cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Radio Frequency Spectroscopy of Trapped Fermi Gases with Population Imbalance
Creators: name: He, Yan
name: Chien, Chih-Chun
name: Chen, Qijin
name: Levin, K.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Motivated by recent experiments, we address, in a fully self consistent fashion, the behavior and evolution of radio frequency (RF) spectra as temperature and polarization are varied in population imbalanced Fermi gases. We discuss a series of scenarios for the experimentally observed zero temperature pseudogap phase and show how present and future RF experiments may help in its elucidation. We conclude that the MIT experiments at the lowest $T$ may well reflect ground state properties, but take issue with their claim that the pairing gap survives up to temperatures of the order of the degeneracy temperature $T_F$ at unitarity.
description: 4 page, 3 figures, submitted to PRA Rapid
Controlling Phase Space Caustics in the Semiclassical Coherent State Propagator
Creators: name: Ribeiro, A. D.
name: de Aguiar, M. A. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The semiclassical formula for the quantum propagator in the coherent state representation $$ is not free from the problem of caustics. These are singular points along the complex classical trajectories specified by $\mathbf{z}'$, $\mathbf{z}''$ and $T$ where the usual quadratic approximation fails, leading to divergences in the semiclassical formula. In this paper we derive third order approximations for this propagator that remain finite in the vicinity of caustics. We use Maslov's method and the dual representation proposed in Phys. Rev. Lett. {\bf 95}, 050405 (2005) to derive uniform, regular and transitional semiclassical approximations for coherent state propagator in systems with two degrees of freedom.
description: 24 pages, to appear in Ann. of Phys
Higgs-free confinement hierarchy in five colour QCD
Creators: name: Walker, M. L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: I consider the monopole condensate of five color QCD. The naive lowest energy state is unobtainable at one-loop for five or more colors due to simple geometric considerations. The consequent adjustment of the vacuum condensate generates a hierarchy of confinement scales in a natural Higgs-free manner. The accompanying symmetry hierarchy contains hints of standard model phenomenology.
description: 9 pages, PTP class file, discussion at bottom of page 5 corrected
Security Engineering for Large Scale Distributed Applications
Creators: name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2005
Subjects: distributed systems security
decision-enforcement paradigm
access control
Engineering Security Mechanisms

description: The way security mechanisms for large-scale distributed applications are engineered today has a number of serious drawbacks. As a result, secure distributed applications are a) very expensive and error-prone to build, deploy, and integrate, b) complex and error-prone to operate and administer, and still c) far from being adequate to the real-life problems. Drawing on my academic and industrial experiences, I will discuss several recently invented techniques that can improve engineering of security mechanisms for distributed systems. I will specifically talk about improving those mechanisms that are based on the decision-enforcement paradigm, and will use access control as a representative example. I will also briefly describe other relevant projects at the Department of Electrical and Computer Engineering, the University of British Columbia.
Magnetic on-off switching of a plasmonic laser
Creators: name: Freire-Fernández, Francisco
name: Cuerda, Javier
name: Daskalakis, Konstantinos S.
name: Perumbilavil, Sreekanth
name: Martikainen, Jani-Petri
name: Arjas, Kristian
name: Törmä, Päivi
name: van Dijken, Sebastiaan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The nanoscale mode volumes of surface plasmon polaritons have enabled plasmonic lasers and condensates with ultrafast operation. Most plasmonic lasers are based on noble metals, rendering the optical mode structure inert to external fields. Here, we demonstrate active magnetic-field control over lasing in a periodic array of Co/Pt multilayer nanodots immersed in an IR-140 dye solution. We exploit the magnetic nature of the nanoparticles combined with mode tailoring to control the lasing action. Under circularly polarized excitation, angle-resolved photoluminescence measurements reveal a transition between lasing action and non-lasing emission as the nanodot magnetization is reversed. Our results introduce magnetization as a means of externally controlling plasmonic nanolasers, complementary to the modulation by excitation, gain medium, or substrate. Further, the results show how effects of magnetization on light that are inherently weak can be observed in the lasing regime, inspiring studies of topological photonics.
Security Engineering for Large Scale Distributed Applications
Creators: name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2005
Subjects: distributed systems security
decision-enforcement paradigm
access control
Engineering Security Mechanisms

description: The way security mechanisms for large-scale distributed applications are engineered today has a number of serious drawbacks. As a result, secure distributed applications are a) very expensive and error-prone to build, deploy, and integrate, b) complex and error-prone to operate and administer, and still c) far from being adequate to the real-life problems.  Drawing on my academic and industrial experiences, I will discuss several recently invented techniques that can improve engineering of security mechanisms for distributed systems. I will specifically talk about improving those mechanisms that are based on the decision-enforcement paradigm, and will use access control as a representative example. I will examine in detail one particular method, Attribute Function, which enables the use of application-specific data in authorization decisions while keeping distributed applications security unaware.  The talkl was given at the following organizations: * Departement Computerwetenschappen, Katholieke Universiteit Leuven, on June 19, 2003. * Department of Electrical and Computer Engineering, University of British Columbia, on March 7, 2003. * The Department of Computing and Software, McMaster University, on February 25, 2003. * Faculty of Computer Science, Dalhousie University, on January 28, 2003.
Proof-of-principle experimental demonstration of quantum secure imaging based on quantum key distribution
Creators: name: Zhao, Yi-Bo
name: Zhang, Wan-Li
name: Wang, Dong
name: Song, Xiao-Tian
name: Zhou, Liang-Jiang
name: Ding, Chi-Biao
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a quantum secure imaging (QSI) scheme based on the phase encoding and weak + vacuum decoy-state BB84 protocol of quantum key distribution (QKD). It allows us to implement a computational ghost imaging (CGI) system with more simplified equipment and reconstructed algorithms by using a digital micro-mirror device (DMD) to preset the specific spatial distribution of the light intensity. What's more, the quantum bit error rate (QBER) and the secure key rate analytical functions of QKD are used to see through the intercept-resend jamming attacks and ensure the authenticity of the imaging information. In the experiment, we obtained the image of the object quickly and efficiently by measuring the signal photon counts with single-photon detector (SPD), and achieved a secure key rate of 571.0 bps and a secure QBER of 3.99%, which is well below the lower bound of QBER of 14.51$\%$. Besides, our imaging system uses a laser with invisible wavelength of 1550 nm, whose intensity is low as single-photon, that can realize weak-light imaging and is immune to the stray light or air turbulence, thus it will become a better choice for quantum security radar against intercept-resend jamming attacks.
description: 7 pages, 5 figures
The Wave Function of Simple Universes, Analytically Continued From Negative to Positive Potentials
Creators: name: Lehners, Jean-Luc
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We elaborate on the correspondence between the canonical partition function in asymptotically AdS universes and the no-boundary proposal for positive vacuum energy. For the case of a pure cosmological constant, the analytic continuation of the AdS partition function is seen to define the no-boundary wave function (in dS) uniquely in the simplest minisuperspace model. A consideration of the AdS gravitational path integral implies that on the dS side, saddle points with Hawking-Moss/Coleman-De Luccia-type tunnelling geometries are irrelevant. This implies that simple topology changing geometries do not contribute to the nucleation of the universe. The analytic AdS/dS equivalence holds up once tensor fluctuations are added. It also works, at the level of the saddle point approximation, when a scalar field with a mass term is included, though in the latter case, it is the mass that must be analytically continued. Our results illustrate the emergence of time from space by means of a Stokes phenomenon, in the case of positive vacuum energy. Furthermore, we arrive at a new characterisation of the no-boundary condition, namely that there should be no momentum flux at the nucleation of the universe.
description: 26 pages, 9 figures, v2: replaced with published version (extended discussion, references added, improvements to Fig. 9)
Noncoherent Low-Decoding-Complexity Space-Time Codes for Wireless Relay Networks
Creators: name: Rajan, G. Susinder
name: Rajan, B. Sundar
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: The differential encoding/decoding setup introduced by Kiran et al, Oggier et al and Jing et al for wireless relay networks that use codebooks consisting of unitary matrices is extended to allow codebooks consisting of scaled unitary matrices. For such codebooks to be used in the Jing-Hassibi protocol for cooperative diversity, the conditions that need to be satisfied by the relay matrices and the codebook are identified. A class of previously known rate one, full diversity, four-group encodable and four-group decodable Differential Space-Time Codes (DSTCs) is proposed for use as Distributed DSTCs (DDSTCs) in the proposed set up. To the best of our knowledge, this is the first known low decoding complexity DDSTC scheme for cooperative wireless networks.
description: 5 pages, no figures. To appear in Proceedings of IEEE ISIT 2007, Nice, France
The effects of intrinsic local distortions vs. dynamic thermal motions on the stability and band gaps of cubic oxide and halide perovskites
Creators: name: Zhao, Xin-Gang
name: Wang, Zhi
name: Malyi, Oleksandr I.
name: Zunger, Alex
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Corner-shared ABX$_3$ perovskites have long featured prominently in solid-state chemistry and condensed matter physics. Still, the joint understanding of their two main subgroups-halides and oxides-has not been fully developed. Indeed, unlike the case that compounds having a single repeated motif ("monomorphous"), certain cubic perovskites can manifest a non-thermal distribution of local motifs ("polymorphous networks"). Such intrinsic deformations can include positional degrees of freedom. Unlike thermal motion, such intrinsic distortions do not time-average to zero. The present study compares electronic structure features of oxide and halide perovskites starting from the intrinsic polymorphous network described by DFT minimization of the internal energy, continuing to finite temperature thermal disorder using AIMD. We find that (i) different oxide vs. halide ABX$_3$ compounds adopt different energy-lowering distortion modes. The DFT calculated pair distribution function (PDF) of SrTiO$_3$ agrees with the recently measured PDF. (ii) In both oxides and halides, such intrinsic distortions lead to bandgap blueshifts with respect to monomorphous structure. (iii) For oxide perovskites, high-temperature AIMD simulations initiated from the polymorphous structures reveal that the thermally-induced distortions can lead to a bandgap redshift. (iv) In contrast, for cubic CsPbI$_3$, both the intrinsic distortions and the thermal distortions contribute in tandem to bandgap blueshift, the former, intrinsic effect being dominant. (v) In the oxide SrTiO$_3$ and CaTiO$_3$ (but not in halide), octahedral tilting leads to the emergence of a distinct $Γ$-$Γ$ direct bandgap component as a secondary valley minimum to the well-known indirect R-$Γ$ gap. Understanding such intrinsic vs. thermal effects on oxide vs. halide perovskites holds the potential for designing target electronic properties.
description: 11 figures
Security Requirements in Healthcare
Creators: name: Beznosov, Konstantin
Publisher: name: Zenodo
Year: 2005
Subjects: healthcare
security requirements
General Computer Security

description: Presentation on requirements in US healthcare organizations to security vendors, given to the joint SecSIG/CORBAmed session.  Outline:  • Risks  • Requirements  – Security requirements to the healthcare organizations  – functional and non-functional requirements for security architectures  • BHSSF example to illustrate
A fitting formula for the merger timescale of galaxies in hierarchical clustering
Creators: name: Jiang, C. Y.
name: Jing, Y. P.
name: Faltenbacher, A.
name: Lin, W. P.
name: Li, Cheng
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study galaxy mergers using a high-resolution cosmological hydro/N-body simulation with star formation, and compare the measured merger timescales with theoretical predictions based on the Chandrasekhar formula. In contrast to Navarro et al., our numerical results indicate, that the commonly used equation for the merger timescale given by Lacey and Cole, systematically underestimates the merger timescales for minor mergers and overestimates those for major mergers. This behavior is partly explained by the poor performance of their expression for the Coulomb logarithm, \ln (m_pri/m_sat). The two alternative forms \ln (1+m_pri/m_sat) and 1/2\ln [1+(m_pri/m_sat)^2] for the Coulomb logarithm can account for the mass dependence of merger timescale successfully, but both of them underestimate the merger time scale by a factor 2. Since \ln (1+m_pri/m_sat) represents the mass dependence slightly better we adopt this expression for the Coulomb logarithm. Furthermore, we find that the dependence of the merger timescale on the circularity parameter εis much weaker than the widely adopted power-law ε^{0.78}, whereas 0.94*ε^{0.60}+0.60 provides a good match to the data. Based on these findings, we present an accurate and convenient fitting formula for the merger timescale of galaxies in cold dark matter models.
description: 16 pages, 14 figures, accepted for publication in ApJ, minor changes in the last few sentences of the discussion
Ricci flow with bounded curvature integrals
Creators: name: Hamanaka, Shota
Publisher: name: arXiv
Year: 2021
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53E20

description: In this paper, we study the Ricci flow on a closed manifold and finite time interval $[0,T)~(T < \infty)$ on which certain integral curvature energies are finite. We prove that in dimension four, such flow converges to a smooth Riemannian manifold except for finitely many orbifold singularities. We also show that in higher dimensions, the same assertions hold for a closed Ricci flow satisfying another conditions of integral curvature bounds. Moreover, we show that such flows can be extended over $T$ by an orbifold Ricci flow.
description: 26 pages. arXiv admin note: text overlap with arXiv:1501.01291 by other authors
Symmetry and parity in Frobenius action on cohomology
Creators: name: Suh, Junecue
Publisher: name: arXiv
Year: 2024
Subjects: subject: Algebraic Geometry (math.AG)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11G25 (Primary) 14F20, 14F30 (Secondary)

description: We prove that the Newton polygons of Frobenius on the crystalline cohomology of proper smooth varieties satisfy a symmetry that results, in the case of projective smooth varieties, from Poincaré duality and the hard Lefschetz theorem. As a corollary, we deduce that the Betti numbers in odd degrees of any proper smooth variety over a field are even (a consequence of Hodge symmetry in characteristic zero), answering an old question of Serre. Then we give a generalization and a refinement for arbitrary varieties over finite fields, in response to later questions of Serre and of Katz.
description: Published in 2012 and being arXived at the persuasion of an independent mathematician
Temporal evolution of the Evershed flow in sunspots. I. Observational characterization of Evershed clouds
Creators: name: Solana, D. Cabrera
name: Rubio, L. R. Bellot
name: Beck, C.
name: Iniesta, J. C. del Toro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: [Abridged] The magnetic and kinematic properties of the photospheric Evershed flow are relatively well known, but we are still far from a complete understanding of its nature. The evolution of the flow with time, which is mainly due to appearance of velocity packets called Evershed clouds (ECs), may provide information to further constrain its origin. Here we undertake a detailed analysis of the evolution of the Evershed flow by studying the properties of ECs. In this first paper we determine the sizes, proper motions, location in the penumbra, and frequency of appearance of ECs, as well as their typical Doppler velocities, linear and circular polarization signals, Stokes V area asymmetries, and continuum intensities. High-cadence, high-resolution, full vector spectropolarimetric measurements in visible and infrared lines are used to derive these parameters. We find that ECs appear in the mid penumbra and propage outward along filaments with large linear polarization signals and enhanced Evershed flows. The frequency of appearance of ECs varies between 15 and 40 minutes in different filaments. ECs exhibit the largest Doppler velocities and linear-to-circular polarization ratios of the whole penumbra. In addition, lines formed deeper in the atmosphere show larger Doppler velocities, much in the same way as the ''quiescent'' Evershed flow. According to our observations, ECs can be classified in two groups: type I ECs, which vanish in the outer penumbra, and type II ECs, which cross the outer penumbral boundary and enter the sunspot moat. Most of the observed ECs belong to type I. On average, type II ECs can be detected as velocity structures outside of the spot for only about 14 min. Their proper motions in the moat are significantly reduced with respect to the ones they had in the penumbra.
description: Accepted for publication in A&A
A relativistic calculation of the deuteron threshold electrodisintegration at backward angles
Creators: name: Arriaga, A.
name: Schiavilla, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The threshold electrodisintegration of the deuteron at backward angles is studied with a relativistic Hamiltonian, including a relativistic one-pion-exchange potential (OPEP) with off-shell terms as predicted by pseudovector coupling of pions to nucleons. The bound and scattering states are obtained in the center-of-mass frame, and then boosted from it to the Breit frame, where the evaluation of the relevant matrix elements of the electromagnetic current operator is carried out. The latter includes, in addition to one-body, also two-body terms due to pion exchange, as obtained, consistently with the OPEP, in pseudovector pion-nucleon coupling theory. The full Lorentz structure of these currents is retained. In order to estimate the magnitude of the relativistic effects we perform, for comparison, the calculation with a non-relativistic phase-equivalent Hamiltonian and the standard non-relativistic expressions for the one-body and two-body pion-exchange currents. Our results for the electrodisintegration cross section show that, in the calculations using one-body currents, relativistic corrections become significant ({\it i.e.}, larger than 10%) only at high momentum transfer $Q$ ($Q^2 \simeq 40$fm$^{-2}$ and beyond). However, the inclusion of two-body currents makes the relativistic predictions considerably smaller than the corresponding non-relativistic results in the $Q^2$ region (18--40) fm$^{-2}$. The calculations based on the relativistic model also confirm the inadequacy, already established in a non-relativistic context, of the present electromagnetic current model to reproduce accurately the experimental data at intermediate values of momentum transfers.
description: 6 figures
Multi-physics Extension of OpenFMO Framework
Creators: name: Takami, Toshiya
name: Maki, Jun
name: Ooba, Jun'ichi
name: Inadomi, Yuuichi
name: Honda, Hiroaki
name: Susukita, Ryutaro
name: Inoue, Koji
name: Kobayashi, Taizo
name: Nogita, Rie
name: Aoyagi, Mutsumi
Publisher: name: arXiv
Year: 2007
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: OpenFMO framework, an open-source software (OSS) platform for Fragment Molecular Orbital (FMO) method, is extended to multi-physics simulations (MPS). After reviewing the several FMO implementations on distributed computer environments, the subsequent development planning corresponding to MPS is presented. It is discussed which should be selected as a scientific software, lightweight and reconfigurable form or large and self-contained form.
description: 4 pages with 11 figure files, to appear in the Proceedings of ICCMSE 2007
Perspectives for the detection and measurement of Supersymmetry in the focus point region of mSUGRA models with the ATLAS detector at LHC
Creators: name: De Sanctis, U.
name: Lari, T.
name: Montesano, S.
name: Troncon, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This paper discusses the ATLAS potential to study Supersymmetry for the "Focus-Point" region of the parameter space of mSUGRA models. The potential to discovery a deviation from Standard Model expectations with the first few ${fb}^{-1}$ of LHC data was studied using the parametrized simulation of the ATLAS detector. Several signatures were considered, involving hard jets, large missing energy, and either $b$-tagged jets, opposite-sign isolated electron or muon pairs, or top quarks reconstructed exploiting their fully hadronic decays. With only 1 ${fb}^{-1}$ of data each of these signatures may allow to observe an excess of events over Standard Model expectation with a statistical significance exceeding 5 standard deviations. An analytical expression was derived for the shape of the distribution of the dilepton invariant mass arising from the three-body leptonic decay of the neutralinos under the hypothesis of heavy scalars, which is appropriate for the focus-point scenario. The resulting function was used to fit the distribution of the dilepton invariant mass obtained with simulated LHC data, and to extract the value of two kinematic endpoints measuring the $\tilde χ^0_2 - \tilde χ^0_1$ and the $\tilde χ^0_3 - \tilde χ^0_1$ mass differences. This information was used to constrain the MSSM parameter space compatible with the data.
Diffusive Hydrodynamics of Inhomogenous Hamiltonians
Creators: name: Durnin, Joseph
name: De Luca, Andrea
name: De Nardis, Jacopo
name: Doyon, Benjamin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Gases (cond-mat.quant-gas)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We derive a large-scale hydrodynamic equation, including diffusive and dissipative effects, for systems with generic static position-dependent driving forces coupling to local conserved quantities. We show that this equation predicts entropy increase and thermal states as the only stationary states. The equation applies to any hydrodynamic system with any number of local, PT-symmetric conserved quantities, in arbitrary dimension. It is fully expressed in terms of elements of an extended Onsager matrix. In integrable systems, this matrix admits an expansion in the density of excitations. We evaluate exactly its 2-particle-hole contribution, which dominates at low density, in terms of the scattering phase and dispersion of the quasiparticles, giving a lower bound for the extended Onsager matrix and entropy production. We conclude with a molecular dynamics simulation, demonstrating thermalisation over diffusive time scales in the Toda interacting particle model with an inhomogeneous energy field.
MPEC 2024-T52 : 2024 TK
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2024 TK

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Self-Bounding Majority Vote Learning Algorithms by the Direct Minimization of a Tight PAC-Bayesian C-Bound
Creators: name: Viallard, Paul
name: Germain, Pascal
name: Habrard, Amaury
name: Morvant, Emilie
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: In the PAC-Bayesian literature, the C-Bound refers to an insightful relation between the risk of a majority vote classifier (under the zero-one loss) and the first two moments of its margin (i.e., the expected margin and the voters' diversity). Until now, learning algorithms developed in this framework minimize the empirical version of the C-Bound, instead of explicit PAC-Bayesian generalization bounds. In this paper, by directly optimizing PAC-Bayesian guarantees on the C-Bound, we derive self-bounding majority vote learning algorithms. Moreover, our algorithms based on gradient descent are scalable and lead to accurate predictors paired with non-vacuous guarantees.
The study of $B\to J/Ψη^{(\prime)}$ decays and determination of $η-η^{\prime}$ mixing angle
Creators: name: Li, Jing-Wu
name: Du, Dong-Sheng
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study $B\to J/Ψη^{(\prime)}$ decays and suggest two methods to determine the $η-η^{\prime}$ mixing angle. We calculate not only the factorizable contribution in QCD facorization scheme but also the nonfactorizable hard spectator corrections in pQCD approach. We get the branching ratio of $B\to J/Ψη$ which is consistent with recent experimental data and predict the branching ratio of $B\to J/Ψη^{\prime}$ to be $7.59\times 10^{-6}$. Two methods for determining $η-η^{\prime}$ mixing angle are suggested in this paper. For the first method, we get the $η-η^{\prime}$ mixing angle to be about $-13.1^{\circ}$, which is in consistency with others in the literature. The second method depends on less parameters so can be used to determine the $η-η^{\prime}$ mixing angle with better accuracy but needs, as an input, the branching ratio for $B\to J/Ψη^{\prime}$which should be measured in the near future.
description: 16pages,4figures
Few-body correlations in two-dimensional Bose and Fermi ultracold mixtures
Creators: name: Bougas, G.
name: Mistakidis, S. I.
name: Giannakeas, P.
name: Schmelcher, P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Few-body correlations emerging in two-dimensional harmonically trapped mixtures, are comprehensively investigated. The presence of the trap leads to the formation of atom-dimer and trap states, in addition to trimers. The Tan's contacts of these eigenstates are studied for varying interspecies scattering lengths and mass ratio, while corresponding analytical insights are provided within the adiabatic hyperspherical formalism. The two- and three-body correlations of trimer states are substantially enhanced compared to the other eigenstates. The two-body contact of the atom-dimer and trap states features an upper bound regardless of the statistics, treated semi-classically and having an analytical prediction in the limit of large scattering lengths. Such an upper bound is absent in the three-body contact. Interestingly, by tuning the interspecies scattering length the contacts oscillate as the atom-dimer and trap states change character through the existent avoided-crossings in the energy spectra. For thermal gases, a gradual suppression of the involved two- and three-body correlations is evinced manifesting the impact of thermal effects. Moreover, spatial configurations of the distinct eigenstates ranging from localized structures to angular anisotropic patterns are captured. Our results provide valuable insights into the inherent correlation mechanisms of few-body mixtures which can be implemented in recent ultracold atom experiments and will be especially useful for probing the crossover from few- to many-atom systems.
description: 21 pages, 12 figures
Influences of habitat interspersion on habitat use by Columbian black-tailed deer
Creators: name: Kremsater, Laurie Lynn
Publisher: name: University of British Columbia
Year: 2010

description: Use of forage, cover, and border habitat by Columbian black-tailed deer (Odocoileus hemionus columblanus (Richardson)) was examined at two levels of selection: within home ranges and during home range establishment. Patterns of habitat use were evaluated in relation to changing seasons, different migratory behaviours, and areas of intensive deer use (defined by concentrations of radio locations). Relative use did not differ from relative availability for forage, cover, and border habitats. Availability of those habitats, however, changed seasonally as deer home ranges changed or different intensities of deer use were examined. Cover and border habitats, particularly borders between old-growth and second-growth forests, were more available in winter than, in summer home ranges. Areas receiving intensive deer use were characterized by more border and cover habitat than areas of less intensive use. Because use was directly proportional to availability, changing availability suggested that habitat selection occurred as home ranges were established. Comparisons of forage, cover, and border composition in actual home ranges and areas where home ranges potentially could have been located suggested preference for cover and border habitats. These comparisons, however, did not indicate disproportionately high use of interspersed habitats, perhaps because of the high degree of habitat interspersion in the study area.
V-Langevin Equations, Continuous Time Random Walks and Fractional Diffusion
Creators: name: Balescu, Radu
Publisher: name: arXiv
Year: 2007
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: The following question is addressed: under what conditions can a strange diffusive process, defined by a semi-dynamical V-Langevin equation or its associated Hybrid kinetic equation (HKE), be described by an equivalent purely stochastic process, defined by a Continuous Time Random Walk (CTRW) or by a Fractional Differential Equation (FDE)? More specifically, does there exist a class of V-Langevin equations with long-range (algebraic) velocity temporal correlation, that leads to a time-fractional superdiffusive process? The answer is always affirmative in one dimension. It is always negative in two dimensions: any algebraically decaying temporal velocity correlation (with a Gaussian spatial correlation) produces a normal diffusive process. General conditions relating the diffusive nature of the process to the temporal exponent of the Lagrangian velocity correlation (in Corrsin approximation) are derived.
description: Latex 69 pages including 23 EPS figures
Winterberg's conjectured breaking of the superluminal quantum correlations over large distances
Creators: name: Gkioulekas, Eleftherios
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We elaborate further on a hypothesis by Winterberg that turbulent fluctuations of the zero point field may lead to a breakdown of the superluminal quantum correlations over very large distances. A phenomenological model that was proposed by Winterberg to estimate the transition scale of the conjectured breakdown, does not lead to a distance that is large enough to be agreeable with recent experiments. We consider, but rule out, the possibility of a steeper slope in the energy spectrum of the turbulent fluctuations, due to compressibility, as a possible mechanism that may lead to an increased lower-bound for the transition scale. Instead, we argue that Winterberg overestimated the intensity of the ZPF turbulent fluctuations. We calculate a very generous corrected lower bound for the transition distance which is consistent with current experiments.
description: 7 pages, submitted to Int. J. Theor. Phys
De Finetti's Theorem in Categorical Probability
Creators: name: Fritz, Tobias
name: Gonda, Tomáš
name: Perrone, Paolo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: Logic in Computer Science (cs.LO)
subject: Category Theory (math.CT)
subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 60A05, 60G09 (Primary) 18M35, 18M05, 62A01 (Secondary)

description: We present a novel proof of de Finetti's Theorem characterizing permutation-invariant probability measures of infinite sequences of variables, so-called exchangeable measures. The proof is phrased in the language of Markov categories, which provide an abstract categorical framework for probability and information flow. The diagrammatic and abstract nature of the arguments makes the proof intuitive and easy to follow. We also show how the usual measure-theoretic version of de Finetti's Theorem for standard Borel spaces is an instance of this result.
description: 26 pages. v3: referee's suggestions incorporated
Estimating Atmospheric Wind Speeds From Gemini Planet Imager AO Telemetry
Creators: name: Du, Zhenxi
name: Perera, Saavidra
name: Levinstein, Daniel
name: Konopacky, Quinn
name: Madurowicz, Alex
name: Macintosh, Bruce
name: Poyneer, Lisa
name: Wilson, Richard
name: Farley, Ollie
Publisher: name: arXiv
Year: 2024
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The Earth's atmosphere is comprised of turbulent layers that result in speckled and blurry images from ground-based visible and infrared observations. Adaptive Optics (AO) systems are employed to measure the perturbed wavefront with a wavefront sensor (WFS) and correct for these distortions with a deformable mirror. Therefore, understanding and characterising the atmosphere is crucial for the design and functionality of AO systems. One parameter for characterizing the atmosphere is the atmospheric coherence time, which is a function of the effective wind velocity of the atmosphere. This parameter dictates how fast the AO system needs to correct for the atmosphere. If not fast enough, phenomena such as the wind butterfly effect can occur, hindering high-contrast coronographic imaging. This effect is a result of fast, strong, high-altitude turbulent layers. This paper presents two methods for estimating the effective wind velocity, using pseudo-open loop WFS slopes. The first method uses a spatial-temporal covariance map and the second uses the power spectral density of the defocus term. We show both simulated results and preliminary results from the Gemini Planet Imager AO telemetry.
description: 7 pages, 7 figures, submitted to SPIE Astronomical + Telescopes 2024
Zero-Interference Containers: a Framework for Orchestrating Mixed-Criticality Applications - Artifact
Creators: name: Ottaviano, Daniele
name: Barletta, Marco
name: Boccola, Francesco
Publisher: name: Zenodo
Year: 2025

description: Artifact DSN2025 from the paper: " Zero-Interference Containers: a Framework for Orchestrating Mixed-Criticality Applications"
Nucleus-electron correlation revising molecular bonding fingerprints from the exact wavefunction factorization
Creators: name: Chen, Ziyong
name: Yang, Jun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We present a novel theory and implementation for computing coupled electronic and quantal nuclear subsystems on a single potential energy surface, moving beyond the standard Born-Oppenheimer (BO) separation of nuclei and electrons. We formulate an exact self-consistent nucleus-electron embedding potential from the single product molecular wavefunction, and demonstrate that the fundamental behavior of correlated nucleus-electron can be computed for mean-field electrons that are responsive to a quantal anharmonic vibration of selected nuclei in a discrete variable representation. Geometric gauge choices are discussed and necessary for formulating energy invariant biorthogonal electronic equations. Our method is further applied to characterize vibrationally averaged molecular bonding properties of molecular energetics, bond length, protonic and electron density. Moreover, post-Hartree-Fock electron correlation can be conveniently computed on the basis of nucleus-electron coupled molecular orbitals, as demonstrated to correlated models of second-order Møllet-Plesset perturbation and full configuration interaction theories. Our approach not only accurately quantifies non-classical nucleus-electron couplings for revising molecular bonding properties, but also provides an alternative time-independent approach for deploying non-BO molecular quantum chemistry.
Fluctuations and Criticality in Quantum Paraelectrics
Creators: name: Das, Nabyendu
name: Mishra, Suresh G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: The temperature dependence of static dielectric susceptibility of a system with strongly coupled fluctuating dipoles is calculated within a self consistent mean fluctuation field approximation. Results are qualitatively in good agreement with, a quantum paraelectric, SrTiO$_3$ in the low temperature regime. We identify this system as a {\it gaped quantum paraelectric} and suggest a possible experimental realization of a {\it quantum critical paraelectric} through the application of hydrostatic pressure or doping by impurity.
description: 9 pages, 3 figures, Published version
Measurement of nuclear spin relaxation time in lanthanum aluminate for development of polarized lanthanum target
Creators: name: Ishizaki, K.
name: Hotta, H.
name: Ide, I.
name: Iinuma, M.
name: Iwata, T.
name: Kitaguchi, M.
name: Kohri, H.
name: Miura, D.
name: Miyachi, Y.
name: Ohta, T.
name: Shimizu, H. M.
name: Yoshikawa, H.
name: Yosoi, M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The nuclear spin-lattice relaxation time ($T_1$) of lanthanum and aluminum nuclei in a single crystal of lanthanum aluminate doped with neodymium ions is studied to estimate the feasibility of the dynamically polarized lanthanum target applicable to beam experiments. The application of our interest is the study of fundamental discrete symmetries in the spin optics of epithermal neutrons. This study requires a highly flexible choice of the applied magnetic field for neutron spin control and favors longer $T_1$ under lower magnetic field and at higher temperature. The $T_1$ of $^{139}{\rm La}$ and ${}^{27}{\rm Al}$ was measured under magnetic fields of $0.5$-$2.5$ T and at temperatures of $0.1$-$1.5$ K and found widely distributed up to 100 h. The result suggests that the $T_1$ can be as long as $T_1 \sim$ 1 h at $0.1$ K with a magnetic field of $0.1$ T, which partially fulfills the requirement of the neutron beam experiment. Possible improvements to achieve a longer $T_1$ are discussed.
description: 10 pages, 8 figures
Robust d-wave superconductivity in the square-lattice $t$-$J$ model
Creators: name: Gong, Shoushu
name: Zhu, W.
name: Sheng, D. N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Unravelling competing orders emergent in doped Mott insulators and their interplay with unconventional superconductivity is one of the major challenges in condensed matter physics. To explore possible superconductivity state in the doped Mott insulator, we study a square-lattice $t$-$J$ model with both the nearest and next-nearest-neighbor electron hoppings and spin Heisenberg interactions. By using the state-of-the-art density matrix renormalization group simulations with imposing charge $U(1)$ and spin $SU(2)$ symmetries on the large-scale six-leg cylinders, we establish a quantum phase diagram including three phases: a stripe charge density wave phase, a superconducting phase without static charge order, and a superconducting phase coexistent with a weak charge stripe order. Crucially, we demonstrate that the superconducting phase has a power-law pairing correlation decaying much slower than the charge density and spin correlations, which is a quasi-1D descendant of the uniform d-wave superconductor in two dimensions. These findings reveal that enhanced charge and spin fluctuations with optimal doping is able to produce robust d-wave superconductivity in doped Mott insulators, providing a foundation for connecting theories of superconductivity to models of strongly correlated systems.
Comparative study of depth-dose distributions for beams of light and heavy nuclei in tissue-like media
Creators: name: Pshenichnov, Igor
name: Mishustin, Igor
name: Greiner, Walter
Publisher: name: arXiv
Year: 2007
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: We study the energy deposition by light and heavy nuclei in tissue-like media as used for cancer therapy. The depth-dose distributions for protons, $^{3}$He, $^{12}$C, $^{20}$Ne, and $^{58}$Ni nuclei are calculated within a Monte Carlo model based on the GEANT4 toolkit. These distributions are compared with each other and with available experimental data. It is demonstrated that nuclear fragmentation reactions essentially reduce the peak-to-plateau ratio of the dose profiles for deeply penetrating energetic ions heavier than $^{3}$He. On the other hand, all projectiles up to $^{20}$Ne were found equally suitable for therapeutic use at low penetration depths.
description: 4 pages, 3 figures
Freeze-out volume of hot dense fireball
Creators: name: Mishra, M.
name: Singh, C. P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A thermodynamically consistent excluded volume model is proposed to account for the particle multiplicities obtained from lowest SIS energies to the highest RHIC energies. The chemical freeze-out volumes lying in a slice of one unit of rapidity for pions and kaons are separately inferred from this analysis and the results are compared with the corresponding thermal freeze-out volumes obtained from the Hanbury-Brown Twiss (HBT) pion interferometry. Furthermore, we extract the variations of freeze-out number densities for pions and nucleons with the center-of-mass energy in our model and compare them with the HBT data.
description: 10 pages, 2 figures
Dark energy from modified F(R)-scalar-Gauss-Bonnet gravity
Creators: name: Nojiri, Shin'ichi
name: Odintsov, Sergei D.
name: Tretyakov, Petr V.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The modified F(R)-scalar-Gauss-Bonnet gravity is proposed as dark energy model. The reconstruction program for such theory is developed. It is explicitly demonstrated that the known classical universe expansion history (deceleration epoch, transition to acceleration and effective quintessence, phantom or cosmological constant era) may naturally occur in such unified theory for some (reconstructed) classes of scalar potentials. Gauss-Bonnet assisted dark energy is also proposed. The possibility of cosmic acceleration is studied there.
description: LaTeX, 8 pages, no figure, refs. added, version to appear in Physics Letters B
Hunting for states in the recent LHCb di-$J/ψ$ invariant mass spectrum
Creators: name: Liang, Ze-Rui
name: Wu, Xiao-Yi
name: Yao, De-Liang
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Partial wave analysis is performed, with effective potentials as dynamical inputs, to scrutinize the recent LHCb data on the di-$J/ψ$ invariant mass spectrum. Coupled-channel effects are incorporated in the production amplitude via final state interactions. The LHCb data can be well described. A dynamical generated pole structure, which can be identified as the $X(6900)$ state, is found. Our analysis also provides hints for the existence of three other possible states: a bound state $X(6200)$, a broad resonant state $X(6680)$ and a narrow resonant state $X(7200)$. The $J^{PC}$ quantum numbers of the $X(6680)$ and $X(6900)$ states should be $2^{++}$, while the $X(6200)$ and $X(7200)$ states prefer $0^{++}$. To determine the above states more precisely, more experimental data for the channels, such as $J/ψψ(2S)$, $J/ψψ(3770)$, di-$ψ(2S)$, are required.
description: More discussions added. Matching the version to be published in PRD