ratio and the presence of a quantum well are indispensable conditions for accommodating the BIC. QRs are unique semiconductor nanostructures, exhibiting this mathematical curiosity predicted 83 years ago by Wigner and von Neumann.

  13. Analytic continuation as a bridge between continuum and bound states

    Directory of Open Access Journals (Sweden)

    Blokhintsev Leonid

    2015-01-01

    Full Text Available The problem of obtaining characteristics of bound nuclear states from continuum states data is discussed. It is shown that the ambiguities due to the existence of phase-equivalent potentials can be resolved by using the analytic properties of scattering amplitudes. The methods of determination of asymptotic normalization coefficients and vertex constants are considered. The asymptotic normalization coefficients for 6Li in the α + d channel are found by analytic continuation of the two-channel effective range expansion. The account of inelastic channels within the effective range approach is discussed.

  14. Photo-production of Bound States with Hidden Charms

    CERN Document Server

    Wu, Jia-Jun

    2012-01-01

    The photo-production of $J/\\Psi$-$^3He$ bound state ($[^3He]_{J/\\Psi}$) on a $^4He$ target has been investigated using the impulse approximation. The calculations have been performed using several $\\gamma+N \\rightarrow J/\\Psi +N$ models based on the Pomeron-exchange and accounting for the pion-exchange mechanism at low energies. The $J/\\Psi$ wavefunctions in $[^3He]_{J/\\Psi}$ are generated from various $J/\\Psi$-nucleus potentials which are constructed by either using a procedure based on the Pomeron-quark coupling mechanism or folding a $J/\\Psi$-N potential ($v_{J/\\Psi,N}$) into the nuclear densities. We consider $v_{J/\\Psi,N}$ derived from the effective field theory approach, Lattice QCD, and Pomeron-quark coupling mechanism. The upper bound of the predicted total cross sections is about $0.1 - 0.3$ pico-barn. We also consider the possibility of photo-production of a six quark-$J/\\Psi$ bound state ($[q^6]_{J/\\Psi})$ on the $^3He$ target. The Compound Bag Model of $NN$ scattering and the quark cluster model o...

  15. Accurate calculations of bound rovibrational states for argon trimer

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, Drew; Poirier, Bill [Department of Chemistry and Biochemistry, and Department of Physics, Texas Tech University, Box 41061, Lubbock, Texas 79409-1061 (United States)

    2014-07-21

    This work presents a comprehensive quantum dynamics calculation of the bound rovibrational eigenstates of argon trimer (Ar{sub 3}), using the ScalIT suite of parallel codes. The Ar{sub 3} rovibrational energy levels are computed to a very high level of accuracy (10{sup −3} cm{sup −1} or better), and up to the highest rotational and vibrational excitations for which bound states exist. For many of these rovibrational states, wavefunctions are also computed. Rare gas clusters such as Ar{sub 3} are interesting because the interatomic interactions manifest through long-range van der Waals forces, rather than through covalent chemical bonding. As a consequence, they exhibit strong Coriolis coupling between the rotational and vibrational degrees of freedom, as well as highly delocalized states, all of which renders accurate quantum dynamical calculation difficult. Moreover, with its (comparatively) deep potential well and heavy masses, Ar{sub 3} is an especially challenging rare gas trimer case. There are a great many rovibrational eigenstates to compute, and a very high density of states. Consequently, very few previous rovibrational state calculations for Ar{sub 3} may be found in the current literature—and only for the lowest-lying rotational excitations.

  16. Accurate calculations of bound rovibrational states for argon trimer

    International Nuclear Information System (INIS)

    This work presents a comprehensive quantum dynamics calculation of the bound rovibrational eigenstates of argon trimer (Ar3), using the ScalIT suite of parallel codes. The Ar3 rovibrational energy levels are computed to a very high level of accuracy (10−3 cm−1 or better), and up to the highest rotational and vibrational excitations for which bound states exist. For many of these rovibrational states, wavefunctions are also computed. Rare gas clusters such as Ar3 are interesting because the interatomic interactions manifest through long-range van der Waals forces, rather than through covalent chemical bonding. As a consequence, they exhibit strong Coriolis coupling between the rotational and vibrational degrees of freedom, as well as highly delocalized states, all of which renders accurate quantum dynamical calculation difficult. Moreover, with its (comparatively) deep potential well and heavy masses, Ar3 is an especially challenging rare gas trimer case. There are a great many rovibrational eigenstates to compute, and a very high density of states. Consequently, very few previous rovibrational state calculations for Ar3 may be found in the current literature—and only for the lowest-lying rotational excitations

  17. Colour-octet bound states, induced by Higgs mechanism

    CERN Document Server

    Bladwell, S; Flambaum, V V; Kozlov, A

    2012-01-01

    The current limits for fourth generation quarks allows to expect their mass of the order of 500 GeV. In this mass region for quark-anti-quark pair the additional Yukawa-type attraction due to Higgs mechanism is expected to emerge. This Higgs induced attraction greatly exceeds strong interaction between quarks and leads to the formation of bound states in both colour octet $S^{(8)}$ and singlet $S^{(1)}$ states. In the key of recent works on significance of colour octet channel for production of colour singlet state of fourth generation $Q\\bar{Q}$ we calculated the binding energies for both octet and singlet states. Such attraction localizes quarks in extremely small area. Hence colour octet pair of fourth generation quarks can form the "nucleus" and together with colour neutralizing light particle that is captured by strong interaction in orbit around the nucleus, create particle, similar by its structure to Deuterium.

  18. A narrow quasi-bound state of the DNN system

    International Nuclear Information System (INIS)

    We have investigated a charmed system of DNN (composed of two nucleons and a D meson) by a complementary study with a variational calculation and a Faddeev calculation with fixed-center approximation (Faddeev-FCA). In the present study, we employ a DN potential based on a vector–meson exchange picture in which a resonant Λc(2595) is dynamically generated as a DN quasi-bound state, similarly to the Λ(1405) as a K¯N one in the strange sector. As a result of the study of variational calculation with an effective DN potential and three kinds of NN potentials, the DNN(Jπ=0−,I=1/2) is found to be a narrow quasi-bound state below Λc(2595)N threshold: total binding energy ∼225 MeV and mesonic decay width ∼25 MeV. On the other hand, the Jπ=1− state is considered to be a scattering state of Λc(2595) and a nucleon. These results are essentially supported by the Faddeev-FCA calculation. By the analysis of the variational wave function, we have found a unique structure in the DNN(Jπ=0−,I=1/2) such that the D meson stays around the center of the total system due to the heaviness of the D meson

  19. Static and dynamic properties of QCD bound states

    International Nuclear Information System (INIS)

    The QCD phenomenology can be faced with the framework of the coupled quark DSE, meson BSE and baryon Faddeev equation, providing non-perturbative, continuum and Poincare invariant scientific approach. The research performed throughout this thesis is twofold. From one perspective we focus on the investigation of mass spectra for mesons with total spin quantum number J=3 and arising Regge-trajectory for natural parity states JPC=1--,2++,3-- within rainbow-ladder single gluon exchange model. The other findings are concerning the impact of the pion cloud effect on J>2 meson states, baryon masses, namely on Nucleon and Delta three-body bound states and meson dynamical properties like the pion form factor.

  20. Static and dynamic properties of QCD bound states

    Energy Technology Data Exchange (ETDEWEB)

    Kubrak, Stanislav

    2015-07-01

    The QCD phenomenology can be faced with the framework of the coupled quark DSE, meson BSE and baryon Faddeev equation, providing non-perturbative, continuum and Poincare invariant scientific approach. The research performed throughout this thesis is twofold. From one perspective we focus on the investigation of mass spectra for mesons with total spin quantum number J=3 and arising Regge-trajectory for natural parity states J{sup PC}=1{sup --},2{sup ++},3{sup --} within rainbow-ladder single gluon exchange model. The other findings are concerning the impact of the pion cloud effect on J>2 meson states, baryon masses, namely on Nucleon and Delta three-body bound states and meson dynamical properties like the pion form factor.

  1. The inverse problem in the case of bound states

    International Nuclear Information System (INIS)

    We investigate the inverse problem for bound states in the D = 3 dimensional space. The potential is assumed to be local and spherically symmetric. The present method is based on relationships connecting the moments of the ground state density to the lowest energy of each state of angular momentum l. The reconstruction of the density ρ(r) from its moments is achieved by means of the series expansion of its Fourier transform F(q). The large q-behavior is described by Pade approximants. The accuracy of the solution depends on the number of known moments. The uniqueness is achieved if this number is infinite. In practice, however, an accuracy better than 1% is obtained with a set of about 15 levels. The method is tested on a simple example, and applied to three different spectra

  2. The search for deeply bound kaonic states with FOPI

    International Nuclear Information System (INIS)

    Full text: New formation mechanisms for the creation of dense, exotic nuclear systems involving strangeness were recently proposed by Y. Akaishi and T. Yamazaki. Their calculations show that a K- might form deeply bound states in light nuclei - so called kaonic clusters - with central densities of several times the normal nuclear density. In the presentation a short overview of these exotic nuclear systems will be given and a new experiment with FOPI at GSI will be discussed. The aim of this experiment was to search for the simplest cluster - a ppK- state. This state is produced at GSI in the following high energy reaction: p + ''d'' → ppK- + K+ + n'' with incident energies of 3.5 GeV. The experimental set-up will be presented in detail. (author)

  3. Autodetachment spectroscopy of the aluminum oxide anion dipole bound state

    Energy Technology Data Exchange (ETDEWEB)

    Mascaritolo, Kyle J.; Gardner, Adrian M.; Heaven, Michael C., E-mail: mheaven@emory.edu [Department of Chemistry, Emory University, Atlanta, Georgia 30322 (United States)

    2015-09-21

    The {sup 1}Σ{sup +}←X{sup 1}Σ{sup +} ground state to dipole bound state (DBS) electronic transition of AlO{sup −} has been studied by means of autodetachment spectroscopy. Vibrational and rotational molecular constants for AlO{sup −} have been determined for both the ground state (υ″ = 0, 1) and the excited DBS (υ′ = 0, 1). These data provide an improved determination of the electron affinity for AlO (2.6110(7) eV) that is consistent with an earlier measurement. The electron binding energy of the DBS was found to be 52 ± 6 cm{sup −1}. Experimental results are compared with the predictions from high level ab initio calculations.

  4. Configuration space Faddeev formalism: Λ + n + n bound state search

    Science.gov (United States)

    Suslov, Vladimir; Filikhin, Igor; Vlahovic, Branislav

    2015-04-01

    The HypHI Collaboration has recently reported the evidence for bound state of Λ + n + n system (Phys. Rev. C 88, 041001(R) (2013)). However, the theoretical analysis did not find Λ3n bound state (see, for instance, Phys. Lett. B 736, 93 (2014)). In the present work we will describe our attempt to construct a phenomenological three-body ΛNN force with the spin-isospin dependence that is attractive in the channel T=1, S=1/2. This dependence was tested to reproduce the value of ground state energy for Λ3H hypernuclei. The formalism of the configuration-space Faddeev equations is applied for Λ + n + n and Λ + n + p systems. As Λ + n interaction the s-wave potential simulating model NSC97f is used. This potential reproduces well the hyperon binding energy for Λ3H nuclei (J. Phys. G: 31, 389 (2005)). The details of the model and obtained results will be presented. This work is supported by the NSF (HRD-1345219) and NASA (NNX09AV07A).

  5. Tetraquark bound states in a Bethe-Salpeter approach

    OpenAIRE

    Heupel, Walter; Eichmann, Gernot; Fischer, Christian S.

    2012-01-01

    We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the o...

  6. Quarkonium-nucleus bound states from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Beane, S.  R. [Univ. of Washington, Seattle, WA (United States); Chang, E. [Univ. of Washington, Seattle, WA (United States); Cohen, S.  D. [Univ. of Washington, Seattle, WA (United States); Detmold, W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lin, H. -W. [Univ. of Washington, Seattle, WA (United States); Orginos, K. [College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Parreño, A. [Univ., de Barcelona, Marti Franques (Spain); Savage, M.  J. [Univ. of Washington, Seattle, WA (United States)

    2015-06-11

    Quarkonium-nucleus systems are composed of two interacting hadronic states without common valence quarks, which interact primarily through multi-gluon exchanges, realizing a color van der Waals force. We present lattice QCD calculations of the interactions of strange and charm quarkonia with light nuclei. Both the strangeonium-nucleus and charmonium-nucleus systems are found to be relatively deeply bound when the masses of the three light quarks are set equal to that of the physical strange quark. Extrapolation of these results to the physical light-quark masses suggests that the binding energy of charmonium to nuclear matter is B < 40 MeV.

  7. Resonantly Trapped Bound State in the Continuum Laser

    CERN Document Server

    Lepetit, Thomas; Kodigala, Ashok; Bahari, Babak; Fainman, Yeshaiahu; Kanté, Boubacar

    2015-01-01

    Cavities play a fundamental role in wave phenomena from quantum mechanics to electromagnetism and dictate the spatiotemporal physics of lasers. In general, they are constructed by closing all "doors" through which waves can escape. We report, at room temperature, a bound state in the continuum laser that harnesses optical modes residing in the radiation continuum but nonetheless may possess arbitrarily high quality factors. These counterintuitive cavities are based on resonantly trapped symmetry-compatible modes that destructively interfere. Our experimental demonstration opens exciting avenues towards coherent sources with intriguing topological properties for optical trapping, biological imaging, and quantum communication.

  8. R-Matrix Calculations for Few-Quark Bound States

    CERN Document Server

    Shalchi, M A

    2016-01-01

    The R-matrix method is implemented to study the heavy charm and bottom diquark, triquark, tetraquark and pentaquarks in configuration space, as the bound states of quark-antiquark, diquark-quark, diquark-antidiquark and diquark-antitriquark systems, respectively. The mass spectrum and the size of these systems are calculated for different partial wave channels. The calculated masses are compared with recent theoretical results obtained by %the solution of Lippmann-Schwinger equation other methods in momentum and configuration spaces and also by available experimental data.

  9. Three-body bound states in finite volume with EFT

    International Nuclear Information System (INIS)

    Three particles with large scattering length display a universal spectrum of three-body bound states called ''Efimov trimers''. We calculate the modification of the Efimov trimers of three identical bosons in a finite cubic box and compute the dependence of their energies on the box size using effective field theory. The renormalization of the effective field theory in the finite volume is explicitly verified. We investigate the effects of partial wave mixing and study the behavior of shallow trimers near the dimer energy. Finally, we present first results for the triton in a finite volume.

  10. Bound-state effects in B→K*γ

    International Nuclear Information System (INIS)

    Applying perturbative QCD methods recently seen to give a good description of the two-body hadronic decays of the B meson, we address the question of bound-state effects on the decay B→K*γ. Consistent with most analyses, we demonstrate that gluonic penguin diagrams, with photonic bremsstrahlung off a quark, change the decay rate by only a few percent. Using an asymptotic distribution amplitude for the K* and just the standard model, we can obtain a branching ratio of a few x10-5, consistent with the observed rate

  11. Stieltjes electrostatic model interpretation for bound state problems

    Indian Academy of Sciences (India)

    K V S Shiv Chaitanya

    2014-07-01

    In this paper, it is shown that Stieltjes electrostatic model and quantum Hamilton Jacobi formalism are analogous to each other. This analogy allows the bound state problem to mimic as unit moving imaginary charges $i\\hbar$, which are placed in between the two fixed imaginary charges arising due to the classical turning points of the potential. The interaction potential between unit moving imaginary charges $i\\hbar$ is given by the logarithm of the wave function. For an exactly solvable potential, this system attains stable equilibrium position at the zeros of the orthogonal polynomials depending upon the interval of the classical turning points.

  12. Bound states of string networks and D-branes

    International Nuclear Information System (INIS)

    We show the existence of nonthreshold bound states of (p, q) string networks and D3-branes, preserving 1/4 of the full type-IIB supersymmetry, interpreted as string networks 'dissolved' in D3-branes. We also explicitly write down the expression for the mass density of the system and discuss the extension of the construction to other Dp -branes. Differences in our construction of string networks with the ones interpreted as dyons in N=4 gauge theories are also pointed out

  13. Pionic instabilities in high-energy heavy ion collisions

    International Nuclear Information System (INIS)

    The study of heavy ion reactions includes the determination of whether pionic instabilities can exist at the densities and excitation energies expected in heavy ion collisions, the calculation of growth rates of unstable pion modes, and the determination of the effect such instabilities would have on the dynamics in heavy ion collisions. 14 references

  14. Fingerprints of Majorana Bound States in Aharonov-Bohm Geometry

    Science.gov (United States)

    Tripathi, Krashna Mohan; Das, Sourin; Rao, Sumathi

    2016-04-01

    We study a ring geometry, coupled to two normal metallic leads, which has a Majorana bound state (MBS) embedded in one of its arms and is threaded by Aharonov-Bohm (A B ) flux ϕ . We show that by varying the A B flux, the two leads go through resonance in an anticorrelated fashion while the resonance conductance is quantized to 2 e2/h . We further show that such anticorrelation is completely absent when the MBS is replaced by an Andreev bound state (ABS). Hence this anti-correlation in conductance when studied as a function of ϕ provides a unique signature of the MBS which cannot be faked by an ABS. We contrast the phase sensitivity of the MBS and ABS in terms of tunneling conductances. We argue that the relative phase between the tunneling amplitude of the electrons and holes from either lead to the level (MBS or ABS), which is constrained to 0 ,π for the MBS and unconstrained for the ABS, is responsible for this interesting contrast in the A B effect between the MBS and ABS.

  15. Topological nature of bound states in the radiation continuum

    CERN Document Server

    Zhen, Bo; Lu, Ling; Stone, A Doug; Soljacic, Marin

    2014-01-01

    Bound states in the continuum (BICs) are unusual solutions of wave equations describing light or matter: they are discrete and spatially bounded, but exist at the same energy as a continuum of states which propagate to infinity. Until recently, BICs were constructed through fine-tuning parameters in the wave equation or exploiting the separability of the wave equation due to symmetry. More recently, BICs that that are both robust and not symmetry-protected (accidental) have been predicted and experimentally realized in periodic structures; the simplest such system is a periodic dielectric slab, which also has symmetry-protected BICs. Here we show that both types of BICs in such systems are vortex centers in the polarization direction of far-field radiation. The robustness of these BICs is due to the existence of conserved and quantized topological charges, defined by the number of times the polarization vectors wind around the vortex centers. Such charges can only be generated or annihilated by making large c...

  16. Bound states and entanglement in the excited states of quantum spin chains

    International Nuclear Information System (INIS)

    We investigate the entanglement properties of the excited states of the spin- (1/2) Heisenberg (XXX) chain with isotropic antiferromagnetic interactions, by exploiting the Bethe ansatz solution of the model. We consider eigenstates obtained from both real and complex solutions (‘strings’) of the Bethe equations. Physically, the former are states of interacting magnons, whereas the latter contain bound states of groups of particles. We first focus on the situation with few particles in the chain. Using exact results and semiclassical arguments, we derive an upper bound SMAX for the entanglement entropy. This exhibits an intermediate behaviour between logarithmic and extensive, and it is saturated for highly-entangled states. As a function of the eigenstate energy, the entanglement entropy is organized in bands. Their number depends on the number of blocks of contiguous Bethe–Takahashi quantum numbers. In the presence of bound states a significant reduction in the entanglement entropy occurs, reflecting that a group of bound particles behaves effectively as a single particle. Interestingly, the associated entanglement spectrum shows edge-related levels. At a finite particle density, the semiclassical bound SMAX becomes inaccurate. For highly-entangled states SA∝ Lc, with Lc the chord length, signalling the crossover to extensive entanglement. Finally, we consider eigenstates containing a single pair of bound particles. No significant entanglement reduction occurs, in contrast with the few-particle case. (paper)

  17. Bound states for non-symmetric evolution Schroedinger potentials

    Energy Technology Data Exchange (ETDEWEB)

    Corona, Gulmaro Corona [Area de Analisis Matematico y sus Aplicaciones, Universidad Autonoma Metropolitana-Azcapotalco, Atzcapotzalco, DF (Mexico)). E-mail: ccg@correo.azc.uam.mx

    2001-09-14

    We consider the spectral problem associated with the evolution Schroedinger equation, (D{sup 2}+ k{sup 2}){phi}=u{phi}, where u is a matrix-square-valued function, with entries in the Schwartz class defined on the real line. The solution {phi}, called the wavefunction, consists of a function of one real variable, matrix-square-valued with entries in the Schwartz class. This problem has been dealt for symmetric potentials u. We found for the present case that the bound states are localized similarly to the scalar and symmetric cases, but by the zeroes of an analytic matrix-valued function. If we add an extra condition to the potential u, we can determine these states by an analytic scalar function. We do this by generalizing the scalar and symmetric cases but without using the fact that the Wronskian of a pair of wavefunction is constant. (author)

  18. Bound states for non-symmetric evolution Schroedinger potentials

    International Nuclear Information System (INIS)

    We consider the spectral problem associated with the evolution Schroedinger equation, (D2+ k2)φ=uφ, where u is a matrix-square-valued function, with entries in the Schwartz class defined on the real line. The solution φ, called the wavefunction, consists of a function of one real variable, matrix-square-valued with entries in the Schwartz class. This problem has been dealt for symmetric potentials u. We found for the present case that the bound states are localized similarly to the scalar and symmetric cases, but by the zeroes of an analytic matrix-valued function. If we add an extra condition to the potential u, we can determine these states by an analytic scalar function. We do this by generalizing the scalar and symmetric cases but without using the fact that the Wronskian of a pair of wavefunction is constant. (author)

  19. The quantum probability equation: I. Bound state perturbation theory

    International Nuclear Information System (INIS)

    The partial-wave Schroedinger equation with real boundary conditions is recast as an equation for the probability density. When a small additional potential is included, the changes in the bound-state energy eigenvalues are obtained, up to third order in the perturbation, purely in terms of the perturbing potential and the unperturbed probability density. Although the approach is different, our results are equivalent to those derived by Bender (Bender C M 1978 Advanced Mathematical Methods for Scientists and Engineers (New York: McGraw-Hill) p 330). Knowledge of neither the unperturbed energy spectrum nor the wavefunctions of excited states is required. Evaluations of the second-order energy shift are given for some soluble S-wave problems. (author)

  20. Shear viscosity of pionic and nucleonic components from their different possible mesonic and baryonic thermal fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sabyasachi, E-mail: sabyaphy@gmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sao Paulo, SP (Brazil). Instituto de Fisica Teorica

    2015-12-15

    Owing to the Kubo relation, the shear viscosities of pionic and nucleonic components have been evaluated from their corresponding retarded correlators of viscous stress tensor in the static limit, which become non-divergent only for the non-zero thermal widths of the constituent particles. In the real-time thermal field theory, the pion and nucleon thermal widths have respectively been obtained from the pion self-energy for different meson, baryon loops, and the nucleon self-energy for different pion-baryon loops. We have found non-monotonic momentum distributions of pion and nucleon thermal widths, which have been integrated out by their respective Bose-enhanced and Pauli-blocked phase space factors during evaluation of their shear viscosities. The viscosity to entropy density ratio for this mixed gas of pion-nucleon system decreases and approaches its lower bound as the temperature and baryon chemical potential increase within the relevant domain of hadronic matter. (author)

  1. Shear viscosity of pionic and nucleonic components from their different possible mesonic and baryonic thermal fluctuations

    International Nuclear Information System (INIS)

    Owing to the Kubo relation, the shear viscosities of pionic and nucleonic components have been evaluated from their corresponding retarded correlators of viscous stress tensor in the static limit, which become non-divergent only for the non-zero thermal widths of the constituent particles. In the real-time thermal field theory, the pion and nucleon thermal widths have respectively been obtained from the pion self-energy for different meson, baryon loops, and the nucleon self-energy for different pion-baryon loops. We have found non-monotonic momentum distributions of pion and nucleon thermal widths, which have been integrated out by their respective Bose-enhanced and Pauli-blocked phase space factors during evaluation of their shear viscosities. The viscosity to entropy density ratio for this mixed gas of pion-nucleon system decreases and approaches its lower bound as the temperature and baryon chemical potential increase within the relevant domain of hadronic matter. (author)

  2. Production and decay of scalar stoponium bound states

    CERN Document Server

    Drees, Manuel

    1994-01-01

    In this paper we discuss possible signatures for the production of scalar \\stst\\ (stoponium) bound states \\sigst\\ at hadron colliders, where \\st\\ is the lighter scalar top eigenstate. We first study the decay of \\sigst; explicit expressions are given for all potentially important decay modes. If \\st\\ has unsuppressed two--body decays, they will always overwhelm the annihilation decays of \\sigst. Among the latter, we find that usually either the $gg$ or $hh$ final state dominates, depending on the size of the off--diagonal entry of the stop mass matrix; $h$ is the lighter neutral scalar Higgs boson of the minimal supersymmetric model. If \\msig\\ happens to be close to the mass of one of the neutral scalar Higgs bosons, $Q \\bar{Q}$ final states dominate ($Q=b$ or $t$). \\ww\\ and $ZZ$ final states are subdominant. We argue that $\\sigst \\rightarrow \\gamgam$ decays offer the best signal for stoponium production at hadron colliders. The tevatron should be able to close the light stop window left open by LEP searches,...

  3. G-factors of hole bound states in spherically symmetric potentials in cubic semiconductors

    Science.gov (United States)

    Miserev, Dmitry; Sushkov, Oleg

    2016-03-01

    Holes in cubic semiconductors have effective spin 3/2 and very strong spin orbit interaction. Due to these factors properties of hole bound states are highly unusual. We consider a single hole bound by a spherically symmetric potential, this can be an acceptor or a spherically symmetric quantum dot. Linear response to an external magnetic field is characterized by the bound state Lande g-factor. We calculate analytically g-factors of all bound states.

  4. G-factors of hole bound states in spherically symmetric potentials in cubic semiconductors

    OpenAIRE

    Miserev, D. S.; Sushkov, O. P.

    2015-01-01

    Holes in cubic semiconductors have effective spin 3/2 and very strong spin orbit interaction. Due to these factors properties of hole bound states are highly unusual. We consider a single hole bound by a spherically symmetric potential, this can be an acceptor or a spherically symmetric quantum dot. Linear response to an external magnetic field is characterized by the bound state Lande g-factor. We calculate analytically g-factors of all bound states.

  5. Universal Bounds on Charged States in 2d CFT and 3d Gravity

    CERN Document Server

    Benjamin, Nathan; Fitzpatrick, A Liam; Kachru, Shamit

    2016-01-01

    We derive an explicit bound on the dimension of the lightest charged state in two dimensional conformal field theories with a global abelian symmetry. We find that the bound scales with $c$ and provide examples that parametrically saturate this bound. We also prove than any such theory must contain a state with charge-to-mass ratio above a minimal lower bound. We comment on the implications for charged states in three dimensional theories of gravity.

  6. Tetra quark bound states in a Bethe-Salpeter approach

    Energy Technology Data Exchange (ETDEWEB)

    Heupel, Walter; Eichmann, Gernot [Institut fuer Theoretische Physik, Justus-Liebig-Universitaet Giessen, D-35392 Giessen (Germany); Fischer, Christian S., E-mail: christian.fischer@theo.physik.uni-giessen.de [Institut fuer Theoretische Physik, Justus-Liebig-Universitaet Giessen, D-35392 Giessen (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, D-64291 Darmstadt (Germany)

    2012-12-05

    We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f{sub 0}(600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.

  7. Tetraquark bound states in a Bethe-Salpeter approach

    CERN Document Server

    Heupel, Walter; Fischer, Christian S

    2012-01-01

    We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f_0(600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.

  8. Tetraquark bound states in a Bethe-Salpeter approach

    Science.gov (United States)

    Heupel, Walter; Eichmann, Gernot; Fischer, Christian S.

    2012-12-01

    We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f0 (600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.

  9. Bound-state properties from field-theory correlators

    CERN Document Server

    Melikhov, Dmitri

    2011-01-01

    We discuss the details of calculating hadron properties from the OPE for correlators of quark currents in QCD, which constitutes the basis of the method of QCD sum rules. The main emphasis is laid on gaining control over the systematic uncertainties of the hadron parameters obtained within this method. We start with examples from quantum mechanics, where bound-state properties may be calculated independently in two ways: exactly, by solving the Schroedinger equation, and approximately, by the method of sum rules. Knowing the exact solution allows us to control each step of the sum-rule extraction procedure. On the basis of this analysis, we formulate several improvements of the method of sum rules. We then apply these modifications to the analysis of the decay constants of heavy mesons.

  10. Bound-state properties from field-theory correlators

    International Nuclear Information System (INIS)

    We discuss the details of calculating hadron properties from the OPE for correlators of quark currents in QCD, which constitutes the basis of the method of QCD sum rules. The main emphasis is laid on gaining control over the systematic uncertainties of the hadron parameters obtained within this method. We start with examples from quantum mechanics, where bound-state properties may be calculated independently in two ways: exactly, by solving the Schroedinger equation, and approximately, by the method of sum rules. Knowing the exact solution allows us to control each step of the sum-rule extraction procedure. On the basis of this analysis, we formulate several improvements of the method of sum rules. We then apply these modifications to the analysis of the decay constants of heavy mesons.

  11. Baryons as relativistic three-quark bound states

    CERN Document Server

    Eichmann, Gernot; Williams, Richard; Alkofer, Reinhard; Fischer, Christian S

    2016-01-01

    We review the spectrum and electromagnetic properties of baryons described as relativistic three-quark bound states within QCD. The composite nature of baryons results in a rich excitation spectrum, whilst leading to highly non-trivial structural properties explored by the coupling to external (electromagnetic and other) currents. Both present many unsolved problems despite decades of experimental and theoretical research. We discuss the progress in these fields from a theoretical perspective, focusing on nonperturbative QCD as encoded in the functional approach via Dyson-Schwinger and Bethe-Salpeter equations. We give a systematic overview as to how results are obtained in this framework and explain technical connections to lattice QCD. We also discuss the mutual relations to the quark model, which still serves as a reference to distinguish 'expected' from 'unexpected' physics. We confront recent results on the spectrum of non-strange and strange baryons, their form factors and the issues of two-photon proce...

  12. The structure of the D0-D4 bound state

    International Nuclear Information System (INIS)

    We derive a set of equations for the wavefunction describing the marginal bound state of a single D0-brane with a single D4-brane. These are equations determining the vacuum of an N=8 Abelian gauge theory with a charged hypermultiplet. We then solve these equations for the most general possible zero-energy solution using a Taylor series. We find that there are an infinite number of such solutions of which only one must be normalizable. We explore the structure of a normalizable solution under the assumption of an asymptotic expansion. Even the leading terms in the asymptotic series, which should reflect the supergravity solution, are unusual. Through the Spin(5) flavor symmetry, the modes which are massive at long distance actually influence the leading behavior. Lastly, we show that the vacuum equations can quite remarkably be reduced to a single equation involving one unknown function. The resulting equation has a surprisingly simple and suggestive form

  13. Cooperativity, partially bound states, and enthalpy-entropy compensation.

    Science.gov (United States)

    Hunter, Christopher A; Tomas, Salvador

    2003-11-01

    Efforts to develop a quantitative understanding of molecular recognition rely on the additivity of individual intermolecular interactions, and cooperativity represents one of the major potential stumbling blocks. A chemical double-mutant cycle has been used to experimentally measure cooperativity between functional group interactions within a complex framework. The interaction between two aromatic groups varies by 0.2 +/- 0.4 kJ mol(-1) in synthetic H-bonded complexes that differ by 8-13 kJ mol(-1) in overall stability. In these systems, the free energies associated with individual intermolecular interactions can therefore be reliably treated in an additive fashion. The results suggest that alternative explanations should be considered for cooperative phenomena observed in other systems, and a rationale based on the population of partially bound states in flexible molecules is proposed to account for the enthalpic chelate effect and enthalpy-entropy compensation. PMID:14652069

  14. Bound states in the continuum in open acoustic resonators

    CERN Document Server

    Lyapina, A A; Pilipchuk, A S; Sadreev, A F

    2015-01-01

    We consider bound states in the continuum (BSC) or embedded trapped modes in two- and three-dimensional acoustic axisymmetric duct-cavity structures. We demonstrate numerically that under variation of the length of the cavity multiple BSCs occur due to the Friedrich-Wintgen two-mode full destructive interference mechanism. The BSCs are detected by tracing the resonant widths to the points of the collapse of Fano resonances where one of the two resonant modes acquires infinite life-time. It is shown that the approach of the acoustic coupled mode theory cast in the truncated form of a two-mode approximation allows us to analytically predict the BSC frequencies and shape functions to a good accuracy in both two and three dimensions.

  15. Dark matter and stable bound states of primordial black holes

    CERN Document Server

    Chavda, L K; Chavda, Abhijit L.

    2002-01-01

    We present three reasons for the formation of gravitational bound states of primordial black holes,called holeums,in the early universe.Using Newtonian gravity and nonrelativistic quantum mechanics we find a purely quantum mechanical mass-dependant exclusion property for the nonoverlap of the constituent black holes in a holeum.This ensures that the holeum occupies space just like ordinary matter.A holeum emits only gravitational radiation whose spectrum is an exact analogue of that of a hydrogen atom. A part of this spectrum lies in the region accessible to the detectors being built.The holeums would form haloes around the galaxies and would be an important component of the dark matter in the universe today.They may also be the constituents of the invisible domain walls in the universe.

  16. Rapid thermal co-annihilation through bound states

    CERN Document Server

    Kim, Seyong

    2016-01-01

    The co-annihilation rate of heavy particles close to thermal equilibrium, which plays a role in many classic dark matter scenarios, can be "simulated" in QCD by considering the pair annihilation rate of a heavy quark and antiquark at a temperature of a few hundred MeV. We show that the so-called Sommerfeld factors, parameterizing the rate, can be defined and measured non-perturbatively within the NRQCD framework. Lattice measurements indicate a modest suppression in the octet channel, in reasonable agreement with perturbation theory, and a large enhancement in the singlet channel, much above the perturbative prediction. We suggest that the additional enhancement originates from bound state formation and subsequent decay, omitted in previous estimates of thermal Sommerfeld factors, which were based on Boltzmann equations governing single-particle phase space distributions.

  17. Tetra quark bound states in a Bethe-Salpeter approach

    International Nuclear Information System (INIS)

    We determine the mass of tetraquark bound states from a coupled system of covariant Bethe-Salpeter equations. Similar in spirit to the quark-diquark model of the nucleon, we approximate the full four-body equation for the tetraquark by a coupled set of two-body equations with meson and diquark constituents. These are calculated from their quark and gluon substructure using a phenomenologically well-established quark-gluon interaction. For the lightest scalar tetraquark we find a mass of the order of 400 MeV and a wave function dominated by the pion-pion constituents. Both results are in agreement with a meson molecule picture for the f0(600). Our results furthermore suggest the presence of a potentially narrow all-charm tetraquark in the mass region 5-6 GeV.

  18. Dark matter and stable bound states of primordial black holes

    International Nuclear Information System (INIS)

    We present three reasons for the formation of gravitational bound states of primordial black holes, called holeums, in the early universe. Using Newtonian gravity and nonrelativistic quantum mechanics we find a purely quantum mechanical mass-dependent exclusion property for the nonoverlap of the constituent black holes in a holeum. This ensures that the holeum occupies space just like ordinary matter. A holeum emits only gravitational radiation whose spectrum is an exact analogue of that of a hydrogen atom. A part of this spectrum lies in the region accessible to the detectors being built. The holeums would form haloes around the galaxies and would be an important component of the dark matter in the universe today. They may also be the constituents of the invisible domain walls in the universe

  19. Probing the Dark Sector with Dark Matter Bound States

    Science.gov (United States)

    An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue

    2016-04-01

    A model of the dark sector where O (few GeV ) mass dark matter particles χ couple to a lighter dark force mediator V , mV≪mχ, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ , such as 0-+ and 1-- states, ηD and ϒD, is an important search channel. We show that e+e-→ηD+V or ϒD+γ production at B factories for αD>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via ηD→2 V →2 (l+l-) and ϒD→3 V →3 (l+l-) (l =e ,μ ,π ). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e+e-→χ χ ¯+n V , resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.

  20. Probing the Dark Sector with Dark Matter Bound States.

    Science.gov (United States)

    An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue

    2016-04-15

    A model of the dark sector where O(few  GeV) mass dark matter particles χ couple to a lighter dark force mediator V, m_{V}≪m_{χ}, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ, such as 0^{-+} and 1^{--} states, η_{D} and ϒ_{D}, is an important search channel. We show that e^{+}e^{-}→η_{D}+V or ϒ_{D}+γ production at B factories for α_{D}>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via η_{D}→2V→2(l^{+}l^{-}) and ϒ_{D}→3V→3(l^{+}l^{-}) (l=e,μ,π). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e^{+}e^{-}→χχ[over ¯]+nV, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter. PMID:27127956

  1. Two-vibron bound states in the β-Fermi-Pasta-Ulam model

    Institute of Scientific and Technical Information of China (English)

    Hu Xin-Guang; Tang Yi

    2008-01-01

    This paper studies the two-vibron bound states in the β-Fermi-Pasta-Ulam model by means of the number conserving approximation combined with the number state method.The results indicate that on-site,adjacent-site and mixed two-vibron bound states may exist in the model.Specially,wave number has a significant effect on such bound states,which may be considered as the quantum effects of the localized states in quantum systems.

  2. Three-nucleon problem: trinucleon bound states and trinucleon interactions

    International Nuclear Information System (INIS)

    The assumptions underlying the formulation and solution of the Schroedinger equation for three nucleons in configuration space are reviewed, in conjunction with those qualitative aspects of the two-nucleon problem which are important. The geometrical features of the problem and the crucial role of the angular momentum barrier are developed. The boundary conditions for scattering are discussed qualitatively, and the Faddeev-Noyes equation is motivated. The method of splines and orthogonal collocation are shown to provide convenient techniques for generating numerical solutions. Properties of the many numerical solutions for the bound states and zero-energy scattering states are discussed. The evidence for three-body forces is reviewed, and the results of the recent calculations including such forces are discussed. The importance of electromagnetic interactions in the three-nucleon systems is motivated. Relativistic corrections and meson-exchange currents are discussed in the context of ''rules of scale'', and the pion-exchange currents of nonrelativistic order are derived. The experimental results for trinucleon electromagnetic interactions are reviewed, including recent tritium data. Conclusions are presented. 56 refs., 23 figs

  3. Lower bound on concurrence for arbitrary-dimensional tripartite quantum states

    Science.gov (United States)

    Chen, Wei; Fei, Shao-Ming; Zheng, Zhu-Jun

    2016-06-01

    In this paper, we study the concurrence of arbitrary-dimensional tripartite quantum states. An explicit operational lower bound of concurrence is obtained in terms of the concurrence of substates. A given example shows that our lower bound may improve the well-known existing lower bounds of concurrence. The significance of our result is to get a lower bound when we study the concurrence of arbitrary m⊗ n⊗ l -dimensional tripartite quantum states.

  4. Pionic contribution in the Drell-Yan dilepton production cross section in p-Cu collision in the framework of the shell and Fermi gas models

    CERN Document Server

    Rostami, R

    2016-01-01

    To investigate the high mass dilepton production cross section produced due to the Drell-Yan process in hadronic collisions such as nucleon- nucleus, the valence and sea quarks distribution functions inside nucleus is used. In this study, in the framework of the shell and Fermi gas models, by adding quarks distribution functions of pions inside nucleus besides the quarks distribution functions of bound nucleons, the changes in the dilepton production cross section were investigated. For this reason, pionic contribution in the structure function of 63Cunucleus and its EMC ratio was first studied using the aforementioned models. Then, in the framework of the Drell-Yan process using GRV's nucleons and pions quarks distribution functions, the high mass dilepton production cross section in p-cu collision was calculated and compared with the available experimental data. The extracted results, based on the two mentioned models, were greatly the same and by considering the pionic contribution, the theoretical results...

  5. Investigation of Pionic Contribution in the Lepton and Antilepton Production Cross Section in p-Cu and p-Pt Collision

    Directory of Open Access Journals (Sweden)

    R. Rostami

    2016-01-01

    Full Text Available For detailed explanation of the experimental results of lepton production cross section in hadronic collisions such as nucleon-nucleon or nucleon-nuclei, it is of great importance to use quarks and sea quarks distribution function inside free and bound nucleons. In this paper, the role of pion cloud inside the nucleus in the structure function of Cu and Pt nuclei and the EMC ratio of these nuclei were investigated by using harmonic oscillator model. Then, in the framework of the Drell-Yan process and conventional nuclear theory, GRV’s quarks distribution functions and pionic quarks distribution functions were used to calculate lepton and antilepton production cross section in p-Cu and p-Pt scattering. From the results and based on the mentioned model, by considering pionic contribution, the theoretical results are improved.

  6. The pionic Drell–Yan process: a brief survey

    International Nuclear Information System (INIS)

    The Drell–Yan process is an invaluable tool for probing the structure of hadrons, and the pion-induced Drell–Yan process is unique in its sensitivity to several subtleties of the partonic structure. This is a brief review of the pionic Drell–Yan process with particular emphasis on the dilepton angular distributions and nuclear modification of the parton distributions (the EMC effect). (author)

  7. Unitary Transformations in Quantum Field Theory and Bound States

    CERN Document Server

    Shebeko, A V

    2001-01-01

    Finding the eigenstates of the total Hamiltonian H or its diagonalization is the important problem of quantum physics. However, in relativistic quantum field theory (RQFT) its complete and exact solution is possible for a few simple models only. Unitary transformations (UT's) considered in this survey do not diagonalize H, but convert H into a form which enables us to find approximately some H eigenstates. During the last years there have appeared many papers devoted to physical applications of such UT's. Our aim is to present a systematic and self-sufficient exposition of the UT method. The two general kinds of UT's are pointed out, distinct variations of each kind being possible. We consider in detail the problem of finding the simplest H eigenstates for interacting mesons and nucleons using the so-called ``clothing'' UT and Okubo's UT. These UT's allow us to suggest definite approaches to the problem of two-particle (deuteron-like) bound states in RQFT. The approaches are shown to yield the same two-nucleo...

  8. Bound States via Higgs Exchanging and Resonant Di-Higgs

    CERN Document Server

    Kang, Zhaofeng

    2016-01-01

    The standard model (SM)-like Higgs boson $h$ has spin zero and light mass around weak scale, so it has the potential to mediate a new and relatively strong force for the particle $\\phi$ in the new physics (NP) sector; then $\\phi$ may form bound state $B_h$ via exchanging $h$. This phenomena may arise in a wide context, for instance composite Higgs, supersymmetry (SUSY) and radiative neutrino (or more widely in the models with a strong Higgs portal for triggering classical scale symmetry breaking or strong first-order phase transition). For illustration we focus on two typical examples, the stop/sbottom sector and an inert Higgs doublet. Furthermore, we point out that $B_h$ must give rise to a clear resonant di-Higgs signature, which recently has been extensively searched for at the large hadron collider (LHC). Moreover, Higgs radiative decay such as to di-photon probably will be significantly modified provided that $\\phi$ is charged or/and colored.

  9. Unified description of bound, resonant and scattering states

    International Nuclear Information System (INIS)

    Recently we have introduced a general method for calculating the discrete Hilbert-space basis representation of the Green's operators of those Hamiltonians which have infinite symmetric tridiagonal matrix forms. The elements of this matrix are used in the calculation of the Green's matrix in terms of a three-term recurrence relation and continued fractions. We specified our general approach to the case of the Coulomb problem and the Coulomb-Sturmian basis associated with it. As a further step, we can combine this new way of calculating the Coulomb-Green's matrix with a technique of solving integral equations in discrete Hilbert-space-basis representations. This provides us with a quantum mechanical approximation method which is rather general in the sense that it is equally applicable to solving bound-, resonant- and scattering-state problems with practically any potential of physical relevance. The method is especially suited to problems where Coulomb-like asymptotics have to be treated, but the formalism also contains the case of the free Green's operator as a special case. (author)

  10. Coexistence of bound and virtual-bound states in shallow-core to valence x-ray spectroscopies

    Science.gov (United States)

    Sen Gupta, Subhra; Bradley, J. A.; Haverkort, M. W.; Seidler, G. T.; Tanaka, A.; Sawatzky, G. A.

    2011-08-01

    With the example of the non-resonant inelastic x-ray scattering (NIXS) at the O45 edges (5d→5f) of the actinides, we develop the theory for shallow-core to valence excitations, where the multiplet spread is larger than the core-hole attraction, such as if the core and valence orbitals have the same principal quantum number. This involves very strong final state configuration interaction (CI), which manifests itself as huge reductions in the Slater-Condon integrals, needed to explain the spectral shapes within a simple renormalized atomic multiplet theory. But more importantly, this results in a cross-over from bound (excitonic) to virtual-bound excited states with increasing energy, within the same core-valance multiplet structure, and in large differences between the dipole and high-order multipole transitions, as observed in NIXS. While the bound states (often higher multipole allowed) can still be modeled using local cluster-like models, the virtual-bound resonances (often dipole-allowed) cannot be interpreted within such local approaches. This is in stark contrast to the more familiar core-valence transitions between different principal quantum number shells, where all the final excited states almost invariably form bound core-hole excitons and can be modeled using local approaches. The possibility of observing giant multipole resonances for systems with high angular momentum ground states is also predicted. The theory is important to obtain ground state information from core-level x-ray spectroscopies of strongly correlated transition metal, rare-earth, and actinide systems.

  11. Supersymmetry Approaches to the Bound States of the Generalized Woods-Saxon Potential

    Science.gov (United States)

    Fakhri, H.; Sadeghi, J.

    Using the associated Jacobi differential equation, we obtain exactly bound states of the generalization of Woods-Saxon potential with the negative energy levels based on the analytic approach. According to the supersymmetry approaches in quantum mechanics, we show that these bound states by four pairs of the first-order differential operators, represent four types of the laddering equations. Two types of these supersymmetry structures, suggest the derivation of algebraic solutions by two different approaches for the bound states.

  12. Normalization of the covariant three-body bound state vertex function

    CERN Document Server

    Adam, J; Savkli, C; Van Orden, J W; Gross, Franz; Savkli, Cetin

    1997-01-01

    The normalization condition for the relativistic three nucleon Bethe-Salpeter and Gross bound state vertex functions is derived, for the first time, directly from the three body wave equations. It is also shown that the relativistic normalization condition for the two body Gross bound state vertex function is identical to the requirement that the bound state charge be conserved, proving that charge is automatically conserved by this equation.

  13. Near optimal bounds on quantum communication complexity of single-shot quantum state redistribution

    OpenAIRE

    Anshu, Anurag; Devabathini, Vamsi Krishna; Jain, Rahul

    2014-01-01

    We show near optimal bounds on the worst case quantum communication of single-shot entanglement-assisted one-way quantum communication protocols for the {\\em quantum state redistribution} task and for the sub-tasks {\\em quantum state splitting} and {\\em quantum state merging}. Our bounds are tighter than previously known best bounds for the latter two sub-tasks. A key technical tool that we use is a {\\em convex-split} lemma which may be of independent interest.

  14. Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state

    OpenAIRE

    Irudayam, Sheeba J.; Pobandt, Tobias; Berkowitz, Max L.

    2013-01-01

    An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energ...

  15. Bound states and critical behavior of the Yukawa potential

    Institute of Scientific and Technical Information of China (English)

    LI; Yongyao

    2006-01-01

    [1]Yukawa,H.,On the interaction of elementary particles,Proc.Phys.Math Soc.Jap.,1935,17:48-57.[2]Sachs,R.,Goeppert-Mayer,M.,Calculations on a new neutron-proton interaction potential,Phys.Rev.,1938,53:991-993.[3]Harris,G.,Attractive two-body interactions in partially ionized plasmas,Phys.Rev.,1962,125:1131-1140.[4]Schey,H.,Schwartz,J.,Counting the bound states in short-range central potentials,Phys.Rev.B,1965,139:1428-1432.[5]Rogers,J.,Graboske,H.,Harwood,E.,Bound eigenstates of the static screened Coulomb poten-tial,Phys.Rev.A,1970,1:1577-1586.[6]McEnnan,J.,Kissel,L.,Pratt,R.,Analytic perturbation theory for screened Coulomb potentials:non-relativistic case,Phys.Rev.A,1976,13:532-559.[7]Gerry,C.,Estimates of the ground states of the Yukawa potential from the Bogoliubov inequality,J.Phys.A,1984,17:L313-L315.[8]Kr(o)ger,H.,Girard,R.,Dufour,G.,Direct calculation of the S matrix in coordinate space,Phys.Rev.C,1988,37:486-496.[9]Girard,R.,Kr(o)ger,H.,Labelle,P.et al.,Computation of a long time evolution in a Schr(o)dinger system,Phys.Rev.A,1988,37:3195-3200.[10]Garavelli,S.,Oliveira,F.,Analytical solution for a Yukawa-type potential,Phys.Rev.Lett.,1991,66:1310-1313.[11]Gomes,O.,Chacham,H.,Mohallem,J.,Variational calculations for the bound-unbound transition of the Yukawa potential,Phys.Rev.A,1994,50:228-231.[12]Yukalov,V.,Yukalova,E.,Oliveira,F.,Renormalization-group solutions for Yukawa potential,J.Phys.A,1998,31:4337-4348.[13]Brau,F.,Necessary and sufficient conditions for existence of bound states in a central potential,J.Phys.A,2003,36:9907-9913.[14]Bertini,L.,Mella,M.,Bressanini,D.et al.,Borromean binding in H-2 with Yukawa potential:a nonadiabatic quantum Monte Carlo study,Phys.Rev.A,2004,69:042504.[15]Dean,D.,Drummond,I.,Horgan,R.,Effective diffusion constant in a two-dimensional medium of charged point scatterers,J.Phys.A,2004,37:2039-2046.[16]De-Leo,S.,Rotelli,P.,Amplification of coupling for Yukawa potentials,Phys.Rev.D,2004,69:034006.[17]Khrapak

  16. Efimov effect and higher bound states in a three particle system

    International Nuclear Information System (INIS)

    The J=0 bound states for a system of three identical spinless particles interacting in pairs through delta-shell potentials are studied. The Efimov states are identified, and their wave functions obtained. A new family of bound states, which occurs for higher values of the attractive coupling strength was found

  17. Continuum bound states as surface states of a finite periodic system

    International Nuclear Information System (INIS)

    We discuss the relation between continuum bound states (CBSs) localized on a defect, and surface states of a finite periodic system. We model an experiment of Capasso et al. [F. Capasso, C. Sirtori, J. Faist, D. L. Sivco, S-N. G. Chu, and A. Y. Cho, Nature (London) 358, 565 (1992)] using the transfer-matrix method. We compute the rate for intrasubband transitions from the ground state to the CBS and derive a sum rule. Finally we show how to improve the confinement of a CBS while keeping the energy fixed

  18. Quantum Chernoff bound as a measure of efficiency of quantum cloning for mixed states

    OpenAIRE

    Ghiu, Iulia

    2014-01-01

    In this paper we investigate the efficiency of quantum cloning of $N$ identical mixed qubits. We employ a recently introduced measure of distinguishability of quantum states called quantum Chernoff bound. We evaluate the quantum Chernoff bound between the output clones generated by the cloning machine and the initial mixed qubit state. Our analysis is illustrated by performing numerical calculation of the quantum Chernoff bound for different scenarios that involves the number of initial qubit...

  19. Phenomenological Lagrangian functions and pionic decays of the heavy lepton tau

    International Nuclear Information System (INIS)

    After a description of the construction of nonlinear realizations of compact groups by means of the example of the three-dimensional realization of the group SU(2)xSU(2) the author constructs a Lagrangian density for the interaction of pions with the tau particle, from which the decay of the tau-particle into one, two, or three pions is calculated. Thereafter an extension of this model is presented, in which by the postulation of gauge invariance a set of vector fields is obtained which can be identified with the rho triplet and the A1 triplet. The pionic decays of the tau are calculated once more under the assumption of the occurrence of these particles as intermediate states. The obtained results are compared with the experimental situation. (HSI)

  20. Scattering and Bound State Solutions of the Yukawa Potential within the Dirac Equation

    International Nuclear Information System (INIS)

    In the presence of spin symmetry case, we obtain bound and scattering states solutions of the Dirac equation for the equal scalar and vector Yukawa potentials for any spin-orbit quantum number κ. The approximate analytical solutions are presented for the bound and scattering states and scattering phase shifts

  1. Solitons in superfluid (He-3)-A - Bound states on domain walls

    Science.gov (United States)

    Ho, T. L.; Fulco, J. R.; Schrieffer, J. R.; Wilczek, F.

    1984-01-01

    The effects of solitons on the spectrum of fermion excitations in superfluid (He-3)-A are investigated. It is found that there is a two-dimensional manifold of bound states with energies within the gap of the bulk superfluid. The bound-state spectrum lacks inversion symmetry parallel to the wall.

  2. The $DKP$ equation in the Woods-Saxon potential well: Bound states

    CERN Document Server

    Boutabia-Chéraitia, Boutheina

    2016-01-01

    We solve the Duffin-Kemmer-P\\'{e}tiau equation in the presence of a spatially one-dimensional symmetric potential well. We compute the scattering state solutions and we derive conditions for transmission resonances. The bound solutions are derived by a graphic study and the appearance of the antiparticle bound state is discussed.

  3. Ensemble-based characterization of unbound and bound states on protein energy landscape

    CERN Document Server

    Ruvinsky, Anatoly M; Tuzikov, Alexander V; Vakser, Ilya A

    2012-01-01

    Characterization of protein energy landscape and conformational ensembles is important for understanding mechanisms of protein folding and function. We studied ensembles of bound and unbound conformations of six proteins to explore their binding mechanisms and characterize the energy landscapes in implicit solvent. First, results show that bound and unbound spectra often significantly overlap. Moreover, the larger the overlap the smaller the RMSD between bound and unbound conformational ensembles. Second, the analysis of the unbound-to-bound changes points to conformational selection as the binding mechanism for four of the proteins. Third, the center of the unbound spectrum has a higher energy than the center of the corresponding bound spectrum of the dimeric and multimeric states for most of the proteins. This suggests that the unbound states often have larger entropy than the bound states considered outside of the complex. Fourth, the exhaustively long minimization, making small intra-rotamer adjustments, ...

  4. Bounds on the Capacity of the Relay Channel with Noncausal State Information at Source

    CERN Document Server

    Zaidi, Abdellatif; Piantanida, Pablo; Vandendorpe, Luc

    2010-01-01

    We consider a three-terminal state-dependent relay channel with the channel state available non-causally at only the source. Such a model may be of interest for node cooperation in the framework of cognition, i.e., collaborative signal transmission involving cognitive and non-cognitive radios. We study the capacity of this communication model. One principal problem in this setup is caused by the relay's not knowing the channel state. In the discrete memoryless (DM) case, we establish lower bounds on channel capacity. For the Gaussian case, we derive lower and upper bounds on the channel capacity. The upper bound is strictly better than the cut-set upper bound. We show that one of the developed lower bounds comes close to the upper bound, asymptotically, for certain ranges of rates.

  5. Bound entangled states with a private key and their classical counterpart.

    Science.gov (United States)

    Ozols, Maris; Smith, Graeme; Smolin, John A

    2014-03-21

    Entanglement is a fundamental resource for quantum information processing. In its pure form, it allows quantum teleportation and sharing classical secrets. Realistic quantum states are noisy and their usefulness is only partially understood. Bound-entangled states are central to this question--they have no distillable entanglement, yet sometimes still have a private classical key. We present a construction of bound-entangled states with a private key based on classical probability distributions. From this emerge states possessing a new classical analogue of bound entanglement, distinct from the long-sought bound information. We also find states of smaller dimensions and higher key rates than previously known. Our construction has implications for classical cryptography: we show that existing protocols are insufficient for extracting private key from our distributions due to their "bound-entangled" nature. We propose a simple extension of existing protocols that can extract a key from them. PMID:24702340

  6. The effect of η-η' mixing in the bound state version of the Skyrme model

    International Nuclear Information System (INIS)

    The η-η' mixing is incorporated in the symmetry breaking term in the extended Skyrme model Lagrangian. Besides η-soliton bound states, an s-wave and a p-wave η'-soliton bound states are found. After fixing the value of the strength parameter X of the ''alternative term'' to fit the s-wave η'-soliton bound state to the N(1535) negative-parity nucleon resonance, the η-soliton bound states disappear. Then only η'-soliton bound states are identified with nucleon resonances (I=1/2) and delta resonances (I=3/2). The predicted resonance masses agree well with experimental values. The decay widths ΓN*→N+η of the relevant nucleon resonances are also calculated to explain why these particles have large branching ratios in the ηN channel. (orig.)

  7. Dynamics of F/D networks: the role of bound states

    International Nuclear Information System (INIS)

    In a field theory model, we study, via numerical experiments, the role of bound states in the evolution of cosmic superstring networks, being composed by p F strings, q D strings and (p,q) bound states. We find robust evidence for scaling of all three components of the network, independently of initial conditions. The novelty of our numerical approach consists of having control over the initial abundance of bound states. This indeed allows us to identify the effect of bound states on the evolution of the network. We also find an additional energy loss mechanism, resulting in a lower overall string network energy, and thus scaling of the network. This new mechanism consists of the formation of bound states with an increasing length

  8. A differential method for bounding the ground state energy

    CERN Document Server

    Mouchet, A

    2005-01-01

    For a wide class of Hamiltonians, a novel method to obtain lower and upper bounds for the lowest energy is presented. Unlike perturbative or variational techniques, this method does not involve the computation of any integral (a normalisation factor or a matrix element). It just requires the determination of the absolute minimum and maximum in the whole configuration space of the local energy associated with a normalisable trial function (the calculation of the norm is not needed). After a general introduction, the method is applied to three non-integrable systems: the asymmetric annular billiard, the many-body spinless Coulombian problem, the hydrogen atom in a constant and uniform magnetic field. Being more sensitive than the variational methods to any local perturbation of the trial function, this method can used to systematically improve the energy bounds with a local skilled analysis; an algorithm relying on this method can therefore be constructed and an explicit example for a one-dimensional problem is...

  9. Interacting quantum walkers: two-body bosonic and fermionic bound states

    Science.gov (United States)

    Krapivsky, P. L.; Luck, J. M.; Mallick, K.

    2015-11-01

    We investigate the dynamics of bound states of two interacting particles, either bosons or fermions, performing a continuous-time quantum walk on a one-dimensional lattice. We consider the situation where the distance between both particles has a hard bound, and the richer situation where the particles are bound by a smooth confining potential. The main emphasis is on the velocity characterizing the ballistic spreading of these bound states, and on the structure of the asymptotic distribution profile of their center-of-mass coordinate. The latter profile generically exhibits many internal fronts.

  10. Quasi-bound states, resonance tunnelling, and tunnelling times generated by twin symmetric barriers

    Indian Academy of Sciences (India)

    A Uma Maheswari; P Prema; S Mahadevan; C S Shastry

    2009-12-01

    In analogy with the definition of resonant or quasi-bound states used in three-dimensional quantal scattering, we define the quasi-bound states that occur in one-dimensional transmission generated by twin symmetric potential barriers and evaluate their energies and widths using two typical examples: (i) twin rectangular barrier and (ii) twin Gaussian-type barrier. The energies at which reflectionless transmission occurs correspond to these states and the widths of the transmission peaks are also the same as those of quasi-bound states. We compare the behaviour of the magnitude of wave functions of quasi-bound states with those for bound states and with the above-barrier state wave function. We deduce a Breit–Wigner-type resonance formula which neatly describes the variation of transmission coefficient as a function of energy at below-barrier energies. Similar formula with additional empirical term explains approximately the peaks of transmission coefficients at above-barrier energies as well. Further, we study the variation of tunnelling time as a function of energy and compare the same with transmission, reflection time and Breit–Wigner delay time around a quasi-bound state energy. We also find that tunnelling time is of the same order of magnitude as lifetime of the quasi-bound state, but somewhat larger.

  11. Versatile mode-locked fiber laser with switchable operation states of bound solitons.

    Science.gov (United States)

    Zou, Xin; Qiu, Jifang; Wang, Xiaodong; Ye, Zi; Shi, Jindan; Wu, Jian

    2016-06-01

    Bound states of two solitons are among the typical forms of bound states and can be observed in various operation states of mode-locked fiber lasers. We experimentally investigated bound solitons (BSs) in a passively mode-locked erbium-doped fiber laser based on a semiconductor saturable absorber mirror, whose operation states can be switched among multiple pulses, passively harmonic mode-locking, and "giant pulses" by simply adjusting the in-line polarization controller with the pump power fixed. Up to four pulses, fourth-order harmonic mode-locking (HML), and a "giant pulse" with four BSs were obtained with increasing pump power. Experimental results showed a correlative relationship among those operation states (N pulses/Nth-order HML/"giant pulses" of N bound solitons) at different pump power levels. The birefringence induced by the erbium-doped fiber inside the laser cavity played a vital role in the transitions of those operation states. PMID:27411182

  12. Photon-assisted tunneling through a topological superconductor with Majorana bound states

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Han-Zhao; Zhang, Ying-Tao, E-mail: zhangyt@mail.hebtu.edu.cn [College of Physics, Hebei Normal University, Shijiazhuang 050024 (China); Liu, Jian-Jun, E-mail: liujj@mail.hebtu.edu.cn [College of Physics, Hebei Normal University, Shijiazhuang 050024 (China); Department of Physics, Shijiazhuang University, Shijiazhuang 050035 (China)

    2015-12-15

    Employing the Keldysh Nonequilibrium Green’s function method, we investigate time-dependent transport through a topological superconductor with Majorana bound states in the presence of a high frequency microwave field. It is found that Majorana bound states driven by photon-assisted tunneling can absorb(emit) photons and the resulting photon-assisted tunneling side band peaks can split the Majorana bound state that then appears at non-zero bias. This splitting breaks from the current opinion that Majorana bound states appear only at zero bias and thus provides a new experimental method for detecting Majorana bound states in the Non-zero-energy mode. We not only demonstrate that the photon-assisted tunneling side band peaks are due to Non-zero-energy Majorana bound states, but also that the height of the photon-assisted tunneling side band peaks is related to the intensity of the microwave field. It is further shown that the time-varying conductance induced by the Majorana bound states shows negative values for a certain period of time, which corresponds to a manifestation of the phase coherent time-varying behavior in mesoscopic systems.

  13. Photon-assisted tunneling through a topological superconductor with Majorana bound states

    Directory of Open Access Journals (Sweden)

    Han-Zhao Tang

    2015-12-01

    Full Text Available Employing the Keldysh Nonequilibrium Green’s function method, we investigate time-dependent transport through a topological superconductor with Majorana bound states in the presence of a high frequency microwave field. It is found that Majorana bound states driven by photon-assisted tunneling can absorb(emit photons and the resulting photon-assisted tunneling side band peaks can split the Majorana bound state that then appears at non-zero bias. This splitting breaks from the current opinion that Majorana bound states appear only at zero bias and thus provides a new experimental method for detecting Majorana bound states in the Non-zero-energy mode. We not only demonstrate that the photon-assisted tunneling side band peaks are due to Non-zero-energy Majorana bound states, but also that the height of the photon-assisted tunneling side band peaks is related to the intensity of the microwave field. It is further shown that the time-varying conductance induced by the Majorana bound states shows negative values for a certain period of time, which corresponds to a manifestation of the phase coherent time-varying behavior in mesoscopic systems.

  14. On accurate computations of bound state properties in three- and four-electron atomic systems

    CERN Document Server

    Frolov, Alexei M

    2016-01-01

    Results of accurate computations of bound states in three- and four-electron atomic systems are discussed. Bound state properties of the four-electron lithium ion Li$^{-}$ in its ground $2^{2}S-$state are determined from the results of accurate, variational computations. We also consider a closely related problem of accurate numerical evaluation of the half-life of the beryllium-7 isotope. This problem is of paramount importance for modern radiochemistry.

  15. Skyrmion model in 2+1 dimensions with soliton bound states

    Energy Technology Data Exchange (ETDEWEB)

    Piette, B.; Zakrzewski, W.J. (Dept. of Mathematical Sciences, Univ. Durham (United Kingdom))

    1993-03-22

    We consider a class of skyrmion models in 2+1 dimensions which possess bound stable solitons. We show that these models have one-soliton solutions as well as static solutions corresponding to their bound states. We study the scattering and stability properties of these solutions, compute their energies and estimate their binding energies. (orig.).

  16. Bound states of fermions on 2D lattice in a dilute limit

    International Nuclear Information System (INIS)

    We examine extended bound states in a dilute limit of the extended Hubbard model on the two-dimensional square lattice. By solving exactly the two-body problem we have determined the binding energies, mobilities and dispersion curves across the Brillouin zone for bound states of various symmetries. It turns out that the d-wave pairing is strongly favoured by the nnn hopping and the intersite local pairs can have small effective masses, even on the case of strong binding.We have also found a possibility of extended s-dx2-y2 mixing of the bound states. (author)

  17. Taming the Yukawa potential singularity: improved evaluation of bound states and resonance energies

    Energy Technology Data Exchange (ETDEWEB)

    Alhaidari, A D [Shura Council, Riyadh 11212 (Saudi Arabia); Bahlouli, H [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Abdelmonem, M S [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2008-01-25

    Using the tools of the J-matrix method, we absorb the 1/r singularity of the Yukawa potential in the reference Hamiltonian, which is handled analytically. The remaining part, which is bound and regular everywhere, is treated by an efficient numerical scheme in a suitable basis using the Gauss quadrature approximation. Analysis of resonance energies and bound states spectrum is performed using the complex scaling method, where we show their trajectories in the complex energy plane and construct a video showing how bound states cross over into resonance states by varying the potential parameters. (fast track communication)

  18. Pair creation induced by transitions between electronic and positronic bound states

    Science.gov (United States)

    Liu, Y.; Lv, Q. Z.; Li, Y. T.; Grobe, R.; Su, Q.

    2015-05-01

    We study the creation process of electron-positron pairs from the quantum electrodynamical vacuum under very strong electric fields by solving the quantum field theoretical Dirac equation on a space-time grid. We investigate the role of bound-bound state mixing in such a process, which can be studied if the external force can be modeled by a combination of a potential barrier and a potential well. By increasing the magnitude of the two potentials, discrete states that originate from the positive and negative energy continua can become quasidegenerate in the mass gap region (between -mc 2 and mc 2). We show that this bound-bound state mixing is quite different from the usual bound-continuum state mixing where the particles are created until the Pauli exclusion principle inhibits this process. In the case of bound-bound mixing the particle number exhibits a characteristic oscillatory behavior that in principle can last forever. These findings can be modeled by an effective two-state model.

  19. An Improved Lower Bound Limit State Optimisation Algorithm

    DEFF Research Database (Denmark)

    Frier, Christian; Damkilde, Lars

    2010-01-01

    Limit State analysis has been used in engineering practice for many years e.g. the yield-line method for concrete slabs and slip-line solutions in geotechnics. In the recent years there has been an increased interest in numerical Limit State analysis, and today algorithms take into account the non...

  20. An Improved Lower Bound Limit State Optimisation Algorithm

    DEFF Research Database (Denmark)

    Frier, Christian; Damkilde, Lars

    2010-01-01

    Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs.......Limit State analysis has been used in manual design methods for decades e.g. the yield line theory for concrete slabs....

  1. Fano effect and Andreev bound states in T-shape double quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Calle, A.M.; Pacheco, M. [Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso (Chile); Orellana, P.A., E-mail: orellana@ucn.cl [Departamento de Física, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile)

    2013-09-02

    In this Letter, we investigate the transport through a T-shaped double quantum dot coupled to two normal metal leads left and right and a superconducting lead. Analytical expressions of Andreev transmission and local density of states of the system at zero temperature have been obtained. We study the role of the superconducting lead in the quantum interferometric features of the double quantum dot. We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. Our results show that as a consequence of quantum interference and proximity effect, the transmission from normal to normal lead exhibits Fano resonances due to Andreev bound states. We find that this interference effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. - Highlights: • Transport properties of a double quantum dot coupled in T-shape configuration to conducting and superconducting leads are studied. • We report Fano antiresonances in the normal transmission due to the Andreev reflections in the superconducting lead. • We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. • Fano effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. • Andreev bound states survives even for strong dot-superconductor coupling.

  2. Fano effect and Andreev bound states in T-shape double quantum dots

    International Nuclear Information System (INIS)

    In this Letter, we investigate the transport through a T-shaped double quantum dot coupled to two normal metal leads left and right and a superconducting lead. Analytical expressions of Andreev transmission and local density of states of the system at zero temperature have been obtained. We study the role of the superconducting lead in the quantum interferometric features of the double quantum dot. We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. Our results show that as a consequence of quantum interference and proximity effect, the transmission from normal to normal lead exhibits Fano resonances due to Andreev bound states. We find that this interference effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. - Highlights: • Transport properties of a double quantum dot coupled in T-shape configuration to conducting and superconducting leads are studied. • We report Fano antiresonances in the normal transmission due to the Andreev reflections in the superconducting lead. • We report for first time the Fano effect produced by Andreev bound states in a side quantum dot. • Fano effect allows us to study the Andreev bound states in the changes in the conductance between two normal leads. • Andreev bound states survives even for strong dot-superconductor coupling

  3. The bound state Aharonov-Bohm effect around a cosmic string revisited

    OpenAIRE

    Filgueiras, C.; Moraes, Fernando

    2005-01-01

    In this article we observe that the self-adjoint extension of the Hamiltonian of a particle moving around a shielded cosmic string gives rise to a gravitational analogue of the bound state Aharonov-Bohm effect.

  4. Sufficient conditions for the existence of a bound state in the N-body problem

    International Nuclear Information System (INIS)

    Simple sufficient conditions for the existence of a bound state in the system of N particles interacting via a purely attractive two-body potential are provided. This method is based on a variational approach. (Author)

  5. The dynamical gluon mass in the massless bound-state formalism

    CERN Document Server

    Ibanez, David

    2014-01-01

    We describe the phenomenon of dynamical gluon mass generation within the massless bound-state formalism, which constitutes the general framework for the systematic implementation of the Schwinger mechanism in non-Abelian gauge theories. The main ingredient of this formalism is the dynamical formation of bound states with vanishing mass, which gives rise to effective vertices containing massless poles; these vertices, in turn, trigger the Schwinger mechanism, and allow for the gauge-invariant generation of an effective gluon mass. In this particular approach, the gluon mass is directly related to quantities that are intrinsic to the bound-state formation itself, such as the "transition amplitude" and the corresponding "bound-state wave-function". Specifically, a set of powerful relations discussed in the text, allows one to determine the dynamical evolution of the gluon mass through a Bethe-Salpeter equation, which controls the dynamics of the relevant wave-function. In addition, it is possible to demonstrate ...

  6. Strongly bound metastable states of B2 + 2

    Science.gov (United States)

    Bruna, Pablo J.; Wright, James S.

    1990-08-01

    The stabilities of about 25 electronic states of B2+2 have been investigated using a multireference CI (MRD-CI) method and an AO basis set composed of 6s4p2d contracted Gaussian species per atom, including semidiffuse functions relevant for an adequate description of charge transfer interactions. The ground state X1∑+g (σ2gσ2u) is repulsive, as expected by its electronic configuration with a zero bond order. In spite of this and the doubly-positive charge, many excited states are found to be metastable, four of them (11∏g, 11∏u, 13∑-g, and 11Δg ) having potential wells from 1.52 eV (11∏u) to 2.83 eV (13∑-g). Relative to the ground state configuration, the metastable states arise from the excitations σu→σg(3∑+u), σu→πu(3,1∏g), σ2u→σgπu(3,1∏u), and σ2u→π2u(3∑-g, 1Δg, 1∑+g); they are analogous to those states showing deep local minima in B2 and B+2. Differences in stabilities among quasibound states can be explained on the basis of the asymptotic ΔE's between repulsive channels B++B+ and appropriate higher-lying limits (states) B+B2+ of bonding character; another important factor governing stability is the actual bonding character of the electronic configurations assigned to each state. The vertical double-ionization potential B2→B2+2(π2u→∞) between both ground states is 27.97 eV, the repulsive X1∑+g dication state being created with 8.37 eV excess energy relative to B++B+. Doubly-ionized states with a chance of being detected because of their long lifetimes against predissociation are those showing a strongly quasibound character, such as (with the vertical double ionization potential in eV given in parentheses): 11∏g(σuπu→∞; 30.29); 11∏u(σ2uπu→σg∞; 31.30); 13∑-g(σ2u→∞; 31.33), and 11Δg(σ2u→∞; 31.95).

  7. Bound states in the dynamics of a dipole in the presence of a conical defect

    CERN Document Server

    De Ribeiro, C A L; Moraes, F; Furtado, Claudio; Moraes, Fernando

    2005-01-01

    In this work we investigate the quantum dynamics of an electric dipole in a $(2+1)$-dimensional conical spacetime. For specific conditions, the Schr\\"odinger equation is solved and bound states are found with the energy spectrum and eigenfunctions determined. We find that the bound states spectrum extends from minus infinity to zero with a point of accumulation at zero. This unphysical result is fixed when a finite radius for the defect is introduced.

  8. Bound states in the two-dimension massive quantum electrodynamics (Qed2)

    International Nuclear Information System (INIS)

    This work studies the fermion-antifermion bound states in the (1+1)D two-dimension massive quantum electrodynamic in the 1/N expansion. The scattering matrices in the non-relativistic approximation have been calculated through TQC, and compared with the cross section in the Born approximation, and therefore the potential responsible by the interactions in the scattering processes have been obtained. Using Schroedinger equation, the existence of possible bound states have been investigated

  9. Two-polariton bound states in the Jaynes-Cummings-Hubbard model

    International Nuclear Information System (INIS)

    We examine the eigenstates of the one-dimensional Jaynes-Cummings-Hubbard model in the two-excitation subspace. We discover that two-excitation bound states emerge when the ratio of vacuum Rabi frequency to the tunneling rate between cavities exceeds a critical value. We determine the critical value as a function of the quasimomentum quantum number, and indicate that the bound states carry a strong correlation in which the two polaritons appear to be spatially confined together.

  10. Quantum Chernoff bound as a measure of the efficiency of quantum cloning for mixed states

    International Nuclear Information System (INIS)

    In this paper we investigate the efficiency of quantum cloning of N identical mixed qubits. We employ a recently introduced measure of distinguishability of quantum states called the quantum Chernoff bound. We evaluate the quantum Chernoff bound between the output clones generated by the cloning machine and the initial mixed qubit state. Our analysis is illustrated by performing numerical calculation of the quantum Chernoff bound for different scenarios that involves the number of initial qubits N and the number of output imperfect copies M. (paper)

  11. QQqq Four-Quark Bound States in Chiral SU(3) Quark Model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming; ZHANG Hai-Xia; ZHANG Zong-Ye

    2008-01-01

    The possibility of QQqq heavy-light four-quark bound states has been analyzed by means of the chiral SU(3) quark model, where Q is the heavy quark (c or b) and q is the light quark (u, d, or s). We obtain a bound state for the bbnn configuration with quantum number JP=1+, I=0 and for the ccnn (JP=1+, I=0) configuration, which is not bound but slightly above the D*D* threshold (n is u or d quark). Meanwhile, we also conclude that a weakly bound state in bbnn system can also be found without considering the chiral quark interactions between the two light quarks, yet its binding energy is weaker than that with the chiral quark interactions.

  12. From the Deuteron to Deusons, an Analysis of Deuteronlike Meson-Meson Bound States

    CERN Document Server

    Törnqvist, N A

    1994-01-01

    A systematic study of possible deuteronlike two-meson bound states, {\\it deusons}, is presented. Previous arguments that many such bound states may exist are elaborated with detailed arguments and numerical calculations including, in particular, the tensor potential. In the heavy meson sector one-pion exchange alone is strong enough to form at least deuteron-like $B\\bar B^*$ and $B^*\\bar B^*$ composites bound by approximately 50 MeV. Composites of $D\\bar D^*$ and $D^*\\bar D^*$ states bound by pion exchange alone are expected near the thresholds, while in the light meson sector one generally needs some additional short range attraction to form bound states. The quantum numbers of these states are I=0, In $B\\bar B^*$ one predictss the states: $\\eta_b(\\approx 10545),\\ \\chi_{b1}(\\approx 10562)$, and in $B^*\\bar B^*$ one finds the states: $\\eta_b(\\approx 10590),\\ \\chi_{b0}(\\approx 10582),\\ h_b(\\approx 10608),\\ \\chi_{b2}(\\approx 10602)$. Near the $D\\bar D^*$ threshold the states: $\\eta_c(\\approx 3870),\\ \\chi_{c0}(\\...

  13. Multichannel quantum defect theory of strontium bound Rydberg states

    International Nuclear Information System (INIS)

    Using the reactance matrix approach, we systematically develop new multichannel quantum defect theory (MQDT) models for the singlet and triplet S, P, D and F states of strontium below the first ionization limit, based on improved energy level measurements. The new models reveal additional insights into the character of doubly excited perturber states, and the improved energy level measurements for certain series allow fine structure to be resolved for those series’ perturbers. Comparison between the predictions of the new models and those of previous empirical and ab initio studies reveals good agreement with most series; however, some discrepancies are highlighted. Using the MQDT wave functions derived from our models we calculate other observables such as Landé gJ-factors and radiative lifetimes. The analysis reveals the impact of perturbers on the Rydberg state properties of divalent atoms, highlighting the importance of including two-electron effects in the calculations of these properties. The work enables future investigations of properties such as Stark maps and long-range interactions of Rydberg states of strontium. (paper)

  14. Description of the general properties of pionic atoms

    International Nuclear Information System (INIS)

    The effects of the finite dimension of the nucleus and the strong interaction effects in the energy levels ls and 2p of pionic atoms are considered. The energy transition between these two levels are calculated using the method of perturbations of first order, considering a uniform distribution of nuclear charge, for the effect of the finite dimension of the nucleus and one local optical potential as a model for the strong interaction. The calculations were realized for 13 elements and the results were compared with the experimentally obtained, founding a relative difference around of 4%. In conclusion the author observed that the effects of the finite dimension and the strong interaction can be considered as first order perturbations in light atoms, and for heavy atoms this effects can be considered as of second order or higher perturbations. (author)

  15. Bethe-Salpeter bound-state structure in Minkowski space

    Science.gov (United States)

    Gutierrez, C.; Gigante, V.; Frederico, T.; Salmè, G.; Viviani, M.; Tomio, Lauro

    2016-08-01

    The quantitative investigation of the scalar Bethe-Salpeter equation in Minkowski space, within the ladder-approximation framework, is extended to include the excited states. This study has been carried out for an interacting system composed by two massive bosons exchanging a massive scalar, by adopting (i) the Nakanishi integral representation of the Bethe-Salpeter amplitude, and (ii) the formally exact projection onto the null plane. Our analysis, on one hand, confirms the reliability of the method already applied to the ground state and, on the other one, extends the investigation from the valence distribution in momentum space to the corresponding quantity in the impact-parameter space, pointing out some relevant features, like (i) the equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and (ii) the leading exponential fall-off of the valence wave function in the impact-parameter space.

  16. Bethe-Salpeter bound-state structure in Minkowski space

    CERN Document Server

    Gutierrez, C; Frederico, T; Salmè, G; Viviani, M; Tomio, Lauro

    2016-01-01

    The quantitative investigation of the scalar Bethe-Salpeter equation in Minkowski space, within the ladder-approximation framework, is extended to include the excited states. This study has been carried out for an interacting system composed by two massive bosons exchanging a massive scalar, by adopting (i) the Nakanishi integral representation of the Bethe-Salpeter amplitude, and (ii) the formally exact projection onto the null plane. Our analysis, on one hand, confirms the reliability of the method already applied to the ground state and, on the other one, extends the investigation from the valence distribution in momentum space to the corresponding quantity in the impact-parameter space, pointing out some relevant features, like (i) the equivalence between Minkowski and Euclidean transverse-momentum amplitudes, and (ii) the leading exponential fall-off of the valence wave function in the impact-parameter space.

  17. Is the exotic $X(5568)$ a bound state?

    CERN Document Server

    Chen, Xiaoyun

    2016-01-01

    Stimulated by the recent observation of the exotic $X(5568)$ state by D0 Collaboration, we study the four-quark system $us\\bar{b}\\bar{d}$ with quantum numbers $J^P=0^+$ in the framework of chiral quark model. Two structures, diquark-antidiquark and meson-meson, with all possible color configurations are investigated by using Gaussian expansion method. The results show that energies of the tetraquark states with diquark-antiquark structure are too high to the candidate of $X(5568)$, and no molecular structure can be formed in our calculations. The calculation is also extended to the four-quark system $us\\bar{c}\\bar{d}$ and the same results as that of $us\\bar{b}\\bar{d}$ are obtained.

  18. Long range coherent magnetic bound states in superconductors

    OpenAIRE

    Ménard, Gerbold C.; Guissart, Sébastien; Brun, Christophe; Pons, Stéphane; Stolyarov, Vasily S.; Debontridder, François; Leclerc, Matthieu V.; Janod, Etienne; Cario, Laurent; Roditchev, Dimitri; Simon, Pascal; Cren, Tristan

    2015-01-01

    The quantum coherent coupling of completely different degrees of freedom is a challenging path towards creating new functionalities for quantum electronics. Usually the antagonistic coupling between spins of magnetic impurities and superconductivity leads to the destruction of the superconducting order. Here we show that a localized classical spin of an iron atom immersed in a superconducting condensate can give rise to new kind of long range coherent magnetic quantum state. In addition to th...

  19. $D^*$ $\\Xi N$ bound state in strange three-body systems

    CERN Document Server

    Garcilazo, H

    2016-01-01

    The recent update of the strangeness $-2$ ESC08c Nijmegen potential incorporating the NAGARA and KISO events predicts a $\\Xi N$ bound state, $D^*$, in the $^3S_1 (I=1)$ channel. We study if the existence of this two-body bound state could give rise to stable three-body systems. For this purpose we solve the bound state problem of three-body systems where the $\\Xi N$ state is merged with $N$'s, $\\Lambda$'s, $\\Sigma's$ or $\\Xi$'s, making use of the most recent updates of the two-body ESC08c Nijmegen potentials. We found that there appear stable states in the $\\Xi NN$ and $\\Xi \\Xi N$ systems, the $\\Xi \\Lambda N$ and $\\Xi \\Sigma N$ systems being unbound.

  20. High-precision measurement of strong-interaction effects in pionic deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Strauch, Thomas

    2009-06-30

    The hadronic ground state shift {epsilon}{sub 1s} and width {gamma}{sub 1s} in pionic deuterium were measured with high precision at the pion factory of the Paul Scherrer Institut (PSI), Switzerland (PSI-Experiment R-06.03). In this experiment the {pi}D(3p-1s) X-ray transition of about 3 keV was measured using a high-resolution Bragg crystal spectrometer equipped with a large-area position sensitive CCD detector. The characteristic X-radiation stems from a de-excitation cascade of the pionic atom. In order to produce an intense X-ray source, the cyclotron trap was used to stop pions in a cryogenic D{sub 2} target after winding up the pion beam in a magnetic field. The hadronic shift {epsilon}{sub 1s} is obtained from the measured transition energy by comparison to the pure electromagnetic value, where the determination of the broadening {gamma}{sub 1s} requires the precise knowledge of the spectrometer response, obtained from measurements of narrow X-ray transitions from highly ionised atoms, produced in an electron cyclotron resonance ion trap. As the formation rate is assumed to be density dependent, the {pi}D(3p-1s) X-ray energy was measured at three different D{sub 2} pressures. Another cascade process (Coulomb de-excitation) transforms the energy release of de-excitation steps into kinetic energy of the collision partners leading to a Doppler broadening of subsequent X-ray transitions. The hadronic broadening {gamma}{sub 1s} is only obtained after deconvolution of the spectrometer response function and the contributions from Doppler broadening. No energy dependence of the {pi}D(3p-1s) was found, and it is concluded that radiative de-excitation from molecular states is negligible within the experimental accuracy. Hence, the result for the shift reads {epsilon}{sub 1s} = (-2.325{+-}0.031) eV, corresponding to an accuracy of 1.3% and represents the average of the three measured densities. The uncertainty is dominated by the accuracy of the gallium K{alpha}{sub 2

  1. Bound states of quarks and gluons and hadronic transitions

    International Nuclear Information System (INIS)

    A potential which incorporates the concepts of confinement and asymptotic freedom, previously utilized in the description of the spectroscopy of mesons and baryons, is extended to the gluon sector. The mass spectroscopy of glueballs and hybrids is analyzed considering only pairwise potentials and massive constituent gluons. The mass spectrum of the color octet two-gluon system is adopted as a suitable description of the intermediate states of hadronic transitions, within the framework of the multipole expansion for quantum chromodynamics. The spin-dependent effects in the gluonium spectrum, associated with the Coulombian potential, are calculated through the inverted first Born approximation for the gluon-gluon scattering. (author). 102 refs, 1 fig, 13 tabs

  2. Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state

    CERN Document Server

    Irudayam, Sheeba J; Berkowitz, Max L

    2013-01-01

    An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energy barrier. The PMFs were calculated for a peptide to lipid (P/L) ratio of 1/128 and 4/128. We observe that the free energy barrier is reduced when the P/L ratio increased. In addition, we study the cooperative effect; specifically we investigate if the barrier is smaller for a second melittin reorientation, given that another neighboring melittin was already in the transmembrane state. We observe that indeed the barrier of the PMF curve is reduced in this case, thus confirming the presence of a cooperative effect.

  3. X(3872) and Bound State Problem of D~0(D)*~0((D)~0D*~0)

    Institute of Scientific and Technical Information of China (English)

    LIU Tan-rui; LIU Xiang; DENG Wei-zhen

    2009-01-01

    We have performed a dynamical calculation of the bound state problem of D~0(D)~(*0) by considering the pion and sigma meson exchange potential.Our preliminary analysis disfavors the molecular interpretation of X(3872) if we use the experimental D~* Dπ coupling constant g=0.59 and a reasonable cutoff around 1 GeV,which is the typical hadronic scale.In contrast,there probably exists a loosely bound S-wave B (-B)~* molecular state.Such a molecular state would be rather stable since its dominant decay mode is the radiative decay through B~*→Bγ.

  4. Effect of quasi-bound states on coherent electron transport in twisted nanowires

    OpenAIRE

    Cuoghi, Giampaolo; Bertoni, Andrea; Sacchetti, Andrea

    2010-01-01

    Quantum transmission spectra of a twisted electron waveguide expose the coupling between traveling and quasi-bound states. Through a direct numerical solution of the open-boundary Schr\\"odinger equation we single out the effects of the twist and show how the presence of a localized state leads to a Breit-Wigner or a Fano resonance in the transmission. We also find that the energy of quasi-bound states is increased by the twist, in spite of the constant section area along the waveguide. While ...

  5. Tunable Plasmonic Reflection by Bound 1D Electron States in a 2D Dirac Metal

    Science.gov (United States)

    Jiang, B.-Y.; Ni, G. X.; Pan, C.; Fei, Z.; Cheng, B.; Lau, C. N.; Bockrath, M.; Basov, D. N.; Fogler, M. M.

    2016-08-01

    We show that the surface plasmons of a two-dimensional Dirac metal such as graphene can be reflected by linelike perturbations hosting one-dimensional electron states. The reflection originates from a strong enhancement of the local optical conductivity caused by optical transitions involving these bound states. We propose that the bound states can be systematically created, controlled, and liquidated by an ultranarrow electrostatic gate. Using infrared nanoimaging, we obtain experimental evidence for the locally enhanced conductivity of graphene induced by a carbon nanotube gate, which supports this theoretical concept.

  6. Spectral Singularities do not Correspond to Bound States in the Continuum

    Directory of Open Access Journals (Sweden)

    Ali Mostafazadeh

    2013-01-01

    Full Text Available We show that, contrary to a claim made in arXiv:1011.0645, the von Neumann-Winger bound states that lie in the continuum of the scattering states are fundamentally different from Naimark’s spectral singularities.

  7. Study of the deeply bound hole states by the (3He,α) reaction

    International Nuclear Information System (INIS)

    The (3He,α) reactions at 110 - 120 MeV on even tin isotopes revealed the presence of the new (1g)-1 state at Ex = 6 -- 7 MeV with a spectroscopic factor comparable to the known (1g sub(9/2))-1 deeply bound hole state. (author)

  8. Normalization and perturbation theory for tightly bound states of the spinor Bethe-Salpeter equation

    NARCIS (Netherlands)

    L.G. Suttorp

    1976-01-01

    The normalisation integrals for the tightly-bound-state solutions of the spinor Bethe-Salpeter equation that have been derived recently are evaluated. Ghost states are found to appear when the continuous parameters characterising the type of fermion-boson interaction reach a critical value. Perturba

  9. Search for $\\eta$'(958)-nucleus bound states by (p,d) reaction at GSI and FAIR

    CERN Document Server

    Fujioka, H; Benlliure, J; Brinkmann, K -T; Friedrich, S; Geissel, H; Gellanki, J; Guo, C; Gutz, E; Haettner, E; Harakeh, M N; Hayano, R S; Higashi, Y; Hirenzaki, S; Hornung, C; Igarashi, Y; Ikeno, N; Itahashi, K; Iwasaki, M; Jido, D; Kalantar-Nayestanaki, N; Kanungo, R; Knoebel, R; Kurz, N; Metag, V; Mukha, I; Nagae, T; Nagahiro, H; Nanova, M; Nishi, T; Ong, H J; Pietri, S; Prochazka, A; Rappold, C; Reiter, M P; Rodríguez-Sánchez, J L; Scheidenberger, C; Simon, H; Sitar, B; Strmen, P; Sun, B; Suzuki, K; Szarka, I; Takechi, M; Tanaka, Y K; Tanihata, I; Terashima, S; Watanabe, Y N; Weick, H; Widmann, E; Winfield, J S; Xu, X; Yamakami, H; Zhao, J

    2015-01-01

    The mass of the {\\eta}' meson is theoretically expected to be reduced at finite density, which indicates the existence of {\\eta}'-nucleus bound states. To investigate these states, we perform missing-mass spectroscopy for the (p, d) reaction near the {\\eta}' production threshold. The overview of the experimental situation is given and the current status is discussed.

  10. Extended supersymmetry for the bound states of the generalized Hulthen potential hierarchy

    International Nuclear Information System (INIS)

    Using the associated hypergeometric differential equation, we analytically solve the bound states corresponding to a hierarchy of the radial potential -v0 e-δr/(1 - e-δr) + c e-δr/(1 - e-δr)2 as a generalization of the Hulthen potential. Then, an analytic solution corresponding to a special case for which the parameter c is expected to be in terms of l(l + 1) is also derived. Meanwhile without introducing a superpotential and in the framework of supersymmetric quantum mechanics, it is shown that these bound states can be calculated by two different algebraic methods. Based on these two approaches, it is noted that the bound states realize an extended supersymmetry structure

  11. Extended supersymmetry for the bound states of the generalized Hulthén potential hierarchy

    Science.gov (United States)

    Fakhri, H.; Chenaghlou, A.

    2004-09-01

    Using the associated hypergeometric differential equation, we analytically solve the bound states corresponding to a hierarchy of the radial potential -v0 e-dgrr/(1 - e-dgrr) + c e-dgrr/(1 - e-dgrr)2 as a generalization of the Hulthén potential. Then, an analytic solution corresponding to a special case for which the parameter c is expected to be in terms of l(l + 1) is also derived. Meanwhile without introducing a superpotential and in the framework of supersymmetric quantum mechanics, it is shown that these bound states can be calculated by two different algebraic methods. Based on these two approaches, it is noted that the bound states realize an extended supersymmetry structure.

  12. Extended supersymmetry for the bound states of the generalized Hulthen potential hierarchy

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, H [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of); Chenaghlou, A [Institute for Studies in Theoretical Physics and Mathematics (IPM), PO Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2004-09-03

    Using the associated hypergeometric differential equation, we analytically solve the bound states corresponding to a hierarchy of the radial potential -v{sub 0} e{sup -{delta}}{sup r}/(1 - e{sup -{delta}}{sup r}) + c e{sup -{delta}}{sup r}/(1 - e{sup -{delta}}{sup r}){sup 2} as a generalization of the Hulthen potential. Then, an analytic solution corresponding to a special case for which the parameter c is expected to be in terms of l(l + 1) is also derived. Meanwhile without introducing a superpotential and in the framework of supersymmetric quantum mechanics, it is shown that these bound states can be calculated by two different algebraic methods. Based on these two approaches, it is noted that the bound states realize an extended supersymmetry structure.

  13. Critical field enhancement of asymptotic optical bound states in the continuum

    Science.gov (United States)

    Yoon, Jae Woong; Song, Seok Ho; Magnusson, Robert

    2015-12-01

    We study spectral singularities and critical field enhancement factors associated with embedded photonic bound states in subwavelength periodic Si films. Ultrahigh-Q resonances supporting field enhancement factor exceeding 108 are obtained in the spectral vicinity of exact embedded eigenvalues in spite of deep surface modulation and vertical asymmetry of the given structure. Treating relations between the partial resonance Q and field enhancement factors with an analytical coupled-mode model, we derive a general strategy to maximize the field enhancement associated with these photonic bound states in the presence of material dissipation. The analytical expression for the field enhancement quantitatively agrees with rigorous numerical calculations. Therefore, our results provide a general knowledge for designing practical resonance elements based on optical bound states in the continuum in various applications.

  14. Propagators for Scalar Bound States at Finite Temperature in an NJL Model

    Institute of Scientific and Technical Information of China (English)

    ZHOU BangRong

    2002-01-01

    We re-examine physical causal propagators for scalar and pseudoscalar bound states at finite temperaturein a chiral Ut(1) x UR(1) NJL model, defined by four-point amputated fimctions subtracted through the gap equation,and prove that they are completely equivalent in the imaginary-time and real-time formalisms by separating carefiullythe imaginary part of the zero-temperature loop integral. It is shown that the same thermal transformation matrix ofthe matrix propagators for these bound states in the real-time formalism is precisely the one of the matrix propagatorfor an elementary scalar particle and this fact shows the similarity of thermodynamic property between a composite andelementary scalar particle. The retarded and advanced propagators for these bound states are also given explicitly fromthe imaginary-time formalism.

  15. Bound states in the continuum and spin filter in quantum-dot molecules

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.P. [Departamento de Física, Universidad Católica del Norte, Casilla 1280, Antofagasta (Chile); Orellana, P.A., E-mail: pedro.orellana@usm.cl [Departamento de Física, Universidad Técnica Federico Santa María, Vicuña Mackenna 3939, Santiago (Chile)

    2014-12-15

    In this paper we study the formation of bound states in the continuum in a quantum dot molecule coupled to leads and their potential application in spintronics. Based on the combination of bound states in the continuum and Fano effect, we propose a new design of a spin-dependent polarizer. By lifting the spin degeneracy of the carriers in the quantum dots by means of a magnetic field the system can be used as a spin-polarized device. A detailed analysis of the spin-dependent conductance and spin polarization as a function of the applied magnetic field and gate voltages is carried out.

  16. Three-particle hyper-spherical harmonics and quark bound states

    Science.gov (United States)

    Salom, Igor; Dmitrašinović, V.

    2016-01-01

    We construct the three-body permutation symmetric hyperspherical harmonics based on the subgroup chain S3 ⊗ SO (3)rot ⊂ O(2) ⊗ SO (3)rot ⊂ O(6) (and the subalgebra chain u(1) ⊗ so(3)rot ⊂ u(3) ⊂ so(6)). These hyperspherical harmonics represent a natural basis for solving non-relativistic three-body Schrodinger equation in three spatial dimensions. In particular, we apply the calculated three-particle harmonics to the three-quark bound state problem. We consider confining Δ- and Y-string three-quark effective potentials, and then calculate the spectrum of low-lying (K < 4) bound states.

  17. Bound states of the $\\phi^4$ model via the Non-Perturbative Renormalization Group

    CERN Document Server

    Rose, F; Leonard, F; Delamotte, B

    2016-01-01

    Using the nonperturbative renormalization group, we study the existence of bound states in the symmetry-broken phase of the scalar $\\phi^4$ theory in all dimensions between two and four and as a function of the temperature. The accurate description of the momentum dependence of the two-point function, required to get the spectrum of the theory, is provided by means of the Blaizot--M\\'endez-Galain--Wschebor approximation scheme. We confirm the existence of a bound state in dimension three, with a mass within 1% of previous Monte-Carlo and numerical diagonalization values.

  18. Propagators for scalar bound states at finite temperature in a NJL model

    CERN Document Server

    Zhou Bang Rong

    2002-01-01

    We show that, in a chiral $U_L(1)\\times U_R(1)$ NJL model, the physical propagators at finite temperature for scalar and pseudoscalar bound states in the imaginary-time formalism defined by amputated four-point functions, may have identical expressions to corresponding ones in the real-time formalism defined by diagonalization of amputated four-point function matrices only if the momentum $p$ of those bound states satisfy the condition $0\\leq p^2 < 4m^2$ ($m$ is the dynamical fermion mass). In the other case, the propagators in the two formalisms will have different imaginary parts in their denominators.

  19. Scattering integral equations and four nucleon problem. Four nucleon bound states and scattering

    International Nuclear Information System (INIS)

    Existing results from the application of integral equation technique four-nucleon bound states and scattering are reviewed. The purpose of this review is to provide a clear and elementary introduction in the integral equation method and to demonstrate its usefulness in physical applications. Developments in the actual numerical solutions of Faddeev-Yakubovsky type equations are such that a detailed comparison can be made with experiment. Bound state calculations indicate that a nonrelativistic description with pairwise nuclear forces does not suffice and additional degrees of freedom are noted

  20. Bound states in the (2+1)D scalar electrodynamics with Chern-Simons term

    International Nuclear Information System (INIS)

    This work studies the existence of bound states for the 3-dimensions scalar electrodynamics, with the Chern-Simons. Quantum field theory is used for calculation of the Mfi scattering matrices, in the non-relativistic approximation. The field propagators responsible for the interaction in the scattering processes have been calculated, and scattering matrices have been constructed. After obtaining the scattering matrix, the cross section in the quantum field theory has been compared with the quantum mechanic cross section in the Born approximation, allowing to obtain the form of the potential responsible for the interactions in the scattering processes. The possibility of bound states are analyzed by using the Schroedinger equation

  1. Shell-model description of weakly bound and unbound nuclear states

    International Nuclear Information System (INIS)

    A consistent description of weakly bound and unbound nuclei requires an accurate description of the particle continuum properties when carrying out multiconfiguration mixing. This is the domain of the Gamow Shell Model (GSM) which is the multiconfigurational shell model in the complex k-plane formulated using a complete Berggren ensemble representing bound single-particle (s.p.) states, s.p. resonances, and non-resonant complex energy continuum states. We discuss the salient features of effective interactions in weakly bound systems and show selected applications of the GSM formalism to p-shell nuclei. Finally, a development of the new non-perturbative scheme based on Density Matrix Renormalization Group methods to select the most significant continuum configurations in GSM calculations is discussed shortly. (orig.)

  2. Heavy quark bound states in a quark-gluon plasma: dissociation and recombination

    CERN Document Server

    Blaizot, Jean-Paul; Faccioli, Pietro; Garberoglio, Giovanni

    2015-01-01

    We present a comprehensive approach to the dynamics of heavy quarks in a quark gluon plasma, including the possibility of bound state formation and dissociation. In this exploratory paper, we restrict ourselves to the case of an Abelian plasma, but the extension of the techniques used to the non Abelian case is straightforward. A chain of well defined approximations leads eventually to a generalized Langevin equation, where the force and the noise terms are determined from a correlation function of the equilibrium plasma, and depend explicitly on the configuration of the heavy quarks. We solve the Langevin equation for various initial conditions, various numbers of heavy quark-antiquark pairs, and various temperatures of the plasma. Results of simulations illustrate various expected phenomena: dissociation of bound states as a result of combined effects of screening of the potential and collisions with the plasma constituent, formation of bound pairs (recombination) that occurs when enough heavy quarks are pr...

  3. Bound-state formation for thermal relic dark matter and unitarity

    International Nuclear Information System (INIS)

    We show that the relic abundance of thermal dark matter annihilating via a long-range interaction, is significantly affected by the formation and decay of dark matter bound states in the early universe, if the dark matter mass is above a few TeV . We determine the coupling required to obtain the observed dark matter density, taking into account both the direct 2-to-2 annihilations and the formation of bound states, and provide an analytical fit. We argue that the unitarity limit on the inelastic cross-section is realized only if dark matter annihilates via a long-range interaction, and we determine the upper bound on the mass of thermal-relic dark matter to be about 197 (139) TeV for (non)-self-conjugate dark matter

  4. Bound states of multi-nucleon channels in N_f=2+1 lattice QCD

    CERN Document Server

    Yamazaki, Takeshi; Kuramashi, Yoshinobu; Ukawa, Akira

    2012-01-01

    We calculate the energies for multi-nucleon ground states with the nuclear mass number less than or equal to 4 in 2+1 flavor QCD at the lattice spacing of a = 0.09 fm employing a relatively heavy quark mass corresponding to m_pi = 0.51 GeV. We investigate the volume dependence of the energy shift of the ground state and the state of free nucleons to distinguish a bound state from attractive scattering states. From the investigation we conclude that ^4He, ^3He, deuteron and dineutron are bound at m_pi = 0.51 GeV. We compare their binding energies with those in our quenched studies and also with some recent investigations.

  5. Detection of Individual Proteins Bound along DNA Using Solid-State Nanopores.

    Science.gov (United States)

    Plesa, Calin; Ruitenberg, Justus W; Witteveen, Menno J; Dekker, Cees

    2015-05-13

    DNA in cells is heavily covered with all types of proteins that regulate its genetic activity. Detection of DNA-bound proteins is a challenge that is well suited to solid-state nanopores as they provide a linear readout of the DNA and DNA-protein volume in the pore constriction along the entire length of a molecule. Here, we demonstrate that we can realize the detection of even individual DNA-bound proteins at the single-DNA-molecule level using solid-state nanopores. We introduce and use a new model system of anti-DNA antibodies bound to lambda phage DNA. This system provides several advantages since the antibodies bind individually, tolerate high salt concentrations, and will, because of their positive charge, not translocate through the pore unless bound to the DNA. Translocation of DNA-antibody samples reveals the presence of short 12 μs current spikes within the DNA traces, with amplitudes that are about 4.5 times larger than that of dsDNA, which are associated with individual antibodies. We conclude that transient interactions between the pore and the antibodies are the primary mechanism by which bound antibodies are observed. This work provides a proof-of-concept for how nanopores could be used for future sensing applications. PMID:25928590

  6. Lower Bound Limit State Analysis using the Interior-Point Method with Spatial Varying Barrier Function

    DEFF Research Database (Denmark)

    Frier, Christian; Damkilde, Lars

    A method of conducting lower bound Limit State analysis is to apply the interior-point method. The aim of the paper is to refine the method by reducing the number of optimization variables considerably by eliminating the equilibrium equations a priori. Another new idea is to adapt a spatially...

  7. Bound State Solutions of Klein-Gordon Equation with the Kratzer Potential

    Institute of Scientific and Technical Information of China (English)

    M. Ko(c)ak

    2007-01-01

    The relativistic problem of spinless particle subject to a Kratzer potential is analysed. Bound state solutions for s-waves are found by separating the Klein-Gordon equation into two parts. Unlike the similar works in the literature, the separation make it possible to see explicitly the relativistic contributions, if any, to the solution in the non-relativistic limit.

  8. Another comment on 'relativistic description of quark-antiquark bound states'

    International Nuclear Information System (INIS)

    We point out some ambiguities in the treatment of fermion-antifermion bound states by solving the reduced Salpeter equation in coordinate space. Our observations allow to cast some doubt on the validity of the conclusion of Gara et al. that moving from a nonrelativistic to a relativistic description makes things worse. (authors)

  9. Exact solutions of the spinor Bethe-Salpeter equation for tightly bound states

    NARCIS (Netherlands)

    L.G. Suttorp

    1975-01-01

    Exact solutions are obtained for the spinor Bethe-Salpeter equation that describes tightly bound states of spin-/sup 1///sub 2/ fermions with massless-boson exchange. The corresponding coupling constants form a discrete spectrum that depends continuously on the parameters characterizing the type of

  10. Modelling light-cone distribution amplitudes from non-relativistic bound states

    International Nuclear Information System (INIS)

    We calculate light-cone distribution amplitudes for non-relativistic bound states, including radiative corrections from relativistic gluon exchange to first order in the strong coupling constant. We distinguish between bound states of quarks with equal (or similar) mass, m1 ∼ m2, and between bound states where the quark masses are hierarchical, m1 >> m2. For both cases we calculate the distribution amplitudes at the non-relativistic scale and discuss the renormalization-group evolution for the leading-twist and 2-particle distributions. Our results apply to hard exclusive reactions with non-relativistic bound states in the QCD factorization approach like, for instance, Bc → ηclν or e+e- → J/ψηc. They also serve as a toy model for light-cone distribution amplitudes of light mesons or heavy B and D mesons, for which certain model-independent properties can be derived. In particular, we calculate the anomalous dimension for the B meson distribution amplitude φB-(ω) in the Wandzura-Wilczek approximation and derive the according solution of the evolution equation at leading logarithmic accuracy

  11. Numerical Implementation of Three-Body Forces in Bound State Faddeev Calculations in Three Dimensions

    CERN Document Server

    Liu, H; Glöckle, W; Elster, Ch.

    2002-01-01

    The Faddeev equations for the three-body bound state are solved directly as thre e-dimensional integral equations without employing partial wave decomposition. Two-body forces of the Malfliet-Tjon type and simple spin independent genuine three-body forces are considered for the calculation of the three-body binding energy.

  12. Bound states of the Dirac equation with some physical potentials by the Nikiforov-Uvarov method

    Energy Technology Data Exchange (ETDEWEB)

    Setare, Mohammad R; Haidari, S [Department of Physics, University of Kurdistan, Pasdaran Avenue, Sanandaj (Iran, Islamic Republic of)], E-mail: rezakord@ipm.ir, E-mail: heidary.somayeh@gmail.com

    2010-01-15

    Exact analytical solutions for the s-wave Dirac equation with the reflectionless-type, Rosen-Morse and Manning-Rosen potentials are obtained, under the condition of spin symmetry. We obtained bound state energy eigenvalues and corresponding spinor wave function in the framework of the Nikiforov-Uvarov (NU) method.

  13. Resonances from QCD bound states and the 750 GeV diphoton excess

    Science.gov (United States)

    Kats, Yevgeny; Strassler, Matthew J.

    2016-05-01

    Pair production of colored particles is in general accompanied by production of QCD bound states (onia) slightly below the pair-production threshold. Bound state annihilation leads to resonant signals, which in some cases are easier to see than the decays of the pair-produced constituents. In a previous paper ( arXiv:1204.1119 URL"/> ) we estimated the bound state signals, at leading order and in the Coulomb approximation, for particles with various spins, color representations and electric charges, and used 7 TeV ATLAS and CMS resonance searches to set rough limits. Here we update our results to include 8 and 13 TeV data. We find that the recently reported diphoton excesses near 750 GeV could indeed be due to a bound state of this kind. A narrow resonance of the correct size could be obtained for a color-triplet scalar with electric charge -4/3 and mass near 375GeV, if (as a recent lattice computation suggests) the wave function at the origin is somewhat larger than anticipated. Pair production of this particle could have evaded detection up to now. Other candidates may include a triplet scalar of charge 5/3, a triplet fermion of charge -4/3, and perhaps a sextet scalar of charge -2/3.

  14. The bound-state Aharonov-Bohm effect around a cosmic string revisited

    International Nuclear Information System (INIS)

    In this Letter we observe that the self-adjoint extension of the Hamiltonian of a particle moving around a cosmic string gives rise to a gravitational analogue of the bound-state Aharonov-Bohm effect without the need of confining walls

  15. The Bound State S-matrix of the Deformed Hubbard Chain

    CERN Document Server

    de Leeuw, Marius; Matsumoto, Takuya

    2011-01-01

    In this work we use the q-oscillator formalism to construct the atypical (short) supersymmetric representations of the centrally extended Uq (su(2|2)) algebra. We then determine the S-matrix describing the scattering of arbitrary bound states. The crucial ingredient in this derivation is the affine extension of the aforementioned algebra.

  16. Applying the relativistic quantization condition to a three-particle bound state in a periodic box

    CERN Document Server

    Hansen, Maxwell T

    2016-01-01

    Using our recently developed relativistic three-particle quantization condition, we study the finite-volume energy shift of a three-particle bound state. We reproduce the result obtained using non-relativistic quantum mechanics by Mei{\\ss}ner, R{\\'i}os and Rusetsky, and generalize the result to a moving frame.

  17. Orthogonality-condition model for bound states with a separable expansion of the potential

    International Nuclear Information System (INIS)

    A very efficient solution of the equation of Saito's orthogonality-condition model (OCM) is reported for bound states by means of a separable expansion of the potential (PSE method). Some simplifications of the published formulae of the PSE method is derived, which facilitate its application to the OCM and may be useful in solving the Schroedinger equation as well. (author)

  18. Double pionic fusion. Towards an understanding of the ABC puzzle by exclusive measurements

    International Nuclear Information System (INIS)

    The ABC effect is a huge unexpected enhancement at twice the pion mass in the invariant mass spectrum of two pions, which are generated in double-pionic fusion to bound nuclear systems. This peculiar phenomenon has been missing a conclusive explanation all the time since it has been discovered 1960 in single-arm measurements of 3He ejectiles in the reaction pd→ 3HeX. One reason for this failure has been that all measurements to this subject have been inclusive, i.e., lacking the full experimentally accessible information. Hence exclusive measurements were performed at CELSIUS/WASA at an energy of Tp=0.895 GeV, where the ABC effect is expected to be strongest. For the first time exclusive data of solid statistics for both the pd→3Heπ0π0 and pd→3Heπ+π- reactions were obtained including also results for the three-pion production total cross-section. The new data are consistent with the previous inclusive data. They provide, however, much more additional information, which rule out all previous explications of the ABC effect. The now available kinematically complete set of data reveals that the low ππ-mass enhancement (ABC-effect): - is not necessarily associated with a high ππ-mass enhancement, - is always connected with the simultaneous excitation of two Δ resonances, - is of scalar-isoscalar nature, i.e. a σ-channel phenomenon, - requires dynamics in the reaction system, which has not been considered hitherto. Various possible solutions are discussed, however, all of them demand a high attraction in the ΔΔ system - a point, which has never been touched so far in theoretical and experimental investigations. For this data analysis new powerful methods based on neural nets have been developed. Their current and possible future applications are discussed. (orig.)

  19. Double-Pionic Fusion of Nuclear Systems and the ''ABC'' Effect: Approaching a Puzzle by Exclusive and Kinematically Complete Measurements

    International Nuclear Information System (INIS)

    The ABC effect--a puzzling low-mass enhancement in the ππ invariant mass spectrum, first observed by Abashian, Booth, and Crowe--is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn→dπ0π0 at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (ππ)I=L=0 channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a ΔΔ system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data

  20. Light-quark mass behaviour of the X(3872 as a molecular state

    Directory of Open Access Journals (Sweden)

    Baru V.

    2016-01-01

    Full Text Available Chiral extrapolations of the binding energy of the X(3872 molecular state are investigated using an explicitly renormalizable framework free of finite cut-off artefacts. Insights into the binding mechanisms are discussed: if the X is less bound with the growing pion mass, its binding energy is governed by the explicit pion mass dependence from one-pion exchange; an opposite behaviour would indicate the importance of the pionmass dependent short-range interactions, in addition to pionic effects. The important role of the three-body DD̄π dynamics is emphasised.

  1. Light-quark mass behaviour of the X(3872) as a molecular state

    Science.gov (United States)

    Baru, V.; Epelbaum, E.; Filin, A. A.; Gegelia, J.; Nefediev, A. V.

    2016-03-01

    Chiral extrapolations of the binding energy of the X(3872) molecular state are investigated using an explicitly renormalizable framework free of finite cut-off artefacts. Insights into the binding mechanisms are discussed: if the X is less bound with the growing pion mass, its binding energy is governed by the explicit pion mass dependence from one-pion exchange; an opposite behaviour would indicate the importance of the pionmass dependent short-range interactions, in addition to pionic effects. The important role of the three-body DD¯π dynamics is emphasised.

  2. Ground-State Entanglement Bound for Quantum Energy Teleportation of General Spin-Chain Models

    CERN Document Server

    Hotta, Masahiro

    2013-01-01

    In protocols of quantum energy teleportation (QET), ground-state entanglement of many-body systems plays a crucial role. For a general class of spin-chain systems, we show analytically that the entanglement entropy is lower bounded by a positive quadratic function of the teleported energy between the regions of a QET protocol. This supports a general conjecture that ground-state entanglement is an evident physical resource for energy transportation in the context of QET

  3. Bound electron states in clusters of inert atoms in magnetic field

    International Nuclear Information System (INIS)

    Electron states in inert gas clusters placed into the magnetic field are considered. It is shown that the external magnetic field leads to two important consequences: first, is leads to electron level deepening and consequently, to stabilization of charged cluster; second, the magnetic field leads to much lower values of atom critical numbers, under which the production of electron and cluster bound state is possible. 6 refs., 1 tab

  4. The lower bound to the concurrence for four-qubit W state under noisy channels

    OpenAIRE

    Espoukeh, Pakhshan; Pedram, Pouria

    2015-01-01

    We study the dynamics of four-qubit W state under various noisy environments by solving analytically the master equation in the Lindblad form in which the Lindblad operators correspond to the Pauli matrices and describe the decoherence of states. Also, we investigate the dynamics of the entanglement using the lower bound to the concurrence. It is found that while the entanglement decreases monotonically for Pauli-Z noise, it decays suddenly for other three noises. Moreover, by studying the ti...

  5. Reflection algebra, Yangian symmetry and bound-states in AdS/CFT

    CERN Document Server

    MacKay, Niall

    2011-01-01

    We present the `Heisenberg picture' of the reflection algebra by explicitly constructing the boundary Yangian symmetry of the AdS/CFT superstring ending on a boundary with degrees of freedom and preserving all of the bulk symmetry algebra. This enables us to present the bound-state reflection matrices in a more elegant, rapidity-difference form. We also consider the spectrum of bulk and boundary states and some automorphisms of the underlying algebras.

  6. Vibrational autodetachment spectroscopy of Au-6 : Image-charge-bound states of a gold ring

    International Nuclear Information System (INIS)

    Spectral experiments on mass-selected negative cluster ions of gold and silver were performed in the wavelength range near the threshold for one-photon photodetachment of the extra electron. The Au-6 cluster ion displayed a uniquely well resolved spectrum consisting of a progression in a single vibrational mode. Details of this threshold photodetachment spectrum and the associated photoelectron energy distribution suggest an explanation based on autodetachment from totally symmetric vibrational levels of very weakly bound excited electronic state (bound by image charge forces) of the Au-6 cluster in the form of a planar, six-fold symmetric, gold ring

  7. Bound states of breathing Airy-Gaussian beams in nonlocal nonlinear medium

    Science.gov (United States)

    Zhang, Xiaping

    2016-05-01

    With a nonlocal model, we investigate the propagation dynamics of a single Airy-Gaussian (AiG) beam and their interaction in one-dimensional condition by means of direct numerical simulations. With the split-step Fourier method, numerical results shows that nonlocality can support periodic intensity distribution of AiG beams leading to the formation of stable bound states. Especially, by tuning the phase difference between the two beams, we can steer the center of the bound AiG beams in nonlocal nonlinear media.

  8. Bounds for the state-modulated resolvent of a linear Boltzmann generator

    CERN Document Server

    Clark, Jeremy

    2011-01-01

    We study a generalized resolvent for the generator of a Markovian semigroup. The Markovian generator appears in a linear Boltzmann equation modeling a one-dimensional test particle in a periodic potential and colliding elastically with particles from an ideal background gas. We obtain bounds for the state-modulated resolvent which are relevant in the regime where the mass ratio between the test particle and a particle from the gas is large. These bounds relate to the typical amount of time that the particle spends in different regions of phase space before arriving to a region around the origin.

  9. A Goppa-like bound on the trellis state complexity of algebraic geometric codes

    OpenAIRE

    Munuera, Carlos; Torres, Fernando

    2002-01-01

    For a linear code $\\cC$ of length $n$ and dimension $k$, Wolf noticed that the trellis state complexity $s(\\cC)$ of $\\cC$ is upper bounded by $w(\\cC):=\\min(k,n-k)$. In this paper we point out some new lower bounds for $s(\\cC)$. In particular, if $\\cC$ is an Algebraic Geometric code, then $s(\\cC)\\geq w(\\cC)-(g-a)$, where $g$ is the genus of the underlying curve and $a$ is the abundance of the code.

  10. Lower bounds for ballistic current and noise in non-equilibrium quantum steady states

    Directory of Open Access Journals (Sweden)

    Benjamin Doyon

    2015-03-01

    Full Text Available Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.

  11. Bound states of massive fermions in Aharonov-Bohm-like fields

    Energy Technology Data Exchange (ETDEWEB)

    Khalilov, V.R. [Moscow State University, Faculty of Physics, Moscow (Russian Federation)

    2014-01-15

    Bound states of massive fermions in Aharonov-Bohm (AB)-like fields have analytically been studied. The Hamiltonians with the (AB)-like potentials are essentially singular and therefore require specification of a one-parameter self-adjoint extension. We construct self-adjoint Dirac Hamiltonians with the AB potential in 2+1 dimensions that are specified by boundary conditions at the origin. It is of interest that for some range of the extension parameter the AB potential can bind relativistic charged massive fermions. The bound-state energy is determined by the AB magnetic flux and depends upon the fermion spin and extension parameter; it is a periodical function of the magnetic flux. We also construct self-adjoint Hamiltonians for the so-called Aharonov-Casher (AC) problem, show that nonrelativistic neutral massive fermions can be bound by the (AC) background, determine the range of the extension parameter in which fermion bound states exist, and find their energies as well as wave functions. (orig.)

  12. Bound states of massive fermions in the Aharonov--Bohm-like fields

    CERN Document Server

    Khalilov, V R

    2014-01-01

    Bound states of massive fermions in the Aharonov-Bohm like fields have analytically been studied. The Hamiltonians with the Aharonov--Bohm like potentials are essentially singular and therefore require specification of a one-parameter self-adjoint extension. We construct self-adjoint Dirac Hamiltonians with the Aharonov-Bohm (AB) potential in 2+1 dimensions that are specified by boundary conditions at the origin. It is of interest that for some range of extension parameter the AB potential can bind relativistic charged massive fermions. The bound-state energy is determined by the AB magnetic flux and depends upon fermion spin and extension parameter; it is a periodical function of the magnetic flux. We also construct self-adjoint Hamiltonians for the so-called Aharonov-Casher (AC) problem, show that nonrelativistic neutral massive fermions can be bound by the Aharonov-Casher background, determine the range of extension parameter in which fermion bound states exist and find their energies as well as wave funct...

  13. Lower bounds for ballistic current and noise in non-equilibrium quantum steady states

    Energy Technology Data Exchange (ETDEWEB)

    Doyon, Benjamin, E-mail: benjamin.doyon@kcl.ac.uk

    2015-03-15

    Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality.

  14. Molecular Andreev bound states and Majorana modes in a double dot system

    Science.gov (United States)

    Vernek, Edson; Silva, Joelson F.

    Nanostructured systems such as quantum dots (QD) connected to superconductors has attracted a lot of attention in the recent years. One of the well known phenomena in such a system is the formation of a pair of bound called Andreev bound states (ABS). Recently, it have been shown that when a QD is coupled to a topological superconductor wire, a Majorana bound state (MBS) leaks from the end of the wire into the dot. The character of these bound states is much reacher in structures like molecules and is far from being completely understood. In this work we study a system composed by a two inter-connected QDs in which one of then is coupled to a normal superconductor and to a normal lead while the other is coupled to a topological superconductor and to a distinct normal metallic lead. We show that in the atomic limit (for small interdot coupling), one of the dot has a pair of ABS whereas the other has a single a MBS. More interestingly, in the molecular regime (large inter-dot coupling) we observe a localized Majorana mode coexisting with a delocalized molecular ABS. We would like to thank financial support from the Brazilian agencies CNPq, CAPES and FAPEMIG.

  15. Lower bounds for ballistic current and noise in non-equilibrium quantum steady states

    International Nuclear Information System (INIS)

    Let an infinite, homogeneous, many-body quantum system be unitarily evolved for a long time from a state where two halves are independently thermalized. One says that a non-equilibrium steady state emerges if there are nonzero steady currents in the central region. In particular, their presence is a signature of ballistic transport. We analyze the consequences of the current observable being a conserved density; near equilibrium this is known to give rise to linear wave propagation and a nonzero Drude peak. Using the Lieb–Robinson bound, we derive, under a certain regularity condition, a lower bound for the non-equilibrium steady-state current determined by equilibrium averages. This shows and quantifies the presence of ballistic transport far from equilibrium. The inequality suggests the definition of “nonlinear sound velocities”, which specialize to the sound velocity near equilibrium in non-integrable models, and “generalized sound velocities”, which encode generalized Gibbs thermalization in integrable models. These are bounded by the Lieb–Robinson velocity. The inequality also gives rise to a bound on the energy current noise in the case of pure energy transport. We show that the inequality is satisfied in many models where exact results are available, and that it is saturated at one-dimensional criticality

  16. Relativistic description of quark-antiquark bound states. Spin-independent treatment

    International Nuclear Information System (INIS)

    We present the results of a detailed study of light- and heavy-quark--antiquark bound states in the context of the reduced Bethe-Salpeter equation with static vector and scalar interactions. In the present paper, we consider the spin-averaged spectra. Spin effects are considered in a separate paper. We find that this approach, although apparently successful for the heavy-quark b bar b and c bar c states, fails for the s bar s, l bar l, and light-heavy states. The reasons for the failure are intrinsic to the method, as we discuss. Difficulties are already evident for the c bar c states

  17. Proximity-induced interface bound states in superconductor-graphene junctions

    Science.gov (United States)

    Burset, P.; Herrera, W.; Levy Yeyati, A.

    2009-07-01

    We show that interface bound states are formed at isolated graphene-superconductor junctions. These states arise due to the interplay of virtual Andreev and normal reflections taking place at these interfaces. Simple analytical expressions for their dispersion are obtained considering interfaces formed along armchair or zig-zag edges. It is shown that the states are sensitive to a supercurrent flowing on the superconducting electrode. The states provide long-range superconducting correlations on the graphene layer, which may be exploited for the detection of crossed Andreev processes.

  18. Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Hetzheim, Henrik

    2009-01-14

    The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)

  19. Ionization and bound-state relativistic quantum dynamics in laser-driven multiply charged ions

    International Nuclear Information System (INIS)

    The interaction of ultra-strong laser fields with multiply charged hydrogen-like ions can be distinguished in an ionization and a bound dynamics regime. Both are investigated by means of numerically solving the Dirac equation in two dimensions and by a classical relativistic Monte-Carlo simulation. For a better understanding of highly nonlinear physical processes the development of a well characterized ultra-intense relativistic laser field strength has been driven forward, capable of studying e.g. the magnetic field effects of the laser resulting in an additional electron motion in the laser propagation direction. A novel method to sensitively measure these ultra-strong laser intensities is developed and employed from the optical via the UV towards the XUV frequency regime. In the bound dynamics field, the determination of multiphoton transition matrixelements has been investigated between different bound states via Rabi oscillations. (orig.)

  20. Schwinger functions and light-quark bound states, and sigma terms

    CERN Document Server

    Höll, A; Roberts, C D; Wright, S V

    2006-01-01

    We explore the viability of using solely spacelike information about a Schwinger function to extract properties of bound states. In a concrete example it is not possible to determine properties of states with masses \\gsim 1.2 GeV. Modern Dyson-Schwinger equation methods supply a well-constrained tool that provide access to hadron masses and \\sigma-terms. We report values of the latter for a range of hadrons. Of interest is analysis relating to a u,d scalar meson, which is compatible with a picture of the lightest 0^{++} as a bound state of a dressed-quark and -antiquark supplemented by a material pion cloud. A constituent-quark \\sigma-term is defined, which affords a means for assessing the flavour-dependence of dynamical chiral symmetry breaking.

  1. Skyrmion-induced bound states on the surface of three-dimensional topological insulators

    Science.gov (United States)

    Andrikopoulos, Dimitrios; Sorée, Bart; De Boeck, Jo

    2016-05-01

    The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Néel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number NSk. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region.

  2. Formation of positron-atom bound states in collisions between Rydberg Ps and neutral atoms

    CERN Document Server

    Swann, A R; Deller, A; Gribakin, G F

    2016-01-01

    Predicted twenty years ago, positron binding to neutral atoms has not yet been observed experimentally. A new scheme is proposed to detect positron-atom bound states by colliding Rydberg positronium (Ps) with neutral atoms. Estimates of the charge-transfer-reaction cross section are obtained using the first Born approximation for a selection of neutral atom targets and a wide range of incident Ps energies and principal quantum numbers. We also estimate the corresponding Ps ionization cross section. The accuracy of the calculations is tested by comparison with earlier predictions for Ps charge transfer in collisions with hydrogen and antihydrogen. We describe an existing Rydberg Ps beam suitable for producing positron-atom bound states and estimate signal rates based on the calculated cross sections and realistic experimental parameters. We conclude that the proposed methodology is capable of producing such states and of testing theoretical predictions of their binding energies.

  3. Bound States of (Anti-)Scalar-Quarks in $SU(3)_{c}$ Lattice QCD

    CERN Document Server

    Iida, H; Takahashi, T T

    2007-01-01

    Light scalar-quarks \\phi (colored scalar particles or idealized diquarks) and their color-singlet hadronic states are studied with quenched SU(3)_c lattice QCD in terms of mass generation. We investigate ``scalar-quark mesons'' \\phi^\\dagger \\phi and ``scalar-quark baryons'' \\phi\\phi\\phi as the bound states of scalar-quarks \\phi. We also investigate the bound states of scalar-quarks \\phi and quarks \\psi, i.e., \\phi^\\dagger \\psi, \\psi\\psi\\phi and \\phi\\phi\\psi, which we name ``chimera hadrons''. All the new-type hadrons including \\phi are found to have a large mass due to large quantum corrections by gluons, even for zero bare scalar-quark mass m_\\phi=0 at a^{-1}\\sim 1{\\rm GeV}. We conjecture that all colored particles generally acquire a large effective mass due to dressed gluon effects.

  4. Small QCD corrections in inclusive O-+ quarkonium decay for the bound state renormalization scheme

    International Nuclear Information System (INIS)

    A consistent field theoretic computation of the first order correction to the total decay of a nonrelativistic heavy quarkonium state must consider contributions from the annihilation amplitude, with a typical scale of the order of the quark mass m, and from the bound state wave-function, where the typical scale is of the order of the Bohr-momentum αsub(s)m. Therefore, not only the latter smaller scale is the one to be taken for the total decay rate, but also a quite specific renormalization, the 'bound-state renormalization scheme', must be used for a computation of the total inclusive decay rate of O-+ → hadrons. Due the important cancellations between large individual contributions, the net result turns out to be small, encouraging the use of pure perturbative QCD in such systems. (Author)

  5. Ghost-gluon and ghost-quark bound states and their role in BRST quartets

    CERN Document Server

    Alkofer, Natalia

    2011-01-01

    A non-perturbative version of the BRST quartet mechanism in infrared Landau gauge QCD is proposed for transverse gluons and quarks. Based on the positivity violation for transverse gluons the content of the respective non-perturbative BRST quartet is derived. To identify the gluon's BRST-daughter and second parent state, a truncated Bethe-Salpeter equation for the gluon-(anti-)ghost bound state is investigated. We comment shortly on several equivalent forms of this equation. Repeating the same construction for quarks leads to a truncated Bethe-Salpeter equation for a fundamentally charged quark-(anti-)ghost bound state. It turns out that a cardinal input to this equation is given by the fully dressed quark-gluon vertex, and that it is indispensable to dress the quark-gluon vertex in this equation in order to obtain a consistent truncation.

  6. Supersymmetrically bounding of asymmetric states and quantum phase transitions by anti-crossing of symmetric states

    CERN Document Server

    Afzal, Muhammad Imran; Lee, Yong Tak

    2016-01-01

    Von Neumann and Wigner theorized bounding of asymmetric eigenstates and anti-crossing of symmetric eigenstates. Experiments have shown that owing to anti-crossing and similar radiation rates, graphene-like resonance of inhomogeneously strained photonic eigenstates can generate pseudomagnetic field, bandgaps and Landau levels, while dissimilar rates induce non-Hermicity. Here, we showed experimentally higher-order supersymmetry and quantum phase transitions by resonance between similar one dimensional lattices. The lattices consisted of inhomgeneously strain-like phases of triangular solitons. The resonance created two dimensional inhomogeneously deformed photonic graphene. All parent eigenstates are annihilated. Where eigenstates of mildly strained solitons are annihilated with similar (power law) rates through one tail only and generated Hermitianally bounded eigenstates. The strongly strained solitons, positive defects are annihilated exponentially through both tails with dissimilar rates. Which bounded eig...

  7. Bound states, resonances, and symmetries of a neutral Dirac particle with anomalous magnetic moment, coupled to a fixed monopole

    International Nuclear Information System (INIS)

    For the system consisting of a neutral Dirac particle with anomalous magnetic moment, interacting with a fixed magnetic monopole, zero-energy bound states are constructed for each possible value of the total angular momentum. Results of Kazama and Yang for the charge--monopole system are used to deduce the existence of other bound states for this system, when the mass of the bound particle is nonzero. In the zero-mass case, there are no other bound states, but there are resonant states, and these are determined exactly. A noncompact, so(3,2) symmetry algebra of the zero-energy bound states is given for the finite-mass case and for the zero-mass case. In each case the infinite number of such states is associated with an irreducible Majorana representation of the algebra

  8. Majorana bound states from exceptional points in non-topological superconductors

    Science.gov (United States)

    San-Jose, Pablo; Cayao, Jorge; Prada, Elsa; Aguado, Ramón

    2016-02-01

    Recent experimental efforts towards the detection of Majorana bound states have focused on creating the conditions for topological superconductivity. Here we demonstrate an alternative route, which achieves fully localised zero-energy Majorana bound states when a topologically trivial superconductor is strongly coupled to a helical normal region. Such a junction can be experimentally realised by e.g. proximitizing a finite section of a nanowire with spin-orbit coupling, and combining electrostatic depletion and a Zeeman field to drive the non-proximitized (normal) portion into a helical phase. Majorana zero modes emerge in such an open system without fine-tuning as a result of charge-conjugation symmetry, and can be ultimately linked to the existence of ‘exceptional points’ (EPs) in parameter space, where two quasibound Andreev levels bifurcate into two quasibound Majorana zero modes. After the EP, one of the latter becomes non-decaying as the junction approaches perfect Andreev reflection, thus resulting in a Majorana dark state (MDS) localised at the NS junction. We show that MDSs exhibit the full range of properties associated to conventional closed-system Majorana bound states (zero-energy, self-conjugation, 4π-Josephson effect and non-Abelian braiding statistics), while not requiring topological superconductivity.

  9. Pion as a Longitudinal Axial-Vector Meson $q\\bar{q}$ Bound State

    CERN Document Server

    Pham, T N

    2013-01-01

    The success of the Adler-Bell-Jackiw(ABJ) chiral anomaly prediction for $\\pi^{0}\\to \\gamma\\gamma$ decay rate shows that non-anomaly terms would make a negligible contribution to the decay rate, in agreement with the Sutherland-Veltman theorem. Thus the conventional $q\\bar{q}$ bound-state description of the pion could not be valid since it would produce a $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude not suppressed in the soft pion limit, in contradiction with the Sutherland-Veltman theorem. Therefore, if the pion is to be treated as a $q\\bar{q}$ bound state, this bound state would be a longitudinal axial-vector meson. In this paper, we consider the pion to be a longitudinal axial-vector meson $q\\bar{q}$ state with derivative coupling for the pion-$q\\bar{q}$ Bethe-Salpeter(BS) amplitude. We shall show that, the longitudinal axial-vector meson solution for the pion $q\\bar{q}$ Bethe-Salpeter wave function could produce a suppressed $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude in the soft pion limit, in agreement with t...

  10. The relativistic bound states of the hyperbolical potential with the centrifugal term

    Energy Technology Data Exchange (ETDEWEB)

    Wei Gaofeng [Department of Physics, Xi' an University of Arts and Science, Xi' an 710065 (China); Liu Xuyang [School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand)], E-mail: fgwei_2000@163.com, E-mail: lxy_gzu2005@126.com

    2008-12-15

    The approximately analytical bound state solutions of the arbitrary l-wave Klein-Gordon and arbitrary k-state Dirac equations for the mixed hyperbolical potentials are carried out by taking a proper approximate expansion of the centrifugal term. The analytical radial wavefunctions of the l-wave Klein-Gordon and k-state Dirac equations for the mixed hyperbolical potentials are presented and the corresponding energy equations are derived. Two special cases of the Klein-Gordon equation are discussed briefly.

  11. The quark-gluon vertex in Landau gauge bound-state studies

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Richard [Justus-Liebig University of Giessen, Institute of Theoretical Physics, Giessen (Germany)

    2015-05-15

    We present a practical method for the solution of the quark-gluon vertex for use in Bethe-Salpeter and Dyson-Schwinger calculations. The efficient decomposition into the necessary covariants is detailed, with the numerical algorithm outlined for both real and complex Euclidean momenta. A truncation of the quark-gluon vertex, that neglects explicit back-coupling to enable the application to bound-state calculations, is given together with results for the quark propagator and quark-gluon vertex for different quark flavours. The relative impact of the various components of the quark-gluon vertex is highlighted with the flavour dependence of the effective quark-gluon interaction obtained, thus providing insight for the construction of phenomenological models within the rainbow ladder. Finally, we solve the corresponding Green's functions for complex Euclidean momenta as required in future bound-state calculations. (orig.)

  12. Looking for bound states and resonances in the $\\eta^\\prime K\\bar K$ system

    CERN Document Server

    Torres, A Martínez

    2016-01-01

    Motivated by the continuous experimental investigations of $X(1835)$ in three-body decay channels like $\\eta^\\prime \\pi^+ \\pi^-$, we investigate the $\\eta^\\prime K \\bar K$ system with the aim of searching for bound states and/or resonances when the dynamics involved in the $K\\bar K$ subsystem can form the resonances: $f_0(980)$ in isospin 0 or $a_0(980)$ in isospin 1. For this, we solve the Faddeev equations for the three-body system. The input two-body $t$-matrices are obtained by solving Bethe-Salpeter equations in a coupled channel formalism. As a result, no signal of a three-body bound state or resonance is found.

  13. Bound states for multiple Dirac-δ wells in space-fractional quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Tare, Jeffrey D., E-mail: jeffreytare@gmail.com; Esguerra, Jose Perico H., E-mail: pesguerra@nip.upd.edu.ph [National Institute of Physics, University of the Philippines, Diliman, Quezon City 1101 (Philippines)

    2014-01-15

    Using the momentum-space approach, we obtain bound states for multiple Dirac-δ wells in the framework of space-fractional quantum mechanics. Introducing first an attractive Dirac-comb potential, i.e., Dirac comb with strength −g (g > 0), in the space-fractional Schrödinger equation we show that the problem of obtaining eigenenergies of a system with N Dirac-δ wells can be reduced to a problem of obtaining the eigenvalues of an N × N matrix. As an illustration we use the present matrix formulation to derive expressions satisfied by the bound-state energies of N = 1, 2, 3 delta wells. We also obtain the corresponding wave functions and express them in terms of Fox's H-function.

  14. Realization of negative mass regime and bound state of solitons in inhomogeneous Bose-Einstein condensates

    Science.gov (United States)

    Das, Priyam; Khan, Ayan; Panigrahi, Prasanta K.

    2016-05-01

    We study the dispersion mechanism (Lieb-mode excitation) of both single and two-component Bose-Einstein condensates, subject to an external trap in a mean-field approach, where the second quantized Lieb-mode is realized as grey soliton. Through the coupling between the centre of mass motion (Kohn mode) and the soliton's momenta arising from the kinematic chirp, induced by time modulated trap, we realize the exotic negative mass regime of the solitonic excitation. We show that the expulsive parabolic trap significantly modifies the energy-momentum dispersion in the low momenta regime, where these modes can be clearly identified, opening up the possibility to observe the Lieb-mode excitation. In case of two-component, we demonstrate the controlled formation of a bound state, in presence of an expulsive harmonic trap, through the shape compatibility of grey and bright solitons. Possible application of such a bound state to information storage and retrieval is pointed out.

  15. Experimental verification of the relativistic fine-structure term of the Klein-Gordon equation in pionic titanium atoms

    International Nuclear Information System (INIS)

    A newly designed, large-aperture and high-resolution bent-crystal spectrometer has been used to observe high-intensity sources of pionic x rays. The pionic x-ray source was a target of natural titanium which was placed adjacent to a copper pion-production target in the external beam of the Nevis synchrocyclotron. The energy difference between the 5g → 4f and 5f → 4d transitions in pionic titanium was measured to be 87.6 +- 1.8 eV. Comparison with the prediction of the Klein-Gordon equation is made

  16. The lower bound to the concurrence for four-qubit W state under noisy channels

    Science.gov (United States)

    Espoukeh, Pakhshan; Pedram, Pouria

    2015-02-01

    We study the dynamics of four-qubit W state under various noisy environments by solving analytically the master equation in the Lindblad form in which the Lindblad operators correspond to the Pauli matrices and describe the decoherence of states. Also, we investigate the dynamics of the entanglement using the lower bound to the concurrence. It is found that while the entanglement decreases monotonically for Pauli-Z noise, it decays suddenly for other three noises. Moreover, by studying the time evolution of entanglement of various maximally entangled four-qubit states, we indicate that the four-qubit W state is more robust under same-axis Pauli channels. Furthermore, three-qubit W state preserves more entanglement with respect to the four-qubit W state, except for the Pauli-Z noise.

  17. Optimal Portfolios in Lévy Markets under State-Dependent Bounded Utility Functions

    OpenAIRE

    Figueroa-López, José E.; Jin Ma

    2010-01-01

    Motivated by the so-called shortfall risk minimization problem, we consider Merton's portfolio optimization problem in a non-Markovian market driven by a Lévy process, with a bounded state-dependent utility function. Following the usual dual variational approach, we show that the domain of the dual problem enjoys an explicit “parametrization,” built on a multiplicative optional decomposition for nonnegative supermartingales due to Föllmer and Kramkov (1997). As a key step we...

  18. Properties of bound states of the Schroedinger equation with attractive Dirac delta potentials

    Energy Technology Data Exchange (ETDEWEB)

    Demiralp, Ersan [Physics Department, Bogazici University, Bebek, 34342 Istanbul (Turkey); Beker, Haluk [Physics Department, Bogazici University, Bebek, 34342 Istanbul (Turkey)

    2003-07-04

    We have studied bound states of the Schroedinger equation for an attractive potential with any finite number (P) of Dirac delta-functions in R{sup n} where n = 1, 2, 3, .... The potential is radially symmetric for n {>=} 2 and is given as V(r) = - h-bar {sup 2}/2m {sigma}{sup P}{sub i=1} {sigma}{sub i}{delta}(r - r{sub i}) where {sigma}{sub i} > 0, r{sub 1} < r{sub 2} < c < r{sub P}, and r{sub i} element of (0, +{infinity}) for n {>=} 2, r{sub i} element of (-{infinity}, +{infinity}) for n 1. By separating angular degrees of freedom, the radial equation is obtained for n {>=} 2 and applications of the boundary conditions lead to P transfer matrices which are used to form an equation for the eigenvalues. We have proven that, for given n and l, the bound state solutions of the radial equation are non-degenerate and there are at most P bound state solutions of the radial equation and hence P bound state energy levels for a potential with P attractive Dirac delta-functions. Given l and n {>=} 2, for P = 1, we have shown that there exists one and only one solution of the radial equation if {sigma}{sub 1} r{sub 1} > 2l + n - 2 and none otherwise. We have also proven that there are at most P positive roots for the equation X{sub 22}(k) = 0 where X ({sup X{sub 1}{sub 1X{sub 2}{sub 1}X{sub 1}{sub 2X{sub 2}{sub 2}}) = M{sub P}M{sub P-1} ... M{sub 1} and M{sub i} element of SL(2, R) are the particular transfer matrices mentioned above.

  19. Dissecting zero modes and bound states on BPS vortices in Ginzburg-Landau superconductors

    CERN Document Server

    Alonso-Izquierdo, Alberto; Guilarte, Juan Mateos

    2016-01-01

    In this paper the zero modes of fluctuation of cylindrically symmetric self-dual vortices are analyzed and described in full detail. These BPS topological defects arise at the critical point between Type II and Type I superconductors, or, equivalently, when the masses of the Higgs particle and the vector boson in the Abelian Higgs model are equal. In addition, novel bound states of Higss and vector bosons trapped by the self-dual vortices at their core are found and investigated.

  20. Dimensionality of space, bound-state postulate and the conservation of baryons and leptons

    International Nuclear Information System (INIS)

    By demanding that the laws of nature be such that the three-dimensionality of space can be deduced from them, it is shown within the framework of general relativity that gravity should be attractive and that there should be stable bound states. There is a discussion of the consistency with this requirement of the conservation of baryons and leptons. It is also proposed that some new gravitational behavior limits the formation of black holes which would violate baryon and lepton conservation

  1. Dimensionality of space, bound-state postulate and the conservation of baryons and leptons

    International Nuclear Information System (INIS)

    By demanding that the laws of nature be such that the three-dimensionality of space can be deduced from them, it is shown within the framework of general relativity theory that gravity should be attractive and that there should be stable bound states. There is a discussion of the consistency with this requirement of the conservation of baryons and leptons. It is also proposed that some new gravitational behaviour limits the formation of black holes which would violate baryon and lepton conservation

  2. Quasi-bound states of Schrodinger and Dirac electrons in magnetic quantum dot

    OpenAIRE

    Masir, M. Ramezani; Matulis, A.; Peeters, F. M.

    2009-01-01

    The properties of a two-dimensional electron are investigated in the presence of a circular step magnetic field profile. Both electrons with parabolic dispersion as well as Dirac electrons with linear dispersion are studied. We found that in such a magnetic quantum dot no electrons can be confined. Nevertheless close to the Landau levels quasi-bound states can exist with a rather long life time.

  3. Study of -nucleus interaction through the formation of -nucleus bound state

    Indian Academy of Sciences (India)

    V Jha; B J Roy; A Chatterjee; H Machner

    2006-05-01

    The question of possible existence of -mesic nuclei is quite intriguing. Answer to this question will deeply enrich our understanding of -nucleus interaction which is not so well-understood. We review the experimental efforts for the search of -mesic nuclei and describe the physics motivation behind it. We present the description of an experiment for the search of -nucleus bound state using the GeV proton beam, currently being performed at COSY.

  4. Second quantization method in the presence of bound states of particles

    OpenAIRE

    Peletminskii, Sergey V.; Slyusarenko, Yuriy V.

    2006-01-01

    We develop an approximate second quantization method for describing the many-particle systems in the presence of bound states of particles at low energies (the kinetic energy of particles is small in comparison to the binding energy of compound particles). In this approximation the compound and elementary particles are considered on an equal basis. This means that creation and annihilation operators of compound particles can be introduced. The Hamiltonians, which specify the interactions betw...

  5. K{sup -} nuclear quasi-bound states in a chirally motivated coupled-channel approach

    Energy Technology Data Exchange (ETDEWEB)

    Mares, Jiri, E-mail: mares@ujf.cas.cz [Nuclear Physics Institute (Czech Republic)

    2012-05-15

    K{sup }- nuclear optical potentials are constructed from in-medium K-bar N scattering amplitudes within a chirally motivated coupled-channel model. The strong energy and density dependence of the scattering amplitudes at and below threshold leads to K{sup }- potential depths -Re V{sub K{sup -}}({rho}{sub 0}) approx. 80 - 100 MeV. Self consistent calculations of K{sup }- nuclear quasi-bound states are discussed.

  6. Two Gamma Decay Width of D Meson in Bound State Model

    International Nuclear Information System (INIS)

    We have estimated the two gamma decay width of D meson by using the bound state model of Holdom and Sutherland. Here we have derived an effective quark level Lagrangian for c → uγ and c → uγγ and hence we have calculated the decay width of D → γγ. We have obtained the branching ratio for the above decay mode as: Br (Do → 2γ) 8.63 x 10-6. (author)

  7. Electroproduction of strangeness on (Lambda)H-3,4 bound states on helium

    Energy Technology Data Exchange (ETDEWEB)

    F. Dohrmann; D. Abbott; A. Ahmidouch; P. Ambrozewicz; C. S. Armstrong; J. Arrington; R. Asaturyan; K. Assamagan; S. Avery; K. Bailey; S. Beedoe; H. Bitao; H. Breuer; D. S. Brown; R. Carlini; J. Cha; N. Chant; E. Christy; A. Cochran; L. Cole; G. Collins; C. Cothran; J. Crowder; W. J. Cummings; S. Danagoulian; F. Duncan; J. Dunne; D. Dutta; T. Eden; M. Elaasar; R. Ent; L. Ewell; H. Fenker; H. T. Fortune; Y. Fujii; L. Gan; H. Gao; K. Garrow; D. F. Geesaman; P. Gueye; K. Gustafsson; K. Hafidi; J. O. Hansen; W. Hinton; H. E. Jackson; H. Juengst; C. Keppel; A. Klein; D. Koltenuk; Y. Liang; J. H. Liu; A. Lung; D. Mack; R. Madey; P. Markowitz; C. J. Martoff; D. Meekins; J. Mitchell; T. Miyoshi; H. Mkrtchyan; R. Mohring; S. K. Mtingwa; B. Mueller; T. G. O& #x27; Neill; G. Niculescu; I. Niculescu; D. Potterveld; J. W. Price; B. A. Raue; P. E. Reimer; J. Reinhold; ; J. Roche; P. Roos; M. Sarsour; Y. Sato; G. Savage; R. Sawafta; R. E. Segel; A. Yu. Semenov; S. Stepanyan; V. Tadevosian; S. Tajima; L. Tang; B. Terburg; A. Uzzle; S. Wood; H. Yamaguchi; C. Yan; C. Yan; L. Yuan; M. Zeier; B. Zeidman; B. Zihlmann

    2005-05-01

    The A(e,eK+)X reaction has been investigated at Jefferson Laboratory. Data were taken for Q{sup 2} approx. 0.35 GeV{sup 2} at a beam energy of 3.245 GeV for 1H,3He and 4He targets. Evidence for Lambda-hypernuclear bound states is seen for 3,4He targets. This is the first time that the electroproduction of these hypernuclei has been observed.

  8. Vertical D4-D2-D0 bound states on K3 fibrations and modularity

    CERN Document Server

    Bouchard, Vincent; Diaconescu, Duiliu-Emanuel; Doran, Charles; Quigley, Callum; Sheshmani, Artan

    2016-01-01

    An explicit formula is derived for the generating function of vertical D4-D2-D0 bound states on smooth K3 fibered Calabi-Yau threefolds, generalizing previous results of Gholampour and Sheshmani. It is also shown that this formula satisfies strong modularity properties, as predicted by string theory. This leads to a new construction of vector valued modular forms which exhibits some of the features of a generalized Hecke transform.

  9. Relativistic theory of di-Holeums - quantized gravitational bound states of two micro black holes

    OpenAIRE

    Chavda, A. L.; Chavda, L. K.

    2014-01-01

    The Klein-Gordon equation is solved for di-Holeums (gravitational bound states of two micro black holes) for scalar and vector gravity in its static limit. The relativistic models confirm the predictions of the nonrelativistic Newtonian gravity model, correct to about six significant figures over almost the entire sub-Planck domain. All three models possess a mass range devoid of physics. This is interpreted as evidence that the universe must have more than four dimensions. We show that the f...

  10. A search for deeply-bound kaonic nuclear states at J-PARC

    Science.gov (United States)

    Ajimura, S.; Beer, G.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Enomoto, S.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Fukuda, Y.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kienle, P.; Kou, H.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Pietreanu, D.; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Sekimoto, M.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Widmann, E.; Yamazaki, T.; Yim, H.; Zmeskal, J.

    2010-04-01

    The J-PARC E15 experiment will be performed to search for the simplest kaonic nuclear bound state, K- pp, by the in-flight 3He(K-,n) reaction. The exclusive measurement can be performed by a simultaneous measurement of the missing mass using the primary neutron and the invariant mass via the expected decay, K- pp → Λp → pπ- p. In this report, an overview of the experiment and the preparation status are presented.

  11. Direct Experimental Evidence of Exciton-Phonon Bound States in Carbon Nanotubes

    OpenAIRE

    Plentz, Flavio; Henrique B. Ribeiro; Jorio, Ado; Pimenta, Marcos A.; Strano, Michael S.

    2005-01-01

    We present direct experimental observation of exciton-phonon bound states in the photoluminescence excitation spectra of isolated single walled carbon nanotubes in aqueous suspension. The photoluminescence excitation spectra from several distinct single-walled carbon nanotubes show the presence of at least one sideband related to the tangential modes, lying {200 meV} above the main absorption/emission peak. Both the energy position and line shapes of the sidebands are in excellent agreement w...

  12. Quantum electrodynamics tests and X-rays standards using pionic atoms and highly charged ions

    International Nuclear Information System (INIS)

    The object of this thesis is to present a new measurement of the pion mass using pionic nitrogen X-ray spectroscopy and results on helium-like argon and sulphur spectroscopy. The new pion mass has been measured with an accuracy of 1.7 ppm, 30% better that the present world average value, and it is obtained from Bragg spectroscopy of 5 ->4 pionic nitrogen transitions using the theoretical predictions provided by quantum electrodynamics. We have got: m(π-) = (139.571042 ± 0.000210 ± 0.000110) where the first error is due to the statistics and the second is the systematic error. I present the calculation of the hyperfine structure and recoil corrections for pionic atoms using a new perturbation method for the Klein-Gordon equation. The spectrometer used for this measurement has been characterized with the relativistic M1 transitions from helium-like ions produced with a new device, the Electron-Cyclotron-Resonance Ion Trap. High statistics spectra from these ions have enabled us to measure transition energies with an accuracy of some ppm which has allowed us to compare theoretical predictions with experiment data. X-ray emission from pionic atoms and multicharged ions can be used to define new types of X-ray standards for energies of a few keV

  13. Phase transitions of energy and wave functions and bound states in the continuum

    Science.gov (United States)

    Zhang, Xiao; Wei, Chaozhen; Liu, Yingming; Luo, Maokang

    2016-04-01

    This paper studies a particle subjected to an infinite potential well in the circumstance of a fractional dimensional Lévy path. To obtain analytic expression for the wave functions and energy levels, we introduce the fractional corresponding operator and a generalized de Moivre's theorem. Phase transitions of the energy and wave functions are found when the Lévy path dimension changes from integer to noninteger in nature. More importantly, we demonstrate the existence of stable bound states in the continuum in a simple potential. The results predict a phenomenon in which all bound states energy levels of the particle are continuous and the particle remains in bound states. This phenomenon can be demonstrated that this is a characteristic phenomenon of a fractional system. This phenomenon provides both an a priori criterion for theoretically describing an unknown quantum system with fractional derivatives and a sufficient condition for verifying the preparation of a fractional quantum system in experiment. Finally, we compare our results for fractional quantum systems with the existing results and explain the cause of the reported phenomenon.

  14. From nonlocal gap solitary waves to bound states in periodic media

    CERN Document Server

    Akylas, T R; Yang, Jianke

    2011-01-01

    Solitary waves in one-dimensional periodic media are discussed employing the nonlinear Schr\\"odinger equation with a spatially periodic potential as a model. This equation admits two families of gap solitons that bifurcate from the edges of Bloch bands in the linear wave spectrum. These fundamental solitons may be positioned only at specific locations relative to the potential; otherwise, they become nonlocal owing to the presence of growing tails of exponentially-small amplitude with respect to the wave peak amplitude. Here, by matching the tails of such nonlocal solitary waves, higher-order locally confined gap solitons, or bound states, are constructed. Details are worked out for bound states comprising two nonlocal solitary waves in the presence of a sinusoidal potential. A countable set of bound-state families, characterized by the separation distance of the two solitary waves, is found, and each family features three distinct solution branches that bifurcate near Bloch-band edges at small, but finite, a...

  15. Coherent-structure theory and bound-state formation in electrified falling films

    Science.gov (United States)

    Lin, Te-Sheng; Tseluiko, Dmitri; Blyth, Mark; Kalliadasis, Serafim

    2015-11-01

    We consider a perfectly conducting viscous liquid film flowing down an inclined wall and subjected to a normal electric filed. The electric field introduces a destabilizing non-local term in the long-wave evolution equation and the solutions may evolve into arrays of interacting pulses. We develop a weak-interaction theory for these pulses using elements from previous coherent-structure interaction theories we have developed. We show that the standard first-neighbor approximation is no longer valid and it is essential to take into account long-range interactions. We also develop numerical continuation techniques to explore bifurcation diagrams in systems possessing translational symmetry, including traveling waves and spatially varying time-periodic solutions. We find that each bound state bifurcates from the primary branch when continuing with respect to the domain size, and we then construct full bifurcation diagrams taking into account all the bound states. Finally, we compare the bound states for the long-wave evolution equation with the ones found in Stokes calculations and find excellent agreement.

  16. Gluon bound state and asymptotic freedom derived from the Bethe--Salpeter equation

    CERN Document Server

    Fukamachi, Hitoshi; Nishino, Shogo; Shinohara, Toru

    2016-01-01

    In this paper we study the two-body bound states for gluons and ghosts in a massive Yang-Mills theory which is obtained by generalizing the ordinary massless Yang-Mills theory in a manifestly Lorentz covariant gauge. First, we give a systematic derivation of the coupled Bethe-Salpeter equations for gluons and ghosts by using the Cornwall-Jackiw-Tomboulis effective action of the composite operators within the framework of the path integral quantization. Then, we obtain the numerical solutions for the Bethe-Salpeter amplitude representing the simultaneous bound states of gluons and ghosts by solving the homogeneous Bethe-Salpeter equation in the ladder approximation. We study how the inclusion of ghosts affects the two-gluon bound states in the cases of the standing and running gauge coupling constant. Moreover, we show explicitly that the approximate solutions obtained for the gluon-gluon amplitude are consistent with the ultraviolet asymptotic freedom signaled by the negative $\\beta$ function.

  17. Experimental study of bound and autoionizing Rydberg states of the europium atom

    Science.gov (United States)

    Xiao, Ying; Dai, Chang-Jian; Qin, Wen-Jie

    2010-06-01

    An isolated-core-excitation (ICE) scheme and stepwise excitation are employed to study the highly excited states of the europium atom. The bound europium spectrum with odd parity in a region of 42400-43500 cm-1 is measured, from which spectral information on 38 transitions, such as level position and relative intensity, can be deduced. Combined with information about excitation calibration and the error estimation process, the selection rules enable us to determine the possible values of total angular momentum J for the observed states. The autoionization spectra of atomic europium, belonging to the 4f76pnl (l = 0, 2) configurations, are systematically investigated by using the three-step laser resonance ionization spectroscopy (RIS) approach. With the ICE scheme, all the experimental spectra of the autoionizing states have nearly symmetric profiles whose peak positions and widths can be easily obtained. A comparison between our results and those from the relevant literature shows that our work not only confirms many reported states, but also discovers 14 bound states and 16 autoionizing states.

  18. Relativistic wave equation for the bound states of a system of interacting particles

    International Nuclear Information System (INIS)

    A method for obtaining the relativistic wave equation for the bound states of a system of interacting charged particles without consideration of spin is proposed. An expansion of the wave function of the system in a complete basis of orthonormal wave functions of vacuum states for each type of particle is used in this equation. It is shown that this equation contains two types of solutions for a proton + electron system. The first type corresponds to Bohr bound states. Exact expressions are obtained for the energy and Bohr radius of the ground state with consideration of the finite mass of the particles. An influence of the energy of translational motion of the system as a whole on the structure of the atomic levels in the laboratory frame is predicted. This effect is due to the finite value of m/M, and leads to removal of the degeneracy of the levels with respect to orbital angular momentum l, and partial removal of the degeneracy with respect to its projection. The second type of solution represents states of the system with binding energy Eb=M+m-√(|M2-m2|) and an exponential wave function damping radius equal to the Compton wavelength of the electron. A complete description of this state requires consideration of the electronic vacuum polarization

  19. Upper bound for SL-invariant entanglement measures of mixed states

    Science.gov (United States)

    Osterloh, Andreas

    2016-05-01

    An algorithm is proposed that serves to handle full-rank density matrices when coming from a lower-rank method to compute the convex roof. This is in order to calculate an upper bound for any polynomial SL-invariant multipartite entanglement measure E . This study exemplifies how this algorithm works based on a method for calculating convex roofs of rank-2 density matrices. It iteratively considers the decompositions of the density matrix into two states each, exploiting the knowledge for the rank-2 case. The algorithm is therefore quasiexact as far as the rank-2 case is concerned, and it also hints where it should include more states in the decomposition of the density matrix. Focusing on the measure of three-way entanglement of qubits (called three-tangle), I show the results the algorithm gives for two states, one of which is the Greenberger-Horne-Zeilinger-Werner (GHZ-W ) state, for which the exact convex roof is known. It overestimates the three-tangle in the state, thereby giving insight into the optimal decomposition the GHZ-W state has. As a proof of principle, I have run the algorithm for the three-tangle on the transverse quantum Ising model. I give qualitative and quantitative arguments why the convex roof should be close to the upper bound found here.

  20. Ground state and excitations of a Bose-Einstein condensate of atoms and their diatomic bound states

    International Nuclear Information System (INIS)

    We study theoretically a many-body system of spinless atoms and their diatomic bound states (or molecules) which form a single Bose-Einstein condensate at zero temperature. The equilibrium states of such a system and its dynamics are analyzed within the Gross-Pitaevskii approach. It is shown that the system exhibits two phases depending on binding energy value: it can be in the states with atomic-molecular condensate or molecular condensate. The basic thermodynamic characteristics of the two phases and their stability conditions are obtained. Both phases are characterized by two branches of collective excitations. The first branch is acoustic mode and the second one is gapfull

  1. Novel properties of bound states of Klein-Gordon equation in gravitational field of massive point

    International Nuclear Information System (INIS)

    We are considering for the first time the solutions of Klein-Gordon equation in gravitational field of massive point source in general relativity (GR). We examine numerically the basic bounded quantum state and the next few states in the discrete spectrum for different values of the orbital momentum. A novel feature of the solutions under consideration is the essential dependence if their physical properties on the gravitational mass defect of the point source. Such mass defect was not introduced up to recently. Its variation yields a repulsion or an attraction of the quantum levels up to their quasi-crossing. (authors)

  2. Introduction to Basis Light-Front Quantization Approach to QCD Bound State Problems

    CERN Document Server

    Li, Yang; Zhao, Xingbo; Maris, Pieter; Vary, James P

    2013-01-01

    Basis Light-Front Quantized Field Theory (BLFQ) is an $\\textit{ab intio}$ Hamiltonian approach that adopts light-cone gauge, light-front quantization and state-of-the-art many-body methods to solve non-perturbative quantum field theory problems. By a suitable choice of basis, BLFQ retains the underlying symmetries to the extent allowed within light-front coordinates. In this talk, we outline the scheme for applying BLFQ to QCD bound state problems. We adopt a 2D Harmonic Oscillator with 1D plane wave basis that corresponds to the AdS/QCD soft-wall solution. Exact treatment of the symmetries will be discussed.

  3. Security bound of continuous-variable quantum key distribution with noisy coherent states and channel

    International Nuclear Information System (INIS)

    Security of a continuous-variable quantum key distribution protocol based on noisy coherent states and channel is analysed. Assuming that the noise of coherent states is induced by Fred, a neutral party relative to others, we prove that the prepare-and-measurement scheme (P and M) and entanglement-based scheme (E-B) are equivalent. Then, we show that this protocol is secure against Gaussian collective attacks even if the channel is lossy and noisy, and, further, a lower bound to the secure key rate is derived.

  4. Formation Mechanism of Guided Resonances and Bound States in the Continuum in Photonic Crystal Slabs

    CERN Document Server

    Gao, Xingwei; Zhen, Bo; Lin, Xiao; Joannopoulos, John D; Soljačić, Marin; Chen, Hongsheng

    2016-01-01

    We develop a formalism, based on the mode expansion method, to describe the guided resonances and bound states in the continuum (BICs) in photonic crystal slabs with one-dimensional periodicity. This approach provides analytic insights to the formation mechanisms of these states: the guided resonances arise from the transverse Fabry-P\\'erot condition, and the divergence of the resonance lifetimes at the BICs is explained by a destructive interference of radiation from different propagating components inside the slab. We show BICs at the center and on the edge of the Brillouin zone protected by symmetry, as well as BICs at generic wave vectors not protected by symmetry.

  5. Two-body bound states ampersand the Bethe-Salpeter equation

    International Nuclear Information System (INIS)

    The Bethe-Salpeter formalism is used to study two-body bound states within a scalar theory: two scalar fields interacting via the exchange of a third massless scalar field. The Schwinger-Dyson equation is derived using functional and diagrammatic techniques, and the Bethe-Salpeter equation is obtained in an analogous way, showing it to be a two-particle generalization of the Schwinger-Dyson equation. The authors also present a numerical method for solving the Bethe-Salpeter equation without three-dimensional reduction. The ground and first excited state masses and wavefunctions are computed within the ladder approximation and space-like form factors are calculated

  6. Excited hadrons and the analytical structure of bound-state interaction kernels

    CERN Document Server

    El-Bennich, Bruno; Rojas, Eduardo; Serna, Fernando E

    2016-01-01

    We highlight Hermiticity issues in bound-state equations whose kernels are subject to a highly asymmetric mass and momentum distribution and whose eigenvalue spectrum becomes complex for radially excited states. We trace back the presence of imaginary components in the eigenvalues and wave functions to truncation artifacts and suggest how they can be eliminated in the case of charmed mesons. The solutions of the gap equation in the complex plane, which play a crucial role in the analytic structure of the Bethe-Salpeter kernel, are discussed for several interaction models and qualitatively and quantitatively compared to analytic continuations by means of complex-conjugate pole models fitted to real solutions.

  7. Bound states induced giant oscillations of the conductance in the quantum Hall regime.

    Science.gov (United States)

    Kadigrobov, A M; Fistul, M V

    2016-06-29

    We theoretically studied the quasiparticle transport in a 2D electron gas biased in the quantum Hall regime and in the presence of a lateral potential barrier. The lateral junction hosts the specific magnetic field dependent quasiparticle states highly localized in the transverse direction. The quantum tunnelling across the barrier provides a complex bands structure of a one-dimensional energy spectrum of these bound states, [Formula: see text], where p y is the electron momentum in the longitudinal direction y. Such a spectrum manifests itself by a large number of peaks and drops in the dependence of the magnetic edge states transmission coefficient D(E ) on the electron energy E. E.g. the high value of D occurs as soon as the electron energy E reaches gaps in the spectrum. These peaks and drops of D(E) result in giant oscillations of the transverse conductance G x with the magnetic field and/or the transport voltage. Our theoretical analysis, based on the coherent macroscopic quantum superposition of the bound states and the magnetic edge states propagating along the system boundaries, is in a good accord with the experimental observations found in Kang et al (2000 Lett. Nat. 403 59). PMID:27166511

  8. Bound states induced giant oscillations of the conductance in the quantum Hall regime

    Science.gov (United States)

    Kadigrobov, A. M.; Fistul, M. V.

    2016-06-01

    We theoretically studied the quasiparticle transport in a 2D electron gas biased in the quantum Hall regime and in the presence of a lateral potential barrier. The lateral junction hosts the specific magnetic field dependent quasiparticle states highly localized in the transverse direction. The quantum tunnelling across the barrier provides a complex bands structure of a one-dimensional energy spectrum of these bound states, {εn}≤ft( {{p}y}\\right) , where p y is the electron momentum in the longitudinal direction y. Such a spectrum manifests itself by a large number of peaks and drops in the dependence of the magnetic edge states transmission coefficient D(E ) on the electron energy E. E.g. the high value of D occurs as soon as the electron energy E reaches gaps in the spectrum. These peaks and drops of D(E) result in giant oscillations of the transverse conductance G x with the magnetic field and/or the transport voltage. Our theoretical analysis, based on the coherent macroscopic quantum superposition of the bound states and the magnetic edge states propagating along the system boundaries, is in a good accord with the experimental observations found in Kang et al (2000 Lett. Nat. 403 59)

  9. Signatures of Majorana bound states in one-dimensional topological superconductors

    International Nuclear Information System (INIS)

    Topological states of matter have fascinated condensed matter physicists for the past three decades. Famous examples include the integer and fractional quantum Hall states exhibiting a spectacular conductance quantization as well as topological insulators in two and three dimensions featuring gapless Dirac fermions at the boundary. Very recently, novel topological phases in superconductors have been subject of intense experimental and theoretical investigation. One-dimensional topological superconductors are particularly intriguing as they host exotic Majorana end states. These are zero-energy bound states with nonabelian exchange statistics potentially useful for topologically protected quantum computing. Recent theoretical and experimental advances have put the realization of Majorana states within reach of current measurement techniques. In this thesis we investigate signatures of Majorana bound states in realistic experiments aiming to improve the theoretical understanding of ongoing experimental efforts and to design novel measurement schemes, which exhibit convincing signatures of Majoranas. In particular we account for nonideal experimental conditions which can lead to qualitatively new features. Possible signatures of Majoranas can be accessed in the Josephson current through a weak link between two topological superconductors although the signatures in the dc Josephson effect are typically obscured by inevitable quasiparticle relaxation in the superconductor. Here we propose a measurement scheme in mesoscopic superconducting rings, where Majorana signatures persist even for infinitely fast relaxation. In a separate project we outline an alternative to the standard Josephson experiment in topological superconductors based on quantum wires. We delineate how Majoranas can be detected, when the Josephson current is induced by noncollinear magnetic fields applied to the two banks of the junction instead of a superconducting phase difference. Another important

  10. Bound states of fermions in external and self-consistent fields

    International Nuclear Information System (INIS)

    The properties of spin-1/2 fields in strong external potentials are investigated in order to determine what happens to the electron orbitals as the charge of the nucleus is increased without bounds. Strongly interacting quantum fields are investigated, motivated by the picture of quark bags, in which light quanta provide all the internal structure. Several general properties of the solutions of fermion fields interacting with meson fields are considered with the help of field theory analogues of virial relations. A description of the algorithm used to generate examples of the self-consistent solutions in three-space dimensions is also presented. Since it is difficult to associate the properties of strongly bound states with those of weakly interacting quasi-particles, several options for the candidates for the relevant interaction are considered. The present investigations deal only with Abelian fields. (Auth.)

  11. Thermoelectric signatures of a Majorana bound state coupled to a quantum dot

    International Nuclear Information System (INIS)

    We theoretically investigate the possibility to use thermolectric measurements to detect Majorana bound states and to investigate their coupling to a dissipative environment. The particle–hole symmetry of Majorana states would normally lead to a vanishing Seebeck coefficient, i.e. a vanishing open-circuit voltage resulting from a temperature gradient. We discuss how coupling to a quantum dot with a gate-controlled energy level breaks particle–hole symmetry in a tunable manner. The resulting gate-dependent Seebeck coefficient provides a new way to evidence the existence of Majorana states, which can be combined with conventional tunnel spectroscopy in the same setup. Furthermore, the thermoelectric properties rely on the ability of the quantum dot–Majorana system to sense the temperature of the bulk superconductor and can be used to extract information about the dissipative decay of Majorana states, which is crucial for quantum information applications. (paper)

  12. Stability of Majorana vortex bound states on the surface of superconducting topological insulators

    Science.gov (United States)

    Zhang, Junyi; Cano, Jennifer; Neupert, Titus

    Fu and Kane showed that superconductivity induced on the surface of a 3D topological insulator results in isolated Majorana bound states that appear in the cores of vortices. Many efforts to realize this idea are based on proximity-induced superconducting order in a heterostructure. Recently, superconductivity has been observed in PbTaSe2, which has the band topology of a topological insulator with Dirac cone surface states. Hence, it nourishes the vision of realizing the Fu and Kane proposal in a stoichiometric material without the need for doping or fabricating heterostructures. Motivated by this possibility, we give a comprehensive analysis of stability and localization properties of the vortex Majorana modes in such a topological superconducting material. In particular, we address the experimentally relevant questions regarding (i) the energy separation between the vortex bound and excited states, (ii) the dependence of the hybridization between Majorana modes from opposite surfaces on the thickness of a thin-film sample, (iii) the influence of the bulk superconducting pockets on the Majorana states.

  13. Double pionic fusion. Towards an understanding of the ABC puzzle by exclusive measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bashkanov, M.

    2006-07-01

    The ABC effect is a huge unexpected enhancement at twice the pion mass in the invariant mass spectrum of two pions, which are generated in double-pionic fusion to bound nuclear systems. This peculiar phenomenon has been missing a conclusive explanation all the time since it has been discovered 1960 in single-arm measurements of {sup 3}He ejectiles in the reaction pd{yields} {sup 3}HeX. One reason for this failure has been that all measurements to this subject have been inclusive, i.e., lacking the full experimentally accessible information. Hence exclusive measurements were performed at CELSIUS/WASA at an energy of T{sub p}=0.895 GeV, where the ABC effect is expected to be strongest. For the first time exclusive data of solid statistics for both the pd{yields}{sup 3}He{pi}{sup 0}{pi}{sup 0} and pd{yields}{sup 3}He{pi}{sup +}{pi}{sup -} reactions were obtained including also results for the three-pion production total cross-section. The new data are consistent with the previous inclusive data. They provide, however, much more additional information, which rule out all previous explications of the ABC effect. The now available kinematically complete set of data reveals that the low {pi}{pi}-mass enhancement (ABC-effect): - is not necessarily associated with a high {pi}{pi}-mass enhancement, - is always connected with the simultaneous excitation of two {delta} resonances, - is of scalar-isoscalar nature, i.e. a {sigma}-channel phenomenon, - requires dynamics in the reaction system, which has not been considered hitherto. Various possible solutions are discussed, however, all of them demand a high attraction in the {delta}{delta} system - a point, which has never been touched so far in theoretical and experimental investigations. For this data analysis new powerful methods based on neural nets have been developed. Their current and possible future applications are discussed. (orig.)

  14. Nuclear Bound States of Molecular Hydrogen Physisorbed on Graphene: An Effective Two-Dimensional Model.

    Science.gov (United States)

    de Lara-Castells, María Pilar; Mitrushchenkov, Alexander O

    2015-11-01

    The interaction potential of molecular hydrogen physisorbed on a graphene sheet is evaluated using the ab initio-based periodic dlDF+Das scheme and its accuracy is assessed by comparing the nuclear bound-state energies supported by the H2(D2/HD)/graphite potentials with the experimental energies. The periodic dlDF+Das treatment uses DFT-based symmetry-adapted perturbation theory on surface cluster models to extract the dispersion contribution to the interaction whereas periodic dispersionless density functional (dlDF) calculations are performed to determine the dispersion-free counterpart. It is shown that the H2/graphene interaction is effectively two-dimensional (2D), with the distance from the molecule center-of-mass to the surface plane and the angle between the diatomic axis and the surface normal as the relevant degrees of freedom. The global potential minimum is found at the orthogonal orientation of the molecule with respect to the surface plane, with an equilibrium distance of 3.17 Å and a binding energy of -51.9 meV. The comparison of the binding energies shows an important improvement of our approach over the vdW-corrected DFT schemes when we are dealing with the very weak H2/surface interaction. Next, the 2D nuclear bound-state energies are calculated numerically. As a cross-validation of the interaction potential, the bound states are also determined for molecular hydrogen on the graphite surface (represented as an assembly of graphene sheets). With the largest absolute deviation being 1.7 meV, the theoretical and experimental energy levels compare very favorably. PMID:26479965

  15. Effect of the velocity-dependent potentials on the bound state energy eigenvalues

    International Nuclear Information System (INIS)

    We investigate the effect of isotropic velocity-dependent potentials on the bound state energy eigenvalues for the first time for any quantum states of the Coulomb and harmonic oscillator potentials within the framework of the asymptotic iteration method. When the velocity-dependent term is selected as a constant parameter ρ0, we present that the energy eigenvalues can be obtained analytically for both Coulomb and harmonic oscillator potentials. However, when the velocity-dependent term is considered as a harmonic oscillator type ρ0r2, taking the velocity-dependent term as a perturbation, we present how to obtain the energy eigenvalues of the Coulomb and harmonic oscillator potentials for any n and ℓ quantum states by using perturbation expansion and numerical calculations in the asymptotic iteration method procedure. (authors)

  16. Effect of the Velocity-Dependent Potentials on the Bound State Energy Eigenvalues

    International Nuclear Information System (INIS)

    We investigate the effect of isotropic velocity-dependent potentials on the bound state energy eigenvalues for the first time for any quantum states of the Coulomb and harmonic oscillator potentials within the framework of the asymptotic iteration method. When the velocity-dependent term is selected as a constant parameter ρ0, we present that the energy eigenvalues can be obtained analytically for both Coulomb and harmonic oscillator potentials. However, when the velocity-dependent term is considered as a harmonic oscillator type ρ0r2, taking the velocity-dependent term as a perturbation, we present how to obtain the energy eigenvalues of the Coulomb and harmonic oscillator potentials for any n and l quantum states by using perturbation expansion and numerical calculations in the asymptotic iteration method procedure. (general)

  17. Application of supersymmetric quantum mechanics to study bound state properties of exotic hypernuclei

    CERN Document Server

    Khan, Md Abdul

    2015-01-01

    Bound state properties of few single and double-$\\Lambda$ hypernuclei is critically examined in the framework of core-$\\Lambda$ and core+$\\Lambda+\\Lambda$ few-body model applying hyperspherical harmonics expansion method (HHEM). The $\\Lambda\\Lambda$ potential is chosen phenomenologically while the core-$\\Lambda$ potential is obtained by folding a phenomenological $\\Lambda N$ interaction into the density distribution of the core. The depth of the effective $\\Lambda N$ potential is adjusted to reproduce the experimental data for the core-$\\Lambda$ subsystem. The three-body Schr\\"odinger equation is solved by hyperspherical adiabatic approximation (HAA) to get the ground state energy and wave function. The ground state wavefunction is used to construct the supersymmetric partner potential following prescription of supersymmetric quantum mechanics (SSQM) algebra. The newly constructed supersymmetric partner potential is used to solve the three-body Schr\\"odinger equation to get the energy and wavefunction for the...

  18. Statistical Production of Antikaon Nuclear Bound States in Heavy Ion Collisions

    CERN Document Server

    Andronic, A; Redlich, K

    2006-01-01

    Recently it was shown that the strongly attractive antikaon--nucleon potential can result in the formation of the antikaon nuclear bound states. We discuss the formation of such states as possible residues in heavy ion collisions. In this context, we calculate the excitation functions of single- and double-K- clusters in terms of the statistical thermal model. We show that, if such objects indeed exist, then, in heavy ion collisions, the single-K- clusters are most abundantly produced at present SIS energies, while the double-$K^-$ clusters show a pronounced maximum yield in the energy domain of the future accelerator at GSI. This is a direct consequence of: i) the baryonic dominance in low energy heavy ion collisions and the large baryonic content of the antikaonic bound states; ii) the strong energy dependence of strangeness production at low energies. The production yields of double-strange clusters is compared with that of double strange baryons. It is shown that at SIS energies there is a linear scaling ...

  19. Bound and continuum states of molecular anions C2H- and C3N-

    Science.gov (United States)

    Harrison, Stephen; Tennyson, Jonathan

    2011-02-01

    Recently a number of molecular anions, closed-shell linear carbon chains of the form CnH- and CnN-, have been detected in space. The molecules C2H- and C3N- are investigated by using the R-matrix method to consider electron scattering from the corresponding neutral targets. Initial target calculations are conducted and refined in order to produce target state characteristics similar to the experimental data. A number of different scattering models are tested including static exchange and close-coupling models, and the use of Hartree-Fock or natural orbitals in the close-coupling calculations. The calculations concentrate on bound and resonances states for the anions as well as eigenphase sums, elastic cross-sections and electronic excitation cross-sections for electron collisions with the neutral. It is found that electronic resonances are all too high in energy to be important for anion formation in the interstellar medium. However, C3N-, unlike C2H-, supports a number of very weakly bound excited states, which may well provide the route to electron attachment for this system.

  20. Studies of K-absorption on light nuclei and the search for bound nuclear kaonic states

    International Nuclear Information System (INIS)

    The available experimental data on K-absorption on nuclei are rather old and scarce: they are not enough to understand the possible formation of aggregates of nucleons bound together by a kaon, known as 'Bound Kaonic Nuclear States'. The existence of such structures, suggested by a few theoretical models, has not been experimentally ascertained yet. To be observed, their width should be less than their binding energy. A possible decay channel for such states is the non mesonic one, leading to hyperon-nucleon (or light nuclei) final states. Therefore, experimental investigations of possible signatures are mainly based on the analysis of hyperon-nucleon(s) correlations (for instance, of Λp(d,t) pairs) and of invariant mass spectra. Complementary information may also be gathered from missing mass distributions. Recent experiments revived, with much larger statistics, the study of K-A absorption in light nuclei: namely, KEK-E549 studied the K-interactions on 4He, while FINUDA at DAΦNE collected a large statistics on K-6,7Li, K-9Be and K-12C. The experimental results obtained so far by the various experiments studying the K-absorption in nuclei are here summarized.

  1. Spectroscopic factors for bound s-wave states derived from neutron scattering lengths

    International Nuclear Information System (INIS)

    A simple and model-independent method is described to derive neutron single-particle spectroscopic factors of bound s-wave states in A+1Z = AZ circle-times n nuclei from neutron scattering lengths. Spectroscopic factors for the nuclei 13C, 14C, 16N, 17O, 19O, 23Ne, 37Ar, and 41Ar are compared to results derived from transfer experiments using the well-known disorted wave Born analysis and to shell model calculations. The scattering length of 14C is calculated from the 15Cg.s. spectroscopic factor. copyright 1997 The American Physical Society

  2. Bound states and threshold resonances in quantum wires with circular bends

    International Nuclear Information System (INIS)

    We study the solutions to the wave equation in a two-dimensional tube of unit width comprised of two straight regions connected by a region of constant curvature. We introduce a numerical method which permits high accuracy at high curvature. We determine the bound state energies as well as the transmission and reflection matrices T and R and focus on the nature of the resonances that occur in the vicinity of channel thresholds. We explore the dependence of these solutions on the curvature of the tube and angle of the bend and discuss several limiting cases where our numerical results confirm analytic predictions. copyright 1996 The American Physical Society

  3. Optical signatures of states bound to vacancy defects in monolayer MoS$_2$

    OpenAIRE

    Erementchouk, Mikhail; Khan, M A; Leuenberger, Michael N.

    2015-01-01

    We show that pristine MoS$_2$ single layer (SL) exhibits two bandgaps $E_{g\\parallel}=1.9$ eV and $E_{g\\perp}=3.2$ eV for the optical in-plane and out-of-plane susceptibilities $\\chi_\\parallel$ and $\\chi_\\perp$, respectively. In particular, we show that odd states bound to vacancy defects (VDs) lead to resonances in $\\chi_\\perp$ inside $E_{g\\perp}$ in MoS$_2$ SL with VDs. We use density functional theory, the tight-binding model, and the Dirac equation to study MoS$_2$ SL with three types of ...

  4. Bound states of massive fermions in the Aharonov--Bohm-like fields

    OpenAIRE

    Khalilov, V. R.

    2014-01-01

    Bound states of massive fermions in the Aharonov-Bohm like fields have analytically been studied. The Hamiltonians with the Aharonov--Bohm like potentials are essentially singular and therefore require specification of a one-parameter self-adjoint extension. We construct self-adjoint Dirac Hamiltonians with the Aharonov-Bohm (AB) potential in 2+1 dimensions that are specified by boundary conditions at the origin. It is of interest that for some range of extension parameter the AB potential ca...

  5. Tube of (Circle F, D0, D2) Bound State in Melvin Background

    OpenAIRE

    Huang, Wung-Hong

    2004-01-01

    By using the Born-Infeld action we show that the $m$ circular fundamental strings, $n$ D2-branes and $k$ D0-branes could become a tubular bound state which is prevented from collapsing by the magnetic force in the Melvin background. However, if the ratio $m/n$ is larger then a critical value the tube will become unstable and collapse to zero radius. We make analyses to find the critical value and tube radius therein. The tube configurations we found are different from the well known tubular b...

  6. Neutrino masses and the dark energy equation of state - relaxing the cosmological neutrino mass bound

    OpenAIRE

    Hannestad, Steen

    2005-01-01

    Cosmology at present provides the nominally strongest constraint on the masses of standard model neutrinos. However, this constraint extremely dependent on the nature of the dark energy component of the Universe. When the dark energy equation of state parameter is taken as a free (but constant) parameter, the neutrino mass bound is sum m_nu < 1.48 eV (95% C.L.), compared with sum m_nu < 0.65 eV (95% C.L.) in the standard model where the dark energy is in the form of a cosmological constant. T...

  7. The beauty of impurities: Two revivals of Friedel's virtual bound-state concept

    Science.gov (United States)

    Georges, Antoine

    2016-03-01

    Jacques Friedel pioneered the theoretical study of impurities and magnetic impurities in metals. He discovered Friedel oscillations, introduced the concept of virtual bound-state, and demonstrated that the charge on the impurity is related to the scattering phase-shift at the Fermi level (Friedel sum-rule). After a brief review of some of these concepts, I describe how they proved useful in two new contexts. The first one concerns the Coulomb blockade in quantum dots, and its suppression by the Kondo effect. The second one is the dynamical mean-field theory of strong electronic correlations. xml:lang="fr"

  8. Quantum localization and bound-state formation in Bose-Einstein condensates

    International Nuclear Information System (INIS)

    We discuss the possibility of exponential quantum localization in systems of ultracold bosonic atoms with repulsive interactions in open optical lattices without disorder. We show that exponential localization occurs in the maximally excited state of the lowest energy band. We establish the conditions under which the presence of the upper energy bands can be neglected, determine the successive stages and the quantum phase boundaries at which localization occurs, and discuss schemes to detect it experimentally by visibility measurements. The discussed mechanism is a particular type of quantum localization that is intuitively understood in terms of the interplay between nonlinearity and a bounded energy spectrum.

  9. Search for the η-mesic Helium bound state with the WASA-at-COSY facility

    Science.gov (United States)

    Skurzok, Magdalena; Krzemień, Wojciech; Rundel, Oleksandr; Moskal, Pawel

    2016-05-01

    We performed a search for 4He-η bound state with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of η-mesic nuclei is searched for in dd → 3Henπ0 and dd → 3Hepπ- reactions by the measurement of the excitation functions in the vicinity of the η production threshold. This paper presents the experimental method and the preliminary results of the data analysis for dd → 3Henπ0 process.

  10. Search for the eta-mesic Helium bound state with the WASA-at-COSY facility

    CERN Document Server

    Skurzok, M; Rundel, O; Moskal, P

    2015-01-01

    We performed a search for 4He-eta bound state with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta-mesic nuclei is searched for in dd -> 3Henpi0 and dd -> 3Heppi- reactions by the measurement of the excitation functions in the vicinity of the {\\eta} production threshold. This paper presents the experimental method and the preliminary results of the data analysis for dd -> 3Henpi0 process.

  11. Quantum entanglement of charges in bound states with finite-size dyons

    International Nuclear Information System (INIS)

    We show that the presence of finite-size monopoles can lead to a number of interesting physical processes involving quantum entanglement of charges. Taking as a model the classical solution of the N=2 SU(2) Yang-Mills theory, we study interaction between dyons and scalar particles in the adjoint and fundamental representation. We find that there are bound states of scalars and dyons, which, remarkably, are always an entangled configuration of the form vertical bar ψ> = vertical bar dyon+> vertical bar scalar-> ± vertical bar dyon-> vertical bar scalar+>. We determine the energy levels and the wave functions and also discuss their stability. (author)

  12. Monopole-fermion and dyon-fermion bound states. Pt. 5

    International Nuclear Information System (INIS)

    We present explicit, approximate, remarkably precise results for the Kazama-Yang hamiltonian, which describes a Dirac monopole interacting with a spin-1/2 fermion that has an extra magnetic moment. The results are valid for bound states of angular momentum j >= Zvertical strokeegvertical stroke+1/2, where the radial wave functions are determined by four coupled differential equations. These equations have been solved analytically for M - E << M, which is a limit of considerable practical interest. Binding energies and wave functions are given. (orig.)

  13. Electric dipole transition rates of the bound states of the b bar b system

    International Nuclear Information System (INIS)

    We calculate the E1 decay rates of the bound states of the b bar b system in the nonsingular potential model of Gupta, Repko, and Suchyta (GRS) and compare them with the recent experimental results. We get predictions somewhat different from the original GRS results and overall these new results are in better agreement with experiment. We point out the importance of including both the relativistic corrections to the wave function and the finite-size corrections to the E1 decay rates, especially for transitions which involve a change of more than one unit in the radial quantum number

  14. Computation of Quantum Bound States on a Singly Punctured Two-Torus

    International Nuclear Information System (INIS)

    We study a quantum mechanical system on a singly punctured two-torus with bound states described by the Maass waveforms which are eigenfunctions of the hyperbolic Laplace—Beltrami operator. Since the discrete eigenvalues of the Maass cusp form are not known analytically, they are solved numerically using an adapted algorithm of Hejhal and Then to compute Maass cusp forms on the punctured two-torus. We report on the computational results of the lower lying eigenvalues for the punctured two-torus and find that they are doubly-degenerate. We also visualize the eigenstates of selected eigenvalues using GridMathematica

  15. A lower bound for the energy of the ground state of bosons moving in one dimension

    International Nuclear Information System (INIS)

    It is shown that the gound state energy of N bosons of mass m moving in one ddimension is greater than E = - m/16h/2π2 N2(N-1)]∫ sup(+ infinite) sub(- infinite) V(x)dx] where V(x) is the two-body potential. It is conjectured that E = - m/24h/2π2N(N2-1)]∫ sup(+ infinite) sup(infinite) V(x)dx]2 provides a lower bound. (Author)

  16. Approximate bound states of the Dirac equation with some physical quantum potentials

    OpenAIRE

    Sameer M. Ikhdair; Sever, Ramazan

    2012-01-01

    The approximate analytical solutions of the Dirac equations with the reflectionless-type and Rosen-Morse potentials including the spin-orbit centrifugal (pseudo-centrifugal) term are obtained. Under the conditions of spin and pseudospin (pspin) symmetry concept, we obtain the bound state energy spectra and the corresponding two-component upper- and lower-spinors of the two Dirac particles by means of the Nikiforov-Uvarov (NU) method in closed form. The special cases of the s-wave {\\kappa}=\\pm...

  17. Approximate bound states of the Dirac equation with some physical quantum potentials

    CERN Document Server

    Ikhdair, Sameer M; 10.1016/j.amc.2012.03.073

    2012-01-01

    The approximate analytical solutions of the Dirac equations with the reflectionless-type and Rosen-Morse potentials including the spin-orbit centrifugal (pseudo-centrifugal) term are obtained. Under the conditions of spin and pseudospin (pspin) symmetry concept, we obtain the bound state energy spectra and the corresponding two-component upper- and lower-spinors of the two Dirac particles by means of the Nikiforov-Uvarov (NU) method in closed form. The special cases of the s-wave {\\kappa}=\\pm1 (l=l=0) Dirac equation and the non-relativistic limit of Dirac equation are briefly studied.

  18. Gluons in the QCD bound state problem - a way to exact solution

    OpenAIRE

    Ter-Martirosyan, K. A.

    2000-01-01

    The colored objects -- quarks and gluons -- being confined in a small volume $V\\sim R_0^3,$ $R_0\\sim 0.5$fm inside the QCD bound state get there not small masses $m_{q\\bar q}\\sim 1$GeV, $m_g\\sim 0.5$GeV. This drastically simplifies the QCD dynamics, as now the probabilities e.g. of production of one extra massive valent gluon or extra $q\\bar q$ pair, turned to be small due to a large gap between corresponding energy levels. The ordinary quantum mechanical perturbation theory calculations made...

  19. Electron-electron bound states in parity-preserving QED{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Belich, H.; Helayel-Neto, J.A. [Universidade Catolica do Petropolis, RJ (Brazil). Grupo de Fisica Teorica]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas; Cima, O.M. del [Universidade Catolica do Petropolis, RJ (Brazil). Grupo de Fisica Teorica; Ferreira Junior, M.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]|[Maranhao Univ., Sao Luis, MA (Brazil). Dept. de Fisica

    2002-04-01

    By considering the Higgs mechanism in the framework of a parity-preserving Planar Quantum Electrodynamics, one shows that an attractive electron-electron interaction may dominate. The e{sup -}e{sup -} interaction potential emerges as the non-relativistic limit of the Moeller scattering amplitude and it results attractive with a suitable choice of parameters. Numerically values of the e{sup -}e{sup -} binding energy are obtained by solving the two-dimensional Schroedinger equation. The existence of bound states is a strong indicative that this model may be adopted to address the pairing mechanism of high-T{sub c} superconductivity. (author)

  20. Is there an {eta}{sup 3}He quasi-bound state?

    Energy Technology Data Exchange (ETDEWEB)

    Wilkin, C. [Physics and Astronomy Department, UCL, London, WC1E 6BT (United Kingdom)], E-mail: cw@hep.ucl.ac.uk; Buescher, M. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Chiladze, D. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); High Energy Physics Institute, Tbilisi State University, 0186 Tbilisi, Georgia (United States); Dymov, S. [Laboratory of Nuclear Problems, JINR, 141980 Dubna (Russian Federation); Hanhart, C.; Hartmann, M.; Hejny, V. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Kacharava, A. [High Energy Physics Institute, Tbilisi State University, 0186 Tbilisi, Georgia (United States); Physikalisches Institut II, Universitaet Erlangen-Nuernberg, 91058 Erlangen (Germany); Keshelashvili, I. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); High Energy Physics Institute, Tbilisi State University, 0186 Tbilisi, Georgia (United States); Khoukaz, A. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Maeda, Y. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Mersmann, T.; Mielke, M. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Mikirtychiants, S. [High Energy Physics Department, Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation); Papenbrock, M. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Rathmann, F. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Rausmann, T. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany); Schleichert, R.; Stroeher, H. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Taeschner, A. [Institut fuer Kernphysik, Universitaet Muenster, 48149 Muenster (Germany)] (and others)

    2007-10-11

    The observed variation of the total cross section for the dp{yields}{sup 3}He{eta} reaction near threshold means that the magnitude of the s-wave amplitude falls very rapidly with the {eta} centre-of-mass momentum. It is shown here that recent measurements of the momentum dependence of the angular distribution imply a strong variation also in the phase of this amplitude. Such a behaviour is that expected from a quasi-bound or virtual {eta}{sup 3}He state. The interpretation can be investigated further through measurements of the deuteron or proton analysing powers and/or spin-correlations.

  1. A search for deeply-bound kaonic nuclear states at J-PARC

    Directory of Open Access Journals (Sweden)

    Sakaguchi A.

    2010-04-01

    Full Text Available The J-PARC E15 experiment will be performed to search for the simplest kaonic nuclear bound state, K− pp, by the in-flight 3He(K−,n reaction. The exclusive measurement can be performed by a simultaneous measurement of the missing mass using the primary neutron and the invariant mass via the expected decay, K− pp → Λp → pπ− p. In this report, an overview of the experiment and the preparation status are presented.

  2. Proposed new signal for scalar top-squark bound-state production

    International Nuclear Information System (INIS)

    We study the production and decay of a scalar (t1t1*) bound state σt1 at hadron supercolliders, where t1 is the lighter scalar top eigenstate. If t1 has no tree-level 2-body decays, the dominant decay modes of σt1 are gg or, if mhti much-lt mt2, a pair of light scalar Higgs bosons h. Nevertheless, the branching ratio into two photons is often large enough to yield a detectable signal

  3. Pion as a Longitudinal Axial-Vector Meson $q\\bar{q}$ Bound State

    OpenAIRE

    Pham, T. N.

    2013-01-01

    The success of the Adler-Bell-Jackiw(ABJ) chiral anomaly prediction for $\\pi^{0}\\to \\gamma\\gamma$ decay rate shows that non-anomaly terms would make a negligible contribution to the decay rate, in agreement with the Sutherland-Veltman theorem. Thus the conventional $q\\bar{q}$ bound-state description of the pion could not be valid since it would produce a $\\pi^{0}\\to \\gamma\\gamma$ decay amplitude not suppressed in the soft pion limit, in contradiction with the Sutherland-Veltman theorem. There...

  4. A Search for Deeply Bound Kaonic Nuclear States at J-PARC

    Science.gov (United States)

    Ajimura, S.; Beer, G.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Enomoto, S.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishiguro, Y.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kawasaki, S.; Kienle, P.; Kou, H.; Ma, Y.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Piscicchia, K.; Lener, M. Poli; Vidal, A. Romero; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Scordo, A.; Sekimoto, M.; Shi, H.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Doce, O. Vazquez; Widmann, E.; Yamazaki, T.; Yim, H.; Zmeskal, J.

    2013-08-01

    The J-PARC E15 experiment has the aims to search for the simplest kaonic nuclear bound state, K - pp, by the in-flight 3He( K -, n) reaction. The exclusive measurement is performed by a simultaneous measurement of the missing mass using the knocked out neutron and the invariant mass via the expected decay, K - pp → Λ p → pπ- p. In this paper, an overview of the experiment and current data analysis of the engineering runs performed in February and June 2012 are presented.

  5. Quark-antiquark bound state equation in the Wilson loop approach with minimal surfaces

    OpenAIRE

    Jugeau, F.; Sazdjian, H.

    2005-01-01

    The quark-antiquark gauge invariant Green function is studied through its dependence on Wilson loops. The latter are saturated, in the large Nc limit and for large contours, by minimal surfaces. A covariant bound state equation is derived which in the center-of-mass frame and at equal-times takes the form of a Breit-Salpeter type equation. The large-distance interaction potentials reduce in the static case to a confining linear vector potential. In general, the interaction potentials involve ...

  6. K$^-$ absorption on two nucleons and ppK$^-$ bound state search in the $\\Sigma^0$p final state

    CERN Document Server

    Doce, O Vazquez; Cargnelli, M; Curceanu, C; Marton, J; Piscicchia, K; Scordo, A; Sirghi, D; Tucakovic, I; Wycech, S; Zmeskal, J; Anastasi, A; Curciarello, F; Czerwinski, E; Krzemien, W; Mandaglio, G; Martini, M; Moskal, P; Patera, V; del Rio, E Perez; Silarski, M

    2015-01-01

    We report the measurement of K$^-$ absorption processes in the $\\Sigma^0$p final state and the first exclusive measurement of the two nucleon absorption (2NA) with the KLOE detector. The 2NA process without further interactions is found to be 12\\% of the sum of all other contributing processes, including absorption on three and more nucleons or 2NA followed by final state interactions with the residual nucleons. We also determine the possible contribution of the ppK$^-$ bound state to the $\\Sigma^0$p final state. A yield of ppK$^- /\\mathrm{K^-_{stop}}$ is found to be $(0.044 \\pm 0.009\\, stat ^{+ 0.004} _{- 0.005} \\,syst) \\cdot 10^{-2}$ but its statistical significance based on an F-test is only 1$\\sigma$.

  7. Quasi bound states in continuum induced by an external oscillating field

    International Nuclear Information System (INIS)

    The presence of quasi bound states in continuum is demonstrated in a system represented by a time-dependent Fano–Anderson Hamiltonian where an impurity coupled with a one-dimensional chain is driven by an external oscillating field. The QBIC state is a metastable state with an extremely small decay rate caused by the competition between a stabilizing effect by the Van Hove singularity in the density of states and a destabilizing effect by the resonance instability. This competition occurs in systems with multiple overlapping energy bands. Although there is only one energy band in our system, multiple bands emerge in the spectrum of the Floquet Hamiltonian. As a result of the overlapping bands in the Floquet spectrum, the QBIC state is induced in the presence of an oscillating field. In terms of the Green's function method, the analytical expression of the complex energy for the QBIC state is obtained as expansion near the band edge in powers of the coupling constant. Our results indicate that the appearance and the disappearance of the QBIC state repeatedly occur as the amplitude of the external field increases. (paper)

  8. Note: Parameter-independent bounding of the stochastic Michaelis-Menten steady-state intrinsic noise variance

    Science.gov (United States)

    Widmer, L. A.; Stelling, J.; Doyle, F. J.

    2013-10-01

    Using the (slow-scale) linear noise approximation, we give parameter-independent bounds to the substrate and product intrinsic noise variance for the stochastic Michaelis-Menten approximation at steady state.

  9. Search for deeply bound Kaonic nuclear states via 3He(K-, n) reaction at J-PARC

    Science.gov (United States)

    Ma, Y.; Ajimura, S.; Beer, G.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Enomoto, S.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishiguro, Y.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kato, Y.; Kawasaki, S.; Kienle, P.; Kou, H.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Piscicchia, K.; Lener, M. Poli; Vidal, A. Romero; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Scordo, A.; Sekimoto, M.; Shi, H.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tanida, K.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Vazquez Doce, O.; Widmann, E.; Wuenschek, B. K.; Yamaga, T.; Yamazaki, T.; Yim, H.; Zhang, Q.; Zmeskal, J.

    2015-10-01

    As the latest effort to search for deeply-bound overline K-nuclear states, E15 experiment has been carried out at K1.8 branch beam line (K1.8BR) at J-PARC. 3He(K-, N) reaction was employed to search for the simplest overline K-nuclear bound state, K--pp. In this proceeding, preliminary results of 3He(K-, n) spectra obtained in the first physics-run will be presented.

  10. Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers

    Directory of Open Access Journals (Sweden)

    A. Komarov

    2012-01-01

    Full Text Available We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.

  11. Shot noise in a quantum dot system coupled with Majorana bound states

    International Nuclear Information System (INIS)

    We investigate the spectral density of shot noise and current for the system of a quantum dot coupled to Majorana bound states (MBS) employing the nonequilibrium Green’s function. The Majorana bound states at the end of the wire strongly affect the shot noise. There are two types of coupling in the system: dot–MBS and MBS–MBS coupling. The curves of shot noise and current versus coupling strength have novel steps owing to the energy-level splitting caused by dot–MBS coupling. The magnitude of these steps increases with the strength of dot–MBS coupling λ but decreases with the strength of MBS–MBS coupling. The steps shift toward the large ∣eV∣ region as λ or ϵM increases. In addition, dot–MBS coupling enhances the shot noise while MBS–MBS coupling suppresses the shot noise. In the absence of MBS–MBS coupling, a sharp jump emerges in the curve of the Fano factor at zero bias owing to the differential conductance being reduced by a factor of 1/2. This provides a novel technique for the detection of Majorana fermions. (paper)

  12. Shot noise in a quantum dot system coupled with Majorana bound states

    Science.gov (United States)

    Chen, Qiao; Chen, Ke-Qiu; Zhao, Hong-Kang

    2014-08-01

    We investigate the spectral density of shot noise and current for the system of a quantum dot coupled to Majorana bound states (MBS) employing the nonequilibrium Green’s function. The Majorana bound states at the end of the wire strongly affect the shot noise. There are two types of coupling in the system: dot-MBS and MBS-MBS coupling. The curves of shot noise and current versus coupling strength have novel steps owing to the energy-level splitting caused by dot-MBS coupling. The magnitude of these steps increases with the strength of dot-MBS coupling λ but decreases with the strength of MBS-MBS coupling. The steps shift toward the large ∣eV∣ region as λ or ɛM increases. In addition, dot-MBS coupling enhances the shot noise while MBS-MBS coupling suppresses the shot noise. In the absence of MBS-MBS coupling, a sharp jump emerges in the curve of the Fano factor at zero bias owing to the differential conductance being reduced by a factor of 1/2. This provides a novel technique for the detection of Majorana fermions.

  13. Relativistic actions for bound-states and applications in the meson spectroscopy

    International Nuclear Information System (INIS)

    We study relativistic equations for bound states of two-body systems using Dirac's constraint formalism and supersymmetry. The two-body system can be of spinless particles, one of them spinning and the other one spinless, or both of them spinning. The interaction is described by scalar, timelike four-vector and spacelike four-vector potentials under Lorentz transformations. As an application we use the relativistic wave equation for two scalar particles and calculate the mass spectra of the mesons treating them as spinless quark-antiquark bound states. The interaction potential in this case is a convenient adaptation of the potential employed in non-relativistic calculations. Finally, we compare our results with more recent experimental data and with theoretical results obtained with the same potential used by us but with a non-relativistic wave equation. We also compare our results with results obtained with the relativistic wave equation but with a different interaction potential. (author). 38 refs, 9 figs, 8 tabs

  14. Semi-inclusive B->K(K*)X decays with initial bound state effects

    International Nuclear Information System (INIS)

    The effects of the initial b quark bound state for the semi-inclusive decays B->K(K*)X are studied using light cone expansion and heavy quark effective theory methods. We find that the initial bound state effects on the branching ratios and CP asymmetries are small. In the light cone expansion approach, the CP-averaged branching ratios are increased by about 2% with respect to the free b-quark decay. For {bar B}0->K-(K*-)X, the CP-averaged branching ratios are sensitive to the phase γ and the CP asymmetry can be as large as 7% (14%), whereas for B-->{bar K}0({bar K}*0)X the CP-averaged branching ratios are not sensitive to γ and the CP asymmetries are small (-4 [(0.25 - 2.0)x10-4] for {bar B}0->K-(K*-)X and (0.77 - 0.84)x10-4 [(0.67 - 0.74)x10-4] for B-->{bar K}0({bar K}*0)X, depending on the value of the CP violating phase γ. In the heavy quark effective theory approach, we find that the branching ratios are decreased by about 10% and the CP asymmetries are not affected. These predictions can be tested in the near future

  15. Quasi-Bound States of the F·CH4 Complex.

    Science.gov (United States)

    Schäpers, Daniela; Manthe, Uwe

    2016-05-19

    The F + CH4 → HF + CH3 reaction is an intensively studied prototypical example of a polyatomic reaction showing an early transition state. Prereactive complexes are assumed to play an important role in the dynamics of the reaction. In this work, the long-living resonance states resulting from the formation of a metastable F·CH4 complex are investigated in detail. Full-dimensional quantum dynamics calculations employing the multiconfigurational time-dependent Hartree (MCTDH) approach and a single adiabatic potential energy surface are used to study the low-lying quasi-bound states of the F·CH4 complex for vanishing total (nuclear) angular momentum. The computed dissociation energy of the F·CH4 complex with respect to the reactant asymptote is 170 cm(-1). About 60 resonance states with energies below the reactant asymptote are found. A detailed analysis of the computed wave function of the low-lying states shows an almost free relative rotation of F and CH4 and an approximately separable F-CH4 stretching vibration. The present results are compared with transition state spectroscopy experiments which study the photodetachment spectrum of the CH4F(-) anion. PMID:26730978

  16. Simulated Annealing for Ground State Energy of Ionized Donor Bound Excitons in Semiconductors

    Institute of Scientific and Technical Information of China (English)

    YAN Hai-Qing; TANG Chen; LIU Ming; ZHANG Hao; ZHANG Gui-Min

    2004-01-01

    We present a global optimization method, called the simulated annealing, to the ground state energies of excitons. The proposed method does not require the partial derivatives with respect to each variational parameter or solving an eigenequation, so the present method is simpler in software programming than the variational method,and overcomes the major difficulties. The ground state energies of ionized-donor-bound excitons (D+, X) have been calculated variationally for all values of effective electron-to-hole mass ratio σ. They are compared with those obtained by the variational method. The results obtained demonstrate that the proposed method is simple, accurate, and has more advantages than the traditional methods in calculation.

  17. Simulated Annealing for Ground State Energy of Ionized Donor Bound Excitons in Semiconductors

    Institute of Scientific and Technical Information of China (English)

    YANHai-Qing; TANGChen; LIUMing; ZHANGHao; ZHANGGui-Min

    2004-01-01

    We present a global optimization method, called the simulated annealing, to the ground state energies of excitons. The proposed method does not require the partial derivatives with respect to each variational parameter or solving an eigenequation, so the present method is simpler in software programming than the variational method,and overcomes the major difficulties. The ground state energies of ionized-donor-bound excitons (D+,X) have beencal culated variationally for all values of effective electron-to-hole mass ratio σ. They are compared with those obtained by the variational method. The results obtained demonstrate that the proposed method is simple, accurate, and has more advantages than the traditional methods in calculation.

  18. Light fermion bound states in two-particle relativistic quantum mechanics

    International Nuclear Information System (INIS)

    We study, in the framework of two-particle relativistic quantum mechanics, spin 1/2 fermion-spin-0 boson systems with general classes of interaction having the following properties: they preserve chiral symmetry, confine the two particles into bound states and possess the short distance behavior of vector interactions. The resulting spectrum displays as ground states an infinite number of light fermions with increasing spins, the masses of which vanish with the vanishing of the constituent particle masses. In the absence of short range interactions these fermions have the quantum numbers j = l +1/2; l=0,1,...; n=0. A secondary interaction, here taken illustratively of the L-S coupling type, is needed to give masses to the light high spin fermions. This problem is relevant for the study of the dynamics of preonic systems

  19. Friedel phase discontinuity and bound states in the continuum in quantum dot systems

    Science.gov (United States)

    Solís, B.; Ladrón de Guevara, M. L.; Orellana, P. A.

    2008-06-01

    In this Letter we study the Friedel phase of the electron transport in two different systems of quantum dots which exhibit bound states in the continuum (BIC). The Friedel phase jumps abruptly in the energies of the BICs, which is associated to the vanishing width of these states, as shown by Friedrich and Wintgen in [H. Friedrich, D. Wintgen, Phys. Rev. A 31 (1985) 3964]. This odd behavior of the Friedel phase has consequences in the charge through the Friedel sum rule. Namely, if the energy of the BIC drops under the Fermi energy the charge changes abruptly in a unity. We show that this behavior closely relates to discontinuities in the conductance predicted for interacting quantum dot systems.

  20. Catching the bound states in the continuum of a phantom atom in graphene

    Science.gov (United States)

    Guessi, L. H.; Machado, R. S.; Marques, Y.; Ricco, L. S.; Kristinsson, K.; Yoshida, M.; Shelykh, I. A.; de Souza, M.; Seridonio, A. C.

    2015-07-01

    We explore theoretically the formation of bound states in the continuum (BICs) in graphene hosting two collinear adatoms situated at different sides of the sheet and at the center of the hexagonal cell, where a phantom atom of a fictitious lattice emulates the six carbons of the cell. We verify that in this configuration the local density of states near the Dirac points exhibits two characteristic features: (i) a cubic dependence on energy instead of a linear one for graphene as found in New J. Phys. 16, 013045 (2014), 10.1088/1367-2630/16/1/013045, and (ii) the formation of BICs as an aftermath of a Fano destructive interference assisted by the Coulomb correlations in the adatoms. For the geometry where adatoms are collinear to carbon atoms, we report an absence of BICs.

  1. The H${}^-$ type isoelectron system: second critical charge, second bound state of H${}^-$ and analytic continuation

    CERN Document Server

    Turbiner, A V; Pilon, H Olivares

    2015-01-01

    The second critical charge in the 3-body quantum Coulomb system $(Z, e, e)$ predicted by F Stillinger has been calculated to be equal to $Z_{B}^{\\infty}\\ =\\ 0.904854$ and $Z_{B}^{m_p}\\ =\\ 0.905138$ for infinite and finite (proton) mass $m_p$ of charge $Z$, respectively. In both cases, the ground state energy has a square-root branch point with exponent 3/2 at $Z=Z_B$ in the complex $Z$-plane. Based on analytic continuation, the second, spin-singlet bound state of negative hydrogen ion H${}^-$ is predicted to be at -0.515541 a.u. (-0.515311 a.u. for the proton mass $m_p$). The first critical charge for which the ionization energy vanishes is found for a finite proton mass in the Lagrange mesh method, $Z^{m_p}_{c}\\ =\\ 0.911\\, 069\\, 724\\, 655$.

  2. Collisional shift and broadening of the transition lines in pionic helium

    Science.gov (United States)

    Obreshkov, Boyan; Bakalov, Dimitar

    2016-06-01

    We calculate the density shift and broadening of selected dipole transition lines of pionic helium in gaseous helium at low temperatures up to T =12 K and pressure up to a few bars. In the approximation of binary collisions the shift and broadening depend linearly on the density; we evaluate the slope of this linear dependence for a few spectral lines of known experimental interest and also investigate its temperature dependence. We find a blueshift of the resonance frequencies of the (n ,l )=(16 ,15 )→(16 ,14 ) , (17 ,16 )→(17 ,15 ) , and (16 ,15 )→(17 ,14 ) unfavored transitions and a redshift for the favored one, (17 ,16 )→(16 ,15 ) . The results are intended to significantly increase the efficiency of the laser spectroscopy investigations of pionic helium and help with the interpretation of the experimental data.

  3. Collisional shift and broadening of the transition lines in pionic helium

    CERN Document Server

    Obreshkov, Boyan

    2016-01-01

    We calculate the density shift and broadening of selected dipole transition lines of pionic helium in gaseous helium at low temperatures up to T=12 K and pressure up to a few bar. In the approximation of binary collisions the shift and broadening depend linearly on the density; we evaluate the slope of this linear dependence a few spectral lines of known experimental interest, and also investigate its temperature dependence. We find blue shift of the resonance frequencies of the $(n,l)=(16,15) \\rightarrow (16,14) $, $(17,16) \\rightarrow (17,15)$, and $(16,15)\\rightarrow(17,14)$ transitions, and red shift for the favored transition $(17,16) \\rightarrow (16,15)$. The results are intended to significantly increase the efficiency of the laser spectroscopy investigation of pionic helium and help the interpretation of the experimental data.

  4. Approximate Relativistic Bound State Solutions of the Tietz-Hua Rotating Oscillator for Any κ-State

    International Nuclear Information System (INIS)

    Approximate analytical solutions of the Dirac equation with Tietz-Hua (TH) potential are obtained for arbitrary spin-orbit quantum number κ using the Pekeris approximation scheme to deal with the spin-orbit coupling terms κ(κ±1)r-2. In the presence of exact spin and pseudo-spin symmetric limitation, the bound state energy eigenvalues and associated two-component wave functions of the Dirac particle moving in the field of attractive and repulsive TH potential are obtained using the parametric generalization of the Nikiforov-Uvarov method. The cases of the Morse potential, the generalized Morse potential and non-relativistic limits are studied. (author)

  5. Monte Carlo simulation of inclusive pionic reaction around resonance and higher energy perspectives

    International Nuclear Information System (INIS)

    We describe all the inclusive pionic reactions in a variety of nuclei around the resonance region by means of a microscopic many-body calculation that evaluates reaction probabilities, followed by a Monte Carlo simulation which follows the evolution of the pions. We also make an intrusion into the higher energy domain by paying attention to the absorption mechanisms and their repercussions in exclusive single-charge exchange reactions. 27 refs., 11 figs

  6. Nonequilibrium process in the $\\sigma$ model and chemical relaxation time in a homogeneous pionic gas

    OpenAIRE

    Ishii, Mitsuru

    1996-01-01

    In a homogeneous pionic gas system, chemical nonequilibrium process is considered to understand its effect in the expansion processes that are realized immediately after heavy ion collisions. The chemical relaxation time is calculated by incorporating the $\\pi+\\pi \\leftrightarrow \\pi+\\pi+\\pi+\\pi$ reaction, which is given in the second order of perturbation in the $\\sigma$ model. The $\\pi+\\pi \\leftrightarrow \\pi+\\pi+\\pi+\\pi$ reaction is assumed to be less frequent than the $\\pi+\\pi \\leftrighta...

  7. The two photon decay of a bound state of exotic colored scalars charged under an additional unbroken gauge interaction

    CERN Document Server

    Foot, Robert

    2016-01-01

    We argue that a charged scalar particle $\\chi$ of mass around 375 GeV charged under both $\\mathrm{SU}(3)_{c}$ and a new confining non-abelian gauge interaction can explain the 750 GeV diphoton excess. After pair production, these interactions confine the exotic scalar into non-relativistic bound states whose decays into photons can explain the discrepancy. Taking the new confining group to be $\\mathrm{SU}(2)$, we find $\\chi$ must carry an electric charge of $Q \\approx 1/2$ to fit the data. Interestingly, we find that pair production of the scalars and the subsequent formation of the bound state dominates over direct bound state resonance production. This explanation is quite weakly constrained by current experimental bounds, and we expect future constraints to come from dijet, mono-jet and possibly dilepton searches.

  8. First clear evidence of quantum chaos in the bound states of an atomic nucleus

    CERN Document Server

    Muñoz, L; Gómez, J M G; Heusler, A

    2016-01-01

    We study the spectral fluctuations of the $^{208}$Pb nucleus using the complete experimental spectrum of 151 states up to excitation energies of $6.20$ MeV recently identified at the Maier-Leibnitz-Laboratorium at Garching, Germany. For natural parity states the results are very close to the predictions of Random Matrix Theory (RMT) for the nearest-neighbor spacing distribution. A quantitative estimate of the agreement is given by the Brody parameter $\\omega$, which takes the value $\\omega=0$ for regular systems and $\\omega \\simeq 1$ for chaotic systems. We obtain $\\omega=0.85 \\pm 0.02$ which is, to our knowledge, the closest value to chaos ever observed in experimental bound states of nuclei. By contrast, the results for unnatural parity states are far from RMT behavior. We interpret these results as a consequence of the strength of the residual interaction in $^{208}$Pb, which, according to experimental data, is much stronger for natural than for unnatural parity states. In addition our results show that ch...

  9. Topological Defects in Topological Insulators and Bound States at Topological Superconductor Vortices

    Directory of Open Access Journals (Sweden)

    Vincenzo Parente

    2014-03-01

    Full Text Available The scattering of Dirac electrons by topological defects could be one of the most relevant sources of resistance in graphene and at the boundary surfaces of a three-dimensional topological insulator (3D TI. In the long wavelength, continuous limit of the Dirac equation, the topological defect can be described as a distortion of the metric in curved space, which can be accounted for by a rotation of the Gamma matrices and by a spin connection inherited with the curvature. These features modify the scattering properties of the carriers. We discuss the self-energy of defect formation with this approach and the electron cross-section for intra-valley scattering at an edge dislocation in graphene, including corrections coming from the local stress. The cross-section contribution to the resistivity, ρ, is derived within the Boltzmann theory of transport. On the same lines, we discuss the scattering of a screw dislocation in a two-band 3D TI, like Bi1-xSbx, and we present the analytical simplified form of the wavefunction for gapless helical states bound at the defect. When a 3D TI is sandwiched between two even-parity superconductors, Dirac boundary states acquire superconductive correlations by proximity. In the presence of a magnetic vortex piercing the heterostructure, two Majorana states are localized at the two interfaces and bound to the vortex core. They have a half integer total angular momentum each, to match with the unitary orbital angular momentum of the vortex charge.

  10. An upper bound on the second order asymptotic expansion for the quantum communication cost of state redistribution

    Science.gov (United States)

    Datta, Nilanjana; Hsieh, Min-Hsiu; Oppenheim, Jonathan

    2016-05-01

    State redistribution is the protocol in which given an arbitrary tripartite quantum state, with two of the subsystems initially being with Alice and one being with Bob, the goal is for Alice to send one of her subsystems to Bob, possibly with the help of prior shared entanglement. We derive an upper bound on the second order asymptotic expansion for the quantum communication cost of achieving state redistribution with a given finite accuracy. In proving our result, we also obtain an upper bound on the quantum communication cost of this protocol in the one-shot setting, by using the protocol of coherent state merging as a primitive.

  11. The effect of bound states on X-ray Thomson scattering for partially ionized plasmas

    CERN Document Server

    Nilsen, J; Cheng, K T

    2013-01-01

    X-ray Thomson scattering is being developed as a method to measure the temperature, electron density, and ionization state of high energy density plasmas such as those used in inertial confinement fusion. X-ray laser sources have always been of interest because of the need to have a bright monochromatic x-ray source to overcome plasma emission and eliminate other lines in the background that complicate the analysis. With the advent of the xray free electron laser (X-FEL) at the SLAC Linac Coherent Light Source (LCLS) and other facilities coming online worldwide, we now have such a source available in the keV regime. Most Thomson scattering codes used to model experimental data greatly simplify or neglect the contributions of the bound electrons to the scattered intensity. In this work we take the existing models of Thomson scattering that include elastic ion-ion scattering and inelastic electron-electron scattering and add the contribution of bound electrons in the partially ionized plasmas. To date, most exp...

  12. Neutron scattering from elemental indium, the optical model, and the bound-state potential

    International Nuclear Information System (INIS)

    Neutron differential elastic-scattering cross sections of elemental indium are measured from 4.5 to 10 MeV at incident-energy intervals of ∼500 keV. Seventy or more differential values are obtained at each incident energy, distributed between ∼18 degree and 160 degree. These experimental results are combined with lower-energy values previously obtained at this laboratory, and with 11 and 14 MeV results in the literature, to form a comprehensive elastic-scattering database extending from ∼1.5 to 14 MeV. These data are interpreted in terms of a conventional spherical optical model. The resulting potential is extrapolated to the bound-state regime. It is shown that in the middle of the 50--82 neutron shell, the potential derived from the scattering results adequately describes the binding energies of article states, but does not do well for hole states. The latter shortcoming is attributed to the holes states having occupational probabilities sufficiently different from unity, so that the exclusion principle become a factor, and to the rearrangement of the neutron core. 68 refs

  13. Ground-state-entanglement bound for quantum energy teleportation of general spin-chain models

    Science.gov (United States)

    Hotta, Masahiro

    2013-03-01

    Many-body quantum systems in the ground states have zero-point energy due to the uncertainty relation. In many cases, the system in the ground state accompanies spatially entangled energy density fluctuation via the noncommutativity of the energy density operators, though the total energy takes a fixed value, i.e., the lowest eigenvalue of the Hamiltonian. Quantum energy teleportation (QET) is a protocol for the extraction of the zero-point energy out of one subsystem using information of a remote measurement of another subsystem. From an operational viewpoint of protocol users, QET can be regarded as an effective rapid energy transportation without breaking all physical laws, including causality and local energy conservation. In the protocol, the ground-state entanglement plays a crucial role. In this paper, we show analytically for a general class of spin-chain systems that the entanglement entropy is lower bounded by a positive quadratic function of the teleported energy between the regions of a QET protocol. This supports a general conjecture that ground-state entanglement is an evident physical resource for energy transportation in the context of QET. The result may also deepen our understanding of the energy density fluctuation in condensed-matter systems from a perspective of quantum information theory.

  14. Photonic Bound State in the Continuum for Strong Light-matter Interaction

    CERN Document Server

    Zou, Chang-Ling; Sun, Fang-Wen; Xiong, Xiao; Zou, Xu-Bo; Han, Zheng-Fu; Guo, Guang-Can

    2013-01-01

    The photonic bound state in the continuum (BIC) is discovered in a hybrid photonic circuit with low refractive index waveguide on a high refractive index thin membrane, where the optical dissipation is forbidden because of the destructive interference of different leakage channels. Based on the photonic BIC, the low mode area in a hybrid waveguide and high quality factor in a microresonator can be applied to enhance the light-matter interaction. Taking the fabrication-friendly polymer structure on diamond membrane as an example, those excellent optical performances can exist in a wide range of structure parameters with large fabrication tolerance and induce the strong coupling between photon and nitrogen-vacancy center in the diamond for scalable quantum information processors and networks. Such a fabrication-friendly structure with photonic BIC is also very promising in laser, nonlinear optical and quantum optical applications.

  15. Three-body bound states in atomic mixtures with resonant p-wave interaction

    CERN Document Server

    Efremov, Maxim A; Ivanov, Misha Yu; Schleich, Wolfgang P

    2013-01-01

    We employ the Born-Oppenheimer approximation to find the effective potential in a three-body system consisting of a light particle and two heavy ones when the heavy-light short-range interaction potential has a resonance corresponding to a non-zero orbital angular momentum. In the case of an exact resonance in the p-wave scattering amplitude, the effective potential is attractive and long-range, namely it decreases as the third power of the inter-atomic distance. Moreover, we show that the range and power of the potential, as well as the number of bound states are determined by the mass ratio of the particles and the parameters of the heavy-light short-range potential.

  16. The three-nucleon bound state with realistic soft- and hard-core potentials

    International Nuclear Information System (INIS)

    The wave function of the three-nucleon bound state is decomposed in the LS coupling scheme and the radial amplitudes of all the channels considered are expanded on a set of correlated basis functions. Two different types of correlated expansions are investigated, namely the pair (PHH) and the Jastrow (CHH) correlated hyperspherical-harmonic expansions. The correlation factor includes only one pair-correlation function per channel in the PHH case, whilst it is a product of three pair-correlation functions per channel in the CHH case. The optimal dependence on the hyperradius is determined by means of a variational technique. For the Argonne AV14 potential the results given by the PHH expansion are in very close agreement with those of Kameyana et al. The CHH expansion allows for treating hard-core interactions too, and the results obtained for the Hamada-Johnston potential noticeably improve those obtained with other methods. (orig.)

  17. Detecting the Exchange Phase of Majorana Bound States in a Corbino Geometry Topological Josephson Junction.

    Science.gov (United States)

    Park, Sunghun; Recher, Patrik

    2015-12-11

    A phase from an adiabatic exchange of Majorana bound states (MBS) reveals their exotic anyonic nature. For detecting this exchange phase, we propose an experimental setup consisting of a Corbino geometry Josephson junction on the surface of a topological insulator, in which two MBS at zero energy can be created and rotated. We find that if a metallic tip is weakly coupled to a point on the junction, the time-averaged differential conductance of the tip-Majorana coupling shows peaks at the tip voltages eV=±(α-2πl)ℏ/T_{J}, where α=π/2 is the exchange phase of the two circulating MBS, T_{J} is the half rotation time of MBS, and l an integer. This result constitutes a clear experimental signature of Majorana fermion exchange. PMID:26705644

  18. Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States

    CERN Document Server

    Hadizadeh, M R

    2010-01-01

    The first step toward the application of an effective non partial wave (PW) numerical approach to few-body atomic bound states has been taken. The two-body transition amplitude which appears in the kernel of three-dimensional Faddeev-Yakubovsky integral equations is calculated as function of two-body Jacobi momentum vectors, i.e. as a function of the magnitude of initial and final momentum vectors and the angle between them. For numerical calculation the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used. The angular and momentum dependence of the fully off-shell transition amplitude is studied at negative energies. It has been numerically shown that, similar to the nuclear case, the transition amplitude exhibits a characteristic angular behavior in the vicinity of 4He dimer pole.

  19. Impurity-bound states and Green's function zeros as local signatures of topology

    Science.gov (United States)

    Slager, Robert-Jan; Rademaker, Louk; Zaanen, Jan; Balents, Leon

    2015-08-01

    We show that the local in-gap Green's function of a band insulator G0(ɛ ,k∥,r⊥=0 ) , with r⊥ the position perpendicular to a codimension-1 or codimension-2 impurity, reveals the topological nature of the phase. For a topological insulator, the eigenvalues of this Green's function attain zeros in the gap, whereas for a trivial insulator the eigenvalues remain nonzero. This topological classification is related to the existence of in-gap bound states along codimension-1 and codimension-2 impurities. Whereas codimension-1 impurities can be viewed as soft edges, the result for codimension-2 impurities is nontrivial and allows for a direct experimental measurement of the topological nature of two-dimensional insulators.

  20. Bound state calculations using separable expansion of the two-body t-matrix

    International Nuclear Information System (INIS)

    It is shown that a separable expansion of local potentials (i.e., square well and Maltfliet-Tjon) using a method introduced by Adhikari and Sloan gives an efficient, exact numerically, method of solving three-body bound state. Contrary to the momentum-space basis functions in the work of Adhikari and Sloan, Y. Koike develops basis functions in configuration space since many two-nucleon potentials are given in that space. Legendre and Laguerre polynomials have been used respectively as base functions in this work. Following Koike's approach, the authors' three-body calculations, with the above potentials, are stable to four significant figures. Such convergence is obtained with only five terms in the expansion

  1. Model Study of Three-Body Forces in the Three-Body Bound State

    CERN Document Server

    Liu, H; Glöckle, W; Elster, Ch.

    2003-01-01

    The Faddeev equations for the three-body bound state with two- and three-body forces are solved directly as three-dimensional integral equation. The numerical feasibility and stability of the algorithm, which does not employ partial wave decomposition is demonstrated. The three-body binding energy and the full wave function are calculated with Malfliet-Tjon-type two-body potentials and scalar Fujita-Miyazawa type three-body forces. The influence of the strength and range of the three-body force on the wave function, single particle momentum distributions and the two-body correlation functions are studied in detail. The extreme case of pure three-body forces is investigated as well.

  2. Three-boson bound states in finite volume with EFT

    Directory of Open Access Journals (Sweden)

    Hammer H.-W.

    2010-04-01

    Full Text Available The universal properties of a three-boson system with large scattering length are well understood within the framework of Effective Field Theory. They include a geometric spectrum of shallow three-body bound states called “Efimov states” and log-periodic dependence of scattering observables on the scattering length. We investigate the modification of this spectrum in a finite cubic box using a partial wave expansion. The dependence of the binding energies on the box size is calculated for systems with positive and negative two-body scattering length. We compare the full results to results obtained using an expansion around the infinite volume binding energy. The renormalization of the Effective Field Theory in the finite volume is verified explicitly.

  3. Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States

    Directory of Open Access Journals (Sweden)

    Hadizadeh M.R.

    2010-04-01

    Full Text Available The first step toward the application of an effective non partial wave (PW numerical approach to few-body atomic bound states has been taken. The two-body transition amplitude which appears in the kernel of three-dimensional Faddeev-Yakubovsky integral equations is calculated as function of two-body Jacobi momentum vectors, i.e. as a function of the magnitude of initial and final momentum vectors and the angle between them. For numerical calculation the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used. The angular and momentum dependence of the fully off-shell transition amplitude is studied at negative energies. It has been numerically shown that, similar to the nuclear case, the transition amplitude exhibits a characteristic angular behavior in the vicinity of 4He dimer pole.

  4. Radiative decays of excited ΛQ baryons in the bound state picture

    International Nuclear Information System (INIS)

    It is shown that, in the bound state picture, the Λc(2593)→Λcγ and Λc(2625)→Λcγ decays are severely suppressed. On the other hand, for their bottom counterparts, which are predicted to have masses of 5900 and 5926 MeV, respectively, they may have significant radiative branching ratios. The Λb(5926)→Λbγ mode possibly dominates over the strong decay mode, while the Λb(5900) resonance lies below the strong decay threshold and can only decay radiatively. The isospin allowed ΛQ**→ΣQγ mode is expected to be small. copyright 1996 The American Physical Society

  5. Hyperon-nucleon bound states and electroproduction of strangeness on light nuclei.

    Energy Technology Data Exchange (ETDEWEB)

    Dohrmann, F.; Abbott, D.; Ahmidouch, A.; Ambrozewicz, P.; Armstrong, C. S.; Arrington, J.; Bailey, K.; Cummings, W. J.; Gao, H.; Garrow, K.; Geesaman, D. F.; Hafidi, K.; Hansen, J. O.; Jackson, H. E.; Mueller, B.; O' Neill, T. G.; Potterveld, D.; Reimer, P. E.; Reinhold, J.; Zeidman, B.

    2002-06-25

    The A(e,e{prime}K{sup +})Y X reaction has been investigated in Hall C at Jefferson Lab. Data were taken for Q{sup 2} {approx} 0.35 and 0.5 GeV{sup 2} at a beam energy of 3.245 GeV for {sup 1}H, {sup 2}H, {sup 3}He and {sup 4}He, C and Al targets. The missing mass spectra are fitted with Monte Carlo simulations including {Lambda}, {Sigma}{sup 0}, {Sigma}{sup -} hyperon production. Models for quasifree production are compared to the data, excess yields close to threshold are attributed to FSI. Evidence for {Lambda}-hypernuclear bound states is seen for {sup 3,4}He targets.

  6. Numerical methods for spin-dependent transport calculations and spin bound states analysis in Rashba waveguides

    CERN Document Server

    Xie, Hang; Sha, Wei E I

    2015-01-01

    Numerical methods are developed in the quantum transport calculations for electron in the waveguides with spin-orbital (Rashba) interaction. The methods are based on a hybrid mode-matching scheme in which the wavefunctions are expressed as the superposition of eigenmodes in the lead regions and in the device region the wavefunction is expressed on the discrete basis. Two versions are presented for the lead without and with the Rashba interaction. In the latter case the eigenmodes are obtained from a quadratic eigenproblem calculation. These methods are suitable for the systems with variable geometries or arbitrary potential profiles. The computation can be effectively accelerated by the sparse matrix technique. We also investigate the Fano-Rashba bound states in the Rashba waveguides by some nonlinear eigenstate calculation. This calculation is based on a mode-matching method and self-consistent results are obtained in our calculations.

  7. Ultraheavy Yukawa-bound states of fourth-generation at Large Hadron Collider

    Indian Academy of Sciences (India)

    Ts Enkhbat

    2012-10-01

    A study of bound states of the fourth-generation quarks in the range of 500–700 GeV is presented, where the binding energies are expected to be mainly of Yukawa origin, with QCD subdominant. Near degeneracy of their masses exhibits a new `isospin'. The production of a colour- octet, isosinglet vector meson via $q\\bar{q} → g$ is the most interesting. Its leading decay modes are $_{8}^{±} W^{\\mp}$, $_{8}^{0} Z^{0}$, and constituent quark decay, with $q\\bar{q}$ and $t\\bar{t'}$ and $b\\bar{b'}$ subdominant. The colour octet, isovector pseudoscalar 8 meson decays via constituent quark decay, or to $W g$. This work calls for more detailed study of fourth-generation phenomena at LHC.

  8. A search for {phi} meson nucleus bound state using antiproton annihilation on nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Ohnishi, H., E-mail: h-ohnishi@riken.jp [RIKEN, RIKEN Nishina Center (Japan); Buehler, P.; Cargnelli, M. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Curceanu, C.; Guaraldo, C. [Laboratori Nazionali di Frascati dellf INFN (Italy); Hartmann, O. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Hicks, K. [Ohio University, Department of Physics and Astronomy (United States); Iwasaki, M. [RIKEN, RIKEN Nishina Center (Japan); Ishiwatari, T. [Stefan-Meyer-Institut fNur subatomare Physik (Austria); Kienle, P. [Technische Universiat Munchen (Germany); Marton, J. [Stefan-Meyer-Institut fuer subatomare Physik (Austria); Muto, R.; Naruki, M. [KEK (High Energy Accelerator Research Organization) (Japan); Niiyama, M. [Kyoto University, Department of Physics (Japan); Noumi, H. [Osaka University, Research Center for Nuclear Physics (Japan); Okada, S.; Vidal, A. Romero [Laboratori Nazionali di Frascati dellf INFN (Italy); Sakaguchi, A. [Osaka University, Department of Physics (Japan); Sakuma, F. [RIKEN, RIKEN Nishina Center (Japan); Sawada, S. [KEK (High Energy Accelerator Research Organization) (Japan); and others

    2012-12-15

    The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the {phi} meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the {phi} meson mass shift in nuclei will be by trying to produce only slowly moving {phi} mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the {phi} meson in the nucleus can be translated as the existence of an attractive force between {phi} meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a {phi}-nucleus bound state, where the {phi} meson is 'trapped' in the nucleus. The purpose of the experiment is to search for a {phi}-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (p-bar, {phi}) spectroscopy together with K{sup + }{Lambda} tagging, using the primary reaction channel p-bar p {yields} {phi} {phi}. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

  9. A search for ϕ meson nucleus bound state using antiproton annihilation on nucleus

    Science.gov (United States)

    Ohnishi, H.; Bühler, P.; Cargnelli, M.; Curceanu, C.; Guaraldo, C.; Hartmann, O.; Hicks, K.; Iwasaki, M.; Ishiwatari, T.; Kienle, P.; Marton, J.; Muto, R.; Naruki, M.; Niiyama, M.; Noumi, H.; Okada, S.; Vidal, A. Romero; Sakaguchi, A.; Sakuma, F.; Sawada, S.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Tsukada, K.; Doce, O. Vazquez; Widmann, E.; Yokkaichi, S.; Zmeskal, J.

    The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the ϕ meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the ϕ meson mass shift in nuclei will be by trying to produce only slowly moving ϕ mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the ϕ meson in the nucleus can be translated as the existence of an attractive force between ϕ meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a ϕ-nucleus bound state, where the ϕ meson is "trapped" in the nucleus. The purpose of the experiment is to search for a ϕ-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (bar{p}, φ) spectroscopy together with K + Λ tagging, using the primary reaction channel bar{p} p rightarrow φ φ. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

  10. Quantum phase transition triggering magnetic bound states in the continuum in graphene

    Science.gov (United States)

    Guessi, L. H.; Marques, Y.; Machado, R. S.; Kristinsson, K.; Ricco, L. S.; Shelykh, I. A.; Figueira, M. S.; de Souza, M.; Seridonio, A. C.

    2015-12-01

    Graphene hosting a pair of collinear adatoms in the phantom atom configuration has density of states vanishing in the vicinity of the Dirac point which can be described in terms of the pseudogap scaling as cube of the energy, Δ ∝|ɛ| 3 , which leads to the appearance of spin-degenerate bound states in the continuum (BICs) [Phys. Rev. B 92, 045409 (2015), 10.1103/PhysRevB.92.045409]. In the case when adatoms are locally coupled to a single carbon atom the pseudogap scales linearly with energy, which prevents the formation of BICs. Here, we explore the effects of nonlocal coupling characterized by the Fano factor of interference q0, tunable by changing the slope of the Dirac cones in the graphene band structure. We demonstrate that three distinct regimes can be identified: (i) for q0qc 2 the cubic scaling of the pseudogap with energy Δ ∝|ɛ| 3 characteristic to the phantom atom configuration is restored and the phase with nonmagnetic BICs is recovered. The phase with magnetic BICs can be described in terms of an effective intrinsic exchange field of ferromagnetic nature between the adatoms mediated by graphene monolayer. We thus propose a new type of QPT resulting from the competition between two ground states, respectively characterized by spin-degenerate and magnetic BICs.

  11. Majorana bound state of a Bogoliubov-de Gennes-Dirac Hamiltonian in arbitrary dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Imura, Ken-Ichiro, E-mail: imura@hiroshima-u.ac.jp [Department of Quantum Matter, AdSM, Hiroshima University, 739-8530 (Japan); Fukui, Takahiro; Fujiwara, Takanori [Department of Physics, Ibaraki University, Mito 310-8512 (Japan)

    2012-01-11

    We study a Majorana zero-energy state bound to a hedgehog-like point defect in a topological superconductor described by a Bogoliubov-de Gennes (BdG)-Dirac type effective Hamiltonian. We first give an explicit wave function of a Majorana state by solving the BdG equation directly, from which an analytical index can be obtained. Next, by calculating the corresponding topological index, we show a precise equivalence between both indices to confirm the index theorem. Finally, we apply this observation to reexamine the role of another topological invariant, i.e., the Chern number associated with the Berry curvature proposed in the study of protected zero modes along the lines of topological classification of insulators and superconductors. We show that the Chern number is equivalent to the topological index, implying that it indeed reflects the number of zero-energy states. Our theoretical model belongs to the BDI class from the viewpoint of symmetry, whereas the spatial dimension d of the system is left arbitrary throughout the paper.

  12. Analytical bounds on SET charge sensitivity for qubit readout in a solid-state quantum computer

    International Nuclear Information System (INIS)

    Full text: Quantum Computing promises processing powers orders of magnitude beyond what is possible in conventional silicon-based computers. It harnesses the laws of quantum mechanics directly, exploiting the in built potential of a wave function for massively parallel information processing. Highly ordered and scaleable arrays of single donor atoms (quantum bits, or qubits), embedded in Si, are especially promising; they are a very natural fit to the existing, highly sophisticated, Si industry. The success of Si-based quantum computing depends on precisely initializing the quantum state of each qubit, and on precise reading out its final form. In the Kane architecture the qubit states are read out by detecting the spatial distribution of the donor's electron cloud using a sensitive electrometer. The single-electron transistor (SET) is an attractive candidate readout device for this, since the capacitive, or charging, energy of a SET's metallic central island is exquisitely sensitive to its electronic environment. Use of SETs as high-performance electrometers is therefore a key technology for data transfer in a solid-state quantum computer. We present an efficient analytical method to obtain bounds on the charge sensitivity of a single electron transistor (SET). Our classic Green-function analysis provides reliable estimates of SET sensitivity optimizing the design of the readout hardware. Typical calculations, and their physical meaning, are discussed. We compare them with the measured SET-response data

  13. Lowest Q2 Measurement of the gamma*p-> Delta Reaction: Probing the Pionic Contribution

    Energy Technology Data Exchange (ETDEWEB)

    Stave, Sean

    2006-06-30

    The first excited state of the proton, the Delat, can be reached through a magnetic dipole spin flip of one of the quarks (M1) or through electric and Coulomb quadrupole terms (E2 and C2) which indicate a deviation from spherical symmetry. The quark models using the color hyperfine interaction underestimate the size of the quadrupole terms by more than an order of magnitude. Models using the pion cloud do a much better job of describing the data. This is expected due to the spontaneous breaking of chiral symmetry which leads to a cloud of virtual p wave pions which introduce the non-spherical amplitudes. The data presented in this work fill gaps in the low Q², long distance region where the pion cloud is expected to dominate and to produce significant Q2 variation. The p(e¯, ép)π° reaction was measured in the Δ region at Q² = 0.060 (GeV/c)², the lowest Q² to date for pion electroproduction, utilizing out-of-plane magnetic spectrometers at the Mainz Microtron in Germany. This work reports results for the dominant transition magnetic dipole amplitude and the quadrupole to dipole ratios obtained from fitting the new data with models using a three parameter, resonant multipole fit: M³/²1+ = (40.33 +- 0.63stat+syst +-model)(10-³/mπ+), E2/M1=Re(E³/²1+M³/²1+) = (-2.28+- 0.29stat+syst +- 0.20model)%, and C2/M1 =Re(S³/²1+/M³/²1+) poles disagree with predictions of the quark models but are in reasonable agreement with a chiral extrapolation of lattice QCD, chiral effective field theory and dynamical model results confirming the dominance and general Q² variation of the long range pionic contribution. While there is qualitative agreement with the models, there is no quantitative agreement thus indicating the need for further improvement of the models.

  14. Thermodynamic properties of highly frustrated quantum spin ladders: Influence of many-particle bound states

    Science.gov (United States)

    Honecker, A.; Wessel, S.; Kerkdyk, R.; Pruschke, T.; Mila, F.; Normand, B.

    2016-02-01

    Quantum antiferromagnets have proven to be some of the cleanest realizations available for theoretical, numerical, and experimental studies of quantum fluctuation effects. At finite temperatures, however, the additional effects of thermal fluctuations in the restricted phase space of a low-dimensional system have received much less attention, particularly the situation in frustrated quantum magnets, where the excitations may be complex collective (bound or even fractionalized) modes. We investigate this problem by studying the thermodynamic properties of the frustrated two-leg S =1/2 spin ladder, with particular emphasis on the fully frustrated case. We present numerical results for the magnetic specific heat and susceptibility, obtained from exact diagonalization and quantum Monte Carlo studies, which we show can be rendered free of the sign problem even in a strongly frustrated system and which allow us to reach unprecedented sizes of L =200 ladder rungs. We find that frustration effects cause an unconventional evolution of the thermodynamic response across the full parameter regime of the model. However, close to the first-order transition they cause a highly anomalous reduction in temperature scales with no concomitant changes in the gap; the specific heat shows a very narrow peak at very low energies and the susceptibility rises abruptly at extremely low temperatures. Unusually, the two quantities have different gaps over an extended region of the parameter space. We demonstrate that these results reflect the presence of large numbers of multiparticle bound-state excitations, whose energies fall below the one-triplon gap in the transition region.

  15. Probing Majorana bound states via counting statistics of a single electron transistor

    Science.gov (United States)

    Li, Zeng-Zhao; Lam, Chi-Hang; You, J. Q.

    2015-06-01

    We propose an approach for probing Majorana bound states (MBSs) in a nanowire via counting statistics of a nearby charge detector in the form of a single-electron transistor (SET). We consider the impacts on the counting statistics by both the local coupling between the detector and an adjacent MBS at one end of a nanowire and the nonlocal coupling to the MBS at the other end. We show that the Fano factor and the skewness of the SET current are minimized for a symmetric SET configuration in the absence of the MBSs or when coupled to a fermionic state. However, the minimum points of operation are shifted appreciably in the presence of the MBSs to asymmetric SET configurations with a higher tunnel rate at the drain than at the source. This feature persists even when varying the nonlocal coupling and the pairing energy between the two MBSs. We expect that these MBS-induced shifts can be measured experimentally with available technologies and can serve as important signatures of the MBSs.

  16. Rovibrational bound states of SO2 isotopologues. II: Total angular momentum J = 11-20

    Science.gov (United States)

    Kumar, Praveen; Poirier, Bill

    2015-11-01

    In a two-part series, the rovibrational bound states of SO2 are investigated in comprehensive detail, for all four stable sulfur isotopes 32-34,36S. All low-lying rovibrational energy levels-both permutation-symmetry-allowed and not allowed-are computed, for all values of total angular momentum in the range J = 0-20. The calculations have carried out using the ScalIT suite of parallel codes. The present study (Paper II) examines the J = 11-20 rovibrational levels, providing symmetry and rovibrational labels for every computed state, relying on a new lambda-doublet splitting technique to make completely unambiguous assignments. Isotope shifts are analyzed, as is the validity of "J-shifting" as a predictor of rotational fine structure. Among other ramifications, this work will facilitate understanding of mass-independent fractionation of sulfur isotopes (S-MIF) observed in the Archean rock record-particularly as this may have arisen from self shielding. S-MIF, in turn is highly relevant in the broader context of understanding the "oxygen revolution".

  17. Electron-electron bound states in Maxwell-Chern-Simons-Proca QED{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Belich, H.; Helayel-Neto, J.A. [Grupo de Fisica Teorica Jose Leite Lopes, Petropolis, RJ (Brazil)]|[Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas]. E-mail: belich@cbpf.br; helayel@gft.ucp.br; Del Cima, O.M. [Grupo de Fisica Teorica Jose Leite Lopes, Petropolis, RJ (Brazil)]. E-mail: delcima@gft.ucp.br; Ferreira, M.M. Jr. [Grupo de Fisica Teorica Jose Leite Lopes, Petropolis, RJ (Brazil)]|[Maranhao Univ., Sao Luis, MA (Brazil). Dept. de Fisica]. E-mail: manojr@cbpf.br

    2002-10-01

    We start from a parity-breaking MCS QED{sub 3} model with spontaneous breaking of the gauge symmetry as a framework for evaluation of the electron-electron interaction potential and for attainment of numerical values for the e{sup -}e{sup -} - bound state. Three expressions (V{sub eff{down_arrow}}{sub {down_arrow}}, V{sub eff{down_arrow}}{sub {up_arrow}}, V{sub eff{down_arrow}}{sub {down_arrow}}) are obtained according to the polarization state of the scattered electrons. In an energy scale compatible with condensed matter electronic excitations, these potentials become degenerated. The resulting potential is implemented in the Schroedinger equation and the variational method is applied to carry out the electronic binding energy. The resulting binding energies in the scale of 10-100 meV and a correlation length in the scale of 10 - 30 Angstrom are possible indications that the MCS-QED{sub 3} model adopted may be suitable to address an eventual case of e{sup -}e{sup -} pairing in the presence of parity-symmetry breakdown. The data analyzed here suggest an energy scale of 10-100 meV to fix the breaking of the U(1)-symmetry. (author)

  18. Magneto-Josephson effects and Majorana bound states in quantum wires

    International Nuclear Information System (INIS)

    A prominent signature of Majorana bound states is the exotic Josephson effects they produce, the classic example being a fractional Josephson current with 4π periodicity in the phase difference across the junction. Recent work established that topological insulator edges support a novel ‘magneto-Josephson effect’, whereby a dissipationless current exhibits 4π-periodic dependence also on the relative orientation of the Zeeman fields in the two banks of the junction. Here, we explore the magneto-Josephson effect in junctions based on spin–orbit-coupled quantum wires. In contrast to the topological insulator case, the periodicities of the magneto-Josephson effect no longer follow from an exact superconductor–magnetism duality of the Hamiltonian. We employ numerical calculations as well as analytical arguments to identify the domain configurations that display exotic Josephson physics for quantum-wire junctions, and elucidate the characteristic differences with the corresponding setups for topological insulators edges. To provide guidance to experiments, we also estimate the magnitude of the magneto-Josephson effects in realistic parameter regimes, and compare the Majorana-related contribution to the coexisting 2π-periodic effects emerging from non-Majorana states. (paper)

  19. Fano effect and Andreev bound states in a hybrid superconductor–ferromagnetic nanostructure

    International Nuclear Information System (INIS)

    In this work, it is considered a hybrid nanostructure composed by a quantum dot coupled to two ferromagnetic leads and a superconductor lead. It is shown that the zero-bias transmittance for the co-tunneling between the ferromagnetic leads presents Fano anti-resonances due to the destructive interference between the two spin channels mixing by the relative orientation of the magnetizations in the leads. When the superconductor is coupled to the system, electron–hole correlations between different spin states lead to a resonance in the place of the dip appearing in the transmittance. Such an effect is accompanied by two Fano anti-resonances explained by a “leakage” of conduction channels from the co-tunneling to the Andreev transport. In the non-equilibrium regime, correlations within the quantum dot introduce a dependence of the resonance condition on the finite bias applied to the ferromagnetic leads. However, it is still possible to observe signatures of the same interference effect in the electrical current. - Highlights: • We have studied an hybrid nanostructure composed by quantum dot coupled to a superconductor and two ferromagnets. • The interplay between spin polarization and Andreev bound states leads to a Fano-like effect. • The Fano-like effect manifests as a resonance in the transmittance for the transport between the ferromagnets

  20. Fano effect and Andreev bound states in a hybrid superconductor–ferromagnetic nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, E.C., E-mail: ezcostta@gmail.com [Departamento de Física, Universidade Tecnológica Federal do Paraná – UTFPR, 84016210, Ponta Grossa, PR (Brazil); Orellana, P.A. [Departamento de Física, Universidad Técnica Federico Santa Maria, Av. Vicuña Mackenna 3939, Santiago (Chile); Cestari, R.C. [Departamento de Física e Química, Universidade Estadual Paulista – UNESP, 15385-000, Ilha Solteira, SP (Brazil); Figueira, M.S. [Instituto de Física, Universidade Federal Fluminense, 24210-340, Niterói, RJ (Brazil); Cabrera, G.G. [Instituto de Física ‘Gleb Wataghin’, Universidade Estadual de Campinas – UNICAMP, Campinas 13083-859, SP (Brazil)

    2015-10-16

    In this work, it is considered a hybrid nanostructure composed by a quantum dot coupled to two ferromagnetic leads and a superconductor lead. It is shown that the zero-bias transmittance for the co-tunneling between the ferromagnetic leads presents Fano anti-resonances due to the destructive interference between the two spin channels mixing by the relative orientation of the magnetizations in the leads. When the superconductor is coupled to the system, electron–hole correlations between different spin states lead to a resonance in the place of the dip appearing in the transmittance. Such an effect is accompanied by two Fano anti-resonances explained by a “leakage” of conduction channels from the co-tunneling to the Andreev transport. In the non-equilibrium regime, correlations within the quantum dot introduce a dependence of the resonance condition on the finite bias applied to the ferromagnetic leads. However, it is still possible to observe signatures of the same interference effect in the electrical current. - Highlights: • We have studied an hybrid nanostructure composed by quantum dot coupled to a superconductor and two ferromagnets. • The interplay between spin polarization and Andreev bound states leads to a Fano-like effect. • The Fano-like effect manifests as a resonance in the transmittance for the transport between the ferromagnets.

  1. On Possible S-Wave Bound States for an N-(N) System Within a Constituent Quark Model

    Institute of Scientific and Technical Information of China (English)

    CHANG Chao-Hsi; PANG Hou-Rong

    2005-01-01

    We try to apply a constituent quark model (a variety chiral constituent quark model) and the resonating group approach for the multi-quark problems to compute the effective potential between the NN- in S-wave (the quarks in the nucleons N and N-, and the two nucleons relatively as well, are in S wave) so as to see the possibility if there may be a tight bound state of six quarks as indicated by a strong enhancement at threshold of pp- in J/ψ and B decays. The effective potential which we obtain in terms of the model and approach shows if the experimental enhancement is really caused by a tight S-wave bound state of six quarks, then the quantum number of the bound state is very likely to be I = 1, JPC= 0-+.

  2. Generation of bound states of pulses in a soliton laser with complex relaxation of a saturable absorber

    Energy Technology Data Exchange (ETDEWEB)

    Zolotovskii, I O; Korobko, D A; Okhotnikov, O G [Ulyanovsk State University, Ulyanovsk (Russian Federation); Gumenyuk, R V [Optoelectronics Research Center, Tampere University of Technology, Tampere (Finland)

    2015-01-31

    A numerical model of a soliton fibre laser with a semiconductor saturable absorber mirror (SESAM), characterised by the complex dynamics of absorption relaxation, is considered. It is shown that stationary bound states of pulses can be formed in this laser as a result of their interaction via the dispersion-wave field. The stability of stationary bound states of several pulses is analysed. It is shown that an increase in the number of pulses in a stationary bound state leads eventually to its decay and formation of a random bunch. It is found that the bunch stability is caused by the manifestation of nonlinear self-phase modulation, which attracts pulses to the bunch centre. The simulation results are in qualitative agreement with experimental data. (nonlinear optical phenomena)

  3. Threshold for formation of atom-photon bound states in a coherent photonic band-gap reservoir

    Science.gov (United States)

    Wu, Yunan; Wang, Jing; Zhang, Hanzhuang

    2016-05-01

    We study the threshold for the formation of atom-photon bound (APB) states from a two-level atom embedded in a coherent photonic band-gap (PBG) reservoir. It is shown that the embedded position of the atom plays an important role in the threshold. By varying the atomic embedded position, a part of formation range of APB states can be moved from inside to outside the band gap. The direct link between the steady-state entanglement and APB states is also investigated. We show that the values of entanglement between reservoir modes reflect the amount of bounded energy caused by APB states. The feasible experimental systems for verifying the above phenomena are discussed. Our results provide a clear clue on how to form and control APB states in PBG materials.

  4. Feshbach resonances and weakly bound molecular states of boson-boson and boson-fermion NaK pairs

    OpenAIRE

    Viel, Alexandra; Simoni, Andrea

    2016-01-01

    We study theoretically magnetically induced Feshbach resonances and near-threshold bound states in isotopic NaK pairs. Our calculations accurately reproduce Feshbach spectroscopy data on Na$^{40}$K and explain the origin of the observed multiplets in the p-wave [Phys. Rev. A 85, 051602(R) (2012)]. We apply the model to predict scattering and bound state threshold properties of the boson-boson Na$^{39}$K and Na$^{41}$K systems. We find that the Na$^{39}$K isotopic pair presents broad magnetic ...

  5. Bound state energy of a Coulomb impurity in gapped bilayer graphene: "Hydrogen atom with a Mexican hat"

    OpenAIRE

    Skinner, Brian; Shklovskii, B. I.; Voloshin, M. B.

    2013-01-01

    Application of a perpendicular electric field induces a band gap in bilayer graphene, and it also creates a "Mexican hat" structure in the dispersion relation. This structure has unusual implications for the hydrogen-like bound state of an electron to a Coulomb impurity. We calculate the ground state energy of this hydrogen-like state as a function of the applied interlayer voltage and the effective fine structure constant. Unlike in the normal hydrogen atom, the resulting wavefunction has ma...

  6. Search for the 4He-eta bound state in dd->(4He-eta)_{bound}->3He n pi0 and dd->(4He-eta)_{bound}->3He p pi- reactions with the WASA-at-COSY facility

    CERN Document Server

    Skurzok, M; Moskal, P

    2014-01-01

    In November 2010, the search for the 4He-{\\eta} bound state was per formed with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta - mesic nuclei is searched for in the measured excitation functions for the two reaction channels: dd ->3He n pi0 and dd ->3He p pi- near the eta production threshold. This report includes the description of the experimental method and the status of the data analysis.

  7. ABC Effect in Double-Pionic Fusion – a New Resonance?

    Directory of Open Access Journals (Sweden)

    Skorodko T.

    2012-12-01

    Full Text Available ABC effect, an intriguing low-mass enhancement in the ππ invariant mass spectrum — known since more than 50 years from inclusive measurements of double-pionic fusion reactions — is reexamined. To this end exclusive and kinematically complete high-statistics experiments of the fusion reactions to d, 3He and 4He have been carried out with WASA at COSY. These measurements cover the full energy region, where the ABC effect has been observed previously. They also complement the systematic measurements of nucleon-nucleon induced two-pion production. An isospin decomposition of all three basic double-pionic fusion reactions leading to the deuteron uniquely shows that solely the isoscalar reaction part exhibits the ABC effect tightly correlated with a narrow resonance structure in the total cross section. The peak energy of the resonance structure is about 90 MeV below the nominal ΔΔ threshold of 2 mΔ and its width of only 70 MeV is much less than the 2 ГΔ expected from the conventional t-channel ΔΔ process. Based on angular distributions the quantum numbers I(JP = 0(3+ have been assigned. In the double-pionic fusion reaction dd→4Heπ0π0 again the ABC effect is observed to be correlated with the appearance of a resonance-like structure in the total cross section at the same excess energy. From this we conclude that this resonance structure obviously is strong enough to survive even in nuclei.

  8. Calculations of K{sup -} nuclear quasi-bound states based on chiral meson-baryon amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Gazda, Daniel [Nuclear Physics Institute, 250 68 Rez (Czech Republic); Mares, Jiri, E-mail: mares@ujf.cas.cz [Nuclear Physics Institute, 250 68 Rez (Czech Republic)

    2012-05-01

    In-medium K{sup Macron}N scattering amplitudes developed within a new chirally motivated coupled-channel model due to Cieply and Smejkal that fits the recent SIDDHARTA kaonic hydrogen 1s level shift and width are used to construct K{sup -} nuclear potentials for calculations of K{sup -} nuclear quasi-bound states. The strong energy and density dependence of scattering amplitudes at and near threshold leads to K{sup -} potential depths -ReV{sub K} Almost-Equal-To 80-120 MeV. Self-consistent calculations of all K{sup -} nuclear quasi-bound states, including excited states, are reported. Model dependence, polarization effects, the role of p-wave interactions, and two-nucleon K{sup -}NN{yields}YN absorption modes are discussed. The K{sup -} absorption widths {Gamma}{sub K} are comparable or even larger than the corresponding binding energies B{sub K} for allK{sup -} nuclear quasi-bound states, exceeding considerably the level spacing. This discourages search for K{sup -} nuclear quasi-bound states in any but the lightest nuclear systems.

  9. The g-factor of the electron bound in {sup 28}Si{sup 13+}. The most stringent test of bound-state quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, Sven

    2012-09-06

    This thesis describes the ultra-precise determination of the g-factor of the electron bound to hydrogenlike {sup 28}Si{sup 13+}. The experiment is based on the simultaneous determination of the cyclotron- and Larmor frequency of a single ion, which is stored in a triple Penning-trap setup. The continuous Stern-Gerlach effect is used to couple the spin of the bound electron to the motional frequencies of the ion via a magnetic bottle, which allows the non-destructive determination of the spin state. To this end, a highly sensitive, cryogenic detection system was developed, which allowed the direct, non-destructive detection of the eigenfrequencies with the required precision. The development of a novel, phase sensitive detection technique finally allowed the determination of the g-factor with a relative accuracy of 4 . 10{sup -11}, which was previously inconceivable. The comparison of the hereby determined value with the value predicted by quantumelectrodynamics (QED) allows the verification of the validity of this fundamental theory under the extreme conditions of the strong binding potential of a highly charged ion. The exact agreement of theory and experiment is an impressive demonstration of the exactness of QED. The experimental possibilities created in this work will allow in the near future not only further tests of theory, but also the determination of the mass of the electron with a precision that exceeds the current literature value by more than an order of magnitude.

  10. The g-factor of the electron bound in 28Si13+. The most stringent test of bound-state quantum electrodynamics

    International Nuclear Information System (INIS)

    This thesis describes the ultra-precise determination of the g-factor of the electron bound to hydrogenlike 28Si13+. The experiment is based on the simultaneous determination of the cyclotron- and Larmor frequency of a single ion, which is stored in a triple Penning-trap setup. The continuous Stern-Gerlach effect is used to couple the spin of the bound electron to the motional frequencies of the ion via a magnetic bottle, which allows the non-destructive determination of the spin state. To this end, a highly sensitive, cryogenic detection system was developed, which allowed the direct, non-destructive detection of the eigenfrequencies with the required precision. The development of a novel, phase sensitive detection technique finally allowed the determination of the g-factor with a relative accuracy of 4 . 10-11, which was previously inconceivable. The comparison of the hereby determined value with the value predicted by quantumelectrodynamics (QED) allows the verification of the validity of this fundamental theory under the extreme conditions of the strong binding potential of a highly charged ion. The exact agreement of theory and experiment is an impressive demonstration of the exactness of QED. The experimental possibilities created in this work will allow in the near future not only further tests of theory, but also the determination of the mass of the electron with a precision that exceeds the current literature value by more than an order of magnitude.

  11. Shot noise as a measure of the lifetime and energy splitting of Majorana bound states

    Science.gov (United States)

    Lü, Hai-Feng; Guo, Zhen; Ke, Sha-Sha; Guo, Yong; Zhang, Huai-Wu

    2015-04-01

    We propose a scheme to measure the lifetime and energy splitting of a pair of Majorana bound states at the ends of a superconducting nanowire by using the shot noise in a dynamical channel blockade system. A quantum dot is coupled to one end of the wire and connected with two electron reservoirs. It is found that a finite Majorana energy splitting tends to produce a super-Poissonian shot noise, while Majorana relaxation process relieves the dynamical channel blockade and suppresses the noise Fano factor. When the dot energy level locates in the middle of the gap of topological superconductor, the Fano factor is independent on Majorana lifetime and Majorana energy splitting is thus extracted. For a finite energy splitting, we could evaluate the Majorana relaxation rate from the suppression of Fano factor. Under a realistic condition, the expected resolution of Majorana energy splitting and its relaxation rate calculated from our model are about 1 μ eV and 0.01 - 1 μ eV , respectively.

  12. Shot noise as a measure of the lifetime and energy splitting of Majorana bound states

    International Nuclear Information System (INIS)

    We propose a scheme to measure the lifetime and energy splitting of a pair of Majorana bound states at the ends of a superconducting nanowire by using the shot noise in a dynamical channel blockade system. A quantum dot is coupled to one end of the wire and connected with two electron reservoirs. It is found that a finite Majorana energy splitting tends to produce a super-Poissonian shot noise, while Majorana relaxation process relieves the dynamical channel blockade and suppresses the noise Fano factor. When the dot energy level locates in the middle of the gap of topological superconductor, the Fano factor is independent on Majorana lifetime and Majorana energy splitting is thus extracted. For a finite energy splitting, we could evaluate the Majorana relaxation rate from the suppression of Fano factor. Under a realistic condition, the expected resolution of Majorana energy splitting and its relaxation rate calculated from our model are about 1μeV and 0.01−1μeV, respectively

  13. Shot noise as a measure of the lifetime and energy splitting of Majorana bound states

    Energy Technology Data Exchange (ETDEWEB)

    Lü, Hai-Feng; Guo, Zhen; Ke, Sha-Sha; Zhang, Huai-Wu [State Key Laboratory of Electronic Thin Films and Integrated Devices and School of Physical Electronics, University of Electronic Science and Technology of China, Chengdu 610054 (China); Guo, Yong [Department of Physics and State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084 (China)

    2015-04-28

    We propose a scheme to measure the lifetime and energy splitting of a pair of Majorana bound states at the ends of a superconducting nanowire by using the shot noise in a dynamical channel blockade system. A quantum dot is coupled to one end of the wire and connected with two electron reservoirs. It is found that a finite Majorana energy splitting tends to produce a super-Poissonian shot noise, while Majorana relaxation process relieves the dynamical channel blockade and suppresses the noise Fano factor. When the dot energy level locates in the middle of the gap of topological superconductor, the Fano factor is independent on Majorana lifetime and Majorana energy splitting is thus extracted. For a finite energy splitting, we could evaluate the Majorana relaxation rate from the suppression of Fano factor. Under a realistic condition, the expected resolution of Majorana energy splitting and its relaxation rate calculated from our model are about 1μeV and 0.01−1μeV, respectively.

  14. Pseudoscalar mesons with symmetric bound state vertex functions on the light front

    CERN Document Server

    Yabusaki, George H S; Paracha, M Ali; de Melo, J P B C; El-Bennich, Bruno

    2015-01-01

    We study the electromagnetic form factors, decay constants and charge radii of the pion and kaon within the framework of light-front field theory formalism where we use an ansatz for the quark-meson interaction bound-state function which is symmetric under exchange of quark and antiquark momentum. The above mentioned observables are evaluated for the $+$ component of the electromagnetic current, $J^+$, in the Breit frame. We also check the invariance of these observables in other frames, whereby both the valance and the non-valence contributions have to be taken into account, and study the sensitivity of the electromagnetic form factors and charge radius to the model's parameters; namely, the quark masses, $m_u=m_d$, $m_{\\bar s}$, and the regulator mass, $m_R$. It is found that after a fine tuning of the regulator mass, i.e. $m_R=0.6$ GeV, the model is suitable to fit the available experimental data within the theoretical uncertainties of both the pion and kaon.

  15. Renormalization group fixed point with a fourth generation: Higgs-induced bound states and condensates

    International Nuclear Information System (INIS)

    In the Standard Model with four generations, the two-loop renormalization group equations for the Higgs quartic and Yukawa couplings show a quasi fixed point structure which does not appear at the one-loop level. This quasi fixed point behavior indicates a possible restoration of scale symmetry above some physical cut-off scale ΛFP. We conjecture that there exists a true fixed point which is reached at a similar energy scale. If the masses of the fourth family are sufficiently large, this cut-off scale, ΛFP, is situated in the range of a few TeV to the order of 102 TeV, above which the Higgs quartic and Yukawa couplings become practically constant. We found that around ΛFP the strong Yukawa couplings make it possible for the fourth generation to form bound states, including composite extra Higgs doublets. In this scenario the fourth generation condensates are obtained without introducing Technicolor or other unknown interactions.

  16. Boosting QED and QCD bound states in the path integral formalism

    CERN Document Server

    Simonov, Yu A

    2014-01-01

    Wave functions and energy eigenvalues of the path integral Hamiltonian are studied in Lorentz frame moving with velocity $v$. The instantaneous interaction produced by the Wilson loop is shown to be reduced by an overall factor $\\sqrt{1-(\\frac{v}{c})^2}$. As a result one obtains the boosted energy eigenvalues in the Lorentz covariant form $E= \\sqrt{\\veP^2+M^2_0}$, where $M_0$ is the c.m. energy, and this form is tested for two free particles and for the Coulomb and linear interaction.Using Lorentz contracted wave functions of the bound states one obtains the scaled parton wave functions and valence quark distributions for large $P$. Matrix elements containing wave functions moving with different velocities strongly decrease with growing relative momentum, e.g. for the time-like formfactors one obtains $F_h(Q_0)\\sim (\\frac{M_h}{Q_0})^{2 n_h} $ with $n_h = 1$ and 2 for mesons and baryons, as in the "quark counting rule".

  17. Three-nucleon bound states and the Wigner-SU(4) limit

    CERN Document Server

    Vanasse, Jared

    2016-01-01

    We examine the extent to which the properties of three-nucleon bound states are well-reproduced in the limit that nuclear forces satisfy Wigner's SU(4) (spin-isospin) symmetry. To do this we compute the charge radii up to next-to-leading order (NLO) in an effective field theory (EFT) that is an expansion in powers of $R/a$, with $R$ the range of the nuclear force and $a$ the nucleon-nucleon ($N\\!N$) scattering lengths. In the Wigner-SU(4) limit, the triton and Helium-3 point charge radii are equal. At NLO in the range expansion both are $1.66$ fm. Adding the first-order corrections due to the breaking of Wigner symmetry in the $N\\!N$ scattering lengths gives a ${}^3\\mathrm{H}$ point charge radius of $1.58$ fm, which is remarkably close to the experimental number, $1.5978\\pm0.040$ fm. For the ${}^3\\mathrm{He}$ point charge radius we find $1.70$ fm, about 4% away from the experimental value of $1.77527\\pm0.0054$ fm. We also examine the Faddeev components that enter the tri-nucleon wave function and find that an...

  18. A spherically symmetric bound state of the coupled Maxwell-Dirac equations with self-interaction alone

    Science.gov (United States)

    Bradford, R. A. W.

    2015-10-01

    Stationary, static, spherically symmetric solutions of the Maxwell-Dirac system, treated as classical fields, have been found which are localised and normalisable. The solutions apply to any bound energy eigenvalue in the range 0 self-energy is negative. It is this which results in the states being bound (E self-sustaining bound state solution of the Maxwell-Dirac system which is localised, normalisable, and requires no arbitrarily added "external" features (i.e., it is a soliton). As far as the author is aware, this is the first time that such an exact solution with a positive energy eigenvalue has been reported. However, the solution is not unique since the energy eigenvalue is arbitrary within the range 0 < E < m. The stability of the solution has not been addressed.

  19. Experimental study of bound states in $^{12}$Be through low-energy $^{11}$Be($d,p$)-transfer reactions

    CERN Document Server

    Johansen, J G; Borge, M J G; Cubero, M; Diriken, J; Elsevier, J; Fraile, L M; Fynbo, H O U; Gaffney, L P; Gernhäuser, R; Jonson, B; Koldste, G T; Konki, J; Kröll, T; Krücken, R; Mücher, D; Nilsson, T; Nowak, K; Pakarinen, J; Pesudo, V; Raabe, R; Riisager, K; Seidlitz, M; Tengblad, O; Törnqvist, H; Voulot, D; Warr, N; Wenander, F; Wimmer, K; De Witte, H

    2013-01-01

    The bound states of $^{12}$Be have been studied through a $^{11}$Be$(d,p)^{12}$Be transfer reaction experiment in inverse kinematics. A 2.8 MeV/u beam of $^{11}$Be was produced using the REX-ISOLDE facility at CERN. The outgoing protons were detected with the T-REX silicon detector array. The MINIBALL germanium array was used to detect $\\gamma$-rays from the excited states in $^{12}$Be. The $\\gamma$-ray detection enabled a clear identification of the four known bound states in $^{12}$Be, and each of the states has been studied individually. Differential cross sections over a large angular range have been extracted. Spectroscopic factors for each of the states have been determined from DWBA calculations and have been compared to previous experimental and theoretical results.

  20. A phenomenological determination of the pion-nucleon scattering lengths from pionic hydrogen

    CERN Document Server

    Ericson, Torleif Eric Oskar; Wycech, S

    2005-01-01

    A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon scattering length, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge distribution, these corrections are derived up to terms of order (alpha)**2 log(alpha) in the limit of a short-range hadronic interaction. We infer a charged pion-proton scattering length of 0.0870(5) in units of inverse pion mass, which gives for the charged pion-proton-neutron coupling, through the GMO relation, a value of 14.04(17).

  1. a Phenomenological Determination of the Pion-Nucleon Scattering Lengths from Pionic Hydrogen

    Science.gov (United States)

    Ericson, T. E. O.; Loiseau, B.; Wycech, S.

    A model independent expression for the electromagnetic corrections to a phenomenological hadronic pion-nucleon (πN) scattering length ah, extracted from pionic hydrogen, is obtained. In a non-relativistic approach and using an extended charge distribution, these corrections are derived up to terms of order α2 log α in the limit of a short-range hadronic interaction. We infer ahπ ^-p=0.0870(5)m-1π which gives for the πNN coupling through the GMO relation g2π ^± pn/(4π )=14.04(17).

  2. Relativistic wave equations for two interacting particles and zero mass bound states

    International Nuclear Information System (INIS)

    We construct relativistic wave equations for two interacting particle systems involving spin-o bosons and/or spin-1/2 fermions. The method consists in quantizing the manifestly covariant formalism with constraints of classical relativistic hamiltonian mechanics. In this formalism the two-particle wave function satisfies two independent, but compatible, wave equations, which thus determine in a definite way its relative time evolution. We classify the interaction potentials according to their tensor structure, such as scalar, pseudoscalar, vector. We apply these results to the construction of confining systems with ground states having zero or small masses. For fermion-antifermion systems, we exhibit a general class of interactions, of the pseudoscalar type, with arbitrary confining potentials, which produce a zero mass pseudoscalar meson bound state. This feature is not altered by the presence of short range vector interactions. For fermion-boson systems, we exhibit a general class of interactions of the vector type, with arbitrary confining potentials, which preserve chiral symmetry except for the free mass terms, and produce an infinite number of light fermions with degenerate masses which are proportional to the free masses of the constituent particles. In the classification scheme of quantum numbers j, l, n these fermions have the quantum numbers j=l+1/2; l=o, 1, ...; n=o. For the massive particles the spectrum displays parity doublets. The introduction of short range vector interactions removes the mass degeneracies but leaves in general unchanged the qualitative feature of the existence of an infinite number of light fermions with increasing spins. We show that the introduction of some additional secondary interactions of the axial vector type, acting as an L-S coupling, might give masses to the high spin light fermions

  3. On the spin- 1/2 Aharonov–Bohm problem in conical space: Bound states, scattering and helicity nonconservation

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, F.M., E-mail: fmandrade@uepg.br [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900 Ponta Grossa-PR (Brazil); Silva, E.O., E-mail: edilbertoo@gmail.com [Departamento de Física, Universidade Federal do Maranhão, Campus Universitário do Bacanga, 65085-580 São Luís-MA (Brazil); Pereira, M., E-mail: marciano@uepg.br [Departamento de Matemática e Estatística, Universidade Estadual de Ponta Grossa, 84030-900 Ponta Grossa-PR (Brazil)

    2013-12-15

    In this work the bound state and scattering problems for a spin- 1/2 particle undergone to an Aharonov–Bohm potential in a conical space in the nonrelativistic limit are considered. The presence of a δ-function singularity, which comes from the Zeeman spin interaction with the magnetic flux tube, is addressed by the self-adjoint extension method. One of the advantages of the present approach is the determination of the self-adjoint extension parameter in terms of physics of the problem. Expressions for the energy bound states, phase-shift and S matrix are determined in terms of the self-adjoint extension parameter, which is explicitly determined in terms of the parameters of the problem. The relation between the bound state and zero modes and the failure of helicity conservation in the scattering problem and its relation with the gyromagnetic ratio g are discussed. Also, as an application, we consider the spin- 1/2 Aharonov–Bohm problem in conical space plus a two-dimensional isotropic harmonic oscillator. -- Highlights: •Planar dynamics of a spin- 1/2 neutral particle. •Bound state for Aharonov–Bohm systems. •Aharonov–Bohm scattering. •Helicity nonconservation. •Determination of the self-adjoint extension parameter.

  4. On the spin- 1/2 Aharonov–Bohm problem in conical space: Bound states, scattering and helicity nonconservation

    International Nuclear Information System (INIS)

    In this work the bound state and scattering problems for a spin- 1/2 particle undergone to an Aharonov–Bohm potential in a conical space in the nonrelativistic limit are considered. The presence of a δ-function singularity, which comes from the Zeeman spin interaction with the magnetic flux tube, is addressed by the self-adjoint extension method. One of the advantages of the present approach is the determination of the self-adjoint extension parameter in terms of physics of the problem. Expressions for the energy bound states, phase-shift and S matrix are determined in terms of the self-adjoint extension parameter, which is explicitly determined in terms of the parameters of the problem. The relation between the bound state and zero modes and the failure of helicity conservation in the scattering problem and its relation with the gyromagnetic ratio g are discussed. Also, as an application, we consider the spin- 1/2 Aharonov–Bohm problem in conical space plus a two-dimensional isotropic harmonic oscillator. -- Highlights: •Planar dynamics of a spin- 1/2 neutral particle. •Bound state for Aharonov–Bohm systems. •Aharonov–Bohm scattering. •Helicity nonconservation. •Determination of the self-adjoint extension parameter

  5. Theoretical study of photoproduction of an η'N bound state on a deuteron target with forward proton emission

    Science.gov (United States)

    Sekihara, Takayasu; Sakai, Shuntaro; Jido, Daisuke

    2016-08-01

    Possibilities of observing a signal of an η'n bound state are investigated by considering photoproductions of the η and η' mesons on a deuteron target with forward proton emission. For this purpose, we take the η'n interaction from the linear σ model with a coupling to η n , in which an s -wave η'n bound state can be dynamically generated, and we fix the γ p →η p and η'p scattering amplitudes so as to reproduce the experimental cross sections with forward proton emission. By using these γ p →η(')p and η(')n →η(')n amplitudes, we calculate cross sections of the γ d →η n p and η'n p reactions with forward proton emission in single and η(')-exchange double-scattering processes. As a result, we find that the signal of the η'n bound state can be seen below the η'n threshold in the η n invariant mass spectrum of the γ d →η n p reaction and is comparable with the contribution from the quasifree η' production above the η'n threshold. We also discuss the behavior of the signal of the η'n bound state in several experimental conditions and model parameters.

  6. Weakly bound states of two- and three-boson systems in the crossover from two to three dimensions

    DEFF Research Database (Denmark)

    Yamashita, Marcelo; Bellotti, Filipe Furlan; Frederico, Tobias;

    2015-01-01

    paper we study weakly bound states of non-relativistic two and three boson systems when passing continuously from a three (3D) to a two-dimensional (2D) regime within a 'squeezed dimension' model. We use periodic boundary conditions to derive a surprisingly simple form of the three-boson Schr...

  7. Bound States of the Klein-Gordon and Dirac equations for potential V0 tanh2(r/d)

    Institute of Scientific and Technical Information of China (English)

    Qiang Wen-Chao

    2004-01-01

    The exact bound state wavefunctions and energy equations of Klein-Gordon and Dirac equations are given with equal scalar and vector potential s(r) = v(r) = V(r)/2 = V0 tanh2(r/d). The relation between the energy equation and that of relativistic harmonic is discussed.

  8. Does the Higgs mechanism favour electron-electron bound states in Maxwell-Chern-Simons QED_3?

    OpenAIRE

    Belich, H.; Del Cima, O. M.; Ferreira Jr, M. M.; Helayel-Neto, J. A.

    2000-01-01

    The low-energy electron-electron scattering potential is derived and discussed for the Maxwell-Chern-Simons model coupled to QED_3 with spontaneous symmetry breaking. One shows that the Higgs mechanism might favour electron-electron bound states.

  9. International Workshop on Exotic hadronic atoms, deeply bound kaonic nuclear states and antihydrogen: present results, future challenges

    CERN Document Server

    Widmann, E; Curceanu, C; Trento 2006; Trento06

    2006-01-01

    These are the miniproceedings of the workshop "Exotic hadronic atoms, deeply bound kaonic nuclear states and antihydrogen: present results, future challenges," which was held at the European Centre for Theoretical Nuclear Physics and Related Studies (ECT*), Trento (Italy), June 19-24, 2006. The document includes a short presentation of the topics, the list of participants, and a short contribution from each speaker.

  10. Reprint of : Effect of a tunnel barrier on the scattering from a Majorana bound state in an Andreev billiard

    Science.gov (United States)

    Marciani, M.; Schomerus, H.; Beenakker, C. W. J.

    2016-08-01

    We calculate the joint distribution P(S , Q) of the scattering matrix S and time-delay matrix Q = - iℏS† dS / dE of a chaotic quantum dot coupled by point contacts to metal electrodes. While S and Q are statistically independent for ballistic coupling, they become correlated for tunnel coupling. We relate the ensemble averages of Q and S and thereby obtain the average density of states at the Fermi level. We apply this to a calculation of the effect of a tunnel barrier on the Majorana resonance in a topological superconductor. We find that the presence of a Majorana bound state is hidden in the density of states and in the thermal conductance if even a single scattering channel has unit tunnel probability. The electrical conductance remains sensitive to the appearance of a Majorana bound state, and we calculate the variation of the average conductance through a topological phase transition.

  11. Scattering coefficients and bound states for high-energy transparent $\\delta-\\delta^{\\prime}$ interactions

    CERN Document Server

    Pedrelli, Danilo C; Braga, Alessandra N; Alves, Danilo T

    2016-01-01

    We propose a model for energy-dependent $\\delta-\\delta^{\\prime}$ interactions which yields scattering coefficients exhibiting full transmission for high-energy incident particles, also computing the bound solutions in one-dimension nonrelativistic quantum mechanics.

  12. Approximate bound-state solutions of the dirac equation for the generalized Yukawa potential plus the generalized tensor interaction

    International Nuclear Information System (INIS)

    In this paper, we obtain the approximate analytical bound-state solutions of the Dirac particle with the generalized Yukawa potential within the framework of spin and pseudospin symmetries for the arbitrary κ state with a generalized tensor interaction. The generalized parametric Nikiforov-Uvarov method is used to obtain the energy eigenvalues and the corresponding wave functions in closed form. We also report some numerical results and present figures to show the effect of the tensor interaction.

  13. Approximate bound-state solutions of the dirac equation for the generalized Yukawa potential plus the generalized tensor interaction

    Energy Technology Data Exchange (ETDEWEB)

    Ikot, Akpan N. [University of Uyo, Uyo (Nigeria); Maghsoodi, Elham; Hassanabadi, Hassan [Islamic Azad University, Shahrood (Iran, Islamic Republic of); Obu, Joseph A. [University of Calabar, Calabar (Nigeria)

    2014-05-15

    In this paper, we obtain the approximate analytical bound-state solutions of the Dirac particle with the generalized Yukawa potential within the framework of spin and pseudospin symmetries for the arbitrary κ state with a generalized tensor interaction. The generalized parametric Nikiforov-Uvarov method is used to obtain the energy eigenvalues and the corresponding wave functions in closed form. We also report some numerical results and present figures to show the effect of the tensor interaction.

  14. Nonlinear bayesian state filtering with missing measurements and bounded noise and its application to vehicle position estimation

    Czech Academy of Sciences Publication Activity Database

    Pavelková, Lenka

    2011-01-01

    Roč. 47, č. 3 (2011), s. 370-384. ISSN 0023-5954 R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : non-linear state space model * bounded uncertainty * missing measurements * state filtering * vehicle position estimation Subject RIV: BC - Control System s Theory Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/AS/pavelkova-0360239.pdf

  15. Scattering and bound states of Dirac Equation in presence of cosmic string for Hulth\\'{e}n potential

    CERN Document Server

    Hosseinpour, Mansoureh; Silva, Edilberto O; Hassanabadi, Hassan

    2016-01-01

    We study the covariant Dirac equation in the space-time generated by a cosmic string in presence of vector and scalar potentials of electromagnetic field. We obtain the solution of the radial part of Dirac equation. We consider the scattering states under the Hulth\\'{e}n potential and obtain the phase shifts. From the poles of the scattering $S$-matrix the bound states energies are determined as well.

  16. Bound State Solutions of the Dirac Equation for the Eckart Potential with Coulomb-Like Yukawa-Like Tensor Interactions

    International Nuclear Information System (INIS)

    In this paper, we present the approximate bound state solutions of the Dirac equation within the framework of spin and pseudospin symmetries for Eckart potential for arbitrary κ—state using Nikiforov–Uvarov method. The tensor interactions of Coulomb-like and Yukawa-like form are considered and the effects of these tensors and the degeneracy removing role are discussed in detail. Numerical results and figures to show the effect of the tensor interactions are also reported. (author)

  17. Ab initio characterization of the Ne-I2 van der Waals complex: Intermolecular potentials and vibrational bound states

    OpenAIRE

    Delgado Tellez, Laura; Valdés, Álvaro; Prosmiti, Rita; Villarreal, Pablo; Delgado Barrio, Gerardo

    2011-01-01

    A theoretical study of the potential energy surface and bound states is performed for the ground state of the NeI2 van der Waals (vdW) complex. The three-dimensional interaction energies are obtained from ab initio coupled-cluster, coupled-cluster single double (triple)/complete basis set, calculations using large basis sets, of quadruple- through quintuple-zeta quality, in conjunction with relativistic effective core potentials for the heavy iodine atoms. For the analytical representation of...

  18. Quantum Transport through a Triple Quantum Dot System in the Presence of Majorana Bound States

    Science.gov (United States)

    Jiang, Zhao-Tan; Cao, Zhi-Yuan; Zhong, Cheng-Cheng

    2016-05-01

    We study the electron transport through a special quantum-dot (QD) structure composed of three QDs and two Majorana bound states (MBSs) using the nonequilibrium Green's function technique. This QD-MBS ring structure includes two channels with the two coupled MBSs being Channel 1 and one QD being Channel 2, and three types of transport processes such as the electron transmission (ET), the Andreev reflection (AR), and the crossed Andreev reflection (CAR). By comparing the ET, AR, and CAR processes through Channels 1 and 2, we make a systematic study on the transport properties of the QD-MBS ring. It is shown that there appear two kinds of characteristic transport patterns for Channels 1 and 2, as well as the interplay between the two patterns. Of particular interest is that there exists an AR-assisted ET process in Channel 2, which is different from that in Channel 1. Thus a clear “X” pattern due to the ET and AR processes appears in the ET, AR, and CAR transmission coefficients. Moreover, we study how Channel 2 affects the three transport processes when Channel 1 is tuned in the ET and CAR regimes. It is shown that the transport properties of the ET, AR and CAR processes can be adjusted by tuning the energy level of the QD embedded in Channel 2. We believe this research should be a helpful reference for understanding the transport properties in the QD-MBS coupled systems. Supported by National Natural Science Foundation of China under Grant No. 11274040, and by the Program for New Century Excellent Talents in University under Grant No. NCET-08-0044

  19. Structural characterization of two metastable ATP-bound states of P-glycoprotein.

    Directory of Open Access Journals (Sweden)

    Megan L O'Mara

    Full Text Available ATP Binding Cassette (ABC transporters couple the binding and hydrolysis of ATP to the transport of substrate molecules across the membrane. The mechanism by which ATP binding and/or hydrolysis drives the conformational changes associated with substrate transport has not yet been characterized fully. Here, changes in the conformation of the ABC export protein P-glycoprotein on ATP binding are examined in a series of molecular dynamics simulations. When one molecule of ATP is placed at the ATP binding site associated with each of the two nucleotide binding domains (NBDs, the membrane-embedded P-glycoprotein crystal structure adopts two distinct metastable conformations. In one, each ATP molecule interacts primarily with the Walker A motif of the corresponding NBD. In the other, the ATP molecules interacts with both Walker A motif of one NBD and the Signature motif of the opposite NBD inducing the partial dimerization of the NBDs. This interaction is more extensive in one of the two ATP binding site, leading to an asymmetric structure. The overall conformation of the transmembrane domains is not altered in either of these metastable states, indicating that the conformational changes associated with ATP binding observed in the simulations in the absence of substrate do not lead to the outward-facing conformation and thus would be insufficient in themselves to drive transport. Nevertheless, the metastable intermediate ATP-bound conformations observed are compatible with a wide range of experimental cross-linking data demonstrating the simulations do capture physiologically important conformations. Analysis of the interaction between ATP and its cofactor Mg(2+ with each NBD indicates that the coordination of ATP and Mg(2+ differs between the two NBDs. The role structural asymmetry may play in ATP binding and hydrolysis is discussed. Furthermore, we demonstrate that our results are not heavily influenced by the crystal structure chosen for initiation

  20. Tunneling spectroscopy of a single quantum dot coupled to a superconductor: From Kondo ridge to Andreev bound states

    Science.gov (United States)

    Pillet, J.-D.; Joyez, P.; Žitko, Rok; Goffman, M. F.

    2013-07-01

    We performed tunneling spectroscopy of a carbon nanotube quantum dot (QD) coupled to a metallic reservoir either in the normal or in the superconducting state. We explore how the Kondo resonance, observed when the QD's occupancy is odd and the reservoir is normal, evolves towards Andreev bound states (ABS) in the superconducting state. Within this regime, the ABS spectrum observed is consistent with a quantum phase transition from a singlet to a degenerate magnetic doublet ground state, in quantitative agreement with a single-level Anderson model with superconducting leads.