Property:NumProdWells | Open Energy Information
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Pfeifer, Holger
1 Complete Quantitative online Analysis of Methanol Electrooxidation Prod- ucts via Electron Impact for application in energy re- lated electrocatalysis is demonstrated using continuous methanol oxidation over
int. j. prod. res., 2001, vol. 39, no. 16, 35613600 A review of agile manufacturing systems
Nagi, Rakesh
(Sheridan 1993, Struebing 1995, Richards 1996, Nagel and Dove 1991). For many, `Lean manufacturing' and `Agile manufacturing' sound similar, but they are di erent. Lean manufacturing is a responseint. j. prod. res., 2001, vol. 39, no. 16, 3561±3600 A review of agile manufacturing systems LUIS M
Nesnas, Nasri
.1021/np100090e |J. Nat. Prod. XXXX, XXX, 000000 NOTE pubs.acs.org/jnp Epiafzelechin from the Root Bark
Scaling up ATLAS production system for the LHC Run 2 and beyond: project ProdSys2
Borodin, Mikhail; The ATLAS collaboration; García Navarro, José Enrique; Golubkov, Dmitry; Klimentov, Alexei; Maeno, Tadashi; Vaniachine, Alexandre
2015-01-01T23:59:59.000Z
The Big Data processing needs of the ATLAS experiment grow continuously, as more data and more use cases emerge. For Big Data processing the ATLAS experiment adopted the data transformation approach, where software applications transform the input data into outputs. In the ATLAS production system, each data transformation is represented by a task, a collection of many jobs, submitted by the ATLAS workload management system (PanDA) and executed on the Grid. Our experience shows that the rate of tasks submission grows exponentially over the years. To scale up the ATLAS production system for new challenges, we started the ProdSys2 project. PanDA has been upgraded with the Job Execution and Definition Interface (JEDI). Patterns in ATLAS data transformation workflows composed of many tasks, provided a scalable production system framework for template definitions of the many-tasks workflows. These workflows are being implemented in the Database Engine for Tasks (DEfT) that generates individual tasks for processing ...
Paired t testsPaired t tests Paired (dependent) t-testPaired (dependent) t test
Wolverton, Steve
Paired t testsPaired t tests #12;Paired (dependent) t-testPaired (dependent) t test · Compares test means from matched pairsCompares test means from matched pairs or two different samples from the same individualsindividuals e.g., pretest & post test scores for the same group of students Ho: d = 0 d is thedifference
Pairings on hyperelliptic curves
Balakrishnan, Jennifer; Chisholm, Sarah; Eisentraeger, Kirsten; Stange, Katherine; Teske, Edlyn
2009-01-01T23:59:59.000Z
We assemble and reorganize the recent work in the area of hyperelliptic pairings: We survey the research on constructing hyperelliptic curves suitable for pairing-based cryptography. We also showcase the hyperelliptic pairings proposed to date, and develop a unifying framework. We discuss the techniques used to optimize the pairing computation on hyperelliptic curves, and present many directions for further research.
Chasman, R.R. [Argonne National Lab., IL (United States). Physics Div.
1996-12-31T23:59:59.000Z
In this contribution, the author mentions some features of pairing forces that are unique to nuclei and cover some areas of major interest in nuclear structure research, that involve pairing. At the level of most nuclear structure studies, nuclei are treated as consisting of two kinds of fermions (protons and neutrons) in a valence space with rather few levels. These features give rise to unique aspects of pairing forces in nuclei: (1) n-p pairing in T = 0 as well as the usual T = 1 pairing that is characteristic of like fermions; (2) a need to correct pairing calculations for the (1/N) effects that can typically be neglected in superconducting solids. An issue of current concern is the nature of the pairing interaction: several recent studies suggest a need for a density dependent form of the pairing interaction. There is a good deal of feedback between the questions of accurate calculations of pairing interactions and the form and magnitude of the pairing interaction. Finally, the authors discuss some many-body wave functions that are a generalization of the BCS wave function form, and apply them to a calculation of energy level spacings in superdeformed rotational bands.
James Valles
2010-01-08T23:59:59.000Z
Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.
Gasoline and Diesel Fuel Update (EIA)
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Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]
Thousand Short Tons Cubic Feet Barrels Barrels State Fossil Fuels Renewable Energy Coal a Natural Gas b Crude Oil c Fuel Ethanol d Thousand Million Thousand U.S....
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Multiprocessor switch with selective pairing
Gara, Alan; Gschwind, Michael K; Salapura, Valentina
2014-03-11T23:59:59.000Z
System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus
Nomura, Kazumasa
2007-01-01T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of $K$-linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfies the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering ${V_i}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering ${V^*_i}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Some Special Fourier Transform Pairs
Vickers, James
Some Special Fourier Transform Pairs 24.3 Introduction ' & $ % Prerequisites Before starting to . . . #12;1. Parseval's Theorem Recall from Unit 2 on Fourier Series that for a periodic signal fT (t) with complex Fourier coefficients cn(n = 0, Â±1, Â±2, . . .) Parseval's Theorem holds: 1 T + T 2 - T 2 f2 T (t
Tridiagonal pairs of Krawtchouk type
Ito, Tatsuro
2007-01-01T23:59:59.000Z
Let $K$ denote an algebraically closed field with characteristic 0 and let $V$ denote a vector space over $K$ with finite positive dimension. Let $A,A^*$ denote a tridiagonal pair on $V$ with diameter $d$. We say that $A,A^*$ has Krawtchouk type whenever the sequence $\\lbrace d-2i\\rbrace_{i=0}^d$ is a standard ordering of the eigenvalues of $A$ and a standard ordering of the eigenvalues of $A^*$. Assume $A,A^*$ has Krawtchouk type. We show that there exists a nondegenerate symmetric bilinear form $$ on $V$ such that $= $ and $= $ for $u,v\\in V$. We show that the following tridiagonal pairs are isomorphic: (i) $A,A^*$; (ii) $-A,-A^*$; (iii) $A^*,A$; (iv) $-A^*,-A$. We give a number of related results and conjectures.
The ion pairs and superconducting bosons
V. N. Minasyan
2009-02-11T23:59:59.000Z
First, it is shown that the creation of the spinless ion pairs in the lattice, which are hold by the binding with neighbor ion pairs together regarded as covalent. These ion pairs are created by the repulsive potential interaction of two ions which is bound as linear oscillator. The repulsive S-wave scattering between ion pairs and electrons is transformed to the attractive effective interaction between electrons which leads to a creation of electron pairs by a binding energy depending on the condensate fraction of ion pairs $\\frac{N_0}{N}$. In this respect, the absence of ion pairs in the condensate destroys a binding energy of electron pairs and in turn so-called superconductimg phase. As new result presented theory is that the number of the superconducting bosons is not changed in the superconducting phase.
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well. Monitor wells with an "SC" suffix are completed in the Upper Sand aquifer of the Wind River Formation. Wells with a "DC" suffix are completed in the Main Sand aquifer, and...
Pairing Correlations in halo Nuclei
H. Sagawa; K. Hagino
2007-09-10T23:59:59.000Z
Paring correlations in weakly bound halo nuclei $^{6}$He and $^{11}$Li are studied by using a three-body model with a density-dependent contact interaction. We investigate the spatial structure of two-neutron wave function in a Borromean nucleus $^{11}$Li.The behavior of the neutron pair at different densities is simulated by calculating the two-neutron wave function at several distances between the core nucleus $^9$Li and the center of mass of the two neutrons. With this representation, a strong concentration of the neutron pair on the nuclear surface is quantitatively established for neutron-rich nuclei. Dipole excitations in $^{6}$He and $^{11}$Li are also studied within the same three-body model and compared with experimental data. The small open angles between the two neutrons from the core are extracted empirically by the B(E1) sum rule together with the rms mass radii, indicating the strong di-neutron correlation in the halo nuclei.
Pairing Effects in Nuclear Fusion Reaction
Shuichiro Ebata; Takashi Nakatsukasa
2013-09-29T23:59:59.000Z
We simulate a heavy-ion collision using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) treating pairing correlation in the three-dimensional coordinate space. We apply the Cb-TDHFB to 22O+22O collision with a contact-type pairing energy functional, and compare results of Cb-TDHFB and TDHF to investigate the effects of pairing correlations in nuclear fusion. Our results seem to indicate that pairing effects do not increase the fusion cross section in this system.
Modularity of Termination Using Dependency Pairs ?
ÃbrahÃ¡m, Erika
Modularity of Termination Using Dependency Pairs ? Thomas Arts 1 and JÂ¨urgen Giesl 2 1 Computer@informatik.tuÂdarmstadt.de Abstract. The framework of dependency pairs allows automated terÂ mination and innermost termination proofs of this framework in order to prove termination in a modular way. Our modÂ ularity results significantly increase
Pairing, pseudogap and Fermi arcs in cuprates
Kaminski, Adam [Iowa State Univ., Ames, IA (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Kondo, Takeshi [The Univ. of Tokyo, Chiba (Japan); Takeuchi, Tsunehiro [Nagoya Univ., Nagoya (Japan)
2014-10-31T23:59:59.000Z
We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below T_{pair} ~ 150K and significantly above T_{c}, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below T_{pair}, and its interplay with strong scattering creates “artificial” Fermi arcs for T_{c} < T < T_{pair}. However, above T_{pair}, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.
Modularity of Termination Using Dependency Pairs ?
ÃbrahÃ¡m, Erika
Modularity of Termination Using Dependency Pairs ? Thomas Arts 1 and JÂ¨urgen Giesl 2 1 Computer@informatik.thÂdarmstadt.de Abstract. The framework of dependency pairs allows automated terÂ mination and innermost termination proofs of this framework in order to prove termination in a modular way. Our modÂ ularity results significantly increase
Exact solution of the nuclear pairing problem
Alexander Volya; B. Alex Brown; Vladimir Zelevinsky
2001-02-20T23:59:59.000Z
In many applications to finite Fermi-systems, the pairing problem has to be treated exactly. We suggest a numerical method of exact solution based on SU(2) quasispin algebras and demonstrate its simplicity and practicality. We show that the treatment of binding energies with the use of the exact pairing and uncorrelated monopole contribution of other residual interactions can serve as an effective alternative to the full shell-model diagonalization in spherical nuclei. A self-consistent combination of the exactly treated pairing and Hartree-Fock method is discussed. Results for Sn isotopes indicate a good agreement with experimental data.
Pair creation in heavy ion channeling
Nikolay A. Belov; Zoltán Harman
2014-11-20T23:59:59.000Z
Heavy ions channeling through crystals with multi-GeV kinetic energies can create electron-positron pairs. In the framework of the ion, the energy of virtual photons arising from the periodic crystal potential may exceed the threshold $2mc^2$. The repeated periodic collisions with the crystal ions yield high pair production rates. When the virtual photon frequency matches a nuclear transition in the ion, the production rate can be resonantly increased. In this two-step excitation-pair conversion scheme, the excitation rates are coherently enhanced, and they scale approximately quadratically with the number of crystal sites along the channel.
90 Seconds of Discovery: Frustrated Lewis Pairs
Kathmann, Shawn; Schenter, Greg; Autrey, Tom
2014-02-14T23:59:59.000Z
Hydrogen activating catalysts play an important role in producing valuable chemicals, such as biofuels and ammonia. As a part of efforts to develop the next generation of these catalysts, PNNL researchers have found potential in Frustrated Lewis Pairs.
90 Seconds of Discovery: Frustrated Lewis Pairs
Kathmann, Shawn; Schenter, Greg; Autrey, Tom
2014-07-21T23:59:59.000Z
Hydrogen activating catalysts play an important role in producing valuable chemicals, such as biofuels and ammonia. As a part of efforts to develop the next generation of these catalysts, PNNL researchers have found potential in Frustrated Lewis Pairs.
Schwinger pair creation in multilayer graphene
M. A. Zubkov
2012-04-05T23:59:59.000Z
The low energy effective field model for the multilayer graphene (at ABC stacking) in external Electric field is considered. The Schwinger pair creation rate and the vacuum persistence probability are calculated using the semi - classical approach.
NONSMOOTH LYAPUNOV PAIRS FOR INFINITE-DIMENSIONAL ...
2010-05-27T23:59:59.000Z
Lyapunov pairs have been considered in [14,15,17,25,30] among many ... The criteria in [14,15,24,25] are given by means of the semigroup generated by.
Leonard pairs from 24 points of view
Paul Terwilliger
2004-06-28T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V\\to V$ and $A^*:V\\to V$ that satisfy both conditions below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal and the matrix representing $A^*$ is irreducible tridiagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A^*$ is diagonal and the matrix representing $A$ is irreducible tridiagonal. We call such a pair a {\\it Leonard pair} on $V$. Referring to the above Leonard pair, we investigate 24 bases for $V$ on which the action of $A$ and $A^*$ takes an attractive form. With respect to each of these bases, the matrices representing $A$ and $A^*$ are either diagonal, lower bidiagonal, upper bidiagonal, or tridiagonal.
Accelerated Cellulose Depolymerization Catalyzed by Paired Metal...
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Cellulose Depolymerization Catalyzed by Paired Metal Chlorides in Ionic Liquid Solvent."Applied Catalysis. A, General 391(1-2):436-442. doi:10.1016j.apcata.2010.09.021 Authors:...
Dense QCD: Overhauser or BCS pairing?
Park, Byung-Yoon [School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea (Korea, Republic of) [School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea (Korea, Republic of); Department of Physics, Chungnam National University, Taejon 305-764, Korea (Korea, Republic of); Rho, Mannque [School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea (Korea, Republic of) [School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea (Korea, Republic of); Service de Physique Theorique, CE Saclay, 91191 Gif-sur-Yvette, (France); Wirzba, Andreas [Department of Physics and Astronomy, SUNY-Stony Brook, New York 11794 (United States) [Department of Physics and Astronomy, SUNY-Stony Brook, New York 11794 (United States); FZ Juelich, Institut fuer Kernphysik (Theorie), D-52425 Juelich, (Germany); Zahed, Ismail [School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea (Korea, Republic of) [School of Physics, Korea Institute for Advanced Study, Seoul 130-012, Korea (Korea, Republic of); Department of Physics and Astronomy, SUNY-Stony Brook, New York 11794 (United States)
2000-08-01T23:59:59.000Z
We discuss the Overhauser effect (particle-hole pairing) versus the BCS effect (particle-particle or hole-hole pairing) in QCD at large quark density. In weak coupling and to leading logarithm accuracy, the pairing energies can be estimated exactly. For a small number of colors, the BCS effect overtakes the Overhauser effect, while for a large number of colors the opposite takes place, in agreement with a recent renormalization group argument. In strong coupling with large pairing energies, the Overhauser effect may be dominant for any number of colors, suggesting that QCD may crystallize into an insulator at a few times nuclear matter density, a situation reminiscent of dense Skyrmions. The Overhauser effect is dominant in QCD in 1+1 dimensions, although susceptible to quantum effects. It is sensitive to temperature in all dimensions. (c) 2000 The American Physical Society.
Pair programming improves student retention, confidence, and program quality
McDowell, C; Werner, L; Bullock, H E; Fernald, J
2006-01-01T23:59:59.000Z
Werner, L.L. Building Pair Programming Knowledge through aJ. The Impact of Pair Programming on Student Performance andto Know About Pair Programming I Learned in Kindergarten.
Nuclear elements in Banach Jordan pairs Ottmar Loos
Nuclear elements in Banach Jordan pairs Ottmar Loos Abstract We introduce nuclear elements in Banach Jordan pairs, generalizing the nuclear elements Jordan pairs and show that the trace form Trintroduced in [3] may be extended to the nuclear
Pair instability supernovae of very massive population III stars...
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Pair instability supernovae of very massive population III stars Citation Details In-Document Search Title: Pair instability supernovae of very massive population III stars...
Two-dimensional simulations of pulsational pair-instability supernovae...
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Two-dimensional simulations of pulsational pair-instability supernovae Citation Details In-Document Search Title: Two-dimensional simulations of pulsational pair-instability...
Pairing, pseudogap and Fermi arcs in cuprates
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kaminski, Adam; Gu, Genda; Kondo, Takeshi; Takeuchi, Tsunehiro
2014-10-31T23:59:59.000Z
We use Angle Resolved Photoemission Spectroscopy (ARPES) to study the relationship between the pseudogap, pairing and Fermi arcs in cuprates. High quality data measured over a wide range of dopings reveals a consistent picture of Fermiology and pairing in these materials. The pseudogap is due to an ordered state that competes with superconductivity rather than preformed pairs. Pairing does occur below Tpair ~ 150K and significantly above Tc, but well below T* and the doping dependence of this temperature scale is distinct from that of the pseudogap. The d-wave gap is present below Tpair, and its interplay with strong scatteringmore »creates “artificial” Fermi arcs for Tc pair. However, above Tpair, the pseudogap exists only at the antipodal region. This leads to presence of real, gapless Fermi arcs close to the node. The length of these arcs remains constant up to T*, where the full Fermi surface is recovered. We demonstrate that these findings resolve a number of seemingly contradictory scenarios.« less
Pairing and specific heat in hot nuclei
Danilo Gambacurta; Denis Lacroix; Nicu Sandulescu
2013-07-15T23:59:59.000Z
The thermodynamics of pairing phase-transition in nuclei is studied in the canonical ensemble and treating the pairing correlations in a finite-temperature variation after projection BCS approach (FT-VAP). Due to the restoration of particle number conservation, the pairing gap and the specific heat calculated in the FT-VAP approach vary smoothly with the temperature, indicating a gradual transition from the superfluid to the normal phase, as expected in finite systems. We have checked that the predictions of the FT-VAP approach are very accurate when compared to the results obtained by an exact diagonalization of the pairing Hamiltonian. The influence of pairing correlations on specific heat is analysed for the isotopes $^{161,162}$Dy and $^{171,172}$Yb. It is shown that the FT-VAP approach, applied with a level density provided by mean field calculations and supplemented, at high energies, by the level density of the back-shifted Fermi gas model, can approximate reasonably well the main properties of specific heat extracted from experimental data. However, the detailed shape of the calculated specific heat is rather sensitive to the assumption made for the mean field.
Isominkowskian theory of Cooper Pairs in superconductors
Animalu, A.O.E. [Univ. of Nigeria, Nsukka (Nigeria)
1993-10-01T23:59:59.000Z
Via the use of Santilli`s isominkowskian space, the author presents a relativistic extension of the author`s recent treatment of the Cooper Pair in superconductivity based on the Lie-isotopic lifting of quantum mechanics known as Hadronic Mechanics. The isominkowskian treatment reduces the solution of the eiganvalue problem for the quasiparticle energy spectrum to a geometric problem of specifying the metric of the isominkowskian space inside the pair in various models of ordinary high T{sub c} superconductors. The use of an intriguing realization of the metric due to Dirac reduces the dimensionality of the interior space to two yielding a spin mutation from 1/2 to zero inside a Cooper pair in two-band BCS and Hubbard models. 12 refs.
An inverse problem for Schwinger pair production
Hebenstreit, Florian
2015-01-01T23:59:59.000Z
The production of electron-positron pairs in time-dependent electric fields (Schwinger mechanism) depends non-linearly on the applied field profile. Accordingly, the resulting momentum spectrum is extremely sensitive to small variations of the field parameters. Owing to this non-linear dependence it is so far unpredictable how to choose a field configuration such that a predetermined momentum distribution is generated. We show that quantum kinetic theory along with optimal control theory can be used to approximately solve this inverse problem for Schwinger pair production. We exemplify this by studying the superposition of a small number of harmonic components resulting in predetermined signatures in the asymptotic momentum spectrum. In the long run, our results could facilitate the observation of this yet unobserved pair production mechanism in quantum electrodynamics by providing suggestions for tailored field configurations.
Thermodynamics of pairing transition in hot nuclei
Lang Liu; Zhen-Hua Zhang; Peng-Wei Zhao
2014-12-16T23:59:59.000Z
The pairing correlations in hot nuclei $^{162}$Dy are investigated in terms of the thermodynamical properties by covariant density functional theory. The heat capacities $C_V$ are evaluated in the canonical ensemble theory and the paring correlations are treated by a shell-model-like approach, in which the particle number is conserved exactly. A S-shaped heat capacity curve, which agrees qualitatively with the experimental data, has been obtained and analyzed in details. It is found that the one-pair-broken states play crucial roles in the appearance of the S shape of the heat capacity curve. Moreover, due to the effect of the particle-number conservation, the pairing gap varies smoothly with the temperature, which indicates a gradual transition from the superfluid to the normal state.
Thermodynamics of pairing in mesoscopic systems
Tony Sumaryada; Alexander Volya
2007-06-12T23:59:59.000Z
Using numerical and analytical methods implemented for different models we conduct a systematic study of thermodynamic properties of pairing correlation in mesoscopic nuclear systems. Various quantities are calculated and analyzed using the exact solution of pairing. An in-depth comparison of canonical, grand canonical, and microcanonical ensemble is conducted. The nature of the pairing phase transition in a small system is of a particular interest. We discuss the onset of discontinuity in the thermodynamic variables, fluctuations, and evolution of zeros of the canonical and grand canonical partition functions in the complex plane. The behavior of the Invariant Correlational Entropy is also studied in the transitional region of interest. The change in the character of the phase transition due to the presence of magnetic field is discussed along with studies of superconducting thermodynamics.
Yoshiaki Tsujimoto; Yukihiro Sugiura; Makoto Ando; Daisuke Katsuse; Rikizo Ikuta; Takashi Yamamoto; Masato Koashi; Nobuyuki Imoto
2015-03-10T23:59:59.000Z
We experimentally demonstrated entanglement extraction scheme by using photons at the telecommunication band for optical-fiber-based quantum communications. We generated two pairs of non-degenerate polarization entangled photons at 780~nm and 1551~nm by spontaneous parametric down-conversion and distributed the two photons at 1551~nm through a collective phase damping channel which gives the same amount of random phase shift on the two photons. Through local operation and classical communication, we extracted an entangled photon pair from two phase-disturbed photon pairs. An observed fidelity of the extracted photon pair to a maximally entangled photon pair was 0.73 $\\pm$ 0.07 which clearly shows the recovery of entanglement.
Photon pair generation in birefringent optical fibers
Brian J. Smith; P. Mahou; Offir Cohen; J. S. Lundeen; I. A. Walmsley
2010-02-09T23:59:59.000Z
We study both experimentally and theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in standard birefringent optical fibers. The ability to produce a range of two-photon spectral states, from highly correlated (entangled) to completely factorable, by means of cross-polarized birefringent phase matching, is explored. A simple model is developed to predict the spectral state of the photon pair which shows how this can be adjusted by choosing the appropriate pump bandwidth, fiber length and birefringence. Spontaneous Raman scattering is modeled to determine the tradeoff between SFWM and background Raman noise, and the predicted results are shown to agree with experimental data.
Subthreshold pair production in short laser pulses
T. Nousch; D. Seipt; B. Kampfer; A. I. Titov
2012-06-01T23:59:59.000Z
The $e^+e^-$ pair production by a probe photon traversing a linearly polarized laser pulse is treated as generalized nonlinear Breit-Wheeler process. For short laser pulses with very few oscillations of the electromagnetic field we find below the perturbative weak-field threshold $\\sqrt{s} = 2m$ a similar enhancement of the pair production rate as for circular polarization. The strong subthreshold enhancement is traced back to the finite bandwidth of the laser pulse. A folding model is developed which accounts for the interplay of the frequency spectrum and the intensity distribution in the course of the pulse.
Quantum Key Distribution with Qubit Pairs
Mohd Asad Siddiqui; Tabish Qureshi
2014-07-17T23:59:59.000Z
We propose a new Quantum Key Distribution method in which Alice sends pairs of qubits to Bob, each in one of four possible states. Bob uses one qubit to generate a secure key and the other to generate an auxiliary key. For each pair he randomly decides which qubit to use for which key. The auxiliary key has to be added to Bob's secure key in order to match Alice's secure key. This scheme provides an additional layer of security over the standard BB84 protocol.
Single top and top pair production
Nikolaos Kidonakis
2012-12-12T23:59:59.000Z
I present results for single-top and top-pair production at the LHC and the Tevatron. Higher-order two-loop corrections are used to achieve NNLL resummation, which is then used to derive NNLO soft-gluon corrections. Results are presented for total cross sections, top transverse momentum distributions, and top rapidity distributions. All results are in excellent agreement with data from the LHC and the Tevatron. I also clarify the differences between various methods in top-pair production and their relation to exact NNLO results.
Improved Modular Termination Proofs Using Dependency Pairs
Middeldorp, Aart
Improved Modular Termination Proofs Using Dependency Pairs RenÂ´e Thiemann, JÂ¨urgen Giesl, Peter) termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality constraints that have to be satisfied by well-founded orders. However, proving innermost termination is considerably easier than
Improved Modular Termination Proofs Using Dependency Pairs
ÃbrahÃ¡m, Erika
Improved Modular Termination Proofs Using Dependency Pairs Renâ??e Thiemann, JË?urgen Giesl, Peter) termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality constraints that have to be satisfied by wellÂfounded orders. However, proving innermost termination is considerably easier than
Efficient Pairings and ECC for Embedded Systems
International Association for Cryptologic Research (IACR)
Efficient Pairings and ECC for Embedded Systems Thomas Unterluggauer and Erich Wenger Graz-based cryptography brought forth a wide range of protocols interesting for future embedded applications. One curve and its reusability for other elliptic-curve based crypto systems offer a great solution for every
Improved Modular Termination Proofs Using Dependency Pairs #
ÃbrahÃ¡m, Erika
Improved Modular Termination Proofs Using Dependency Pairs # Renâ??e Thiemann, JË?urgen Giesl, Peter) termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality constraints that have to be satisfied by wellÂfounded orders. However, proving innermost termination is considerably easier than
Abstract polymer models with general pair interactions
Aldo Procacci
2008-11-26T23:59:59.000Z
A convergence criterion of cluster expansion is presented in the case of an abstract polymer system with general pair interactions (i.e. not necessarily hard core or repulsive). As a concrete example, the low temperature disordered phase of the BEG model with infinite range interactions, decaying polynomially as $1/r^{d+\\lambda}$ with $\\lambda>0$, is studied.
Resonant tunneling of fluctuation Cooper pairs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Galda, Alexey; Mel'nikov, A. S.; Vinokur, V. M.
2015-02-09T23:59:59.000Z
Superconducting fluctuations have proved to be an irreplaceable source of information about microscopic and macroscopic material parameters that could be inferred from the experiment. According to common wisdom, the effect of thermodynamic fluctuations in the vicinity of the superconducting transition temperature, Tc, is to round off all of the sharp corners and discontinuities, which otherwise would have been expected to occur at Tc. Here we report the current spikes due to radiation-induced resonant tunneling of fluctuation Cooper pairs between two superconductors which grow even sharper and more pronounced upon approach to Tc. This striking effect offers an unprecedented tool formore »direct measurements of fluctuation Cooper pair lifetime, which is key to our understanding of the fluctuation regime, most notably to nature of the pseudogap state in high-temperature superconductors. Our finding marks a radical departure from the conventional view of superconducting fluctuations as a blurring and rounding phenomenon.« less
On the pairing effects in triaxial nuclei
Oudih, M. R. [Laboratoire de Physique Théorique, Faculté de Physique,USTHB BP 32, El Alia, 16111 Bab Ezzouar, Algiers (Algeria); Fellah, M.; Allal, N. H. [Centre de Recherche Nucléaire d'Alger, 2 Bd. Frantz Fanon, BP. 399 Alger-Gare, Algiers, Algeria and Laboratoire de Physique Théorique, Faculté de Physique,USTHB BP 32, El Alia, 16111 Bab Ezzouar, Algiers (Algeria)
2014-03-05T23:59:59.000Z
Triaxial deformation effect on the pairing correlations is studied in the framework of the Skyrme Hartree-Fock-Bogoliubov theory. Quantities such as binding energy, gap parameter and particle-number fluctuation are considered in neutron-rich Mo isotopes. The results are compared with those of axially symmetric calculation and with available experimental data. The role played by the particle-number projection is outlined.
Vortex Bubble Formation in Pair Plasmas
Berezhiani, V I; Mahajan, S M; Aleksi?, B N
2013-01-01T23:59:59.000Z
It is shown that delocalized vortex solitons in relativistic pair plasmas with small temperature asymmetries can be unstable for intermediate intensities of the background electromagnetic field. Instability leads to the generation of ever-expanding cavitating bubbles in which the electromagnetic fields are zero. The existence of such electromagnetic bubbles is demonstrated by qualitative arguments based on a hydrodynamic analogy, and by numerical solutions of the appropriate Nonlinear Schr\\"odinger equation with a saturating nonlinearity.
Persistent Ion Pairing in Aqueous Hydrochloric Acid
Baer, Marcel D.; Fulton, John L.; Balasubramanian, Mahalingam; Schenter, Gregory K.; Mundy, Christopher J.
2014-07-03T23:59:59.000Z
For strong acids, like hydrochloric acid, the complete dissociation into an excess proton and conjugated base as well as the formation of independent solvated charged fragments is assumed. The existence of a chloride-Hyronium (Cl-H3O+) contact ion pairs even in moderate concentration hydrochloric acid (2.5 m) demonstrates that the counter ions do not behave merely as spectators. Through the use of modern extended X-ray absorption fine structure (EXAFS) measurements in conjunction with state-of-the-art density functional theory (DFT) simulations, we are able to obtain an unprecedented view into the molecular structure of medium to high concentrated electrolytes. Here we report that the Cl-H3O+ contact ion pair structure persists throughout the entire concentration range studied and that these structures differ significantly from moieties studied in micro-solvated hydrochloric acid clusters. Characterizing distinct populations of these ion pairs gives rise to a novel molecular level description of how to think about the activity of the proton that impacts our picture of the pH scale. Funding for CJM, GKS, and JLF was provided by DOE Office of Science, Office of Basic Energy Science, Division of Chemical Sciences, Geosciences, and Biosciences. Funding for MDB was provided throught the Laboratory Directed Research and Development program at Pacific Northwest National Laboratory. MB was funded through Argonne National Laboratory.
Efficient Implementation of the T Pairing Yosuke Katoh1
International Association for Cryptologic Research (IACR)
of characteristics 3. We report the performance results of implementa- tions on NVIDIA GTX 285, GTX 480, Tesla C1060, and Tesla C2050 graphics cards. We have implemented T pairing in three different ways, namely, one pairing
E cient Implementation of the Pairing on Mobilephones using BREW
International Association for Cryptologic Research (IACR)
E cient Implementation of the Pairing on Mobilephones using BREW Motoi Yoshitomiy, Tsuyoshi Takagiy processors on BREW achieves under 100 milliseconds using the supersingular curve over F397 . It has become e encryption, using the pairing on BREW mobilephones. Keywords: Pairing Based Cryptosystem, Mobilephone, BREW
Method for sequencing DNA base pairs
Sessler, Andrew M. (Oakland, CA); Dawson, John (Pacific Palisades, CA)
1993-01-01T23:59:59.000Z
The base pairs of a DNA structure are sequenced with the use of a scanning tunneling microscope (STM). The DNA structure is scanned by the STM probe tip, and, as it is being scanned, the DNA structure is separately subjected to a sequence of infrared radiation from four different sources, each source being selected to preferentially excite one of the four different bases in the DNA structure. Each particular base being scanned is subjected to such sequence of infrared radiation from the four different sources as that particular base is being scanned. The DNA structure as a whole is separately imaged for each subjection thereof to radiation from one only of each source.
Paired Straight Hearth Furnace | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:DepartmentExecutive Secretariat, MA-70 ActingOverviewEnergy 0 - InSite This is a RequestPaired
Paired Straight Hearth Furnace | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasma | Department ofEnergy 9 LehmanDepartmentEnergyVerenium1of Page This final ruleForThe8015Paired
Nuclear Pairing from Two-body Microscopic Forces: Analysis of the Cooper Pair Wavefunctions
P. Finelli; S. Maurizio; J. W. Holt
2014-11-27T23:59:59.000Z
In a recent paper we studied the behavior of the pairing gaps $\\Delta_F$ as a function of the Fermi momentum $k_F$ for neutron and nuclear matter in all relevant angular momentum channels where superfluidity is believed to naturally emerge. The calculations employed realistic chiral nucleon-nucleon potentials with the inclusion of three-body forces and self-energy effects. In this contribution, after a detailed description of the numerical method we employed in the solution of the BCS equations, we will show a preliminary analysis of the Cooper pair wavefunctions.
Higher rank stable pairs and virtual localization
Artan Sheshmani
2015-02-08T23:59:59.000Z
We introduce a higher rank analog of the Pandharipande-Thomas theory of stable pairs on a Calabi-Yau threefold $X$. More precisely, we develop a moduli theory for frozen triples given by the data $O^r(-n)\\rightarrow F$ where $F$ is a sheaf of pure dimension 1. The moduli space of such objects does not naturally determine an enumerative theory: that is, it does not naturally possess a perfect symmetric obstruction theory. Instead, we build a zero-dimensional virtual fundamental class by hand, by truncating a deformation-obstruction theory coming from the moduli of objects in the derived category of $X$. This yields the first deformation-theoretic construction of a higher-rank enumerative theory for Calabi-Yau threefolds. We calculate this enumerative theory for local $\\mathbb{P}^1$ using the Graber-Pandharipande virtual localization technique.
Method for sequencing DNA base pairs
Sessler, A.M.; Dawson, J.
1993-12-14T23:59:59.000Z
The base pairs of a DNA structure are sequenced with the use of a scanning tunneling microscope (STM). The DNA structure is scanned by the STM probe tip, and, as it is being scanned, the DNA structure is separately subjected to a sequence of infrared radiation from four different sources, each source being selected to preferentially excite one of the four different bases in the DNA structure. Each particular base being scanned is subjected to such sequence of infrared radiation from the four different sources as that particular base is being scanned. The DNA structure as a whole is separately imaged for each subjection thereof to radiation from one only of each source. 6 figures.
Imaging with power controlled source pairs
Bardsley, Patrick
2015-01-01T23:59:59.000Z
Scatterers in a homogeneous medium are imaged by probing the medium with two point sources of waves modulated by correlated signals and by measuring only intensities at one single receiver. For appropriately chosen source pairs, we show that full waveform array measurements can be recovered from such intensity measurements by solving a linear least squares problem. The least squares solution can be used to image with Kirchhoff migration, even if the solution is determined only up to a known one-dimensional nullspace. The same imaging strategy can be used when the medium is probed with point sources driven by correlated Gaussian processes and autocorrelations are measured at a single location. Since autocorrelations are robust to noise, this can be used for imaging when the probing wave is drowned in background noise.
Pairing in bulk nuclear matter beyond BCS
Ding, D; Dickhoff, W H; Dussan, H; Rios, A; Polls, A
2014-01-01T23:59:59.000Z
The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the ${}^3P_2-{}^3F_2$ coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the ${}^3P_2-{}^3F_2$ coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.
Photoproduction of a ??Pair and Transversity GPDs
M. El Beiyad; B. Pire; L. Szymanowski; S. Wallon
2010-07-16T23:59:59.000Z
We demonstrate that the chiral-odd transversity generalized parton distributions (GPDs) of the nucleon can be accessed through the exclusive photoproduction process gamma + N -> pi + rho + N', in the kinematics where the meson pair has a large invariant mass and the final nucleon has a small transverse momentum, provided the vector meson is produced in a transversely polarized state. We calculate perturbatively the scattering amplitude at leading order in alpha_s: We build a simple model for the dominant transversity GPD HT (x; chi; t) based on the concept of double distribution. Counting rates estimates show that the experiment looks feasible with the real photon beam characteristics expected at JLab@12 GeV, in low Q2 leptoproduction at Jlab@12 GeV and in the COMPASS experiment.
Analysis of food pairing in regional cuisines of India
Jain, Anupam; Bagler, Ganesh
2015-01-01T23:59:59.000Z
Any national cuisine is a sum total of its variety of regional cuisines, which are the cultural and historical identifiers of their respective regions. India is home to a number of regional cuisines that showcase its culinary diversity. Here, we study recipes from eight different regional cuisines of India spanning various geographies and climates. We investigate the phenomenon of food pairing which examines compatibility of two ingredients in a recipe in terms of their shared flavor compounds. Food pairing was enumerated at the level of cuisine, recipes as well as ingredient pairs by quantifying flavor sharing between pairs of ingredients. Our results indicate that each regional cuisine follows negative food pairing pattern; more the extent of flavor sharing between two ingredients, lesser their co-occurrence in that cuisine. We find that frequency of ingredient usage is central in rendering the characteristic food pairing in each of these cuisines. Spice and dairy emerged as the most significant ingredient ...
Large Higgs energy region in Higgs associated top pair production...
Office of Scientific and Technical Information (OSTI)
Large Higgs energy region in Higgs associated top pair production at the Linear Collider Citation Details In-Document Search Title: Large Higgs energy region in Higgs associated...
Theoretical overview on top pair production and single top production
Stefan Weinzierl
2012-01-19T23:59:59.000Z
In this talk I will give an overview on theoretical aspects of top quark physics. The focus lies on top pair production and single top production.
Jacobi Elliptic Monopole-Antimonopole Pair Solutions
Rosy Teh; Pei-Yen Tan; Khai-Ming Wong
2012-10-01T23:59:59.000Z
We present new classical generalized Jacobi elliptic one monopole - antimonopole pair (MAP) solutions of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. These generalized 1-MAP solutions are solved with $\\theta$-winding number $m$=1 and $\\phi$-winding number $n$=1, 2, 3, ... 6. Similar to the generalized Jacobi elliptic one monopole solutions, these generalized 1-MAP solutions are solved by generalizing the large distance behaviour of the solutions to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing ($\\lambda$=0) and non vanishing ($\\lambda$=1). These generalized 1-MAP solutions possess total energies that are comparable to the total energy of the standard 1-MAP solution with winding number $m$=1. However these total energies are significantly lower than the total energy of the standard 1-MAP solution with winding number $m$=2. All these new generalized solutions are regular numerical finite energy non-BPS solutions of the Yang-Mills-Higgs field theory.
Pairing in bulk nuclear matter beyond BCS
Ding, D.; Dickhoff, W. H.; Dussan, H. [Department of Physics, Washington University, St. Louis, Missouri 63130 (United States); Witte, S. J. [Department of Physics, Washington University, St. Louis, Missouri 63130, USA and Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Rios, A. [Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Polls, A. [Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, E-08028 Barcelona (Spain)
2014-10-15T23:59:59.000Z
The influence of short-range correlations on the spectral distribution of neutrons is incorporated in the solution of the gap equation for the {sup 3}P{sub 2}?{sup 3}F{sub 2} coupled channel in pure neutron matter. This effect is studied for different realistic interactions including one based on chiral perturbation theory. The gap in this channel vanishes at all relevant densities due to the treatment of these correlations. We also consider the effect of long-range correlations by including polarization terms in addition to the bare interaction which allow the neutrons to exchange density and spin fluctuations governed by the strength of Landau parameters allowed to have reasonable values consistent with the available literature. Preliminary results indicate that reasonable values of these parameters do not generate a gap in the {sup 3}P{sub 2}?{sup 3}F{sub 2} coupled channel either for all three realistic interactions although the pairing interaction becomes slightly more attractive.
Nebular spectra of pair-instability supernovae
Jerkstrand, A; Heger, A
2015-01-01T23:59:59.000Z
If very massive stars (M >~ 100 Msun) can form and avoid too strong mass loss during their evolution, they are predicted to explode as pair-instability supernovae (PISNe). One critical test for candidate events is whether their nucleosynthesis yields and internal ejecta structure, being revealed through nebular-phase spectra at t >~ 1 yr, match those of model predictions. Here we compute theoretical spectra based on model PISN ejecta at 1-3 years post-explosion to allow quantitative comparison with observations. The high column densities of PISNe lead to complete gamma-ray trapping for t >~ 2 years which, combined with fulfilled conditions of steady state, leads to bolometric supernova luminosities matching the 56Co decay. Most of the gamma-rays are absorbed by the deep-lying iron and silicon/sulphur layers. The ionization balance shows a predominantly neutral gas state, which leads to emission lines of Fe I, Si I, and S I. For low-mass PISNe the metal core expands slowly enough to produce a forest of distinc...
Pair correlations in crystalline solid solutions
Ice, G.E.; Sparks, C.J. [Oak Ridge National Lab., TN (United States); Shaffer, L. [Anderson Univ., IN (United States). Dept. of Physics; Zschack, P. [Oak Ridge Institute of Science and Education, TN (United States)
1994-06-01T23:59:59.000Z
Recent measurements of pair correlations in metallic solid solutions challenge simple models of atomic size in alloy structure. These measurements take advantage of intense and tunable synchrotron X radiation to control the x-ray scattering contrast between atoms in a solid solution. For binary alloys with elements nearby in the periodic table it is possible to tune the x-ray energy near the K edge so that the scattering contrast varies from near zero to {plus_minus}5 electron units. Even larger contrast variation is possible near L edges or with complementary x-ray and neutron diffraction data sets. With adjusted scattering contrast it is possible to measure short-range-order (SRO), even in alloys with elements nearby in the periodic table. It is also possible to detect chemically-specific static displacements of {plus_minus}0.001 {angstrom} or less and with fewer assumptions than with previous experimental methods. We compare the measured chemically-specific static displacements in Fe{sub 22.5}Ni{sub 77.5} and Cr{sub 47}Fe{sub 53} with previous models and with the results of other experiments.
Tridiagonal pairs of $q$-Racah type
Ito, Tatsuro
2008-01-01T23:59:59.000Z
Let $K$ denote an algebraically closed field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
How to sharpen a tridiagonal pair
Ito, Tatsuro
2008-01-01T23:59:59.000Z
Let $\\F$ denote a field and let $V$ denote a vector space over $\\F$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
A classification of sharp tridiagonal pairs
Ito, Tatsuro; Terwilliger, Paul
2010-01-01T23:59:59.000Z
Let $F$ denote a field and let $V$ denote a vector space over $F$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
On the shape of a tridiagonal pair
Nomura, Kazumasa
2009-01-01T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\lbrace V_i\\rbrace_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\lbrace V^*_i\\rbrace_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
The structure of a tridiagonal pair
Nomura, Kazumasa
2008-01-01T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\{V_i\\}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_i + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\{V^*_i\\}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_i + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv)there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Tridiagonal pairs and the $\\mu$-conjecture
Nomura, Kazumasa
2009-01-01T23:59:59.000Z
Let $F$ denote a field and let $V$ denote a vector space over $F$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\{V_i\\}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\{V^*_i\\}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Towards a classification of the tridiagonal pairs
Nomura, Kazumasa
2008-01-01T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. Let $End(V)$ denote the $K$-algebra consisting of all $K$-linear transformations from $V$ to $V$. We consider a pair $A,A^* \\in End(V)$ that satisfy (i)--(iv) below: (i) Each of $A,A^*$ is diagonalizable. (ii) There exists an ordering $\\{V_i\\}_{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$. (iii) There exists an ordering $\\{V^*_i\\}_{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$. (iv) There is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Pairing-induced speedup of nuclear spontaneous fission
Jhilam Sadhukhan; J. Dobaczewski; W. Nazarewicz; J. A. Sheikh; A. Baran
2014-10-06T23:59:59.000Z
Collective inertia is strongly influenced at the level crossing at which quantum system changes diabatically its microscopic configuration. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of those configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of $^{264}$Fm and $^{240}$Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM$^*$ and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of $^{264}$Fm, where the effect of triaxiality on the fission barrier is large, the geometry of fission pathway in the space of shape degrees of freedom is weakly impacted by pairing. This is not the case for $^{240}$Pu where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. Consequently, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.
Crew Pairing Optimization with Genetic Harry Kornilakis and Panagiotis Stamatopoulos
Panagiotis, Stamatopoulos
- tions. The purpose of the crew pairing problem is to generate a set of pairings with minimal cost with near optimal cost. This problem, which is modelled by a set covering formulation, is solved with a genetic algorithm. The presented method was tested on actual flight data of Olympic Airways. 1
Pair Production of Topological anti de Sitter Black Holes
R. B. Mann
1996-07-28T23:59:59.000Z
The pair creation of black holes with event horizons of non-trivial topology is described. The spacetimes are all limiting cases of the cosmological $C$ metric. They are generalizations of the $(2+1)$ dimensional black hole and have asymptotically anti de Sitter behaviour. Domain walls instantons can mediate their pair creation for a wide range of mass and charge.
Density-matrix functionals for pairing in mesoscopic superconductors
Denis Lacroix; Guillaume Hupin
2010-09-03T23:59:59.000Z
A functional theory based on single-particle occupation numbers is developed for pairing. This functional, that generalizes the BCS approach, directly incorporates corrections due to particle number conservation. The functional is benchmarked with the pairing Hamiltonian and reproduces perfectly the energy for any particle number and coupling.
LCPHSM2004005 Study of Higgs Boson Pair Production at
LCÂPHSMÂ2004Â005 March 2004 Study of Higgs Boson Pair Production at Linear Collider K. Desch a , TV for the measurement of the neutral Higgs boson properties within the framework of the MSSM. The process of associated Higgs boson production with subsequent decays of Higgs bosons into bÂquark and #Âlepton pairs
Efficient Implementation of Bilinear Pairings on ARM Processors
International Association for Cryptologic Research (IACR)
Efficient Implementation of Bilinear Pairings on ARM Processors Gurleen Grewal1 , Reza Azarderakhsh-Ate pairing over Barreto-Naehrig curves in software at differ- ent security levels on ARM processors. We computation on ARM-powered devices, outperforming by at least a factor of 3.7 the best previous results
Liquid pair correlations in four spatial dimensions: Theory versus simulation
M. Heinen; J. Horbach; H. Löwen
2014-11-06T23:59:59.000Z
Using liquid integral equation theory, we calculate the pair correlations of particles that interact via a smooth repulsive pair potential in d = 4 spatial dimensions. We discuss the performance of different closures for the Ornstein-Zernike equation, by comparing the results to computer simulation data. Our results are of relevance to understand crystal and glass formation in high-dimensional systems.
An interatomic pair potential for cadmium selenide Eran Rabani
Rabani, Eran
in all three crystal structures: wurtzite, zinc blende, and rocksalt. Using the new pair potential we have studied the pressure-induced phase transition from the fourfold-coordinate wurtzite structure for wurtzite cadmium selenide.6 In this paper we derive a set of interatomic pair poten- tials for cadmium
ON WAVELETS INTERPOLATED FROM A PAIR OF WAVELET SETS
Speegle, Darrin
ON WAVELETS INTERPOLATED FROM A PAIR OF WAVELET SETS Ziemowit Rzeszotnik and Darrin Speegle September 1, 2000 Abstract. We show that any wavelet, with the support of its Fourier transform small enough, can be interpolated from a pair of wavelet sets. The interpolation procedure, which was introduced
Computing local p-adic height pairings on hyperelliptic curves
Balakrishnan, Jennifer S
2010-01-01T23:59:59.000Z
We describe an algorithm to compute the local component at p of the Coleman-Gross p-adic height pairing on divisors on hyperelliptic curves. As the height pairing is given in terms of a Coleman integral, we also provide new techniques to evaluate Coleman integrals of meromorphic differentials and present our algorithms as implemented in Sage.
Some Efficient Algorithms for the Final Exponentiation of T Pairing
International Association for Cryptologic Research (IACR)
Some Efficient Algorithms for the Final Exponentiation of T Pairing Masaaki Shirase1 , Tsuyoshi by the recent improvements, e.g., the Duursma-Lee algorithm and T pairing. In this paper we discuss how propose some efficient algorithms using the torus T2(F33n ) that can efficiently compute an inversion
Pairing-induced speedup of nuclear spontaneous fission
Sadhukhan, Jhilam; Nazarewicz, W; Sheikh, J A; Baran, A
2014-01-01T23:59:59.000Z
Collective inertia is strongly influenced at the level crossing at which quantum system changes diabatically its microscopic configuration. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of those configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of $^{264}$Fm and $^{240}$Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM$^*$ and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action princip...
Semiclassical pair production rate for rotating electric fields
Eckhard Strobel; She-Sheng Xue
2015-02-09T23:59:59.000Z
We semiclassically investigate Schwinger pair production for pulsed rotating electric fields depending on time. To do so we solve the Dirac equation for two-component fields in a WKB-like approximation. The result shows that for two-component fields the spin distribution of produced pairs is generally not $1:1$. As a result the pair creation rates of spinor and scalar quantum electro dynamics (QED) are different even for one pair of turning points. For rotating electric fields the pair creation rate is dominated by particles with a specific spin depending on the sense of rotation for a certain range of pulse lengths and frequencies. We present an analytical solution for the momentum spectrum of the constant rotating field. We find interference effects not only in the momentum spectrum but also in the total particle number of rotating electric fields.
Leonard pairs and the q-Racah polynomials
Paul Terwilliger
2008-07-24T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider an ordered pair of linear transformations $A:V\\to V$ and $A^*:V\\to V$ that satisfy conditions (i), (ii) below. (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A$ is diagonal and the matrix representing $A^*$ is irreducible tridiagonal. We call such a pair a {\\it Leonard pair} on $V$. We discuss a correspondence between Leonard pairs and a class of orthogonal polynomials consisting of the $q$-Racah polynomials and some related polynomials of the Askey scheme. For the polynomials in this class we obtain the 3-term recurrence, difference equation, Askey-Wilson duality, and orthogonality in a uniform manner using the corresponding Leonard pair.
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Property:GrossProdCapacity | Open Energy Information
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pp: 118 (col.fig.: 2) PROD. TYPE: COM
Bergmann, Michel
.990 1 Note on the determination of the ignition point in forest fires propagation using a control, France SUMMARY7 This paper is devoted to the determination of the origin point in forest fires propagation using a control algorithm. The forest fires propagation are mathematically modelled starting from
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Prod-Trees: Semantic Search for Earth Observation Products
Koubarakis, Manolis
of set of self-describing, machine-independent data formats and software libraries that support search- ing for EO products by selecting some high level categories (e.g., the mission from which and temporal filtering criteria. Although this might suit the needs of very advanced users that know exactly
Effective field theory for dilute fermions with pairing
Furnstahl, R.J. [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)], E-mail: furnstahl.1@osu.edu; Hammer, H.-W. [Helmholtz-Institut fuer Strahlen- und Kernphysik (Theorie), Universitaet Bonn, Nussallee 14-16, D-53115 Bonn (Germany)], E-mail: hammer@itkp.uni-bonn.de; Puglia, S.J. [SBIG PLC, Berkeley Square House, London W1J 6BR (United Kingdom)], E-mail: spuglia@sbiguk.com
2007-11-15T23:59:59.000Z
Effective field theory (EFT) methods for a uniform system of fermions with short-range, natural interactions are extended to include pairing correlations, as part of a program to develop a systematic Kohn-Sham density functional theory (DFT) for medium and heavy nuclei. An effective action formalism for local composite operators leads to a free-energy functional that includes pairing by applying an inversion method order by order in the EFT expansion. A consistent renormalization scheme is demonstrated for the uniform system through next-to-leading order, which includes induced-interaction corrections to pairing.
Pairs Emission in a Uniform Background Field: an Algebraic Approach
Roberto Soldati
2011-06-23T23:59:59.000Z
A fully algebraic general approach is developed to treat the pairs emission and absorption in the presence of some uniform external background field. In particular, it is shown that the pairs production and annihilation operators, together with the pairs number operator, do actually fulfill the SU(2) functional Lie algebra. As an example of application, the celebrated Schwinger formula is consistently and nicely recovered, within this novel approach, for a Dirac spinor field in the presence of a constant and homogeneous electric field in four spacetime dimensions.
Emission of neutrino-antineutrino pairs by hadronic bremsstrahlung processes
Bacca, Sonia; Schwenk, Achim
2015-01-01T23:59:59.000Z
We review our recent calculations of neutrino-antineutrino pair production from bremsstrahlung processes in hadronic collisions at temperature and densities relevant for core-collapse supernovae. We focus on neutron-neutron and neutron-alpha collisions.
Macro-coherent two photon and radiative neutrino pair emission
M. Yoshimura; C. Ohae; A. Fukumi; K. Nakajima; I. Nakano; H. Nanjo; N. Sasao
2008-05-14T23:59:59.000Z
We discuss a possibility of detecting a coherent photon pair emission and related radiative neutrino pair emission from excited atoms. It is shown that atoms of lambda- and ladder-type three level system placed in a pencil-like cylinder give a back to back emission of two photons of equal energy $\\Delta/2$, sharply peaked with a width $\\propto $ 1/(target size) and well collimated along the cylinder axis. This process has a measurable rate $\\propto$ (target number density) $^2 \\times$ target volume, while a broader spectral feature of one-photon distribution separated by (mass sum of a neutrino pair)$^2/(2\\Delta)$ from the two photon peak may arise from radiative neutrino pair emission, with a much smaller rate.
Polarization operator approach to pair creation in short laser pulses
Meuren, Sebastian; Keitel, Christoph H; Di Piazza, Antonino
2014-01-01T23:59:59.000Z
We investigate the nonlinear Breit-Wheeler process inside short laser pulses, i.e. the creation of an electron-positron pair induced by a gamma photon inside a plane-wave background field. To obtain the total pair-creation probability we verify (to leading-order) the cutting rule for the polarization operator in the realm of strong-field QED by an explicit calculation. Furthermore, a double-integral representation for the leading-order contribution to the field-dependent part of the polarization operator is derived. The combination of both results yields a compact expression for the total pair-creation probability inside an arbitrary plane-wave background field. It is shown numerically that with presently available technology pair-creation probabilities of the order of ten percent could be reached for a single gamma photon.
Visualizing the Optical Interaction Tensor of a Gold Nanoparticle Pair
Novotny, Lukas
Visualizing the Optical Interaction Tensor of a Gold Nanoparticle Pair Bradley Deutsch, Rainer Hillenbrand,,§ and Lukas Novotny*, Institute of Optics, University of Rochester, Rochester, New York 14627, Basque Foundation for Science, 48011 Bilbao, Spain ABSTRACT The control of optical fields
Prolific pair production with high-power lasers
A. R. Bell; John G. Kirk
2008-10-16T23:59:59.000Z
Prolific electron-positron pair production is possible at laser intensities approaching 10^{24} W/cm^2 at a wavelength of 1 micron. An analysis of electron trajectories and interactions at the nodes (B=0) of two counter-propagating, circularly polarised laser beams shows that a cascade of gamma-rays and pairs develops. The geometry is generalised qualitatively to linear polarisation and laser beams incident on a solid target.
Prolific pair production with high-power lasers
Bell, A R
2008-01-01T23:59:59.000Z
Prolific electron-positron pair production is possible at laser intensities approaching 10^{24} W/cm^2 at a wavelength of 1 micron. An analysis of electron trajectories and interactions at the nodes (B=0) of two counter-propagating, circularly polarised laser beams shows that a cascade of gamma-rays and pairs develops. The geometry is generalised qualitatively to linear polarisation and laser beams incident on a solid target.
Observer dependence of bubble nucleation and Schwinger pair production
Garriga, Jaume [Departament de Física Fonamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona (Spain); Kanno, Sugumi; Vilenkin, Alexander [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155 (United States); Sasaki, Misao [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan); Soda, Jiro, E-mail: jaume.garriga@ub.edu, E-mail: sugumi@cosmos.phy.tufts.edu, E-mail: misao@yukawa.kyoto-u.ac.jp, E-mail: jiro@tap.scphys.kyoto-u.ac.jp, E-mail: vilenkin@cosmos.phy.tufts.edu [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
2012-12-01T23:59:59.000Z
Pair production in a constant electric field is closely analogous to bubble nucleation in a false vacuum. The classical trajectories of the pairs are Lorentz invariant, but it appears that this invariance should be broken by the nucleation process. Here, we use a model detector, consisting of other particles interacting with the pairs, to investigate how pair production is seen by different Lorentzian observers. We focus on the idealized situation where a constant external electric field is present for an infinitely long time, and we consider the in-vacuum state for a charged scalar field that describes the nucleating pairs. The in-vacuum is defined in terms of modes which are positive frequency in the remote past. Even though the construction uses a particular reference frame and a gauge where the vector potential is time dependent, we show explicitly that the resulting quantum state is Lorentz invariant. We then introduce a ''detector'' particle which interacts with the nucleated pairs, and show that all Lorentzian observers will see the particles and antiparticles nucleating preferentially at rest in the detector's rest frame. Similar conclusions are expected to apply to bubble nucleation in a sufficiently long lived vacuum. We also comment on certain unphysical aspects of the Lorentz invariant in-vacuum, associated with the fact that it contains an infinite density of particles. This can be easily remedied by considering Lorentz breaking initial conditions.
Pair-instability supernovae in the local universe
Whalen, Daniel J. [Zentrum für Astronomie, Institut für Theoretische Astrophysik, Universität Heidelberg, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Smidt, Joseph [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Hirschi, Raphael [Astrophysics Group, EPSAM, University of Keele, Lennard-Jones Labs, Keele ST5 5BG (United Kingdom); Yusof, Norhasliza [Department of Physics, University of Malaysia, 50603 Kuala Lampur (Malaysia); Even, Wesley; Fryer, Chris L. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Chen, Ke-Jung [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States); Joggerst, Candace C. [XTD-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-12-10T23:59:59.000Z
The discovery of 150-300 M {sub ?} stars in the Local Group and pair-instability supernova candidates at low redshifts has excited interest in this exotic explosion mechanism. Realistic light curves for pair-instability supernovae at near-solar metallicities are key to identifying and properly interpreting these events as more are found. We have modeled pair-instability supernovae of 150-500 M {sub ?} Z ? 0.1-0.4 Z {sub ?} stars. These stars lose up to 80% of their mass to strong line-driven winds and explode as bare He cores. We find that their light curves and spectra are quite different from those of Population III pair-instability explosions, which therefore cannot be used as templates for low-redshift events. Although non-zero metallicity pair-instability supernovae are generally dimmer than their Population III counterparts, in some cases they will be bright enough to be detected at the earliest epochs at which they can occur, the formation of the first galaxies at z ? 10-15. Others can masquerade as dim, short duration supernovae that are only visible in the local universe and that under the right conditions could be hidden in a wide variety of supernova classes. We also report for the first time that some pair-instability explosions can create black holes with masses of ?100 M {sub ?}.
On magnon mediated Cooper pair formation in ferromagnetic superconductors
Kar, Rakesh; Paul, Bikash Chandra [Department of Physics, University of North Bengal, Raja Rammohunpur, Darjeeling 734013, West Bengal (India); Goswami, Tamal; Misra, Anirban, E-mail: anirbanmisra@yahoo.com [Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling 734013, West Bengal (India)
2014-08-15T23:59:59.000Z
Identification of pairing mechanism leading to ferromagnetic superconductivity is one of the most challenging issues in condensed matter physics. Although different models have been proposed to explain this phenomenon, a quantitative understanding about this pairing is yet to be achieved. Using the localized-itinerant model, we find that in ferromagnetic superconducting materials both triplet pairing and singlet pairing of electrons are possible through magnon exchange depending upon whether the Debye cut off frequency of magnons is greater or lesser than the Hund's coupling (J) multiplied by average spin (S) per site. Taking into account the repulsive interaction due to the existence of paramagnons, we also find an expression for effective interaction potential between a pair of electrons with opposite spins. We apply the developed formalism in case of UGe{sub 2} and URhGe. The condition of singlet pairing is found to be fulfilled in these cases, as was previously envisaged by Suhl [Suhl, Phys. Rev. Lett. 87, 167007 (2001)]. We compute the critical temperatures of URhGe at ambient pressure and of UGe{sub 2} under different pressures for the first time through BCS equation. Thus, this work outlines a very simple way to evaluate critical temperature in case of a superconducting system. A close match with the available experimental results strongly supports our theoretical treatment.
Formation of Cooper pairs as a consequence of exchange interaction
Stanislav Dolgopolov
2015-04-13T23:59:59.000Z
The pairing of two electrons with antiparallel spins may minimize the energy of each of the paired electrons. Thus the exchange interaction and the Pauli Exclusion Principle cause a bond between two electrons in a crystal. This can be proved analyzing the energy of each conduction electron in the field of a crystal on assumption that all other kinds of magnetic spin ordering in the crystal are weak. The superconductivity in a metallic crystal occurs only if conduction electrons before the pairing are put closely on the Fermi surface in the momentum space. The motion of conduction electrons in the crystal may disturb the formation of Cooper pairs, because the kinetic energy of the motion is usually much larger than the energy gap of superconductor. The conduction electrons as standing waves have a zero momentum, hence their momentums are synchronous; consequently the formation of Cooper pairs is more probable than in case of electrons with nonzero momentums. The total momentum of the pair of two electrons as standing waves is zero.
Polarization operator approach to pair creation in short laser pulses
Sebastian Meuren; Karen Z. Hatsagortsyan; Christoph H. Keitel; Antonino Di Piazza
2015-01-28T23:59:59.000Z
Short-pulse effects are investigated for the nonlinear Breit-Wheeler process, i.e. the production of an electron-positron pair induced by a gamma photon inside an intense plane-wave laser pulse. To obtain the total pair-creation probability we verify (to leading-order) the cutting rule for the polarization operator in the realm of strong-field QED by an explicit calculation. Using a double-integral representation for the leading-order contribution to the polarization operator, compact expressions for the total pair-creation probability inside an arbitrary plane-wave background field are derived. Correspondingly, the photon wave function including leading-order radiative corrections in the laser field is obtained via the Schwinger-Dyson equation in the quasistatic approximation. Moreover, the influence of the carrier-envelope phase and of the laser pulse shape on the total pair-creation probability in a linearly polarized laser pulse is investigated, and the validity of the (local) constant-crossed field approximation analyzed. It is shown that with presently available technology pair-creation probabilities of the order of ten percent could be reached for a single gamma photon.
Rotation Rate of Particle Pairs in Homogeneous Isotropic Turbulence
Daddi-Moussa-Ider, Abdallah
2015-01-01T23:59:59.000Z
Understanding the dynamics of particles in turbulent flow is important in many environmental and industrial applications. In this paper, the statistics of particle pair orientation is numerically studied in homogeneous isotropic turbulent flow, with Taylor microscale Rynolds number of 300. It is shown that the Kolmogorov scaling fails to predict the observed probability density functions (PDFs) of the pair rotation rate and the higher order moments accurately. Therefore, a multifractal formalism is derived in order to include the intermittent behavior that is neglected in the Kolmogorov picture. The PDFs of finding the pairs at a given angular velocity for small relative separations, reveals extreme events with stretched tails and high kurtosis values. Additionally, The PDFs are found to be less intermittent and follow a complementary error function distribution for larger separations.
Effect of pairing on transfer and fusion reactions
Scamps, Guillaume
2014-01-01T23:59:59.000Z
In the present contribution, the effect of pairing on nuclear transfer and fusion reactions close to the Coulomb barrier is discussed. A Time-Dependent Hartree-Fock + BCS (TDHF+BCS) microscopic theory has been developed to incorporate pairing. One- and two-particle transfer probabilities can be obtained showing the importance of pairing. The calculated transfer probabilities are compared to the recent experimental results obtained for the $^{96}$Zr+$^{40}$Ca. Reactions involving the $^{18}$O with lead isotopes are also presented, that are also of current experimental interest. Finally, a study of the fusion barrier height predicted with the TDHF+BCS theory is compared to the experimental values for the $^{40,44,48}$Ca+$^{40}$Ca reactions.
Spices form the basis of food pairing in Indian cuisine
Jain, Anupam; Bagler, Ganesh
2015-01-01T23:59:59.000Z
Culinary practices are influenced by climate, culture, history and geography. Molecular composition of recipes in a cuisine reveals patterns in food preferences. Indian cuisine encompasses a number of diverse sub-cuisines separated by geographies, climates and cultures. Its culinary system has a long history of health-centric dietary practices focused on disease prevention and promotion of health. We study food pairing in recipes of Indian cuisine to show that, in contrast to positive food pairing reported in some Western cuisines, Indian cuisine has a strong signature of negative food pairing; more the extent of flavor sharing between any two ingredients, lesser their co-occurrence. This feature is independent of recipe size and is not explained by ingredient category-based recipe constitution alone. Ingredient frequency emerged as the dominant factor specifying the characteristic flavor sharing pattern of the cuisine. Spices, individually and as a category, form the basis of ingredient composition in Indian...
A pair spectrometer for measuring multipolarities of energetic nuclear transitions
J. Gulyás; T. J. Ketel; A. J. Krasznahorkay; M. Csatlós; L. Csige; Z. Gácsi; M. Hunyadi; A. Krasznahorkay; A. Vitéz; T. G. Tornyi
2015-04-02T23:59:59.000Z
A multi-detector array has been designed and constructed for the simultaneous measurement of energy- and angular correlations of electron-positron pairs. Experimental results are obtained over a wide angular range for high-energy transitions in 16O, 12C and 8Be. A comparison with GEANT simulations demonstrates that angular correlations between 50 and 180 degrees of the electron-positron pairs in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency.
Measurements of the Top Quark Pair-Production Cross Section
Frank-Peter Schilling
2013-02-19T23:59:59.000Z
Measurements of the inclusive and differential cross section for the production of top quark pairs in proton-(anti)proton collision at center-of-mass energies of 1.96, 7.0 and 8.0 TeV are presented and compared with the latest theory predictions and Monte-Carlo models. In addition, first measurements of the production of top quark pairs in association with additional jets or with a boson are highlighted. All measurements are in good agreement with the Standard Model.
Tailored photon-pair generation in optical fibers
Offir Cohen; Jeff S. Lundeen; Brian J. Smith; Graciana Puentes; Peter J. Mosley; Ian A. Walmsley
2009-04-14T23:59:59.000Z
We experimentally control the spectral structure of photon pairs created via spontaneous four-wave mixing in microstructured fibers. By fabricating fibers with designed dispersion, one can manipulate the photons' wavelengths, joint spectrum, and, thus, entanglement. As an example, we produce photon-pairs with no spectral correlations, allowing direct heralding of single photons in pure-state wave packets without filtering. We achieve an experimental purity of $85.9\\pm1.6%$, while theoretical analysis and preliminary tests suggest 94.5% purity is possible with a much longer fiber.
Flexible generation of correlated photon pairs in different frequency ranges
Fernando Oster; Christoph H Keitel; Mihai Macovei
2012-05-30T23:59:59.000Z
The feasibility to generate correlated photon pairs at variable frequencies is investigated. For this purpose, we consider the interaction of an off-resonant laser field with a two-level system possessing broken inversion symmetry. We show that the system generates non-classical photon pairs exhibiting strong intensity-intensity correlations. The intensity of the applied laser tunes the degree of correlation while the detuning controls the frequency of one of the photons which can be in the THz-domain. Furthermore, we observe the violation of a Cauchy-Schwarz inequality characterizing these photons.
Error-prevention scheme with two pairs of qubits
Chu, Shih-I; Yang, Chui-Ping; Han, Siyuan
2002-09-04T23:59:59.000Z
Ei jue ie j&5ue je i& , e iP$0,1% @6#!. The expressions for HS and HSB are as follows: HS5e0~s I z 1s II z !, *Email address: cpyang@floquet.chem.ku.edu †Email address: sichu@ku.edu ‡ Email address: han@ku.eduError-prevention scheme Chui-Ping Yang.... The sche two pairs of qubits and through error-prevention proc through a decoherence-free subspace for collective p pairs; leakage out of the encoding space due to amp addition, how to construct decoherence-free states for n discussed. DOI: 10.1103/Phys...
A pair spectrometer for measuring multipolarities of energetic nuclear transitions
Gulyás, J; Krasznahorkay, A J; Csatlós, M; Csige, L; Gácsi, Z; Hunyadi, M; Krasznahorkay, A; Vitéz, A; Tornyi, T G
2015-01-01T23:59:59.000Z
A multi-detector array has been designed and constructed for the simultaneous measurement of energy- and angular correlations of electron-positron pairs. Experimental results are obtained over a wide angular range for high-energy transitions in 16O, 12C and 8Be. A comparison with GEANT simulations demonstrates that angular correlations between 50 and 180 degrees of the electron-positron pairs in the energy range between 6 and 18 MeV can be determined with sufficient resolution and efficiency.
The Schwinger pair production rate in confining theories via holography
Daisuke Kawai; Yoshiki Sato; Kentaroh Yoshida
2014-06-02T23:59:59.000Z
We study the Schwinger pair production in confining theories. The production rate in an external electric field E is numerically evaluated by using the holographic description. There exist two kinds of critical values of the electric field, i) E=E_c, above which there is no potential barrier and particles are freely generated, ii) E=E_s, below which the confining string tension dominates the electric field and the pair production does not occur. We argue the universal exponents associated with the critical behaviors.
Gomez-Ceballos, Guillelmo
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant ...
Batool, Nazia; Saleem, H. [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan)] [National Centre for Physics (NCP), Quaid-i-Azam University Campus, Islamabad (Pakistan)
2013-10-15T23:59:59.000Z
The linear and nonlinear dynamics of pair-ion (PI) and pair-ion-electron plasmas (PIE) have been investigated in a cylindrical geometry with a sheared plasma flow along the axial direction having radial dependence. The coupled linear dispersion relation of low frequency electrostatic waves has been presented taking into account the Guassian profile of density and linear gradient of sheared flow. It is pointed out that the quasi-neutral cold inhomogeneous pure pair ion plasma supports only the obliquely propagating convective cell mode. The linear dispersion relation of this mode has been solved using boundary conditions. The nonlinear structures in the form of vortices formed by different waves have been discussed in PI and PIE plasmas.
Cherenkov radiation and pair production by particles traversing laser beams
I. M. Dremin
2002-03-01T23:59:59.000Z
It is shown that Cherenkov radiation can be observed at TESLA in electron collisions with optical laser pulses. The prospects for it to be observed at SLC, LEP, LHC and RHIC are discussed. The conclusions are compared with results for pair production.
The Dependency Pair Framework: Combining Techniques for Automated Termination Proofs #
ÃbrahÃ¡m, Erika
The Dependency Pair Framework: Combining Techniques for Automated Termination Proofs # J of the most powerful techniques for automated termination proofs of term rewrite systems. Up to now of new methods for termination analyÂ sis. To demonstrate this, we present several new techniques within
Pair spectrometer hodoscope for Hall D at Jefferson Lab
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Barbosa, Fernando J.; Hutton, Charles L.; Sitnikov, Alexandre; Somov, Alexander S.; Somov, S.; Tolstukhin, Ivan
2015-09-01T23:59:59.000Z
We present the design of the pair spectrometer hodoscope fabricated at Jefferson Lab and installed in the experimental Hall D. The hodoscope consists of thin scintillator tiles; the light from each tile is collected using wave-length shifting fibers and detected using a Hamamatsu silicon photomultiplier. Light collection was measured using relativistic electrons produced in the tagger area of the experimental Hall B.
Creation and pinning of vortex-antivortex pairs
Kim, Sangbum; Hu, Chia-Ren; Andrews, Malcolm J.
2006-01-01T23:59:59.000Z
Computer modeling is reported about the creation and pinning of a magnetic vortex-antivortex (V-AV) pair in a superconducting thin film, due to the magnetic field of a vertical magnetic dipole above the film, and two antidot pins inside the film...
Matched Pairs Procedures Two Sample Procedures General Guidelines t Procedures
Watkins, Joseph C.
this, researchers randomly chose a collection of bags of wheat soy blend bound for Haiti, marked them blend. Factory Haiti Factory Haiti Factory Haiti Factory Haiti 44 40 45 38 39 43 50 37 50 37 32 40 52 38, respectively, at the factory and in Haiti. > t.test(factory, haiti, alternative = c("greater"),mu = 0, paired
Bose Einstein correlations of neutral pion pairs at LEP
M. Boutemeur; G. Giacomelli
2005-10-10T23:59:59.000Z
With the OPAL detector at LEP we measured at energies around the Z0 peak the Bose-Einstein Correlations (BECs) of neutral pion pairs. We compare the results of this measurement with former results obtained at LEP for hadrons including those obtained from Fermi-Dirac Correlations (FDCs).
Experimental Pair Trawling for Squid in New England
warps in front of the net to frighten the fish. Midwater and bottom pair trawl- ing for various fish an area of good squid catches. During this trip, two tows were made after dark. All other tows with only one warp from each boat leading to two 20-fathom bri- dles (legs) on each side of the net
Creation and pinning of vortex-antivortex pairs
Kim, Sangbum; Hu, Chia-Ren; Andrews, Malcolm J.
2006-01-01T23:59:59.000Z
in a superconducting thin film, due to the magnetic field of a vertical magnetic dipole above the film, and two antidot pins inside the film. For film thickness =0.1 xi, kappa=2, and no pins, we find the film carries two V-AV pairs at steady state...
A Comparison of h2 and MMM for Mutex Pair
Holte, Robert
are different from one another. The purpose of this paper is to study the effects on search performance when%-24%) whereas MMM's errors have very little effect on search speed or subop- timality, even when its sample size Edmonton, AB, Canada T6G 2E8, holte@cs.ualberta.ca Abstract. In state space search or planning, a pair
A PLANAR PARALLEL MANIPULATOR WITH HOLONOMIC HIGHER PAIRS: INVERSE KINEMATICS
Hayes, John
kinematic analysis. Very little literature on such planar mechanisms was found. The e ects of initialA PLANAR PARALLEL MANIPULATOR WITH HOLONOMIC HIGHER PAIRS: INVERSE KINEMATICS Matthew John D. HAYES of Mechanical Engineering 817 r. Sherbrooke O., Rm 454, Montreal, Quebec, H3A 2K6 Canada, Tel: (514) 398
Bragg reflection waveguides as integrated sources of entangled photon pairs
to design an electrically pumped entangled photon source. © 2012 Optical Society of America OCIS codes: 230Bragg reflection waveguides as integrated sources of entangled photon pairs Sergei V. Zhukovsky,1 of Physics and Institute for Optical Sciences, University of Toronto, 60 St. George Street, Toronto, Ontario
Calculating coherent pair production with Monte Carlo methods
Bottcher, C.; Strayer, M.R.
1989-01-01T23:59:59.000Z
We discuss calculations of the coherent electromagnetic pair production in ultra-relativistic hadron collisions. This type of production, in lowest order, is obtained from three diagrams which contain two virtual photons. We discuss simple Monte Carlo methods for evaluating these classes of diagrams without recourse to involved algebraic reduction schemes. 19 refs., 11 figs.
Collapsibility of Lung Volume by Paired Inspiratory and Expiratory CT
Collapsibility of Lung Volume by Paired Inspiratory and Expiratory CT Scans: Correlations with Lung Function and Mean Lung Density Tsuneo Yamashiro, MD, Shin Matsuoka, MD, PhD, Brian J. Bartholmai, MD, Rau: To evaluate the relationship between measurements of lung volume (LV) on inspiratory/expiratory computed
Observation of the Nernst signal generated by fluctuating Cooper pairs
Loss, Daniel
. The Nernst effect, the generation of a transverse electric field by a longitudinal thermal gradient, has with the quanta of electric1 (e2 /h) or thermal11 (2 k2 BT/3h) conductance. However, in the notation used by USHLETTERS Observation of the Nernst signal generated by fluctuating Cooper pairs A. POURRET1 , H
Abstract polymer models with general pair interactions Aldo Procacci
Procacci, Aldo
Abstract polymer models with general pair interactions Aldo Procacci Dep. MatemÂ´atica-ICEx, UFMG (i.e. not necessarily hard core or repulsive). A concrete example is given in which polymers are r0 (possibly attractive), of the type 1/rd+ with > 0. 1. Introduction The abstract polymer gas is an important
Transition maps between the 24 bases for a Leonard pair
Nomura, Kazumasa
2007-01-01T23:59:59.000Z
Let $V$ denote a vector space with finite positive dimension. We consider a pair of linear transformations $A : V \\to V$ and $A^* : V \\to V$ that satisfy (i) and (ii) below: (i) There exists a basis for $V$ with respect to which the matrix representing $A$ is irreducible tridiagonal and the matrix representing $A^*$ is diagonal. (ii) There exists a basis for $V$ with respect to which the matrix representing $A^*$ is irreducible tridiagonal and the matrix representing $A$ is diagonal. We call such a pair a Leonard pair on $V$. In an earlier paper we described 24 special bases for $V$. One feature of these bases is that with respect to each of them the matrices that represent $A$ and $A^*$ are (i) diagonal and irreducible tridiagonal or (ii) irreducible tridiagonal and diagonal or (iii) lower bidiagonal and upper bidiagonal or (iv) upper bidiagonal and lower bidiagonal. For each ordered pair of bases among the 24, there exists a unique linear transformation from $V$ to $V$ that sends the first basis to the seco...
Singlet Free Energies of a Static Quark-Antiquark Pair
Konstantin Petrov
2004-09-01T23:59:59.000Z
We study the singlet part of the free energy of a static quark anti-quark pair at finite temperature in three flavor QCD with degenerate quark masses using $N_{\\tau}=4$ and 6 lattices with Asqtad staggered fermion action. We look at thermodynamics of the system around phase transition and study its scaling with lattice spacing and quark masses.
RELAXATION OF BLAZAR-INDUCED PAIR BEAMS IN COSMIC VOIDS
Miniati, Francesco [Physics Department, Wolfgang-Pauli-Strasse 27, ETH-Zuerich, CH-8093 Zuerich (Switzerland); Elyiv, Andrii, E-mail: fm@phys.ethz.ch [Institut d'Astrophysique et de Geophysique, Universite de Liege, B-4000 Liege (Belgium)
2013-06-10T23:59:59.000Z
The stability properties of a low-density ultrarelativistic pair beam produced in the intergalactic medium (IGM) by multi-TeV gamma-ray photons from blazars are analyzed. The problem is relevant for probes of magnetic field in cosmic voids through gamma-ray observations. In addition, dissipation of such beams could considerably affect the thermal history of the IGM and structure formation. We use a Monte Carlo method to quantify the properties of the blazar-induced electromagnetic shower, in particular the bulk Lorentz factor and the angular spread of the pair beam generated by the shower, as a function of distance from the blazar itself. We then use linear and nonlinear kinetic theory to study the stability of the pair beam against the growth of electrostatic plasma waves, employing the Monte Carlo results for our quantitative estimates. We find that the fastest growing mode, like any perturbation mode with even a very modest component perpendicular to the beam direction, cannot be described in the reactive regime. Due to the effect of nonlinear Landau damping, which suppresses the growth of plasma oscillations, the beam relaxation timescale is found to be significantly longer than the inverse Compton loss time. Finally, density inhomogeneities associated with cosmic structure induce loss of resonance between the beam particles and plasma oscillations, strongly inhibiting their growth. We conclude that relativistic pair beams produced by blazars in the IGM are stable on timescales that are long compared with the electromagnetic cascades. There appears to be little or no effect of pair beams on the IGM.
Observation of ?c1 Decays into Vector Meson Pairs ??, ?? and, ??
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ablikim, M.; Achasov, M. N.; An, L.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, M. Y.; Fan, R. R.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Grishin, S.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kavatsyuk, M.; Komamiya, S.; Kuehn, W.; Lange, J. S.; Leung, J. K. C.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Lei; Li, N. B.; Li, Q. J.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, G. C.; Liu, H.; Liu, H. B.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Z. Q.; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu.; Nefedov, Y.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Sonoda, S.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tang, X. F.; Tian, H. L.; Toth, D.; Varner, G. S.; Wan, X.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, M.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, L.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.; Zweber, P.
2011-08-01T23:59:59.000Z
Using (106±4)×10? ?(3686) events accumulated with the BESIII detector at the BEPCII e?e? collider, we present the first measurement of decays of ?c1 to vector meson pairs ??, ??, and ??. The branching fractions are measured to be (4.4±0.3±0.5)×10??, (6.0±0.3±0.7)×10??, and (2.2±0.6±0.2)×10??, for ?c1 ???, ??, and ??, respectively, which indicates that the hadron helicity selection rule is significantly violated in ?cJ decays. In addition, the measurement of ?cJ??? provides the first indication of the rate of doubly OZI-suppressed ?cJ decay. Finally, we present improved measurements for the branching fractions of ?c0 and ?c2 to vector meson pairs.
Transversity Signal in two Hadron Pair Production in COMPASS
H. Wollny; for the COMPASS collaboration
2009-07-06T23:59:59.000Z
Measuring single spin asymmetries in semi-inclusive deep-inelastic scattering (SIDIS) on a transversely polarized target gives a handle to investigate the transversity distribution and transverse momentum dependent distribution functions. In the years 2002, 2003 and 2004 COMPASS took data with a transversely polarized deuteron target and in the year 2007 with a proton target. Three channels for accessing transversity have been analysed. Azimuthal asymmetries in the production of hadron pairs, involving the polarized two hadron interference fragmentation function, azimuthal asymmetries in the production of single hadrons, involving the Collins fragmentation function and polarization measurements of spin-${1/2} \\hbar$ particles like $\\Lambda$-Hyperons via their self analyzing weak decay. In the following we will focus on new preliminary results from the analysis of two hadron pair asymmetries measured with the proton target.
Threshold energy surface and Frenkel-pair resistivity for Cu
King, W.E.; Merkle, K.L.; Meshii, M.
1982-01-01T23:59:59.000Z
In-situ electrical resistivity damage-rate measurements in the high voltage electron microscope have been used to study electron-irradiation-induced defect production in copper single crystals at T < 10/sup 0/K. Analysis of the directional and energy dependence yields a threshold energy surface that is significantly different from those of previous investigations: two pockets of low threshold energy centered at <100> and <110> surrounded by regions of much higher threshold energy. The corresponding damage function exhibits a plateau of 0.6 Frenkel pairs. the present results imply a Frenkel pair resistivity for C of (2.75/sub -0.2//sup +0.6/) x ..cap omega..-cm.
Flow localization in sheet specimens with pairs of holes
Geltmacher, A.B. [FM Technologies, Fairfax, VA (United States); Koss, D.A. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Metals Science and Engineering; Stout, M.G. [Los Alamos National Lab., NM (United States); Matic, P. [Naval Research Lab., Washington, DC (United States). Mechanics of Materials Dept.
1998-03-01T23:59:59.000Z
The deformation localization behavior of sheet specimens containing geometric perturbations in the form of pairs of through-thickness holes is examined. Both experiments and computational modeling are performed in either uniaxial or equal-biaxial tension in order to examine the effect of applied loading path on the far-field strain needed to initiate localized necking in the ligament between the hole pairs. The models also examine the influence of hole spacing and matrix strain hardening on ligament localization. The far-field strain needed to cause the localization of the ligament is shown to increase as the biaxiality of the loading path increases, the hole spacing increases, and the strain-hardening exponent increases. The present study also indicates that the onset of localized necking can be predicted by employing the Hill criterion, if the local strain states within the ligament are taken into account.
Eigenstate Localization in an Asymmetric Coupled Quantum Well Pair
Mialitsin, A.; Schmult, S.; Solov'yov, I. A.; Fluegel, B.; Mascarenhas, A.
2012-06-01T23:59:59.000Z
Optical pumping of a type-I/type-II coupled asymmetric quantum well pair induces a spatially separated two dimensional charge carriers plasma in the well's wide and narrow parts. Treating the two coupled wells as a single system we find that the eigenstate probability distribution localizes exclusively either in the wide or the narrow parts of the well pair. The energy of the narrow-well localized state determines the minimal excitation energy for optically pumped charge carriers separation. In a previously used design [Guliamov et al., PRB 64 035314 (2001)] this narrow well transition energy was measured to correspond to a wavelength of 646 nm. We propose modifications to the design suggested earlier with the purpose of pushing up the energy required for the optical pumping of the two-dimensional plasma into the green and blue regions of the visible spectrum.
Electron and positron pair production of compact stars
Wen-Biao Han; Remo Ruffini; She-Sheng Xue
2012-09-15T23:59:59.000Z
Neutral stellar core at or over nuclear densities is described by a positive charged baryon core and negative charged electron fluid since they possess different masses and interactions. Based on a simplified model of a gravitationally collapsing or pulsating baryon core, we approximately integrate the Einstein-Maxwell equations and the equations for the number and energy-momentum conservation of complete degenerate electron fluid. We show possible electric processes that lead to the production of electron-positron pairs in the boundary of a baryon core and calculate the number and energy of electron-positron pairs. This can be relevant for understanding the energetic sources of supernovae and gamma-ray bursts.
Pair Instability Supernovae of Very Massive Population III Stars
Chen, Ke-Jung; Woosley, Stan; Almgren, Ann; Whalen, Daniel
2014-01-01T23:59:59.000Z
Numerical studies of primordial star formation suggest that the first stars in the universe may have been very massive. Stellar models indicate that non-rotating Population III stars with initial masses of 140-260 Msun die as highly energetic pair-instability supernovae. We present new two-dimensional simulations of primordial pair-instability supernovae done with the CASTRO code. Our simulations begin at earlier times than previous multidimensional models, at the onset of core collapse, to capture any dynamical instabilities that may be seeded by collapse and explosive burning. Such instabilities could enhance explosive yields by mixing hot ash with fuel, thereby accelerating nuclear burning, and affect the spectra of the supernova by dredging up heavy elements from greater depths in the star at early times. Our grid of models includes both blue supergiants and red supergiants over the range in progenitor mass expected for these events. We find that fluid instabilities driven by oxygen and helium burning ari...
Pair Creation and an X-ray Free Electron Laser
R. Alkofer; M. B. Hecht; C. D. Roberts; S. M. Schmidt; D. V. Vinnik
2001-08-17T23:59:59.000Z
Using a quantum kinetic equation coupled to Maxwell's equation we study the possibility that focused beams at proposed X-ray free electron laser facilities can generate electric field strengths large enough to cause spontaneous electron-positron pair production from the QED vacuum. Our approach yields the time and momentum dependence of the single particle distribution function. Under conditions reckoned achievable at planned facilities, repeated cycles of particle creation and annihilation take place in tune with the laser frequency. However, the peak particle number density is insensitive to this frequency and one can anticipate the production of a few hundred particle pairs per laser period. Field-current feedback and quantum statistical effects are small and can be neglected in this application of non-equilibrium quantum mean field theory.
Proton-neutron pairing energies in N=Z nuclei at finite temperature
K. Kaneko; M. Hasegawa
2005-08-27T23:59:59.000Z
Thermal behavior of isoscalar and isovector proton-neutron (pn) pairing energies at finite temperature are investigated by the shell model calculations. These pn pairing energies can be estimated by double differences of "thermal" energies which are extended from the double differences of binding energies as the indicators of pn pairing energies at zero temperature. We found that the delicate balance between isoscalar and isovector pn pairing energies at zero temperature disappears at finite temperature. When temperature rises, while the isovector pn pairing energy decreases, the isoscalar pn pairing energy rather increases. We discuss also the symmetry energy at finite temperature.
Fourier Transform Pairs The Fourier transform transforms a function of
Masci, Frank
Fourier Transform Pairs The Fourier transform transforms a function of time, f(t), into a function of frequency, F(s): F {f(t)}(s) = F(s) = Z - f(t)e- j2st dt. The inverse Fourier transform transforms a func. The inverse Fourier transform of the Fourier trans- form is the identity transform: f(t) = Z - Z - f()e- j2s
Double Pair Production by Ultra High Energy Cosmic Ray Photons
S. V. Demidov; O. E. Kalashev
2008-12-22T23:59:59.000Z
With use of CompHEP package we've made the detailed estimate of the influence of double e+e- pair production by photons (DPP) on the propagation of ultra high energy electromagnetic cascade. We show that in the models in which cosmic ray photons energy reaches few thousand EeV refined DPP analysis may lead to substantial difference in predicted photon spectrum compared to previous rough estimates.
Sedimentation of pairs of hydrodynamically interacting semiflexible filaments
Isaac Llopis; Ignacio Pagonabarraga; Marco Cosentino Lagomarsino; Christopher P. Lowe
2007-10-08T23:59:59.000Z
We describe the effect of hydrodynamic interactions in the sedimentation of a pair of inextensible semiflexible filaments under a uniform constant force at low Reynolds numbers. We have analyzed the different regimes and the morphology of such polymers in simple geometries, which allow us to highlight the peculiarities of the interplay between elastic and hydrodynamic stresses. Cooperative and symmetry breaking effects associated to the geometry of the fibers gives rise to characteristic motion which give them distinct properties from rigid and elastic filaments.
HBT interferometry with quantum transport of the interfering pair
Yu, Li-Li; Wong, Cheuk-Yin
2008-01-01T23:59:59.000Z
In the late stage of the evolution of a pion system in high-energy heavy-ion collisions when pions undergo multiple scatterings, the quantum transport of the interfering pair of identical pions plays an important role in determining the characteristics of the Hanbury-Brown-Twiss (HBT) interference. We study the quantum transport of the interfering pair using the path-integral method, in which the evolution of the bulk matter is described by relativistic hydrodynamics while the paths of the two interfering pions by test particles following the fluid positions and velocity fields. We investigate in addition the effects of secondary pion sources from particle decays, for nuclear collisions at AGS and RHIC energies. We find that quantum transport of the interfering pair leads to HBT radii close to those for the chemical freeze-out configuration. Particle decays however lead to HBT radii greater than those for the chemical freeze-out configuration. As a consequence, the combined effects give rise to HBT radii betw...
Equilibrium cluster fluids: Pair interactions via inverse design
Ryan B. Jadrich; Jonathan A. Bollinger; Beth A. Lindquist; Thomas M. Truskett
2015-09-14T23:59:59.000Z
Inverse methods of statistical mechanics are becoming productive tools in the design of materials with specific microstructures or properties. While initial studies have focused on solid-state design targets (e.g, assembly of colloidal superlattices), one can alternatively design fluid states with desired morphologies. This work addresses the latter and demonstrates how a simple iterative Boltzmann inversion strategy can be used to determine the isotropic pair potential that reproduces the radial distribution function of a fluid of amorphous clusters with prescribed size. The inverse designed pair potential of this "ideal" cluster fluid, with its broad attractive well and narrow repulsive barrier at larger separations, is qualitatively different from the so-called SALR form most commonly associated with equilibrium cluster formation in colloids, which features short-range attractive (SA) and long-range repulsive (LR) contributions. These differences reflect alternative mechanisms for promoting cluster formation with an isotropic pair potential, and they in turn produce structured fluids with qualitatively different static and dynamic properties. Specifically, equilibrium simulations show that the amorphous clusters resulting from the inverse designed potentials display more uniformity in size and shape, and they also show greater spatial and temporal resolution than those resulting from SALR interactions.
RG-Improved Predictions for Top-Quark Pair Production at
California at Santa Cruz, University of
RG-Improved Predictions for Top-Quark Pair Production at Hadron Colliders Matthias Neubert Johannes Threshold resummation for Higgs production Threshold resummation for top-quark pair production Valentin
Azevedo, Ricardo
of Refugees Job Description Houston-based Partnership for the Advancement & Immersion of Refugees (PAIR) (www volunteers serving more than 200 refugees per year, PAIR empowers refugee youth to reach their full potential in the community to foster an understanding of the needs of young refugees and the role of PAIR's programs
Single-molecule derivation of salt dependent base-pair free energies in DNA
Ritort, Felix
Single-molecule derivation of salt dependent base-pair free energies in DNA Josep M. Hugueta measurements of base-pair free energies in DNA are obtained in thermal denaturation experiments, which depend on several as- sumptions. Here we report measurements of the DNA base-pair free energies based
Hydrologic calibration of paired watersheds using a MOSUM approach
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ssegane, H.; Amatya, D. M.; Muwamba, A.; Chescheir, G. M.; Appelboom, T.; Tollner, E. W.; Nettles, J. E.; Youssef, M. A.; Birgand, F.; Skaggs, R. W.
2015-01-09T23:59:59.000Z
Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1–3 year intensively managedmore »loblolly pine (Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass (Panicum virgatum), 14–15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash–Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.« less
Free energy and criticality in the nucleon pair breaking process
M. Guttormsen; R. Chankova; M. Hjorth-Jensen; J. Rekstad; S. Siem; A. Schiller; D. J. Dean
2003-07-29T23:59:59.000Z
Experimental level densities for 171,172Yb, 166,167Er, 161,162Dy, and 148,149Sm are analyzed within the microcanonical ensemble. In the even isotopes at excitation energies E energy F signals the transition from zero to two quasiparticles. For E > 2 MeV, the odd and even isotopes reveal a surprisingly constant F at a critical temperature Tc of appr. 0.5 MeV, indicating the continuous melting of nucleon Cooper pairs as function of excitation energy.
Gluon polarisation from high transverse momentum hadron pairs production (COMPASS)
L. Silva; for the COMPASS Collaboration
2010-10-08T23:59:59.000Z
A new preliminary result of a gluon polarisation \\Delta G/G obtained selecting high transverse momentum hadron pairs in DIS events with Q^2>1 (GeV/c)^2 is presented. Data has been collected by COMPASS at CERN during the 2002-2004 years. In the extraction of $\\Delta G/G$ contributions coming from the leading order $\\gamma q$ and QCD processes are taken into account. A new weighting method based on a neural network approach is used. Also a preliminary result of \\Delta G/G for events with Q^2<1 (GeV/c)^2 is presented.
Lepton-pair production in nuclear collisions - past, present, future
H. J. Specht
2007-10-29T23:59:59.000Z
The key results on lepton-pair production in ultra-relativistic nuclear collisions are shortly reviewed, starting at the roots of pp collisions in the seventies, and ending at the perspectives of the colliders RHIC and LHC. The presence is dominated by the recent precision results from NA60 at the CERN SPS, culminating in the first measurement of the in-medium rho spectral function and the transverse flow of the associated thermal radiation. The seeming cut-off of the flow above the rho may well be the first direct hint for thermal radiation of partonic origin in nuclear collisions. The major milestones in the theoretical developments are also covered.
A semiconductor source of triggered entangled photon pairs?
A. Gilchrist; K. J. Resch; A. G. White
2006-08-08T23:59:59.000Z
The realisation of a triggered entangled photon source will be of great importance in quantum information, including for quantum key distribution and quantum computation. We show here that: 1) the source reported in ``A semiconductor source of triggered entangled photon pairs''[1. Stevenson et al., Nature 439, 179 (2006)]} is not entangled; 2) the entanglement indicators used in Ref. 1 are inappropriate, relying on assumptions invalidated by their own data; and 3) even after simulating subtraction of the significant quantity of background noise, their source has insignificant entanglement.
Automated Complexity Analysis Based on the Dependency Pair Method
Hirokawa, Nao
2011-01-01T23:59:59.000Z
This article is concerned with automated complexity analysis of term rewrite systems (TRSs for short). Since these systems underlie much of declarative programming, time complexity of functions defined by TRSs is of particular interest. Among other results, we present a variant of the dependency pair method for analysing runtime complexities of term rewrite systems automatically. The established results significantly extent previously known techniques: we give examples of TRSs subject to our methods that could previously not been analysed automatically. Furthermore, the techniques have been implemented in the Tyrolean Complexity Tool. We provide ample numerical data for assessing the viability of the method.
Paired Straight Hearth Furnace-Transformational Ironmaking Process
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:DepartmentExecutive Secretariat, MA-70 ActingOverviewEnergy 0 - InSite This is a RequestPaired
HOM Survey of the First CEBAF Upgrade Style Cavity Pair
Marhauser, Frank; Davis, G; Drury, Michael; Grenoble, Christiana; Hogan, John; Manus, Robert; Preble, Joseph; Reece, Charles; Rimmer, Robert; Tian, Kai
2009-05-01T23:59:59.000Z
The planned upgrade of the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Laboratory (JLab) requires ten new superconducting rf (SRF) cavity cryomodules to double the beam energy to the envisaged 12 GeV. Adequate cavity Higher Order Mode (HOM) suppression is essential to avoid multipass, multibunch beam break-up (BBU) instabilities of the recirculating beam. We report on detailed HOM surveys performed for the first two upgrade style cavities tested in a dedicated cavity pair cryomodule at 2K. The safety margin to the BBU threshold budget at 12 GeV has been assessed.
Radiative emission of neutrino pair free of quantum electrodynamic backgrounds
M. Yoshimura; N. Sasao; M. Tanaka
2015-01-23T23:59:59.000Z
A scheme of quantum electrodynamic (QED) background-free radiative emission of neutrino pair (RENP) is proposed in order to achieve precision determination of neutrino properties so far not accessible. The important point for the background rejection is the fact that the dispersion relation between wave vector along propagating direction in wave guide (and in a photonic-crystal type fiber) and frequency is modified by a discretized non-vanishing effective mass. This effective mass acts as a cutoff of allowed frequencies, and one may select the RENP photon energy region free of all macro-coherently amplified QED processes by choosing the cutoff larger than the mass of neutrinos.
Infinitely many pairs of primes $p$ and $p+2$
Guangchang Dong
2015-03-20T23:59:59.000Z
When $p$ and $p+2$ are primes, such as $3,5; 5,7; 11,13; 17,19; ...$. We call them pairs of prime twins. In this paper we use sieve method (Liu sieve) to construct the weak solution (i.e. formal solution) of prime twins. Then we use auxiliary special 4 sieve problem and its biological model to prove that weak equals classical, i.e. the weak solution is a classical one, hence the numbers of prime twins are infinite.
Seems a Fate in It: Misdirection and Foreshadowing in Bleak House and A Pair of Blue Eyes
Bradfield, Meredith
2013-01-01T23:59:59.000Z
for Action in A Pair of Blue Eyes. ” English Literature in2013). Hardy, Thomas. A Pair of Blue Eyes. Harmondsworth,aware of Thomas Hardy. A Pair of Blue Eyes. (Harmondsworth,
Electrostatic ion waves in non-Maxwellian pair-ion plasmas
Arshad, Kashif [Department of Physics, Quaid-i-Azam University, Islamabad 44000 (Pakistan); National Centre for Physics, Quaid-i-Azam University Campus, Shadhra Valley Road, Islamabad 44000 (Pakistan); Mahmood, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); National Centre for Physics, Quaid-i-Azam University Campus, Shadhra Valley Road, Islamabad 44000 (Pakistan)
2010-12-15T23:59:59.000Z
The electrostatic ion waves are studied for non-Maxwellian or Lorentzian distributed unmagnetized pair-ion plasmas. The Vlasov equation is solved and damping rates are calculated for electrostatic waves in Lorentzian pair-ion plasmas. The damping rates of the electrostatic ion waves are studied for the equal and different ion temperatures of pair-ion species. It is found that the Landau damping rate of the ion plasma wave is increased in Lorentzian plasmas in comparison with Maxwellian pair-ion plasmas. The numerical results are also presented for illustration by taking into account the parameters reported in fullerene pair-ion plasma experiments.
Hartree-Fock-Bogoliubov solution of the pairing Hamiltonian in finite nuclei
Dobaczewski, J
2012-01-01T23:59:59.000Z
We present an overview of the Hartree-Fock-Bogoliubov (HFB) theory of nucleonic superfluidity for finite nuclei. After introducing basic concepts related to pairing correlations, we show how the correlated pairs are incorporated into the HFB wave function. Thereafter, we present derivation and structure of the HFB equations within the superfluid nuclear density functional formalism and discuss several aspects of the theory, including the unitarity of the Bogoliubov transformation in truncated single-particle and quasiparticle spaces, form of the pairing functional, structure of the HFB continuum, regularization and renormalization of pairing fields, and treatment of pairing in systems with odd particle numbers.
Creation of Electron Spinless Pairs in the Superconductivity
V. N. Minasyan
2009-03-28T23:59:59.000Z
First, it is demonstrated that the Froolich Hamiltonian of system in the superconductivity, proposed by the model of a phonon gas and an electron gas mixture, contains a subtle error. In this respect, we present a correct form of the Froolich Hamiltonian of system where the term of the interaction between the phonon modes and the density modes of the electron modes is described by the term of scattering, introduced by the Froolich in a phonon gas electron gas mixture. The later is removed by a canonical transformation of the Froolich Hamiltonian by an appearance of the attractive interaction mediated via the electron modes, which leads to a bound state on a spinless electron pairs. In this letter, we show that the Cooper approximation as the constancy of the density states within around of the Fermi level has a flaw because the effective attractive forces cannot create the Cooper pairs into energetic gap at the Fermi level. In this letter, we find a condition for density metal which determines metal as superconductor.
Pair production of color-octet scalars at the LHC
Idilbi, Ahmad [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Departamento de Fisica Teorica II, Universidad Complutense de Madrid, 28040 Madrid (Spain); Kim, Chul [Department of Physics, Duke University, Durham, North Carolina 27708 (United States); Theory Division, Department of Physics, CERN, CH-1211, Geneva 23 (Switzerland); Mehen, Thomas [Department of Physics, Duke University, Durham, North Carolina 27708 (United States)
2010-10-01T23:59:59.000Z
Heavy colored scalar particles, which exist in many models of new physics, can be pair produced at the LHC via gluon-gluon fusion and possibly form quarkoniumlike bound states. If the scalars are also charged under the electroweak gauge group, these bound states can then decay into electroweak bosons. This yields a resonant cross section for final states such as {gamma}{gamma} that can exceed standard model backgrounds. This paper studies this process in the Manohar-Wise model of color-octet scalars (COS). Important threshold logarithms and final state Coulomb-like QCD interactions are resummed using effective field theory. We compute the resummed cross section for gluon-gluon fusion to COS pairs at the LHC as well as the resonant cross section for octetonium decaying to {gamma}{gamma}. The latter cross section exceeds the standard model diphoton cross section when the COS mass is less than 500 (350) GeV for {radical}(s)=14(7) TeV. Nonobservation of resonances below these energies can significantly improve existing bounds on COS masses.
Pair instability supernovae of very massive population III stars
Chen, Ke-Jung; Woosley, Stan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Almgren, Ann [Center for Computational Sciences and Engineering, Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States); Whalen, Daniel J., E-mail: kchen@ucolick.org [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-09-01T23:59:59.000Z
Numerical studies of primordial star formation suggest that the first stars in the universe may have been very massive. Stellar models indicate that non-rotating Population III stars with initial masses of 140-260 M {sub ?} die as highly energetic pair-instability supernovae. We present new two-dimensional simulations of primordial pair-instability supernovae done with the CASTRO code. Our simulations begin at earlier times than previous multidimensional models, at the onset of core contraction, to capture any dynamical instabilities that may be seeded by core contraction and explosive burning. Such instabilities could enhance explosive yields by mixing hot ash with fuel, thereby accelerating nuclear burning, and affect the spectra of the supernova by dredging up heavy elements from greater depths in the star at early times. Our grid of models includes both blue supergiants and red supergiants over the range in progenitor mass expected for these events. We find that fluid instabilities driven by oxygen and helium burning arise at the upper and lower boundaries of the oxygen shell ?20-100 s after core bounce. Instabilities driven by burning freeze out after the SN shock exits the helium core. As the shock later propagates through the hydrogen envelope, a strong reverse shock forms that drives the growth of Rayleigh-Taylor instabilities. In red supergiant progenitors, the amplitudes of these instabilities are sufficient to mix the supernova ejecta.
FINDING THE FIRST COSMIC EXPLOSIONS. I. PAIR-INSTABILITY SUPERNOVAE
Whalen, Daniel J.; Smidt, Joseph; Lovekin, C. C. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Even, Wesley; Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Frey, Lucille H. [HPC-3, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Johnson, Jarrett L.; Hungerford, Aimee L. [XTD-6, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Holz, Daniel E. [Enrico Fermi Institute, Department of Physics, and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Victoria 3800 (Australia); Woosley, S. E. [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States)
2013-11-10T23:59:59.000Z
The first stars are the key to the formation of primitive galaxies, early cosmological reionization and chemical enrichment, and the origin of supermassive black holes. Unfortunately, in spite of their extreme luminosities, individual Population III (Pop III) stars will likely remain beyond the reach of direct observation for decades to come. However, their properties could be revealed by their supernova explosions, which may soon be detected by a new generation of near-IR (NIR) observatories such as JWST and WFIRST. We present light curves and spectra for Pop III pair-instability supernovae calculated with the Los Alamos radiation hydrodynamics code RAGE. Our numerical simulations account for the interaction of the blast with realistic circumstellar envelopes, the opacity of the envelope, and Lyman absorption by the neutral intergalactic medium at high redshift, all of which are crucial to computing the NIR signatures of the first cosmic explosions. We find that JWST will detect pair-instability supernovae out to z ?> 30, WFIRST will detect them in all-sky surveys out to z ? 15-20, and LSST and Pan-STARRS will find them at z ?< 7-8. The discovery of these ancient explosions will probe the first stellar populations and reveal the existence of primitive galaxies that might not otherwise have been detected.
Top quark pair production and top quark properties at CDF
Chang-Seong Moon
2014-11-01T23:59:59.000Z
We present the most recent measurements of top quark pairs production and top quark properties in proton-antiproton collisions with center-of-mass energy of 1.96 TeV using CDF II detector at the Tevatron. The combination of top pair production cross section measurements and the direct measurement of top quark width are reported. The test of Standard Model predictions for top quark decaying into $b$-quarks, performed by measuring the ratio $R$ between the top quark branching fraction to $b$-quark and the branching fraction to any type of down quark is shown. The extraction of the CKM matrix element $|V_{tb}|$ from the ratio $R$ is discussed. We also present the latest measurements on the forward-backward asymmetry ($A_{FB}$) in top anti-top quark production. With the full CDF Run II data set, the measurements are performed in top anti-top decaying to final states that contain one or two charged leptons (electrons or muons). In addition, we combine the results of the leptonic forward-backward asymmetry in $t\\bar t$ system between the two final states. All the results show deviations from the next-to-leading order (NLO) standard model (SM) calculation.
Search for pair production of second generation scalar leptoquarks
Abazov, V.M.; /Dubna, JINR; Abbott, B.; /Oklahoma U.; Abolins, M.; /Michigan State U.; Acharya, B.S.; /Tata Inst.; Adams, M.; /Illinois U., Chicago; Adams, T.; /Florida State U.; Aguilo, E.; /Alberta U. /Simon Fraser U. /York U., Canada /McGill U.; Ahsan, M.; /Kansas State U.; Alexeev, G.D.; /Dubna, JINR; Alkhazov, Georgiy D.; /St. Petersburg, INP; Alton, Andrew K.; /Michigan U. /Northeastern U.
2008-08-01T23:59:59.000Z
We report on a search for the pair production of second generation scalar leptoquarks (LQ) in p{bar p} collisions at the center of mass energy {radical}s = 1.96TeV using a data set corresponding to an integrated luminosity of 1.0 fb{sup -1} collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies arising from the LQ{ovr LQ} {yields} {mu}q{nu}q and LQ{ovr LQ} {yields} {mu}q{mu}q decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction {beta} for the decay LQ {yields} {mu}q. These are interpreted as lower limits on the leptoquark mass as a function of {beta}. For {beta} = 1 (0.5), scalar second generation leptoquarks with masses up to 316GeV (270GeV) are excluded.
State recovery and lockstep execution restart in a system with multiprocessor pairing
Gara, Alan; Gschwind, Michael K; Salapura, Valentina
2014-01-21T23:59:59.000Z
System, method and computer program product for a multiprocessing system to offer selective pairing of processor cores for increased processing reliability. A selective pairing facility is provided that selectively connects, i.e., pairs, multiple microprocessor or processor cores to provide one highly reliable thread (or thread group). Each paired microprocessor or processor cores that provide one highly reliable thread for high-reliability connect with a system components such as a memory "nest" (or memory hierarchy), an optional system controller, and optional interrupt controller, optional I/O or peripheral devices, etc. The memory nest is attached to a selective pairing facility via a switch or a bus. Each selectively paired processor core is includes a transactional execution facility, whereing the system is configured to enable processor rollback to a previous state and reinitialize lockstep execution in order to recover from an incorrect execution when an incorrect execution has been detected by the selective pairing facility.
Dynamically tunable Fano resonance in periodically asymmetric graphene nanodisk pair
Zhang, Zhengren; Fan, Yuancheng; Yin, Pengfei; Zhang, Liwei; Shi, Xi
2015-01-01T23:59:59.000Z
We present a dynamically frequency tunable Fano resonance planar device composed of periodically asymmetric graphene nanodisk pair for the mid-infrared region. There are two kinds of modes in this structure, that is, the symmetric mode and the antisymmetric mode. The resonance coupling between the symmetric and antisymmetric modes creates a classical Fano resonance. Both of the Fano resonance amplitude and frequency of the structure can be dynamically controlled by varying the Fermi energy of graphene. Resonance transition in the structure is studied to reveal the physical mechanism behind the dynamically tunable Fano resonance. The features of the Fano resonant graphene nanostructures should have promising applications in tunable THz filters, switches, and modulators.
Reduction in maximum time uncertainty of paired time signals
Theodosiou, George E. (West Chicago, IL); Dawson, John W. (Clarendon Hills, IL)
1983-01-01T23:59:59.000Z
Reduction in the maximum time uncertainty (t.sub.max -t.sub.min) of a series of paired time signals t.sub.1 and t.sub.2 varying between two input terminals and representative of a series of single events where t.sub.1 .ltoreq.t.sub.2 and t.sub.1 +t.sub.2 equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t.sub.min) of the first signal t.sub.1 closer to t.sub.max and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20-800.
Reduction in maximum time uncertainty of paired time signals
Theodosiou, G.E.; Dawson, J.W.
1983-10-04T23:59:59.000Z
Reduction in the maximum time uncertainty (t[sub max]--t[sub min]) of a series of paired time signals t[sub 1] and t[sub 2] varying between two input terminals and representative of a series of single events where t[sub 1][<=]t[sub 2] and t[sub 1]+t[sub 2] equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t[sub min]) of the first signal t[sub 1] closer to t[sub max] and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20--800. 6 figs.
Reduction in maximum time uncertainty of paired time signals
Theodosiou, G.E.; Dawson, J.W.
1981-02-11T23:59:59.000Z
Reduction in the maximum time uncertainty (t/sub max/ - t/sub min/) of a series of paired time signals t/sub 1/ and t/sub 2/ varying between two input terminals and representative of a series of single events where t/sub 1/ less than or equal to t/sub 2/ and t/sub 1/ + t/sub 2/ equals a constant, is carried out with a circuit utilizing a combination of OR and AND gates as signal selecting means and one or more time delays to increase the minimum value (t/sub min/) of the first signal t/sub 1/ closer to t/sub max/ and thereby reduce the difference. The circuit may utilize a plurality of stages to reduce the uncertainty by factors of 20 to 800.
Valley pair qubits in double quantum dots of gapped graphene
G. Y. Wu; N. -Y. Lue; L. Chang
2011-07-03T23:59:59.000Z
The rise of graphene opens a new door to qubit implementation, as discussed in the recent proposal of valley pair qubits in double quantum dots of gapped graphene (Wu et al., arXiv: 1104.0443 [cond-mat.mes-hall]). The work here presents the comprehensive theory underlying the proposal. It discusses the interaction of electrons with external magnetic and electric fields in such structures. Specifically, it examines a strong, unique mechanism, i.e., the analogue of the 1st-order relativistic effect in gapped graphene. This mechanism is state mixing free and allows, together with the electrically tunable exchange coupling, a fast, all-electric manipulation of qubits via electric gates, in the time scale of ns. The work also looks into the issue of fault tolerance in a typical case, yielding at 10oK a long qubit coherence time (~O(ms)).
One-photon pair production on de Sitter spacetime
Blaga, Robert
2015-01-01T23:59:59.000Z
We study the one-photon scalar pair production QED process on the expanding de Sitter spacetime. Using perturbation theory, we obtain the transition probability and study its properties as a function of the expansion parameter $\\omega$. On flat space the process is forbidden by energy-momentum conservation. It is expected that for a dynamical background there is an energy exchange correlate to the strength of the gravitational field. We use momentum space plots and compute the mean production angle to illustrate this. We show that the mean angle grows with $\\omega$, but also find that in the flat limit the fall-off is unexpectedly slow. To investigate this further we obtain the probability around different angular configuration, at leading order in $m/\\omega$, and find that the $\\omega$ dependence at small angles is very weak. We comment on the possible astrophysical implications.
EPR pairing dynamics in Hubbard model with resonant $U$
X. Z. Zhang; Z. Song
2015-04-28T23:59:59.000Z
We study the dynamics of the collision between two fermions in Hubbard model with on-site interaction strength $U$. The exact solution shows that the scattering matrix for two-wavepacket collision is separable into two independent parts, operating on spatial and spin degrees of freedom, respectively. The S-matrix for spin configuration is equivalent to that of Heisenberg-type pulsed interaction with the strength depending on $U$ and relative group velocity $\\upsilon _{r}$. This can be applied to create distant EPR pair, through a collision process for two fermions with opposite spins in the case of $\\left\\vert \\upsilon _{r}/U\\right\\vert =1$,\\ without the need for temporal control and measurement process. Multiple collision process for many particles is also discussed.
Reexamination of an anomaly in near-threshold pair production
De Braeckeleer, L.; Adelberger, E.G.; Garcia, A. (Physics Department FM-15, University of Washington, Seattle, Washington 98195 (United States))
1992-11-01T23:59:59.000Z
We investigated a reported anomaly in near-threshold pair production, using radioactive sources to measure the {gamma}+Ge{r arrow}{ital e}{sup +}+{ital e}{sup {minus}}+Ge cross-section at {ital E}{sub {gamma}}=1063, 1086, 1112, 1173, 1213, 1299, 1332, and 1408 keV. Although the data agree with the theory (numerical calculations based on an exact partial-wave formulation for a screened central potential) at the higher energies, the data lie above the theory at 1063, 1082, and 1112 keV. The discrepancy is reduced by including the final-state Coulomb interaction between the {ital e}{sup +} and {ital e}{sup {minus}}.
Reconstructing particle masses from pairs of decay chains
Mihoko M. Nojiri; Kazuki Sakurai; Bryan R. Webber
2010-06-01T23:59:59.000Z
A method is proposed for determining the masses of the new particles N,X,Y,Z in collider events containing a pair of effectively identical decay chains Z to Y+jet, Y to X+l_1, X to N+l_2, where l_1, l_2 are opposite-sign same-flavour charged leptons and N is invisible. By first determining the upper edge of the dilepton invariant mass spectrum, we reduce the problem to a curve for each event in the 3-dimensional space of mass-squared differences. The region through which most curves pass then determines the unknown masses. A statistical approach is applied to take account of mismeasurement of jet and missing momenta. The method is easily visualized and rather robust against combinatorial ambiguities and finite detector resolution. It can be successful even for small event samples, since it makes full use of the kinematical information from every event.
Kaon pair production in proton-nucleus collisions
Yu. T. Kiselev; M. Hartmann; A. Polyanskiy; E. Ya. Paryev; S. Barsov; M. Buescher; S. Dymov; R. Gebel; V. Hejny; A. Kacharava; I. Keshelashvili; B. Lorentz; Y. Maeda; S. Merzliakov; S. Mikirtytchiants; H. Ohm; V. Serdyuk; A. Sibirtsev; V. Y. Sinitsyna; H. J. Stein; H. Stroeher; S. Trusov; Yu. Valdau; C. Wilkin; P. Wuestner; Q. J. Ye
2015-09-16T23:59:59.000Z
The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.
Kaon pair production in proton-nucleus collisions
Kiselev, Yu T; Polyanskiy, A; Paryev, E Ya; Barsov, S; Buescher, M; Dymov, S; Gebel, R; Hejny, V; Kacharava, A; Keshelashvili, I; Lorentz, B; Maeda, Y; Merzliakov, S; Mikirtytchiants, S; Ohm, H; Serdyuk, V; Sibirtsev, A; Sinitsyna, V Y; Stein, H J; Stroeher, H; Trusov, S; Valdau, Yu; Wilkin, C; Wuestner, P; Ye, Q J
2015-01-01T23:59:59.000Z
The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.
The Holmberg effect of Main galaxy pairs of the SDSS Data Release 4 (SDSS4)
Deng Xin-Fa; Ma Xin-Sheng; He Con-Gen; Luo Cheng-Hong; He Ji-Zhou
2006-05-12T23:59:59.000Z
We have investigated the Holmberg effect of Main galaxy pairs of the SDSS Data Release 4 (SDSS4). It is found that except i-z color the color indices between the two components of Main galaxy pairs clearly have significantly larger correlation coefficients. Further analyses also show that the Holmberg Effect of galaxies not only depends on the color indices but also on the morphological type for two components of pairs.
M. Hendrych; M. Mi?uda; A. Valencia; J. P. Torres
2009-08-13T23:59:59.000Z
We present an experimental demonstration of the full control of the frequency correlations of entangled photon pairs. The joint spectrum of photon pairs is continuously varied from photons that exhibit anticorrelation in frequency to photons that exhibit correlation in frequency, passing through the case of uncorrelated photons. Highly entangled frequency-anticorrelated photon pairs were obtained even when an ultrafast laser was used as a pump. The different kinds of correlations are obtained without changing neither the wavelength, nor the nonlinear crystal.
Pairing effect in thermal shape fluctuation model on the width of giant dipole resonance
A. K. Rhine Kumar; P. Arumugam; N. Dinh Dang
2014-09-23T23:59:59.000Z
We present an approach that includes temperature-dependent shell effects and fluctuations of the pairing field in the thermal shape fluctuation model (TSFM). We apply this approach to study the width of giant dipole resonance (GDR) in $^{97}$Tc, $^{120}$Sn and $^{208}$Pb. Our results demonstrate that the TSFM that includes pairing fluctuations can explain the recently observed quenching in the GDR width. We also show that to validate pairing prescriptions and the parameters involved, we require more and precise data.
Pair correlations in nuclei involved in neutrinoless double beta decay: 76Ge and 76Se
S. J. Freeman; J. P. Schiffer; A. C. C. Villari; J. A. Clark; C. Deibel; S. Gros; A. Heinz; D. Hirata; C. L. Jiang; B. P. Kay; A. Parikh; P. D. Parker; J. Qian; K. E. Rehm; X. D. Tang; V. Werner; C. Wrede
2007-03-23T23:59:59.000Z
Precision measurements were carried out to test the similarities between the ground states of 76Ge and 76Se. The extent to which these two nuclei can be characterized as consisting of correlated pairs of neutrons in a BCS-like ground state was studied. The pair removal (p,t) reaction was measured at the far forward angle of 3 degrees. The relative cross sections are consistent (at the 5% level) with the description of these nuclei in terms of a correlated pairing state outside the N=28 closed shells with no pairing vibrations. Data were also obtained for 74Ge and 78Se.
Cherenkov Radiation from e+e- Pairs and Its Effect on nu e Induced Showers
Mandal, Sourav K.; Klein, Spencer R.; Jackson, J. David
2005-01-01T23:59:59.000Z
5] J. V. Jelley, Cherenkov Radiation and its applications (calculated the Cherenkov radiation from e + e ? pairs as a? 2 [1?? 2 ?(?)]), the radiation is suppressed compared to
Dynamics of iron-acceptor-pair formation in co-doped silicon
Bartel, T.; Gibaja, F.; Graf, O.; Gross, D.; Kaes, M.; Heuer, M.; Kirscht, F. [Calisolar GmbH, Magnusstrasse 11, 12489 Berlin (Germany)] [Calisolar GmbH, Magnusstrasse 11, 12489 Berlin (Germany); Möller, C. [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany) [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany); TU Ilmenau, Institut für Physik, Weimarer Str. 32, 98693 Ilmenau (Germany); Lauer, K. [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany)] [CiS Forschungsinstitut für Mikrosensorik und Photovoltaik GmbH, Konrad-Zuse-Str. 14, 99099 Erfurt (Germany)
2013-11-11T23:59:59.000Z
The pairing dynamics of interstitial iron and dopants in silicon co-doped with phosphorous and several acceptor types are presented. The classical picture of iron-acceptor pairing dynamics is expanded to include the thermalization of iron between different dopants. The thermalization is quantitatively described using Boltzmann statistics and different iron-acceptor binding energies. The proper understanding of the pairing dynamics of iron in co-doped silicon will provide additional information on the electronic properties of iron-acceptor pairs and may become an analytical method to quantify and differentiate acceptors in co-doped silicon.
What Signals Do Packet-Pair Dispersions Carry? Xiliang Liu, Kaliappa Ravindran, and Dmitri Loguinov
Loguinov, Dmitri
of packet-pair probing in the context of a single-hop path and non-fluid cross-traffic. We identify three
What Signals Do Packet-pair Dispersions Carry? Xiliang Liu, Kaliappa Ravindran, and Dmitri Loguinov
Liu, Xiliang
of packet-pair probing in the context of a single-hop path and non-fluid cross-traffic. We identify three
Natural orbits of atomic Cooper pairs in a nonuniform Fermi gas
Y. H. Pong; C. K. Law
2006-05-08T23:59:59.000Z
We examine the basic mode structure of atomic Cooper pairs in an inhomogeneous Fermi gas. Based on the properties of Bogoliubov quasi-particle vacuum, the single particle density matrix and the anomalous density matrix share the same set of eigenfunctions. These eigenfunctions correspond to natural pairing orbits associated with the BCS ground state. We investigate these orbits for a Fermi gas in a spherical harmonic trap, and construct the wave function of a Cooper pair in the form of Schmidt decomposition. The issue of spatial quantum entanglement between constituent atoms in a pair is addressed.
Momentum signatures for Schwinger pair production in short laser pulses with a sub-cycle structure
Florian Hebenstreit; Reinhard Alkofer; Gerald V. Dunne; Holger Gies
2009-04-20T23:59:59.000Z
We investigate electron-positron pair production from vacuum for short laser pulses with sub-cycle structure, in the nonperturbative regime (Schwinger pair production). We use the non-equilibrium quantum kinetic approach, and show that the momentum spectrum of the created electron-positron pairs is extremely sensitive to the sub-cycle dynamics -- depending on the laser frequency $\\omega$, the pulse length $\\tau$, and the carrier phase $\\phi$ -- and shows several distinctive new signatures. This observation could help not only in the design of laser pulses to optimize the experimental signature of Schwinger pair production, but also ultimately lead to new probes of light pulses at extremely short time scales.
Paho Lurie-Gregg; Jeff B. Schulte; David Roundy
2014-09-24T23:59:59.000Z
We introduce an approximation for the pair distribution function of the inhomogeneous hard sphere fluid. Our approximation makes use of our recently published averaged pair distribution function at contact which has been shown to accurately reproduce the averaged pair distribution function at contact for inhomogeneous density distributions. This approach achieves greater computational efficiency than previous approaches by enabling the use of exclusively fixed-kernel convolutions and thus allowing an implementation using fast Fourier transforms. We compare results for our pair distribution approximation with two previously published works and Monte-Carlo simulation, showing favorable results.
Xiaoying Li; Xiaoxin Ma; Limei Quan; Lei Yang; Liang Cui; Xueshi Guo
2010-07-14T23:59:59.000Z
Using the correlated signal and idler photon pairs generated in a dispersion shifted fiber by a pulsed pump, we measure the quantum efficiency of a InGaAs/InP avalanche photodiode-based single photon detector. Since the collection efficiency of photon pairs is a key parameter to correctly deduce the quantum efficiency, we carefully characterize the collection efficiency by studying correlation dependence of photon pairs upon the spectra of pump, signal and idler photons. This study allows us to obtain quantum efficiency of the single photon detector by using photon pairs with various kinds of bandwidths.
Two-dimensional simulations of pulsational pair-instability supernovae
Chen, Ke-Jung; Woosley, Stan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Melbourne, Victoria 3800 (Australia); Almgren, Ann [Center for Computational Sciences and Engineering, Lawrence Berkeley National Lab, Berkeley, CA 94720 (United States); Whalen, Daniel J., E-mail: kchen@ucolick.org [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-09-01T23:59:59.000Z
Massive stars that end their lives with helium cores in the range of 35-65 M {sub ?} are known to produce repeated thermonuclear outbursts due to a recurring pair-instability. In some of these events, solar masses of material are ejected in repeated outbursts of several × 10{sup 50} erg each. Collisions between these shells can sometimes produce very luminous transients that are visible from the edge of the observable universe. Previous one-dimensional (1D) studies of these events produce thin, high-density shells as one ejection plows into another. Here, in the first multi-dimensional simulations of these collisions, we show that the development of a Rayleigh-Taylor instability truncates the growth of the high-density spike and drives mixing between the shells. The progenitor is a 110 M {sub ?} solar-metallicity star that was shown in earlier work to produce a superluminous supernova. The light curve of this more realistic model has a peak luminosity and duration that are similar to those of 1D models but a structure that is smoother.
Modeling exclusive meson pair production at hadron colliders
L. A. Harland-Lang; V. A. Khoze; M. G. Ryskin
2014-07-21T23:59:59.000Z
We present a study of the central exclusive production of light meson pairs, concentrating on the region of lower invariant masses of the central system and/or meson transverse momentum, where perturbative QCD cannot be reliably applied. We describe in detail a phenomenological model, using the tools of Regge theory, that may be applied with some success in this regime, and we present the new, publicly available, Dime Monte Carlo (MC) implementation of this for $\\pi\\pi$, $KK$ and $\\rho\\rho$ production. The MC includes a fully differential treatment of the survival factor, which in general depends on all kinematic variables, as well as allowing for the so far reasonably unconstrained model parameters to be set by the user. We present predictions for the Tevatron and LHC and show how future measurements may further test this Regge--based approach, as well as the soft hadronic model required to calculate the survival factor, in particular in the presence of tagged protons.
Space qualified nanosatellite electronics platform for photon pair experiments
Cheng, Cliff; Tan, Yue Chuan; Ling, Alexander
2015-01-01T23:59:59.000Z
We report the design and implementation of a complete electronics platform for conducting a quantum optics experiment that will be operated on board a 1U CubeSat (a 10 x 10 x 10 cm satellite). The quantum optics experiment is designed to produce polarization-entangled photon pairs using non-linear optical crystals and requires opto-electronic components such as a pump laser, single photon detectors and liquid crystal based polarization rotators in addition to passive optical elements. The platform provides mechanical support for the optical assembly. It also communicates autonomously with the host satellite to provide experiment data for transmission to a ground station. A limited number of commands can be transmitted from ground to the platform enabling it to switch experimental modes. This platform requires less than 1.5W for all operations, and is space qualified. The implementation of this electronics platform is a major step on the road to operating quantum communication experiments using nanosatellites.
Space qualified nanosatellite electronics platform for photon pair experiments
Cliff Cheng; Rakhitha Chandrasekara; Yue Chuan Tan; Alexander Ling
2015-05-25T23:59:59.000Z
We report the design and implementation of a complete electronics platform for conducting a quantum optics experiment that will be operated on board a 1U CubeSat (a 10 x 10 x 10 cm satellite). The quantum optics experiment is designed to produce polarization-entangled photon pairs using non-linear optical crystals and requires opto-electronic components such as a pump laser, single photon detectors and liquid crystal based polarization rotators in addition to passive optical elements. The platform provides mechanical support for the optical assembly. It also communicates autonomously with the host satellite to provide experiment data for transmission to a ground station. A limited number of commands can be transmitted from ground to the platform enabling it to switch experimental modes. This platform requires less than 1.5W for all operations, and is space qualified. The implementation of this electronics platform is a major step on the road to operating quantum communication experiments using nanosatellites.
Neutrino-pair bremsstrahlung by electrons in neutron star crusts
A. D. Kaminker; C. J. Pethick; A. Y. Potekhin; V. Thorsson; D. G. Yakovlev
1998-12-25T23:59:59.000Z
Neutrino-pair bremsstrahlung by relativistic degenerate electrons in a neutron-star crust at densities (10^9 - 1.5x10^{14}) g/cm^3 is analyzed. The processes taken into account are neutrino emission due to Coulomb scattering of electrons by atomic nuclei in a Coulomb liquid, and electron-phonon scattering and Bragg diffraction (the static-lattice contribution) in a Coulomb crystal. The static-lattice contribution is calculated including the electron band-structure effects for cubic Coulomb crystals of different types and also for the liquid crystal phases composed of rod- and plate-like nuclei in the neutron-star mantle (at 10^{14} - 1.5x10^{14} g/cm^3). The phonon contribution is evaluated with proper treatment of the multi-phonon processes which removes a jump in the neutrino bremsstrahlung emissivity at the melting point obtained in previous works. Below 10^{13} g/cm^3, the results are rather insensitive to the nuclear form factor, but results for the solid state near the melting point are affected significantly by the Debye-Waller factor and multi-phonon processes. At higher densities, the nuclear form factor becomes more significant. A comparison of the various neutrino generation mechanisms in neutron star crusts shows that electron bremsstrahlung is among the most important ones.
The Drinfel'd polynomial of a tridiagonal pair
Ito, Tatsuro
2008-01-01T23:59:59.000Z
Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \\to V$ and $A^*:V \\to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\\{V_i\\}{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \\subseteq V_{i-1} + V_{i} + V_{i+1}$ for $0 \\leq i \\leq d$, where $V_{-1}=0$ and $V_{d+1}=0$; (iii) there exists an ordering $\\{V^*_i\\}{i=0}^\\delta$ of the eigenspaces of $A^*$ such that $A V^*_i \\subseteq V^*_{i-1} + V^*_{i} + V^*_{i+1}$ for $0 \\leq i \\leq \\delta$, where $V^*_{-1}=0$ and $V^*_{\\delta+1}=0$; (iv) there is no subspace $W$ of $V$ such that $AW \\subseteq W$, $A^* W \\subseteq W$, $W \
Top Quark Properties from Top Pair Events and Decays
Andrew G. Ivanov; for the CDF; Dzero Collaborations
2008-10-19T23:59:59.000Z
Over a decade since the discovery of the top quark we are still trying to unravel mysteries of the heaviest observed particle and learn more about its nature. The continuously accumulating statistics of CDF and Dzero data provide the means for measuring top quark properties with ever greater precision and the opportunity to search for signs of new physics that could be manifested through subtle deviations from the standard model in the production and decays of top quarks. In the following we present a slice of the rich program in top quark physics at the Fermilab Tevatron: measurements of the properties of top quark decays and searches for unusual phenomena in events with pair produced tops. In particular, we discuss the most recent and precise CDF and Dzero measurements of the transverse polarization of W bosons from top decays, branching ratios and searches for flavor-changing neutral current decays, decays into charged Higgs and invisible decays. These analyses correspond to integrated luminosities ranging from 0.9 to 2.7 inv. fb.
RPT_PERIOD","R_S_NAME","LINE_NUM","PROD_CODE","PROD_NAME","PORT_CODE","PORT_CITY
U.S. Energy Information Administration (EIA) Indexed Site
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page onsource History View NewUS NationalStocks 2009 2010 2011 2012 2013Feet) Decade Year-076,706.13:Price
Induction logging device with a pair of mutually perpendicular bucking coils
Koelle, Alfred R. (Los Alamos, NM); Landt, Jeremy A. (Los Alamos, NM)
1981-01-01T23:59:59.000Z
An instrument is disclosed for mapping vertical conductive fractures in a resistive bedrock, magnetically inducing eddy currents by a pair of vertically oriented, mutually perpendicular, coplanar coils. The eddy currents drive magnetic fields which are picked up by a second, similar pair of coils.
EFFICIENT PARTICLE-PAIR FILTERING FOR ACCELERATION OF MOLECULAR DYNAMICS SIMULATION
Herbordt, Martin
EFFICIENT PARTICLE-PAIR FILTERING FOR ACCELERATION OF MOLECULAR DYNAMICS SIMULATION Matt Chiu ABSTRACT The acceleration of molecular dynamics (MD) simulations using high performance reconfigurable: determining the short-range force between particle pairs. In particular, we present the first FPGA study
Bose-Einstein correlations in K K pairs from Z 0 decays into two hadronic jets
Bose-Einstein correlations in K #6; K #6; pairs from Z 0 decays into two hadronic jets The OPAL collaboration Abstract Bose-Einstein correlations in pairs of charged kaons produced in a sample of 3.9 million function. The parameters of the Bose- Einstein correlations were measured to be #21; = 0.82 #6; 0.22 + 0
Affine Pairings on ARM Tolga Acar, Kristin Lauter, Michael Naehrig, and Daniel Shumow
International Association for Cryptologic Research (IACR)
Affine Pairings on ARM Tolga Acar, Kristin Lauter, Michael Naehrig, and Daniel Shumow Microsoft and projective pairings on a dual-core Cortex A9 ARM processor and compare perfor- mance of the same implementation across three platforms: x86, x86-64 and ARM. Using a fast inversion in the base field and doing
Universal Design Rules from Product Pairs and Association Rule Based Learning
Cowen, Nicholas L.
2010-07-14T23:59:59.000Z
A product pair is two products with similar functionality that satisfy the same high level need but are different by design. The goal of this research is to apply association rule-based learning to product pairs and develop universal design rules...
High-Speed Software Implementation of the Optimal Ate Pairing over BarretoNaehrig
International Association for Cryptologic Research (IACR)
High-Speed Software Implementation of the Optimal Ate Pairing over BarretoÂNaehrig Curves Jean-0052 Abstract. This paper describes the design of a fast software library for the computation of the optimal ate, finite field arithmetic, bilinear pairing software implementation. 1 Introduction The protocol solutions
AN ASSESSMENT OF WOOD DUCK DISTRIBUTION, ABUNDANCE AND RIPARIAN BREEDING PAIR HABITATS IN SOUTH #12;AN ASSESSMENT OF WOOD DUCK DISTRIBUTION, ABUNDANCE AND RIPARIAN BREEDING PAIR HABITATS IN SOUTH Wildlife and Fisheries Sciences #12;AN ASSESSMENT OF WOOD DUCK DISTRIBUTION, ABUNDANCE AND RIPARIAN
Pairing properties and specific heat of the inner crust of a neutron star
A. Pastore
2014-12-29T23:59:59.000Z
We investigate the pairing properties at finite temperature of the Wigner-Seitz cells in the inner crust of a neutron star obtained with the recent Brussels-Montreal Skyrme functional BSk21. In particular we analyze the phenomena of persistence and reentrance of pairing correlations and their impact on the specific heat in the low-density region of the inner crust.
Pairing properties and specific heat of the inner crust of a neutron star
Pastore, A
2014-01-01T23:59:59.000Z
We investigate the pairing properties at finite temperature of the Wigner-Seitz cells in the inner crust of a neutron star obtained with the recent Brussels-Montreal Skyrme functional BSk21. In particular we analyze the phenomena of persistence and reentrance of pairing correlations and their impact on the specific heat in the low-density region of the inner crust.
Differential top pair cross section and top anti-top plus jets Physics
Malgorzata Worek
2013-02-14T23:59:59.000Z
A brief summary of the current status of the next-to-leading order QCD corrections to top quark pair production and the associated production of top anti-top with jet(s) in different configurations, i.e. with one jet, two jets and another top anti-top pair, is presented.
Flexibility of short DNA helices with finite-length effect: from base pairs to tens of base pairs
Wu, Yuan-Yan; Zhang, Xi; Tan, Zhi-Jie
2015-01-01T23:59:59.000Z
Flexibility of short DNA helices is important for the biological functions such as nucleosome formation and DNA-protein recognition. Recent experiments suggest that short DNAs of tens of base pairs (bps) may have apparently higher flexibility than those of kilo bps, while there is still the debate on such high flexibility. In the present work, we have studied the flexibility of short DNAs with finite-length of 5 to 50 bps by the all-atomistic molecular dynamics simulations and Monte Carlo simulations with the worm-like chain model. Our microscopic analyses reveal that short DNAs have apparently high flexibility which is attributed to the significantly strong bending and stretching flexibilities of ~6 bps at each helix end. Correspondingly, the apparent persistence length lp of short DNAs increases gradually from ~29nm to ~45nm as DNA length increases from 10 to 50 bps, in accordance with the available experimental data. Our further analyses show that the short DNAs with excluding ~6 bps at each helix end have...
The Radical Pair Mechanism and the Avian Chemical Compass: Quantum Coherence and Entanglement
Zhang, Yiteng; Kais, Sabre
2015-01-01T23:59:59.000Z
We review the spin radical pair mechanism which is a promising explanation of avian navigation. This mechanism is based on the dependence of product yields on (1) the hyperfine interaction involving electron spins and neighboring nuclear spins and (2) the intensity and orientation of the geomagnetic field. One surprising result is that even at ambient conditions quantum entanglement of electron spins can play an important role in avian magnetoreception. This review describes the general scheme of chemical reactions involving radical pairs generated from singlet and triplet precursors; the spin dynamics of the radical pairs; and the magnetic field dependence of product yields caused by the radical pair mechanism. The main part of the review includes a description of the chemical compass in birds. We review: the general properties of the avian compass; the basic scheme of the radical pair mechanism; the reaction kinetics in cryptochrome; quantum coherence and entanglement in the avian compass; and the effects o...
Origin of the low-mass electron pair excess in light nucleus-nucleus collisions
The HADES Collaboration; G. Agakishiev; A. Balanda; D. Belver; A. V. Belyaev; A. Blanco; M. Böhmer; J. L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Díaz; F. Dohrmann; A. Dybczak; L. Fabbietti; O. V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Fröhlich; T. Galatyuk; J. A. Garzón; R. Gernhäuser; A. Gil; C. Gilardi; M. Golubeva; D. González-Díaz; F. Guber; T. Hennino; R. Holzmann; I. Iori; A. Ivashkin; M. Jurkovic; B. Kämpfer; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B. W. Kolb; R. Kotte; F. Krizek; R. Krücken; W. Kühn; A. Kugler; A. Kurepin; S. Lang; J. S. Lange; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; E. Morinière; J. Mousa; C. Müntz; L. Naumann; J. Otwinowski; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; A. Rustamov; A. Sadovsky; P. Salabura; A. Schmah; E. Schwab; Yu. G. Sobolev; S. Spataro; B. Spruck; H. Ströbele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebacz; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wüstenfeld; S. Yurevich; Y. V. Zanevsky; P. Zhou
2009-10-30T23:59:59.000Z
We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For the first time, the electron pairs were reconstructed for n+p reactions by detecting the proton spectator from the deuteron breakup. We find that the yield of electron pairs with invariant mass Me+e- > 0.15 GeV/c2 is about an order of magnitude larger in n+p reactions as compared to p+p. A comparison to model calculations demonstrates that the production mechanism is not sufficiently described yet. The electron pair spectra measured in C+C reactions are compatible with a superposition of elementary n+p and p+p collisions, leaving little room for additional electron pair sources in such light collision systems.
A weak-value interpretation of the Schwinger mechanism of massless/massive pair productions
Kazuhiro Yokota; Nobuyuki Imoto
2015-04-28T23:59:59.000Z
According to the Schwinger mechanism, a uniform electric field brings about pair productions in vacuum; the relationship between the production rate and the electric field is different, depending on the dimension of the system. In this paper, we make an offer of another model for the pair productions, in which weak values are incorporated: energy fluctuations trigger the pair production, and a weak value appears as the velocity of a particle there. Although our model is only available for the approximation of the pair production rates, the weak value reveals a new aspect of the pair production. Especially, within the first order, our estimation approximately agrees with the exponential decreasing rate of the Landau-Zener tunneling through the mass energy gap. In other words, such tunneling can be associated with energy fluctuations via the weak value, when the tunneling gap can be regarded as so small due to the high electric field.
MULTI-DIMENSIONAL SIMULATIONS OF ROTATING PAIR-INSTABILITY SUPERNOVAE
Chatzopoulos, E.; Wheeler, J. Craig [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States); Couch, Sean M., E-mail: manolis@astro.as.utexas.edu [Department of Astronomy and Astrophysics, Flash Center for Computational Science, University of Chicago, Chicago, IL 60637 (United States)
2013-10-20T23:59:59.000Z
We study the effects of rotation on the dynamics, energetics, and {sup 56}Ni production of pair instability supernova (PISN) explosions by performing rotating two-dimensional ({sup 2}.5D{sup )} hydrodynamics simulations. We calculate the evolution of eight low-metallicity (Z = 10{sup –3}, 10{sup –4} Z{sub ?}) massive (135-245 M{sub ?}) PISN progenitors with initial surface rotational velocities of 50% of the critical Keplerian value using the stellar evolution code MESA. We allow for both the inclusion and the omission of the effects of magnetic fields in the angular momentum transport and in chemical mixing, resulting in slowly rotating and rapidly rotating final carbon-oxygen cores, respectively. Increased rotation for carbon-oxygen cores of the same mass and chemical stratification leads to less energetic PISN explosions that produce smaller amounts of {sup 56}Ni due to the effect of the angular momentum barrier that develops and slows the dynamical collapse. We find a non-monotonic dependence of {sup 56}Ni production on rotational velocity in situations when smoother composition gradients form at the outer edge of the rotating cores. In these cases, the PISN energetics are determined by the competition of two factors: the extent of chemical mixing in the outer layers of the core due to the effects of rotation in the progenitor evolution and the development of angular momentum support against collapse. Our 2.5D PISN simulations with rotation are the first presented in the literature. They reveal hydrodynamic instabilities in several regions of the exploding star and increased explosion asymmetries with higher core rotational velocity.
Measurements of Baryon Pair Decays of $?_{cJ}$ Mesons
M. Ablikim; M. N. Achasov; O. Albayrak; D. J. Ambrose; F. F. An; Q. An; J. Z. Bai; Y. Ban; J. Becker; J. V. Bennett; M. Bertani; J. M. Bian; E. Boger; O. Bondarenko; I. Boyko; R. A. Briere; V. Bytev; X. Cai; O. Cakir; A. Calcaterra; G. F. Cao; S. A. Cetin; J. F. Chang; G. Chelkov; G. Chen; H. S. Chen; J. C. Chen; M. L. Chen; S. J. Chen; X. Chen; Y. B. Chen; H. P. Cheng; Y. P. Chu; D. Cronin-Hennessy; H. L. Dai; J. P. Dai; D. Dedovich; Z. Y. Deng; A. Denig; I. Denysenko; M. Destefanis; W. M. Ding; Y. Ding; L. Y. Dong; M. Y. Dong; S. X. Du; J. Fang; S. S. Fang; L. Fava; C. Q. Feng; R. B. Ferroli; P. Friedel; C. D. Fu; Y. Gao; C. Geng; K. Goetzen; W. X. Gong; W. Gradl; M. Greco; M. H. Gu; Y. T. Gu; Y. H. Guan; A. Q. Guo; L. B. Guo; T. Guo; Y. P. Guo; Y. L. Han; F. A. Harris; K. L. He; M. He; Z. Y. He; T. Held; Y. K. Heng; Z. L. Hou; C. Hu; H. M. Hu; J. F. Hu; T. Hu; G. M. Huang; G. S. Huang; J. S. Huang; L. Huang; X. T. Huang; Y. Huang; Y. P. Huang; T. Hussain; C. S. Ji; Q. Ji; Q. P. Ji; X. B. Ji; X. L. Ji; L. L. Jiang; X. S. Jiang; J. B. Jiao; Z. Jiao; D. P. Jin; S. Jin; F. F. Jing; N. Kalantar-Nayestanaki; M. Kavatsyuk; B. Kopf; M. Kornicer; W. Kuehn; W. Lai; J. S. Lange; M. Leyhe; C. H. Li; Cheng Li; Cui Li; D. M. Li; F. Li; G. Li; H. B. Li; J. C. Li; K. Li; Lei Li; Q. J. Li; S. L. Li; W. D. Li; W. G. Li; X. L. Li; X. N. Li; X. Q. Li; X. R. Li; Z. B. Li; H. Liang; Y. F. Liang; Y. T. Liang; G. R. Liao; X. T. Liao; D. Lin; B. J. Liu; C. L. Liu; C. X. Liu; F. H. Liu; Fang Liu; Feng Liu; H. Liu; H. B. Liu; H. H. Liu; H. M. Liu; H. W. Liu; J. P. Liu; K. Liu; K. Y. Liu; Kai Liu; P. L. Liu; Q. Liu; S. B. Liu; X. Liu; Y. B. Liu; Z. A. Liu; Zhiqiang Liu; Zhiqing Liu; H. Loehner; G. R. Lu; H. J. Lu; J. G. Lu; Q. W. Lu; X. R. Lu; Y. P. Lu; C. L. Luo; M. X. Luo; T. Luo; X. L. Luo; M. Lv; C. L. Ma; F. C. Ma; H. L. Ma; Q. M. Ma; S. Ma; T. Ma; X. Y. Ma; F. E. Maas; M. Maggiora; Q. A. Malik; Y. J. Mao; Z. P. Mao; J. G. Messchendorp; J. Min; T. J. Min; R. E. Mitchell; X. H. Mo; C. Morales Morales; N. Yu. Muchnoi; H. Muramatsu; Y. Nefedov; C. Nicholson; I. B. Nikolaev; Z. Ning; S. L. Olsen; Q. Ouyang; S. Pacetti; J. W. Park; M. Pelizaeus; H. P. Peng; K. Peters; J. L. Ping; R. G. Ping; R. Poling; E. Prencipe; M. Qi; S. Qian; C. F. Qiao; L. Q. Qin; X. S. Qin; Y. Qin; Z. H. Qin; J. F. Qiu; K. H. Rashid; G. Rong; X. D. Ruan; A. Sarantsev; B. D. Schaefer; M. Shao; C. P. Shen; X. Y. Shen; H. Y. Sheng; M. R. Shepherd; X. Y. Song; S. Spataro; B. Spruck; D. H. Sun; G. X. Sun; J. F. Sun; S. S. Sun; Y. J. Sun; Y. Z. Sun; Z. J. Sun; Z. T. Sun; C. J. Tang; X. Tang; I. Tapan; E. H. Thorndike; D. Toth; M. Ullrich; G. S. Varner; B. Q. Wang; D. Wang; D. Y. Wang; K. Wang; L. L. Wang; L. S. Wang; M. Wang; P. Wang; P. L. Wang; Q. J. Wang; S. G. Wang; X. F. Wang; X. L. Wang; Y. F. Wang; Z. Wang; Z. G. Wang; Z. Y. Wang; D. H. Wei; J. B. Wei; P. Weidenkaff; Q. G. Wen; S. P. Wen; M. Werner; U. Wiedner; L. H. Wu; N. Wu; S. X. Wu; W. Wu; Z. Wu; L. G. Xia; Z. J. Xiao; Y. G. Xie; Q. L. Xiu; G. F. Xu; G. M. Xu; Q. J. Xu; Q. N. Xu; X. P. Xu; Z. R. Xu; F. Xue; Z. Xue; L. Yan; W. B. Yan; Y. H. Yan; H. X. Yang; Y. Yang; Y. X. Yang; H. Ye; M. Ye; M. H. Ye; B. X. Yu; C. X. Yu; H. W. Yu; J. S. Yu; S. P. Yu; C. Z. Yuan; Y. Yuan; A. A. Zafar; A. Zallo; Y. Zeng; B. X. Zhang; B. Y. Zhang; C. Zhang; C. C. Zhang; D. H. Zhang; H. H. Zhang; H. Y. Zhang; J. Q. Zhang; J. W. Zhang; J. Y. Zhang; J. Z. Zhang; R. Zhang; S. H. Zhang; X. J. Zhang; X. Y. Zhang; Y. Zhang; Y. H. Zhang; Z. P. Zhang; Z. Y. Zhang; Zhenghao Zhang; G. Zhao; H. S. Zhao; J. W. Zhao; K. X. Zhao; Lei Zhao; Ling Zhao; M. G. Zhao; Q. Zhao; Q. Z. Zhao; S. J. Zhao; T. C. Zhao; Y. B. Zhao; Z. G. Zhao; A. Zhemchugov; B. Zheng; J. P. Zheng; Y. H. Zheng; B. Zhong; Z. Zhong; L. Zhou; X. K. Zhou; X. R. Zhou; C. Zhu; K. Zhu; K. J. Zhu; S. H. Zhu; X. L. Zhu; Y. C. Zhu; Y. M. Zhu; Y. S. Zhu; Z. A. Zhu; J. Zhuang; B. S. Zou; J. H. Zou
2013-03-05T23:59:59.000Z
Using 106 $\\times 10^{6}$ $\\psi^{\\prime}$ decays collected with the BESIII detector at the BEPCII, three decays of $\\chi_{cJ}$ ($J=0,1,2$) with baryon pairs ($\\llb$, $\\ssb$, $\\SSB$) in the final state have been studied. The branching fractions are measured to be $\\cal{B}$$(\\chi_{c0,1,2}\\rightarrow\\Lambda\\bar\\Lambda) =(33.3 \\pm 2.0 \\pm 2.6)\\times 10^{-5}$, $(12.2 \\pm 1.1 \\pm 1.1)\\times 10^{-5}$, $(20.8 \\pm 1.6 \\pm 2.3)\\times 10^{-5}$; $\\cal{B}$$(\\chi_{c0,1,2}\\rightarrow\\Sigma^{0}\\bar\\Sigma^{0})$ = $(47.8 \\pm 3.4 \\pm 3.9)\\times 10^{-5}$, $(3.8 \\pm 1.0 \\pm 0.5)\\times 10^{-5}$, $(4.0 \\pm 1.1 \\pm 0.5) \\times 10^{-5}$; and $\\cal{B}$$(\\chi_{c0,1,2}\\rightarrow\\Sigma^{+}\\bar\\Sigma^{-})$ = $(45.4 \\pm 4.2 \\pm 3.0)\\times 10^{-5}$, $(5.4 \\pm 1.5 \\pm 0.5)\\times 10^{-5}$, $(4.9 \\pm 1.9 \\pm 0.7)\\times 10^{-5}$, where the first error is statistical and the second is systematic. Upper limits on the branching fractions for the decays of $\\chi_{c1,2}\\rightarrow\\Sigma^{0}\\bar\\Sigma^{0}$, $\\Sigma^{+}\\bar\\Sigma^{-}$, are estimated to be $\\cal{B}$$(\\chi_{c1}\\rightarrow\\Sigma^{0}\\bar\\Sigma^{0}) < 6.2\\times 10^{-5}$, $\\cal{B}$$(\\chi_{c2}\\rightarrow\\Sigma^{0}\\bar\\Sigma^{0}) < 6.5\\times 10^{-5}$, $\\cal{B}$$(\\chi_{c1}\\rightarrow\\Sigma^{+}\\bar\\Sigma^{-}) < 8.7\\times 10^{-5}$ and $\\cal{B}$$(\\chi_{c2}\\rightarrow\\Sigma^{+}\\bar\\Sigma^{-}) < 8.8\\times 10^{-5}$ at the 90% confidence level.
Coherent chemical kinetics as quantum walks I: Reaction operators for radical pairs
A. Chia; A. Gorecka; K. C. Tan; L. Pawela; P. Kurzynski; T. Paterek; D. Kaszlikowski
2015-08-20T23:59:59.000Z
Classical chemical kinetics use rate-equation models to describe how a reaction proceeds in time. Such models are sufficient for describing state transitions in a reaction where coherences between different states do not arise, or in other words, a reaction which contain only incoherent transitions. A prominent example reaction containing coherent transitions is the radical-pair model. The kinetics of such reactions is defined by the so-called reaction operator which determines the radical-pair state as a function of intermediate transition rates. We argue that the well-known concept of quantum walks from quantum information theory is a natural and apt framework for describing multisite chemical reactions. By composing Kraus maps that act only on two sites at a time, we show how the quantum-walk formalism can be applied to derive a reaction operator for the standard avian radical-pair reaction. Our reaction operator predicts a recombination dephasing rate consistent with recent experiments [J. Chem. Phys. {\\bf 139}, 234309 (2013)], in contrast to previous work by Jones and Hore [Chem. Phys. Lett. {\\bf 488}, 90 (2010)]. The standard radical-pair reaction has conventionally been described by either a normalised density operator incorporating both the radical pair and reaction products, or by a trace-decreasing density operator that considers only the radical pair. We demonstrate a density operator that is both normalised and refers only to radical-pair states. Generalisations to include additional dephasing processes and an arbitrary number of sites are also discussed.
Coherent chemical kinetics as quantum walks I: Reaction operators for radical pairs
A. Chia; A. Gorecka; K. C. Tan; L. Pawela; P. Kurzynski; T. Paterek; D. Kaszlikowski
2015-06-13T23:59:59.000Z
Classical chemical kinetics use rate-equation models to describe how a reaction proceeds in time. Such models are sufficient for describing state transitions in a reaction where coherences between different states do not arise, or in other words, a reaction which contain only incoherent transitions. A prominent example reaction containing coherent transitions is the radical-pair model. The kinetics of such reactions is defined by the so-called reaction operator which determines the radical-pair state as a function of intermediate transition rates. We argue that the well-known concept of quantum walks from quantum information theory is a natural and apt framework for describing multisite chemical reactions. By composing Kraus maps that act only on two sites at a time, we show how the quantum-walk formalism can be applied to derive a reaction operator for the standard avian radical-pair reaction. Our reaction operator predicts a recombination dephasing rate consistent with recent experiments [J. Chem. Phys. {\\bf 139}, 234309 (2013)], in contrast to previous work by Jones and Hore [Chem. Phys. Lett. {\\bf 488}, 90 (2010)]. The standard radical-pair reaction has conventionally been described by either a normalised density operator incorporating both the radical pair and reaction products, or by a trace-decreasing density operator that considers only the radical pair. We demonstrate a density operator that is both normalised and refers only to radical-pair states. Generalisations to include additional dephasing processes and an arbitrary number of sites are also discussed.
Theory of nodal s±-wave pairing symmetry in the Pu-based 115 superconductor family
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Das, Tanmoy; Zhu, Jian -Xin; Graf, Matthias J.
2015-02-27T23:59:59.000Z
The spin-fluctuation mechanism of superconductivity usually results in the presence of gapless or nodal quasiparticle states in the excitation spectrum. Nodal quasiparticle states are well established in copper-oxide, and heavy-fermion superconductors, but not in iron-based superconductors. Here, we study the pairing symmetry and mechanism of a new class of plutonium-based high-Tc superconductors and predict the presence of a nodal s?? wave pairing symmetry in this family. Starting from a density-functional theory (DFT) based electronic structure calculation we predict several three-dimensional (3D) Fermi surfaces in this 115 superconductor family. We identify the dominant Fermi surface “hot-spots” in the inter-band scattering channel,more »which are aligned along the wavevector Q = (?, ?, ?), where degeneracy could induce sign-reversal of the pairing symmetry. Our calculation demonstrates that the s?? wave pairing strength is stronger than the previously thought d-wave pairing; and more importantly, this pairing state allows for the existence of nodal quasiparticles. Finally, we predict the shape of the momentum- and energy-dependent magnetic resonance spectrum for the identification of this pairing symmetry.« less
Cal Latin-Small-Letter-Dotless-I k, A. E., E-mail: engincalik@yahoo.com [Dumlupinar University, Department of Physics, Faculty of Arts and Sciences (Turkey); Gerceklioglu, M. [Ege University, Department of Physics, Faculty of Science (Turkey); Selam, C. [Mus Alparslan University, Department of Physics, Faculty of Arts and Sciences (Turkey)
2013-05-15T23:59:59.000Z
Within the framework of quasi-particle random phase approximation, the isospin breaking correction of superallowed 0{sup +} {yields} 0{sup +} beta decay and unitarity of Cabibbo-Kobayashi-Maskawa mixing matrix have been investigated. The broken isotopic symmetry of nuclear part of Hamiltonian has been restored by Pyatov's method. The isospin symmetry breaking correction with pairing correlations has been compared with the previous results without pairing. The effect of pairing interactions has been examined for nine superallowed Fermi beta decays; their parent nuclei are {sup 26}Al, {sup 34}Cl, {sup 38}K, {sup 42}Sc, {sup 46}V, {sup 50}Mn, {sup 54}Co, {sup 62}Ga, {sup 74}Rb.
Non-Archimedian integrals and stringy Euler numbers of log terminal pairs
Victor V. Batyrev
1998-03-16T23:59:59.000Z
Using non-Archimedian integration over spaces of arcs of algebraic varieties, we define stringy Euler numbers associated with arbitrary Kawamata log terminal pairs. There is a natural Kawamata log terminal pair corresponding to an algebraic variety V having a regular action of a finite group G. In this situation we show that the stringy Euler number of this pair coincides with the physicists' orbifold Euler number defined by the Dixon-Harvey-Vafa-Witten formula. As an application, we prove a conjecture of Miles Reid on the Euler numbers of crepant desingularizations of Gorenstein quotient singularities.
Distribution of Primes and of Interval Prime Pairs Based on $?$ Function
Yifang Fan; Zhiyu Li
2010-04-19T23:59:59.000Z
$\\Theta$ function is defined based upon Kronecher symbol. In light of the principle of inclusion-exclusion, $\\Theta$ function of sine function is used to denote the distribution of composites and primes. The structure of Goldbach Conjecture has been analyzed, and $\\Xi$ function is brought forward by the linear diophantine equation; by relating to $\\Theta$ function, the interval distribution of composite pairs and prime pairs (i.e. the Goldbach Conjecture) is thus obtained. In the end, Abel's Theorem (Multiplication of Series) is used to discuss the lower limit of the distribution of the interval prime pairs.
Shenanigans at the black hole horizon: pair creation or Boulware accretion?
Israel, Werner
2015-01-01T23:59:59.000Z
The current scenario of black hole evaporation holds that the Hawking energy flux $F$ is powered by pair creation at the horizon. However, pair creation produces entanglements, some of which must necessarily be broken before the black hole evaporates completely. That leads to loss of information and violation of unitarity. In this paper, an alternative scenario is suggested that reproduces the essential features of Hawking evaporation, but does not invoke pair creation with its attendant problems. In this "accreting Boulware" scenario, a positive flux $F$ is still an outflux at infinity, but near the horizon it becomes an influx of negative energy. This negative energy flux (marginally) satisfies the Flanagan energy inequality.
Choi, Mahn-Soo
2014-01-01T23:59:59.000Z
PHYSICAL REVIEW B 89, 045137 (2014) Hanbury Brown and Twiss correlations of Cooper pairs in helical; published 29 January 2014) We propose a Hanbury Brown and Twiss (HBT) experiment of Cooper pairs on the edge a Hanbury Brown and Twiss (HBT) experiment of Cooper pairs on the edge channels of quantum spin Hall
Shepelyansky, Dima
Disordered Hubbard model with attraction: The coupling energy of Cooper pairs in small clusters of disorder. We show that the Cooper pair energy is strongly enhanced by disorder, which at the same time us to determine the depen- dence of the Cooper pair coupling energy on the strength of disorder
Pair correlations in the neutrinoless double-{beta} decay candidate {sup 130}Te
Bloxham, T.; Freedman, S. J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kay, B. P.; Schiffer, J. P.; Clark, J. A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Deibel, C. M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48825 (United States); Freeman, S. J.; Howard, A. M.; McAllister, S. A.; Sharp, D. K.; Thomas, J. S. [Schuster Laboratory, University of Manchester, Manchester, M13 9PL (United Kingdom); Parker, P. D. [A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06520 (United States)
2010-08-15T23:59:59.000Z
Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.
Pair correlations in neutrinoless double {beta} decay candidate {sup 130}Te.
Bloxham, T.; Kay, B. P.; Schiffer, J. P.; Clark, J. A.; Deibel, C. M.; Freeman, S. J.; Freedman, S. J.; Howard, A. M.; McAllister, S. A.; Parker, P. D.; Sharp, D. K.; Thomas, J. S. (Physics); ( PSC-USR); (LBNL); (Michigan State Univ.); (Univ. of Manchester); (Yale Univ.)
2010-08-16T23:59:59.000Z
Pair correlations in the ground state of {sup 130}Te have been investigated using pair-transfer experiments to explore the validity of approximations in calculating the matrix element for neutrinoless double-{beta} decay. This nucleus is a candidate for the observation of such decay, and a good understanding of its structure is crucial for eventual calculations of the neutrino mass, should such a decay indeed be observed. For proton-pair adding, strong transitions to excited 0{sup +} states had been observed in the Te isotopes by Alford et al. [Nucl. Phys. A 323, 339 (1979)], indicating a breaking of the BCS approximation for protons in the ground state. We measured the neutron-pair removing (p,t) reaction on {sup 130}Te and found no indication of a corresponding splitting of the BCS nature of the ground state for neutrons.
Glutamate-receptor-mediated encoding and retrieval of paired-associate learning
Day, M; Langston, R; Morris, Richard G M
2003-07-10T23:59:59.000Z
Paired-associate learning is often used to examine episodic memory in humans (1). Animal models include the recall of foodcache locations by scrub jays (2) and sequential memory (3,4). Here we report a model in which ...
Top Quark Pair Production Measurements Using the ATLAS Detector at the LHC
Bertsche, Carolyn; The ATLAS collaboration
2015-01-01T23:59:59.000Z
Measurements of the inclusive top quark pair production cross sections in protonproton collisions with the ATLAS detector at the Large Hadron Collider are presented. The most precise result requires opposite sign electrons and muons and uses the full dataset at a centreofmass energy of 7 and 8 TeV. In addition, differential measurements of the top transverse momentum and kinematic properties of the topantitop pair are discussed. These measurements, including results using boosted tops, probe our understanding of top pair production in the TeV regime. The results, unfolded to particle and parton level, are compared to recent Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations. In addition, measurements of the production of top quark pairs in association with gauge bosons or jets are presented.
Search for new ?[superscript 0]-like particles produced in association with a ?-lepton pair
Lees, J.?P.
We report on a search in e[superscript +]e[superscript -] annihilations for new ?[superscript 0]-like particles produced in association with a ?-lepton pair. These objects, with a similar mass and similar decay modes to ...
Pairing of valence electrons as necessary condition for energy minimization in a crystal
Dolgopolov Stanislav Olegovich
2014-10-21T23:59:59.000Z
Pairing of valence electrons can lead to energy minimization of a crystal. It can be proved by use of representation of the valence electrons as plane waves in periodic potential of the crystal.
A. V. Borisov; P. E. Sizin
2014-06-12T23:59:59.000Z
We calculate the neutrino luminosity of a degenerate electron gas in a strong magnetic field via plasmon decay to a neutrino pair due to neutrino electromagnetic moments and obtain the relative upper bounds on the effective neutrino magnetic moment.
Nonequilibrium superconducting thin films with sub-gap and pair-breaking photon illumination
Guruswamy, T.; Goldie, D. J.; Withington, S.
2015-04-08T23:59:59.000Z
We calculate nonequilibrium quasiparticle and phonon distributions for a number of widely-used low transition temperature thin-film superconductors under constant, uniform illumination by sub-gap probe and pair-breaking signal photons simultaneously...
Conversion of relativistic pair energy into radiation in the jets of active galactic nuclei
Schlickeiser, R; Böttcher, M; Lerche, I; Pohl, M; Schuster, C
2002-01-01T23:59:59.000Z
It is generally accepted that relativistic jet outflows power the nonthermal emission from active galactic nuclei (AGN). The composition of these jets -- leptonic versus hadronic -- is still under debate. We investigate the microphysical details of the conversion process of the kinetic energy in collimated relativistic pair outflows into radiation through interactions with the ambient interstellar medium. Viewed from the coordinate system comoving with the pair outflow, the interstellar protons and electrons represent a proton-electron beam propagating with relativistic speed in the pair plasma. We demonstrate that the beam excites both electrostatic and low-frequency magnetohydrodynamic Alfven-type waves via a two-stream instability in the pair background plasma, and we calculate the time evolution of the distribution functions of the beam particles and the generated plasma wave turbulence power spectra. For standard AGN jet outflow and environment parameters we show that the initial beam distributions of in...
Pairing within the self-consistent quasiparticle random-phase approximation at finite temperature
Dang, N Dinh
2008-01-01T23:59:59.000Z
An approach to pairing in finite nuclei at nonzero temperature is proposed, which incorporates the effects due to the quasiparticle-number fluctuation (QNF) around Bardeen-Cooper-Schrieffer (BCS) mean field and dynamic coupling to quasiparticle-pair vibrations within the self-consistent quasiparticle random-phase approximation (SCQRPA). The numerical calculations of pairing gap, total energy, and heat capacity were carried out within a doubly folded multilevel model as well as realistic nuclei $^{56}$Fe and $^{120}$Sn. The results obtained show that, under the effect of QNF, in the region of moderate and strong couplings, the sharp transition between the superconducting and normal phases is smoothed out, resulting in a thermal pairing gap, which does not collapse at the BCS critical temperature, but has a tail, which extends to high temperature. The dynamic coupling of quasiparticles to SCQRPA vibrations significantly improves the agreement with the results of exact calculations and those obtained within the ...
Gomez-Ceballos, Guillelmo
We combine six measurements of the inclusive top-quark pair (t[bar over t]) production cross section (?[subscript tt]-) from data collected with the CDF and D0 detectors at the Fermilab Tevatron with proton-antiproton ...
Correlating structure and thermodynamics of hydrophobicâ??hydrophilic ion pairs in water
Benjamin, Ilan
2015-01-01T23:59:59.000Z
TMA-halide ion pairs in water at 298K. r is the distanceshows the nitrogen(TMA)-oxygen(water) radial distributionfunction in pure water. The main plot shows the peak value (
Ooi, C. H. Raymond; Scully, Marlan O.; Sun, Qingqing; Zubairy, M. Suhail
2007-01-01T23:59:59.000Z
We present a largely analytical theory for two-photon correlations G((2)) between Stokes (s) and anti-Stokes (a) photon pairs from an extended medium (amplifier) composed of double-Lambda atoms in counterpropagating geometry. We generalize...
Parallel Assembly of Large Genomes from Paired Short Reads (2010 JGI/ANL HPC Workshop)
Aluru, Srinivas [Iowa State University
2011-06-08T23:59:59.000Z
Srinivas Aluru from Iowa State University gives a presentation on "Parallel Assembly of Large Genomes from Paired Short Reads" at the JGI/Argonne HPC Workshop on January 25, 2010.
Nucleon and nucleon-pair momentum distributions in A?12 nuclei
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Wiringa, Robert B. [ANL; Schiavilla, Rocco [ODU, JLAB; Pieper, Steven C. [ANL; Carlson, Joseph A. [LANL
2014-02-01T23:59:59.000Z
We report variational Monte Carlo calculations of single-nucleon momentum distributions for A?12 nuclei and nucleon-pair and nucleon-cluster momentum distributions for A?8. The wave functions have been generated for a Hamiltonian containing the Argonne ?18 two-nucleon and Urbana X three-nucleon potentials. The single-nucleon and nucleon-pair momentum distributions exhibit universal features attributable to the one-pion-exchange tensor interaction The single-nucleon distributions are broken down into proton and neutron components and spin-up and spin-down components where appropriate. The nucleon-pair momentum distributions are given separately for pp and pn pairs. The nucleon-cluster momentum distributions include dp in 3He, tp and dd in S4He, ?d in 6Li,?t in 7Li, and ?? in 8Be. Detailed tables are provided on-line for download.
Pairing preferences of the model mono-valence mono-atomic ions investigated by molecular simulation
Zhang, Qiang [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China) [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China); Department of Chemistry, Bohai University, Jinzhou 121000 (China); Zhang, Ruiting; Zhao, Ying; Li, HuanHuan; Zhuang, Wei, E-mail: wzhuang@dicp.ac.cn, E-mail: gaoyq@pku.edu.cn [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China)] [State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning (China); Gao, Yi Qin, E-mail: wzhuang@dicp.ac.cn, E-mail: gaoyq@pku.edu.cn [College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871 (China)
2014-05-14T23:59:59.000Z
We carried out a series of potential of mean force calculations to study the pairing preferences of a series of model mono-atomic 1:1 ions with evenly varied sizes. The probabilities of forming the contact ion pair (CIP) and the single water separate ion pair (SIP) were presented in the two-dimensional plots with respect to the ion sizes. The pairing preferences reflected in these plots largely agree with the empirical rule of matching ion sizes in the small and big size regions. In the region that the ion sizes are close to the size of the water molecule; however, a significant deviation from this conventional rule is observed. Our further analysis indicated that this deviation originates from the competition between CIP and the water bridging SIP state. The competition is mainly an enthalpy modulated phenomenon in which the existing of the water bridging plays a significant role.
Formation of O Adatom Pairs and Charge Transfer upon O-2 Dissociation...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
details of O2 dissociation leading to the formation of oxygen adatom (Oa) pairs at terminal Ti sites. An intermediate, metastable Oa-Oa configuration with two nearest-neighbor O...
Mao, James X.; Lee, Anita S.; Kitchin, John R.; Nulwala, Hunaid B; Luebke, David R.; Damodaran, Krishnan
2013-04-24T23:59:59.000Z
Density Functional Theory is used to investigate a weakly coordinating room-temperature ionic liquid, 1-ethyl-3-methyl imidazolium tetracyanoborate ([Emim]{sup +}[TCB]{sup -}). Four locally stable conformers of the ion pair were located. Atoms-in-molecules (AIM) and electron density analysis indicated the existence of several hydrogen bonds. Further investigation through the Natural Bond Orbital (NBO) and Natural Energy Decomposition Analysis (NEDA) calculations provided insight into the origin of interactions in the [Emim]{sup +}[TCB]{sup -} ion pair. Strength of molecular interactions in the ionic liquid was correlated with frequency shifts of the characteristic vibrations of the ion pair. Harmonic vibrations of the ion pair were also compared with the experimental Raman and Infrared spectra. Vibrational frequencies were assigned by visualizing displacements of atoms around their equilibrium positions and through Potential Energy Distribution (PED) analysis.
Characterization process of emission sources of spin entangled pairs with several species
Francisco Delgado
2011-03-24T23:59:59.000Z
Normally, sources of entangled pairs generate several species of them. This work proposes a characterization algorithm for relatively general bipartite entangled states, generating several standard Bell states with controlled population as output.
Heralding efficiency and correlated-mode coupling of near-IR fiber-coupled photon pairs
Rosenberg, Danna
We report on a systematic experimental study of the heralding efficiency and generation rate of telecom-band infrared photon pairs generated by spontaneous parametric down-conversion and coupled to single-mode optical ...
Interacting vortex pairs in inviscid and viscous planar flows Thierry Gallay
Gallay, Thierry
Interacting vortex pairs in inviscid and viscous planar flows Thierry Gallay Universitâ??e de Grenoble I Institut Fourier, UMR CNRS 5582 B.P. 74 FÂ38402 SaintÂMartinÂd'Hâ??eres, France Thierry.Gallay
Interacting vortex pairs in inviscid and viscous planar flows Thierry Gallay
Gallay, Thierry
Interacting vortex pairs in inviscid and viscous planar flows Thierry Gallay UniversitÂ´e de Grenoble I Institut Fourier, UMR CNRS 5582 B.P. 74 F-38402 Saint-Martin-d'H`eres, France Thierry.Gallay
Synaptonemal complex analysis of chromosomal pairing in two species of quail
Ryder, Elizabeth Jeanne
1989-01-01T23:59:59.000Z
SYNAPTONEMAL COMPLEX ANALYSIS OF CHROMOSOMAL PAIRING IN TWO SPECIES OF QUAIL A THESIS by ELIZABETH JEANNE RYDER Submitted to the Office of Graduate Studies of Texas A & M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1989 Maj or subj ect: Genetics SYNAPTONEMAL COMPLEX ANALYSIS OF CHROMOSOMAL PAIRING IN TWO SPECIES OF QUAIL A THESIS by ELIZABETH JEANNE RYDER Approved as to style and content by: / '. '/, ( ~ P /, g/? Ira F...
Reaction operators for spin-selective chemical reactions of radical pairs
Jonathan A. Jones; Kiminori Maeda; Peter J. Hore
2011-03-30T23:59:59.000Z
Spin-selective reactions of radical pairs have traditionally been modelled theoretically by adding phenomenological rate equations to the quantum mechanical equation of motion of the radical pair spin density matrix. More recently an alternative set of rate expressions, based on a quantum measurement approach, has been suggested. Here we show how these two reaction operators can be seen as limiting cases of a more general reaction scheme.
On Evolution of the Pair-Electromagnetic Pulse of a Charge Black Hole
Remo Ruffini; Jay D. Salmonson; James R. Wilson; She-Sheng Xue
1999-05-04T23:59:59.000Z
Using hydrodynamic computer codes, we study the possible patterns of relativistic expansion of an enormous pair-electromagnetic-pulse (P.E.M. pulse); a hot, high density plasma composed of photons, electron-positron pairs and baryons deposited near a charged black hole (EMBH). On the bases of baryon-loading and energy conservation, we study the bulk Lorentz factor of expansion of the P.E.M. pulse by both numerical and analytical methods.
Towards laser based improved experimental schemes for multiphoton e+ e- pair production from vacuum
I. Ploumistakis; S. D. Moustaizis; I. Tsohantjis
2009-07-15T23:59:59.000Z
Numerical estimates for pair production from vacuum in the presence of strong electromagnetic fields are derived, for two experimental schemes : the First concerns a laser based X-FEL and the other imitates the E144 experiment. The approximation adopted in this work is that of two level multiphoton on resonance. Utilizing achievable values of laser beam parameters, an enhancedproduction efficiency of up to 10^11 and 10^15 pairs can be obtained, for the two schemes respectively.
Relativistic mean field plus exact pairing approach to open shell nuclei
Wei-Chia Chen; J. Piekarewicz; A. Volya
2013-11-20T23:59:59.000Z
Background: Pairing correlations play a critical role in determining numerous properties of open-shell nuclei. Traditionally, they are included in a mean-field description of atomic nuclei through the approximate Bardeen-Cooper-Schrieffer or Hartree-Fock-Bogoliubov formalism. Purpose: We propose a new hybrid ''relativistic-mean-field-plus-pairing'' approach in which pairing is treated exactly so the number of particles is conserved. To verify the reliability of the formalism, we apply it to the study of both ground-state properties and isoscalar monopole excitations of the Tin isotopes. Methods: Accurately-calibrated relativistic mean-field models supplemented by an exact treatment of pairing correlations are used to compute ground-state observables along the isotopic chain in Tin. In turn, ground-state densities are used as input to the calculation of giant monopole resonances through a constrained-relativistic approach. Results: We compute a variety of ground-state observables sensitive to pairing correlations as well as the evolution of giant monopole energies along the isotopic chain in Tin. Whereas ground-state properties are consistent with experiment, we find that pairing correlations have a minor effect on the giant monopole energies. Conclusions: A new mean-field-plus-pairing approach is introduced to compute properties of open-shell nuclei. The formalism provides an efficient and powerful alternative to the computation of both ground-state properties and monopole energies of open-shell nuclei. We find ground-state properties to be well reproduced in this approach. However, as many have concluded before us, we find that pairing correlations are unlikely to provide an answer to the question of ''why is Tin so soft?''
Generation, characterization and use of atom-resonant indistinguishable photon pairs
Morgan W. Mitchell
2015-02-26T23:59:59.000Z
We describe the generation of atom-resonant indistinguishable photon pairs using nonlinear optical techniques, their spectral purification using atomic filters, characterization using multi-photon interference, and application to quantum-enhanced sensing with atoms. Using either type-I or type-II cavity-enhanced spontaneous parametric down-conversion, we generate pairs of photons in the resonant modes of optical cavities with linewidths comparable to the 6 MHz natural linewidth of the D$_1$ line of atomic rubidium. The cavities and pump lasers are tuned so that emission occurs in a mode or a pair of orthogonally-polarized modes that are resonant to the D$_1$ line, at 794.7 nm. The emission from these frequency-degenerate modes is separated from other cavity emission using ultra-narrow atomic frequency filters, either a Faraday anomalous dispersion optical filter (FADOF) with a 445MHz linewidth and 57 dB of out-of-band rejection or an induced dichroism filter with an 80 MHz linewidth and $\\ge$35dB out-of-band rejection. Using the type-I source, we demonstrate interference of photon pair amplitudes against a coherent state and a new method for full characterization of the temporal wave-function of narrow-band photon pairs. With the type-II source we demonstrate high-visibility super-resolving interference, a high-fidelity atom-tuned NooN state, and quantum enhanced sensing of atoms using indistinguishable photon pairs.
Optical Flashes from Internal Pairs Formed in Gamma-Ray Burst Afterglows
Panaitescu, A
2015-01-01T23:59:59.000Z
We develop a numerical formalism for calculating the distribution with energy of the (internal) pairs formed in a relativistic source from unscattered MeV--TeV photons. For GRB afterglows, this formalism is more suitable if the relativistic reverse-shock that energizes the ejecta is the source of the GeV photons. The number of pairs formed is set by the source GeV output (calculated from the Fermi-LAT fluence), the unknown source Lorentz factor, and the unmeasured peak energy of the LAT spectral component. We show synchrotron and inverse-Compton light-curves expected from pairs formed in the shocked medium and identify some criteria for testing a pair origin of GRB optical counterparts. Pairs formed in bright LAT afterglows with a Lorentz factor in the few hundreds may produce bright optical counterparts (R < 10) lasting for up to one hundred seconds. The number of internal pairs formed from unscattered seed photons decreases very strongly with the source Lorentz factor, thus bright GRB optical counterpart...
P. A. Marchetti; F. Ye; Z. B. Su; L. Yu
2011-05-25T23:59:59.000Z
Within a gauge approach to the t-J model, we propose a new, non-BCS mechanism of superconductivity for underdoped cuprates. We implement the no-double occupancy constraint with a (semionic) slave-particle formalism. The dopant generates a vortex-like quantum distortion of the AF background centered on the empty sites, with opposite chirality for cores on the two N\\'eel sublattices. Empty sites are described in terms of spinless fermionic holons and the long-range attraction between spin vortices on two opposite N\\'eel sublattices is the holon pairing force, leading eventually to SC. The spin fluctuations are described by bosonic spinons with a gap generated by scattering on spin vortices. Due to the occupation constraint, there is a gauge attraction between holon and spinon, binding them into a physical hole. Through gauge interaction the spin vortex attraction induces the formation of spin-singlet RVB pairs reducing the spinon gap. Lowering T, there are two crossovers as precursors of the SC transition: at the higher one a gas of holon pairs appears, reducing the hole spectral weight, while at the lower one a gas of spinon pairs also appears, giving rise to a gas of incoherent preformed hole pairs with magnetic vortices in the plasma phase, supporting a Nernst signal. At an even lower T the hole pairs become coherent and SC appears beyond a critical doping. The proposed SC mechanism is not of the BCS-type, because it involves a gain in kinetic energy (lowering of spinon gap) and it is "almost" of the classical 3D XY-type. Since both the spinon gap and the holon pairing originate from the same term in the slave-particle representation of the t-J model, this approach incorporates a strong interplay between AF and SC, giving rise to a universal relation between Tc and the energy of the resonance mode, as observed in neutron scattering experiments.
Possible Effects of Pair Echoes on Gamma-Ray Burst Afterglow Emission
Kohta Murase; Bing Zhang; Keitaro Takahashi; Shigehiro Nagataki
2009-02-27T23:59:59.000Z
High-energy emission from gamma-ray bursts (GRBs) is widely expected but had been sparsely observed until recently when the Fermi satellite was launched. If >TeV gamma rays are produced in GRBs and can escape from the emission region, they are attenuated by the cosmic infrared background photons, leading to regeneration of GeV-TeV secondary photons via inverse-Compton scattering. This secondary emission can last for a longer time than the duration of GRBs, and it is called a pair echo. We investigate how this pair echo emission affects spectra and light curves of high energy afterglows, considering not only prompt emission but also afterglow as the primary emission. Detection of pair echoes is possible as long as the intergalactic magnetic field (IGMF) in voids is weak. We find (1) that the pair echo from the primary afterglow emission can affect the observed high-energy emission in the afterglow phase after the jet break, and (2) that the pair echo from the primary prompt emission can also be relevant, but only when significant energy is emitted in the TeV range, typically E_{gamma, >0.1 TeV} > (Y/(1+Y)) epsilon_e E_k. Even non-detections of the pair echoes could place interesting constraints on the strength of IGMF. The more favorable targets to detect pair echoes may be the "naked" GRBs without conventional afterglow emission, although energetic naked GRBs would be rare. If the IGMF is weak enough, it is predicted that the GeV emission extends to >30-300 s.
Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey
D. R. Patton; C. J. Pritchet; R. G. Carlberg; R. O. Marzke; H. K. C. Yee; P. B. Hall; H. Lin; S. L. Morris; M. Sawicki; C. W. Shepherd; G. D. Wirth
2001-09-24T23:59:59.000Z
We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12 < z < 0.55 and R_C < 21.5. We identify 88 galaxies in close (5 < r_p < 20 h^{-1} kpc) dynamical (delta v < 500 km/s) pairs. These galaxies are used to compute global pair statistics, after accounting for selection effects resulting from the flux limit, k-corrections, luminosity evolution, and spectroscopic incompleteness. We find that the number of companions per galaxy (for -21 < M_B^{k,e} < -18) is Nc = 0.0321 +/- 0.0077 at z=0.3. The luminosity in companions, per galaxy, is Lc = 0.0294 +/- 0.0084 x 10^10 h^2 L_sun. We assume that Nc is proportional to the galaxy merger rate, while Lc is directly related to the mass accretion rate. After increasing the maximum pair separation to 50 h^{-1} kpc, and comparing with the low redshift SSRS2 pairs sample, we infer evolution in the galaxy merger and accretion rates of (1+z)^{2.3 +/- 0.7} and (1+z)^{2.3 +/- 0.9} respectively. These are the first such estimates to be made using only confirmed dynamical pairs. When combined with several additional assumptions, this implies that approximately 15% of present epoch galaxies with -21 < M_B < -18 have undergone a major merger since z=1.
Interesting features of nonlinear shock equations in dissipative pair-ion-electron plasmas
Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 54000 (Pakistan); National Centre for Physics (NCP), Shahdara Valley Road, 44000 Islamabad (Pakistan); Rizvi, H. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 54000 (Pakistan)
2011-09-15T23:59:59.000Z
Two dimensional nonlinear electrostatic waves are studied in unmagnetized, dissipative pair-ion-electron plasmas in the presence of weak transverse perturbation. The dissipation in the system is taken into account by incorporating the kinematic viscosity of both positive and negative ions. In the linear case, a biquadratic dispersion relation is obtained, which yields the fast and slow modes in a pair-ion-electron plasma. It is shown that the limiting cases of electron-ion and pair-ion can be retrieved from the general biquadratic dispersion relation, and the differences in the characters of the waves propagating in both the cases are also highlighted. Using the small amplitude approximation method, the nonlinear Kadomtsev Petviashvili Burgers as well as Burgers-Kadomtsev Petviashvili equations are derived and their applicability for pair-ion-electron plasma is explained in detail. The present study may have relevance to understand the formation of two dimensional electrostatic shocks in laboratory produced pair-ion-electron plasmas.
The Radical Pair Mechanism and the Avian Chemical Compass: Quantum Coherence and Entanglement
Yiteng Zhang; Gennady P. Berman; Sabre Kais
2015-03-23T23:59:59.000Z
We review the spin radical pair mechanism which is a promising explanation of avian navigation. This mechanism is based on the dependence of product yields on (1) the hyperfine interaction involving electron spins and neighboring nuclear spins and (2) the intensity and orientation of the geomagnetic field. One surprising result is that even at ambient conditions quantum entanglement of electron spins can play an important role in avian magnetoreception. This review describes the general scheme of chemical reactions involving radical pairs generated from singlet and triplet precursors; the spin dynamics of the radical pairs; and the magnetic field dependence of product yields caused by the radical pair mechanism. The main part of the review includes a description of the chemical compass in birds. We review: the general properties of the avian compass; the basic scheme of the radical pair mechanism; the reaction kinetics in cryptochrome; quantum coherence and entanglement in the avian compass; and the effects of noise. We believe that the "quantum avian compass" can play an important role in avian navigation and can also provide the foundation for a new generation of sensitive and selective magnetic-sensing nano-devices.
Generation of potential/surface density pairs in flat disks Power law distributions
J. -M. Hure; D. Pelat; A. Pierens
2007-06-25T23:59:59.000Z
We report a simple method to generate potential/surface density pairs in flat axially symmetric finite size disks. Potential/surface density pairs consist of a ``homogeneous'' pair (a closed form expression) corresponding to a uniform disk, and a ``residual'' pair. This residual component is converted into an infinite series of integrals over the radial extent of the disk. For a certain class of surface density distributions (like power laws of the radius), this series is fully analytical. The extraction of the homogeneous pair is equivalent to a convergence acceleration technique, in a matematical sense. In the case of power law distributions, the convergence rate of the residual series is shown to be cubic inside the source. As a consequence, very accurate potential values are obtained by low order truncation of the series. At zero order, relative errors on potential values do not exceed a few percent typically, and scale with the order N of truncation as 1/N**3. This method is superior to the classical multipole expansion whose very slow convergence is often critical for most practical applications.
Mechanics and Dynamics of X-Chromosome Pairing at X Inactivation
A. Scialdone; M. Nicodemi
2009-10-13T23:59:59.000Z
At the onset of X Chromosomes Inactivation, the vital process whereby female mammal cells equalize X products with respect to males, the X chromosomes are colocalized along their Xic (X-Inactivation Center) regions. The mechanism inducing recognition and pairing of the X's remains, though, elusive. Starting from recent discoveries on the molecular factors and on the DNA sequences (the so-called ``pairing sites'') involved, we dissect the mechanical basis of Xic colocalization by using a Statistical Physics model. We show that soluble DNA specific binding molecules, as those experimentally identified, can be indeed sufficient to induce the spontaneous colocalization of the homologous chromosomes, but only when their concentration, or chemical affinity, rises above a threshold value, as a consequence of a thermodynamic phase transition. We derive the likelihood of pairing and its probability distribution. Chromosome dynamics has two stages: an initial independent Brownian diffusion followed, after a characteristic time scale, by recognition and pairing. Finally, we investigate the effects of DNA deletion/insertions in the region of pairing sites and compare model predictions to available experimental data.
Comparison of Three Cre-LoxP Based Paired-End Library Construction Methods
Peng, Ze; Nath, Nandita; Tritt, Andrew; Liang, Shoudan; Han, James; Pennacchio, Len; Chen, Feng
2013-03-26T23:59:59.000Z
Paired-end library sequencing has been proven useful in scaffold construction during de novo whole genome shotgun assembly. The ability of generating mate pairs with > 8 Kb insert sizes is especially important for genomes containing long repeats. To make mate paired libraries for next generation sequencing, DNA fragments need to be circularized to bring the ends together. There are several methods that can be used for DNA circulation, namely ligation, hybridization and Cre-LoxP recombination. With higher circularization efficiency with large insert DNA fragments, Cre-LoxP recombination method generally has been used for constructing >8 kb insert size paired-end libraries. Second fragmentation step is also crucial for maintaining high library complexity and uniform genome coverage. Here we will describe the following three fragmentation methods: restriction enzyme digestion, random shearing and nick translation. We will present the comparison results for these three methods. Our data showed that all three methods are able to generate paired-end libraries with greater than 20 kb insert. Advantages and disadvantages of these three methods will be discussed as well.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aaltonen, T.; Albin, E.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M. A.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d’Ascenzo, N.; Datta, M.; De Barbaro, P.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Sorin, V.; Song, H.; Stancari, M.; Denis, R. St.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.
2013-07-01T23:59:59.000Z
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.6 fb?¹. We find the data to be consistent with nonresonant production. We report limits on ?(pp??jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aaltonen, T.; Albin, E.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; et al
2013-07-01T23:59:59.000Z
We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at ?s=1.96 TeV corresponding to an integrated luminosity of 6.6 fb?¹. We find the data to be consistent with nonresonant production. We report limits on ?(pp??jjjj) as a function of the masses of themore »hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.« less
PROD. TYPE: FLP PP:1-11 (col.fig.: nil)
Gutierrez, Jaime
of this topic. Corresponding author. E-mail address: jaime.gutierrez@unican.es (J. Gutierrez). 1 Partially.08.004 #12;U N C O R R EC TED PR O O F 2 J. Gutierrez, D. Sevilla/Finite Fields and Their Applications. #12;U N C O R R EC TED PR O O F YFFTA534 ARTICLE IN PRESS J. Gutierrez, D. Sevilla/Finite Fields
http://cemp.dri.edu/cgi-bin/cemp_stations.pl?stn=tono&prod=11
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020,holidayCFRTheSeismicity of8/%2A en Office3 Community
http://cemp.dri.edu/cgi-bin/cemp_stations.pl?stn=tono&prod=11
National Nuclear Security Administration (NNSA)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23Tribal EnergyCatalytic Coby Mods 002, 006, 020,holidayCFRTheSeismicity of8/%2A en Office3 Community1
PROD. TYPE: COM PP:1-11 (col.fig.: nil) CES7571 MODE+
Ferguson, Thomas S.
Ltd.17 Keywords: Fluid mixing; Periodic shear; Chaotic advection; Low-Reynolds-number flow 19 1 it takes large Reynolds numbers to achieve even laminar mixing of viscous fluid in large cylindrical: Vijay -- SCAN: Raghwho ARTICLE IN PRESS Chemical Engineering Science ( ) www.elsevier.com/locate/ces 1
PROD. TYPE: COM PP:1-17 (col.fig.: nil) CBM856 MODE+
Serpen, Gursel
). The main premise is that there exists substantial and significant specialized knowledge in the domain of PE reserved. doi:10.1016/j.compbiomed.2007.10.001 ventilationperfusion scans along with correlated chest X
Search for pair-produced resonances decaying to jet pairs in proton-proton collisions at ?s = 8 TeV
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan
2015-07-01T23:59:59.000Z
Results are reported of a general search for pair production of heavy resonances decaying to pairs of jets in events with at least four jets. The study is based on up to 19.4 inverse femtobarns of integrated luminosity from proton-proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The firstmore »assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV.« less
Statistics of simulated and observed pair separations in the Gulf of Mexico
Beron-Vera, F J
2015-01-01T23:59:59.000Z
Pair-separation statistics of in-situ and synthetic surface drifters deployed near the \\emph{Deepwater Horizon} site in the Gulf of Mexico are investigated. The synthetic trajectories derive from synthetic particles advected by surface velocities from a 1-km-resolution data-assimilative Navy Coastal Ocean Model (NCOM) simulation. The in-situ drifters were launched in the Grand LAgrangian Deployment (GLAD). The statistical measures are of two classes---those which are functions of time, including the probability distribution function (PDF) of pair separations, the relative dispersion and the kurtosis, and those which are functions of separation, including the second-order velocity structure function and the relative diffusivity. The measures yield a consistent picture of the dispersion with the simulated pairs, with nonlocal dispersion from separations of 1 km to the Rossby deformation radius, $L_\\mathrm{D}$, and diffusive dispersion above $L_\\mathrm{D}$. The measures are less consistent with the GLAD drifters...
Coherent chemical kinetics as quantum walks II: Radical-pair reactions in Arabidopsis thaliana
A. Chia; A. Gorecka; P. Kurzynski; T. Paterek; D. Kaszlikowski
2015-08-20T23:59:59.000Z
We apply the quantum-walk approach recently proposed in arXiv:quant-ph-1506.04213 to a radical-pair reaction where realistic estimates for the intermediate transition rates are available. The well-known average hitting time from quantum walks can be adopted as a measure of how quickly the reaction occurs and we calculate this for varying degrees of dephasing in the radical pair. The time for the radical pair to react to a product is found to be independent of the amount of dephasing introduced, even in the limit of no dephasing where the transient population dynamics exhibit strong coherent oscillations. This can be seen to arise from the existence of a rate-limiting step in the reaction and we argue that in such examples, a purely classical model based on rate equations can be used for estimating the timescale of the reaction but not necessarily its population dynamics.
HIV-1 sequence variation between isolates from mother-infant transmission pairs
Wike, C.M.; Daniels, M.R.; Furtado, M.; Wolinsky, M.; Korber, B.; Hutto, C.; Munoz, J.; Parks, W.; Saah, A.
1991-12-31T23:59:59.000Z
To examine the sequence diversity of human immunodeficiency virus type 1 (HIV-1) between known transmission sets, sequences from the V3 and V4-V5 region of the env gene from 4 mother-infant pairs were analyzed. The mean interpatient sequence variation between isolates from linked mother-infant pairs was comparable to the sequence diversity found between isolates from other close contacts. The mean intrapatient variation was significantly less in the infants` isolates then the isolates from both their mothers and other characterized intrapatient sequence sets. In addition, a distinct and characteristic difference in the glycosylation pattern preceding the V3 loop was found between each linked transmission pair. These findings indicate that selection of specific genotypic variants, which may play a role in some direct transmission sets, and the duration of infection are important factors in the degree of diversity seen between the sequence sets.
HIV-1 sequence variation between isolates from mother-infant transmission pairs
Wike, C.M.; Daniels, M.R.; Furtado, M.; Wolinsky, M.; Korber, B.; Hutto, C.; Munoz, J.; Parks, W.; Saah, A.
1991-01-01T23:59:59.000Z
To examine the sequence diversity of human immunodeficiency virus type 1 (HIV-1) between known transmission sets, sequences from the V3 and V4-V5 region of the env gene from 4 mother-infant pairs were analyzed. The mean interpatient sequence variation between isolates from linked mother-infant pairs was comparable to the sequence diversity found between isolates from other close contacts. The mean intrapatient variation was significantly less in the infants' isolates then the isolates from both their mothers and other characterized intrapatient sequence sets. In addition, a distinct and characteristic difference in the glycosylation pattern preceding the V3 loop was found between each linked transmission pair. These findings indicate that selection of specific genotypic variants, which may play a role in some direct transmission sets, and the duration of infection are important factors in the degree of diversity seen between the sequence sets.
Neutral Higgs boson pair production at the linear collider in the noncommutative standard model
Das, Prasanta Kumar; Prakash, Abhishodh; Mitra, Anupam [Birla Institute of Technology and Science-Pilani, K.K. Birla Goa Campus, NH-17B, Zuarinagar, Goa-403726 (India)
2011-03-01T23:59:59.000Z
We study the Higgs boson pair production at the linear collider in the noncommutative extension of the standard model using the Seiberg-Witten map of this to the first order of the noncommutative parameter {Theta}{sub {mu}{nu}}. Unlike the standard model (where the process is forbidden) here the Higgs boson pair directly interacts with the photon. We find that the pair production cross section can be quite significant for the noncommutative scale {Lambda} lying in the range 0.5 TeV to 1.0 TeV. Using the experimental (LEP 2, Tevatron, and global electroweak fit) bound on the Higgs mass, we obtain 626 GeV{<=}{Lambda}{<=}974 GeV.
Observable effects caused by vacuum pair creation in the field of high-power optical lasers
David B. Blaschke; Andrey V. Filatov; Irina A. Egorova; Alexander V. Prozorkevich; Stanislav A. Smolyansky
2008-11-29T23:59:59.000Z
We consider the possibility of an experimental proof of vacuum e+e- pair creation in the focus of two counter-propagating optical laser beams with an intensity of the order of 10^20 - 10^22 W/cm^2. Our approach is based on the collisionless kinetic equation for the distribution function of the e+e- pairs with the source term for particle production. As a possible experimental signal of vacuum pair production we consider the refraction of a high-frequency probe laser beam by the produced e+e- plasma to be observed by an interference filter. The generation of higher harmonics of the laser frequency in the self-consistent electric field is also investigated.
Tunable cavity-enhanced photon pairs source in Hermite-Gaussian mode
Zhou, Zhi-Yuan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen; Guo, Guang-Can
2015-01-01T23:59:59.000Z
The spatial modes of light have grasped great research interests because of its great potentials in optical communications, optical manipulation and trapping, optical metrology and quantum information processing. Here we report on generating of photon pairs in Hermite-Gaussian (HG) mode in a type-I optical parametric oscillator (OPO) operated far below threshold. The bandwidths of the photon pairs are 11.4 MHz and 20.8MHz for two different HG modes respectively, which is capable to be stored in cold Rubidium atomic ensembles. From correlation measurements, non-classical properties of HG modes in different directions are verified by tuning the cavity. Our study provides an effective way to generate photon pairs with narrow bandwidth in high order spatial modes for high dimensional quantum communication.
The vacuum bubbles in de Sitter background and black hole pair creation
Bum-Hoon Lee; Wonwoo Lee
2009-10-07T23:59:59.000Z
We study the possible types of the nucleation of vacuum bubbles. We classify vacuum bubbles in de Sitter background and present some numerical solutions. The thin-wall approximation is employed to obtain the nucleation rate and the radius of vacuum bubbles. With careful analysis we confirm that Parke's formula is also applicable to the large true vacuum bubbles. The nucleation of the false vacuum bubble in de Sitter background is also evaluated. The tunneling process in the potential with degenerate vacua is analyzed as the limiting cases of the large true vacuum bubble and false vacuum bubble. Next, we consider the pair creation of black holes in the background of bubble solutions. We obtain static bubble wall solutions of junction equation with black hole pair. The masses of created black holes are uniquely determined by the cosmological constant and surface tension on the wall. Finally, we obtain the rate of pair creation of black holes.
Krawtchouk polynomials, the Lie algebra $\\mathfrak{sl}_2$, and Leonard pairs
Nomura, Kazumasa
2012-01-01T23:59:59.000Z
A Leonard pair is a pair of diagonalizable linear transformations of a finite-dimensional vector space, each of which acts in an irreducible tridiagonal fashion on an eigenbasis for the other one. In the present paper we give an elementary but comprehensive account of how the following are related: (i) Krawtchouk polynomials; (ii) finite-dimensional irreducible modules for the Lie algebra ${\\mathfrak{sl}_2}$; (iii) a class of Leonard pairs said to have Krawtchouk type. Along the way we obtain elementary proofs of some well-known facts about Krawtchouk polynomials, such as the three-term recurrence, the orthogonality, the difference equation, and the generating function. The paper is a tutorial meant for a graduate student or a researcher unfamiliar with the above topics.
Study of correlation of PDF uncertainty in single top and top pair production at the LHC
The ATLAS collaboration
2015-01-01T23:59:59.000Z
The incomplete knowledge of parton distribution functions is an important source of systematic uncertainty for top-quark measurements, including top-quark pair and single top-quark production cross sections, as well as for analyses that have a large background from these processes. The correlation of the parton-distribution-function uncertainty is studied for top-quark pair production and single top-quark production in association with a W boson, in final states with two reconstructed leptons. Four types of correlation are studied: between total production cross-sections, between cross-section and acceptance correction, between the two processes for common selection requirements, and between different jet multiplicity requirements. The uncertainty correlation is evaluated for several sets of parton distribution functions using simulated samples of top-quark pair and single top-quark events.
Long-range Cooper pair splitter with high entanglement production rate
Wei Chen; D. N. Shi; D. Y. Xing
2015-01-05T23:59:59.000Z
Cooper pairs in the superconductor are a natural source of spin entanglement. The existing proposals of the Cooper pair splitter can only realize a low efficiency of entanglement production, and its size is constrained by the superconducting coherence length. Here we show that a long-range Cooper pair splitter can be implemented in a normal metal-superconductor-normal metal (NSN) junction by driving a supercurrent in the S. The supercurrent results in a band gap modification of the S, which significantly enhances the crossed Andreev reflection (CAR) of the NSN junction and simultaneously quenches its elastic cotunneling. Therefore, a high entanglement production rate close to its saturation value can be achieved by the inverse CAR. Interestingly, in addition to the conventional entangled electron states between opposite energy levels, novel entangled states with equal energy can also be induced in our proposal.
A CLOSE-PAIR ANALYSIS OF DAMP MERGERS AT INTERMEDIATE REDSHIFTS
Chou, Richard C. Y.; Abraham, Roberto G. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Bridge, Carrie R., E-mail: chou@astro.utoronto.ca, E-mail: abraham@astro.utoronto.ca, E-mail: bridge@astro.caltech.edu [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
2012-12-01T23:59:59.000Z
We have studied the kinematics of {approx}2800 candidate close-pair galaxies at 0.1 < z < 1.2 identified from the Canada-France-Hawaii Telescope Legacy Survey fields. Spectra of these systems were obtained using spectrometers on the 6.5 m Magellan and 5 m Hale telescopes. These data allow us to constrain the rate of dry mergers at intermediate redshifts and to test the 'hot halo' model for quenching of star formation. Using virial radii estimated from the correlation between dynamical and stellar masses published by Leauthaud et al., we find that around 1/5 of our candidate pairs are likely to share a common dark matter halo (our metric for close physical association). These pairs are divided into red-red, blue-red, and blue-blue systems using the rest-frame colors classification method introduced in Chou et al.. Galaxies classified as red in our sample have very low star formation rates, but they need not be totally quiescent, and hence we refer to them as 'damp', rather than 'dry', systems. After correcting for known selection effects, the fraction of blue-blue pairs is significantly greater than that of red-red and blue-red pairs. Red-red pairs are almost entirely absent from our sample, suggesting that damp mergers are rare at z {approx} 0.5. Our data support models with a short merging timescale (<0.5 Gyr) in which star formation is enhanced in the early phase of mergers, but quenched in the late phase. Hot halo models may explain this behavior, but only if virial shocks that heat gas are inefficient until major mergers are nearly complete.
Synchrotron and inverse-Compton emissions from pairs formed in GRB afterglows (analytical treatment)
Panaitescu, A.; Vestrand, W. T. [Space and Remote Sensing, MS B244, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)
2014-10-01T23:59:59.000Z
We calculate the synchrotron and inverse-Compton emissions from pairs formed in gamma-ray burst (GRB) afterglows from high-energy photons (above 100 MeV), assuming a power-law photon spectrum C {sub ?}??{sup –2} and considering only the pairs generated from primary high-energy photons. The essential properties of these pairs (number, minimal energy, cooling energy, distribution with energy) and of their emission (peak flux, spectral breaks, spectral slope) are set by the observables GeV fluence ?(t) = Ft and spectrum, and by the Lorentz factor, ?, and magnetic field, B, of the source of high-energy photons, at observer time, t. Optical and X-ray pseudo light curves, F {sub ?}(?), are calculated for the given B; proper synchrotron self-Compton light curves are calculated by setting the dynamics ?(t) of the high-energy photon source to be that of a decelerating, relativistic shock. It is found that the emission from pairs can accommodate the flux and decays of the optical flashes measured during the prompt (GRB) phase, but it decays faster than the X-ray plateaus observed during the delayed (afterglow) phase. The brightest pair optical emission is obtained for 100 < ? < 500, and depends mostly on the GeV fluence, being independent of the source redshift. Emission from pairs formed during the GRB phase offers an alternate explanation to reverse-shock optical flashes. These two models may be distinguished based on their corresponding flux decay index-spectral slope relations, different correlations with the Large Area Telescope fluence, or through modeling of the afterglow multiwavelength data.
Conversion of relativistic pair energy into radiation in the jets of active galactic nuclei
R. Schlickeiser; R. Vainio; M. Boettcher; I. Lerche; M. Pohl; C. Schuster
2002-07-02T23:59:59.000Z
It is generally accepted that relativistic jet outflows power the nonthermal emission from active galactic nuclei (AGN). The composition of these jets -- leptonic versus hadronic -- is still under debate. We investigate the microphysical details of the conversion process of the kinetic energy in collimated relativistic pair outflows into radiation through interactions with the ambient interstellar medium. Viewed from the coordinate system comoving with the pair outflow, the interstellar protons and electrons represent a proton-electron beam propagating with relativistic speed in the pair plasma. We demonstrate that the beam excites both electrostatic and low-frequency magnetohydrodynamic Alfven-type waves via a two-stream instability in the pair background plasma, and we calculate the time evolution of the distribution functions of the beam particles and the generated plasma wave turbulence power spectra. For standard AGN jet outflow and environment parameters we show that the initial beam distributions of interstellar protons and electrons quickly relax to plateau-distributions in parallel momentum, transferring thereby one-half of the initial energy density of the beam particles to electric field fluctuations of the generated electrostatic turbulence. On considerably longer time scales, the plateaued interstellar electrons and protons will isotropise by their self-generated transverse turbulence and thus be picked-up in the outflow pair plasma. These longer time scales are also characteristic for the development of transverse hydromagnetic turbulence from the plateaued electrons and protons. This hydromagnetic turbulence upstream and downstream is crucial for diffusive shock acceleration to operate at external or internal shocks associated with pair outflows.
A Method for Constructing a Lax Pair for the Ernst Equation
C. J. Papachristou; B. Kent Harrison
2009-10-26T23:59:59.000Z
A systematic construction of a Lax pair and an infinite set of conservation laws for the Ernst equation is described. The matrix form of this equation is rewritten as a differential ideal of gl(2,R)-valued differential forms, and its symmetry condition is expressed as an exterior equation which is linear in the symmetry characteristic and has the form of a conservation law. By means of a recursive process, an infinite collection of such laws is then obtained, and the conserved "charges" are used to derive a linear exterior equation whose components constitute a Lax pair.
Discovering Higgs boson pair production through rare final states at a 100 TeV collider
Papaefstathiou, Andreas
2015-01-01T23:59:59.000Z
We consider Higgs boson pair production at a future proton collider with centre-of-mass energy of 100 TeV, focusing on rare final states that include a bottom-anti-bottom quark pair and multiple isolated leptons: $hh \\rightarrow (b\\bar{b}) + n \\ell + X$, $n = \\{2,4\\}$, $X = \\{ E_T^\\mathrm{miss}, \\gamma, -\\}$. We construct experimental search strategies for observing the process through these channels and make suggestions on the desired requirements for the detector design of the future collider.
Gap anisotropy and universal pairing scale in a spin-fluctuation model of cuprate superconductors
Abanov, Artem; Chubukov, A. V.; Norman, M. R.
2008-01-01T23:59:59.000Z
Gap anisotropy and universal pairing scale in a spin-fluctuation model of cuprate superconductors Ar. Abanov,1 A. V. Chubukov,2 and M. R. Norman3 1Department of Physics, Texas A&M University, College Station, Texas 77843, USA 2Department...-Tc cu- prate superconductors is a key problem.1 Some argue that the pseudogap originates from #1;quasi-#2;long-range order in a non- pairing channel #1;two-gap scenario#2;.2 Others argue instead that the pseudogap is a phase in which fermions already...
Equal-spin pairing state of superfluid {sup 3}He in aerogel
Aoyama, Kazushi; Ikeda, Ryusuke [Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)
2005-07-01T23:59:59.000Z
The equal-spin pairing state, the so-called A-like phase, of superfluid {sup 3}He in aerogels is studied theoretically in the Ginzburg-Landau region by examining thermodynamics, and the resulting equilibrium phase diagram is mapped out. We find that the ABM pairing state with presumably quasi-long-ranged superfluid order has a lower free energy than the planar and 'robust' states and is the best candidate of the A-like phase with a strange lowering of the polycritical point observed experimentally.
Time-bin entangled photon pair generation from Si micro-ring resonator
Ryota Wakabayashi; Mikio Fujiwara; Ken-ichiro Yoshino; Yoshihiro Nambu; Masahide Sasaki; Takao Aoki
2015-01-23T23:59:59.000Z
We demonstrate time-bin entanglement generation in telecom wavelength using a 7 {\\mu}m radius Si micro-ring resonator pumped by a continuous wave laser. The resonator structure can enhance spontaneous four wave mixing, leading to a photon pair generation rate of about 90-100 Hz with a laser pump power of as low as -3.92 dBm (0.41 mW). We succeed in observing time-bin entanglement with the visibility over 92%. Moreover, wavelength-tunability of the entangled photon pair is demonstrated by changing the operation temperature.
Reduced effect of impurities on the universal pairing scale in the cuprates
Vorontsov, A. B.; Abanov, Artem; Vavilov, M. G.; Chubukov, A. V.
2010-01-01T23:59:59.000Z
corrections are small numerically.22 The set of equations includes fermionic and bosonic self- energies in the normal state and the linearized equation for the d-wave pairing vertex #11;pf #12; #1; m#2; #1;Ref. 1#2; pf#1; m#2; = #5;T #1;#7; m#1; #8...; /2#5;T #1;#2;?#7;#1;1 /2#2;, where #7;#1;x#2; is the di-Gamma function and T 0 #1; is the pairing temperature in the absence of impurities #1;for an s-wave and magnetic impurities, the formula is the same,7 but with #3; /2 instead of #3...
Spin polarized electron-positron pair production via elliptical polarized laser fields
Anton Wöllert; Heiko Bauke; Christoph H. Keitel
2015-02-23T23:59:59.000Z
We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.
Power-efficient production of photon pairs in a tapered chalcogenide microwire
Meyer-Scott, Evan; Ahmad, Raja; Li, Lizhu; Rochette, Martin; Jennewein, Thomas
2015-01-01T23:59:59.000Z
Using tapered fibers of As2Se3 chalcogenide glass, we produce photon pairs at telecommunication wavelengths with pump power as low as 250 nW for a single pump, and 191 nW for the weak pump in a two-pump non-degenerate scheme. Our results show that the ultrahigh nonlinearity in these microwires could allow single-photon pumping to produce photon pairs, enabling the production of large entangled states, heralding of single photons after lossy transmission, and photonic quantum information processing with nonlinear optics.
Recent results from HADES on electron pair production in relativistic heavy-ion collisions
The HADES Collaboration; T. Galatyuk; G. Agakishiev; A. Balanda; D. Belver; A. V. Belyaev; A. Blanco; M. Böhmer; J. L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Díaz; F. Dohrmann; A. Dybczak; L. Fabbietti; O. V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Fröhlich; J. A. Garzón; R. Gernhäuser; A. Gil; C. Gilardi; M. Golubeva; D. González-Díaz; F. Guber; T. Hennino; R. Holzmann; I. Iori; A. Ivashkin; M. Jurkovic; B. Kämpfer; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B. W. Kolb; R. Kotte; F. Krizek; R. Krücken; W. Kühn; A. Kugler; A. Kurepin; S. Lang; J. S. Lange; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; E. Morinière; J. Mousa; C. Müntz; L. Naumann; J. Otwinowski; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; A. Rustamov; A. Sadovsky; P. Salabura; A. Schmah; E. Schwab; Yu. G. Sobolev; S. Spataro; B. Spruck; H. Ströbele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebacz; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wüstenfeld; S. Yurevich; Y. V. Zanevsky; P. Zhou
2009-11-12T23:59:59.000Z
Systematic investigations of dilepton production are performed at the SIS accelerator of GSI with the HADES spectrometer. The goal of this program is a detailed understanding of di-electron emission from hadronic systems at moderate temperatures and densities. New results obtained in HADES experiments focussing on electron pair production in elementary collisions are reported here. They pave the way to a better understanding of the origin of the so-called excess pairs earlier on observed in heavy-ion collisions by the DLS collaboration and lately confirmed in two measurements of the HADES collaboration using C+C and Ar+KCl collisions. Results of these studies are discussed.
Spin polarized electron-positron pair production via elliptical polarized laser fields
Wöllert, Anton; Keitel, Christoph H
2015-01-01T23:59:59.000Z
We study nonperturbative multiphoton electron-positron pair creation in ultra-strong electromagnetic fields formed by two counterpropagating pulses with elliptic polarization. Our numerical approach allows us to take into account the temporal as well as the spatial variation of the standing electromagnetic field. The spin and momentum resolved pair creation probabilities feature characteristic Rabi oscillations and resonance spectra. Therefore, each laser frequency features a specific momentum distribution of the created particles. We find that depending on the relative polarization of both pulses the created electrons may be spin polarized along the direction of field propagation.
Reduced effect of impurities on the universal pairing scale in the cuprates
Vorontsov, A. B.; Abanov, Artem; Vavilov, M. G.; Chubukov, A. V.
2010-01-01T23:59:59.000Z
corrections are small numerically.22 The set of equations includes fermionic and bosonic self- energies in the normal state and the linearized equation for the d-wave pairing vertex #11;pf #12; #1; m#2; #1;Ref. 1#2; pf#1; m#2; = #5;T #1;#7; m#1; #8...; /2#5;T #1;#2;?#7;#1;1 /2#2;, where #7;#1;x#2; is the di-Gamma function and T 0 #1; is the pairing temperature in the absence of impurities #1;for an s-wave and magnetic impurities, the formula is the same,7 but with #3; /2 instead of #3...
Shape and pairing fluctuations effects on neutrinoless double beta decay nuclear matrix elements
Nuria López Vaquero; Tomás R. Rodríguez; J. Luis Egido
2014-01-03T23:59:59.000Z
Nuclear matrix elements (NME) for the most promising candidates to detect neutrinoless double beta decay have been computed with energy density functional methods including deformation and pairing fluctuations explicitly on the same footing. The method preserves particle number and angular momentum symmetries and can be applied to any decay without additional fine tunings. The finite range density dependent Gogny force is used in the calculations. An increase of $10\\%-40\\%$ in the NME with respect to the ones found without the inclusion of pairing fluctuations is obtained, reducing the predicted half-lives of these isotopes.
Study of correlations between photoproduced pairs of charmed particles at Experiment E831/FOCUS
Castromonte Flores, Cesar Manuel; /Rio de Janeiro, CBPF
2008-08-01T23:59:59.000Z
The authors present the study of the charm-pair correlations produced in photon-nucleon interactions at
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher; Wu, Ning; Santoro, Stephen; Schultz, Peter G
2014-03-11T23:59:59.000Z
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher (San Francisco, CA); Wu, Ning (Brookline, MA); Santoro, Stephen (Cambridge, MA); Schultz, Peter G. (La Jolla, CA)
2011-10-04T23:59:59.000Z
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher (San Francisco, CA); Wu, Ning (Brookline, MA); Santoro, Stephen (Cambridge, MA); Schultz, Peter G. (La Jolla, CA)
2009-08-18T23:59:59.000Z
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof
Anderson, J. Christopher (San Francisco, CA); Wu, Ning (Brookline, MA); Santoro, Stephen (Cambridge, MA); Schultz, Peter G. (La Jolla, CA)
2009-12-29T23:59:59.000Z
Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.
NIR Luminosity Function of Galaxies in Close Major-Merger Pairs and Mass Dependence of Merger Rate
C. K. Xu; Y. C. Sun; X. T. He
2004-02-07T23:59:59.000Z
A sample of close major-merger pairs (projected separation ${\\rm 5 \\leq r \\leq 20 h^{-1}}$ kpc, ${\\rm K_s}$ band magnitude difference $\\delta {\\rm K_s} \\leq 1$ mag) is selected from the matched 2MASS-2dFGRS catalog of Cole et al. (2001). The pair primaries are brighter than ${\\rm K_s} = 12.5$ mag. After corrections for various biases, the comparison between counts in the paired galaxy sample and counts in the parent sample shows that for the local `M* galaxies' sampled by flux limited surveys, the fraction of galaxies in the close major-merger pairs is 1.70$\\pm 0.32%$. Using 38 paired galaxies in the sample, a ${\\rm K_s}$ band luminosity function (LF) is calculated. This is the first unbiased LF for a sample of objectively defined interacting/merging galaxies in the local universe, while all previously determined LFs of paired galaxies are biased by mistreating paired galaxies as singles. A stellar mass function (MF) is translated from the LF. Compared to the LF/MF of 2MASS galaxies, a differential pair fraction function is derived. The results suggest a trend in the sense that less massive galaxies may have lower chance to be involved in close major-merger pairs than more massive galaxies. The algorithm presented in this paper can be easily applied to much larger samples of 2MASS galaxies with redshifts in near future.
Pair Production and Radiation Effects in Clouds Illuminated by Gamma Ray Sources
C. D. Dermer; M. Boettcher; E. P. Liang
2001-07-12T23:59:59.000Z
Many classes of gamma-ray sources, such as gamma-ray bursts, blazars, Seyfert galaxies, and galactic black hole sources are surrounded by large amounts of gas and dust. X-rays and gamma-rays that traverse this material will be attenuated by Compton scattering and photoelectric absorption. One signature of an intervening scattering cloud is radiation-hardening by electrons that have been scattered and heated by the incident radiation, as illustrated by a Monte Carlo calculation. Compton scattering provides backscattered photons that will attenuate subsequent gamma rays through \\gamma\\gamma pair-production processes. We calculate the pair efficiency for a cloud illuminated by gamma-ray burst radiation. An analytic calculation of the flux of X-rays and gamma rays Thomson scattered by an intervening cloud is presented. Illuminated clouds near GRBs will form relativistic plasmas containing large numbers of electron-positron pairs that can be detected within ~1-2 days of the explosion before expanding and dissipating. Localized regions of pair annihilation radiation in the Galaxy could reveal gamma-ray sources embedded in dense clouds, or sites of past GRB explosions.
proteinsSTRUCTURE O FUNCTION O BIOINFORMATICS Integrating statistical pair potentials into
Weng, Zhiping
they are typical of many approaches to problems in computational biology. In this work, we have chosen the popularproteinsSTRUCTURE O FUNCTION O BIOINFORMATICS Integrating statistical pair potentials into protein and Zhiping Weng1,2 * 1 Bioinformatics Program Boston University, Massachusetts 02215 2 Biomedical Engineering
proteinsSTRUCTURE O FUNCTION O BIOINFORMATICS Integrating statistical pair potentials into
Weng, Zhiping
they are typical of many approaches to problems in computational biology. In this work, we have chosen the popularproteinsSTRUCTURE O FUNCTION O BIOINFORMATICS Integrating statistical pair potentials into protein , and Zhiping Weng1,2 * 1 Bioinformatics Program Boston University, Massachusetts 02215 2 Biomedical Engineering
Dynamically Close Galaxy Pairs and Merger Rate Evolution in the CNOC2 Redshift Survey
Patton, D R; Carlberg, R G; Marzke, R O; Yee, H K C; Hall, P B; Lin, H; Morris, S L; Sawicki, M; Shepherd, C W; Wirth, G D
2001-01-01T23:59:59.000Z
We investigate redshift evolution in the galaxy merger and accretion rates, using a well-defined sample of 4184 galaxies with 0.12 < z < 0.55 and R_C < 21.5. We identify 88 galaxies in close (5 < r_p < 20 h^{-1} kpc) dynamical (delta v < 500 km/s) pairs. These galaxies are used to compute global pair statistics, after accounting for selection effects resulting from the flux limit, k-corrections, luminosity evolution, and spectroscopic incompleteness. We find that the number of companions per galaxy (for -21 < M_B^{k,e} < -18) is Nc = 0.0321 +/- 0.0077 at z=0.3. The luminosity in companions, per galaxy, is Lc = 0.0294 +/- 0.0084 x 10^10 h^2 L_sun. We assume that Nc is proportional to the galaxy merger rate, while Lc is directly related to the mass accretion rate. After increasing the maximum pair separation to 50 h^{-1} kpc, and comparing with the low redshift SSRS2 pairs sample, we infer evolution in the galaxy merger and accretion rates of (1+z)^{2.3 +/- 0.7} and (1+z)^{2.3 +/- 0.9} r...
Performance comparison of pulse-pair and wavelets methods for the pulse Doppler weather radar
Paris-Sud XI, Université de
- eters. The radar reflectivity (Z), the radial velocity (Vr) and the spectral width of velocities (W). [1). Generally, the meteorological targets move with speeds lower than 50 m/secs. The Doppler Effect wouldPerformance comparison of pulse-pair and wavelets methods for the pulse Doppler weather radar
Product measurements and fully symmetric measurements in qubit-pair tomography: A numerical study
Yong Siah Teo; Huangjun Zhu; Berthold-Georg Englert
2009-07-24T23:59:59.000Z
State tomography on qubit pairs is routinely carried out by measuring the two qubits separately, while one expects a higher efficiency from tomography with highly symmetric joint measurements of both qubits. Our numerical study of simulated experiments does not support such expectations.
CDF Note 10436 Measurement of the Forward Backward Asymmetry in Top Pair Production in the
Quigg, Chris
CDF Note 10436 Measurement of the Forward Backward Asymmetry in Top Pair Production in the Dilepton) We report on a measurement of the inclusive forward-backward asymmetry in tÂ¯t production production at energies at the Tevatron, which has been measured to be consistent with standard model
Bose–Einstein correlations of ?^0 pairs from hadronic Z^0 decays
Wilson, Graham Wallace; OPAL Collaboration; Abbiendi, G.; Ainsley, C.; Å kesson, P.F.; Alexander, G.; Allison, J.; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.
2003-05-01T23:59:59.000Z
We observe Bose–Einstein correlations in ?^0 pairs using back-to-back two jet hadronic events from Z^0 decays in the data sample collected by the OPAL detector at LEP 1 from 1991 to 1995. Using a static Gaussian picture for the pion emitter source...
Use of Exchangeable Pairs in the Analysis of Simulations Charles Stein with
labels (the so-called magnetization), direct or theoretical evaluation of EW is impossible e.g. when N are introduced. The relation with reversible Markov chains is recalled. A basic identity for an exchangeable pair (Stein [23]) and to derive combinatorial formulae for balls and boxes and cycle lengths in random
A Standard Reference Frame for the Description of Nucleic Acid Base-pair Geometry
Gerstein, Mark
uncertainties in this data set closely match numerical values reported in the recent survey of nucleic acid baseA Standard Reference Frame for the Description of Nucleic Acid Base-pair Geometry These preliminary (Rockefeller University), Richard E. Dickerson (University of California, Los Angeles), Mark Gerstein (Yale
Bugeaud, Yann
of view: rather than giving su#cient conditions ensuring the transcendence of a given number #, we take the fact that if the sequence of partial quotients of a real irrational number # has some special#cient conditions ensuring the transcendence of a given number #, we take a pair (#, # # ) of real numbers, and we
Visual Image of Cooper Pairing in Superconductors A. O. E. Animalu
Nigeria Nsukka, Nigeria and Tepper L. Gill Department of Electrical & Computer Engineering Computational-relativistic quasiparticle energy in (k-space) of a Cooper pair, Ek = k 2 + k( ), as an eigenvalue of a 4 × 4 Hamiltonian construction of a positive energy relativistic wave equation for an integral spin particle. We find a new class
Drell-Yan Lepton pair production at NNLO QCD with parton showers
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hoeche, Stefan [SLAC National Accelerator Lab., Menlo Park, CA (United States); Li, Ye [SLAC National Accelerator Lab., Menlo Park, CA (United States); Prestel, Stefan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2015-04-01T23:59:59.000Z
We present a simple approach to combine NNLO QCD calculations and parton showers, based on the UNLOPS technique. We apply the method to the computation of Drell-Yan lepton-pair production at the Large Hadron Collider. We comment on possible improvements and intrinsic uncertainties.
Research Statement Algebraic combinatorics is my research area, with the focus on Jones pairs,
Chan, Ada Sze Sze
Ada Chan 1 Research Statement Algebraic combinatorics is my research area, with the focus on Jones pairs, type II matrices and their relations to association schemes. Association schemes encode that satisfy three types of conditions cor- responding to the three Reidemeister moves on link diagrams [5
RELATIVE ORIENTATION OF PAIRS OF SPIRAL GALAXIES IN THE SLOAN DIGITAL SKY SURVEY
Buxton, Jesse; Ryden, Barbara S., E-mail: buxton.45@osu.edu, E-mail: ryden@astronomy.ohio-state.edu [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)
2012-09-10T23:59:59.000Z
From our study of binary spiral galaxies in the Sloan Digital Sky Survey Data Release 6, we find that the relative orientation of disks in binary spiral galaxies is consistent with their being drawn from a random distribution of orientations. For 747 isolated pairs of luminous disk galaxies, the distribution of {phi}, the angle between the major axes of the galaxy images, is consistent with a uniform distribution on the interval [0 Degree-Sign , 90 Degree-Sign ]. With the assumption that the disk galaxies are oblate spheroids, we can compute cos {beta}, where {beta} is the angle between the rotation axes of the disks. In the case that one galaxy in the binary is face-on or edge-on, the tilt ambiguity is resolved, and cos {beta} can be computed unambiguously. For 94 isolated pairs with at least one face-on member, and for 171 isolated pairs with at least one edge-on member, the distribution of cos {beta} is statistically consistent with the distribution of cos i for isolated disk galaxies. This result is consistent with random orientations of the disks within pairs.
29 Nov 2001 A. Bacchetta -Fragmentation to probe transversity 31 Hadron pair azimuthal angle
1 29 Nov 2001 A. Bacchetta - Fragmentation to probe transversity 31 Hadron pair azimuthal angle 29 Nov 2001 A. Bacchetta - Fragmentation to probe transversity 32 Center of mass angle hadron decay plane Center of mass direction in lab frame Center of mass frame R #12;2 29 Nov 2001 A. Bacchetta
Vortex-Pair Dynamics in Anisotropic Bistable Media: A Kinematic Approach Aric Hagberg1
Meron, Ehud
Alamos, New Mexico 87545, USA 2 Department of Solar Energy and Environmental Physics, BIDR, Ben Gurion type upon rotation by =2. We study vortex-pair dynamics by deriving kinematic equations for a front with contour lines that form a closed loop. Equations of this kind, but for isotropic systems and infinite
Costa, Eunice
The layer-by-layer (LbL) assembly of polyelectrolyte pairs on temperature and pH-sensitive cross-linked poly(N-isopropylacrylamide)-co-(methacrylic acid), poly(NIPAAm-co-MAA), microgels enabled a fine-tuning of the gel ...
Pairs and heptamers of C70 molecules ordered via PTCDI-melamine supramolecular networks
Castell, Martin
Pairs and heptamers of C70 molecules ordered via PTCDI-melamine supramolecular networks Fabien Silly Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom and Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands Adam
Measurement of prompt J/? pair production in pp collisions at ?s = 7 Tev
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan [Yerevan Physics Institute (Armenia)
2014-09-01T23:59:59.000Z
Production of prompt J/? meson pairs in proton-proton collisions at ?s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb?¹. The two J/? mesons are fully reconstructed via their decays into ?? ?? pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/? transverse momentum (pTJ/?) and rapidity (|yJ/?|): |yJ/?| TJ/? > 6.5 GeV/c, 1.2 J/?| T threshold that scales linearly with |yJ/?| from 6.5 to 4.5 GeV/c, and 1.43 J/?| TJ/? > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from ?31% to +27%.
PHYSICAL REVIEW C 85, 034328 (2012) Pairing dynamics in particle transport
Bertsch George F.
2012-01-01T23:59:59.000Z
PHYSICAL REVIEW C 85, 034328 (2012) Pairing dynamics in particle transport Guillaume Scamps on particle transport in time-dependent theories based on the Hartree-Fock- Bogoliubov (HFB) or BCS in particle densities. This can be ameliorated by freezing the occupation numbers during the evolution in TDHF
Random perturbations of spiking activity in a pair of coupled neurons
Random perturbations of spiking activity in a pair of coupled neurons Boris Gutkin , J¨urgen Jost on the firing be- haviour of two coupled Type 1 or Type 2 neurons. In Hodgkin-Huxley model neurons with standard that regular spiking and fast spiking neurons in the rat somatosensory cortex exhibit Type 1 and Type 2 firing
ENVIRONMENTAL BENZENE EXPOSURE ASSESSMENT FOR PARENT-CHILD PAIRS IN ROUEN, FRANCE
Boyer, Edmond
1 ENVIRONMENTAL BENZENE EXPOSURE ASSESSMENT FOR PARENT-CHILD PAIRS IN ROUEN, FRANCE Amin KOUNIALIa environmental benzene exposure. In this study we compared personal benzene exposure and inhalation uptake in a group of children to those of their parents. We also compared levels of urinary benzene metabolites
Model Calculations of Protein Pair Interference Functions P. B. MOORE AND D. I~. ENGELMAN
of the interference cross term, derived from neutron scattering studies of structures containing pairs of deuterated by the neutron scattering method, and should help clarify the interpretation of such data. A2. Method Our and -~2 are the radii of the spheres in question, px and p2 are their respective scattering densities
Swigon, David
DNA stretching modeled at the base pair level: Overtwisting and shear instability in elastic Accepted 28 October 2011 Available online 12 November 2011 Keywords: DNA mechanics Overstretching Discrete elastic model Simplex algorithm Bifurcations a b s t r a c t Stretching experiments on single DNA
Donor-vacancy pairs in irradiated n-Ge: A searching look at the problem
Emtsev, Vadim; Oganesyan, Gagik [IoffePhysicotechnical Institute, Russian Academy of Sciences, Politekhnicheskaya ulitsa 26, 194021 St. Petersburg (Russian Federation)
2014-02-21T23:59:59.000Z
The present situation concerning the identification of vacancy-donor pairs in irradiated n-Ge is discussed. The challenging points are the energy states of these defects deduced from DLTS spectra. Hall effect data seem to be at variance with some important conclusions drawn from DLTS measurements. Critical points of the radiation-produced defect modeling in n-Ge are highlighted.
Monolithic Source of Photon Pairs Rolf Horn,1,* Payam Abolghasem,2
Monolithic Source of Photon Pairs Rolf Horn,1,* Payam Abolghasem,2 Bhavin J. Bijlani,2 Dongpeng and Astronomy, University of Waterloo, 200 University Avenue W, Waterloo, Ontario, N2L 3G1, Canada 2 The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King
Generation of paired photons in a quantum separable state in Bragg
50A, 772 07 Olomouc, Czech Republic 3Edward S. Rodgers Department of Electrical and Computer Engineering, University of Toronto, 10 King's Collage Road, Toronto, Ontario M5S3G4, Canada 4Departament photon pair sources," N. J. Phys. 12, 093027 (2010). 5. T. Aichele, A. I. Lvovsky, and S. Schiller
Nuclear Physics A 781 (2007) 317341 Symmetry energies, pairing energies, and mass
O'Donnell, Tom
2007-01-01T23:59:59.000Z
Nuclear Physics A 781 (2007) 317341 Symmetry energies, pairing energies, and mass equations J of the respective mass equation since symmetry energies are related to the curvature of the nuclear mass surface.10.Dr; 21.10.Hw; 21.30.Fe; 21.60.-n Keywords: NUCLEAR STRUCTURE Z = 1118; analyzed isobaric analog
A Distributed Scheme for Efficient Pair-wise Comparison of Complete Genomes
Bansal, Arvind K.
#12;48 A Distributed Scheme for Efficient Pair-wise Comparison of Complete Genomes Valerian S}@mcs.kent.edu 1 Corresponding author Abstract The comparisons of newly sequenced genomes against a genome and a CORBA-based implementation to compare and align gene sequences in large complete genomes, using multiple
Measurement of prompt J/? pair production in pp collisions at ?s = 7 Tev
Khachatryan, Vardan [Yerevan Physics Institute (Armenia)
2014-09-01T23:59:59.000Z
Production of prompt J/? meson pairs in proton-proton collisions at ?s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb?¹. The two J/? mesons are fully reconstructed via their decays into ?? ?? pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/? transverse momentum (p_{T}^{J/?}) and rapidity (|y^{J/?}|): |y^{J/?}| < 1.2 for p_{T}^{J/?} > 6.5 GeV/c, 1.2 < |y^{J/?}| < 1.43 for a p_{T} threshold that scales linearly with |y^{J/?}| from 6.5 to 4.5 GeV/c, and 1.43 < |y^{J/?}| < 2.2 for p_{T}^{J/?} > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%.
Peck, Mason A.
American Institute of Aeronautics and Astronautics 1 A Flux-Pinned Magnet-Superconductor Pair consisting of combinations of magnets and Type II superconductors, establishing a non-contacting interaction between the modules thanks to magnetic flux pinning. This stable action-at-a- distance interaction
Pair-wise Cryptographic Models for Secure Data Exchange in P2P Database Management Systems
International Association for Cryptologic Research (IACR)
Pair-wise Cryptographic Models for Secure Data Exchange in P2P Database Management Systems Sk. Md, University of Tsukuba, Tsukuba, 305-8573 Japan okamoto@risk.tsukuba.ac.jp ABSTRACT A peer-to-peer database augments a conventional database man- agement system with an inter-operability layer (i.e. map- pings
Eleven Guidelines for Implementing Pair Programming in the Classroom Laurie Williams1
McCrickard, Scott
requires specific classroom management techniques. We have created nine guidelines for successfully in the classroom. Implementing effective pair programming requires several specific classroom management techniques on the part of the teaching staff. Based upon our experiences, we previously documented classroom management
Search for pair production of excited top quarks in the lepton + jets final state
Apyan, Aram
A search is performed for pair-produced spin-3/2 excited top quarks (t[superscript ?][¯ over t][superscript ?]), each decaying to a top quark and a gluon. The search uses data collected with the CMS detector from pp ...
Stillinger, Frank
Synthetic diamond and wurtzite structures self-assemble with isotropic pair interactions Mikael C with strongly repulsive cores that cause the tetrahedrally coordinated diamond and wurtzite lattices-dimensional diamond and wurtzite structures can self-assemble with isotropic in- teractions possessing a strongly
Isosuperconductivity: A nonlocal-nonhamiltonian theory of pairing in high-T{sub c} superconductivity
Animalu, A.O.E. [Univ. of Nigeria, Nsukka (Nigeria)]|[The Institute for Basic Research, Palm Harbor, FL (United States)
1994-08-01T23:59:59.000Z
The author presents a review and reformulation of the author`s recent nonlocal-nonhamiltonian generalization of the standard BCS (Bardeen-Cooper-Schrieffer) theory of electron pairing in superconductors, here called iso-superconductivity or iso-standard model for short, by drawing two analogies. The first analogy is a geometrical (relativistic) one between the internal (isominkowskian) structures of the neutral pion and the Cooper pair envisaged in the generalization; and the second analogy is a dynamical (fluid mechanics) one between the classical Hamilton-Santilli limit of the generalization and its apparent local/nonlocal two-dimensional (London) superfluid mechanics realizations for flows in the CuO{sub 2} planes of the high-T{sub c} cuprate superconductors. By using the analogies and physical considerations, the author elucidates the origins of the interactions responsible for the fluctuations in the iso-characteristics of the electron within the pair due to the mutual overlapping of the paired electron wavefunctions. The fluctuations are defined in terms of a single quantity, namely an integral operator or {open_quotes}iso unit{close_quotes}. 33 refs., 5 figs., 4 tabs.
Next-to-leading order QCD corrections to light Higgs Pair production via vector boson fusion
Terrance Figy
2008-06-15T23:59:59.000Z
We present the NLO QCD corrections for light Higgs pair production via vector boson fusion at the LHC within the CP conserving type II two higgs doublet model in the form of a fully flexible parton--level Monte Carlo program. Scale dependences on integrated cross sections and distributions are reduced with QCD K-factors of order unity.
QCD Corrections to Vector Boson Pair Production via Weak Boson Fusion
B. Jager; C. Oleari; D. Zeppenfeld
2006-08-24T23:59:59.000Z
NLO-QCD corrections to vector boson pair production via weak boson fusion have recently been calculated and implemented into flexible parton-level Monte-Carlo programs. These allow for the computation of cross sections and kinematical distributions within realistic experimental cuts. We summarize the basic elements of the calculation and review phenomenological results for the LHC.
Evidence for the 125 GeV Higgs boson decaying to a pair of ? leptons
Apyan, Aram
A search for a standard model Higgs boson decaying into a pair of ? leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 ...
Search for the associated production of the Higgs boson with a top-quark pair
CMS Collaboration
A search for the standard model Higgs boson produced in association with a top-quark pair (tt¯H) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?1 and 19.7 fb?1 collected in pp ...
Anomalous pairing vibration in neutron-rich Sn isotopes beyond the N=82 magic number
Hirotaka Shimoyama; Masayuki Matsuo
2011-06-09T23:59:59.000Z
Two-neutron transfer associated with the pair correlation in superfluid neutron-rich nuclei is studied with focus on low-lying $0^+$ states in Sn isotopes beyond the N=82 magic number. We describe microscopically the two-neutron addition and removal transitions by means of the Skyrme-Hartree-Fock-Bogoliubov mean-field model and the continuum quasiparticle random phase approximation formulated in the coordinate space representation. It is found that the pair transfer strength for the transitions between the ground states becomes significantly large for the isotopes with $A \\ge 140$, reflecting very small neutron separation energy and long tails of the weakly bound $3p$ orbits. In $^{132-140}$Sn, a peculiar feature of the pair transfer is seen in transitions to low-lying excited $0^+$ states. They can be regarded as a novel kind of pair vibrational mode which is characterized by an anomalously long tail of the transition density extending to far outside of the nuclear surface, and a large strength comparable to that of the ground-state transitions. The presence of the weakly bound neutron orbits plays a central role for these anomalous behaviors.
Chan, Yingguang
METHODS Fish sampling Threespine sticklebacks of the Japanese sympatric pair were collected- 2008, as described previously19,36 . Fish collected in 2007 and 2008 were used for cytogenetic analysis, fish collected in 2006 and 2007 were used for population genetic analysis, fish collected in 2005, 2007
Kinetic Energy Driven Pairing in Cuprate Superconductors Th. A. Maier,1
Jarrell, Mark
Kinetic Energy Driven Pairing in Cuprate Superconductors Th. A. Maier,1 M. Jarrell,2 A. Macridin,2, Tennessee 37831-6164, USA 2 Department of Physics, University of Cincinnati, Cincinnati Ohio 45221, USA 3 of the electronic potential energy accompanied by an increase in kinetic energy. In the underdoped cuprates, optical
Electron-positron pair production by linearly polarized photon in the nuclear field
Bakmaev, S; Peresunko, Yu P; Shapoval, I; Peresunko, Yu. P.
2008-01-01T23:59:59.000Z
Process of lepton pair production by polarized photon can be used to measure the degree of linear polarization of high energy photon. The differential cross section and the analyzing power are calculated with taking into account higher powers of expansion on $Z\\alpha$. Pure Coulomb and screened potential are considered.
Measurement of prompt J/? pair production in pp collisions at ?s = 7 Tev
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan
2014-09-17T23:59:59.000Z
Production of prompt J/? meson pairs in proton-proton collisions at ?s = 7 TeV is measured with the CMS experiment at the LHC in a data sample corresponding to an integrated luminosity of about 4.7 fb?¹. The two J/? mesons are fully reconstructed via their decays into ?? ?? pairs. This observation provides for the first time access to the high-transverse-momentum region of J/? pair production where model predictions are not yet established. The total and differential cross sections are measured in a phase space defined by the individual J/? transverse momentum (pTJ/?) and rapidity (|yJ/?|): |yJ/?| more »pTJ/? > 6.5 GeV/c, 1.2 J/?| T threshold that scales linearly with |yJ/?| from 6.5 to 4.5 GeV/c, and 1.43 J/?| TJ/? > 4.5 GeV/c. The total cross section, assuming unpolarized prompt J/? pair production is 1.49 ± 0.07 (stat) ±0.13 (syst) nb. Different assumptions about the J/? polarization imply modifications to the cross section ranging from -31% to +27%.« less
Tunneling into black hole, escape from black hole, reflection from horizon and pair creation
V. V. Flambaum
2004-08-05T23:59:59.000Z
Within classical general relativity, a particle cannot reach the horizon of a black hole during a finite time, in the reference frame of an external observer; a particle inside cannot escape from a black hole; and the horizon does not produce any reflection. We argue that these processes may possibly be allowed in the quantum world. It is known that quantum mechanics allows pair creation at the horizon (one particle inside, another particle outside) and Hawking radiation. One can extend this idea to propose other processes. Tunneling of an external particle inside black hole may be produced by the creation of a pair at the horizon, followed by the annihilation of one created particle with the initial particle outside, with the other created particle appearing inside. Escape of a particle from a black hole may result from the creation of a pair, followed by the annihilation of one created particle with the particle inside, with the other created particle appearing outside. The escape may allow the transfer of information to the outside.Finally, the reflection of an external particle from the horizon may be modelled by a combination of the two processes presented above. The relationship between these "pair creation-annihilation'' mechanisms and the "horizon tunneling" calculations [1-5] is discussed.
Prioritized interaction testing for pair-wise coverage with seeding and constraints q
Bryce, Renee
them in the earliest tests of a test suite. A test case prioritization problem is formally definedPrioritized interaction testing for pair-wise coverage with seeding and constraints q Rene´e C 85287-8809, USA Received 27 February 2006; accepted 21 March 2006 Available online 4 May 2006 Abstract
Eeckhout, Lieven
for the given benchmark. This method- ology is validated by showing that program-input pairs that are close in the impact of input data sets on program behavior and profile-guided compiler optimizations. 1 Introduction product [1, 7]. A work- load then typically consists of a number of benchmarks with respective input data
Detecting W/Z pairs and Higgs at high energy pp colliders: Main experimental issues
Alverson, G.; Bengtsson, H.U.; Hauptman, J.; Hedin, D.; Herrero, M.J.; Wang, E.; Linn, S.; Young, C.; Milliken, B.; Paige, F.
1987-03-01T23:59:59.000Z
The main detection issues implied by the search for W and Z/sup 0/ pairs and Higgs in a high energy pp collider context are discussed here. It includes: precise electron identification, missing energy measurement, multilepton recognition, sophisticated jet pattern recognition, and pile-up. The study uses, as much as possible, a ''realistic simulation of life.''
Drell-Yan Lepton pair production at NNLO QCD with parton showers
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Hoeche, Stefan; Li, Ye; Prestel, Stefan
2015-04-13T23:59:59.000Z
We present a simple approach to combine NNLO QCD calculations and parton showers, based on the UNLOPS technique. We apply the method to the computation of Drell-Yan lepton-pair production at the Large Hadron Collider. We comment on possible improvements and intrinsic uncertainties.
Peng, Ze [DOE JGI
2013-01-25T23:59:59.000Z
Ze Peng from DOE JGI presents "Fosmid Cre-LoxP Inverse PCR Paired-End (Fosmid CLIP-PE), a Novel Method for Constructing Fosmid Pair-End Library" at the 7th Annual Sequencing, Finishing, Analysis in the Future (SFAF) Meeting held in June, 2012 in Santa Fe, NM.
Peng, Ze [DOE JGI] [DOE JGI
2012-06-01T23:59:59.000Z
Ze Peng from DOE JGI presents "Fosmid Cre-LoxP Inverse PCR Paired-End (Fosmid CLIP-PE), a Novel Method for Constructing Fosmid Pair-End Library" at the 7th Annual Sequencing, Finishing, Analysis in the Future (SFAF) Meeting held in June, 2012 in Santa Fe, NM.
John, Volker
48 2 Functional Analysis for Linear Saddle Point Problems 2.4 Examples of Pairs of Finite Element Spaces Violating the Discrete Inf-Sup Condition Remark 2.50. On simple pairs of finite element spaces. The simplest and most common finite element spaces are spaces of continuous functions which are piecewise
California at Berkeley, University of
Generation region of pulsating aurora obtained simultaneously by the FAST satellite and a Syowa-Iceland), with reference to simultaneous data obtained by a Syowa-Iceland conjugate pair of observatories. The aurora simultaneously by the FAST satellite and a Syowa-Iceland conjugate pair of observatories, J. Geophys. Res., 109
Hu, Jiangping
Impurity-induced bound states in iron-based superconductors with s-wave cos kxÂ·cos ky pairing an explicit cos kxÂ·cos ky form of the pairing sym- metry in momentum space, as long as two general conditions are small near the aforementioned spots in the FBZ. Further- more, this simple form, cos kxÂ·cos ky
Cohn, Martin
Biphasic Hoxd Gene Expression in Shark Paired Fins Reveals an Ancient Origin of the Distal Limb of expression occurs at later stages of shark fin development, in which Hoxd12 and Hoxd13 are re-expressed along GJ, Cohn MJ (2007) Biphasic Hoxd Gene Expression in Shark Paired Fins Reveals an Ancient Origin
Method of Extracting Is-A and Part-Of Relations Using Pattern Pairs in Mass Corpus
Method of Extracting Is-A and Part-Of Relations Using Pattern Pairs in Mass Corpus Se-Jong Kim, yhlee95, jhlee}@postech.ac.kr Abstract. This paper proposes a method that extracts term pairs satisfying to a coreference resolution (Yang and Su, 2007). However, these methods consider only single sentences to extract
Gentry, Cale M; Wade, Mark W; Stevens, Martin J; Dyer, Shellee D; Zeng, Xiaoge; Pavanello, Fabio; Gerrits, Thomas; Nam, Sae Woo; Mirin, Richard P; Popovi?, Miloš A
2015-01-01T23:59:59.000Z
Correlated photon pairs are a fundamental building block of quantum photonic systems. While pair sources have previously been integrated on silicon chips built using customized photonics manufacturing processes, these often take advantage of only a small fraction of the established techniques for microelectronics fabrication and have yet to be integrated in a process which also supports electronics. Here we report the first demonstration of quantum-correlated photon pair generation in a device fabricated in an unmodified advanced (sub-100nm) complementary metal-oxide-semiconductor (CMOS) process, alongside millions of working transistors. The microring resonator photon pair source is formed in the transistor layer structure, with the resonator core formed by the silicon layer typically used for the transistor body. With ultra-low continuous-wave on-chip pump powers ranging from 5 $\\mu$W to 400 $\\mu$W, we demonstrate pair generation rates between 165 Hz and 332 kHz using >80% efficient WSi superconducting nano...
Four-nucleon alpha-type correlations and proton-neutron pairing away of N=Z line
N. Sandulescu; D. Negrea; C. W. Johnson
2012-09-15T23:59:59.000Z
We study the competition between alpha-type and conventional pair condensation in the ground state of nuclei with neutrons and protons interacting via a charge-independent pairing interaction. The ground state is described by a product of two condensates, one of alpha-like quartets and the other one of pairs in excess relative to the isotope with N=Z. It is shown that this ansatz for the ground state gives very accurate pairing correlation energies for nuclei with the valence nucleons above the closed cores 16O, 40Ca and 100Sn. These results indicate that alpha-type correlations are important not only for the self-conjugate nuclei but also for nuclei away of N=Z line. In the latter case alpha-like quartets coexist with the collective Cooper pairs formed by the nucleons in excess.
Four-nucleon alpha-type correlations and proton-neutron pairing away of N=Z line
Sandulescu, N; Johnson, C W
2012-01-01T23:59:59.000Z
We study the competition between alpha-type and conventional pair condensation in the ground state of nuclei with neutrons and protons interacting via a charge-independent pairing interaction. The ground state is described by a product of two condensates, one of alpha-like quartets and the other one of pairs in excess relative to the isotope with N=Z. It is shown that this ansatz for the ground state gives very accurate pairing correlation energies for nuclei with the valence nucleons above the closed cores 16O, 40Ca and 100Sn. These results indicate that alpha-type correlations are important not only for the self-conjugate nuclei but also for nuclei away of N=Z line. In the latter case alpha-like quartets coexist with the collective Cooper pairs formed by the nucleons in excess.
Electromagnetic Heavy Lepton Pair Production in Relativistic Heavy-Ion Collisions
Sengul, M Y; Mercan, O; Karakus, N G
2015-01-01T23:59:59.000Z
We calculate the cross sections of electromagnetic productions of muon and tauon pair productions from the ultra-relativistic heavy ion collisions. Since the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions, nuclear form factors play important roles for calculating the cross sections. Recent measurement [1] indicates that the neutrons are differently distributed from the protons therefore this affects the cross section of the heavy lepton pair production. In order to see the effects of the neutron distributions in the nucleus, we used analytical expression of the Fourier transforms of the Wood-Saxon distribution. Cross section calculations show that Wood-Saxon distribution function is more sensitive to the parameter R compare to the parameter a.
Maeda, Kiminori [Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford (United Kingdom)] [Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford (United Kingdom); Liddell, Paul; Gust, Devens [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, 85287-1604 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona, 85287-1604 (United States); Hore, P. J. [Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford (United Kingdom)] [Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, Oxford (United Kingdom)
2013-12-21T23:59:59.000Z
Spin-selective reactions of radical pairs are conventionally modelled using an approach that dates back to the 1970s [R. Haberkorn, Mol. Phys. 32, 1491 (1976)]. An alternative approach based on the theory of quantum measurements has recently been suggested [J. A. Jones and P. J. Hore, Chem. Phys. Lett. 488, 90 (2010)]. We present here the first experimental attempt to discriminate between the two models. Pulsed electron paramagnetic resonance spectroscopy has been used to investigate intramolecular electron transfer in the radical pair form of a carotenoid-porphyrin-fullerene molecular triad. The rate of spin-spin relaxation of the fullerene radical in the triad was found to be inconsistent with the quantum measurement description of the spin-selective kinetics, and in accord with the conventional model when combined with spin-dephasing caused by rotational modulation of the anisotropic g-tensor of the fullerene radical.
Outgoing electromagnetic power induced from pair plasma falling into a rotating black hole
Kojima, Yasufumi
2015-01-01T23:59:59.000Z
We examine energy conversion from accreting pair plasma to outgoing Poynting flux by black hole rotation. Our approach is based on a two-fluid model consisting of collisionless pair plasma. The electric potential is not constant along magnetic field lines, unlike an ideal magnetohydrodynamics approximation. We show how and where longitudinal electric fields and toroidal magnetic fields are generated by the rotation, whereas they vanish everywhere for radial flow in a split monopole magnetic field in a Schwarzschild black hole. Outgoing electromagnetic power in a steady state is calculated by applying the WKB method to the perturbation equations for a small spin parameter. In our model, the luminosity has a peak in the vicinity of the black hole, but is damped toward the event horizon and infinity. The power at the peak is of the same order as that in the Blandford--Znajek process, although the physical mechanism is different.
Optimising the signal-to-noise ratio in measurement of photon pairs with detector arrays
Eric Lantz; Paul-Antoine Moreau; Fabrice Devaux
2014-11-24T23:59:59.000Z
To evidence multimode spatial entanglement of spontaneous down-conversion, detector arrays allow a full field measurement, without any a priori selection of the paired photons. We show by comparing results of the recent literature that electron-multiplying CCD (EMCCD) cameras allow, in the present state of technology, the detection of quantum correlations with the best signal-to-noise ratio (SNR), while intensified CCD (ICCD) cameras allow at best to identify pairs. The SNR appears to be proportional to the square root of the number of coherence cells in each image, or Schmidt number. Then, corrected estimates are derived for extended coherence cells and not very low and not space-stationary photon fluxes. Finally, experimental measurements of the SNR confirm our model.
Testing the local-void alternative to dark energy using galaxy pairs
Wang, F Y
2013-01-01T23:59:59.000Z
The possibility that we live in a special place in the universe, close to the center of a large, radially inhomogeneous void, has attracted attention recently as an alternative to dark energy or modified gravity to explain the accelerating universe. We show that the distribution of orientations of galaxy pairs can be used to test the Copernican principle that we are not in a central or special region of Universe. The popular void models can not fit both the latest type Ia supernova, cosmic microwave background data and the distribution of orientations of galaxy pairs simultaneously. Our results rule out the void models at the $4\\sigma$ confidence level as the origin of cosmic acceleration and favor the Copernican principle.
Search for the standard model Higgs boson in tau lepton pair final states
D0 Collaboration
2012-05-16T23:59:59.000Z
We present a search for the standard model Higgs boson in final states with an electron or muon and a hadronically decaying tau lepton in association with zero, one, or two or more jets using data corresponding to an integrated luminosity of up to 7.3 fb^{-1} collected with the D0 detector at the Fermilab Tevatron collider. The analysis is sensitive to Higgs boson production via gluon gluon fusion, associated vector boson production, and vector boson fusion, and to Higgs boson decays to tau lepton pairs or W boson pairs. Observed (expected) limits are set on the ratio of 95% C.L. upper limits on the cross section times branching ratio, relative to those predicted by the Standard Model, of 14 (22) at a Higgs boson mass of 115 GeV and 7.7 (6.8) at 165 GeV.
Can pair-instability supernova models match the observations of superluminous supernovae?
Kozyreva, Alexandra
2015-01-01T23:59:59.000Z
An increasing number of so-called superluminous supernovae (SLSNe) are discovered. It is believed that at least some of them with slowly fading light curves originate in stellar explosions induced by the pair instability mechanism. Recent stellar evolution models naturally predict pair instability supernovae (PISNe) from very massive stars at wide range of metallicities (up to Z=0.006, Yusof et al. 2013). In the scope of this study we analyse whether PISN models can match the observational properties of SLSNe with various light curve shapes. Specifically, we explore the influence of different degrees of macroscopic chemical mixing in PISN explosive products on the resulting observational properties. We artificially apply mixing to the 250 Msun PISN evolutionary model from Kozyreva et al. (2014) and explore its supernova evolution with the one-dimensional radiation hydrodynamics code STELLA. The greatest success in matching SLSN observations is achieved in the case of an extreme macroscopic mixing, where all r...
Nonlinear pair production in scattering of photons on ultra-short laser pulses at high energy
Kirill Tuchin
2010-02-15T23:59:59.000Z
We consider scattering of a photon on a short intense laser pulse at high energy. We argue that for ultra-short laser pulses the interaction is coherent over the entire length of the pulse. At low pulse intensity $I$ the total cross section for electron-positron pair production is proportional to $I$. However, at pulse intensities higher than the characteristic value $I_s$, the total cross section saturates -- it becomes proportional to the logarithm of intensity. This nonlinear effect is due to multi-photon interactions. We derive the total cross section for pair production at high energies by resuming the multi-photon amplitudes to all orders in intensity. We calculate the saturation intensity $I_s$ and show that it is significantly lower than the Schwinger's critical value. We discuss possible experimental tests.
Power-efficient production of photon pairs in a tapered chalcogenide microwire
Evan Meyer-Scott; Audrey Dot; Raja Ahmad; Lizhu Li; Martin Rochette; Thomas Jennewein
2015-02-25T23:59:59.000Z
Using tapered fibers of As2Se3 chalcogenide glass, we produce photon pairs at telecommunication wavelengths with low pump powers. We found maximum coincidences-to-accidentals ratios of $2.13\\pm0.07$ for degenerate pumping with 3.2 {\\mu}W average power, and $1.33\\pm0.03$ for non-degenerate pumping with 1.0 {\\mu}W and 1.5 {\\mu}W average power of the two pumps. Our results show that the ultrahigh nonlinearity in these microwires could allow single-photon pumping to produce photon pairs, enabling the production of large entangled states, heralding of single photons after lossy transmission, and photonic quantum information processing with nonlinear optics.
Optical-fiber source of polarization-entangled photon pairs in the 1550nm telecom band
Xiaoying Li; Paul L. Voss; Jay E. Sharping; Prem Kumar
2004-08-12T23:59:59.000Z
We present a fiber based source of polarization-entangled photon pairs that is well suited for quantum communication applications in the 1550nm band of standard fiber-optic telecommunications. Polarization entanglement is created by pumping a nonlinear-fiber Sagnac interferometer with two time-delayed orthogonally-polarized pump pulses and subsequently removing the time distinguishability by passing the parametrically scattered signal-idler photon pairs through a piece of birefringent fiber. Coincidence detection of the signal-idler photons yields biphoton interference with visibility greater than 90%, while no interference is observed in direct detection of either the signal or the idler photons. All four Bell states can be prepared with our setup and we demonstrate violations of CHSH form of Bell's inequalities by up to 10 standard deviations of measurement uncertainty.
Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A
Lev B. Leinson
2014-12-16T23:59:59.000Z
In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.
Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A
Leinson, Lev B
2015-01-01T23:59:59.000Z
In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.
On detection of narrow angle e+e- pairs from dark photon decays
A. V. Dermenev; S. V. Donskov; S. N. Gninenko; S. B. Kuleshov; V. A. Matveev; V. V. Myalkovskiy; V. D. Peshekhonov; V. A. Poliakov; A. A. Savenkov; V. O. Tikhomirov; I. A. Zhukov
2015-03-19T23:59:59.000Z
A class of models of dark sectors consider new very weak interaction between the ordinary and dark matter transmitted by U'(1) gauge bosons A' (dark photons) mixing with our photons. If such A's exist, they could be searched for in a light-shining-through-a-wall experiment with a high energy electron beam from the CERN SPS. The proposed search scheme suggests detection of the e+e- pairs produced in the A' -> e+e- decay with a very small opening angle. Coordinate chambers based on the thin-wall drift tubes with a minimal material budget and a two-hit resolution for e+ and e- tracks separated by more than 0.5 mm are considered as an option for detecting such pairs.
Masood, W. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 54000 (Pakistan); National Centre for Physics (NCP), Shahdara Valley Road, Islamabad 44000 (Pakistan); Rizvi, H. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad 54000 (Pakistan)
2011-04-15T23:59:59.000Z
Nonlinear electrostatic shock waves are studied in unmagnetized, dissipative pair-ion plasmas. The dissipation in the system is taken into account by considering the effect of kinematic viscosity of both positive and negative ions in plasmas. The system of fluid equations for asymmetric pair-ion plasma is reduced to Korteweg-deVries-Burgers equation in the limit of small amplitude perturbation. It is observed that the system under consideration admits rarefactive shocks. Keeping in view the practical applications, the nonlinear propagation of both the exploding and imploding shocks is investigated and the differences are expounded in detail. The present study may have relevance in the study of the formation of electrostatic shocks in laser-induced implosion devices, star formation, supernovae explosion, etc.
Mushtaq, A. [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45660 (Pakistan); School of Physics, University of Sydney, New South Wales 2006 (Australia); Saeed, R.; Haque, Q. [Theoretical Plasma Physics Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45660 (Pakistan)
2011-04-15T23:59:59.000Z
Linear and nonlinear coupled electrostatic drift and ion acoustic waves are studied in inhomogeneous, collisional pair ion-electron plasma. The Korteweg-de Vries-Burgers (KdVB) equation for a medium where both dispersion and dissipation are present is derived. An attempt is made to obtain exact solution of KdVB equation by using modified tanh-coth method for arbitrary velocity of nonlinear drift wave. Another exact solution for KdVB is obtained, which gives a structure of shock wave. Korteweg-de Vries (KdV) and Burgers equations are derived in limiting cases with solitary and monotonic shock solutions, respectively. Effects of species density, magnetic field, obliqueness, and the acoustic to drift velocity ratio on the solitary and shock solutions are investigated. The results discussed are useful in understanding of low frequency electrostatic waves at laboratory pair ion plasmas.
Observation of ?_{c1} Decays into Vector Meson Pairs ??, ?? and, ??
Ablikim, M.; Achasov, M. N.; An, L.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, M. Y.; Fan, R. R.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Grishin, S.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kavatsyuk, M.; Komamiya, S.; Kuehn, W.; Lange, J. S.; Leung, J. K. C.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Lei; Li, N. B.; Li, Q. J.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, G. C.; Liu, H.; Liu, H. B.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Z. Q.; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu.; Nefedov, Y.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Sonoda, S.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tang, X. F.; Tian, H. L.; Toth, D.; Varner, G. S.; Wan, X.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, M.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, L.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.; Zweber, P.
2011-08-01T23:59:59.000Z
Using (106±4)×10? ?(3686) events accumulated with the BESIII detector at the BEPCII e?e? collider, we present the first measurement of decays of ?_{c1} to vector meson pairs ??, ??, and ??. The branching fractions are measured to be (4.4±0.3±0.5)×10??, (6.0±0.3±0.7)×10??, and (2.2±0.6±0.2)×10??, for ?_{c1} ???, ??, and ??, respectively, which indicates that the hadron helicity selection rule is significantly violated in ?_{cJ} decays. In addition, the measurement of ?_{cJ}??? provides the first indication of the rate of doubly OZI-suppressed ?_{cJ} decay. Finally, we present improved measurements for the branching fractions of ?_{c0} and ?_{c2} to vector meson pairs.
Nonlinear pair production in scattering of photons on ultra-short laser pulses at high energy
Tuchin, Kirill
2009-01-01T23:59:59.000Z
We consider scattering of a photon on a short intense laser pulse at high energy. We argue that for ultra-short laser pulses the interaction is coherent over the entire length of the pulse. At low pulse intensity $I$ the total cross section for electron-positron pair production is proportional to $I$. However, at pulse intensities higher than the characteristic value $I_s$, the total cross section saturates -- it becomes proportional to the logarithm of intensity. This nonlinear effect is due to multi-photon interactions. We derive the total cross section for pair production at high energies by resuming the multi-photon amplitudes to all orders in intensity. We calculate the saturation intensity $I_s$ and show that it is significantly lower than the Schwinger's critical value. We discuss possible experimental tests.
Two-step quantum direct communication protocol using the Einstein-Podolsky-Rosen pair block
Deng Fuguo; Liu Xiaoshu [Department of Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory For Quantum Information and Measurements, Beijing 100084 (China); Long Guilu [Department of Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory For Quantum Information and Measurements, Beijing 100084 (China); Center for Atomic and Molecular NanoSciences, Tsinghua University, Beijing 100084 (China); Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100080 (China)
2003-10-01T23:59:59.000Z
A protocol for quantum secure direct communication using blocks of Einstein-Podolsky-Rosen (EPR) pairs is proposed. A set of ordered N EPR pairs is used as a data block for sending secret message directly. The ordered N EPR set is divided into two particle sequences, a checking sequence and a message-coding sequence. After transmitting the checking sequence, the two parties of communication check eavesdropping by measuring a fraction of particles randomly chosen, with random choice of two sets of measuring bases. After insuring the security of the quantum channel, the sender Alice encodes the secret message directly on the message-coding sequence and sends them to Bob. By combining the checking and message-coding sequences together, Bob is able to read out the encoded messages directly. The scheme is secure because an eavesdropper cannot get both sequences simultaneously. We also discuss issues in a noisy channel.
Spatial correlation of photon pairs produced in spontaneous parametric down-conversion
Procopio, L. M. [Departamento de Fisica, Cinvestav, A.P. 14-740, Mexico D.F. 07000 (Mexico); Rosas-Ortiz, O. [Departamento de Fisica, Cinvestav, A.P. 14-740, Mexico D.F. 07000 (Mexico); Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, Mexico D.F. 01000 (Mexico); Velazquez, V. [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, A.P. 20-364, Mexico D.F. 04510 (Mexico)
2010-10-11T23:59:59.000Z
We report the observation of spatial biphoton correlation in spontaneous parametric down conversion. The optical bench includes a type-I BBO crystal of effective length 2 mm, pumped by a 100 mW violet laser diode centered at 405.38 nm. Photon pairs are created with degenerate wavelength {approx_equal}810.76 nm. Once the horizontal counting rates have been measured, a simple geometrical recipe is shown to be useful in calculating bounds for the width of vertical counting rates. The spatial correlation between idler and signal photons is illustrated with a coincidence distribution of the coordinate pair (x{sub s},x{sub i}), with x{sub i,s} the idler (signal) detector position in horizontal scan.
First Measurement of the Fraction of Top Quark Pair Production Through Gluon-Gluon Fusion
CDF Collaboration; T. Aaltonen
2008-04-08T23:59:59.000Z
We present the first measurement of the fraction of top quark pair production through gluon-gluon fusion. We use 0.96/fb of s**(1/2)=1.96 TeV p-pbar collision data recorded with the CDF II detector at Fermilab. We identify the candidate t-tbar events with a high-energy charged lepton, a neutrino candidate, and four or more jets. Using charged particles with low transverse momentum in t-tbar events, we find the fraction of top quark pair production through gluon-gluon fusion to be 0.07+/-0.14(stat)+/-0.07(syst), corresponding to a 95% confidence level upper limit of 0.33, in agreement with the standard model NLO prediction of 0.15+/-0.05.
Pair dispersion in a chaotic flow reveals the role of the memory of initial velocity
Afik, Eldad
2015-01-01T23:59:59.000Z
The leading paradigm for chaotic flows dominated by dissipation predicts an exponential growth of the mean distance between pairs of fluid elements, in the long run. This is reflected in the analysis of experimental results on tracer particles and the discussions which follow, as reported in recent experimental and numerical publications. To quantitatively validate this prediction, we have conducted a microfluidic experiment generating elastic turbulence, a flow characterised in the literature as smooth in space and random in time. To our great surprise, we discovered that the pair separation follows a much slower power-law --- also known as ballistic --- a notion overlooked so far for flows of this type. We provide conclusive experimental evidence that this scaling is well-desribed by the same coefficients derived from the short-time dynamics. Our finding reinforces the role of the ballistic regime over a significant range in time and space, providing a quantitative estimation for the spreading of particles ...
The latest results on top quark pair cross-section measurement
Yamauchi, Katsuya; The ATLAS collaboration
2015-01-01T23:59:59.000Z
The latest results on top quark pair production cross-section measurement in proton-proton collisions at $\\sqrt{s} = 7\\ TeV$ and $\\sqrt{s} = 8\\ TeV$ with the ATLAS detector are reported. The inclusive cross-section was measured with 4% of uncertainty using di-lepton e-mu events. The measurement of the differential cross-section as functions of various observables such as transverse momentum and rapidity of the top quark and invariant mass of the pseudo-top-quark pair system including the results in boosted topologies are also reported. These results are compared with the various generators such as Powheg, Alpgen and MC@NLO and the various PDF sets.
Flavor Pairing in Medieval European Cuisine: A Study in Cooking with Dirty Data
Varshney, Kush R; Wang, Jun; Myers, Daniel
2013-01-01T23:59:59.000Z
An important part of cooking with computers is using statistical methods to create new, flavorful ingredient combinations. The flavor pairing hypothesis states that culinary ingredients with common chemical flavor components combine well to produce pleasant dishes. It has been recently shown that this design principle is a basis for modern Western cuisine and is reversed for Asian cuisine. Such data-driven analysis compares the chemistry of ingredients to ingredient sets found in recipes. However, analytics-based generation of novel flavor profiles can only be as good as the underlying chemical and recipe data. Incomplete, inaccurate, and irrelevant data may degrade flavor pairing inferences. Chemical data on flavor compounds is incomplete due to the nature of the experiments that must be conducted to obtain it. Recipe data may have issues due to text parsing errors, imprecision in textual descriptions of ingredients, and the fact that the same ingredient may be known by different names in different recipes. ...
On detection of narrow angle e+e- pairs from dark photon decays
Dermenev, A V; Gninenko, S N; Kuleshov, S B; Matveev, V A; Myalkovskiy, V V; Peshekhonov, V D; Poliakov, V A; Savenkov, A A; Tikhomirov, V O; Zhukov, I A
2015-01-01T23:59:59.000Z
A class of models of dark sectors consider new very weak interaction between the ordinary and dark matter transmitted by U'(1) gauge bosons A' (dark photons) mixing with our photons. If such A's exist, they could be searched for in a light-shining-through-a-wall experiment with a high energy electron beam from the CERN SPS. The proposed search scheme suggests detection of the e+e- pairs produced in the A' -> e+e- decay with a very small opening angle. Coordinate chambers based on the thin-wall drift tubes with a minimal material budget and a two-hit resolution for e+ and e- tracks separated by more than 0.5 mm are considered as an option for detecting such pairs.
Finding the first cosmic explosions. III. Pulsational pair-instability supernovae
Whalen, Daniel J.; Smidt, Joseph [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Even, Wesley; Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Woosley, S. E. [Department of Astronomy and Astrophysics, UCSC, Santa Cruz, CA 95064 (United States); Heger, Alexander [Monash Centre for Astrophysics, Monash University, Clayton, Victoria 3800 (Australia); Stiavelli, Massimo [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
2014-02-01T23:59:59.000Z
Population III supernovae have been the focus of growing attention because of their potential to directly probe the properties of the first stars, particularly the most energetic events that can be seen at the edge of the observable universe. But until now pulsational pair-instability supernovae, in which explosive thermonuclear burning in massive stars fails to unbind them but can eject their outer layers into space, have been overlooked as cosmic beacons at the earliest redshifts. These shells can later collide and, like Type IIn supernovae, produce superluminous events in the UV at high redshifts that could be detected in the near infrared today. We present numerical simulations of a 110 M {sub ?} pulsational pair-instability explosion done with the Los Alamos radiation hydrodynamics code Radiation Adaptive Grid Eulerian. We find that collisions between consecutive pulsations are visible in the near infrared out to z ? 15-20 and can probe the earliest stellar populations at cosmic dawn.
NNLL threshold resummation for top-pair and single-top production
Nikolaos Kidonakis
2012-12-17T23:59:59.000Z
I discuss threshold resummation at NNLL accuracy in the standard moment-space approach in perturbative QCD for top-pair and single-top production. For top quark pair production I present new approximate NNLO results for the total cross section and for the top quark transverse momentum and rapidity distributions at 8 TeV LHC energy. I discuss the accuracy of the soft-gluon approximation and show that the NLO and NNLO approximate results from resummation are practically indistinguishable from exact NLO and partial NNLO results. For single top production I present new approximate NNLO results for the total cross sections in all three channels at the LHC and also for the top quark transverse momentum distributions in t-channel production and in top-quark associated production with a W boson. For both ttbar and single-top production the agreement of theoretical results with LHC and Tevatron data is excellent.
Contributions of different neutron pairs in different approaches for neutrinoless double beta decay
Alberto Escuderos; Amand Faessler; Vadim Rodin; Fedor Simkovic
2010-06-07T23:59:59.000Z
The methods used till now to calculate the neutrinoless double beta decay matrix elements are: the Quasiparticle Random Phase Approximation (QRPA), the Shell Model (SM), the angular momentum projected Hartee-Fock-Bogoliubov approach (HFB) and the Interacting Boson Model (IBM). The different approaches are compared specifically concerning the the angular momenta and parities of the neutron pairs, which are changed into two protons by the $0\
Top quark pair production measurements using the ATLAS detector at the LHC
Trincaz-Duvoid, Sophie; The ATLAS collaboration
2015-01-01T23:59:59.000Z
Inclusive and differential cross sections of top quark pair production at have been measured with the ATLAS detector at the LHC at ?s = 7 TeV and ?s = 8 TeV. Inclusive measurements are in good agreement with Standard Model predictions. Differential cross section measurements are compared to different sets of generators, parton showering and hadronization simulations, PDF and calculations. This provides constraints to improve the MC modeling.
Relativistic Quantization of Cooper Pairs and Distributed Electrons in Rotating Superconductors
I. E. Bulyzhenkov
2009-07-02T23:59:59.000Z
Relativistic time synchronization along closed integral lines maintains magnetic flux quantization independently from gravitation. All Fermi-volume electrons form time-averaged electromagnetic fields within rotating conductors, while Fermi-surface superelectrons enable flux quantization in SQUID experiments. Inertia is not related to instantaneous self-coherent states of the distributed electric charge and, therefore, the Cooper pair mass can not be measured in principle from magnetic flux quantization.
Fast vacuum decay into particle pairs in strong electric and magnetic fields
Yoshimasa Hidaka; Takumi Iritani; Hideo Suganuma
2011-02-01T23:59:59.000Z
We discuss fermion pair productions in strong electric and magnetic fields. We point out that, in the case of massless fermions, the vacuum persistency probability per unit time and volume is zero in the strong electric and magnetic fields, while it is finite when the magnetic field is absent. The contribution from the lowest Landau level (LLL) dominates this phenomenon. We also discuss dynamics of the vacuum decay, using an effective theory of the LLL projection, taking into account the back reaction.
Borisov, A. V.; Kerimov, B. K.; Sizin, P. E., E-mail: borisov@phys.msu.ru [Moscow State University (Russian Federation)
2012-11-15T23:59:59.000Z
Expressions for the power of neutrino radiation from a degenerate electron gas in a strong magnetic field are derived for the case of neutrino-pair photoproduction via the weak and electromagnetic interaction mechanisms (it is assumed that the neutrino possesses electromagnetic form factors). It is shown that the neutrino luminosity of a medium in the electromagnetic reaction channel may exceed substantially the luminosity in the weak channel. Relative upper bounds on the effective neutrino magnetic moment are obtained.
X-shooter Science Verification Proposal A special co-moving white dwarfmain sequence pair
Liske, Jochen
and HD 122750 form a co-moving proper motion pair (PM in mas/yr: RA, Dec, from UCAC-2): WD 1401-147 (-170: The white dwarf (WD) WD 1401-147 and the main sequence (MS) star HD 122750 form a co-moving proper motion laboratory to study the complex physics of pulsating WDs in a quantitative manner. Scientific Case: WD 1401-147
A proposal for testing subcritical vacuum pair production with high power lasers
Gregori, G; Rajeev, P P; Chen, H; Clarke, R J; Huffman, T; Murphy, C D; Prozorkevich, A V; Roberts, C D; Röpke, G; Schmidt, S M; Smolyansky, S A; Wilks, S; Bingham, R; 10.1016/j.hedp.2009.11.001
2010-01-01T23:59:59.000Z
We present a proposal for testing the prediction of non-equilibrium quantum field theory below the Schwinger limit. The proposed experiments should be able to detect a measurable number of gamma rays resulting from the annihilation of pairs in the focal spot of two opposing high intensity laser beams. We discuss the dependence of the expected number of gamma rays with the laser parameters and compare with the estimated background level of gamma hits for realistic laser conditions.
A proposal for testing subcritical vacuum pair production with high power lasers
G. Gregori; D. B. Blaschke; P. P. Rajeev; H. Chen; R. J. Clarke; T. Huffman; C. D. Murphy; A. V. Prozorkevich; C. D. Roberts; G. Röpke; S. M. Schmidt; S. A. Smolyansky; S. Wilks; R. Bingham
2010-05-18T23:59:59.000Z
We present a proposal for testing the prediction of non-equilibrium quantum field theory below the Schwinger limit. The proposed experiments should be able to detect a measurable number of gamma rays resulting from the annihilation of pairs in the focal spot of two opposing high intensity laser beams. We discuss the dependence of the expected number of gamma rays with the laser parameters and compare with the estimated background level of gamma hits for realistic laser conditions.
The avoidance of a previously neutral stimulus paired with frustrative nonreward
Beard, William Washington
1975-01-01T23:59:59.000Z
involved pairing of a CS (light) with frustra- tive nonreward in Goal Box 1. During Phase III, Ss were tested in a separate hurdle-jump apparatus to de- monstrate avoidance of the now aversive CS by jumping at the sound of a buzzer. It was found... Ss conditioned to the CS jumped the hurdle significantly faster than any of the other subgroups. However, an analysis of the frequency of avoidance re- sponses revealed no statistically significant differ- ences between all subgroups...
Direct generation of photon triplets using cascaded photon-pair sources
H. Hübel; D. R. Hamel; A. Fedrizzi; S. Ramelow; K. J. Resch; T. Jennewein
2010-07-28T23:59:59.000Z
Non-classical states of light, such as entangled photon pairs and number states, are essential for fundamental tests of quantum mechanics and optical quantum technologies. The most widespread technique for creating these quantum resources is the spontaneous parametric down-conversion (SPDC) of laser light into photon pairs. Conservation of energy and momentum in this process, known as phase-matching, gives rise to strong correlations which are used to produce two-photon entanglement in various degrees of freedom. It has been a longstanding goal of the quantum optics community to realise a source that can produce analogous correlations in photon triplets, but of the many approaches considered, none have been technically feasible. In this paper we report the observation of photon triplets generated by cascaded down-conversion. Here each triplet originates from a single pump photon, and therefore quantum correlations will extend over all three photons in a way not achievable with independently created photon pairs. We expect our photon-triplet source to open up new avenues of quantum optics and become an important tool in quantum technologies. Our source will allow experimental interrogation of novel quantum correlations, the post-selection free generation of tripartite entanglement without post- selection and the generation of heralded entangled-photon pairs suitable for linear optical quantum computing. Two of the triplet photons have a wavelength matched for optimal transmission in optical fibres, ideally suited for three-party quantum communication. Furthermore, our results open interesting regimes of non-linear optics, as we observe spontaneous down-conversion pumped by single photons, an interaction also highly relevant to optical quantum computing.
Electron-Positron Pair Production by an Electron in a Magnetic Field Near the Process Threshold
O. P. Novak; R. I. Kholodov; P. I. Fomin
2011-01-13T23:59:59.000Z
The electron-positron pair production by an electron in a strong magnetic field near the process threshold is considered. The process is shown to be more probable if the spin of the initial electron is oriented along the field. In this case, the probability of the process is $\\sim10^{13} s^{-1}$ when the magnetic field strength is $H=4\\cdot 10^{12}$ G.
Two pairs of interacting EBs towards the LMC in the OGLE database
Aviv Ofir
2008-12-17T23:59:59.000Z
A single point source on the OGLE LMC database shows the characteristics of two superimposed eclipsing binaries (EBs). The two EBs happen to have periods very close to the 3:2 resonance. The telescope's small PSF and the apparent resonance between the two EBs raises the suspicion that this is not chance alignment but rather a compact hierarchical system of two pairs of interacting EBs in 3:2 resonance.
Next-to-leading order QCD corrections to slepton pair production via vector-boson fusion
Partha Konar; Dieter Zeppenfeld
2006-12-11T23:59:59.000Z
Slepton pairs can be produced in vector-boson fusion processes at hadron colliders. The next-to-leading order QCD corrections to the electroweak production cross section for p p -> slepton+ slepton- +2jets at order alpha_s alpha^4 have been calculated and implemented in a NLO parton-level Monte Carlo program. Numerical results are presented for the CERN Large Hadron Collider.
Thomas Garrity
2012-05-25T23:59:59.000Z
A new classification scheme for pairs of real numbers is given, generalizing earlier work of the author that used continued fraction, which in turn was motivated by ideas from statistical mechanics in general and work of Knauf and Fiala and Kleban in particular. Critical for this classification are the number theoretic and geometric properties of the triangle map, a type of multi-dimensional continued fraction.
Two-color ghost interference with photon pairs generated in hot atoms
Ding Dongsheng; Zhou Zhiyuan; Shi Baosen; Zou Xubo; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026 (China)
2012-09-15T23:59:59.000Z
We report on an experimental observation of a two-photon ghost interference experiment. A distinguishing feature of our experiment is that the photons are generated via a non-degenerated spontaneous four-wave mixing process in a hot atomic ensemble; therefore the photon has narrow bandwidth. Besides, there is a large difference in frequency between two photons in a pair. Our works may be important to achieve more secure, large transmission capacity long-distance quantum communication.
HIGHER PICARD VARIETIES AND THE HEIGHT PAIRING KLAUS KU"NNEMANN
defined under suitable assumptions height pai* *rings (1) XK: CHp(XK )0Q x CHd+1-p of the Hodge index theorem should hold for the pairing (1). We denote by Ap(XK )Q the subgroup of CHp(XK )0Q of this note is to show that these theorems hold for the subquotients Bp(AK )Q of CHp(AK )0Q . The hard
A new measure of phase synchronization for a pair of time series and seizure focus localization
Kaushik Majumdar
2006-12-22T23:59:59.000Z
Defining and measuring phase synchronization in a pair of nonlinear time series are highly nontrivial. This can be done with the help of Fourier transform, when it exists, for a pair of stored (hence stationary) signals. In a time series instantaneous phase is often defined with the help of Hilbert transform. In this paper phase of a time series has been defined with the help of Fourier transform. This gives rise to a deterministic method to detect phase synchronization in its most general form between a pair of time series. Since this is a stricter method than the statistical methods based on instantaneous phase, this can be used for lateralization and source localization of epileptic seizures with greater accuracy. Based on this method a novel measure of phase synchronization, called syn function, has been defined, which is capable of quantifying neural phase synchronization and asynchronization as important parameters of epileptic seizure dynamics. It has been shown that such a strict measure of phase synchronization has potential application in seizure focus localization from scalp electroencephalogram (EEG) data, without any knowledge of electrical conductivity of the head.
The Merger Rate to Redshift One from Kinematic Pairs: Caltech Faint Galaxy Redshift Survey XI
R. G. Carlberg; Judith G. Cohen; D. R. Patton; Roger Blandford; David W. Hogg; H. K. C. Yee; S. L. Morris; H. Lin; Lennox L. Cowie; Esther Hu; Antoinette Songaila
2000-02-01T23:59:59.000Z
The rate of mass accumulation due to galaxy merging depends on the mass, density, and velocity distribution of galaxies in the near neighborhood of a host galaxy. The fractional luminosity in kinematic pairs combines all of these effects in a single estimator which is relatively insensitive to population evolution. Here we use a k-corrected and evolution compensated volume-limited sample drawing about 300 redshifts from CFGRS and 3000 from CNOC2 to measure the rate and redshift evolution of merging. We identify kinematic pairs with projected separations less than either 50 or 100 \\hkpc and rest-frame velocity differences of less than 1000\\kms. The fractional luminosity in pairs is modeled as f_L(Delta v,r_p,M_r^{ke})(1+z)^{m_L} where [f_L,m_L] are [0.14+/-0.07,0+/-1.4] and [0.37+/-0.7,0.1+/-0.5] for r_p= 0.2 M*) is 0.02+/-0.01(1+z)^{0.1+/-0.5} M*~Gyr^{-1}. Present day high-luminosity galaxies therefore have accreted approximately 0.15M* of their mass over the approximately 7 Gyr to redshift one. (abridged)
Top quark pair properties using the ATLAS detector at the LHC
Barone, Gaetano; The ATLAS collaboration
2015-01-01T23:59:59.000Z
Top quark pair properties using the ATLAS detector at the LHC The latest measurements of the properties of the top quark using the ATLAS experiment are presented. The top quark mass is one of the fundamental parameters of the Standard Model. A measurement based on a multidimensional template fit that can constrain the uncertainties on the energy measurements of jets is presented and combined with a measurement using dilepton events. In addition, novel measurements aiming to measure the mass in a welldefined scheme are presented. The top quark pair charge asymmetry is an asymmetry predicted to occur beyond leadingorder QCD in the Standard Model, and may be significantly enhanced by the presence of new physics. The ttbar production charge asymmetry is measured inclusively and differentially using the 7 and 8 TeV ATLAS datasets. Making use of the large number of top quark pairs collected, we also present measurements of the spin correlation between top and antitop quarks and discuss their sensitivities t...
Non-astigmatic imaging with matched pairs of spherically bent reflectors
Bitter, Manfred Ludwig (Princeton, NJ); Hill, Kenneth Wayne (Plainsboro, NJ); Scott, Steven Douglas (Wellesley, MA); Feder, Russell (Newton, PA); Ko, Jinseok (Cambridge, MA); Rice, John E. (N. Billerica, MA); Ince-Cushman, Alexander Charles (New York, NY); Jones, Frank (Manalapan, NJ)
2012-07-10T23:59:59.000Z
Arrangements for the point-to-point imaging of a broad spectrum of electromagnetic radiation and ultrasound at large angles of incidence employ matched pairs of spherically bent reflectors to eliminate astigmatic imaging errors. Matched pairs of spherically bent crystals or spherically bent multi-layers are used for X-rays and EUV radiation; and matched pairs of spherically bent mirrors that are appropriate for the type of radiation are used with microwaves, infrared and visible light, or ultrasound. The arrangements encompass the two cases, where the Bragg angle--the complement to the angle of incidence in optics--is between 45.degree. and 90.degree. on both crystals/mirrors or between 0.degree. and 45.degree. on the first crystal/mirror and between 45.degree. and 90.degree. on the second crystal/mirror, where the angles of convergence and divergence are equal. For x-rays and EUV radiation, also the Bragg condition is satisfied on both spherically bent crystals/multi-layers.
STUDYING INTERCLUSTER GALAXY FILAMENTS THROUGH STACKING gmBCG GALAXY CLUSTER PAIRS
Zhang Yuanyuan; Dietrich, Joerg P.; McKay, Timothy A.; Nguyen, Alex T. Q. [Department of Physics, University of Michigan, Ann Arbor, MI (United States); Sheldon, Erin S. [Brookhaven National Laboratory, Upton, NY (United States)
2013-08-20T23:59:59.000Z
We present a method to study the photometric properties of galaxies in filaments by stacking the galaxy populations between pairs of galaxy clusters. Using Sloan Digital Sky Survey data, this method can detect the intercluster filament galaxy overdensity with a significance of {approx}5{sigma} out to z = 0.40. Using this approach, we study the g - r color and luminosity distribution of filament galaxies as a function of redshift. Consistent with expectation, filament galaxies are bimodal in their color distribution and contain a larger blue galaxy population than clusters. Filament galaxies are also generally fainter than cluster galaxies. More interestingly, the observed filament population seems to show redshift evolution at 0.12 < z < 0.40: the blue galaxy fraction has a trend to increase at higher redshift; such evolution is parallel to the ''Butcher-Oemler effect'' of galaxy clusters. We test the dependence of the observed filament density on the richness of the cluster pair: richer clusters are connected by higher density filaments. We also test the spatial dependence of filament galaxy overdensity: this quantity decreases when moving away from the intercluster axis between a cluster pair. This method provides an economical way to probe the photometric properties of filament galaxies and should prove useful for upcoming projects like the Dark Energy Survey.
Nuclear pairing from microscopic forces: singlet channels and higher-partial waves
S. Maurizio; J. W. Holt; P. Finelli
2014-08-26T23:59:59.000Z
Background: An accurate description of nuclear pairing gaps is extremely important for understanding static and dynamic properties of the inner crusts of neutron stars and to explain their cooling process. Purpose: We plan to study the behavior of the pairing gaps $\\Delta_F$ as a function of the Fermi momentum $k_F$ for neutron and nuclear matter in all relevant angular momentum channels where superfluidity is believed to naturally emerge. The calculations will employ realistic chiral nucleon-nucleon potentials with the inclusion of three-body forces and self-energy effects. Methods: The superfluid states of neutron and nuclear matter are studied by solving the BCS gap equation for chiral nuclear potentials using the method suggested by Khodel et al., where the original gap equation is replaced by a coupled set of equations for the dimensionless gap function $\\chi(p)$ defined by $\\Delta(p) = \\Delta_F \\chi(p)$ and a non-linear algebraic equation for the gap magnitude $\\Delta_F = \\Delta(p_F)$ at the Fermi surface. This method is numerically stable even for small pairing gaps, such as that encountered in the coupled $^3PF_2$ partial wave. Results: We have successfully applied Khodel's method to singlet ($S$) and coupled channel ($SD$ and $PF$) cases in neutron and nuclear matter. Our calculations agree with other ab-initio approaches, where available, and provide crucial inputs for future applications in superfluid systems.
Neutrino pair emission due to scattering of electrons off fluxoids in superfluid neutron star cores
A. D. Kaminker; D. G. Yakovlev; P. Haensel
1997-02-18T23:59:59.000Z
We study the emission of neutrinos, resulting from the scattering of electrons off magnetic flux tubes (fluxoids) in the neutron star cores with superfluid (superconducting) protons. In the absence of proton superfluidity (T> T_{cp}), this process transforms into the well known electron synchrotron emission of neutrino pairs in a locally uniform magnetic field B, with the neutrino energy loss rate Q proportional to B^2 T^5. For temperatures T not much below T_{cp}, the synchrotron regime (Q \\propto T^5) persists and the emissivity Q can be amplified by several orders of magnitude due to the appearance of the fluxoids and associated enhancement of the field within them. For lower T, the synchrotron regime transforms into the bremsstrahlung regime (Q \\propto T^6) similar to the ordinary neutrino-pair bremsstrahlung of electrons which scatter off atomic nuclei. We calculate Q numerically and represent our results through a suitable analytic fit. In addition, we estimate the emissivities of two other neutrino-production mechanisms which are usually neglected -- neutrino-pair bremsstrahlung processes due to electron-proton and electron-electron collisions. We show that the electron-fluxoid and electron-electron scattering can provide the main neutrino production mechanisms in the neutron star cores with highly superfluid protons and neutrons at T scattering is significant if the initial, locally uniform magnetic field B > 10^{13} G.
Pair Production of Heavy Quarkonium and $B_c(^*)$ Mesons at Hadron Colliders
Rong Li; Yu-Jie Zhang; Kuang-Ta Chao
2009-03-12T23:59:59.000Z
We investigate the pair production of S-wave heavy quarkonium at the LHC in the color-singlet mechanism (CSM) and estimate the contribution from the gluon fragmentation process in the color-octet mechanism (COM) for comparison. With the matrix elements extracted previously in the leading order calculations, the numerical results show that the production rates are quite large for the pair production processes at the LHC. The $p_t$ distribution of double $J/\\psi$ production in the CSM is dominant over that in the COM when $p_t$ is smaller than about 8GeV. For the production of double $\\Upsilon$, the contribution of the COM is always larger than that in the CSM. The large differences in the theoretical predictions between the CSM and COM for the $p_t$ distributions in the large $p_t$ region are useful in clarifying the effects of COM on the quarkonium production. We also investigate the pair production of S-wave $B_c$ and $B_c^*$ mesons, and the measurement of these processes is useful to test the CSM and extract the LDMEs for the $B_c$ and $B_c^*$ mesons.
Pair dispersion in a chaotic flow reveals the role of the memory of initial velocity
Eldad Afik; Victor Steinberg
2015-02-10T23:59:59.000Z
The leading paradigm for chaotic flows dominated by dissipation predicts an exponential growth of the mean distance between pairs of fluid elements, in the long run. This is reflected in the analysis of experimental results on tracer particles and the discussions which follow, as reported in recent experimental and numerical publications. To quantitatively validate this prediction, we have conducted a microfluidic experiment generating elastic turbulence, a flow characterised in the literature as smooth in space and random in time. To our great surprise, we discovered that the pair separation follows a much slower power-law --- also known as ballistic --- a notion overlooked so far for flows of this type. We provide conclusive experimental evidence that this scaling is well-desribed by the same coefficients derived from the short-time dynamics. Our finding reinforces the role of the ballistic regime over a significant range in time and space, providing a quantitative estimation for the spreading of particles in mixing microfluidic flows based on the initial velocity snapshot. Finally we note that the conditions for the asymptotic exponential pair separation are quite stringent when it comes to tracer particles and are unlikely to be realised in wall-bounded flows. Therefore this work raises questions regarding the relevance and applicability of the currently leading paradigm.
Pair Production from Vacuum at the Focus of an X-Ray Free Electron Laser
A. Ringwald
2001-03-16T23:59:59.000Z
There are definite plans for the construction of X-ray free electron lasers (FEL), both at DESY, where the so-called XFEL is part of the design of the electron-positron linear collider TESLA, as well as at SLAC, where the so-called Linac Coherent Light Source (LCLS) has been proposed. Such an X-ray laser would allow for high-field science applications: One could make use of not only the high energy and transverse coherence of the X-ray beam, but also of the possibility of focusing it to a spot with a small radius, hopefully in the range of the laser wavelength. Along this route one obtains very large electric fields, much larger than those obtainable with any optical laser of the same power. In this letter we discuss the possibility of obtaining an electric field so high that electron-positron pairs are spontaneously produced in vacuum (Schwinger pair production). We find that if X-ray optics can be improved to approach the diffraction limit of focusing, and if the power of the planned X-ray FELs can be increased to the terawatt region, then there is ample room for an investigation of the Schwinger pair production mechanism.
Khachatryan, V.
A search is performed for long-lived massive neutral particles decaying to quark-antiquark pairs. The experimental signature is a distinctive topology of a pair of jets, originating at a secondary vertex. Events were ...
NOETHERIAN BANACH JORDAN PAIRS N. Boudi*, A. Fern'andez L'opezy, E. Garc'ia
by Benslimane and Boudi [BeB1] to the alternative case. For a Jordan algebra J or a Jordan pair V a* *nd Boudi [BeB2] proved that a complex Noetherian Banach Jordan algebra is finite dimensional
Unhavaithaya, Yingdee
Meiotic chromosome segregation involves pairing and segregation of homologous chromosomes in the first division and segregation of sister chromatids in the second division. Although it is known that the centromere and ...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mani, Tomoyasu [Brookhaven National Lab. (BNL), Upton, NY (United States); Grills, David C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Miller, John R. [Brookhaven National Lab. (BNL), Upton, NY (United States)
2015-01-28T23:59:59.000Z
A recently-developed instrument for time-resolved infrared detection following pulse radiolysis has been used to measure the ?(C?N) IR band of the radical anion of a CN-substituted fluorene in tetrahydrofuran. Specific vibrational frequencies can exhibit distinct frequency shifts due to ion-pairing, which can be explained in the framework of the vibrational Stark effect. Measurements of the ratio of free ions and ion-pairs in different electrolyte concentrations allowed us to obtain an association constant and free energy change for ion-pairing. This new method has the potential to probe the geometry of ion-pairing and allows the reduction potentials of molecules to be determined in the absence of electrolyte in an environment of low dielectric constant.
Gomez-Ceballos, Guillelmo
We measure the inclusive forward–backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton–antiproton collisions and decaying to final states that contain two charged leptons (electrons ...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Mani, Tomoyasu; Grills, David C.; Miller, John R.
2015-01-02T23:59:59.000Z
A recently-developed instrument for time-resolved infrared detection following pulse radiolysis has been used to measure the ?(C?N) IR band of the radical anion of a CN-substituted fluorene in tetrahydrofuran. Specific vibrational frequencies can exhibit distinct frequency shifts due to ion-pairing, which can be explained in the framework of the vibrational Stark effect. Measurements of the ratio of free ions and ion-pairs in different electrolyte concentrations allowed us to obtain an association constant and free energy change for ion-pairing. This new method has the potential to probe the geometry of ion-pairing and allows the reduction potentials of molecules to be determinedmore »in the absence of electrolyte in an environment of low dielectric constant.« less
Constraints on the Higgs boson width from off-shell production and decay to Z-boson pairs
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan; et al.,
2014-09-01T23:59:59.000Z
Constraints are presented on the total width of the recently discovered Higgs boson, Gamma[H], using its relative on-shell and off-shell production and decay rates to a pair of Z bosons, where one Z boson decays to an electron or muon pair, and the other to an electron, muon, or neutrino pair. The analysis is based on the data collected by the CMS experiment at the LHC in 2011 and 2012, corresponding to integrated luminosities of 5.1 inverse femtobarns at a centre-of-mass energy sqrt(s) = 7 TeV and 19.7 inverse femtobarns at sqrt(s) = 8 TeV. A simultaneous maximum likelihood fitmore »to the measured kinematic distributions near the resonance peak and above the Z-boson pair production threshold leads to an upper limit on the Higgs boson width of Gamma[H] « less
2009-01-01T23:59:59.000Z
2002). Gene expression profile of human bone marrow stromal2003). Gene expression profile of mouse bone marrow stromalRNA (ncRNA) expression profiles of MSC from match-paired UC
Popovych, Roman
]). Terwilliger showed [5, 10] that a Leonard pair X, Y satisfies a certain algebraic relations with respect to commutators. In turn, the Terwilliger relations follow from to the so-called relations of the AW
Gordon, Sarah Elisabeth; Gordon, Sarah Elisabeth
2012-01-01T23:59:59.000Z
all students? names on a popsicle stick and have studentsthe big T-P-S cards ? popsicle sticks with each student?seach pair, but using the popsicle sticks to call on a few.
Particle Acceleration Zones Above Pulsar Polar Caps: Electron and Positron Pair Formation Fronts
Alice K. Harding; Alexander G. Muslimov
1998-05-11T23:59:59.000Z
We investigate self-consistent particle acceleration near a pulsar polar cap (PC) by the electrostatic field due to the effect of inertial frame dragging. Test particles gain energy from the electric field parallel to the open magnetic field lines and lose energy by both curvature radiation (CR) and resonant and non-resonant inverse Compton scattering (ICS) with soft thermal X-rays from the neutron star (NS) surface. Gamma-rays radiated by electrons accelerated from the stellar surface produce pairs in the strong magnetic field, which screen the electric field beyond a pair formation front (PFF). Some of the created positrons can be accelerated back toward the surface and produce gamma-rays and pairs that create another PFF above the surface. We find that ICS photons control PFF formation near the surface, but due to the different angles at which the electron and positron scatter the soft photons, positron initiated cascades develop above the surface and screen the accelerating electric field. Stable acceleration from the NS surface is therefore not possible in the presence of dominant ICS energy losses. However, we find that stable acceleration zones may occur at some distance above the surface, where CR dominates the electron and positron energy losses, and there is up-down symmetry between the electron and positron PFFs. We examine the dependence of CR-controlled acceleration zone voltage, width and height above the surface on parameters of the pulsar and its soft X-ray emission. For most pulsars, we find that acceleration will start at a height of 0.5 - 1 stellar radii above the NS surface.
Vacuum Potentials for the Two Only Permanent Free Particles, Proton and Electron. Pair Productions
J. X. Zheng-Johansson
2015-02-26T23:59:59.000Z
The two only species of isolatable, smallest, or unit charges +e and -e present in nature interact with the universal vacuum in a polarisable dielectric representation through two uniquely defined vacuum potential functions. All of the non-composite subatomic particles containing one-unit charges, +e or -e, are therefore formed in terms of the IED model of the respective charges, of zero rest masses, oscillating in either of the two unique vacuum potential fields, together with the radiation waves of their own charges. In this paper we give a first principles treatment of the dynamics of charge in a dielectric vacuum, based on which, combined with solutions for the radiation waves obtained previously, we subsequently derive the vacuum potential function for a given charge q, which we show to be quadratic and consist each of quantised potential levels, giving therefore rise to quantised characteristic oscillation frequencies of the charge and accordingly quantised, sharply-defined masses of the IED particles. By further combining with relevant experimental properties as input information, we determine the IED particles built from the charges +e,-e at their first excited states in the respective vacuum potential wells to be the proton and the electron, the observationally two only stable (permanently lived) and "free" particles containing one-unit charges. Their antiparticles as produced in pair productions can be accordingly determined. The characteristics of all of the other more energetic non-composite subatomic particles can also be recognised. We finally discuss the energy condition for pair production, which requires two successive energy supplies to (1) first disintegrate the bound pair of vaculeon charges +e,-e composing a vacuuon of the vacuum and (2) impart masses to the disintegrated charges.
Aggelen, Helen van [Department of Inorganic and Physical Chemistry, Ghent University, Ghent (Belgium) [Department of Inorganic and Physical Chemistry, Ghent University, Ghent (Belgium); Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Yang, Yang [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States)] [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Yang, Weitao [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)] [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)
2014-05-14T23:59:59.000Z
Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H{sub 2}, and eliminates delocalization errors in H{sub 2}{sup +} and other single-bond systems. It gives surprisingly good non-bonded interaction energies – competitive with the ph-RPA – with the correct R{sup ?6} asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Alves, Gilvan Augusto; Aoki, Masato
2011-10-11T23:59:59.000Z
We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb-1 collected with the D0 detector at the Fermilab Tevatron Collider in pp? collisions at ?s = 1.96 TeV. In the channel LQLQ ? eq?eq?, where q,q? are u or d quarks, no significant excess of data over background is observed, and we set a 95% C.L. lower limit of 326 GeV on the leptoquark mass, assuming equal probabilities of leptoquark decays to eq and ?eq?.
Evidence for spin selectivity of triplet pairs in superconducting spin valves
Banerjee, N.; Smiet, C. B.; Smits, R. G. J.; Ozaeta, A.; Bergeret, F. S.; Blamire, M. G.; Robinson, J. W. A.
2014-01-09T23:59:59.000Z
Evidence for spin-selectivity of triplet pairs in superconducting spin-valves N. Banerjee1, C. B. Smiet1, R. G. J. Smits1, A. Ozaeta2, F. S. Bergeret2, M. G. Blamire1, J. W. A. Robinson1* 1Department of Materials Science and Metallurgy, University... . Pang, B. S. H., Bell, C., Tomov, R. I., Durrell, J. H., & Blamire, M. G. Pseudo spin-valve behavior in oxide ferromagnet/superconductor/ferromagnet trilayers. Phys. Lett. A 341, 313–319 (2005). 35. Kalcheim, Y., Kirzhner, T., Koren, G. & Millo, O...
First measurement of the forward-backward charge asymmetry in top quark pair production
D0 Collaboration; V. M. Abazov
2007-12-05T23:59:59.000Z
We present the first measurement of the integrated forward-backward charge asymmetry in top-antitop quark pair (ttbar) production in proton-antiproton collisions in the lepton plus jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming ttbar+X production and decay, a sample of 0.9fb-1 of data, collected by the D0 experiment at the Fermilab Tevatron Collider, is used to measure the asymmetry for different jet multiplicities. The result is also used to set upper limits on ttbar+X production via a Z' resonance.
Biexciton emission from single isoelectronic traps formed by nitrogen-nitrogen pairs in GaAs
Takamiya, Kengo; Fukushima, Toshiyuki; Yagi, Shuhei; Hijikata, Yasuto; Yaguchi, Hiroyuki [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku , Saitama 338-8570 (Japan); Mochizuki, Toshimitsu; Yoshita, Masahiro; Akiyama, Hidefumi [Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Kuboya, Shigeyuki; Onabe, Kentaro [Department of Advanced Materials Science, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Katayama, Ryuji [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)
2013-12-04T23:59:59.000Z
We have studied photoluminescence (PL) from individual isoelectronic traps formed by nitrogen-nitrogen (NN) pairs in GaAs. Sharp emission lines due to exciton and biexciton were observed from individual isoelectronic traps in nitrogen atomic-layer doped (ALD) GaAs. The binding energy of biexciton bound to individual isoelectronic traps was approximately 8 meV. Both the exciton and biexciton luminescence lines show completely random polarization and no fine-structure splitting. These results are desirable to the application to the quantum cryptography used in the field of quantum information technology.
Dynamical view of pair creation in uniform electric and magnetic fields
Naoto Tanji
2009-05-12T23:59:59.000Z
Pair creation in a uniform classical electromagnetic field (Schwinger mechanism) is studied focusing on the time evolution of the distribution of created particles. The time evolution of the distribution in time-dependent fields is also presented as well as effects of back reaction. Motivated by the Glasma flux tube, which may be formed at the initial stage of heavy-ion collisions, we investigate effects of a magnetic field parallel to an electric field, and find that the magnetic field makes the evolution of a fermion system faster.
Electron pair emission detected by time-of-flight spectrometers: Recent progress
Huth, Michael; Schumann, Frank O. [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Chiang, Cheng-Tien; Trützschler, Andreas; Kirschner, Jürgen [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Saale) (Germany); Widdra, Wolf [Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Saale) (Germany); Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany)
2014-02-10T23:59:59.000Z
We present results for electron coincidence spectroscopy using two time-of-flight (ToF) spectrometers. Excited by electron impact, the energy and momentum distribution of electron pairs emitted from the Cu(111) surface are resolved and a spectral feature related to the Shockley surface state is identified. By combining the two ToF spectrometers with a high-order harmonic generation light source, we demonstrate double photoemission spectroscopy in the laboratory that required synchrotron radiation in the past. Utilizing this setup, we report results for (?,2e) on NiO(001) on Ag(001) excited with light at 30?eV photon energy.
Self-regulation of the reconnecting current layer in relativistic pair plasma reconnection
S. Zenitani; M. Hesse
2008-08-07T23:59:59.000Z
We investigate properties of the reconnecting current layer in relativistic pair plasma reconnection. We found that the current layer self-regulates its thickness when the current layer runs out current carriers, and so relativistic reconnection retains a fast reconnection rate. Constructing a steady state Sweet-Parker model, we discuss conditions for the current sheet expansion. Based on the energy argument, we conclude that the incompressible assumption is invalid in relativistic Sweet-Parker reconnection. The guide field cases are more incompressible than the anti-parallel cases, and we find a more significant current sheet expansion.
Static Electron-Positron Pair Creation in Strong Fields for a Nonlinear Dirac model
Julien Sabin
2011-12-12T23:59:59.000Z
We consider the Hartree-Fock approximation of Quantum Electrodynamics, with the exchange term neglected. We prove that the probability of static electron-positron pair creation for the Dirac vacuum polarized by an external field of strength $Z$ behaves as $1-\\exp(-\\kappa Z^{2/3})$ for $Z$ large enough. Our method involves two steps. First we estimate the vacuum expectation of general quasi-free states in terms of their total number of particles, which can be of general interest. Then we study the asymptotics of the Hartree-Fock energy when $Z\\to+\\infty$ which gives the expected bounds.
Static quark anti-quark pair in SU(2) gauge theory
A. Bazavov; P. Petreczky; A. Velytsky
2008-09-11T23:59:59.000Z
We study singlet and triplet correlation functions of static quark anti-quark pair defined through gauge invariant time-like Wilson loops and Polyakov loop correlators in finite temperature SU(2) gauge theory. We use the Luescher-Weisz multilevel algorithm, which allows to calculate these correlators at very low temperatures. We observe that the naive separation of singlet and triplet states in general does not hold non-perturbatively, however, is recovered in the limit of small separation and the temperature dependence of the corresponding correlators is indeed very different.
A. Moujahid; A. D'Anjou; F. J. Torrealdea; C. Sarasola
2012-04-17T23:59:59.000Z
Many biological processes involve synchronization between nonequivalent systems, i.e, systems where the difference is limited to a rather small parameter mismatch. The maintenance of the synchronized regime in this cases is energetically costly \\cite{1}. This work studies the energy implications of synchronization phenomena in a pair of structurally flexible coupled neurons that interact through electrical coupling. We show that the forced synchronization between two nonidentical neurons creates appropriate conditions for an efficient actuation of adaptive laws able to make the neurons structurally approach their behaviours in order to decrease the flow of energy required to maintain the synchronization regime.
Measurement of Delta G/G from high transverse momentum hadron pairs in COMPASS
Marcin Stolarski
2008-09-10T23:59:59.000Z
The new COMPASS Delta G/G result obtained from high transverse momentum hadron pairs in the Q^2>1 GeV^2 region is presented. Comparing to the previous analysis in this region the statistical error of Delta G/G is reduced by a factor 3 to 0.10. A weighted method of the Delta G/G measurement based on neural network approach is used. In addition, the formula for the Delta G/G extraction used in the analysis has been updated. The contributions coming from the leading order and QCD Compton processes are no longer neglected.
Moujahid, A; Torrealdea, F J; Sarasola, C; 10.1007/978-3-642-12433-4_77
2012-01-01T23:59:59.000Z
Many biological processes involve synchronization between nonequivalent systems, i.e, systems where the difference is limited to a rather small parameter mismatch. The maintenance of the synchronized regime in this cases is energetically costly \\cite{1}. This work studies the energy implications of synchronization phenomena in a pair of structurally flexible coupled neurons that interact through electrical coupling. We show that the forced synchronization between two nonidentical neurons creates appropriate conditions for an efficient actuation of adaptive laws able to make the neurons structurally approach their behaviours in order to decrease the flow of energy required to maintain the synchronization regime.
Quantum statistics effect in Schwinger pair production in short laser pulses
Florian Hebenstreit; Reinhard Alkofer; Gerald V. Dunne; Holger Gies
2009-10-23T23:59:59.000Z
We investigate non-perturbative pair production from vacuum (the Schwinger effect) in the focal region of two counter-propagating, ultra-short laser pulses with sub-cycle structure. We use the quantum kinetic formulation to calculate the momentum spectrum of created particles and show the extreme sensitivity to the laser frequency $\\omega$, the pulse length $\\tau$ and the carrier-envelope absolute phase $\\phi$. We apply this formalism to both fermions and bosons to illustrate the influence of quantum statistics in this type of electric background field.
Formation of Cooper pairs in quantum oscillations of electrons in plasma
Dvornikov, Maxim
2009-01-01T23:59:59.000Z
We study low energy quantum oscillations of electron gas in plasma. It is shown that two electrons participating in these oscillations acquire additional negative energy when they interact by means of a virtual plasmon. The additional energy leads to the formation a Cooper pair and possible existence of the superconducting phase in the system. We suggest that this mechanism supports slowly damping oscillations of electrons without any energy supply. Basing on our model we put forward the hypothesis the superconductivity can occur in a low energy ball lightning.
Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41cloth Documentation DataDepartment of EnergyOn-Farm1 of 62.1 PrintBetter BuildingsBeyond the Lone-Pair Model for
Beyond the Lone-Pair Model for Structurally Distorted Metal Oxides
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41cloth Documentation DataDepartment of EnergyOn-Farm1 of 62.1 PrintBetter BuildingsBeyond the Lone-Pair Model forBeyond
A monolithic polarization-independent frequency-filter system for filtering of photon pairs
Ahlrichs, Andreas; Berkemeier, Christoph; Sprenger, Benjamin; Benson, Oliver [Institute of Physics, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)] [Institute of Physics, Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin (Germany)
2013-12-09T23:59:59.000Z
We set up a long-term stable filtering system that consists of cascaded monolithic Fabry-Pérot filters to enhance the suppression and free spectral range. An effective free spectral range of hundreds of GHz allows the system to be used as a high resolution monochromator, with a linewidth of 192 MHz. As an important application a single mode is filtered from photon pairs generated by a parametric down-conversion source, and their indistinguishability is proven by measuring the Hong-Ou-Mandel effect with a visibility of 96%. We report that undesired birefringence, which is often encountered with monolithic cavities, can be avoided by stress-free mounting.
SUSY QCD Corrections to Higgs Pair Production from Bottom Quark Fusion
Sally Dawson; Chung Kao; Yili Wang
2007-10-23T23:59:59.000Z
We present a complete next-to-leading order (NLO) calculation for the total cross section for inclusive Higgs pair production via bottom-quark fusion at the CERN Large Hadron Collider (LHC) in the minimal supersymmetric standard model (MSSM) and the minimal supergravity model (mSUGRA). We emphasize the contributions of squark and gluino loops (SQCD) and the decoupling properties of our results for heavy squark and gluino masses. The enhanced couplings of the b quark to the Higgs bosons in supersymmetric models with large tanb yield large NLO SQCD corrections in some regions of parameter space.
S. Frixione; E. Laenen; P. Motylinski; B. R. Webber
2007-02-20T23:59:59.000Z
We explain how angular correlations in leptonic decays of vector bosons and top quarks can be included in Monte Carlo parton showers, in particular those matched to NLO QCD computations. We consider the production of $n$ pairs of leptons, originating from the decays of $n$ electroweak vector bosons or of $n$ top quarks, in the narrow-width approximation. In the latter case, the information on the $n$ $b$ quarks emerging from the decays is also retained. We give results of implementing this procedure in MC@NLO
Permanent Magnet Development for Automotive Traction Motors
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Permanent Magnet Development for Automotive Traction Motors Includes: Beyond Rare Earth Magnets (BREM) Iver E. Anderson Ames Laboratory (USDOE) Email: andersoni@ameslab.gov Phone:...
Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions
Khachatryan, V. [Yerevan Physics Institute (Armenia); et al.,
2014-10-01T23:59:59.000Z
A search for neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM) decaying to tau-lepton pairs in pp collisions is performed, using events recorded by the CMS experiment at the LHC. The dataset corresponds to an integrated luminosity of 24.6 fb$^{?1}$, with 4.9 fb$^{?1}$ at 7 TeV and 19.7 fb$^{?1}$ at 8 TeV. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes the case where the Higgs boson is produced in association with a b-quark jet. No excess is observed in the tau-lepton-pair invariant mass spectrum. Exclusion limits are presented in the MSSM parameter space for different benchmark scenarios, m$_{h}^{max}$ , m$_{h}^{mod?+}$ , m$_{h}^{mod??}$ , light-stop, light-stau, ?-phobic, and low-m$_{H}$. Upper limits on the cross section times branching fraction for gluon fusion and b-quark associated Higgs boson production are also given.
The curious case of HD41248. A pair of static signals buried behind red-noise
Jenkins, James S
2014-01-01T23:59:59.000Z
Gaining a better understanding of the effects of stellar induced radial velocity noise is critical for the future of exoplanet studies, since the discovery of the lowest-mass planets using this method will require us to go below the intrinsic stellar noise limit. An interesting test case in this respect is that of the southern solar analogue HD41248. The radial velocity time series of this star has been proposed to contain either a pair of signals with periods of around 18 and 25 days, that could be due to a pair of resonant super-Earths, or a single and varying 25 day signal that could arise due to a complex interplay between differential rotation and modulated activity. In this letter we build-up more evidence for the former scenario, showing that the signals are still clearly significant even after more than 10 years of observations and they likely do not change in period, amplitude, or phase as a function of time, the hallmarks of static Doppler signals. We show that over the last two observing seasons th...
Signature of heavy Majorana neutrinos at a linear collider: Enhanced charged Higgs pair production
Atwood, David [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Bar-Shalom, Shaouly [Physics Department, Technion-Institute of Technology, Haifa 32000 (Israel); Soni, Amarjit [Theory Group, Brookhaven National Laboratory, Upton, New York 11973 (United States)
2007-08-01T23:59:59.000Z
A charged Higgs pair can be produced at an ee collider through a t-channel exchange of a heavy neutrino (N) via e{sup +}e{sup -}{yields}H{sup +}H{sup -} and, if N is a Majorana particle, also via the lepton number violating (LNV) like-sign reaction e{sup {+-}}e{sup {+-}}{yields}H{sup {+-}}H{sup {+-}}. Assuming no a priori relation between the effective eNH{sup +} coupling ({xi}) and light neutrino masses, we show that this interaction vertex can give a striking enhancement to these charged Higgs pair production processes. In particular, the LNV H{sup -}H{sup -} signal can probe N at the International Linear Collider (ILC) in the mass range 100 GeV < or approx. m{sub N} < or approx. 10{sup 4} TeV and with the effective mixing angle {xi} in the range 10{sup -4} < or approx. {xi}{sup 2} < or approx. 10{sup -8}--well within its perturbative unitarity bound and the {beta}{beta}{sub 0{nu}} limit. The lepton number conserving e{sup +}e{sup -}{yields}H{sup +}H{sup -} mode can be sensitive to, e.g., an O(10) TeV heavy Majorana neutrino at a 500 GeV ILC, if {xi}{sup 2} > or approx. 0.001.
Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field
Vincent L. Fish; Mark J. Reid; Alice L. Argon; Karl M. Menten
2003-07-08T23:59:59.000Z
We have identified and classified Zeeman pairs in the survey by Argon, Reid, & Menten of massive star-forming regions with 18 cm (2 Pi 3/2, J = 3/2) OH maser emission. We have found a total of more than 100 Zeeman pairs in more than 50 massive star-forming regions. The magnetic field deduced from the Zeeman splitting has allowed us to assign an overall line-of-sight magnetic field direction to many of the massive star-forming regions. Combining these data with other data sets obtained from OH Zeeman splitting, we have looked for correlations of magnetic field directions between star-forming regions scattered throughout the Galaxy. Our data do not support a uniform, Galactic-scale field direction, nor do we find any strong evidence of magnetic field correlations within spiral arms. However, our data suggest that in the Solar neighborhood the magnetic field outside the Solar circle is oriented clockwise as viewed from the North Galactic Pole, while inside the Solar circle it is oriented counterclockwise. This pattern, including the magnetic field reversal near the Sun, is in agreement with results obtained from pulsar rotation measures.
Search for neutral MSSM Higgs bosons decaying to a pair of tau leptons in pp collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, V.
2014-10-28T23:59:59.000Z
A search for neutral Higgs bosons in the minimal supersymmetric extension of the standard model (MSSM) decaying to tau-lepton pairs in pp collisions is performed, using events recorded by the CMS experiment at the LHC. The dataset corresponds to an integrated luminosity of 24.6 fb?¹, with 4.9 fb?¹ at 7 TeV and 19.7 fb?¹ at 8 TeV. To enhance the sensitivity to neutral MSSM Higgs bosons, the search includes the case where the Higgs boson is produced in association with a b-quark jet. No excess is observed in the tau-lepton-pair invariant mass spectrum. Exclusion limits are presented in the MSSMmore »parameter space for different benchmark scenarios, mhmax, mhmod+ , mhmod– , light-stop, light-stau, ?-phobic, and low-mH. Upper limits on the cross section times branching fraction for gluon fusion and b-quark associated Higgs boson production are also given.« less
Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP
Schael, S; Bruneliere, R; Buskulic, D; De Bonis, I; Decamp, D; Ghez, P; Goy, C; Jezequel, S; Lees, J P; Lucotte, A; Martin, F; Merle, E; Minard, M N; Nief, J Y; Odier, P; Pietrzyk, B; Trocme, B; Bravo, S; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Fernandez, E; Fernandez-Bosman, M; Garrido, Ll; Grauges, E; Juste, A; Martinez, M; Merino, G; Miquel, R; Mir, Ll. M; Orteu, S; Pacheco, A; Park, I C; Perlas, J; Riu, I; Ruiz, H; Sanchez, F; Colaleo, A; Creanza, D; De Filippis, N; De Palma, M; Iaselli, G; Maggi, G; Maggi, M; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Bazarko, A; Becker, U; Boix, G; Bird, F; Blucher, E; Bonvicini, B; Bright-Thomas, P; Barklow, T; Buchmuller, O; Cattaneo, M; Cerutti, F; Ciulli, V; Clerbaux, B; Drevermann, H; Forty, R W; Frank, M; Greening, T C; Hagelberg, R; Halley, A W; Gianotti, F; Girone, M; Hansen, J B; Harvey, J; Jacobsen, R; Hutchcroft, D E; Janot, P; Jost, B; Knobloch, J; Kado, M; Lehraus, I; Lazeyras, P; Maley, P; Mato, P; May, J; Moutoussi, A; Pepe-Altarelli, M; Ranjard, F; Rolandi, L; Schlatter, D; Schmitt, B; Schneider, O; Tejessy, W; Teubert, F; Tomalin, I R; Tournefier, E; Veenhof, R; Valassi, A; Wiedenmann, W; Wright, A E; Ajaltouni, Z; Badaud, F; Chazelle, G; Deschamps, O; Dessagne, S; Falvard, A; Ferdi, C; Fayolle, D; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Pascolo, J M; Perret, P; Podlyski, F; Bertelsen, H; Fernley, T; Hansen, J D; Hansen, J R; Hansen, P H; Kraan, A C; Lindahl, A; Mollerud, R; Nilsson, B S; Rensch, B; Waananen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, E; Siotis, I; Vayaki, A; Zachariadou, K; Blondel, A; Bonneaud, G; Brient, J C; Machefert, F; Rouge, A; Rumpf, M; Swynghedauw, M; Tanaka, R; Verderi, M; Videau, H; Ciulli, V; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C; Antonelli, A; Antonelli, M; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Cerutti, F; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, G P; Passalacqua, L; Picchi, P; Colrain, P; Have, I. ten; Hughes, I S; Kennedy, J; Knowles, I G; Lynch, J G; Morton, W T; Negus, P; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Turnbull, R M; Wasserbaech, S; Buchmuller, O; Cavanaugh, R; Dhamotharan, S; Geweniger, C; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Sommer, J; Stenzel, H; Tittel, K; Werner, W; Wunsch, M; Beuselinck, R; Binnie, D M; Cameron, W; Davies, G; Dornan, P J; Goodsir, S; Marinelli, N; Martin, E B; Nash, J; Nowell, J; Rutherford, S A; Sedgbeer, J K; Thompson, J C; White, R; Williams, M D; Ghete, V M; Girtler, P; Kneringer, E; Kuhn, D; Rudolph, G; Bouhova-Thacker, E; Bowdery, C K; Buck, P G; Clarke, D P; Ellis, G; Finch, A J; Foster, F; Hughes, G; Jones, R.W L; Keemer, N R; Pearson, M R; Robertson, N A; Sloan, T; Smizanska, M; Snow, S W; Williams, M I; van der Aa, O; Delaere, C; Leibenguth, G; Lemaitre, V; Bauerdick, L.A T; Blumenschein, U; van Gemmeren, P; Giehl, I; Holldorfer, F; Jakobs, K; Kasemann, M; Kayser, F; Kleinknecht, K; Muller, A S; Quast, G; Renk, B; Rohne, E; Sander, H G; Schmeling, S; Wachsmuth, H; Wanke, R; Zeitnitz, C; Ziegler, T; Aubert, J J; Benchouk, C; Bonissent, A; Carr, J; Coyle, P; Curtil, C; Ealet, A; Etienne, F; Fouchez, D; Motsch, F; Payre, P; Rousseau, D; Tilquin, A; Talby, M; Thulasidas, M; Aleppo, M; Antonelli, M; Ragusa, F; Buscher, V; David, A; Dietl, H; Ganis, G; Huttmann, K; Lutjens, G; Mannert, C; Manner, W; Moser, H G; Settles, R; Seywerd, H; Stenzel, H; Villegas, M; Wiedenmann, W; Wolf, G; Azzurri, P; Boucrot, J; Callot, O; Chen, S; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, Ph; Jacholkowska, A; Le Diberder, F; Lefrancois, J; Mutz, A M; Schune, M H; Serin, L; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Bettarini, S; Boccali, T; Bozzi, C; Calderini, G; Dell'Orso, R; Fantechi, R; Ferrante, I; Fidecaro, F; Foa, L; Giammanco, A; Giassi, A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, F; Rizzo, G; Sanguinetti, G; Sciaba, A; Sguazzoni, G; Spagnolo, P; Steinberger, J; Tenchini, R; Vannini, C; Venturi, A; Verdini, P G; Awunor, O; Blair, G A; Cowan, G; Garcia-Bellido, A; Green, M G; Medcalf, T; Misiejuk, A; Strong, J A; Teixeira-Dias, P; Botterill, D R; Clifft, R W; Edgecock, T R; Edwards, M; Haywood, S J; Norton, P R; Tomalin, I R; Ward, J J; Bloch-Devaux, B; Boumediene, D; Colas, P; Emery, S; Fabbro, B; Kozanecki, W; Lancon, E; Lemaire, M C; Locci, E; Perez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Tuchming, B; Vallage, B; Black, S N; Dann, J H; Kim, H Y; Konstantinidis, N; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Cartwright, S
2013-01-01T23:59:59.000Z
Electroweak measurements performed with data taken at the electron-positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3~fb$^{-1}$ collected by the four LEP experiments ALEPH, DELPHI, L3 and OPAL, at centre-of-mass energies ranging from $130~GeV$ to $209~GeV$. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron-positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose-Einstein correlations between the two W decay systems arising ...
New Statistical Techniques in the Measurement of the inclusive Top Pair Production Cross Section
Ji?í Franc; Petr Bou?; Michal Št?pánek; Václav K?s
2014-12-12T23:59:59.000Z
We present several different types of multivariate statistical techniques used in the measurement of the inclusive top pair production cross section in $p \\bar{p}$-collisions at $\\sqrt{s} = 1.96 \\text{TeV}$ employing the full RunII data ($9.7\\textrm{ fb}^{-1}$) collected with the D0 detector at the Fermilab Tevatron Collider. We consider the final state of the top quark pair decays containing one electron or muon and at least two jets. We proceed various statistical homogeneity tests such as Anderson - Darling, Kolmogorov - Smirnov, and $\\varphi$-divergences tests to determine, which variables have good data-MC agreement, as well as a good separation power. We adjusted all tests for using weighted empirical distribution functions. Further we separate $t\\bar{t}$ signal from the background by the application of Generalized Linear Models, Gaussian Mixture Models, Neural Networks with Switching Units and confront them with familiar methods from ROOT TMVA package such as Boosted Decision Trees, and Multi-layer Perceptron. We compare results by area under receiver operating characteristic curve and verify the quality of the discrimination from all methods.
Electrostatic soliton and double layer structures in unmagnetized degenerate pair plasmas
Mahmood, S. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); National Centre for Physics, Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Department of Physics and Applied Mathematics (DPAM), PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan); Khan, S. A. [National Centre for Physics, Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Department of Physics, COMSATS Institute of Information Technology (CIIT), Islamabad 44000 (Pakistan); Ur-Rehman, H. [Theoretical Plasma Physics Division (TPPD), PINSTECH, P.O. Nilore, Islamabad 44000 (Pakistan); Department of Physics and Applied Mathematics (DPAM), PIEAS, P.O. Nilore, Islamabad 44000 (Pakistan)
2010-11-15T23:59:59.000Z
The acoustic solitons and double layers are studied in unmagnetized quantum electron-positron plasmas in the presence of stationary ions. The quantum hydrodynamic model is employed and reductive perturbation method is used to derive the Korteweg-de Vries (KdV) and extended KdV equations for solitons and double layers, respectively. It is found that in the linear limit both slow acoustic and fast Langmuir waves can propagate in such type of quantum plasmas like in classical pair-ion or pair plasmas. The amplitude and width of the electrostatic solitons are found to be decreasing with the increase in concentration of positrons (or decrease in the concentration of ions) in degenerate electron-positron-ion plasmas. It is found that only rarefactive double layer can exist in such plasmas which depend on various parameters. The dependence of double layer structure on ion concentration and quantum diffraction effects of electrons and positrons are also discussed. The results are also elaborated graphically by considering dense plasma parameters in the outer layers of astrophysical objects such as white dwarfs and neutron stars.
Compass Results on Gluon Polarisation from High pT hadron pairs
L. Silva; for the COMPASS Collaboration
2010-10-13T23:59:59.000Z
One of the goals of the COMPASS experiment is the determination of the gluon polarisation \\Delta G/G, for a deep understanding of the spin structure of the nucleon. In DIS the gluon polarisation can be measured via the Photon-Gluon-Fusion (PGF) process, identified by open charm production or by selecting high p_T hadron pairs in the final state. The data used for this work were collected by the COMPASS experiment during the years 2002-2004, using a 160 GeV naturally polarised positive muon beam scattering on a polarised nucleon target. A new preliminary result of the gluon polarisation \\Delta G/G from high p_T hadron pairs in events with Q^2>1 (GeV/c)^2 is presented. In order to extract \\Delta G/G, this analysis takes into account the leading process \\gamma q contribution together with the PGF and QCD Compton processes. A new weighted method based on a neural network approach is used. A preliminary \\Delta G/G result for events from quasi-real photoproduction (Q^2<1 (GeV/c)^2) is also presented.
Search for Resonances in the Photoproduction of Proton-Antiproton Pairs
Burnham Stokes
2006-06-30T23:59:59.000Z
Results are reported on the reaction {gamma}p {yields} p{bar p}p with beam energy in the range 4.8-5.5 GeV. The data were collected at the Thomas Jefferson National Accelerator Facility in CLAS experiment E01-017(G6C). The focus of this study is an understanding of the mechanisms of photoproduction of proton-antiproton pairs, and to search for intermediate resonances, both narrow and broad, which decay to p{bar p}. The total measured cross section in the photon energy range 4.8-5.5 GeV is {sigma} = 33 {+-} 2 nb. Measurement of the cross section as a function of energy is provided. An upper limit on the production of a narrow resonance state previously observed with a mass of 2.02 GeV/c{sup 2} is placed at 0.35 nb. No intermediate resonance states were observed. Meson exchange production appears to dominate the production of the proton-antiproton pairs.
Marchetti, P A; Su, Z B; Yu, L
2011-01-01T23:59:59.000Z
Within a gauge approach to the t-J model, we propose a new, non-BCS mechanism of superconductivity for underdoped cuprates. We implement the no-double occupancy constraint with a (semionic) slave-particle formalism. The dopant generates a vortex-like quantum distortion of the AF background centered on the empty sites, with opposite chirality for cores on the two N\\'eel sublattices. Empty sites are described in terms of spinless fermionic holons and the long-range attraction between spin vortices on two opposite N\\'eel sublattices is the holon pairing force, leading eventually to SC. The spin fluctuations are described by bosonic spinons with a gap generated by scattering on spin vortices. Due to the occupation constraint, there is a gauge attraction between holon and spinon, binding them into a physical hole. Through gauge interaction the spin vortex attraction induces the formation of spin-singlet RVB pairs reducing the spinon gap. Lowering T, there are two crossovers as precursors of the SC transition: at t...
The Contribution of Electron-Positron Pair Production to the Vacuum Energy
Durney, Bernard R
2012-01-01T23:59:59.000Z
The vacuum, defined as the state where no particles can be observed, is interpreted here to imply that the lifetime of the e-p pair should be equal to the Planck time. Concerning the title's subject, a perfect theory would require that the true vacuum expectation value of the operator associated with pair production, be compatible with the normalization of the true vacuum. At present, a calculation of the vacuum energy based on Feynman diagrams reveals a serious difficulty: if only second order terms of the S-matrix are retained, and because there are no external lines, it follows that the space-time integrations over the coordinates, involved in the calculation of the vacuum expectation value of the S-matrix, give rise to two identical delta functions: the amplitude is thus proportional to the space-time volume of integration, L4. The square of the amplitude defies then any physically meaningful interpretation. One is faced here with two evils: modify the interaction Lagrangian so that the amplitude becomes ...
Development of Hard X-ray Imaging Optics with Two Pairs of Elliptical and Hyperbolic Mirrors
Matsuyama, S.; Fujii, M.; Wakioka, T.; Mimura, H.; Handa, S.; Kimura, T. [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishino, Y.; Tamasaku, K.; Makina, Y.; Ishikawa, T. [SPring-8/RIKEN, 1-1-1 Kouto, Sayoucho, Sayogun, Hyogo 679-5148 (Japan); Yamauchi, K. [Department of Precision Science and Technology, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Research Center for Ultra-Precision Science and Technology, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)
2010-06-23T23:59:59.000Z
To form a magnified hard X-ray image with a 50 nm resolution, we have studied total reflection mirror optics with two pairs of elliptical and hyperbolic mirrors, which is called 'Advanced Kirkpatrick-Baez system'. A designed optical system has 200x and 300x magnifications in vertical and horizontal directions. Also diffraction limit size in the optical system is 40 nmx45 nm. We fabricated a pair of elliptical and hyperbolic mirrors for horizontal imaging with a figure accuracy of 2 nm using elastic emission machining (EEM), microstitching interferometry (MSI) and relative-angle-determinable stitching interferometry (RADSI). One-dimensional tests for forming a demagnified image of a slit were carried out at an X-ray energy of 11.5 keV at BL29XUL (EH2) of SPring-8. As a result, a shape beam with a FWHM of 78 nm was observed. This demonstrates that we realized one-dimensional Wolter optics that has a spatial resolution of 78 nm.
Non-resonant kaon pair production and medium effects in proton-nucleus collisions
E. Ya. Paryev; M. Hartmann; Yu. T. Kiselev
2015-05-08T23:59:59.000Z
We study the non-resonant (non-$\\phi$) production of $K^+K^-$ pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets within the collision model, based on the nuclear spectral function, for incoherent primary proton--nucleon and secondary pion--nucleon creation processes. The model takes into account the initial proton and final kaon absorption, target nucleon binding and Fermi motion as well as nuclear mean-field potential effects on these processes. We calculate the antikaon momentum dependences of the exclusive absolute and relative $K^+K^-$ pair yields in the acceptance window of the ANKE magnetic spectrometer, used in a recent experiment performed at COSY, within the different scenarios for the antikaon-nucleus optical potential. We demonstrate that the above observables are strongly sensitive to this potential. Therefore, they can be useful to help determine the $K^-$ optical potential from the direct comparison of the results of our calculations with the data from the respective ANKE-at-COSY experiment. We also show that the pion--nucleon production channels dominate in the low-momentum $K^-$, $K^+$ production in the considered kinematics and, hence, they have to be accounted for in the analysis of these data.
Non-resonant kaon pair production and medium effects in proton-nucleus collisions
Paryev, E Ya; Kiselev, Yu T
2015-01-01T23:59:59.000Z
We study the non-resonant (non-$\\phi$) production of $K^+K^-$ pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets within the collision model, based on the nuclear spectral function, for incoherent primary proton--nucleon and secondary pion--nucleon creation processes. The model takes into account the initial proton and final kaon absorption, target nucleon binding and Fermi motion as well as nuclear mean-field potential effects on these processes. We calculate the antikaon momentum dependences of the exclusive absolute and relative $K^+K^-$ pair yields in the acceptance window of the ANKE magnetic spectrometer, used in a recent experiment performed at COSY, within the different scenarios for the antikaon-nucleus optical potential. We demonstrate that the above observables are strongly sensitive to this potential. Therefore, they can be useful to help determine the $K^-$ optical potential from the direct comparison of the results of our calculations with the data from the respective ANKE-a...
Johnson, John Asher [California Institute of Technology, Department of Astrophysics, MC 249-17, Pasadena, CA 91125 (United States); Payne, Matthew; Ford, Eric B. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, P.O. Box 112055, Gainesville, FL 32611-2055 (United States); Howard, Andrew W.; Marcy, Geoffrey W. [Department of Astronomy, University of California, Mail Code 3411, Berkeley, CA 94720 (United States); Clubb, Kelsey I. [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Bowler, Brendan P. [Institute for Astronomy, University of Hawai'i, Honolulu, HI 96822 (United States); Henry, Gregory W. [Center of Excellence in Information Systems, Tennessee State University, 3500 John A. Merritt Boulevard, Box 9501, Nashville, TN 37209 (United States); Fischer, Debra A.; Brewer, John M.; Schwab, Christian [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Reffert, Sabine [ZAH-Landessternwarte, Koenigstuhl 12, D-69117 Heidelberg (Germany); Lowe, Thomas B., E-mail: johnjohn@astro.caltech.edu [UCO/Lick Observatory, Santa Cruz, CA 95064 (United States)
2011-01-15T23:59:59.000Z
We report radial velocity (RV) measurements of the G-type subgiants 24 Sextanis (= HD 90043) and HD 200964. Both are massive, evolved stars that exhibit periodic variations due to the presence of a pair of Jovian planets. Photometric monitoring with the T12 0.80 m APT at Fairborn Observatory demonstrates both stars to be constant in brightness to {<=}0.002 mag, thus strengthening the planetary interpretation of the RV variations. Based on our dynamical analysis of the RV time series, 24 Sex b, c have orbital periods of 452.8 days and 883.0 days, corresponding to semimajor axes 1.333 AU and 2.08 AU, and minimum masses 1.99 M{sub Jup} and 0.86 M{sub Jup}, assuming a stellar mass M{sub *}= 1.54 M{sub sun}. HD 200964 b, c have orbital periods of 613.8 days and 825.0 days, corresponding to semimajor axes 1.601 AU and 1.95 AU, and minimum masses 1.99 M{sub Jup} and 0.90 M{sub Jup}, assuming M{sub *}= 1.44 M{sub sun}. We also carry out dynamical simulations to properly account for gravitational interactions between the planets. Most, if not all, of the dynamically stable solutions include crossing orbits, suggesting that each system is locked in a mean-motion resonance that prevents close encounters and provides long-term stability. The planets in the 24 Sex system likely have a period ratio near 2:1, while the HD 200964 system is even more tightly packed with a period ratio close to 4:3. However, we caution that further RV observations and more detailed dynamical modeling will be required to provide definitive and unique orbital solutions for both cases, and to determine whether the two systems are truly resonant.
Hard photo-disintegration of proton pairs in {sup 3}He nuclei
Ishay Pomerantz
2011-09-01T23:59:59.000Z
Extensive studies of high-energy deuteron photodisintegration over the past two decades have probed the limits of meson-baryon descriptions of nuclei and nuclear reactions. At high energies, photodisintegration cross sections have been shown to scale as a power law in s (the total cm energy squared), which suggests that quarks are the relevant degrees of freedom. In an attempt to more clearly identify the underlying dynamics at play, JLab/Hall A experiment 03-101 measured the hard photodisintegration of {sup 3}He into p-p and p-d pairs at ?{sub c.m.} = 90? and E{sub {gamma}} = 0.8 - 4.7 GeV. The basic idea is that the measurement should be able to test theoretical predictions for the relative size of pp versus pn disintegrations. This document presents data for the energy dependence of the high energy 90? c.m. photodisintegration of {sup3]He: d?/dt(? + {sup3}He ? p + p + n{sub spectator}), and d?/dt(? + {sup 3}He ? p + d). The cross sections were observed to scale as a function of s{sup ?n} where n was found to be 11.1±0.1 and 17.4±0.5 for the two reactions respectively. The degree of scaling found for d#27;{sigma}/dt (? + {sup 3}He ? p + d) is the highest degree of scaling ever observed in a nuclear process. The onset of the observed scaling are at photon energy of 2.2 GeV for the pp breakup and 0.7 GeV for the pd breakup. The magnitude of the invariant cross section for pp pair breakup was found to be dramatically lower than for the breakup of pn pairs and theoretical predictions. At energies below the scaling region, the scaled cross section was found to present a strong energy-dependent structure not observed in the pn breakup. The data indicate a transition from three-nucleon hadronic photodisintegration processes at low energies to two-nucleon quark-dominated photodisintegration processes at high energies.
Predissociation of high-lying Rydberg states of molecular iodine via ion-pair states
Bogomolov, Alexandr S. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation)] [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Grüner, Barbara; Mudrich, Marcel [Physikalisches Institut, Universität Freiburg, D-79104 Freiburg (Germany)] [Physikalisches Institut, Universität Freiburg, D-79104 Freiburg (Germany); Kochubei, Sergei A. [Institute of Semiconductor Physics, ac. Lavrent'yev ave., 13, Novosibirsk 630090 (Russian Federation)] [Institute of Semiconductor Physics, ac. Lavrent'yev ave., 13, Novosibirsk 630090 (Russian Federation); Baklanov, Alexey V. [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation) [Institute of Chemical Kinetics and Combustion, Institutskaya Str. 3, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 (Russian Federation)
2014-03-28T23:59:59.000Z
Velocity map imaging of the photofragments arising from two-photon photoexcitation of molecular iodine in the energy range 73?500–74?500 cm{sup ?1} covering the bands of high-lying gerade Rydberg states [{sup 2}?{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}?{sub 1/2}]{sub c}6d;2{sub g} has been applied. The ion signal was dominated by the atomic fragment ion I{sup +}. Up to 5 dissociation channels yielding I{sup +} ions with different kinetic energies were observed when the I{sub 2} molecule was excited within discrete peaks of Rydberg states and their satellites in this region. One of these channels gives rise to images of I{sup +} and I{sup ?} ions with equal kinetic energy indicating predissociation of I{sub 2} via ion-pair states. The contribution of this channel was up to about 50% of the total I{sup +} signal. The four other channels correspond to predissociation via lower lying Rydberg states giving rise to excited iodine atoms providing I{sup +} ions by subsequent one-photon ionization by the same laser pulse. The ratio of these channels varied from peak to peak in the spectrum but their total ionic signal was always much higher than the signal of (2 + 1) resonance enhanced multi-photon ionization of I{sub 2}, which was previously considered to be the origin of ionic signal in this spectral range. The first-tier E0{sub g}{sup +} and D{sup ?}2{sub g} ion-pair states are concluded to be responsible for predissociation of Rydberg states [{sup 2}?{sub 1/2}]{sub c}6d;0{sub g}{sup +} and [{sup 2}?{sub 1/2}]{sub c}6d;2{sub g}, respectively. Further predissociation of these ion-pair states via lower lying Rydberg states gives rise to excited I(5s{sup 2}5p{sup 4}6s{sup 1}) atoms responsible for major part of ion signal. The isotropic angular distribution of the photofragment recoil directions observed for all channels indicates that the studied Rydberg states are long-lived compared with the rotational period of the I{sub 2} molecule.
Search for Light Resonances Decaying into Pairs of Muons as a Signal of New Physics
Chatrchyan, S. [Yerevan Physics Institute(Armenia)
2011-07-01T23:59:59.000Z
A search for groups of collimated muons is performed using a data sample collected by the CMS experiment at the LHC, at a centre-of-mass energy of 7 TeV, and corresponding to an integrated luminosity of 35 inverse picobarns. The analysis searches for production of new low-mass states decaying into pairs of muons and is designed to achieve high sensitivity to a broad range of models predicting leptonic jet signatures. With no excess observed over the background expectation, upper limits on the production cross section times branching fraction times acceptance are set, ranging from 0.1 to 0.5 pb at the 95% CL depending on event topology. In addition, the results are interpreted in several benchmark models in the context of supersymmetry with a new light dark sector exploring previously inaccessible parameter space.
Higgs boson pair production: top quark mass effects at NLO and NNLO
Grigo, Jonathan; Steinhauser, Matthias
2015-01-01T23:59:59.000Z
We compute next-to-next-to-leading order QCD corrections to the gluon-induced production cross section of Higgs boson pairs in the large top quark mass limit using the soft-virtual approximation. In the limit of infinitely-heavy top quark we confirm the results in the literature. We add two more expansion terms in the inverse top quark mass to the $M_t\\to\\infty$ result. Since the $1/M_t$ expansion converges poorly, we try to improve on it by factorizing the exact leading order cross section. We discuss two ways of doing that and conclude that the finite top quark mass effects shift the cross section at most by about 10\\% at next-to-leading order and by about 5\\% at next-to-next-to-leading order.
Shota Kino; Taiki Nii; Holger F. Hofmann
2015-08-13T23:59:59.000Z
Joint measurements of non-commuting observables are characterized by unavoidable measurement uncertainties that can be described in terms of the error statistics for input states with well-defined values for the target observables. However, a complete characterization of measurement errors must include the correlations between the errors of the two observables. Here, we show that these correlations appear in the experimentally observable measurement statistics obtained by performing the joint measurement on maximally entangled pairs. For two-level systems, the results indicate that quantum theory requires imaginary correlations between the measurement errors of X and Y since these correlations are represented by the operator product XY=iZ in the measurement operators. Our analysis thus reveals a directly observable consequence of non-commutativity in the statistics of quantum measurements.
Search for the associated production of the Higgs boson with a top-quark pair
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Khachatryan, Vardan [Yerevan Physics Institute (Armenia)
2014-09-01T23:59:59.000Z
A search for the standard model Higgs boson produced in association with a top-quark pair (t?tH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?¹ and 19.7 fb?¹ collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H ? hadrons, H ? photons, and H ? leptons. The results are characterized by an observed t?tH signal strength relative to the standard model cross section, ?=?/?SM, under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is ? = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.
Conformal Transformations and Strings for an Accelerating Quark-Antiquark Pair in AdS3
Shijong Ryang
2014-12-08T23:59:59.000Z
From a simple moving open string solution dual to a moving heavy quark with constant velocity in the Poincare AdS_3 spacetime, we construct an accerlerating open string solution dual to a heavy quark-antiquark pair accelerated in opposite directions by performing the three mappings such as the SL(2,R)_L x SL(2,R)_R isometry transformation, the special conformal transformation and the conformal SO(2,2) transformation. Using the string sigma model action we construct two open string solutions staying in two different regions whose dividing line is associated with the event horizon appeared on the string worldsheet and obtain the accelerating open string solution by gluing two such solutions.
Homoclinic orbits and chaos in a pair of parametrically-driven coupled nonlinear resonators
Eyal Kenig; Yuriy A. Tsarin; Ron Lifshitz
2010-07-22T23:59:59.000Z
We study the dynamics of a pair of parametrically-driven coupled nonlinear mechanical resonators of the kind that is typically encountered in applications involving microelectromechanical and nanoelectromechanical systems (MEMS & NEMS). We take advantage of the weak damping that characterizes these systems to perform a multiple-scales analysis and obtain amplitude equations, describing the slow dynamics of the system. This picture allows us to expose the existence of homoclinic orbits in the dynamics of the integrable part of the slow equations of motion. Using a version of the high-dimensional Melnikov approach, developed by Kovacic and Wiggins [Physica D, 57, 185 (1992)], we are able to obtain explicit parameter values for which these orbits persist in the full system, consisting of both Hamiltonian and non-Hamiltonian perturbations, to form so-called Shilnikov orbits, indicating a loss of integrability and the existence of chaos. Our analytical calculations of Shilnikov orbits are confirmed numerically.
Search for the associated production of the Higgs boson with a top-quark pair
Khachatryan, Vardan [Yerevan Physics Institute (Armenia). et al.
2014-09-16T23:59:59.000Z
A search for the standard model Higgs boson produced in association with a top-quark pair (t?tH) is presented, using data samples corresponding to integrated luminosities of up to 5.1 fb?¹ and 19.7 fb?¹ collected in pp collisions at center-of-mass energies of 7 TeV and 8 TeV respectively. The search is based on the following signatures of the Higgs boson decay: H ? hadrons, H ? photons, and H ? leptons. The results are characterized by an observed t?tH signal strength relative to the standard model cross section, ?=?/?_{SM}, under the assumption that the Higgs boson decays as expected in the standard model. The best fit value is ? = 2.8 ± 1.0 for a Higgs boson mass of 125.6 GeV.