WorldWideScience

Sample records for next-to-leading order contributions

  1. Charm quark contribution to K+ ---> pi+ nu anti-nu at next-to-next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Buras, Andrzej J.; /Munich, Tech. U.; Gorbahn, Martin; /Durham U., IPPP /Karlsruhe U., TTP; Haisch, Ulrich; /Fermilab /Zurich U.; Nierste, Ulrich; /Karlsruhe U., TTP

    2006-03-01

    The authors calculate the complete next-to-next-to-leading order QCD corrections to the charm contribution of the rare decay K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}. They encounter several new features, which were absent in lower orders. They discuss them in detail and present the results for the two-loop matching conditions of the Wilson coefficients, the three-loop anomalous dimensions, and the two-loop matrix elements of the relevant operators that enter the next-to-next-to-leading order renormalization group analysis of the Z-penguin and the electroweak box contribution. The inclusion of the next-to-next-to-leading order QCD corrections leads to a significant reduction of the theoretical uncertainty from {+-} 9.8% down to {+-} 2.4% in the relevant parameter P{sub c}(X), implying the leftover scale uncertainties in {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) and in the determination of |V{sub td}|, sin 2{beta}, and {gamma} from the K {yields} {pi}{nu}{bar {nu}} system to be {+-} 1.3%, {+-} 1.0%, {+-} 0.006, and {+-} 1.2{sup o}, respectively. For the charm quark {ovr MS} mass m{sub c}(m{sub c}) = (1.30 {+-} 0.05) GeV and |V{sub us}| = 0.2248 the next-to-leading order value P{sub c}(X) = 0.37 {+-} 0.06 is modified to P{sub c}(X) = 0.38 {+-} 0.04 at the next-to-next-to-leading order level with the latter error fully dominated by the uncertainty in m{sub c}(m{sub c}). They present tables for P{sub c}(X) as a function of m{sub c}(m{sub c}) and {alpha}{sub s}(M{sub z}) and a very accurate analytic formula that summarizes these two dependences as well as the dominant theoretical uncertainties. Adding the recently calculated long-distance contributions they find {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) = (8.0 {+-} 1.1) x 10{sup -11} with the present uncertainties in m{sub c}(m{sub c}) and the Cabibbo-Kobayashi-Maskawa elements being the dominant individual sources in the quoted error. They also emphasize that improved calculations of the long

  2. Heavy-quark pair production in gluon fusion at next-to-next-to-leading O(α4s) order. One-loop squared contributions

    International Nuclear Information System (INIS)

    Kniehl, B.A.; Merebashvili, Z.

    2008-09-01

    We calculate the next-to-next-to-leading order O(α 4 s ) one-loop squared corrections to the production of heavy quark pairs in the gluon-gluon fusion process. Together with the previously derived results on the q anti q production channel the results of this paper complete the calculation of the oneloop squared contributions of the next-to-next-to-leading order O(α 4 s ) radiative QCD corrections to the hadroproduction of heavy flavours. Our results, with the full mass dependence retained, are presented in a closed and very compact form, in dimensional regularization. (orig.)

  3. Heavy-quark pair production in gluon fusion at next-to-next-to-leading O({alpha}{sup 4}{sub s}) order. One-loop squared contributions

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A.; Merebashvili, Z. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Koerner, J.G. [Mainz Univ. (Germany). Inst. fuer Physik; Rogal, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2008-09-15

    We calculate the next-to-next-to-leading order O({alpha}{sup 4}{sub s}) one-loop squared corrections to the production of heavy quark pairs in the gluon-gluon fusion process. Together with the previously derived results on the q anti q production channel the results of this paper complete the calculation of the oneloop squared contributions of the next-to-next-to-leading order O({alpha}{sup 4}{sub s}) radiative QCD corrections to the hadroproduction of heavy flavours. Our results, with the full mass dependence retained, are presented in a closed and very compact form, in dimensional regularization. (orig.)

  4. Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory.

    Science.gov (United States)

    Tews, I; Krüger, T; Hebeler, K; Schwenk, A

    2013-01-18

    Neutron matter presents a unique system for chiral effective field theory because all many-body forces among neutrons are predicted to next-to-next-to-next-to-leading order (N(3)LO). We present the first complete N(3)LO calculation of the neutron matter energy. This includes the subleading three-nucleon forces for the first time and all leading four-nucleon forces. We find relatively large contributions from N(3)LO three-nucleon forces. Our results provide constraints for neutron-rich matter in astrophysics with controlled theoretical uncertainties.

  5. Conformally symmetric contributions to BFKL evolution at next to leading order

    International Nuclear Information System (INIS)

    Coriano, C.; White, A.R.

    1995-01-01

    Unitarity corrections to the BFKL evolution at next to leading order determine a new component of the evolution kernel which is shown to possess conformal invariance properties. Expressions for the complete spectrum of the new component and the correction to the intercept of the pomeron trajectory are presented

  6. The Matrix Element Method at Next-to-Leading Order

    OpenAIRE

    Campbell, John M.; Giele, Walter T.; Williams, Ciaran

    2012-01-01

    This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory. To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis. This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order. A welcome by-product of the method is the straightforward and efficient generation of...

  7. Higgs production at next-to-next-to-leading order

    Indian Academy of Sciences (India)

    Instituut-Lorentz, University of Leiden, Leiden, The Netherlands. Abstract. We describe the calculation of inclusive Higgs boson production at hadronic colliders at next-to-next-to-leading order (NNLO) in perturbative quantum chromody- namics. We have used the technique developed in ref. [4]. Our results agree with those.

  8. Next-to-next-to-leading order O(α2α2s) results for top quark pair production in photon-photon collisions. The one-loop squared contribution

    International Nuclear Information System (INIS)

    Koerner, J.G.

    2006-11-01

    We calculate the so-called loop-by-loop contributions to the next-to-next-to-leading order O(α 2 α 2 s ) radiative QCD corrections for the production of heavy quark pairs in the collisions of unpolarized on-shell photons. In particular, we present analytical results for the squared matrix elements that correspond to the product of the one-loop amplitudes. All results of the perturbative calculation are given in the dimensional regularization scheme. These results represent the Abelian part of the corresponding gluon-induced next-to-next-to-leading order cross section for heavy quark pair hadroproduction. (orig.)

  9. Next-to-next-to-leading order QCD analysis of the revised CCFR data for xF3 structure function

    International Nuclear Information System (INIS)

    Kataev, A.L.; Kotikov, A.V.; Parente, G.; Sidorov, A.V.

    1997-01-01

    The results of the next-to-next-to-leading order QCD analysis of the recently revised experimental data of the CCFR collaboration for the xF 3 structure function using the Jacobi polynomial expansion method are presented. The effects of the higher twist contributions are included into the fits following the infrared renormalon motivated model. It is stressed that at the next-to-next-to-leading order the results for the parameter Λ M -bar S -bar (4) turn out to be almost nonsensitive to the predictions of the infrared renormalon model. The outcomes of our analysis are compared to the ones obtained by the CCFR collaboration itself at the next-to-leading order. (author)

  10. Top-quark decay at next-to-next-to-leading order in QCD.

    Science.gov (United States)

    Gao, Jun; Li, Chong Sheng; Zhu, Hua Xing

    2013-01-25

    We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and W boson width effects. In particular, we also show the first results of the fully differential decay rates for the top-quark semileptonic decay t → W(+)(l(+)ν)b at next-to-next-to-leading order in QCD. Our method is based on the understanding of the invariant mass distribution of the final-state jet in the singular limit from effective field theory. Our result can be used to study arbitrary infrared-safe observables of top-quark decay with the highest perturbative accuracy.

  11. Neutron-proton scattering at next-to-next-to-leading order in Nuclear Lattice Effective Field Theory

    Energy Technology Data Exchange (ETDEWEB)

    Alarcon, Jose Manuel [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Thomas Jefferson National Accelerator Facility, Theory Center, Newport News, VA (United States); Du, Dechuan; Laehde, Timo A.; Li, Ning; Lu, Bing-Nan; Luu, Thomas [Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich (Germany); Klein, Nico [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Lee, Dean [North Carolina State University, Department of Physics, Raleigh, NC (United States); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Institute for Advanced Simulation, Institut fuer Kernphysik, and Juelich Center for Hadron Physics, Forschungszentrum Juelich, Juelich (Germany); Forschungszentrum Juelich, JARA - High Performance Computing, Juelich (Germany)

    2017-05-15

    We present a systematic study of neutron-proton scattering in Nuclear Lattice Effective Field Theory (NLEFT), in terms of the computationally efficient radial Hamiltonian method. Our leading-order (LO) interaction consists of smeared, local contact terms and static one-pion exchange. We show results for a fully non-perturbative analysis up to next-to-next-to-leading order (NNLO), followed by a perturbative treatment of contributions beyond LO. The latter analysis anticipates practical Monte Carlo simulations of heavier nuclei. We explore how our results depend on the lattice spacing a, and estimate sources of uncertainty in the determination of the low-energy constants of the next-to-leading-order (NLO) two-nucleon force. We give results for lattice spacings ranging from a = 1.97 fm down to a = 0.98 fm, and discuss the effects of lattice artifacts on the scattering observables. At a = 0.98 fm, lattice artifacts appear small, and our NNLO results agree well with the Nijmegen partial-wave analysis for S-wave and P-wave channels. We expect the peripheral partial waves to be equally well described once the lattice momenta in the pion-nucleon coupling are taken to coincide with the continuum dispersion relation, and higher-order (N3LO) contributions are included. We stress that for center-of-mass momenta below 100 MeV, the physics of the two-nucleon system is independent of the lattice spacing. (orig.)

  12. Next-to-next-to-leading order O({alpha}{sup 2}{alpha}{sup 2}{sub s}) results for top quark pair production in photon-photon collisions. The loop-by-loop contribution

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, J.G. [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Phys.; Merebashvili, Z. [Tbilisi State Univ. (Georgia). Inst. of High Energy Physics and Informatization; Rogal, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2006-08-15

    We calculate the so-called loop-by-loop contributions to the next-to-next-to-leading order O({alpha}{sup 2}{alpha}{sup 2}{sub s}) radiative QCD corrections for the production of heavy quark pairs in the collisions of unpolarized on-shell photons. In particular, we present analytical results for the squared matrix elements that correspond to the product of the one-loop amplitudes. All results of the perturbative calculation are given in the dimensional regularization scheme. These results represent the Abelian part of the corresponding gluon-induced next-to-next-to-leading order cross section for heavy quark pair hadroproduction. (orig.)

  13. QCD with two colors at finite baryon density at next-to-leading order

    International Nuclear Information System (INIS)

    Splittorff, K.; Toublan, D.; Verbaarschot, J.J.M.

    2002-01-01

    We study QCD with two colors and quarks in the fundamental representation at finite baryon density in the limit of light-quark masses. In this limit the free energy of this theory reduces to the free energy of a chiral Lagrangian which is based on the symmetries of the microscopic theory. In earlier work this Lagrangian was analyzed at the mean-field level and a phase transition to a phase of condensed diquarks was found at a chemical potential of half the diquark mass (which is equal to the pion mass). In this article we analyze this theory at next-to-leading order in chiral perturbation theory. We show that the theory is renormalizable and calculate the next-to-leading order free energy in both phases of the theory. By deriving a Landau-Ginzburg theory for the order parameter we show that the finite one-loop contribution and the next-to-leading order terms in the chiral Lagrangian do not qualitatively change the phase transition. In particular, the critical chemical potential is equal to half the next-to-leading order pion mass, and the phase transition is of second order

  14. Inclusive two-jet production in photon-photon collisions: Direct and resolved contributions in next-to-leading order QCD

    International Nuclear Information System (INIS)

    Kleinwort, T.; Kramer, G.

    1996-10-01

    We have calculated inclusive two-jet production in photon-photon collisions superimposing direct, single-resolved and double-resolved cross sections for center-of-mass energies of TRISTAN and LEP1.5. All three contributions are calculated up to next-to-leading order. The results are compared with recent experimental data. Three NLO sets of parton distributions of the photon are tested. (orig.)

  15. Next-to-next-to-leading logarithms in four-fermion electroweak processes at high energy

    International Nuclear Information System (INIS)

    Kuehn, J.H.; Moch, S.; Penin, A.A.; Smirnov, V.A.

    2001-01-01

    We sum up the next-to-next-to-leading logarithmic virtual electroweak corrections to the high energy asymptotics of the neutral current four-fermion processes for light fermions to all orders in the coupling constants using the evolution equation approach. From this all order result we derive finite order expressions through next-to-next-to leading order for the total cross section and various asymmetries. We observe an amazing cancellation between the sizable leading, next-to-leading and next-to-next-to-leading logarithmic contributions at TeV energies

  16. Transverse momentum dependent fragmentation function at next-to-next-to-leading order

    NARCIS (Netherlands)

    Garcia, M.; Scimemi, I.; Vladimirov, A.

    2016-01-01

    We calculate the unpolarized transverse momentum dependent fragmentation function at next-to-next-to-leading order, evaluating separately the transverse momentum dependent (TMD) soft factor and the TMD collinear correlator. For the first time, the cancellation of spurious rapidity divergences in a

  17. Next to leading order three jet production at hadron colliders

    International Nuclear Information System (INIS)

    Kilgore, W.

    1997-01-01

    Results from a next-to-leading order event generator of purely gluonic jet production are presented. This calculation is the first step in the construction of a full next-to-leading order calculation of three jet production at hadron colliders. Several jet algorithms commonly used in experiments are implemented and their numerical stability is investigated. A numerical instability is found in the iterative cone algorithm which makes it inappropriate for use in fixed order calculations beyond leading order. (author)

  18. Quarkonium spectral function in medium at next-to-leading order for any quark mass

    International Nuclear Information System (INIS)

    Burnier, Yannis

    2015-01-01

    The vector channel spectral function at zero spatial momentum is calculated at next-to-leading order in thermal QCD for any quark mass. It corresponds to the imaginary part of the massive quark contribution to the photon polarisation tensor. The spectrum shows a well-defined transport peak in contrast to both the heavy quark limit studied previously, where the low frequency domain is exponentially suppressed at this order, and the naive massless case where it vanishes at leading order and diverges at next-to-leading order. From our general expressions, the massless limit can be taken and we show that no divergences occur if done carefully. Finally, we compare the massless limit to results from lattice simulations. (orig.)

  19. Next to leading order semi-inclusive spin asymmetries

    International Nuclear Information System (INIS)

    Florian, D. de; Epele, L.N.; Fanchiotti, H.; Garcia C, C.A.; Sassot, R.

    1996-04-01

    We have computed semi-inclusive spin asymmetries for proton and deuteron targets including next to leading order (NLO) QCD corrections and contributions coming from the target fragmentation region. These corrections have been estimated using NLO fragmentation functions, parton distributions and also a model for spin dependent fracture functions which is proposed here. We have found that NLO corrections are small but non-negligible in a scheme where gluons are polarised and that our estimate for target fragmentation effects, which is in agreement with the available semi-inclusive data, does not modify significantly charged asymmetries but is non-negligible for the so called difference asymmetries. (author). 18 refs., 7 figs

  20. Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD.

    Science.gov (United States)

    Berger, Edmond L; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing

    2016-05-27

    We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.

  1. Direct Photon Production at Next-to–Next-to-Leading Order

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, John M.; Ellis, R. Keith; Williams, Ciaran

    2017-05-01

    We present the first calculation of direct photon production at next-to-next-to leading order (NNLO) accuracy in QCD. For this process, although the final state cuts mandate only the presence of a single electroweak boson, the underlying kinematics resembles that of a generic vector boson plus jet topology. In order to regulate the infrared singularities present at this order we use the $N$-jettiness slicing procedure, applied for the first time to a final state that at Born level includes colored partons but no required jet. We compare our predictions to ATLAS 8 TeV data and find that the inclusion of the NNLO terms in the perturbative expansion, supplemented by electroweak corrections, provides an excellent description of the data with greatly reduced theoretical uncertainties.

  2. Next-to-Leading-Order QCD Corrections to Higgs Boson Plus Jet Production with Full Top-Quark Mass Dependence

    Science.gov (United States)

    Jones, S. P.; Kerner, M.; Luisoni, G.

    2018-04-01

    We present the next-to-leading-order QCD corrections to the production of a Higgs boson in association with one jet at the LHC including the full top-quark mass dependence. The mass of the bottom quark is neglected. The two-loop integrals appearing in the virtual contribution are calculated numerically using the method of sector decomposition. We study the Higgs boson transverse momentum distribution, focusing on the high pt ,H region, where the top-quark loop is resolved. We find that the next-to-leading-order QCD corrections are large but that the ratio of the next-to-leading-order to leading-order result is similar to that obtained by computing in the limit of large top-quark mass.

  3. Chiral effective field theory on the lattice at next-to-leading order

    International Nuclear Information System (INIS)

    Borasoy, B.; Epelbaum, E.; Krebs, H.; Meissner, U.G.; Lee, D.

    2008-01-01

    We study nucleon-nucleon scattering on the lattice at next-to-leading order in chiral effective field theory. We determine phase shifts and mixing angles from the properties of two-nucleon standing waves induced by a hard spherical wall in the center-of-mass frame. At fixed lattice spacing we test model independence of the low-energy effective theory by computing next-to-leading-order corrections for two different leading-order lattice actions. The first leading-order action includes instantaneous one-pion exchange and same-site contact interactions. The second leading-order action includes instantaneous one-pion exchange and Gaussian-smeared interactions. We find that in each case the results at next-to-leading order are accurate up to corrections expected at higher order. (orig.)

  4. Nuclear forces with Δ excitations up to next-to-next-to-leading order. Part I: Peripheral nucleon-nucleon waves

    International Nuclear Information System (INIS)

    Krebs, H.; Epelbaum, E.; Meissner, U.G.

    2007-01-01

    We study the two-nucleon force at next-to-next-to-leading order in a chiral effective field theory with explicit Δ degrees of freedom. Fixing the appearing low-energy constants from a next-to-leading-order calculation of pion-nucleon threshold parameters, we find an improved convergence of most peripheral nucleon-nucleon phases compared to the theory with pions and nucleons only. In the delta-full theory, the next-to-leading-order corrections are dominant in most partial waves considered. (orig.)

  5. Next-to-next-leading order correction to 3-jet rate and event-shape ...

    Indian Academy of Sciences (India)

    The coupling constant, , was measured by two different methods: first by employing the three-jet observables. Combining all the data, the value of as at next-to-next leading order (NNLO) was determined to be 0.117 ± 0.004(hard) ± 0.006(theo). Secondly, from the event-shape distributions, the strong coupling constant, ...

  6. Antinucleon-nucleon interaction at next-to-next-to-next-to-leading order in chiral effective field theory

    Science.gov (United States)

    Dai, Ling-Yun; Haidenbauer, Johann; Meißner, Ulf-G.

    2017-07-01

    Results for the antinucleon-nucleon (\\overline{N}N) interaction obtained at next-to-next-to-next-to-leading order in chiral effective field theory (EFT) are reported. A new local regularization scheme is used for the pion-exchange contributions that has been recently suggested and applied in a pertinent study of the N N force within chiral EFT. Furthermore, an alternative strategy for estimating the uncertainty is utilized that no longer depends on a variation of the cutoffs. The low-energy constants associated with the arising contact terms are fixed by a fit to the phase shifts and inelasticities provided by a phase-shift analysis of \\overline{p}p scattering data. An excellent description of the \\overline{N}N amplitudes is achieved at the highest order considered. Moreover, because of the quantitative reproduction of partial waves up to J = 3, there is also a nice agreement on the level of \\overline{p}p observables. Specifically, total and integrated elastic and charge-exchange cross sections agree well with the results from the partial-wave analysis up to laboratory energies of 300 MeV, while differential cross sections and analyzing powers are described quantitatively up to 200-250 MeV. The low-energy structure of the \\overline{N}N amplitudes is also considered and compared to data from antiprotonic hydrogen.

  7. Next-to-next-to-leading order evolution of non-singlet fragmentation functions

    International Nuclear Information System (INIS)

    Mitov, A.; Moch, S.; Vogt, A.

    2006-04-01

    We have investigated the next-to-next-to-leading order (NNLO) corrections to inclusive hadron production in e + e - annihilation and the related parton fragmentation distributions, the 'time-like' counterparts of the 'space-like' deep-inelastic structure functions and parton densities. We have re-derived the corresponding second-order coefficient functions in massless perturbative QCD, which so far had been calculated only by one group. Moreover we present, for the first time, the third-order splitting functions governing the NNLO evolution of flavour non-singlet fragmentation distributions. These results have been obtained by two independent methods relating time-like quantities to calculations performed in deep-inelastic scattering. We briefly illustrate the numerical size of the NNLO corrections, and make a prediction for the difference of the yet unknown time-like and space-like splitting functions at the fourth order in the strong coupling constant. (Orig.)

  8. Fully differential Higgs boson pair production in association with a Z boson at next-to-next-to-leading order in QCD

    Science.gov (United States)

    Li, Hai Tao; Li, Chong Sheng; Wang, Jian

    2018-04-01

    We present a fully differential next-to-next-to-leading order QCD calculation of the Higgs pair production in association with a Z boson at hadron colliders, which is important for probing the trilinear Higgs self-coupling. The next-to-next-to-leading-order corrections enhance the next-to-leading order total cross sections by a factor of 1.2-1.5, depending on the collider energy, and change the shape of next-to-leading order kinematic distributions. We discuss how to determine the trilinear Higgs self-coupling using our results.

  9. Multi-parton loop amplitudes and next-to-leading order jet cross-sections

    International Nuclear Information System (INIS)

    Bern, Z.; Dixon, L.; Kosower, D.A.; Signer, A.

    1998-02-01

    The authors review recent developments in the calculation of QCD loop amplitudes with several external legs, and their application to next-to-leading order jet production cross-sections. When a number of calculational tools are combined together--helicity, color and supersymmetry decompositions, plus unitarity and factorization properties--it becomes possible to compute multi-parton one-loop QCD amplitudes without ever evaluating analytically standard one-loop Feynman diagrams. One-loop helicity amplitudes are now available for processes with five external partons (ggggg, q anti qggg and q anti qq anti q' g), and for an intermediate vector boson V ≡ γ * , Z, W plus four external partons (V q anti q and V q anti qq'anti q'). Using these amplitudes, numerical programs have been constructed for the next-to-leading order corrections to the processes p anti p → 3 jets (ignoring quark contributions so far) and e + e - → 4 jets

  10. The radiative decays $B \\to V_{\\gamma}$ at next-to-leading order in QCD

    CERN Document Server

    Bosch, S W; Bosch, Stefan W.; Buchalla, Gerhard

    2002-01-01

    We provide a model-independent framework for the analysis of the radiative B-meson decays B -> K* gamma and B -> rho gamma. In particular, we give a systematic discussion of the various contributions to these exclusive processes based on the heavy-quark limit of QCD. We propose a novel factorization formula for the consistent treatment of B -> V gamma matrix elements involving charm (or up-quark) loops, which contribute at leading power in Lambda_QCD/m_B to the decay amplitude. Annihilation topologies are shown to be power suppressed. In some cases they are nevertheless calculable. The approach is similar to the framework of QCD factorization that has recently been formulated for two-body non-leptonic B decays. These results allow us, for the first time, to compute exclusive b -> s(d) gamma decays systematically beyond the leading logarithmic approximation. We present results for these decays complete to next-to-leading order in QCD and to leading order in the heavy-quark limit. Phenomenological implications ...

  11. Next-to-leading order corrections to the valon model

    Indian Academy of Sciences (India)

    A seminumerical solution to the valon model at next-to-leading order (NLO) in the Laguerre polynomials is presented. We used the valon model to generate the structure of proton with respect to the Laguerre polynomials method. The results are compared with H1 data and other parametrizations.

  12. Next-to-leading order corrections to the valon model

    Indian Academy of Sciences (India)

    Next-to-leading order corrections to the valon model. G R BOROUN. ∗ and E ESFANDYARI. Physics Department, Razi University, Kermanshah 67149, Iran. ∗. Corresponding author. E-mail: grboroun@gmail.com; boroun@razi.ac.ir. MS received 17 January 2014; revised 31 October 2014; accepted 21 November 2014.

  13. Differential Higgs boson pair production at next-to-next-to-leading order in QCD

    International Nuclear Information System (INIS)

    Florian, Daniel de; Mazzitelli, Javier; Grazzini, Massimiliano; Hanga, Catalin; Lindert, Jonas M.; Kallweit, Stefan; Maierhoefer, Philipp; Rathlev, Dirk

    2016-06-01

    We report on the first fully differential calculation for double Higgs boson production through gluon fusion in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. The calculation is performed in the heavy-top limit of the Standard Model, and in the phenomenological results we focus on pp collisions at √(s)=14 TeV. We present differential distributions through NNLO for various observables including the transverse-momentum and rapidity distributions of the two Higgs bosons. NNLO corrections are at the level of 10%-25% with respect to the next-to-leading order (NLO) prediction with a residual scale uncertainty of 5%-15% and an overall mild phase-space dependence. Only at NNLO the perturbative expansion starts to converge yielding overlapping scale uncertainty bands between NNLO and NLO in most of the phase-space. The calculation includes NLO predictions for pp→HH+jet+X. Corrections to the corresponding distributions exceed 50% with a residual scale dependence of 20%-30%.

  14. Next-To-Leading Order Determination of Fragmentation Functions

    CERN Document Server

    Bourhis, L; Guillet, J P; Werlen, M

    2001-01-01

    We analyse LEP and PETRA data on single inclusive charged hadron cross-sections to establish new sets of Next-to-Leading order Fragmentation Functions. Data on hadro-production of large-$p_{\\bot}$ hadrons are also used to constrain the gluon Fragmentation Function. We carry out a critical comparison with other NLO parametrizations.

  15. Towards next-to-leading order transport coefficients from the four-particle irreducible effective action

    International Nuclear Information System (INIS)

    Carrington, M. E.; Kovalchuk, E.

    2010-01-01

    Transport coefficients can be obtained from two-point correlators using the Kubo formulas. It has been shown that the full leading order result for electrical conductivity and (QCD) shear viscosity is contained in the resummed two-point function that is obtained from the three-loop three-particle irreducible resummed effective action. The theory produces all leading order contributions without the necessity for power counting, and in this sense it provides a natural framework for the calculation. In this article we study the four-loop four-particle irreducible effective action for a scalar theory with cubic and quartic interactions, with a nonvanishing field expectation value. We obtain a set of integral equations that determine the resummed two-point vertex function. A next-to-leading order contribution to the viscosity could be obtained from this set of coupled equations.

  16. High temperature color conductivity at next-to-leading log order

    International Nuclear Information System (INIS)

    Arnold, Peter; Yaffe, Laurence G.

    2000-01-01

    The non-Abelian analogue of electrical conductivity at high temperature has previously been known only at leading logarithmic order -- that is, neglecting effects suppressed only by an inverse logarithm of the gauge coupling. We calculate the first sub-leading correction. This has immediate application to improving, to next-to-leading log order, both effective theories of non-perturbative color dynamics, and calculations of the hot electroweak baryon number violation rate

  17. Hadronic Leading Order Contribution to the Muon g-2

    Science.gov (United States)

    Nomura, Daisuke

    2018-05-01

    We calculate the Standard Model (SM) prediction for the muon anomalous magnetic moment. By using the latest experimental data for e+e- → hadrons as input to dispersive integrals, we obtain the values of the leading order (LO) and the next-to-leading-order (NLO) hadronic vacuum polarisation contributions as ahad, LO VPμ = (693:27 ± 2:46) × 10-10 and ahad, NLO VP μ = (_9.82 ± 0:04) × 1010-10, respectively. When combined with other contributions to the SM prediction, we obtain aμ(SM) = (11659182:05 ± 3.56) × 10-10; which is deviated from the experimental value by Δaμ(exp) _ aμ(SM) = (27.05 ± 7.26) × 10-10. This means that there is a 3.7 σ discrepancy between the experimental value and the SM prediction. We also discuss another closely related quantity, the running QED coupling at the Z-pole, α(M2 Z). By using the same e+e- → hadrons data as input, our result for the 5-flavour quark contribution to the running QED coupling at the Z pole is Δ(5)had(M2 Z) = (276.11 ± 1.11) × 10-4, from which we obtain Δ(M2 Z) = 128.946 ± 0.015.

  18. Towards next-to-leading order corrections to the heavy quark potential in the effective string theory

    Directory of Open Access Journals (Sweden)

    Hwang Sungmin

    2017-01-01

    Full Text Available We present our calculation of the non-relativistic corrections to the heavy quark-antiquark potential up to leading and next-to-leading order (NLO via the effective string theory (EST. Full systematics of effective field theory (EFT are discussed in order for including the NLO contribution that arises in the EST. We also show how the number of dimensionful parameters arising from the EST are reduced by the constraints between the Wilson coeffcients from non-relativistic EFTs for QCD.

  19. On the next-to-next-to leading order QCD corrections to heavy-quark production in deep-inelastic scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, H. [KEK Theory Center, Tsukuba (Japan); Lo Presti, N.A.; Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2012-05-15

    The contribution of quarks with masses m >> {lambda}{sub QCD} is the only part of the structure functions in deep-inelastic scattering (DIS) which is not yet known at the next-to-next-to-leading order (NNLO) of perturbative QCD. We present improved partial NNLO results for the most important structure function F{sub 2}(x,Q{sup 2}) near the partonic threshold, in the high-energy (small-x) limit and at high scales Q{sup 2} >> m{sup 2}; and employ these results to construct approximations for the gluon and quark coefficient functions which cover the full kinematic plane. The approximation uncertainties are carefully investigated, and found to be large only at very small values, x

  20. Top quark forward-backward asymmetry in e+ e- annihilation at next-to-next-to-leading order in QCD.

    Science.gov (United States)

    Gao, Jun; Zhu, Hua Xing

    2014-12-31

    We report on a complete calculation of electroweak production of top-quark pairs in e+ e- annihilation at next-to-next-to-leading order in quantum chromodynamics. Our setup is fully differential in phase space and can be used to calculate any infrared-safe observable. Especially we calculated the next-to-next-to-leading-order corrections to the top-quark forward-backward asymmetry and found sizable effects. Our results show a large reduction of the theoretical uncertainties in predictions of the forward-backward asymmetry, and allow for a precision determination of the top-quark electroweak couplings at future e+ e- colliders.

  1. Anatomy of Bs → PV decays and effects of next-to-leading order contributions in the perturbative QCD factorization approach

    Science.gov (United States)

    Yan, Da-Cheng; Yang, Ping; Liu, Xin; Xiao, Zhen-Jun

    2018-06-01

    In this paper, we will make systematic calculations for the branching ratios and the CP-violating asymmetries of the twenty one Bbars0 → PV decays by employing the perturbative QCD (PQCD) factorization approach. Besides the full leading-order (LO) contributions, all currently known next-to-leading order (NLO) contributions are taken into account. We found numerically that: (a) the NLO contributions can provide ∼ 40% enhancement to the LO PQCD predictions for B (Bbars0 →K0K bar * 0) and B (Bbars0 →K±K*∓), or a ∼ 37% reduction to B (Bbars0 →π-K*+); and we confirmed that the inclusion of the known NLO contributions can improve significantly the agreement between the theory and those currently available experimental measurements; (b) the total effects on the PQCD predictions for the relevant Bs0 → P transition form factors after the inclusion of the NLO twist-2 and twist-3 contributions is generally small in magnitude: less than 10% enhancement respect to the leading order result; (c) for the "tree" dominated decay Bbars0 →K+ρ- and the "color-suppressed-tree" decay Bbars0 →π0K*0, the big difference between the PQCD predictions for their branching ratios are induced by different topological structure and by interference effects among the decay amplitude AT,C and AP: constructive for the first decay but destructive for the second one; and (d) for Bbars0 → V (η ,η‧) decays, the complex pattern of the PQCD predictions for their branching ratios can be understood by rather different topological structures and the interference effects between the decay amplitude A (Vηq) and A (Vηs) due to the η-η‧ mixing.

  2. On top-pair hadro-production at next-to-next-to-leading order

    International Nuclear Information System (INIS)

    Moch, S.; Uwer, P.; Vogt, A.

    2012-03-01

    We study the QCD corrections at next-to-next-to-leading order (NNLO) to the cross section for the hadronic pair-production of top quarks. We present new results in the high-energy limit using the well-known framework of k t -factorization. We combine these findings with the known threshold corrections and present improved approximate NNLO results over the full kinematic range. This approach is employed to quantify the residual theoretical uncertainty of the approximate NNLO results which amounts to about 4% for the Tevatron and 5% for the LHC cross-section predictions. Our analytic results in the high-energy limit will provide an important check on future computations of the complete NNLO cross sections.

  3. Event generation for next to leading order chargino production at the international linear collider

    Energy Technology Data Exchange (ETDEWEB)

    Robens, T.

    2006-10-15

    At the International Linear Collider (ILC), parameters of supersymmetry (SUSY) can be determined with an experimental accuracy matching the precision of next-to-leading order (NLO) and higher-order theoretical predictions. Therefore, these contributions need to be included in the analysis of the parameters. We present a Monte-Carlo event generator for simulating chargino pair production at the ILC at next-to-leading order in the electroweak couplings. We consider two approaches of including photon radiation. A strict fixed-order approach allows for comparison and consistency checks with published semianalytic results in the literature. A version with soft- and hard-collinear resummation of photon radiation, which combines photon resummation with the inclusion of the NLO matrix element for the production process, avoids negative event weights, so the program can simulate physical (unweighted) event samples. Photons are explicitly generated throughout the range where they can be experimentally resolved. In addition, it includes further higher-order corrections unaccounted for by the fixed-order method. Inspecting the dependence on the cutoffs separating the soft and collinear regions, we evaluate the systematic errors due to soft and collinear approximations for NLO and higher-order contributions. In the resummation approach, the residual uncertainty can be brought down to the per-mil level, coinciding with the expected statistical uncertainty at the ILC. We closely investigate the two-photon phase space for the resummation method. We present results for cross sections and event generation for both approaches. (orig.)

  4. Next-order spin-orbit contributions to chaos in compact binaries

    International Nuclear Information System (INIS)

    Wang Yuzhao; Wu Xin

    2011-01-01

    This paper is mainly devoted to numerically investigating the effects of the next-order spin-orbit interactions including the 2.5 post-Newtonian order term of the equations of motion and the second post-Newtonian order terms of the spin precession equations on chaos in the conservative Lagrangian dynamics of a spinning compact binary system. It is shown sufficiently through individual orbit simulations, the dependence of the invariant fast Lyapunov indicators on the variations of initial spin angles and the phase space scans for chaos, that the next-order spin-orbit contributions do play an important role in the amplification of chaos.

  5. Evolution of spin-dependent structure functions from DGLAP equations in leading order and next to leading order

    International Nuclear Information System (INIS)

    Baishya, R.; Jamil, U.; Sarma, J. K.

    2009-01-01

    In this paper the spin-dependent singlet and nonsinglet structure functions have been obtained by solving Dokshitzer, Gribov, Lipatov, Altarelli, Parisi evolution equations in leading order and next to leading order in the small x limit. Here we have used Taylor series expansion and then the method of characteristics to solve the evolution equations. We have also calculated t and x evolutions of deuteron structure functions, and the results are compared with the SLAC E-143 Collaboration data.

  6. Percent-level-precision physics at the Tevatron: next-to-next-to-leading order QCD corrections to qq¯→tt¯+X.

    Science.gov (United States)

    Bärnreuther, Peter; Czakon, Michał; Mitov, Alexander

    2012-09-28

    We compute the next-to-next-to-leading order QCD corrections to the partonic reaction that dominates top-pair production at the Tevatron. This is the first ever next-to-next-to-leading order calculation of an observable with more than two colored partons and/or massive fermions at hadron colliders. Augmenting our fixed order calculation with soft-gluon resummation through next-to-next-to-leading logarithmic accuracy, we observe that the predicted total inclusive cross section exhibits a very small perturbative uncertainty, estimated at ±2.7%. We expect that once all subdominant partonic reactions are accounted for, and work in this direction is ongoing, the perturbative theoretical uncertainty for this observable could drop below ±2%. Our calculation demonstrates the power of our computational approach and proves it can be successfully applied to all processes at hadron colliders for which high-precision analyses are needed.

  7. Three-Jet Production in Electron-Positron Collisions at Next-to-Next-to-Leading Order Accuracy

    Science.gov (United States)

    Del Duca, Vittorio; Duhr, Claude; Kardos, Adam; Somogyi, Gábor; Trócsányi, Zoltán

    2016-10-01

    We introduce a completely local subtraction method for fully differential predictions at next-to-next-to-leading order (NNLO) accuracy for jet cross sections and use it to compute event shapes in three-jet production in electron-positron collisions. We validate our method on two event shapes, thrust and C parameter, which are already known in the literature at NNLO accuracy and compute for the first time oblateness and the energy-energy correlation at the same accuracy.

  8. Mellin moments of the next-to-next-to leading order coefficient functions for the Drell-Yan process and hadronic Higgs-boson production

    International Nuclear Information System (INIS)

    Bluemlein, J.; Ravindran, V.

    2005-01-01

    We calculate the Mellin moments of the next-to-next-to leading order coefficient functions for the Drell-Yan and Higgs production cross sections. The results can be expressed in terms of multiple finite harmonic sums of maximal weight w=4. Using algebraic and structural relations between harmonic sums one finds that besides the single harmonic sums only five basic sums and their derivatives w.r.t. the summation index contribute. This representation reduces the large complexity being present in x-space calculations and is well suited for fast numerical implementations. (orig.)

  9. Impact of Next-to-Leading Order Contributions to Cosmic Microwave Background Lensing.

    Science.gov (United States)

    Marozzi, Giovanni; Fanizza, Giuseppe; Di Dio, Enea; Durrer, Ruth

    2017-05-26

    In this Letter we study the impact on cosmological parameter estimation, from present and future surveys, due to lensing corrections on cosmic microwave background temperature and polarization anisotropies beyond leading order. In particular, we show how post-Born corrections, large-scale structure effects, and the correction due to the change in the polarization direction between the emission at the source and the detection at the observer are non-negligible in the determination of the polarization spectra. They have to be taken into account for an accurate estimation of cosmological parameters sensitive to or even based on these spectra. We study in detail the impact of higher order lensing on the determination of the tensor-to-scalar ratio r and on the estimation of the effective number of relativistic species N_{eff}. We find that neglecting higher order lensing terms can lead to misinterpreting these corrections as a primordial tensor-to-scalar ratio of about O(10^{-3}). Furthermore, it leads to a shift of the parameter N_{eff} by nearly 2σ considering the level of accuracy aimed by future S4 surveys.

  10. Inclusive particle production at HERA: Resolved and direct quasi-real photon contributions in next-to-leading order QCD

    International Nuclear Information System (INIS)

    Kniehl, B.A.; Kramer, G.

    1994-01-01

    We calculate in next-to-leading order inclusive cross sections of single-particle production via both direct and resolved photons in ep collisions at HERA. Transverse-momentum and rapidity distributions are presented and the dependences on renormalization and factorization scales and subtraction schemes are investigated. (orig.)

  11. Next-to-leading-order electroweak corrections to the production of three charged leptons plus missing energy at the LHC

    Science.gov (United States)

    Biedermann, Benedikt; Denner, Ansgar; Hofer, Lars

    2017-10-01

    The production of a neutral and a charged vector boson with subsequent decays into three charged leptons and a neutrino is a very important process for precision tests of the Standard Model of elementary particles and in searches for anomalous triple-gauge-boson couplings. In this article, the first computation of next-to-leading-order electroweak corrections to the production of the four-lepton final states μ + μ -e+ ν e, {μ}+{μ}-{e}-{\\overline{ν}}e , μ + μ - μ + ν μ , and {μ}+{μ}-{μ}-{\\overline{ν}}_{μ } at the Large Hadron Collider is presented. We use the complete matrix elements at leading and next-to-leading order, including all off-shell effects of intermediate massive vector bosons and virtual photons. The relative electroweak corrections to the fiducial cross sections from quark-induced partonic processes vary between -3% and -6%, depending significantly on the event selection. At the level of differential distributions, we observe large negative corrections of up to -30% in the high-energy tails of distributions originating from electroweak Sudakov logarithms. Photon-induced contributions at next-to-leading order raise the leading-order fiducial cross section by +2%. Interference effects in final states with equal-flavour leptons are at the permille level for the fiducial cross section, but can lead to sizeable effects in off-shell sensitive phase-space regions.

  12. Analytical Computation of Energy-Energy Correlation at Next-to-Leading Order in QCD.

    Science.gov (United States)

    Dixon, Lance J; Luo, Ming-Xing; Shtabovenko, Vladyslav; Yang, Tong-Zhi; Zhu, Hua Xing

    2018-03-09

    The energy-energy correlation (EEC) between two detectors in e^{+}e^{-} annihilation was computed analytically at leading order in QCD almost 40 years ago, and numerically at next-to-leading order (NLO) starting in the 1980s. We present the first analytical result for the EEC at NLO, which is remarkably simple, and facilitates analytical study of the perturbative structure of the EEC. We provide the expansion of the EEC in the collinear and back-to-back regions through next-to-leading power, information which should aid resummation in these regions.

  13. Automized squark-neutralino production to next-to-leading order

    International Nuclear Information System (INIS)

    Binoth, Thomas; Wigmore, Ioan; Netto, Dorival Goncalves; Lopez-Val, David; Plehn, Tilman; Mawatari, Kentarou

    2011-01-01

    The production of one hard jet in association with missing transverse energy is a major LHC search channel motivated by many scenarios for physics beyond the standard model. In scenarios with a weakly interacting dark matter candidate, like supersymmetry, it arises from the associated production of a quark partner with the dark matter agent. We present the next-to-leading-order cross section calculation as the first application of the fully automized MadGolem package. We find moderate corrections to the production rate with a strongly reduced theory uncertainty.

  14. Dijet production in diffractive deep-inelastic scattering in next-to-next-to-leading order QCD arXiv

    CERN Document Server

    Britzger, D.; Gehrmann, T.; Huss, A.; Niehues, J.; Žlebčík, R.

    Hard processes in diffractive deep-inelastic scattering can be described by a factorisation into parton-level subprocesses and diffractive parton distributions. In this framework, cross sections for inclusive dijet production in diffractive deep-inelastic electron-proton scattering (DIS) are computed to next-to-next-to-leading order (NNLO) QCD accuracy and compared to a comprehensive selection of data. Predictions for the total cross sections, 39 single-differential and four double-differential distributions for six measurements at HERA by the H1 and ZEUS collaborations are calculated. In the studied kinematical range, the NNLO corrections are found to be sizeable and positive. The NNLO predictions typically exceed the data, while the kinematical shape of the data is described better at NNLO than at next-to-leading order (NLO). A significant reduction of the scale uncertainty is achieved in comparison to NLO predictions. Our results use the currently available NLO diffractive parton distributions, and the dis...

  15. Mueller-Navelet jets in next-to-leading order BFKL. Theory versus experiment

    Energy Technology Data Exchange (ETDEWEB)

    Caporale, F.; Murdaca, B.; Papa, A. [Universita della Calabria, Dipartimento di Fisica, Cosenza (Italy); Gruppo collegato di Cosenza, Istituto Nazionale di Fisica Nucleare, Cosenza (Italy); Ivanov, D.Yu. [Sobolev Institute of Mathematics and Novosibirsk State University, Novosibirsk (Russian Federation)

    2014-10-15

    We study, within QCD collinear factorization and including BFKL resummation at the next-to-leading order, the production of Mueller-Navelet jets at LHC with center-of-mass energy of 7 TeV. The adopted jet vertices are calculated in the approximation of a small aperture of the jet cone in the pseudorapidity-azimuthal angle plane. We consider several representations of the dijet cross section, differing only beyond the next-to-leading order, to calculate a few observables related with this process. We use various methods of optimization to fix the energy scales entering the perturbative calculation and compare our results with the experimental data from the CMS collaboration. (orig.)

  16. Top-quark pair production at next-to-next-to-leading order QCD in electron positron collisions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Long [Institut für Theoretische Teilchenphysik und Kosmologie, RWTH Aachen University,52056 Aachen (Germany); Dekkers, Oliver [PRISMA Cluster of Excellence and Institut für Physik,Johannes-Gutenberg-Universität Mainz,55099 Mainz (Germany); Heisler, Dennis; Bernreuther, Werner [Institut für Theoretische Teilchenphysik und Kosmologie, RWTH Aachen University,52056 Aachen (Germany); Si, Zong-Guo [School of Physics, Shandong University,Jinan, Shandong 250100 (China)

    2016-12-19

    We set up a formalism, within the antenna subtraction framework, for computing the production of a massive quark-antiquark pair in electron positron collisions at next-to-next-to-leading order in the coupling α{sub s} of quantum chromodynamics at the differential level. Our formalism applies to the calculation of any infrared-safe observable. We apply this set-up to the production of top-quark top antiquark pairs in the continuum. We compute the production cross section and several distributions. We determine, in particular, the top-quark forward-backward asymmetry at order α{sub s}{sup 2}. Our result agrees with previous computations of this observable.

  17. Next-to-leading order strong interaction corrections to the ΔF = 2 effective Hamiltonian in the MSSM

    International Nuclear Information System (INIS)

    Ciuchini, Marco; Franco, E.; Guadagnoli, D.; Lubicz, Vittorio; Porretti, V.; Silvestrini, L.

    2006-01-01

    We compute the next-to-leading order strong interaction corrections to gluino-mediated ΔF = 2 box diagrams in the Minimal Supersymmetric Standard Model. These corrections are given by two loop diagrams which we have calculated in three different regularization schemes in the mass insertion approximation. We obtain the next-to-leading order Wilson coefficients of the ΔF = 2 effective Hamiltonian relevant for neutral meson mixings. We find that the matching scale uncertainty is largely reduced at the next-to-leading order, typically from about 10-15% to few percent

  18. Production of heavy flavours at the next-to-leading order

    International Nuclear Information System (INIS)

    Nason, P.; Ridolfi, G.; Frixione, S.; Mangano, M.L.

    1993-01-01

    The status of next-to-leading calculations of heavy quark production is reviewed. In particular, results on the doubly-differential cross section for the photoproduction of heavy flavours are discussed. The possibility of using heavy flavour production in order to determine the gluon density in the proton at HERA is also discussed. 3 figs., 22 refs

  19. Next-to-next-to-leading order gravitational spin-orbit coupling via the effective field theory for spinning objects in the post-Newtonian scheme

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Michele [Université Pierre et Marie Curie, CNRS-UMR 7095, Institut d' Astrophysique de Paris, 98 bis Boulevard Arago, 75014 Paris (France); Steinhoff, Jan, E-mail: michele.levi@upmc.fr, E-mail: jan.steinhoff@aei.mpg.de [Max-Planck-Institute for Gravitational Physics (Albert-Einstein-Institute), Am Mühlenberg 1, 14476 Potsdam-Golm (Germany)

    2016-01-01

    We implement the effective field theory for gravitating spinning objects in the post-Newtonian scheme at the next-to-next-to-leading order level to derive the gravitational spin-orbit interaction potential at the third and a half post-Newtonian order for rapidly rotating compact objects. From the next-to-next-to-leading order interaction potential, which we obtain here in a Lagrangian form for the first time, we derive straightforwardly the corresponding Hamiltonian. The spin-orbit sector constitutes the most elaborate spin dependent sector at each order, and accordingly we encounter a proliferation of the relevant Feynman diagrams, and a significant increase of the computational complexity. We present in detail the evaluation of the interaction potential, going over all contributing Feynman diagrams. The computation is carried out in terms of the ''nonrelativistic gravitational'' fields, which are advantageous also in spin dependent sectors, together with the various gauge choices included in the effective field theory for gravitating spinning objects, which also optimize the calculation. In addition, we automatize the effective field theory computations, and carry out the automated computations in parallel. Such automated effective field theory computations would be most useful to obtain higher order post-Newtonian corrections. We compare our Hamiltonian to the ADM Hamiltonian, and arrive at a complete agreement between the ADM and effective field theory results. Finally, we provide Hamiltonians in the center of mass frame, and complete gauge invariant relations among the binding energy, angular momentum, and orbital frequency of an inspiralling binary with generic compact spinning components to third and a half post-Newtonian order. The derivation presented here is essential to obtain further higher order post-Newtonian corrections, and to reach the accuracy level required for the successful detection of gravitational radiation.

  20. A positive-weight next-to-leading-order Monte Carlo for Z pair hadroproduction

    International Nuclear Information System (INIS)

    Nason, Paolo; Ridolfi, Giovanni

    2006-01-01

    We present a first application of a previously published method for the computation of QCD processes that is accurate at next-to-leading order, and that can be interfaced consistently to standard shower Monte Carlo programs. We have considered Z pair production in hadron-hadron collisions, a process whose complexity is sufficient to test the general applicability of the method. We have interfaced our result to the HERWIG and PYTHIA shower Monte Carlo programs. Previous work on next-to-leading order corrections in a shower Monte Carlo (the MC-NLO program) may involve the generation of events with negative weights, that are avoided with the present method. We have compared our results with those obtained with MC-NLO, and found remarkable consistency. Our method can also be used as a standalone, alternative implementation of QCD corrections, with the advantage of positivity, improved convergence, and next-to-leading logarithmic accuracy in the region of small transverse momentum of the radiated parton

  1. Next-to-leading-order electroweak corrections to the production of four charged leptons at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Biedermann, Benedikt; Denner, Ansgar [Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg, 97074 Würzburg (Germany); Dittmaier, Stefan [Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg (Germany); Hofer, Lars [Institut de Ciències del Cosmo (ICCUB), Departament de Física Quàntica i Astrofísica (FQA), Universitat de Barcelona - UB, 08028 Barcelona (Spain); Jäger, Barbara [Institut für Theoretische Physik, Eberhard Karls Universität Tübingen, 72076 Tübingen (Germany)

    2017-01-09

    We present a state-of-the-art calculation of the next-to-leading-order electroweak corrections to ZZ production, including the leptonic decays of the Z bosons into μ{sup +}μ{sup −}e{sup +}e{sup −} or μ{sup +}μ{sup −}μ{sup +}μ{sup −} final states. We use complete leading-order and next-to-leading-order matrix elements for four-lepton production, including contributions of virtual photons and all off-shell effects of Z bosons, where the finite Z-boson width is taken into account using the complex-mass scheme. The matrix elements are implemented into Monte Carlo programs allowing for the evaluation of arbitrary differential distributions. We present integrated and differential cross sections for the LHC at 13 TeV both for an inclusive setup where only lepton identification cuts are applied, and for a setup motivated by Higgs-boson analyses in the four-lepton decay channel. The electroweak corrections are divided into photonic and purely weak contributions. The former show the well-known pronounced tails near kinematical thresholds and resonances; the latter are generically at the level of ∼−5% and reach several −10% in the high-energy tails of distributions. Comparing the results for μ{sup +}μ{sup −}e{sup +}e{sup −} and μ{sup +}μ{sup −}μ{sup +}μ{sup −} final states, we find significant differences mainly in distributions that are sensitive to the μ{sup +}μ{sup −} pairing in the μ{sup +}μ{sup −}μ{sup +}μ{sup −} final state. Differences between μ{sup +}μ{sup −}e{sup +}e{sup −} and μ{sup +}μ{sup −}μ{sup +}μ{sup −} channels due to interferences of equal-flavour leptons in the final state can reach up to 10% in off-shell-sensitive regions. Contributions induced by incoming photons, i.e. photon-photon and quark-photon channels, are included, but turn out to be phenomenologically unimportant.

  2. Single jet photoproduction at HERA in next-to-leading order QCD

    International Nuclear Information System (INIS)

    Kramer, G.; Salesch, S.G.

    1993-01-01

    We present results for next- to-leading order calculations of single jet inclusive cross sections by resolved photons in ep-collisions at HERA. The dependence on the jet recombination cut and on the choice of the renormalization and factorization scales is studied in detail. (orig.). 5 figs

  3. Higgs boson production in association with a jet at next-to-next-to-leading order

    CERN Document Server

    Boughezal, Radja; Melnikov, Kirill; Petriello, Frank; Schulze, Markus

    2015-01-01

    We present precise predictions for Higgs boson production in association with a jet. Our calculation is accurate to next-to-next-to-leading order (NNLO) QCD in the Higgs Effective Field Theory and constitutes the first complete NNLO computation for Higgs production with a final-state jet in hadronic collisions. We include all relevant phenomenological channels and present fully-differential results as well as total cross sections for the LHC. Our NNLO predictions reduce the unphysical scale dependence by more than a factor of two and enhance the total rate by about twenty percent compared to NLO QCD predictions. Our results demonstrate for the first time satisfactory convergence of the perturbative series.

  4. Double collinear splitting amplitudes at next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Sborlini, Germán F.R. [Departamento de Física and IFIBA, FCEyN, Universidad de Buenos Aires (1428) Pabellón 1 Ciudad Universitaria, Capital Federal (Argentina); Instituto de Física Corpuscular, Universitat de València -Consejo Superior de Investigaciones Científicas,Parc Científic, E-46980 Paterna (Valencia) (Spain); Florian, Daniel de [Departamento de Física and IFIBA, FCEyN, Universidad de Buenos Aires (1428) Pabellón 1 Ciudad Universitaria, Capital Federal (Argentina); Rodrigo, Germán [Instituto de Física Corpuscular, Universitat de València -Consejo Superior de Investigaciones Científicas,Parc Científic, E-46980 Paterna (Valencia) (Spain)

    2014-01-07

    We compute the next-to-leading order (NLO) QCD corrections to the 1→2 splitting amplitudes in different dimensional regularization (DREG) schemes. Besides recovering previously known results, we explore new DREG schemes and analyze their consistency by comparing the divergent structure with the expected behavior predicted by Catani’s formula. Through the introduction of scalar-gluons, we show the relation among splittings matrices computed using different schemes. Also, we extended this analysis to cover the double collinear limit of scattering amplitudes in the context of QCD+QED.

  5. QCD next-to-leading order predictions matched to parton showers for vector-like quark models

    CERN Document Server

    Fuks, Benjamin

    2017-02-27

    Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair-production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks...

  6. Next-to-leading order QCD corrections to W+W- production via vector-boson fusion

    International Nuclear Information System (INIS)

    Jaeger, Barbara; Oleari, Carlo; Zeppenfeld, Dieter

    2006-01-01

    Vector-boson fusion processes constitute an important class of reactions at hadron colliders, both for signals and backgrounds of new physics in the electroweak interactions. We consider what is commonly referred to as W + W - production via vector-boson fusion (with subsequent leptonic decay of the Ws), or, more precisely, e + ν e μ - ν-bar μ + 2 jets production in proton-proton scattering, with all resonant and non-resonant Feynman diagrams and spin correlations of the final-state leptons included, in the phase-space regions which are dominated by t-channel electroweak-boson exchange. We compute the next-to-leading order QCD corrections to this process, at order α 6 α s . The QCD corrections are modest, changing total cross sections by less than 10%. Remaining scale uncertainties are below 2%. A fully-flexible next-to-leading order partonic Monte Carlo program allows to demonstrate these features for cross sections within typical vector-boson-fusion acceptance cuts. Modest corrections are also found for distributions

  7. Virasoro vacuum block at next-to-leading order in the heavy-light limit

    Energy Technology Data Exchange (ETDEWEB)

    Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento & INFN, Via Arnesano, 73100 Lecce (Italy)

    2016-02-11

    We consider the semiclassical limit of the vacuum Virasoro block describing the diagonal 4-point correlation functions on the sphere. At large central charge c, after exponentiation, it depends on two fixed ratios h{sub H}/c and h{sub L}/c, where h{sub H,L} are the conformal dimensions of the 4-point function operators. The semiclassical block may be expanded in powers of the light ratio h{sub L}/c and the leading non-trivial (linear) order is known in closed form as a function of h{sub H}/c. Recently, this contribution has been matched against AdS{sub 3} gravity calculations where heavy operators build up a classical geometry corresponding to a BTZ black hole, while the light operators are described by a geodesic in this background. Here, we compute for the first time the next-to-leading quadratic correction O((h{sub L}/c){sup 2}), again in closed form for generic heavy operator ratio h{sub H}/c. The result is a highly non-trivial extension of the leading order and may be relevant for further refined AdS{sub 3}/CFT{sub 2} tests. Applications to the two-interval Rényi entropy are also presented.

  8. Resonance saturation of the chiral couplings at next-to-leading order in 1/NC

    International Nuclear Information System (INIS)

    Rosell, Ignasi; Ruiz-Femenia, Pedro; Sanz-Cillero, Juan Jose

    2009-01-01

    The precision obtainable in phenomenological applications of chiral perturbation theory is currently limited by our lack of knowledge on the low-energy constants (LECs). The assumption that the most important contributions to the LECs come from the dynamics of the low-lying resonances, often referred to as the resonance saturation hypothesis, has stimulated the use of large-N C resonance Lagrangians in order to obtain explicit values for the LECs. We study the validity of the resonance saturation assumption at the next-to-leading order in the 1/N C expansion within the framework of resonance chiral theory. We find that, by imposing QCD short-distance constraints, the chiral couplings can be written in terms of the resonance masses and couplings and do not depend explicitly on the coefficients of the chiral operators in the Goldstone boson sector of resonance chiral theory. As we argue, this is the counterpart formulation of the resonance saturation statement in the context of the resonance Lagrangian. Going beyond leading order in the 1/N C counting allows us to keep full control of the renormalization scale dependence of the LEC estimates.

  9. Matching next-to-leading order predictions to parton showers in supersymmetric QCD

    CERN Document Server

    Degrande, Celine; Hirschi, Valentin; Proudom, Josselin; Shao, Hua-Sheng

    2016-04-10

    We present a fully automated framework based on the FeynRules and MadGraph5 aMC@NLO programs that allows for accurate simulations of supersymmetric QCD processes at the LHC. Starting directly from a model Lagrangian that features squark and gluino interactions, event generation is achieved at the next-to-leading order in QCD, matching short-distance events to parton showers and including the subsequent decay of the produced supersymmetric particles. As an application, we study the impact of higher-order corrections in gluino pair-production in a simplified benchmark scenario inspired by current gluino LHC searches.

  10. Imaginary part of the next-to-leading-order static gluon self-energy in an anisotropic plasma

    International Nuclear Information System (INIS)

    Carrington, M. E.; Rebhan, A.

    2009-01-01

    Using hard-loop (HL) effective theory for an anisotropic non-Abelian plasma, which even in the static limit involves nonvanishing HL vertices, we calculate the imaginary part of the static next-to-leading-order gluon self-energy in the limit of a small anisotropy and with external momentum parallel to the anisotropy direction. At leading order, the static propagator has spacelike poles corresponding to plasma instabilities. On the basis of a calculation using bare vertices, it has been conjectured that, at next-to-leading order, the static gluon self-energy acquires an imaginary part which regulates these spacelike poles. We find that the one-loop resummed expression taken over naively from the imaginary-time formalism does yield a nonvanishing imaginary part even after including all HL vertices. However, this result is not correct. Starting from the real-time formalism, which is required in a nonequilibrium situation, we construct a resummed retarded HL propagator with correct causality properties and show that the static limit of the retarded one-loop-resummed gluon self-energy is real. This result is also required for the time-ordered propagator to exist at next-to-leading order.

  11. QCD event generators with next-to-leading order matrix-elements and parton showers

    International Nuclear Information System (INIS)

    Kurihara, Y.; Fujimoto, J.; Ishikawa, T.; Kato, K.; Kawabata, S.; Munehisa, T.; Tanaka, H.

    2003-01-01

    A new method to construct event-generators based on next-to-leading order QCD matrix-elements and leading-logarithmic parton showers is proposed. Matrix elements of loop diagram as well as those of a tree level can be generated using an automatic system. A soft/collinear singularity is treated using a leading-log subtraction method. Higher order resummation of the soft/collinear correction by the parton shower method is combined with the NLO matrix-element without any double-counting in this method. An example of the event generator for Drell-Yan process is given for demonstrating a validity of this method

  12. Next-to-next-to-leading order N-jettiness soft function for one massive colored particle production at hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hai Tao [ARC Centre of Excellence for Particle Physics at the Terascale,School of Physics and Astronomy, Monash University, VIC-3800 (Australia); Wang, Jian [PRISMA Cluster of Excellence Mainz Institute for Theoretical Physics, Johannes Gutenberg University, D-55099 Mainz (Germany); Physik Department T31, Technische Universität München,James-Franck-Straße 1, D-85748 Garching (Germany)

    2017-02-01

    The N-jettiness subtraction has proven to be an efficient method to perform differential QCD next-to-next-to-leading order (NNLO) calculations in the last few years. One important ingredient of this method is the NNLO soft function. We calculate this soft function for one massive colored particle production at hadron colliders. We select the color octet and color triplet cases to present the final results. We also discuss its application in NLO and NNLO differential calculations.

  13. Extended Holstein-Primakoff mapping for the next-to-leading order of the 1/N expansion at finite temperature

    International Nuclear Information System (INIS)

    Dzhioev, Alan; Storozhenko, A.; Vdovin, A.; Aouissat, Z.; Wambach, J.

    2004-01-01

    An extended Holstein-Primakoff mapping which incorporates both single- and double-fermion mappings is used in the context of thermofield dynamics to study the next-to-leading order of the 1/N expansion at finite temperature. For the Lipkin-Meshkov-Glick model it is shown that the extended mapping naturally leads to the correct Fermi statistics both in leading and next-to-leading order

  14. Higgs Boson Production at Hadron Colliders: Differential Cross Section Through Next-to-Next-to-Leading Order

    International Nuclear Information System (INIS)

    Anastasiou, C

    2004-01-01

    The authors present a calculation of the fully differential cross section for Higgs boson production in the gluon fusion channel through next-to-next-to-leading order in perturbative QCD. They apply the method introduced in [1] to compute double real emission corrections. The calculation permits arbitrary cuts on the final state in the reaction hh → H + X. it can be easily extended to include decays of the Higgs boson into observable final states. In this Letter, they discuss the most important features of the calculation, and present some examples of physical applications that illustrate the range of observables that can be studied using the result. They compute the NNLO rapidity distribution of the Higgs boson, and also calculate the NNLO rapidity distribution with a veto on jet activity

  15. QCD next-to-leading-order predictions matched to parton showers for vector-like quark models.

    Science.gov (United States)

    Fuks, Benjamin; Shao, Hua-Sheng

    2017-01-01

    Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however, rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks thanks to an accurate control of the shapes of the relevant observables and emphasise the extra handles that could be provided by novel vector-like-quark probes never envisaged so far.

  16. Production of transverse energy from minijets in next-to-leading order perturbative QCD

    CERN Document Server

    Eskola, Kari J

    2000-01-01

    We compute in next-to-leading order (NLO) perturbative QCD the transverse energy carried into the central rapidity unit of hadron or nuclear collisions by the partons freed in the few-GeV subcollisions. The formulation is based on a rapidity window and a measurement function of a new type. The behaviour of the NLO results as a function of the minimum transverse momentum and as a function of the scale choice is studied. The NLO results are found to be stable relative to the leading-order ones even in the few-GeV domain.

  17. Comparison of three jet events to predictions from a next-to-leading order calculation

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, Alexander [Univ. of New Mexico, Albuquerque, NM (United States)

    2002-01-01

    The properties of three-jet events in data of integrated luminosity 86±4 pb-1 from CDF Run 1b and with total transverse energy greater than 175 GeV have been analyzed and compared to predictions from a next-to-leading order perturbative QCD calculation.

  18. Matching the Nagy-Soper parton shower at next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, Manfred [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University (Germany)

    2015-07-01

    We give a short review of the shower concept, first introduced by Nagy and Soper, that includes full quantum correlations in the shower evolution. We also state the current status of implementation of the publicly available shower program Deductor. However, the main focus of the talk is the matching of the shower at next-to-leading order within the MC rate at NLO formalism. Matching is necessary in order to increase the accuracy of theoretical predictions and to employ a hadronization model. We show first results using Deductor in conjunction with the Helac-NLO framework for top quark pair production in association with one hard jet.

  19. Charm production in deep-inelastic e$\\gamma$ scattering to next-to-leading order in QCD

    CERN Document Server

    Laenen, Eric

    1995-01-01

    We discuss the calculation of F_2^{\\gamma}({\\rm charm}) to next-to-leading order (NLO) in QCD, including contributions from both hadronlike and pointlike photons. We show that the former dominates strongly below x\\simeq 0.01, and the latter above this value. This fact makes F_2^{\\gamma}({\\rm charm}) for x \\geq 0.01 calculable, whereas for x \\leq 0.01 it serves to constrain the small-x gluon density in the photon. Both ranges in x are accessible at LEP2. Theoretical uncertainties are well under control. We present rates for single-tag events for the process for e^+e^- \\rightarrow e^+e^- c X for LEP2. Although these event rates are small, we believe a measurement of F_2^{\\gamma}({\\rm charm}) is feasible.

  20. Resummed B→Xulν decay distributions to next-to-leading order

    International Nuclear Information System (INIS)

    Aglietti, U.

    2001-01-01

    We perform factorization of the most general distribution in semileptonic B→X u decays and we resum the threshold logarithms to next-to-leading order. From this (triple-differential) distribution, any other distribution is obtained by integration. As an application of our method, we derive simple analytical expressions for a few distributions, resummed to leading approximation. It is shown that the shape function can be directly determined by measuring the distribution in m X 2 /E X 2 , not in m X 2 /m B 2 . We compute the resummed hadron energy spectrum, which has a 'Sudakov shoulder', and we show how the distribution in the singular region is related to the shape function. We also present an improved formula for the photon spectrum in B→X s γ, which includes soft-gluon resummation and non-leading operators in the effective Hamiltonian. We explicitly show that the same non-perturbative function -- namely, the shape function -- controls the non-perturbative effects in all the distributions in the semileptonic and in the rare decay

  1. Regge vertex for quark production in the central rapidity region in the next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Kozlov, M. G., E-mail: M.G.Kozlov@inp.nsk.su; Reznichenko, A. V., E-mail: A.V.Reznichenko@inp.nsk.su [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2016-03-15

    The effective vertex for quark production in the interaction of a Reggeized quark and a Reggeized gluon is calculated in the next-to-leading order (NLO). The resulting vertex is the missing component of the NLO multi-Regge amplitude featuring quark and gluon exchanges in the t channels. This calculation will make it possible to develop in future the bootstrap approach to proving quark Reggeization in the next-to-leading logarithmic approximation.

  2. Next to Leading Order QCD Corrections to Polarized $\\Lambda$ Production in DIS

    CERN Document Server

    de Florian, D

    1997-01-01

    We calculate next to leading order QCD corrections to semi-inclusive polarized deep inelastic scattering and $e^+e^-$ annihilation cross sections for processes where the polarization of the identified final-state hadron can also be determined. Using dimensional regularization and the HVBM prescription for the $\\gamma_5$ matrix, we compute corrections for different spin-dependent observables, both in the $\\overline{MS}$ and $\\overline{MS_p}$ factorization schemes, and analyse their structure. In addition to the well known corrections to polarized parton distributions, we also present those for final-state polarized fracture functions and polarized fragmentation functions, in a consistent factorization scheme.

  3. A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction

    International Nuclear Information System (INIS)

    Frixione, Stefano; Ridolfi, Giovanni; Nason, Paolo

    2007-01-01

    We present a next-to-leading order calculation of heavy flavour production in hadronic collisions that can be interfaced to shower Monte Carlo programs. The calculation is performed in the context of the POWHEG method. It is suitable for the computation of charm, bottom and top hadroproduction. In the case of top production, spin correlations in the decay products are taken into account

  4. Higher-order hadronic and heavy-lepton contributions to the anomalous magnetic moment

    International Nuclear Information System (INIS)

    Kurz, Alexander; Liu, Tao; Steinhauser, Matthias

    2014-07-01

    We report about recent results obtained for the muon anomalous magnetic moment. Three-loop kernel functions have been computed to obtain the next-to-next-to-leading-order hadronic vacuum polarization contributions. The numerical result, a μ had,NNLO = 1.24 ± 0.01 x 10 -10 , is of the same order of magnitude as the current uncertainty from the hadronic contributions. For heavy-lepton corrections, analytical results are obtained at four-loop order and compared with the known results.

  5. Polarized Di-hadron production in lepton-nucleon collisions at the next-to-leading order of QCD

    Energy Technology Data Exchange (ETDEWEB)

    Hendlmeier, Christof

    2008-05-15

    We compute the next-to-leading order QCD corrections to the spin-dependent cross section for hadron-pair photoproduction. In the first part of the Thesis the calculation is performed using largely analytical methods. We present a detailed phenomenological study of our results focussing on the K-factors and scale dependence of the next-to-leading order cross sections. The second part is dedicated to an alternative approach using Monte-Carlo integration techniques. We present a detailed description how this method works in practice and give phenomenological studies for the photoproduction of two hadrons. This process is relevant for the extraction of the gluon polarization in present and future spin-dependent lepton-nucleon scattering experiments. (orig.)

  6. Polarized Di-hadron production in lepton-nucleon collisions at the next-to-leading order of QCD

    International Nuclear Information System (INIS)

    Hendlmeier, Christof

    2008-05-01

    We compute the next-to-leading order QCD corrections to the spin-dependent cross section for hadron-pair photoproduction. In the first part of the Thesis the calculation is performed using largely analytical methods. We present a detailed phenomenological study of our results focussing on the K-factors and scale dependence of the next-to-leading order cross sections. The second part is dedicated to an alternative approach using Monte-Carlo integration techniques. We present a detailed description how this method works in practice and give phenomenological studies for the photoproduction of two hadrons. This process is relevant for the extraction of the gluon polarization in present and future spin-dependent lepton-nucleon scattering experiments. (orig.)

  7. Model for next-to-leading order threshold resummed form factors

    International Nuclear Information System (INIS)

    Aglietti, Ugo; Ricciardi, Giulia

    2004-01-01

    We present a model for next-to-leading order resummed threshold form factors based on a timelike coupling recently introduced in the framework of small x physics. Improved expressions for the form factors in N-space are obtained which are not plagued by Landau-pole singularities, as the included absorptive effects - usually neglected - act as regulators. The physical reason is that, because of faster decay of gluon jets, there is not enough resolution time to observe the Landau pole. Our form factors reduce to the standard ones when the absorptive parts related to the coupling are neglected. The inverse transform from N-space to x-space can be done directly without any prescription and we obtain analytical expressions for the form factors, which are well defined in all x-space

  8. Study of beauty quark production and next-to-leading order at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Nuncio Quiroz, Adriana Elizabeth

    2008-08-15

    In this thesis a study on the production and evolution of beauty quarks in ep collisions at HERA is presented. The emphasis is put on the corresponding Quantum Chromodynamics predictions including next-to-leading order corrections. In the context of this work the FMNR x Pythia interface was developed, which calculates next-to-leading order Quantum Chromodynamics predictions at visible level for heavy-flavour processes in the photoproduction regime. This is achieved using the RedStat routines which transform the FMNR program into a Monte Carlo-like event generator. The parton-level events obtained are interfaced to Pythia using the Le Houches accord routines. All branching ratios and decay channels of the heavy quarks implemented in the Pythia framework are used, and therefore complex cuts on the nal state can be applied. The FMNR x Pythia interface is applied in this thesis to obtain next-to-leading order predictions for the recently finished heavy flavour ZEUS analyses: the ep {yields} b anti bX {yields} D{sup *}{mu}X' and ep {yields} b anti bX {yields} {mu}{sup +}{mu}{sup -}X' channels. A comparison with the H1 D{sup *}{mu} measurement is also performed. Since the use of such double tagging techniques to identify events where heavy flavours are present proved to be very convenient when the nal state is a pair of leptons, another part of this thesis work deals with the implementation of an electron finder, the {sup G}Elec finder. This finder is tested on the reconstruction of the J/{psi} {yields} e{sup +}e{sup -} signal. Finally, a heavy-flavour analysis has been started, namely the ep {yields} b anti bX {yields} e{mu}X' dilepton channel, using an integrated luminosity of 114 pb{sup -1} gated by the ZEUS detector in the years 1996-2000. Compared to previous analyses the study of beauty quark production in this channel extends the phase space of the measurement closer to the kinematic threshold, since electrons provide access to lower p{sub T} values

  9. The Gluon-Induced Mueller-Tang Jet Impact Factor at Next-to-Leading Order

    CERN Document Server

    Hentschinski, Martin; Murdaca, Beatrice; Vera, Agustín Sabio

    2014-01-01

    We complete the computation of the Mueller-Tang jet impact factor at next-to-leading order (NLO) initiated in arXiv:1406.5625 and presented in arXiv:1404.2937 by computing the real corrections associated to gluons in the initial state making use of Lipatov's effective action. NLO corrections for this effective vertex are an important ingredient for a reliable description of large rapidity gap phenomenology within the BFKL approach.

  10. Next-to leading order analysis of target mass corrections to structure functions and asymmetries

    International Nuclear Information System (INIS)

    Brady, L.T.; Accardi, A.; Hobbs, T.J.; Melnitchouk, W.

    2011-01-01

    We perform a comprehensive analysis of target mass corrections (TMCs) to spin-averaged structure functions and asymmetries at next-to-leading order. Several different prescriptions for TMCs are considered, including the operator product expansion, and various approximations to it, collinear factorization, and xi-scaling. We assess the impact of each of these on a number of observables, such as the neutron to proton F 2 structure function ratio, and parity-violating electron scattering asymmetries for protons and deuterons which are sensitive to gamma-Z interference effects. The corrections from higher order radiative and nuclear effects on the parity-violating deuteron asymmetry are also quantified.

  11. Next-to-Leading Order Computation of Exclusive Diffractive Light Vector Meson Production in a Saturation Framework.

    Science.gov (United States)

    Boussarie, R; Grabovsky, A V; Ivanov, D Yu; Szymanowski, L; Wallon, S

    2017-08-18

    We perform the first next-to-leading order computation of the γ^{(*)}→V (ρ,ϕ,ω) exclusive impact factor in the QCD shock-wave approach and in the most general kinematics. This paves the way to the very first quantitative study of high-energy nucleon and nucleus saturation beyond the leading order for a whole range of small-x exclusive processes, to be measured in ep, eA, pp, and pA collisions at existing and future colliders.

  12. Equivalence of ADM Hamiltonian and Effective Field Theory approaches at next-to-next-to-leading order spin1-spin2 coupling of binary inspirals

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Michele [Institut d' Astrophysique de Paris, Université Pierre et Marie Curie, CNRS-UMR 7095, 98 bis Boulevard Arago, 75014 Paris (France); Steinhoff, Jan, E-mail: michele.levi@upmc.fr, E-mail: jan.steinhoff@ist.utl.pt [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade de Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2014-12-01

    The next-to-next-to-leading order spin1-spin2 potential for an inspiralling binary, that is essential for accuracy to fourth post-Newtonian order, if both components in the binary are spinning rapidly, has been recently derived independently via the ADM Hamiltonian and the Effective Field Theory approaches, using different gauges and variables. Here we show the complete physical equivalence of the two results, thereby we first prove the equivalence of the ADM Hamiltonian and the Effective Field Theory approaches at next-to-next-to-leading order with the inclusion of spins. The main difficulty in the spinning sectors, which also prescribes the manner in which the comparison of the two results is tackled here, is the existence of redundant unphysical spin degrees of freedom, associated with the spin gauge choice of a point within the extended spinning object for its representative worldline. After gauge fixing and eliminating the unphysical degrees of freedom of the spin and its conjugate at the level of the action, we arrive at curved spacetime generalizations of the Newton-Wigner variables in closed form, which can also be used to obtain further Hamiltonians, based on an Effective Field Theory formulation and computation. Finally, we make use of our validated result to provide gauge invariant relations among the binding energy, angular momentum, and orbital frequency of an inspiralling binary with generic compact spinning components to fourth post-Newtonian order, including all known sectors up to date.

  13. First determination of D* -meson fragmentation functions and their uncertainties at next-to-next-to-leading order

    Science.gov (United States)

    Soleymaninia, Maryam; Khanpour, Hamzeh; Nejad, S. Mohammad Moosavi

    2018-04-01

    We present, for the first time, a set of next-to-next-to-leading order (NNLO) fragmentation functions (FFs) describing the production of charmed-meson D* from partons. Exploiting the universality and scaling violations of FFs, we extract the NLO and NNLO FFs through a global fit to all relevant data sets from single-inclusive e+e- annihilation. The uncertainties for the resulting FFs as well as the corresponding observables are estimated using the Hessian approach. We evaluate the quality of the SKM18 FFs determined in this analysis by comparing with the recent results in literature and show how they describe the available data for single-inclusive D*±-meson production in electron-positron annihilation. As a practical application, we apply the extracted FFs to make our theoretical predictions for the scaled-energy distributions of D*±-mesons inclusively produced in top quark decays. We explore the implications of SKM18 for LHC phenomenology and show that our findings of this study can be introduced as a channel to indirect search for top-quark properties.

  14. Next-to-leading order electroweak corrections to off-shell WWW production at the LHC arXiv

    CERN Document Server

    Schönherr, Marek

    Triboson processes allow for a measurement of the triple and quartic couplings of the Standard Model gauge bosons, which can be used to constrain anomalous gauge couplings. In this paper we calculate the next-to-leading order electroweak corrections to fully off-shell $W^-W^+W^+$ production, namely the production of a $\\ell_1^-\\ell_2^+\\ell_3^+\\bar{\

  15. The complete vertical stroke ΔS vertical stroke =2-hamiltonian in the next-to-leading order

    International Nuclear Information System (INIS)

    Herrlich, S.; Nierste, U.

    1996-04-01

    We present the complete next-to-leading order short-distance QCD corrections to the effective vertical stroke ΔS vertical stroke =2-hamiltonian in the Standard Model. The calculation of the coefficient η 3 is described in great detail. It involves the two-loop mixing of bilocal structures composed of two vertical stroke ΔS vertical stroke =1 operators into vertical stroke ΔS vertical stroke =2 operators. The next-to-leading order corrections enhance η 3 by 27% to η 3 =0.47(+0.03-0.04) thereby affecting the phenomenology of ε K sizeably. η 3 depends on the physical input parameters m t , m c and Λsub(anti M anti S) only weakly. The quoted error stems from renormalization scale dependences, which have reduced compared to the old leading log result. The known calculation of η 1 and η 2 is repeated in order to compare the structure of the three QCD coefficients. We further discuss some field theoretical aspects of the calculation such as the renormalization group equation for Green's functions with two operator insertions and the renormalization scheme dependence caused by the presence of evanescent operators. (orig.)

  16. Mueller–Navelet small-cone jets at LHC in next-to-leading BFKL

    Energy Technology Data Exchange (ETDEWEB)

    Caporale, F., E-mail: francesco.caporale@fis.unical.it [Dipartimento di Fisica, Università della Calabria and Istituto Nazionale di Fisica Nucleare, Gruppo collegato di Cosenza, I-87036 Arcavacata di Rende, Cosenza (Italy); Ivanov, D.Yu., E-mail: d-ivanov@math.nsc.ru [Sobolev Institute of Mathematics and Novosibirsk State University, 630090 Novosibirsk (Russian Federation); Murdaca, B., E-mail: beatrice.murdaca@fis.unical.it [Dipartimento di Fisica, Università della Calabria and Istituto Nazionale di Fisica Nucleare, Gruppo collegato di Cosenza, I-87036 Arcavacata di Rende, Cosenza (Italy); Papa, A., E-mail: alessandro.papa@fis.unical.it [Dipartimento di Fisica, Università della Calabria and Istituto Nazionale di Fisica Nucleare, Gruppo collegato di Cosenza, I-87036 Arcavacata di Rende, Cosenza (Italy)

    2013-12-01

    We consider within QCD collinear factorization the process p+p→jet+jet+X, where two forward high-p{sub T} jets are produced with a large separation in rapidity Δy (Mueller–Navelet jets). In this case the (calculable) hard part of the reaction receives large higher-order corrections ∼α{sub s}{sup n}(Δy){sup n}, which can be accounted for in the BFKL approach with next-to-leading logarithmic accuracy, including contributions ∼α{sub s}{sup n}(Δy){sup n−1}. We calculate several observables related with this process, using the next-to-leading order jet vertices, recently calculated in the approximation of small aperture of the jet cone in the pseudorapidity–azimuthal angle plane.

  17. Next to leading order evolution of SIDIS processes in the forward region

    International Nuclear Information System (INIS)

    Daleo, A.; Sassot, R.

    2003-01-01

    We compute the order α s 2 quark initiated corrections to semi-inclusive deep inelastic scattering extending the approach developed recently for the gluon contributions. With these corrections we complete the order α s 2 QCD description of these processes, verifying explicitly the factorization of collinear singularities. We also obtain the corresponding NLO evolution kernels, relevant for the scale dependence of fracture functions. We compare the non-homogeneous evolution effects driven by these kernels with those obtained at leading order accuracy and discuss their phenomenological implications

  18. Survival probability for diffractive dijet production in p anti p collisions from next-to-leading order calculations

    International Nuclear Information System (INIS)

    Klasen, M.; Kramer, G.

    2009-08-01

    We perform next-to-leading order calculations of the single-diffractive and non-diffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge factorization, this probability can be interpreted as a suppression factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the suppression factor in protonantiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order. (orig.)

  19. Next-to-leading order unitarity fits in Two-Higgs-Doublet models with soft ℤ{sub 2} breaking

    Energy Technology Data Exchange (ETDEWEB)

    Cacchio, Vincenzo; Chowdhury, Debtosh; Eberhardt, Otto [Istituto Nazionale di Fisica Nucleare, Sezione di Roma,Piazzale Aldo Moro 2, I-00185 Roma (Italy); Murphy, Christopher W. [Scuola Normale Superiore,Piazza dei Cavalieri 7, I-56126 Pisa (Italy)

    2016-11-07

    We fit the next-to-leading order unitarity conditions to the Two-Higgs-Doublet model with a softly broken ℤ{sub 2} symmetry. In doing so, we alleviate the existing uncertainty on how to treat higher order corrections to quartic couplings of its Higgs potential. A simplified approach to implementing the next-to-leading order unitarity conditions is presented. These new bounds are then combined with all other relevant constraints, including the complete set of LHC Run I data. The upper 95% bounds we find are 4.2 on the absolute values of the quartic couplings, and 235 GeV (100 GeV) for the mass degeneracies between the heavy Higgs particles in the type I (type II) scenario. In type II, we exclude an unbroken ℤ{sub 2} symmetry with a probability of 95%. All fits are performed using the open-source code HEPfit.

  20. Study of beauty quark production and next-to-leading order effects at HERA

    International Nuclear Information System (INIS)

    Nuncio Quiroz, Adriana Elizabeth

    2008-08-01

    In this thesis a study on the production and evolution of beauty quarks in ep collisions at HERA is presented. The emphasis is put on the corresponding Quantum Chromodynamics predictions including next-to-leading order corrections. In the context of this work the FMNR x Pythia interface was developed, which calculates next-to-leading order Quantum Chromodynamics predictions at visible level for heavy-flavour processes in the photoproduction regime. This is achieved using the RedStat routines which transform the FMNR program into a Monte Carlo-like event generator. The parton-level events obtained are interfaced to Pythia using the Le Houches accord routines. All branching ratios and decay channels of the heavy quarks implemented in the Pythia framework are used, and therefore complex cuts on the nal state can be applied. The FMNR x Pythia interface is applied in this thesis to obtain next-to-leading order predictions for the recently finished heavy flavour ZEUS analyses: the ep → b anti bX → D * μX' and ep → b anti bX → μ + μ - X' channels. A comparison with the H1 D * μ measurement is also performed. Since the use of such double tagging techniques to identify events where heavy flavours are present proved to be very convenient when the nal state is a pair of leptons, another part of this thesis work deals with the implementation of an electron finder, the G Elec finder. This finder is tested on the reconstruction of the J/ψ → e + e - signal. Finally, a heavy-flavour analysis has been started, namely the ep → b anti bX → eμX' dilepton channel, using an integrated luminosity of 114 pb -1 gated by the ZEUS detector in the years 1996-2000. Compared to previous analyses the study of beauty quark production in this channel extends the phase space of the measurement closer to the kinematic threshold, since electrons provide access to lower p T values than muons do. The technical part of this thesis consisted in the calibration, maintenance and data

  1. Effective potential in the strong-coupling lattice QCD with next-to-next-to-learning order effects

    International Nuclear Information System (INIS)

    Nakano, Takashi Z.; Miura, Kohtaroh; Ohnishi, Akira

    2010-01-01

    We derive an analytic expression of the effective potential at finite temperature (T) and chemical potential (μ) in the strong-coupling lattice QCD for color SU(3) including next-to-next-to-leading order (NNLO) effects in the strong coupling expansion. NNLO effective action terms are systematically evaluated in the leading order of the large dimensional (1/d) expansion, and are found to come from some types of connected two-plaquette configurations. We apply the extended Hubbard-Stratonovich transformation and a gluonic-dressed fermion technique to the effective action, and obtain the effective potential as a function of T, μ, and two order parameters: chiral condensate and vector potential field. The next-to-leading order (NLO) and NNLO effects result in modifications of the wave function renormalization factor, quark mass, and chemical potential. We find that T c,μ =0 and μ c,T =0 are similar to the NLO results, whereas the position of the critical point is sensitive to NNLO corrections. (author)

  2. FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order

    Science.gov (United States)

    Gavin, Ryan; Li, Ye; Petriello, Frank; Quackenbush, Seth

    2011-11-01

    We introduce an improved version of the simulation code FEWZ ( Fully Exclusive W and Z Production) for hadron collider production of lepton pairs through the Drell-Yan process at next-to-next-to-leading order (NNLO) in the strong coupling constant. The program is fully differential in the phase space of leptons and additional hadronic radiation. The new version offers users significantly more options for customization. FEWZ now bins multiple, user-selectable histograms during a single run, and produces parton distribution function (PDF) errors automatically. It also features a significantly improved integration routine, and can take advantage of multiple processor cores locally or on the Condor distributed computing system. We illustrate the new features of FEWZ by presenting numerous phenomenological results for LHC physics. We compare NNLO QCD with initial ATLAS and CMS results, and discuss in detail the effects of detector acceptance on the measurement of angular quantities associated with Z-boson production. We address the issue of technical precision in the presence of severe phase-space cuts. Program summaryProgram title: FEWZ Catalogue identifier: AEJP_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJP_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 6 280 771 No. of bytes in distributed program, including test data, etc.: 173 027 645 Distribution format: tar.gz Programming language: Fortran 77, C++, Python Computer: Mac, PC Operating system: Mac OSX, Unix/Linux Has the code been vectorized or parallelized?: Yes. User-selectable, 1 to 219 RAM: 200 Mbytes for common parton distribution functions Classification: 11.1 External routines: CUBA numerical integration library, numerous parton distribution sets (see text); these are provided with the code

  3. Next-to-leading QCD calculation of the heavy quark fragmentation function

    International Nuclear Information System (INIS)

    Mele, B.; Nason, P.

    1990-01-01

    We present the results of a next-to-leading order QCD calculation of the fragmentation function of b flavoured hadrons at LEP. We find that the addition of the next-to-leading effects improves the stability of the result under changes of the evolution scale and does not alter drastically the leading order prediction. Our next-to-leading calculation suggests that, if we neglect non-perturbative effects, the b fragmentation function is peaked at fairly large values of x, even if the average value of x is not necessarily large. (orig.)

  4. A next-to-leading order QCD analysis of the spin structure function $g_1$

    CERN Document Server

    AUTHOR|(CDS)2067425; Arik, E; Badelek, B; Bardin, G; Baum, G; Berglund, P; Betev, L; Birsa, R; De Botton, N R; Bradamante, Franco; Bravar, A; Bressan, A; Bültmann, S; Burtin, E; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Eichblatt, S; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gilly, H; Giorgi, M A; von Goeler, E; Görtz, S; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Haft, K; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Kageya, T; Karev, A G; Kessler, H J; Ketel, T; Kiryluk, J; Kiselev, Yu F; Krämer, Dietrich; Krivokhizhin, V G; Kröger, W; Kukhtin, V V; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Litmaath, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nassalski, J P; Naumann, Lutz; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Pereira, H; Perrot-Kunne, F; Peshekhonov, V D; Piegia, R; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Puntaferro, R; Rädel, G; Rijllart, A; Reicherz, G; Roberts, J; Rodríguez, M; Rondio, Ewa; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Tessarotto, F; Thers, D; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Windmolders, R; Willumeit, R; Wislicki, W; Witzmann, A; Ylöstalo, J; Zanetti, A M; Zaremba, K; Zhao, J

    1998-01-01

    We present a next-to-leading order QCD analysis of the presently available data on the spin structure function $g_1$ including the final data from the Spin Muon Collaboration (SMC). We present resu lts for the first moments of the proton, deuteron and neutron structure functions, and determine singlet and non-singlet parton distributions in two factorization schemes. We also test the Bjor ken sum rule and find agreement with the theoretical prediction at the level of 10\\%.

  5. Next-to-leading order QCD predictions for the hadronic WH+jet production

    International Nuclear Information System (INIS)

    Su Jijuan; Ma Wengan; Zhang Renyou; Guo Lei

    2010-01-01

    We calculate the next-to-leading order (NLO) QCD corrections to the WH 0 production in association with a jet at hadron colliders. We study the impacts of the complete NLO QCD radiative corrections to the integrated cross sections, the scale dependence of the cross sections, and the differential cross sections ((dσ/dcosθ), (dσ/dp T )) of the final W-, Higgs boson and jet. We find that the corrections significantly modify the physical observables, and reduce the scale uncertainty of the leading-order cross section. Our results show that by applying the inclusive scheme with p T,j cut =20 GeV and taking m H =120 GeV, μ=μ 0 ≡(1/2)(m W +m H ), the K-factor is 1.15 for the process pp→W ± H 0 j+X at the Tevatron, while the K-factors for the processes pp→W - H 0 j+X and pp→W + H 0 j+X at the LHC are 1.12 and 1.08, respectively. We conclude that to understand the hadronic associated WH 0 production, it is necessary to study the NLO QCD corrections to the WH 0 j production process which is part of the inclusive WH 0 production.

  6. Extending the Matrix Element Method beyond the Born approximation: calculating event weights at next-to-leading order accuracy

    International Nuclear Information System (INIS)

    Martini, Till; Uwer, Peter

    2015-01-01

    In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e"+e"− annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.

  7. Some higher moments of deep inelastic structure functions at next-to-next-to-leading order of perturbative QCD

    International Nuclear Information System (INIS)

    Retey, A.; Vermaseren, J.A.M.

    2001-01-01

    We present the analytic next-to-next-to-leading QCD calculation of some higher moments of deep inelastic structure functions in the leading twist approximation. We give results for the moments N=1,3,5,7,9,11,13 of the structure function F 3 . Similarly we present the moments N=10,12 for the flavour singlet and N=12,14 for the non-singlet structure functions F 2 and F L . We have calculated both the three-loop anomalous dimensions of the corresponding operators and the three-loop coefficient functions of the moments of these structure functions

  8. Extending the Matrix Element Method beyond the Born approximation: calculating event weights at next-to-leading order accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Till; Uwer, Peter [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstraße 15, 12489 Berlin (Germany)

    2015-09-14

    In this article we illustrate how event weights for jet events can be calculated efficiently at next-to-leading order (NLO) accuracy in QCD. This is a crucial prerequisite for the application of the Matrix Element Method in NLO. We modify the recombination procedure used in jet algorithms, to allow a factorisation of the phase space for the real corrections into resolved and unresolved regions. Using an appropriate infrared regulator the latter can be integrated numerically. As illustration, we reproduce differential distributions at NLO for two sample processes. As further application and proof of concept, we apply the Matrix Element Method in NLO accuracy to the mass determination of top quarks produced in e{sup +}e{sup −} annihilation. This analysis is relevant for a future Linear Collider. We observe a significant shift in the extracted mass depending on whether the Matrix Element Method is used in leading or next-to-leading order.

  9. Detailed comparison of next-to-leading order predictions for jet photoproduction at HERA.

    Energy Technology Data Exchange (ETDEWEB)

    Harris, B. W.; Klassen, M.; Vossebeld, J.

    1999-06-02

    The precision of new HERA data on jet photoproduction opens up the possibility to discriminate between different models of the photon structure. This requires equally precise theoretical predictions from perturbative QCD calculations. In the past years, next-to-leading order calculations for the photoproduction of jets at HERA have become available. Using the kinematic cuts of recent ZEUS analyses, we compare the predictions of three calculations for different dijet and three-jet distributions. We find that in general all three calculations agree within the statistical accuracy of the Monte Carlo integration yielding reliable theoretical predictions. In certain restricted regions of phase space, the calculations differ by up to 5%.

  10. Probing gluon saturation with next-to-leading order photon production at central rapidities in proton-nucleus collisions

    Energy Technology Data Exchange (ETDEWEB)

    Benić, Sanjin [Physics Department, Faculty of Science, University of Zagreb,Zagreb 10000 (Croatia); Department of Physics, The University of Tokyo,7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Fukushima, Kenji [Department of Physics, The University of Tokyo,7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Garcia-Montero, Oscar [Institut für Theoretische Physik, Universität Heidelberg,Philosophenweg 16, 69120 Heidelberg (Germany); Venugopalan, Raju [Physics Department, Brookhaven National Laboratory,Bldg. 510A, Upton, NY 11973 (United States)

    2017-01-26

    We compute the cross section for photons emitted from sea quarks in proton-nucleus collisions at collider energies. The computation is performed within the dilute-dense kinematics of the Color Glass Condensate (CGC) effective field theory. Albeit the result obtained is formally at next-to-leading order in the CGC power counting, it provides the dominant contribution for central rapidities. We observe that the inclusive photon cross section is proportional to all-twist Wilson line correlators in the nucleus. These correlators also appear in quark-pair production; unlike the latter, photon production is insensitive to hadronization uncertainties and therefore more sensitive to multi-parton correlations in the gluon saturation regime of QCD. We demonstrate that k{sub ⊥} and collinear factorized expressions for inclusive photon production are obtained as leading twist approximations to our result. In particular, the collinearly factorized expression is directly sensitive to the nuclear gluon distribution at small x. Other results of interest include the realization of the Low-Burnett-Kroll soft photon theorem in the CGC framework and a comparative study of how the photon amplitude is obtained in Lorenz and light-cone gauges.

  11. Next-to-leading order QCD-analysis of EMC deep inelastic μp and μd scattering data

    International Nuclear Information System (INIS)

    Bilen'kaya, S.I.; Stamenov, D.B.

    1987-01-01

    A combined next-to-leading order QCD analysis of the European Muon Collaboration (EMC) μH 2 and μD 2 scattering data is presented. The nucleon structure functions are given in terms of parton distributions. The Buras-Gaemers method is used to solve the QCD equations for these distributions. The higher twist corrections are not taken into account. As has been shown their contribution to the structure functions is negligible in the EMC kinematic region. Unlike most of the papers on this subject the cross section data (not the value for the structure functions obtained from these data by additional extrapolations and assumptions) are fitted. the following values for the QCD scale parameter Λ MS-bar are found: Λ MS-bar =218 ±73 MeV for the non-singlet fit to the data in the range x>0.3 and Λ MS-bar =65±20 MeV if the whole x data are fitted

  12. Next-to-next-to-leading order QCD analysis of combined data for xF3 structure function and higher-twist contribution

    International Nuclear Information System (INIS)

    Sidorov, A.V.

    1996-01-01

    The simultaneous QCD analysis of the xF 3 structure function measured in deep-inelastic scattering by several collaborations is done up to 3-loop order of QCD. The x dependence of the higher-twist contribution is evaluated and turns out to be in a qualitative agreement with the results of 'old' CCFR data analysis and with renormalon approach predictions. The Gross-Llewellyn Smith sum rule and its higher-twist corrections are evaluated. 32 refs., 1 figs., 1 tab

  13. Inclusive hadron production in photon-photon collisions at next-to-leading order

    International Nuclear Information System (INIS)

    Binnewies, J.

    1996-01-01

    We study inclusive charged-hadron production in collisions of quasireal photons at next-to-leading order (NLO) in the QCD-improved parton model, using fragmentation functions recently extracted from PEP and LEP1 data of e + e - annihilation. We consistently superimpose the direct (DD), single-resolved (DR), and double-resolved (RR) γγ channels. We consider photon spectra generated by electromagnetic bremsstrahlung and/or beamstrahlung off colliding e + and e - beams as well as those which result from backscattering of laser light off such beams. First, we revisit existing single-tag data taken by TASSO at PETRA and by MARK II at PEP (with e + e - energy √S∼30 GeV) and confront them with our NLO calculations imposing the respective experimental cuts. We also make comparisons with the neutral-kaon to charged-hadron ratio measured by MARK II. Then, we present NLO predictions for LEP2, a next-generation e + e - linear collider (NLC) in the TESLA design with √S=500 GeV, and a Compton collider obtained by converting a 500-GeV NLC. We analyze transverse-momentum and rapidity spectra with regard to the scale dependence, the interplay of the DD, DR, and RR components, the sensitivity to the gluon density inside the resolved photon, and the influence of gluon fragmentation. It turns out that the inclusive measurement of small-p T hadrons at a Compton collider would greatly constrain the gluon density of the photon and the gluon fragmentation function. (orig.)

  14. Leading-order hadronic contribution to g-2 from lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Dru B.; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Feng, Xu [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Muenster Univ. (Germany). Inst. fuer Theoretische Physik; Petschlies, Marcus [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik

    2011-03-15

    We calculate the leading-order hadronic correction to the anomalous magnetic moments of each of the three charged leptons in the Standard Model: the electron, muon and tau. Working in two-flavor lattice QCD, we address essentially all sources of systematic error: lattice artifacts, finite-size effects, quark-mass extrapolation, momentum extrapolation and disconnected diagrams. The most significant remaining systematic error, the exclusion of the strange and charm quark contributions, is addressed in our four-flavor calculation. We achieve a statistical accuracy of 2% or better for the physical values for each of the three leptons and the systematic errors are at most comparable. (orig.)

  15. Production of massless bottom jets in p anti p and pp collisions at next-to-leading order of QCD

    International Nuclear Information System (INIS)

    Bierenbaum, Isabella; Kramer, Gustav

    2016-03-01

    We present predictions for the inclusive production of bottom jets in proton-antiproton collisions at 1.96 TeV and proton-proton collisions at 7 TeV. The bottom quark is considered massless. In this scheme, we find that at small transverse momentum (p T ) the ratio of the next-to-leading order to the leading-order cross section (K factor) is smaller than one. It increases with increasing p T and approaches one at larger p T at a value depending essentially on the choice of the renormalization scale. Adding non-perturbative corrections obtained from PYTHIA Monte Carlo calculations leads to reasonable agreement with experimental b-jet cross sections obtained by the CDF and the CMS collaborations.

  16. The next-to-leading order (NLO) gluon distribution from DGLAP ...

    Indian Academy of Sciences (India)

    leading order (NLO) is obtained by applying the method of characteristics. Its compatibility with double leading logarithmic approximation (DLLA) asymptotics is discussed and comparison with the exact ones like GRV98NLO is made. The solution ...

  17. Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions

    Energy Technology Data Exchange (ETDEWEB)

    Kamiński, Wojciech, E-mail: wkaminsk@fuw.edu.pl [Wydział Fizyki, Uniwersytet Warszawski, Hoża 69, 00-681, Warsaw (Poland); Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Max Planck Institute for Gravitational Physics, Am Mühlenberg 1, D-14476 Potsdam (Germany); Steinhaus, Sebastian, E-mail: steinhaus.sebastian@gmail.com [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Max Planck Institute for Gravitational Physics, Am Mühlenberg 1, D-14476 Potsdam (Germany)

    2013-12-15

    We present the first complete derivation of the well-known asymptotic expansion of the SU(2) 6j symbol using a coherent state approach, in particular we succeed in computing the determinant of the Hessian matrix. To do so, we smear the coherent states and perform a partial stationary point analysis with respect to the smearing parameters. This allows us to transform the variables from group elements to dihedral angles of a tetrahedron resulting in an effective action, which coincides with the action of first order Regge calculus associated to a tetrahedron. To perform the remaining stationary point analysis, we compute its Hessian matrix and obtain the correct measure factor. Furthermore, we expand the discussion of the asymptotic formula to next to leading order terms, prove some of their properties and derive a recursion relation for the full 6j symbol.

  18. Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions

    International Nuclear Information System (INIS)

    Kamiński, Wojciech; Steinhaus, Sebastian

    2013-01-01

    We present the first complete derivation of the well-known asymptotic expansion of the SU(2) 6j symbol using a coherent state approach, in particular we succeed in computing the determinant of the Hessian matrix. To do so, we smear the coherent states and perform a partial stationary point analysis with respect to the smearing parameters. This allows us to transform the variables from group elements to dihedral angles of a tetrahedron resulting in an effective action, which coincides with the action of first order Regge calculus associated to a tetrahedron. To perform the remaining stationary point analysis, we compute its Hessian matrix and obtain the correct measure factor. Furthermore, we expand the discussion of the asymptotic formula to next to leading order terms, prove some of their properties and derive a recursion relation for the full 6j symbol

  19. Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions

    Science.gov (United States)

    Kamiński, Wojciech; Steinhaus, Sebastian

    2013-12-01

    We present the first complete derivation of the well-known asymptotic expansion of the SU(2) 6j symbol using a coherent state approach, in particular we succeed in computing the determinant of the Hessian matrix. To do so, we smear the coherent states and perform a partial stationary point analysis with respect to the smearing parameters. This allows us to transform the variables from group elements to dihedral angles of a tetrahedron resulting in an effective action, which coincides with the action of first order Regge calculus associated to a tetrahedron. To perform the remaining stationary point analysis, we compute its Hessian matrix and obtain the correct measure factor. Furthermore, we expand the discussion of the asymptotic formula to next to leading order terms, prove some of their properties and derive a recursion relation for the full 6j symbol.

  20. On some aspects of optimisation of factorisation scheme dependence at the next-to-leading order in QCD

    International Nuclear Information System (INIS)

    Chyla, J.

    1989-01-01

    Several recent papers attempting to apply the optimised QCD perturbation theory to reactions involving real or virtual photons are discussed with particular attention paid to the ambiguity appearing in the definition of parton distribution and fragmentation functions at the next-to-leading order (NLO). The necessity to use NLO parametrisations of quark densities is stressed and the problem with respect to the factorisation mass M for the 'physical' definition of parton densities is pointed out. (orig.)

  1. Production of massless bottom jets in p anti p and pp collisions at next-to-leading order of QCD

    Energy Technology Data Exchange (ETDEWEB)

    Bierenbaum, Isabella [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Kramer, Gustav [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2016-03-15

    We present predictions for the inclusive production of bottom jets in proton-antiproton collisions at 1.96 TeV and proton-proton collisions at 7 TeV. The bottom quark is considered massless. In this scheme, we find that at small transverse momentum (p{sub T}) the ratio of the next-to-leading order to the leading-order cross section (K factor) is smaller than one. It increases with increasing p{sub T} and approaches one at larger p{sub T} at a value depending essentially on the choice of the renormalization scale. Adding non-perturbative corrections obtained from PYTHIA Monte Carlo calculations leads to reasonable agreement with experimental b-jet cross sections obtained by the CDF and the CMS collaborations.

  2. On the next-to-next-to-leading order evolution of flavour-singlet fragmentation functions

    International Nuclear Information System (INIS)

    Almasy, A.A.; Moch, S.; Vogt, A.

    2012-01-01

    We present the third-order contributions to the quark-gluon and gluon-quark timelike splitting functions for the evolution of fragmentation functions in perturbative QCD. These quantities have been derived by studying physical evolution kernels for photon- and Higgs-exchange structure functions in deep-inelastic scattering and their counterparts in semi-inclusive annihilation, together with constraints from the momentum sum rule and the supersymmetric limit. For this purpose we have also calculated the second-order coefficient functions for one-hadron inclusive Higgs decay in the heavy-top limit. A numerically tolerable uncertainty remains for the quark-gluon splitting function, which does not affect the endpoint logarithms for small and large momentum fractions. We briefly discuss these limits and illustrate the numerical impact of the third-order corrections. Compact and accurate parametrizations are provided for all third-order timelike splitting functions.

  3. On the next-to-next-to-leading order evolution of flavour-singlet fragmentation functions

    Energy Technology Data Exchange (ETDEWEB)

    Almasy, A.A.; Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2011-07-15

    We present the third-order contributions to the quark-gluon and gluon-quark timelike splitting functions for the evolution of fragmentation functions in perturbative QCD. These quantities have been derived by studying physical evolution kernels for photon- and Higgs-exchange structure functions in deep-inelastic scattering and their counterparts in semi-inclusive annihilation, together with constraints from the momentum sum rule and the supersymmetric limit. For this purpose we have also calculated the second-order coefficient functions for one-hadron inclusive Higgs decay in the heavy-top limit. A numerically tolerable uncertainty remains for the quark-gluon splitting function, which does not affect the endpoint logarithms for small and large momentum fractions. We briefly discuss these limits and illustrate the numerical impact of the third-order corrections. Compact and accurate parametrizations are provided for all third-order timelike splitting functions. (orig.)

  4. Next-to-leading-order tests of NRQCD factorization with J/{psi} yield and polarization

    Energy Technology Data Exchange (ETDEWEB)

    Butenschoen, Mathias [Wien Univ. (Austria). Fakultaet fuer Physik; Kniehl, Bernd A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2012-12-15

    We report on recent progress in testing the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) at next-to-leading order (NLO) for J/{psi} yield and polarization. We demonstrate that it is possible to unambiguously determine the leading color-octet long-distance matrix elements (LDMEs) in compliance with the velocity scaling rules through a global fit to experimental data of unpolarized J/{psi} production in pp, p anti p, ep, {gamma}{gamma}, and e{sup +}e{sup -} collisions.Three data sets not included in the fit, from hadroproduction and from photoproduction in the fixed-target and colliding-beam modes, are nicely reproduced. The polarization observables measured in different frames at DESY HERA and CERN LHC reasonably agree with NLO NRQCD predictions obtained using the LDMEs extracted from the global fit, while measurements from the FNAL Tevatron exhibit severe disagreement. We demonstrate that alternative LDME sets recently obtained in two other NLO NRQCD analyses of J/{psi} yield and polarization, with different philosophies, also fail to reconcile the Tevatron polarization data with the other available world data.

  5. Leading and Next-to-Leading Order Gluon Polarization in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

    CERN Document Server

    Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Antonov, A A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Berlin, A; Bernhard, J; Bertini, R; Bettinelli, M; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Buchele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M Jr; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Hoppner, Ch; d'Hose, N; Huber, S; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kunne, F; Kurek, K; Lauser, L; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Morreale, A; Mutter, A; Nagaytsev, A; Nagel, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nowak, W D; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Rocco, E; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schluter, T; Schmidt, A; Schmidt, K; Schmitt, L; Schmiden, H; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Sznajder, P; Takekawa, S; Ter Wolbeek, J; Tessaro, S; Tessarotto, F; Tkatchev, L G; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vlassov, N V; Wang, L; Weisrock, T; Wilfert, M; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhuravlev, N; Zvyagin, A

    2013-01-01

    The gluon polarisation in the nucleon was measured using open charm production by scattering 160 GeV/c polarised muons off longitudinally polarised protons or deuterons. The data were taken by the COMPASS collaboration between 2002 and 2007. A detailed account is given of the analysis method that includes the application of neural networks. Several decay channels of $D^0$ mesons are investigated. Longitudinal spin asymmetries of the D meson production cross-sections are extracted in bins of $D^0$ transverse momentum and energy. At leading order QCD accuracy the average gluon polarisation is determined as $(\\Delta g/g)^{LO}=-0.06 \\pm 0.21 (stat.) \\pm 0.08 (syst.)$ at the scale $ \\approx 13$ (GeV/c)$^2$ and an average gluon momentum fraction $\\approx$ 0.11. The average gluon polarisation is also obtained at next-to-leading order QCD accuracy as $(\\Delta g/g) NLO = -0.13 \\pm 0.15 (stat.) \\pm 0.15 (syst.)$ at the scale $ \\approx $ 13 (GeV/c)$^2$ and $ \\approx $ 0.20.

  6. Regge behaviour of structure functions and evolution of gluon structure function upto next-to-leading order at low-x

    International Nuclear Information System (INIS)

    Jamil, U.; Sarma, J.K.

    2011-01-01

    Evolution of gluon structure function from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations upto next-to-leading order at low-x is presented assuming the Regge behaviour of structure functions. We compare our results of gluon structure function with GRV 98 global parameterization and show the compatibility of Regge behaviour of structure functions with PQCD. (author)

  7. Next-to-leading order prediction for the decay μ→e (e{sup +}e{sup −}) νν̄

    Energy Technology Data Exchange (ETDEWEB)

    Fael, M.; Greub, C. [Albert Einstein Center for Fundamental Physics,Institute for Theoretical Physics, University of Bern,CH-3012 Bern (Switzerland)

    2017-01-19

    We present the differential decay rates and the branching ratios of the muon decay with internal conversion, μ→e (e{sup +}e{sup −}) νν̄, in the Standard Model at next-to-leading order (NLO) in the on-shell scheme. This rare decay mode of the muon is among the main sources of background to the search for μ→eee decay. We found that in the phase space region where the neutrino energies are small, and the three-electron momenta have a similar signature as in the μ→eee decay, the NLO corrections decrease the leading-order prediction by about 10−20% depending on the applied cut.

  8. Next-to-next-to-leading order gravitational spin-squared potential via the effective field theory for spinning objects in the post-Newtonian scheme

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Michele [Université Pierre et Marie Curie, CNRS-UMR 7095, Institut d' Astrophysique de Paris, 98 bis Boulevard Arago, 75014 Paris (France); Steinhoff, Jan, E-mail: michele.levi@upmc.fr, E-mail: jan.steinhoff@aei.mpg.de [Max-Planck-Institute for Gravitational Physics (Albert-Einstein-Institute), Am Mühlenberg 1, 14476 Potsdam-Golm (Germany)

    2016-01-01

    The next-to-next-to-leading order spin-squared interaction potential for generic compact binaries is derived for the first time via the effective field theory for gravitating spinning objects in the post-Newtonian scheme. The spin-squared sector is an intricate one, as it requires the consideration of the point particle action beyond minimal coupling, and mainly involves the spin-squared worldline couplings, which are quite complex, compared to the worldline couplings from the minimal coupling part of the action. This sector also involves the linear in spin couplings, as we go up in the nonlinearity of the interaction, and in the loop order. Hence, there is an excessive increase in the number of Feynman diagrams, of which more are higher loop ones. We provide all the Feynman diagrams and their values. The beneficial ''nonrelativistic gravitational'' fields are employed in the computation. This spin-squared correction, which enters at the fourth post-Newtonian order for rapidly rotating compact objects, completes the conservative sector up to the fourth post-Newtonian accuracy. The robustness of the effective field theory for gravitating spinning objects is shown here once again, as demonstrated in a recent series of papers by the authors, which obtained all spin dependent sectors, required up to the fourth post-Newtonian accuracy. The effective field theory of spinning objects allows to directly obtain the equations of motion, and the Hamiltonians, and these will be derived for the potential obtained here in a forthcoming paper.

  9. NLL order contributions for exclusive processes in jet-calculus scheme

    International Nuclear Information System (INIS)

    Tanaka, Hidekazu

    2011-01-01

    We investigate the next-to-leading logarithmic (NLL) order contributions of the quantum chromodynamics (QCD) for exclusive processes evaluated by Monte Carlo methods. Ambiguities of the Monte Carlo calculation based on the leading-logarithmic (LL) order approximations are pointed out. To remove these ambiguities, we take into account the NLL order terms. In a model presented in this paper, interference contributions due to the NLL order terms are included for the generation of the transverse momenta in initial-state parton radiations. Furthermore, a kinematical constraint due to parton radiation, which is also a part of the NLL order contributions, is taken into account. This method guarantees a proper phase space boundary for hard scattering cross sections as well as parton radiations. As an example, cross sections for lepton pair productions mediated by a virtual photon in hadron-hadron collisions are calculated, using the jet-calculus scheme for flavor nonsinglet quarks. (author)

  10. Four-flavour leading-order hadronic contribution to the muon anomalous magnetic moment

    International Nuclear Information System (INIS)

    Burger, Florian; Feng, Xu; Hotzel, Grit; Jansen, Karl; Petschlies, Marcus; Renner, Dru B.

    2014-01-01

    We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a μ hvp , arising from quark-connected Feynman graphs. It is based on ensembles featuring N f =2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Incorporating the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a μ hvp . Our final result including an estimate of the systematic uncertainty a μ hvp =6.74(21)(18)⋅10 −8 shows a good overall agreement with these computations

  11. IVS contribution to the next ITRF

    Science.gov (United States)

    Bachmann, Sabine; Messerschmitt, Linda; Thaller, Daniela

    2015-04-01

    Generating the contribution of the International VLBI Service (IVS) to the next ITRF (ITRF2013 or ITRF2014) was the main task of the IVS Combination Center at the Federal Agency for Cartography and Geodesy (BKG, Germany) in 2014. Starting with the ITRF2005, the IVS contribution to the ITRF is an intra-technique combined solution using multiple individual contributions from different institutions. For the upcoming ITRF ten international institutions submitted data files for a combined solution. The data files contain 24h VLBI sessions from the late 1970s until the end of 2014 in SINEX file format containing datum free normal equations with station coordinates and Earth Orientation Parameters (EOP). All contributions have to meet the IVS standards for ITRF contribution in order to guarantee a consistent combined solution. In the course of the generation of the intra-technique combined solution, station coordinate time series for each station as well as a Terrestrial Reference Frame based on the contributed VLBI data (VTRF) were generated and analyzed. Preliminary results using data until the end of 2013 show a scaling factor of -0.47 ppb resulting from a 7-parameter Helmert transformation of the VTRF w.r.t. ITRF2008, which is comparable to the scaling factor that was determined in the precedent ITRF generation. An internal comparison of the EOPs between the combined solution and the individual contributions as well as external comparisons of the EOP series were carried out in order to assure a consistent quality of the EOPs. The data analyses, the combination procedure and results of the combined solution for station coordinates and EOP will be presented.

  12. Revisiting the vector form factor at next-to-leading order in 1/N{sub C}

    Energy Technology Data Exchange (ETDEWEB)

    Rosell, Ignasi, E-mail: rosell@uch.ceu.e [Departamento de Ciencias Fisicas, Matematicas y de la Computacion, Universidad CEU Cardenal Herrera, c/ Sant Bartomeu 55, E-46115 Alfara del Patriarca, Valencia (Spain); IFIC, Universitat de Valencia - CSIC, Apt. Correus 22085, E-46071 Valencia (Spain)

    2010-10-15

    Using the Resonance Chiral Theory lagrangian, we perform a calculation of the vector form factor of the pion at the next-to-leading order (NLO) in the 1/N{sub C} expansion. Imposing the correct QCD short-distance constraints, one determines it in terms of F, G{sub V}, F{sub A} and resonance masses. Its low momentum expansion fixes then the low-energy chiral couplings L{sub 9} and C{sub 88} -C{sub 90} at NLO, keeping full control of their renormalization scale dependence. At {mu}{sub 0} = 0.77 GeV, we obtain L{sup r}{sub 9}({mu}{sub 0}) = (7.6 {+-} 0.6) . 10{sup -3} and C{sup r}{sub 88}({mu}{sub 0}) -C{sup r}{sub 90}({mu}{sub 0}) = (-4.5 {+-} 0.5) . 10{sup -5}.

  13. Factorization for groomed jet substructure beyond the next-to-leading logarithm

    Energy Technology Data Exchange (ETDEWEB)

    Frye, Christopher; Larkoski, Andrew J.; Schwartz, Matthew D.; Yan, Kai [Center for the Fundamental Laws of Nature, Harvard University,17 Oxford Street, Cambridge, MA 02138 (United States)

    2016-07-12

    Jet grooming algorithms are widely used in experimental analyses at hadron colliders to remove contaminating radiation from within jets. While the algorithms perform a great service to the experiments, their intricate algorithmic structure and multiple parameters has frustrated precision theoretic understanding. In this paper, we demonstrate that one particular groomer called soft drop actually makes precision jet substructure easier. In particular, we derive a factorization formula for a large class of soft drop jet substructure observables, including jet mass. The essential observation that allows for this factorization is that, without the soft wide-angle radiation groomed by soft drop, all singular contributions are collinear. The simplicity and universality of the collinear limit in QCD allows us to show that to all orders, the normalized differential cross section has no contributions from non-global logarithms. It is also independent of process, up to the relative fraction of quark and gluon jets. In fact, soft drop allows us to define this fraction precisely. The factorization theorem also explains why soft drop observables are less sensitive to hadronization than their ungroomed counterparts. Using the factorization theorem, we resum the soft drop jet mass to next-to-next-to-leading logarithmic accuracy. This requires calculating some clustering effects that are closely related to corresponding effects found in jet veto calculations. We match our resummed calculation to fixed order results for both e{sup +}e{sup −}→ dijets and pp→Z+j events, producing the first jet substructure predictions (groomed or ungroomed) to this accuracy for the LHC.

  14. Factorization for groomed jet substructure beyond the next-to-leading logarithm

    International Nuclear Information System (INIS)

    Frye, Christopher; Larkoski, Andrew J.; Schwartz, Matthew D.; Yan, Kai

    2016-01-01

    Jet grooming algorithms are widely used in experimental analyses at hadron colliders to remove contaminating radiation from within jets. While the algorithms perform a great service to the experiments, their intricate algorithmic structure and multiple parameters has frustrated precision theoretic understanding. In this paper, we demonstrate that one particular groomer called soft drop actually makes precision jet substructure easier. In particular, we derive a factorization formula for a large class of soft drop jet substructure observables, including jet mass. The essential observation that allows for this factorization is that, without the soft wide-angle radiation groomed by soft drop, all singular contributions are collinear. The simplicity and universality of the collinear limit in QCD allows us to show that to all orders, the normalized differential cross section has no contributions from non-global logarithms. It is also independent of process, up to the relative fraction of quark and gluon jets. In fact, soft drop allows us to define this fraction precisely. The factorization theorem also explains why soft drop observables are less sensitive to hadronization than their ungroomed counterparts. Using the factorization theorem, we resum the soft drop jet mass to next-to-next-to-leading logarithmic accuracy. This requires calculating some clustering effects that are closely related to corresponding effects found in jet veto calculations. We match our resummed calculation to fixed order results for both e + e − → dijets and pp→Z+j events, producing the first jet substructure predictions (groomed or ungroomed) to this accuracy for the LHC.

  15. Next-to-leading-logarithmic power corrections for N -jettiness subtraction in color-singlet production

    Science.gov (United States)

    Boughezal, Radja; Isgrò, Andrea; Petriello, Frank

    2018-04-01

    We present a detailed derivation of the power corrections to the factorization theorem for the 0-jettiness event shape variable T . Our calculation is performed directly in QCD without using the formalism of effective field theory. We analytically calculate the next-to-leading logarithmic power corrections for small T at next-to-leading order in the strong coupling constant, extending previous computations which obtained only the leading-logarithmic power corrections. We address a discrepancy in the literature between results for the leading-logarithmic power corrections to a particular definition of 0-jettiness. We present a numerical study of the power corrections in the context of their application to the N -jettiness subtraction method for higher-order calculations, using gluon-fusion Higgs production as an example. The inclusion of the next-to-leading-logarithmic power corrections further improves the numerical efficiency of the approach beyond the improvement obtained from the leading-logarithmic power corrections.

  16. Next to Leading Logarithms and the PHOTOS Monte Carlo

    CERN Document Server

    Golonka, P

    2007-01-01

    With the approaching start-up of the experiments at LHC, the urgency to quantify systematic uncertainties of the generators, used in the interpretation of the data, is becoming pressing. The PHOTOS Monte Carlo program is often used for the simulationof experimental, selection-sensitive, QED radiative corrections in decays of Z bosons and other heavy resonances and particles. Thanks to its complete phase-space coverage it is possible, with no approximations for any decay channel, to implement the matrix-element. The present paper will be devoted to those parts of the next-to-leading order corrections for Z decays which are normally missing in PHOTOS. The analytical form of the exact and truncated (standard) kernel used in PHOTOS will be explicitly given. The correction, being the ratio of the exact to the approximate kernel, can be activated as an optional contribution to the internal weight of PHOTOS. To calculate the weight, the information on the effective Born-level Z/gamma* couplings and even directions o...

  17. Single Top Production at Next-to-Leading Order in the Standard Model Effective Field Theory.

    Science.gov (United States)

    Zhang, Cen

    2016-04-22

    Single top production processes at hadron colliders provide information on the relation between the top quark and the electroweak sector of the standard model. We compute the next-to-leading order QCD corrections to the three main production channels: t-channel, s-channel, and tW associated production, in the standard model including operators up to dimension six. The calculation can be matched to parton shower programs and can therefore be directly used in experimental analyses. The QCD corrections are found to significantly impact the extraction of the current limits on the operators, because both of an improved accuracy and a better precision of the theoretical predictions. In addition, the distributions of some of the key discriminating observables are modified in a nontrivial way, which could change the interpretation of measurements in terms of UV complete models.

  18. Four-flavour leading-order hadronic contribution to the muon anomalous magnetic moment

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Florian [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstr. 15, D-12489 Berlin (Germany); Feng, Xu [High Energy Accelerator Research Organization (KEK),Tsukuba 305-0801 (Japan); Hotzel, Grit [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstr. 15, D-12489 Berlin (Germany); Jansen, Karl [NIC, DESY,Platanenallee 6, D-15738 Zeuthen (Germany); Department of Physics, University of Cyprus,P.O.Box 20537, 1678 Nicosia (Cyprus); Petschlies, Marcus [The Cyprus Institute,P.O.Box 27456, 1645 Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab,12000 Jefferson Avenue, Newport News, VA 23606 (United States); Collaboration: The ETM Collaboration

    2014-02-24

    We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a{sub μ}{sup hvp}, arising from quark-connected Feynman graphs. It is based on ensembles featuring N{sub f}=2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Incorporating the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a{sub μ}{sup hvp}. Our final result including an estimate of the systematic uncertainty a{sub μ}{sup hvp}=6.74(21)(18)⋅10{sup −8} shows a good overall agreement with these computations.

  19. Universality of next-to-leading power threshold effects for colourless final states in hadronic collisions

    NARCIS (Netherlands)

    Duca, Vittorio del; Laenen, E.; Magnea, L.; Vernazza, L.; White, C.D.

    2017-01-01

    We consider the production of an arbitrary number of colour-singlet particles near partonic threshold, and show that next-to-leading order cross sections for this class of processes have a simple universal form at next-to-leading power (NLP) in the energy of the emitted gluon radiation. Our analysis

  20. Inclusive photoproduction of D*± mesons at next-to-leading order in the general-mass variable-flavor-number scheme

    International Nuclear Information System (INIS)

    Kniehl, B.A.; Kramer, G.; Schienbein, I.; Spiesberger, H.

    2009-02-01

    We discuss the inclusive production of D *± mesons in γp collisions at DESY HERA, based on a calculation at next-to-leading order in the general-mass variable-flavor-number scheme. In this approach, MS subtraction is applied in such a way that large logarithmic corrections are resummed in universal parton distribution and fragmentation functions and finite mass terms are taken into account. We present detailed numerical results for a comparison with data obtained at HERA and discuss various sources of theoretical uncertainties. (orig.)

  1. Inclusive photoproduction of D{sup *{+-}} mesons at next-to-leading order in the general-mass variable-flavor-number scheme

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, B.A.; Kramer, G. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Schienbein, I. [Univ. Joseph Fourier/CNRS-IN2P3, INPG, Grenoble (France). Lab. de Physique Subatomique et de Cosmologie; Spiesberger, H. [Mainz Univ. (Germany). Inst. fuer Physik

    2009-02-15

    We discuss the inclusive production of D{sup *{+-}} mesons in {gamma}p collisions at DESY HERA, based on a calculation at next-to-leading order in the general-mass variable-flavor-number scheme. In this approach, MS subtraction is applied in such a way that large logarithmic corrections are resummed in universal parton distribution and fragmentation functions and finite mass terms are taken into account. We present detailed numerical results for a comparison with data obtained at HERA and discuss various sources of theoretical uncertainties. (orig.)

  2. Topics in perturbative QCD beyond the leading order

    International Nuclear Information System (INIS)

    Buras, A.J.

    1979-08-01

    The basic structure of QCD formulae for various inclusive and semi-inclusive processes is presented. Next to leading order QCD corrections to inclusive deep-inelastic scattering are discussed in some detail. The methods for calculations of QCD corrections (leading, next to leading) to semi-inclusive processes are outlined. Some results of these calculations are discussed. 58 references

  3. Higher order corrections to mixed QCD-EW contributions to Higgs boson production in gluon fusion

    Science.gov (United States)

    Bonetti, Marco; Melnikov, Kirill; Tancredi, Lorenzo

    2018-03-01

    We present an estimate of the next-to-leading-order (NLO) QCD corrections to mixed QCD-electroweak contributions to the Higgs boson production cross section in gluon fusion, combining the recently computed three-loop virtual corrections and the approximate treatment of real emission in the soft approximation. We find that the NLO QCD corrections to the mixed QCD-electroweak contributions are nearly identical to NLO QCD corrections to QCD Higgs production. Our result confirms an earlier estimate of these O (α αs2) effects by Anastasiou et al. [J. High Energy Phys. 04 (2009) 003, 10.1088/1126-6708/2009/04/003] and provides further support for the factorization approximation of QCD and electroweak corrections.

  4. BFKL equation for the adjoint representation of the gauge group in the next-to-leading approximation at N=4 SUSY

    Energy Technology Data Exchange (ETDEWEB)

    Fadin, V.S. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Budker Nuclear Physics Institute, Novosibirsk (Russian Federation); Novosibirskij Gosudarstvennyj Univ., Novosibirsk (Russian Federation); Lipatov, L.N. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); St. Petersburg State Univ., Gatchina (Russian Federation)

    2011-12-15

    We calculate the eigenvalues of the next-to-leading kernel for the BFKL equation in the adjoint representation of the gauge group SU(N{sub c}) in the N=4 supersymmetric Yang-Mills model. These eigenvalues are used to obtain the high energy behavior of the remainder function for the 6-point scattering amplitude with the maximal helicity violation in the kinematical regions containing the Mandelstam cut contribution. The leading and next-to-leading singularities of the corresponding collinear anomalous dimension are calculated in all orders of perturbation theory. We compare our result with the known collinear limit and with the recently suggested ansatz for the remainder function in three loops and obtain the full agreement providing that the numerical parameters in this anzatz are chosen in an appropriate way.

  5. Next-to-leading-order QCD and electroweak corrections to WWW production at proton-proton colliders

    Science.gov (United States)

    Dittmaier, Stefan; Huss, Alexander; Knippen, Gernot

    2017-09-01

    Triple-W-boson production in proton-proton collisions allows for a direct access to the triple and quartic gauge couplings and provides a window to the mechanism of electroweak symmetry breaking. It is an important process to test the Standard Model (SM) and might be background to physics beyond the SM. We present a calculation of the next-to-leading order (NLO) electroweak corrections to the production of WWW final states at proton-proton colliders with on-shell W bosons and combine the electroweak with the NLO QCD corrections. We study the impact of the corrections to the integrated cross sections and to kinematic distributions of the W bosons. The electroweak corrections are generically of the size of 5-10% for integrated cross sections and become more pronounced in specific phase-space regions. The real corrections induced by quark-photon scattering turn out to be as important as electroweak loops and photon bremsstrahlung corrections, but can be reduced by phase-space cuts. Considering that prior determinations of the photon parton distribution function (PDF) involve rather large uncertainties, we compare the results obtained with different photon PDFs and discuss the corresponding uncertainties in the NLO predictions. Moreover, we determine the scale and total PDF uncertainties at the LHC and a possible future 100 TeV pp collider.

  6. Transverse energy-energy correlations in next-to-leading order in {alpha}{sub s} at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed; Wang, Wei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Barreiro, Fernando; Llorente, Javier [Universidad Autonoma de Madrid (Spain). Dept. de Fisica

    2012-05-15

    We compute the transverse energy-energy correlation (EEC) and its asymmetry (AEEC) in next-to-leading order (NLO) in {alpha}{sub s} in proton-proton collisions at the LHC with the center-of-mass energy E{sub c.m.}=7 TeV. We show that the transverse EEC and the AEEC distributions are insensitive to the QCD factorization- and the renormalization-scales, structure functions of the proton, and for a judicious choice of the jet-size, also the underlying minimum bias events. Hence they can be used to precisely test QCD in hadron colliders and determine the strong coupling {alpha}{sub s}. We illustrate these features by defining the hadron jets using the anti-k{sub T} jet algorithm and an event selection procedure employed in the analysis of jets at the LHC and show the {alpha}{sub s}(M{sub Z})-dependence of the transverse EEC and the AEEC in the anticipated range 0.11{<=} {alpha}{sub s}(M{sub Z}){<=}0.13.

  7. Leading-order hadronic contribution to the electron and muon g-2

    International Nuclear Information System (INIS)

    Jegerlehner, Fred; Humboldt-Univ. Berlin

    2015-11-01

    I present a new data driven update of the hadronic vacuum polarization effects for the muon and the electron g-2. For the leading order contributions I find a had(1) μ =(686.99±4.21)[687.19±3.48] x 10 -10 based on e + e - data [incl. τ data], a had(2) μ =(-9.934± 0.091) x 10 -10 (NLO) and a had(3) μ =(1.226±0.012) x 10 -10 (NNLO) for the muon, and a had(1) e =(184.64±1.21) x 10 -14 (LO), a had(2) e =(-22.10±0.14) x 10 -14 (NLO) and a had(3) e =(2.79±0.02) x 10 -14 (NNLO) for the electron. A problem with vacuum polarization undressing of cross-sections (time-like region) is addressed. I also add a comment on properly including axial mesons in the hadronic light-by-light scattering contribution. My estimate here reads aμ[a 1 ,f 1 ' ,f 1 ]∝(7.51±2.71) x 10 -11 . With these updates a exp μ - the μ =(32.73±8.15) x 10 -10 a 4.0σ deviation, while a exp e -a the e =(-1.10±0.82) x 10 -12 shows no significant deviation.

  8. Electroweak penguin contributions in charmless B→VV decays beyond leading logarithms

    International Nuclear Information System (INIS)

    Dongsheng Du; Libo Guo

    1997-01-01

    Using the next-to-leading-order, low-energy effective Hamiltonian for vertical bar ΔB vertical bar = 1, ΔC = ΔU = 0 transitions, the contributions of electroweak penguin operators in charmless B→VV decays are estimated in the standard model. We find that, for some channels, the electroweak penguin effects can enhance or reduce the QCD penguin and/or tree-level contributions by at least 20%, and can even play a dominant role in decay widths and CP-asymmetries, but the corrections to the angular distribution are negligible. (author)

  9. Leading-order hadronic contributions to the electron and tau anomalous magnetic moments

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Florian; Pientka, Grit [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Berlin (Germany); Jansen, Karl [NIC, DESY, Zeuthen (Germany); Petschlies, Marcus [The Cyprus Institute, P.O.Box 27456, Nicosia (Cyprus); Rheinische Friedrich-Wilhelms-Universitaet Bonn, Institut fuer Strahlen- und Kernphysik, Bonn (Germany)

    2016-08-15

    The leading hadronic contributions to the anomalous magnetic moments of the electron and the τ-lepton are determined by a four-flavour lattice QCD computation with twisted mass fermions. The results presented are based on the quark-connected contribution to the hadronic vacuum polarisation function. The continuum limit is taken and systematic uncertainties are quantified. Full agreement with results obtained by phenomenological analyses is found. (orig.)

  10. Higgs Boson Pair Production in Gluon Fusion at Next-to-Leading Order with Full Top-Quark Mass Dependence.

    Science.gov (United States)

    Borowka, S; Greiner, N; Heinrich, G; Jones, S P; Kerner, M; Schlenk, J; Schubert, U; Zirke, T

    2016-07-01

    We present the calculation of the cross section and invariant mass distribution for Higgs boson pair production in gluon fusion at next-to-leading order (NLO) in QCD. Top-quark masses are fully taken into account throughout the calculation. The virtual two-loop amplitude has been generated using an extension of the program GoSam supplemented with an interface to Reduze for the integral reduction. The occurring integrals have been calculated numerically using the program SecDec. Our results, including the full top-quark mass dependence for the first time, allow us to assess the validity of various approximations proposed in the literature, which we also recalculate. We find substantial deviations between the NLO result and the different approximations, which emphasizes the importance of including the full top-quark mass dependence at NLO.

  11. Next-to-leading-order QCD corrections to e+e−→H+γ

    Directory of Open Access Journals (Sweden)

    Wen-Long Sang

    2017-12-01

    Full Text Available The associated production of Higgs boson with a hard photon at lepton collider, i.e., e+e−→Hγ, is known to bear a rather small cross section in Standard Model, and can serve as a sensitive probe for the potential new physics signals. Similar to the loop-induced Higgs decay channels H→γγ,Zγ, the e+e−→Hγ process also starts at one-loop order provided that the tiny electron mass is neglected. In this work, we calculate the next-to-leading-order (NLO QCD corrections to this associated H+γ production process, which mainly stem from the gluonic dressing to the top quark loop. The QCD corrections are found to be rather modest at lower center-of-mass energy range (s<300 GeV, thus of negligible impact on Higgs factory such as CEPC. Nevertheless, when the energy is boosted to the ILC energy range (s≈400 GeV, QCD corrections may enhance the leading-order cross section by 20%. In any event, the e+e−→Hγ process has a maximal production rate σmax≈0.08 fb around s=250 GeV, thus CEPC turns out to be the best place to look for this rare Higgs production process. In the high energy limit, the effect of NLO QCD corrections become completely negligible, which can be simply attributed to the different asymptotic scaling behaviors of the LO and NLO cross sections, where the former exhibits a milder decrement ∝1/s , but the latter undergoes a much faster decrease ∝1/s2. Keywords: Standard Model, Higgs boson, QCD corrections

  12. NNLO contributions to jet photoproduction and determination of {alpha}{sub s}

    Energy Technology Data Exchange (ETDEWEB)

    Klasen, Michael; Michael, Markus [Muenster Univ. (Germany). Inst. fuer Theoretische Physik 1; Kramer, Gustav [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2013-10-15

    We present the first calculation of inclusive jet photoproduction with next-to-next-to-leading order (NNLO) contributions, obtained from a unified threshold resummation formalism. The leading coefficients for direct photoproduction are computed analytically. Together with the coefficients pertinent to parton-parton scattering, they are shown to agree with those appearing in our full next-to-leading order calculations. For hadron-hadron scattering, numerical agreement is found with a previous calculation of jet production at the Tevatron. We show that the direct and resolved NNLO contributions considerably improve the description of final ZEUS data on jet photoproduction and that the error on the determination of the strong coupling constant is significantly reduced.

  13. Next-to-leading order γγ+2-jet production at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Z.; Dixon, L. J.; Febres Cordero, F.; Höche, S.; Ita, H.; Kosower, D. A.; Lo Presti, N. A.; Maître, D.

    2014-09-01

    We present next-to-leading-order QCD predictions for cross sections and for a comprehensive set of distributions in γγ+2-jet production at the Large Hadron Collider. We consider the contributions from loop amplitudes for two photons and four gluons, but we neglect top quarks. We use BlackHat together with SHERPA to carry out the computation. We use a Frixione cone isolation for the photons. We study standard sets of cuts on the jets and the photons and also sets of cuts appropriate for studying backgrounds to Higgs-boson production via vector-boson fusion.

  14. Determination of the strong coupling constant α{sub s}(m{sub Z}) in next-to-next-to-leading order QCD using H1 jet cross section measurements

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, V.; Belousov, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Malinovski, E.; Soloviev, Y.; Vazdik, Y. [Lebedev Physical Institute, Moscow (Russian Federation); Baghdasaryan, A.; Zohrabyan, H. [Yerevan Physics Institute, Yerevan (Armenia); Begzsuren, K.; Ravdandorj, T. [Institute of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar (Mongolia); Bertone, V. [Vrije University, Department of Physics and Astronomy, Amsterdam (Netherlands); National Institute for Subatomic Physics (NIKHEF), Amsterdam (Netherlands); Bolz, A.; Britzger, D.; Huber, F.; Sauter, M.; Schoening, A. [Universitaet Heidelberg, Physikalisches Institut, Heidelberg (Germany); Boudry, V.; Specka, A. [LLR, Ecole Polytechnique, CNRS/IN2P3, Palaiseau (France); Brandt, G. [Universitaet Goettingen, II. Physikalisches Institut, Goettingen (Germany); Brisson, V.; Jacquet, M.; Pascaud, C.; Zhang, Z.; Zomer, F. [LAL, Universite Paris-Sud, CNRS/IN2P3, Orsay (France); Buniatyan, A.; Newman, P.R.; Thompson, P.D. [University of Birmingham, School of Physics and Astronomy, Birmingham (United Kingdom); Bylinkin, A. [Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region (Russian Federation); Bystritskaya, L.; Fedotov, A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Campbell, A.J.; Dodonov, V.; Eckerlin, G.; Elsen, E.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Haidt, D.; Jung, H.; Katzy, J.; Kleinwort, C.; Kruecker, D.; Krueger, K.; Levonian, S.; Lipka, K.; List, B.; List, J.; Meyer, A.B.; Meyer, J.; Niebuhr, C.; Olsson, J.E.; Pirumov, H.; Pitzl, D.; Placakyte, R.; Schmitt, S.; Sefkow, F.; South, D.; Steder, M.; Wuensch, E.; Zlebcik, R. [DESY, Hamburg (Germany); Cantun Avila, K.B.; Contreras, J.G. [CINVESTAV, Departamento de Fisica Aplicada, Merida, Yucatan (Mexico); Cerny, K.; Salek, D.; Valkarova, A.; Zacek, J. [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Chekelian, V.; Grindhammer, G.; Kiesling, C.; Lobodzinski, B. [Max-Planck-Institut fuer Physik, Munich (Germany); Cvach, J.; Hladky, J.; Reimer, P. [Academy of Sciences of the Czech Republic, Institute of Physics, Prague (Czech Republic); Currie, J. [Durham University, Institute for Particle Physics Phenomenology, Ogden Centre for Fundamental Physics, Durham (United Kingdom); Dainton, J.B.; Gabathuler, E.; Greenshaw, T.; Klein, M.; Kostka, P.; Kretzschmar, J.; Laycock, P.; Maxfield, S.J.; Mehta, A.; Patel, G.D. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Daum, K.; Meyer, H. [Fachbereich C, Universitaet Wuppertal, Wuppertal (Germany); Diaconu, C.; Hoffmann, D.; Vallee, C. [Aix Marseille Universite, CNRS/IN2P3, CPPM UMR 7346, Marseille (France); Dobre, M.; Rotaru, M. [Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering (IFIN-HH), Bucharest (Romania); Egli, S.; Horisberger, R.; Ozerov, D. [Paul Scherrer Institute, Villigen (Switzerland); Favart, L.; Grebenyuk, A.; Hreus, T.; Janssen, X.; Roosen, R.; Mechelen, P.Van [Brussels and Universiteit Antwerpen, Inter-University Institute for High Energies ULB-VUB, Antwerp (Belgium); Feltesse, J.; Schoeffel, L. [Irfu/SPP, CE Saclay, Gif-sur-Yvette (France); Gehrmann, T.; Mueller, K.; Niehues, J.; Robmann, P.; Straumann, U.; Truoel, P. [Physik-Institut der Universitaet Zuerich, Zurich (Switzerland); Goerlich, L.; Mikocki, S.; Nowak, G.; Sopicki, P. [Polish Academy of Sciences, Institute of Nuclear Physics, Krakow (Poland); Gouzevitch, M.; Petrukhin, A. [IPNL, Universite Claude Bernard Lyon 1, CNRS/IN2P3, Villeurbanne (France); Grab, C.; Huss, A. [ETH Zuerich, Institut fuer Teilchenphysik, Zurich (Switzerland); Gwenlan, C.; Radescu, V. [Oxford University, Department of Physics, Oxford (United Kingdom); Henderson, R.C.W. [University of Lancaster, Department of Physics, Lancaster (United Kingdom); Jung, A.W. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Kapichine, M.; Morozov, A.; Spaskov, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kogler, R. [Universitaet Hamburg, Institut fuer Experimentalphysik, Hamburg (Germany); Landon, M.P.J.; Rizvi, E.; Traynor, D. [Queen Mary University of London, School of Physics and Astronomy, London (United Kingdom); Lange, W.; Naumann, T. [DESY, Zeuthen (Germany); Martyn, H.U. [I. Physikalisches Institut der RWTH, Aachen (Germany); Perez, E. [CERN, Geneva (Switzerland); Picuric, I.; Raicevic, N. [University of Montenegro, Faculty of Science, Podgorica (Montenegro); Polifka, R. [Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); University of Toronto, Department of Physics, Toronto, ON (Canada); Rabbertz, K. [Karlsruher Institut fuer Technologie (KIT), Institut fuer Experimentelle Teilchenphysik (ETP), Karlsruhe (Germany); Rostovtsev, A. [Institute for Information Transmission Problems RAS, Moscow (Russian Federation); Sankey, D.P.C. [STFC, Rutherford Appleton Laboratory, Didcot, Oxfordshire (United Kingdom); Sauvan, E. [Aix Marseille Universite, CNRS/IN2P3, CPPM UMR 7346, Marseille (France); Universite de Savoie, CNRS/IN2P3, LAPP, Annecy-le-Vieux (France); Shushkevich, S. [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Stella, B. [Universita di Roma Tre, Dipartimento di Fisica, Rome (Italy); INFN Roma 3 (Italy); Sutton, M.R. [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); Sykora, T. [Brussels and Universiteit Antwerpen, Inter-University Institute for High Energies ULB-VUB, Antwerp (Belgium); Charles University, Faculty of Mathematics and Physics, Prague (Czech Republic); Tsakov, I. [Institute for Nuclear Research and Nuclear Energy, Sofia (Bulgaria); Tseepeldorj, B. [Institute of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar (MN); Ulaanbaatar University, Ulaanbaatar (MN); Wegener, D. [TU Dortmund, Institut fuer Physik, Dortmund (DE); Collaboration: H1 Collaboration

    2017-11-15

    The strong coupling constant α{sub s} is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of α{sub s}(m{sub Z}) at the Z-boson mass m{sub Z} are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be α{sub s}(m{sub Z}) = 0.1157(20){sub exp}(29){sub th}. Complementary, α{sub s}(m{sub Z}) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value α{sub s}(m{sub Z}) = 0.1142(28){sub tot} obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations. (orig.)

  15. Next to leading order analysis of DVCS and TCS

    Directory of Open Access Journals (Sweden)

    Wagner J.

    2014-03-01

    Full Text Available The study of O(αs QCD contributions to the timelike and spacelike virtual Compton scattering amplitudes in the generalized Bjorken scaling regime demonstrates that gluonic contributions are by no means negligible even in the medium energy range which will be studied intensely at JLab12 and in the COMPASS-II experiment at CERN.

  16. CGC factorization for forward particle production in proton-nucleus collisions at next-to-leading order

    International Nuclear Information System (INIS)

    Iancu, E.; Mueller, A.H.; Triantafyllopoulos, D.N.

    2016-01-01

    Within the Color Glass Condensate effective theory, we reconsider the next-to-leading order (NLO) calculation of the single inclusive particle production at forward rapidities in proton-nucleus collisions at high energy. Focusing on quark production for definiteness, we establish a new factorization scheme, perturbatively correct through NLO, in which there is no ‘rapidity subtraction’. That is, the NLO correction to the impact factor is not explicitly separated from the high-energy evolution. Our construction exploits the skeleton structure of the (NLO) Balitsky-Kovchegov equation, in which the first step of the evolution is explicitly singled out. The NLO impact factor is included by computing this first emission with the exact kinematics for the emitted gluon, rather than by using the eikonal approximation. This particular calculation has already been presented in the literature http://dx.doi.org/10.1103/PhysRevLett.108.122301, http://dx.doi.org/10.1103/PhysRevD.86.054005, but the reorganization of the perturbation theory that we propose is new. As compared to the proposal in http://dx.doi.org/10.1103/PhysRevLett.108.122301, http://dx.doi.org/10.1103/PhysRevD.86.054005, our scheme is free of the fine-tuning inherent in the rapidity subtraction, which might be the origin of the negativity of the NLO cross-section observed in previous studies.

  17. CGC factorization for forward particle production in proton-nucleus collisions at next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Iancu, E. [Institut de physique théorique, Université Paris Saclay,CNRS, CEA, F-91191 Gif-sur-Yvette (France); Mueller, A.H. [Department of Physics, Columbia University,New York, NY 10027 (United States); Triantafyllopoulos, D.N. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas - ECT*, Trento (Italy); Fondazione Bruno Kessler, Strada delle Tabarelle 286, I-38123 Villazzano (Italy)

    2016-12-13

    Within the Color Glass Condensate effective theory, we reconsider the next-to-leading order (NLO) calculation of the single inclusive particle production at forward rapidities in proton-nucleus collisions at high energy. Focusing on quark production for definiteness, we establish a new factorization scheme, perturbatively correct through NLO, in which there is no ‘rapidity subtraction’. That is, the NLO correction to the impact factor is not explicitly separated from the high-energy evolution. Our construction exploits the skeleton structure of the (NLO) Balitsky-Kovchegov equation, in which the first step of the evolution is explicitly singled out. The NLO impact factor is included by computing this first emission with the exact kinematics for the emitted gluon, rather than by using the eikonal approximation. This particular calculation has already been presented in the literature http://dx.doi.org/10.1103/PhysRevLett.108.122301, http://dx.doi.org/10.1103/PhysRevD.86.054005, but the reorganization of the perturbation theory that we propose is new. As compared to the proposal in http://dx.doi.org/10.1103/PhysRevLett.108.122301, http://dx.doi.org/10.1103/PhysRevD.86.054005, our scheme is free of the fine-tuning inherent in the rapidity subtraction, which might be the origin of the negativity of the NLO cross-section observed in previous studies.

  18. Leading-order hadronic contributions to the electron and tau anomalous magnetic moments

    International Nuclear Information System (INIS)

    Burger, Florian; Hotzel, Grit

    2015-01-01

    The leading hadronic contributions to the anomalous magnetic moments of the electron and the τ-lepton are determined by a four-flavour lattice QCD computation with twisted mass fermions. The continuum limit is taken and systematic uncertainties are quantified. Full agreement with results obtained by phenomenological analyses is found.

  19. Leading order relativistic chiral nucleon-nucleon interaction

    Science.gov (United States)

    Ren, Xiu-Lei; Li, Kai-Wen; Geng, Li-Sheng; Long, Bingwei; Ring, Peter; Meng, Jie

    2018-01-01

    Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the {}1S0 and {}3P0 phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥slant 1, the relativistic results are almost the same as their leading order non-relativistic counterparts. )

  20. Top Quark Pair Production in Association with a Jet with Next-to-Leading-Order QCD Off-Shell Effects at the Large Hadron Collider.

    Science.gov (United States)

    Bevilacqua, G; Hartanto, H B; Kraus, M; Worek, M

    2016-02-05

    We present a complete description of top quark pair production in association with a jet in the dilepton channel. Our calculation is accurate to next-to-leading order (NLO) in QCD and includes all nonresonant diagrams, interferences, and off-shell effects of the top quark. Moreover, nonresonant and off-shell effects due to the finite W gauge boson width are taken into account. This calculation constitutes the first fully realistic NLO computation for top quark pair production with a final state jet in hadronic collisions. Numerical results for differential distributions as well as total cross sections are presented for the Large Hadron Collider at 8 TeV. With our inclusive cuts, NLO predictions reduce the unphysical scale dependence by more than a factor of 3 and lower the total rate by about 13% compared to leading-order QCD predictions. In addition, the size of the top quark off-shell effects is estimated to be below 2%.

  1. Next-to-next-to-eikonal corrections in the CGC

    Energy Technology Data Exchange (ETDEWEB)

    Altinoluk, Tolga; Armesto, Néstor [Departamento de Física de Partículas and IGFAE,Universidade de Santiago de Compostela,E-15706 Santiago de Compostela, Galicia (Spain); Beuf, Guillaume [Department of Physics, Ben-Gurion University of the Negev,Beer Sheva 84105 (Israel); Moscoso, Alexis [Departamento de Física de Partículas and IGFAE,Universidade de Santiago de Compostela,E-15706 Santiago de Compostela, Galicia (Spain)

    2016-01-19

    We extend the study of corrections to the eikonal approximation that was initiated in ref. http://dx.doi.org/10.1007/JHEP07(2014)068 to higher orders. These corrections associated with the finite width of the target are investigated and the gluon propagator in background field is calculated at next-to-next-to-eikonal accuracy. The result is then applied to the single inclusive gluon production cross section at central rapidities and the single transverse spin asymmetry with a transversely polarized target, in pA collisions, in order to analyze these observables beyond the eikonal limit. The next-to-next-to-eikonal corrections to the unpolarized cross section are non-zero and provide the first corrections to the usual k{sub ⊥}-factorized expression. In contrast, the eikonal and next-to-next-to-eikonal contributions to the single transverse spin asymmetry vanish, while the next-to-eikonal ones are non-zero.

  2. A Hybrid Strategy for the Lattice Evaluation of the Leading Order Hadronic Contribution to (g - 2)μ

    Science.gov (United States)

    Golterman, Maarten; Maltman, Kim; Peris, Santiago

    2016-04-01

    The leading-order hadronic contribution to the muon anomalous magentic moment, aμLO,HVP, can be expressed as an integral over Euclidean Q2 of the vacuum polarization function. We point out that a simple trapezoid-rule numerical integration of the current lattice data is good enough to produce a result with a less-than-1% error for the contribution from the interval above Q2 ≳ 0.1 - 0.2GeV2. This leaves the interval below this value of Q2 as the one to focus on in the future. In order to achieve an accurate result also in this lower window Q2 ≲ 0.1 - 0.2GeV2, we indicate the usefulness of three possible tools. These are: Padé Approximants, polynomials in a conformal variable and a NNLO Chiral Perturbation Theory representation supplemented by a Q4 term. The combination of the numerical integration in the upper Q2 interval together with the use of these tools in the lower Q2 interval provides a hybrid strategy which looks promising as a means of reaching the desired goal on the lattice of a sub-percent precision in the hadronic vacuum polarization contribution to the muon anomalous magnetic moment.

  3. The next-next-to-leading QCD approximation for non-singlet moments of deep inelastic structure functions

    International Nuclear Information System (INIS)

    Larin, S.A.; Ritbergen, T. van; Vermaseren, J.A.M.

    1993-12-01

    We obtain the analytic next-next-to-leading perturbative QCD corrections in the leading twist approximation for the moments N = 2, 4, 6, 8 of the non-singlet deep inelastic structure functions F 2 and F L . We calculate the three-loop anomalous dimensions of the corresponding non-singlet operators and the three-loop coefficient functions of the structure function F L . (orig.)

  4. A factorization approach to next-to-leading-power threshold logarithms

    Energy Technology Data Exchange (ETDEWEB)

    Bonocore, D. [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Laenen, E. [Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); ITFA, University of Amsterdam,Science Park 904, Amsterdam (Netherlands); ITF, Utrecht University,Leuvenlaan 4, Utrecht (Netherlands); Magnea, L. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino,Via P. Giuria 1, I-10125, Torino (Italy); Melville, S. [School of Physics and Astronomy, University of Glasgow,Glasgow, G12 8QQ (United Kingdom); Vernazza, L. [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, University of Edinburgh,Edinburgh, EH9 3JZ, Scotland (United Kingdom); White, C.D. [School of Physics and Astronomy, University of Glasgow,Glasgow, G12 8QQ (United Kingdom)

    2015-06-03

    Threshold logarithms become dominant in partonic cross sections when the selected final state forces gluon radiation to be soft or collinear. Such radiation factorizes at the level of scattering amplitudes, and this leads to the resummation of threshold logarithms which appear at leading power in the threshold variable. In this paper, we consider the extension of this factorization to include effects suppressed by a single power of the threshold variable. Building upon the Low-Burnett-Kroll-Del Duca (LBKD) theorem, we propose a decomposition of radiative amplitudes into universal building blocks, which contain all effects ultimately responsible for next-to-leading-power (NLP) threshold logarithms in hadronic cross sections for electroweak annihilation processes. In particular, we provide a NLO evaluation of the radiative jet function, responsible for the interference of next-to-soft and collinear effects in these cross sections. As a test, using our expression for the amplitude, we reproduce all abelian-like NLP threshold logarithms in the NNLO Drell-Yan cross section, including the interplay of real and virtual emissions. Our results are a significant step towards developing a generally applicable resummation formalism for NLP threshold effects, and illustrate the breakdown of next-to-soft theorems for gauge theory amplitudes at loop level.

  5. Singularity-free next-to-leading order ΔS=1 renormalization group evolution and ϵ{sub K}{sup ′}/ϵ{sub K} in the Standard Model and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Kitahara, Teppei [Institute for Theoretical Particle Physics (TTP), Karlsruhe Institute of Technology,Engesserstraße 7, Karlsruhe, D-76128 (Germany); Institute for Nuclear Physics (IKP), Karlsruhe Institute of Technology,Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, D-76344 (Germany); Nierste, Ulrich; Tremper, Paul [Institute for Theoretical Particle Physics (TTP), Karlsruhe Institute of Technology,Engesserstraße 7, Karlsruhe, D-76128 (Germany)

    2016-12-16

    The standard analytic solution of the renormalization group (RG) evolution for the ΔS=1 Wilson coefficients involves several singularities, which complicate analytic solutions. In this paper we derive a singularity-free solution of the next-to-leading order (NLO) RG equations, which greatly facilitates the calculation of ϵ{sub K}{sup ′}, the measure of direct CP violation in K→ππ decays. Using our new RG evolution and the latest lattice results for the hadronic matrix elements, we calculate the ratio ϵ{sub K}{sup ′}/ϵ{sub K} (with ϵ{sub K} quantifying indirect CP violation) in the Standard Model (SM) at NLO to ϵ{sub K}{sup ′}/ϵ{sub K}=(1.06±5.07)×10{sup −4}, which is 2.8 σ below the experimental value. We also present the evolution matrix in the high-energy regime for calculations of new physics contributions and derive easy-to-use approximate formulae. We find that the RG amplification of new-physics contributions to Wilson coefficients of the electroweak penguin operators is further enhanced by the NLO corrections: if the new contribution is generated at the scale of 1–10 TeV, the RG evolution between the new-physics scale and the electroweak scale enhances these coefficients by 50–100%. Our solution contains a term of order α{sub EM}{sup 2}/α{sub s}{sup 2}, which is numerically unimportant for the SM case but should be included in studies of high-scale new-physics.

  6. Leading-order hadronic contributions to aμ and αQED from Nf=2+1+1 twisted mass fermions

    International Nuclear Information System (INIS)

    Feng, Xu; Hotzel, Grit; Renner, Dru B.

    2012-11-01

    We present the first four-flavour lattice calculation of the leading-order hadronic vacuum-polarisation contribution to the anomalous magnetic moment of the muon, a hvp μ , and the hadronic running of the QED coupling constant, Δα hvp QED (Q 2 ). In the heavy sector a mixed-action setup is employed. The bare quark masses are determined from matching the K- and D-meson masses to their physical values. Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass by utilising a recently proposed improved method. We demonstrate that this method also works in the four-flavour case.

  7. The next-next-to-leading QCD approximation for non-singlet moments of deep inelastic structure functions

    Energy Technology Data Exchange (ETDEWEB)

    Larin, S.A.; Ritbergen, T. van; Vermaseren, J.A.M.

    1993-12-01

    We obtain the analytic next-next-to-leading perturbative QCD corrections in the leading twist approximation for the moments N = 2, 4, 6, 8 of the non-singlet deep inelastic structure functions F{sub 2} and F{sub L}. We calculate the three-loop anomalous dimensions of the corresponding non-singlet operators and the three-loop coefficient functions of the structure function F{sub L}. (orig.).

  8. Fourth generation CP violation effects on B-->Kpi, phiK, and rhoK in next-to-leading-order perturbative QCD.

    Science.gov (United States)

    Hou, Wei-Shu; Li, Hsiang-nan; Mishima, Satoshi; Nagashima, Makiko

    2007-03-30

    We study the effect from a sequential fourth generation quark on penguin-dominated two-body nonleptonic B meson decays in the next-to-leading order perturbative QCD formalism. With an enhancement of the color-suppressed tree amplitude and possibility of a new CP phase in the electroweak penguin amplitude, we can account better for A(CP)(B(0)-->K+ pi-)-A(CP)(B+-->K+ pi0). Taking |V(t's)V(t'b)| approximately 0.02 with a phase just below 90 degrees, which is consistent with the b-->sl+ l- rate and the B(s) mixing parameter Deltam(B)(s), we find a downward shift in the mixing-induced CP asymmetries of B(0)-->K(S)(pi 0) and phi(K)(S). The predicted behavior for B(0)-->rho(0)(K)(S) is opposite.

  9. Production of heavy neutrino in next-to-leading order QCD at the LHC and beyond

    International Nuclear Information System (INIS)

    Das, Arindam; Konar, Partha; Majhi, Swapan

    2016-01-01

    Majorana and pseudo-Dirac heavy neutrinos are introduced into the type-I and inverse seesaw models, respectively, in explaining the naturally small neutrino mass. TeV scale heavy neutrinos can also be accommodated to have a sizable mixing with the Standard Model light neutrinos, through which they can be produced and detected at the high energy colliders. In this paper we consider the Next-to-Leading Order QCD corrections to the heavy neutrino production, and study the scale variation in cross-sections as well as the kinematic distributions with different final states at 14 TeV LHC and also in the context of 100 TeV hadron collider. The repertoire of the Majorana neutrino is realized through the characteristic signature of the same-sign dilepton pair, whereas, due to a small lepton number violation, the pseudo-Dirac heavy neutrino can manifest the trileptons associated with missing energy in the final state. Using the √s=8 TeV, 20.3 fb"−"1 and 19.7 fb"−"1 data at the ATLAS and CMS respectively, we obtain prospective scale dependent upper bounds of the light-heavy neutrino mixing angles for the Majorana heavy neutrinos at the 14 TeV LHC and 100 TeV collider. Further exploiting a recent study on the anomalous multilepton search by CMS at √s=8 TeV with 19.5 fb"−"1 data, we also obtain the prospective scale dependent upper bounds on the mixing angles for the pseudo-Dirac neutrinos. We thus project a scale dependent prospective reach using the NLO processes at the 14 TeV LHC.

  10. Heavy-quark fragmentation functions at next-to-leading perturbative QCD

    Energy Technology Data Exchange (ETDEWEB)

    Moosavi Nejad, S.M. [Yazd University, Faculty of Physics, Yazd (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of); Sartipi Yarahmadi, P. [Yazd University, Faculty of Physics, Yazd (Iran, Islamic Republic of)

    2016-10-15

    It is well known that the dominant mechanism to produce hadronic bound states with large transverse momentum is fragmentation. This mechanism is described by the fragmentation functions (FFs) which are the universal and process-independent functions. Here, we review the perturbative FFs formalism as an appropriate tool for studying these hadronization processes and detail the extension of this formalism at next-to-leading order (NLO). Using Suzuki's model, we calculate the perturbative QCD FF for a heavy quark to fragment into a S-wave heavy meson at NLO. As an example, we study the LO and NLO FFs for a charm quark to split into the S-wave D-meson and compare our analytic results both with experimental data and well-known phenomenological models. (orig.)

  11. Non-leading contributions in QCD: Summing the perturbative series

    International Nuclear Information System (INIS)

    Trentadue, L.

    1984-01-01

    This paper presents the results of a systematic analysis of the leading and non-leading contributions in perturbative QCD and addresses the question of logarithmic contributions to all orders of the perturbative series

  12. Non-abelian factorisation for next-to-leading-power threshold logarithms

    International Nuclear Information System (INIS)

    Bonocore, D.; Laenen, E.; Magnea, L.; Vernazza, L.; White, C.D.

    2016-01-01

    Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this paper, we generalise a previously proposed all-order NLP factorisation formula to include non-abelian corrections. We define a non-abelian radiative jet function, organising collinear enhancements at NLP, and compute it for quark jets at one loop. We discuss in detail the issue of double counting between soft and collinear regions. Finally, we verify our prescription by reproducing all NLP logarithms in Drell-Yan production up to NNLO, including those associated with double real emission. Our results constitute an important step in the development of a fully general resummation formalism for NLP threshold effects.

  13. Non-abelian factorisation for next-to-leading-power threshold logarithms

    Energy Technology Data Exchange (ETDEWEB)

    Bonocore, D. [Nikhef, Science Park 105, NL-1098 XG Amsterdam (Netherlands); Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, Sommerfeldstr. 16, 52074 Aachen (Germany); Laenen, E. [Nikhef, Science Park 105, NL-1098 XG Amsterdam (Netherlands); ITFA, University of Amsterdam, Science Park 904, Amsterdam (Netherlands); ITF, Utrecht University, Leuvenlaan 4, Utrecht (Netherlands); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 (United States); Magnea, L. [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino, Via P. Giuria 1, I-10125 Torino (Italy); Vernazza, L. [Higgs Centre for Theoretical Physics, School of Physics and Astronomy, The University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); White, C.D. [Centre for Research in String Theory, School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London E1 4NS (United Kingdom)

    2016-12-22

    Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this paper, we generalise a previously proposed all-order NLP factorisation formula to include non-abelian corrections. We define a non-abelian radiative jet function, organising collinear enhancements at NLP, and compute it for quark jets at one loop. We discuss in detail the issue of double counting between soft and collinear regions. Finally, we verify our prescription by reproducing all NLP logarithms in Drell-Yan production up to NNLO, including those associated with double real emission. Our results constitute an important step in the development of a fully general resummation formalism for NLP threshold effects.

  14. SU(N)-QCD2 meson equation in next-to-leading order

    International Nuclear Information System (INIS)

    Durgut, M.; Pak, N.K.

    1982-08-01

    We compute the 1/N corrections to the meson equation in the regular cut-off scheme. We illustrate that although the quark and gluon self energy and vertex corrections do not vanish explicitly as in the singular cut-off scheme, their contributions to the meson Bethe-Salpeter equation get cancelled within the whole set of contributing diagrams. We also argue that 0(1/N) corrections to the meson equation remove the massless boson from the spectrum in accordance with the Coleman theorem. (author)

  15. Properties of three-body decay functions derived with time-like jet calculus beyond leading order

    International Nuclear Information System (INIS)

    Sugiura, Tetsuya

    2002-01-01

    Three-body decay functions in time-like parton branching are calculated using the jet calculus to the next-to-leading logarithmic (NLL) order in perturbative quantum chromodynamics (QCD). The phase space contributions from each of the ladder diagrams and interference diagrams are presented. We correct part of the results for the three-body decay functions calculated previously by two groups. Employing our new results, the properties of the three-body decay functions in the regions of soft partons are examined numerically. Furthermore, we examine the contribution of the three-body decay functions modified by the restriction resulting from the kinematical boundary of the phase space for two-body decay in the parton shower model. This restriction leads to some problems for the parton shower model. For this reason, we propose a new restriction introduced by the kinematical boundary of the phase space for two-body decay. (author)

  16. Non-abelian factorisation for next-to-leading-power threshold logarithms

    NARCIS (Netherlands)

    Bonocore, D.; Laenen, E.; Magnea, L.; Vernazza, L.; White, C.D.

    2016-01-01

    Soft and collinear radiation is responsible for large corrections to many hadronic cross sections, near thresholds for the production of heavy final states. There is much interest in extending our understanding of this radiation to next-to-leading power (NLP) in the threshold expansion. In this

  17. Second-order contributions to the structure functions in deep inelastic scattering III The singlet

    CERN Document Server

    González-Arroyo, A

    1980-01-01

    For pt.II see ibid., vol.159, p.512 (1979). Pointlike QCD predictions for the singlet part of the structure functions are given up to next- to-leading order of perturbation theory. This generalises the result obtained in pt.I (see ibid., vol.153, p.161, 1979) which deals with the non-singlet case. An interesting by-product is an exact and simple analytical expression for the anomalous dimension matrix to second non-trivial order in the QCD coupling constant. (18 refs).

  18. Heavy Quark Impact Factor at Next-to-leading Level

    OpenAIRE

    Ciafaloni, Marcello; Rodrigo, German

    2000-01-01

    We further analyze the definition and the calculation of the heavy quark impact factor at next-to-leading (NL) log(s) level, and we provide its analytical expression in a previously proposed k-factorization scheme. Our results indicate that k-factorization holds at NL level with a properly chosen energy scale, and with the same gluonic Green's function previously found in the massless probe case.

  19. Chiral 2π exchange at fourth order and peripheral NN scattering

    International Nuclear Information System (INIS)

    Entem, D.R.; Machleidt, R.

    2002-01-01

    We calculate the impact of the complete set of two-pion exchange contributions at chiral fourth order (also known as next-to-next-to-next-to-leading order) on peripheral partial waves of nucleon-nucleon scattering. Our calculations are based upon the analytical studies by Kaiser. It turns out that the contribution of fourth order is substantially smaller than the one of third order, indicating convergence of the chiral expansion. We compare the prediction from chiral pion exchange with the corresponding one from conventional meson theory as represented by the Bonn full model and find, in general, good agreement. Our calculations provide a sound basis for investigating the issue whether the low-energy constants determined from πN lead to reasonable predictions for NN

  20. Two-loop current–current operator contribution to the non-leptonic QCD penguin amplitude

    Directory of Open Access Journals (Sweden)

    G. Bell

    2015-11-01

    Full Text Available The computation of direct CP asymmetries in charmless B decays at next-to-next-to-leading order (NNLO in QCD is of interest to ascertain the short-distance contribution. Here we compute the two-loop penguin contractions of the current–current operators Q1,2 and provide a first estimate of NNLO CP asymmetries in penguin-dominated b→s transitions.

  1. Automated next-to-leading order predictions for new physics at the LHC: the case of colored scalar pair production

    CERN Document Server

    Degrande, Céline; Hirschi, Valentin; Proudom, Josselin; Shao, Hua-Sheng

    2015-01-01

    We present for the first time the full automation of collider predictions matched with parton showers at the next-to-leading accuracy in QCD within non-trivial extensions of the Standard Model. The sole inputs required from the user are the model Lagrangian and the process of interest. As an application of the above, we explore scenarios beyond the Standard Model where new colored scalar particles can be pair produced in hadron collisions. Using simplified models to describe the new field interactions with the Standard Model, we present precision predictions for the LHC within the MadGraph5 aMC@NLO framework.

  2. Leading-order hadronic contributions to a{sub {mu}} and {alpha}{sub QED} from N{sub f}=2+1+1 twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xu [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Hotzel, Grit [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab, Newport News, VA (United States)

    2012-11-15

    We present the first four-flavour lattice calculation of the leading-order hadronic vacuum-polarisation contribution to the anomalous magnetic moment of the muon, a{sup hvp}{sub {mu}}, and the hadronic running of the QED coupling constant, {Delta}{alpha}{sup hvp}{sub QED}(Q{sup 2}). In the heavy sector a mixed-action setup is employed. The bare quark masses are determined from matching the K- and D-meson masses to their physical values. Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass by utilising a recently proposed improved method. We demonstrate that this method also works in the four-flavour case.

  3. Leading order hadronic contributions to a{sub {mu}} and {alpha}{sub QED} from N{sub f} = 2 + 1 + 1 twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Xu Feng, Grit Hotzel, Karl Jansen, Marcus Petschlies, Dru B. Renner

    2012-12-01

    We present the first four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a{sub {mu}}{sup hvp}, and the hadronic running of the QED coupling constant, {Delta}{alpha}{sup hvp}{sub QED}(Q{sup 2}). In the heavy sector a mixed-action setup is employed. The bare quark masses are determined from matching the K- and D-meson masses to their physical values. Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass by utilising a recently proposed improved method. We demonstrate that this method also works in the four-flavour case.

  4. Leading-order hadronic contributions to a{sub μ} and α{sub QED} from N{sub f}=2+1+1 twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xu [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Hotzel, Grit [Humboldt-Universitaet zu Berlin, Institut fuer Physik, Berlin (Germany); Jansen, Karl [NIC, DESY, Zeuthen (Germany); Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus); Renner, Dru [Jefferson Lab, Newport News (United States)

    2013-07-01

    We present the first four-flavour lattice calculation of the leading-order hadronic vacuum-polarisation contribution to the anomalous magnetic moment of the muon, a{sub μ}{sup hvp}, and the hadronic running of the QED coupling constant, Δ α{sub QED}{sup hvp} (Q{sup 2}). In the heavy sector a mixed-action setup is employed. The bare quark masses are determined from matching the K- and D-meson masses to their physical values. Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass by utilising a recently proposed improved method. We demonstrate that this method also works in the four-flavour case.

  5. Semileptonic decays of B mesons into excited charm mesons: leading order and 1/mc contributions

    International Nuclear Information System (INIS)

    Mannel, T.

    1994-01-01

    We use the heavy quark effective theory to investigate the form factors that describe the semileptonic decays of a B meson into excited daughter mesons. For an excited daughter meson with charm, a single form factor is needed at leading order, while five form factors and two dimensionful constants are needed to order 1/m c in the heavy quark expansion. For non-charmed final states, a total of four form factors are needed at leading order. For the process B→D(*)Xlν, four form factors are also needed at leading order. (orig.)

  6. Parton distributions beyond the leading order

    International Nuclear Information System (INIS)

    Chyla, J.

    1993-01-01

    The importance of properly taking into account the factorization scheme dependence of parton distribution functions is emphasized. A serious error in the usual handling of this topic is pointed out and the correct procedure for transforming parton distribution functions from one factorization scheme to another recalled. It is shown that the conventional M bar S and DIS definitions thereof are ill defined due to the lack of distinction between the factorization scheme dependence of parton distribution functions and renormalization scheme dependence of the strong coupling constant α s . A novel definition of parton distribution functions is suggested and its role in the construction of consistent next-to-leading-order event generators briefly outlined

  7. A next-to-leading determination of the singlet axial charge and the polarized gluon content of the nucleon

    CERN Document Server

    Ball, R D; Ridolfi, G

    1996-01-01

    We perform a full next-to-leading analysis of the the available experimental data on the polarized structure function g_1 of the nucleon, and give a precise determination of its singlet axial charge together with a thorough assessment of the theoretical uncertainties. We find that the data are now sufficient to separately determine first moments of the polarized quark and gluon distributions and show in particular that the gluon contribution is large and positive.

  8. Higher-order threshold resummation for semi-inclusive e+e- annihilation

    International Nuclear Information System (INIS)

    Moch, S.; Vogt, A.

    2009-08-01

    The complete soft-enhanced and virtual-gluon contributions are derived for the quark coefficient functions in semi-inclusive e + e - annihilation to the third order in massless perturbative QCD. These terms enable us to extend the soft-gluon resummation for the fragmentation functions by two orders to the next-to-next-to-next-to-leading logarithmic (N 3 LL) accuracy. The resummation exponent is found to be the same as for the structure functions in inclusive deep-inelastic scattering. This finding, together with known results on the higher-order quark form factor, facilitates the determination of all soft and virtual contributions of the fourth-order difference of the coefficient functions for these two processes. Unlike the previous (N 2 LL) order in the exponentiation, the numerical effect of the N 3 LL contributions turns out to be negligible at LEP energies. (orig.)

  9. The development of the light cone in the quantum chromodynamics up to the first non-leading order

    International Nuclear Information System (INIS)

    Kaschluhn, L.

    1986-01-01

    For the product of two electromagnetic currents in QCD there is derived in a systematic way a nonlocal light-cone expansion up to next-to-leading order. Thereby the gauge-invariance of the underlying theory has been taken into acccount by using the known general solutions of the Ward identities in axial gauge. (author)

  10. Next-to-Leading Order Differential Cross Sections for J/ψ, ψ(2S), and Υ Production in Proton-Proton Collisions at a Fixed-Target Experiment Using the LHC Beams

    OpenAIRE

    Yu Feng; Jian-Xiong Wang

    2015-01-01

    Using nonrelativistic QCD (NRQCD) factorization, we calculate the yields for J/ψ , ψ(2S) , and Υ(1S) hadroproduction at s=72  GeV and 115 GeV including the next-to-leading order QCD corrections. Both these center-of-mass energies correspond to those obtained with 7 TeV and 2.76 TeV nucleon beam impinging a fixed target. We study the cross section integrated in pt as a function of the (center-of-mass) rapidity as well as the pt differential cross section in the central rapidity region. Using d...

  11. Third-order QCD corrections to the charged-current structure function F3

    International Nuclear Information System (INIS)

    Moch, S.; Vermaseren, J.A.M.; Vogt, A.

    2008-12-01

    We compute the coefficient function for the charge-averaged W ± -exchange structure function F 3 in deep-inelastic scattering (DIS) to the third order in massless perturbative QCD. Our new three-loop contribution to this quantity forms, at not too small values of the Bjorken variable x, the dominant part of the next-to-next-to-next-to-leading order corrections. It thus facilitates improved determinations of the strong coupling α s and of 1/Q 2 power corrections from scaling violations measured in neutrino-nucleon DIS. The expansion of F 3 in powers of α s is stable at all values of x relevant to measurements at high scales Q 2 . At small x the third-order coefficient function is dominated by diagrams with the colour structure d abc d abc not present at lower orders. At large x the coefficient function for F 3 is identical to that of F 1 up to terms vanishing for x→1. (orig.)

  12. High-quality two-nucleon potentials up to fifth order of the chiral expansion

    Science.gov (United States)

    Entem, D. R.; Machleidt, R.; Nosyk, Y.

    2017-08-01

    We present NN potentials through five orders of chiral effective field theory ranging from leading order (LO) to next-to-next-to-next-to-next-to-leading order (N4LO ). The construction may be perceived as consistent in the sense that the same power counting scheme as well as the same cutoff procedures are applied in all orders. Moreover, the long-range parts of these potentials are fixed by the very accurate π N low-energy constants (LECs) as determined in the Roy-Steiner equations analysis by Hoferichter, Ruiz de Elvira, and coworkers. In fact, the uncertainties of these LECs are so small that a variation within the errors leads to effects that are essentially negligible, reducing the error budget of predictions considerably. The NN potentials are fit to the world NN data below the pion-production threshold of the year 2016. The potential of the highest order (N4LO ) reproduces the world NN data with the outstanding χ2/datum of 1.15, which is the highest precision ever accomplished for any chiral NN potential to date. The NN potentials presented may serve as a solid basis for systematic ab initio calculations of nuclear structure and reactions that allow for a comprehensive error analysis. In particular, the consistent order by order development of the potentials will make possible a reliable determination of the truncation error at each order. Our family of potentials is nonlocal and, generally, of soft character. This feature is reflected in the fact that the predictions for the triton binding energy (from two-body forces only) converges to about 8.1 MeV at the highest orders. This leaves room for three-nucleon-force contributions of moderate size.

  13. Electroweak production of top-quark pairs in e+e- annihilation at NNLO in QCD: The vector current contributions

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jun [Southern Methodist Univ., Dallas, TX (United States); Zhu, Hua Xing [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2014-12-17

    We report on a calculation of the vector current contributions to the electroweak production of top quark pairs in e+e annihilation at next-to-next-to-leading order in quantum chromodynamics. Our setup is fully differential and can be used to calculate any infrared-safe observable. The real emission contributions are handled by a next-to-next-to-leading order generalization of the phase-space slicing method. As a result, we demonstrate the power of our technique by considering its application to various inclusive and exclusive observables.

  14. Higher Order Heavy Quark Corrections to Deep-Inelastic Scattering

    Science.gov (United States)

    Blümlein, Johannes; DeFreitas, Abilio; Schneider, Carsten

    2015-04-01

    The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities Q2. We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring αs (MZ), the charm quark mass mc, and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.

  15. Higher order heavy quark corrections to deep-inelastic scattering

    International Nuclear Information System (INIS)

    Bluemlein, J.; Freitas, A. de; Johannes Kepler Univ., Linz; Schneider, C.

    2014-11-01

    The 3-loop heavy flavor corrections to deep-inelastic scattering are essential for consistent next-to-next-to-leading order QCD analyses. We report on the present status of the calculation of these corrections at large virtualities Q 2 . We also describe a series of mathematical, computer-algebraic and combinatorial methods and special function spaces, needed to perform these calculations. Finally, we briefly discuss the status of measuring α s (M Z ), the charm quark mass m c , and the parton distribution functions at next-to-next-to-leading order from the world precision data on deep-inelastic scattering.

  16. Next-to-next-to-leading order calculation of the strong coupling ...

    Indian Academy of Sciences (India)

    Pramana – J. Phys., Vol. 81, No. ... of the higher moments of the different shape variable is similar to what was observed for the first moments. Although ... Figure 1. First moment of four event-shape variables: (a) 1 − T, (b) ρ, (c) BT,. (d) Bw. 3.

  17. Consistent, high-quality two-nucleon potentials up to fifth order of the chiral expansion

    Science.gov (United States)

    Machleidt, R.

    2018-02-01

    We present N N potentials through five orders of chiral effective field theory ranging from leading order (LO) to next-to-next-to-next-to-next-to-leading order (N4LO). The construction may be perceived as consistent in the sense that the same power counting scheme as well as the same cutoff procedures are applied in all orders. Moreover, the long-range parts of these potentials are fixed by the very accurate πN low-energy constants (LECs) as determined in the Roy-Steiner equations analysis by Hoferichter, Ruiz de Elvira and coworkers. In fact, the uncertainties of these LECs are so small that a variation within the errors leads to effects that are essentially negligible, reducing the error budget of predictions considerably. The N N potentials are fit to the world N N data below pion-production threshold of the year of 2016. The potential of the highest order (N4LO) reproduces the world N N data with the outstanding χ 2/datum of 1.15, which is the highest precision ever accomplished for any chiral N N potential to date. The N N potentials presented may serve as a solid basis for systematic ab initio calculations of nuclear structure and reactions that allow for a comprehensive error analysis. In particular, the consistent order by order development of the potentials will make possible a reliable determination of the truncation error at each order. Our family of potentials is non-local and, generally, of soft character. This feature is reflected in the fact that the predictions for the triton binding energy (from two-body forces only) converges to about 8.1 MeV at the highest orders. This leaves room for three-nucleon-force contributions of moderate size.

  18. Next-to-leading order corrections to the spin-dependent energy spectrum of hadrons from polarized top quark decay in the general two Higgs doublet model

    Directory of Open Access Journals (Sweden)

    S. Mohammad Moosavi Nejad

    2017-08-01

    Full Text Available In recent years, searches for the light and heavy charged Higgs bosons have been done by the ATLAS and the CMS collaborations at the Large Hadron Collider (LHC in proton–proton collision. Nevertheless, a definitive search is a program that still has to be carried out at the LHC. The experimental observation of charged Higgs bosons would indicate physics beyond the Standard Model. In the present work, we study the scaled-energy distribution of bottom-flavored mesons (B inclusively produced in polarized top quark decays into a light charged Higgs boson and a massless bottom quark at next-to-leading order in the two-Higgs-doublet model; t(↑→bH+→BH++X. This spin-dependent energy distribution is studied in a specific helicity coordinate system where the polarization vector of the top quark is measured with respect to the direction of the Higgs momentum. The study of these energy distributions could be considered as a new channel to search for the charged Higgs bosons at the LHC. For our numerical analysis and phenomenological predictions, we restrict ourselves to the unexcluded regions of the MSSM mH+−tan⁡β parameter space determined by the recent results of the CMS [13] and ATLAS [14] collaborations.

  19. J/ψ -pair production at large momenta: Indications for double parton scatterings and large α$_s^5$ contributions

    CERN Document Server

    Lansberg, Jean-Philippe

    2015-01-01

    The recent observations of prompt J/psi-pair production by CMS at the LHC and by D0 at the Tevatron reveal the presence of different production mechanisms in different kinematical regions. We find out that next-to-leading-order single-parton-scattering contributions at alpha_s^5 dominate the yield at large transverse momenta of the pair. Our analysis further emphasises the importance of double-parton-scatterings --which are expected to dominate the yield at large rapidity differences-- at large invariant masses of the pair in the CMS acceptance. In addition, we provide the first exact --gauge-invariant and infrared-safe-- evaluation of a class of leading-P_T next-to-next-to-leading-order contributions, which are dominant in the region of large sub-leading transverse momenta, precisely where the colour-octet contributions can be non-negligible. Finally, we discuss the contribution from decays of excited charmonium states within both single- and double-parton scatterings and suggest measurements to distinguish ...

  20. The BFKL high energy asymptotic in the next-to-leading approximation

    International Nuclear Information System (INIS)

    Levin, Eugene

    1999-01-01

    We discuss the high energy asymptotic in the next-to-leading (NLO) BFKL equation. We find a general solution for the Green functions and consider two properties of the NLO BFKL kernel: running QCD coupling and large NLO corrections to the conformal part of the kernel. Both these effects lead to Regge-BFKL asymptotic only in the limited range of energy (y = ln(s/qq 0 ) ≤ (α S ) ((-5)/(3)) ) and change the energy behaviour of the amplitude for higher values of energy. We confirm the oscillation in the total cross section found by D.A. Ross [SHEP-98-06, hep-ph/9804332] in the NLO BFKL asymptotic, which shows that the NLO BFKL has a serious pathology

  1. Intermediate-range order in lead metasilicate glass

    Energy Technology Data Exchange (ETDEWEB)

    Suzuya, Kentaro [Japan Atomic Energy Research Inst., Ako, Hyogo (Japan)]|[Argonne National Lab., IL (United States). Materials Science Div.; Price, D.L.; Saboungi, M.L. [Argonne National Lab., IL (United States). Materials Science Div.; Ohno, Hideo [Japan Atomic Energy Research Inst., Ako, Hyogo (Japan)

    1997-03-01

    The complementarity of anomalous X-ray scattering (AXS) and neutron diffraction (ND) techniques is used here to investigate the nature and origin of intermediate-range order in lead metasilicate glass. Both X-ray and neutron source factors reveal small peaks at low wave vector which are shown to be associated with intermediate-range order of the Pb-O network. The combination of AXS and ND is shown to be a powerful tool to correlate contributions from the different atom pairs to such a peak. The information thus derived is compared with results from alkali germanate glasses and with structural data on corresponding crystalline compounds.

  2. Quark mass relations to four-loop order

    International Nuclear Information System (INIS)

    Marquard, Peter; Smirnov, Alexander V.; Smirnov, Vladimir A.; Steinhauser, Matthias

    2015-02-01

    We present results for the relation between a heavy quark mass defined in the on-shell and MS scheme to four-loop order. The method to compute the four-loop on-shell integral is briefly described and the new results are used to establish relations between various short-distance masses and the MS quark mass to next-to-next-to-next-to-leading order accuracy. These relations play an important role in the accurate determination of the MS heavy quark masses.

  3. Extrinsic Contribution and Instability Properties in Lead-Based and Lead-Free Piezoceramics

    Directory of Open Access Journals (Sweden)

    José Eduardo García

    2015-11-01

    Full Text Available Piezoceramic materials generally exhibit a notable instability of their functional properties when they work under real external conditions. This undesirable effect, known as nonlinear behavior, is mostly associated with the extrinsic contribution to material response. In this article, the role of the ferroelectric domain walls’ motion in the nonlinear response in the most workable lead-based and lead-free piezoceramics is reviewed. Initially, the extrinsic origin of the nonlinear response is discussed in terms of the temperature dependence of material response. The influence of the crystallographic phase and of the phase boundaries on the material response are then reviewed. Subsequently, the impact of the defects created by doping in order to control the extrinsic contribution is discussed as a way of tuning material properties. Finally, some aspects related to the grain-size effect on the nonlinear response of piezoceramics are surveyed.

  4. Next-to-next-to-leading order calculation of the strong coupling ...

    Indian Academy of Sciences (India)

    It is observed that the NNLO correction gives a better agreement between the theory and the experimental data. Also, by using the above observables, the strong coupling constant () is determined and how much its value is affected by the NNLO correction is demonstrated. By combining the results for all variables at ...

  5. Leading hadronic contributions to the running of the electroweak coupling constants from lattice QCD

    International Nuclear Information System (INIS)

    Burger, Florian; Jansen, Karl; Petschlies, Marcus; Pientka, Grit

    2015-12-01

    The quark-connected leading-order hadronic contributions to the running of the electromagnetic fine structure constant, α QED , and the weak mixing angle, θ W , are determined by a four-flavour lattice QCD computation with twisted mass fermions. Full agreement of the results with a phenomenological analysis is observed with an even comparable statistical uncertainty. We show that the uncertainty of the lattice calculation is dominated by systematic effects which then leads to significantly larger errors than obtained by the phenomenological analysis.

  6. All order running coupling BFKL evolution from GLAP (and vice versa)

    International Nuclear Information System (INIS)

    Ball, Richard D.; Forte, Stefano

    2006-01-01

    We present a systematic formalism for the derivation of the kernel of the BFKL equation from that of the GLAP equation and conversely to any given order, with full inclusion of the running of the coupling. The running coupling is treated as an operator, reducing the inclusion of running coupling effects and their factorization to a purely algebraic problem. We show how the GLAP anomalous dimensions which resum large logs of 1x can be derived from the running-coupling BFKL kernel order by order, thereby obtaining a constructive all-order proof of small x factorization. We check this result by explicitly calculating the running coupling contributions to GLAP anomalous dimensions up to next-to-next-to leading order. We finally derive an explicit expression for BFKL kernels which resum large logs of Q 2 up to next-to-leading order from the corresponding GLAP kernels, thus making possible a consistent collinear improvement of the BFKL equation up to the same order

  7. Third-order QCD corrections to the charged-current structure function F{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Vermaseren, J.A.M. [NIKHEF, Amsterdam (Netherlands); Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences

    2008-12-15

    We compute the coefficient function for the charge-averaged W{sup {+-}}-exchange structure function F{sub 3} in deep-inelastic scattering (DIS) to the third order in massless perturbative QCD. Our new three-loop contribution to this quantity forms, at not too small values of the Bjorken variable x, the dominant part of the next-to-next-to-next-to-leading order corrections. It thus facilitates improved determinations of the strong coupling {alpha}{sub s} and of 1/Q{sup 2} power corrections from scaling violations measured in neutrino-nucleon DIS. The expansion of F{sub 3} in powers of {alpha}{sub s} is stable at all values of x relevant to measurements at high scales Q{sup 2}. At small x the third-order coefficient function is dominated by diagrams with the colour structure d{sup abc}d{sub abc} not present at lower orders. At large x the coefficient function for F{sub 3} is identical to that of F{sub 1} up to terms vanishing for x{yields}1. (orig.)

  8. Parton-shower uncertainties with Herwig 7: benchmarks at leading order

    Energy Technology Data Exchange (ETDEWEB)

    Bellm, Johannes; Schichtel, Peter [Durham University, Department of Physics, IPPP, Durham (United Kingdom); Nail, Graeme [University of Manchester, Particle Physics Group, School of Physics and Astronomy, Manchester (United Kingdom); Karlsruhe Institute of Technology, Institute for Theoretical Physics, Karlsruhe (Germany); Plaetzer, Simon [Durham University, Department of Physics, IPPP, Durham (United Kingdom); University of Manchester, Particle Physics Group, School of Physics and Astronomy, Manchester (United Kingdom); Siodmok, Andrzej [CERN, TH Department, Geneva (Switzerland); Polish Academy of Sciences, The Henryk Niewodniczanski Institute of Nuclear Physics in Cracow, Krakow (Poland)

    2016-12-15

    We perform a detailed study of the sources of perturbative uncertainty in parton-shower predictions within the Herwig 7 event generator. We benchmark two rather different parton-shower algorithms, based on angular-ordered and dipole-type evolution, against each other. We deliberately choose leading order plus parton shower as the benchmark setting to identify a controllable set of uncertainties. This will enable us to reliably assess improvements by higher-order contributions in a follow-up work. (orig.)

  9. Parton Shower Uncertainties with Herwig 7: Benchmarks at Leading Order

    CERN Document Server

    Bellm, Johannes; Plätzer, Simon; Schichtel, Peter; Siódmok, Andrzej

    2016-01-01

    We perform a detailed study of the sources of perturbative uncertainty in parton shower predictions within the Herwig 7 event generator. We benchmark two rather different parton shower algorithms, based on angular-ordered and dipole-type evolution, against each other. We deliberately choose leading order plus parton shower as the benchmark setting to identify a controllable set of uncertainties. This will enable us to reliably assess improvements by higher-order contributions in a follow-up work.

  10. The gluon Green's function in the BFKL approach at next-to-leading logarithmic accuracy

    International Nuclear Information System (INIS)

    Andersen, Jeppe R.; Sabio Vera, Agustin

    2004-01-01

    We investigate the gluon Green's function in the high energy limit of QCD using a recently proposed iterative solution of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation at next-to-leading logarithmic (NLL) accuracy. To establish the applicability of this method in the NLL approximation we solve the BFKL equation as originally written by Fadin and Lipatov, and compare the results with previous studies in the leading logarithmic (LL) approximation

  11. Four-flavour leading hadronic contribution to the muon anomalous magnetic moment

    International Nuclear Information System (INIS)

    Burger, Florian; Hotzel, Grit; Jansen, Karl; Renner, Dru B.

    2013-11-01

    We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a hvp μ , arising from quark-connected Feynman graphs. It is based on ensembles featuring N f =2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Including the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a hvp μ . Our final result involving an estimate of the systematic uncertainty a hvp μ =6.74(21)(18) x 10 -8 shows a good overall agreement with these computations.

  12. The quark induced Mueller-Tang jet impact factor at next-to-leading order

    CERN Document Server

    Hentschinski, M.; Murdaca, B.; Vera, A. Sabio

    2014-01-01

    We present the NLO corrections for the quark induced forward production of a jet with an associated rapidity gap. We make use of Lipatov's QCD high energy effective action to calculate the real emission contributions to the so-called Mueller-Tang impact factor. We combine them with the previously calculated virtual corrections and verify ultraviolet and collinear finiteness of the final result.

  13. Four-flavour leading hadronic contribution to the muon anomalous magnetic moment

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Florian; Hotzel, Grit [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Feng, Xu [KEK National High Energy Physics, Tsukuba (Japan); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Cyprus Univ. Nicosia (Cyprus). Dept. of Physics; Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab, Newport News, VA (United States)

    2013-11-15

    We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a{sup hvp}{sub {mu}}, arising from quark-connected Feynman graphs. It is based on ensembles featuring N{sub f}=2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Including the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a{sup hvp}{sub {mu}}. Our final result involving an estimate of the systematic uncertainty a{sup hvp}{sub {mu}}=6.74(21)(18) x 10{sup -8} shows a good overall agreement with these computations.

  14. Second-order QCD effects in Higgs boson production through vector boson fusion

    Science.gov (United States)

    Cruz-Martinez, J.; Gehrmann, T.; Glover, E. W. N.; Huss, A.

    2018-06-01

    We compute the factorising second-order QCD corrections to the electroweak production of a Higgs boson through vector boson fusion. Our calculation is fully differential in the kinematics of the Higgs boson and of the final state jets, and uses the antenna subtraction method to handle infrared singular configurations in the different parton-level contributions. Our results allow us to reassess the impact of the next-to-leading order (NLO) QCD corrections to electroweak Higgs-plus-three-jet production and of the next-to-next-to-leading order (NNLO) QCD corrections to electroweak Higgs-plus-two-jet production. The NNLO corrections are found to be limited in magnitude to around ± 5% and are uniform in several of the kinematical variables, displaying a kinematical dependence only in the transverse momenta and rapidity separation of the two tagging jets.

  15. Shining LUX on isospin-violating dark matter beyond leading order

    DEFF Research Database (Denmark)

    Cirigliano, V.; Graesser, M. L.; Ovanesyan, G.

    2014-01-01

    Isospin-violating dark matter (IVDM) has been proposed as a viable scenario to reconcile conflicting positive and null results from direct detection dark matter experiments. We show that the lowest-order dark matter-nucleus scattering rate can receive large and nucleus-dependent corrections at next......-to-leading order (NLO) in the chiral expansion. The size of these corrections depends on the specific couplings of dark matter to quark flavors and gluons. In general the full NLO dark-matter-nucleus cross-section is not adequately described by just the zero-energy proton and neutron couplings. These statements...... are concretely illustrated in a scenario where the dark matter couples to quarks through scalar operators. We find the canonical IVDM scenario can reconcile the null XENON and LUX results and the recent CDMS-Si findings provided its couplings to second and third generation quarks either lie on a special line...

  16. Next-to-next-leading order correction to 3-jet rate and event-shape ...

    Indian Academy of Sciences (India)

    portunity to test QCD by measuring the energy dependence of different ... event shape data was not satisfactory largely due to the scale uncertainty of the pertur- .... )3 d ¯C dy. + O. ( α4 s. ) . (5). Here the event-shape distribution is normalized to the ..... [1] A Gehrmann-De Ridder, T Gehrmann, E W N Glover and G Heinrich, J.

  17. On the covariant formalism of the effective field theory of gravity and leading order corrections

    DEFF Research Database (Denmark)

    Codello, Alessandro; Jain, Rajeev Kumar

    2016-01-01

    We construct the covariant effective field theory of gravity as an expansion in inverse powers of the Planck mass, identifying the leading and next-to-leading quantum corrections. We determine the form of the effective action for the cases of pure gravity with cosmological constant as well...... as gravity coupled to matter. By means of heat kernel methods we renormalize and compute the leading quantum corrections to quadratic order in a curvature expansion. The final effective action in our covariant formalism is generally non-local and can be readily used to understand the phenomenology...... on different spacetimes. In particular, we point out that on curved backgrounds the observable leading quantum gravitational effects are less suppressed than on Minkowski spacetime....

  18. On a residual freedom of the next-to-leading BFKL eigenvalue in color adjoint representation in planar N=4 SYM

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, Sergey; Prygarin, Alex [Physics Department, Ariel University,Ariel 40700, territories administered by (Israel)

    2016-07-15

    We discuss a residual freedom of the next-to-leading BFKL eigenvalue that originates from ambiguity in redistributing the next-to-leading (NLO) corrections between the adjoint BFKL eigenvalue and eigenfunctions in planar N=4 super-Yang-Mills (SYM) Theory. In terms of the remainder function of the Bern-Dixon-Smirnov (BDS) amplitude this freedom is translated to reshuffling correction between the eigenvalue and the impact factors in the multi-Regge kinematics (MRK) in the next-to-leading logarithm approximation (NLA). We show that the modified NLO BFKL eigenvalue suggested by the authors in ref. http://arxiv.org/abs/1510.00589 can be introduced in the MRK expression for the remainder function by shifting the anomalous dimension in the impact factor in such a way that the two and three loop remainder function is left unchanged to the NLA accuracy.

  19. Leading-order hadronic contribution to the anomalous magnetic moment of the muon from N_f=2+1+1 twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Florian [Humboldt U. Berlin; Feng, Xu [KEK; Hotzel, Grit [Humboldt U. Berlin; Jansen, Karl [DESY; Petschlies, Marcus [The Cyprus Institute; Renner, Dru B. [JLAB

    2013-11-01

    We present results for the leading order QCD correction to the anomalous magnetic moment of the muon including the first two generations of quarks as dynamical degrees of freedom. Several light quark masses are examined in order to yield a controlled extrapolation to the physical pion mass. We analyse ensembles for three different lattice spacings and several volumes in order to investigate lattice artefacts and finite-size effects, respectively. We also provide preliminary results for this quantity for two flavours of mass-degenerate quarks at the physical value of the pion mass.

  20. A Self-Interaction Leading to Fluctuations of Order $n^{5/6}$

    OpenAIRE

    Gorny, Matthias

    2014-01-01

    In arXiv:1301.6911, we built and studied a Curie-Weiss model exhibiting self-organized criticality : it is a model with a self-interaction leading to fluctuations of order $n^{3/4}$ and a limiting law proportional to $\\exp(-x^4/12)$. In this paper we modify our model in order to "kill the term $x^4$" and to obtain a self-interaction leading to fluctuations of order $n^{5/6}$ and a limiting law $C\\,\\exp(-\\lambda x^6)\\,dx$, for suitable positive constants $C$ and $\\lambda$.

  1. Quark mass relations to four-loop order in perturbative QCD.

    Science.gov (United States)

    Marquard, Peter; Smirnov, Alexander V; Smirnov, Vladimir A; Steinhauser, Matthias

    2015-04-10

    We present results for the relation between a heavy quark mass defined in the on-shell and minimal subtraction (MS[over ¯]) scheme to four-loop order. The method to compute the four-loop on-shell integral is briefly described and the new results are used to establish relations between various short-distance masses and the MS[over ¯] quark mass to next-to-next-to-next-to-leading order accuracy. These relations play an important role in the accurate determination of the MS[over ¯] heavy quark masses.

  2. On the covariant formalism of the effective field theory of gravity and leading order corrections

    International Nuclear Information System (INIS)

    Codello, Alessandro; Jain, Rajeev Kumar

    2016-01-01

    We construct the covariant effective field theory of gravity as an expansion in inverse powers of the Planck mass, identifying the leading and next-to-leading quantum corrections. We determine the form of the effective action for the cases of pure gravity with cosmological constant as well as gravity coupled to matter. By means of heat kernel methods we renormalize and compute the leading quantum corrections to quadratic order in a curvature expansion. The final effective action in our covariant formalism is generally non-local and can be readily used to understand the phenomenology on different spacetimes. In particular, we point out that on curved backgrounds the observable leading quantum gravitational effects are less suppressed than on Minkowski spacetime. (paper)

  3. Total contribution of airborne lead to blood lead.

    OpenAIRE

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone.

  4. Total contribution of airborne lead to blood lead.

    Science.gov (United States)

    Manton, W I

    1985-01-01

    A nine year study of blood lead concentrations and isotope ratios carried out on a married couple shows that pulmonary deposition cannot account for all the airborne lead in blood; that lead from bone may comprise 70% of blood lead; and that during pregnancy blood lead may double due to mobilisation of lead from bone. PMID:3970881

  5. Higher-order radiative corrections for b b ¯→H-W+

    Science.gov (United States)

    Kidonakis, Nikolaos

    2018-02-01

    I present higher-order radiative corrections from collinear and soft-gluon emission for the associated production of a charged Higgs boson with a W boson. The calculation uses expressions from resummation at next-to-leading-logarithm accuracy. From the resummed cross section I derive analytical formulas at approximate next-to-next-to-leading order and next-to-next-to-next-to-leading order. Total cross sections are presented for the process b b ¯→H-W+ at various LHC energies. The transverse momentum and rapidity distributions of the charged Higgs boson are also calculated.

  6. Flavor effects on the electric dipole moments in supersymmetric theories: A beyond leading order analysis

    International Nuclear Information System (INIS)

    Hisano, Junji; Nagai, Minoru; Paradisi, Paride

    2009-01-01

    The standard model predictions for the hadronic and leptonic electric dipole moments (EDMs) are considerably far from the present experimental resolutions; thus, the EDMs represent very clean probes of new physics effects. Especially, within supersymmetric frameworks with flavor-violating soft terms, large and potentially visible effects to the EDMs are typically expected. In this work, we systematically evaluate the predictions for the EDMs at the beyond leading order. In fact, we show that beyond-leading-order contributions to the EDMs dominate over the leading-order effects in large regions of the supersymmetric parameter space. Hence, their inclusion in the evaluation of the EDMs is unavoidable. As an example, we show the relevance of beyond-leading-order effects to the EDMs for a supersymmetric SU(5) model with right-handed neutrinos.

  7. Lattice calculation of the leading strange quark-connected contribution to the muon $g-2$

    CERN Document Server

    Blum, T.; Del Debbio, L.; Hudspith, R.J.; Izubuchi, T.; Jüttner, A.; Lehner, C.; Lewis, R.; Maltman, K.; Krstić Marinković, M.; Portelli, A.; Spraggs, M.

    2016-04-11

    We present results for the leading hadronic contribution to the muon anomalous magnetic moment due to strange quark-connected vacuum polarisation effects. Simulations were performed using RBC--UKQCD's $N_f=2+1$ domain wall fermion ensembles with physical light sea quark masses at two lattice spacings. We consider a large number of analysis scenarios in order to obtain solid estimates for residual systematic effects. Our final result in the continuum limit is $a_\\mu^{(2)\\,{\\rm had},\\,s}=53.1(9)\\left(^{+1}_{-3}\\right)\\times10^{-10}$.

  8. Lattice calculation of the leading strange quark-connected contribution to the muon g−2

    International Nuclear Information System (INIS)

    Blum, T.; Boyle, P.A.; Debbio, L. Del; Hudspith, R.J.; Izubuchi, T.; Jüttner, A.; Lehner, C.; Lewis, R.; Maltman, K.; Marinković, M. Krstić; Portelli, A.; Spraggs, M.

    2016-01-01

    We present results for the leading hadronic contribution to the muon anomalous magnetic moment due to strange quark-connected vacuum polarisation effects. Simulations were performed using RBC-UKQCD’s N f =2+1 domain wall fermion ensembles with physical light sea quark masses at two lattice spacings. We consider a large number of analysis scenarios in order to obtain solid estimates for residual systematic effects. Our final result in the continuum limit is a μ (2) had, s =53.1(9)( −3 +1 )×10 −10 .

  9. Wind energy in the next millennium and the next year

    International Nuclear Information System (INIS)

    Chabot, B.

    1999-01-01

    The rapid development of wind energy was once again confirmed in 1998 and everything points to the fact that this road will in the next century rapidly become the third channel of primary electricity production in the world, both in terms of annual sales and contribution of energy. In particular, a scenario for the development, of wind energy in the coming century is proposed, taking as model and minimum objective the historical development of success of wind energy should prove perfectly feasible, it is difficult to foresee in the short term the actual impact of the liberalization of electricity markets on existing inducements in favour of wind energy and even more difficult to estimate the effectiveness of new inducements more in line with this liberalization process. These difficulties may be overcome by selecting - for the long term scenario - a starting point within the next decade which is in line with the best market studies currently available and by constructing the model for variations in operational stock world-wide on the basis of a Rayleigh distribution, adjusted for the market conditions defined in the short term, in order that the future contributions defined in the short term, in order that the future contribution of wind energy might come to equal that of hydro-electricity before the end of the next century. (author)

  10. Competency Evaluations in the Next Accreditation System: Contributing to Guidelines and Implications.

    Science.gov (United States)

    Park, Yoon Soo; Zar, Fred A; Norcini, John J; Tekian, Ara

    2016-01-01

    CONSTRUCT: This study examines validity evidence of end-of-rotation evaluation scores used to measure competencies and milestones as part of the Next Accreditation System (NAS) of the Accreditation Council for Graduate Medical Education (ACGME). Since the implementation of the milestones, end-of-rotation evaluations have surfaced as a potentially useful assessment method. However, validity evidence on the use of rotation evaluation scores as part of the NAS has not been studied. This article examines validity evidence for end-of-rotation evaluations that can contribute to developing guidelines that support the NAS. Data from 2,701 end-of-rotation evaluations measuring 21 out of 22 Internal Medicine milestones for 142 residents were analyzed (July 2013-June 2014). Descriptive statistics were used to measure the distribution of ratings by evaluators (faculty, n = 116; fellows, n = 59; peer-residents, n = 131), by postgraduate years. Generalizability analysis and higher order confirmatory factor analysis were used to examine the internal structure of ratings. Psychometric implications for combining evaluation scores using composite score reliability were examined. Milestone ratings were significantly higher for each subsequent year of training (15/21 milestones). Faculty evaluators had greater variability in ratings across milestones, compared to fellows and residents; faculty ratings were generally correlated with milestone ratings from fellows (r = .45) and residents (r = .25), but lower correlations were found for Professionalism and Interpersonal and Communication Skills. The Φ-coefficient was .71, indicating good reliability. Internal structure supported a 6-factor solution, corresponding to the hierarchical relationship between the milestones and the 6 core competencies. Evaluation scores corresponding to Patient Care, Medical Knowledge, and Practice-Based Learning and Improvement had higher correlations to milestones reported to the ACGME. Mean evaluation

  11. Lattice calculation of the leading strange quark-connected contribution to the muon g−2

    Energy Technology Data Exchange (ETDEWEB)

    Blum, T. [Physics Department, University of Connecticut,Storrs, CT 06269-3046 (United States); Boyle, P.A.; Debbio, L. Del [School of Physics and Astronomy, University of Edinburgh,Peter Guthrie Tait Road, Edinburgh EH9 3JZ (United Kingdom); Hudspith, R.J. [Department of Physics and Astronomy, York University,4700 Keele Street, Toronto, Ontario, M3J 1P3 (Canada); Izubuchi, T. [Physics Department, Brookhaven National Laboratory,Upton, NY 11973 (United States); RIKEN-BNL Research Center, Brookhaven National Laboratory,Upton, NY 11973 (United States); Jüttner, A. [School of Physics and Astronomy, University of Southampton,Southampton SO17 1BJ (United Kingdom); Lehner, C. [Physics Department, Brookhaven National Laboratory,Upton, NY 11973 (United States); Lewis, R. [Department of Physics and Astronomy, York University,4700 Keele Street, Toronto, Ontario, M3J 1P3 (Canada); Maltman, K. [Department of Mathematics and Statistics, York University,4700 Keele Street, Toronto, Ontario, M3J 1P3 (Canada); CSSM, University of Adelaide,Adelaide, SA 5005 (Australia); Marinković, M. Krstić [School of Physics and Astronomy, University of Southampton,Southampton SO17 1BJ (United Kingdom); CERN, Theoretical Physics Department, CERN,Geneva (Switzerland); Portelli, A. [School of Physics and Astronomy, University of Edinburgh,Peter Guthrie Tait Road, Edinburgh EH9 3JZ (United Kingdom); School of Physics and Astronomy, University of Southampton,Southampton SO17 1BJ (United Kingdom); Spraggs, M. [School of Physics and Astronomy, University of Southampton,Southampton SO17 1BJ (United Kingdom); Collaboration: The RBC/UKQCD collaboration

    2016-04-11

    We present results for the leading hadronic contribution to the muon anomalous magnetic moment due to strange quark-connected vacuum polarisation effects. Simulations were performed using RBC-UKQCD’s N{sub f}=2+1 domain wall fermion ensembles with physical light sea quark masses at two lattice spacings. We consider a large number of analysis scenarios in order to obtain solid estimates for residual systematic effects. Our final result in the continuum limit is a{sub μ}{sup (2)} {sup had,} {sup s}=53.1(9)({sub −3}{sup +1})×10{sup −10}.

  12. Leading-order hadronic contribution to the anomalous magnetic moment of the muon from N{sub f}=2+1+1 twisted mass fermions

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Florian; Hotzel, Grit [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Feng, Xu [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Petschlies, Marcus [The Cyprus Institute, Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab, Newport News, VA (United States)

    2013-12-15

    We present results for the leading order QCD correction to the anomalous magnetic moment of the muon including the first two generations of quarks as dynamical degrees of freedom. Several light quark masses are examined in order to yield a controlled extrapolation to the physical pion mass. We analyse ensembles for three different lattice spacings and several volumes in order to investigate lattice artefacts and finite-size effects, respectively. We also provide preliminary results for this quantity for two flavours of mass-degenerate quarks at the physical value of the pion mass.

  13. The Electric Dipole Form Factor of the Nucleon in Chiral Perturbation Theory to Sub-leading Order

    CERN Document Server

    Mereghetti, E; Hockings, W H; Maekawa, C M; van Kolck, U

    2011-01-01

    The electric dipole form factor (EDFF) of the nucleon stemming from the QCD theta term and from the quark color-electric dipole moments is calculated in chiral perturbation theory to sub-leading order. This is the lowest order in which the isoscalar EDFF receives a calculable, non-analytic contribution from the pion cloud. In the case of the theta term, the expected lower bound on the deuteron electric dipole moment is |d_d| > 1.4 10^(-4) \\theta e fm. The momentum dependence of the isovector EDFF is proportional to a non-derivative time-reversal-violating pion-nucleon coupling, and the scale for momentum variation ---appearing, in particular, in the radius of the form factor--- is the pion mass.

  14. Supersymmetric contribution to B{yields}{rho}K and B{yields}{pi}K{sup Low-Asterisk} decays in SCET

    Energy Technology Data Exchange (ETDEWEB)

    Faisel, Gaber, E-mail: gfaisel@cc.ncu.edu.tw [Department of Physics and Center for Mathematics and Theoretical Physics, National Central University, Chung-li, 32054, Taiwan (China); Egyptian Center for Theoretical Physics, Modern University for Information and Technology, Cairo (Egypt); Delepine, David [Departamento de Fisica, DCI, Campus Leon, Universidad de Guanajuato, C.P. 37150, Leon, Guanajuato (Mexico); Shalaby, M. [Ain Shams University, Faculty of Science, Cairo 11566 (Egypt)

    2011-11-17

    We analyze the supersymmetric contributions to the direct CP asymmetries of the decays B{yields}{pi}K{sup Low-Asterisk} and B{yields}{rho}K within Soft Collinear Effective Theory. We extend the Standard Model analysis of these asymmetries to include the next leading order QCD corrections. We find that, even with QCD correction, the Standard Model predictions cannot accommodate the direct CP asymmetries in these decay modes. Using Mass Insertion Approximation (MIA), we show that non-minimal flavor SUSY contributions mediated by gluino exchange can enhance the CP asymmetries significantly and thus can accommodate the experimental results.

  15. Holographic QCD beyond the leading order

    International Nuclear Information System (INIS)

    Kim, Youngman; Ko, P.; Wu, Xiao-Hong

    2008-01-01

    We consider a holographic QCD model for light mesons beyond the leading order in the context of 5-dim gauged linear sigma model on the interval in the AdS 5 space. We include two dimension-6 operators in addition to the canonical bulk kinetic terms, and study chiral dynamics of π, ρ, a 1 and some of their KK modes. As novel features of dim-6 operators, we get non-vanishing Br(a 1 → πγ), the electromagnetic form factor and the charge radius of a charged pion, which improve the leading order results significantly and agree well with the experimental results.

  16. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    CERN Document Server

    Adolph, C.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jorg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; J.Matou s; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; M. Pe s; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Weisrock, T.; Wilfert, M.; Wolbeek, J. ter; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2017-01-01

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_T$, the different $p_T$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\\mu^2 = \\langle Q^2\\rangle = 3(GeV=c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_g$, covering the range $0.04 \\!<\\! x_{ \\rm g}\\! <\\! 0.28$ . and does not exhibit a significant dependence on $x_{\\rm g}$. Average...

  17. Electroweak contributions to squark-pair production processes at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Germer, Jan

    2011-04-28

    We study the electroweak (EW) contributions to squark-squark and sbottom-anti-sbottom production processes at the LHC within the framework of the Minimal Supersymmetric Standard Model (MSSM). Aiming at precise theoretical predictions, the EW contributions are considered up to next-to leading order (NLO) which are of O({alpha}{sup 2}{sub s}{alpha}). Since the EW interaction distinguishes flavor and chirality of the initial- and final-state quarks and squarks, respectively, the contributing processes are manifold and their interplay is non-trivial. All technical details needed in order to calculate the NLO EW contributions to the hadronic cross section for the abovementioned processes are given within this dissertation. This includes appropriate regularization and renormalization prescriptions and a proper treatment of mass singularities in order to get ultraviolet finite and infrared and collinear safe observables. Squark-squark production consists of 36 processes and the same amount for anti-squark- anti-squark production. The tree-level EW contributions of O({alpha}{sub s}{alpha}+{alpha}{sup 2}) and the NLO EW contributions are calculated for all processes. Depending on the flavor and chirality of the produced squarks, many interferences between EW-mediated and QCD-mediated diagrams give non-zero contributions at tree-level and NLO EW. While the tree-level EW contributions to the integrated cross section can reach the 20% level, the NLO EW corrections typically lower the LO prediction by a few percent. Sbottom-anti-sbottom pair production exhibits specific features like left-right mixing and the renormalization of the sbottom sector which has to be chosen with care in order to get reliable predictions. In addition, Yukawa couplings get enhanced for large values of tan {beta} with the related need of resummation. This renders the computation of the electroweak contributions substantially different from the corresponding computations for squark-anti- squark and stop

  18. Electroweak contributions to squark-pair production processes at the LHC

    International Nuclear Information System (INIS)

    Germer, Jan

    2011-01-01

    We study the electroweak (EW) contributions to squark-squark and sbottom-anti-sbottom production processes at the LHC within the framework of the Minimal Supersymmetric Standard Model (MSSM). Aiming at precise theoretical predictions, the EW contributions are considered up to next-to leading order (NLO) which are of O(α 2 s α). Since the EW interaction distinguishes flavor and chirality of the initial- and final-state quarks and squarks, respectively, the contributing processes are manifold and their interplay is non-trivial. All technical details needed in order to calculate the NLO EW contributions to the hadronic cross section for the abovementioned processes are given within this dissertation. This includes appropriate regularization and renormalization prescriptions and a proper treatment of mass singularities in order to get ultraviolet finite and infrared and collinear safe observables. Squark-squark production consists of 36 processes and the same amount for anti-squark- anti-squark production. The tree-level EW contributions of O(α s α+α 2 ) and the NLO EW contributions are calculated for all processes. Depending on the flavor and chirality of the produced squarks, many interferences between EW-mediated and QCD-mediated diagrams give non-zero contributions at tree-level and NLO EW. While the tree-level EW contributions to the integrated cross section can reach the 20% level, the NLO EW corrections typically lower the LO prediction by a few percent. Sbottom-anti-sbottom pair production exhibits specific features like left-right mixing and the renormalization of the sbottom sector which has to be chosen with care in order to get reliable predictions. In addition, Yukawa couplings get enhanced for large values of tan β with the related need of resummation. This renders the computation of the electroweak contributions substantially different from the corresponding computations for squark-anti- squark and stop-anti-stop production. The tree-level EW

  19. The contribution of next generation sequencing to epilepsy genetics

    DEFF Research Database (Denmark)

    Møller, Rikke S.; Dahl, Hans A.; Helbig, Ingo

    2015-01-01

    During the last decade, next generation sequencing technologies such as targeted gene panels, whole exome sequencing and whole genome sequencing have led to an explosion of gene identifications in monogenic epilepsies including both familial epilepsies and severe epilepsies, often referred to as ...

  20. The contribution of second-order processes to (3He, n) calculations

    International Nuclear Information System (INIS)

    Brissaud, I.

    1978-01-01

    The reactions 90 Zr, 116 Cd( 3 He, n) have been analysed by adding two second-order processes to the usual one-step DWBA calculations: sequential stripping or inelastic transition followed by double stripping. These second-order contributions increase the cross sections, especially for 90 Zr, and improve the shape of the angular distribution for 116 Cd. It shows that such second-order processes cannot be omitted in the analysis of two-particle stripping reactions. (author)

  1. Next-to-leading order QCD corrections to the decay of Higgs to vector meson and Z boson

    Science.gov (United States)

    Sun, Qing-Feng; Wang, An-Min

    2018-02-01

    The exclusive decay of the Higgs boson to a vector meson (J/ψ or Υ(1S)) and Z boson is studied in this work. The decay amplitudes are separated into two parts in a gauge invariant manner. The first part comes from the direct coupling of the Higgs boson to the charm (bottom) quark and the other from the HZZ* or the loop-induced HZ γ* vertexes in the standard model. While the branching ratios from the direct channel are much smaller than those of the indirect channel, their interference terms give nontrivial contributions. We further calculate the QCD radiative corrections to both channels, which reduce the total branching ratios by around 20% for both (J/ψ or Υ(1S)) production. Our results provide a possible chance to check the SM predictions of the {{Hc}}\\bar{{{c}}}({{Hb}}\\bar{{{b}}}) coupling and to seek for hints of new physics at the High Luminosity LHC or future hadron colliders. Supported by National Natural Science Foundation of China (11375168)

  2. Jet calculus beyond leading logarithms

    International Nuclear Information System (INIS)

    Kalinowski, J.; Konishi, K.; Taylor, T.R.

    1981-01-01

    It is shown that the evolution of hadronic jets produced in hard processes can be studied in terms of a simple parton branching picture, beyond the leading log approximation of QCD. The jet calculus is generalized to any given order of logs (but always to all orders of αsub(s)). We discuss the general structure of the formalism. Universality of jet evolution is discussed. We consider also a jet calorimetry measure and the multiplicity distribution of final states in a form which allows a systematic improvement of approximation. To the next-to-leading order, we prove the finiteness and elucidate the scheme dependence of parton subprocess probabilities. The physical inclusive cross section is shown to be scheme independent: next-to-leading results for e + e - → q (nonsinglet) + X agree with those of Curci and others. (orig.)

  3. Direct CP violation in KL→π0e+e- beyond leading logarithms

    International Nuclear Information System (INIS)

    Buras, A.J.; Lautenbacher, Markus E.; Misiak, Mikolaj; Muenz, Manfred

    1994-01-01

    We analyze the direct CP violation in the rare decay K L →π 0 e + e - with QCD effects taken into account consistently in the next-to-leading order. We calculate the two-loop mixing between the four-quark ΔS=1 operators and the operator Q 7V =(sd) V-A (ee) V in the NDR and HV renormalization schemes. Using the known two-loop anomalous dimension matrix of the four-quark operators, we find that the coefficient C 7V (μ) depends only very weakly on μ, renormalization scheme and Λ MS . The next-to-leading QCD corrections enhance the direct CP violating contribution over its leading order estimate so that it remains dominant in spite of the recent decrease of vertical stroke V ub /V cb vertical stroke and vertical stroke V cb vertical stroke . We expect typically BR(K L →π 0 e + e - ) dir ∼6x10 -12 , although values as high as 10 -11 are not yet excluded. ((orig.))

  4. The complete NLO corrections to dijet hadroproduction

    Science.gov (United States)

    Frederix, R.; Frixione, S.; Hirschi, V.; Pagani, D.; Shao, H.-S.; Zaro, M.

    2017-04-01

    We study the production of jets in hadronic collisions, by computing all contributions proportional to α S n α m , with n + m = 2 and n + m = 3. These correspond to leading and next-to-leading order results, respectively, for single-inclusive and dijet observables in a perturbative expansion that includes both QCD and electroweak effects. We discuss issues relevant to the definition of hadronic jets in the context of electroweak corrections, and present sample phenomenological predictions for the 13-TeV LHC. We find that both the leading and next-to-leading order contributions largely respect the relative hierarchy established by the respective coupling-constant combinations.

  5. The complete NLO corrections to dijet hadroproduction

    Energy Technology Data Exchange (ETDEWEB)

    Frederix, R. [Physik Department T31, Technische Universität München,James-Franck-Str. 1, D-85748 Garching (Germany); Frixione, S. [INFN - Sezione di Genova,Via Dodecaneso 33, I-16146, Genoa (Italy); Hirschi, V. [SLAC, National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, CA 94025-7090 (United States); Pagani, D. [Physik Department T31, Technische Universität München,James-Franck-Str. 1, D-85748 Garching (Germany); Centre for Cosmology, Particle Physics and Phenomenology (CP3),Université Catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Shao, H.-S. [TH Department, CERN, CH-1211 Geneva 23 (Switzerland); Zaro, M. [Sorbonne Universités, UPMC University Paris 06,UMR 7589, LPTHE, F-75005, Paris (France); CNRS,UMR 7589, LPTHE, F-75005, Paris (France)

    2017-04-12

    We study the production of jets in hadronic collisions, by computing all contributions proportional to α{sub S}{sup n}α{sup m}, with n+m=2 and n+m=3. These correspond to leading and next-to-leading order results, respectively, for single-inclusive and dijet observables in a perturbative expansion that includes both QCD and electroweak effects. We discuss issues relevant to the definition of hadronic jets in the context of electroweak corrections, and present sample phenomenological predictions for the 13-TeV LHC. We find that both the leading and next-to-leading order contributions largely respect the relative hierarchy established by the respective coupling-constant combinations.

  6. Decoupling of charm beyond leading order

    OpenAIRE

    Knechtli, Francesco; Korzec, Tomasz; Leder, Björn; Moir, Graham

    2017-01-01

    We study the effective theory of decoupling of a charm quark at low energies. We do this by simulating a model, QCD with two mass-degenerate charm quarks. At leading order the effective theory is a pure gauge theory. By computing ratios of hadronic scales we have direct access to the power corrections in the effective theory. We show that these corrections follow the expected leading behavior, which is quadratic in the inverse charm quark mass.

  7. Next-to-leading order corrections to e+e-→W+W-Z and e+e-→ZZZ

    International Nuclear Information System (INIS)

    Boudjema, Fawzi; Hao Sun; Ninh, Le Duc; Weber, Marcus M.

    2010-01-01

    We calculate the one-loop electroweak corrections to e + e - →W + W - Z and e + e - →ZZZ and analyze their impacts on both the total cross section and some key distributions. These processes are important for the measurements of the quartic couplings of the massive gauge bosons which can be a window on the mechanism of spontaneous symmetry breaking. We find that even after subtracting the leading QED corrections, the electroweak corrections can still be large, especially as the energy increases. We compare and implement different methods of dealing with potential instabilities in the routines pertaining to the loop integrals. For the real corrections we apply a dipole subtraction formalism and compare it to a phase-space slicing method.

  8. Spectator scattering at NLO in non-leptonic B decays: Leading penguin amplitudes

    International Nuclear Information System (INIS)

    Beneke, M.; Jaeger, S.

    2007-01-01

    We complete the computation of the 1-loop (α s 2 ) corrections to hard spectator scattering in non-leptonic B decays at leading power in Λ/m b by evaluating the penguin amplitudes. This extends the knowledge of these next-to-next-to-leading-order contributions in the QCD factorization formula for B decays to a much wider class of final states, including all pseudoscalar-pseudoscalar, pseudoscalar-vector, and longitudinally polarized vector-vector final states, except final states with η or η ' mesons. The new 1-loop correction is significant for the colour-suppressed amplitudes, but turns out to be strongly suppressed for the leading QCD penguin amplitude α 4 p . We provide numerical values of the phenomenological P/T and C/T amplitude ratios for the ππ, πρ and ρρ final states, and discuss corrections to several relations between electroweak penguin and tree amplitudes

  9. The QED contribution to J/{psi} plus light hadrons production at B-factories

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhi-Guo [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Wang, Jian-Xiong [Chinese Academy of Science, Beijing (China). Inst. of High Energy Physics; Chinese Academy of Science, Beijing (China). Theoretical Physics Center for Science Facilities

    2013-01-15

    To understand the direct J/{psi}+X{sub non-c} {sub anti} {sub c} production mechanism in e{sup +}e{sup -} annihilation, in this work, we propose to measure the inclusive J/{psi} plus light hadrons (LH) production at B-factories and present a detailed study on its QED production due to {psi}(2S) feed-down, where the {psi}(2S) are produced in e{sup +}e{sup -}{yields}{psi}(2S)+{gamma} and e{sup +}e{sup -}{yields}{psi}(2S) +f anti f, f = lepton, lightquark, and QED contribution to direct J/{psi}+q anti q production with q = u, d, s quark. We find that the QED contribution is huge in the whole phase space region, but can be reduced largely and is in the same order as the QCD contribution when a suitable cut on the angel {theta}{sub J/{psi}} between J/{psi} and the e{sup +}e{sup -} beam is made. In this way, the cross section of J/{psi} + LH QCD production % which was predicted theoretical at next-to-leading order QCD together with relativistic correction, can be obtained by subtracting the QED contribution from the experimental measurement on inclusive J/{psi} plus light hadrons. To help to remove the QED background, we also calculate the angular and momentum distribution of J/{psi} in the QED contribution.

  10. The angular ordering in soft-gluon emission

    International Nuclear Information System (INIS)

    Tesima, K.

    1987-01-01

    The way to evaluate multi-parton cross-sections systematically is discussed. In the leading-double-log approximation in QCD, the successive emission of soft gluons is at successively smaller angles. The angular ordering, however, is violated in the next-to-leading order

  11. New heavy flavor contributions to DIS at the 3-loop order: different masses and nested topologies

    Energy Technology Data Exchange (ETDEWEB)

    Ablinger, Jakob; Schneider, Carsten [RISC - JKU Linz (Austria); Bluemlein, Johannes; Wissbrock, Fabian [DESY (Germany)

    2013-07-01

    We present recent results on the heavy flavor Wilson coefficients of the deep-inelastic structure function F{sub 2} stemming from diagrams which contain both charm- and bottom-quarks. Starting at 3-loop order these contributions cannot be incorporated into the variable flavor number scheme (VFSN). We also present new results on the computation of diagrams of more advanced topologies (knotted ladder, Benz, and others) which have been obtained via the method of hyperlogarithms. They require the use of extensions to the basic formalism leading to the more general class of generalized hyperlogarithms, resp. the associated nested sums. Both the x- and Mellin N-space representations are discussed.

  12. Leading-order calculation of hadronic contributions to the Muon g-2 using the Dyson-Schwinger approach

    Science.gov (United States)

    Goecke, Tobias; Fischer, Christian S.; Williams, Richard

    2011-10-01

    We present a calculation of the hadronic vacuum polarisation (HVP) tensor within the framework of Dyson-Schwinger equations. To this end we use a well-established phenomenological model for the quark-gluon interaction with parameters fixed to reproduce hadronic observables. From the HVP tensor we compute both the Adler function and the HVP contribution to the anomalous magnetic moment of the muon, aμ. We find aμHVP = 6760 ×10-11 which deviates about two percent from the value extracted from experiment. Additionally, we make comparison with a recent lattice determination of aμHVP and find good agreement within our approach. We also discuss the implications of our result for a corresponding calculation of the hadronic light-by-light scattering contribution to aμ.

  13. Leading-order calculation of hadronic contributions to the Muon g-2 using the Dyson-Schwinger approach

    International Nuclear Information System (INIS)

    Goecke, Tobias; Fischer, Christian S.; Williams, Richard

    2011-01-01

    We present a calculation of the hadronic vacuum polarisation (HVP) tensor within the framework of Dyson-Schwinger equations. To this end we use a well-established phenomenological model for the quark-gluon interaction with parameters fixed to reproduce hadronic observables. From the HVP tensor we compute both the Adler function and the HVP contribution to the anomalous magnetic moment of the muon, a μ . We find a μ HVP =6760x10 -11 which deviates about two percent from the value extracted from experiment. Additionally, we make comparison with a recent lattice determination of a μ HVP and find good agreement within our approach. We also discuss the implications of our result for a corresponding calculation of the hadronic light-by-light scattering contribution to a μ .

  14. TMD parton distributions based on three-body decay functions in NLL order of QCD

    International Nuclear Information System (INIS)

    Tanaka, Hidekazu

    2015-01-01

    Three-body decay functions in space-like parton branches are implemented to evaluate transverse-momentum-dependent (TMD) parton distribution functions in the next-to-leading logarithmic (NLL) order of quantum chromodynamics (QCD). Interference contributions due to the next-to-leading-order terms are taken into account for the evaluation of the transverse momenta in initial state parton radiations. Some properties of the decay functions are also examined. As an example, the calculated results are compared with those evaluated by an algorithm proposed in [M. A. Kimber, A. D. Martin, and M. G. Ryskin, Eur. Phys. J. C 12, 655 (2000)], [M. A. Kimber, A. D. Martin, and M. G. Ryskin, Phys. Rev. D 63, 11402 (2001)], [G. Watt, A. D. Martin, and M. G. Ryskin, Eur. Phys. J. C 31, 73 (2003)], and [A. D. Martin, M. G. Ryskin, and G. Watt, Eur. Phys. J. C 66, 167 (2010)], in which the TMD parton distributions are defined based on the k t -factorization method with angular ordering conditions due to interference effects

  15. Next-generation science information network for leading-edge applications

    International Nuclear Information System (INIS)

    Urushidani, S.; Matsukata, J.

    2008-01-01

    High-speed networks are definitely essential tools for leading-edge applications in many research areas, including nuclear fusion research. This paper describes a number of advanced features in the Japanese next-generation science information network, called SINET3, and gives researchers clues on the uses of advanced high-speed network for their applications. The network services have four categories, multiple layer transfer, enriched virtual private network, enhanced quality-of-service, and bandwidth on demand services, and comprise a versatile service platform. The paper also describes the network architecture and advanced networking capabilities that enable economical service accommodation and flexible network resource assignment as well as effective use of Japan's first 40-Gbps lines

  16. Next-generation science information network for leading-edge applications

    Energy Technology Data Exchange (ETDEWEB)

    Urushidani, S. [National Institute of Informatics, 2-1-2 Hitotsubashi Chiyoda-ku, Tokyo 101-8430 (Japan)], E-mail: urushi@nii.ac.jp; Matsukata, J. [National Institute of Informatics, 2-1-2 Hitotsubashi Chiyoda-ku, Tokyo 101-8430 (Japan)

    2008-04-15

    High-speed networks are definitely essential tools for leading-edge applications in many research areas, including nuclear fusion research. This paper describes a number of advanced features in the Japanese next-generation science information network, called SINET3, and gives researchers clues on the uses of advanced high-speed network for their applications. The network services have four categories, multiple layer transfer, enriched virtual private network, enhanced quality-of-service, and bandwidth on demand services, and comprise a versatile service platform. The paper also describes the network architecture and advanced networking capabilities that enable economical service accommodation and flexible network resource assignment as well as effective use of Japan's first 40-Gbps lines.

  17. Degenerate Perturbation Theory for Electronic g Tensors: Leading-Order Relativistic Effects.

    Science.gov (United States)

    Rinkevicius, Zilvinas; de Almeida, Katia Julia; Oprea, Cornel I; Vahtras, Olav; Ågren, Hans; Ruud, Kenneth

    2008-11-11

    A new approach for the evaluation of the leading-order relativistic corrections to the electronic g tensors of molecules with a doublet ground state is presented. The methodology is based on degenerate perturbation theory and includes all relevant contributions to the g tensor shift up to order O(α(4)) originating from the one-electron part of the Breit-Pauli Hamiltonian-that is, it allows for the treatment of scalar relativistic, spin-orbit, and mixed corrections to the spin and orbital Zeeman effects. This approach has been implemented in the framework of spin-restricted density functional theory and is in the present paper, as a first illustration of the theory, applied to study relativistic effects on electronic g tensors of dihalogen anion radicals X2(-) (X = F, Cl, Br, I). The results indicate that the spin-orbit interaction is responsible for the large parallel component of the g tensor shift of Br2(-) and I2(-), and furthermore that both the leading-order scalar relativistic and spin-orbit corrections are of minor importance for the perpendicular component of the g tensor in these molecules since they effectively cancel each other. In addition to investigating the g tensors of dihalogen anion radicals, we also critically examine the importance of various relativistic corrections to the electronic g tensor of linear molecules with Σ-type ground states and present a two-state model suitable for an approximate estimation of the g tensor in such molecules.

  18. Leading-order calculation of hadronic contributions to the Muon g-2 using the Dyson-Schwinger approach

    Energy Technology Data Exchange (ETDEWEB)

    Goecke, Tobias [Institut fuer Theoretische Physik, Universitaet Giessen, 35392 Giessen (Germany); Fischer, Christian S., E-mail: christian.fischer@theo.physik.uni-giessen.de [Institut fuer Theoretische Physik, Universitaet Giessen, 35392 Giessen (Germany); Gesellschaft fuer Schwerionenforschung mbH, Planckstr. 1, D-64291 Darmstadt (Germany); Williams, Richard [Dept. Fisica Teorica I, Universidad Complutense, 28040 Madrid (Spain)

    2011-10-13

    We present a calculation of the hadronic vacuum polarisation (HVP) tensor within the framework of Dyson-Schwinger equations. To this end we use a well-established phenomenological model for the quark-gluon interaction with parameters fixed to reproduce hadronic observables. From the HVP tensor we compute both the Adler function and the HVP contribution to the anomalous magnetic moment of the muon, a{sub {mu}}. We find a{sub {mu}}{sup HVP}=6760x10{sup -11} which deviates about two percent from the value extracted from experiment. Additionally, we make comparison with a recent lattice determination of a{sub {mu}}{sup HVP} and find good agreement within our approach. We also discuss the implications of our result for a corresponding calculation of the hadronic light-by-light scattering contribution to a{sub {mu}.}

  19. Scrutinizing the top quark at lepton colliders with higher orders. From fixed order to resummation and matching

    International Nuclear Information System (INIS)

    Nejad, Bijan Chokoufe

    2017-01-01

    In this thesis, we present detailed studies of top-pair production with (t anti tH) and without association of a Higgs boson (t anti t) in e"+e"- collisions. These processes are of utmost interest for the top physics program of future lepton colliders. They allow in particular a precise measurement of the top quark mass and the Yukawa coupling. For this purpose, we present predictions for off-shell t anti t and t anti tH production including non-resonant and interference contributions up to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD). This allows for top-quark phenomenology in the continuum at an unprecedented level of accuracy. We show that off-shell effects and NLO QCD corrections for these processes do not factorize in general. In particular, we present the Yukawa coupling dependence of the cross section, which receives negative corrections due to sizable interference terms. We also add a discussion of p_T resummation in the form of combining the NLO prediction via POWHEG matching with the parton shower and the associated uncertainties. To handle large Coulomb singularities at threshold, we include the next-to-leading log (NLL) threshold resummation derived in nonrelativistic QCD (NRQCD) for t anti t production. This results in a form factor that we incorporate in a fully relativistic cross section, which is factorized within an extended double-pole approximation. Fixed-order QCD corrections are included, hereby, for the top decay. We combine this calculation with the full fixed-order QCD results at NLO for W"+W"-b anti b production to obtain a computation that is not only valid at threshold but smoothly interpolates to the continuum. This allows us to present the first prediction for exclusive W"+W"-b anti b production at a lepton collider with a consistent matching between the top-antitop threshold and continuum regions. This computation is not only required to describe the intermediate energy region but also allows to study

  20. Contribution of 210Pb bremsstrahlung to the background of lead shielded gamma spectrometers

    International Nuclear Information System (INIS)

    Mrda, D.; Bikit, I.; Veskovic, M.; Forkapic, S.

    2007-01-01

    Lead, which is often used as a shielding material, contains 210 Pb (T 1/2 =22.3 y). The 46.54 keV γ-intensity of 210 Pb can be easily reduced by an inner lining, but the bremsstrahlung caused by the β-decay of its daughter, 210 Bi, with a maximal electron energy of 1.16 MeV, will contribute to the gamma detector background. The spectrum of this bremsstrahlung is calculated by numerically fitting the β-spectrum and integrating the Koch-Motz formula. The absorption of the bremsstrahlung in the lead and detection efficiencies for the HPGe detector are calculated by the effective solid angle algorithm, using corrections for the photopeak/Compton ratio of cross-sections in Ge. By comparison with the measured background spectrum, it is shown that, for the lead with 25 Bq/kg of 210 Pb up to 500 keV of gamma spectrum, the bremsstrahlung contribution to the background is about 20% for our surface-based detector system. Also, we compared our calculations with a Monte Carlo simulation of another detector system with a shield containing 1 Bq/kg of 210 Pb and found that our analytical method gives a value of roughly two times higher than the Monte Carlo one for the total bremsstrahlung contribution. The quality of the analytical semi-empirical method is proved by the reasonable agreement with the experimental results published

  1. Two-loop corrections to the triple Higgs boson production cross section

    Energy Technology Data Exchange (ETDEWEB)

    Florian, Daniel de [International Center for Advanced Studies (ICAS), ECyT-UNSAM, Campus Miguelete, 25 de Mayo y Francia (1650) Buenos Aires (Argentina); Mazzitelli, Javier [International Center for Advanced Studies (ICAS), ECyT-UNSAM, Campus Miguelete, 25 de Mayo y Francia (1650) Buenos Aires (Argentina); Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland)

    2017-02-22

    In this paper we compute the QCD corrections for the triple Higgs boson production cross section via gluon fusion, within the heavy-top approximation. We present, for the first time, analytical results for the next-to-leading order corrections, and also compute the soft and virtual contributions of the next-to-next-to-leading order cross section. We provide predictions for the total cross section and the triple Higgs invariant mass distribution. We find that the QCD corrections are large at both perturbative orders, and that the scale uncertainty is substantially reduced when the second order perturbative corrections are included.

  2. Second-order contributions to relativistic time delay in the parametrized post-Newtonian formalism

    International Nuclear Information System (INIS)

    Richter, G.W.; Matzner, R.A.

    1983-01-01

    Using a parametrized expansion of the solar metric to second order in the Newtonian potential, we calculate the relativistic delay in the round-trip travel time of a radar signal reflected from a nearby planet. We find that one second-order contribution to the delay is on the order of ten nanoseconds, which is comparable to the uncertainties in present-day experiments involving the Viking spacecraft

  3. Studies on mathematical modeling of the leaching process in order to efficiently recover lead from the sulfate/oxide lead paste.

    Science.gov (United States)

    Buzatu, Traian; Ghica, Gabriel Valeriu; Petrescu, Ionuţ Mircea; Iacob, Gheorghe; Buzatu, Mihai; Niculescu, Florentina

    2017-02-01

    Increasing global lead consumption has been mainly supported by the acid battery manufacturing industry. As the lead demand will continue to grow, to provide the necessary lead will require an efficient approach to recycling lead acid batteries. In this paper was performed a mathematical modeling of the process parameters for lead recovery from spent lead-acid batteries. The results of the mathematical modeling compare well with the experimental data. The experimental method applied consists in the solubilisation of the sulfate/oxide paste with sodium hydroxide solutions followed by electrolytic processing for lead recovery. The parameters taken into considerations were NaOH molarity (4M, 6M and 8M), solid/liquid ratio - S/L (1/10, 1/30 and 1/50) and temperature (40°C, 60°C and 80°C). The optimal conditions resulted by mathematical modeling of the electrolytic process of lead deposition from alkaline solutions have been established by using a second-order orthogonal program, in order to obtain a maximum efficiency of current without exceeding an imposed energy specific consumption. The optimum value for the leaching recovery efficiency, obtained through mathematical modeling, was 89.647%, with an error of δ y =3.623 which leads to a maximum recovery efficiency of 86.024%. The optimum values for each variable that ensure the lead extraction efficiency equal to 89.647% are the following: 3M - NaOH, 1/35 - S/L, 70°C - temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Extra dimension searches at hadron colliders to next-to-leading order-QCD

    Science.gov (United States)

    Kumar, M. C.; Mathews, Prakash; Ravindran, V.

    2007-11-01

    The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton distribution functions are studied. Uncertainties arising from the error on experimental data are estimated using the MRST parton distribution functions.

  5. Fixation of theoretical ambiguities in the improved fits to $xF_{3}$ CCFR data at the next-to-next-to-leading order and beyond

    CERN Document Server

    Kataev, A L; Sidorov, A V

    2003-01-01

    Using new theoretical information on the NNLO and N$^3$LO perturbative QCD corrections to renormalization-group quantities of odd $xF_3$ Mellin moments, we perform the reanalysis of the CCFR'97 data for $xF_3$ structure function. The fits were done without and with twist-4 power suppressed terms. Theoretical questions of applicability of the renormalon-inspired large-$\\beta_0$ approximation for estimating NNLO and N$^3$LO terms in the coefficient functions of odd $xF_3$ moments and even non-singlet moments of $F_2$ are considered. The comparison with [1/1] Pad\\'e estimates is presented. The small $x$ behaviour of the phenomenological model for $xF_3$ is compared with available theoretical predictions. The $x$-shape of the twist-4 contributions is determined. Indications of oscillating-type behaviour of $h(x)$ are obtained from more detailed NNLO fits when only statistical uncertainties are taken into account. The scale-dependent uncertainties of $\\alpha_s(M_Z)$ are analyzed. The obtained NNLO and approximate ...

  6. The role of leading twist operators in the Regge and Lorentzian OPE limits

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Miguel S. [Centro de Física do Porto, Departamento de Física e Astronomia,Faculdade de Ciências da Universidade do Porto,Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Drummond, James [CERN,Geneva 23 (Switzerland); School of Physics and Astronomy, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom); LAPTH, CNRS et Université de Savoie,F-74941 Annecy-le-Vieux Cedex (France); Gonçalves, Vasco; Penedones, João [Centro de Física do Porto, Departamento de Física e Astronomia,Faculdade de Ciências da Universidade do Porto,Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2014-04-14

    We study two kinematical limits, the Regge limit and the Lorentzian OPE limit, of the four-point function of the stress-tensor multiplet in Super Yang-Mills at weak coupling. We explain how both kinematical limits are controlled by the leading twist operators. We use the known expression of the four-point function up to three loops, to extract the pomeron residue at next-to-leading order. Using this data and the known form of pomeron spin up to next-to-leading order, we predict the behaviour of the four-point function in the Regge limit at higher loops. Specifically, we determine the leading log behaviour at any loop order and the next-to-leading log at four loops. Finally, we check the consistency of our results with conformal Regge theory. This leads us to predict the behaviour around J=1 of the OPE coefficient of the spin J leading twist operator in the OPE of two chiral primary operators.

  7. Scaling violations beyond the leading order

    CERN Document Server

    Petronzio, R

    1981-01-01

    The authors are concerned with the explicit construction of a method which generalizes beyond leading order the simple probabilistic interpretation of leading scaling violations. The results obtained in this language allow to predict the evolution with the variation of external invariants not only of 'space-like' processes, where the off- shell partons starting the hard interaction have space-like four momenta, like in the case of deep inelastic scattering or Drell-Yan, but also of 'time-like' processes, like the one-particle inclusive e /sup +/e/sup -/ annihilation, where the partons acting in the fragmentation functions have 'time-like' off-shell invariant masses. (9 refs).

  8. Higher twist contributions to deep-inelastic structure functions

    International Nuclear Information System (INIS)

    Bluemlein, J.; Boettcher, H.

    2008-07-01

    We report on a recent extraction of the higher twist contributions to the deep inelastic structure functions F ep,ed 2 (x,Q 2 ) in the large x region. It is shown that the size of the extracted higher twist contributions is strongly correlated with the higher order corrections applied to the leading twist part. A gradual lowering of the higher twist contributions going from NLO to N 4 LO is observed, where in the latter case only the leading large x terms were considered. (orig.)

  9. Electroweak two-loop corrections to the effective weak mixing angle

    International Nuclear Information System (INIS)

    Awramik, Malgorzata; Czakon, Michal; Freitas, Ayres

    2006-01-01

    Recently exact results for the complete electroweak two-loop contributions to the effective weak mixing angle were published. This paper illustrates the techniques used for this computation, in particular the methods for evaluating the loop diagrams and the proper definition of Z-pole observables at next-to-next-to-leading order. Numerical results are presented in terms of simple parametrization formulae and compared in detail with a previous result of an expansion up to next-to-leading order in the top-quark mass. Finally, an estimate of the remaining theoretical uncertainties from unknown higher-order corrections is given

  10. The heavy quarkonium spectrum at order $m\\alpha_{s}^{5}\\ln\\alpha_{s}$

    CERN Document Server

    Brambilla, Nora; Soto, Joan; Vairo, Antonio

    1999-01-01

    We compute the complete leading-log terms of the next-to-next-to-next-to-leading-order corrections to potential NRQCD. As a by-product we obtain the leading logs at $O(m\\alpha_s^5)$ in the heavy quarkonium spectrum. These leading logs, when $\\Lambda_{QCD} \\ll m\\alpha_s^2$, give the complete $O(m\\alpha_s^5 \\ln \\alpha_s)$ corrections to the heavy quarkonium spectrum.

  11. Order-disorder phenomenon in lead scandium tantalate

    International Nuclear Information System (INIS)

    Wang, H.C.; Schulze, W.A.

    1990-01-01

    Lead scandium tatalate (PST) is a ferroelectric relaxor with the perovskite structure of A(B'B double-prime)O 3 . By suitable heat treatment, the B-site cations can be brought from a structurally disordered state into various degree of ordering. The degree of ordering is strongly affected by the amount of vacancies present in the materials. To suppress PbO loss during the sintering or annealing process, a PbO-rich atmosphere is supplied by materials having high PbO vapor pressure, such as PbZrO 3 . For PST ceramics with nearly zero weight loss, very long annealing times and higher annealing temperatures are required for ordering. The higher PbO-loss materials are found to be easily ordered. The introduction of a reducing atmosphere during annealing enhances the ordering process. The ordering process is characterized quantitatively by X-ray diffraction and qualitatively by Raman spectroscopy

  12. Average gluon and quark jet multiplicities at higher orders

    Energy Technology Data Exchange (ETDEWEB)

    Bolzoni, Paolo; Kniehl, Bernd A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Kotikov, Anatoly V. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Joint Institute of Nuclear Research, Moscow (Russian Federation). Bogoliubov Lab. of Theoretical Physics

    2013-05-15

    We develop a new formalism for computing and including both the perturbative and nonperturbative QCD contributions to the scale evolution of average gluon and quark jet multiplicities. The new method is motivated by recent progress in timelike small-x resummation obtained in the MS factorization scheme. We obtain next-to-next-to-leading-logarithmic (NNLL) resummed expressions, which represent generalizations of previous analytic results. Our expressions depend on two nonperturbative parameters with clear and simple physical interpretations. A global fit of these two quantities to all available experimental data sets that are compatible with regard to the jet algorithms demonstrates by its goodness how our results solve a longstanding problem of QCD. We show that the statistical and theoretical uncertainties both do not exceed 5% for scales above 10 GeV. We finally propose to use the jet multiplicity data as a new way to extract the strong-coupling constant. Including all the available theoretical input within our approach, we obtain {alpha}{sub s}{sup (5)}(M{sub Z})=0.1199{+-}0.0026 in the MS scheme in an approximation equivalent to next-to-next-to-leading order enhanced by the resummations of ln(x) terms through the NNLL level and of ln Q{sup 2} terms by the renormalization group, in excellent agreement with the present world average.

  13. arXiv Leading Pomeron Contributions and the TOTEM Data at 13 TeV

    CERN Document Server

    Broilo, M.; Menon, M.J.

    The recent data by the TOTEM Collaboration on $\\sigma_{tot}$ and $\\rho$ at 13 TeV, have shown agreement with a leading Odderon contribution at the highest energies, as demonstrated in the very recent analysis by Martynov and Nicolescu (MN). In order to investigate the same dataset by means of Pomeron dominance, we introduce a general class of forward scattering amplitude, with leading contributions even under crossing, associated with simple, double and triple poles in the complex angular momentum plane. For the lower energy region, we consider the usual non-degenerated Regge trajectories, with even and odd symmetry. The analytic connection between $\\sigma_{tot}$ and $\\rho$ is obtained by means of dispersion relations and we carry out fits to $pp$ and $\\bar{p}p$ data in the interval $\\sqrt{s}=5$ GeV - 13 TeV; following MN we consider only the TOTEM data at the LHC energy region. From the fits, we conclude that the general analytic model, as well as some particular cases representing standard parameterizations...

  14. Universality of non-leading logarithmic contributions in transverse-momentum distributions

    CERN Document Server

    Catani, S; Grazzini, Massimiliano

    2001-01-01

    We consider the resummation of the logarithmic contributions to the region of small transverse momenta in the distributions of high-mass systems (lepton pairs, vector bosons, Higgs particles, ....) produced in hadron collisions. We point out that the resummation formulae that are usually used to compute the distributions in perturbative QCD involve process-dependent form factors and coefficient functions. We present a new universal form of the resummed distribution, in which the dependence on the process is embodied in a single perturbative factor. The new form simplifies the calculation of non-leading logarithms at higher perturbative orders. It can also be useful to systematically implement process-independent non-perturbative effects in transverse-momentum distributions. We also comment on the dependence of these distributions on the factorization and renormalization scales.

  15. Electroweak Higgs boson production in the standard model effective field theory beyond leading order in QCD

    Energy Technology Data Exchange (ETDEWEB)

    Degrande, Celine [CERN, Theory Division, Geneva 23 (Switzerland); Fuks, Benjamin [Sorbonne Universites, UPMC Univ. Paris 06, Paris (France); CNRS, Paris (France); Mawatari, Kentarou [Universite Grenoble-Alpes, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Vrije Universiteit Brussel, Theoretische Natuurkunde and IIHE/ELEM, International Solvay Institutes, Brussels (Belgium); Mimasu, Ken [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); Universite catholique de Louvain, Centre for Cosmology, Particle Physics and Phenomenology (CP3), Louvain-la-Neuve (Belgium); Sanz, Veronica [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)

    2017-04-15

    We study the impact of dimension-six operators of the standard model effective field theory relevant for vector-boson fusion and associated Higgs boson production at the LHC. We present predictions at the next-to-leading order accuracy in QCD that include matching to parton showers and that rely on fully automated simulations. We show the importance of the subsequent reduction of the theoretical uncertainties in improving the possible discrimination between effective field theory and standard model results, and we demonstrate that the range of the Wilson coefficient values allowed by a global fit to LEP and LHC Run I data can be further constrained by LHC Run II future results. (orig.)

  16. Determination of the strong coupling constant αs(MZ2) under regardment of completely resummed leading and next-to-leading logarithms. Analysis of global event variables measured in hadronic Z decays

    International Nuclear Information System (INIS)

    Wehr, A.

    1994-06-01

    The value of the strong coupling constant α s is determined from a combined analysis of the global event shape variables thrust, heavy jet mass and total and wide jet broadening. The extraction of α s includes the full calculation of O(α s 2 ) terms and leading and next-to-leading logarithms resummed to all orders of α s . The analysis is based on data taken with the DELPHI detector at LEP during 1991 and 1992. The dependence of the result on the detailed matching of the resummed and fixed order terms is studied. The result from the combined theory is compared with values coming from a pure NLLA analysis and as pure O(α s 2 ) analysis, respectively. It is found that the inclusion of the resummed logarithms allows the description of the data in the two jet range and reduces the scale dependence of α s (M Z 2 ) compared to pure O(α s 2 ) theory. The value using the combined NLLA+O(α s 2 ) theory at the scale μ 2 =M Z 2 is α S (M Z 2 )=0.118±0.007. The running of α s is measured from the 1991 data in an energy range from 88.5 to 93.7 GeV. The slope of α s obtained at the Z peak is dα s /dQ/ Q=Mz =-(2.9±2.8)x10 -4 GeV -1 . This value is compatible with QCD and exludes an abelian gluon model with more than two standard deviations. (orig.)

  17. Dexterity Test Data Contribute To Reduction in Leaded Glovebox Glove Use

    International Nuclear Information System (INIS)

    Cournoyer, M.E.; Lawton, C.M.; Castro, A.M.; Costigan, S.A.; Schreiber, S.

    2009-01-01

    Programmatic operations at the Los Alamos National Laboratory Plutonium Facility (TA-55) involve working with various amounts of plutonium and other highly toxic, alpha-emitting materials. The spread of radiological contamination on surfaces, airborne contamination, and excursions of contaminants into the operator's breathing zone are prevented through the use of a variety of gloveboxes. Using an integrated approach, controls have been developed and implemented through an efficient Glovebox Glove Integrity Program. A key element of this program is to consider measures that lower the overall risk of glovebox operations. Line management who own glovebox processes through this program make decisions on which type of glovebox gloves (hereafter referred to as gloves), the weakest component of this safety-significant system, would perform best in these aggressive environments. As Low as Reasonably Achievable considerations must be balanced with glove durability and worker dexterity, both of which affect the final overall risk of the operation. In the past, lead-loaded (leaded) gloves made from Hypalon R were the primary glove for programmatic operations at TA-55. Replacing leaded gloves with unleaded gloves for certain operations would lower the overall risk as well as reduce the amount of mixed transuranic waste. This effort contributes to the Los Alamos National Laboratory Continuous Improvement Program by improving the efficiency, cost-effectiveness, and formality of glovebox operations. In this report, the pros and cons of wearing leaded gloves, the effect of leaded gloves versus unleaded gloves on task performance using standard dexterity tests, the justification for switching from leaded to unleaded gloves, and the pollution prevention benefits of this dramatic change in the glovebox system are presented. (authors)

  18. Analytic treatment of leading-order parton evolution equations: Theory and tests

    International Nuclear Information System (INIS)

    Block, Martin M.; Durand, Loyal; McKay, Douglas W.

    2009-01-01

    We recently derived an explicit expression for the gluon distribution function G(x,Q 2 )=xg(x,Q 2 ) in terms of the proton structure function F 2 γp (x,Q 2 ) in leading-order (LO) QCD by solving the LO Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equation for the Q 2 evolution of F 2 γp (x,Q 2 ) analytically, using a differential-equation method. We showed that accurate experimental knowledge of F 2 γp (x,Q 2 ) in a region of Bjorken x and virtuality Q 2 is all that is needed to determine the gluon distribution in that region. We rederive and extend the results here using a Laplace-transform technique, and show that the singlet quark structure function F S (x,Q 2 ) can be determined directly in terms of G from the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi gluon evolution equation. To illustrate the method and check the consistency of existing LO quark and gluon distributions, we used the published values of the LO quark distributions from the CTEQ5L and MRST2001 LO analyses to form F 2 γp (x,Q 2 ), and then solved analytically for G(x,Q 2 ). We find that the analytic and fitted gluon distributions from MRST2001LO agree well with each other for all x and Q 2 , while those from CTEQ5L differ significantly from each other for large x values, x > or approx. 0.03-0.05, at all Q 2 . We conclude that the published CTEQ5L distributions are incompatible in this region. Using a nonsinglet evolution equation, we obtain a sensitive test of quark distributions which holds in both LO and next-to-leading order perturbative QCD. We find in either case that the CTEQ5 quark distributions satisfy the tests numerically for small x, but fail the tests for x > or approx. 0.03-0.05--their use could potentially lead to significant shifts in predictions of quantities sensitive to large x. We encountered no problems with the MRST2001LO distributions or later CTEQ distributions. We suggest caution in the use of the CTEQ5 distributions.

  19. Dexterity tests data contribute to reduction in leaded glovebox gloves use

    Energy Technology Data Exchange (ETDEWEB)

    Cournoyer, Michael E [Los Alamos National Laboratory; Lawton, Cindy M [Los Alamos National Laboratory; Castro, Amanda M [Los Alamos National Laboratory

    2008-01-01

    Programmatic operations at the Los Alamos National Laboratory Plutonium Facility (TA-55) involve working with various amounts of plutonium and other highly toxic, alphaemitting materials. The spread of radiological contamination on surfaces and airborne contamination and excursions of contaminants into the operator's breathing zone are prevented through the use of a variety of gloveboxes. Through an integrated approach, controls have been developed and implemented through an efficient Glovebox Glove Integrity Program (GGJP). A key element of this program is to consider measures that lower the overall risk of glovebox operations. Line management owning glovebox processes through this program make decisions on which type of glovebox gloves (the weakest component of this safety significant system) would perform in these aggressive environments. As Low As Reasonably Achievable (ALARA) considerations must be balanced with glove durability and worker dexterity, both of which affect the final overall risk of the operation. In the past, lead-loaded (leaded) glovebox gloves made from Hypalon(reg.) had been the workhorse of programmatic operations at TA-55. Replacing leaded gloves with unleaded gloves for certain operations would lower the overall risk as well as reduced the amount of mixed TRU waste. This effort contributes to Los Alamos National Laboratory Continuous Improvement Program by improving the efficiency, cost effectiveness, and formality of glovebox operations. In the following report, the pros and cons of wearing leaded glovebox gloves, the effect of leaded gloves versus unleaded gloves on task performance using standard dexterity tests, the justification for switching from leaded to unleaded gloves, and pollution prevention benefits of this dramatic change in the glovebox system are presented.

  20. Next generation light water reactors

    International Nuclear Information System (INIS)

    Omoto, Akira

    1992-01-01

    In the countries where the new order of nuclear reactors has ceased, the development of the light water reactors of new type has been discussed, aiming at the revival of nuclear power. Also in Japan, since it is expected that light water reactors continue to be the main power reactor for long period, the technology of light water reactors of next generation has been discussed. For the development of nuclear power, extremely long lead time is required. The light water reactors of next generation now in consideration will continue to be operated till the middle of the next century, therefore, they must take in advance sufficiently the needs of the age. The improvement of the way men and the facilities should be, the simple design, the flexibility to the trend of fuel cycle and so on are required for the light water reactors of next generation. The trend of the development of next generation light water reactors is discussed. The construction of an ABWR was started in September, 1991, as No. 6 plant in Kashiwazaki Kariwa Power Station. (K.I.)

  1. Scrutinizing the top quark at lepton colliders with higher orders. From fixed order to resummation and matching

    Energy Technology Data Exchange (ETDEWEB)

    Nejad, Bijan Chokoufe

    2017-07-12

    In this thesis, we present detailed studies of top-pair production with (t anti tH) and without association of a Higgs boson (t anti t) in e{sup +}e{sup -} collisions. These processes are of utmost interest for the top physics program of future lepton colliders. They allow in particular a precise measurement of the top quark mass and the Yukawa coupling. For this purpose, we present predictions for off-shell t anti t and t anti tH production including non-resonant and interference contributions up to next-to-leading order (NLO) in perturbative quantum chromodynamics (QCD). This allows for top-quark phenomenology in the continuum at an unprecedented level of accuracy. We show that off-shell effects and NLO QCD corrections for these processes do not factorize in general. In particular, we present the Yukawa coupling dependence of the cross section, which receives negative corrections due to sizable interference terms. We also add a discussion of p{sub T} resummation in the form of combining the NLO prediction via POWHEG matching with the parton shower and the associated uncertainties. To handle large Coulomb singularities at threshold, we include the next-to-leading log (NLL) threshold resummation derived in nonrelativistic QCD (NRQCD) for t anti t production. This results in a form factor that we incorporate in a fully relativistic cross section, which is factorized within an extended double-pole approximation. Fixed-order QCD corrections are included, hereby, for the top decay. We combine this calculation with the full fixed-order QCD results at NLO for W{sup +}W{sup -}b anti b production to obtain a computation that is not only valid at threshold but smoothly interpolates to the continuum. This allows us to present the first prediction for exclusive W{sup +}W{sup -}b anti b production at a lepton collider with a consistent matching between the top-antitop threshold and continuum regions. This computation is not only required to describe the intermediate energy

  2. The Agent of extracting Internet Information with Lead Order

    Science.gov (United States)

    Mo, Zan; Huang, Chuliang; Liu, Aijun

    In order to carry out e-commerce better, advanced technologies to access business information are in need urgently. An agent is described to deal with the problems of extracting internet information that caused by the non-standard and skimble-scamble structure of Chinese websites. The agent designed includes three modules which respond to the process of extracting information separately. A method of HTTP tree and a kind of Lead algorithm is proposed to generate a lead order, with which the required web can be retrieved easily. How to transform the extracted information structuralized with natural language is also discussed.

  3. An approach to next step device optimisation

    International Nuclear Information System (INIS)

    Salpietro, E.

    2000-01-01

    The requirements for ITER EDA were to achieve ignition with a good safety margin, and controlled long inductive burn. These requirements lead to a big device, which requested a too ambitious step to be undertaken by the world fusion community. More realistic objectives for a next step device shall be to demonstrate the net production of energy with a high energy gain factor (Q) and a high boot strap current fraction (>60%) which is required for a Fusion Power Plant (FPP). The Next Step Device (NSD) shall also allow operation flexibility in order to explore a large range of plasma parameters to find out the optimum concept for the fusion power plant prototype. These requirements could be too demanding for one single device and could probably be better explored in a strongly integrated world programme. The cost of one or more devices is the decisive factor for the choice of the fusion power development programme strategy. The plasma elongation and triangularity have a strong impact in the cost of the device and are limited by the plasma vertical position control issue. The distance between plasma separatrix and the toroidal field conductor does not vary a lot between devices. It is determined by the sum of the distance between first wall-plasma sepratrix and the thickness of the nuclear shield required to protect the toroidal field coil insultation. The thickness of the TF coil is determined by the allowable stresses and superconducting characteristics. The outer radius of the central solenoid is the result of an optimisation to provide the magnetic flux to inductively drive the plasma. Therefore, in order to achieve the objectives for Q and boot-strap current fractions at the minimum cost, the plasma aspect ratio and magnetic field value shall be determined. The paper will present the critical issues for the next device and will make considerations on the optimal way to proceed towards the realisation of the fusion power plant

  4. Severe Neonatal Hyperbilirubinemia; Causes and Contributing Factors Leading to Exchange Transfusion at Ghaem Hospital in Mashhad

    Directory of Open Access Journals (Sweden)

    Farhad Heydarian

    2010-12-01

    Full Text Available Hyperbilirubinemia is common in neonates; it can have a serious rising course. Due to its critical morbidity called "kernicterus", severe neonatal hyperbilirubinemia causes which lead to exchange transfusion, should be clarified. This descriptive cross sectional study performed with reviewing of files of 118 neonates weighting 2kg and more who had exchange transfusion in pediatrics ward at Ghaem training hospital in Mashhad from April 2004 to March 2007. Among 118 patients, 75 (63.6% were male, and 43 patients (36.4% were female. The most common cause of exchange transfusion was ABO incompatibility (38.1%. In order of frequency, unknown etiology (25.4%, Rh incompatibility (16.1% with no immune hydrops, Sepsis(8.5%, urinary tract infection (5.1% and others (3.4% (Including Crigler-Najjar and cephalohematoma were next ones. Vaginal delivery and exclusive breast feeding were detected as associated factors. Mean serum bilirubin levels was 28.7 mg/dl (SD. 9.2 ABO incompatibility. ABO incompatibility was the main cause of exchange transfusion. Male gender, vaginal delivery and exclusive breast feeding were seen more among patients who need to be exchanged. So in case of ABO incompatibility especially when delivery route is vaginal, newborns should be visited soon again after early discharge from hospital.

  5. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    International Nuclear Information System (INIS)

    Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Zink, A.; Aghasyan, M.; Birsa, R.; Dalla Torre, S.; Levorato, S.; Santos, C.; Sozzi, F.; Tessaro, S.; Tessarotto, F.; Akhunzyanov, R.; Alexeev, G.D.; Anfimov, N.V.; Anosov, V.; Efremov, A.; Gavrichtchouk, O.P.; Guskov, A.; Ivanshin, Yu.; Kisselev, Yu.; Kouznetsov, O.M.; Kroumchtein, Z.V.; Meshcheryakov, G.V.; Nagaytsev, A.; Olshevsky, A.G.; Orlov, I.; Peshekhonov, D.V.; Rossiyskaya, N.S.; Rybnikov, A.; Savin, I.A.; Selyunin, A.; Shevchenko, O.Yu.; Slunecka, M.; Smolik, J.; Tasevsky, M.; Zavada, P.; Zemlyanichkina, E.; Alexeev, M.G.; Amoroso, A.; Balestra, F.; Chiosso, M.; Gnesi, I.; Grasso, A.; Ivanov, A.; Kotzinian, A.M.; Longo, R.; Parsamyan, B.; Takekawa, S.; Andrieux, V.; Boer, M.; Curiel, Q.; Ferrero, A.; Fuchey, E.; Hose, N. d'; Kunne, F.; Levillain, M.; Magnon, A.; Marchand, C.; Neyret, D.; Platchkov, S.; Seder, E.; Thibaud, F.; Augustyniak, W.; Klimaszewski, K.; Kurek, K.; Marianski, B.; Sandacz, A.; Szabelski, A.; Sznajder, P.; Austregesilo, A.; Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Huber, S.; Kraemer, M.; Krinner, F.; Paul, S.; Uhl, S.; Azevedo, C.D.R.; Pereira, F.; Veloso, J.; Badelek, B.; Barth, J.; Hahne, D.; Klein, F.; Pretz, J.; Schmieden, H.; Beck, R.; Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Ketzer, B.; Mikhasenko, M.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Mallot, G.K.; Schoenning, K.; Bodlak, M.; Finger, M.; Finger, M. Jr.; Matousek, J.; Pesek, M.; Roskot, M.; Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M.; Bradamante, F.; Bressan, A.; Dasgupta, S.; Makke, N.; Martin, A.; Sbrizzai, G.; Schiavon, P.; Buechele, M.; Fischer, H.; Gorzellik, M.; Grussenmeyer, T.; Heinsius, F.H.; Herrmann, F.; Joerg, P.; Koenigsmann, K.; Kremser, P.; Nowak, W.D.; Regali, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Szameitat, T.; Wolbeek, J. ter; Chang, W.C.; Hsieh, C.Y.; Sawada, T.; Choi, I.; Giordano, F.; Grosse Perdekamp, M.; Heitz, R.; Kulinich, Y.; Makins, N.; Montuenga, P.; Peng, J.C.; Riedl, C.; Cicuttin, A.; Crespo, M.L.; Dasgupta, S.S.; Dhara, L.; Sarkar, S.; Sinha, L.; Denisov, O.Yu.; Maggiora, A.; Panzieri, D.; Tosello, F.; Donskov, S.V.; Khaustov, G.V.; Khokhlov, Yu.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D.; Doshita, N.; Hashimoto, R.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Nukazuka, G.; Suzuki, H.; Duic, V.; Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Rychter, A.; Zaremba, K.; Ziembicki, M.; Fresne von Hohenesche, N. du; Harrach, D. von; Kabuss, E.; Nerling, F.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M.

    2017-01-01

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q"2 > 1 (GeV/c)"2. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised "6LiD target. By analysing the full range in hadron transverse momentum p_T, the different p_T-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g is evaluated at leading order in pQCD at a hard scale of μ"2 = left angle Q"2 right angle = 3 (GeV/c)"2. It is determined in three intervals of the nucleon momentum fraction carried by gluons, x_g, covering the range 0.04 < x_g < 0.28 and does not exhibit a significant dependence on x_g. The average over the three intervals, left angle Δg/g right angle = 0.113 ± 0.038_(_s_t_a_t_._) ± 0.036_(_s_y_s_t_._) at left angle x_g right angle ∼ 0.10, suggests that the gluon polarisation is positive in the measured x_g range. (orig.)

  6. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Zink, A. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Aghasyan, M.; Birsa, R.; Dalla Torre, S.; Levorato, S.; Santos, C.; Sozzi, F.; Tessaro, S.; Tessarotto, F. [INFN, Trieste (Italy); Akhunzyanov, R.; Alexeev, G.D.; Anfimov, N.V.; Anosov, V.; Efremov, A.; Gavrichtchouk, O.P.; Guskov, A.; Ivanshin, Yu.; Kisselev, Yu.; Kouznetsov, O.M.; Kroumchtein, Z.V.; Meshcheryakov, G.V.; Nagaytsev, A.; Olshevsky, A.G.; Orlov, I.; Peshekhonov, D.V.; Rossiyskaya, N.S.; Rybnikov, A.; Savin, I.A.; Selyunin, A.; Shevchenko, O.Yu.; Slunecka, M.; Smolik, J.; Tasevsky, M.; Zavada, P.; Zemlyanichkina, E. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Alexeev, M.G. [University of Turin, Department of Physics, Turin (Italy); Amoroso, A.; Balestra, F.; Chiosso, M.; Gnesi, I.; Grasso, A.; Ivanov, A.; Kotzinian, A.M.; Longo, R.; Parsamyan, B.; Takekawa, S. [University of Turin, Department of Physics, Turin (Italy); INFN, Turin (Italy); Andrieux, V.; Boer, M.; Curiel, Q.; Ferrero, A.; Fuchey, E.; Hose, N. d' ; Kunne, F.; Levillain, M.; Magnon, A.; Marchand, C.; Neyret, D.; Platchkov, S.; Seder, E.; Thibaud, F. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Augustyniak, W.; Klimaszewski, K.; Kurek, K.; Marianski, B.; Sandacz, A.; Szabelski, A.; Sznajder, P. [National Centre for Nuclear Research, Warsaw (Poland); Austregesilo, A.; Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Huber, S.; Kraemer, M.; Krinner, F.; Paul, S.; Uhl, S. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Azevedo, C.D.R.; Pereira, F.; Veloso, J. [University of Aveiro, Department of Physics, Aveiro (Portugal); Badelek, B. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Barth, J.; Hahne, D.; Klein, F.; Pretz, J.; Schmieden, H. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Beck, R.; Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Ketzer, B.; Mikhasenko, M. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bedfer, Y. [CERN, Geneva 23 (Switzerland); CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Bernhard, J. [CERN, Geneva 23 (Switzerland); Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Bicker, K. [CERN, Geneva 23 (Switzerland); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Bielert, E.R.; Mallot, G.K.; Schoenning, K. [CERN, Geneva 23 (Switzerland); Bodlak, M.; Finger, M.; Finger, M. Jr.; Matousek, J.; Pesek, M.; Roskot, M. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M. [LIP, Lisbon (Portugal); Bradamante, F.; Bressan, A.; Dasgupta, S.; Makke, N.; Martin, A.; Sbrizzai, G.; Schiavon, P. [University of Trieste, Department of Physics, Trieste (Italy); INFN, Trieste (Italy); Buechele, M.; Fischer, H.; Gorzellik, M.; Grussenmeyer, T.; Heinsius, F.H.; Herrmann, F.; Joerg, P.; Koenigsmann, K.; Kremser, P.; Nowak, W.D.; Regali, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Szameitat, T.; Wolbeek, J. ter [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Chang, W.C.; Hsieh, C.Y.; Sawada, T. [Academia Sinica, Institute of Physics, Taipei (China); Choi, I.; Giordano, F.; Grosse Perdekamp, M.; Heitz, R.; Kulinich, Y.; Makins, N.; Montuenga, P.; Peng, J.C.; Riedl, C. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, IL (United States); Cicuttin, A.; Crespo, M.L. [INFN, Trieste (Italy); Abdus Salam ICTP, Trieste (Italy); Dasgupta, S.S.; Dhara, L.; Sarkar, S.; Sinha, L. [Matrivani Institute of Experimental Research and Education, Calcutta (India); Denisov, O.Yu.; Maggiora, A.; Panzieri, D.; Tosello, F. [INFN, Turin (Italy); Donskov, S.V.; Khaustov, G.V.; Khokhlov, Yu.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D. [State Scientific Center Institute for High Energy Physics of National Research Center ' Kurchatov Institute' , Protvino (Russian Federation); Doshita, N.; Hashimoto, R.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Nukazuka, G.; Suzuki, H. [Yamagata University, Yamagata (Japan); Duic, V. [University of Trieste, Department of Physics, Trieste (Italy); Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Rychter, A.; Zaremba, K.; Ziembicki, M. [Warsaw University of Technology, Institute of Radioelectronics, Warsaw (Poland); Fresne von Hohenesche, N. du; Harrach, D. von; Kabuss, E.; Nerling, F.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Collaboration: COMPASS Collaboration; and others

    2017-04-15

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q{sup 2} > 1 (GeV/c){sup 2}. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised {sup 6}LiD target. By analysing the full range in hadron transverse momentum p{sub T}, the different p{sub T}-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g is evaluated at leading order in pQCD at a hard scale of μ{sup 2} = left angle Q{sup 2} right angle = 3 (GeV/c){sup 2}. It is determined in three intervals of the nucleon momentum fraction carried by gluons, x{sub g}, covering the range 0.04 < x{sub g} < 0.28 and does not exhibit a significant dependence on x{sub g}. The average over the three intervals, left angle Δg/g right angle = 0.113 ± 0.038{sub (stat.)} ± 0.036{sub (syst.)} at left angle x{sub g} right angle ∼ 0.10, suggests that the gluon polarisation is positive in the measured x{sub g} range. (orig.)

  7. Taking the Lead in Science Education: Forging Next-Generation Science Standards. International Science Benchmarking Report. Appendix

    Science.gov (United States)

    Achieve, Inc., 2010

    2010-01-01

    This appendix accompanies the report "Taking the Lead in Science Education: Forging Next-Generation Science Standards. International Science Benchmarking Report," a study conducted by Achieve to compare the science standards of 10 countries. This appendix includes the following: (1) PISA and TIMSS Assessment Rankings; (2) Courses and…

  8. Next-to-leading order QCD corrections to five jet production at the LHC

    DEFF Research Database (Denmark)

    David Badger, Simon; Biedermann, Benedikt; Uwer, Peter

    2014-01-01

    -to-two ratio and are promising candidates for future αs measurements. Furthermore, we present a detailed analysis of uncertainties related to parton distribution functions. The full color virtual matrix elements used in the computation were obtained with the NJet package [1], a publicly available library...

  9. The heavy-quark forward-backward asymmetry to order {alpha}{sup 2}{sub s}; Die Vorwaerts-Rueckwaerts-Asymmetrie fuer schwere Quarks zur Ordnung {alpha}{sup 2}{sub s}

    Energy Technology Data Exchange (ETDEWEB)

    Waninger, Karl Constantin

    2011-02-28

    The goal of this thesis was the computation of the forward-backward asymmetry in the e{sup +}e{sup -}-production of heavy quarks to next-to-next-to-leading order in QCD (NNLO-QCD). Final states comprising up to four partons contribute to the corrections of order {alpha}{sup 2}{sub s}. The two-parton contributions are known for a while. The novel part is the computation of the three- and four-parton contributions. One main task of these computation was to explicitly show the cancellation of the infrared singularities arising in many of the contributing expressions. The other task was to ensure a stable numerical evaluation of the forward-backward asymmetry. The ultraviolet-divergences of the one loop integrals in the three-parton contributions are removed using renormalized perturbation theory. The infrared-divergence in the the three-parton final state contribution to the symmetric and antisymmetric cross sections cancels when building the forward-backward asymmetry out of these cross sections. This has been shown explicitly in this thesis by performing a Laurent-expansion of the relevant differential cross sections around the singular point in phase space. The infrared-divergences in the second-order three-parton contribution to the forward-backward asymmetry arising in the loop integrals, which are regularized in d = 4 - 2{epsilon} dimensions are quantified by {epsilon}-poles of up to second order and proportional to the leading-order contribution to the observable. The symmetric and antisymmetric contributions to the four-parton final state exhibit one-parton and two-parton unresolved infrared-singularities. In this thesis a modified version of the dipole subtraction formalism has been used to show that the one-parton-unresolved singularities of the four-parton final state cancel the infrared-singularities in the loop integrals of the contributions from the three-parton final states. Identifying the points in the four-parton phase space corresponding to the two

  10. On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution

    International Nuclear Information System (INIS)

    Moch, S.; Vogt, A.

    2015-06-01

    We discuss the prescription for the Dirac matrix γ 5 in dimensional regularization used in most second- and third-order QCD calculations of collider cross sections. We provide an alternative implementation of this approach that avoids the use of an explicit form of γ 5 and of its (anti-) commutation relations in the most important case of no more than one γ 5 in each fermion trace. This treatment is checked by computing the third-order corrections to the structure functions F 2 and g 1 in charged-current deep-inelastic scattering with axial-vector couplings to the W-bosons. We derive the so far unknown third-order helicity-difference splitting function ΔP ns (2)s that contributes to the next-to-next-to-leading order (NNLO) evolution of the polarized valence quark distribution of the nucleon. This function is negligible at momentum fractions x>or similar 0.3 but relevant at x<<1.

  11. Soft and hard contributions to hard pion photoproduction

    International Nuclear Information System (INIS)

    Afanasev, Andrei; Carlson, Carl E.; Wahlquist, Christian

    2000-01-01

    Pion photoproduction at high transverse momentum supplements what can be learned in the standard probes of deep inelastic scattering and Drell-Yan processes. With polarized initial states there is sensitivity to the polarized gluon distribution, Δg, in leading order. This contrasts to other processes mentioned, which have no leading order gluon contribution. Additionally, in some kinematic regions the process occurs mainly due to pion production at short distances ('direct pion production', resulting in kinematically isolated pions), which gives sensitivity to the high-x valence quark distribution

  12. Order-disorder transition in conflicting dynamics leading to rank-frequency generalized beta distributions

    Science.gov (United States)

    Alvarez-Martinez, R.; Martinez-Mekler, G.; Cocho, G.

    2011-01-01

    The behavior of rank-ordered distributions of phenomena present in a variety of fields such as biology, sociology, linguistics, finance and geophysics has been a matter of intense research. Often power laws have been encountered; however, their validity tends to hold mainly for an intermediate range of rank values. In a recent publication (Martínez-Mekler et al., 2009 [7]), a generalization of the functional form of the beta distribution has been shown to give excellent fits for many systems of very diverse nature, valid for the whole range of rank values, regardless of whether or not a power law behavior has been previously suggested. Here we give some insight on the significance of the two free parameters which appear as exponents in the functional form, by looking into discrete probabilistic branching processes with conflicting dynamics. We analyze a variety of realizations of these so-called expansion-modification models first introduced by Wentian Li (1989) [10]. We focus our attention on an order-disorder transition we encounter as we vary the modification probability p. We characterize this transition by means of the fitting parameters. Our numerical studies show that one of the fitting exponents is related to the presence of long-range correlations exhibited by power spectrum scale invariance, while the other registers the effect of disordering elements leading to a breakdown of these properties. In the absence of long-range correlations, this parameter is sensitive to the occurrence of unlikely events. We also introduce an approximate calculation scheme that relates this dynamics to multinomial multiplicative processes. A better understanding through these models of the meaning of the generalized beta-fitting exponents may contribute to their potential for identifying and characterizing universality classes.

  13. Test of the Flavour Independence of $\\alpha_{s}$ using Next-to-Leading Order Calculations for Heavy Quarks

    CERN Document Server

    Abbiendi, G.; Alexander, G.; Allison, John; Altekamp, N.; Anderson, K.J.; Anderson, S.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Bechtluft, J.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Davis, R.; De Jong, S.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Fiedler, F.; Fierro, M.; Fleck, I.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gascon-Shotkin, S.M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gibson, V.; Gibson, W.R.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herndon, M.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lawson, I.; Layter, J.G.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Lui, D.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poffenberger, P.; Poli, B.; Polok, J.; Przybycien, M.; Quadt, A.; Rembser, C.; Rick, H.; Robertson, S.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Sittler, A.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Steuerer, J.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Wagner, A.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.

    1999-01-01

    We present a test of the flavour independence of the strong coupling constant for charm and bottom quarks with respect to light (uds) quarks, based on a hadronic event sample obtained with the OPAL detector at LEP. Five observables related to global event shapes were used to measure alpha_s in three flavour tagged samples (uds, c and b). The event shape distributions were fitted by Order(alpha_s**2) calculations of jet production taking into account mass effects for the c and b quarks. We find: = 0.997 +- 0.038(stat.) +- 0.030(syst.) +- 0.012(theory) and = 0.993 +- 0.008(stat.) +- 0.006(syst.) +- 0.011(theory) for the ratios alpha_s(charm)/alpha_s(uds) and alpha_s(b)/alpha_s(uds) respectively.

  14. Analyzing Bs - anti Bs mixing. Non-perturbative contributions to bag parameters from sum rules

    International Nuclear Information System (INIS)

    Mannel, T.; Pivovarov, A.A.; Russian Academy of Sciecnes, Moscow

    2007-03-01

    We use QCD sum rules to compute matrix elements of the ΔB=2 operators appearing in the heavy-quark expansion of the width difference of the B s mass eigenstates. Our analysis includes the leading-order operators Q and Q S , as well as the subleading operators R 2 and R 3 , which appear at next-to-leading order in the 1/m b expansion. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1-2%. (orig.)

  15. On Higgs-exchange DIS, physical evolution kernels and fourth-order splitting functions at large x

    International Nuclear Information System (INIS)

    Soar, G.; Vogt, A.; Vermaseren, J.A.M.

    2009-12-01

    We present the coefficient functions for deep-inelastic scattering (DIS) via the exchange of a scalar φ directly coupling only to gluons, such as the Higgs boson in the limit of a very heavy top quark and n f effectively massless light flavours, to the third order in perturbative QCD. The two-loop results are employed to construct the next-to-next-to-leading order physical evolution kernels for the system (F 2 ,F φ ) of flavour-singlet structure functions. The practical relevance of these kernels as an alternative to MS factorization is bedevilled by artificial double logarithms at small values of the scaling variable x, where the large top-mass limit ceases to be appropriate. However, they show an only single-logarithmic enhancement at large x. Conjecturing that this feature persists to the next order also in the present singlet case, the three-loop coefficient functions facilitate exact predictions (backed up by their particular colour structure) of the double-logarithmic contributions to the fourth-order singlet splitting functions, i.e., of the terms (1-x) a ln k (1-x) with k=4,5,6 and k=3,4,5, respectively, for the off-diagonal and diagonal quantities to all powers a in (1-x). (orig.)

  16. Leading order finite size effects with spins for inspiralling compact binaries

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Michele [Université Pierre et Marie Curie-Paris VI, CNRS-UMR 7095, Institut d’Astrophysique de Paris, 98 bis Boulevard Arago, 75014 Paris (France); Sorbonne Universités, Institut Lagrange de Paris, 98 bis Boulevard Arago, 75014 Paris (France); Steinhoff, Jan [Max-Planck-Institute for Gravitational Physics - Albert-Einstein-Institute,Am Mühlenberg 1, 14476 Potsdam-Golm (Germany); Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2015-06-10

    The leading order finite size effects due to spin, namely that of the cubic and quartic in spin interactions, are derived for the first time for generic compact binaries via the effective field theory for gravitating spinning objects. These corrections enter at the third and a half and fourth post-Newtonian orders, respectively, for rapidly rotating compact objects. Hence, we complete the leading order finite size effects with spin up to the fourth post-Newtonian accuracy. We arrive at this by augmenting the point particle effective action with new higher dimensional nonminimal coupling worldline operators, involving higher-order derivatives of the gravitational field, and introducing new Wilson coefficients, corresponding to constants, which describe the octupole and hexadecapole deformations of the object due to spin. These Wilson coefficients are fixed to unity in the black hole case. The nonminimal coupling worldline operators enter the action with the electric and magnetic components of the Weyl tensor of even and odd parity, coupled to even and odd worldline spin tensors, respectively. Moreover, the non relativistic gravitational field decomposition, which we employ, demonstrates a coupling hierarchy of the gravito-magnetic vector and the Newtonian scalar, to the odd and even in spin operators, respectively, which extends that of minimal coupling. This observation is useful for the construction of the Feynman diagrams, and provides an instructive analogy between the leading order spin-orbit and cubic in spin interactions, and between the leading order quadratic and quartic in spin interactions.

  17. Third-order nonlinearity of Er3+-doped lead phosphate glass

    Energy Technology Data Exchange (ETDEWEB)

    Santos, C. C. [Universidade Federal do Ceara, Ceara, Brazil; Guedes Da Silva, Ilde [ORNL; Siqueira, J. P. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Misoguti, L. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Zilio, S. C. [Instituto de Física de São Carlos, Universidade de São Paulo, Brazil; Boatner, Lynn A [ORNL

    2010-01-01

    The third-order optical susceptibility and dispersion of the linear refractive index of Er3+-doped lead phosphate glass were measured in the wavelength range between 400 and 1940 nm by using the spectrally resolved femtosecond Maker fringes technique. The nonlinear refractive index obtained from the third-order susceptibility was found to be five times higher than that of silica, indicating that Er3+-doped lead phosphate glass is a potential candidate to be used as the base component for the fabrication of photonic devices. For comparison purposes, the Z-scan technique was also employed to obtain the values of the nonlinear refractive index of E-doped lead phosphate glass at several wavelengths, and the values obtained using the two techniques agree to within 15%.

  18. Orientational and electronic contributions to the third-order susceptibilities of cryogenic liquids

    International Nuclear Information System (INIS)

    Kildal, H.; Brueck, S.R.J.

    1980-01-01

    Alternating current Kerr effect and third-harmonic generation (THG) are reported for the cryogenic liquids CO, O 2 , N 2 , and Ar pumped by CO 2 TEA laser radiation. The THG experiments measure the hyperpolarizability, while the Kerr effect measurements probe the total nonresonant third-order susceptibility chi/sup( 3 ), arising from both molecular orientation and electronic hyperpolarizability. The THG process in liquid CO is dominated by a vibrational two-photon resonant contribution for the CO 2 R(6) pump line at 9.35 μm. By studying the interference between the resonant and nonresonant contributions in liquid CO--O 2 mixtures the hyperpolarizability of liquid O 2 has been determined relative to the two-photon resonant chi/sup( 3 ) of liquid CO. These measurements give the first experimental confirmation for liquid media that the two-photon resonance contribution to polarized scattering consists of both narrow and broad linewidth components associated with, respectively, the isotropic and anisotropic Raman polarizabilities

  19. Heavy quark threshold dynamics in higher order

    Energy Technology Data Exchange (ETDEWEB)

    Piclum, J.H.

    2007-05-15

    In this work we discuss an important building block for the next-to-next-to-next-to leading order corrections to the pair production of top quarks at threshold. Specifically, we explain the calculation of the third order strong corrections to the matching coefficient of the vector current in non-relativistic Quantum Chromodynamics and provide the result for the fermionic part, containing at least one loop of massless quarks. As a byproduct, we obtain the matching coefficients of the axial-vector, pseudo-scalar and scalar current at the same order. Furthermore, we calculate the three-loop corrections to the quark renormalisation constants in the on-shell scheme in the framework of dimensional regularisation and dimensional reduction. Finally, we compute the third order strong corrections to the chromomagnetic interaction in Heavy Quark Effective Theory. The calculational methods are discussed in detail and results for the master integrals are given. (orig.)

  20. Leading-order classical Lagrangians for the nonminimal standard-model extension

    Science.gov (United States)

    Reis, J. A. A. S.; Schreck, M.

    2018-03-01

    In this paper, we derive the general leading-order classical Lagrangian covering all fermion operators of the nonminimal standard-model extension (SME). Such a Lagrangian is considered to be the point-particle analog of the effective field theory description of Lorentz violation that is provided by the SME. At leading order in Lorentz violation, the Lagrangian obtained satisfies the set of five nonlinear equations that govern the map from the field theory to the classical description. This result can be of use for phenomenological studies of classical bodies in gravitational fields.

  1. A second order QCD effect. quark-quark bremsstrahlung contribution to transverse momentum of lepton pairs

    International Nuclear Information System (INIS)

    Chaichian, M.; Hayashi, M.; Honkaranta, T.

    1980-01-01

    We consider in QCD the second order, in gluon-quark coupling constant, contribution of the quark-quark scatte-ring (bremsstrahlung) to the transverse momentum distribution of muon pairs produced in proton-proton collisions. In certain kinematical regions accesible to experimental tests, this contribution is quite large in comparison with the first order calculations. This happens for a specific choice of scale violating structure functions which fit the deep inelastic data. Thus the first order QCD calcula-tion alone is not conclusive in trying to fit the data -one must necessarily check the effect of the second order quark-quark scattering as compared with the first order quark-gluon and the quark-antiquark scattering. This remark concerns also the case when in the first order diagrams the effect of primordial transverse momentum of partons is included as well as the case when the first order is replaced by DDT type of formulae. Mass regularization and different prescriptions for the constant term in q → g + q vertex are considered. Results are presented for the energies √s=6.5, 27, 63, 800 GeV and are compared with experiment. Implications of these results for the detection of W +- -mesons via psub(T) distribution of their decay products μ +- in proton-proton collisions are mentioned. (author)

  2. Higher order light-cone distribution amplitudes of the Lambda baryon

    International Nuclear Information System (INIS)

    Liu, Yong-Lu; Huang, Ming-Qiu; Cui, Chun-Yu

    2014-01-01

    The improved light-cone distribution amplitudes (LCDAs) of the Λ baryon are examined on the basis of the QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of conformal spin accuracy with consideration of twist 6. The next leading order conformal expansion coefficients are related to the nonperturbative parameters defined by the local three-quark operator matrix elements with different Lorentz structures with a covariant derivative. The nonperturbative parameters are determined with the QCD sum rule method. The explicit expressions of the LCDAs are provided as the main results. (orig.)

  3. Higher order light-cone distribution amplitudes of the Lambda baryon

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yong-Lu; Huang, Ming-Qiu [National University of Defense Technology, College of Science, Hunan (China); Cui, Chun-Yu [Third Military Medical University, Department of Physics, School of Biomedical Engineering, Chongqing (China)

    2014-09-15

    The improved light-cone distribution amplitudes (LCDAs) of the Λ baryon are examined on the basis of the QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of conformal spin accuracy with consideration of twist 6. The next leading order conformal expansion coefficients are related to the nonperturbative parameters defined by the local three-quark operator matrix elements with different Lorentz structures with a covariant derivative. The nonperturbative parameters are determined with the QCD sum rule method. The explicit expressions of the LCDAs are provided as the main results. (orig.)

  4. Nonperturbative dynamics of hot non-Abelian gauge fields: Beyond the leading log approximation

    International Nuclear Information System (INIS)

    Arnold, Peter; Yaffe, Laurence G.

    2000-01-01

    Many aspects of high-temperature gauge theories, such as the electroweak baryon number violation rate, color conductivity, and the hard gluon damping rate, have previously been understood only at leading logarithmic order (that is, neglecting effects suppressed only by an inverse logarithm of the gauge coupling). We discuss how to systematically go beyond leading logarithmic order in the analysis of physical quantities. Specifically, we extend to next-to-leading-log order (NLLO) the simple leading-log effective theory due to Bo''deker that describes non-perturbative color physics in hot non-Abelian plasmas. A suitable scaling analysis is used to show that no new operators enter the effective theory at next-to-leading-log order. However, a NLLO calculation of the color conductivity is required, and we report the resulting value. Our NLLO result for the color conductivity can be trivially combined with previous numerical work by Moore to yield a NLLO result for the hot electroweak baryon number violation rate

  5. Dynamics of High-Order Spin-Orbit Couplings about Linear Momenta in Compact Binary Systems*

    International Nuclear Information System (INIS)

    Huang Li; Wu Xin; Huang Guo-Qing; Mei Li-Jie

    2017-01-01

    This paper relates to the post-Newtonian Hamiltonian dynamics of spinning compact binaries, consisting of the Newtonian Kepler problem and the leading, next-to-leading and next-to-next-to-leading order spin-orbit couplings as linear functions of spins and momenta. When this Hamiltonian form is transformed to a Lagrangian form, besides the terms corresponding to the same order terms in the Hamiltonian, several additional terms, third post-Newtonian (3PN), 4PN, 5PN, 6PN and 7PN order spin-spin coupling terms, yield in the Lagrangian. That means that the Hamiltonian is nonequivalent to the Lagrangian at the same PN order but is exactly equivalent to the full Lagrangian without any truncations. The full Lagrangian without the spin-spin couplings truncated is integrable and regular. Whereas it is non-integrable and becomes possibly chaotic when any one of the spin-spin terms is dropped. These results are also supported numerically. (paper)

  6. Two-flavor QCD correction to lepton magnetic moments at leading-order in the electromagnetic coupling

    Energy Technology Data Exchange (ETDEWEB)

    Dru Renner, Xu Feng, Karl Jansen, Marcus Petschlies

    2011-08-01

    We present a reliable nonperturbative calculation of the QCD correction, at leading-order in the electromagnetic coupling, to the anomalous magnetic moment of the electron, muon and tau leptons using two-flavor lattice QCD. We use multiple lattice spacings, multiple volumes and a broad range of quark masses to control the continuum, infinite-volume and chiral limits. We examine the impact of the commonly ignored disconnected diagrams and introduce a modification to the previously used method that results in a well-controlled lattice calculation. We obtain 1.513 (43) 10^-12, 5.72 (16) 10^-8 and 2.650 (54) 10^-6 for the leading-order QCD correction to the anomalous magnetic moment of the electron, muon and tau respectively, each accurate to better than 3%.

  7. Electronic Contributions to the Phonon Damping in Metals

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rune

    1968-07-15

    An imaginary part of the dielectric matrix is derived based on a first order perturbation expansion of the valence electron states in a local potential model of the crystal. The results are used to estimate the electronic contributions to the phonon damping in aluminum and lead. The corrections which have been obtained are of the same order of magnitude at small phonon momenta as the damping earlier calculated for the free electrons. However, the discrepancies between the theoretical and experimental results still remain. The major contribution to damping seems to originate in anharmonic effects, even at 80 deg K.

  8. Standard model Wilson coefficients for c → ul{sup +}l{sup -} transitions at next-to-leading order

    Energy Technology Data Exchange (ETDEWEB)

    Boer, Stefan de [TU Dortmund (Germany); Mueller, Bastian; Seidel, Dirk [Uni Siegen (Germany)

    2016-07-01

    The standard theoretical framework to deal with exclusive, weak decays of heavy mesons is the so-called weak effective Hamiltonian. It involves the short-distance Wilson coefficients, which depend on the renormalization scale μ. For specific calculations one has to evolve the Wilson coefficients down from the electroweak scale μ{sub W} to the typical mass scale of the decay under consideration. This is done by solving a renormalization group equation for the effective operator basis. In this talk the results of a consistent two-step running of the c → ul{sup +}l{sup -} Wilson coefficients are presented. This running involves the intermediate scale μ{sub b} (with μ{sub W} > μ{sub b} > μ{sub c}) where the bottom quark is integrated out. All the matching coefficients and anomalous dimensions are taken to the required order by generalizing and extending results from b → s or s → d transitions available in the literature.

  9. Contributing factors in self-poisoning leading to hospital admission in adolescents in northern Finland.

    Science.gov (United States)

    Liisanantti, Janne Henrik; Ala-Kokko, Tero Ilmari; Dunder, Teija Sinikka; Ebeling, Hanna Elina

    2010-07-01

    To evaluate the frequencies of different agents used in self-poisonings and acute factors contributing to intoxication of patients aged 12-18 years in northern Finland. Retrospective medical record review of all hospitalized patients during the period from January 1, 1991 to December 31, 2006. Cause of the admission, contributing factors, readmissions within one year. There were 309 admissions during the period, 54% were females. The leading cause of admission was alcohol, in 222 cases (71.8%). Hospitalizations related to alcohol consumption were associated with accidental poisoning in recreational use. There were no acute contributing factors in the majority of all patients. Over one-third of all intoxications were intentional self-harm, although previously diagnosed psychiatric diseases were rare. It is crucial to recognize adolescent psychiatric disorders in time and consult child and adolescent psychiatrist in case of poisoning.

  10. AgMIP: Next Generation Models and Assessments

    Science.gov (United States)

    Rosenzweig, C.

    2014-12-01

    Next steps in developing next-generation crop models fall into several categories: significant improvements in simulation of important crop processes and responses to stress; extension from simplified crop models to complex cropping systems models; and scaling up from site-based models to landscape, national, continental, and global scales. Crop processes that require major leaps in understanding and simulation in order to narrow uncertainties around how crops will respond to changing atmospheric conditions include genetics; carbon, temperature, water, and nitrogen; ozone; and nutrition. The field of crop modeling has been built on a single crop-by-crop approach. It is now time to create a new paradigm, moving from 'crop' to 'cropping system.' A first step is to set up the simulation technology so that modelers can rapidly incorporate multiple crops within fields, and multiple crops over time. Then the response of these more complex cropping systems can be tested under different sustainable intensification management strategies utilizing the updated simulation environments. Model improvements for diseases, pests, and weeds include developing process-based models for important diseases, frameworks for coupling air-borne diseases to crop models, gathering significantly more data on crop impacts, and enabling the evaluation of pest management strategies. Most smallholder farming in the world involves integrated crop-livestock systems that cannot be represented by crop modeling alone. Thus, next-generation cropping system models need to include key linkages to livestock. Livestock linkages to be incorporated include growth and productivity models for grasslands and rangelands as well as the usual annual crops. There are several approaches for scaling up, including use of gridded models and development of simpler quasi-empirical models for landscape-scale analysis. On the assessment side, AgMIP is leading a community process for coordinated contributions to IPCC AR6

  11. NNLOPS accurate associated HZ production with NLO decay ${\\rm{H}} \\to b\\bar{b}$ arXiv

    CERN Document Server

    Astill, William; Re, Emanuele; Zanderighi, Giulia

    We present a next-to-next-to-leading order (NNLO) accurate description of associated HZ production, followed by the Higgs boson decay into a pair of $b$-quarks treated at next-to-leading order (NLO), consistently matched to a parton shower (PS). The matching is achieved by performing reweighting of the $\\texttt{HZJ-MiNLO}$ events, using multi-dimensional distributions that are fully-differential in the HZ Born kinematics, to the NNLO results obtained by using the $\\texttt{MCFM-8.0}$ fixed-order calculation. Additionally we include the $gg\\to\\rm{HZ}$ contribution to the discussed process that appears at the $\\mathcal{O}(\\alpha_s^2)$. We present phenomenological results obtained for 13 TeV hadronic collisions.

  12. Global analysis of nuclear parton distribution functions at leading and next-to-leading order perturbative QCD

    Science.gov (United States)

    Pesznyak, Csilla

    The aim of the investigation is to give answer to some questions of the QC in the mega-voltage therapy for the sake of making the treatments more trouble-free. We investigated the terms of the usage of CT and PET/CT equipments in treatment planning that were made originally for diagnostic purposes. We compared the calculation algorithms of the Varian CadPlan(TM) and CMS XiORTM treatment planning systems (TPS) for photon and electron radiations of different energy. We also investigated the terms of usage of the PTW EPID QC PHANTOMRTM in the quality control of the EPID's and the portal images, as well. We laid down the terms in a protocol that make the diagnostic CT and PET/CT equipments capable for radiation treatment planning. The protocols should contain the exact patient setup, the tube voltage, detailed directions for use of patient immobilization tools, the review and use of the necessary QA/QC devices, the time consumption of the procedure, the frequency of controls and the worksheet to be used during the measurements. On the base of the measurements, it can be stated that on photon energies the superposition algorithm can be used for patient treatments in the case of the CMS XiORTM TPS while in the case of Varian CadPlan(TM) TPS the PBMB algorithm is the proper choice. It is not allowed to use the TPS without inhomogeneity correction. The CIRS Thorax IMRT phantom can be used for electron measurement only at higher than 10 MeV since only the Farmer chamber can be inserted into the holes of the phantom. On the base of the electron measurements, it can be stated that both planning systems give good results in soft tissue. In lung equivalent material the calculated values of the Varian CadPlan(TM) are in better agreement with the measured values, but the calculated values behind the bones are not accurate enough. In the QA/QC process the PTW EPID QC PHANTOMRTM is usable not only for the amorphous silicon EPID's but the image quality can be analysed on the video

  13. Two-flavor QCD correction to lepton magnetic moments at leading-order in the electromagnetic coupling

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xu [DESY, Zeuthen (Germany). NIC; Muenster Univ. (Germany). Inst. fuer Theoretische Physik; Jansen, Karl; Renner, Dru B. [DESY, Zeuthen (Germany). NIC; Petschlies, Marcus [Humboldt Univ. Berlin (Germany). Inst. fuer Physik

    2011-03-15

    We present a reliable nonperturbative calculation of the QCD correction, at leading-order in the electromagnetic coupling, to the anomalous magnetic moment of the electron, muon and tau leptons using two-flavor lattice QCD. We use multiple lattice spacings, multiple volumes and a broad range of quark masses to control the continuum, in nite-volume and chiral limits. We examine the impact of the commonly ignored disconnected diagrams and introduce a modi cation to the previously used method that results in a well-controlled lattice calculation. We obtain 1.513(43).10{sup -12}, 5.72(16).10{sup -8} and 2.650(54).10{sup -6} for the leading-order QCD correction to the anomalous magnetic moment of the electron, muon and tau respectively, each accurate to better than 3%. (orig.)

  14. The electric dipole form factor of the nucleon in chiral perturbation theory to sub-leading order

    NARCIS (Netherlands)

    Mereghetti, E.; de Vries, J.; Hockings, W. H.; Maekawa, C. M.; van Kolck, U.

    2011-01-01

    The electric dipole form factor (EDFF) of the nucleon stemming from the QCD (theta) over bar term and from the quark color-electric dipole moments is calculated in chiral perturbation theory to sub-leading order. This is the lowest order in which the isoscalar EDFF receives a calculable,

  15. Collinear limits beyond the leading order from the scattering equations

    Energy Technology Data Exchange (ETDEWEB)

    Nandan, Dhritiman; Plefka, Jan; Wormsbecher, Wadim [Institut für Physik and IRIS Adlershof, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, D-12489 Berlin (Germany)

    2017-02-08

    The structure of tree-level scattering amplitudes for collinear massless bosons is studied beyond their leading splitting function behavior. These near-collinear limits at sub-leading order are best studied using the Cachazo-He-Yuan (CHY) formulation of the S-matrix based on the scattering equations. We compute the collinear limits for gluons, gravitons and scalars. It is shown that the CHY integrand for an n-particle gluon scattering amplitude in the collinear limit at sub-leading order is expressed as a convolution of an (n−1)-particle gluon integrand and a collinear kernel integrand, which is universal. Our representation is shown to obey recently proposed amplitude relations in which the collinear gluons of same helicity are replaced by a single graviton. Finally, we extend our analysis to effective field theories and study the collinear limit of the non-linear sigma model, Einstein-Maxwell-Scalar and Yang-Mills-Scalar theory.

  16. Contribution of lead in wine to the total dietary intake of lead in humans with and without a meal

    International Nuclear Information System (INIS)

    Gulson, B.L.; Gray, B.; Mizon, K.J.; Patison, N.

    2000-01-01

    We have undertaken a case-control study using high precision lead isotopes to evaluate the contribution to blood lead when a normal quantity of wine is consumed with a meal and compared this with consumption under fasting conditions. White wine dosed with a 207 Pb tracer was consumed with a meal by a male subject and blood, urine and faeces monitored for up to four months. In addition to the spiked wine, the male subject and a female control subject residing in the same household consumed approximately equal proportions of unspiked red and white wine from the same vintage and vineyard over the four months. On a succeeding occasion, the male subject consumed 207 Pb-spiked wine under fasting conditions. As the 207 Pb/ 204 Pb ratio in blood and urine prior to the experiment was 15.48 compared with a value of 355 in the doped wine, changes in the 207 Pb/ 204 Pb ratio would be easily discernible. Over the four months of the trial, the results confirmed that there is a minimal uptake of lead from vine when consumed with food

  17. QCD leading order study of the J/ψ leptoproduction at HERA within the nonrelativistic QCD framework

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhan [Guizhou Minzu University, School of Science, Guiyang (China); Zhang, Hong-Fei [Third Military Medical University, Department of Physics, School of Biomedical Engineering, Chongqing (China)

    2017-11-15

    As indicated in our previous paper (Zhang and Sun in Phys. Rev. D 96:034002, 2017), the existing literature studying the J/ψ production in deeply inelastic scattering (DIS) in collinear factorisation is on the basis of a formalism that will lead to wrong results when the ranges of the transverse momentum or the rapidity of the J/ψ in the laboratory frame do not cover all values possible for them. In this paper, we present the renewed results for the J/ψ production in DIS at HERA within the nonrelativistic QCD framework at QCD leading order (LO). Three different sets of the long-distance matrix elements are employed for comparison. The predictions via the colour-singlet (CS) model at QCD LO are generally below the experimental data especially in the regions where perturbation theory are expected to work well, while the colour-octet contributions are of the same order of magnitude as the CS ones, however, in general make the agreement between theory and experiment better. (orig.)

  18. Role of Airborne Lead in Increased Body Burden of Lead in Hartford Children*

    Science.gov (United States)

    Lepow, Martha L.; Bruckman, Leonard; Rubino, Robert A.; Markowitz, Steven; Gillette, Marybeth; Kapish, Janet

    1974-01-01

    The ingestion of airborne lead fallout is the mechanism responsible for increased lead body burdens found in 10 urban Connecticut children. The mean indoor lead levels found in housedust was 11,000 μg/g; highest concentrations occurred on windowsills and in floor dust. The mean lead content of Hartford street dirt was 1,200 μg/g; levels were highest near the street and next to the buildings. The mean lead concentration of hand samples taken from the subject children was 2,400 μg/g; the mean weight of hand samples was 11 mg. The concentration of lead in dirt and househould dust was high enough to theoretically result in excessive lead accumulation in young children who are putting their dusty, dirty hands in their mouths during play. While we believe that lead emitted from automobiles contributes significantly to air, dirt and dust lead levels the environmental impact of reducing or eliminating lead from gasoline is not yet completely understood. PMID:4133903

  19. HQET at order 1/m. Pt. 3. Decay constants in the quenched approximation

    International Nuclear Information System (INIS)

    Blossier, Benoit; Della Morte, Michele; Garron, Nicolas; Edinburgh Univ.; Hippel, Georg von; DESY, Zeuthen; Mendes, Tereza; Sao Paulo Univ., Sao Carlos; Simma, Hubert; Sommer, Rainer

    2010-06-01

    We report on the computation of the B s meson decay constant in Heavy Quark Effective Theory on the lattice. The next to leading order corrections in the HQET expansion are included non-perturbatively. We estimate higher order contributions to be very small. The results are extrapolated to the continuum limit, the main systematic error affecting the computation is therefore the quenched approximation used here. The Generalized Eigenvalue Problem and the use of all-to-all propagators are important technical ingredients of our approach that allow to keep statistical and systematic errors under control. We also report on the decay constant f B s ' of the first radially excited state in the B s sector, computed in the static limit. (orig.)

  20. HQET at order 1/m. Pt. 3. Decay constants in the quenched approximation

    Energy Technology Data Exchange (ETDEWEB)

    Blossier, Benoit [CNRS et Paris-Sud XI Univ., Orsay (France). Lab. de Physique Theorique; Della Morte, Michele [Mainz Univ. (Germany). Inst. fuer Kernphysik; Garron, Nicolas [Universidad Autonoma de Madrid (Spain). Dept. de Fisica Teorica e Inst. de Fisica Teorica IFT-UAM/CSIC; Edinburgh Univ. (United Kingdom). SUPA, School of Physics; Hippel, Georg von [Mainz Univ. (Germany). Inst. fuer Kernphysik; DESY, Zeuthen (Germany). NIC; Mendes, Tereza [DESY, Zeuthen (Germany). NIC; Sao Paulo Univ., Sao Carlos (Brazil). IFSC; Simma, Hubert; Sommer, Rainer [DESY, Zeuthen (Germany). NIC

    2010-06-15

    We report on the computation of the B{sub s} meson decay constant in Heavy Quark Effective Theory on the lattice. The next to leading order corrections in the HQET expansion are included non-perturbatively. We estimate higher order contributions to be very small. The results are extrapolated to the continuum limit, the main systematic error affecting the computation is therefore the quenched approximation used here. The Generalized Eigenvalue Problem and the use of all-to-all propagators are important technical ingredients of our approach that allow to keep statistical and systematic errors under control. We also report on the decay constant f{sub B{sub s}{sup '}} of the first radially excited state in the B{sub s} sector, computed in the static limit. (orig.)

  1. A single-vendor and a single-buyer integrated inventory model with ordering cost reduction dependent on lead time

    Science.gov (United States)

    Vijayashree, M.; Uthayakumar, R.

    2017-09-01

    Lead time is one of the major limits that affect planning at every stage of the supply chain system. In this paper, we study a continuous review inventory model. This paper investigates the ordering cost reductions are dependent on lead time. This study addressed two-echelon supply chain problem consisting of a single vendor and a single buyer. The main contribution of this study is that the integrated total cost of the single vendor and the single buyer integrated system is analyzed by adopting two different (linear and logarithmic) types ordering cost reductions act dependent on lead time. In both cases, we develop effective solution procedures for finding the optimal solution and then illustrative numerical examples are given to illustrate the results. The solution procedure is to determine the optimal solutions of order quantity, ordering cost, lead time and the number of deliveries from the single vendor and the single buyer in one production run, so that the integrated total cost incurred has the minimum value. Ordering cost reduction is the main aspect of the proposed model. A numerical example is given to validate the model. Numerical example solved by using Matlab software. The mathematical model is solved analytically by minimizing the integrated total cost. Furthermore, the sensitivity analysis is included and the numerical examples are given to illustrate the results. The results obtained in this paper are illustrated with the help of numerical examples. The sensitivity of the proposed model has been checked with respect to the various major parameters of the system. Results reveal that the proposed integrated inventory model is more applicable for the supply chain manufacturing system. For each case, an algorithm procedure of finding the optimal solution is developed. Finally, the graphical representation is presented to illustrate the proposed model and also include the computer flowchart in each model.

  2. Exact calculation of three-body contact interaction to second order

    International Nuclear Information System (INIS)

    Kaiser, N.

    2012-01-01

    For a system of fermions with a three-body contact interaction the second-order contributions to the energy per particle anti E(k f ) are calculated exactly. The three-particle scattering amplitude in the medium is derived in closed analytical form from the corresponding two-loop rescattering diagram. We compare the (genuine) second-order three-body contribution to anti E(k f )∝k f 10 with the second-order term due to the density-dependent effective two-body interaction, and find that the latter term dominates. The results of the present study are of interest for nuclear many-body calculations where chiral three-nucleon forces are treated beyond leading order via a density-dependent effective two-body interaction. (orig.)

  3. Framework for Leading Next Generation Science Standards Implementation

    Science.gov (United States)

    Stiles, Katherine; Mundry, Susan; DiRanna, Kathy

    2017-01-01

    In response to the need to develop leaders to guide the implementation of the Next Generation Science Standards (NGSS), the Carnegie Corporation of New York provided funding to WestEd to develop a framework that defines the leadership knowledge and actions needed to effectively implement the NGSS. The development of the framework entailed…

  4. Higher order constraints on the Higgs production rate from fixed-target DIS data

    International Nuclear Information System (INIS)

    Alekhin, S.; Bluemlein, J.; Moch, S.

    2011-01-01

    The constraints of fixed-target DIS data in fits of parton distributions including QCD corrections to next-to-next-to leading order are studied. We point out a potential problem in the analysis of the NMC data which can lead to inconsistencies in the extracted value for α s (M Z ) and the gluon distribution at higher orders in QCD. The implications for predictions of rates for Standard Model Higgs boson production at hadron colliders are investigated. We conclude that the current range of excluded Higgs boson masses at the Tevatron appears to be much too large. (orig.)

  5. Lorentz-covariant coordinate-space representation of the leading hadronic contribution to the anomalous magnetic moment of the muon

    Science.gov (United States)

    Meyer, Harvey B.

    2017-09-01

    We present a Lorentz-covariant, Euclidean coordinate-space expression for the hadronic vacuum polarisation, the Adler function and the leading hadronic contribution to the anomalous magnetic moment of the muon. The representation offers a high degree of flexibility for an implementation in lattice QCD. We expect it to be particularly helpful for the quark-line disconnected contributions.

  6. Lorentz-covariant coordinate-space representation of the leading hadronic contribution to the anomalous magnetic moment of the muon

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Harvey B. [Mainz Univ., PRISMA Cluster of Excellence, Inst. fuer Kernphysik und Helmholtz Institut Mainz (Germany)

    2017-09-15

    We present a Lorentz-covariant, Euclidean coordinate-space expression for the hadronic vacuum polarisation, the Adler function and the leading hadronic contribution to the anomalous magnetic moment of the muon. The representation offers a high degree of flexibility for an implementation in lattice QCD. We expect it to be particularly helpful for the quark-line disconnected contributions. (orig.)

  7. The contribution of housing renovation to children’s blood lead levels: a cohort study

    Science.gov (United States)

    2013-01-01

    Background Routine renovation of older housing is a risk factor for childhood lead poisoning, but the contribution to children’s blood lead levels is poorly defined for children with lower exposure levels. Methods We examined a prospective cohort of 276 children followed from 6 to 24 months of age. We conducted surveys of renovation activities and residential lead hazards and obtained blood lead level (B-Pb) every six months. We analyzed B-Pb in a repeated measures design using a mixed effects linear model. Results Parent reported interior renovation ranged from 11 to 25% of housing units at the four, 6-month periods. In multivariable analysis, children whose housing underwent interior renovation had a 12% higher mean B-Pb by two years of age compared with children whose housing units were not renovated (p children in non-renovated housing, children whose housing units underwent renovation in the prior month had a 17% higher mean B-Pb at two years of age, whereas children whose housing renovation occurred in the prior 2–6 months had an 8% higher mean B-Pb. We also found an association between higher paint lead loading, measured using an X-ray fluorescence (XRF) based paint lead index, and child B-Pb (p = 0.02); for every 10 mg/cm2 increase in paint lead loading index there was a 7.5% higher mean childhood B-Pb. Conclusions In an analysis of data collected before the recent changes to Environmental Protection Agency’s Lead, Renovation, Repair and Painting Rule, routine interior housing renovation was associated with a modest increase in children’s B-Pb. These results are important for the provision of clinical advice, for housing and public health professionals, and for policymakers. PMID:23981571

  8. Critical spare parts ordering decisions using conditional reliability and stochastic lead time

    International Nuclear Information System (INIS)

    Godoy, David R.; Pascual, Rodrigo; Knights, Peter

    2013-01-01

    Asset-intensive companies face great pressure to reduce operation costs and increase utilization. This scenario often leads to over-stress on critical equipment and its spare parts associated, affecting availability, reliability, and system performance. As these resources impact considerably on financial and operational structures, the opportunity is given by demand for decision-making methods for the management of spare parts processes. We proposed an ordering decision-aid technique which uses a measurement of spare performance, based on the stress–strength interference theory; which we have called Condition-Based Service Level (CBSL). We focus on Condition Managed Critical Spares (CMS), namely, spares which are expensive, highly reliable, with higher lead times, and are not available in store. As a mitigation measure, CMS are under condition monitoring. The aim of the paper is orienting the decision time for CMS ordering or just continuing the operation. The paper presents a graphic technique which considers a rule for decision based on both condition-based reliability function and a stochastic/fixed lead time. For the stochastic lead time case, results show that technique is effective to determine the time when the system operation is reliable and can withstand the lead time variability, satisfying a desired service level. Additionally, for the constant lead time case, the technique helps to define insurance spares. In conclusion, presented ordering decision rule is useful to asset managers for enhancing the operational continuity affected by spare parts

  9. Geometric contribution leading to anomalous estimation of two-dimensional electron gas density in GaN based heterostructures

    Science.gov (United States)

    Upadhyay, Bhanu B.; Jha, Jaya; Takhar, Kuldeep; Ganguly, Swaroop; Saha, Dipankar

    2018-05-01

    We have observed that the estimation of two-dimensional electron gas density is dependent on the device geometry. The geometric contribution leads to the anomalous estimation of the GaN based heterostructure properties. The observed discrepancy is found to originate from the anomalous area dependent capacitance of GaN based Schottky diodes, which is an integral part of the high electron mobility transistors. The areal capacitance density is found to increase for smaller radii Schottky diodes, contrary to a constant as expected intuitively. The capacitance is found to follow a second order polynomial on the radius of all the bias voltages and frequencies considered here. In addition to the quadratic dependency corresponding to the areal component, the linear dependency indicates a peripheral component. It is further observed that the peripheral to areal contribution is inversely proportional to the radius confirming the periphery as the location of the additional capacitance. The peripheral component is found to be frequency dependent and tends to saturate to a lower value for measurements at a high frequency. In addition, the peripheral component is found to vanish when the surface is passivated by a combination of N2 and O2 plasma treatments. The cumulative surface state density per unit length of the perimeter of the Schottky diodes as obtained by the integrated response over the distance between the ohmic and Schottky contacts is found to be 2.75 × 1010 cm-1.

  10. Order and correlation contributions to the entropy of hydrophobic solvation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Maoyuan; Besford, Quinn Alexander; Mulvaney, Thomas; Gray-Weale, Angus, E-mail: gusgw@gusgw.net [School of Chemistry, The University of Melbourne, Victoria 3010 (Australia)

    2015-03-21

    The entropy of hydrophobic solvation has been explained as the result of ordered solvation structures, of hydrogen bonds, of the small size of the water molecule, of dispersion forces, and of solvent density fluctuations. We report a new approach to the calculation of the entropy of hydrophobic solvation, along with tests of and comparisons to several other methods. The methods are assessed in the light of the available thermodynamic and spectroscopic information on the effects of temperature on hydrophobic solvation. Five model hydrophobes in SPC/E water give benchmark solvation entropies via Widom’s test-particle insertion method, and other methods and models are tested against these particle-insertion results. Entropies associated with distributions of tetrahedral order, of electric field, and of solvent dipole orientations are examined. We find these contributions are small compared to the benchmark particle-insertion entropy. Competitive with or better than other theories in accuracy, but with no free parameters, is the new estimate of the entropy contributed by correlations between dipole moments. Dipole correlations account for most of the hydrophobic solvation entropy for all models studied and capture the distinctive temperature dependence seen in thermodynamic and spectroscopic experiments. Entropies based on pair and many-body correlations in number density approach the correct magnitudes but fail to describe temperature and size dependences, respectively. Hydrogen-bond definitions and free energies that best reproduce entropies from simulations are reported, but it is difficult to choose one hydrogen bond model that fits a variety of experiments. The use of information theory, scaled-particle theory, and related methods is discussed briefly. Our results provide a test of the Frank-Evans hypothesis that the negative solvation entropy is due to structured water near the solute, complement the spectroscopic detection of that solvation structure by

  11. Combining higher-order resummation with multiple NLO calculations and parton showers in GENEVA

    Energy Technology Data Exchange (ETDEWEB)

    Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Vermilion, Christopher K.; Walsh, Jonathan R.; Zuberi, Saba [California Univ., Berkeley, CA (United States). Ernest Orlando Lawrence Berkeley National Laboratory; Hornig, Andrew [Washington Univ., Seattle, WA (United States). Dept. of Physics; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie

    2012-11-15

    We extend the lowest-order matching of tree-level matrix elements with parton showers to give a complete description at the next higher perturbative accuracy in {alpha}{sub s} at both small and large jet resolutions, which has not been achieved so far. This requires the combination of the higher-order resummation of large Sudakov logarithms at small values of the jet resolution variable with the full next-to-leading order (NLO) matrix-element corrections at large values. As a by-product, this combination naturally leads to a smooth connection of the NLO calculations for different jet multiplicities. In this paper, we focus on the general construction of our method and discuss its application to e{sup +}e{sup -} and pp collisions. We present first results of the implementation in the GENEVA Monte Carlo framework. We employ N-jettiness as the jet resolution variable, combining its next-to-next-to-leading logarithmic resummation with fully exclusive NLO matrix elements, and PYTHIA 8 as the backend for further parton showering and hadronization. For hadronic collisions, we take Drell-Yan production as an example to apply our construction. For e{sup +}e{sup -} {yields} jets, taking {alpha}{sub s}(m{sub Z}) = 0.1135 from fits to LEP thrust data, together with the PYTHIA 8 hadronization model, we obtain good agreement with LEP data for a variety of 2-jet observables.

  12. The importance and use of asymptotic freedom beyond the leading order

    International Nuclear Information System (INIS)

    Duke, D.W.

    1979-05-01

    The theoretical and phenomenological importance of asymptotic freedom beyond the leading order is discussed. The two main topics are (1) the determination of the fundamental scale Λ, and (2) ambiguities in parton model definitions when using the higher order effects of asymptotic freedom. (author)

  13. Maternal factors contributing to under-five mortality at birth order 1 to 5 in India: a comprehensive multivariate study.

    Science.gov (United States)

    Singh, Rajvir; Tripathi, Vrijesh

    2013-01-01

    The objective of the study is to assess maternal factors contributing to under-five mortality at birth order 1 to 5 in India. Data for this study was derived from the children's record of the 2007 India National Family Health Survey, which is a nationally representative cross-sectional household survey. Data is segregated according to birth order 1 to 5 to assess mother's occupation, Mother's education, child's gender, Mother's age, place of residence, wealth index, mother's anaemia level, prenatal care, assistance at delivery , antenatal care, place of delivery and other maternal factors contributing to under-five mortality. Out of total 51555 births, analysis is restricted to 16567 children of first birth order, 14409 of second birth order, 8318 of third birth order, 5021 of fourth birth order and 3034 of fifth birth order covering 92% of the total births taken place 0-59 months prior to survey. Mother's average age in years for birth orders 1 to 5 are 23.7, 25.8, 27.4, 29 and 31 years, respectively. Most mothers whose children died are Hindu, with no formal education, severely anaemic and working in the agricultural sector. In multivariate logistic models, maternal education, wealth index and breastfeeding are protective factors across all birth orders. In birth order model 1 and 2, mother's occupation is a significant risk factor. In birth order models 2 to 5, previous birth interval of lesser than 24 months is a risk factor. Child's gender is a risk factor in birth order 1 and 5. Information regarding complications in pregnancy and prenatal care act as protective factors in birth order 1, place of delivery and immunization in birth order 2, and child size at birth in birth order 4. Prediction models demonstrate high discrimination that indicates that our models fit the data. The study has policy implications such as enhancing the Information, Education and Communication network for mothers, especially at higher birth orders, in order to reduce under

  14. Evidence that DNA polymerase δ contributes to initiating leading strand DNA replication in Saccharomyces cerevisiae.

    Science.gov (United States)

    Garbacz, Marta A; Lujan, Scott A; Burkholder, Adam B; Cox, Phillip B; Wu, Qiuqin; Zhou, Zhi-Xiong; Haber, James E; Kunkel, Thomas A

    2018-02-27

    To investigate nuclear DNA replication enzymology in vivo, we have studied Saccharomyces cerevisiae strains containing a pol2-16 mutation that inactivates the catalytic activities of DNA polymerase ε (Pol ε). Although pol2-16 mutants survive, they present very tiny spore colonies, increased doubling time, larger than normal cells, aberrant nuclei, and rapid acquisition of suppressor mutations. These phenotypes reveal a severe growth defect that is distinct from that of strains that lack only Pol ε proofreading (pol2-4), consistent with the idea that Pol ε is the major leading-strand polymerase used for unstressed DNA replication. Ribonucleotides are incorporated into the pol2-16 genome in patterns consistent with leading-strand replication by Pol δ when Pol ε is absent. More importantly, ribonucleotide distributions at replication origins suggest that in strains encoding all three replicases, Pol δ contributes to initiation of leading-strand replication. We describe two possible models.

  15. NASA's Next Generation Space Geodesy Program

    Science.gov (United States)

    Merkowitz, S. M.; Desai, S. D.; Gross, R. S.; Hillard, L. M.; Lemoine, F. G.; Long, J. L.; Ma, C.; McGarry, J. F.; Murphy, D.; Noll, C. E.; hide

    2012-01-01

    Requirements for the ITRF have increased dramatically since the 1980s. The most stringent requirement comes from critical sea level monitoring programs: a global accuracy of 1.0 mm, and 0.1mm/yr stability, a factor of 10 to 20 beyond current capability. Other requirements for the ITRF coming from ice mass change, ground motion, and mass transport studies are similar. Current and future satellite missions will have ever-increasing measurement capability and will lead to increasingly sophisticated models of these and other changes in the Earth system. Ground space geodesy networks with enhanced measurement capability will be essential to meeting the ITRF requirements and properly interpreting the satellite data. These networks must be globally distributed and built for longevity, to provide the robust data necessary to generate improved models for proper interpretation of the observed geophysical signals. NASA has embarked on a Space Geodesy Program with a long-range goal to build, deploy and operate a next generation NASA Space Geodetic Network (SGN). The plan is to build integrated, multi-technique next-generation space geodetic observing systems as the core contribution to a global network designed to produce the higher quality data required to maintain the Terrestrial Reference Frame and provide information essential for fully realizing the measurement potential of the current and coming generation of Earth Observing spacecraft. Phase 1 of this project has been funded to (1) Establish and demonstrate a next-generation prototype integrated Space Geodetic Station at Goddard's Geophysical and Astronomical Observatory (GGAO), including next-generation SLR and VLBI systems along with modern GNSS and DORIS; (2) Complete ongoing Network Design Studies that describe the appropriate number and distribution of next-generation Space Geodetic Stations for an improved global network; (3) Upgrade analysis capability to handle the next-generation data; (4) Implement a modern

  16. Taming the Goldstone contributions to the effective potential

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P.

    2014-07-01

    The standard perturbative effective potential suffers from two related problems of principle involving the field-dependent Goldstone boson squared mass, G. First, in general G can be negative, and it actually is negative in the Standard Model; this leads to imaginary contributions to the effective potential that are not associated with a physical instability, and therefore spurious. Second, in the limit that G approaches zero, the effective potential minimization condition is logarithmically divergent already at two-loop order, and has increasingly severe power-law singularities at higher loop orders. I resolve both issues by resumming the Goldstone boson contributions to the effective potential. For the resulting resummed effective potential, the minimum value and the minimization condition that gives the vacuum expectation value are obtained in forms that do not involve G at all.

  17. Analyzing B{sub s} - anti B{sub s} mixing. Non-perturbative contributions to bag parameters from sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Mannel, T. [Siegen Univ. (Germany). FB 7, Theoretische Physik; Pecjak, B.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pivovarov, A.A. [Siegen Univ. (Germany). FB 7, Theoretische Physik]|[Russian Academy of Sciecnes, Moscow (Russian Federation). Inst. for Nuclear Research

    2007-03-15

    We use QCD sum rules to compute matrix elements of the {delta}B=2 operators appearing in the heavy-quark expansion of the width difference of the B{sub s} mass eigenstates. Our analysis includes the leading-order operators Q and Q{sub S}, as well as the subleading operators R{sub 2} and R{sub 3}, which appear at next-to-leading order in the 1/m{sub b} expansion. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1-2%. (orig.)

  18. Photoproduction of the J/{psi} meson at HERA at next-to-leading order within the framework of nonrelativistic QCD

    Energy Technology Data Exchange (ETDEWEB)

    Butenschoen, Mathias

    2009-06-15

    Nonrelativistic QCD (NRQCD) provides a rigorous factorization scheme which describes the production and decay of heavy quarkonia. It has been a desire for 13 years to know the NRQCD NLO predictions for both J/{psi} hadroproduction and photoproduction, in order to be able to check the universality of the color octet long distance matrix elements (MEs) by comparing Tevatron and HERA data. In this work we calculate for the rst time the NRQCD NLO prediction for direct photoproduction at HERA and compare our result with recent H1 data. Our results show clear evidence that the color octet mechanism of NRQCD is indeed realized in J/{psi} photoproduction at HERA. We solved a number of open conceptual problems, probably the most important one being the issue of Coulomb singularities. We found a way to evaluate the virtual corrections without having to deal with them. (orig.)

  19. Contribution of higher order terms in the reductive perturbation theory, 2

    International Nuclear Information System (INIS)

    Ichikawa, Y.H.; Mitsuhashi, Teruo; Konno, Kimiaki.

    1977-01-01

    Contribution of higher order terms in the reductive perturbation theory has been investigated for nonlinear propagation of strongly dispersive ion plasma wave. The basic set of fluid equation is reduced to a coupled set of the nonlinear Schroedinger equation for the first order perturbed potential and a linear inhomogeneous equation for the second order perturbed potential. A steady state solution of the coupled set of equations has been solved analytically in the asymptotic limit of small wave number. (auth.)

  20. Research Quality, Fairness, and Authorship Order

    DEFF Research Database (Denmark)

    Ackerman, Margareta; Branzei, Simina

    2012-01-01

    of their last names, implying that all contributed equally, and by contribution, where authors are listed in decreasing order of their contribution to the paper. We perform a game theoretic analysis of the impact of author ordering schemes, uncovering two considerable advantages of alphabetical ordering......The order in which authors are listed on an academic paper determines the credit that each receives on a co-authored publication, influencing hiring, tenure and promotions. Two of the prevalent author ordering schemes are alphabetical, which involves listing authors in lexicographical order......: it leads to improved research quality, and it is the more fair of the two approaches in the worst case. On the other hand, contribution-based ordering results in a denser collaboration network and a greater number of publications than is achieved using alphabetical author ordering. Furthermore, authors can...

  1. Spin nematics next to spin singlets

    Science.gov (United States)

    Yokoyama, Yuto; Hotta, Chisa

    2018-05-01

    We provide a route to generate nematic order in a spin-1/2 system. Unlike the well-known magnon-binding mechanism, our spin nematics requires neither the frustration effect nor spin polarization in a high field or in the vicinity of a ferromagnet, but instead appears next to the spin singlet phase. We start from a state consisting of a quantum spin-1/2 singlet dimer placed on each site of a triangular lattice, and show that interdimer ring exchange interactions efficiently dope the SU(2) triplets that itinerate and interact, easily driving a stable singlet state to either Bose-Einstein condensates or a triplet crystal, some hosting a spin nematic order. A variety of roles the ring exchange serves includes the generation of a bilinear-biquadratic interaction between nearby triplets, which is responsible for the emergent nematic order separated from the singlet phase by a first-order transition.

  2. NNLO QCD corrections to jet production at hadron colliders from gluon scattering

    International Nuclear Information System (INIS)

    Currie, James; Ridder, Aude Gehrmann-De; Glover, E.W.N.; Pires, João

    2014-01-01

    We present the next-to-next-to-leading order (NNLO) QCD corrections to dijet production in the purely gluonic channel retaining the full dependence on the number of colours. The sub-leading colour contribution in this channel first appears at NNLO and increases the NNLO correction by around 10% and exhibits a p T dependence, rising from 8% at low p T to 15% at high p T . The present calculation demonstrates the utility of the antenna subtraction method for computing the full colour NNLO corrections to dijet production at the Large Hadron Collider

  3. On the physical contributions to the third-order nonlinear optical response in plasmonic nanocomposites

    International Nuclear Information System (INIS)

    Fernández-Hernández, Roberto Carlos; Gleason-Villagran, Roberto; Rodríguez-Fernández, Luis; Crespo-Sosa, Alejandro; Cheang-Wong, Juan Carlos; López-Suárez, Alejandra; Oliver, Alicia; Reyes-Esqueda, Jorge Alejandro; Torres-Torres, Carlos; Rangel-Rojo, Raúl

    2012-01-01

    Au and Ag isotropic and anisotropic nanocomposites were prepared using the ion implantation technique. Their optical properties were studied at several wavelengths in the optical range 300–800 nm, across their plasmon resonances. The linear regime was characterized by measuring the absorption spectrum and the third-order nonlinear regime by means of the Z-scan technique using a tunable picosecond pulsed laser system (26 ps). Open-aperture Z-scan traces show a superposition of different optical nonlinear absorption (NLA) processes in the whole range studied. We associate these phenomena with the excitation of inter- and intra-band electronic transitions, which contribute with a positive sign to NLA, and to the formation of hot-electrons, which contribute with opposite sign to NLA. Closed-aperture traces for measuring nonlinear refraction (NLR) show different signs for Au and Ag samples, and a change of sign in Au is found when purely inter-band transitions are excited. In this work, for the appropriate wavelength, it is worth remarking on the free-electron response to the exciting light and its strong contribution to the nonlinear optical properties for low (intra-band) and high (hot-electrons) irradiances. (paper)

  4. Extensions of guiding center motion to higher order

    International Nuclear Information System (INIS)

    Northrop, T.G.; Rome, J.A.

    1978-01-01

    In a static magnetic field, some well-known guiding center equations maintain their form when extended to next order in gyroradius. In these cases, it is only necessary to include the next order term in the magnetic moment series. The differential equation for guiding center motion which describes both the parallel and perpendicular velocities correctly through first order in gyroradius is given. The question of how to define the guiding center position through second order arises and is discussed, and second order drifts are derived for one usual definition. The toroidal canonical angular momentum, P/sub phi/, of the guiding center in an axisymmetric field is shown to be conserved using the guiding center velocity correct through first order. When second-order motion is included, P/sub phi/ is no longer a constant. The above extensions of guiding center theory help to resolve the different tokamak orbits obtained either by using the guiding center equations of motion or by using conservation of P/sub phi/

  5. Extensions of guiding center motion to higher order

    International Nuclear Information System (INIS)

    Northrop, T.G.; Rome, J.A.

    1977-07-01

    In a static magnetic field, some well-known guiding center equations maintain their form when extended to next order in gyroradius. In these cases, it is only necessary to include the next order term in the magnetic moment series. The differential equation for guiding center motion which describes both the parallel and perpendicular velocities correctly through first order in gyroradius is given. The question of how to define the guiding center position through second order arises and is discussed, and second order drifts are derived for one usual definition. The toroidal canonical angular momentum, P/sub phi/, of the guiding center in an axisymmetric field is shown to be conserved using the guiding center velocity correct through first order. When second order motion is included, P/sub phi/ is no longer a constant. The above extensions of guiding center theory help to resolve the different tokamak orbits obtained either by using the guiding center equations of motion or by using conservation of P/sub phi/

  6. Second-order phase transition in gφ42 theory

    International Nuclear Information System (INIS)

    Ganbold, G.; Efimov, G.V.

    1993-08-01

    We have suggested a regular scheme for calculating systematically the leading term and next corrections to it up to the fourth order for the effective potential in the scalar φ 4 2 theory. The obtained results give evidence in favour of a second-order phase transition at (g/2πm 2 ) crit ≅ 0.9 in the theory under consideration. (author). 18 refs, 1 fig

  7. Second-order Hydrodynamics in QCD at NLO arXiv

    CERN Document Server

    Ghiglieri, Jacopo; Teaney, Derek

    We compute the hydrodynamic relaxation times $\\tau_\\pi$ and $\\tau_j$ for hot QCD at next-to-leading order in the coupling by using kinetic theory. We show that certain dimensionless ratios of second-order to first-order transport coefficients obey bounds which apply whenever a kinetic theory description is possible; the computed values lie somewhat above these bounds. Strongly coupled theories with holographic duals strongly violate these bounds, highlighting their distance from a quasiparticle description.

  8. Inclusive cross sections in ME+PS merging

    International Nuclear Information System (INIS)

    Plaetzer, Simon

    2013-07-01

    We discuss an extension of matrix element plus parton shower merging at leading and next-to-leading order. The algorithm does preserve inclusive cross sections at the respective input order. This constraint avoids potentially large logarithmic contributions, which would require approximate (N)NLO contributions to cancel against.

  9. Evolution of parton densities beyond leading order

    International Nuclear Information System (INIS)

    Curci, G.; Petronzio, R.; Furmanski, W.

    1980-01-01

    We develop a technique, based explicitly on the factorization properties of mass singularities, which allows one to calculate the evolution of parton densities beyond leading order. We present the results for the evolution of hadronic structure functions as well as for parton fragmentation functions into hadrons. Within our scheme the predictions for a particular process are obtained by convoluting a universal parton density with a short-distance cross section specific to the process. As an application, we calculate the QCD predictions for the Q 2 dependence of deep inelastic lepton-hadron scattering and of one-particle inclusive e + e - annihilation cross sections. Our results for electroproduction agree with those obtained with the operator product expansion technique. Physical quantitites in scattering are related to the corresponding ones in annihilation by analytic continuation, whereas the Gribov-Lipatov relation is strongly violated. (orig.)

  10. A review of fractional-order techniques applied to lithium-ion batteries, lead-acid batteries, and supercapacitors

    Science.gov (United States)

    Zou, Changfu; Zhang, Lei; Hu, Xiaosong; Wang, Zhenpo; Wik, Torsten; Pecht, Michael

    2018-06-01

    Electrochemical energy storage systems play an important role in diverse applications, such as electrified transportation and integration of renewable energy with the electrical grid. To facilitate model-based management for extracting full system potentials, proper mathematical models are imperative. Due to extra degrees of freedom brought by differentiation derivatives, fractional-order models may be able to better describe the dynamic behaviors of electrochemical systems. This paper provides a critical overview of fractional-order techniques for managing lithium-ion batteries, lead-acid batteries, and supercapacitors. Starting with the basic concepts and technical tools from fractional-order calculus, the modeling principles for these energy systems are presented by identifying disperse dynamic processes and using electrochemical impedance spectroscopy. Available battery/supercapacitor models are comprehensively reviewed, and the advantages of fractional types are discussed. Two case studies demonstrate the accuracy and computational efficiency of fractional-order models. These models offer 15-30% higher accuracy than their integer-order analogues, but have reasonable complexity. Consequently, fractional-order models can be good candidates for the development of advanced battery/supercapacitor management systems. Finally, the main technical challenges facing electrochemical energy storage system modeling, state estimation, and control in the fractional-order domain, as well as future research directions, are highlighted.

  11. Magnetic dipole moment of the Δ(1232) in chiral perturbation theory

    International Nuclear Information System (INIS)

    Hacker, C.; Wies, N.; Scherer, S.; Gegelia, J.

    2006-01-01

    The magnetic dipole moment of the Δ(1232) is calculated in the framework of manifestly Lorentz-invariant baryon chiral perturbation theory in combination with the extended on-mass-shell renormalization scheme. As in the case of the nucleon, at leading order both isoscalar and isovector anomalous magnetic moments are given in terms of two low-energy constants. In contrast to the nucleon case, at next-to-leading order the isoscalar anomalous magnetic moment receives a (real) loop contribution. Moreover, due to the unstable nature of the Δ(1232), at next-to-leading order the isovector anomalous magnetic moment not only receives a real but also an imaginary loop contribution. (orig.)

  12. DORIS and GNSS processing at CNES/CLS for the contribution to the next ITRF2013

    Science.gov (United States)

    Loyer, Sylvain; Capdeville, Hugues; Soudarin, Laurent; Mezerette, Adrien; Lemoine, Jean-Michel; Mercier, Flavien; Perosanz, Felix

    2014-05-01

    CNES serves as Analysis Center in the International DORIS Service (IDS) and the International GNSS Service (IGS). DORIS and GNSS data are processed by its subsidiary CLS with the GRGS package software GINS/DYNAMO. For the contribution to the next release of the International Terrestrial Reference Frame planned this year (ITRF2013), two decades of data were analyzed (1993-2013 for DORIS, 1998-2013 for GPS, and 2009-2013 for GLONASS). In this context, the CNES/CLS Analysis Centers provided SINEX solutions to the IDS and IGS Combination Centers, respectively multi-satellite weekly solutions and daily solutions. Normal equations derived from this analysis are also made available to the GRGS Combination Center for the combination at the observation level of the geodetic parameters measured by DORIS, GPS, SLR and VLBI techniques. The purpose of this presentation is to point out how the overall quality of the DORIS and GNSS data processing benefits from the use of the same software and a common basis of models. Here, we present the modeling standards, the networks and the processing strategies. Assessments of some models are also discussed. The quality and the homogeneity of the products (orbits, station coordinates and Earth Orientation Parameters) over the complete period are shown, as well as the temporal variations of some parameters (dynamical parameters, orbit residuals, internal orbit overlaps ...). Some examples of time series of DORIS and GNSS station positions at collocated sites complete this presentation.

  13. Bottom-quark effects in Higgs production at intermediate transverse momentum arXiv

    CERN Document Server

    Caola, Fabrizio; Melnikov, Kirill; Monni, Pier Francesco; Tancredi, Lorenzo; Wever, Christopher

    We provide a precise description of the Higgs boson transverse momentum distribution including top and bottom quark contributions, that is valid for transverse momenta in the range mb < pt < mt, where mb and mt are the bottom and top quark masses. This description is based on a combination of fixed next-to-leading order (NLO) results with next-to-next-to-leading logarithmic (NNLL) transverse momentum resummation. We show that ambiguities in the resummation procedure for the b-quark loops are of the same order as the related fixed-order uncertainties. We conclude that the current uncertainty in the top-bottom interference contribution to the Higgs transverse momentum spectrum is O(20%).

  14. Epidemiological Studies to Support the Development of Next Generation Influenza Vaccines.

    Science.gov (United States)

    Petrie, Joshua G; Gordon, Aubree

    2018-03-26

    The National Institute of Allergy and Infectious Diseases recently published a strategic plan for the development of a universal influenza vaccine. This plan focuses on improving understanding of influenza infection, the development of influenza immunity, and rational design of new vaccines. Epidemiological studies such as prospective, longitudinal cohort studies are essential to the completion of these objectives. In this review, we discuss the contributions of epidemiological studies to our current knowledge of vaccines and correlates of immunity, and how they can contribute to the development and evaluation of the next generation of influenza vaccines. These studies have been critical in monitoring the effectiveness of current influenza vaccines, identifying issues such as low vaccine effectiveness, reduced effectiveness among those who receive repeated vaccination, and issues related to egg adaptation during the manufacturing process. Epidemiological studies have also identified population-level correlates of protection that can inform the design and development of next generation influenza vaccines. Going forward, there is an enduring need for epidemiological studies to continue advancing knowledge of correlates of protection and the development of immunity, to evaluate and monitor the effectiveness of next generation influenza vaccines, and to inform recommendations for their use.

  15. Threshold resummation and higher order effects in QCD

    International Nuclear Information System (INIS)

    Ringer, Felix Maximilian

    2015-01-01

    Quantum chromodynamics (QCD) is a quantum field theory that describes the strong interactions between quarks and gluons, the building blocks of all hadrons. Thanks to the experimental progress over the past decades, there has been an ever-growing need for QCD precision calculations for scattering processes involving hadrons. For processes at large momentum transfer, perturbative QCD offers a systematic approach for obtaining precise predictions. This approach relies on two key concepts: the asymptotic freedom of QCD and factorization. In a perturbative calculation at higher orders, the infrared cancellation between virtual and real emission diagrams generally leaves behind logarithmic contributions. In many observables relevant for hadronic scattering these logarithms are associated with a kinematic threshold and are hence known as ''threshold logarithms''. They become large when the available phase space for real gluon emission shrinks. In order to obtain a reliable prediction from QCD, the threshold logarithms need to be taken into account to all orders in the strong coupling constant, a procedure known as ''threshold resummation''. The main focus of my PhD thesis is on studies of QCD threshold resummation effects beyond the next-to-leading logarithmic order. Here we primarily consider the production of hadron pairs in hadronic collisions as an example. In addition, we also consider hadronic jet production, which is particularly interesting for the phenomenology at the LHC. For both processes, we fully take into account the non-trivial QCD color structure of the underlying partonic hard- scattering cross sections. We find that threshold resummation leads to sizable numerical effects in the kinematic regimes relevant for comparisons to experimental data.

  16. Improving a 1 meter telescope in order to follow giant planets in a pro-am collaboration. Next step : an affordable adaptive optic system.=

    Science.gov (United States)

    Dauvergne, J.-L.; Colas, F.; Delcroix, M.; Lecacheux, J.

    2017-09-01

    We already have very good result with the 1 meter telescope of Pic du Midi. Our goal is to have more and more people in the team in order to make a survey has long as possible of Jupiter, Uranus and Neptune. The next step is an OA system, we want to make it work on the 1 meter telescope and also make it available on the market to help other observatories to produce high resolution images of the solar system with middle size telescopes.

  17. The Analysis of the Contribution of Human Factors to the In-Flight Loss of Control Accidents

    Science.gov (United States)

    Ancel, Ersin; Shih, Ann T.

    2012-01-01

    In-flight loss of control (LOC) is currently the leading cause of fatal accidents based on various commercial aircraft accident statistics. As the Next Generation Air Transportation System (NextGen) emerges, new contributing factors leading to LOC are anticipated. The NASA Aviation Safety Program (AvSP), along with other aviation agencies and communities are actively developing safety products to mitigate the LOC risk. This paper discusses the approach used to construct a generic integrated LOC accident framework (LOCAF) model based on a detailed review of LOC accidents over the past two decades. The LOCAF model is comprised of causal factors from the domain of human factors, aircraft system component failures, and atmospheric environment. The multiple interdependent causal factors are expressed in an Object-Oriented Bayesian belief network. In addition to predicting the likelihood of LOC accident occurrence, the system-level integrated LOCAF model is able to evaluate the impact of new safety technology products developed in AvSP. This provides valuable information to decision makers in strategizing NASA's aviation safety technology portfolio. The focus of this paper is on the analysis of human causal factors in the model, including the contributions from flight crew and maintenance workers. The Human Factors Analysis and Classification System (HFACS) taxonomy was used to develop human related causal factors. The preliminary results from the baseline LOCAF model are also presented.

  18. Structure/Processing Relationships of Highly Ordered Lead Salt Nanocrystal Superlattices

    KAUST Repository

    Hanrath, Tobias; Choi, Joshua J.; Smilgies, Detlef-M.

    2009-01-01

    We investigated the influence of processing conditions, nanocrystal/substrate interactions and solvent evaporation rate on the ordering of strongly interacting nanocrystals by synergistically combining electron microscopy and synchrotron-based small-angle X-ray scattering analysis. Spin-cast PbSe nanocrystal films exhibited submicrometer-sized supracrystals with face-centered cubic symmetry and (001)s planes aligned parallel to the substrate. The ordering of drop-cast lead salt nanocrystal films was sensitive to the nature of the substrate and solvent evaporation dynamics. Nanocrystal films drop-cast on rough indium tin oxide substrates were polycrystalline with small grain size and low degree of orientation with respect to the substrate, whereas films drop-cast on flat Si substrates formed highly ordered face-centered cubic supracrystals with close-packed (111)s planes parallel to the substrate. The spatial coherence of nanocrystal films drop-cast in the presence of saturated solvent vapor was significantly improved compared to films drop-cast in a dry environment. Solvent vapor annealing was demonstrated as a postdeposition technique to modify the ordering of nanocrystals in the thin film. Octane vapor significantly improved the long-range order and degree of orientation of initially disordered or polycrystalline nanocrystal assemblies. Exposure to 1,2-ethanedithiol vapor caused partial displacement of surface bound oleic acid ligands and drastically degraded the degree of order in the nanocrystal assembly. © 2009 American Chemical Society.

  19. Structure/Processing Relationships of Highly Ordered Lead Salt Nanocrystal Superlattices

    KAUST Repository

    Hanrath, Tobias

    2009-10-27

    We investigated the influence of processing conditions, nanocrystal/substrate interactions and solvent evaporation rate on the ordering of strongly interacting nanocrystals by synergistically combining electron microscopy and synchrotron-based small-angle X-ray scattering analysis. Spin-cast PbSe nanocrystal films exhibited submicrometer-sized supracrystals with face-centered cubic symmetry and (001)s planes aligned parallel to the substrate. The ordering of drop-cast lead salt nanocrystal films was sensitive to the nature of the substrate and solvent evaporation dynamics. Nanocrystal films drop-cast on rough indium tin oxide substrates were polycrystalline with small grain size and low degree of orientation with respect to the substrate, whereas films drop-cast on flat Si substrates formed highly ordered face-centered cubic supracrystals with close-packed (111)s planes parallel to the substrate. The spatial coherence of nanocrystal films drop-cast in the presence of saturated solvent vapor was significantly improved compared to films drop-cast in a dry environment. Solvent vapor annealing was demonstrated as a postdeposition technique to modify the ordering of nanocrystals in the thin film. Octane vapor significantly improved the long-range order and degree of orientation of initially disordered or polycrystalline nanocrystal assemblies. Exposure to 1,2-ethanedithiol vapor caused partial displacement of surface bound oleic acid ligands and drastically degraded the degree of order in the nanocrystal assembly. © 2009 American Chemical Society.

  20. The apeNEXT project

    International Nuclear Information System (INIS)

    Belletti, F.; Bodin, F.; Boucaud, Ph.; Cabibbo, N.; Lonardo, A.; De Luca, S.; Lukyanov, M.; Micheli, J.; Morin, L.; Pene, O.; Pleiter, D.; Rapuano, F.; Rossetti, D.; Schifano, S.F.; Simma, H.; Tripiccione, R.; Vicini, P.

    2006-01-01

    Numerical simulations in theoretical high-energy physics (Lattice QCD) require huge computing resources. Several generations of massively parallel computers optimised for these applications have been developed within the APE (array processor experiment) project. Large prototype systems of the latest generation, apeNEXT, are currently being assembled and tested. This contribution explains how the apeNEXT architecture is optimised for Lattice QCD, provides an overview of the hardware and software of apeNEXT, and describes its new features, like the SPMD programming model and the C compiler

  1. Combining higher-order resummation with multiple NLO calculations and parton showers in the Geneva Monte Carlo framework

    International Nuclear Information System (INIS)

    Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Vermilion, Christopher K.; Walsh, Jonathan R.; Zuberi, Saba; Hornig, Andrew; Tackmann, Frank J.

    2013-05-01

    We discuss the GENEVA Monte Carlo framework, which combines higher-order resummation (NNLL) of large Sudakov logarithms with multiple next-to-leading-order (NLO) matrix-element corrections and parton showering (using PYTHIA 8) to give a complete description at the next higher perturbative accuracy in α s at both small and large jet resolution scales. Results for e + e - →jets compared to LEP data and pp→(Z/γ * →l + l - )+jets are presented.

  2. The Higgs transverse momentum spectrum with finite quark masses beyond leading order

    CERN Document Server

    Caola, Fabrizio; Marzani, Simone; Muselli, Claudio; Vita, Gherardo

    2016-01-01

    We apply the leading-log high-energy resummation technique recently derived by some of us to the transverse momentum (pt) distribution for production of a Higgs boson in gluon fusion. We use our results to obtain information on mass-dependent corrections to this observable, which is only known at leading order when exact mass dependence is included. In the low pt region we discuss the all-order exponentiation of collinear bottom mass logarithms. In the high pt region we show that the infinite top mass approximation loses accuracy as a power of pt, while the accuracy of the high-energy approximation is approximately constant as pt grows. We argue that a good approximation to the NLO result for pt >~200 GeV can be obtained by combining the full LO result with a K-factor computed using the high-energy approximation.

  3. Product-related research: how research can contribute to successful life-cycle management.

    Science.gov (United States)

    Sandner, Peter; Ziegelbauer, Karl

    2008-05-01

    Declining productivity with decreasing new molecular entity output combined with increased R&D spending is one of the key challenges for the entire pharmaceutical industry. In order to offset decreasing new molecular entity output, life-cycle management activities for established drugs become more and more important to maintain or even expand clinical indication and market opportunities. Life-cycle management covers a whole range of activities from strategic pricing to a next generation product launch. In this communication, we review how research organizations can contribute to successful life-cycle management strategies using phosphodiesterase 5 inhibitors as an example.

  4. NextGEOSS: The Next Generation Data Hub For Earth Observations

    Science.gov (United States)

    Lilja Bye, Bente; De Lathouwer, Bart; Catarino, Nuno; Concalves, Pedro; Trijssenaar, Nicky; Grosso, Nuno; Meyer-Arnek, Julian; Goor, Erwin

    2017-04-01

    The Group on Earth observation embarked on the next 10 year phase with an ambition to streamline and further develop its achievements in building the Global Earth Observing System of Systems (GEOSS). The NextGEOSS project evolves the European vision of GEOSS data exploitation for innovation and business, relying on the three main pillars of engaging communities, delivering technological developments and advocating the use of GEOSS, in order to support the creation and deployment of Earth observation based innovative research activities and commercial services. In this presentation we will present the NextGEOSS concept, a concept that revolves around providing the data and resources to the users communities, together with Cloud resources, seamlessly connected to provide an integrated ecosystem for supporting applications. A central component of NextGEOSS is the strong emphasis put on engaging the communities of providers and users, and bridging the space in between.

  5. Executive Order 13693: Planning for Federal Sustainability in the Next Decade; Guidance for Federal Agencies on Executive Order 13693 -- Federal Fleet Management

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-01

    The U.S. Department of Energy (DOE) and U.S. General Services Administration (GSA) are issuing comprehensive guidance on the federal fleet requirements of Executive Order (E.O.) 13693, Planning for Federal Sustainability in the Next Decade (E.O. 13693), to help federal agencies subject to the executive order develop an overall approach for reducing total fleet greenhouse gas (GHG) emissions and fleet-wide per-mile GHG emissions, and ensure the approach helps these agencies meet their requirements. Three key GHG emissions reduction strategies - right-sizing fleets to mission, increasing fleet fuel efficiency, and displacing petroleum with alternative fuel use - are essential to meeting the requirements and are discussed further in this document. This guidance document is intended to help agency Chief Sustainability Officers (CSOs) and headquarters fleet managers craft tailored executable plans that achieve the purpose of E.O. 13693. The guidance will assist agencies in completing the first phase of a comprehensive fleet management framework by identifying the strategies each agency will then implement to meet or exceed its requirements.

  6. Next-to-soft corrections to high energy scattering in QCD and gravity

    Energy Technology Data Exchange (ETDEWEB)

    Luna, A.; Melville, S. [SUPA, School of Physics and Astronomy, University of Glasgow,Glasgow G12 8QQ, Scotland (United Kingdom); Naculich, S.G. [Department of Physics, Bowdoin College,Brunswick, ME 04011 (United States); White, C.D. [Centre for Research in String Theory, School of Physics and Astronomy,Queen Mary University of London,327 Mile End Road, London E1 4NS (United Kingdom)

    2017-01-12

    We examine the Regge (high energy) limit of 4-point scattering in both QCD and gravity, using recently developed techniques to systematically compute all corrections up to next-to-leading power in the exchanged momentum i.e. beyond the eikonal approximation. We consider the situation of two scalar particles of arbitrary mass, thus generalising previous calculations in the literature. In QCD, our calculation describes power-suppressed corrections to the Reggeisation of the gluon. In gravity, we confirm a previous conjecture that next-to-soft corrections correspond to two independent deflection angles for the incoming particles. Our calculations in QCD and gravity are consistent with the well-known double copy relating amplitudes in the two theories.

  7. Examination of higher-order twist contributions in parity-violating deep-inelastic electron-deuteron scattering

    International Nuclear Information System (INIS)

    Mantry, Sonny; Ramsey-Musolf, Michael J.; Sacco, Gian Franco

    2010-01-01

    We show that parity-violating deep-inelastic scattering (PVDIS) of longitudinally polarized electrons from deuterium can in principle be a relatively clean probe of higher twist quark-quark correlations beyond the parton model. As first observed by Bjorken and Wolfenstein, the dominant contribution to the electron polarization asymmetry, proportional to the axial vector electron coupling, receives corrections at twist four from the matrix element of a single four-quark operator. We reformulate the Bjorken-Wolfenstein argument in a matter suitable for the interpretation of experiments planned at the Thomas Jefferson National Accelerator Facility (JLab). In particular, we observe that because the contribution of the relevant twist-four operator satisfies the Callan-Gross relation, the ratio of parity-violating longitudinal and transverse cross sections, R γZ , is identical to that for purely electromagnetic scattering, R γ , up to perturbative and power-suppressed contributions. This result simplifies the interpretation of the asymmetry in terms of other possible novel hadronic and electroweak contributions. We use the results of MIT Bag Model calculations to estimate contributions of the relevant twist-four operator to the leading term in the asymmetry as a function of Bjorken x and Q 2 . We compare these estimates with possible leading twist corrections from violation of charge symmetry in the parton distribution functions.

  8. (U) Second-Order Sensitivity Analysis of Uncollided Particle Contributions to Radiation Detector Responses Using Ray-Tracing

    Energy Technology Data Exchange (ETDEWEB)

    Favorite, Jeffrey A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-30

    The Second-Level Adjoint Sensitivity System (2nd-LASS) that yields the second-order sensitivities of a response of uncollided particles with respect to isotope densities, cross sections, and source emission rates is derived in Refs. 1 and 2. In Ref. 2, we solved problems for the uncollided leakage from a homogeneous sphere and a multiregion cylinder using the PARTISN multigroup discrete-ordinates code. In this memo, we derive solutions of the 2nd-LASS for the particular case when the response is a flux or partial current density computed at a single point on the boundary, and the inner products are computed using ray-tracing. Both the PARTISN approach and the ray-tracing approach are implemented in a computer code, SENSPG. The next section of this report presents the equations of the 1st- and 2nd-LASS for uncollided particles and the first- and second-order sensitivities that use the solutions of the 1st- and 2nd-LASS. Section III presents solutions of the 1st- and 2nd-LASS equations for the case of ray-tracing from a detector point. Section IV presents specific solutions of the 2nd-LASS and derives the ray-trace form of the inner products needed for second-order sensitivities. Numerical results for the total leakage from a homogeneous sphere are presented in Sec. V and for the leakage from one side of a two-region slab in Sec. VI. Section VII is a summary and conclusions.

  9. A next-to-leading-log Monte Carlo study of photon pairs and the search for the intermediate mass Higgs Boson

    International Nuclear Information System (INIS)

    Bailey, B.R.

    1993-01-01

    Symmetry breaking and the question of the origin of mass are the reasons the Superconducting Super Collider and the Large Hadron Collider are being built. The Standard Model of particle physics provides a solution to this problem by proposing the existence of a neutral scalar particle, the Higgs boson. This particle, via its interactions, gives mass to all of the particles in the Standard Model. The question of whether the Higgs boson can be detected at these machines depends critically on its final state decays. These decays in turn depend crucially on the mass of the Higgs boson, an unknown parameter of the theory. A lower bound of the Higgs mass has been set by experiment and a upper bound via theoretical arguments. Throughout much of the mass range Higgs decays via weak gauge bosons yield a clear signal. However, near the lower limit, the so-called intermediate mass region, the situation is less clear. In this region Higgs decays into photon pairs have been suggested as a viable signal. The significance of such a signal depends on other competing processes or backgrounds. This dissertation attempts to answer the question, open-quotes Can the Intermediate mass Higgs boson be detected via its electromagnetic decays?close quotes To answer this question various Standard Model processes are calculated to the leading-log and next-to-leading-log level in a Monte Carlo environment

  10. Next-to-leading order effective field theory Lambda N -> NN potential in coordinate space

    Czech Academy of Sciences Publication Activity Database

    Peréz-Obiol Castaneda, Axel; Entem, D. R.; Julia-Diaz, B.; Parreno, A.

    2016-01-01

    Roč. 954, OCT (2016), s. 213-241 ISSN 0375-9474 R&D Projects: GA ČR(CZ) GA15-04301S Institutional support: RVO:61389005 Keywords : non-mesonic weak decay * effective field theory * hypernuclei Subject RIV: BE - Theoretical Physics Impact factor: 1.916, year: 2016

  11. Zeroth-order design report for the next linear collider. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Raubenheimer, T.O. [ed.

    1996-05-01

    This Zeroth Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The design presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume one covers the following: the introduction; electron source; positron source; NLC damping rings; bunch compressors and prelinac; low-frequency linacs and compressors; main linacs; design and dynamics; and RF systems for main linacs.

  12. Zeroth-order design report for the next linear collider. Volume 1

    International Nuclear Information System (INIS)

    Raubenheimer, T.O.

    1996-05-01

    This Zeroth Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The design presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume one covers the following: the introduction; electron source; positron source; NLC damping rings; bunch compressors and prelinac; low-frequency linacs and compressors; main linacs; design and dynamics; and RF systems for main linacs

  13. Next-Generation Pathology.

    Science.gov (United States)

    Caie, Peter D; Harrison, David J

    2016-01-01

    The field of pathology is rapidly transforming from a semiquantitative and empirical science toward a big data discipline. Large data sets from across multiple omics fields may now be extracted from a patient's tissue sample. Tissue is, however, complex, heterogeneous, and prone to artifact. A reductionist view of tissue and disease progression, which does not take this complexity into account, may lead to single biomarkers failing in clinical trials. The integration of standardized multi-omics big data and the retention of valuable information on spatial heterogeneity are imperative to model complex disease mechanisms. Mathematical modeling through systems pathology approaches is the ideal medium to distill the significant information from these large, multi-parametric, and hierarchical data sets. Systems pathology may also predict the dynamical response of disease progression or response to therapy regimens from a static tissue sample. Next-generation pathology will incorporate big data with systems medicine in order to personalize clinical practice for both prognostic and predictive patient care.

  14. Doublet channel neutron-deuteron scattering in leading order effective field theory

    OpenAIRE

    B. BlankleiderFlinders U.; J. Gegelia(INFN)

    2015-01-01

    The doublet channel neutron-deuteron scattering amplitude is calculated in leading order effective field theory (EFT). It is shown that this amplitude does not depend on a constant contact interaction three-body force. Satisfactory agreement with available data is obtained when only two-body forces are included.

  15. Top quark mass effects in Higgs boson pair production up to NNLO

    International Nuclear Information System (INIS)

    Hoff, Jens

    2016-09-01

    We consider the production of pairs of Standard Model Higgs bosons via gluon fusion. Until recently the full dependence on the top quark mass M_t was not known at next-to-leading order. For this reason we apply an approximation based on the expansion for large top quark masses up to O(1/M"1"2_t). At next-to-next-to-leading order we avoid the calculation of real corrections via the soft-virtual approximation and obtain top quark mass corrections up to O(1/M"4_t). We use our results to estimate the residual uncertainty of the total cross section due to a finite top quark mass to be O(10%) at next-to-leading order and O(5%) at next-to-next-to-leading order.

  16. Answers to Teachers' Questions about the Next Generation Science Standards

    Science.gov (United States)

    Workosky, Cindy; Willard, Ted

    2015-01-01

    K-12 teachers of science have been digging into the "Next Generation Science Standards" ("NGSS") (NGSS Lead States 2013) to begin creating plans and processes for translating them for classroom instruction. As teachers learn about the NGSS, they have asked about the general structure of the standards document and how to read…

  17. Nilton Hebling's career and contribution to carcinology

    Directory of Open Access Journals (Sweden)

    Maria Lucia Negreiros-Fransozo

    Full Text Available Abstract This is a brief comment on Nilton Hebling's career and contribution to carcinology. Our intention is to show to next generation of carcinologists some insights of his professional life, and to acknowledge his great attitude while teaching and mentoring many Brazilian carcinologists.

  18. Classical equation of motion and anomalous dimensions at leading order

    International Nuclear Information System (INIS)

    Nii, Keita

    2016-01-01

    Motivated by a recent paper by Rychkov-Tan http://dx.doi.org/10.1088/1751-8113/48/29/29FT01 , we calculate the anomalous dimensions of the composite operators at the leading order in various models including a ϕ"3-theory in (6−ϵ) dimensions. The method presented here relies only on the classical equation of motion and the conformal symmetry. In case that only the leading expressions of the critical exponents are of interest, it is sufficient to reduce the multiplet recombination discussed in http://dx.doi.org/10.1088/1751-8113/48/29/29FT01 to the classical equation of motion. We claim that in many cases the use of the classical equations of motion and the CFT constraint on two- and three-point functions completely determine the leading behavior of the anomalous dimensions at the Wilson-Fisher fixed point without any input of the Feynman diagrammatic calculation. The method developed here is closely related to the one presented in http://dx.doi.org/10.1088/1751-8113/48/29/29FT01 but based on a more perturbative point of view.

  19. 76 FR 9613 - USEC Inc. (American Centrifuge Lead Cascade Facility and American Centrifuge Plant); Order...

    Science.gov (United States)

    2011-02-18

    ... NUCLEAR REGULATORY COMMISSION [EA-11-013] USEC Inc. (American Centrifuge Lead Cascade Facility and American Centrifuge Plant); Order Approving Direct Transfer of Licenses and Conforming Amendment I USEC... Centrifuge Lead Cascade Facility (Lead Cascade) and American Centrifuge Plant (ACP), respectively, which...

  20. Towards the Development of a Second-Order Approximation in Activity Coefficient Models Based on Group Contributions

    DEFF Research Database (Denmark)

    Abildskov, Jens; Constantinou, Leonidas; Gani, Rafiqul

    1996-01-01

    A simple modification of group contribution based models for estimation of liquid phase activity coefficients is proposed. The main feature of this modification is that contributions estimated from the present first-order groups in many instances are found insufficient since the first-order groups...... correlation/prediction capabilities, distinction between isomers and ability to overcome proximity effects....

  1. NLO corrections to the twist-3 amplitude in DVCS on a nucleon in the Wandzura-Wilczek approximation: quark case

    Energy Technology Data Exchange (ETDEWEB)

    Kivel, N.; Mankiewicz, L. E-mail: lech@cft.edu.pl

    2003-11-10

    We computed the NLO corrections to twist-3, L{yields}T, flavor nonsinglet amplitude in DVCS on a nucleon in the Wandzura-Wilczek approximation. Explicit calculation shows that factorization holds for NLO contribution to this amplitude, although the structure of the factorized amplitude at the NLO is more complicated than in the leading-order formula. Next-to-leading order coefficient functions for matrix elements of twist-3 vector and axial-vector quark string operators and their LO evolution equations are presented.

  2. NLO corrections to the twist-3 amplitude in DVCS on a nucleon in the Wandzura-Wilczek approximation: quark case

    International Nuclear Information System (INIS)

    Kivel, N.; Mankiewicz, L.

    2003-01-01

    We computed the NLO corrections to twist-3, L→T, flavor nonsinglet amplitude in DVCS on a nucleon in the Wandzura-Wilczek approximation. Explicit calculation shows that factorization holds for NLO contribution to this amplitude, although the structure of the factorized amplitude at the NLO is more complicated than in the leading-order formula. Next-to-leading order coefficient functions for matrix elements of twist-3 vector and axial-vector quark string operators and their LO evolution equations are presented

  3. Optimal Ordering Policy and Coordination Mechanism of a Supply Chain with Controllable Lead-Time-Dependent Demand Forecast

    Directory of Open Access Journals (Sweden)

    Hua-Ming Song

    2011-01-01

    Full Text Available This paper investigates the ordering decisions and coordination mechanism for a distributed short-life-cycle supply chain. The objective is to maximize the whole supply chain's expected profit and meanwhile make the supply chain participants achieve a Pareto improvement. We treat lead time as a controllable variable, thus the demand forecast is dependent on lead time: the shorter lead time, the better forecast. Moreover, optimal decision-making models for lead time and order quantity are formulated and compared in the decentralized and centralized cases. Besides, a three-parameter contract is proposed to coordinate the supply chain and alleviate the double margin in the decentralized scenario. In addition, based on the analysis of the models, we develop an algorithmic procedure to find the optimal ordering decisions. Finally, a numerical example is also presented to illustrate the results.

  4. Three-nucleon force contribution in the distorted-wave theory of (d ,p ) reactions

    Science.gov (United States)

    Timofeyuk, N. K.

    2018-05-01

    The distorted-wave theory of A (d ,p )B reactions, widely used to analyze experimental data, is based on a Hamiltonian that includes only two-nucleon interactions. However, numerous studies of few-nucleon systems and many modern developments in nuclear structure theory show the importance of the three-nucleon (3 N ) force. The purpose of this paper is to study the contribution of the 3 N force of the simplest possible form to the A (d ,p )B reaction amplitude. This contribution is given by a new term that accounts for the interaction of the neutron and proton in the incoming deuteron with one of the target nucleons. This term involves a new type of nuclear matrix elements containing an infinite number of target excitations in addition to the main part associated with the traditional overlap function between A and B . The nuclear matrix elements are calculated for double-closed shell targets within a mean field theory where target excitations are shown to be equivalent to exchanges between valence and core nucleons. These matrix elements can be readily incorporated into available reaction codes if the 3 N interaction has a spin-independent zero-range form. Distorted-wave calculations are presented for a contact 3 N force with the volume integral fixed by the chiral effective field theory at the next-to-next-to-leading order. For this particular choice, the 3 N contribution is noticeable, especially at high deuteron incident energies. No 3 N effects are seen for incident energies below the Coulomb barrier. The finite range can significantly affect the 3 N contribution to the (d ,p ) cross sections. Finite-range studies require new formal developments and, therefore, their contribution is preliminarily assessed within the plane-wave Born approximation, together with sensitivity to the choice of the deuteron model.

  5. The S-wave resonance contributions in the B{sup 0}{sub s} decays into ψ(2S,3S) plus pion pair

    Energy Technology Data Exchange (ETDEWEB)

    Rui, Zhou [North China University of Science and Technology, College of Sciences, Tangshan (China); Li, Ya [Nanjing Normal University, Department of Physics and Institute of Theoretical Physics, Nanjing, Jiangsu (China); Wang, Wen-Fei [Shanxi University, Institute of Theoretical Physics, Taiyuan, Shanxi (China)

    2017-03-15

    The three-body decays B{sup 0}{sub s} → ψ(2S,3S)π{sup +}π{sup -} are studied based on the perturbative QCD approach. With the help of the nonperturbative two-pion distribution amplitudes, the analysis is simplified into the quasi-two-body processes. Besides the traditional factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order vertex corrections are also included to cancel the scale dependence. The f{sub 0}(980), f{sub 0}(1500) resonance contributions as well as the nonresonant contributions are taken into account using the presently known ππ time-like scalar form factor for the s anti s component. It is found that the predicted B{sup 0}{sub s} → ψ(2S)π{sup +}π{sup -} decay spectra in the pion pair invariant mass shows a similar behavior as the experiment. The calculated S-wave contributions to the branching ratio of B{sup 0}{sub s} → ψ(2S)π{sup +}π{sup -} is 6.0 x 10{sup -5}, which is in agreement with the LHCb data B(B{sup 0}{sub s} → ψ(2S)π{sup +}π{sup -}) = (7.2±1.2) x 10{sup -5} within errors. The estimate of B(B{sup 0}{sub s} → ψ(3S)π{sup +}π{sup -}) can reach the order of 10{sup -5}, pending the corresponding measurements. (orig.)

  6. A next-to-leading-order QCD analysis of neutrino-iron structure functions at the Tevatron

    International Nuclear Information System (INIS)

    Seligman, W.G.

    1997-01-01

    Nucleon structure functions measured in neutrino-iron and antineutrino-iron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 GeV. The structure functions F 2 and xF 3 are compared with the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives value of ΛNLO,(4)/MS = 337 ± 28 (exp.) MeV, which corresponds to α S (M Z 2 ) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by xG(x,Q 0 2 = 5GeV 2 ) = (2.22 ± 0.34) x (1 - x) 4.65±0.68

  7. A Next-to-Leading Order QCD Analysis of Neutrino - Iron Structure Functions at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Seligman, William Glenn [Nevis Labs, Columbia U.

    1997-01-01

    Nucleon structure functions measured in neutrino-iron and antineutrinoiron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 Ge V. The structure functions $F_2$ and $xF_3$ are compared with the the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives NL0(4) . 2 value of $\\Lambda^{NLO,(4)}_{\\overline MS}$ = 337 ± 28 (exp.) MeV, which corresponds to $\\alpha_s$ ($M^2_z$) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by $xG(x,Q^2_0 = 5 GeV^2$ ) = (2.22±0.34) x ($1-x)^{4.65 \\pm 0.68}$

  8. A next-to-leading-order QCD analysis of neutrino-iron structure functions at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Seligman, William Glenn [Columbia Univ., New York, NY (United States)

    1997-01-01

    Nucleon structure functions measured in neutrino-iron and antineutrino-iron charged-current interactions are presented. The data were taken in two high-energy high-statistics runs by the LAB-E detector at the Fermilab Tevatron. Structure functions are extracted from a sample of 950,000 neutrino and 170,000 antineutrino events with neutrino energies from 30 to 360 GeV. The structure functions F2 and xF3 are compared with the predictions of perturbative Quantum Chromodynamics (PQCD). The combined non-singlet and singlet evolution in the context of PQCD gives value of ΛNLO,(4)/MS = 337 ± 28 (exp.) MeV, which corresponds to αS(MZ2) = 0.119 ± 0.002 (exp.) ± 0.004 (theory), and with a gluon distribution given by xG(x,Q02 = 5GeV2) = (2.22 ± 0.34) x (1 - x)4.65±0.68.

  9. Production of H H H and H H V (V =γ ,Z ) at the hadron colliders

    Science.gov (United States)

    Agrawal, Pankaj; Saha, Debashis; Shivaji, Ambresh

    2018-02-01

    We consider the production of two Higgs bosons in association with a gauge boson or another Higgs boson at the hadron colliders. We compute the cross sections and distributions for the processes p p →H H H and H H Z within the standard model. In particular, we compute the gluon-gluon fusion one-loop contributions mediated via heavy quarks in the loop. It is the leading order contribution to p p →H H H process. To the process p p →H H Z , it is next-to-next-to-leading-order (NNLO) contribution in QCD coupling. We also compare this contribution to the next-to-leading-order (NLO) QCD contribution to this process. The NNLO contribution can be similar to NLO contribution at the Large Hadron Collider (LHC), and significantly more at higher center-of-mass energy machines. We also study new physics effects in these processes by considering t t H , H H H , H H H H , H Z Z , and H H Z Z interactions as anomalous. The anomalous couplings can enhance the cross sections significantly. The g g →H H H process is specially sensitive to anomalous trilinear Higgs boson self-coupling. For the g g →H H Z process, there is some modest dependence on anomalous H Z Z couplings.

  10. Efficient analytic computation of higher-order QCD amplitudes

    International Nuclear Information System (INIS)

    Bern, Z.; Chalmers, G.; Dunbar, D.C.; Kosower, D.A.

    1995-01-01

    The authors review techniques simplifying the analytic calculation of one-loop QCD amplitudes with many external legs, for use in next-to-leading-order corrections to multi-jet processes. Particularly useful are the constraints imposed by perturbative unitarity, collinear singularities and a supersymmetry-inspired organization of helicity amplitudes. Certain sequences of one-loop helicity amplitudes with an arbitrary number of external gluons have been obtained using these constraints

  11. Upgrade of the Gas Flow Control System of the Resistive Current Leads of the LHC Inner Triplet Magnets: Simulation and Experimental Validation

    CERN Document Server

    Perin, A; Casas-Cubillos, J; Pezzetti, M

    2014-01-01

    The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

  12. Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Perin, A.; Casas-Cubillos, J.; Pezzetti, M. [CERN, CH-1211 Geneva 23 (Switzerland); Almeida, M. [Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte (Brazil)

    2014-01-29

    The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

  13. Quantifying the contribution of airborne lead (Pb) to surface waters in northeastern Oklahoma

    Science.gov (United States)

    Li, J. J.; McDonald, J.; Curtis, H.

    2017-12-01

    The northeastern Oklahoma, home to a number of Native American Tribes, is part of the well-known Tri-State Mining District (TSMD). One hundred years of mining production in this area has left numerous, large chat piles on the surrounding environment, directly affecting the town of Picher and many other tribe communities. Byproducts of the mining, including lead (Pb)-contain dust have been transported to the atmosphere and seeped into groundwater, lakes, ponds and rivers. Due to this contamination, many children in the area have elevated levels of Pb in their bodies. Despite a substantial number of studies and efforts on the restoration of heavy metal contamination in this area (e.g. The Tar Creek Superfund Site, EPA), no studies have attempted to distinguish the contributions of different sources, particularly from the atmospheric deposition, of heavy metals to the aquatic environment. In this study, we analyzed the atmospheric deposition of Pb from 4 sites located close to the chat piles for the period of 2010 to 2016. Our preliminary analysis showed that atmospheric Pb has a strong seasonal pattern with two peak times in early spring and late fall, which largely correspond with the dry periods in the this area. Atmospheric concentrations of Pb monitored at these sites frequently exceeded 0.15 μg/m3, the National Ambient Air Quality Standards (NAAQS) standard for ambient air Pb, and was generally 10 times higher than atmospheric Pb monitored in Tulsa, OK, a major metropolitan area 150 km southwest of the monitoring sites. With the known Pb flux to the sediments of the water bodies, we estimated that the contribution of Pb from the atmospheric deposition to the surface waters is up to 25%, depending on the distance of the water bodies to concentrated distribution of the chat piles.

  14. Spin-dependent hadro- and photoproduction of heavy quarks at next-to-leading order of QCD

    International Nuclear Information System (INIS)

    Riedl, Johann

    2014-01-01

    In this thesis, we have studied heavy quark hadro- and photoproduction in detail and examined the possibilities of using heavy quark production for the extraction of the polarised parton distribution functions. All calculations are performed at O(α s 3 ) and O(αα s 2 ) accuracy, respectively, and theoretical uncertainties due to the choice of scales μ f,r and the heavy quark mass m Q have been discussed in detail. Based on our theoretical results we have presented detailed phenomenological studies for the existing PHENIX and STAR experiments at BNL-RHIC and the COMPASS experiment at CERN. Predictions have been made for possible future experiments at a low-energy antiproton-proton collider at GSI-FAIR, a proton-proton collider at J-PARC and an upcoming high-energy electron-ion collider (EIC).

  15. Higher-order spin and charge dynamics in a quantum dot-lead hybrid system.

    Science.gov (United States)

    Otsuka, Tomohiro; Nakajima, Takashi; Delbecq, Matthieu R; Amaha, Shinichi; Yoneda, Jun; Takeda, Kenta; Allison, Giles; Stano, Peter; Noiri, Akito; Ito, Takumi; Loss, Daniel; Ludwig, Arne; Wieck, Andreas D; Tarucha, Seigo

    2017-09-22

    Understanding the dynamics of open quantum systems is important and challenging in basic physics and applications for quantum devices and quantum computing. Semiconductor quantum dots offer a good platform to explore the physics of open quantum systems because we can tune parameters including the coupling to the environment or leads. Here, we apply the fast single-shot measurement techniques from spin qubit experiments to explore the spin and charge dynamics due to tunnel coupling to a lead in a quantum dot-lead hybrid system. We experimentally observe both spin and charge time evolution via first- and second-order tunneling processes, and reveal the dynamics of the spin-flip through the intermediate state. These results enable and stimulate the exploration of spin dynamics in dot-lead hybrid systems, and may offer useful resources for spin manipulation and simulation of open quantum systems.

  16. QCD corrections to $e^{+} e^{-} \\to u \\overline {d} s \\overline {c}$ at LEP 2 and the Next Linear Collider CC11 at O $\\alpha_{s}$

    CERN Document Server

    Maina, E; Pizzio, M

    1998-01-01

    QCD one-loop corrections to the full gauge invariant set of electroweak diagrams describing the hadronic process $e^+ e^- \\to u~\\bar d~s~\\bar c$ are computed. Four-jet shape variables for $WW$ events are studied at next-to-leading order and the effects of QCD corrections on the determination of the $W$--mass in the hadronic channel at Lep 2 and NLC is discussed. We compare the exact calculation with a ``naive''approach to strong radiative corrections which has been widely used in the literature.

  17. NLO QCD corrections to the production of two bottom-antibottom pairs at the LHC

    International Nuclear Information System (INIS)

    Greiner, Nicolas; Reuter, Juergen; Freiburg Univ.

    2011-05-01

    We report the results of a computation of the full next-to-leading order QCD corrections to the production of two b anti b pairs at the LHC. This calculation at the parton level provides predictions for well separated b-jets. The results show that the next-to-leading order corrections lead to an enhancement of the cross-section for the central scale choice by roughly 50% with respect to the leading order result. The theoretical uncertainty estimated by variation of the renormalization and factorization scales is strongly reduced by the inclusion of next-to-leading order corrections. (orig.)

  18. NLO QCD corrections to the production of two bottom-antibottom pairs at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, Nicolas [Illinois Univ., Urbana-Champaign, IL (United States). Dept. of Physics; Guffanti, Alberto [Freiburg Univ. (Germany). Physikalisches Inst.; Reiter, Thomas [Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands); Max-Planck-Institut fuer Physik, Muenchen (Germany); Reuter, Juergen [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Freiburg Univ. (Germany). Physikalisches Inst.

    2011-05-15

    We report the results of a computation of the full next-to-leading order QCD corrections to the production of two b anti b pairs at the LHC. This calculation at the parton level provides predictions for well separated b-jets. The results show that the next-to-leading order corrections lead to an enhancement of the cross-section for the central scale choice by roughly 50% with respect to the leading order result. The theoretical uncertainty estimated by variation of the renormalization and factorization scales is strongly reduced by the inclusion of next-to-leading order corrections. (orig.)

  19. MoonNEXT: A European Mission to the Moon

    Science.gov (United States)

    Carpenter, J. D.; Koschny, D.; Crawford, I.; Falcke, H.; Kempf, S.; Lognonne, P.; Ricci, C.; Houdou, B.; Pradier, A.

    2008-09-01

    MoonNEXT is a mission currently being studied, under the direction of the European Space Agency, whose launch is foreseen between 2015 and 2018. MoonNEXT is intended to prepare the way for future exploration activities on the Moon, while addressing key science questions. Exploration Objectives The primary goal for the MoonNEXT mission is to demonstrate autonomous soft precision landing with hazard avoidance; a key capability for future exploration missions. The nominal landing site is at the South Pole of the Moon, at the edge of the Aitken basin and in the region of Shackleton crater, which has been identified as an optimal location for a future human outpost by the NASA lunar architecture team [1]. This landing site selection ensures a valuable contribution by MoonNEXT to the Global Exploration Strategy [2]. MoonNEXT will also prepare for future lunar exploration activities by characterising the environment at the lunar surface. The potentially hazardous radiation environment will me monitored while a dedicated instrument package will investigate the levitation and mobility of lunar dust. Experience on Apollo demonstrated the potentially hazardous effects of dust for surface operations and human activities and so an understanding of these processes is important for the future. Life sciences investigations will be carried out into the effects of the lunar environment (including radiation, gravity and illumination conditions) on a man made ecosystem analogous to future life support systems. In doing so MoonNEXT will demonstrate the first extraterrestrial man made ecosystem and develop valuable expertise for future missions. Geological and geochemical investigations will explore the possibilities for In Situ Resource Utilisation (ISRU), which will be essential for long term human habitation on the Moon and is of particular importance at the proposed landing site, given its potential as a future habitat location. Science Objectives In addition to providing extensive

  20. Melatonin reduces lead levels in blood, brain and bone and increases lead excretion in rats subjected to subacute lead treatment.

    Science.gov (United States)

    Hernández-Plata, Everardo; Quiroz-Compeán, Fátima; Ramírez-Garcia, Gonzalo; Barrientos, Eunice Yáñez; Rodríguez-Morales, Nadia M; Flores, Alberto; Wrobel, Katarzina; Wrobel, Kazimierz; Méndez, Isabel; Díaz-Muñoz, Mauricio; Robles, Juvencio; Martínez-Alfaro, Minerva

    2015-03-04

    Melatonin, a hormone known for its effects on free radical scavenging and antioxidant activity, can reduce lead toxicity in vivo and in vitro.We examined the effects of melatonin on lead bio-distribution. Rats were intraperitoneally injected with lead acetate (10, 15 or 20mg/kg/day) with or without melatonin (10mg/kg/day) daily for 10 days. In rats intoxicated with the highest lead doses, those treated with melatonin had lower lead levels in blood and higher levels in urine and feces than those treated with lead alone, suggesting that melatonin increases lead excretion. To explore the mechanism underlying this effect, we first assessed whether lead/melatonin complexes were formed directly. Electronic density functional (DFT) calculations showed that a lead/melatonin complex is energetically feasible; however, UV spectroscopy and NMR analysis showed no evidence of such complexes. Next, we examined the liver mRNA levels of metallothioneins (MT) 1 and 2. Melatonin cotreatment increased the MT2 mRNA expression in the liver of rats that received the highest doses of lead. The potential effects of MTs on the tissue distribution and excretion of lead are not well understood. This is the first report to suggest that melatonin directly affects lead levels in organisms exposed to subacute lead intoxication. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Zeroth-order design report for the next linear collider. Volume 2

    International Nuclear Information System (INIS)

    Raubenheimer, T.O.

    1996-05-01

    This Zeroth-Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The ''design'' presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume II covers the following: collimation systems; IP switch and big bend; final focus; the interaction region; multiple bunch issues; control systems; instrumentation; machine protection systems; NLC reliability considerations; NLC conventional facilities. Also included are four appendices on the following topics: An RF power source upgrade to the NLC; a second interaction region for gamma-gamma, gamma-electron; ground motion: theory and measurement; and beam-based feedback: theory and implementation

  2. Zeroth-order design report for the next linear collider. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Raubenheimer, T.O. [ed.

    1996-05-01

    This Zeroth-Order Design Report (ZDR) for the Next Linear Collider (NLC) has been completed as a feasibility study for a TeV-scale linear collider that incorporates a room-temperature accelerator powered by rf microwaves at 11.424 GHz--similar to that presently used in the SLC, but at four times the rf frequency. The purpose of this study is to examine the complete systems of such a collider, to understand how the parts fit together, and to make certain that every required piece has been included. The ``design`` presented here is not fully engineered in any sense, but to be assured that the NLC can be built, attention has been given to a number of critical components and issues that present special challenges. More engineering and development of a number of mechanical and electrical systems remain to be done, but the conclusion of this study is that indeed the NLC is technically feasible and can be expected to reach the performance levels required to perform research at the TeV energy scale. Volume II covers the following: collimation systems; IP switch and big bend; final focus; the interaction region; multiple bunch issues; control systems; instrumentation; machine protection systems; NLC reliability considerations; NLC conventional facilities. Also included are four appendices on the following topics: An RF power source upgrade to the NLC; a second interaction region for gamma-gamma, gamma-electron; ground motion: theory and measurement; and beam-based feedback: theory and implementation.

  3. Measurement of Dijet Cross Sections in ep Interactions with a Leading Neutron at HERA

    CERN Document Server

    Aktas, A.; Anthonis, T.; Aplin, S.; Asmone, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Brown, D.P.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Delcourt, B.; Demirchyan, R.; De Roeck, A.; Desch, K.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Elsen, E.; Erdmann, W.; Essenov, S.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Fleming, Y.H.; Flucke, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Frising, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grindhammer, Guenter; Gwilliam, C.; Haidt, D.; Hajduk, L.; Haller, J.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Henshaw, O.; Herrera, G.; Herynek, I.; Heuer, R.-D.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, H.; Kapichine, M.; Karlsson, M.; Katzy, J.; Keller, N.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Koutouev, R.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kuckens, J.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebedev, A.; Leiner, B.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxeld, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, J.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Poschl, R.; Portheault, B.; Povh, B.; Prideaux, P.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Scheins, J.; Schilling, F.-P.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schroder, V.; Schultz-Coulon, H.-C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, Marcel; Usik, A.; Utkin, D.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Van Remortel, N.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Vujicic, B.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Wigmore, C.; Winter, G.-G.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zimmermann, J.; Zohrabyan, H.; Zomer, F.

    2005-01-01

    Measurements are reported of the production of dijet events with a leading neutron in ep interactions at HERA. Differential cross sections for photoproduction and deep inelastic scattering are presented as a function of several kinematic variables. Leading order QCD simulation programs are compared with the measurements. Models in which the real or virtual photon interacts with a parton of an exchanged pion are able to describe the data. Next-to-leading order perturbative QCD calculations based on pion exchange are found to be in good agreement with the measured cross sections. The fraction of leading neutron dijet events with respect to all dijet events is also determined. The dijet events with a leading neutron have a lower fraction of resolved photon processes than do the inclusive dijet data.

  4. Implementing NLO DGLAP evolution in parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Höche, Stefan; Krauss, Frank; Prestel, Stefan

    2017-10-01

    We present a parton shower which implements the DGLAP evolution of parton densities and fragmentation functions at next-to-leading order precision up to effects stemming from local four-momentum conservation. The Monte-Carlo simulation is based on including next-to-leading order collinear splitting functions in an existing parton shower and combining their soft enhanced contributions with the corresponding terms at leading order. Soft double counting is avoided by matching to the soft eikonal. Example results from two independent realizations of the algorithm, implemented in the two event generation frameworks Pythia and Sherpa, illustrate the improved precision of the new formalism.

  5. NextGen Future Safety Assessment Game

    Science.gov (United States)

    Ancel, Ersin; Gheorghe, Adrian; Jones, Sharon Monica

    2011-01-01

    The successful implementation of the next generation infrastructure systems requires solid understanding of their technical, social, political and economic aspects along with their interactions. The lack of historical data that relate to the long-term planning of complex systems introduces unique challenges for decision makers and involved stakeholders which in turn result in unsustainable systems. Also, the need to understand the infrastructure at the societal level and capture the interaction between multiple stakeholders becomes important. This paper proposes a methodology in order to develop a holistic approach aiming to provide an alternative subject-matter expert (SME) elicitation and data collection method for future sociotechnical systems. The methodology is adapted to Next Generation Air Transportation System (NextGen) decision making environment in order to demonstrate the benefits of this holistic approach.

  6. Universality of transverse-momentum resummation and hard factors at the NNLO

    Energy Technology Data Exchange (ETDEWEB)

    Catani, Stefano [INFN, Sezione di Firenze and Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino, Florence (Italy); Cieri, Leandro [Dipartimento di Fisica, Università di Roma “La Sapienza” and INFN, Sezione di Roma, I-00185 Rome (Italy); Florian, Daniel de [Departamento de Física, FCEYN, Universidad de Buenos Aires, (1428) Pabellón 1 Ciudad Universitaria, Capital Federal (Argentina); Ferrera, Giancarlo [Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano, I-20133 Milan (Italy); Grazzini, Massimiliano [Institut für Theoretische Physik, Universität Zürich, CH-8057 Zürich (Switzerland)

    2014-04-15

    We consider QCD radiative corrections to the production of colorless high-mass systems in hadron collisions. The logarithmically-enhanced contributions at small transverse momentum are treated to all perturbative orders by a universal resummation formula that depends on a single process-dependent hard factor. We show that the hard factor is directly related to the all-order virtual amplitude of the corresponding partonic process. The direct relation is universal (process-independent), and it is expressed by an all-order factorization formula that we explicitly evaluate up to the next-to-next-to-leading order (NNLO) in QCD perturbation theory. Once the NNLO scattering amplitude is available, the corresponding hard factor is directly determined: it controls NNLO contributions in resummed calculations at full next-to-next-to-leading logarithmic accuracy, and it can be used in applications of the q{sub T} subtraction formalism to perform fully-exclusive perturbative calculations up to NNLO. The universality structure of the hard factor and its explicit NNLO form are also extended to the related formalism of threshold resummation.

  7. Radiative corrections in supersymmetry and application to relic density calculation beyond leading order

    International Nuclear Information System (INIS)

    Chalons, G.

    2010-07-01

    This thesis focuses on the evaluation of supersymmetric radiative corrections for processes involved in the calculation of the relic density of dark matter, in the MSSM (Minimal Supersymmetric Standard Model) and the standard cosmological scenario, as well as the impact of the choice renormalisation scheme in the neutralino/chargino sector based on the measure of three physical masses. This study has been carried out with the help of an automatic program dedicated the the computation of physical observables at one-loop in the MSSM, called SloopS. For the relic density calculation we investigated scenarios where the most studied dark matter candidate, the neutralino, annihilates into gauge boson pair. We covered cases where its mass was of the order of hundreds of GeV to 2 TeV. The full set of electroweak and strong corrections has been taken into account, involved in sub-leading channels with quarks. In the case of very heavy neutralinos, two important effects were outlined: the Sommerfeld enhancement due to massive gauge bosons and maybe even more important some corrections of Sudakov type. (authors)

  8. Fully double-logarithm-resummed cross sections

    International Nuclear Information System (INIS)

    Albino, S.; Bolzoni, P.; Kniehl, B.A.; Kotikov, A.

    2011-01-01

    We calculate the complete double logarithmic contribution to cross sections for semi-inclusive hadron production in the modified minimal-subtraction (MS-bar) scheme by applying dimensional regularization to the double logarithm approximation. The full double logarithmic contribution to the coefficient functions for inclusive hadron production in e + e - annihilation is obtained in this scheme for the first time. Our result agrees with all fixed order results in the literature, which extend to next-to-next-to-leading order.

  9. Fetal Kidney Anomalies: Next Generation Sequencing

    DEFF Research Database (Denmark)

    Rasmussen, Maria; Sunde, Lone; Nielsen, Marlene Louise

    Aim and Introduction Identification of abnormal kidneys in the fetus may lead to termination of the pregnancy and raises questions about the underlying cause and recurrence risk in future pregnancies. In this study, we investigate the effectiveness of targeted next generation sequencing in fetuses...... with prenatally detected kidney anomalies in order to uncover genetic explanations and assess recurrence risk. Also, we aim to study the relation between genetic findings and post mortem kidney histology. Methods The study comprises fetuses diagnosed prenatally with bilateral kidney anomalies that have undergone...... postmortem examination. The approximately 110 genes included in the targeted panel were chosen on the basis of their potential involvement in embryonic kidney development, cystic kidney disease, or the renin-angiotensin system. DNA was extracted from fetal tissue samples or cultured chorion villus cells...

  10. Improving predictions for collider observables by consistently combining fixed order calculations with resummed results in perturbation theory

    International Nuclear Information System (INIS)

    Schoenherr, Marek

    2011-01-01

    With the constantly increasing precision of experimental data acquired at the current collider experiments Tevatron and LHC the theoretical uncertainty on the prediction of multiparticle final states has to decrease accordingly in order to have meaningful tests of the underlying theories such as the Standard Model. A pure leading order calculation, defined in the perturbative expansion of said theory in the interaction constant, represents the classical limit to such a quantum field theory and was already found to be insufficient at past collider experiments, e.g. LEP or HERA. Such a leading order calculation can be systematically improved in various limits. If the typical scales of a process are large and the respective coupling constants are small, the inclusion of fixed-order higher-order corrections then yields quickly converging predictions with much reduced uncertainties. In certain regions of the phase space, still well within the perturbative regime of the underlying theory, a clear hierarchy of the inherent scales, however, leads to large logarithms occurring at every order in perturbation theory. In many cases these logarithms are universal and can be resummed to all orders leading to precise predictions in these limits. Multiparticle final states now exhibit both small and large scales, necessitating a description using both resummed and fixed-order results. This thesis presents the consistent combination of two such resummation schemes with fixed-order results. The main objective therefor is to identify and properly treat terms that are present in both formulations in a process and observable independent manner. In the first part the resummation scheme introduced by Yennie, Frautschi and Suura (YFS), resumming large logarithms associated with the emission of soft photons in massive QED, is combined with fixed-order next-to-leading matrix elements. The implementation of a universal algorithm is detailed and results are studied for various precision

  11. Moral judgment and its relation to second-order theory of mind.

    Science.gov (United States)

    Fu, Genyue; Xiao, Wen S; Killen, Melanie; Lee, Kang

    2014-08-01

    Recent research indicates that moral judgment and 1st-order theory of mind abilities are related. What is not known, however, is how 2nd-order theory of mind is related to moral judgment. In the present study, we extended previous findings by administering a morally relevant theory of mind task (an accidental transgressor) to 4- to 7-year-old Chinese children (N = 79) and analyzing connections with 2nd-order theory of mind understanding. Using hierarchical multiple regression analyses, we found that above and beyond age, children's 1st-order theory of mind and 2nd-order theory of mind each significantly and uniquely contributed to children's moral evaluations of the intention in the accidental transgression. These findings highlight the important roles that 1st- and 2nd-order theory of mind play in leading children to make appropriate moral judgments based on an actor's intention in a social situation. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  12. Historical record of lead accumulation and source in the tidal flat of Haizhou Bay, Yellow Sea: Insights from lead isotopes

    International Nuclear Information System (INIS)

    Zhang, Rui; Guan, Minglei; Shu, Yujie; Shen, Liya; Chen, Xixi; Zhang, Fan; Li, Tiegang

    2016-01-01

    In order to investigate the historical records of lead contamination and source in coastal region of Haizhou Bay, Yellow Sea, a sediment core was collected from tidal flat, dated by 210 Pb and 137 Cs. Lead and its stable isotopic ratios were determined. The profiles of enrichment factor (EF) and Pb isotope ratios showed increasing trend upward throughout the core, correlating closely with the experience of a rapid economic and industrial development of the catchment. According to Pb isotopic ratios, coal combustion emission mainly contributed to the Pb burden in sediments. Based on end-member model, coal combustion emission dominated anthropogenic Pb sources in recent decades contributing from 48% to 67% in sediment. And the contribution of leaded gasoline was lower than 20%. A stable increase of coal combustion source was found in sediment core, while the contribution of leaded gasoline had declined recently, with the phase-out of leaded gasoline in China. - Highlights: •Pb contamination in tidal flat of Haizhou Bay was chronicled by a sediment core. •The coal combustion source dominated Pb contamination of Haizhou Bay. •Coal combustion source showed an increasing trend in four decades in Haizhou Bay.

  13. Visualization and processing of higher order descriptors for multi-valued data

    CERN Document Server

    Schultz, Thomas

    2015-01-01

    Modern imaging techniques and computational simulations yield complex multi-valued data that require higher-order mathematical descriptors. This book addresses topics of importance when dealing with such data, including frameworks for image processing, visualization, and statistical analysis of higher-order descriptors. It also provides examples of the successful use of higher-order descriptors in specific applications and a glimpse of the next generation of diffusion MRI. To do so, it combines contributions on new developments, current challenges in this area, and state-of-the-art surveys.   Compared to the increasing importance of higher-order descriptors in a range of applications, tools for analysis and processing are still relatively hard to come by. Even though application areas such as medical imaging, fluid dynamics, and structural mechanics are very different in nature they face many shared challenges. This book provides an interdisciplinary perspective on this topic with contributions from key rese...

  14. Reevaluation of the Hadronic Contributions to the Muon g-2 and to alpha(MZ)

    CERN Document Server

    Davier, Michel; Malaescu, Bogdan; Zhang, Zhiqing

    2011-01-01

    We reevaluate the hadronic contributions to the muon magnetic anomaly, and to the running of the electromagnetic coupling constant at the Z-boson mass. We include new pi+pi- cross-section data from KLOE, all available multi-hadron data from BABAR, a reestimation of missing low-energy contributions using results on cross sections and process dynamics from BABAR, a reevaluation of all experimental contributions using the software package HVPTools together with a reanalysis of inter-experiment and inter-channel correlations, and a reevaluation of the continuum contributions from perturbative QCD at four loops. These improvements lead to a decrease in the hadronic contributions with respect to earlier evaluations. For the muon g-2 we find lowest-order hadronic contributions of (692.3 +- 4.2) 10^-10 and (701.5 +- 4.7) 10^-10 for the e+e- based and tau-based analyses, respectively, and full Standard Model predictions that differ by 3.6 sigma and 2.4 sigma from the experimental value. For the e+e- based five-quark h...

  15. Exposure to lead from intake of coffee

    DEFF Research Database (Denmark)

    Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

    Food and beverages is one of the primary sources of intake of and exposure to lead, with beverages accounting for almost 50%. Previous studies from Denmark have estimated that the intake of lead from coffee is very high and may contribute to up to 20% of the total lead intake from food and bevera......Food and beverages is one of the primary sources of intake of and exposure to lead, with beverages accounting for almost 50%. Previous studies from Denmark have estimated that the intake of lead from coffee is very high and may contribute to up to 20% of the total lead intake from food...... and beverages. This estimate is, however, based on older, non-published data. In the current project extensive chemical analyses of coffee beans, drinking water and ready-to-drink coffee have been performed. The results hereof have been compared to calculations of the total intake of lead from food...... and beverages. The results show that the intake of lead from coffee is considerably lower than previously estimated and account for 4.2% and 3.3% of the total lead intake from food and beverages for Danish men and women, respectively. It can generally be concluded that the intake of lead from coffee is low...

  16. Contribution of the irreversible displacement of domain walls to the piezoelectric effect in barium titanate and lead zirconate titanate ceramics

    CERN Document Server

    Damjanovic, D

    1997-01-01

    The contribution from the irreversible displacement of non-180 deg domain walls to the direct longitudinal piezoelectric d sub 3 sub 3 coefficient of BaTiO sub 3 and Pb(Zr, Ti)O sub 3 ceramics was determined quantitatively by using the Rayleigh law. Effects of the crystal structure and microstructure of the ceramics as well as the external d.c. pressure on the domain wall contribution to d sub 3 sub 3 were examined. In barium titanate, this domain wall contribution is large (up to 35% of the total d sub 3 sub 3 , under the experimental conditions used) and dependent on the external d.c. pressure in coarse grained ceramics, and much smaller and independent of the external d.c. pressure in fine-grained samples. The presence of internal stresses in fine-grained ceramics could account for the observed behaviour. The analysis shows that the domain-wall contribution to the d sub 3 sub 3 in lead zirconate titanate ceramics is large in compositions close to the morphotropic phase boundary that contain a mixture of te...

  17. Measurement of the cross section for prompt isolated diphoton production using the full CDF run II data sample.

    Science.gov (United States)

    Aaltonen, T; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Butti, P; Buzatu, A; Calamba, A; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Chokheli, D; Ciocci, M A; Clark, A; Clarke, C; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; d'Ascenzo, N; Datta, M; De Barbaro, P; Demortier, L; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dorigo, M; Driutti, A; Ebina, K; Edgar, R; Elagin, A; Erbacher, R; Errede, S; Esham, B; Eusebi, R; Farrington, S; Fernández Ramos, J P; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Frisch, H; Funakoshi, Y; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Hahn, S R; Han, J Y; Happacher, F; Hara, K; Hare, M; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hays, C; Heinrich, J; Herndon, M; Hocker, A; Hong, Z; Hopkins, W; Hou, S; Hughes, R E; Husemann, U; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kambeitz, M; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kurata, M; Laasanen, A T; Lammel, S; Lancaster, M; Lannon, K; Latino, G; Lee, H S; Lee, J S; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lipeles, E; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, P; Martínez, M; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagliarone, C; Palencia, E; Palni, P; Papadimitriou, V; Parker, W; Pauletta, G; Paulini, M; Paus, C; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Ranjan, N; Redondo Fernández, I; Renton, P; Rescigno, M; Riddick, T; Rimondi, F; Ristori, L; Robson, A; Rodriguez, T; Rolli, S; Ronzani, M; Roser, R; Rosner, J L; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schwarz, T; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sinervo, P; Sliwa, K; Smith, J R; Snider, F D; Sorin, V; Song, H; Stancari, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Vázquez, F; Velev, G; Vellidis, C; Vernieri, C; Vidal, M; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wallny, R; Wang, S M; Warburton, A; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Zanetti, A M; Zeng, Y; Zhou, C; Zucchelli, S

    2013-03-08

    This Letter reports a measurement of the cross section for producing pairs of central prompt isolated photons in proton-antiproton collisions at a total energy sqrt[s] = 1.96 TeV using data corresponding to 9.5 fb(-1) integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. The measured differential cross section is compared to three calculations derived from the theory of strong interactions. These include a prediction based on a leading order matrix element calculation merged with a parton shower model, a next-to-leading order calculation, and a next-to-next-to-leading order calculation. The first and last calculations reproduce most aspects of the data, thus showing the importance of higher-order contributions for understanding the theory of strong interaction and improving measurements of the Higgs boson and searches for new phenomena in diphoton final states.

  18. Higher-order corrections in the cut vertex theory and the reciprocity relation in (PHI3)6 field theory

    International Nuclear Information System (INIS)

    Kubota, T.

    1980-01-01

    Higher-order corrections to deep inelastic and inclusive annihilation processes in the asymptotically free (PHI 3 ) 6 theory are calculated by using the method of cut vertices proposed by Mueller. Renormalization of the cut vertices is carried out up the two-loop level and it is found that, in the minimal subtraction scheme, the equality between the anomalous dimension of the space-like cut vertex and that of the corresponding time-like cut vertex does not hold beyond the leading order. Corrections to the coefficient functions are also calculated to study the Q 2 dependence of the moment up to the next-to-leading order. It is shown that the reciprocity relation suggested by Gribov and Lipatov on the basis of the leading-order calculation does not hold in the higher order. (orig.)

  19. Observation and analysis of nanodomain textures in dielectric relaxor lead magnesium niobate

    International Nuclear Information System (INIS)

    Bursill, L.A.; Qian, Hua; Peng, Julin; Fan, X.D.

    1995-01-01

    High-resolution (0.2nm) images are used to locate chemical domains occurring with length scales of 1-5nm in the dielectric relaxor lead magnesium niobate (PMN). The experimental HRTEM images are analysed using computer-simulations and image matching in order to clarify and characterize the nature of the chemical ordering. Madelung electrostatic energy calculations are used to rank a set of structural models for possible ordered and disordered distributions of Nb and Mg over the B-sites of perovskite ABO 3 . Next, the chemical domain textures are modelled using next-nearest-neighbour Ising (NNNI) models and Monte Carlo methods. This results in a preferred model for the B-site distribution (the extended NNN-Ising model), which is used for image simulations. Both HRTEM many-beam bright-and dark-field and single-beam dark-field TEM images are obtained and compared with the experimental images. The final result is a realistic atomic model for the Nb, Mg distribution of PMN. 42 refs., 2 tabs., 10 figs

  20. Lead mobilisation in the hyporheic zone and river bank sediments of a contaminated stream. Contribution to diffuse pollution

    Energy Technology Data Exchange (ETDEWEB)

    Palumbo-Roe, Barbara; Wragg, Joanna; Banks, Vanessa J. [British Geological Survey, Keyworth Nottingham (United Kingdom)

    2012-12-15

    Purpose: Past metal mining has left a legacy of highly contaminated sediments representing a significant diffuse source of contamination to water bodies in the UK and worldwide. This paper presents the results of an integrated approach used to define the role of sediments in contributing to the dissolved lead (Pb) loading to surface water in a mining-impacted catchment. Materials and methods: The Rookhope Burn catchment, northern England, UK is affected by historical mining and processing of lead ore. Quantitative geochemical loading determinations, measurements of interstitial water chemistry from the stream hyporheic zone and inundation tests of bank sediments were carried out. Results and discussion: High concentrations of Pb in the sediments from the catchment, identified from the British Geological Survey Geochemical Baseline Survey of the Environment (GBASE) data, demonstrate both the impact of mineralisation and widespread historical mining. The results from stream water show that the stream Pb load increased in the lower part of the catchment, without any apparent or significant contribution of point sources of Pb to the stream. Relative to surface water, the interstitial water of the hyporheic zone contained high concentrations of dissolved Pb in the lower reaches of the Rookhope Burn catchment, downstream of a former mine washing plant. Concentrations of 56 {mu}g l{sup -1} of dissolved Pb in the interstitial water of the hyporheic zone may be a major cause of the deterioration of fish habitats in the stream and be regarded as a serious risk to the target of good ecological status as defined in the European Water Framework Directive. Inundation tests provide an indication that bank sediments have the potential to contribute dissolved Pb to surface water. Conclusions: The determination of Pb in the interstitial water and in the inundation water, taken with water Pb mass balance and sediment Pb distribution maps at the catchment scale, implicate the

  1. Four-loop relation between the MS and on-shell quark mass

    International Nuclear Information System (INIS)

    Marquard, Peter; Smirnov, Alexander V.; Smirnov, Vladimir A.; Steinhauser, Matthias

    2016-01-01

    In this contribution we discuss the four-loop relation between the on-shell and MS definition of heavy quark masses which is applied to the top, bottom and charm case. We also present relations between the MS quark mass and various threshold mass definitions and discuss the uncertainty at next-to-next-to-next-to-leading order.

  2. Structural contribution to the ferroelectric fatigue in lead zirconate titanate ceramics

    Science.gov (United States)

    Hinterstein, M.; Rouquette, J.; Haines, J.; Papet, Ph.; Glaum, J.; Knapp, M.; Eckert, J.; Hoffman, M.

    2014-09-01

    Many ferroelectric devices are based on doped lead zirconate titanate (PZT) ceramics with compositions near the morphotropic phase boundary (MPB), at which the relevant material's properties approach their maximum. Based on a synchrotron x-ray diffraction study of MPB PZT, bulk fatigue is unambiguously found to arise from a less effective field induced tetragonal-to-monoclinic transformation, at which the degradation of the polarization flipping is detected by a less intense and more diffuse anomaly in the atomic displacement parameter of lead. The time dependence of the ferroelectric response on a structural level down to 250 μs confirms this interpretation in the time scale of the piezolectric strain response.

  3. Higher-order QCD predictions for dark matter production at the LHC in simplified models with s-channel mediators.

    Science.gov (United States)

    Backović, Mihailo; Krämer, Michael; Maltoni, Fabio; Martini, Antony; Mawatari, Kentarou; Pellen, Mathieu

    Weakly interacting dark matter particles can be pair-produced at colliders and detected through signatures featuring missing energy in association with either QCD/EW radiation or heavy quarks. In order to constrain the mass and the couplings to standard model particles, accurate and precise predictions for production cross sections and distributions are of prime importance. In this work, we consider various simplified models with s -channel mediators. We implement such models in the FeynRules/MadGraph5_aMC@NLO framework, which allows to include higher-order QCD corrections in realistic simulations and to study their effect systematically. As a first phenomenological application, we present predictions for dark matter production in association with jets and with a top-quark pair at the LHC, at next-to-leading order accuracy in QCD, including matching/merging to parton showers. Our study shows that higher-order QCD corrections to dark matter production via s -channel mediators have a significant impact not only on total production rates, but also on shapes of distributions. We also show that the inclusion of next-to-leading order effects results in a sizeable reduction of the theoretical uncertainties.

  4. Higher-order QCD predictions for dark matter production at the LHC in simplified models with s-channel mediators

    Energy Technology Data Exchange (ETDEWEB)

    Backović, Mihailo [Centre for Cosmology, Particle Physics and Phenomenology (CP3), Université catholique de Louvain, 1348, Louvain-la-Neuve (Belgium); Krämer, Michael [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056, Aachen (Germany); Maltoni, Fabio; Martini, Antony [Centre for Cosmology, Particle Physics and Phenomenology (CP3), Université catholique de Louvain, 1348, Louvain-la-Neuve (Belgium); Mawatari, Kentarou, E-mail: kentarou.mawatari@vub.ac.be [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Pleinlaan 2, 1050, Brussels (Belgium); Pellen, Mathieu [Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056, Aachen (Germany)

    2015-10-07

    Weakly interacting dark matter particles can be pair-produced at colliders and detected through signatures featuring missing energy in association with either QCD/EW radiation or heavy quarks. In order to constrain the mass and the couplings to standard model particles, accurate and precise predictions for production cross sections and distributions are of prime importance. In this work, we consider various simplified models with s-channel mediators. We implement such models in the FeynRules/MadGraph5{sub a}MC@NLO framework, which allows to include higher-order QCD corrections in realistic simulations and to study their effect systematically. As a first phenomenological application, we present predictions for dark matter production in association with jets and with a top-quark pair at the LHC, at next-to-leading order accuracy in QCD, including matching/merging to parton showers. Our study shows that higher-order QCD corrections to dark matter production via s-channel mediators have a significant impact not only on total production rates, but also on shapes of distributions. We also show that the inclusion of next-to-leading order effects results in a sizeable reduction of the theoretical uncertainties.

  5. Higher-order QCD predictions for dark matter production at the LHC in simplified models with s-channel mediators

    Energy Technology Data Exchange (ETDEWEB)

    Backovic, Mihailo; Maltoni, Fabio; Martini, Antony [Universite catholique de Louvain, Centre for Cosmology, Particle Physics and Phenomenology (CP3), Louvain-la-Neuve (Belgium); Kraemer, Michael; Pellen, Mathieu [RWTH Aachen University, Institute for Theoretical Particle Physics and Cosmology, Aachen (Germany); Mawatari, Kentarou [Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Brussels (Belgium)

    2015-10-15

    Weakly interacting dark matter particles can be pair-produced at colliders and detected through signatures featuring missing energy in association with either QCD/EW radiation or heavy quarks. In order to constrain the mass and the couplings to standard model particles, accurate and precise predictions for production cross sections and distributions are of prime importance. In this work, we consider various simplified models with s-channel mediators. We implement such models in the FeynRules/MadGraph5{sub a}MC rate at NLO framework, which allows to include higher-order QCD corrections in realistic simulations and to study their effect systematically. As a first phenomenological application, we present predictions for dark matter production in association with jets and with a top-quark pair at the LHC, at next-to-leading order accuracy in QCD, including matching/merging to parton showers. Our study shows that higher-order QCD corrections to dark matter production via s-channel mediators have a significant impact not only on total production rates, but also on shapes of distributions. We also show that the inclusion of next-to-leading order effects results in a sizeable reduction of the theoretical uncertainties. (orig.)

  6. Higher-order QCD predictions for dark matter production at the LHC in simplified models with s-channel mediators

    International Nuclear Information System (INIS)

    Backovic, Mihailo; Maltoni, Fabio; Martini, Antony; Kraemer, Michael; Pellen, Mathieu; Mawatari, Kentarou

    2015-01-01

    Weakly interacting dark matter particles can be pair-produced at colliders and detected through signatures featuring missing energy in association with either QCD/EW radiation or heavy quarks. In order to constrain the mass and the couplings to standard model particles, accurate and precise predictions for production cross sections and distributions are of prime importance. In this work, we consider various simplified models with s-channel mediators. We implement such models in the FeynRules/MadGraph5 a MC rate at NLO framework, which allows to include higher-order QCD corrections in realistic simulations and to study their effect systematically. As a first phenomenological application, we present predictions for dark matter production in association with jets and with a top-quark pair at the LHC, at next-to-leading order accuracy in QCD, including matching/merging to parton showers. Our study shows that higher-order QCD corrections to dark matter production via s-channel mediators have a significant impact not only on total production rates, but also on shapes of distributions. We also show that the inclusion of next-to-leading order effects results in a sizeable reduction of the theoretical uncertainties. (orig.)

  7. Separation of gravitational-wave and cosmic-shear contributions to cosmic microwave background polarization.

    Science.gov (United States)

    Kesden, Michael; Cooray, Asantha; Kamionkowski, Marc

    2002-07-01

    Inflationary gravitational waves (GW) contribute to the curl component in the polarization of the cosmic microwave background (CMB). Cosmic shear--gravitational lensing of the CMB--converts a fraction of the dominant gradient polarization to the curl component. Higher-order correlations can be used to map the cosmic shear and subtract this contribution to the curl. Arcminute resolution will be required to pursue GW amplitudes smaller than those accessible by the Planck surveyor mission. The blurring by lensing of small-scale CMB power leads with this reconstruction technique to a minimum detectable GW amplitude corresponding to an inflation energy near 10(15) GeV.

  8. EU ambition to build the world's leading bioeconomy-Uncertain times demand innovative and sustainable solutions.

    Science.gov (United States)

    Bell, John; Paula, Lino; Dodd, Thomas; Németh, Szilvia; Nanou, Christina; Mega, Voula; Campos, Paula

    2018-01-25

    This article outlines the current context and the development of the European Bioeconomy Strategy. It analyses the current situation, challenges and needs for EU action and concludes with the next steps that the European Commission will undertake to review and update the Bioeconomy Strategy. Bioeconomy offers great opportunities to realising a competitive, circular and sustainable economy with a sound industrial base that is less dependent on fossil carbon. A sustainable bioeconomy also contributes to climate change mitigation, with oceans, forests and soils being major carbon sinks and fostering negative CO 2 emissions. The EU has invested significantly in research and innovation in this field and the European Commission is committed to lead on European bioeconomy strategy. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Threshold-improved predictions for charm production in deep-inelastic scattering

    International Nuclear Information System (INIS)

    Lo Presti, N.A.; Kawamura, H.; Vogt, A.

    2010-08-01

    We have extended previous results on the threshold expansion of the gluon coefficient function for the charm contribution to the deep-inelastic structure function F 2 by deriving all thresholdenhanced contributions at the next-to-next-to-leading order. The size of these corrections is briefly illustrated, and a first step towards extending this improvement to more differential charmproduction cross sections is presented. (orig.)

  10. The Youth Space Vision for the Decade to Come: The Next Generation Network Looks Back to Look Forward

    Science.gov (United States)

    Cornell, Ariane

    2010-05-01

    The Space Generation Advisory Council in support of the United Nations Programme on Space Applications (SGAC) is a non-governmental organization of 4,000 members in 90+ countries which aims to represent university students and young space professionals to the United Nations, States, and other space agencies and organizations. In 2009, SGAC celebrated its ten year anniversary, and it was this milestone that inspired its 10 Year Anniversary Conference in June 2009, which was attended by members of the SGAC community from six continents and 21 States. The conference aimed to lead the attendees in a review of the past ten years of the politics of space as well as the "spacescape" (i.e., the overview of the organizations conducting space activities such as launching vehicles, owning satellites, or purchasing space-based services). The point of this review was to help analyze how SGAC and the youth it represents should position themselves for the next ten years. What resulted is a decadal vision from the youth (approximately 18-35 year olds) of the direction of global development and challenges, the role of the space sector in this development, and how SGAC and the youth it represents could best contribute to the development. The international community stands at a crossroads in the progress of humans in space. This paper represents a first step the youth are making in taking advantage of this watershed moment to develop an updated, pertinent role for the next ten years.

  11. Leading and Next-to-Leading Order Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

    Czech Academy of Sciences Publication Activity Database

    Adolph, C.; Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Antonov, A. A.; Austregisilio, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Braun, C.; Bravar, A.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Crespo, M.; Dalla Torre, S.; Das, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O.; Dhara, L.; Donskov, S.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.V.; Elia, C.; Eversheim, P.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Fresne von Hohenesche, N.; Friedrich, J.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Guthörl, T.; Haas, F.; von Harrach, D.; Heinsius, F.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Höppner, Ch.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Joosten, R.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.; Khokhlov, Y.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.; Kolosov, V.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V.; Korzenev, A.; Kotzinian, A.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z.; Kunne, F.; Kurek, K.; Lauser, L.; Lednev, A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Y.; Morreale, A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.; Nowak, W. D.; Nunes, A.S.; Olshevsky, A.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.; Pretz, J.; Quaresma, M.; Quintans, C.; Rajotte, J.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Rocco, E.; Rondio, E.; Rossiyskaya, N. S.; Ryabchikov, D.; Samoylenko, V.; Sandacz, A.; Sapozhnikov, M.; Sarkar, S.; Savin, I.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlütter, T.; Schmidt, A.; Schmidt, K.; Schmiden, H.; Schmitt, L.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O.; Silva, L.; Sinha, L.; Sissakian, A.; Slunecka, M.; Smirnov, G.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Tkatchev, L.; Uhl, S.; Uman, I.; Vandenbroucke, M.; Virius, M.; Vlassov, N.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhuravlev, N.; Ziembicki, M.; Zvyagin, A.

    2013-01-01

    Roč. 87, č. 5 (2013), 052018:1-22 ISSN 1550-7998 Institutional support: RVO:68081731 Keywords : dependent structure-function * Monte-Carlo generator Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 4.864, year: 2013

  12. A subtraction scheme for computing QCD jet cross sections at NNLO: regularization of doubly-real emissions

    International Nuclear Information System (INIS)

    Somogyi, Gabor; Trocsanyi, Zoltan; Del Duca, Vittorio

    2007-01-01

    We present a generalization of the dipole subtraction scheme for computing jet cross sections in electron-positron annihilation at next-to-next-to-leading order accuracy in perturbative QCD. In this first part we deal with the regularization of the doubly-real contribution to the NNLO correction

  13. A subtraction scheme for computing QCD jet cross sections at NNLO: regularization of doubly-real emissions

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, Gabor [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, PO Box 51 (Hungary); Trocsanyi, Zoltan [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, PO Box 51 (Hungary); Del Duca, Vittorio [Istituto Nazionale di Fisica Nucleare, Sez. di Torino, via P. Giuria, 1 - 10125 Turin (Italy)

    2007-01-15

    We present a generalization of the dipole subtraction scheme for computing jet cross sections in electron-positron annihilation at next-to-next-to-leading order accuracy in perturbative QCD. In this first part we deal with the regularization of the doubly-real contribution to the NNLO correction.

  14. A subtraction scheme for computing QCD jet cross sections at NNLO: regularization of real-virtual emission

    Energy Technology Data Exchange (ETDEWEB)

    Somogyi, Gabor; Trocsanyi, Zoltan [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen, PO Box 51 (Hungary)

    2007-01-15

    We present a generalization of the dipole subtraction scheme for computing jet cross sections in electron-positron annihilation at next-to-next-to-leading order accuracy in perturbative QCD. In this second part we deal with the regularization of the real-virtual contribution to the NNLO correction.

  15. arXiv Higgs boson pair production at NNLO with top quark mass effects

    CERN Document Server

    Grazzini, Massimiliano; Jones, Stephen; Kallweit, Stefan; Kerner, Matthias; Lindert, Jonas M.; Mazzitelli, Javier

    2018-05-09

    We consider QCD radiative corrections to Higgs boson pair production through gluon fusion in proton collisions. We combine the exact next-to-leading order (NLO) contribution, which features two-loop virtual amplitudes with the full dependence on the top quark mass M$_{t}$ , with the next-to-next-to-leading order (NNLO) corrections computed in the large-M$_{t}$ approximation. The latter are improved with different reweighting techniques in order to account for finite-M$_{t}$ effects beyond NLO. Our reference NNLO result is obtained by combining one-loop double-real corrections with full M$_{t}$ dependence with suitably reweighted real-virtual and double-virtual contributions evaluated in the large-M$_{t}$ approximation. We present predictions for inclusive cross sections in pp collisions at $ \\sqrt{s} $ = 13, 14, 27 and 100 TeV and we discuss their uncertainties due to missing M$_{t}$ effects. Our approximated NNLO corrections increase the NLO result by an amount ranging from +12% at $ \\sqrt{s}=13 $ TeV to +7%...

  16. Two-photon contributions to the elastic electron-nucleon scattering in the Skyrme model; Zwei-Photon-Beitraege zur elastischen Elektron-Nukleon-Streuung im Skyrme-Modell

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, Markus

    2008-09-23

    The electromagnetic form factors are crucial for our understanding of the inner structure of the proton. Recently it has become feasible to measure them by the use of polarisation transfer techniques in addition to the traditional Rosenbluth separation method. Thereby emerged an incompatibility of the results obtained by these two different experimental methods. It is commonly assumed that the discrepance is induced by higher order corrections to the cross section, especially through two-photon exchange processes. Unfortunately these processes cannot be calculated in a model independent manner because off-shell photon nucleon vertices arise. Effective chiral lagrangians contain already local two-photon couplings and therefore seem exceptionally well suited to study the anomaly contribution to the two-photon exchange. These couplings give two-photon exchange contributions that can be understood as the coupling of the nucleon to pions, decaying into two virtual photons. A particular contribution emerges from the chiral anomaly of QCD, that describes the two-photon decay of the neutral pion. The most important goal of this work is the calculation of the contribution arising from the anomaly to the elastic electron-proton scattering. The results are expected to be widely model independent since the anomaly directly reflects a QCD property. Based on the Skyrme model the protons are realized as soliton solutions in effective chiral theories. The next to leading order contribution to the cross section is given by the interference between the one- and two-photon exchange. The latter contains an ultraviolet divergence, which is renormalized by a local effective counterterm. This counterterm contributes to the width of the neutral pion decay which determines the finite part of the counterterm coefficient. The affect of the anomaly to the Rosenbluth separation of the electromagnetic form factors as well as the discrepance regarding the polarization measurements is extensively

  17. Getting Ahead Three Steps to Take Your Career to the Next Level

    CERN Document Server

    Garfinkle, Joel A

    2011-01-01

    A leading executive coach pinpoints three vital traits necessary to advance your career In Getting Ahead, one of the top 50 executive coaches in the United States, Joel Garfinkle reveals his signature model for mastering three skills to take your career to the next level: Perception, Visibility, and Influence. The PVI-model of professional advancement will teach you to: (1) Actively promote yourself as an asset and valuable person inside the organization, (2) Increase your visibility to gain others' recognition and appreciation for your efforts and (3) Become a person of influence who makes ke

  18. Building next-generation converged networks theory and practice

    CERN Document Server

    Pathan, Al-Sakib Khan

    2013-01-01

    Supplying a comprehensive introduction to next-generation networks, Building Next-Generation Converged Networks: Theory and Practice strikes a balance between how and why things work and how to make them work. It compiles recent advancements along with basic issues from the wide range of fields related to next generation networks. Containing the contributions of 56 industry experts and researchers from 16 different countries, the book presents relevant theoretical frameworks and the latest research. It investigates new technologies such as IPv6 over Low Power Wireless Personal Area Network (6L

  19. Contribution of lead and thorium to the history of the Oklo reactors

    International Nuclear Information System (INIS)

    Devillers, C.; Menes, J.

    1978-01-01

    The authors report the results of measuring lead and thorium in a series of representative samples of the superconcentrations of uranium found in the Oklo mineralization. Interpretation of the data reveals the complexity of the history of lead in the deposit, but makes it possible to derive a number of important facts, namely early disturbance and recent, massive remobilization of lead. One is led to conclude that the date of the uranium emplacement may be greater than 1900 million years. The absence of high thorium contents in the ''normal'' rich ore confirms the importance of dating the nuclear reaction on the basis of the Th/U balance. This determination, which draws on the same set of data as for the Nd/U balance, gives a mean value close to 1930 million years. (author)

  20. Vision-21: Space Travel for the Next Millennium

    International Nuclear Information System (INIS)

    Landis, G.A.

    1990-04-01

    The papers from this symposium, that was held at the NASA Lewis Research Center on April 3-4, 1990, are presented. The theme selected for the symposium was space travel for the next millennium. It was hoped that the participants would allow their focus to consider possible advances in technologies for space travel not just for currently envisioned projects, but for possibilities beyond the next generation and the next thousand years. About half of the contributed papers focussed on propulsion and the other half on other issues related to space travel

  1. Pressure-induced decoupling of the order-disorder and displacive contributions to the phase transition in diguanidinium tetrachlorostannate

    DEFF Research Database (Denmark)

    Szafranski, M.; Ståhl, Kenny

    2000-01-01

    The crystals of diguanidinium tetrachlorostannate [C(NH2)(3)](2)(+).SnCl4-2, were studied by single-crystal x-ray diffraction at various temperatures and by calorimetric and dielectric measurements at ambient and high hydrostatic pressures. At room temperature the crystal structure is orthorhombic......) cations. At ambient pressure the crystals undergo two first-order phase transitions at 354.8 and 395.4 K. The former, between two orthorhombic phases (Pbca --> Cmca), is characterized by antiphase displacement of the double sheets along the b direction of the low-temperature unit cell which is coupled...... to dynamical disordering of G(2) and transformation of its hydrogen bonding scheme. At elevated pressures the coupling between the displacive and order-disorder contributions is modified and its breaking near a triple point at 180 MPa and 270 K results in a pressure-induced phase observed between Pbca and Cmca...

  2. Measurement of dijet production in diffractive deep-inelastic scattering with a leading proton at HERA

    International Nuclear Information System (INIS)

    Aaron, F.D.; Alexa, C.; Rotaru, M.; Stoicea, G.; Andreev, V.; Belousov, A.; Eliseev, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Malinovski, E.; Rusakov, S.; Shtarkov, L.N.; Soloviev, Y.; Vazdik, Y.; Backovic, S.; Dubak, A.; Lastovicka-Medin, G.; Picuric, I.; Raicevic, N.; Baghdasaryan, A.; Baghdasaryan, S.; Zohrabyan, H.; Barrelet, E.; Bartel, W.; Belov, P.; Brandt, G.; Brinkmann, M.; Britzger, D.; Campbell, A.J.; Eckerlin, G.; Elsen, E.; Felst, R.; Fischer, D.J.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Gouzevitch, M.; Grebenyuk, A.; Grell, B.R.; Habib, S.; Haidt, D.; Helebrant, C.; Kleinwort, C.; Kogler, R.; Kraemer, M.; Levonian, S.; Lipka, K.; List, B.; List, J.; Meyer, A.B.; Meyer, J.; Niebuhr, C.; Nowak, K.; Olsson, J.E.; Pahl, P.; Panagoulias, I.; Papadopoulou, T.; Petrukhin, A.; Piec, S.; Pitzl, D.; Schmitt, S.; Sefkow, F.; Shushkevich, S.; South, D.; Steder, M.; Wuensch, E.; Begzsuren, K.; Ravdandorj, T.; Tseepeldorj, B.; Bizot, J.C.; Brisson, V.; Delcourt, B.; Jacquet, M.; Pascaud, C.; Tran, T.H.; Zhang, Z.; Zomer, F.; Boudry, V.; Moreau, F.; Specka, A.; Bozovic-Jelisavcic, I.; Mudrinic, M.; Pandurovic, M.; Smiljanic, I.; Bracinik, J.; Kenyon, I.R.; Newman, P.R.; Thompson, P.D.; Bruncko, D.; Cerny, V.; Ferencei, J.; Bunyatyan, A.; Buschhorn, G.; Chekelian, V.; Dossanov, A.; Grindhammer, G.; Kiesling, C.; Bystritskaya, L.; Fedotov, A.; Lubimov, V.; Ozerov, D.; Rostovtsev, A.; Zhokin, A.; Cantun Avila, K.B.; Contreras, J.G.; Ruiz Tabasco, J.E.; Ceccopieri, F.; Delvax, J.; Wolf, E.A. de; Favart, L.; Hreus, T.; Janssen, X.; Marage, P.; Roosen, R.; Staykova, Z.; Mechelen, P. van; Cerny, K.; Pokorny, B.; Polifka, R.; Salek, D.; Valkarova, A.; Zacek, J.; Coughlan, J.A.; Morris, J.V.; Sankey, D.P.C.; Cvach, J.; Reimer, P.; Zalesak, J.; Dainton, J.B.; Gabathuler, E.; Greenshaw, T.; Klein, M.; Kluge, T.; Kretzschmar, J.; Laycock, P.; Maxfield, S.J.; Mehta, A.; Patel, G.D.; Daum, K.; Meyer, H.; Diaconu, C.; Hoffmann, D.; Sauvan, E.; Vallee, C.; Dobre, M.; Placakyte, R.; Dodonov, V.; Povh, B.; Egli, S.; Hildebrandt, M.; Horisberger, R.; Feltesse, J.; Perez, E.; Schoeffel, L.; Goerlich, L.; Mikocki, S.; Milcewicz-Mika, I.; Nowak, G.; Sopicki, P.; Turnau, J.; Grab, C.; Henderson, R.C.W.; Sloan, T.; Hennekemper, E.; Herbst, M.; Krueger, K.; Lendermann, V.; Schultz-Coulon, H.C.; Henschel, H.; Hiller, K.H.; Kostka, P.; Lange, W.; Naumann, T.; Herrera, G.; Lopez-Fernandez, R.; Huber, F.; Pirumov, H.; Radescu, V.; Sauter, M.; Schoening, A.; Joensson, L.; Jung, H.; Kapichine, M.; Makankine, A.; Morozov, A.; Nikitin, D.; Palichik, V.; Spaskov, V.; Landon, M.P.J.; Rizvi, E.; Traynor, D.; Martyn, H.U.; Mueller, K.; Robmann, P.; Straumann, U.; Truoel, P.; Stella, B.; Sykora, T.; Tsakov, I.; Wegener, D.

    2012-01-01

    The cross section of diffractive deep-inelastic scattering ep→eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement is performed for fractional proton longitudinal momentum loss x P 2 in squared four-momentum transfer at the proton vertex and 4 2 2 in photon virtuality. The differential cross sections extrapolated to vertical stroke t vertical stroke 2 are in agreement with next-to-leading order QCD predictions based on diffractive parton distribution functions extracted from measurements of inclusive and dijet cross sections in diffractive deep-inelastic scattering. The data are also compared with leading order Monte Carlo models. (orig.)

  3. Connected, disconnected and strange quark contributions to HVP

    Energy Technology Data Exchange (ETDEWEB)

    Bijnens, Johan; Relefors, Johan [Department of Astronomy and Theoretical Physics, Lund University,Sölvegatan 14A, SE 223-62 Lund (Sweden)

    2016-11-14

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of −1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  4. Connected, disconnected and strange quark contributions to HVP

    Science.gov (United States)

    Bijnens, Johan; Relefors, Johan

    2016-11-01

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of -1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  5. Connected, disconnected and strange quark contributions to HVP

    International Nuclear Information System (INIS)

    Bijnens, Johan; Relefors, Johan

    2016-01-01

    We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ratio of −1/10 derived earlier in two flavour ChPT at one-loop order to a large part of the higher order contributions and discuss corrections to it. Our final estimate of the ratio disconnected to connected is negative and a few % in magnitude.

  6. On the twist-2 contributions to polarized structure functions and new sum rules

    International Nuclear Information System (INIS)

    Bluemlein, J.; Kochelev, N.

    1996-03-01

    The twist-2 contributions to the polarized structure functions in deep inelastic lepton-hadron scattering are calculated including the exchange of weak bosons and using both the operator product expansion and the covariant parton model. A new relation between two structure functions leading to a sequence of new sum rules is found. The light quark mass corrections to the structure functions are derived in lowest order QCD. (orig.)

  7. Changes in predicted protein disorder tendency may contribute to disease risk

    Directory of Open Access Journals (Sweden)

    Hu Yang

    2011-12-01

    Full Text Available Abstract Background Recent studies suggest that many proteins or regions of proteins lack 3D structure. Defined as intrinsically disordered proteins, these proteins/peptides are functionally important. Recent advances in next generation sequencing technologies enable genome-wide identification of novel nucleotide variations in a specific population or cohort. Results Using the exonic single nucleotide variations (SNVs identified in the 1,000 Genomes Project and distributed by the Genetic Analysis Workshop 17, we systematically analysed the genetic and predicted disorder potential features of the non-synonymous variations. The result of experiments suggests that a significant change in the tendency of a protein region to be structured or disordered caused by SNVs may lead to malfunction of such a protein and contribute to disease risk. Conclusions After validation with functional SNVs on the traits distributed by GAW17, we conclude that it is valuable to consider structure/disorder tendencies while prioritizing and predicting mechanistic effects arising from novel genetic variations.

  8. Lithographed Superconducting Resonator Development for Next-Generation Frequency Multiplexing Readout of Transition-Edge Sensors

    Science.gov (United States)

    Faramarzi, F.; De Haan, T.; Kusaka, A.; Lee, A.; Neuhauser, B.; Plambeck, R.; Raum, C.; Suzuki, A.; Westbrook, B.

    2018-03-01

    Ground-based cosmic microwave background (CMB) experiments are undergoing a period of exponential growth. Current experiments are observing with 1000-10,000 detectors, and the next-generation experiment (CMB stage 4) is proposing to deploy approximately 500,000 detectors. This order of magnitude increase in detector count will require a new approach for readout electronics. We have developed superconducting resonators for next-generation frequency-domain multiplexing (fMUX) readout architecture. Our goal is to reduce the physical size of resonators, such that resonators and detectors can eventually be integrated on a single wafer. To reduce the size of these resonators, we have designed spiral inductors and interdigitated capacitors that resonate around 10-100 MHz, an order of magnitude higher frequency compared to current fMUX readout systems. The higher frequency leads to a wider bandwidth and would enable higher multiplexing factor than the current ˜ 50 detectors per readout channel. We will report on the simulation, fabrication method, characterization technique, and measurement of quality factor of these resonators.

  9. Studies of tt+cc production with MadGraph5_aMC@NLO and Herwig++ for the ATLAS experiment

    CERN Document Server

    The ATLAS collaboration

    2016-01-01

    Studies of the simulation of ttcc at the LHC, at a centre-of-mass energy of 13 TeV, based on next-to-leading order calculations with MadGraph5_aMC@NLO matched to Herwig++ are presented. Samples with ttcc in the three flavour scheme, in a next-to-leading order matrix element are compared to an inclusive tt sample with the charm contribution coming from the parton shower. The effects of generator-level cuts, the functional form of the renormalization and factorization scales, and the starting scale of the parton shower are investigated.

  10. The Next Generation Science Standards

    Science.gov (United States)

    Pruitt, Stephen L.

    2015-01-01

    The Next Generation Science Standards (NGSS Lead States 2013) were released almost two years ago. Work tied to the NGSS, their adoption, and implementation continues to move forward around the country. Stephen L. Pruitt, senior vice president, science, at Achieve, an independent, nonpartisan, nonprofit education reform organization that was a lead…

  11. Events Leading to One Person's Career in Forest Entomology

    Science.gov (United States)

    John C. Moser

    2000-01-01

    Today, I'm going to discuss the subject that I know most about--the important events and the many mentors leading to my career in Forest Entomology at the Southern Research Station, as well as my past and present cooperators. This includes my views on the present state of SPB Research, as well as my future plans for the next 40 years.

  12. A precise determination of the HVP contribution to the muon anomalous magnetic moment from lattice QCD

    Science.gov (United States)

    Lehner, Christoph

    2018-03-01

    In this talk I present the current status of a precise first-principles calculation of the quark connected, quark disconnected, and leading QED and strong isospin-breaking contributions to the leading-order hadronic vacuum polarization by the RBC and UKQCD collaborations. The lattice data is also combined with experimental e+e- scattering data, consistency between the two datasets is checked, and a combined result with smaller error than the lattice data and e+e- scattering data individually is presented.

  13. Electroweak penguin contributions to non-leptonic ΔF=1 decays at NNLO

    International Nuclear Information System (INIS)

    Buras, Andrzej J.; Gambino, Paolo; Haisch, Ulrich A.

    2000-01-01

    We calculate the O(α s ) corrections to the Z 0 -penguin and electroweak box diagrams relevant for non-leptonic ΔF=1 decays with F=S,B. This calculation provides the complete O(α W α s ) and O(α W α s sin 2 θ W m t 2 ) corrections (α W =α/sin 2 θ W ) to the Wilson coefficients of the electroweak penguin four quark operators relevant for non-leptonic K- and B-decays. We argue that this is the dominant part of the next-next-to-leading (NNLO) contributions to these coefficients. Our results allow us to reduce considerably the uncertainty due to the definition of the top quark mass present in the existing NLO calculations of non-leptonic decays. The NNLO corrections to the coefficient of the color singlet (V-A)x(V-A) electroweak penguin operator Q 9 relevant for B-decays are generally moderate, amount to a few percent for the choice m t (μ t =m t ) and depend only weakly on the renormalization scheme. Larger NNLO corrections with substantial scheme dependence are found for the coefficients of the remaining electroweak penguin operators Q 7 , Q 8 and Q 10 . In particular, the strong scheme dependence of the NNLO corrections to C 8 allows us to reduce considerably the scheme dependence of C 8 8 > 2 relevant for the ratio ε'/ε

  14. Generation 'Next' and nuclear power

    International Nuclear Information System (INIS)

    Sergeev, A.A.

    2001-01-01

    My generation was labeled by Russian mass media as generation 'Next.' My technical education is above average. My current position is as a mechanical engineer in the leading research and development institute for Russian nuclear engineering for peaceful applications. It is noteworthy to point out that many of our developments were really first-of-a-kind in the history of engineering. However, it is difficult to grasp the importance of these accomplishments, especially since the progress of nuclear technologies is at a standstill. Can generation 'Next' be independent in their attitude towards nuclear power or shall we rely on the opinions of elder colleagues in our industry? (authors)

  15. Leading non-cancelling infra-red divergences in perturbative QCD

    International Nuclear Information System (INIS)

    Carneiro, C.E.; Frenkel, J.; Thomaz, M.T.; Day, M.; Taylor, J.C.

    1980-01-01

    In QCD in perturbative theory, for the inclusive cross-section for the scattering of two coloured particles, graphs which contribute to the general leading order αs(αs/nΛ)(sup n) are identified and these contributions are added (Λ is the IR cut-off). The work is done in the Coulomb gauge; an appendix discusses the Feynman gauge. (Author) [pt

  16. Observation and analysis of nanodomain textures in dielectric relaxor lead magnesium niobate

    Energy Technology Data Exchange (ETDEWEB)

    Bursill, L A; Qian, Hua; Peng, Julin; Fan, X D

    1995-10-01

    High-resolution (0.2nm) images are used to locate chemical domains occurring with length scales of 1-5nm in the dielectric relaxor lead magnesium niobate (PMN). The experimental HRTEM images are analysed using computer-simulations and image matching in order to clarify and characterize the nature of the chemical ordering. Madelung electrostatic energy calculations are used to rank a set of structural models for possible ordered and disordered distributions of Nb and Mg over the B-sites of perovskite ABO{sub 3}. Next, the chemical domain textures are modelled using next-nearest-neighbour Ising (NNNI) models and Monte Carlo methods. This results in a preferred model for the B-site distribution (the extended NNN-Ising model), which is used for image simulations. Both HRTEM many-beam bright-and dark-field and single-beam dark-field TEM images are obtained and compared with the experimental images. The final result is a realistic atomic model for the Nb, Mg distribution of PMN. 42 refs., 2 tabs., 10 figs.

  17. Topology distribution of the contribution of diagrams of a one-matrix integral of Hermitian matrices of high order

    International Nuclear Information System (INIS)

    Saakyan, D.B.; Shagoyan, R.M.

    1992-01-01

    Matrix models of strings have recently been studied intensively, especially in connection with the possibility of calculating nonperturbative effects (in the sense of expanding in the genera). Here, a one-matrix model with quartic interaction is considered. Equations are obtained for the contributions of diagrams with surface genus k and with M sites. The distributions of the contributions of the diagrams of order M over the genera k are studied numerically for orders up to M = 16

  18. Impact of beauty and charm H1-ZEUS combined measurements on PDFs and determination of the strong coupling

    Energy Technology Data Exchange (ETDEWEB)

    Vafaee, A. [National Foundation of Elites, Tehran (Iran, Islamic Republic of); Khorramian, A. [Semnan University, Faculty of Physics, Semnan (Iran, Islamic Republic of)

    2017-11-15

    In this QCD analysis, we investigate the impact of recent measurements of heavy-flavor charm and beauty cross sections data sets on the simultaneous determination of Parton Distribution Functions (PDFs) and the strong coupling, α{sub s}(M{sup 2}{sub Z}). We perform three different fits based on Variable-Flavour Number Scheme (VFNS) at the Leading Order (LO) and Next-to-Leading Order (NLO) and choose the full HERA run I and II combined data as a new measurement of inclusive Deep Inelastic Scattering (DIS) cross sections for our base data set. We show that including charm and beauty cross sections data reduces the uncertainty of gluon distribution and improves the fit quality up to 4.1% from leading order to next-to-leading order and up to 1.7% for only NLO without and with beauty and charm data contributions. (orig.)

  19. Applications of the leading-order Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations to the combined HERA data on deep inelastic scattering

    International Nuclear Information System (INIS)

    Block, Martin M.; Durand, Loyal; Ha, Phuoc; McKay, Douglas W.

    2011-01-01

    We recently derived explicit solutions of the leading-order Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equations for the Q 2 evolution of the singlet structure function F s (x,Q 2 ) and the gluon distribution G(x,Q 2 ) using very efficient Laplace transform techniques. We apply our results here to a study of the HERA data on deep inelastic ep scattering as recently combined by the H1 and ZEUS groups. We use initial distributions F 2 γp (x,Q 0 2 ) and G(x,Q 0 2 ) determined for x s (x,Q 0 2 ) from F 2 γp (x,Q 0 2 ) using small nonsinglet quark distributions taken from either the CTEQ6L or the MSTW2008LO analyses, evolve F s and G to arbitrary Q 2 , and then convert the results to individual quark distributions. Finally, we show directly from a study of systematic trends in a comparison of the evolved F 2 γp (x,Q 2 ) with the HERA data that the assumption of leading-order DGLAP evolution is inconsistent with those data.

  20. Effect of leading-edge geometry on boundary-layer receptivity to freestream sound

    Science.gov (United States)

    Lin, Nay; Reed, Helen L.; Saric, W. S.

    1991-01-01

    The receptivity to freestream sound of the laminar boundary layer over a semi-infinite flat plate with an elliptic leading edge is simulated numerically. The incompressible flow past the flat plate is computed by solving the full Navier-Stokes equations in general curvilinear coordinates. A finite-difference method which is second-order accurate in space and time is used. Spatial and temporal developments of the Tollmien-Schlichting wave in the boundary layer, due to small-amplitude time-harmonic oscillations of the freestream velocity that closely simulate a sound wave travelling parallel to the plate, are observed. The effect of leading-edge curvature is studied by varying the aspect ratio of the ellipse. The boundary layer over the flat plate with a sharper leading edge is found to be less receptive. The relative contribution of the discontinuity in curvature at the ellipse-flat-plate juncture to receptivity is investigated by smoothing the juncture with a polynomial. Continuous curvature leads to less receptivity. A new geometry of the leading edge, a modified super ellipse, which provides continuous curvature at the juncture with the flat plate, is used to study the effect of continuous curvature and inherent pressure gradient on receptivity.

  1. Hadronic correlation functions with quark-disconnected contributions in lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Guelpers, Vera Magdalena

    2015-09-14

    One of the fundamental interactions in the Standard Model of particle physics is the strong force, which can be formulated as a non-abelian gauge theory called Quantum Chromodynamics (QCD). In the low-energy regime, where the QCD coupling becomes strong and quarks and gluons are confined to hadrons, a perturbative expansion in the coupling constant is not possible. However, the introduction of a four-dimensional Euclidean space-time lattice allows for an ab initio treatment of QCD and provides a powerful tool to study the low-energy dynamics of hadrons. Some hadronic matrix elements of interest receive contributions from diagrams including quark-disconnected loops, i.e. disconnected quark lines from one lattice point back to the same point. The calculation of such quark loops is computationally very demanding, because it requires knowledge of the all-to-all propagator. In this thesis we use stochastic sources and a hopping parameter expansion to estimate such propagators. We apply this technique to study two problems which relay crucially on the calculation of quark-disconnected diagrams, namely the scalar form factor of the pion and the hadronic vacuum polarization contribution to the anomalous magnet moment of the muon. The scalar form factor of the pion describes the coupling of a charged pion to a scalar particle. We calculate the connected and the disconnected contribution to the scalar form factor for three different momentum transfers. The scalar radius of the pion is extracted from the momentum dependence of the form factor. The use of several different pion masses and lattice spacings allows for an extrapolation to the physical point. The chiral extrapolation is done using chiral perturbation theory (χPT). We find that our pion mass dependence of the scalar radius is consistent with χPT at next-to-leading order. Additionally, we are able to extract the low energy constant anti l{sub 4} from the extrapolation, and our result is in agreement with results

  2. Hadronic correlation functions with quark-disconnected contributions in lattice QCD

    International Nuclear Information System (INIS)

    Guelpers, Vera Magdalena

    2015-01-01

    One of the fundamental interactions in the Standard Model of particle physics is the strong force, which can be formulated as a non-abelian gauge theory called Quantum Chromodynamics (QCD). In the low-energy regime, where the QCD coupling becomes strong and quarks and gluons are confined to hadrons, a perturbative expansion in the coupling constant is not possible. However, the introduction of a four-dimensional Euclidean space-time lattice allows for an ab initio treatment of QCD and provides a powerful tool to study the low-energy dynamics of hadrons. Some hadronic matrix elements of interest receive contributions from diagrams including quark-disconnected loops, i.e. disconnected quark lines from one lattice point back to the same point. The calculation of such quark loops is computationally very demanding, because it requires knowledge of the all-to-all propagator. In this thesis we use stochastic sources and a hopping parameter expansion to estimate such propagators. We apply this technique to study two problems which relay crucially on the calculation of quark-disconnected diagrams, namely the scalar form factor of the pion and the hadronic vacuum polarization contribution to the anomalous magnet moment of the muon. The scalar form factor of the pion describes the coupling of a charged pion to a scalar particle. We calculate the connected and the disconnected contribution to the scalar form factor for three different momentum transfers. The scalar radius of the pion is extracted from the momentum dependence of the form factor. The use of several different pion masses and lattice spacings allows for an extrapolation to the physical point. The chiral extrapolation is done using chiral perturbation theory (χPT). We find that our pion mass dependence of the scalar radius is consistent with χPT at next-to-leading order. Additionally, we are able to extract the low energy constant anti l 4 from the extrapolation, and our result is in agreement with results from

  3. A precise determination of the HVP contribution to the muon anomalous magnetic moment from lattice QCD

    Directory of Open Access Journals (Sweden)

    Lehner Christoph

    2018-01-01

    Full Text Available In this talk I present the current status of a precise first-principles calculation of the quark connected, quark disconnected, and leading QED and strong isospin-breaking contributions to the leading-order hadronic vacuum polarization by the RBC and UKQCD collaborations. The lattice data is also combined with experimental e+e− scattering data, consistency between the two datasets is checked, and a combined result with smaller error than the lattice data and e+e− scattering data individually is presented.

  4. Software Defined Radio Architecture Contributions to Next Generation Space Communications

    Science.gov (United States)

    Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John

    2015-01-01

    systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.

  5. Skyrme interaction to second order in nuclear matter

    Science.gov (United States)

    Kaiser, N.

    2015-09-01

    Based on the phenomenological Skyrme interaction various density-dependent nuclear matter quantities are calculated up to second order in many-body perturbation theory. The spin-orbit term as well as two tensor terms contribute at second order to the energy per particle. The simultaneous calculation of the isotropic Fermi-liquid parameters provides a rigorous check through the validity of the Landau relations. It is found that published results for these second order contributions are incorrect in most cases. In particular, interference terms between s-wave and p-wave components of the interaction can contribute only to (isospin or spin) asymmetry energies. Even with nine adjustable parameters, one does not obtain a good description of the empirical nuclear matter saturation curve in the low density region 0\\lt ρ \\lt 2{ρ }0. The reason for this feature is the too strong density-dependence {ρ }8/3 of several second-order contributions. The inclusion of the density-dependent term \\frac{1}{6}{t}3{ρ }1/6 is therefore indispensable for a realistic description of nuclear matter in the Skyrme framework.

  6. Pressure derivatives of the second-order elastic constants of strontium, barium, and lead nitrate

    International Nuclear Information System (INIS)

    Bedi, S.S.; Verma, M.P.

    1980-01-01

    An interpretation is given of the measured results on the pressure derivatives of second-order elastic constants (SOEC) of strontium barium, and lead nitrate crystallizing in the fluorite type structure from the Lundquist potential. Potential parameters are determined from the experimental values of SOEC and the equilibrium condition

  7. Triviality bound on lightest Higgs mass in next to minimal supersymmetric model

    International Nuclear Information System (INIS)

    Choudhury, S.R.; Mamta; Dutta, Sukanta

    1998-01-01

    We study the implication of triviality on Higgs sector in next to minimal supersymmetric model (NMSSM) using variational field theory. It is shown that the mass of the lightest Higgs boson in NMSSM has an upper bound ∼ 10 M w which is of the same order as that in the standard model. (author)

  8. Scattering amplitudes to all orders in meson exchange

    International Nuclear Information System (INIS)

    Silbar, R.R.; Mattis, M.P.

    1990-01-01

    As the number of colors in QCD, N C , becomes large, it is possible to sum up all meson-exchange contributions, however arbitrarily complicated, to meson-baryon and baryon-baryon scattering. A semi-classical structure for the two-flavor theory emerges, in close correspondence to vector-meson-augmented Skyrme models. In this limit, baryons act as extended static sources for the classical meson fields. This leads to non-linear differential equations for the classical meson fields which can be solved numerically for static radial (hedgehog-like) solutions. The non-linear terms in the equations of motion for the quantized meson fields can then be simplified, to leading order in 1/N C , by replacing all factors of the meson field but one by the previously-found classical field. This results in linear, Schroedinger-like equations, which are easily solved. For the meson-baryon case the solution can be subsequently analyzed to obtain the phase shifts for the scattering and, from these, the baryon resonance spectrum of the model. As the warm-up, we have carried out this calculation for the simple case of σ mesons only, finding sensible results. 8 refs., 3 figs

  9. Australian contribution to the science of radioastronomy

    International Nuclear Information System (INIS)

    Mills, B.Y.

    1988-01-01

    Australia has made numerous major contributions to the science of radioastronomy and played a leading role in its early development. The history of the Australian effort is reviewed, from this early seminal work until the present day when contributions continue at an important level

  10. AugerNext: innovative research studies for the next generation ground-based ultra-high energy cosmic ray experiment

    Directory of Open Access Journals (Sweden)

    Haungs Andreas

    2013-06-01

    Full Text Available The findings so far of the Pierre Auger Observatory and also of the Telescope Array define the requirements for a possible next generation experiment: it needs to be considerably increased in size, it needs a better sensitivity to composition, and it should cover the full sky. AugerNext aims to perform innovative research studies in order to prepare a proposal fulfilling these demands. Such R&D studies are primarily focused in the following areas iconsolidation of the detection of cosmic rays using MHz radio antennas; iiproof-of-principle of cosmic-ray microwave detection; iiitest of the large-scale application of a new generation photo-sensors; ivgeneralization of data communication techniques; vdevelopment of new ways of muon detection with surface arrays. These AugerNext studies on new innovative detection methods for a next generation cosmic-ray experiment are performed at the Pierre Auger Observatory. The AugerNext consortium consists presently of fourteen partner institutions from nine European countries supported by a network of European funding agencies and it is a principal element of the ASPERA/ApPEC strategic roadmaps.

  11. Renormalization group improved bottom mass from {Upsilon} sum rules at NNLL order

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Andre H.; Stahlhofen, Maximilian [Wien Univ. (Austria). Fakultaet fuer Physik; Ruiz-Femenia, Pedro [Wien Univ. (Austria). Fakultaet fuer Physik; Valencia Univ. - CSIC (Spain). IFIC

    2012-09-15

    We determine the bottom quark mass from non-relativistic large-n {Upsilon} sum rules with renormalization group improvement at next-to-next-to-leading logarithmic order. We compute the theoretical moments within the vNRQCD formalism and account for the summation of powers of the Coulomb singularities as well as of logarithmic terms proportional to powers of {alpha}{sub s} ln(n). The renormalization group improvement leads to a substantial stabilization of the theoretical moments compared to previous fixed-order analyses, which did not account for the systematic treatment of the logarithmic {alpha}{sub s} ln(n) terms, and allows for reliable single moment fits. For the current world average of the strong coupling ({alpha}{sub s}(M{sub Z})=0.1183{+-}0.0010) we obtain M{sub b}{sup 1S}=4.755{+-}0.057{sub pert} {+-}0.009{sub {alpha}{sub s}}{+-}0.003{sub exp} GeV for the bottom 1S mass and anti m{sub b}(anti m{sub b})=4.235{+-}0.055{sub pert}{+-}0.003{sub exp} GeV for the bottom MS mass, where we have quoted the perturbative error and the uncertainties from the strong coupling and the experimental data.

  12. Drinking Water Contamination Due To Lead-based Solder

    Science.gov (United States)

    Garcia, N.; Bartelt, E.; Cuff, K. E.

    2004-12-01

    The presence of lead in drinking water creates many health hazards. Exposure to lead-contaminated water can affect the brain, the central nervous system, blood cells, and kidneys, causing such problems as mental retardation, kidney disease, heart disease, stroke, and death. One way in which lead can contaminate our water supply is through the use of lead solder to join pipes. Lead solder was widely used in the past because of its ease of application as well as its low cost. Lead contamination in residential areas has previously been found to be a particularly serious problem in first-draw samples, of water that has sat stagnant in pipes overnight. To investigate the time-dependence of drinking water lead contamination, we analyzed samples taken hourly of water exposed to lead solder. While our preliminary data was insufficient to show more than a rough correlation between time of exposure and lead concentration over short periods (1-3 hours), we were able to confirm that overnight exposure of water to lead-based solder results in the presence high levels of lead. We also investigated other, external factors that previous research has indicated contribute to increased concentrations of lead. Our analysis of samples of lead-exposed water at various pH and temperatures suggests that these factors can be equally significant in terms of their contribution to elevated lead concentration levels. In particular, water that is slightly corrosive appears to severely impact the solubility of lead. As this type of water is common in much of the Northeast United States, the presence of lead-based solder in residential areas there is especially problematic. Although lead-based solder has been banned since the 1980s, it remains a serious concern, and a practical solution still requires further research.

  13. Born to Lead? The Effect of Birth Order on Non-Cognitive Abilities

    OpenAIRE

    Black, Sandra E.; Grönqvist, Erik; Öckert, Björn

    2017-01-01

    We study the effect of birth order on personality traits among men using population data on enlistment records and occupations for Sweden. We find that earlier born men are more emotionally stable, persistent, socially outgoing, willing to assume responsibility, and able to take initiative than later-borns. In addition, we find that birth order affects occupational sorting; first-born children are more likely to be managers, while later-born children are more likely to be self-employed. We al...

  14. Workload control and order release : A lean solution for make-to-order companies

    NARCIS (Netherlands)

    Thurer, M.; Stevenson, M.; Silva, C.; Land, M.J.; Fredendall, L.D.

    2012-01-01

    Protecting throughput from variance is the key to achieving lean. Workload control (WLC) accomplishes this in complex make-to-order job shops by controlling lead times, capacity, and work-in-process (WIP). However, the concept has been dismissed by many authors who believe its order release

  15. Gluon contribution to the Sivers effect. COMPASS results on deuteron target

    Directory of Open Access Journals (Sweden)

    Szabelski Adam

    2015-01-01

    Full Text Available Sivers effect for gluons is connected to gluon orbital angular momentum which may be the missing part of the nucleon spin puzzle. We present a method of extraction of Sivers effect for gluons from COMPASS SIDIS data on transversely polarised target. In order to access the Sivers effect for gluons photon-gluon fusion (PGF process is used. To enhance the fraction of PGF in the sample high-pT hadron pair events are selected. The method is based on a assumption that there are 3 processes contributing to the muon-nucleon scattering: PGF, leading process and QCD Compton process. Then one performs a weighting procedure which enables to extract the asymmetries for the 3 contributing processes simultaneously. In order to do that a neural network trained by a Monte Carlo to assign to each event 3 probabilities corresponding to the 3 processes is needed. Finaly we show results of Sivers effect for gluons extraction on COMPASS data with transversely polarised deuteron target. APGFsinΦ2h–ΦS = −0.14 ± 0.15 (stat. at ‹XG› = 0.126.

  16. Counterbalancing for Serial Order Carryover Effects in Experimental Condition Orders

    Science.gov (United States)

    Brooks, Joseph L.

    2012-01-01

    Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed…

  17. The O(αs3TF2) contributions to the gluonic operator matrix element

    International Nuclear Information System (INIS)

    Ablinger, J.; Blümlein, J.; De Freitas, A.; Hasselhuhn, A.; Manteuffel, A. von; Round, M.; Schneider, C.

    2014-01-01

    The O(α s 3 T F 2 C F (C A )) contributions to the transition matrix element A gg,Q relevant for the variable flavor number scheme at 3-loop order are calculated. The corresponding graphs contain two massive fermion lines of equal mass leading to terms given by inverse binomially weighted sums beyond the usual harmonic sums. In x-space two root-valued letters contribute in the iterated integrals in addition to those forming the harmonic polylogarithms. We outline technical details needed in the calculation of graphs of this type, which are as well of importance in the case of two different internal massive lines

  18. Two-loop contributions in the supersymmetric Higgs sector

    International Nuclear Information System (INIS)

    Rzehak, H.A.

    2005-01-01

    Corrections to the one-loop contributions of the order O(α b ) with α b =λ b 62/(4π) within the MSSM with real parameters are the main topic in the first part of the thesis. The mass of the lightest Higgs boson was calculated up to order O(α b αs) for arbitrary tan β by means of the Feynman-diagrammatic method. In the bottom-sbottom sector four renormalization schemes were studied. With a suitably chosen bottom-Yukawa coupling the leading tan β-amplified corrections, which result from the bottom-sbottom sector, can be regarded already on the one-loop level. For this in the present thesis the bottom quark mass in the DR scheme with a resummation of the tan β-amplified terms was applied. In the analysis especially the non-leading contributions, which exceed in a complete calculation of the order O(α b α s ) corrections the one-loop result with resummed tan β-amplified terms. In the second part of the thesis the main topic lied on the study of the order O(α t α s ) corrections in the MSSM with complex parameters

  19. Next generation toroidal devices

    International Nuclear Information System (INIS)

    Yoshikawa, Shoichi

    1998-10-01

    A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one's view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)

  20. Next generation toroidal devices

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Shoichi [Princeton Plasma Physics Lab., Princeton Univ., NJ (United States)

    1998-10-01

    A general survey of the possible approach for the next generation toroidal devices was made. Either surprisingly or obviously (depending on one`s view), the technical constraints along with the scientific considerations lead to a fairly limited set of systems for the most favorable approach for the next generation devices. Specifically if the magnetic field strength of 5 T or above is to be created by superconducting coils, it imposes minimum in the aspect ratio for the tokamak which is slightly higher than contemplated now for ITER design. The similar technical constraints make the minimum linear size of a stellarator large. Scientifically, it is indicated that a tokamak of 1.5 times in the linear dimension should be able to produce economically, especially if a hybrid reactor is allowed. For the next stellarator, it is strongly suggested that some kind of helical axis is necessary both for the (almost) absolute confinement of high energy particles and high stability and equilibrium beta limits. The author still favors a heliac most. Although it may not have been clearly stated in the main text, the stability afforded by the shearless layer may be exploited fully in a stellarator. (author)

  1. HFCs contribution to the greenhouse effect. Present and projected estimations

    Energy Technology Data Exchange (ETDEWEB)

    Libre, J.M.; Elf-Atochem, S.A. [Central Research & Development, Paris (France)

    1997-12-31

    This paper reviews data that can be used to calculate hydrofluorocarbon (HFC) contribution to the greenhouse effect and compare it to other trace gas contributions. Projections are made for 2010 and 2100 on the basis of available emission scenarios. Industrial judgement on the likelihood of those scenarios is also developed. Calculations can be made in two different ways: from Global Warming Potential weighted emissions of species or by direct calculation of radiative forcing based on measured and projected atmospheric concentrations of compounds. Results show that HFCs corresponding to commercial uses have a negligible contribution to the greenhouse effect in comparison with other trace gases. The projected contributions are also very small even if very high emission scenarios are maintained for decades. In 2010 this contribution remains below 1%. Longer term emissions projections are difficult. However, based on the IPCC scenario IS92a, in spite of huge emissions projected for the year 2100, the HFC contribution remains below 3%. Actually many factors indicate that the real UFC contribution to the greenhouse effect will be even smaller than presented here. Low emissive systems and small charges will likely improve sharply in the future and have drastically improved in the recent past. HFC technology implementation is likely to grow in the future, reach a maximum before the middle of the next century; the market will stabilise driven by recycling, closing of systems and competitive technologies. This hypothesis is supported by previous analysis of the demand for HTCs type applications which can be represented by {open_quotes}S{close_quotes} type curves and by recent analysis indicating that the level of substitution of old products by HFCs is growing slowly. On the basis of those data and best industrial judgement, the contribution of HFCs to the greenhouse effect is highly likely to remain below 1% during the next century. 11 refs., 2 figs., 5 tabs.

  2. Diffractive Dijet Production with a Leading Proton in ep Collisions at HERA

    CERN Document Server

    Andreev, V.; Begzsuren, K.; Belousov, A.; Belov, P.; Boudry, V.; Brandt, G.; Brinkmann, M.; Brisson, V.; Britzger, D.; Buniatyan, A.; Bylinkin, A.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Ceccopieri, F.; Cerny, K.; Chekelian, V.; Contreras, J.G.; Cvach, J.; Dainton, J.B.; Daum, K.; Diaconu, C.; Dobre, M.; Dodonov, V.; Dossanov, A.; Eckerlin, G.; Egli, S.; Elsen, E.; Favart, L.; Fedotov, A.; Feltesse, J.; Ferencei, J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Grebenyuk, A.; Greenshaw, T.; Grindhammer, G.; Haidt, D.; Henderson, R.C.W.; Herbst, M.; Hladky, J.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Huber, F.; Jacquet, M.; Janssen, X.; Jung, H.; Kapichine, M.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kogler, R.; Kostka, P.; Kretzschmar, J.; Krüger, K.; Landon, M.P.J.; Lange, W.; Laycock, P.; Lebedev, A.; Levonian, S.; Lipka, K.; List, B.; List, J.; Lobodzinski, B.; Malinovski, E.; Martyn, H.U.; Maxfield, S.J.; Mehta, A.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Morozov, A.; Müller, K.; Naumann, Th.; Newman, P.R.; Niebuhr, C.; Nowak, G.; Olsson, J.E.; Ozerov, D.; Pahl, P.; Pascaud, C.; Patel, G.D.; Perez, E.; Petrukhin, A.; Picuric, I.; Pirumov, H.; Pitzl, D.; Placakyte, R.; Pokorny, B.; Polifka, R.; Radescu, V.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Rusakov, S.; Šálek, D.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.C.; Sefkow, F.; Shushkevich, S.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Straumann, U.; Sykora, T.; Thompson, P.D.; Traynor, D.; Truöl, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Vazdik, Y.; Wegener, D.; Wünsch, E.; Žáček, J.; Zhang, Z.; Žlebčík, R.; Zohrabyan, H.; Zomer, F.

    2015-05-11

    The cross section of the diffractive process e^+p -> e^+Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q^2 <2 GeV^2 and in deep-inelastic scattering with 4 GeV^2to next-to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering.

  3. Diffractive dijet production with a leading proton in ep collisions at HERA

    International Nuclear Information System (INIS)

    Andreev, V.; Baghdasaryan, A.; Begzsuren, K.

    2014-12-01

    The cross section of the diffractive process e + p→e + Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q 2 <2 GeV 2 and in deep-inelastic scattering with 4 GeV 2 to next-to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering.

  4. Next Generation NASA Initiative for Space Geodesy

    Science.gov (United States)

    Merkowitz, S. M.; Desai, S.; Gross, R. S.; Hilliard, L.; Lemoine, F. G.; Long, J. L.; Ma, C.; McGarry J. F.; Murphy, D.; Noll, C. E.; hide

    2012-01-01

    Space geodesy measurement requirements have become more and more stringent as our understanding of the physical processes and our modeling techniques have improved. In addition, current and future spacecraft will have ever-increasing measurement capability and will lead to increasingly sophisticated models of changes in the Earth system. Ground-based space geodesy networks with enhanced measurement capability will be essential to meeting these oncoming requirements and properly interpreting the sate1!ite data. These networks must be globally distributed and built for longevity, to provide the robust data necessary to generate improved models for proper interpretation ofthe observed geophysical signals. These requirements have been articulated by the Global Geodetic Observing System (GGOS). The NASA Space Geodesy Project (SGP) is developing a prototype core site as the basis for a next generation Space Geodetic Network (SGN) that would be NASA's contribution to a global network designed to produce the higher quality data required to maintain the Terrestrial Reference Frame and provide information essential for fully realizing the measurement potential of the current and coming generation of Earth Observing spacecraft. Each of the sites in the SGN would include co-located, state of-the-art systems from all four space geodetic observing techniques (GNSS, SLR, VLBI, and DORIS). The prototype core site is being developed at NASA's Geophysical and Astronomical Observatory at Goddard Space Flight Center. The project commenced in 2011 and is scheduled for completion in late 2013. In January 2012, two multiconstellation GNSS receivers, GODS and GODN, were established at the prototype site as part of the local geodetic network. Development and testing are also underway on the next generation SLR and VLBI systems along with a modern DORIS station. An automated survey system is being developed to measure inter-technique vector ties, and network design studies are being

  5. NNLO QCD corrections to Higgs boson production at large transverse momentum

    Energy Technology Data Exchange (ETDEWEB)

    Chen, X. [Center for High Energy Physics, Peking University,Beijing 100871 (China); Cruz-Martinez, J. [Institute for Particle Physics Phenomenology, Department of Physics, University of Durham,Durham, DH1 3LE (United Kingdom); Gehrmann, T. [Department of Physics, University of Zürich,CH-8057 Zürich (Switzerland); Glover, E.W.N. [Institute for Particle Physics Phenomenology, Department of Physics, University of Durham,Durham, DH1 3LE (United Kingdom); Jaquier, M. [Albert-Ludwigs-Universität Freiburg, Physikalisches Institut,D-79104 Freiburg (Germany)

    2016-10-13

    We derive the second-order QCD corrections to the production of a Higgs boson recoiling against a parton with finite transverse momentum, working in the effective field theory in which the top quark contributions are integrated out. To account for quark mass effects, we supplement the effective field theory result by the full quark mass dependence at leading order. Our calculation is fully differential in the final state kinematics and includes the decay of the Higgs boson to a photon pair. It allows one to make next-to-next-to-leading order (NNLO)-accurate theory predictions for Higgs-plus-jet final states and for the transverse momentum distribution of the Higgs boson, accounting for the experimental definition of the fiducial cross sections. The NNLO QCD corrections are found to be moderate and positive, they lead to a substantial reduction of the theory uncertainty on the predictions. We compare our results to 8 TeV LHC data from ATLAS and CMS. While the shape of the data is well-described for both experiments, we agree on the normalization only for CMS. By normalizing data and theory to the inclusive fiducial cross section for Higgs production, good agreement is found for both experiments, however at the expense of an increased theory uncertainty. We make predictions for Higgs production observables at the 13 TeV LHC, which are in good agreement with recent ATLAS data. At this energy, the leading order mass corrections to the effective field theory prediction become significant at large transverse momenta, and we discuss the resulting uncertainties on the predictions.

  6. NNLO QCD corrections to Higgs boson production at large transverse momentum

    Science.gov (United States)

    Chen, X.; Cruz-Martinez, J.; Gehrmann, T.; Glover, E. W. N.; Jaquier, M.

    2016-10-01

    We derive the second-order QCD corrections to the production of a Higgs boson recoiling against a parton with finite transverse momentum, working in the effective field theory in which the top quark contributions are integrated out. To account for quark mass effects, we supplement the effective field theory result by the full quark mass dependence at leading order. Our calculation is fully differential in the final state kinematics and includes the decay of the Higgs boson to a photon pair. It allows one to make next-to-next-to-leading order (NNLO)-accurate theory predictions for Higgs-plus-jet final states and for the transverse momentum distribution of the Higgs boson, accounting for the experimental definition of the fiducial cross sections. The NNLO QCD corrections are found to be moderate and positive, they lead to a substantial reduction of the theory uncertainty on the predictions. We compare our results to 8 TeV LHC data from ATLAS and CMS. While the shape of the data is well-described for both experiments, we agree on the normalization only for CMS. By normalizing data and theory to the inclusive fiducial cross section for Higgs production, good agreement is found for both experiments, however at the expense of an increased theory uncertainty. We make predictions for Higgs production observables at the 13 TeV LHC, which are in good agreement with recent ATLAS data. At this energy, the leading order mass corrections to the effective field theory prediction become significant at large transverse momenta, and we discuss the resulting uncertainties on the predictions.

  7. Development of next BWR plant

    International Nuclear Information System (INIS)

    Moriya, Kumiaki; Tanikawa, Naoshi; Kinoshita, Shoichiro; Utena, Shunsuke

    1995-01-01

    It is expected that BWR power generation will be main nuclear power generation for long period hereafter, and in the ABWRs being constructed at present, the safety, reliability, operation performance, economical efficiency and so on are further heightend as compared with conventional BWRs. On the other hand, in order to cope with future social change, the move to develop the next reactor type following ABWRs was begun already by the cooperation of electirc power companies and plant manufacturers. Hitachi Ltd. has advanced eagerly the development of new light water reactors. Also the objective of BWR power generation hereafter is to heighten the safety, reliability, operation performance and economical efficiency, and the development has been advanced, aiming at bearing the main roles of nuclear power generation. At present, ABWRs are under construction as No. 6 and 7 plants in Kashiwazaki Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc. In order to let ABWRs take root, the further improvement of economy by the standardization, the rationalization by revising the specification and the improvement of machinery and equipment is necessary. As the needs of the development of next generation BWRs, the increase of power output, the heightening of safety and economical efficiency are discussed. The concept of the next generation BWR plant aiming at the start of operation around 2010 is shown. (K.I.)

  8. Development of next BWR plant

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Kumiaki; Tanikawa, Naoshi; Kinoshita, Shoichiro; Utena, Shunsuke [Hitachi Ltd., Ibaraki (Japan). Hitachi Works

    1995-04-01

    It is expected that BWR power generation will be main nuclear power generation for long period hereafter, and in the ABWRs being constructed at present, the safety, reliability, operation performance, economical efficiency and so on are further heightend as compared with conventional BWRs. On the other hand, in order to cope with future social change, the move to develop the next reactor type following ABWRs was begun already by the cooperation of electirc power companies and plant manufacturers. Hitachi Ltd. has advanced eagerly the development of new light water reactors. Also the objective of BWR power generation hereafter is to heighten the safety, reliability, operation performance and economical efficiency, and the development has been advanced, aiming at bearing the main roles of nuclear power generation. At present, ABWRs are under construction as No. 6 and 7 plants in Kashiwazaki Kariwa Nuclear Power Station, Tokyo Electric Power Co., Inc. In order to let ABWRs take root, the further improvement of economy by the standardization, the rationalization by revising the specification and the improvement of machinery and equipment is necessary. As the needs of the development of next generation BWRs, the increase of power output, the heightening of safety and economical efficiency are discussed. The concept of the next generation BWR plant aiming at the start of operation around 2010 is shown. (K.I.).

  9. Temperature dependence of the domain wall magneto-Seebeck effect: avoiding artifacts of lead contributions

    Science.gov (United States)

    Fernández Scarioni, Alexander; Krzysteczko, Patryk; Sievers, Sibylle; Hu, Xiukun; Schumacher, Hans W.

    2018-06-01

    We study the resistive and thermopower signatures of a single domain wall in a magnetic nanowire in the temperature range from 4 K to 204 K. The results are compared to the anisotropic magnetoresistance (AMR) and anisotropic magneto-Seebeck (AMS) data of the whole permalloy nanowire. The AMS ratio of the nanowire reveals a sign change at a temperature of 98 K, while the AMR ratio is positive over the complete temperature range. This behavior is also observed for the domain wall, allowing an attribution of the measured signatures to the domain wall magneto-Seebeck and domain wall magnetoresistive contributions. However, the observed zero crossing of the AMS ratio, in both types of measurements is not expected for permalloy, since the Mott formula predicts a temperature dependency of the AMS identical to the AMR. We discuss the origin of this behavior and can attribute it to the contributions of the lead and the protective platinum layer used in our devices. A correction scheme is presented and applied. Such contributions could also play a role in the analysis of magneto-Seebeck effects in other nanoscale devices, such as the tunnel magneto-Seebeck effect of magnetic tunnel junctions.

  10. Large orders in strong-field QED

    Energy Technology Data Exchange (ETDEWEB)

    Heinzl, Thomas [School of Mathematics and Statistics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Schroeder, Oliver [Science-Computing ag, Hagellocher Weg 73, D-72070 Tuebingen (Germany)

    2006-09-15

    We address the issue of large-order expansions in strong-field QED. Our approach is based on the one-loop effective action encoded in the associated photon polarization tensor. We concentrate on the simple case of crossed fields aiming at possible applications of high-power lasers to measure vacuum birefringence. A simple next-to-leading order derivative expansion reveals that the indices of refraction increase with frequency. This signals normal dispersion in the small-frequency regime where the derivative expansion makes sense. To gain information beyond that regime we determine the factorial growth of the derivative expansion coefficients evaluating the first 82 orders by means of computer algebra. From this we can infer a nonperturbative imaginary part for the indices of refraction indicating absorption (pair production) as soon as energy and intensity become (super)critical. These results compare favourably with an analytic evaluation of the polarization tensor asymptotics. Kramers-Kronig relations finally allow for a nonperturbative definition of the real parts as well and show that absorption goes hand in hand with anomalous dispersion for sufficiently large frequencies and fields.

  11. Lattice QCD results for the HVP contribution to the anomalous magnetic moments of leptons

    Directory of Open Access Journals (Sweden)

    Borsanyi Szabolcs

    2018-01-01

    Full Text Available We present lattice QCD results by the Budapest-Marseille-Wuppertal (BMW Collaboration for the leading-order contribution of the hadron vacuum polarization (LOHVP to the anomalous magnetic moments of all charged leptons. Calculations are performed with u, d, s and c quarks at their physical masses, in volumes of linear extent larger than 6 fm, and at six values of the lattice spacing, allowing for controlled continuum extrapolations. All connected and disconnected contributions are calculated for not only the muon but also the electron and tau anomalous magnetic moments. Systematic uncertainties are thoroughly discussed and comparisons with other calculations and phenomenological estimates are made.

  12. Lattice QCD results for the HVP contribution to the anomalous magnetic moments of leptons

    Science.gov (United States)

    2018-03-01

    We present lattice QCD results by the Budapest-Marseille-Wuppertal (BMW) Collaboration for the leading-order contribution of the hadron vacuum polarization (LOHVP) to the anomalous magnetic moments of all charged leptons. Calculations are performed with u, d, s and c quarks at their physical masses, in volumes of linear extent larger than 6 fm, and at six values of the lattice spacing, allowing for controlled continuum extrapolations. All connected and disconnected contributions are calculated for not only the muon but also the electron and tau anomalous magnetic moments. Systematic uncertainties are thoroughly discussed and comparisons with other calculations and phenomenological estimates are made.

  13. Occupational exposure to lead--granulometric distribution of airborne lead in relation to risk assessment.

    Science.gov (United States)

    Carelli, G; Masci, O; Altieri, A; Castellino, N

    1999-07-01

    The amount of airborne lead absorbed by the body during occupational exposure depends not only on lead concentration in workplace air, but also on the granulometric distribution of the aerosol. The Occupational Safety and Health Administration (OSHA) set the lead Permissible Exposure Limit (PEL) at 50 micrograms/m3 on the basis of Bernard's model and a number of assumptions, including assumption "C", which predicts that the first 12.5 micrograms/m3 are made up of fine particles (aerodynamic diameter 1 micron. Occupational exposure to airborne lead at a concentration of 50 micrograms/m3 and a granulometric distribution calculated according to the above mentioned assumption, leads, in the model, to a mean blood level of 40 micrograms/dl. In the present study, we tested the validity of assumption "C" in the environmental air of a factory that manufactured crystal glassware containing 24% lead oxide. An 8-stage impactor was used to measure the particle size of airborne dust collected from personal and area samplings. Results indicate that, on the whole, assumption "C" cannot be considered valid in the work environment investigated in this study. As a result, lead absorption levels in exposed workers may be noticeably different from those predicted by the OSHA model. We therefore suggest that in order to make a correct evaluation of the risk of occupational exposure to lead, it is essential to integrate total airborne lead concentration with a measurement of the granulometric distribution of the aerosol.

  14. Decoupling of the Leading Order DGLAP Evolution Equation with Spin Dependent Structure Functions

    Science.gov (United States)

    Azadbakht, F. Teimoury; Boroun, G. R.

    2018-02-01

    We propose an analytical solution for DGLAP evolution equations with polarized splitting functions at the Leading Order (LO) approximation based on the Laplace transform method. It is shown that the DGLAP evolution equations can be decoupled completely into two second order differential equations which then are solved analytically by using the initial conditions δ FS(x,Q2)=F[partial δ FS0(x), δ FS0(x)] and {δ G}(x,Q2)=G[partial δ G0(x), δ G0(x)]. We used this method to obtain the polarized structure function of the proton as well as the polarized gluon distribution function inside the proton and compared the numerical results with experimental data of COMPASS, HERMES, and AAC'08 Collaborations. It was found that there is a good agreement between our predictions and the experiments.

  15. Post-Newtonian corrections to the gravitational-wave memory for quasicircular, inspiralling compact binaries

    International Nuclear Information System (INIS)

    Favata, Marc

    2009-01-01

    The Christodoulou memory is a nonlinear contribution to the gravitational-wave field that is sourced by the gravitational-wave stress-energy tensor. For quasicircular, inspiralling binaries, the Christodoulou memory produces a growing, nonoscillatory change in the gravitational-wave 'plus' polarization, resulting in the permanent displacement of a pair of freely-falling test masses after the wave has passed. In addition to its nonoscillatory behavior, the Christodoulou memory is interesting because even though it originates from 2.5 post-Newtonian (PN) order multipole interactions, it affects the waveform at leading (Newtonian/quadrupole) order. The memory is also potentially detectable in binary black-hole mergers. While the oscillatory pieces of the gravitational-wave polarizations for quasicircular, inspiralling compact binaries have been computed to 3PN order, the memory contribution to the polarizations has only been calculated to leading order (the next-to-leading order 0.5PN term has previously been shown to vanish). Here the calculation of the memory for quasicircular, inspiralling binaries is extended to 3PN order. While the angular dependence of the memory remains qualitatively unchanged, the PN correction terms tend to reduce the memory's magnitude. Explicit expressions are given for the memory contributions to the plus polarization and the spin-weighted spherical-harmonic modes of the metric and curvature perturbations. Combined with the recent results of Blanchet et al.[Classical Quantum Gravity 25, 165003 (2008)], this completes the waveform polarizations to 3PN order. This paper also discusses: (i) the difficulties in extracting the memory from numerical relativity simulations, (ii) other nonoscillatory effects that enter the waveform polarizations at high PN orders, and (iii) issues concerning the observability of the memory in gravitational-wave detectors.

  16. Leading the Development of Concepts of Operations for Next-Generation Remotely Piloted Aircraft

    Science.gov (United States)

    2016-01-01

    danced around the next-generation RPA CONOPS through technology demonstration for several years. Individual programs have developed key enabling...party system to take command of the aircraft and sensor payload. Aircraft equipped with Link 16 have the option of slaving their sensor payloads to...collection, shift transmission to theater nodes, and continue to slave the payloads to cues given by joint partners in-theater. Embracing Leadership in

  17. Contribution of hot spring bacterial consortium in cadmium and lead bioremediation through quadratic programming model

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Sudip Kumar; Raut, Sangeeta; Dora, Tapas Kumar [Department of Biotechnology, Gandhi Institute of Engineering and Technology, Gunupur, Rayagada 765 022, Odisha (India); Mohapatra, Pradeep Kumar Das, E-mail: pkdmvu@gmail.com [Department of Microbiology, Vidyasagar University, Midnapore 721 102, West Bengal (India)

    2014-01-30

    Highlights: • Adsorption of cadmium and lead using hot spring microbial consortium. • Development of empirical models for % adsorption using ANOVA and response surface methodology. • Fitting of the kinetics of adsorption to Freundlich and Langmuir model. • Optimization of the operating parameters to maximize the % of adsorption. -- Abstract: In the present investigation, a number of experiments have been conducted to isolate microbial strains from Taptapani Hot Spring Odisha, India for bioremediation of cadmium and lead. The strains Stenotrophomonas maltophilia (SS1), Aeromonas veronii (SS2) and Bacillus barbaricus (SS3) have shown better adaptation to metal tolerance test, with different concentrations of cadmium and lead and hence have been selected for further studies of metal microbial interaction and optimization. The results of bioremediation process indicate that consortium of thermophilic isolates adsorbed heavy metals more effectively than the individually treated isolates. Therefore, A 24 full factorial central composite design has been employed to analyze the effect of metal ion concentration, microbial concentration and time on removal of heavy metals with consortium. Analysis of variance (ANOVA) shows a high coefficient of determination value. The kinetic data have been fitted to pseudo-first order and second-order models. The isotherm equilibrium data have been well fitted by the Langmuir and Freundlich models. The optimum removal conditions determined for initial ion concentration was 0.3 g/l; contact time 72 h; microbial concentration, 3 ml/l; and pH 7. At optimum adsorption conditions, the adsorption of cadmium and lead are found to be 92% and 93%, respectively, and presence of metals was confirmed through EDS analysis.

  18. Contribution of hot spring bacterial consortium in cadmium and lead bioremediation through quadratic programming model

    International Nuclear Information System (INIS)

    Sen, Sudip Kumar; Raut, Sangeeta; Dora, Tapas Kumar; Mohapatra, Pradeep Kumar Das

    2014-01-01

    Highlights: • Adsorption of cadmium and lead using hot spring microbial consortium. • Development of empirical models for % adsorption using ANOVA and response surface methodology. • Fitting of the kinetics of adsorption to Freundlich and Langmuir model. • Optimization of the operating parameters to maximize the % of adsorption. -- Abstract: In the present investigation, a number of experiments have been conducted to isolate microbial strains from Taptapani Hot Spring Odisha, India for bioremediation of cadmium and lead. The strains Stenotrophomonas maltophilia (SS1), Aeromonas veronii (SS2) and Bacillus barbaricus (SS3) have shown better adaptation to metal tolerance test, with different concentrations of cadmium and lead and hence have been selected for further studies of metal microbial interaction and optimization. The results of bioremediation process indicate that consortium of thermophilic isolates adsorbed heavy metals more effectively than the individually treated isolates. Therefore, A 24 full factorial central composite design has been employed to analyze the effect of metal ion concentration, microbial concentration and time on removal of heavy metals with consortium. Analysis of variance (ANOVA) shows a high coefficient of determination value. The kinetic data have been fitted to pseudo-first order and second-order models. The isotherm equilibrium data have been well fitted by the Langmuir and Freundlich models. The optimum removal conditions determined for initial ion concentration was 0.3 g/l; contact time 72 h; microbial concentration, 3 ml/l; and pH 7. At optimum adsorption conditions, the adsorption of cadmium and lead are found to be 92% and 93%, respectively, and presence of metals was confirmed through EDS analysis

  19. Consistency requirements on Δ contributions to the NN potential

    International Nuclear Information System (INIS)

    Rinat, A.S.

    1982-04-01

    We discuss theories leading to intermediate state NΔ and ΔΔ contributions to Vsub(NN). We focus on the customary addition of Lsub(ΔNπ)' to Lsub(πNN)' in a conventional field theory and argue that overcounting of contributions to tsub(πN) and Vsub(NN) will be the rule. We then discuss the cloudy bag model where a similar interaction naturally arises and which leads to a consistent theory. (author)

  20. Behaviour at x = 0,1, sum rules and parametrizations for structure functions beyond the leading order

    International Nuclear Information System (INIS)

    Lopez, C.

    1981-01-01

    We write the simplest possible parametrizations of deep inelastic structure functions which satisfy the following requirements: (i) exact compatibility with QCD at the endpoints x = 0,1, to second order; (ii) fulfilment of sum rules to second order; (iii) leading and subleading Regge behaviour. In all we find that, including the QCD scale Λ, such parametrizations describe in a simple manner the three standard functions W 1 , W 2 , W 3 for all x, Q 2 in terms of four to six parameters only (two more if allowing for higher twists). (orig.)