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This paper analyzes nonlinear free vibration of plates that move axially and in partial contact with liquid. The von Kármán nonlinear plate theory is employed in the theoretical model. The fluid is characterized as an ideal fluid and represented using the velocity potential and Bernoulli's equation. The fluid pressure exerted on the plate is equivalent to a virtual additional mass, which is considered as part of the total mass of the structure. Employing the Hamilton's principle to derive the immersed moving plates' governing equations. Afterward, the nonlinear frequencies of plates moving axially and contacting with liquid are evaluated by the Chebyshev collocation method combined with the direct iterative technique. The results indicate that the Chebyshev collocation method exhibits excellent convergence and exceptional accuracy. It has been observed that the immersed moving plates' nonlinear frequencies gradually increase with the decrease of the axial velocity. The increase of immersion level or fluid density reduces nonlinear frequencies, but has little influence on nonlinear to linear frequency ratios. [ABSTRACT FROM AUTHOR]

AMFlow is a Mathematica package to numerically compute dimensionally regularized Feynman integrals via the recently proposed auxiliary mass flow method. In this framework, integrals are treated as functions of an auxiliary mass parameter and their results can be obtained by constructing and solving linear differential systems with respect to this parameter, in an automatic way. The usage of this package is described in detail through an explicit example of double-box family involved in two-loop t t ¯ hadroproduction. Program title: AMFlow CPC Library link to program files: https://doi.org/10.17632/nrkrw83bw5.1 Developer's repository link: https://gitlab.com/multiloop-pku/amflow Licensing provisions: MIT Programming language: Wolfram Mathematica 11.3 or higher External routines: Wolfram Mathematica [1], FiniteFlow [2], LiteRed [3], Kira [4], FIRE [5] Nature of problem: Automatically obtaining high-precision numerical results for dimensionally regularized Feynman integrals at arbitrary points in phase-space. Solution method: The program implements recently proposed auxiliary mass flow method, which introduces an auxiliary mass parameter to Feynman integrals and solves differential equations with respect to this parameter to obtain physical results. [1] http://www.wolfram.com/mathematica , commercial algebraic software. [2] https://github.com/peraro/finiteflow , open source. [3] http://www.inp.nsk.su/~lee/programs/LiteRed , open source. [4] https://gitlab.com/kira-pyred/kira , open source. [5] https://bitbucket.org/feynmanIntegrals/fire , open source. [ABSTRACT FROM AUTHOR]

Bayesian empirical likelihood (BEL) method with missing data depends heavily on the prior specification and missing data mechanism assumptions. It is well known that the resulting Bayesian estimations and tests may be sensitive to these assumptions and observations. To this end, a Bayesian local influence procedure is proposed to assess the effect of various perturbations to the individual observations, priors, estimating equations (EEs) and missing data mechanism in general EEs with nonignorable missing data. A perturbation model is introduced to simultaneously characterize various perturbations, and a Bayesian perturbation manifold is constructed to characterize the intrinsic structure of these perturbations. The first- and second-order adjusted local influence measures are developed to quantify the effect of various perturbations. The proposed methods are adopted to systematically investigate the tenability of nonignorable missing mechanism assumption, the sensitivity of the choice of the nonresponse instrumental variable and the sensitivity of EEs assumption, and goodness-of-fit statistics are presented to assess the plausibility of the posited EEs. Simulation studies are conducted to investigate the performance of the proposed methodologies. An example is analyzed. [ABSTRACT FROM AUTHOR]

We apply a color glass condensate+nonrelativistic QCD (CGC+NRQCD) framework to compute J/ψ production in deuteron-nucleus collisions at RHIC and proton-nucleus collisions at the LHC. Our results match smoothly at high p⊥ to a next-to-leading order perturbative QCD+NRQCD computation. Excellent agreement is obtained for p⊥ spectra at the RHIC and LHC for central and forward rapidities, as well as for the normalized ratio RpA of these results to spectra in proton-proton collisions. In particular, we observe that the RpA data are strongly bounded by our computations of the same for each of the individual NRQCD channels; this result provides strong evidence that our description is robust against uncertainties in initial conditions and hadronization mechanisms. [ABSTRACT FROM AUTHOR]

We calculate the O(αs³) short-distance, QCD collinear-factorized coefficient functions for all partonic channels that include the production of a heavy quark pair at short distances. This provides the first power correction to the collinear-factorized inclusive hadronic production of heavy quarkonia at large transverse momentum, pT, including the full leading-order perturbative contributions to the production of heavy quark pairs in all color and spin states employed in NRQCD treatments of this process. We discuss the role of the first power correction in the production rates and the polarizations of heavy quarkonia in high-energy hadronic collisions. The consistency of QCD collinear factorization and nonrelativistic QCD factorization applied to heavy quarkonium production is also discussed. [ABSTRACT FROM AUTHOR]

We present a perturbative QCD factorization formalism for inclusive production of heavy quarkonia of large transverse momentum, pT at collider energies, including both leading power (LP) and next-to-leading power (NLP) behavior in pT. We demonstrate that both LP and NLP contributions can be factorized in terms of perturbatively calculable short-distance partonic coefficient functions and universal nonperturbative fragmentation functions, and derive the evolution equations that are implied by the factorization. We identify projection operators for all channels of the factorized LP and NLP infrared safe short-distance partonic hard parts, and corresponding operator definitions of fragmentation functions. For the NLP, we focus on the contributions involving the production of a heavy quark pair, a necessary condition for producing a heavy quarkonium. We evaluate the first nontrivial order of evolution kernels for all relevant fragmentation functions, and discuss the role of NLP contributions. [ABSTRACT FROM AUTHOR]

Induced by three gluons symmetry, Mandelstam variables s, t, u symmetric expressions are widely involved in collider physics, especially in heavy quarkonium physics. In this work we study the general form of s, t, u symmetric polynomials, and find that they can be expressed as polynomials where the symmetry is manifest. The general form is then used to simplify expressions which asymptotically reduces the length of original expression to one-sixth. Based on the general form, we reproduce the exact differential cross section of J/? hadron production at leading order in ν2 up to four unknown constant numbers by simple analysis. Furthermore, we prove that differential cross section at higher order in ν2 is proportional to that at leading order. This proof explains the proportion relation at next-to-leading order in ν2 found in previous work and generalizes it to all order. [ABSTRACT FROM AUTHOR]

With nonrelativistic QCD factorization, we calculate the &ggr;(1S) prompt production at hadron colliders at next-to-leading order in &agr;s. In addition to the color-singlet contribution, color-octet channels (especially the P-wave channel) up to O(&ngr;4) are all considered. Aside from direct production, the feed-down contributions from higher excited S-wave and P-wave b&bmacr; states to &ggr;(15) production are also included. We use the potential model estimates as input for color-singlet long-distance matrix elements (LDMEs). While for color-octet contributions, we find they can be approximately described by three LDMEs: 〈…(3S[8]>1)&rlang;, 〈…(1S[8]>0)&rlang; and 〈…(3S[8]>0)&rlang;. By fitting the Tevatron data we can determine some hnear combinations of these LDMEs, and then use them to predict &ggr;(1S) production at the LHC. Our predictions are consistent with the new experimental data of CMS and LHCb. [ABSTRACT FROM AUTHOR]

A complete next-to-leading-order calculation in αs for the J/ψ and ψ' prompt production at the Tevatron, LHC, and RHIC in nonrelativistic QCD is presented. We argue that the next-to-next-to-leading-order color-singlet contribution may not be so important as to resolve the large discrepancy between theory and experiment in J/ψ large PT production cross sections. Therefore, a complete next-to-leading-order calculation, including both color-singlet and color-octet contribution, is necessary and essential to give a good description for J/ψ and ψ' production. We also study the methods to fit the long-distance matrix elements using either two linear combined matrix elements or three matrix elements, and find these two methods can give consistent results. Compared with the measurements at the LHC and RHIC for prompt J/ψ and ψ' production, our predictions are found to agree with all data. In particular, the recently released large pT data (up to 60-70 GeV) at the LHC are in good agreement with our predictions. Our results imply that the universality of color-octet matrix elements holds approximately in charmonium hadroproduction, when one uses fixed-order perturbative calculation to describe data (the data in small pT region are not included). Our work may provide a new test for the universality of color-octet matrix elements, and the color-octet mechanism in general. [ABSTRACT FROM AUTHOR]

We analytically calculate the cross sections of double charmonium production in e+e- → J/ψ(ψ(2S))χcJ (J = 0, 1, 2) at next-to-leading order (NLO) in αs in nonrelativistic QCD, and confirm factorization of these processes. In contrast to χc0 production, for which the NLO correction is large and positive, the NLO corrections for χc1,2 production can be negative, resulting in decreased K factors of 0.91 and 0.78 for J = 1 and 2, respectively, when μ = 2mc. Consequently, the NLO QCD corrections markedly enlarge the difference between cross sections of χc0 and χc1,2. This may explain why e+e- → J/ψ(ψ(2S))χc0 but not e+e- → J/ψ(ψ(2S))χc1,2 is observed experimentally. Moreover, for J/ψ(ψ(2S))χc1,2, the NLO QCD corrections substantially reduce the μ dependence and lead to predictions with small theoretical uncertainties. [ABSTRACT FROM AUTHOR]

χcJ (J=0, 1, 2) production associated with a charm quark pair in hadron collisions is calculated in the framework of nonrelativistic QCD at the Tevatron and LHC. It is found that the color-singlet contribution is small and the color-octet contribution may be dominant in the large pT region. The differential cross section of pp¯ →χc+cc¯ is at least 1 order of magnitude smaller than the next-to-leading order result of χcJ inclusive production pp¯ → χc+X; therefore χcJ production in pp¯ → χc+cc¯ may have negligible influence on the ratio Rχc=σχc2/σχc1 measured by CDF Collaboration at the Tevatron. The feed-down contribution from χcJ+c+c¯ to J/Ψ+c+c¯ is found to be large compared with J/Ψ direct production and may have important influence on the measurement of J/Ψ+c+c¯. The validity of fragmentation approximation for the process is also discussed. [ABSTRACT FROM AUTHOR]

We study O(αsv2) corrections to decays of 1S0 heavy quarkonium into light hadrons and two photons within the framework of nonrelativistic QCD and find these O(αsv2) corrections to have significant contributions especially for the decay into light hadrons. With these new results, experimental measurements of the hadronic width and the γγ width of ηc can be described more consistently. By fitting experimental data, we find the long-distance matrix elements of ηc to be ∣Rηc(0)∣2=0.834-0.197+0.281??GeV3 and «v2»ηc=0.232-0.098+0.121. Moreover, ηc(2S) is also discussed and the γγ decay width is predicted to be 3.34-2.10+2.06??KeV. [ABSTRACT FROM AUTHOR]

To clarify the outstanding problem in charmonium production that existing theories cannot explain the observed cross sections of χcJ(J=0,1,2) and ratio Rχc=σ c2/σ c1≈0.75 (in contrast to the spin counting value 5/3) at the Tevatron, we study the complete next-to-leading order radiative corrections in nonrelativistic QCD, and find next-to-leading order contributions of 3PJ[1] are more important than leading order at high pT, and 3P1[1] decreases slower than 3P2[1], implying a natural explanation for the Rχc puzzle. By fitting Rχc, the predicted cross sections of χcJ are found to agree with data. The result indicates color-octet contribution is crucially needed, thus providing a unique test for heavy quarkonium production mechanisms. Feed-down contributions of χcJ to prompt J/ψ production are estimated to be substantial, about 30%-40% at pT=20??GeV. Production of χcJ(J=0,1,2) at the LHC is also predicted. [ABSTRACT FROM AUTHOR]

Focuses on a study in which the intrinsic mechanisms among t-norms, t-conorms, negation, CNF, DNF, and axioms are analyzed in two aspects, based on Yin-Yang analysis. Presentation of basic definitions and theorems for t-norms and t-conorms; Discussion on intrinsically mathematical and philosophical principles; Analysis of basic concepts relating to the Boolean system, fuzzy system and uncertain system.

This paper aims to investigate the stability and nonlinear dynamics of an initially curved viscoelastic clamped–clamped pipe conveying pulsatile fluid, with special attention to the non-smooth dynamics of this gyroscopic system under the influence of initial curvature and gravity. In this study, the impacting contact is modeled as a trilinear repulsive force. Based on the Euler–Bernoulli beam theory, the nonlinear governing equations, which take into account geometric, curvature, and damping nonlinearities, are developed using Hamilton's principle. The continuous model is discretized using the Galerkin method and then solved using the arc-length technique and a time integration method. A linear analysis of the natural frequency and complex mode shape shows the unexpected frequency intersection and modal asymmetry. The qualitative changes in the nonlinear dynamics of the impacting pipe in both sub- and super-critical regions are examined and presented in the form of bifurcation diagrams, frequency–amplitude curves, force–amplitude curves, time histories, and phase portraits. Numerical results show that some complex dynamical behaviors can occur in different impact constraint cases, including a grazing bifurcation, sticking, period doubling, and chaos at the impact location, may occur. The initial curvature and gravity result in different behaviors, such as the asymmetry change of the equilibrium configuration and the occurrence of the flutter instability. The current analysis is significant to understand the non-smooth dynamic mechanisms and also provide design and technology guidance for the pipe system with motion-limiting constraints. • A theoretical model is developed for an impacting viscoelastic pipe conveying fluid. • The effects of initial curvature and gravity on vibration characteristics are shown. • Symmetry and asymmetry of the non-smooth vibration characteristics are presented. • Grazing bifurcation, sticking, period doubling, and chaos at impacts are found. • Sensitivity of the nonlinear dynamics to impact constraint parameters are discussed. [ABSTRACT FROM AUTHOR]

The article reports on the increasing number of Chinese students who want to attend U.S. universities as they offer abundant educational opportunities. China only has roughly 2,000 institutions of higher learning which are not sufficient to meet the demands of its 1.3 billion population. The trend has resulted in the emergence of specialist educational organizations as well as English language-training institutions. Exchange programs were launched by Chinese universities with their foreign counterparts.

By simulating the finite temperature magnetized background at the Relativistic Heavy Ion Collider and LHC energies, we systematically study the characteristics of the thermal width and potential of heavy quarkonia. It is found that the magnetic field has less influence on the real potential but has a significant influence on the imaginary potential, especially in the low deconfined temperature. Extracted from the effect of thermal worldsheet fluctuations about the classical configuration, the thermal width of Υ(1S) at the finite temperature magnetized background is investigated. It is found that at the low deconfined temperature the magnetic field can generate a significant thermal fluctuation of the thermal width of Υ(1S), but with the increase of temperature, the effect of magnetic field on the thermal width becomes less important, which means the effect of high temperature completely exceeds that of magnetic field and magnetic field becomes less important at high temperature. The thermal width decreases with the increasing rapidity at the finite temperature magnetized background. It is also observed that the effect of the magnetic field on the thermal width when the dipole is moving perpendicular to the magnetic field is larger than that moving parallel to the magnetic field at Tc2Tc, the effect of magnetic field on the thermal fluctuation is almost the same whether dipole moving perpendicular or parallel to the magnetic field. [ABSTRACT FROM AUTHOR]

The widely used nonrelativistic QCD (NRQCD) factorization theory now encounters some notable difficulties in describing quarkonium production. This may be due to the inadequate treatment of soft hadrons emitted in the hadronization process, which causes bad convergence of velocity expansion in NRQCD. In this paper, starting from QCD we propose a rigorously defined factorization approach, soft gluon factorization (SGF), to better deal with the effects of soft hadrons. After a careful velocity expansion, the SGF can be as simple as the NRQCD factorization in phenomenological studies, but has a much better convergence. The SGF may provide a new insight to understand the mechanisms of quarkonium production and decay. [ABSTRACT FROM AUTHOR]

High-order calculation at the semihard scale in high-energy collisions is very important, but a satisfactory calculation framework is still missing. We propose a systematic method to regularize the rapidity divergence in color glass condensate (CGC) factorization, which makes higher-order calculation rigorous and straightforward. By applying this method to the single hadron production in the pA collision, we find the kinematic constraint effect introduced by hand in previous works comes out automatically, but with different values. The difference is crucial for our next-to-leading-order result to have a smaller theoretical uncertainty compared with leading-order result, which makes the high-order calculation in CGC factorization be useful. As a byproduct, the negativity problem found in the literature can also be overcome in our framework by properly choosing the factorization scale. [ABSTRACT FROM AUTHOR]

High-order calculation at the semihard scale in high-energy collisions is very important, but a satisfactory calculation framework is still missing. We propose a systematic method to regularize the rapidity divergence in color glass condensate (CGC) factorization, which makes higher-order calculation rigorous and straightforward. By applying this method to the single hadron production in the pA collision, we find the kinematic constraint effect introduced by hand in previous works comes out automatically, but with different values. The difference is crucial for our next-to-leading-order result to have a smaller theoretical uncertainty compared with leading-order result, which makes the high-order calculation in CGC factorization be useful. As a byproduct, the negativity problem found in the literature can also be overcome in our framework by properly choosing the factorization scale. [ABSTRACT FROM AUTHOR]

By introducing an auxiliary parameter, we find a new representation for Feynman integrals, which defines a Feynman integral by analytical continuation of a series containing only vacuum integrals. The new representation therefore conceptually translates the problem of computing Feynman integrals to the problem of performing analytical continuations. As an application of the new representation, we use it to construct a novel reduction method for multiloop Feynman integrals, which is expected to be more efficient than the known integration-by-parts reduction method. Using the new method, we successfully reduced all complicated two-loop integrals in the gg → HH process and gg → ggg process. [ABSTRACT FROM AUTHOR]

Heavy flavor measurements in high multiplicity proton-proton and proton-nucleus collisions at collider energies enable unique insights into their production and hadronization mechanism because experimental and theoretical uncertainties cancel in ratios of their cross sections relative to minimum bias events. We explore such event engineering using the color glass condensate (CGC) effective field theory to compute short-distance charmonium cross sections. The CGC is combined with heavy-quark fragmentation functions to compute D-meson cross sections; for the J/ψ, hadronization is described employing nonrelativistic QCD (NRQCD) and an improved color evaporation model. Excellent agreement is found between the CGC computations and the LHC heavy flavor data in high multiplicity events. Event engineering in this CGC+NRQCD framework reveals a very rapid growth in the fragmentation of the ³S[8]1 state in rare events relative to minimum bias events. [ABSTRACT FROM AUTHOR]

Parton distribution functions (PDFs) are nonperturbative quantities describing the relation between a hadron and the quarks and gluons within it. We propose to extract PDFs from QCD global analysis of "data" generated by lattice QCD calculations of good "lattice cross sections," which are basically single-hadron matrix elements that are lattice QCD calculable and perturbative QCD factorizable into the PDFs. To demonstrate the existence of good "lattice cross sections," we take quasiquark distribution introduced by Ji [Phys. Rev. Lett. 110, 262002 (2013)] as a case study to show that it could be factorized into the PDFs to all orders in perturbation theory if it can be multiplicatively renormalized. We calculate the factorized coefficients at the next-to-leading order in αs. [ABSTRACT FROM AUTHOR]

Fragmentation is the dominant mechanism for hadron production with high transverse momentum. For spin-triplet S-wave heavy quarkonium production, contribution of gluon fragmenting to color-singlet channel has been numerically calculated since 1993. However, there is still no analytic expression available up to now because of its complexity. In this paper, we calculate both polarization-summed and polarized fragmentation functions of gluon fragmenting to a heavy quark-antiquark pair with quantum number ³S1[1]. Our calculations are performed in two different frameworks. One is the widely used nonrelativistic QCD factorization, and the other is the newly proposed soft gluon factorization. In either case, we calculate at both leading order and next-to-leading order in velocity expansion. All of our final results are presented in terms of compact analytic expressions. [ABSTRACT FROM AUTHOR]

Quasiparton distribution functions have received a lot of attention in both the perturbative QCD and lattice QCD communities in recent years because they not only carry good information on the parton distribution functions but also could be evaluated by lattice QCD simulations. However, unlike the parton distribution functions, the quasiparton distribution functions have perturbative ultraviolet power divergences because they are not defined by twist-2 operators. In this paper, we identify all sources of ultraviolet divergences for the quasiparton distribution functions in coordinate space and demonstrate that power divergences as well as all logarithmic divergences can be renormalized multiplicatively to all orders in QCD perturbation theory. [ABSTRACT FROM AUTHOR]

We propose an improved version of the color evaporation model to describe heavy quarkonium production. In contrast to the traditional color evaporation model, we impose the constraint that the invariant mass of the intermediate heavy quark-antiquark pair be larger than the mass of produced quarkonium. We also introduce a momentum shift between the heavy quark-antiquark pair and the quarkonium. Numerical calculations show that our model can describe the charmonium yields as well as the ratio of ψ ′ over J / ψ better than the traditional color evaporation model. [ABSTRACT FROM AUTHOR]

• The wing-wing interaction of normal tandem foils is detrimental to lifting capacity. • Modifying the deviation distance of the fore foil can enhance the overall lift generation. • The lift enhancement originates from the vortex interaction between both foils. • The lift enhancement is valid when the inter-foil gap is below 2 chord length. Dragonfly-like flapping wings and foils take an in-line arrangement and their performance is strongly affected by the wing–wing interaction. In this study of tandem pitching-plunging foils, the effects of flapping deviation on the hovering performance are studied numerically. A two-dimensional model is established, and the flapping deviation is represented by the non-dimensional deviation distance Δ L/c , the effects of which are investigated, together with those of the phase angle φ in plunging motion and the non-dimensional inter-foil spacing G / c. In the hovering status, our results support that the wing–wing interaction at Δ L/c = 0 is detrimental to the lifting capacity of tandem pitching-plunging foils. More importantly, we prove that a modification of Δ L/c in which the fore foil is below the hind foil during hovering can compensate for the loss of lift and may even provide a lift greater than that generated by a single foil. The mechanism of this compensation is dependent on the interaction between the wake vortices of the fore foil and the leading-edge vortex of the hind foil. Our results also indicate that the effects of Δ L/c and φ are coupled. The lift enhancement by a negative Δ L/c is maintained within the ranges φ = 45°–90° and G / c <2, beyond which an abrupt drop may occur. These findings suggest that the control of flapping deviation may enhance the performance of dragonfly-like micro air vehicles. [ABSTRACT FROM AUTHOR]

The emergence of optical micro- or nanofibers (MNFs) with subwavelength diameter, which have ultralight mass and an intense light field, provides an opportunity for developing fiber-based optomechanical systems. In this study we show theoretically an optomechanical effect in silica MNF Bragg gratings (MNFBGs). The light-induced mechanical effect results in continuously distributed strain along the grating and the power-related strain introduces an optically reconfigurable chirp in the grating period. We develop optomechanical coupled-mode equations and analyze theoretically the influence of the optical-force-induced nonlinearity and chirp on the grating performance. Compared with the weak Kerr effect, the optomechanical effect dominates in the properties' evolution of MNFBGs. Significant group-velocity reduction and switching effect have been demonstrated theoretically at medium power level. This kind of optomechanical MNFBG with optically reconfigurable chirp may offer a path toward an all-optical tunable bandwidth of Bragg resonance and may lead to useful applications such as all-optical switching, optically controlled dispersion, and slow or fast light. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we present a genetic fuzzy feature transformation method for support vector machines (SVMs) to do more accurate data classification. Given data are first transformed into a high feature space by a fuzzy system, and then SVMs are used to map data into a higher feature space and then construct the hyperplane to make a final decision. Genetic algorithms are used to optimize the fuzzy feature transformation so as to use the newly generated features to help SVMs do more accurate biomedical data classification under uncertainty. The experimental results show that the new genetic fuzzy SVMs have better generalization abilities than the traditional SVMs in terms of prediction accuracy. [Copyright &y& Elsevier]

Using the guage/gravity correspondence, we study the free energy, entropy, binding energy, and internal energy of a heavy quarkonium in the rotating quark-gluon plasma (QGP). First, we extend the static black hole with planar horizon to the spinning case, which is dual to the rotating matter. Subsequently, we use the Wilson loop to get the free energy of heavy quarkonium. Entropy, binding energy, and internal energy are naturally given by the thermodynamic relationship. It is found that angular velocity will suppress the dissociation temperature of heavy quarkonium and change the system from confined to deconfined phase with the increase of angular velocity. Thus, the heavy quarkonium will dissolve at a certain separating distance in the deconfined phase. We also compare these thermodynamic quantities of the quark-antiquark pair in the direction parallel and transverse to the rotation direction. At last, the free energy, entropy, and internal energy of a single quark are discussed. It is found that these quantities are decreasing functions of temperature. [ABSTRACT FROM AUTHOR]

We study the effect of magnetic field on heavy quark-antiquark pair in both Einstein-Maxwell (EM) and Einstein-Maxwell-dilaton (EMD) model. The interquark distance, free energy, entropy, binding energy, and internal energy of the heavy quarkonium are calculated. It is found that the free energy suppresses and the entropy increases quickly with the increase of the magnetic field B. The binding energy vanishes at smaller distance when increasing the magnetic field, which indicates the quark-antiquark pair dissociates at smaller distance. The internal energy which consists of free energy and entropy will increase at large separating distance for a nonvanishing magnetic field. These conclusions are consistent both in the EM and EMD model. Moreover, we also find that the quarkonium will dissociate easier in the parallel direction than that in the transverse direction for EMD model, but the conclusion is opposite in EM model. Lattice results are in favor of EMD model. Besides, a Coulomb-plus-linear potential (Cornell potential) can be realized only in EMD model. Thus, a dilaton field is proved to be important in holographic model. Finally, we also show that the free energy, entropy, and internal energy of a single quark in EMD model with the presence of magnetic field. [ABSTRACT FROM AUTHOR]

With the QCD sum rules approach, we study the newly discovered doubly heavy baryon Ξcc++. We analytically calculate the next-to-leading-order (NLO) contribution to the perturbative part of the JP = 1/2+ baryon current with two identical heavy quarks, and then reanalyze the mass of Ξcc++ at the NLO level. We find that the NLO correction significantly improves both scheme dependence and scale dependence, whereas it is hard to control these theoretical uncertainties at leading order. With the NLO contribution, the baryon mass is estimated to be mΞcc++ = 3.66-0.10+0.08 GeV, which is consistent with the LHCb measurement. [ABSTRACT FROM AUTHOR]

Oryzaeins A–D (1-4), four new isocoumarin derivatives, along with five known ones (5-9) were isolated from solid cultures of an endophytic fungus Aspergillus oryzae. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data of related derivatives. Among them, compounds 1 and 2 represent the first examples of isocoumarins possessing an unusual 2-oxopropyl group and a rare 3-hydroxypropyl group. Compounds 1 and 2 displayedmoderate anti-tobacco mosaic virus activities with inhibition rates of 28.4% and 30.6%, respectively, at the concentration of 20 μM. The new compounds showed moderate inhibitory activities against several human tumor cell lines with IC50 values in the range of 2.8-8.8 μM. [ABSTRACT FROM AUTHOR]

Versicolactones A-D (1-4), four new butyrolactones, along with four known butyrolactones (5-8) were isolated from the fermentation products of the endophytic fungus Aspergillus versicolor. The structures of compounds 1-4, including absolute configuration, were elucidated by interpretation of the NMR and CD data. Compound 2 was further confirmed by single-crystal X-ray diffraction analysis. In particular, compound 1 is the first naturally occurring butyrolactone possessing an unusual 2-oxopropyl group. More importantly, compounds 1 and 8 displayed significant antitobacco mosaic virus activities with inhibition rates of 46.4% and 35.4%, even more potent than the positive control ningnanmycin (30.8%). Compound 1 also showed moderate cytotoxicity against A549 and MCF7 cells with IC50 values of 3.2 and 2.5 μM, respectively. [ABSTRACT FROM AUTHOR]

The ultrashort-range force, ihe van der Waals force (VWF), rises rapidly when one nanoscale waveguide (NW) is close to another one, and is stronger than the external transverse gradient force. We theoretically investigate the great influence of the VWF on the device performance in a typical NW optomechanical system consisting of a suspended silicon waveguide and a silica substrate including waveguide deformation stiction and failure mechanism. The device shows unique optically activated plastic and elastic behaviors and stiction due to the VWF. When the input optical power is above the critical power, the waveguide is sticking to the substrate and the deformation is plastic and unrecoverable, even though the total force is less than the yield strength of the waveguide material. This is important and helpful for the design and applications of optomechanical devices. [ABSTRACT FROM AUTHOR]

We propose and investigate the quasi-phase-matched (QPM) nonlinear optical frequency conversion of optical vortices in periodically poled lithium niobate. Laguerre-Gaussian (LG) modes are used to represent the orbital angular momentum (OAM) states, characterized with the azimuthal and radial indices. Typical three-wave nonlinear interactions among the involved OAM modes are studied with the help of coupling wave equations. Being different from normal QPM process where the energy and quasimomentum conservations are satisfied, both of the azimuthal and radial indices of the OAM states stay constant in most of the cases. However, abnormal change of the radial index is observed when there is asynchronous nonlinear conversion in different parts of the beams. The QPM nonlinear evolution of fractional OAM states is also discussed showing some interesting properties. In comparison with the traditional birefringent phase matching, the QPM technique avoids the undesired walk-off effect to reserve high-quality LG modes. We believe the QPM is an effective way to convert, amplify, and switch OAM states in various optical vortex related applications. [ABSTRACT FROM AUTHOR]

We extract the pion valence quark distribution qπv(x) from lattice QCD (LQCD) calculated matrix elements of spacelike correlations of one vector and one axial vector current analyzed in terms of QCD collinear factorization, using a new short-distance matching coefficient calculated to one-loop accuracy. We derive the Ioffe time distribution of the two-current correlations in the physical limit by investigating the finite lattice spacing, volume, quark mass, and higher-twist dependencies in a simultaneous fit of matrix elements computed on four gauge ensembles. We find remarkable consistency between our extracted qvπ(x) and that obtained from experimental data across the entire x range. Further, we demonstrate that the one-loop matching coefficient relating the LQCD matrix computed in position space to the qvπ(x) in momentum space has well-controlled behavior with Ioffe time. This justifies that LQCD-calculated current-current correlations are good observables for extracting partonic structures by using QCD factorization, which complements to the global effort to extract partonic structure from experimental data. [ABSTRACT FROM AUTHOR]

Photons with complicated spatial mode structures can be applied for different quantum information tasks. Here, we show the entanglement of photons with complex singularity patterns called Hermite-Laguerre-Gaussian (HLG) modes. Measuring one photon of the entangled pairs by HLG mode basis to define its singularity pattern, we can steer the singularity structure of its partner, while the initial singularity structure of the photons is undefined. We also calculate the HLG specific quantum-correlation function. It can be used to extend the quantum key distribution protocols and to tune experiments dealing with high-order transverse modes. In addition we discuss orbital angular momentum properties of the HLG modes and summarize some features of the singularity pattern of the HLG modes with varying angle parameter. [ABSTRACT FROM AUTHOR]