CERN Document Server

A significant asymmetry in baryon/antibaryon yields in the central region of high energy collisions is observed when the initial state has non-zero baryon charge. This asymmetry is connected with the possibility of a baryon charge diffusion in rapidity space. Evidently, such a diffusion should decrease the baryon charge in the fragmentation region leading to the corresponding decrease of the multiplicity of leading baryons. As a result, a new mechanism for Feynman scaling violation in the fragmentation region is obtained. We present the quantitative predictions for the Feynman scaling violation at LHC energies and even at highier energies that can be important for cosmic ray physics.

International Nuclear Information System (INIS)

Counter rotating longitudinal vortices produced by winglet in a channel are known to enhance heat transfer. In the present investigation the flow structure and heat-transfer enhancement by a winglet pair of non-zero thickness has been studied. A delta winglet pair type vortex generator is placed in a hydrodynamically developed and thermally developing laminar channel flow. Computations are done by solving the unsteady, three-dimensional, incompressible Navier-Strokes equations and energy equation using a modified Marker-and-Cell (MAC) method. The flow structure is complex and consists of main, corner and induced vortices. It is observed that as compared to a channel without winglets, the heat transfer is enhanced by 33% when single winglet is used and by 67% when a winglet pair is employed. Effects of thickness of the winglets and Reynolds number on the heat transfer augmentation are presented.

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$\\gamma/\\phi_3$ at hadron colliders

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A survey is given on the present status of the nucleon parton distributions and related precision calculations and precision measurements of the strong coupling constant {alpha}{sub s}(M{sup 2}{sub Z}). We also discuss the impact of these quantities on precision observables at hadron colliders. (orig.)

CERN Document Server

We consider the role of quantum effects in the transfer of hyrogen-like species in enzyme-catalysed reactions. This study is stimulated by claims that the observed magnitude and temperature dependence of kinetic isotope effects imply that quantum tunneling below the energy barrier associated with the transition state significantly enhances the reaction rate in many enzymes. We use a path integral approach which provides a general framework to understand tunneling in a quantum system which interacts with an environment at non-zero temperature. Here the quantum system is the active site of the enzyme and the environment is the surrounding protein and water. Tunneling well below the barrier only occurs for temperatures less than a temperature $T_0$ which is determined by the curvature of potential energy surface near the top of the barrier. We argue that for most enzymes this temperature is less than room temperature. For physically reasonable ...

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The paper describes an application of the tree classification method Random Forest (RF), as used in the analysis of data from the ground-based gamma telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to be discriminated against a dominating background of hadronic cosmic-ray particles. We describe the application of RF for this gamma/hadron separation. The RF method often shows superior performance in comparison with traditional semi-empirical techniques. Critical issues of the method and its implementation are discussed. An application of the RF method for estimation of a continuous parameter from related variables, rather than discrete classes, is also discussed.

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Quark-hadron duality and its potential applications are discussed. We focus on theoretical efforts to model duality.

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The authors analyze the consequences of models of structure formation for higher-order (n-point) galaxy correlation functions in the mildly non-linear regime. Several variations of the standard {Omega} = 1 cold dark matter model with scale-invariant primordial perturbations have recently been introduced to obtain more power on large scales, R{sub p} {approximately}20 h{sup {minus}1} Mpc, e.g., low-matter-density (non-zero cosmological constant) models, {open_quote}tilted{close_quote} primordial spectra, and scenarios with a mixture of cold and hot dark matter. They also include models with an effective scale-dependent bias, such as the cooperative galaxy formation scenario of Bower, et al. The authors show that higher-order (n-point) galaxy correlation functions can provide a useful test of such models and can discriminate between models with true large-scale power in the density field and those where the galaxy power arises from scale-dependent bias: a bias with ...

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We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process {gamma}{gamma} {yields} ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f{sub 2}(1270) meson.

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The author notes that if hadrons are gravitationally stabilized ``black holes``, as discrete physics suggests, it is possible that partons, and in particular quarks, could be modeled as tachyons, i.e. particles having v{sup 2} > c{sup 2}, without conflict with the observational fact that neither quarks nor tachyons have appeared as ``free particles``. Some consequences of this model are explored.

International Nuclear Information System (INIS)

The optical absorption of the Tm"3"+ ion in the gadolinium oxychloride (GdOCl) matrix in the UV, visible, and NIR range was studied at temperatures between 9 and 300 K. The visible luminescence of GdOCl:Tm"3"+ under Ar"+ ion laser and mercury lamp excitation was recorded at 9, 77, and 300 K, too. The crystal field (CF) splitting of the "3H_4_-_6, "3F_2_-_4, "1G_4, "1D_2, and "1I_6 levels of the Tm"3"+ ion deduced from the spectra was analysed according to the C_4_v point symmetry of the RE"3"+ site. The resulting energy level scheme, consisting of 39 levels (i.e. 55 Stark components) out of the total of 70 (91) for the whole 4f"1"2 configuration, was simulated with the aid of a phenomenological theory taking simultaneously into account both the free-ion and CF effects. The model included 13 adjustable parameters describing the electrostatic (the Racah parameters E_0_-_3) and the configuration interaction (the Trees parameters #alpha#, #beta#, and #gamma#) as well as the spin-orbit ...

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Quark-hadron duality addresses some of the most fundamental issues in strong interaction physics, in particular the nature of the transition from the perturbative to non-perturbative regions of QCD. I summarize recent developments in quark-hadron duality in lepton-hadron scattering, and outline how duality can be studied at future high-luminosity facilities such as Jefferson Lab at 12 GeV, or an electron-hadron collider such as EPIC.

CERN Document Server

multi-parton interactions and underlying event structure, $\\gamma$-mediated processes and luminosity determination, Monte Carlo tuning and even MSSM Higgs discovery in central exclusive production. In this article, the forward detector instrumentation around the CMS interaction point is described and the prospects for diffractive and forward physics using the CMS forward detectors are summarized. In addition, first observation of forward jets as well as early measurements of the forward energy flow in the pseudorapidity range $3.15

International Nuclear Information System (INIS)

The geodesic equation for space-like objects moving along a circular trajectory in the expanding universe is considered. Our analysis leads to the conclusion that ancient cosmological tachyons may exist in the present-day world and may play an important role in (i) the internal structure of hadrons conceived as nonlocal objects called strings, (ii) the T-symmetry violation observed in the weak K-decays, (iii) the multidimensional unified field theories of Kaluza-Klein type, and in (iv) the classical models of charged particles which combine ordinary electromagnetism with a self-interacting version of Newtonian gravity. 18 refs.

CERN Document Server

The study of flavor changing neutrinos is a very active field of research. I will discuss the status of ongoing and near term experiments investigating neutrino properties at short distances from the source. In the next few years, the Double Chooz, RENO and Daya Bay reactor neutrino experiments will start looking for signatures of a non-zero value of the mixing angle $\\theta_{13}$ with much improved sensitivities. The MiniBooNE experiment is investigating the LSND anomaly by looking at both the $\

International Nuclear Information System (INIS)

After some preliminary comments on prevailing attitudes about tachyons, the author discusses superluminal transformations and the electromagnetic properties of tachyons. Their role in quantum mechanics is examined and a relativistically invariant hadron bootstrap model, which appears to account for many hadron states, is presented. (W.D.L).

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The current status of rare B decays is reviewed based on recent observation of the penguin-diagram decay B {yields} K{sup *}{gamma} at CLEO. Rare B decays provide valuable information on the Standard Model parameters, and also could be a source of direct CP violation. It is emphasized that new physics beyond the Standard Model can appear in rare B decays, in some cases more drastically than in the CP Asymmetry of the B system. Inclusive measurement of the radiative transition b {yields} s{gamma} is promising. Hadronic penguin modes are very close to being observed at CLEO, and a discovery might be just around the corner. (author). 48 refs., 6 figs., 4 tabs.

Science.gov (United States)

... PHYSICS ATOMIC AND MOLECULAR PHYSICS AND SPECTROSCOPY NUCLEAR PHYSICS & ELEMENTARY PARTICLE PHYSICS. ...

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We evaluate the sphere level S-matrix element of two tachyons and two massless NS states, the S-matrix element of four tachyons, and the S-matrix element of two tachyons and two Ramond-Ramond vertex operators, in type 0 theory. We then find an expansion for theses amplitudes that their leading order terms correspond to a covariant tachyon action. To the order considered, there are no T4, T2(-bar T)2, T2H2, nor T2R tachyon couplings, whereas, the tachyon couplings FF-bar T and T2F2 are non-zero.

CERN Document Server

Associated production of a baryonic Z' boson with the W boson can account for the excess in Wjj production observed by the CDF collaboration at the Tevatron. We analyze other possible channels of this Z' at the Tevatron and at the LHC, including \\gamma Z' and Z Z' with the Z' -> jj. We show that the chances of confirming this baryonic Z' is better at the Tevatron than at the LHC because of the faster growing backgrounds at the LHC. Unfortunately the current systematic uncertainties of the order of 10% cannot yield any significant excess in both \\gamma Z' and Z Z' channels at the Tevatron and also at the LHC. Nevertheless the search using the b\\bar b decay mode of Z' is much more feasible at the LHC, provided that the branching ratio B(Z' -> b\\bar b) > 0.1. In particular, the W Z' -> l \

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This Report includes copies of transparencies and notes from the presentations made at the Center for Accelerator Physics at Brookhaven National Laboratory Editing and changes to the authors` contributions in this Report were made only to fulfill the publication requirements. This volume includes notes and transparencies on nine presentations: ``The Energy Exchange and Efficiency Consideration in Klystrons``, ``Some Properties of Microwave RF Sources for Future Colliders + Overview of Microwave Generation Activity at the University of Maryland``, ``Field Quality Improvements in Superconducting Magnets for RHIC``, ``Hadronic B-Physics``, ``Spiking Pulses from Free Electron Lasers: Observations and Computational Models``, ``Crystalline Beams in Circular Accelerators``, ``Accumulator Ring for AGS & Recent AGS Performance``, ``RHIC Project Machine Status``, and ``Gamma-Gamma Colliders.``

CERN Document Server

An analysis of the cross section for hadronic production of gluino-squark pairs close to threshold is presented. Within the framework of non-relativistic QCD a significant enhancement compared to fixed order perturbation theory is observed which originates from the characteristic remnants of the gluino-squark resonances below the nominal pair threshold. The analysis includes all colour configurations of S-wave gluino-squark pairs, i.e. triplet, sextet and 15 representation. Matching coefficients at leading order are separately evaluated for all colour configurations. The dominant QCD corrections, arising from initial- and final-state radiation are included. The non-relativistic dynamics of the gluino pair is solved by calculating the Green's function in Next-to-Leading Order (NLO). The results are applied to benchmark scenarios, based on Snowmass Points and Slopes (SPS). As a consequence of the large decay rate of at least one of the ...

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The authors report the observation of B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations from a time-dependent measurement of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillation frequency {Delta}m{sub s}. Using a data sample of 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, they find signals of 5600 fully reconstructed hadronic B{sub s} decays, 3100 partially reconstructed hadronic B{sub s} decays, and 61,500 partially reconstructed semileptonic B{sub s} decays. They measure the probability as a function of proper decay time that the B{sub s} decays with the same, or opposite, flavor as the flavor at production, and they find a signal for B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10{sup -8}, which exceeds 5{sigma} significance. They measure {Delta}m{sub s} = ...

International Nuclear Information System (INIS)

I present results for the mass spectrum of excited baryons and pentaquarks using overlap fermions and Bayesian curve-fitting method; and magnetic moments and polarizabilities for a variety of hadrons in the background field method.

CERN Document Server

Being able to distinguish light-quark jets from gluon jets on an event-by-event basis could significantly enhance the reach for many new physics searches at the Large Hadron Collider. Through an exhaustive search of existing and novel jet substructure observables, we find that a multivariate approach can filter out over 95% of the gluon jets while keeping more than half of the light-quark jets. Moreover, a combination of two simple variables, the charge track multiplicity and the pT-weighted linear radial moment (girth), can achieve similar results. While this pair appears very promising, our study is only Monte Carlo based, and other discriminants may work better with real data in a realistic experimental environment. To that end, we explore many other observables constructed using different jet sizes and parameters, and highlight those that deserve further theoretical and experimental scrutiny. Additional information, ...

International Nuclear Information System (INIS)

We investigate the possibility of kaon condensation in the dense interior of neutron stars through the s-wave interaction of kaons with nucleons. We include nucleon-nucleon interactions by using simple parametrizations of realistic forces, and include electrons and muons in #beta#-equilibrium. The equation of state above the condensate threshold is derived in the mean field approximation. The conditions under which kaon condensed cores undergo a transition to quark matter containing strange quarks are also established.The critical density for kaon condensation lies in the range (2.3-5.0)#rho#_0, where #rho#_0=0.16 fm"-"3 is the equilibrium density of nuclear matter. The critical density depends largely on the value of the strangeness content of the proton, the size of which is controversial. For too large a value of the strangeness content, matter with a kaon condensate is not sufficiently stiff to support the lower limit of 1.44 M_o_e_d_o_t for a neutron star. Kaon condensation ...

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This thesis describes hadron reconstruction at the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN, Geneva. The focus is on the particle flow reconstruction of these objects. This thesis revisits the subject of the CMS calorimeters' non-linear response to hadrons. Data from testbeam experiments conducted in 2006 & 2007 is compared with simulations and substantial differences are found. A particle flow calibration to correct the energy response of the testbeam data is evaluated. The reconstructed jet response is found to change by ~ 5% when a data-driven calibration is used in place of the calibration derived from simulation. Collision data taken at the early stage of CMS' commissioning is also presented. The hadron response in data is determined to be compatible with testbeam results presented in this thesis. This thesis also details the use of neural networks to ...

CERN Document Server

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These moments back-react on the trajectories of the expectation values of the state and hence alter the energy density at the bounce. This analysis is performed for isotropic loop quantum cosmology coupled to a scalar field with a small but non-zero constant potential, hence in a regime in which the kinetic energy of matter dominates. Analytic restrictions on the existence of dynamical coherent states and the meaning of semi-classicality within these systems are discussed. A numerical investigation of the trajectories of states that remain semi-classical across the bounce demonstrates that, at least for such states, the bounce persists and that its properties are similar to the standard case, in which the moments of the states are ...

International Nuclear Information System (INIS)

The spectroscopic properties of Pr"3"+ doping two lanthanum chlorotungstate hosts: the orthorhombic LaWO4Cl (1-1) and the hexagonal La3WO4Cl6 (3-1), as well as those of PrWO4Cl and Pr3wO613 have been investigated. The simulations of the energy level schemes are carried out within the crystal field theory frame. Each simulation involves 7 free ion parameters and 14 non-zero crystal field parameters (cfps), corresponding to the C_s point symmetry of the site occupied by the rare earth, in both structures.

CERN Document Server

General relativity postulates the Minkowski space-time to be the standard flat geometry against which we compare all curved space-times and the gravitational ground state where particles, quantum fields and their vacuum states are primarily conceived. On the other hand, experimental evidences show that there exists a non-zero cosmological constant, which implies in a deSitter space-time, not compatible with the assumed Minkowski structure. Such inconsistency is shown to be a consequence of the lack of a application independent curvature standard in Riemann's geometry, leading eventually to the cosmological constant problem in general relativity. We show how the curvature standard in Riemann's geometry can be fixed by Nash's theorem on locally embedded Riemannian geometries, which imply in the existence of extra dimensions. The resulting gravitational theory is more general than general relativity, similar to brane-world gravity, but where the propagation of the ...

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We study the ground state of an ideal coupled two-component gas of ultracold atoms in a one dimensional optical lattice, either bosons or fermions. Due to the internal two-level structure of the atoms, the Brillouin zone is twice as large as imposed by the periodicity of the lattice potential. This is reflected in the Bloch dispersion curves, where the energy bands regularly possess several local minima. As a consequence, when the system parameters are tuned across a resonance condition, a non-zero temperature topological first order phase transition occurs which arises from an interplay between initernal and kinetic atomic energies. It is shown that these phenomena are also captured for two and three dimensional optical lattices.

International Nuclear Information System (INIS)

Conditions for the construction of polynomial eigen-operators for the Hamiltonian of collective string field theories are explored. Such eigen-operators arise for only one monomial potential v(x)=#mu#x"2 in the collective field theory. They form a w_#infinity#-algebra isomorphic to the algebra of vertex operators in 2d gravity. Polynomial potentials of orders only strictly larger or smaller than 2 have no non-zero-energy polynomial eigen-operators. This analysis leads us to consider a particular potential #nu#(x)=#mu#x"2+g/x"2. A Lie algebra of polynomial eigen-operators is then constructed for this potential. It is a symmetric 2-index Lie algebra, also represented as a subalgebra of U(sl(2)). (orig.).

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The authors present a search for excited and exotic muon states {mu}*, conducted using an integrated luminosity of 371 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron with the CDF II detector. They search for associated production of {mu}{mu}* followed by the decay {mu}* {yields} {mu}{gamma}, resulting in the {mu}{mu}{gamma} final state. They compare the data to model predictions as a function of the mass of the excited muon M{sub {mu}*}, the compositeness energy scale {Lambda}, and the gauge coupling factor f. No signal above the standard model expectation is observed in the {mu}{gamma} mass spectrum. In the contact interaction model, they exclude 107 < M{sub {mu}*} < 853 GeV/c{sup 2} for {Lambda} = M{sub {mu}*}; in the gauge-mediated model, they exclude 100 < M{sub {mu}*} < 410 GeV/c{sup 2} for f/{Lambda} = 10{sup -2} GeV{sup -1}. These 95% confidence level exclusions extend previous limits ...

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The availability of new, high-intensity, cold and thermal neutron sources has opened the possibility of performing high-precision fundamental neutron physics experiments, including measurements that study the hadronic weak interaction and standard model test measurements, using neutron decay. The observables in these experiments are usually correlated with the direction of neutron polarization and are often very small (10 8 10 6). Mott-Schwinger scattering of polarized neutrons can produce spin-dependent shifts in beam centroids, which has the potential to produce significant systematic effects for these types of experiments. An accurate calculation of this process for neutral atoms and basic molecules has not been carried out for low neutron energies. In this work, we derive a general expression for the electromagnetic (Mott-Schwinger) contributions to the analyzing power for low-energy neutron scattering. We obtain numerical results for 11 ...

CERN Document Server

We consider the possibility of "Higgs counterfeits" - scalars that can be produced with cross sections comparable to the SM Higgs, and which decay with identical relative observable branching ratios, but which are nonetheless not responsible for electroweak symmetry breaking. We also consider a related scenario involving "Higgs friends," fields similarly produced through gg fusion processes, which would be discovered through diboson channels WW, ZZ, gamma gamma, or even gamma Z, potentially with larger cross sections times branching ratios than for the Higgs. The discovery of either a Higgs friend or a Higgs counterfeit, rather than directly pointing towards the origin of the weak scale, would indicate the presence of new colored fields necessary for the sizable production cross section (and possibly new colorless but electroweakly charged states as well, in the case of the diboson decays of a Higgs friend). These particles could easily be confused for an ordinary ...

International Nuclear Information System (INIS)

We summarize the predictions of different models for total #gamma##gamma# cross-sections. The experimentally observed rise of #sigma#_#gamma#_#gamma# with s radical _#gamma#_#gamma#, faster than that for #sigma#_p_-_b_a_r_p, #sigma#_#gamma#_p is in agreement with the predictions of the Eikonalized Minijet Models as opposed to those of the Regge-Pomeron models. We then show that a measurement of #sigma#_#gamma#_#gamma# with an accuracy of < or approx. 8-9% (6-7%) is necessary to distinguish among different Regge-Pomeron type models (the different parameterisations of the EMM models) and a precision of < or approx. 20% is required to distinguish the predictions of the EMMs and of those models which treat 'photon like a proton', for the energy range 300< s radical_#gamma#_#gamma# <500 GeV. We further show that the difference in model predictions for #sigma#_#gamma#_#gamma# of about a factor 2 at s radical _#gamma#_#gamma# = 700 GeV reduces to #approx# 30% ...

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This report discusses the following topics: study of Z{sup 0} decays; QCD; new particles; Higgs bosons; and forward hadron calorimeter system.

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I report on a lattice computation of the energy of a system of two light quarks and two static antiquarks as a function of the separation of the static antiquarks. In terms of hadrons such a system corresponds to a pair of B mesons and its energy to the hadronic potential. I present selected results for different isospin, spin and parity combinations of the individual B mesons mainly focusing on those channels relevant to determine, whether two B mesons may form a bound tetraquark state.

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Using data collected with the BESII detector at $e^{+}e^{-}$ storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo suppressed hadronic weak decays $D^0 \\to K^- K^+$, $\\pi^+ \\pi^-$, $K^- K^+ \\pi^+ \\pi^-$ and $\\pi^+ \\pi^+ \\pi^- \\pi^-$, $D^+ \\to \\bar{K^0} K^+$, $K^- K^+ \\pi^+$ and $\\pi^- \\pi^+ \\pi^+$ are presented.

CERN Document Server

This paper deals with the computation of sectional curvature for the manifolds of~$N$ landmarks (or feature points) in~$D$ dimensions, endowed with the Riemannian metric induced by the group action of diffeomorphisms. The inverse of the metric tensor for these manifolds (i.e.~the cometric), when written in coordinates, is such that each of its elements depends on at most~$2D$ of the~$ND$ coordinates. This makes the matrices of partial derivatives of the cometric very sparse in nature, thus suggesting solving the highly non-trivial problem of developing a formula that expresses sectional curvature in terms of the cometric and its first and second partial derivatives (we call this Mario's formula). We apply such formula to the manifolds of landmarks and in particular we fully explore the case of geodesics on which only two points have non-zero momenta and compute the sectional curvatures of 2-planes spanned by the tangents to such geodesics. The latter example gives ...

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We consider the most general supersymmetric model with minimal particle content and an additional discrete Z_3 symmetry (instead of R-parity), which allows lepton number violating terms and results in non-zero Majorana neutrino masses. We investigate whether the currently measured values for lepton masses and mixing can be reproduced. We set up a framework in which Lagrangian parameters can be initialised without recourse to assumptions concerning trilinear or bilinear superpotential terms, CP-conservation or intergenerational mixing and analyse in detail the one loop corrections to the neutrino masses. We present scenarios in which the experimental data are reproduced and show the effect varying lepton number violating couplings has on the predicted atmospheric and solar mass^2 differences. We find that with bilinear lepton number violating couplings in the superpotential of the order 1 MeV the atmospheric mass scale can be reproduced. Certain trilinear ...

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This paper addresses the problem of blind separation of convolutive mixtures of BPSK and circular linearly modulated signals with unknown (and possibly different) baud rates and carrier frequencies. In previous works, we established that the Constant Modulus Algorithm (CMA) is able to extract a source from a convolutive mixture of circular linearly modulated signals. We extend the analysis of the extraction capabilities of the CMA when the mixing also contains BPSK signals. We prove that if the various source signals do not share any non zero cyclic frequency nor any non conjugate cyclic frequencies, the local minima of the constant modulus cost function are separating filters. Unfortunately, the minimization of the Godard cost function generally fails when considering BPSK signals that have the same rates and the same carrier frequencies. This failure is due to the existence of non-separating local minima of the Godard cost function. In order ...

CERN Document Server

This Resource Letter provides a guide to the literature on Quantum Chromodynamics (QCD), the relativistic quantum field theory of the strong interactions. Journal articles, books, and other documents are cited for the following topics: quarks and color, the parton model, Yang-Mills theory, experimental evidence for color, QCD as a color gauge theory, asymptotic freedom, QCD for heavy hadrons, QCD on the lattice, the QCD vacuum, pictures of quark confinement, early and modern applications of perturbative QCD, the determination of the strong coupling and quark masses, QCD and the hadron spectrum, hadron decays, the quark-gluon plasma, the strong nuclear interaction, and QCD's role in nuclear physics. The letter {E} after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter {I}, for intermediate level, indicates material of a somewhat more specialized nature, ...

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Event generators that handle neutrino-nucleon interaction have been developed for the FLUKA code [1]. In earlier FLUKA versions only quasi-elastic (QEL) interactions were included, and the code relied on external event generators for the resonance (RES) and deep inelastic scattering (DIS). The new DIS+RES event generator is fully integrated in FLUKA and uses the same hadronization routines as those used for simulating hadron-nucleon interactions. Nuclear effects in neutrino-nucleus interactions are simulated within the same framework as in the FLUKA hadron-nucleus interaction model (PEANUT), thus profiting from its detailed physics modelling and longstanding benchmarking. The generators are available in the standard FLUKA distribution. They are presently under development and several improvements are planned to be implemented. The physics relevant to the neutrino-nucleon interactions and the results of comparisons with ...

CERN Document Server

By analyzing the $R$ values measured at 68 energy points in the energy region between 3.650 and 3.872 GeV reported in our previous paper, we have precisely measured the mass, the total width, the leptonic width and the leptonic decay branching fraction of the $\\psi(3770)$ to be ${M}_{\\psi(3770)}=3772.4 \\pm 0.4 \\pm 0.3$ MeV, $\\Gamma_{\\psi(3770)}^{\\rm tot} = 28.6 \\pm 1.2 \\pm 0.2$ MeV, $\\Gamma_{\\psi(3770)}^{ee} = 279 \\pm 11 \\pm 13$ eV and $B[\\psi(3770)\\to e^+e^-]=(0.98\\pm 0.04\\pm 0.04)\\times 10^{-5}$, respectively, which result in the observed cross section $\\sigma^{\\rm obs}[e^+e^-\\to \\psi(3770)]=7.25\\pm 0.27 \\pm 0.34$ nb at $\\sqrt{s}=3772.4$ MeV. We have also measured $R_{\\rm uds}=2.121\\pm 0.023 \\pm 0.084$ for the continuum light hadron production in the region from 3.650 to 3.872 GeV.

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When it was first developed, the standard model predicted a collection of particles, and thanks to more and more powerful colliders, physicsists have been able to find them all except one: the Higgs-Boson.

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We study the large-Q{sup 2} behavior of the meson form factor F{sub M} (Q{sup 2}) constructed using the holographic light-front wave functions.

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The HARP experiment at CERN is performing extensive measurements of hadron production cross sections and secondary particle yields, in the momentum range 1.5-15 GeV/c, over the full solid angle and using a large set of cryogenic and solid targets. First measurements of hadron production cross-sections in the forward region are reported using an aluminium target 5% of an interaction length thick and a proton beam of 12.9 GeV/c. A preliminary analysis in the large angle region of elastic scattering events produced with the cryogenic hydrogen target at 3 GeV/c beam momentum is also presented.

International Nuclear Information System (INIS)

The 'elementary' particle physics began in 1935, when Hideki Yukawa published his pioneering pi-meson theory, and the problem of strong interaction was finally solved 40 years later by the establishment of the Standard Model. The composite models of hadrons by the Sakata school and Sin-itiro Tomonaga's renormalization theory for quantum electrodynamics played essential roles for finding this beautiful solution. It is really surprising that it took only 40 years to solve such desperately difficult problem. The 'elementary' particle physics then split into two new fields, quark-hadron physics' and 'unified (ultimate) theory of particle physics', which are now 30 years old already. (author)

International Nuclear Information System (INIS)

We calculate the normalized factorial moments of multiplicity distributions through three models for elastic hadron scattering (Chou-Yang, Henzi-Valin and Menon-Pimentel). Connections between the moments and the inelastic overlap function and/or eikonal function are obtained by means of an impact parameter representation for the multiplicity distribution. The predictions are compared with experimental data on factorial moments from both inelastic and non-single-diffractive events. The model results present best agreement with the inelastic events and data favour the model by Henzi and Valin. (author)

CERN Document Server

\\lhcb is one of the four major experiments at the Large Hadron Collider (\\lhc) at CERN. It is custom built to look for CP violation and New Physics in rare decays of heavy flavour hadrons, like the B and D systems. Rare decays that occur via loop diagrams provide a way to probe New Physics at energy scales much higher than can be probed by direct production in experiments. In this article, the \\lhcb prospects for such measurements with exclusive decays of the type $B \\to \\Xs \\gamma$ and $B \\to X_{s} l^{+} l^{-}$ are presented.

International Nuclear Information System (INIS)

A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find that bottom-baryon lifetimes follow the pattern #tau#(#OMEGA#_b)#approx =##tau#(#XI#_b"-)>#tau#(#LAMBDA#_b)#approx =##tau#(#XI#_b"0). However, neither the lifetime ratio #tau#(#LAMBDA#_b)/#tau#(B_d) nor the absolute decay rates of the #LAMBDA#_b baryon and B mesons can be explained. One way of solving both difficulties is to allow the presence of linear 1/m_Q corrections by scaling the inclusive nonleptonic width with the fifth power of the hadron mass m_H__Q rather than the heavy quark mass m_Q. The hierarchy of bottom baryon lifetimes is dramatically modified to #tau#(#LAMBDA#_b)>#tau#(#XI#_b"-)>#tau#(#XI#_b"0)>#tau#(#OMEGA#_b): The longest-lived #OMEGA#_b among bottom baryons in the OPE ...

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The UV-vis-NIR absorption spectra of DyOCl were measured at selected temperatures between 9 and 300 K. The emission spectra of Dy{sup 3+} in LaOCl and GdOCl were obtained at 77 K and room temperature. The energy level scheme of Dy{sup 3+} was simulated with the aid of a phenomenological theory of simultaneously taking into account both the free ion and crystal field (c.f.) effects. The model included 14 adjustable parameters describing the electrostatic and the configuration interaction as well as the spin-orbit coupling. The c.f. effect was accounted for by the five non-zero B{sup k}{sub q} parameters according to the C{sub 4v} point symmetry of Dy{sup 3+}. Good simulation of the experimental energy level scheme was achieved with a r.m.s. deviation of 21 cm{sup -1} between the experimental and calculated energy level schemes of 179 Kramers doublets. A comparison to Pr{sup 3+}(4f{sup 2}), Nd{sup 3+} (4f{sup 3}), Sm{sup 3+} (4f{sup 5}), Eu{sup 3+} (4f{sup 6}), ...

International Nuclear Information System (INIS)

We show how to obtain positive energy representations of the group G of smooth maps from a union of circles to U(N) from geometric data associated with a Riemann surface having these circles as boundary. Using covering spaces we can reduce to the case where N=1. Then our main result shows that Mackey induction may be applied and yields representations of the connected component of the identity of G which have the form of a Fock representation of an infinite dimensional Heisenberg group tensored with a finite dimensional representation of a subgroup isomorphic to the first cohomology group of the surface obtained by capping the boundary circles with discs. We give geometric sufficient conditions for the correlation functions to be positive definite and derive explicit formulae for them and for the vacuum (or cyclic) vector. (This gives a geometric construction of correlation functions which had been obtained earlier using tau functions.) By choosing particular functions in G with ...

CERN Document Server

It has by now been established that standard QCD factorization using transverse momentum dependent parton distribution functions fails in hadro-production of nearly back-to-back hadrons with high transverse momentum. The essential problem is that gauge invariant transverse momentum dependent parton distribution functions cannot be defined with process-independent Wilson line operators, thus implying a breakdown of universality. This has led naturally to proposals that a correct approach is to instead use a type of "generalized" transverse momentum dependent factorization in which the basic factorized structure is assumed to remain valid, but with transverse momentum dependent parton distribution functions that contain non-standard, process dependent Wilson line structures. In other words, to recover a factorization formula, it has become common to assume that it is sufficient to simply modify the Wilson lines in the parton correlation functions for each separate ...

CERN Document Server

Complete factorization scheme analysis of $F_2^{\\gamma}(x,Q^2)$ in the next--to--leading order QCD is performed. It is shown that the presence of the inhomogenous term in the evolution equations for parton distribution functions of the photon implies qualitative change in the way factorization mechanism works in photon--hadron and photon--photon collisions as compared to hadron--hadron ones. The incompletness of the existing NLO analyses of $F_2^{\\gamma}(x,Q^2)$ is pointed out and its origins traced back to the misinterpretation of the behaviour of $q^{\\gamma}(x,M)$ as a function of in the LO photonic coefficient function $C_{\\gamma}^{(0)}(x)$ is given and smooth transition between the properties of virtual and real photon discussed. A simple way of avoiding the problems with the term $\\ln(1-x)$ appearing in the standard expression for $C_{\\gamma}^{(0)}(x)$ in the case of the reaal photon is proposed.

British Library Electronic Table of Contents (United Kingdom)

This study emphasizes the need for a systematic and in-depth connection between the progress in quantum theory of energetic ion collisions and applications to hadron therapy. Scattering theory for fast ion beams has reached its stage of development where accurate and robustly applicable methodologies can advantageously be exported to applied fields such as space research, fusion energy program, medicine, etc. In particular, distorted wave collision theories at high energies readily provide total, partial and fully differential cross sections for inelastic collisions of ionic projectiles with any target system. By numerous and thorough testings, such theoretical cross sections were found to exhibit excellent agreement with experimental data on atomic targets. Adequate extensions of these me...

CERN Document Server

Measurements of branching fractions and CP-asymmetries of B^{-} \\rightarrow D^{0}K^{-} modes allow a theoretically-clean extraction of the CKM angle \\gamma. The method proposed by Atwood, Dunietz and Soni (ADS) makes use of a decay chain where color and Cabibbo suppression interfere, which produces large CP-violating asymmetries. The CDF experiment reports the first measurement at a hadron collider of branching fractions and CP-asymmetries of suppressed B^{-} \\rightarrow D^{0}h^{-} signals, where h is \\pi or K. Using 5.0 fb^{-1} of data we found a combined significance exceeding 5\\sigma and we determined the ADS parameters with accuracy comparable with B-factories.

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We review the physics of structure functions at low Q{sup 2}, focusing on the phenomenon of quark-hadron duality and the resonance-scaling transition, both phenomenologically and in the context of quark models. We also present a new implementation of target mass corrections to nucleon structure functions which, unlike existing treatments, has the correct kinematic threshold behavior at finite Q{sup 2} in the x -> 1 limit.

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We discuss the origin of Bloom-Gilman duality and the relationship between resonances and scaling in deep-inelastic scattering. We present a simple quantum mechanical model which reproduces the essential features of Bloom-Gilman duality at low Q{sup 2}, and describe applications of local duality relating structure functions at x{approximately}1 and elastic electromagnetic form factors.

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The success of the Randall-Sundrum scenario relies on stabilization of the modulus field or the radion, which is the scalar field about the background geometry. The stabilization mechanism proposed by Goldberger and Wise has the consequence that this radion is lighter than the graviton Kaluza-Klein states so that the first particle to be discovered is the radion. In this work, we study in detail the decay, production, and detection of the radion at hadronic, e{sup +}e{sup -}, and {gamma}{gamma} colliders.

International Nuclear Information System (INIS)

It is shown that account of nuclear effects in nucleon channel is of principle importance when analyzing hadron-nucleon process at high energies. This enables to make correct conclusions both about the contribution of multiquark systems - fluctons - to nuclear wave function and about quark distribution in them. Analysis of these distributions shows that color degrees of freedom in flucton are partially unfrozen and flucton contains with high probability one or two quarks.

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We discuss the main stages of a physical program for photon linear colliders. We consider the problems in electroweak theory, hadron physics, QCD, and nonlinear QED, as well as new particles and interactions, etc. The discussed stages constitute the parts of an entire ambitious program for linear colliders. ((orig.)).

International Nuclear Information System (INIS)

The research of the CELLO collaboration is reviewed. After a description of the CELLO detector tests of QCD and hadronic final states by determination of the strong coupling constant and studies of inclusive production of electrons and muons in multihadronic events in e"+e"- annihilation are described. Then studies of deep inelastic e#gamma# scattering with lepton pair production and the study of the structure function of the photon are briefly described. Finally studies on QED processes are described together with tau decays. (HSI).

International Nuclear Information System (INIS)

Quark models of cumulative particle production and EMS effect are analyzed. All the models are characterized by a universal relationship between the spectrum of cumulative nucleons and the cross section of cumulative particles containing valence nuclear quarks. This relationship is tested for a deuteron. The role is discussed played by secondary nuclear processes for heavy nuclei. A special role of ''sea'' cumulative particles (K"-, p-bar) is pointed out in understanding the nature of the difference between the structure functions of a nucleus and of free nucleon.

International Nuclear Information System (INIS)

In this talk I briefly summarize different models for #sigma#_2_#gamma#"t"o"t (e"+e"-#->##gamma##gamma##->#hadrons) and contrast model predictions with the data. I will then discuss the capability of the future e"+e"- and #gamma##gamma# colliders to distinguish between various models and end with an outlook for future work.

CERN Document Server

We present the complete next-to-leading order (NLO) QCD corrections to the top quark associated with $\\gamma$ production induced by model-independent $tq\\gamma$ and $tqg$ flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the $tq\\gamma$ and $tqg$ FCNC couplings for this process. Our results show that, for the $tq\\gamma$ couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the $tq\\gamma$, $tqg$ FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the $tu\\gamma$ and $tug$ FCNC couplings, and by about the 80% for the $tc\\gamma$ and $tcg$ FCNC couplings at the LHC, respectively. Moreover, the NLO corrections reduce the dependence of the total cross section on the renormalization and factorization scale ...

CERN Document Server

We discuss the impact for light neutralinos in an effective Minimal Supersymmetric extension of the Standard Model of the recent results presented by the CMS and ATLAS Collaborations at the CERN Large Hadron Collider for a search of supersymmetry in proton-proton collisions at a center-of-mass energy of 7 TeV with an integrated luminosity of 35 inverse pb. We find that, in the specific case of light neutralinos, efficiencies for the specific signature searched by ATLAS (jets+missing transverse energy and an isolated lepton) imply a lower sensitivity compared to CMS (which searches for jets +missing transverse energy). Focusing on the CMS bound, if squark soft masses of the three families are assumed to be degenerate, the combination of the ensuing constraint on squark and gluino masses with the experimental limit on the b to s + gamma decay imply a lower bound on the neutralino mass that can reach the value of 11.9 GeV, depending on the gluino mass. On the other ...

CERN Document Server

A distinct feature of Coulomb gauge QCD is that it can be formulated in terms of physical, transverse gluons and quarks alone. The state-counting is then transparent, and the gauge is suited for studies of the excited spectrum. Leaving aside exotic spectroscopy, which has been the subject of other publications, in this note I call attention on two recent applications. One is that the running quark mass in the mid-infrared can be probed from excited baryons thanks to parity doubling, a consequence of insensitivity to chiral symmetry breaking. Fast quarks are asymptotically free and behave as massless, so hadrons containing fast quarks decouple from the condensate. Their (power-law) rate of decoupling reflects on the rate of decreasing parity splittings, which can be measured. The second is that, in analogy with the Franck-Condon principle of molecular physics, the velocity distribution of the heavy quarks inside a heavy hadron can be mapped out ...

International Nuclear Information System (INIS)

Complete calculations of the accelerator related background in the muon spectrometer of the CMS detector at the Large Hadron Collider are presented. The simulations have been performed with the STRUCT multi-turn tracking code and the MARS and FLUKA cascade codes taking into account latest information of the LHC lattice, vacuum conditions, beam cleaning system and the shielding and layout of the CMS experiment. Beam loss distributions in the interaction regions and their vicinities and their contribution to the background levels in the muon spectrometer of CMS are analyzed. The studies show that hadronic and electromagnetic components of machine background are efficiently suppressed by the proposed CMS shielding. High energy muons penetrate through the shielding, but in positions of significance they do not contribute more than a few percent compared to the background generated by the pp-collisions. It is anticipated that the relative ...

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Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting the joint project integrating both the Neutron Science Project (NSP) of JAERI and the Japan Hadron Facility Project (JHF) of KEK for comprehensive studies on basic science and technology using high-intensity proton accelerator. This document describes the joint project prepared by the Joint Project Team of JAERI and KEK to construct accelerators and research facilities necessary both for the NSP and the JHF at the site of JAERI Tokai Establishment. It was originally written in English and translated into Japanese with some corrections. (author)

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Thomas Jefferson National Accelerator Facility experiment E01-012 measured the 3He spin structure functions and virtual photon asymmetries in the resonance region in the momentum transfer range 1.0 < Q2 < 4.0 (GeV/c)2. Our date, when compared with existing deep inelastic scattering data, can be used to test quark-hadron duality in g1 and A1 for 3He and the neutron. Preliminary results for A{sub 1}{sup {sup 3}He} are presented, as well as some details about the experiment.

CERN Document Server

We consider the impact of a 4th generation on Higgs to $\\gamma\\gamma$ and $WW,ZZ$ signals and demonstrate that the Tevatron and LHC have essentially eliminated the possibility of a 4th generation if the Higgs is SM-like and has mass below 200 GeV. We also show that the absence of enhanced Higgs signals in current data sets in the $\\gamma\\gamma$ and $WW,ZZ$ final states can strongly constrain (almost eliminate) the possibility of a 4th generation in two-Higgs-doublet models of type II (in the MSSM).

International Nuclear Information System (INIS)

#pi#"#+-# and K"#+-# cumulative production in pA #-># #pi#"#+-#+x and pA #-># K"#+-#+x reactions at 10.14 GeV proton beam energy on nuclei (Be-Ta) was invesigated. Measurements were conducted using FAS-1 focusing hadron spectrometer. Invariant cross sections of #pi#"#+-# and K"#+-# cumulative production, values of ratio of this cross sections, dependences of production cross sections for pions and kaons on cumulative number and mass number of nucleus target, as well as on transverse momentum are measured. Difference of cumulative meson spectra occurring in different nuclei fragmentation is discussed in terms of flucton model. 17 refs.; 14 figs.

Energy Technology Data Exchange (ETDEWEB)

We analyse data on forward {eta} -meson photoproduction off a proton target and extract the {eta}{yields}{gamma}{gamma} decay width utilizing the Primakoff effect. The hadronic amplitude that enters into our analysis is strongly constrained because it is fixed from a global fit to available {gamma}p{yields}p{eta} data for differential cross-sections and polarizations. We compare our results with present information on the two-photon {eta} -decay from the literature. We provide predictions for future PrimEx experiments at Jefferson Laboratory in order to motivate further studies. (orig.)

CERN Document Server

First measurements of inclusive Z production cross sections in muon and electron decay channels at 7 TeV are presented for proton-proton collisions in the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The comparison of the kinematic quantities as well as the studies of selection efficiencies demonstrate a good agreement between simulated events and current data. The measured inclusive cross section for Z($\\gamma^{*}$) production agrees with NNLO QCD cross section calculations and current parton distribution functions.

CERN Document Server

The Compact Muon Solenoid (CMS) is one of the experiments which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.38 m and the aperture is 6.36 m. This is achieved with a 4 layer-5 module superconducting Al-stabilized coil energised at a nominal current of 20 kA. The finite element analysis (FEA) carried out is axisymmetric elasto-plastic. FEA has also been carried out on the suspension system and on the conductor. (8 refs).

CERN Document Server

Using the finite-range regularisation (FRR) of chiral effective field theory, the chiral extrapolation formula for the vector meson mass is derived for the case of partially-quenched QCD. We re-analyse the dynamical fermion QCD data for the vector meson mass from the CP-PACS collaboration. A global fit, including finite lattice spacing effects, of all 16 of their ensembles is performed. We study the FRR method together with a naive polynomial approach and find excellent agreement ~1% with the experimental value of M_rho from the former approach. These results are extended to the case of the nucleon mass.

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In radiation therapy with hadron beams, conformal irradiation to a tumour can be achieved by using the properties of incident ions such as the high dose concentration around the Bragg peak. For the effective utilization of such properties, it is necessary to evaluate the volume irradiated with hadron beams and the deposited dose distribution in a patient's body. Several methods have been proposed for this purpose, one of which uses the positron emitters generated through fragmentation reactions between incident ions and target nuclei. In the previous paper, we showed that the maximum likelihood estimation (MLE) method could be applicable to the estimation of beam end-point from the measured positron emitting activity distribution for mono-energetic beam irradiations. In a practical treatment, a spread-out Bragg peak (SOBP) beam is used to achieve a uniform biological dose distribution in the whole target volume. Therefore, in the ...

Energy Technology Data Exchange (ETDEWEB)

This thesis describes the analysis of the semileptonic decay D{sup 0} {yields} {bar K}{sup 0} {pi}{sup -} {mu}{sup +}{nu} using FOCUS data. FOCUS is a fixed target experiment at Fermilab that studies the physics of the charm quark. Particles containing charm are produced by photon-gluon fusion from the collision of a photon beam on a BeO target. The experiment is characterized by excellent vertex resolution and particle identification. The spectrometer consists of three systems for track reconstruction (two silicon systems and one multiwire proportional chamber system) and two magnets of opposite polarity. The polarity of the magnet is such that the events of e{sup +}e{sup -} pairs produced in the target (which constitutes the main background) travel through a central opening in the detectors without interactions. Particle momentum is measured from the deflection angle in the magnets. Three multicell Cerenkov counters are used for charged particle identification (for e, {pi}, K, and ...

CERN Document Server

An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.

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We estimate the TeV {gamma}-ray fluxes expected from the population of young pulsars in terms of the self-consistent time-dependent hadronic-leptonic model for the high-energy processes inside the pulsar wind nebulae (PWNe). This radiation model is based on the hypothesis of Arons and collaborators who postulate that leptons are accelerated inside the nebulae as a result of resonant scattering on heavy nuclei, which in turn are accelerated in the pulsar wind region or the pulsar inner magnetosphere. Our aim is to find out which PWNe on the northern hemisphere are the best candidates for detection at energies above 60 GeV and 200 GeV by the next generation of low-threshold Cherenkov telescopes.

CERN Document Server

In pp collisions at 1.25 GeV kinetic energy, the HADES collaboration aimed at investigating the di-electron production related to $\\Delta$ (1232) Dalitz decay ($\\Delta^+ \\to pe^+e^-$). In order to constrain the models predicting the cross section and the production mechanisms of $\\Delta$ resonance, the hadronic channels have been measured and studied in parallel to the leptonic channels. The analyses of $pp\\to np\\pi^+$ and $pp\\to pp\\pi^0$ channels and the comparison to simulations are presented in this contribution, in particular the angular distributions being sensitive to $\\Delta$ production and decay. The accurate acceptance corrections have been performed as well, which could be tested in all the phase space region thanks to the high statistic data. These analyses result in an overall agreement with the one-$\\pi$ exchange model and previous data.

International Nuclear Information System (INIS)

The proposed Superconducting Super Collider (SSC) in the US and plans for a Large Hadron Collider LHC at CERN are likely to require micron size filaments to reduce micron size filaments to reduce magnetization effects at the low injection fields envisioned. Superconductors of NbTi, designed to meet these requirements, are described. These conductors contain from 6000 to 36,613 filaments. Results are presented on NbTi conductors made by multiple extrusion techniques. Filament sizes of between 2.2 and 17 micron have been obtained. Current densities of between 2400 A/mm"2 and nearly 3400 A/mm"2 at 5 Tesla have been achieved. Metallurgical aspects of these conductors are presented using both optical and SEM views of conductor cross section and filament surface.

CERN Document Server

The ATLAS High Level Trigger (HLT) is a distributed real-time software system that performs the final online selection of events produced during proton-proton collisions at the Large Hadron Collider (LHC). It is designed as a two-stage trigger and event filter running on a farm of commodity PC hardware. Currently the system consists of about 850 processing nodes and will be extended incrementally following the expected increase in luminosity of the LHC to about 2000 nodes. The event selection within the HLT applications is carried out by specialized reconstruction algorithms. The selection can be controlled via properties that are stored in a central database and are retrieved at the startup of the HLT processes, which then usually run continuously for many hours. To be able to respond to changes in the LHC beam conditions, it is essential that the algorithms can be re-configured without disrupting data taking while ensuring a consistent and reproducible ...

CERN Document Server

We compute QCD corrections to the production of a ttbar pair in association with a hard photon at the Tevatron and the LHC. This process allows a direct measurement of the top quark electromagnetic couplings that, at the moment, are only loosely constrained. We include top quark decays, treating them in the narrow width approximation, and retain spin correlations of final-state particles. Photon radiation off top quark decay products is included in our calculation and yields a significant contribution to the cross-section. We study next-to-leading order QCD corrections to the ppbar -> ttbar+gamma process at the Tevatron for the selection criteria used in a recent measurement by the CDF collaboration. We also discuss the impact of QCD corrections to the pp -> ttbar+gamma process on the measurement of the top quark electric charge at the 14 TeV LHC.

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Heavy Ion Collisions at RHIC and LHC energies are potentially an interesting laboratory for the study of QED. In these collisions, a Heavy Ion in one beam sees a highly Lorentz contracted electric field due to an oncoming beam particle. The Electric field reaches a maximum value of E {approx_equal} {gamma}{sub eff} {center_dot} Z {center_dot} e/b{sup 2}, where the apparent Lorentz factor, {gamma}{sub eff} = 2 {center_dot} {gamma}{sub beam}{sup 2} - 1. The collision may be viewed in terms of a flux of photons colliding with a stationary ion target using the equivalent photon approximation, originally introduced by Fermi in 1924. We show that the cross section for Inelastic Electromagnetic Interactions of Heavy Ions are both calculable and have been measured in the first RHIC running period.

British Library Electronic Table of Contents (United Kingdom)

The RD50 collaboration has been exploring the development of radiation hard semiconductor devices for very high-luminosity colliders since 2002. The target fluence to qualify detectors set by the anticipated dose for the innermost tracking layers of the future upgrade of the CERN large hadron collider (LHC) is 1016 1MeV neutron equivalent (neq) cm-2. This is about an order of magnitude higher than the maximum dose for the most exposed silicon detectors in the current machine. RD50 investigates the radiation hardening of silicon sensors from many angles: improvement of the intrinsic tolerance of the substrate material, optimisation of the readout geometry and study of novel design of detectors. A review of some of the recent activities within RD50 is here presented.

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The AdS/CFT correspondence is a powerful tool to study the properties of conformal QCD at strong coupling in terms of a higher dimensional dual gravity theory. The power-law falloff of scattering amplitudes in the non-perturbative regime and calculable hadron spectra follow from holographic models dual to QCD with conformal behavior at short distances and confinement at large distances. String modes and fluctuations about the AdS background are identified with QCD degrees of freedom and orbital excitations at the AdS boundary limit. A description of form factors in space and time-like regions and the behavior of light-front wave functions can also be understood in terms of a dual gravity description in the interior of AdS.

International Nuclear Information System (INIS)

The postulate that negative-energy particles do not exist (travelling forward in time) leads automatically to the 'Reinterpretation Principle' by Stueckelberg and by Feynman. It has been already shown that such a 'principle', assumed as the Third postulate of special relativity, ensures the validity of the law of (retarded) casuality both in standard relativity and in (extended) relativity with tachyons and with Superluminal inertial frames. Our Thir postulate, moreover, allows predicting antiparticle existence in a purely relativistic context. In this paper it is shown that the Third postulate is enough to implement the law of casuality even in macrophysics, when usual macro-objects interact with micro-tachyons and macrotachyons. To that aim, some tachyon kinematics is further developed, which can be useful even in understanding elementary-particle interactions (and may be hadron structure). Many other related problems are discussed.

Science.gov (United States)

We compute the corrections from two-photon and {gamma}-Z exchange in parity-violating elastic electron-proton scattering, used to extract the strange form factors of the proton. We use a hadronic formalism that successfully reconciled the earlier discrepancy in the proton's electron to magnetic form factor ratio, suitably extended to the weak sector. Implementing realistic electroweak form factors, we find effects of the order 2%-3% at Q{sup 2} < or approx. 0.1 GeV{sup 2}, which are largest at backward angles and have a strong Q{sup 2} dependence at low Q{sup 2}. Two-boson contributions to the weak axial current are found to be enhanced at low Q{sup 2} and for forward angles. We provide corrections at kinematics relevant for recent and upcoming parity-violating experiments.

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A pillbox RF output window was developed for the L-band pulsed klystron for the Japanese Hadron Project (JHP) 1-GeV proton linac. The window was designed to withstand a peak RF power of 6 MW, where the pulse width is 600 {mu}sec and the repetition rate is 50 Hz. A high power model was fabricated using an alumina ceramic which has a low loss tangent of 2.5x10{sup -5}. A high power test was successfully performed up to a 113 kW RF average power with a 4 MW peak power, a 565 {mu}sec pulse width and a 50 Hz repetition rate. By extrapolating the data of this high power test, the temperature rise of the ceramic is estimated low enough at the full RF power of 6 MW. Thus this RF window is expected to satisfy the specifications of the L-band Klystron. (author).

Energy Technology Data Exchange (ETDEWEB)

Energy flows in deep inelastic electron-proton scattering are investigated at a centre-of-mass energy of 296 GeV for the range Q{sup 2}{>=}10 GeV{sup 2} using the ZEUS detector. A comparison is made between events with and without a large rapidity gap between the hadronic system and the proton direction. The energy flows, corrected for detector acceptance and resolution, are shown for these two classes of events in both the HERA laboratory frame and the Breit frame. From the differences in the shapes of these energy flows we conclude that QCD radiation is suppressed in the large-rapidity-gap events compared to the events without a large rapidity gap. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The {rvec n} + p {yields} d + {gamma} experiment under construction at LANSCE studies the weak interaction between neutrons and protons. The experiments will measure the directional dependence of the parity-violating {gamma}-ray asymmetry, A{sub {gamma}}, in the polarized cold neutron capture by para-hydrogen. The goal is to measure A{sub {gamma}} with uncertainty of 0.5 x 10{sup -8}, 10% of its predicted value. A{sub {gamma}} primarily isolates the {Delta}I = 1 component of the hadronic weak interaction and thus will determine the long-range weak pion-nucleon coupling constant H{sub {pi}}{sup 1}. The experiment is carefully designed for the LANSCE pulsed spallation neutron source to achieve the proposed statistical precision and to control systematic errors. We discuss the experiment and its status.

CERN Multimedia

LECTURE SERIES 14, 15, 17 January 2008 11:00 to 12:00 - Council Chamber, bldg. 503-1-001 Applications of accelerators to tumour therapy U. AMALDI, TERA Foundation & University of Milano Bicocca The first lecture is devoted to an historical review of the developments of the teletherapy techniques which make use of hadron beams and are collectively called "hadrontherapy". The main emphasis is on the use of protons and light ions, but also neutrons, pions and antiprotons are considered. The second lecture reviews the rationale behind the use of carbon ions in the treatment of radioresistant tumours and the results obtained both with proton and carbon ion beams on the 60 000 patients treated worldwide. The numbers of patients who would profit from hadrontherapy are presented together with the current landscape of running and planned hospital based centres. The main technical challenges set by this therapeutic modality are discussed in the third lecture together ...

International Nuclear Information System (INIS)

The status of Monte Carlo system for the simulation of Bremsstrahlung in arbitrary decays and for the decay itself of #tau# -lepton is reviewed. During the last #tau# -lepton conference in 2010 several developments of the last two years have been presented: (i) For the TAUOLA Monte Carlo generator of #tau# -lepton decays, automated and simultaneous use of many versions of form-factors for the calculation of optional weights for fits was developed and checked to work in Belle and BaBar software environment. On-going work on alternative parameterizations of hadronic decays is presented too. (ii) The TAUOLA universal interface based on HepMC (the C++ event record) is now public. A similar interface for PHOTOS is now also public. (iii) Extension of PHOTOS Monte Carlo for QED Bremsstrahlung in decays featuring kernels based on complete first order matrix element are gradually becoming widely available thanks to properties of the new, HepMC based interface. (iv) Tests of ...

CERN Document Server

PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range (protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of $10^{-8}$). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15 2006 in a $350\\times 600 km$ orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. In self-trigger ...

Energy Technology Data Exchange (ETDEWEB)

A dipole magnet based on the common coil design, using prereacted Nb{sub 3}Sn superconductor, is under development at Fermilab, for a future Very Large Hadron Collider. This magnet has some innovative design and technological features such as single layer coils, a 22 mm wide 60-strand Rutherford type cable and stainless steel collars reinforced by horizontal bridges inserted between coil blocks. Both left and right coils are wound simultaneously into the collar structure and then impregnated with epoxy. In order to optimize the design and fabrication techniques an R&D program is underway. The production of cables with the required characteristics was shown possible. Collar laminations were produced, assembled and tested in order to check the effectiveness of the bridges and the validity of the mechanical design. A mechanical model consisting of a 165 mm long section of the magnet straight section was assembled and tested. This paper summarizes the status of ...

CERN Document Server

We exhibit static solutions of multi-flavour QCD in two dimensions that have the quantum numbers of baryons and mesons, constructed out of quark and anti-quark solitons. In isolation the latter solitons have infinite energy, corresponding to the presence of a string carrying the non-singlet colour flux off to spatial infinity. When $N_c$ solitons of this type are combined, a static, finite-energy, colour singlet solution is formed, corresponding to a baryon. Similarly, static meson solutions are formed out of a soliton and an anti-soliton of different flavours. The stability of the mesons against annihilation is ensured by flavour conservation. The static solutions exist only when the fundamental fields of the bosonized Lagrangian belong to $U(N_c{\\times}N_f)$ rather than to $SU(N_c) \\times U(N_f)$. Discussion of flavour symmetry breaking requires a careful treatment of the normal ordering ambiguity. Our results can be viewed as a derivation of the constituent quark model in QCD$_2$, ...

Energy Technology Data Exchange (ETDEWEB)

Wonderful opportunities await particle physics over the next decade, with the coming of the Large Hadron Collider at CERN to explore the 1-TeV scale (extending efforts at LEP and the Tevatron to unravel the nature of electroweak symmetry breaking) and many initiatives to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the B factories and the Tevatron collider on CP violation and the weak interactions of the b quark; the wonderfully sensitive experiments at Brookhaven, CERN, Fermilab, and Frascati on CP violation and rare decays of kaons; the prospect of definitive accelerator experiments on neutrino oscillations and the nature of the neutrinos; and a host of new experiments on the sensitivity frontier. We might even learn to read experiment for clues about the dimensionality of spacetime. If we are inventive enough, we may be able to follow this rich menu with the ...

CERN Document Server

In this paper we will report on the operation and the performance of the ATLAS data-flow system during the 2010 physics run of the Large Hadron Collider (LHC) at 7 TeV. The data-flow system is responsible for reading out, formatting and conveying the event data, eventually saving the selected events into the mass storage. By the second quarter of 2010, for the first time, the system will be capable of the full event building capacity and improved data-logging throughput. We will in particular detail the tools put in place to predict and track the system working point, with the aim of optimizing the bandwidth and the computing resource sharing, and anticipate possible limits. Naturally, the LHC duty cycle, the trigger performance, and the detector configuration influence the system working point. Therefore, numerical studies of the data-flow system capabilities have been performed considering different scenarios. This is crucial for the first phase of the LHC ...

CERN Document Server

ALICE (A Large Ion Collider Experiment) is the heavy-ion detector designed to study the physics of strongly interacting matter and the quark-gluon plasma at the CERN Large Hadron Collider (LHC). Some specific calibration tasks are performed regularly for each of the 18 ALICE sub-detectors in order to achieve most accurate physics measurements. These procedures involve events analysis in a wide range of experimental conditions, implicating various trigger types, data throughputs, electronics settings, and algorithms, both during short sub-detector standalone runs and long global physics runs. A framework was designed to collect statistics and compute some of the calibration parameters directly online, using resources of the Data Acquisition System (DAQ), and benefiting from its inherent parallel architecture to process events. This system has been used at the experimental area for one year, and includes more than 30 calibration routines in production. This paper ...

CERN Document Server

W and Z bosons are expected to be produced abundantly at the Large Hadron Collider (LHC). This large dataset and the high LHC energy will allow for detailed studies of their properties in a previously unexplored kinematic domain of low parton momentum fraction and high energy scale thus providing, together with the proton-proton nature of the collisions, new constraints on the parton distribution functions and precise tests of perturbative QCD. First determinations of the W -> lnu and Z -> ll (l = e,mu) production cross sections for proton-proton collisions at sqrt(s) = 7 TeV were performed using about 320/nb of data recorded by the ATLAS experiment at the LHC. The results of these measurements for W and Z bosons for proton-proton collisions at sqrt(s) = 7 TeV are presented. In addition ?rst measurements of the ratio between the W and Z/gamma*-cross sections and of the W -> lnu charge asymmetry are also discussed.

CERN Document Server

Precise measurements of the top quark decay properties at hadron colliders offer interesting new possibilities of testing the standard model. At the same time, recent intriguing experimental results concerning CP violation in the B_d and B_s systems have stimulated many studies of physics beyond the standard model. We investigate anomalous t W d_j interactions as a possible source of new effects in B_{d,s} - bar B_{d,s} oscillations within a model independent approach based on the assumptions of Minimal Flavor Violation. After matching our effective operators onto the low-energy effective Lagrangian describing B_{d,s} meson mixing and evolving it down to the B-mass scale, we extract the preferred ranges of the anomalous t W d_j interactions at the weak scale. These values are then compared to previously considered constraints coming from the rare radiative B --> X_s gamma decay. Finally, we reconsider the associated effects in the t --> b W decays and find ...

Energy Technology Data Exchange (ETDEWEB)

Particle physics is driven by five great topics. Neutrino oscillations and masses are now at the fore. The standard model with extensions to supersymmetry and a Higgs to generate mass explains much of the field. The origins of CP violation are not understood. The possibility of extra dimensions has raised tantalizing new questions. A fifth topic lurking in the background is the possibility of something totally different. Many of the questions raised by these topics require powerful new accelerators. It is not an overstatement to say that for some of the issues, the accelerator is almost the experiment. Indeed some of the questions require machines beyond our present capability. As this volume attests, there are parts of the particle physics program that have been significantly advanced without the use of accelerators such as the subject of neutrino oscillations and many aspects of the particle-cosmology interface. At this stage in the development of physics, both approaches are needed ...

CERN Document Server

The aim of this set of lectures is to review different avenues of electroweak symmetry breaking explored over the years. This constitutes a timely exercise as the world's largest and the highest energy particle accelerator, namely, the Large Hadron Collider (LHC) at CERN near Geneva, is all set to start running whose primary mission is to unravel the mysteries of electroweak phase transition. In the beginning, we discuss the Standard Model Higgs mechanism. After that we review the Higgs sector of the Minimal Supersymmetric Standard Model. Then we take up three relatively recent ideas: Little Higgs, Gauge-Higgs Unification, and Higgsless scenarios. For the latter three cases, we present the basic ideas and restrict our illustrations to some instructive toy models, as our intention is rather to provide an intuitive feel of the underlying dynamics than to get into an in-depth analysis of realistic scenarios. Wherever possible, we provide enough pedagogical details, ...

Science.gov (United States)

of satellite, aircraft and ground-based observations. In ..... swarm traps by Utah Department of Food and Agriculture (DAF) personnel. Preliminary Results ..... the 150th anniversary of the book's publication and the 200th anniversary of Darwin's birth. ...... cold war submarine missions to find that Arctic Ocean ...

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High-resolution near-infrared and far-infrared observations are presented of the southeastern molecular cloud fragment in the IC 5146 dark cloud. These observations rule out earlier suggestions for the formation of massive stars in this fragment.

CERN Document Server

A sequential problem in decentralized detection is considered. Two observers can make repeated noisy observations of a binary hypothesis on the state of the environment. At any time, observer 1 can stop and send a final binary message to observer 2 or it may continue to take more measurements. Every time observer 1 postpones its final message to observer 2, it incurs a penalty. Observer 2's operation under two different scenarios is explored. In the first scenario, observer 2 waits to receive the final message from observer 1 and then starts taking measurements of its own. It is then faced with a stopping problem on whether to stop and declare a decision on the hypothesis or to continue taking measurements. In the second scenario, observer 2 starts taking measurements from the ...

UK PubMed Central (United Kingdom)

The muscles of three different arthropods, a mite, a fly, and an ostracod, show variations in the length of the A region within a given individual. There is no indication that the observed differences...Full Text Available

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Published in summary form only.

International Nuclear Information System (INIS)

A previous study described the basic theoretical expectations of the magnetic dipole radiation and unipolar induction of pulsars and presented observational results. This paper further discusses the difference between the two braking mechanisms and analyses the results of a statistical study through observed data of apparent beamwidth's distributions and a geometrical method. The theory of magnetic dipole radiation of pulsars agrees with the observations. Unipolar induction as a braking mechanism is not consistent with the observations.

CERN Document Server

We present results for a complete set of polarization observables for jet production in lepton proton collision, where the final state lepton is not observed. The calculations are carried out in collinear factorization at the level of Born diagrams. For all the observables we also provide numerical estimates for typical kinematics of a potential future Electron Ion Collider. On the basis of this numerical study, the prospects for the transverse single target spin asymmetry are particularly promising. This observable is given by a certain quark-gluon correlation function, which has a direct relation to the transverse momentum dependent Sivers parton distribution.

Energy Technology Data Exchange (ETDEWEB)

Future insertion quadrupoles with large apertures and high gradients will be required for the Phase II luminosity upgrade (10{sup 35} cm{sup -2}s{sup -1}) of the Large Hadron Collider (LHC). Although improved designs, based on NbTi, are being considered as an intermediate step for the Phase I upgrade, the Nb{sub 3}Sn conductor is presently the best option that meets the ultimate performance goals for both operating field and temperature margin. As part of the development of Nb{sub 3}Sn magnet technology, the LHC Accelerator Research Program (LARP) developed and tested several 1-meter long, 90-mm aperture Nb{sub 3}Sn quadrupoles. The first two series of magnet used OST MJR 54/61 (TQ01 series) and OST RRP 54/61 (TQ02 series) strands. The third series (TQ03) used OST RRP 108/127 conductor. The larger number of sub-elements and the consequent reduction of the effective filament size, together with an increased fraction of copper and a lower Jc were expected to improve ...

Energy Technology Data Exchange (ETDEWEB)

In the last 30 years high energy physics could write an impressive story of success. Since the introduction of the Standard Model (SM), it has met every experimental test. However the final confirmation has to prove the mechanism of electroweak symmetry breaking, which could not be confirmed yet. The most favored theory, which includes the introduction of a Higgs field, could not be verified experimentally. Furthermore there is clear evidence, that the SM is only a low energy description of nature and its principles, as the SM describes only 4 % of the known matter in the universe. There are two different approaches in accelerator driven high energy physics to clarify the open questions. The Large Hadron Collider (LHC) have a good opportunity to measure some of the missing pieces with its high center of mass energy. The International Linear Collider (ILC) will then measure their parameters with high precision. To guarantee this high precision the detectors have to ...

International Nuclear Information System (INIS)

The quenched chiral logarithms are examined on a 163x28 lattice with Iwasaki gauge action and overlap fermions. The pion decay constant fpi is used to set the lattice spacing, a = 0.200(3) fm. With pion mass as low as #approx#180 MeV, we see the quenched chiral logarithms clearly in mpi2/m and fP, the pseudoscalar decay constant. The authors analyze the data to determine how low the pion mass needs to be in order for the quenched one-loop chiral perturbation theory (chiPT) to apply. With the constrained curve-fitting method, they are able to extract the quenched chiral logarithmic parameter delta together with other low-energy parameters. Only for mpi<=300 MeV do we obtain a consistent and stable fit with a constant delta which they determine to be 0.24(3)(4) (at the chiral scale Lambdachi = 0.8 GeV). By comparing to the 123x28 lattice, they estimate the finite volume effect to be about 2.7% for the smallest pion mass. They also fitted the pion mass to the form for the re-summed ...

Science.gov (United States)

of Colorado at Boulder Search This Site Natural Hazards Observer Disaster Research CU Web Site CU People go Search This Site Natural Hazards Observer Disaster Research CU Web...

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The paper reviews the main observational data on pulsars, both the individual characteristics of pulsars and the properties they possess as members of the Galaxy. Consideration is then given to pulsar ages and to pulsar initial periods. An attempt is made to clarify the 'true' ages of pulsars.

National Aeronautics and Space Administration (NASA)

This video compiles 10 days' worth of observations from the GOES-12 satellite and shows the storms that dumped heavy rainfall on the Northeastern United States in the latter part of March 2010.

UK PubMed Central (United Kingdom)

Systematic observations of man/water contact in a valley endemic for S. mansoni in St Lucia were carried out prior to the introduction of a household water supply. The observations...Full Text Available

CERN Document Server

We study luminosities of millisecond pulsars in globular clusters by fitting the observed luminosity distribution with single and double power laws. We use simulations to model the observed distribution as the brighter part of some parent distribution for Terzan 5 and try to find a model which simultaneously agrees with the observed diffuse radio flux, total predicted number of pulsars and observed luminosity distribution. We find that wide ranges of parameters for log-normal and power-law distributions give such good models. No clear difference between the luminosity distributions of millisecond pulsars in globular clusters and normal disk pulsars was seen.

KoreaScience (Korea)

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The double-mode cepheid Y Car has been found to have a variable centre-of-mass velocity. Though the observations did not cover a cycle, an orbital period of about 400-600 days was estimated. Radial-velocity observations of this star have now been continued in order to derive the orbital elements. Observations were made with the photoelectric radial-velocity spectrophotometer at the coude focus of the 1.88-m reflector at Sutherland. The velocity system was standardized by frequent nightly observations of stars in the Mount Wilson catalogue with 'a'-quality radial velocities.

Energy Technology Data Exchange (ETDEWEB)

Four topics in nuclear astrophysics, namely; pulsars, star evolution, nucleosynthesis and solar neutrinos are reviewed through the discussion of the observational data.

Science.gov (United States)

Moisture ingression was studied in several composite sandwich panels.No observable ingression was

Science.gov (United States)

... outside observers, and updated counseling requirements for the Army's OER, non-commissioned officer efficiency report (NCOER), and civilian ...

Science.gov (United States)

... Considering these observations, it is most likely that Brucela proteins involved in protective immunity will preferentially stimulate INF-g producing T ...

CERN Document Server

A simple experiment to observe weak localization in thin Ag films is presented. A clear theoretical signature of weak localization is predicted in mangetoresistive measurements of thin films samples. We present a simple method for making thin Ag film samples, using evaporative deposition, and observing the small magnetoresistive signal, using a resistance bridge technique. Typical results from our students show that Ag films show the predicted behavior for weak localization with spin effects. These effects can be easily observed in a liquid helium dewar.

Science.gov (United States)

... High water temper- atures from June through October also contributed to the observed high catch probabilities in 1995. ...

International Nuclear Information System (INIS)

Contrary to the electronic excitation induced phenomena of desorption and sputtering, we observed incorporation of oxygen in a thin Fe film during its irradiation with swift heavy ions. It is observed that the adsorbed oxygen diffuses in to the Fe film. The incorporation of oxygen and its diffusion in the bulk of the film is a manifestation of extremely large electronic energy deposition by the incident ions. It is shown that the experimentally observed high diffusivity of oxygen in Fe during irradiation is due to the existence of transient melt phase of Fe.

CERN Document Server

We report an observation of a delayed all-optical routing/switching phenomenon based on ultraslow group velocity of light via nondegenerate four-wave mixing processes in a defected solid medium. Unlike previous demonstrations of enhanced four-wave mixing processes using the slow light effects, the present observation demonstrates a direct retrieval of the resonant Raman-pulse excited spin coherence into photon coherence through coherence conversion processes.

International Nuclear Information System (INIS)

The first successful observation of double analog states in "8"8Zr and "9"0Mo has been made by means of the (#pi#"+,#pi#"-) pion double charge exchange (DCX) reaction. The systematics of the (N - Z) and the A dependence of analog DCX, made possible by these observations, is discussed. (orig.).

Energy Technology Data Exchange (ETDEWEB)

In this study we extend the analysis of magnetopause crossings observed with Magnetospheric Plasma Analyzer measurements to examine a much larger statistical data set. This study examines 39 maiznetosheath/LLBL intervals from 79 spacecraft-months of observations: these observations were taken from a survey of data from the start of each spacecraft mission and extending through March 1993. In contrast to the previous findings, we find no evidence for a significant dawn/dusk asymmetry in geosynchronous magnetopause crossings.

CERN Document Server

This paper presents three non-linear asymptotic observers corresponding to three examples of engineering interest: a chemical reactor, a non-holonomic car, and an inertial navigation system. For each example, the design is based on physical symmetries. This motivates the theoretical development of invariant observers, i.e, symmetry-preserving observers. We consider an observer to consist in a copy of the system equation and a correction term, and we give a constructive method (based on the Cartan moving-frame method) to find all the symmetry-preserving correction terms. They rely on an invariant frame (a classical notion) and on an invariant output-error, a less standard notion precisely defined here. For each example, the convergence analysis relies also on symmetries consideration with a key use of invariant state-errors. For the non-holonomic car and the inertial navigation system, the invariant ...

International Nuclear Information System (INIS)

Coherent spontaneous radiation has now been observed in several FELs, and is a subject of great importance to the design of self-amplified spontaneous emission (SASE) devices. We report observations of coherent spontaneous radiation in both FIREFLY and the mid-infrared FEL at the Stanford Picosecond FEL Center. Coherent emission has been observed at wavelengths as short as 5 microns, and enhancement over incoherent levels by as much as a factor of 4x10"4 has been observed at longer wavelengths. The latter behavior was observed at 45 microns in FIREFLY with short bunches produced by off-peak acceleration and dispersive compression. We present temporal measurements of the highly bunched electron distributions responsible for the large enhancements, using both transition radiation and energy-phase techniques.

CERN Document Server

We develop and demonstrate the methodology of testing multi-dimensional supernova models against observations by studying the properties of one example of the detonation from failed deflagration (DFD) explosion model of thermonuclear supernovae. Using time-dependent multi-dimensional radiative transfer calculations, we generate the synthetic broadband optical light curves, near-infrared light curves, color evolution curves, full spectral time-series, and spectropolarization of the model, as seen from various viewing angles. All model observables are critically evaluated against examples of well-observed, standard Type Ia supernovae (SNe Ia). We explore the consequences of the intrinsic model asphericity by studying the dependence of the model emission on viewing angle, and by quantifying the resulting dispersion in (and internal correlations between) various model observables. These statistical ...

International Nuclear Information System (INIS)

After presenting a general account of the observed global properties of single stars of low, intermediate, and high mass, together with their theoretical Hertzsprung-Russell diagram evolution, attention is given to the observed properties of various evolved close binaries and to an assessment of the value of comparisons between observation and crude theory in characterizing the physics of mass transfer within interacting binary systems. Detailed consideration is then undertaken of such topics as stellar evolution in globular clusters, interior star changes due to nucleosynthesis and mixing, asymptotic giant branch stars of intermediate mass, the response of white dwarfs in binary systems to mass accretion, and scenarios for binary star evolution tending toward close white dwarf pairs.

DEFF Research Database (Denmark)

X-ray observations of the RSCVn system sigma Geminorum have been undertaken with the ROSAT observatory. Several spectra of very good signal-to-noise ratio were obtained. Spectral fitting using metal abundances amounting to 50% of solar values reveal two temperature components at 2 MK and 12 MK. Previous EXOSAT observations showed another component at 40 MK. Particular interest is focused on the temporal variations of the X-ray emission. It is found that variations occur on time scales ranging from years to hours and minutes.

Energy Technology Data Exchange (ETDEWEB)

In this paper we studied the behavior of commercially pure niobium immersed in molten aluminum. The experiments were carried out 800 and 900 deg C during 2 to 128 hours. Chemical and metallographic analyses, as well as microhardness measurements of the niobium specimens were accomplished. An increase of niobium content in the aluminum bath with time was observed. Metallographic observations revealed the formation of Nb Al{sub 3} external intermetallic compound. During dissolution, fragments of this compound settled at the bottom of the crucible. This behaviour was also observed at 900 deg C, nevertheless with higher intensity. (author) 10 refs., 5 figs., 3 tabs.

CERN Document Server

Using an exactly soluble one-dimensional atomic model we explore the idea that the recently observed high-order nonlinearity in optical filaments is due to virtual transitions involving the continuum states. We show that the model's behavior is qualitatively comparable with the experimentally observed cross-over from self-focusing to de-focusing at high intensities, and only occurs at intensities which result in significant ionization. Based on these observations, we conjecture that this continuum electron nonlinear refraction exhibits strong memory effects, and most importantly, the change of its sign is effectively masked by the de-focusing due to free electrons.

International Nuclear Information System (INIS)

A LiF crystal analyzer has been used to measure phonon creation events when a low energy He beam scatters from a Cu(001) surface at low temperature (16 "0K). As only phonon creation events were observed, the inelastic scattering was subspecular. Atom parallel momentum gain and loss events were observed and both bulk and surface modes contributed to the inelastic scattering. An elastic component of scattering was observed over a wide angular range.

Energy Technology Data Exchange (ETDEWEB)

High interelectrode voltage peaks have been observed simultaneously with the emission of hard X-ray bursts from a flash X-ray tube. The magnitude of the voltage peaks may exceed twice the initial charging voltage. It has also been observed that the discharge emits bursts of X-and P-band microwaves radiation which are coincident with the emission of the hard X-ray bursts. The results indicate that the microwaves and X-rays have a common origin in discharge plasma movements and an acceleration model for electrons in the plasma is presented as one possible explanation of the observed phenomena.

Science.gov (United States)

The goal of this research program has been to add to our understanding of the breakup of molten fuel jets penetrating reactor coolant. Easily handled working fluids are used to simulate fuel jet breakup, so that detailed observations may be obtained from a relatively large number of experiments. The tools used for observing this behavior are high speed notion picture photography, Flash X-radiography, and X-ray cine. Jet breakup lengths are determined from motion pictures; the mechanisms by which the jets are fragmented may be inferred from radiographs.

CERN Document Server

The Ludwig-Soret effect, the migration of a species due to a temperature gradient, has been extensively studied without a complete picture of its cause emerging. Here we investigate the dynamics of DNA and spherical particles sub jected to a thermal gradient using a combination of Brownian dynamics and the lattice Boltzmann method. We observe that the DNA molecules will migrate to colder regions of the channel, an observation also made in the experiments of Duhr, et al[1]. In fact, the thermal diffusion coefficient found agrees quantitatively with the experimental value. We also observe that the thermal diffusion coefficient decreases as the radius of the studied spherical particles increases. Furthermore, we observe that the thermal fluctuations-fluid momentum flux coupling induces a gradient in the stress which leads to thermal migration in both systems.

Energy Technology Data Exchange (ETDEWEB)

We have examined the theory of NMR multiple echoes developed for solid {sup 3}He to determine whether multiple echoes could be observed in solid hydrogen. We were particularly interested in the possibility of testing for low frequency quantum tunneling motions in solid hydrogen by the observation of multiple echoes. We find that for easily accessible nuclear spin polarizations, P > 12%, multiple echoes would be observed for HD impurities in solid parahydrogen if motional narrowing is effective in increasing the HD nuclear spin-spin relaxation time T{sub 2} to the order of 1 msec. These values for T{sub 2}, which have been observed for HD impurity concentrations of the order of 1%, are larger than the calculated rigid lattice values and can be attributed to quantum tunneling at frequencies of the order of 1kHz.

UK PubMed Central (United Kingdom)

Objective. To describe the diverse patterns observed with the use of autofluorescence fundus photography (FAF) in patients with Birdshot chorioretinopathy (BSCR). Methods....Full Text Available

Science.gov (United States)

... Title : The Numerical Weather Prediction System at the Italian Air Force Weather Service: Impact of Non-Conventional Observations and Increased ...

Energy Technology Data Exchange (ETDEWEB)

Strong-interaction effects have been observed in the x-ray spectra of atoms formed with [Sigma][sup [minus

Science.gov (United States)

... point dried and mounted on aluminum stubs using colloidal silver paste. Mounted specimens were observed and photographed using ... ...

Science.gov (United States)

we have a colloquium scheduled. Computing: register your machine and check our network security and visitor computer policies. For Our Information: Once arranged, please let us...

Science.gov (United States)

... their clothes set afire. One patient fell into a hot cupola furnace. Steam burns were observed for four patients. In the clinical ...

UK PubMed Central (United Kingdom)

BackgroundSeveral studies have suggested an association between periodontal disease and prematurity but this finding has not been consistently observed.MethodsCase...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

At the occasion of the OECS conference in Madrid, we give a succinct account of some recent predictions in the spectroscopy of a quantum dot in a microcavity that remain to be observed experimentally, sometimes within the reach of the current state of the art.

International Nuclear Information System (INIS)

Macroparticle acceleration driven by low current, high voltage cathode spots has been investigated for potential applications ranging from micrometeoroid simulation to nanoparticle deposition/implantation. Acceleration by this process was observed to occur when nanometer and micrometer-sized particles were exposed to a high voltage pulse in the presence of a plasma discharge. The applied negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provide the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. Cathode spot behavior was also documented. The particle impact craters observed at the surface of downstream witness badges were documented using scanning electron microscopy and light microscopy. The observed impacts suggest the presence of energetic macroparticles formed ...

Science.gov (United States)

... This paper presents our research in neural learning for predicting ... Denote this feature set as F4. ... can be observed that the SOC curves generated by ...

Science.gov (United States)

coupled heat/mass transfer Stefan problem. Taking the diffusion coefficient of Bi as a free parameter, the best fit was observed for the published value, ...

UK PubMed Central (United Kingdom)

BACKGROUNDNew diagnostic tools are urgently needed to interrupt the transmission of tuberculosis and multidrug-resistant tuberculosis. Rapid,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Observation of lithium lines in two halo stars could bring some information about /sup 7/Li abundance at the time of the formation of the galaxy.

Science.gov (United States)

Jul 25, 2011 ... Koji Mukai's Bibliography. Invited Reviews. Mukai, K. 1994, "ASCA PV Phase Observations of Cataclysmic Variables," in "New Horizon of X-ray ...

Energy Technology Data Exchange (ETDEWEB)

A variety of observations suggest that the Universe had a hot dense origin and that the pregalactic composition of the Universe was determined by nuclear reactions that occurred in the first few minutes. There is no unique hot Big Bang theory, but the simplest version produces a primeval chemical composition that is in good qualitative agreement with the abundances deduced from observation. Whether or not any Big Bang theory will provide quantitative agreement with observations depends on a variety of factors in elementary particle physics (number and masses of stable or long-lived particles, half-life of neutron, structure of grand unified theories) and from observational astronomy (present mean baryon density of the Universe, the Hubble constant and deceleration parameter). The influence of these factors on the abundances is discussed, as is the effect of departures from homogeneity and isotropy in ...

International Nuclear Information System (INIS)

... Energy Agency, Quantum Beam Science Directorate, Sayo, Hyogo (Japan)

Science.gov (United States)

... 2.5.6 Development of Observation Equations . . . . . 25 2.6 Inertial Navigation Error Model . . . . . ... 2 , as expected. 2.6 Inertial Navigation Error Model ...

International Nuclear Information System (INIS)

Excited states in the T_z=(1/2) nucleus "8"5Mo have been observed for the first time with the reaction "5"8Ni("3"2S,#alpha#n#gamma#) at 105 MeV. #gamma#-ray transitions in this nucleus have been assigned unambiguously by combining the information from the GASP #gamma#-ray array, the ISIS silicon ball, and the n-Ring neutron detector. Two band structures have been observed in this nucleus; they continue the smooth evolution of the known bands from the lighter N=43 isotones and have been tentatively assigned spins and parity on this basis. After reaching a maximum of collectivity at "8"3Zr, the trend with increasing mass is reversed, showing a smaller collectivity at "8"5Mo. The rotational behavior of the observed bands is discussed on the basis of the projected shell model calculations.

Science.gov (United States)

... At the same time, we observed that the neoplastic properties of rat mammary gland tumor cells can be restrained and "normalized" so that they ...

CERN Document Server

The next decade promises an observational revolution which will change cosmology forever. The precise measurement of the angular anisotropy of the cosmic microwave background should specify to a few percent all of the parameters of the cosmological model which effect astrophysics. The growth of structure will then be determined (but not yet observed) until gravitational collapse becomes highly non-linear and stars, galaxies and active galactic nuclei (AGN) form. These processes are hard to model with basic physics because they are complex and allow a rich variety of expression. Instead observations will determine when the first stars and quasars formed, and how and when galaxies assembled. If we can reconcile the numerous contradictions which characterize the subject today, cosmology will become a mature subject, founded on the agreement between detailed, inclusive and realistic models, which make precise predictions, and ...

UK PubMed Central (United Kingdom)

In contrast to the increasing availability of information pertaining to the care of children with chronic kidney disease (CKD) from large-scale observational and interventional studies, epidemiological...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A brief review of standard big bang nucleosynthesis theory and the related observations of the light element isotopes is presented. Implications of BBN on chemical evolution and constraints on particle properties will also be discussed.

International Nuclear Information System (INIS)

Observations concerned with the formation of isothermal #omega# in the beta-titanium alloy RMI (38-6-44) are presented as part of a more general study of the aging characteristics of the alloy.

CERN Document Server

Suppose an astronomer is equipped with a device capable of detecting emissions -- whether they be electromagnetic, gravitational, or neutrino -- from transient sources distributed throughout the cosmos. Because of source rate density evolution and variation of cosmological volume elements, the sources first detected when the machine is switched on are likely to be ones in the high-redshift universe; as observation time increases, rarer, more local, events will be found. We characterize the observer's evolving record of events in terms of a "probability event horizon", converging on the observer from great distances at enormous speed, and illustrate it by simulating neutron star birth events distributed throughout the cosmos. As an initial application of the concept, we determine the approach of this horizon for gamma-ray bursts (GRBs) by fitting to redshift data. The event rates required to fit the model are consistent with ...

International Nuclear Information System (INIS)

Surface-sensitive UV photoelectron yield spectroscopy was employed to study electron acceptor levels at surfaces of chalcopyrite structure Cu-In-Se thin films. Surface Fermi level pinning was observed for Cu-rich films. Shallow acceptor levels ascribable to defects Cu_I_n and V_C_u were observed for near-stoichiometric and In-rich films respectively. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Transverse form factors have been extracted for the low-lying neutron hole (particle) states of /sup 207/Pb from inelastic-electron-scattering data. A systematic, multipolarity-and momentum-transfer-independent quenching of approx.55% in the transverse amplitude is observed when compared with single particle predictions for both electric and magnetic transitions. The magnitude of the observed effect is not readily explained by our present theoretical understanding of this nucleus.

International Nuclear Information System (INIS)

The paper is concerned with the results of a morphological study following chemoradiotherapy in 25 patients with Ewing's sarcoma and 14 patients with reticulum cell carcoma. The signs of therapeutic pathomophosis were observed in the first 3 days, and substitution of the connective tissue for a necrotized tumor started by the 3rd-4th week after the initiation of therapy. In some cases tumor growth and recurrences at the site of a treated tumor were observed.

Energy Technology Data Exchange (ETDEWEB)

The extent measurement error on CT colonography influences polyp categorisation according to established management guidelines is studied using twenty-eight observers of varying experience to classify polyps seen at CT colonography as either 'medium' (maximal diameter 6-9 mm) or 'large' (maximal diameter 10 mm or larger). Comparison was then made with the reference diameter obtained in each patient via colonoscopy. The Bland-Altman method was used to assess agreement between observer measurements and colonoscopy, and differences in measurement and categorisation was assessed using Kruskal-Wallis and Chi-squared test statistics respectively. Observer measurements on average underestimated the diameter of polyps when compared to the reference value, by approximately 2-3 mm, irrespective of observer experience. Ninety-five percent limits of agreement were relatively wide ...

Energy Technology Data Exchange (ETDEWEB)

A model for generating the observed cosmic-ray antiproton spectrum in plasma consisting mainly of electron--positron pairs (n/sub plus-or-minus//n/sub p/> or approx. =10) is discussed. Coulomb collisions in the plasma would cause additional energy losses, significantly enhancing the antiproton flux at energies < or approx. =1 GeV. The computed p-bar/p ratio satisfactorily fits the observations.

International Nuclear Information System (INIS)

Monte Carlo calculations performed to validate observed capture reaction rates of "1"2"9I and "2"3"7Np were in a reasonable agreement with experimental data obtained by the Joint Institute for Nuclear Research. The most significant discrepancy between the measurements and calculations (within a factor of 3) was observed for the NpO_2 sample and Pb target at 3.7 GeV proton energy

Energy Technology Data Exchange (ETDEWEB)

In a theory where the local observables are determined by local field algebras as the fixed points under a (a priori noncommutative) group of gauge transformations of the first kind, we show that, if the field algebras possess intermediate type I factors, we can construct observables having the meaning of local charge measurements, and local current algebras in the field algebras.

International Nuclear Information System (INIS)

Levels in "7"2Se were observed via in-beam gamma spectroscopy following the "5"8Ni("1"6O,2p) reaction. Spectra and partial energy level schemes are shown. (3 figures) (U.S.).

Energy Technology Data Exchange (ETDEWEB)

Two general categories are discussed concerning the evolution of the solar system: the dualistic view, the planetesimal approach and the monistic view, the nebular hypothesis. The major points of each view are given and the models that are developed from these views are described. Possible applications of gamma ray astronomical observations to the question of the dynamic evolution of the solar system are discussed.

International Nuclear Information System (INIS)

We discuss the search of excited leptons and quarks with spin 1/2 at #gamma##gamma# and at #gamma#e colliders. We show that #gamma##gamma# colliders have important advantages for the observation of excited leptons and quarks in comparison with ee, ep, and pp colliders discussed in previous papers. These collisions give a simple test for the chirality of the l"*l#gamma# transition. The anomalous magnetic moment of excited leptons can be observed when its value is not too small. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The authors summarize EUVE's contribution to the study of the boundary layer emission of high accretion-rate nonmagnetic cataclysmic variables, especially the dwarf novae SS Cyg, U Gem, VW Hyi, and OY Car in outburst. They discuss the optical and EUV light curves of dwarf nova outbursts, the quasi-coherent oscillations of the EUV flux of SS Cyg, the EUV spectra of dwarf novae, and the future of EUV observations of cataclysmic variables.

Science.gov (United States)

In this activity, students will make a turbidity current. They will discover how fluids of differing densities interact with one another, learn some ways the densities of fluids can be changed and observe how density currents transport and deposit tremendous amounts of sediment in lakes and in the ocean. Additional options allow students to create and observe different kinds of density currents.

Energy Technology Data Exchange (ETDEWEB)

Asymptotic giant branch stars are red supergiant stars of low-to-intermediate mass. This class of stars is of particular interest because many of these stars can have nuclear processed material brought up repeatedly from the deep interior to the surface where it can be observed. A review of recent theoretical and observational work on stars undergoing the asymptotic giant branch phase is presented. 41 refs.

CERN Document Server

We present high-precision time-series photometry of the classical delta Scuti star HD 144277 obtained with the MOST (Microvariability and Oscillations of STars) satellite in two consecutive years. The observed regular frequency patterns are investigated asteroseismologically. HD 144277 is a hot A-type star that is located on the blue border of the classical instability strip. While we mostly observe low radial order modes in classical delta Scuti stars, HD 144277 presents a different case. Its high observed frequencies, i.e., between 59.9c/d (693.9 microHz) and 71.1c/d (822.8microHz), suggest higher radial orders. We examine the progression of the regular frequency spacings from the low radial order to the asymptotic frequency region. Frequency analysis was performed using Period04 and SigSpec. The results from the MOST observing runs in 2009 and 2010 were compared to each other. The resulting ...

International Nuclear Information System (INIS)

As part of the 1999 NARSTO Northeast Oxidant and Particulate Study (NE-OPS) field campaign, the DOE G-1 aircraft sampled trace gases and aerosols in and around the Philadelphia metropolitan area. Twenty research flights were conducted between July 25 and August 11. The overall goals of these flights were to obtain a mechanistic understanding of O(sub 3) production; to characterize the spatial and temporal behavior of photo-oxidants and aerosols; and to study the evolution of aerosol size distributions, including the process of new particle formation. Within the NE-OPS program, other groups provided additional trace gas, aerosol, and meteorological observations using aircraft, balloon, remote sensing, and surface based instruments (Phillbrick et al., 2000). In this article we provide an overview of the G-1 observations related to O(sub 3) production, focusing on the vertical distribution of pollutants. Ozone production rates are calculated using ...

CERN Document Server

We make a comparison of the predicted effective weak mixing angle, the Z-on resonance asymmetries and the W-boson mass to the LEP and SLD data at their present status. We find that the predicted MSSM values for the effective weak mixing angle are in agreement with the LEP+SLD average value for a ``heavy'' SUSY breaking scale while we observe an agreement with SLD data in the case of a ``light'' SUSY breaking scale. The resulting values for the W-boson mass and for the electron left-right asymmetries are compatible with CDF,UA2,DO and LEP data respectively. Unexpectedly we find that the supersymmetric QCD contributions to the Z-observables tend to vanish everywhere in the M1/2-M0 plane. Furthermore, values of M1/2 which are greater than 500 GeV are favoured by the MSSM if one considers the current experimental value for the strong coupling.

CERN Document Server

Very high energy (VHE; >100 GeV) observations of a sample of selected active galactic nuclei (AGN) were performed between January 2005 and April 2007 with the High Energy Stereoscopic System (HESS), an array of imaging atmospheric-Cherenkov telescopes. Significant detections are reported elsewhere for many of these objects. Here, integral flux upper limits for twelve candidate very high energy (VHE; >100 GeV) gamma-ray emitters are presented. In addition, results from HESS observations of four known VHE-bright AGN are given although no significant signal is measured. For three of these AGN (1ES 1101-232, 1ES 1218+304, and Mkn 501) simultaneous data were taken with the Suzaku X-ray satellite.

Energy Technology Data Exchange (ETDEWEB)

The authors have studied in detail the transient enhanced diffusion observed during furnace or rapid-thermal-annealing of ion-implanted Si. The authors show that the effect originates in the trapping of Si atoms by dopant atoms during implantation, which are retained during solid-phase epitaxial (SPE) growth but released by subsequent annealing to cause a transient dopant precipitation or profile broadening. The interstitials condense to form a band of dislocation loops located at the peak of the dopant profile, which may be distinct from the band formed at the original amorphous/crystalline interface. The band can develop into a network and effectively getter the dopant. They discuss the conditions under which the various effects may or may not be observed, and discuss preliminary observations on As/sup +/ implanted Si. 12 references, 12 figures.

International Nuclear Information System (INIS)

The authors have studied in detail the transient enhanced diffusion observed during furnace or rapid-thermal-annealing of ion-implanted Si. The authors show that the effect originates in the trapping of Si atoms by dopant atoms during implantation, which are retained during solid-phase epitaxial (SPE) growth but released by subsequent annealing to cause a transient dopant precipitation or profile broadening. The interstitials condense to form a band of dislocation loops located at the peak of the dopant profile, which may be distinct from the band formed at the original amorphous/crystalline interface. The band can develop into a network and effectively getter the dopant. They discuss the conditions under which the various effects may or may not be observed, and discuss preliminary observations on As"+ implanted Si. 12 references, 12 figures.

CERN Document Server

We propose an X-ray mission called Xenia to search for decaying superweakly interacting Dark Matter particles (super-WIMP) with a mass in the keV range. The mission and its observation plan are capable of providing a major break through in our understanding of the nature of Dark Matter (DM). It will confirm, or reject, predictions of a number of particle physics models by increasing the sensitivity of the search for decaying DM by about two orders of magnitude through a wide-field imaging X-ray spectrometer in combination with a dedicated observation program. The proposed mission will provide unique limits on the mixing angle and mass of neutral leptons, right handed partners of neutrinos, which are important Dark Matter candidates. The existence of these particles is strongly motivated by observed neutrino flavor oscillations and the problem of baryon asymmetry of the Universe. In super-WIMP models, the details of the ...

International Nuclear Information System (INIS)

Contradictory reports in the literature on the reliability of lymphography stimulated the authors to test the diagnostic accuracy, employing methods which are approximately analogous to practice, using carcinoma of the cervix as the model on which the study was carried out. Using 21 observers it was found that there was no correlation between their experience and on-target accuracy of the diagnosis. Good observers obtained an accuracy of 85% with good proportions between sensitivity in the recognition of detail, specificity and readiness to arrive at a decision on the basis of discriminatory ability. With the help of the concept of the ROC curves, the position taken up by the observers in respect of diagnostic decisions, and a complex manner of assessing the various characteristic factors determining diagnostic accuracy, are demonstrated. This form of test, which permits manipulation of different variants of diagnosis, is ...

Energy Technology Data Exchange (ETDEWEB)

Contents include: index for 1970-1980; January 1981 data -- alert periods, daily solar indices, solar flares, solar radio emission, coronal holes, inferred interplanetary magnetic field polarities, mean solar magnetic field, spacecraft observations, December 1980 data -- daily solar-activity centers, sudden ionospheric disturbances, spacecraft observations, solar radio emission, cosmic rays, geomagnetic indices, radio-propagation indices; late data -- solar radio emission November, December 1980, spacecraft observations November 1980, cosmic rays, Huancayo Oct 1980 -- climax, alert, Deep River Nov 1980.

Energy Technology Data Exchange (ETDEWEB)

The general objective of this workshop is to investigate and discuss methods by which uncertainties in mass balance models for toxics in the Great Lakes may be reduced. As described by the workshop prospectus, this paper is focused on problems of reducing (and quantifying) uncertainty as they relate to in situ field observations/system response measurements for the establishment of initial conditions, boundary conditions, calibration/confirmation data sets, and model post-audit data sets.'' I have taken this description to refer not only to the evaluation of uncertainty in the field observations themselves, but also to the uncertainty associated the analyses of in situ observations as they interact in the overall modeling process. Thus, I will be concerned here with quantification and reduction of uncertainty both (1) as they may be applied to descriptions of the system that is being modeled and (2) as ...

British Library Electronic Table of Contents (United Kingdom)

High-level expression of mitotic arrest defective protein 2 (MAD2), a central component of the spindle assembly checkpoint, has been observed in a variety of human malignancies. Aim of the present study was to observe the expression of MAD2 in human non-small-cell lung cancer (NSCLC) and explore its clinicopathologic significance and evaluate MAD2 expression as a prognostic marker. MAD2 transcript was found to be overexpressed in the great majority of lung cancers by semi-quantitative RT-PCR. A total of 358 NSCLCs were analyzed immunohistochemically on tissue microarrays. High-level MAD2 expression was observed in 26.3% (94 of 358 cases), and correlated with male sex (P=0.0002), tumor progression (pT status) (P=0.0009), visceral or parietal pleural invasion (P=0.0151), non-adenocarcinoma, ...

International Nuclear Information System (INIS)

Upon irradiation of aqueous ethylene glycol/water solutions of native chloroperoxidase (CPO) with "6"0Co-gamma rays at 77K one observes the one-electron reduction of the enzyme active site by radiolytically generated thermolyzed electrons. In the present study the first absorption spectrum of a low-spin ferrous form of CPO is reported which has peaks at 438, 532 and 563 nm, similar to those observed previously for cytochrome P-450. All previously described ferrous forms of CPO are high spin. In order to observe the final results of the CPO reaction with electrons, the spectral changes of native enzyme after room temperature-gamma-irradiation have also been investigated. Evidence of changes is also presented probably connected with disruption of the tertiary structure of enzyme, correlated with decrease of enzyme activity.