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Although experimental results so far agree with predictions of the standard model, it is widely felt to be incomplete. Many prospective theories beyond the standard model predict extra neutral gauge bosons, denoted by Z', which might be light enough to be accessible at the LHC. Observables sensitive to the properties of these extra gauge bosons might be used to discriminate between the different theories beyond the standard model. In the present work several of these observables (total decay width, leptonic cross-section and forward-backward asymmetries) are studied at generation level and with a full simulation in the ATLAS detector. The Z' {yields} e{sup +}e{sup -} decay channel was chosen and 2 values for the mass of Z': 1.5 TeV and 4 TeV. Background is studied as well and it is confirmed that a Z' ...

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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 ...

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Tree-level scattering amplitudes of longitudinally polarized electroweak vector bosons in the Standard Model are calculated using Mathematica package Feyncalc. The modifications of low-energy theorems for longitudinally polarized W and Z in the Standard Model are discussed.

CERN Document Server

Modifications of low-energy theorems for the scattering of longitudinally polarized W and Z bosons in an alternative model of electroweak symmetry breaking are discussed. The symmetry breaking pattern SU(4)/SU(2) leads to light (compared to 1 TeV) pseudo-Goldstone bosons. Their interactions with electroweak gauge bosons are described by chiral (or effective) lagrangian. Tree-level contribution of the pseudo-Goldstone bosons to the scattering amplitudes are computed. Comparison with the Standard Model is given.

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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.

International Nuclear Information System (INIS)

Future #gamma##gamma# colliders allow the production of the heavy neutral MSSM Higgs bosons H and A as single resonances. The prospects of finding these particles in the bb-bar and the neutralino-pair final states have been analyzed. The H, A bosons can be discovered for medium values of tan #beta# with masses up to 70-80% of the initial e"#+-#e"- c.m. energy. This production mode thus covers parts of the supersymmetric parameter space that are not accessible at other colliders.

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In this paper we discuss possible signatures for the production of scalar t_1t_1"* (top squarkonium) bound states #sigma#_t_1 at hadron colliders, where t_1 is the lighter scalar top eigenstate. We first study the decay of #sigma#_t_1; explicit expressions are given for all potentially important decay modes. If t_1 has unsuppressed two-body decays, they will always overwhelm the annihilation decays of #sigma#_t_1. Among the latter, we find that usually either the gg or hh final state dominates, depending on the size of the off-diagonal entry of the top squark mass matrix; h is the lighter neutral scalar Higgs boson of the minimal supersymmetric model. If m_#sigma#_t happens to be close to the mass of one of the neutral scalar Higgs bosons, Q bar Q final states dominate (Q=b or t). W"+W"- and ZZ final states are subdominant. We argue that #sigma#_t_1#->##gamma##gamma# decays offer the best signal for ...

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The electroweak radiative correction, which turned out to be marginal within the standard electroweak model having the minimal Higgs sector in view of the present experimental information, fits well the experiment when the Higgs sector is extended to have two Higgs doublets. We predict the range where the charged and CP odd Higgs boson masses would lie, taking the two CP even neutral Higgs boson masses to be degenerate which makes the analysis in multiparameter space feasible. It is shown that the mass of neutral Higgs doublet boson can arbitrarily be large consistently with the $W$ mass, if the charged Higgs boson is present and it's mass lies in some appropriate ranges.

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Recent experimental results in direct dark matter detection may be interpreted in terms of a dark matter particle of mass around 10 GeV/c^2. We show that the required scenario can be realized with a new dark matter particle charged under an extra abelian gauge boson Z' that couples to quarks but not leptons. This is possible provided the Z' gauge boson is very light, around 10-20 GeV/c^2 in mass, and the gauge coupling constant is small, alpha' ~ 10^(-5). Such scenarios are not constrained by accelerator data.

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Motivated by recent anomalous CDF data on $Wjj$ events, we study a possible explanation within the framework of the two-Higgs doublet model. We find that a charged Higgs boson of mass $\\sim$ 140 GeV with appropriate couplings can account for the observed excess. In addition, we consider the flavor-changing neutral current effects induced at loop level by the charged Higgs boson on the $B$ meson system to further constrain the model. Our study shows that the like-sign charge asymmetry $A_{s\\ell}^b$ can be of ${\\cal O}(10^{-3})$ in this scenario.

International Nuclear Information System (INIS)

In this report, I surveyed physics potential of the #gamma##gamma# option of a linear e"+e"- collider with the following questions in mind: What new discovery can be expected at a #gamma##gamma# collider in addition to what will be learned at its 'parent' e"+e"- linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e"- beams, we find that a #gamma##gamma# collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e"-e"- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a #gamma##gamma# collider. CP property of the scalar sector can be explored in detail by making use of linear ...

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We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at {gamma}{gamma} colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of {mu}{sup +}{mu}{sup -}, {tau}{sup +}{tau}{sup -}, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan{beta}-bar 5 (30) and large (small) charged Higgs-boson masses.

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We study the production of three gauge bosons (W"+W"-Z"0 and W"+W"-#gamma#) at the next generation of linear e"+e"- colliders operating in the #gamma##gamma# mode. We analyze the total cross sections as well as several kinematical distributions of the final state particles. We find out that a linear e"+e"- machine operating in the #gamma##gamma# mode will produce 5--10 times more three-gauge-boson states compared to the standard e"+e"- mode at high energies.

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The mean-field pictures based on the standard time-dependent variational approach have widely been used in the study of nonlinear many-boson systems such as the Bose-Hubbard model. The mean-field schemes relevant to Gutzwiller-like trial states $|F>$, number-preserving states $|\\xi >$ and Glauber-like trial states $|Z>$ are compared to evidence the specific properties of such schemes. After deriving the Hamiltonian picture relevant to $|Z>$ from that based on $|F>$, the latter is shown to exhibit a Poisson algebra equipped with a Weyl-Heisenberg subalgebra which preludes to the $|Z>$-based picture. Then states $|Z>$ are shown to be a superposition of $\\cal N$-boson states $|\\xi>$ and the similarities/differences of the $|Z>$-based and $|\\xi>$-based pictures are discussed. Finally, after proving that the ...

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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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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.

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We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider (LHC), within the so-called M-SUGRA scenario, i.e., the Supergravity (SUGRA) inspired Minimal Supersymmetric Standard Model (MSSM). For low values of \\tan\\beta only the cases \\tilde{t}_1\\tilde{t}_1^* H, \\tilde{t}_1\\tilde{t}_1^* h and than 30 a variety of signals involving all Higgs bosons can be accessed, at high collider luminosity. The dependence of these reactions on the M-SUGRA parameters might further allow one to pin down the actual structure of the underlying Supersymmetric (SUSY) model.

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The authors search Z{prime} bosons in dielectron events produced in p{bar p} collisions at {radical}s = 1.96 TeV, using a 0.45 fb{sup -1} dataset accumulated with the CDF II detector at the Fermilab Tevatron. To identify the Z{prime} {yields} e{sup +}e{sup -} signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z{prime} mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z{prime}, as well as on the contact interaction mass scales for different helicity structure scenarios.

International Nuclear Information System (INIS)

We study double Higgs boson production at future linear colliders while paying special attention to the option of high-energy and high-luminosity photon beams. The main purpose is to examine the feasibility of e"+e"-, #gamma#e, and #gamma##gamma# colliders in order to establish bounds on the value of triple Higgs coupling, which could be crucial for understanding a spontaneous breaking mechanism. We consider mainly those cases of light and intermediate Higgs bosons, including an analysis of the electroweak backgrounds. The mass range M_H#approx#M_Z is discussed separately. It is shown that for a light Higgs boson the H"3 coupling can be visible, even at a future linear e"+e"- collider at 500 GeV. For an intermediate Higgs boson, a collider with TeV energies is suitable for investigations. We estimate the bounds on the anomalous H"3 coupling which can be experimentally established at ...

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 ...

International Nuclear Information System (INIS)

In the context of stellar reionization in the standard cold dark matter model, we analyze observations at z #approx# 6 and are able to draw three significant conclusions with respect to star formation and the state of the intergalactic medium (IGM) at z #approx# 6. (1) An initial stellar mass function (IMF) more efficient, by a factor of 10-20, in producing ionizing photons than the standard Salpeter IMF is required at z #approx# 6. This may be achieved by having either (a) a metal-enriched IMF with a lower mass cutoff of #>=#30 M_s_u_n or (b) 2%-4% of stellar mass being Population III massive metal-free stars at z #approx# 6. While there is no compelling physical reason or observational evidence to support (a), (b) could plausibly be fulfilled by continued existence of some pockets of uncontaminated, metal-free gas for star formation. (2) The volume-weighted neutral fraction of ...

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We compute the potential for localized closed string tachyons in bosonic string theory on the orbifold C/Z{sub 4} using level-truncated closed string field theory. The critical points of the potential exhibit features which agree with their conjectured identification as lower-order orbifolds. However this case also raises some questions regarding the quantitative predictions associated with these conjectures. (author)

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We analyze the potential of the e"+e"- linear colliders, operating in the e#gamma# and #gamma##gamma# modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2)_L(circle times)U(1)_Y chiral operators of order p"4 that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e#gamma# and #gamma##gamma# modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10"-"2 at 90% C.L. Moreover, the information gathered in the e#gamma# mode can be used to reduce the ambiguities of the e"+e"- mode.

CERN Document Server

We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider, within the supergravity inspired minimal supersymmetric standard model We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider, within the Supergravity inspired Minimal Supersymmetric Standard Model. The phenomenological relevance of such reactions is twofold. Firstly, they constitute a novel production mechanism of Higgs particles, either through a decay of a heavier (anti)squark into a lighter one or via a Higgs bremsstrahlung process. Secondly, their production rates are extremely sensitive to the values assumed by the five input parameters of the model, this possibly allowing one to put stringent constraints on the latter. After an exhaustive scan of the parameter space, we find that the majority of such ...

CERN Document Server

An anisotropic power spectrum will have a clear signature in the 21cm radiation from high- redshift hydrogen. We calculate the expected power spectrum of the intensity fluctuations in neutral hydrogen from before the epoch of reionization, and predict the accuracy to which future experiments could constrain a quadrupole anisotropy in the power spectrum. We find that the Square Kilometer Array will have marginal detection abilities for this signal at z~17 if the process of reionization has not yet started; reionization could enhance the detectability substantially. Pushing to higher redshifts and higher sensitivity will allow highly precise (percent level) measurements of anisotropy.

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We have combined perturbative unitarity and renormalisation group equation arguments in order to find a dynamical way to constrain the space of the gauge couplings ($g'_1$, \\widetilde{g}$) of the so-called "Minimal $Z'$ Models". We have analysed the role of the gauge couplings evolution in the perturbative stability of the two-to-two body scattering amplitudes of the vector and scalar sectors of these models and we have shown that perturbative unitarity imposes an upper bound that is generally stronger than the triviality constraint. We have also demonstrated how this method quantitatively refines the usual triviality bound in the case of benchmark scenarios such as the $U(1)_\\chi$, the $U(1)_R$ or the "pure" $U(1)_{B-L}$ extension of the Standard Model. Finally, a description of the underlying model structure in Feynman gauge is provided.

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In this paper, we study the J/#psi#(#UPSILON#) production in Z boson decay in a color-singlet model (CSM). We calculate the next-to-leading-order (NLO) QCD correction to Z#->#quarkonium+QQ, the dominant contribution in the CSM, with the vector and axial-vector parts in the ZQQ vertex being treated separately. The results show that the vector and axial-vector parts have the same K factor (the ratio of the NLO result to the leading-order result) 1.13 with the renormalization scale #mu#=2m_c and m_c=1.5 GeV, and the K factor falls to 0.918 when applying the Brodsky, Lepage, and Mackenzie (BLM) renormalization scale scheme with obtained #mu#_B_L_M=2.28 GeV and m_c=1.5 GeV. By including the contributions from the next-dominant ones, the photon and gluon fragmentation processes, the branching ratio for Z#->#J/#psi#_p_r_o_m_p_t+X is (7.3-10.0)x10"-"5 with the uncertainty consideration for the ...

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This document deals with the couplings between the W boson and Z and gamma particles. WWZ and WW{gamma} vertex are predicted by the electroweak theory based on the symmetry group SU(2){sub L}*U(1){sub Y}, their existence is confirmed by the measurement of the production cross-section of W pairs at LEP. The effective values of the couplings are modified by the introduction of standard model particle loops at the vertex level, the impact on the coupling value is assessed to reach 10{sup -3}. These loops can also include beyond-the-standard-model particles, their impact is in the magnitude order of 10{sup -3} for most models. The fully description of these loops requires the values of 14 complex parameters whose measurement will give information about the existence of new particles. Nevertheless the number of events at LEP is not sufficient to measure all the parameters simultaneously. As a consequence the analysis is limited to the 3 most ...

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The subject of cosmic ray antiproton production is reexamined by considering other choices for the nature of the Majorana fermion chi other than the photino considered in a previous article. The calculations are extended to include cosmic-ray positrons and cosmic gamma rays as annihilation products. Taking chi to be a generic higgsino or simply a heavy Majorana neutrino with standard couplings to the Z-zero boson allows the previous interpretation of the cosmic antiproton data to be maintained. In this case also, the annihilation cross section can be calculated independently of unknown particle physics parameters. Whereas the relic density of photinos with the choice of parameters in the previous paper turned out to be only a few percent of the closure density, the corresponding value for Omega in the generic higgsino or Majorana case is about 0.2, in excellent agreement with the value associated with galaxies and one which is sufficient to ...

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We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes #gamma##gamma##->#4f and #gamma##gamma##->#4f#gamma# in the standard model and extensions thereof by an effective #gamma##gamma#H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes #gamma##gamma##->#4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. Moreover, the size of various contributions to cross sections, such as from weak charged- or ...

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We consider the possibility of detecting a heavy Higgs boson ([ital m][sub [ital H

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Amplitudes for fermion-fermion, boson-boson and fermion-boson interactions are calculated in the second order of perturbation theory in the Lobachevsky space. An essential ingredient of the model is the Weinberg's 2(2j+1)-component formalism for describing a particle of spin j. The boson-boson amplitude is then compared with the two-fermion amplitude obtained long ago by Skachkov on the basis of the Hamiltonian formulation of quantum field theory on the mass hyperboloid, p_0^2 - p^2=M^2, proposed by Kadyshevsky. The parametrization of the amplitudes by means of the momentum transfer in the Lobachevsky space leads to same spin structures in the expressions of T-matrices for the fermion case and the boson case. However, certain differences are found. Possible physical applications are discussed.

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In light of the recent measurements of the top quark forward-backward asymmetry at the Fermilab Tevatron experiment, which in some regions of the parameter space shows a discrepancy of 3$\\sigma$ compared to the SM prediction, we analyze top quark pair production and asymmetry in the context of left-right models both at the Tevatron and LHC. We use the minimal manifest left-right model and an asymmetric left-right model where gauge couplings and flavor mixing in the right-handed sector are allowed to differ from those in the left-handed sector. We explore the consequences of including effects from $W_R$ and $Z_R$ gauge bosons, consistent with phenomenological constraints from meson mixing and new bounds from ATLAS and CMS, for the $t \\bar{t}$ cross section, invariant mass distribution and forward-backward asymmetry at the Tevatron, and predict their values at the LHC. We show that, varying the parameters of the model while preserving agreement ...

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No abstract prepared.

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UE p?aci za zaj?cia z fizyki

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... purww{u{sz p~z} |sppuspmimdjmhghgxoiiqh_ befbdhge^cheiz sxuz}vum {v|vuvx z~~ u z}z{wp wvxtvv{ptrksn xmrv~z qxl|tqnnhlicgniidkhcehfdh[bb``cbbjbf`q nsxusx ...

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Observations of anisotropies in the brightness temperature of the 21 cm line of neutral hydrogen from the period before reionization would shed light on the dawn of the first stars and galaxies. In this paper, we use large-scale semi-numerical simulations to analyse the imprint on the 21 cm signal of spatial fluctuations in the Lyman-alpha flux arising from the clustering of the first galaxies. We show that an experiment like the Square Kilometer Array (SKA) can probe this signal at the onset of reionization giving us important information about the UV emission spectra of the first stars and characterizing their host galaxies. SKA-pathfinders with ~ 10% of the full collecting area should be capable of making a statistical detection of the 21 cm power spectrum at redshifts $z\\lesssim 20$. We then show that the SKA should be able to measure the three dimensional power spectrum as a function of the angle with the line of sight and discuss the use ...

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The baryogenesis process in the early hot universe is investigated by means of relativistic kinetic theory. An exact solution to the kinetic equations for supermassive bosons serves to refine previous results: the optimum baryon-production domain is now complemented by bosons of low mass, thus removing the cosmological lower bound that had limited the mass of superheavy bosons. 14 references.

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We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in {gamma}{gamma} mode at the TeV energy scale. Final states with one or two H{sup {+-}} bosons are considered, as produced by both tree- and loop-level interactions. (orig.)

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The authors present some precision measurements on electroweak physics performed at the Tevatron collider at Fermilab. Namely they report on the boson-pair production cross sections and on triple gauge boson couplings using proton anti-proton collisions collected by the CDF and D0 experiments at the center-of-mass energy of 1.96 TeV. The data correspond to an integrated luminosity of up to 324 pb{sup -1}.

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High oleic acid sunflower oils have been commercially available for some years now. Due to their high content of monounsaturated fatty acids these oils have a number of potential applications in the oleochemical industry, especially where technical oleic acids and their derivatives are used. Whereas conventional sunflower oil contains approx. 68% linoleic acid (C{sub 1}8:2), it is now possible through breeding measures to obtain ''new sunflower oils'' (NSb oils) with oleic acid levels of 70-95% oleic acid (C{sub 1}8:1). The oil itself is of interest for technical applications: it is light-coloured, has a neutral odour and is relatively resistant to oxidation. Plant oils, especially those with a low content of polyunsaturated fatty acids, are increasingly gaining interest as ester oils in technical application areas, e.g. as lubricants. However, there are limits to the technical applicability of triglycerides due to their ...

International Nuclear Information System (INIS)

Casimir operators and the Cartan subalgebra are used to construct the scalar superfields in 10-dimensions. In massless case it is shown that the scalar superfield contains two irreducible pieces, one bosonic and one fermionic. The bosonic one contains the supergravity multiplet. Supersymmetric version of the Cartan subalgebra is used to obtain the explicit expressions of the irreducible superfields. In massive case the scalar superfield contains two bosonic and one fermionic irreducible components. It is shown explicitly that the one of the bosonic pieces reduces to the above mentioned massless bosonic piece containing the supergravity multiplet in the massless limit. Supersymmetric generators corresponding to the root vectors of the Lie algebra are found and used with the Cartan subalgebra to construct the irreducible scalar superfields. Finally this method is also applied to the ...

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We discuss various reactions at future e"+e"- and #gamma##gamma# colliders involving real (beamstrahlung or backscattered laser) or quasi-real (bremsstrahlung) photons in the initial state and hadrons in the final state. The production of two central jets with large transverse momentum p_T is described in some detail; we give distributions for the rapidity and p_T of the jets as well as the di-jet invariant mass, and discuss the relative importance of various initial state configurations and the uncertainties that arise from the at present rather poor knowledge of the parton content of the photon. We also present results for 'mono-jet' production where one jet goes down a beam pipe, for the production of charm, bottom and top quarks, and for single production of W and Z bosons. Where appropriate, the two-photon processes are compared with annihilation reactions leading to similar final states. We also argue that the behaviour of the total ...

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Recent studies have provided data that make it possible to estimate the efficiency and cost of future beamlines using a chemical oxygen-iodine laser as a neutralizer. These studies indicate that a 400-keV neutral deuterium beam of more than 20 A will operate at an efficiency >60%, with the capital cost of the neutralizer at less than $2/W of neutral beam output. Beamlines of lower current and less energy will operate at poorer efficiencies and higher neutralizer costs per watt of neutral beam. These are estimates. As they are very sensitive to changes in the assumptions from which they were derived, they must be used with some caution. Additional studies are expected to provide more reliable estimates.

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The heavy Higgs bosons H,A of the minimal supersymmetric extension of the Standard Model can be produced as resonances in high-energy {gamma}{gamma} colliders. Prospects of the search for these particles in bb-bar and neutralino-pair final states are studied in this report. Heavy Higgs bosons can be found with masses up to about 70-80% of the initial e{sup +}e{sup -} collider energy for moderate values of tan {beta}, i.e. in areas of the parameter space not accessible at other colliders.

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In this letter, they present the results on a global fit to precision electroweak data in a Higgs triplet model. In models with a triplet Higgs boson, a consistent renormalization scheme differs from that of the Standard Model and the global fit shows that a light Higgs boson with mass of 100-200 GeV is preferred. Triplet Higgs bosons arise in many extensions of the Standard Model, including the left-right model and the Little Higgs models. The result demonstrates the importance of the scalar loops when there is a large mass splitting between the heavy scalars. It also indicates the significance of the global fit.

International Nuclear Information System (INIS)

Properties of unique parity states in odd-proton (_7_7Ir, _7_9Au) and odd-neutron nuclei (_7_8Pt) are investigated in the framework of the interacting boson-fermion approximation model. The core (boson)-particle (fermion) interaction is represented by a quadrupole-quadrupole interaction and an exchange term, which takes into account the effects of the Pauli exclusion principle. The even-even core nucleus is described in terms of the IBA-1 hamiltonian. The change in the properties of the corresponding odd-A nuclei can be interpreted in terms of a transition of the core hamiltonian between the O(6) and SU(3) limiting cases. (orig.).

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The possibility of applying the near infrared gas dynamic lasers (GDL) for neutralization of negative ion beams is examined. A criterion of neutralization is suggested. The use of the criterion makes it possible to select an optically active medium for a negative ion neutralization. To demonstrate the method media containing hydrohalogens as imitating molecules are taken. ((orig.))

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The authors present the results of a search for W{prime} boson decaying to electron-neutrino pairs in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb{sup -1} of integrated luminosity collected by the CDF II detector at Fermilab. They observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from W{prime} boson decays to be light. If they assume the manifest left-right symmetric model, they exclude a W{prime} boson with mass less than 788 GeV/c{sup 2} at the 95% confidence level.

International Nuclear Information System (INIS)

We present the effects of heavy CP-even (H) and CP-odd (A) Higgs bosons on the production cross section of the process #gamma##gamma##->#tt at the energy around the mass poles of the Higgs bosons. It is found that interference between H and A with small mass gap, as well as the ones between Higgs bosons and continuum, contributes to the cross section, if the photon beams are polarized and if we observe the helicity of the top quarks. It is demonstrated in the framework of the minimal supersymmetric extension of the standard model that the H and A contributions can be sizable at future #gamma##gamma# colliders for small values of tan #beta#. The methods to measure the CP-parity of the Higgs boson are also presented. The statistical significance of detecting the Higgs signals and measuring the Higgs CP-parity is evaluated. (orig.)

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We consider the Pauli theorem on the spin-statistics connection for faster-than-light particles. As the consequence of the unlocalizability of tachyons in space we conclude that their spin-statistics correlations are inverted.

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The BNL Neutral Beam Development Group has been active in the program for the development of high energy, high power neutral beam systems since 1973. These injectors are based on the production, acceleration and neutralization of negative hydrogen or deuterium ions and are supposed to be used for plasma heating and current drive in the next generation of fusion devices. Over the span of 10 years the group has studied plasma-surface type of negative hydrogen ion sources, transport and acceleration of negative ion beams and neutralization of negative ions in gases and plasmas. As the required source parameters (current, pulse length, efficiency) were changing over this period of time, the group developed several types of sources, resulting finally in the design of a steady state device operating with an excellent gas efficiency and having the possibility of scaling-up to the size necessary for a high ...

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The Cutkosky rules are generalized to include tachyons. A consequence is that Lorentz-invariant interacting theories which possess tachyons cannot obey even the weakest possible form of unitarity beyond the tree level. The problem (although not the cutting rules) is shown to extend to bosonic string theory. Thus unitarity cannot be used to determine the range of modular integration in bosonic string loop amplitudes.

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In this paper para boson-fermion supersymmetry is exemplified in simple oscillator systems. The parasupercharge satisfies the ordinary supersymmetry algebra. The parabosonic and parafermionic oscillators do not commute and the energy spectra are non-trivial for even the one level system. The authors calculate the partition functions and compare with those for the non-supersymmetric systems.

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We extend the analysis of a previous paper to the bosonic case and find the one-derivative effective action valid in the vicinity of rolling tachyons with an energy not larger than that of the original D-brane. For on-shell tachyons rolling down the well-behaved side of the potential in this theory, the energy is conserved and the pressure eventually decreases exponentially. For tachyons rolling down the 'wrong' side, the pressure instead blows up in a finite time. (author)

CERN Document Server

We report an uncertainty evaluation of an optical lattice clock based on the $^1S_0\\leftrightarrow^3P_0$ transition in the bosonic isotope $^{174}$Yb by use of magnetically induced spectroscopy. The absolute frequency of the $^1S_0\\leftrightarrow^3P_0$ transition has been determined through comparisons with optical and microwave standards at NIST. The weighted mean of the evaluations is $\

International Nuclear Information System (INIS)

Bosonic colored group field theory is considered. Focusing first on dimension four, namely the colored Ooguri group field model, the main properties of Feynman graphs are studied. This leads to a theorem on optimal perturbative bounds of Feynman amplitudes in the ''ultraspin'' (large spin) limit. The results are generalized in any dimension. Finally, integrating out two colors we write a new representation, which could be useful for the constructive analysis of this type of models. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The radical cations from aziridine and azetidine have been characterized by ESR spectroscopy following their generation in the solid state by ..gamma.. irradiation of dilute solutions of the parent compounds in the CFCl/sub 3/ matrix at 77 K. The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me/sub 2/NH*/sup +/. On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical. The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2p/sub z/ orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ring-opened planar isomer with the unpaired electron in a nonbonding ..pi.. orbital centered mainly on the two end carbon atoms. The ...

International Nuclear Information System (INIS)

The crystal structure and phonon densities of states (DOS) of #beta#'-SiAlON ceramics, Si_6_-_zAl_zO"zN_8_-_z (0 #<=# z #<=# 4), prepared by a novel slipcast method, are studied by neutron-scattering techniques. The samples with z < 4 form a single-phase solid solution of Si-Al-O-N isostructural to #beta#-Si_3N_4 (space group P6_3/m). A consistent preferential occupation of the 2c sites by oxygen atoms and the 6h sites by nitrogen atoms exists within this structure. The phonon DOS of #beta#'-SiAlON displays phonon bands at #approx#50 and 115 meV. These features are considerably broader than the corresponding ones in #beta#-Si_3N_4 powder.

UK PubMed Central (United Kingdom)

Neutral endopeptidase 24.11 (NEP, CD10) is a cell-surface enzyme expressed by prostatic epithelial cells that cleaves and inactivates neuropeptides implicated in the growth of androgen-independent prostate...Full Text Available

International Nuclear Information System (INIS)

Perovskite-type cobaltates in the system La2Co1+z(MgxTi1-x)1-zO6 were studied for z=0?x?0.6 and 0?xoC. The space group symmetry of the structure changes from P21/n via Pbnm to R3-bar c with both increasing Mg content and increasing Co content. The La2Co(MgxTi1-x)O6 (z=0) compounds show anti-ferromagnetic couplings of the magnetic moments for the Co below 15 K for x=0, 0.1 and 0.2. XANES spectra show for the compositions 0?x?0.5 a linear decrease in the L3/(L3+L2) Co-L2,3 edge branching ratio with x, in agreement with a decrease of the average Co ion spin-state, from a high-spin to a lower-spin-state, with decreasing nominal Co2+ ion content. -- Graphical abstract: XRPD patterns for perovskite compounds along the lines La2Co(MgxTi1-x)O6 and La2Co1+z(Mg0.5Ti0.5)1-zO6. Display Omitted Research Highlights: ?Tuning of the oxidation state of Co in the perovskite ...

Science.gov (United States)

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Science.gov (United States)

... wherever possible. The primary interface for mechanical modeling is through PATRAN, a ... PATRAN Neutral File. PATRAN ...

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... listed certifications are vendor (CCNA) and Server Plus (Server neutral such as the Certified Information S ... CCNA ITIL NET+ GSEC SECURITY+ ...

Energy Technology Data Exchange (ETDEWEB)

Neutral beam systems for the next generation of magnetic fusion devices will be based on negative ions. Development are progressing steadily, and large negative ion-based systems are prepared for JT60-U and LHD, and are being considered for ITER. An overview of the physics of the production, acceleration and neutralization of large negative ion beams is given. the present state of the art in Research and Development is also surveyed. (author). 55 refs., 10 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

To suppress space charge blowup in an ion beam passing through a photoneutralizer, it is necessary to introduce some background gas. An analysis is presented of the neutralization of a high-energy, >200-keV negative deuterium ion beam, exposed to photodetachment while in the presence of deuterium. With a gas thickness of <0.01 Torr.cm, the neutral fraction in the output beam is found to be about the same as that gotten from the photoneutralizer operating in vacuum. Neutral atom beam injection for plasma heating is discussed.

CERN Document Server

We directly measure the evolution of the intergalactic Lyman-alpha effective optical depth, tau_eff, over the redshift range 2 is <1% at z=2, 4% at z=3, and 12% at z=4. Previous measurements of tau_eff at 3<z<4.5 based on directly fitting the quasar continua in the Ly-alpha forest have generally neglected this effect and are therefore likely biased low. We provide estimates of the level of absorption arising from metals in the Ly-alpha forest based on both direct and statistical metal removal results in the literature, finding that this contribution is ~6-9% at z=3 and decreases monotonically with redshift. The high precision of our measurement, attaining 3% in redshift bins of width Delta z=0.2 aro und z=3, indicates significant departures from the best-fit power-law redshift evolution ...

CERN Document Server

We complete the effective potential calculation of the two-loop, top/bottom Yukawa corrections to the Higgs boson masses in the Minimal Supersymmetric Standard Model, by computing the O(at^2 + at*ab + ab^2) contributions for arbitrary values of the bottom Yukawa coupling. We also compute the corrections to the minimization conditions of the effective potential at the same perturbative order. Our results extend the existing O(at^2) calculation, and are relevant in regions of the parameter space corresponding to tan(beta) >> 1. We extend to the Yukawa corrections a convenient renormalization scheme, previously proposed for the O(ab*as) corrections, that avoids unphysically large threshold effects associated with the bottom mass and absorbs the bulk of the corrections into the one-loop expression. For large values of tan(beta), the new contributions can account for a variation of several GeV in the lightest Higgs boson mass.

International Nuclear Information System (INIS)

We have measured the redshift evolution of the density of Lyman limit systems (LLSs) in the intergalactic medium over the redshift range 0 < z < 6. We have used two new quasar samples to (1) improve coverage at z #approx# 1, with GALEX grism spectrograph observations of 50 quasars with 0.8 < z_e_m < 1.3, and (2) extend coverage to z #approx# 6, with Keck ESI spectra of 25 quasars with 4.17 < z_e_m < 5.99. Using these samples together with published data, we find that the number density of LLS per unit redshift, n(z), can be well fit by a simple evolution of the form n(z) = n_3_._5[(1 + z)/4.5]"#gamma# with n_3_._5 = 2.80 #+-# 0.33 and #gamma# = 1.94"+"0"."3"6_-_0_._3_2 for the entire range 0 < z < 6. We have also reanalyzed the evolution of damped Ly#alpha# systems (DLAs) in ...

International Nuclear Information System (INIS)

The connection between W-algebras and the algebra of differential operators is conjectured. The bosonized representation of the differential operator algebra with c=-2n and all the subalgebras are examined. The degenerate representations and null-state classifications for c=-2 are presented. (orig.).

Energy Technology Data Exchange (ETDEWEB)

We study the static potential of open bosonic membranes in the 1/d approximation, where d is the space-time dimensionality. For a fixed square boundary of side length R we find, in contrast to the string potential, no critical distance below which tachyons appear. Instead, we find a correction factor to the classical potential, V/sub cl/=kR/sup 2/, which for small distances shifts the perturbative ground state energy by a positive constant. We interpret the shift as the mass gap of this quantum membrane.

Energy Technology Data Exchange (ETDEWEB)

An extension of the Polyakov path-integral formulation to compute off-shell amplitudes for open bosonic strings is derived. Boundary conditions require evaluating the path integral on open surfaces with corners on the boundaries. The contribution to the topological term in the action from the corners is exactly that required for unitarity. The presence of corners introduces a Weyl anomaly in the Polyakov measure. This requires a gauge-fixing procedure for the off-shell amplitudes. Consistent factorization of amplitudes with one or two off-shell strings and any number of on-shell tachyons is established.

International Nuclear Information System (INIS)

The crystal structure, electronic structure, and photoluminescence properties of EuxSi6-zAlz-xOz+xN8-z-x (x=0-0.1, 0xMySi6-zAlz-x-yOz+x+yN8-z-x-y (M=2Li, Mg, Ca, Sr, Ba) have been studied. Single-phase EuxSi6-zAlz-xOz+xN8-z-x can be obtained in very narrow ranges of x?0.06 (z=0.15) and z2+ ions can be incorporated into nitrogen-rich Si6-zAlzOzN8-z. The Eu2+ ion is found to occupy the 2b site in a hexagonal unit cell (P63/m) and directly connected by six adjacent nitrogen/oxygen atoms ranging 2.4850-2.5089 A. The calculated host band gaps by the relativistic DV-X? method are about 5.55 and 5.45 eV (without Eu2+ 4f5d levels) for x=0 and 0.013 in EuxSi6-zAlz-xOz+xN8-z-x (z=0.15), in which the top of the 5d orbitals ...

International Nuclear Information System (INIS)

A review of the experimental work performed at the GASP array with the purpose of the identification and first spectroscopic measurements of the heaviest even-even N = Z and odd-A N = Z + 1 nuclei (mass larger than 80) is made. Systematic experiments in this mass region led to the first study of seven such nuclei: "8"8Ru, "8"1Zr, "8"5Mo, "8"9Ru, "9"1Rh, "9"3Pd, and "9"5Ag, and extensive data on many other nuclei in their neighborhood. The systematic evolution of the level structures in both even-even and odd-A nuclei, between N #approx# Z #approx# 40 and N #approx# Z #approx# 47 is briefly presented. The possibility that effects of the neutron-proton pairing have been observed, as well as the type of collectivity observed in this region are discussed. (author)

International Nuclear Information System (INIS)

The experimental study of the proton-rich nuclei close to the N=Z line is a constant challenge for nuclear spectroscopy, mainly due to the difficulty to produce them with the currently available beam/target combinations. Significant advances on this direction were obtained from experiments performed with the GASP array during the last two years: the yrast line of "8"4Mo was extended up to 10"+, "8"8Ru observed for the first time, and the N=Z+1 line was mapped from "8"1Zr to "9"5Ag. These new results allow us to have a more complete image of the transition from the well-deformed shell closure at N,Z=40 to the spherical-shell closure at N,Z=50, and highlights some particular effects that can be observed only in the vicinity of the N=Z line. (orig.)

Science.gov (United States)

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CERN Document Server

In a holomorphic family $(X_b)_{b\\in B}$ of non-K\\"ahlerian compact manifolds, the holomorphic curves representing a fixed 2-homology class do not form a proper family in general. The deep source of this fundamental difficulty in non-K\\"ahler geometry is the {\\it explosion of the area} phenomenon: the area of a curve $C_b\\subset X_b$ in a fixed 2-homology class can diverge as $b\\to b_0$. This phenomenon occurs frequently in the deformation theory of class VII surfaces. For instance it is well known that any minimal GSS surface $X_0$ is a degeneration of a 1-parameter family of simply blown up primary Hopf surfaces $(X_z)_{z\\in D\\setminus\\{0\\}}$, so one obtains non-proper families of exceptional divisors $E_z\\subset X_z$ whose area diverge as $z\\to 0$. Our main goal is to study in detail this non-properness phenomenon in the case of class VII surfaces. We will prove that, under certain ...

Energy Technology Data Exchange (ETDEWEB)

An unexpectedly high probability of collisions between the fission particles and the atoms in an ionization chamber along the entire particle track causes a strong fluctuation of the shapes of the Bragg curves. This fluctuation imposes an upper limit of the charge resolution ..delta..Z/Z which can be achieved.

Science.gov (United States)

... 89 11 August 195Z SCINTILLATION COUNTERS *Subtask uder Effects of Irradiation, AMRL Project No. ... 89 SCINTILLATION COUNTERS* by ...

Energy Technology Data Exchange (ETDEWEB)

A large Bragg-curve spectrometer has been constructed and tested. The detector has a cylindrical geometry and operates with a homogeneous electric field. Energy resolutions of <0.8% and Z resolutions of Z/..delta..Z=80 have been achieved for eleastically scattered /sup 58/Ni ions. These results demonstrate the suitability of this large solid-angle detector for use in a wide variety of heavy-ion scattering experiments.

Science.gov (United States)

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Energy Technology Data Exchange (ETDEWEB)

Neutral atom beams with energies above 200 keV may be required for various purposes in magnetic fusion devices following TFTR, JET and MFTF-B. These beams can be produced much more efficiently by electron detachment from negative ion beams than by electron capture by positive ions. We have investigated the efficiency with which such neutral atoms can be produced by electron detachment in partially ionized hydrogen plasma neutralizers.

Science.gov (United States)

Consideration is given to the stability of negative ion beams which are neutralized through ionization of a background gas. Two types of instabilities are examined. First, beam-plasma instabilities are analyzed with the dispersion relation showing that they are unimportant if the beam velocity is less than the electron thermal velocity. Second, results of a computer simulation on the flow of a cylindrical beam and the resulting background plasma show that when the background neutral gas density is less than or approximately equal to a critical density as instability occurs. This critical density is the density that would be needed to space-charge neutralize the beam if the positive ions were not retarded by the beam. An approximate dispersion relation indicates that the nature of the instability is a transverse positive-ion acoustic wave which couples to the beam.

Czech Academy of Sciences Repository

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Science.gov (United States)

The Ames infrared spectral database of isolated, neutral and ionized polycyclic aromatic

Energy Technology Data Exchange (ETDEWEB)

Yields of light fission products (A = 68, 70-84, 87, 88, 94, 96, 98, 102 and 106-108), their kinetic energies and nuclear charge distributions (A 71-84, 87 and 88) in the thermal neutron induced fission of the odd-Z nucleus {sup 242m}Am(Z = 95) were measured using the mass-separator Lohengrin at the Institute Laue-Langevin in Grenoble (France). The mass yield curve shows a fine structure at A = 70, probably due to shell and/or odd-even effects affecting also the nuclear charge distribution. The analysis of isotopic chain yields gives evidence for a very low excitation energy of the lightest fission fragments observed. A preferential formation of fragments with even Z is found for this odd-Z compound nucleus. Calculated values for the local odd-even effect are comparable with those for the neighbouring even-Z fissile nuclides and increase from 13% to 30% with increasing asymmetry of ...

International Nuclear Information System (INIS)

Adduct formation between U(TTA)_4 and several neutral donor (S) was investigated by utilizing the changes in the absorption spectra of U(IV) resulting from the addition of neutral donors to a solution of U(TTA)_4. All the donors used in the present work from 1:1 adducts with U(TTA)_4. From the spectral changes, the equilibrium constants #beta#sub(AB) for the adduct formation reaction viz U(TTA)_4 S reversible U(TTA)_4.S were calculated for a few neutral donors. The log #beta#sub(AB) values obtained in benzene medium, are :TOPO (6.23), TBPO (6.13), TPPO (4.72), DBBP(4.04) TBP(3.04), TIOTP(1.27) and MIBK(-0.10) and a value of 3.98 for TOPO in chloroform medium. The adduct formation was found to result in increasing the coordination number of U(IV) from 8 in U(TTA)_4 to 9 in the adducts it forms with the neutral donors. Similar absorption spectral studies with U(DBM)_4 revealed that it forms much weaker ...

Energy Technology Data Exchange (ETDEWEB)

The Doublet III device is operating with an extensive system of plasma limiters and wall protective armor. Operations with up to 8MW of neutral beam power and 1.5MA plasma current are planned. Design and operational performance of the following systems are discussed: 1. Water-cooled graphite moveable limiter. 2. Water-cooled graphite fixed limiter and neutral beam wall armor. 3. Radiatively cooled Inconel divertor plates.

UK PubMed Central (United Kingdom)

Dengue virus (DENV) infection is a worsening global health problem. The plaque reduction neutralization test (PRNT) is currently considered to be the “gold standard” to characterize...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A new, magnetically insulated negative ion source has recently been discovered which can produce pulsed negative ion beams (H/sup -/, Li/sup -/, and C/sup -/) with intensities of 100-300 A/cm/sup 2/ at 1-4 MeV. This source may provide the basis for a high energy neutral beam system for heating large tokamaks.

CERN Document Server

A method for systematically including topological degrees of freedom in perturbation theory is developed. This is not bound by the restrictions of semi-classical techniques. The Yang-Mills theory in three Euclidean dimensions is considered here. A well-defined separation of the topological and the ``spin wave'' degrees of freedom is obtained, motivated by a singular gauge. This has ``photons'' distorting the spherically symmetric magnetic fields of Dirac monopoles, and massless charged vector bosons ``W'' scattering off the latter. It is explicitly shown that the Dirac string does not contribute. The mode of the charged vector bosons with total angular momentum J=0 provides precisely the core to give a finite energy to the monopole. The radial equation for W is remarkably simplified and only two polarization states survive exactly for the anomalous magnetic moment required by the Yang-Mills interaction.

International Nuclear Information System (INIS)

We derive the exchange currents of pseudoscalar, vector, and scalar mesons from Feynman diagrams, and use them to calculate the magnetic form factors of nucleon and ?(1232). The magnetic moments and electromagnetic radii are obtained by using those form factors and the parameters determined from the masses of nucleon and ?(1232). We find the magnetic moments and electromagnetic radii of nucleon and ?(1232) can be produced very well in the extended Goldstone-Boson-exchange model in which all of pseudoscalar, vector, and scalar meson nonet are included. The magnetic moments of ?(1232) are closer to experiment values and results from lattice calculation than the results obtained by the model without other mesons except for pion and sigma.

International Nuclear Information System (INIS)

An extensive analysis of the 1/N expansion of O(N)-symmetric lambdaphi"4 theory in four dimensions shows it to be a consistent approximation method. It is confirmed that the ground state of the theory is O(N(-symmetric, and that spontaneous symmetry breaking is not possible in the large-N limit. The Green's functions are free of tachyons if constructed relative to this ground state. A natural upper bound is derived for the parameters of the theory to ensure the existence of a ground state. In the strong-coupling domain there exist a bound state and a resonance in the identity representation of the O(N) group, which disappear in the weak-coupling regime. It is shown that, to leading order in N, a zero-mass interacting ''charged'' boson cannot be sustained in this theory. If the boson mass goes to zero, the model becomes a free-field theory.

Energy Technology Data Exchange (ETDEWEB)

The functioning of animal as well as human societies fundamentally relies on cooperation. Yet, defection is often favorable for the selfish individual, and social dilemmas arise. Selection by individuals' fitness, usually the basic driving force of evolution, quickly eliminates cooperators. However, evolution is also governed by fluctuations that can be of greater importance than fitness differences, and can render evolution effectively neutral. Here, we investigate the effects of selection versus fluctuations in social dilemmas. By studying the mean extinction times of cooperators and defectors, a variable sensitive to fluctuations, we are able to identify and quantify an emerging 'edge of neutral evolution' that delineates regimes of neutral and Darwinian evolution. Our results reveal that cooperation is significantly maintained in the neutral regimes. In contrast, the ...

CERN Document Server

We investigate the sky distribution of z ~ 6 Lyman break galaxies selected as i'-dropouts having i' - z' > 1.45 down to z' < 26.5 in the Subaru Deep Field (SDF). We discover 37 i'-dropouts clustered in a projected comoving 21.6 x 21.6 Mpc^2 region at z = 6, showing a local density excess. Carrying out follow-up spectroscopy, we identify four of them as Lyman-alpha emitters at z = 5.92, 6.01, 6.03 and 6.03 (spread over a distance of 46.6 Mpc). The number density of the cluster itself in SDF is ~ 2.2 x 10^{-7} Mpc^{-3}, smaller than those of protoclusters (i.e., forming galaxy clusters) at z ~ 2-5.7. Also, the structure shows ~4-21 times larger galaxy number density than those of z ~ 6 galaxies in a general field. It has a mass of M ~ 1.5^{+1.8}_{-0.5} x 10^{15}M_sun, comparable to those of z ~ 0-5 protoclusters. ...

CERN Document Server

We construct a sample of low-redshift Ly-alpha emission-line selected sources from GALEX grism spectroscopy of nine deep fields to study the role of Ly-alpha emission in galaxy populations with cosmic time. Our final sample consists of 122 (142) sources selected in the redshift interval z=0.195-0.44 (z=0.65-1.25) from the FUV (NUV) channel. We classify the Ly-alpha sources as AGNs if high-ionization emission lines are present in their UV spectra and as galaxies otherwise. These classifications are broadly supported by comparisons with X-ray and optical spectroscopic observations. We classify additional sources as AGNs using line widths for our Ly-alpha emitter (LAE) analysis. Defining the GALEX LAE sample in the same way as high-redshift LAE samples, we show that LAEs constitute only about 5% of NUV-continuum selected galaxies at z~0.3. We also show that they are less common at z~0.3 than they are at ...

Energy Technology Data Exchange (ETDEWEB)

We study the condensation of localized closed string tachyons on AdS orbifolds both from the bulk and boundary theory viewpoints. We first extend the known results for AdS{sub 5}/Z{sub k} to AdS{sub 3}/Z{sub k} case, and we proposed that the AdS{sub 3}/Z{sub k} decays into AdS{sub 3}/Z{sub k'} with k{sup '} < k. From the bulk viewpoint, we obtain a time-dependent gravity solution describing the decay of AdS orbifold numerically. From the dual gauge theory viewpoint, we calculated the Casimir energies of gauge theory vacua and it is found that their values are exactly the same as the masses of dual geometries, even though they are in different parameter regimes of 't Hooft coupling. We also consider AdS{sub 5} orbifold. The decay of AdS{sub 5}/Z{sub k} is dual to the transition between the vacua of dual gauge theory on R{sub t} x S{sup ...

Energy Technology Data Exchange (ETDEWEB)

This paper gives a Coulomb gas representation for level kN = 1 supersymmetric SU(2) Kac-Moody algebra in terms of three free scalar superfields. It is clarified how this representation reduces to a Coulomb gas representation for the corresponding bosonic SU(2) Kac-Moody algebra and the free fermionic algebra. The primary superfields and the correlation functions, which satisfy the supersymmetric Knizhnik-Zamolodchikov equation, are also discussed.

Energy Technology Data Exchange (ETDEWEB)

A summary of the latest results of Standard Model Higgs boson searches from CDF and D0 presented at the DIS 2007 conference is reported in this paper. All analyses presented use 1 fb{sup -1} of Tevatron data. The strategy of the different analyses is determined by the Higgs production mechanism and decay channel.

CERN Document Server

The discovery of a new particle in the Higgs searches being prepared for LHC will not guarantee that the Standard Model Higgs boson has been seen. This paper discusses the possibilities for measuring the spin, parity and couplings of the particle, under the assumption that it does in fact behave like the Standard Model Higgs. The key question, which cannot alas be answered, is: if it looks like a dog, and barks like a dog, how much of the DNA must we analyse to be sure that it is a dog?

Energy Technology Data Exchange (ETDEWEB)

An F-theory dual of a non-supersymmetric orientifold is considered. It is argued that the condensation of both open and closed string tachyons in the orientifold corresponds to the annihilation of branes and antibranes in the F-theory dual. One likely end-point of tachyon condensation is thus expected to be the vacuum of Type-IIB superstring. Some speculations are presented about the F-theory dual of the bosonic string and tachyon condensation thereof.

Energy Technology Data Exchange (ETDEWEB)

The data taken at the Tevatron experiments have been analyzed to search for Higgs bosons. For the Standard Model Higgs searches, no excess is observed, the data are in good agreement with the expectations, so that limits are set on the production rates. For various theoretical models beyond the Standard Model, there is no excess either, which allows to derive constraints in their respective parameter spaces.

Energy Technology Data Exchange (ETDEWEB)

The electroweak-symmetry-breaking sector of the standard model can be weakly-coupled or can be strongly-coupled, which is characterized by some kinds of strong interaction among the Goldstone bosons of the electroweak-symmetry-breaking sector. In this paper, we summarize an investigation of probing the strong electroweak-symmetry-breaking effects at photon colliders. ((orig.)).

International Nuclear Information System (INIS)

Constraining the SL(3) WZW-model we construct a reduced theory which is invariant with respect to the new chiral algebra W_3"2. This symmetry is generated by the stress-energy tensor, two bosonic currents with spins 3/2 and the U(1) current. We conjecture a Kac formula that describes the highly reducible representation for this algebra. We also discuss the quantum Hamiltonian reduction for the general type of constraints that leads to the new extended conformal algebras. (orig.).

International Nuclear Information System (INIS)

The dimensionally reduced effective action of the bosonic sector of the heterotic string in critical dimensions is employed to derive a Wheeler-DeWitt equation for the Bianchi type-IX cosmology. An exact solution is found that becomes strongly peaked around the isotropic limit as the volume of the three-geometry increases. In principle the global O(6,6) symmetry of the effective action can be employed to generate new solutions from the one presented here.

Wastenet

...A-Z list of ESDS guides Economic and Social Data Service - User support - ESDS guides | Home | A-Z index ...uk Telephone: +44 (0)1206 872143 Fax: 01206 872003 Print-friendly page A-Z list of ESDS guides Printing tips Printing tips The majority of these guides are web pages with a ... To print these guides at their best: select 'print friendly' at the top-right of the content of the page go to File/...via Beyond 20/20 WDS Advice for new users Analysing Change Over Time: A guide to ESDS resources CommonGIS functionality guide Countries and Citizens: Linking ...

International Nuclear Information System (INIS)

The K_#beta#/K_#alpha# X-ray intensity ratios are measured for Mn and Fe and for six other elements with Z lying in the range 49<=Z<=82 following electron capture decay and photon excitation using "2"4"1Am and "5"7Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence of K_#beta#/K_#alpha# values on the mode of excitation in the case of Mn and Fe is attribuited to the chemical effects, while no such dependence is found for the high-Z elements.

CERN Document Server

We iterate Manolescu's unoriented skein exact triangle in knot Floer homology with coefficients in the fraction field of the group ring (Z/2Z)[Z]. The result is a spectral sequence which converges to a stabilized version of delta-graded knot Floer homology. The (E_2,d_2) page of this spectral sequence is an algorithmically computable chain complex expressed in terms of spanning trees, and we show that there are no higher differentials. This gives the first combinatorial spanning tree model for knot Floer homology.

Science.gov (United States)

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Science.gov (United States)

Methods for the synthesis and quantitation of the novel choline analogues, telluronium choline and acetyltelluronium choline, are described. An assay procedure utilizing pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) with cold trapping was developed with [2H4]telluronium choline and [2H4]acetyltelluronium choline as internal standards. The telluronium compounds were ion-pair extracted from tissue with dipicrylamine, washed with 2-butanone, and pyrolyzed prior to GC-MS analysis. The compounds were monitored using selected ion monitoring at m/z 232 and m/z 190 for acetyltelluronium and telluronium choline, respectively, and at m/z 236 and m/z 194 for the analogous deuterated internal standards. The assay was linear over a range of 20 pmol-20 nmol of compound taken through the assay. PMID:8130881

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Enter Search terms A-Z Index Home Food Drugs Medical Devices Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Radiation-Emitting Products Tobacco ...

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1976. Germany Ramaswamy, MK Birla Inst. of Tech. and Science, Pilani

Science.gov (United States)

_! Packaging, Cleanlines_, Preparation j Handling ..... 35. 'I. 40. WATER ................ , ......... Sterile, High Purity, Ethylene Glycol-Water Solutions. Requirement For . ...

Science.gov (United States)

... The AAT Z mutation involves a single amino acid substitution (glutamine for lysine) at position 342, resulting in abnormal folding and polymerization of the ...

Science.gov (United States)

Countries and Regions A-Z List of Countries and Other Areas Africa (Sub-Sahara) East Asia and the Pacific Europe and Eurasia Near East (northern Africa, Middle East) South and...

Energy Technology Data Exchange (ETDEWEB)

The relative abundances of iron-peak elements produced by the e-process in a supernova outburst are calculated. The results agree quite well with the cosmic abundances of elements in the range Z=23--28.

Science.gov (United States)

... Construction, Geology, and Aquifer Testing of the Maalo ... 8-98) Prescribed by ANSI Std Z39-18 Page 3. Construction, Geology, and Aquifer Testing ...

International Nuclear Information System (INIS)

We study the constraints on the anomalous coupling g_5"Z that can be obtained from the analysis of the reaction #gamma##gamma##->#W"+W"-Z at future linear e"+e"- colliders. We find out that a 0.5 (1) TeV e"+e"- collider operating in the #gamma##gamma# mode can probe values of g_5"Z of the order of 0.15 (4.5x10"-"2) for an integrated luminosity of 10 fb"-"1. This shows that the ability to search for this anomalous interaction of the #gamma##gamma# mode is better than the one of the usual e"+e"- mode, and it is similar to the ability of the e#gamma# mode.

Science.gov (United States)

A common reinforced liner material is a cloth formed of PTFE fibers and fiber of ... and ablation protection provided. All of these methods of thermal ..... The influence of fiber content on the microstructures of the composites is ...

Science.gov (United States)

%++")-""# $$ (& 06DJDD84468:DPX\\Z`dhnnljr| vh^Zntx???|`?R ?? `|njThh^PVd\\\\VZXTJ<(&:FLXX\\`hljlrtxpb^\\VVNL@8.(*2,&($"&,,2.260" ? Y "A ...

Energy Technology Data Exchange (ETDEWEB)

Generation of anomalous resistivity and dynamical development of collisionless reconnection in the vicinity of a magnetically neutral sheet are investigated by means of a three-dimensional particle simulation. For no external driving source, two different types of plasma instabilities are excited in the current layer. The lower hybrid drift instability (LHDI) is observed to grow in the periphery of current layer in an early period, while a drift kink instability (DKI) is triggered at the neutral sheet in a late period as a result of the nonlinear deformation of the current sheet by the LHDI. A reconnection electric field grows at the neutral sheet in accordance with the excitation of the DKI. When an external driving field exists, the convective electric field penetrates into the current layer through the particle kinetic effect and collisionless reconnection is triggered by the convective electric field earlier than the ...

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT With corn starch as raw material, dextrin was prepared by the combined application of common neutral and thermostable a-amylases in this study. The effects of reaction temperature, reaction time, addition of common neutral and thermostable a-amylases on dextrose equivalent (DE)-value of dextrin were investigated. The obtained dextrin with a DE value of 20.43 was evaluated for morphology, crystallography, particle size distribution and thermal property by scanning electron microscope, X-ray diffractometer, light scattering particle size analyzer and thermogravimetric analyzer. The results showed that the amorphous regions in the core part of corn starch were completely hydrolyzed and only the fractured crystalline surface remained. The particle size of the dextrin change significan...

British Library Electronic Table of Contents (United Kingdom)

This is a report of extraction and identification of 1-O-alkyl glycerol present in the dried leaves of Bauhinia scandens. Fifty percent aqueous ethanolic extract of the plant at room temperature was fractionated over petroleum ether and diethyl ether. The diethyl ether soluble fraction showed positive bioactivity in Brine Shrimp bioassay. Isolation and purification of the active principle was subsequently done from diethyl ether fraction. The diethyl ether fraction was separated into acidic and neutral part. The acid free fraction was screened to be positive in Brine Shrimp bioassay. The NMR spectra (in CDCl3) indicated the probability of its lipoidal nature. The total lipid fraction was resolved into neutral, glyco, and phospho-lipids by column chromatography. Only the neutral fraction sh...

Science.gov (United States)

One of the least understood regions of the upper atmosphere is the thermosphere, principally due to the difficulty of making observations. The neutral atmosphere is known to be highly variable, and its composition and density varies by several orders of magnitude due to solar activity, diurnal cycles, latitude, geomagnetic activity, and gravity waves. In the past, most in-situ measurements of the neutral atmosphere have utilized detectors that are dependent on arrival angle and energy accommodation of incoming species, so that information related to nascent velocity distribution and reactive species abundances is often masked. This paper will review design concepts and laboratory tests related to the development of a novel open-ionizer, neutral particle detector for space environment measurements which can overcome these limitations. The sensor features a very large field-of-view suitable for sounding rocket missions. ...

International Nuclear Information System (INIS)

Arguments in favour of the possibility of the existence and the non-existence of tachyons are put forward. Some of the theoretical and experimental attempts which have either supported the view that tachyons exist or not are mentioned. In the light of evidence, available as of now, it is surmised that they may not exist and if they do, they may be neutral in charge. (K.B.).

International Nuclear Information System (INIS)

Progress in the development of negative ion sources and their application in fusion research is reviewed. (U.K.).

UK PubMed Central (United Kingdom)

In the presence of electrochemical energy, several branched-chain neutral and acidic amino acids were found to accumulate in membrane vesicles of Bacillus stearothermophilus. The membrane vesicles contained...Full Text Available

UK PubMed Central (United Kingdom)

Approximately 30% of foxes given two doses of an inactivated rabies antigen delivered directly into the intestinal tract developed an immune response as measured by rabies serum neutralizing antibodies....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In support of a project on lifetime calculation experiments were carried out to evaluate the resistance to environmentally assisted cracking (EAC) of steam generator tubes during operation. Estimations of the incubation period for crack initiation and the threshold K value, K{sup Iscc}, and the crack growth rate were made to predict evolution of damage in tube walls. The paper summarizes results of experiments of C ring specimen for the initiation testing and results of SENT (single edge notch tensile) specimen for the crack growth rate (CGR) testing. The specimens were exposed to concentrated environments at elevated temperatures simulating crevice environments in secondary side crevices in horizontal steam generators. The results show that the material of SG tubes is sensitive to transgranular environmentally assisted cracking in the three basic concentrated environments used, alkaline, neutral and acid. The most corrosive medium was the acid environment. The ...

UK PubMed Central (United Kingdom)

A commercial multiplex real-time PCR assay (Cepheid Xpert C. difficile assay) for the diagnosis of Clostridium difficile infection was evaluated. The sensitivity and...Full Text Available

UK PubMed Central (United Kingdom)

Amino acid transport was studied in membrane vesicles of the thermophilic anaerobic bacterium Clostridium fervidus. Neutral, acidic, and basic as well as aromatic amino acids were transported at 40...Full Text Available

UK PubMed Central (United Kingdom)

Abs facilitate humoral immunity via the classical mechanisms of opsonization, complement activation, Ab-dependent cellular cytotoxicity, and toxin/viral neutralization. There is also evidence that some...Full Text Available

Science.gov (United States)

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Science.gov (United States)

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International Nuclear Information System (INIS)

L_#alpha#/L_l X-ray intensity ratios have been measured in elements Ta, W, Au, Hg, Tl, Pb, Bi, Th and U using L-shell photoionization by 60 keV photons. The present results are found to agree with the calculated values of Scofield within experimental uncertainties. (author).

Science.gov (United States)

... L z xyx 0 0 0 0 0 0 0 0 0 0 0 0 -V 0 0 0 0 oj A ~ 0 0 1 0 v 0 I - z Fiue2. Inertial Navigation Error Lquation-i in the Platform Frame t 'I A Page 35. ...

International Nuclear Information System (INIS)

We have developed a set of modeled nuclear reaction cross sections for use in radiochemical diagnostics. Systematics for the input parameters required by the Hauser-Feshbach statistical model were developed and used to calculate neutron induced nuclear reaction cross sections for targets ranging from osmium (Z = 76) to gold (Z = 79). Of particular interest are the cross sections on Ir and Au including reactions on isomeric targets.

Energy Technology Data Exchange (ETDEWEB)

The nuclear interaction probability of light charged particles in BaF[sub 2] crystals has been studied as a function of the incident particle energy. Light charged particles were identified in charge and mass by measuring their magnetic rigidity and their time-of-flight. The percentage of particles undergoing nuclear interactions has been measured for particles of charge from Z=1 to Z=6 and the experimental data are compared with the results of a model calculation. (orig.)

Energy Technology Data Exchange (ETDEWEB)

In a reactor environment, the surface of a limiter or wall is primarily determined by the mechanism of erosion and deposition of surface material. It should be possible to use pellet injection to reduce net erosion to zero everywhere if low-Z materials are used for the surface. Erosion rates can, in general, be minimized by large area limiters and high plasma temperatures, which transmit power to the walls with less sputtering. Under ideal steady state conditions the wall surface is dominated by metallurgical effects in the wall.

UK PubMed Central (United Kingdom)

The endogenous levels of several plant growth substances (indole acetic acid, IAA; abscisic acid, ABA; zeatin, Z; zeatin riboside, [9R]Z; isopentenyladenine, iP; and isopentenyladenosine, [9R]iP were...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundUpon CD95/Fas ligation, the initiator caspase-8 is known to activate effector caspases leading to apoptosis. In the presence of zVAD-fmk, a broad-spectrum caspase inhibitor,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A series of pentaamminerhodium(III) complexes, Rh(NH/sub 3/)/sub 5/Z/sup n+/, has been prepared with 80% enrichment in /sup 15/N (Z = H/sub 2/O, OH/sup /minus//, Cl/sup /minus//, Br/sup /minus//, I/sup /minus//, NH/sub 3/, /minus/ONO/sup /minus//, /minus/NO/sub 2//sup /minus//, /minus/NCS/sup /minus//, /minus/SCN/sup /minus//, /minus/NCO/sup /minus//, CN/sup /minus//). The /sup 1/H-decoupled /sup 15/N NMR spectra show two doublets (from coupling to /sup 103/Rh) with approximate intensity ratio 4:1. /delta//sub N/ and /sup 1/J(rh-N) are sensitive to Z, especially for the unique amine trans to Z. Good correlations exist between /delta//sub N/ in this series of /delta//sub N/ in this series and /delta//sub N/ in the corresponding cobalt(III) complexes Co(NH/sub 3/)/sub 5/Z/sup n+/ and platinum(II) complexes Pt(NH/sub 3/)/sub 3/Z/sup m+/, J(Rh-N) trans to ...

International Nuclear Information System (INIS)

The adsorptive removal of boron from aqueous solution by using the neutralized red mud was studied in batch equilibration technique. The effects of pH, adsorbent dosage, initial boron concentration and contact time on the adsorption were investigated. The experiments demonstrated that boron removal was of a little fluctuation in pH range of 2-7 and it takes 20 min to attain equilibrium. The adsorption data was analyzed using the Langmuir and the Freundlich isotherm models and it was found that the Freundlich isotherm model represented the measured sorption data well.

Energy Technology Data Exchange (ETDEWEB)

The isotopic enrichment of copper ions in a positive column Cu-Nu discharge using optogalvanic excitation is analyzed with a rate equation model With excitation at 510.6 nm, the fraction of the ions belonging to the 63-amu isotope of copper is enriched relative to the neutral abundance. Enrichment as large as 10% is calculated when the initial abundance of the neutral isotope is small (< or =0.1) and the discharge current density is large (> or =75 mA/cm/sup 2/). The degree of enrichment is examined as a function of the initial abundance, discharge current, the rate of charge exchange, and the diameter of the discharge tube.

International Nuclear Information System (INIS)

We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c"2_s > 1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilize an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed. (letter to the editor)

Energy Technology Data Exchange (ETDEWEB)

This paper reports on three series of laboratory experiments designed to test the performance of the Hahn-Noll revenue neutral auction (RNA). An alternative institution, a no-rebate uniform price auction (UPA), is also examined as a benchmark. In these experiments, the RNA markets were little different from UPA markets in terms of either prices or market efficiencies. The two institutions did differ in terms of the distribution of the gains from exchange and of the propensity of bidders to engage in a certain type of overbidding. 25 refs., 13 figs., 3 tabs.

International Nuclear Information System (INIS)

Ozone levels observed during a field campaign in Houston were significantly higher than that observed in Phoenix or Philadelphia. An examination of the slope of O(sub x) versus NO(sub z) in the urban plumes shows that NO(sub x) is used 2 to 3 times more efficiently in Houston as compared with Phoenix and Philadelphia. Representative values of OPEx are 7-12, 3, and 4, in Houston, Phoenix, and Philadelphia. Aircraft observations have been used to calculate P(O(sub 3))/P(NO(sub z)). Values in Houston are significantly higher than in Phoenix and Philadelphia. We show that P(O(sub 3))/P(NO(sub z)) is proportional to a VOC/NO(sub 2)-OH reactivity ratio. High values of P(O(sub 3))/P(NO(sub z)) in Houston are due to emissions of reactive olefins from the ship channel region. It is significant that high values of P(O(sub 3))/P(NO(sub z)) occur at NO(sub x) levels up to several 10's of ppb. ...

Energy Technology Data Exchange (ETDEWEB)

We have created quasiprojectiles of varying isospin via peripheral reactions of {sup 28}Si+{sup 112}Sn and {sup 124}Sn at 30 and 50 MeV/nucleon. The quasiprojectiles have been reconstructed from completely isotopically identified fragments. The difference in N/Z of the reconstructed quasiprojectiles allows the investigation of the disassembly as a function of the isospin of the fragmenting system. The isobaric yield ratio {sup 3}H/{sup 3}He depends strongly on N/Z ratio of quasiprojectiles. The dependences of mean fragment multiplicity and mean N/Z ratio of the fragments on N/Z ratio of the quasiprojectile are different for light charged particles and intermediate mass fragments. Observation of a different N/Z ratio of light charged particles and intermediate mass fragments is consistent with an inhomogeneous distribution of isospin in the fragmenting system.

CERN Document Server

We present deep two-dimensional spectra of 22 candidate and confirmed Lyman break galaxies (LBGs) at redshifts 2<z<4 in the Hubble Deep Field (HDF) obtained at the Keck II telescope. The targets were preferentially selected with spatial extent and/or multiple knot morphologies, and we used slitmasks and individual slits tilted to optimize measurement of any spatially resolved kinematics. The median target magnitude was I_814=25.3, and total exposure times ranged from 10 to 50 ks. We measure redshifts, some new, ranging from z=0.2072 to z=4.056, including two interlopers at z<1, and resulting in a sample of 14 LBGs with a median redshift z=2.424. The morphologies and kinematics of the close pairs and multiple knot sources in our sample are generally inconsistent with galaxy formation scenarios postulating that LBGs occur only at the bottom of the potential wells of massive ...

International Nuclear Information System (INIS)

There has been a good deal of interest in the sialon system of ceramics in recent years due to their combination of important engineering properties #beta# including strength, hardness, low thermal expansion and good thermal shock resistance. #beta#-sialon (Si_6_-_zAl_zO_zN_8_-_z ;0<z<4.2) can be prepared from various aluminosilicates by carbothermal reduction and nitridation. The process presents an attractive and potentially cost efficient route for the manufacture of sialons. Brown coal from the Loy Yang deposits of Victoria's La Trobe Valley provided a novel and reactive source of carbon for the current investigation. This paper looks at the mechanisms of formation of #beta#-sialon via the carbothermal reduction route and reports specifically on the utilisation of "2"9Si and "2"7Al solid state Nuclear Magnetic Resonance techniques in determining the nature of intermediate phases which occur. 9 refs., 1 tab., 1 ...

Energy Technology Data Exchange (ETDEWEB)

Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they ...

Energy Technology Data Exchange (ETDEWEB)

At future {gamma} {gamma} colliders a massive production of tt-bar pairs is possible. This would allow a detailed investigation of the interactions involving the top quark. The authors propose some correlations which are sensitive to tt-bar final state interactions and compute the QCD and standard model Higgs boson contributions to these correlation. QCD-induced transverse polarization of top quarks is found to be sizeable and measurable at a high-energy e{sup +} e{sup -} collider with an integrated luminosity of 10(fb){sup -1} which is converted into a photon collider by backscattering of laser photons. 16 refs.

International Nuclear Information System (INIS)

The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed.

CERN Document Server

Supersymmetry, a new symmetry that relates bosons and fermions in particle physics, still escapes observation. Search for SUSY is one of the main aims of the recently launched Large Hadron Collider. The other possible manifestation of SUSY is the Dark Matter in the Universe. The present lectures contain a brief introduction to supersymmetry in particle physics. The main notions of supersymmetry are introduced. The supersymmetric extension of the Standard Model - the Minimal Supersymmetric Standard Model - is considered in more detail. Phenomenological features of the MSSM as well as possible experimental signatures of SUSY at the LHC are described. The DM problem and its possible SUSY solution is presented.

Energy Technology Data Exchange (ETDEWEB)

We present methods to measure the beam polarizations and the luminosity of [gamma][gamma] colliders at TeV energy scale. The beam polarizations of a [gamma][gamma] collider can easily be monitored by comparing the numbers of events of the processes [gamma][gamma] [yields] l[sup +]l[sup -] and [gamma][gamma] [yields] W[sup +] W[sup -], where l means e or [mu]. The luminosity of a [gamma][gamma] collider is also measurable by the event rate of W boson pair productions and the light lepton pair productions. (orig.)

International Nuclear Information System (INIS)

We present the efficient technique to extract the signal of the intermediate mass Higgs boson from the backgrounds at future #gamma##gamma# colliders. For a clear Higgs detection, it is important to fit the original electron accelerator energy depending on the Higgs mass, to set the polarization of the photon beams and to apply the efficient b quark tagging method. we demonstrate the extraction of information of Higgs parameters and the new physics from the observable physical quantities. It is clearly shown that a future #gamma##gamma# collider will have a rich potential for study on the new physics, as well as the Higgs physics. (author).

International Nuclear Information System (INIS)

A #gamma##gamma# collider would extend and complement the physics capability of a linear collider; e.g. it would be suitable for direct measurement of the partial decay width of a Higgs boson into two gamma quanta. This paper discusses choice of laser parameters, luminosity optimization, electron and laser parameters for a gamma- gamma collider as a second interaction region for the Next Linear Collider, laser path, and the lasers. It is concluded that a gamma- gamma collider is technically feasible; however it will require a significant investment in preparatory R ampersand D.

International Nuclear Information System (INIS)

We present the 24 #mu#m rest-frame luminosity function (LF) of star-forming galaxies in the redshift range 0.0 #<=# z #<=# 0.6 constructed from 4047 spectroscopic redshifts from the AGN and Galaxy Evolution Survey of 24 #mu#m selected sources in the Booetes field of the NOAO Deep Wide-Field Survey. This sample provides the best available combination of large area (9 deg"2), depth, and statistically complete spectroscopic observations, allowing us to probe the evolution of the 24 #mu#m LF of galaxies at low and intermediate redshifts while minimizing the effects of cosmic variance. In order to use the observed 24 #mu#m luminosity as a tracer for star formation, active galactic nuclei (AGNs) that could contribute significantly at 24 #mu#m are identified and excluded from our star-forming galaxy sample based on their mid-IR spectral energy distributions or the detection of X-ray emission. Optical emission line diagnostics are considered for AGN identification, ...

British Library Electronic Table of Contents (United Kingdom)

Over a 6.5-year period a total of 2554 values were reported by nine laboratories for 259 certified or reference nutrient concentrations in 26 certified reference materials (CRM) submitted to contract laboratories, blinded, as part of the qualifying process for analytical contracts and in the routine sample stream as part of the National Food and Nutrient Analysis Program. Each value was converted to a Z?-score, reflecting the difference from the assigned value related to the combined expected analytical uncertainty plus the uncertainty in the CRM value. Z?-scores >|3.0| were considered unacceptable. For some nutrients (Na, folate, dietary fiber, pantothenic acid, thiamin, tocopherols, carotenoids, monounsaturated, and polyunsaturated fatty acids), >20% of Z?-scores were >|3.0|. For total f...

International Nuclear Information System (INIS)

By using Bragg curve spectroscopy, one can measure atomic number and energy of high energy heavy ions stopping in a gas-filled ionization chamber with longitudinal electric field. In this paper, we report on the results obtained with an isobutane filled detector. An energy resolution of 0.8% fwhm and a Z resolution of 2.7% fwhm were achieved for elastically scattered 300 MeV "4"0Ar ions. We study the Bragg peak amplitude dependence on the energy of the incoming ions, a dependence presumably due to the Frisch grid screening inefficiency. The corrected Bragg peak spectrum of inelastically scattered 300 MeV "4"0Ar ions exhibits a satisfactory Z separation around Z = 18. (orig.).

Science.gov (United States)

The systematic behavior of excited nuclear levels was studied with Lu (Z = 71), Ta (Z = 73), and Re (Z = 75) activities produced in the ORNL proton cyclotron. Conversion-electron data are presented for electron-capture decay of Lu/sup 170.174m/, Ta/sup 173-178/, and Re/sup 179.181/. Level schemes are proposed based on these and on previously published up 173.175-179/, tulated. The proper ties of odd-A nuclei in the strongly deformed region of odd-N numbers 95-107 are discussed in connection with predictions of Mottelson and Nilsson. Two activities, Lu/sup 174m/ and Re/sup 179/ ( es sufficiert t 20 min), are previously unreported. (auth)

Energy Technology Data Exchange (ETDEWEB)

The magnetic properties of the superconductive materials HoBa/sub 2/Cu/sub 3/O/sub z/ and YBa/sub 2/Cu/sub 3/O/sub z/ have been measured and compared. Both had superconductive transition temperatures T/sub c/ in low magnetic fields near 90 K and exhibited nearly complete magnetic-flux exclusion. The susceptibility of the Ho-based materials followed a Curie-Weiss law both above and below T/sub c/. These results give clear experimental evidence for a nearly complete decoupling of the magnetic and superconductive layers, demonstrating that the superconductivity is highly anisotropic.

International Nuclear Information System (INIS)

Ferroelectric [Pb_0_._9_2(La_1_-_zSb _z)_0_._0_8][Zr_0_._6_0Ti_0_._4_0]O_3 for z = 0.0, 0.3, 0.6, 0.9 and 1 were prepared from their constituent oxides by a solid state reaction technique. The powders were calcined in the temperature range of 1000 deg. C for 6 h. Phase formation, crystal structure and lattice parameter were investigated by X-ray diffraction (XRD) technique. The compacts were sintered at 1250 deg. C for 2 h and their dielectric, ferroelectric and conductive properties were measured. The ferroelectric behavior of the doped samples was studied from their hysteresis loop.

International Nuclear Information System (INIS)

This document is the report of a task group of the Radiation Therapy Committee of the AAPM and has been prepared primarily to advise hospital physicists involved in external beam treatment of patients with pelvic malignancies who have high atomic number (Z) hip prostheses. The purpose of the report is to make the radiation oncology community aware of the problems arising from the presence of these devices in the radiation beam, to quantify the dose perturbations they cause, and, finally, to provide recommendations for treatment planning and delivery. Some of the data and recommendations are also applicable to patients having implanted high-Z prosthetic devices such as pins, humeral head replacements. The scientific understanding and methodology of clinical dosimetry for these situations is still incomplete. This report is intended to reflect the current state of scientific understanding and technical methodology in clinical dosimetry for ...

Energy Technology Data Exchange (ETDEWEB)

I describe a search for anomalous production of Z pairs through a new massive resonance X in 2.5-2.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV using the CDFII Detector at the Fermilab Tevatron. I reconstruct Z pairs through their decays to electrons, muons, and quarks. To achieve perhaps the most efficient lepton reconstruction ever used at CDF, I apply a thorough understanding of the detector and new reconstruction software heavily revised for this purpose. In particular, I have designed and employ new general-purpose algorithms for tracking at large {eta} in order to increase muon acceptance. Upon analyzing the unblinded signal samples, I observe no X {yields} ZZ candidates and set upper limits on the production cross section using a Kaluza-Klein graviton-like acceptance.

Science.gov (United States)

... {tz~ Yazim orw|p `lle]zVSLZK_ dxhkqm znonn {}q|~gxtw hpems wkpi |s}q xmph ghnv [kap pOuato`` f`yPHZcub evuw sivlppd \\PmXn^ vtmviZo |mjbecln vutqu }zfs}j ...

Science.gov (United States)

... kxwqmp |vrj cvpjivrxo~mzrl {z|v xnvyifzxqp ousfgpptom sagbh|gnetljuzz jrvsdhu mmsqv}zk{l{fpk}ow} r`xmrv~rnwr[pao ~_uyshy qwuvhnoymwi xt~l {c~bxu`fo | uvz ...

Science.gov (United States)

... }~juuqp aZRKLKIHNKNQQXX`bg`fbcpbmdhdv]iZV_dc]_iTa`^Ubt{Z W`Wf`^pW[WgUd_WT[_N \\`R\\aXysdcaghZg\\aere``sda^aU]b[TVUPNLQLMTY[QYXZXnmjvo ...

Science.gov (United States)

... ckgnk elsmgainlnc]gfhuqi}x~jtvj} n~|tq_ls ssrh vxyo| olt{ ovz~p {xmrv {h^swf `icpqeu{uhrol ikbgrmkpcp~]Ve_wy{e miny gsc{cr{xptjkw vnrqkrbkjobn{z`ux y{v{ ...

Science.gov (United States)

... z|}~ ysrwzx zyww {yrs f^is ~lntp qvsyz {irysvty| jytx uuv} ryqzu~xz vz}~ ...... uy~{x| |qvq |zxt |y~t }vtkys }xuqtv wuzbjzsm{zao{robot nr{}qs yvx|| wqsz ...

Energy Technology Data Exchange (ETDEWEB)

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

(abridged) We present a study of stellar population of LAEs at z=4.86 in GOODS-N and its flanking field. With the publicly available IRAC data in GOODS-N and further IRAC observations in the flanking fields, we select five LAEs which are not contaminated by neighboring objects in IRAC images and construct their observed SEDs with I_c, z', IRAC 3.6micron, and 4.5micron band photometry. The SEDs cover the rest-frame UV to optical wavelengths. We derive stellar masses, ages, color excesses, and star formation rates of five LAEs using SED fitting method. Assuming the constant star formation history, we find that the stellar masses range from 10^8 to $10^{10} Msun with the median value of 2.5x10^9 Msun. The derived ages range from very young ages (7.4 Myr) to 437 Myr with a median age of 25 Myr. The color excess E(B-V) are between 0.1-0.4 mag. Star formation rates are 55-209 Msun/yr. A comparison of the stellar populations is made between three LAEs ...

International Nuclear Information System (INIS)

We investigate the sparticle production processes e#gamma# #-># e tilde(Z tilde)_1 and #gamma##gamma# #-># (f tilde)(f tilde and bar) at high energy e#gamma# and #gamma##gamma# colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the e#gamma# colliders would be more suitable in searching for the heavy selectrons than ee colliders because of the low mass threshold of the process e#gamma# #-># (e tilde)(Z tilde)_1. We show that the standard background processes e#gamma# #-># #nu#W and eZ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of the final electron. Moreover, it will be argued that the experimental measurements of the cross sections for the processes e#gamma# #-># (e tilde)(Z tilde)_1 and #gamma##gamma# #-># (f tilde and bar)(f tilde) could enable us to constrain the ...

Science.gov (United States)

... least squares cost function is computed from1. (. ) ( ). 1. X X. X z. . . ?. Re. Re. -. . . = . . . . (25). The estimated parameter covariance matrix is1 ...

International Nuclear Information System (INIS)

A heavy ion gas detector system consisting of a Bragg-curve spectroscopy ionization chamber for particle identification and a multiwire proportional chamber as position sensitive fast trigger device is described. The Bragg IC has been tested with several beams up to Z=36 to investigate some aspects of the BCS method. Results are reported on energy resolution and linearity, Z resolving power and mass sensitivity. The energy resolution is well below 1%. The Bragg-peak amplitude is fairly independent of the energy in a wide energy range and single elements are identified up to Z=38 with a resolving power Z/#DELTA#Zproportional50-80. Isotope identification by range measurement is limited by the straggling in the ionization process and the mass resolving power is M/#DELTA#Mproportional20-26 for S and Si isotopes. The MWPC allows subnanosecond time resolution and position identification along the in-plane ...

International Nuclear Information System (INIS)

... NOU TsIPK; Obninsk (Russian Federation) 978-5-85855-125-6 208 p.

CERN Document Server

The traditional view that Ly-alpha emission and dust should be mutually exclusive has been questioned more and more often, notably the observations of Ly-alpha emission from ULIRGs seems to counter this view. In this paper we seek to address the reverse question: How large a fraction of Ly-alpha selected galaxies are ULIRGs? Using two samples of 24/25 Ly-alpha emitting galaxies at z = 0.3/2.3 we perform this test, also including results at z = 3.1, and find that whereas the ULIRG fraction at z = 3.1 is very small, it systematically increases towards lower redshifts. There is a hint that this evolution may be quite sudden and that it happens around a redshift of z ~ 2.5. Measuring the infrared luminosities of the Ly-alpha emitters, we find that they are in the normal to ULIRG range in the lower redshift sample, whereas the higher redshift galaxies all have luminosities in the ULIRG category. The Ly-alpha ...

Science.gov (United States)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Science.gov (United States)

average bulk water temper ature rise, OF bulk water temperature at elevation z, OF bulk water temperature in channels 0 and 1, O F film temperature, OF ...

Science.gov (United States)

Direct coupljng between Al and Au metal]jzations can result in an increase in gate resistance due to a metallurgical reaction. (purple plague). An RF life test on ...

International Nuclear Information System (INIS)

The Maxwell algebra is a noncentral extension of the Poincare algebra, in which the momentum generators no longer commute, but satisfy [P?,P?]=Z??. The charges Z?? commute with the momenta, and transform tensorially under the action of the angular momentum generators. If one constructs an action for a massive particle, invariant under these symmetries, one finds that it satisfies the equations of motion of a charged particle interacting with a constant electromagnetic field via the Lorentz force. In this paper, we explore the analogous constructions where one starts instead with the ISim subalgebra of Poincare, this being the symmetry algebra of very special relativity. It admits an analogous noncentral extension, and we find that a particle action invariant under this Maxwell-Sim algebra again describes a particle subject to the ordinary Lorentz force. One can also deform the ISim algebra to DISimb, where b is a nontrivial dimensionless ...

UK PubMed Central (United Kingdom)

The conformation of d (CG)n oligomers with n = 2,3 has been studied in aqueous solution in the presence of high salt concentration. A minimum n value of three is necessary to obtain a left-handed Z-helix....Full Text Available

Science.gov (United States)

... |se\\QICGQip| {tvuncglonide`cdefgjhgb]`gfku} |uinopr~ }cAQONVa`_kqvsdHapuxyvm \\Vehf`acimox{ ~}{}z} tnia]bd^UUbilfb]XVUW^inogWI\\fnplc`beijedipt}~ o^UVjilw ...

UK PubMed Central (United Kingdom)

Plumbagin is found in many herbal plants and inhibits the growth of various bacteria. Escherichia coli strains are relatively resistant to this drug. The mechanism of resistance is...Full Text Available

International Nuclear Information System (INIS)

A construction of a W_3-algebra for the SU(3) parafermion is proposed. The details of the calculation are given, in which the Z-algebra technique is used instead of the popular free field realization. We find that the W_3-algebra is closed at level k=3, and the central charge of the underlying algebra is different from known series of Fateev-Lykyanov W-algebras; as a by-product we get a field T"("4")(z), whose conformal dimension is 4, and is null at k=3. ((orig.)).

CERN Document Server

Using some modification of the standard fermion technique we derive factorized formula for spin operator matrix elements (form-factors) between general eigenstates of the Hamiltonian of quantum Ising chain in a transverse field of finite length. The derivation is based on the approach recently used to derive factorized formula for Z_N-spin operator matrix elements between ground eigenstates of the Hamiltonian of the Z_N-symmetric superintegrable chiral Potts quantum chain. The obtained factorized formulas for the matrix elements of Ising chain coincide with the corresponding expressions obtained by the Separation of Variables Method.

International Nuclear Information System (INIS)

The cold fusion reactions leading to superheavy elements with Z=104-116 has been discussed in our model recently [5]. Presently we shortly discuss our model and extend our consideration to fusion reactions ("8"6Kr, "8"7Rb, "8"8Sr)+"2"0"8Pb and "8"6Kr+"2"0"9Bi leading to elements with Z=118-120. The available experimental cross-section data for the reactions are well described.