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.
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%.
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.
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.)
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.
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, ...
Dijet production in diffractive deep-inelastic scattering in next-to-next-to-leading order QCD arXiv
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...
Three-Jet Production in Electron-Positron Collisions at Next-to-Next-to-Leading Order Accuracy
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.
Higgs boson production in association with a jet at next-to-next-to-leading order
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.
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.
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)
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
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
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.)
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.
Top-quark decay at next-to-next-to-leading order in QCD.
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.
Neutron matter at next-to-next-to-next-to-leading order in chiral effective field theory.
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.
The Matrix Element Method at Next-to-Leading Order
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...
Transverse momentum dependent fragmentation function at next-to-next-to-leading order
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
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.
FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order
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
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
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.)
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.
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)
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
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.)
Top quark forward-backward asymmetry in e+ e- annihilation at next-to-next-to-leading order in QCD.
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.
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)
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.
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
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.
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.)
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.
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.
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.
Next-To-Leading Order Determination of Fragmentation Functions
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.
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.
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.
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 ...
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.)
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
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
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
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.)
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.
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
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.
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.
Analytical Computation of Energy-Energy Correlation at Next-to-Leading Order in QCD.
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.
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.)
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.
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
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
Parton distribution functions and benchmark cross sections at NNLO
Energy Technology Data Exchange (ETDEWEB)
Alekhin, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute for High Energy Physics (IHEP), Protvino (Russian Federation); Bluemlein, J.; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2012-02-15
We present a determination of parton distribution functions (ABM11) and the strong coupling constant {alpha}{sub s} at next-to-leading order and next-to-next-to-leading order (NNLO) in QCD based on world data for deep-inelastic scattering and fixed-target data for the Drell-Yan process. The analysis is performed in the fixed-flavor number scheme for n{sub f}=3,4,5 and uses the MS-scheme for {alpha}{sub s} and the heavy-quark masses. At NNLO we obtain the value {alpha}{sub s}(MZ)=0.1134{+-}0.0011. The fit results are used to compute benchmark cross sections at hadron colliders to NNLO accuracy and to compare to data from the LHC. (orig.)
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
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.
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.)
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
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.)
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.
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
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.
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
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.
NNLO splitting and coefficient functions with time-like kinematics
International Nuclear Information System (INIS)
Mitov, A.; Moch, S.; Vogt, A.; Liverpool Univ.
2006-09-01
We discuss recent results on the three-loop (next-to-next-to-leading order, NNLO) time-like splitting functions of QCD and the two-loop (NNLO) coefficient functions in one-particle inclusive e + e - -annihilation. These results form the basis for extracting fragmentation functions for light and heavy flavors with NNLO accuracy that will be needed at the LHC and ILC. The two-loop calculations have been performed in Mellin space bases on a new method, the main features of which we also describe briefly. (orig.)
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.)
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
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.
Diphoton production at the LHC: a QCD study up to NNLO
Catani, Stefano; Cieri, Leandro; de Florian, Daniel; Ferrera, Giancarlo; Grazzini, Massimiliano
2018-04-01
We consider the production of prompt-photon pairs at the LHC and we report on a study of QCD radiative corrections up to the next-to-next-to-leading order (NNLO). We present a detailed comparison of next-to-leading order (NLO) results obtained within the standard and smooth cone isolation criteria, by studying the dependence on the isolation parameters. We highlight the role of different partonic subprocesses within the two isolation criteria, and we show that they produce large radiative corrections for both criteria. Smooth cone isolation is a consistent procedure to compute QCD radiative corrections at NLO and beyond. If photon isolation is sufficiently tight, we show that the NLO results for the two isolation procedures are consistent with each other within their perturbative uncertainties. We then extend our study to NNLO by using smooth cone isolation. We discuss the impact of the NNLO corrections and the corresponding perturbative uncertainties for both fiducial cross sections and distributions, and we comment on the comparison with some LHC data. Throughout our study we remark on the main features that are produced by the kinematical selection cuts that are applied to the photons. In particular, we examine soft-gluon singularities that appear in the perturbative computations of the invariant mass distribution of the photon pair, the transverse-momentum spectra of the photons, and the fiducial cross section with asymmetric and symmetric photon transverse-momentum cuts, and we present their behaviour in analytic form.
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.
Matching next-to-leading order predictions to parton showers in supersymmetric QCD
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.
Higgs production in gluon fusion beyond NNLO
Energy Technology Data Exchange (ETDEWEB)
Ball, Richard D. [Edinburgh Univ. (United Kingdom). Tait Inst.; Bonvini, Marco [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Forte, Stefano [Milano Univ. (Italy). Dipt. di Fisica; INFN, Sezione di Milano (Italy); Marzani, Simone [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Ridolfi, Giovanni [Genova Univ. (Italy). Dipt. di Fisica; INFN, Sezione di Genova (Italy)
2013-03-15
We construct an approximate expression for the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N{sup 3}LO) in {alpha}{sub s} with finite top mass. We argue that an accurate approximation can be constructed by exploiting the analiticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummation. We support our argument with an explicit comparison of the approximate and the exact expressions up to the highest (NNLO) order at which the latter are available. We find that the approximate N{sup 3}LO result amounts to a correction of 17% to the NNLO QCD cross section for production of a 125 GeV Higgs at the LHC (8 TeV), larger than previously estimated, and it significantly reduces the scale dependence of the NNLO result.
Higgs production in gluon fusion beyond NNLO
International Nuclear Information System (INIS)
Ball, Richard D.; Bonvini, Marco; Forte, Stefano; Marzani, Simone; Ridolfi, Giovanni
2013-01-01
We construct an approximate expression for the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N 3 LO) in α s with finite top mass. We argue that an accurate approximation can be constructed by exploiting the analyticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummation. We support our argument with an explicit comparison of the approximate and the exact expressions up to the highest (NNLO) order at which the latter are available. We find that the approximate N 3 LO result amounts to a correction of 17% to the NNLO QCD cross section for production of a 125 GeV Higgs at the LHC (8 TeV), larger than previously estimated, and it significantly reduces the scale dependence of the NNLO result
Higgs production in gluon fusion beyond NNLO
Energy Technology Data Exchange (ETDEWEB)
Ball, Richard D. [Tait Institute, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); Bonvini, Marco [Deutsches Elektronen-Synchroton, DESY, Notkestraße 85, D-22603 Hamburg (Germany); Forte, Stefano, E-mail: forte@mi.infn.it [Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Marzani, Simone [Institute for Particle Physics Phenomenology, Durham University, Durham DH1 3LE, England (United Kingdom); Ridolfi, Giovanni [Dipartimento di Fisica, Università di Genova and INFN, Sezione di Genova, Via Dodecaneso 33, I-16146 Genova (Italy)
2013-09-21
We construct an approximate expression for the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N{sup 3}LO) in α{sub s} with finite top mass. We argue that an accurate approximation can be constructed by exploiting the analyticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummation. We support our argument with an explicit comparison of the approximate and the exact expressions up to the highest (NNLO) order at which the latter are available. We find that the approximate N{sup 3}LO result amounts to a correction of 17% to the NNLO QCD cross section for production of a 125 GeV Higgs at the LHC (8 TeV), larger than previously estimated, and it significantly reduces the scale dependence of the NNLO result.
Higgs production in gluon fusion beyond NNLO
International Nuclear Information System (INIS)
Ball, Richard D.; Forte, Stefano; Marzani, Simone
2013-03-01
We construct an approximate expression for the cross section for Higgs production in gluon fusion at next-to-next-to-next-to-leading order (N 3 LO) in α s with finite top mass. We argue that an accurate approximation can be constructed by exploiting the analiticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummation. We support our argument with an explicit comparison of the approximate and the exact expressions up to the highest (NNLO) order at which the latter are available. We find that the approximate N 3 LO result amounts to a correction of 17% to the NNLO QCD cross section for production of a 125 GeV Higgs at the LHC (8 TeV), larger than previously estimated, and it significantly reduces the scale dependence of the NNLO result.
Top quark pair production beyond NNLO
Energy Technology Data Exchange (ETDEWEB)
Muselli, Claudio [TIF Lab, Dipartimento di Fisica, Università di Milano, and INFN - Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy); Bonvini, Marco [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, OX1 3NP, Oxford (United Kingdom); Forte, Stefano [TIF Lab, Dipartimento di Fisica, Università di Milano, and INFN - Sezione di Milano,Via Celoria 16, I-20133 Milano (Italy); Marzani, Simone [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Ridolfi, Giovanni [Dipartimento di Fisica, Università di Genova and INFN - Sezione di Genova,Via Dodecaneso 33, I-16146 Genova (Italy)
2015-08-17
We construct an approximate expression for the total cross section for the production of a heavy quark-antiquark pair in hadronic collisions at next-to-next-to-next-to-leading order (N{sup 3}LO) in α{sub s}. We use a technique which exploits the analyticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummations, previously introduced and used in the case of Higgs production. We validate our method by comparing to available exact results up to NNLO. We find that N{sup 3}LO corrections increase the predicted top pair cross section at the LHC by about 4% over the NNLO.
Top quark pair production beyond NNLO
International Nuclear Information System (INIS)
Muselli, Claudio; Bonvini, Marco; Forte, Stefano; Marzani, Simone; Ridolfi, Giovanni
2015-01-01
We construct an approximate expression for the total cross section for the production of a heavy quark-antiquark pair in hadronic collisions at next-to-next-to-next-to-leading order (N 3 LO) in α s . We use a technique which exploits the analyticity of the Mellin space cross section, and the information on its singularity structure coming from large N (soft gluon, Sudakov) and small N (high energy, BFKL) all order resummations, previously introduced and used in the case of Higgs production. We validate our method by comparing to available exact results up to NNLO. We find that N 3 LO corrections increase the predicted top pair cross section at the LHC by about 4% over the NNLO.
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.)
Subtraction with hadronic initial states at NLO: an NNLO-compatible scheme
Somogyi, Gábor
2009-05-01
We present an NNLO-compatible subtraction scheme for computing QCD jet cross sections of hadron-initiated processes at NLO accuracy. The scheme is constructed specifically with those complications in mind, that emerge when extending the subtraction algorithm to next-to-next-to-leading order. It is therefore possible to embed the present scheme in a full NNLO computation without any modifications.
Subtraction with hadronic initial states at NLO: an NNLO-compatible scheme
International Nuclear Information System (INIS)
Somogyi, Gabor
2009-01-01
We present an NNLO-compatible subtraction scheme for computing QCD jet cross sections of hadron-initiated processes at NLO accuracy. The scheme is constructed specifically with those complications in mind, that emerge when extending the subtraction algorithm to next-to-next-to-leading order. It is therefore possible to embed the present scheme in a full NNLO computation without any modifications.
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.
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
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.)
Next to Leading Order QCD Corrections to Polarized $\\Lambda$ Production in DIS
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.
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.
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.
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
Production of transverse energy from minijets in next-to-leading order perturbative QCD
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.
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
arXiv Higgs boson pair production at NNLO with top quark mass effects
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%...
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.
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
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.
Color-singlet production at NNLO in MCFM
Energy Technology Data Exchange (ETDEWEB)
Boughezal, Radja [Argonne National Laboratory, High Energy Physics Division, Argonne, IL (United States); Campbell, John M.; Giele, Walter [Fermilab, P.O.Box 500, Batavia, IL (United States); Ellis, R.K. [University of Durham, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Focke, Christfried [Northwestern University, Department of Physics and Astronomy, Evanston, IL (United States); Liu, Xiaohui [University of Maryland, Maryland Center for Fundamental Physics, College Park, Maryland (United States); Petriello, Frank [Argonne National Laboratory, High Energy Physics Division, Argonne, IL (United States); Northwestern University, Department of Physics and Astronomy, Evanston, IL (United States); Williams, Ciaran [University at Buffalo, The State University of New York, Department of Physics, Buffalo (United States)
2017-01-15
We present the implementation of several color-singlet final-state processes at Next-to-Next-to Leading Order (NNLO) accuracy in QCD to the publicly available parton-level Monte Carlo program MCFM. Specifically we discuss the processes pp → H, pp → Z, pp → W, pp → HZ, pp → HW and pp → γγ. Decays of the unstable bosons are fully included, resulting in a flexible fully differential Monte Carlo code. The NNLO corrections have been calculated using the non-local N-jettiness subtraction approach. Special attention is given to the numerical aspects of running MCFM for these processes at this order. We pay particular attention to the systematic uncertainties due to the power corrections induced by the N-jettiness regularization scheme and the evaluation time needed to run the hybrid openMP/MPI version of MCFM at NNLO on multi-processor systems. (orig.)
Update of the NNLO PDFs in the 3-, 4- and 5-flavour schemes
International Nuclear Information System (INIS)
Alekhin, Sergey; Bluemlein, Johannes; Moch, Sven-Olaf
2010-07-01
We report on an update of the next-to-next-to-leading order (NNLO) ABKM09 parton distributions functions. They are obtained with the use of the combined HERA collider Run I inclusive deep-inelastic scattering (DIS) data and the partial NNLO corrections to the heavy quark electro-production taken into account. The value of the strong couplig constant α NNLO s (M Z )=0.1147(12) is obtained. The standard candle cross sections for the Tevatron collider and the LHC estimated with the updated PDFs are provided. (orig.)
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.)
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.)
NNLO massive corrections to Bhabha scattering and theoretical precision of BabaYaga rate at NLO
International Nuclear Information System (INIS)
Carloni Calame, C.M.; Nicrosini, O.; Piccinini, F.; Riemann, T.; Worek, M.
2011-12-01
We provide an exact calculation of next-to-next-to-leading order (NNLO) massive corrections to Bhabha scattering in QED, relevant for precision luminosity monitoring at meson factories. Using realistic reference event selections, exact numerical results for leptonic and hadronic corrections are given and compared with the corresponding approximate predictions of the event generator BabaYaga rate at NLO. It is shown that the NNLO massive corrections are necessary for luminosity measurements with per mille precision. At the same time they are found to be well accounted for in the generator at an accuracy level below the one per mille. An update of the total theoretical precision of BabaYaga rate at NLO is presented and possible directions for a further error reduction are sketched. (orig.)
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
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
The Gluon-Induced Mueller-Tang Jet Impact Factor at Next-to-Leading Order
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.
Next-to-leading order electroweak corrections to off-shell WWW production at the LHC arXiv
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{\
The radiative decays $B \\to V_{\\gamma}$ at next-to-leading order in QCD
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 ...
Somogyi, Gábor; Trócsányi, Zoltán
2008-08-01
In previous articles we outlined a subtraction scheme for regularizing doubly-real emission and real-virtual emission in next-to-next-to-leading order (NNLO) calculations of jet cross sections in electron-positron annihilation. In order to find the NNLO correction these subtraction terms have to be integrated over the factorized unresolved phase space and combined with the two-loop corrections. In this paper we perform the integration of all one-parton unresolved subtraction terms.
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.
NNLO QCD corrections to the polarized top quark decay t (↑)→Xb+W+
Czarnecki, A.; Groote, S.; Körner, J. G.; Piclum, J. H.
2018-05-01
We compute the next-to-next-to-leading order (NNLO) QCD corrections to the decay t (↑)→Xb+W+ of a polarized top quark. The spin-momentum correlation in this quasi two-body decay is described by the polar angle distribution d Γ /d cos θP=Γ/2 (1 +PtαPcos θP) , where Pt is the polarization of the top quark and αP denotes the asymmetry parameter of the decay. For the latter we find αPNNLO=0.3792 ±0.0037 .
Matching fully differential NNLO calculations and parton showers
International Nuclear Information System (INIS)
Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Walsh, Jonathan R.; Zuberi, Saba
2013-11-01
We present a general method to match fully differential next-to-next-to-leading (NNLO) calculations to parton shower programs. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy. Our method is based on consistently improving a given NNLO calculation with the leading-logarithmic (LL) resummation in a chosen jet resolution variable. The resulting NNLO+LL calculation is cast in the form of an event generator for physical events that can be directly interfaced with a parton shower routine, and we give an explicit construction of the input ''Monte Carlo cross sections'' satisfying all required criteria. We also show how other proposed approaches naturally arise as special cases in our method.
NNLO corrections to anti B {yields} X{sub u}l anti {nu} in the shape-function region
Energy Technology Data Exchange (ETDEWEB)
Asatrian, H.M. [Erevanskij Fizicheskij Inst., Erevan (Armenia); Greub, C. [Bern Univ. (Switzerland). Inst. for Theoretical Physics; Pecjak, B.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2008-10-15
The inclusive decay anti B {yields} X{sub u}l anti {nu} is of much interest because of its potential to constrain the CKM element vertical stroke V{sub ub} vertical stroke. Experimental cuts required to suppress charm background restrict measurements of this decay to the shape-function region, where the hadronic final state carries a large energy but only a moderate invariant mass. In this kinematic region, the differential decay distributions satisfy a factorization formula of the form H.J x S, where S is the non-perturbative shape function, and the object H.J is a perturbatively calculable hard-scattering kernel. In this paper we present the calculation of the hard function H at next-to-next-to-leading order (NNLO) in perturbation theory. Combined with the known NNLO result for the jet function J, this completes the perturbative part of the NNLO calculation for this process. (orig.)
Three-jet production in electron-positron collisions using the CoLoRFulNNLO method
Del Duca, Vittorio
2016-01-01
We introduce a subtraction method for jet cross sections at next-to-next-to-leading order (NNLO) accuracy in the strong coupling 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.
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.)
N-jettiness Subtractions for NNLO QCD calculations
International Nuclear Information System (INIS)
Gaunt, Jonathan R.; Stahlhofen, Maximilian; Tackmann, Frank J.; Walsh, Jonathan R.; California Univ., CA
2015-05-01
We present a subtraction method utilizing the N-jettiness observable, Τ N , to perform QCD calculations for arbitrary processes at next-to-next-to-leading order (NNLO). Our method employs soft-collinear effective theory (SCET) to determine the IR singular contributions of N-jet cross sections for Τ N → 0, and uses these to construct suitable Τ N -subtractions. The construction is systematic and economic, due to being based on a physical observable. The resulting NNLO calculation is fully differential and in a form directly suitable for combining with resummation and parton showers. We explain in detail the application to processes with an arbitrary number of massless partons at lepton and hadron colliders together with the required external inputs in the form of QCD amplitudes and lower-order calculations. We provide explicit expressions for the Τ N -subtractions at NLO and NNLO. The required ingredients are fully known at NLO, and at NNLO for processes with two external QCD partons. The remaining NNLO ingredient for three or more external partons can be obtained numerically with existing NNLO techniques. As an example, we employ our method to obtain the NNLO rapidity spectrum for Drell-Yan and gluon-fusion Higgs production. We discuss aspects of numerical accuracy and convergence and the practical implementation. We also discuss and comment on possible extensions, such as more-differential subtractions, necessary steps for going to N 3 LO, and the treatment of massive quarks.
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.
NNLO QCD corrections to Higgs boson production at large transverse momentum
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.
Matching fully differential NNLO calculations and parton showers
Energy Technology Data Exchange (ETDEWEB)
Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Walsh, Jonathan R.; Zuberi, Saba [California Univ., Berkeley, CA (United States). Ernest Orlando Lawrence Berkeley National Laboratory; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2013-11-15
We present a general method to match fully differential next-to-next-to-leading (NNLO) calculations to parton shower programs. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy. Our method is based on consistently improving a given NNLO calculation with the leading-logarithmic (LL) resummation in a chosen jet resolution variable. The resulting NNLO+LL calculation is cast in the form of an event generator for physical events that can be directly interfaced with a parton shower routine, and we give an explicit construction of the input ''Monte Carlo cross sections'' satisfying all required criteria. We also show how other proposed approaches naturally arise as special cases in our method.
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.)
$ZZ$ production at the LHC: NNLO predictions for $2\\ell2\
Kallweit, Stefan
We consider QCD radiative corrections to $ZZ$ production for all experimentally relevant leptonic processes. We report on a novel computation of next-to-next-to-leading-order (NNLO) corrections to the diboson signature with two charged leptons and missing transverse energy ($\\ell\\ell$+$E_T^{\\rm miss}$). All relevant final states are considered: $\\ell\\ell\
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
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.)
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.
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.
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.
NNLO QCD corrections to associated W H production and H →b b ¯ decay
Caola, Fabrizio; Luisoni, Gionata; Melnikov, Kirill; Röntsch, Raoul
2018-04-01
We present a computation of the next-to-next-to-leading-order (NNLO) QCD corrections to the production of a Higgs boson in association with a W boson at the LHC and the subsequent decay of the Higgs boson into a b b ¯ pair, treating the b quarks as massless. We consider various kinematic distributions and find significant corrections to observables that resolve the Higgs decay products. We also find that a cut on the transverse momentum of the W boson, important for experimental analyses, may have a significant impact on kinematic distributions and radiative corrections. We show that some of these effects can be adequately described by simulating QCD radiation in Higgs boson decays to b quarks using parton showers. We also describe contributions to Higgs decay to a b b ¯ pair that first appear at NNLO and that were not considered in previous fully differential computations. The calculation of NNLO QCD corrections to production and decay sub-processes is carried out within the nested soft-collinear subtraction scheme presented by some of us earlier this year. We demonstrate that this subtraction scheme performs very well, allowing a computation of the coefficient of the second-order QCD corrections at the level of a few per mill.
A next-to-leading order QCD analysis of the spin structure function $g_1$
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\\%.
Zγ production at NNLO including anomalous couplings
Campbell, John M.; Neumann, Tobias; Williams, Ciaran
2017-11-01
In this paper we present a next-to-next-to-leading order (NNLO) QCD calculation of the processes pp → l + l -γ and pp\\to ν \\overline{ν}γ that we have implemented in MCFM. Our calculation includes QCD corrections at NNLO both for the Standard Model (SM) and additionally in the presence of Zγγ and ZZγ anomalous couplings. We compare our implementation, obtained using the jettiness slicing approach, with a previous SM calculation and find broad agreement. Focusing on the sensitivity of our results to the slicing parameter, we show that using our setup we are able to compute NNLO cross sections with numerical uncertainties of about 0.1%, which is small compared to residual scale uncertainties of a few percent. We study potential improvements using two different jettiness definitions and the inclusion of power corrections. At √{s}=13 TeV we present phenomenological results and consider Zγ as a background to H → Zγ production. We find that, with typical cuts, the inclusion of NNLO corrections represents a small effect and loosens the extraction of limits on anomalous couplings by about 10%.
Wgamma and Zgamma production at the LHC in NNLO QCD
International Nuclear Information System (INIS)
Grazzini, Massimiliano; Kallweit, Stefan; Rathlev, Dirk
2016-01-01
We consider the production of Wγ and Zγ pairs at the LHC, and report on the fully differential computation of next-to-next-to-leading order (NNLO) corrections in QCD perturbation theory. The calculation includes leptonic vector-boson decays with the corresponding spin correlations, off-shell effects and final-state photon radiation. We present numerical results for pp collisions at 7 TeV, and compare them with available ATLAS data. In the case of Zγ production, the impact of NNLO corrections is generally moderate, ranging from 8% to 17%, depending on the applied cuts. In the case of Wγ production, the NNLO effects are more important, and range from 19% to 26%, thereby improving the agreement of the theoretical predictions with the data. As expected, a veto against jets significantly reduces the impact of QCD radiative corrections.
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.
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
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.
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.
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 ...
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.
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%.
QCD next-to-leading order predictions matched to parton showers for vector-like quark models
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...
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.
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.)
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.
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.
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.
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.
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.)
Vector boson fusion NNLO in QCD. SM Higgs and beyond
Energy Technology Data Exchange (ETDEWEB)
Bolzoni, Paolo [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Maltoni, Fabio; Zaro, Marco [Catholique Univ. Louvain-la-Neuve (BE). Center for Cosmology, Particle Phyics and Phenomenology (CP3); Moch, Sven-Olaf [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2011-09-15
Weak vector boson fusion provides a unique channel to directly probe the mechanism of electroweak symmetry breaking at hadron colliders. We present a method that allows to calculate total cross sections to next-to-next-to-leading order (NNLO) in QCD for an arbitrary V{sup *}V{sup *}{yields}X process, the so-called structure function approach. By discussing the case of Higgs production in detail, we estimate several classes of previously neglected contributions and we argue that such method is accurate at a precision level well above the typical residual scale and PDF uncertainties at NNLO. Predictions for cross sections at the Tevatron and the LHC are presented for a variety of cases: the Standard Model Higgs (including anomalous couplings), neutral and charged scalars in extended Higgs sectors and (fermiophobic) vector resonance production. Further results can be easily obtained through the public use of the VBF rate at NNLO code. (orig.)
Higgs boson decay into b-quarks at NNLO accuracy
Del Duca, Vittorio; Duhr, Claude; Somogyi, Gábor; Tramontano, Francesco; Trócsányi, Zoltán
2015-04-01
We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in αs. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.
Higgs boson decay into b-quarks at NNLO accuracy
Del Duca, Vittorio; Somogyi, Gábor; Tramontano, Francesco; Trócsányi, Zoltán
2015-01-01
We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in alpha_S. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.
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.).
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
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.)
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
Higgs production via vector-boson fusion at NNLO in QCD
International Nuclear Information System (INIS)
Bolzoni, Paolo; Moch, Sven-Olaf; Maltoni, Fabio; Zaro, Marco
2010-03-01
We present the total cross sections at next-to-next-to-leading order (NNLO) in the strong coupling for Higgs production via weak boson fusion. Our results are obtained via the structure function approach, which builds upon the approximate, though very accurate, factorization of the QCD corrections between the two quark lines. The theoretical uncertainty on the total cross sections at the LHC from higher order corrections and the parton distribution uncertainties are estimated at the 2% level each for a wide range of Higgs boson masses. (orig.)
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.
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.
QCD next-to-leading-order predictions matched to parton showers for vector-like quark models.
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.
Higgs boson pair production at NNLO with top quark mass effects
Grazzini, M.; Heinrich, G.; Jones, S.; Kallweit, S.; Kerner, M.; Lindert, J. M.; Mazzitelli, J.
2018-05-01
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 √{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 √{s}=13 TeV to +7% at √{s}=100 TeV, and the residual uncertainty of the inclusive cross section from missing M t effects is estimated to be at the few percent level. Our calculation is fully differential in the Higgs boson pair and the associated jet activity: we also present predictions for various differential distributions at √{s}=14 and 100 TeV, and discuss the size of the missing M t effects, which can be larger, especially in the tails of certain observables. Our results represent the most advanced perturbative prediction available to date for this process.
Higgs boson decay into b-quarks at NNLO accuracy
Energy Technology Data Exchange (ETDEWEB)
Duca, Vittorio Del [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati,Via E. Fermi 40, I-00044 Frascati (Italy); Duhr, Claude [PH Department, TH Unit, CERN,CH-1211 Geneva 23 (Switzerland); Center for Cosmology, Particle Physics and Phenomenology (CP3),Université Catholique de Louvain, Chemin du Cyclotron 2,B-1348 Louvain-La-Neuve (Belgium); Somogyi, Gábor [University of Debrecen and MTA-DE Particle Physics Research Group,H-4010 Debrecen, PO Box 105 (Hungary); Tramontano, Francesco [Dipartimento di Fisica, Università degli studi di Napoli andINFN - Sezione di Napoli, 80125 Napoli (Italy); Trócsányi, Zoltán [University of Debrecen and MTA-DE Particle Physics Research Group,H-4010 Debrecen, PO Box 105 (Hungary)
2015-04-08
We compute the fully differential decay rate of the Standard Model Higgs boson into b-quarks at next-to-next-to-leading order (NNLO) accuracy in α{sub s}. We employ a general subtraction scheme developed for the calculation of higher order perturbative corrections to QCD jet cross sections, which is based on the universal infrared factorization properties of QCD squared matrix elements. We show that the subtractions render the various contributions to the NNLO correction finite. In particular, we demonstrate analytically that the sum of integrated subtraction terms correctly reproduces the infrared poles of the two-loop double virtual contribution to this process. We present illustrative differential distributions obtained by implementing the method in a parton level Monte Carlo program. The basic ingredients of our subtraction scheme, used here for the first time to compute a physical observable, are universal and can be employed for the computation of more involved processes.
Charm production in deep-inelastic e$\\gamma$ scattering to next-to-leading order in QCD
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.
Charged Higgs production via vector-boson fusion at NNLO in QCD
International Nuclear Information System (INIS)
Zaro, Marco; Maltoni, Fabio
2010-12-01
We present the total cross sections at next-to-next-to-leading order (NNLO) in the strong coupling for single and double charged Higgs production via weak boson fusion. Results are obtained via the structure function approach, which builds upon the approximate, though very accurate, factorization of the QCD corrections between the two quark lines. The theoretical uncertainty on the total cross sections at the LHC from higher order corrections and the parton distribution uncertainties are estimated at the 2% level each for a wide range of Higgs boson masses. (orig.)
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.
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.
Salajegheh, Maral; Nejad, S. Mohammad Moosavi; Khanpour, Hamzeh; Tehrani, S. Atashbar
2018-05-01
In this paper, we present SMKA18 analysis, which is a first attempt to extract the set of next-to-next-leading-order (NNLO) spin-dependent parton distribution functions (spin-dependent PDFs) and their uncertainties determined through the Laplace transform technique and Jacobi polynomial approach. Using the Laplace transformations, we present an analytical solution for the spin-dependent Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations at NNLO approximation. The results are extracted using a wide range of proton g1p(x ,Q2) , neutron g1n(x ,Q2) , and deuteron g1d(x ,Q2) spin-dependent structure functions data set including the most recent high-precision measurements from COMPASS16 experiments at CERN, which are playing an increasingly important role in global spin-dependent fits. The careful estimations of uncertainties have been done using the standard Hessian error propagation. We will compare our results with the available spin-dependent inclusive deep inelastic scattering data set and other results for the spin-dependent PDFs in literature. The results obtained for the spin-dependent PDFs as well as spin-dependent structure functions are clearly explained both in the small and large values of x .
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.
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.)
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.)
NNLO QCD corrections for the differential Higgs boson production cross-section in gluon fusion
International Nuclear Information System (INIS)
Anastasiou, Charalampos
2006-01-01
I describe a recent computation of the NNLO QCD corrections for the fully differential cross-section for Higgs boson production in the gluon fusion channel. This result is an application of a new method for calculating perturbative corrections beyond the next-to-leading order
Fully-differential NNLO predictions for vector-boson pair production with MATRIX
Wiesemann, Marius; Kallweit, Stefan; Rathlev, Dirk
2016-01-01
We review the computations of the next-to-next-to-leading order (NNLO) QCD corrections to vector-boson pair production processes in proton–proton collisions and their implementation in the numerical code MATRIX. Our calculations include the leptonic decays of W and Z bosons, consistently taking into account all spin correlations, off-shell effects and non-resonant contributions. For massive vector-boson pairs we show inclusive cross sections, applying the respective mass windows chosen by ATLAS and CMS to define Z bosons from their leptonic decay products, as well as total cross sections for stable bosons. Moreover, we provide samples of differential distributions in fiducial phase-space regions inspired by typical selection cuts used by the LHC experiments. For the vast majority of measurements, the inclusion of NNLO corrections significantly improves the agreement of the Standard Model predictions with data.
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.
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
Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions
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.
NNLO QCD corrections to the Drell-Yan cross section in models of TeV-scale gravity
Energy Technology Data Exchange (ETDEWEB)
Ahmed, Taushif; Banerjee, Pulak; Dhani, Prasanna K.; Rana, Narayan [The Institute of Mathematical Sciences, Chennai, Tamil Nadu (India); Homi Bhabha National Institute, Mumbai (India); Kumar, M.C. [Indian Institute of Technology Guwahati, Department of Physics, Guwahati (India); Mathews, Prakash [Saha Institute of Nuclear Physics, Kolkata, West Bengal (India); Ravindran, V. [The Institute of Mathematical Sciences, Chennai, Tamil Nadu (India)
2017-01-15
The first results on the complete next-to-next-to-leading order (NNLO) Quantum Chromodynamic (QCD) corrections to the production of di-leptons at hadron colliders in large extra dimension models with spin-2 particles are reported in this article. In particular, we have computed these corrections to the invariant mass distribution of the di-leptons taking into account all the partonic sub-processes that contribute at NNLO. In these models, spin-2 particles couple through the energy-momentum tensor of the Standard Model with the universal coupling strength. The tensorial nature of the interaction and the presence of both quark annihilation and gluon fusion channels at the Born level make it challenging computationally and interesting phenomenologically. We have demonstrated numerically the importance of our results at Large Hadron Collider energies. The two-loop corrections contribute an additional 10% to the total cross section. We find that the QCD corrections are not only large but also important to make the predictions stable under renormalisation and factorisation scale variations, providing an opportunity to stringently constrain the parameters of the models with a spin-2 particle. (orig.)
NNLO corrections for LHC processes
Caola, Fabrizio
2015-01-01
To fully profit from the remarkable achievements of the experimental program at the LHC, very precise theoretical predictions for signal and background processes are required. In this contribution, I will review some of the recent progress in fully exclusive next-to-next-toleading-order (NNLO) QCD computations. As an example of the phenomenological relevance of these results, I will present LHC predictions for t-channel single-top production and Higgs boson production in association with one hard jet.
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)
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.
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.
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.
W{sup ±}Z production at the LHC: fiducial cross sections and distributions in NNLO QCD
Energy Technology Data Exchange (ETDEWEB)
Grazzini, Massimiliano [Physik-Institut, Universität Zürich,CH-8057 Zürich (Switzerland); Kallweit, Stefan [TH Division, Physics Department, CERN,CH-1211 Geneva 23 (Switzerland); Rathlev, Dirk [Physik-Institut, Universität Zürich,CH-8057 Zürich (Switzerland); Wiesemann, Marius [Physik-Institut, Universität Zürich,CH-8057 Zürich (Switzerland); TH Division, Physics Department, CERN,CH-1211 Geneva 23 (Switzerland)
2017-05-26
We report on the first fully differential calculation for W{sup ±}Z production in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. Leptonic decays of the W and Z bosons are consistently taken into account, i.e. we include all resonant and non-resonant diagrams that contribute to the process pp→ℓ{sup ′±}ν{sub ℓ{sup ′}}ℓ{sup +}ℓ{sup −}+X both in the same-flavour (ℓ{sup ′}=ℓ) and the different-flavour (ℓ{sup ′}≠ℓ) channel. Fiducial cross sections and distributions are presented in the presence of standard selection cuts applied in the experimental W{sup ±}Z analyses by ATLAS and CMS at centre-of-mass energies of 8 and 13 TeV. As previously shown for the inclusive cross section, NNLO corrections increase the NNLO result by about 10%, thereby leading to an improved agreement with experimental data. The importance of NNLO accurate predictions is also shown in the case of new-physics scenarios, where, especially in high-p{sub T} categories, their impact can reach O(20%). The availability of differential NNLO predictions will play a crucial role in the rich physics programme that is based on precision studies of W{sup ±}Z signatures at the LHC.
Higgs production at NNLO in QCD. The VBF channel
International Nuclear Information System (INIS)
Bolzoni, P.; Moch, S.; Zaro, M.; Maltoni, F.
2010-06-01
We present a phenomenological study for the production of the Higgs boson at next-to-next-to-leading order (NNLO) in QCD via the vector boson fusion (VBF) process. After a general discussion about the different production channels of the Higgs, we show results for hadron colliders like LHC and Tevatron in VBF. The theoretical predictions are obtained using the structure function approach. This approximation turns out to be more accurate than the precision to which the VBF Higgs production channel can be considered a well defined process by itself and the theoretical uncertainty which are of the order of 1-2%. The uncertainties due to parton distributions are also discussed and are estimated to be at the same level. (orig.)
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.
Towards the NNLO evolution of polarised parton distributions
Energy Technology Data Exchange (ETDEWEB)
Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences; Moch, S.; Rogal, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Vermaseren, J.A.M. [Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands)
2008-07-15
We report on the first calculation of the structure function g{sub 1} in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding unpolarised cases of F{sub 2,L}, but additionally involves higher tensor integrals and the Dirac matrix {gamma}{sub 5} in D {ne} 4 dimensions. Our results confirm all known two-loop expressions including the coefficient functions of Zijlstra and van Neerven not independently verified before. At three loops we extract the helicity-difference next-to-next-to-leading order (NNLO) quark-quark and gluon-quark splitting functions {delta}P{sub qq} and {delta}P{sub qg}. The results exhibit interesting features concerning sum rules and the momentum-fraction limits x {yields} 1 and x {yields} 0. (orig.)
Towards the NNLO evolution of polarised parton distributions
International Nuclear Information System (INIS)
Vogt, A.; Vermaseren, J.A.M.
2008-07-01
We report on the first calculation of the structure function g 1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding unpolarised cases of F 2,L , but additionally involves higher tensor integrals and the Dirac matrix γ 5 in D ≠ 4 dimensions. Our results confirm all known two-loop expressions including the coefficient functions of Zijlstra and van Neerven not independently verified before. At three loops we extract the helicity-difference next-to-next-to-leading order (NNLO) quark-quark and gluon-quark splitting functions ΔP qq and ΔP qg . The results exhibit interesting features concerning sum rules and the momentum-fraction limits x → 1 and x → 0. (orig.)
W+W- production at the LHC. Fiducial cross sections and distributions in NNLO QCD
International Nuclear Information System (INIS)
Grazzini, Massimiliano; Wiesemann, Marius; Kallweit, Stefan; California Univ., Santa Barbara, CA; Pozzorini, Stefano; California Univ., Santa Barbara, CA; Rathlev, Dirk
2016-05-01
We consider QCD radiative corrections to W + W - production at the LHC and present the first fully differential predictions for this process at next-to-next-to-leading order (NNLO) in perturbation theory. Our computation consistently includes the leptonic decays of the W bosons, taking into account spin correlations, off-shell effects and non-resonant contributions. Detailed predictions are presented for the different-flavour channel pp→μ + e - ν μ anti ν e +X at √(s)=8 and 13 TeV. In particular, we discuss fiducial cross sections and distributions in the presence of standard selection cuts used in experimental W + W - and H→W + W - analyses at the LHC. The inclusive W + W - cross section receives large NNLO corrections, and, due to the presence of a jet veto, typical fiducial cuts have a sizeable influence on the behaviour of the perturbative expansion. The availability of differential NNLO predictions, both for inclusive and fiducial observables, will play an important role in the rich physics programme that is based on precision studies of W + W - signatures at the LHC.
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}.
Single Top Production at Next-to-Leading Order in the Standard Model Effective Field Theory.
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.
The impact of LHC jet data on the MMHT PDF fit at NNLO
Harland-Lang, L. A.; Martin, A. D.; Thorne, R. S.
2018-03-01
We investigate the impact of the high precision ATLAS and CMS 7 TeV measurements of inclusive jet production on the MMHT global PDF analysis at next-to-next-to-leading order (NNLO). This is made possible by the recent completion of the long-term project to calculate the NNLO corrections to the hard cross section. We find that a good description of the ATLAS data is not possible with the default treatment of experimental systematic errors, and propose a simplified solution that retains the dominant physical information of the data. We then investigate the fit quality and the impact on the gluon PDF central value and uncertainty when the ATLAS and CMS data are included in a MMHT fit. We consider both common choices for the factorization and renormalization scale, namely the inclusive jet transverse momentum, p_\\perp , and the leading jet p_\\perp , as well as the different jet radii for which the ATLAS and CMS data are made available. We find that the impact of these data on the gluon is relatively insensitive to these inputs, in particular the scale choice, while the inclusion of NNLO corrections tends to improve the data description somewhat and has a qualitatively similar though not identical impact on the gluon in comparison to NLO.
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.
Energy Technology Data Exchange (ETDEWEB)
Carloni Calame, C. [Southampton Univ. (United Kingdom). School of Physics; Czyz, H.; Gluza, J.; Gunia, M. [Silesia Univ., Katowice (Poland). Dept. of Field Theory and Particle Physics; Montagna, G. [Pavia Univ. (Italy). Dipt. di Fisica Nucleare e Teorica; INFN, Sezione di Pavia (Italy); Nicrosini, O.; Piccinini, F. [INFN, Sezione di Pavia (Italy); Riemann, T. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Worek, M. [Wuppertal Univ. (Germany). Fachbereich C Physik
2011-07-15
Virtual fermionic N{sub f}=1 and N{sub f}=2 contributions to Bhabha scattering are combined with realistic real corrections at next-to-next-to-leading order in QED. The virtual corrections are determined by the package BHANNLOHF, and real corrections with the Monte Carlo generators BHAGEN-1PH, HELAC-PHEGAS and EKHARA. Numerical results are discussed at the energies of and with realistic cuts used at the {phi} factory DA{phi}NE, at the B factories PEP-II and KEK, and at the charm/{tau} factory BEPC II. We compare these complete calculations with the approximate ones realized in the generator BABAYAGA rate at NLO used at meson factories to evaluate their luminosities. For realistic reference event selections we find agreement for the NNLO leptonic and hadronic corrections within 0.07% or better and conclude that they are well accounted for in the generator by comparison with the present experimental accuracy. (orig.)
Analytic integration of real-virtual counterterms in NNLO jet cross sections I
Aglietti, Ugo; Del Duca, Vittorio; Duhr, Claude; Somogyi, Gábor; Trócsányi, Zoltán
2008-09-01
We present analytic evaluations of some integrals needed to give explicitly the integrated real-virtual counterterms, based on a recently proposed subtraction scheme for next-to-next-to-leading order (NNLO) jet cross sections. After an algebraic reduction of the integrals, integration-by-parts identities are used for the reduction to master integrals and for the computation of the master integrals themselves by means of differential equations. The results are written in terms of one- and two-dimensional harmonic polylogarithms, once an extension of the standard basis is made. We expect that the techniques described here will be useful in computing other integrals emerging in calculations in perturbative quantum field theories.
Second-order QCD effects in Higgs boson production through vector boson fusion
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.
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.)
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.)
Associated production of a Higgs boson decaying into bottom quarks at the LHC in full NNLO QCD
Ferrera, Giancarlo; Somogyi, Gábor; Tramontano, Francesco
2018-05-01
We consider the production of a Standard Model Higgs boson decaying to bottom quarks in association with a vector boson W± / Z in hadron collisions. We present a fully exclusive calculation of QCD radiative corrections both for the production cross section and for the Higgs boson decay rate up to next-to-next-to-leading order (NNLO) accuracy. Our calculation also includes the leptonic decay of the vector boson with finite-width effects and spin correlations. We consider typical kinematical cuts applied in the experimental analyses at the Large Hadron Collider (LHC) and we find that the full NNLO QCD corrections significantly decrease the accepted cross section and have a substantial impact on the shape of distributions. We point out that these additional effects are essential to obtain precise theoretical predictions to be compared with the LHC data.
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.
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.
Non-abelian factorisation for next-to-leading-power threshold logarithms
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
Next-to-leading-order QCD and electroweak corrections to WWW production at proton-proton colliders
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.
Heavy Quark Impact Factor at Next-to-leading Level
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.
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.)
NNLOPS accurate associated HZ production with NLO decay ${\\rm{H}} \\to b\\bar{b}$ arXiv
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.
Next to Leading Logarithms and the PHOTOS Monte Carlo
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...
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.
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.
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.
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.
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.
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.
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
International Nuclear Information System (INIS)
Kataev, A.L; Parente, G.; Sidorov, A.V.
1999-05-01
The more detailed next-to-next-to-leading order (NNLO) QCD analysis of the experimental data of the CCFR collaboration for the xF 3 structure function is performed. The factorization scale uncertainties are analyzed. The theoretical ambiguities of the results of our NNLO fits are estimated by means of the Pade resummation technique. The NNLO and the N 3 LO α s (Q 2 ) MS-matching conditions are used. In the process of the fits we are taking into account the twist-4 1/Q 2 -terms. We found that the amplitude of the x-shape of the twist-4 factor is consequently decreasing at the NLO and NNLO, though some remaining twist-4 structure seems to retain at the NNLO in the case when only statistical uncertainties are taken into account. The question of the stability of these results to the application of the [0/2] Pade resummation technique is considered. Our NNLO results for α s (M z ) values, extracted from the CCFR xF 3 data, are α s (M z ) = 0.118 ± 0.002(stat) ± 0.005(syst) ± 0.003(theory) provided the twist-4 contributions are fixed through the infrared renormalon model and α s (M z ) 0.121 -0.010 +0.007 (stat)±0.005(syst)±0.003(theory) provided the twist-4 terms are considered as the free parameters. (author)
Impact of Next-to-Leading Order Contributions to Cosmic Microwave Background Lensing.
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.
Driving missing data at the LHC: NNLO predictions for the ratio of \gamma +j and Z+j
Energy Technology Data Exchange (ETDEWEB)
Campbell, John M.; Ellis, R. Keith; Williams, Ciaran
2017-07-01
In this paper we present a calculation of the $\\gamma+j$ process at next-to-next-to-leading order (NNLO) in QCD and compare the resulting predictions to 8 TeV CMS data. We find good agreement with the shape of the photon $p_T$ spectrum, particularly after the inclusion of additional electroweak corrections, but there is a tension between the overall normalization of the theoretical prediction and the measurement. We use our results to compute the ratio of $Z(\\to \\ell^+\\ell^-)+j$ to $\\gamma+j$ events as a function of the vector boson transverse momentum at NNLO, a quantity that is used to normalize $Z(\\rightarrow\
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 ...
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.
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.
Next-to-leading-order QCD corrections to e+eââH+Î³
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+eââHÎ³, 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 HâÎ³Î³,ZÎ³, the e+eââHÎ³ 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+Î³ 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<300Â GeV, thus of negligible impact on Higgs factory such as CEPC. Nevertheless, when the energy is boosted to the ILC energy range (sâ400Â GeV, QCD corrections may enhance the leading-order cross section by 20%. In any event, the e+eââHÎ³ process has a maximal production rate Ïmaxâ0.08Â fb around s=250Â 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 â1/s , but the latter undergoes a much faster decrease â1/s2. Keywords: Standard Model, Higgs boson, QCD corrections
International Nuclear Information System (INIS)
Sidorov, A.V.; Tokarev, M.V.
1997-01-01
A detailed NNLO QCD analysis of new CCFR data on xF 3 structure function including the target mass, higher twist and nuclear corrections was performed and parametrizations of the perturbative and power terms of the structure function were constructed. The results of QCD analysis of the structure function were used to study the Q 2 -dependence of the Gross-Llewellyn Smith sum rule. The α S /π-expansion of S GLS (Q 2 ) was studied and parameters of the expansion were found to be s 1 =2.74±0.01, s 2 =-2.22±0.23, s 3 =-7.86±1.74 which are in good agreement with the perturbative QCD predictions for the Gross-Llewellyn Smith sum rule in the next-to-leading and next-to-next-to-leading order
International Nuclear Information System (INIS)
Sidorov, A.V.; Tokarev, M.V.
1997-01-01
A detailed NNLO QCD analysis of new CCFR data on xF 3 structure function including the target mass, higher twist and nuclear corrections was performed and parametrizations of the perturbative and power terms of the structure function were constructed. The results of QDC analysis of the structure function were used to study the Q 2 -dependence of the Gross-Llewellyn-Smith sum rule. The α s /π-expansion of S GLS (Q 2 ) was studied and parameters of the expansion were found to be s 1 =2.74±0.01, s 2 =-2.22±0.23, s 3 =-7.86±1.74 which are in good agreement with the perturbative QCD predictions for the Gross-Llewellyn-Smith sum rule in the next-to-leading and next-to-next-leading order
d'Enterria, David
Total and fiducial top pair ($t\\bar{t}$) production cross sections in proton-lead (pPb) collisions at $\\sqrt{s_{NN}}$ = 8.16 TeV are computed at next-to-next-to-leading-order (NNLO) accuracy including next-to-next-to-leading-log (NNLL) gluon resummation, using the CT14 and CT10 proton parton distribution functions (PDF), and the EPPS16 and EPS09 nuclear PDF parametrizations for the lead ion. The total cross sections amount to $\\sigma(pPb\\to t\\bar{t}+X) = 59.0 \\pm 5.3$(CT14+EPPS16)$\\,^{+1.6}_{-2.1}$(scale) nb, and $57.5 \\pm \\,^{+4.3}_{-3.3}$(CT10+EPS09)$\\,^{+1.5}_{-2.0}$(scale) nb, with small modifications with respect to the result computed using the free proton PDF alone. The normalized ratio of pPb to pp cross sections (nuclear modification factor) is $R_{pPb} = 1.04 \\,^{\\pm 0.07(EPPS16)}_{\\pm0.03(EPS09)}$. In the lepton+jets decay mode, $t\\bar{t} \\to b\\bar{b} W(\\ell\
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.
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.
Matrix elements for the anti B→Xsγ decay at NNLO
International Nuclear Information System (INIS)
Schutzmeier, Thomas Paul
2009-01-01
In the context of the indirect search for non-standard physics in the flavour sector of the Standard Model (SM), one of the most interesting processes is the rare inclusive anti B→ X s γ decay. On the one hand, being a flavour-changing neutral current, this B decay is sensitive to new physics, as it is loop-suppressed in the SM. On the other hand, it is only mildly affected by non-perturbative effects, and thus allows for precise theoretical predictions in the framework of renormalization-group improved perturbation theory. Accurate measurements as well as precise theoretical predictions with a good control over both perturbative and non-perturbative contributions have to be provided in order to derive stringent constraints on the parameter space of physics beyond the SM. On the experimental side, an outstanding accuracy in the measurement of the anti B→X s γ decay rate has been achieved, which is mainly due the specialized experiments BaBar and Belle at the so-called B factories. To match the small experimental uncertainty, higher order computations within an effective low-energy theory of the SM are mandatory. In fact, next-to-next-to-leading order (NNLO) QCD corrections are required to provide a prediction for the decay rate with the same precision as the measurement. The NNLO evaluation of the anti B→X s γ decay rate has been pursued by various groups over the last decade. The project was completed to a large extent and a first estimate at this level of perturbation theory was obtained in 2006. This prediction, however, lacks important contributions from yet unknown matrix elements, that were estimated from results which are only partially known to date. In this work, we provide a framework for the systematic study of the missing matrix elements at the NNLO. As main results of this thesis, we determine fermionic corrections to the charm quark mass dependent matrix elements of four-quark operators in the effective theory at NNLO. For the first time, the
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.
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.)
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
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%.
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.
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
αs and |Vcs| determination, and CKM unitarity test, from W decays at NNLO
Directory of Open Access Journals (Sweden)
David d'Enterria
2016-12-01
Full Text Available The hadronic (ΓhadW and total (ΓtotW widths of the W boson, computed at least at next-to-next-to-leading-order (NNLO accuracy, are combined to derive a new precise prediction for the hadronic W branching ratio BhadW ≡ ΓhadW/ΓtotW=0.682±0.011par, using the experimental Cabibbo–Kobayashi–Maskawa (CKM matrix elements, with uncertainties dominated by the input parameters of the calculations, or BhadW=0.6742±0.0002th±0.0001par assuming CKM unitarity. Comparing the theoretical predictions and experimental measurements for various W decay observables, the NNLO strong coupling constant at the Z pole, αs(mZ2=0.117±0.042exp±0.004th±0.001par, as well as the charm-strange CKM element, |Vcs|=0.973±0.004exp±0.002par, can be extracted under different assumptions. We also show that W decays provide today the most precise test of CKM unitarity for the 5 quarks lighter than mW, ∑u,c,d,s,b|Vij|2=1.999±0.008exp±0.001th. Perspectives for αs and |Vcs| extractions from W decays measurements at the LHC and future e+e− colliders are presented.
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.
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.
Higher Order Corrections in the CoLoRFulNNLO Framework
Somogyi, G.; Kardos, A.; Szőr, Z.; Trócsányi, Z.
We discuss the CoLoRFulNNLO method for computing higher order radiative corrections to jet cross sections in perturbative QCD. We apply our method to the calculation of event shapes and jet rates in three-jet production in electron-positron annihilation. We validate our code by comparing our predictions to previous results in the literature and present the jet cone energy fraction distribution at NNLO accuracy. We also present preliminary NNLO results for the three-jet rate using the Durham jet clustering algorithm matched to resummed predictions at NLL accuracy, and a comparison to LEP data.
Matrix elements for the anti B{yields}X{sub s}{gamma} decay at NNLO
Energy Technology Data Exchange (ETDEWEB)
Schutzmeier, Thomas Paul
2009-12-17
In the context of the indirect search for non-standard physics in the flavour sector of the Standard Model (SM), one of the most interesting processes is the rare inclusive anti B{yields} X{sub s}{gamma} decay. On the one hand, being a flavour-changing neutral current, this B decay is sensitive to new physics, as it is loop-suppressed in the SM. On the other hand, it is only mildly affected by non-perturbative effects, and thus allows for precise theoretical predictions in the framework of renormalization-group improved perturbation theory. Accurate measurements as well as precise theoretical predictions with a good control over both perturbative and non-perturbative contributions have to be provided in order to derive stringent constraints on the parameter space of physics beyond the SM. On the experimental side, an outstanding accuracy in the measurement of the anti B{yields}X{sub s}{gamma} decay rate has been achieved, which is mainly due the specialized experiments BaBar and Belle at the so-called B factories. To match the small experimental uncertainty, higher order computations within an effective low-energy theory of the SM are mandatory. In fact, next-to-next-to-leading order (NNLO) QCD corrections are required to provide a prediction for the decay rate with the same precision as the measurement. The NNLO evaluation of the anti B{yields}X{sub s}{gamma} decay rate has been pursued by various groups over the last decade. The project was completed to a large extent and a first estimate at this level of perturbation theory was obtained in 2006. This prediction, however, lacks important contributions from yet unknown matrix elements, that were estimated from results which are only partially known to date. In this work, we provide a framework for the systematic study of the missing matrix elements at the NNLO. As main results of this thesis, we determine fermionic corrections to the charm quark mass dependent matrix elements of four-quark operators in the
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
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
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.
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.)
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.
Resummed Higgs cross section at N3LL
International Nuclear Information System (INIS)
Bonvini, Marco; Marzani, Simone
2014-05-01
We present accurate predictions for the inclusive production of a Higgs boson in proton-proton collisions, via gluon-gluon fusion. Our calculation includes next-to-next-to-leading order (NNLO) corrections in perturbative QCD, as well as the resummation of threshold-enhanced contributions to next-to-next-to-next-to-leading logarithmic (N 3 LL) accuracy, with the inclusion of the recently-determined three-loop constant coefficient (sometimes referred to as N 3 LL' accuracy). Our result correctly accounts for finite top, bottom and charm masses at leading order (LO) and next-to-leading order (NLO), and includes the exact top mass dependence at NNLO. At the resummed level the dependence on top, bottom and charm mass is accounted for at NLL, while only the top mass at NNLL. The all-order calculation is improved by a suitable choice of the soft terms, dictated by analyticity conditions and by the inclusion of subleading corrections of collinear origin, which improve the accuracy of the resummation away from the threshold region. We present results for different collider energies and we study perturbative uncertainties by varying renormalization and factorization scales. We find that, at current LHC energies, the resummation corrects the NNLO result by as much as 20 % at μ R =μ F =m H , while the correction is much smaller, 5.5 %, at μ R =μ F =m H /2. While the central value of NNLO+N 3 LL result depends very mildly on the scale choice, we argue that a more realiable estimate of the theoretical uncertainty is found if the perturbative scales are canonically varied about m H .
The ABM parton distributions tuned to LHC data
International Nuclear Information System (INIS)
Alekhin, S.; Bluemlein, J.; Moch, S.; Hamburg Univ.
2013-10-01
We present a global fit of parton distributions at next-to-next-to-leading order (NNLO) in QCD. The fit is based on the world data for deep-inelastic scattering, fixed-target data for the Drell-Yan process and includes, for the first time, data from the Large Hadron Collider (LHC) for the Drell-Yan process and the hadro-production of top-quark pairs. The analysis applies the fixed-flavor number scheme for n f =3,4,5, uses the MS scheme for the strong coupling α s and the heavy-quark masses and keeps full account of the correlations among all non-perturbative parameters. At NNLO this returns the values of α s (M Z )=0.1132±0.0011 and m t (pole)=171.2±2.4 GeV for the top-quark pole mass. The fit results are used to compute benchmark cross sections for Higgs production at the LHC to NNLO accuracy. We compare our results to those obtained by other groups and show that differences can be linked to different theoretical descriptions of the underlying physical processes.
Associated production of a top pair and a Higgs boson beyond NLO
Energy Technology Data Exchange (ETDEWEB)
Broggio, Alessandro [Paul Scherrer Institut,CH-5232 Villigen PSI (Switzerland); Physik Department T31, Technische Universität München,James Franck-Straße 1, D-85748 Garching (Germany); Ferroglia, Andrea [Physics Department, New York City College of Technology,300 Jay St, Brooklyn, NY 11201 (United States); The Graduate School and University Center, The City University of New York,365 5th Ave, New York, NY 10016 (United States); Pecjak, Ben D. [Institute for Particle Physics Phenomenology, Ogden Centre for Fundamental Physics,Department of Physics, University of Durham, Science Laboratories,South Rd, Durham DH1 3LE (United Kingdom); Signer, Adrian [Paul Scherrer Institut,CH-5232 Villigen PSI (Switzerland); Physik-Institut, Universität Zürich,Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Yang, Li Lin [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University,No. 5 Yiheyuan Road, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter,Beijing (China); Center for High Energy Physics, Peking University,No. 5 Yiheyuan Road, Beijing 100871 (China)
2016-03-17
We consider soft gluon emission corrections to the production of a top-antitop pair in association with a Higgs boson at hadron colliders. In particular, we present a soft-gluon resummation formula for this production process and gather all elements needed to evaluate it at next-to-next-to-leading logarithmic order. We employ these results to obtain approximate next-to-next-to-leading order (NNLO) formulas, and implement them in a bespoke parton-level Monte Carlo program which can be used to calculate the total cross section along with arbitrary differential distributions. We use this tool to study the phenomenological impact of the approximate NNLO corrections, finding that they increase the total cross section and the differential distributions which we evaluated in this work.
Energy-energy correlation in electron-positron annihilation at NNLL + NNLO accuracy
Energy Technology Data Exchange (ETDEWEB)
Tulipant, Zoltan; Kardos, Adam; Somogyi, Gabor [University of Debrecen, MTA-DE Particle Physics Research Group, Debrecen (Hungary)
2017-11-15
We present the computation of energy-energy correlation in e{sup +}e{sup -} collisions in the back-to-back region at next-to-next-to-leading logarithmic accuracy matched with the next-to-next-to-leading order perturbative prediction. We study the effect of the fixed higher-order corrections in a comparison of our results to LEP and SLC data. The next-to-next-to-leading order correction has a sizable impact on the extracted value of α{sub S}(M{sub Z}), hence its inclusion is mandatory for a precise measurement of the strong coupling using energy-energy correlation. (orig.)
Energy-energy correlation in electron-positron annihilation at NNLL + NNLO accuracy
Tulipánt, Zoltán; Kardos, Adam; Somogyi, Gábor
2017-11-01
We present the computation of energy-energy correlation in e^+e^- collisions in the back-to-back region at next-to-next-to-leading logarithmic accuracy matched with the next-to-next-to-leading order perturbative prediction. We study the effect of the fixed higher-order corrections in a comparison of our results to LEP and SLC data. The next-to-next-to-leading order correction has a sizable impact on the extracted value of α S(M_Z), hence its inclusion is mandatory for a precise measurement of the strong coupling using energy-energy correlation.
Subtraction method of computing QCD jet cross sections at NNLO accuracy
Trócsányi, Zoltán; Somogyi, Gábor
2008-10-01
We present a general subtraction method for computing radiative corrections to QCD jet cross sections at next-to-next-to-leading order accuracy. The steps needed to set up this subtraction scheme are the same as those used in next-to-leading order computations. However, all steps need non-trivial modifications, which we implement such that that those can be defined at any order in perturbation theory. We give a status report of the implementation of the method to computing jet cross sections in electron-positron annihilation at the next-to-next-to-leading order accuracy.
Subtraction method of computing QCD jet cross sections at NNLO accuracy
Energy Technology Data Exchange (ETDEWEB)
Trocsanyi, Zoltan [University of Debrecen and Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4001 Debrecen P.O.Box 51 (Hungary)], E-mail: Zoltan.Trocsanyi@cern.ch; Somogyi, Gabor [University of Zuerich, Winterthurerstrasse 190, CH-8057 Zuerich (Switzerland)], E-mail: sgabi@physik.unizh.ch
2008-10-15
We present a general subtraction method for computing radiative corrections to QCD jet cross sections at next-to-next-to-leading order accuracy. The steps needed to set up this subtraction scheme are the same as those used in next-to-leading order computations. However, all steps need non-trivial modifications, which we implement such that that those can be defined at any order in perturbation theory. We give a status report of the implementation of the method to computing jet cross sections in electron-positron annihilation at the next-to-next-to-leading order accuracy.
The ABM parton distributions tuned to LHC data
Energy Technology Data Exchange (ETDEWEB)
Alekhin, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute for High Energy Physics, Protvino (Russian Federation); Bluemlein, J. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik
2013-10-15
We present a global fit of parton distributions at next-to-next-to-leading order (NNLO) in QCD. The fit is based on the world data for deep-inelastic scattering, fixed-target data for the Drell-Yan process and includes, for the first time, data from the Large Hadron Collider (LHC) for the Drell-Yan process and the hadro-production of top-quark pairs. The analysis applies the fixed-flavor number scheme for n{sub f}=3,4,5, uses the MS scheme for the strong coupling {alpha}{sub s} and the heavy-quark masses and keeps full account of the correlations among all non-perturbative parameters. At NNLO this returns the values of {alpha}{sub s}(M{sub Z})=0.1132{+-}0.0011 and m{sub t}(pole)=171.2{+-}2.4 GeV for the top-quark pole mass. The fit results are used to compute benchmark cross sections for Higgs production at the LHC to NNLO accuracy. We compare our results to those obtained by other groups and show that differences can be linked to different theoretical descriptions of the underlying physical processes.
NextGEOSS: The Next Generation Data Hub For Earth Observations
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.
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...
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
SIMP model at NNLO in chiral perturbation theory
Hansen, Martin; Langæble, Kasper; Sannino, Francesco
2015-10-01
We investigate the phenomenological viability of a recently proposed class of composite dark matter models where the relic density is determined by 3 →2 number-changing processes in the dark sector. Here the pions of the strongly interacting field theory constitute the dark matter particles. By performing a consistent next-to-leading- and next-to-next-to-leading-order chiral perturbative investigation we demonstrate that the leading-order analysis cannot be used to draw conclusions about the viability of the model. We further show that higher-order corrections substantially increase the tension with phenomenological constraints challenging the viability of the simplest realization of the strongly interacting massive particle paradigm.
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+−tanβ parameter space determined by the recent results of the CMS [13] and ATLAS [14] collaborations.
Pramana – Journal of Physics | Indian Academy of Sciences
Indian Academy of Sciences (India)
We describe the calculation of inclusive Higgs boson production at hadronic colliders at next-to-next-to-leading order (NNLO) in perturbative quantum chromodynamics. We have used the technique developed in ref. [4]. Our results agree with those published earlier in the literature.
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.
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.
Higgs boson pair production: Top quark mass effects at NLO and NNLO
Directory of Open Access Journals (Sweden)
Jonathan Grigo
2015-11-01
Full Text Available We compute next-to-next-to-leading order QCD corrections to the gluon-induced production cross section of Higgs boson pairs in the large top quark mass limit using the soft-virtual approximation. In the limit of infinitely-heavy top quark we confirm the results in the literature. We add two more expansion terms in the inverse top quark mass to the Mt→∞ result. Since the 1/Mt expansion converges poorly, we try to improve on it by factorizing the exact leading order cross section. We discuss two ways of doing that and conclude that the finite top quark mass effects shift the cross section at most by about 10% at next-to-leading order and by about 5% at next-to-next-to-leading order.
Beauty and charm production in fixed target experiments
International Nuclear Information System (INIS)
Kidonakis, Nikolaos; Vogt, Ramona
2004-01-01
We present calculations of NNLO threshold corrections for beauty and charm production in π - p and pp interactions at fixed-target experiments. Recent calculations for heavy quark hadroproduction have included next-to-next-to-leading-order (NNLO) soft-gluon corrections [1] to the double differential cross section from threshold resummation techniques [2]. These corrections are important for near-threshold beauty and charm production at fixed-target experiments, including HERA-B and some of the current and future heavy ion experiments
Spin nematics next to spin singlets
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.
NNLL momentum-space resummation for stop-pair production at the LHC
International Nuclear Information System (INIS)
Broggio, Alessandro; Ferroglia, Andrea; Neubert, Matthias; Vernazza, Leonardo; Yang, Li Lin
2014-01-01
If supersymmetry near the TeV scale is realized in Nature, the pair production of scalar top squarks is expected to be observable at the Large Hadron Collider. Recently, effective field-theory methods were employed to obtain approximate predictions for the cross section for this process, which include soft-gluon emission effects up to next-to-next-to-leading order (NNLO) in perturbation theory. In this work we employ the same techniques to resum soft-gluon emission effects to all orders in perturbation theory and with next-to-next-to-logarithmic (NNLL) accuracy. We analyze the effects of NNLL resummation on the stop-pair production cross section by obtaining NLO+NNLL predictions in pair invariant mass and one-particle inclusive kinematics. We compare the results of these calculations to the approximate NNLO predictions for the cross sections
NNLL momentum-space resummation for stop-pair production at the LHC
Energy Technology Data Exchange (ETDEWEB)
Broggio, Alessandro [Paul Scherrer Institute,CH-5232 Villigen (Switzerland); Ferroglia, Andrea [New York City College of Technology, The City University of New York,300 Jay Street, Brooklyn, NY 11201 (United States); Neubert, Matthias [PRISMA Cluster of Excellence & Mainz Institut for Theoretical Physics,Johannes Gutenberg University, D-55099 Mainz (Germany); Department of Physics, LEPP, Cornell University,Ithaca, NY 14853 (United States); Vernazza, Leonardo [Dipartimento di Fisica, Università di Torino & INFN - Sezione di Torino,Via P. Giuria 1, I-10125 Torino (Italy); Yang, Li Lin [School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University, 100871 Beijing (China); Collaborative Innovation Center of Quantum Matter,Beijing (China); Center for High Energy Physics, Peking University,Beijing 100871 (China)
2014-03-12
If supersymmetry near the TeV scale is realized in Nature, the pair production of scalar top squarks is expected to be observable at the Large Hadron Collider. Recently, effective field-theory methods were employed to obtain approximate predictions for the cross section for this process, which include soft-gluon emission effects up to next-to-next-to-leading order (NNLO) in perturbation theory. In this work we employ the same techniques to resum soft-gluon emission effects to all orders in perturbation theory and with next-to-next-to-logarithmic (NNLL) accuracy. We analyze the effects of NNLL resummation on the stop-pair production cross section by obtaining NLO+NNLL predictions in pair invariant mass and one-particle inclusive kinematics. We compare the results of these calculations to the approximate NNLO predictions for the cross sections.
Next-to-leading order \gamma \gamma +2\text{-}\mathrm{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.
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.
Answers to Teachers' Questions about the Next Generation Science Standards
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…
Higher Order Heavy Quark Corrections to Deep-Inelastic Scattering
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.
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.
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)
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.
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.
ABM11 parton distributions and benchmarks
International Nuclear Information System (INIS)
Alekhin, Sergey; Bluemlein, Johannes; Moch, Sven-Olaf
2012-08-01
We present a determination of the nucleon parton distribution functions (PDFs) and of the strong coupling constant α s at next-to-next-to-leading order (NNLO) in QCD based on the world data for deep-inelastic scattering and the fixed-target data for the Drell-Yan process. The analysis is performed in the fixed-flavor number scheme for n f =3,4,5 and uses the MS scheme for α s and the heavy quark masses. The fit results are compared with other PDFs and used to compute the benchmark cross sections at hadron colliders to the NNLO accuracy.
ABM11 parton distributions and benchmarks
Energy Technology Data Exchange (ETDEWEB)
Alekhin, Sergey [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institut Fiziki Vysokikh Ehnergij, Protvino (Russian Federation); Bluemlein, Johannes; Moch, Sven-Olaf [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2012-08-15
We present a determination of the nucleon parton distribution functions (PDFs) and of the strong coupling constant {alpha}{sub s} at next-to-next-to-leading order (NNLO) in QCD based on the world data for deep-inelastic scattering and the fixed-target data for the Drell-Yan process. The analysis is performed in the fixed-flavor number scheme for n{sub f}=3,4,5 and uses the MS scheme for {alpha}{sub s} and the heavy quark masses. The fit results are compared with other PDFs and used to compute the benchmark cross sections at hadron colliders to the NNLO accuracy.
MoonNEXT: A European Mission to the Moon
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
NextGen Future Safety Assessment Game
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.
Study of the s - s bar asymmetry in the proton
Goharipour, Muhammad
2018-05-01
The study of s - s bar asymmetry is essential to better understand of the structure of nucleon and also the perturbative and nonperturbative mechanisms for sea quark generation. Actually, the nature and dynamical origins of this asymmetry have always been an interesting subject to research both experimentally and theoretically. One of the most powerful models can lead to s - s bar asymmetry is the meson-baryon model (MBM). In this work, using a simplified configuration of this model suggested by Pumplin, we calculate the s - s bar asymmetry for different values of cutoff parameter Λ, to study the dependence of model to this parameter and also to estimate the theoretical uncertainty imposed on the results due to its uncertainty. Then, we study the evolution of distributions obtained both at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) using different evolution schemes. It is shown that the evolution of the intrinsic quark distributions from a low initial scale, as suggested by Chang and Pang, is not a good choice at NNLO using variable flavor number scheme (VFNS).
Framework for Leading Next Generation Science Standards Implementation
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…
NNLO time-like splitting functions in QCD
International Nuclear Information System (INIS)
Moch, S.; Vogt, A.
2008-07-01
We review the status of the calculation of the time-like splitting functions for the evolution of fragmentation functions to the next-to-next-to-leading order in perturbative QCD. By employing relations between space-like and time-like deep-inelastic processes, all quark-quark and the gluon-gluon time-like splitting functions have been obtained to three loops. The corresponding quantities for the quark-gluon and gluon-quark splitting at this order are presently still unknown except for their second Mellin moments. (orig.)
Ethical challenges related to next of kin - nursing staffs' perspective.
Tønnessen, Siri; Solvoll, Betty-Ann; Brinchmann, Berit Støre
2016-11-01
Patients in clinical settings are not lonely islands; they have relatives who play a more or less active role in their lives. The purpose of this article is to elucidate the ethical challenges nursing staff encounter with patients' next of kin and to discuss how these challenges affect clinical practice. The study is based on data collected from ethical group discussions among nursing staff in a nursing home. The discussions took place in 2011 and 2012. The data were analysed and interpreted by using hermeneutic methodology. All the data have been anonymised and handled with confidentiality. Written informed consent was obtained from all participants. Ethical challenges relating to patients' next of kin were found to be an issue frequently discussed in the groups. Our findings indicate that next of kin have different characteristics, categorised as 'the professionals' and 'the shadows'. In this article, we will describe the next of kin's characteristics and the ethical challenges and practical implications that nursing staff experience in this connection. We will discuss the findings in the light of the four basic principles of medical ethics and propose interventions to help nurses manage ethical challenges related to next of kin. The study reveals the need to enhance nursing staffs' communicative and ethical skills on an individual level, but most importantly, to establish routines in clinical settings for informing and following up next of kin in a systematic and structured way. © The Author(s) 2015.
Longitudinal structure function from logarithmic slopes of F2 at low x
Boroun, G. R.
2018-01-01
Using Laplace transform techniques, I calculate the longitudinal structure function FL(x ,Q2) from the scaling violations of the proton structure function F2(x ,Q2) and make a critical study of this relationship between the structure functions at leading order (LO) up to next-to-next-to leading order (NNLO) analysis at small x . Furthermore, I consider heavy quark contributions to the relation between the structure functions, which leads to compact formula for Nf=3 +Heavy . The nonlinear corrections to the longitudinal structure function at LO up to NNLO analysis are shown in the Nf=4 (light quark flavor) based on the nonlinear corrections at R =2 and R =4 GeV-1 . The results are compared with experimental data of the longitudinal proton structure function FL in the range of 6.5 ≤Q2≤800 GeV2 .
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.
DEFF Research Database (Denmark)
2015-01-01
Ian Ingram: Next Animals is an exhibition catalogue presenting research on the work by Ian Ingram in relation to his exhibition Next Animals at Nikolaj Kunsthal in 2015.......Ian Ingram: Next Animals is an exhibition catalogue presenting research on the work by Ian Ingram in relation to his exhibition Next Animals at Nikolaj Kunsthal in 2015....
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
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.
Being next of kin to an elderly person with cancer
DEFF Research Database (Denmark)
Esbensen, Bente Appel
2010-01-01
Background: Being next of kin to an elderly person with cancer and its impact on everyday life has been sparsely researched. Such understanding is needed to support both the sufferers and their relatives in dealing with issues arising after a cancer diagnosis in old age. Aim: To illuminate...... the experience of life as next of kin to an elderly person with cancer. Method: A qualitative study was used to illuminate the experience of next of kin of elderly people with cancer. In total, 16 (mean age 61, range 42-80) persons were interviewed. Open-ended interviews were used to get closer...... to their experiences. Manifest and latent content analysis were used. Findings: Two main categories Transformations of roles and Changed frames of mind were identified, as well as four subcategories. The study showed that the cancer activated perceptions in the next of kin about aging and growing old. The onset...
Δ isobars and nuclear saturation
Ekström, A.; Hagen, G.; Morris, T. D.; Papenbrock, T.; Schwartz, P. D.
2018-02-01
We construct a nuclear interaction in chiral effective field theory with explicit inclusion of the Δ -isobar Δ (1232 ) degree of freedom at all orders up to next-to-next-to-leading order (NNLO). We use pion-nucleon (π N ) low-energy constants (LECs) from a Roy-Steiner analysis of π N scattering data, optimize the LECs in the contact potentials up to NNLO to reproduce low-energy nucleon-nucleon scattering phase shifts, and constrain the three-nucleon interaction at NNLO to reproduce the binding energy and point-proton radius of 4He. For heavier nuclei we use the coupled-cluster method to compute binding energies, radii, and neutron skins. We find that radii and binding energies are much improved for interactions with explicit inclusion of Δ (1232 ) , while Δ -less interactions produce nuclei that are not bound with respect to breakup into α particles. The saturation of nuclear matter is significantly improved, and its symmetry energy is consistent with empirical estimates.
Getting Ahead Three Steps to Take Your Career to the Next Level
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
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)
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)
Li, Xingguo; The ATLAS collaboration
2017-01-01
A measurement of the production cross section for two isolated photons in proton-proton collisions at a centre-of-mass energy of √ s = 8 TeV is presented. The results are based on an integrated luminosity of 20.24 fb−1 recorded by the ATLAS detector at the Large Hadron Collider. The measurement considers photons with pseudorapidities satisfying |η γ | 40 GeV and Eγ T,2 > 30 GeV for the highest and second highest Eγ T photon produced in the interaction. The background due to hadronic jets and electrons is subtracted using data-driven techniques. The fiducial cross sections are corrected for detector effects and measured differentially as a function of six kinematic observables. The data are compared to fixed-order QCD calculations at 16 next-to-leading order (NLO) and next-to-next-to-leading-order (NNLO) accuracy as well as NLO computations including resummation of initial-state gluon radiation at next-to-next-to-leading-logarithm or matched to a parton shower.
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)
Achieving universal access to next generation networks
DEFF Research Database (Denmark)
Falch, Morten; Henten, Anders
The paper examines investment dimensions of next generation networks in a universal service perspective in a European context. The question is how new network infrastructures for getting access to communication, information and entertainment services in the present and future information society...
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.
Energy Technology Data Exchange (ETDEWEB)
Motyka, Leszek; Sadzikowski, Mariusz; Slominski, Wojciech [Jagiellonian University, Institute of Physics, Krakow (Poland); Wichmann, Katarzyna [DESY, Hamburg (Germany)
2018-01-15
The combined HERA data for the inclusive deep inelastic scattering (DIS) cross sections for the momentum transfer Q{sup 2} > 1 GeV{sup 2} are fitted within the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) framework at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) accuracy, complemented by a QCD-inspired parameterisation of twist 4 corrections. A modified form of the input parton density functions is also included, motivated by parton saturation mechanism at small Bjorken x and at a low scale. These modifications lead to a significant improvement of the data description in the region of low Q{sup 2}. For the whole data sample, the new benchmark NNLO DGLAP fit yields χ{sup 2}/d.o.f. ≅ 1.19 to be compared to 1.46 resulting from the standard NNLO DGLAP fit. We discuss the results in the context of the parton saturation picture and describe the impact of the higher-twist corrections on the derived parton density functions. The resulting description of the longitudinal proton structure function F{sub L} is consistent with the HERA data. Our estimates of higher-twist contributions to the proton structure functions are comparable to the leading-twist contributions at low Q{sup 2} ≅ 2 GeV{sup 2} and x ≅ 10{sup -5}. The x-dependence of the twist 4 corrections obtained from the best fit is consistent with the leading twist 4 quasi-partonic operators, corresponding to an exchange of four interacting gluons in the t-channel. (orig.)
International Nuclear Information System (INIS)
Nath, N.M.; Mukharjee, A.; Das, M.K.; Sarma, J.K.
2016-01-01
We present an analysis of the xF 3 (x,Q 2 ) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented in [N.M. Nath, et al, Indian J. Phys. 90 (2016) 117]. The corrections due to nuclear effects predicted in several earlier analysis are incorporated to our results of xF 3 (x,Q 2 ) structure function and GLS sum rule for free nucleon, corrected upto next-next-to-leading order (NNLO) perturbative order and calculate the nuclear structure function as well as sum rule for nuclei. In addition, by means of a simple model we have extracted the higher twist contributions to the non-singlet structure function xF 3 (x,Q 2 ) and GLS sum rule in NNLO perturbative orders and then incorporated them to our results. Our NNLO results along with nuclear effect and higher twist corrections are observed to be compatible with corresponding experimental data and other phenomenological analysis. (paper)
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.
Pinning down the large-x gluon with NNLO top-quark pair differential distributions
Energy Technology Data Exchange (ETDEWEB)
Czakon, Michał [Institut für Theoretische Teilchenphysik und Kosmologie, RWTH Aachen University,D-52056 Aachen (Germany); Hartland, Nathan P. [Department of Physics and Astronomy, VU University Amsterdam,De Boelelaan 1081, NL-1081, HV Amsterdam (Netherlands); Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands); Mitov, Alexander [Cavendish Laboratory, University of Cambridge,Cambridge CB3 0HE (United Kingdom); Nocera, Emanuele R. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, OX1 3NP, Oxford (United Kingdom); Rojo, Juan [Department of Physics and Astronomy, VU University Amsterdam,De Boelelaan 1081, NL-1081, HV Amsterdam (Netherlands); Nikhef,Science Park 105, NL-1098 XG Amsterdam (Netherlands)
2017-04-10
Top-quark pair production at the LHC is directly sensitive to the gluon PDF at large x. While total cross-section data is already included in several PDF determinations, differential distributions are not, because the corresponding NNLO calculations have become available only recently. In this work we study the impact on the large-x gluon of top-quark pair differential distributions measured by ATLAS and CMS at √s=8 TeV. Our analysis, performed in the NNPDF3.0 framework at NNLO accuracy, allows us to identify the optimal combination of LHC top-quark pair measurements that maximize the constraints on the gluon, as well as to assess the compatibility between ATLAS and CMS data. We find that differential distributions from top-quark pair production provide significant constraints on the large-x gluon, comparable to those obtained from inclusive jet production data, and thus should become an important ingredient for the next generation of global PDF fits.
Pinning down the large-x gluon with NNLO top-quark pair differential distributions
International Nuclear Information System (INIS)
Czakon, Michał; Hartland, Nathan P.; Mitov, Alexander; Nocera, Emanuele R.; Rojo, Juan
2017-01-01
Top-quark pair production at the LHC is directly sensitive to the gluon PDF at large x. While total cross-section data is already included in several PDF determinations, differential distributions are not, because the corresponding NNLO calculations have become available only recently. In this work we study the impact on the large-x gluon of top-quark pair differential distributions measured by ATLAS and CMS at √s=8 TeV. Our analysis, performed in the NNPDF3.0 framework at NNLO accuracy, allows us to identify the optimal combination of LHC top-quark pair measurements that maximize the constraints on the gluon, as well as to assess the compatibility between ATLAS and CMS data. We find that differential distributions from top-quark pair production provide significant constraints on the large-x gluon, comparable to those obtained from inclusive jet production data, and thus should become an important ingredient for the next generation of global PDF fits.
Vu, Kim-Phuong L; Kiken, Ariana; Chiappe, Dan; Strybel, Thomas Z; Battiste, Vernol
2013-01-01
The Next Generation Air Transportation System (NextGen) will use advanced technologies and new concepts of operation to accommodate projected increases in air travel over the next few decades. Use of NextGen tools requires air traffic controllers (ATCos) to use different procedures than those required to manage NextGen-unequipped aircraft, and ATCos will need to integrate the 2 skill sets when managing a sector consisting of NextGen-equipped and unequipped aircraft. The goal of the present study was to determine the effectiveness of 2 procedures in the training of student controllers to manage both equipage types. We applied a variant of the part-whole training paradigm in the present study. Using a quasi-experimental design, we trained students from 2 different labs of an internship course to manage air traffic with potential NextGen tools concurrent with their traditional training (whole-task group) or after they had time to learn traditional air traffic management skills (part-whole group). Participants were then tested in their ability to manage a simulated sector consisting of different percentages of NextGen-equipped and unequipped aircraft at the mid-term and after the final week of their internship. Results showed that it is better to train students in manual ATCo skills before introducing NextGen tools, unless the students are of higher aptitude. For more skilled students, simultaneously introducing NextGen and manual tools into their curriculum had little negative impact.
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
International Nuclear Information System (INIS)
Abazov, V.M.; Abbott, B.; Acharya, B.S.; Adams, M.; Adams, T.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; Anikeev, V.B.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D.V.; Banerjee, S.; Barberis, E.; Baringer, P.
2013-01-01
We present measurements of direct photon pair production cross sections using 8.5 fb −1 of data collected with the D0 detector at the Fermilab Tevatron pp ¯ collider. The results are presented as differential distributions of the photon pair invariant mass dσ/dM γγ , pair transverse momentum dσ/dp T γγ , azimuthal angle between the photons dσ/dΔϕ γγ , and polar scattering angle in the Collins–Soper frame dσ/d|cosθ ⁎ |. Measurements are performed for isolated photons with transverse momenta p T γ >18(17) GeV for the leading (next-to-leading) photon in p T , pseudorapidities |η γ | γγ >0.4. We present comparisons with the predictions from Monte Carlo event generators DIPHOX and RESBOS implementing QCD calculations at next-to-leading order, 2γNNLO at next-to-next-to-leading order, and SHERPA using matrix elements with higher-order real emissions matched to parton shower
Next Gen One Portal Usability Evaluation
Cross, E. V., III; Perera, J. S.; Hanson, A. M.; English, K.; Vu, L.; Amonette, W.
2018-01-01
Each exercise device on the International Space Station (ISS) has a unique, customized software system interface with unique layouts / hierarchy, and operational principles that require significant crew training. Furthermore, the software programs are not adaptable and provide no real-time feedback or motivation to enhance the exercise experience and/or prevent injuries. Additionally, the graphical user interfaces (GUI) of these systems present information through multiple layers resulting in difficulty navigating to the desired screens and functions. These limitations of current exercise device GUI's lead to increased crew time spent on initiating, loading, performing exercises, logging data and exiting the system. To address these limitations a Next Generation One Portal (NextGen One Portal) Crew Countermeasure System (CMS) was developed, which utilizes the latest industry guidelines in GUI designs to provide an intuitive ease of use approach (i.e., 80% of the functionality gained within 5-10 minutes of initial use without/limited formal training required). This is accomplished by providing a consistent interface using common software to reduce crew training, increase efficiency & user satisfaction while also reducing development & maintenance costs. Results from the usability evaluations showed the NextGen One Portal UI having greater efficiency, learnability, memorability, usability and overall user experience than the current Advanced Resistive Exercise Device (ARED) UI used by astronauts on ISS. Specifically, the design of the One-Portal UI as an app interface similar to those found on the Apple and Google's App Store, assisted many of the participants in grasping the concepts of the interface with minimum training. Although the NextGen One-Portal UI was shown to be an overall better interface, observations by the test facilitators noted specific exercise tasks appeared to have a significant impact on the NextGen One-Portal UI efficiency. Future updates to
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…
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.
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)
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.
Particle collider to fire up next may
Higgins, Alexander G
2007-01-01
"The world's biggest particle colider will start up next May, six months behind schedule because of problems, including the failure of a keyU.S. designed part, the European Organization for Nuclear Research said Friday." (1 page)
The Next Generation Science Standards
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…
Quark mass relations to four-loop order in perturbative QCD.
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.
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.)
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.).
Penguin diagrams in the charm sector in K{sup +}→π{sup +}νν{sup ¯}
Energy Technology Data Exchange (ETDEWEB)
Mondéjar, J., E-mail: jorge.marin@kit.edu; Rittinger, J.
2013-06-21
We evaluate at next-to-next-to-leading order (NNLO) the QCD corrections to the charm contribution from penguin diagrams to the decay K{sup +}→π{sup +}νν{sup ¯}. A NNLO calculation is already available in the literature (Buras et al., 2006 [1]). We provide an independent check of the results of non-anomalous and anomalous diagrams. We use Renormalization Group improvement and an effective theory framework to resum the large logarithms that appear. In the case of the non-anomalous diagrams, our results for the decoupling coefficients and anomalous dimensions, as well as the final numerical result, are in agreement with those of Buras et al. (2006) [1]. In the anomalous case, analytical and numerical disagreements are observed.
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)
The three-loop splitting functions in QCD. The helicity-dependent case
International Nuclear Information System (INIS)
Moch, S.; Vogt, A.
2014-09-01
We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting functions have been obtained by extending our previous all Mellin-N calculations to the structure function g 1 in electromagnetic deep-inelastic scattering (DIS). Their quark-gluon and gluon-gluon counterparts have been derived using third-order fixed-N calculations of structure functions in graviton-exchange DIS, relations to the unpolarized case and mathematical tools for systems of Diophantine equations. The NNLO corrections to the splitting functions are small outside the region of small momentum fractions x where they exhibit a large double-logarithmic enhancement, yet the corrections to the evolution of the parton densities can be unproblematic down to at least x∼10 -4 .
Pseudo-scalar Higgs boson production at N"3LO_A+N"3LL"'
International Nuclear Information System (INIS)
Ahmed, Taushif; Rana, Narayan; Ravindran, V.; Bonvini, Marco; Rottoli, Luca; Kumar, M.C.; Mathews, Prakash
2016-01-01
We consider the production of a pseudo-scalar particle A at the LHC, and present accurate theoretical predictions for its inclusive cross section in gluon fusion. The prediction is based on combining fixed-order perturbation theory and all-order threshold resummation. At fixed order we include the exact next-to-next-to-leading order (NNLO) plus an approximate next-to-next-to-next-to-leading order (N"3LO_A) which is based on the recent computation at this order for the scalar case. We then add threshold resummation at next-to-next-to-next-to leading logarithmic accuracy (N"3LL"'). Various forms of threshold resummation are considered, differing by the treatment of subleading terms, allowing a robust estimate of the theoretical uncertainties due to missing higher orders. With particular attention to pseudo-scalar masses of 200 and 750 GeV, we also observe that perturbative convergence is much improved when resummation is included. Additionally, results obtained with threshold resummation in direct QCD are compared with analogous results as computed in soft-collinear effective theory, which turn out to be in good agreement. We provide precise predictions for pseudo-scalar inclusive cross section at 13 TeV LHC for a wide range of masses. The results are available through updated versions of the public codes ggHiggs and TROLL. (orig.)
Environmental Information for the U.S. Next Generation Air Transportation System (NextGen)
Murray, J.; Miner, C.; Pace, D.; Minnis, P.; Mecikalski, J.; Feltz, W.; Johnson, D.; Iskendarian, H.; Haynes, J.
2009-09-01
It is estimated that weather is responsible for approximately 70% of all air traffic delays and cancellations in the United States. Annually, this produces an overall economic loss of nearly 40B. The FAA and NASA have determined that weather impacts and other environmental constraints on the U.S. National Airspace System (NAS) will increase to the point of system unsustainability unless the NAS is radically transformed. A Next Generation Air Transportation System (NextGen) is planned to accommodate the anticipated demand for increased system capacity and the super-density operations that this transformation will entail. The heart of the environmental information component that is being developed for NextGen will be a 4-dimensional data cube which will include a single authoritative source comprising probabilistic weather information for NextGen Air Traffic Management (ATM) systems. Aviation weather constraints and safety hazards typically comprise meso-scale, storm-scale and microscale observables that can significantly impact both terminal and enroute aviation operations. With these operational impacts in mind, functional and performance requirements for the NextGen weather system were established which require significant improvements in observation and forecasting capabilities. This will include satellite observations from geostationary and/or polar-orbiting hyperspectral sounders, multi-spectral imagers, lightning mappers, space weather monitors and other environmental observing systems. It will also require improved in situ and remotely sensed observations from ground-based and airborne systems. These observations will be used to better understand and to develop forecasting applications for convective weather, in-flight icing, turbulence, ceilings and visibility, volcanic ash, space weather and the environmental impacts of aviation. Cutting-edge collaborative research efforts and results from NASA, NOAA and the FAA which address these phenomena are summarized
A simple next-best alternative to seasonal predictions in Europe
Buontempo, Carlo; De Felice, Matteo
2016-04-01
In order to build a climate proof society, we need to learn how to best use the climate information we have. Having spent time and resources in developing complex numerical models has often blinded us on the value some of this information really has in the eyes of a decision maker. An effective way to assess this is to check the quality of the forecast (and its cost) to the quality of the forecast from a prediction system based on simpler assumption (and thus cheaper to run). Such a practice is common in marketing analysis where it is often referred to as the next-best alternative. As a way to facilitate such an analysis, climate service providers should always provide alongside the predictions a set of skill scores. These are usually based on climatological means, anomaly persistence or more recently multiple linear regressions. We here present an equally simple benchmark based on a Markov chain process locally trained at a monthly or seasonal time-scale. We demonstrate that in spite of its simplicity the model easily outperforms not only the standard benchmark but also most of the seasonal predictions system at least in EUROPE. We suggest that a benchmark of this kind could represent a useful next-best alternative for a number of users.
Momentum-space resummation for transverse observables and the Higgs p ⊥ at N3LL+NNLO
Bizoń, Wojciech; Monni, Pier Francesco; Re, Emanuele; Rottoli, Luca; Torrielli, Paolo
2018-02-01
We present an approach to the momentum-space resummation of global, recursively infrared and collinear safe observables that can vanish away from the Sudakov region. We focus on the hadro-production of a generic colour singlet, and we consider the class of observables that depend only upon the total transverse momentum of the radiation, prime examples being the transverse momentum of the singlet, and ϕ ∗ in Drell-Yan pair production. We derive a resummation formula valid up to next-to-next-to-next-to-leading-logarithmic accuracy for the considered class of observables. We use this result to compute state-of-the-art predictions for the Higgs-boson transverse-momentum spectrum at the LHC at next-to-next-to-next-to-leading-logarithmic accuracy matched to fixed next-to-next-to-leading order. Our resummation formula reduces exactly to the customary resummation performed in impact-parameter space in the known cases, and it also predicts the correct power-behaved scaling of the cross section in the limit of small value of the observable. We show how this formalism is efficiently implemented by means of Monte Carlo techniques in a fully exclusive generator that allows one to apply arbitrary cuts on the Born variables for any colour singlet, as well as to automatically match the resummed results to fixed-order calculations.
Hadronic Leading Order Contribution to the Muon g-2
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.
Next-Generation Sequencing: From Understanding Biology to Personalized Medicine
Directory of Open Access Journals (Sweden)
Benjamin Meder
2013-03-01
Full Text Available Within just a few years, the new methods for high-throughput next-generation sequencing have generated completely novel insights into the heritability and pathophysiology of human disease. In this review, we wish to highlight the benefits of the current state-of-the-art sequencing technologies for genetic and epigenetic research. We illustrate how these technologies help to constantly improve our understanding of genetic mechanisms in biological systems and summarize the progress made so far. This can be exemplified by the case of heritable heart muscle diseases, so-called cardiomyopathies. Here, next-generation sequencing is able to identify novel disease genes, and first clinical applications demonstrate the successful translation of this technology into personalized patient care.
Directory of Open Access Journals (Sweden)
Chan Cheong Xin
2013-01-01
Full Text Available Abstract Thanks to advances in next-generation technologies, genome sequences are now being generated at breadth (e.g. across environments and depth (thousands of closely related strains, individuals or samples unimaginable only a few years ago. Phylogenomics – the study of evolutionary relationships based on comparative analysis of genome-scale data – has so far been developed as industrial-scale molecular phylogenetics, proceeding in the two classical steps: multiple alignment of homologous sequences, followed by inference of a tree (or multiple trees. However, the algorithms typically employed for these steps scale poorly with number of sequences, such that for an increasing number of problems, high-quality phylogenomic analysis is (or soon will be computationally infeasible. Moreover, next-generation data are often incomplete and error-prone, and analysis may be further complicated by genome rearrangement, gene fusion and deletion, lateral genetic transfer, and transcript variation. Here we argue that next-generation data require next-generation phylogenomics, including so-called alignment-free approaches. Reviewers Reviewed by Mr Alexander Panchin (nominated by Dr Mikhail Gelfand, Dr Eugene Koonin and Prof Peter Gogarten. For the full reviews, please go to the Reviewers’ comments section.
Production of H H H and H H V (V =γ ,Z ) at the hadron colliders
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.
Next-generation approaches to the microbial ecology of food fermentations
Directory of Open Access Journals (Sweden)
Nicholas A. Bokulich1,2,3 & David A. Mills1,2,3*
2012-07-01
Full Text Available Food fermentations have enhanced human health since the dawnof time and remain a prevalent means of food processing andpreservation. Due to their cultural and nutritional importance,many of these foods have been studied in detail using moleculartools, leading to enhancements in quality and safety. Furthermore,recent advances in high-throughput sequencing technologyare revolutionizing the study of food microbial ecology,deepening insight into complex fermentation systems. Thisreview provides insight into novel applications of selectmolecular techniques, particularly next-generation sequencingtechnology, for analysis of microbial communities in fermentedfoods. We present a guideline for integrated molecular analysis offood microbial ecology and a starting point for implementingnext-generation analysis of food systems.
RES-E-NEXT: Next Generation of RES-E Policy Instruments
Energy Technology Data Exchange (ETDEWEB)
Miller, M.; Bird, L.; Cochran, J.; Milligan, M.; Bazilian, M. [National Renewable Energy Laboratory, Golden, CO (United States); Denny, E.; Dillon, J.; Bialek, J.; O’Malley, M. [Ecar Limited (Ireland); Neuhoff, K. [DIW Berlin (Germany)
2013-07-04
The RES-E-NEXT study identifies policies that are required for the next phase of renewable energy support. The study analyses policy options that secure high shares of renewable electricity generation and adequate grid infrastructure, enhance flexibility and ensure an appropriate market design. Measures have limited costs or even save money, and policies can be gradually implemented.
Helmuth, Douglas B.; Bell, Raymond M.; Grant, David A.; Lentz, Christopher A.
2012-09-01
Architecting the operational Next Generation of earth monitoring satellites based on matured climate modeling, reuse of existing sensor & satellite capabilities, attention to affordability and evolutionary improvements integrated with constellation efficiencies - becomes our collective goal for an open architectural design forum. Understanding the earth's climate and collecting requisite signatures over the next 30 years is a shared mandate by many of the world's governments. But there remains a daunting challenge to bridge scientific missions to 'operational' systems that truly support the demands of decision makers, scientific investigators and global users' requirements for trusted data. In this paper we will suggest an architectural structure that takes advantage of current earth modeling examples including cross-model verification and a first order set of critical climate parameters and metrics; that in turn, are matched up with existing space borne collection capabilities and sensors. The tools used and the frameworks offered are designed to allow collaborative overlays by other stakeholders nominating different critical parameters and their own treaded connections to existing international collection experience. These aggregate design suggestions will be held up to group review and prioritized as potential constellation solutions including incremental and spiral developments - including cost benefits and organizational opportunities. This Part IV effort is focused on being an inclusive 'Next Gen Constellation' design discussion and is the natural extension to earlier papers.
Applications of SCET to the pair production of supersymmetric particles at hadron colliders
Energy Technology Data Exchange (ETDEWEB)
Broggio, Alessandro
2013-02-04
In this thesis we investigate the phenomenology of supersymmetric particles at hadron colliders beyond next-to-leading order (NLO) in perturbation theory. We discuss the foundations of Soft-Collinear Effective Theory (SCET) and, in particular, we explicitly construct the SCET Lagrangian for QCD. As an example, we discuss factorization and resummation for the Drell-Yan process in SCET. We use techniques from SCET to improve existing calculations of the production cross sections for slepton-pair production and top-squark-pair production at hadron colliders. As a first application, we implement soft-gluon resummation at next-to-next-to-next-to-leading logarithmic order (NNNLL) for slepton-pair production in the minimal supersymmetric extension of the Standard Model (MSSM). This approach resums large logarithmic corrections arising from the dynamical enhancement of the partonic threshold region caused by steeply falling parton luminosities. We evaluate the resummed invariant-mass distribution and total cross section for slepton-pair production at the Tevatron and LHC and we match these results, in the threshold region, onto NLO fixed-order calculations. As a second application we present the most precise predictions available for top-squark-pair production total cross sections at the LHC. These results are based on approximate NNLO formulas in fixed-order perturbation theory, which completely determine the coefficients multiplying the singular plus distributions. The analysis of the threshold region is carried out in pair invariant mass (PIM) kinematics and in single-particle inclusive (1PI) kinematics. We then match our results in the threshold region onto the exact fixed-order NLO results and perform a detailed numerical analysis of the total cross section.
NASA's Next Generation Space Geodesy Program
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.;
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
The three-loop splitting functions in QCD: The helicity-dependent case
Directory of Open Access Journals (Sweden)
S. Moch
2014-12-01
Full Text Available We present the next-to-next-to-leading order (NNLO contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark–quark and gluon–quark splitting functions have been obtained by extending our previous all Mellin-N calculations to the structure function g1 in electromagnetic deep-inelastic scattering (DIS. Their quark–gluon and gluon–gluon counterparts have been derived using third-order fixed-N calculations of structure functions in graviton-exchange DIS, relations to the unpolarized case and mathematical tools for systems of Diophantine equations. The NNLO corrections to the splitting functions are small outside the region of small momentum fractions x where they exhibit a large double-logarithmic enhancement, yet the corrections to the evolution of the parton densities can be unproblematic down to at least x≈10−4.
77 FR 33777 - General Aviation Safety Forum: Climbing to the Next Level
2012-06-07
... NATIONAL TRANSPORTATION SAFETY BOARD General Aviation Safety Forum: Climbing to the Next Level The National Transportation Safety Board (NTSB) will convene a 2- day forum focused on safety issues related to... the Next Level,'' will be chaired by NTSB Chairman Deborah A. P. Hersman and all five Board Members...
AgMIP: Next Generation Models and Assessments
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
Fiber to the home: next generation network
Yang, Chengxin; Guo, Baoping
2006-07-01
Next generation networks capable of carrying converged telephone, television (TV), very high-speed internet, and very high-speed bi-directional data services (like video-on-demand (VOD), Game etc.) strategy for Fiber To The Home (FTTH) is presented. The potential market is analyzed. The barriers and some proper strategy are also discussed. Several technical problems like various powering methods, optical fiber cables, and different network architecture are discussed too.
Overview of NASA's Next Generation Air Transportation System (NextGen) Research
Swenson, Harry N.
2009-01-01
This slide presentation is an overview of the research for the Next Generation Air Transportation System (NextGen). Included is a review of the current air transportation system and the challenges of air transportation research. Also included is a review of the current research highlights and significant accomplishments.
An electronic flight bag for NextGen avionics
Zelazo, D. Eyton
2012-06-01
The introduction of the Next Generation Air Transportation System (NextGen) initiative by the Federal Aviation Administration (FAA) will impose new requirements for cockpit avionics. A similar program is also taking place in Europe by the European Organisation for the Safety of Air Navigation (Eurocontrol) called the Single European Sky Air Traffic Management Research (SESAR) initiative. NextGen will require aircraft to utilize Automatic Dependent Surveillance-Broadcast (ADS-B) in/out technology, requiring substantial changes to existing cockpit display systems. There are two ways that aircraft operators can upgrade their aircraft in order to utilize ADS-B technology. The first is to replace existing primary flight displays with new displays that are ADS-B compatible. The second, less costly approach is to install an advanced Class 3 Electronic Flight Bag (EFB) system. The installation of Class 3 EFBs in the cockpit will allow aircraft operators to utilize ADS-B technology in a lesser amount of time with a decreased cost of implementation and will provide additional benefits to the operator. This paper describes a Class 3 EFB, the NexisTM Flight-Intelligence System, which has been designed to allow users a direct interface with NextGen avionics sensors while additionally providing the pilot with all the necessary information to meet NextGen requirements.
CEATI distribution roadmap : what's next?
International Nuclear Information System (INIS)
2006-01-01
The future of the electric distribution utility environment over the next 20 years was discussed. A study was conducted to assist utilities in developing future implementation plans. Twenty-one scenarios were created in order to obtain a list of technologies that may impact the future of the distribution grid. Scenarios considered potential policies and regulation, and investigated technologies required to implement each scenario. The scenarios considered future energy markets; business environments; distribution assets; and workforce developments. A distribution value chain classification was used to identify potential synergies. Results of the study showed that distributed resources will become more important in the next 20 years. Employee and system safety will require active consideration as the electricity grid becomes more complex. A second phase of the project will identify key technologies, common infrastructure needs, and guidelines for transforming distribution utilities in the future
1989-01-01
The first website at CERN - and in the world - was dedicated to the World Wide Web project itself and was hosted on Berners-Lee's NeXT computer. The website described the basic features of the web; how to access other people's documents and how to set up your own server. This NeXT machine - the original web server - is still at CERN. As part of the project to restore the first website, in 2013 CERN reinstated the world's first website to its original address.
Community access networks: how to connect the next billion to the ...
International Development Research Centre (IDRC) Digital Library (Canada)
Community access networks: how to connect the next billion to the Internet. Despite recent progress with mobile technology diffusion, more than four billion people worldwide are unconnected and have limited access to global communication infrastructure. The cost of implementing connectivity infrastructure in underserved ...
Sensitivity of NEXT-100 to neutrinoless double beta decay
Martín-Albo, J.; Ferrario, P.; Nebot-Guinot, M.; Gómez-Cadenas, J.J.; Álvarez, V.; Azevedo, C.D.R.; Borges, F.I.G.; Cárcel, S.; Cebrián, S.; Cervera, A.; Conde, C.A.N.; Díaz, J.; Diesburg, M.; Esteve, R.; Fernandes, L.M.P.; Ferreira, A.L.; Freitas, E.D.C.; Gehman, V.M.; Goldschmidt, A.; González-Díaz, D.; Gutiérrez, R.M.; Henriques, C.A.O.; Hernando Morata, J.A.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Lorca, D.; Losada, M.; Martínez-Lema, G.; Martínez, A.; Miller, T.; Monrabal, F.; Monserrate, M.; Monteiro, C.M.B.; Mora, F.J.; Moutinho, L.M.; Novella, P.; Nygren, D.; Para, A.; Perez, J.; Perez Aparicio, J.L.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Santos, F.P.; dos Santos, J.M.F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J.F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J.F.C.A.; Villar, J.A.; Webb, R.; White, J.T.; Yahlali, N.; Yepes-Ramírez, H.; Hauptman, J.
2016-01-01
NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta decay of Xe-136. The detector possesses two features of great value in neutrinoless double beta decay searches: very good energy resolution (better than 1% FWHM at the Q value of Xe-136) and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Detailed Monte Carlo detector simulations and material-screening measurements predict a background rate for NEXT-100 of at most 0.0004 counts/(keV kg yr). Accordingly, the detector will reach a sensitivity to the neutrinoless double beta decay half-life of 6.E25 years after running for 3 effective years.
Planning Instruction to Meet the Intent of the Next Generation Science Standards
Krajcik, Joseph; Codere, Susan; Dahsah, Chanyah; Bayer, Renee; Mun, Kongju
2014-03-01
The National Research Council's Framework for K- 12 Science Education and the Next Generation Science Standards (NGSS Lead States in Next Generation Science Standards: For states, by states. The National Academies Press, Washington, 2013) move teaching away from covering many isolated facts to a focus on a smaller number of disciplinary core ideas (DCIs) and crosscutting concepts that can be used to explain phenomena and solve problems by engaging in science and engineering practices. The NGSS present standards as knowledge-in-use by expressing them as performance expectations (PEs) that integrate all three dimensions from the Framework for K- 12 Science Education. This integration of core ideas, practices, and crosscutting concepts is referred to as three-dimensional learning (NRC in Division of Behavioral and Social Sciences and Education. The National Academies Press, Washington, 2014). PEs state what students can be assessed on at the end of grade level for K-5 and at the end of grade band for 6-8 and 9-12. PEs do not specify how instruction should be developed nor do they serve as objectives for individual lessons. To support students in developing proficiency in the PEs, the elements of the DCIs will need to be blended with various practices and crosscutting concepts. In this paper, we examine how to design instruction to support students in meeting a cluster or "bundle" of PEs and how to blend the three dimensions to develop lesson level PEs that can be used for guiding instruction. We provide a ten-step process and an example of that process that teachers and curriculum designers can use to design lessons that meet the intent of the Next Generation of Science Standards.
IVS contribution to the next ITRF
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.
Community access networks: how to connect the next billion to the ...
International Development Research Centre (IDRC) Digital Library (Canada)
Community access networks: how to connect the next billion to the Internet ... services is a prerequisite to sustainable socio-economic development. ... It will provide case studies and formulate recommendations with respect to ... An IDRC delegation will join international delegates and city representatives at the ICLEI World ...
Next generation initiation techniques
Warner, Tom; Derber, John; Zupanski, Milija; Cohn, Steve; Verlinde, Hans
1993-01-01
Four-dimensional data assimilation strategies can generally be classified as either current or next generation, depending upon whether they are used operationally or not. Current-generation data-assimilation techniques are those that are presently used routinely in operational-forecasting or research applications. They can be classified into the following categories: intermittent assimilation, Newtonian relaxation, and physical initialization. It should be noted that these techniques are the subject of continued research, and their improvement will parallel the development of next generation techniques described by the other speakers. Next generation assimilation techniques are those that are under development but are not yet used operationally. Most of these procedures are derived from control theory or variational methods and primarily represent continuous assimilation approaches, in which the data and model dynamics are 'fitted' to each other in an optimal way. Another 'next generation' category is the initialization of convective-scale models. Intermittent assimilation systems use an objective analysis to combine all observations within a time window that is centered on the analysis time. Continuous first-generation assimilation systems are usually based on the Newtonian-relaxation or 'nudging' techniques. Physical initialization procedures generally involve the use of standard or nonstandard data to force some physical process in the model during an assimilation period. Under the topic of next-generation assimilation techniques, variational approaches are currently being actively developed. Variational approaches seek to minimize a cost or penalty function which measures a model's fit to observations, background fields and other imposed constraints. Alternatively, the Kalman filter technique, which is also under investigation as a data assimilation procedure for numerical weather prediction, can yield acceptable initial conditions for mesoscale models. The
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.
Direct photon production and PDF fits reloaded
Energy Technology Data Exchange (ETDEWEB)
Campbell, John M.; Rojo, Juan; Slade, Emma; Williams, Ciaran
2018-02-08
Direct photon production in hadronic collisions provides a handle on the gluon PDF by means of the QCD Compton scattering process. In this work we revisit the impact of direct photon production on a global PDF analysis, motivated by the recent availability of the next-to-next-to-leading (NNLO) calculation for this process. We demonstrate that the inclusion of NNLO QCD and leading-logarithmic electroweak corrections leads to a good quantitative agreement with the ATLAS measurements at 8 TeV and 13 TeV, except for the most forward rapidity region in the former case. By including the ATLAS 8 TeV direct photon production data in the NNPDF3.1 NNLO global analysis, we assess its impact on the medium-x gluon. We also study the constraining power of the direct photon production measurements on PDF fits based on different datasets, in particular on the NNPDF3.1 no-LHC and collider-only fits. We also present updated NNLO theoretical predictions for direct photon production at 13 TeV that include the constraints from the 8 TeV measurements.
Banerjee, Pulak; Dhani, Prasanna K.; Kumar, M. C.; Mathews, Prakash; Ravindran, V.
2018-05-01
We study the phenomenological impact of the interaction of spin-2 fields with those of the Standard Model in a model independent framework up to next-to-next-to-leading order in perturbative quantum chromodynamics. We use the invariant mass distribution of the pair of leptons produced at the Large Hadron Collider to demonstrate this. A minimal scenario where the spin-2 fields couple to two gauge invariant operators with different coupling strengths has been considered. These operators not being conserved show very different ultraviolet behavior increasing the searches options of spin-2 particles at the colliders. We find that our results using the higher order quantum corrections stabilize the predictions with respect to renormalization and factorization scales. We also find that corrections are appreciable which need to be taken into account in such searches at the colliders.
Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment
International Nuclear Information System (INIS)
Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Gil, A; Borges, F I G; Conde, C A N; Dias, T H V T; Fernandes, L M P; Freitas, E D C; Castel, J; Cebrián, S; Dafni, T; Egorov, M; Gehman, V M; Goldschmidt, A; Esteve, R; Evtoukhovitch, P; Ferreira, A L
2013-01-01
NEXT-DEMO is a large-scale prototype of the NEXT-100 detector, an electroluminescent time projection chamber that will search for the neutrinoless double beta decay of XE using 100–150 kg of enriched xenon gas. NEXT-DEMO was built to prove the expected performance of NEXT-100, namely, energy resolution better than 1% FWHM at 2.5 MeV and event topological reconstruction. In this paper we describe the prototype and its initial results. A resolution of 1.75% FWHM at 511 keV (which extrapolates to 0.8% FWHM at 2.5 MeV) was obtained at 10 bar pressure using a gamma-ray calibration source. Also, a basic study of the event topology along the longitudinal coordinate is presented, proving that it is possible to identify the distinct dE/dx of electron tracks in high-pressure xenon using an electroluminescence TPC.
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 ...
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
Leading order relativistic chiral nucleon-nucleon interaction
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. )
Next Generation Microshutter Arrays Project
National Aeronautics and Space Administration — We propose to develop the next generation MicroShutter Array (MSA) as a multi-object field selector for missions anticipated in the next two decades. For many...
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...
Next generation solar energy. From fundamentals to applications
Energy Technology Data Exchange (ETDEWEB)
NONE
2011-07-01
Within the International Conference between 12th and 14th December, 2011 in Erlangen (Federal Republic of Germany) the following lectures were presented: (1) The opto-electronic physics required to approach the Shockley-Queisser efficiency limit (E. Yablonovitch); (2) The Shockley-Queisser-limit and beyond (G.H. Bauer); (3) Designing composite nanomaterials for photovoltaic devices (B. Rech); (4) Light-Material interactions in energy conversion (H. Atwater); (5) Functional imaging of hybrid nanostructures - Visualizing mechanisms of solar energy utilization (L. Lauhon); (6) Are photosynthetic proteins suitable for PV applications (Y. Rosenwaks); (7) Detailed balance limit in photovoltaic systems (U. Rau); (8) Plasmonics and nanophotonics for next generation photovoltaics (E. Garnett); (9) Dispersion, wave propagation and efficiency analysis of nanowire solar cells (B. Witzigmann); (10) Application of nanostructures to next generation photovoltaics - Opportunities and challenges from an industrial research perspective (L. Tsakalakos); (11) Triplet states in organic and organometallic photovoltaic cells (K.S. Schanze); (12) New photoelectrode architectures (J.T. Hupp); (13) Dendrimers for optoelectronic and photovoltaic applications (P. Ceroni); (14) Photon management with luminescent materials (J. Goldschmidt); (15) Economical aspects of next generation solar cell technologies (W. Hoffmann); (16) Scalability in solar energy conversion - First-row transition metal-based chromophores for dye-sensitized solar cells (J. McCusker); (17) Designing organic materials for photovoltaic devices (A. Harriman); (18) Molecular photovoltaics - What can we learn from model studies (B. Albinsson); (19) Porphyrin-sensitised titanium dioxide solar cells (D. Officer); (20) Light-harvesting: Charge separation, and charge-transportation properties of novel materials for organic photovoltaics (H. Imahori); (21) Phthalocyanines for molecular photovoltaics (T. Torres); (22) Photophysics of
On the Drell-Levy-Yan relation to O(α2s)
International Nuclear Information System (INIS)
Bluemlein, J.; Ravindran, V.; Neerven, W.L. van; Rijksuniversiteit Leiden
2000-03-01
We study the validity of a relation by Drell, Levy and Yan (DLY) connecting the deep inelastic structure (DIS) functions and the single-particle fragmentation functions in e + e - annihilation which are defined in the spacelike (q 2 2 > 0) regions respectively. Here q denotes the momentum of the virtual photon exchanged in the deep inelastic scattering process or the annihilation process. An extension of the DLY-relation, which originally was only derived in the scaling parton model, to all orders in QCD leads to a connection between the two evolution kernels determining the q 2 -dependence of the DIS structure functions and the fragmentation functions respectively. In relation to this we derive the transformation relations between the space-and time-like splitting functions up to next-to-leading order (NLO) and the coefficient functions up to NNLO both for unpolarized and polarized scattering. It is shown that the evolution kernels describing the combined singlet evolution for the structure functions F 2 (x, Q 2 ), F L (x, Q 2 ) where Q 2 = vertical stroke q 2 vertical stroke or F 2 (x, Q 2 ), ∂F 2 (x,Q 2 )/∂ln(Q 2 ) and the corresponding fragmentation functions satisfy the DLY relation up to next-to-leading order. We also comment on a relation proposed by Gribov and Lipatov. (orig.)
Nuclear Knowledge to the Next Generation
International Nuclear Information System (INIS)
Mazour, Thomas; Kossilov, Andrei
2004-01-01
The safe, reliable, and cost-effective operation of Nuclear Power Plants (NPPs) requires that personnel possess and maintain the requisite knowledge, skills, and attitudes to do their jobs properly. Such knowledge includes not only the technical competencies required by the nature of the technology and particular engineering designs, but also the softer competencies associated with effective management, communication and teamwork. Recent studies have shown that there has been a loss of corporate knowledge and memory. Both explicit knowledge and tacit knowledge must be passed on to the next generation of workers in the industry to ensure a quality workforce. New and different techniques may be required to ensure timely and effective knowledge retention and transfer. The IAEA prepared a report on this subject. The main conclusions from the report regarding strategies for managing the aging workforce are included. Also included are main conclusions from the report regarding the capture an d preservation of mission critical knowledge, and the effective transfer of this knowledge to the next generation of NPP personnel. The nuclear industry due to its need for well-documented procedures, specifications, design basis, safety analyses, etc., has a greater fraction of its mission critical knowledge as explicit knowledge than do many other industries. This facilitates the task of knowledge transfer. For older plants in particular, there may be a need for additional efforts to transfer tacit knowledge to explicit knowledge to support major strategic initiatives such as plant license extensions/renewals, periodic safety reviews, major plant upgrades, and plant specific control room simulator development. The challenge in disseminating explicit knowledge is to make employees aware that it is available and provide easy access in formats and forms that are usable. Tacit knowledge is more difficult to identify and disseminate. The challenge is to identify what can be converted to
Gap size and wall lesion development next to composite
Kuper, N.K.; Opdam, N.J.M.; Ruben, J.L.; de Soet, J.J.; Cenci, M.S.; Bronkhorst, E.M.; Huysmans, M.C.D.N.J.M.
2014-01-01
This in situ study investigated whether there is a relationship between gap size and wall lesion development in dentin next to 2 composite materials, and whether a clinically relevant threshold for the gap size could be established. For 21 days, 14 volunteers wore a modified occlusal splint
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.
Clinical mastitis from calving to next conception negatively affected ...
African Journals Online (AJOL)
The purpose of this study was to evaluate the effect of clinical mastitis between calving and next conception on reproductive performance in Chinese Holstein cows. Six hundred and three multiparous Holstein cows from a commercial dairy farm were divided into three groups respectively: cows with first clinical mastitis ...
Top-quark production at the LHC. Differential cross section and phenomenological applications
International Nuclear Information System (INIS)
Guzzi, Marco; Lipka, Katerina; Moch, Sven-Olaf
2013-08-01
We discuss top-quark pair production at hadron colliders and review available calculations of differential top-pair production cross section in perturbative QCD at approximate next-to-next-to-leading order (NNLO) within the threshold resummation formalism. These calculations are implemented into an open source program under development. We present phenomenological studies at the LHC that include transverse momentum and rapidity distribution of the top quarks at a center-of-mass energy of 7 TeV. Preliminary results obtained with this program are in very good agreement with the recent LHC measurements.
Epidemiological Studies to Support the Development of Next Generation Influenza Vaccines.
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.
Pharmacokinetic and pharmacodynamic considerations for the next generation protein therapeutics.
Shah, Dhaval K
2015-10-01
Increasingly sophisticated protein engineering efforts have been undertaken lately to generate protein therapeutics with desired properties. This has resulted in the discovery of the next generation of protein therapeutics, which include: engineered antibodies, immunoconjugates, bi/multi-specific proteins, antibody mimetic novel scaffolds, and engineered ligands/receptors. These novel protein therapeutics possess unique physicochemical properties and act via a unique mechanism-of-action, which collectively makes their pharmacokinetics (PK) and pharmacodynamics (PD) different than other established biological molecules. Consequently, in order to support the discovery and development of these next generation molecules, it becomes important to understand the determinants controlling their PK/PD. This review discusses the determinants that a PK/PD scientist should consider during the design and development of next generation protein therapeutics. In addition, the role of systems PK/PD models in enabling rational development of the next generation protein therapeutics is emphasized.
Extra dimension searches at hadron colliders to next-to-leading order-QCD
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.
High-Precision Differential Predictions for Top-Quark Pairs at the LHC.
Czakon, Michal; Heymes, David; Mitov, Alexander
2016-02-26
We present the first complete next-to-next-to-leading order (NNLO) QCD predictions for differential distributions in the top-quark pair production process at the LHC. Our results are derived from a fully differential partonic Monte Carlo calculation with stable top quarks which involves no approximations beyond the fixed-order truncation of the perturbation series. The NNLO corrections improve the agreement between existing LHC measurements [V. Khachatryan et al. (CMS Collaboration), Eur. Phys. J. C 75, 542 (2015)] and standard model predictions for the top-quark transverse momentum distribution, thus helping alleviate one long-standing discrepancy. The shape of the top-quark pair invariant mass distribution turns out to be stable with respect to radiative corrections beyond NLO which increases the value of this observable as a place to search for physics beyond the standard model. The results presented here provide essential input for parton distribution function fits, implementation of higher-order effects in Monte Carlo generators, as well as top-quark mass and strong coupling determination.
Direct photon production and PDF fits reloaded
Campbell, John M.; Rojo, Juan; Slade, Emma; Williams, Ciaran
2018-01-01
Direct photon production in hadronic collisions provides a handle on the gluon PDF by means of the QCD Compton scattering process. In this work we revisit the impact of direct photon production on a global PDF analysis, motivated by the recent availability of the next-to-next-to-leading (NNLO)
What to measure next to improve decision making? On top-down task driven feature saliency
DEFF Research Database (Denmark)
Hansen, Lars Kai; Karadogan, Seliz; Marchegiani, Letizia
2011-01-01
Top-down attention is modeled as decision making based on incomplete information. We consider decisions made in a sequential measurement situation where initially only an incomplete input feature vector is available, however, where we are given the possibility to acquire additional input values...... among the missing features. The procecure thus poses the question what to do next? We take an information theoretical approach implemented for generality in a generative mixture model. The framework allows us reduce the decision about what to measure next in a classification problem to the estimation...
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.
Lee, Paul U.; Sheridan, Tom; Poage, james L.; Martin, Lynne Hazel; Jobe, Kimberly K.
2010-01-01
This report identifies key human-performance-related issues associated with Next Generation Air Transportation System (NextGen) research in the NASA NextGen-Airspace Project. Four Research Focus Areas (RFAs) in the NextGen-Airspace Project - namely Separation Assurance (SA), Airspace Super Density Operations (ASDO), Traffic Flow Management (TFM), and Dynamic Airspace Configuration (DAC) - were examined closely. In the course of the research, it was determined that the identified human performance issues needed to be analyzed in the context of NextGen operations rather than through basic human factors research. The main gaps in human factors research in NextGen were found in the need for accurate identification of key human-systems related issues within the context of specific NextGen concepts and better design of the operational requirements for those concepts. By focusing on human-system related issues for individual concepts, key human performance issues for the four RFAs were identified and described in this report. In addition, mixed equipage airspace with components of two RFAs were characterized to illustrate potential human performance issues that arise from the integration of multiple concepts.
Energy Technology Data Exchange (ETDEWEB)
Monrabal, F.; et al.
2018-04-06
Conceived to host 5 kg of xenon at a pressure of 15 bar in the fiducial volume, the NEXT- White (NEW) apparatus is currently the largest high pressure xenon gas TPC using electroluminescent amplification in the world. It is also a 1:2 scale model of the NEXT-100 detector scheduled to start searching for $\\beta\\beta 0\
Pilot/Controller Coordinated Decision Making in the Next Generation Air Transportation System
Bearman, Chris; Miller, Ronald c.; Orasanu, Judith M.
2011-01-01
Introduction: NextGen technologies promise to provide considerable benefits in terms of enhancing operations and improving safety. However, there needs to be a thorough human factors evaluation of the way these systems will change the way in which pilot and controllers share information. The likely impact of these new technologies on pilot/controller coordinated decision making is considered in this paper using the "operational, informational and evaluative disconnect" framework. Method: Five participant focus groups were held. Participants were four experts in human factors, between x and x research students and a technical expert. The participant focus group evaluated five key NextGen technologies to identify issues that made different disconnects more or less likely. Results: Issues that were identified were: Decision Making will not necessarily improve because pilots and controllers possess the same information; Having a common information source does not mean pilots and controllers are looking at the same information; High levels of automation may lead to disconnects between the technology and pilots/controllers; Common information sources may become the definitive source for information; Overconfidence in the automation may lead to situations where appropriate breakdowns are not initiated. Discussion: The issues that were identified lead to recommendations that need to be considered in the development of NextGen technologies. The current state of development of these technologies provides a good opportunity to utilize recommendations at an early stage so that NextGen technologies do not lead to difficulties in resolving breakdowns in coordinated decision making.
Digital citizens Digital nations: the next agenda
A.W. (Bert) Mulder; M.W. (Martijn) Hartog
2015-01-01
DIGITAL CITIZENS CREATE A DIGITAL NATION Citizens will play the lead role as they – in the next phase of the information society – collectively create a digital nation. Personal adoption of information and communication technology will create a digital infrastructure that supports individual and
Special Issue: Next Generation DNA Sequencing
Directory of Open Access Journals (Sweden)
Paul Richardson
2010-10-01
Full Text Available Next Generation Sequencing (NGS refers to technologies that do not rely on traditional dideoxy-nucleotide (Sanger sequencing where labeled DNA fragments are physically resolved by electrophoresis. These new technologies rely on different strategies, but essentially all of them make use of real-time data collection of a base level incorporation event across a massive number of reactions (on the order of millions versus 96 for capillary electrophoresis for instance. The major commercial NGS platforms available to researchers are the 454 Genome Sequencer (Roche, Illumina (formerly Solexa Genome analyzer, the SOLiD system (Applied Biosystems/Life Technologies and the Heliscope (Helicos Corporation. The techniques and different strategies utilized by these platforms are reviewed in a number of the papers in this special issue. These technologies are enabling new applications that take advantage of the massive data produced by this next generation of sequencing instruments. [...
Higher-order radiative corrections for b b ¯→H-W+
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.
On next-to-eikonal corrections to threshold resummation for the Drell-Yan and DIS cross sections
International Nuclear Information System (INIS)
Laenen, Eric; Magnea, Lorenzo; Stavenga, Gerben
2008-01-01
We study corrections suppressed by one power of the soft gluon energy to the resummation of threshold logarithms for the Drell-Yan cross section and for Deep Inelastic structure functions. While no general factorization theorem is known for these next-to-eikonal (NE) corrections, it is conjectured that at least a subset will exponentiate, along with the logarithms arising at leading power. Here we develop some general tools to study NE logarithms, and we construct an ansatz for threshold resummation that includes various sources of NE corrections, implementing in this context the improved collinear evolution recently proposed by Dokshitzer, Marchesini and Salam (DMS). We compare our ansatz to existing exact results at two and three loops, finding evidence for the exponentiation of leading NE logarithms and confirming the predictivity of DMS evolution
Energy Technology Data Exchange (ETDEWEB)
Hein, Franz [mpc management project coaching, Esslingen (Germany)
2011-07-01
The upcoming radical change in energy market will be more than complete shift to renewables. It will change the usage of energy. Up to now we lived in an ''energy paradise''. Without a thought about the needs of the next generations we reduced the storages of fossil fuels. In the future we will use only energy offered by the sun - directly or indirectly (e.g. wind energy) - or energy we stored before. We will have to make the next cultural step. We have to cope the extremely volatility of energy production. It is similar to the times, when we made the change from hunters and gatherers to tillers and stockbreeders: They had to learn how to manage the volatile offering of water and to store harvest. (orig.)
Next-generation sequencing approaches to understanding the oral microbiome
Zaura, E.
2012-01-01
Until recently, the focus in dental research has been on studying a small fraction of the oral microbiome—so-called opportunistic pathogens. With the advent of next-generation sequencing (NGS) technologies, researchers now have the tools that allow for profiling of the microbiomes and metagenomes at
A calculation of the three-loop helicity-dependent splitting functions in QCD
International Nuclear Information System (INIS)
Vogt, A.
2014-05-01
We have calculated the complete matrix of three-loop helicity-difference ('polarized') splitting functions ΔP ik (2) (x), i,k=q,g, in massless perturbative QCD. In this note we briefly discuss some properties of the polarized splitting functions and our non-standard determination of the hitherto missing lower-row quantities ΔP gq (2) and ΔP gg (2) . The resulting next-to-next-to-leading order (NNLO) corrections to the evolution of polarized parton distributions are illustrated and found to be small even at rather large values of the strong coupling constant α s .
Jet production in the CoLoRFulNNLO method: event shapes in electron-positron collisions
Del Duca, Vittorio
2016-01-01
We present the CoLoRFulNNLO method to compute higher order radiative corrections to jet cross sections in perturbative QCD. We apply our method to the computation of event shape observables in electron-positron collisions at NNLO accuracy and validate our code by comparing our predictions to previous results in the literature. We also calculate for the first time jet cone energy fraction at NNLO.
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)
Visions 2025 and Linkage to NEXT
Wiscombe, W.; Lau, William K. M. (Technical Monitor)
2002-01-01
This talk will describe the progress to date on creating a science-driven vision for the NASA Earth Science Enterprise (ESE) in the post-2010 period. This effort began in the Fall of 2001 by organizing five science workgroups with representatives from NASA, academia and other agencies: Long-Term Climate, Medium-Term Climate, Extreme Weather, Biosphere & Ecosystems, and Solid Earth, Ice Sheets, & Sea Level. Each workgroup was directed to scope out one Big Question, including not just the science but the observational and modeling requirements, the information system requirements, and the applications and benefits to society. This first set of five Big Questions is now in hand and has been presented to the ESE Director. It includes: water resources, intraseasonal predictability, tropical cyclogenesis, invasive species, and sea level. Each of these topics will be discussed briefly. How this effort fits into the NEXT vision exercise and into Administrator O'Keefe's new vision for NASA will also be discussed.
Decommissioning: demonstrating the solution to a problem for the next century
International Nuclear Information System (INIS)
Anon.
1987-01-01
Tables are presented showing present decommissioning experience with shut-down reactors, and listing the oldest operating reactors to illustrate the likely extent of decommissioning work early in the next century. (author)
High-quality two-nucleon potentials up to fifth order of the chiral expansion
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.
Energy and luminosity requirements for the next generation of linear colliders
International Nuclear Information System (INIS)
Amaldi, U.
1987-01-01
In order to gain new knowledge ('new physics') from 'next generation' linear colliders energy and luminosity are important variables when considering the design of these new elementary particle probes. The standard model of the electroweak interaction is reviewed and stipulations for postulated Higgs particle, a new neutral Z particle, and a new quark and a neutral lepton searches with next generation colliders are given
Project control - the next generation
International Nuclear Information System (INIS)
Iorii, V.F.; McKinnon, B.L.
1993-01-01
The Yucca Mountain Site Characterization Project (YMP) is the U.S. Department of Energy's (DOE) second largest Major System Acquisition Project. We have developed an integrated planning and control system (called PACS) that we believe represents the 'Next Generation' in project control. PACS integrates technical scope, cost, and schedule information for over 50 participating organizations and produces performances measurement reports for science and engineering managers at all levels. Our 'Next Generation' project control too, PACS, has been found to be in compliance with the new DOE Project Control System Guidelines. Additionally, the nuclear utility oversight group of the Edison Electric Institute has suggested PACS be used as a model for other civilian radioactive waste management projects. A 'Next Generation' project control tool will be necessary to do science in the 21st century
Hawkins, B. Denise
2010-01-01
There is a shortage of accounting professors with Ph.D.s who can prepare the next generation. To help reverse the faculty deficit, the American Institute of Certified Public Accountants (CPAs) has created the new Accounting Doctoral Scholars program by pooling more than $17 million and soliciting commitments from more than 70 of the nation's…
What's Next for Particle Physics?
White, Martin
2017-10-01
Following the discovery of the Higgs boson in 2012, particle physics has entered its most exciting and crucial period for over 50 years. In this book, I first summarise our current understanding of particle physics, and why this knowledge is almost certainly incomplete. We will then see that the Large Hadron Collider provides the means to search for the next theory of particle physics by performing precise measurements of the Higgs boson, and by looking directly for particles that can solve current cosmic mysteries such as the nature of dark matter. Finally, I will anticipate the next decade of particle physics by placing the Large Hadron Collider within the wider context of other experiments. The results expected over the next ten years promise to transform our understanding of what the Universe is made of and how it came to be.
Ammendola, R.; Boucaud, Philippe; Cabibbo, N.; Di Carlo, F.; De Pietri, R.; Di Renzo, F.; Errico, W.; Fucci, A.; Guagnelli, M.; Kaldass, H.; Lonardo, A.; de Luca, S.; Micheli, J.; Morenas, V.; Pene, O.; Petronzio, R.; Palombi, F.; Pleiter, D.; Paschedag, N.; Rapuano, F.; De Riso, P.; Rossetti, D.; Salamon, A.; Salina, G.; Sartori, L.; Schifano, F.; Simma, H.; Tripiccione, R.; Vicini, P.; Boucaud, Ph.; 10.1016/S0920-5632(03)01755-9
2003-01-01
We present the current status of the apeNEXT project. Aim of this project is the development of the next generation of APE machines which will provide multi-teraflop computing power. Like previous machines, apeNEXT is based on a custom designed processor, which is specifically optimized for simulating QCD. We discuss the machine design, report on benchmarks, and give an overview on the status of the software development.
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
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.)
Bybee, Seth M; Bracken-Grissom, Heather; Haynes, Benjamin D; Hermansen, Russell A; Byers, Robert L; Clement, Mark J; Udall, Joshua A; Wilcox, Edward R; Crandall, Keith A
2011-01-01
Next-gen sequencing technologies have revolutionized data collection in genetic studies and advanced genome biology to novel frontiers. However, to date, next-gen technologies have been used principally for whole genome sequencing and transcriptome sequencing. Yet many questions in population genetics and systematics rely on sequencing specific genes of known function or diversity levels. Here, we describe a targeted amplicon sequencing (TAS) approach capitalizing on next-gen capacity to sequence large numbers of targeted gene regions from a large number of samples. Our TAS approach is easily scalable, simple in execution, neither time-nor labor-intensive, relatively inexpensive, and can be applied to a broad diversity of organisms and/or genes. Our TAS approach includes a bioinformatic application, BarcodeCrucher, to take raw next-gen sequence reads and perform quality control checks and convert the data into FASTA format organized by gene and sample, ready for phylogenetic analyses. We demonstrate our approach by sequencing targeted genes of known phylogenetic utility to estimate a phylogeny for the Pancrustacea. We generated data from 44 taxa using 68 different 10-bp multiplexing identifiers. The overall quality of data produced was robust and was informative for phylogeny estimation. The potential for this method to produce copious amounts of data from a single 454 plate (e.g., 325 taxa for 24 loci) significantly reduces sequencing expenses incurred from traditional Sanger sequencing. We further discuss the advantages and disadvantages of this method, while offering suggestions to enhance the approach.
THE TRAINING OF NEXT GENERATION DATA SCIENTISTS IN BIOMEDICINE.
Garmire, Lana X; Gliske, Stephen; Nguyen, Quynh C; Chen, Jonathan H; Nemati, Shamim; VAN Horn, John D; Moore, Jason H; Shreffler, Carol; Dunn, Michelle
2017-01-01
With the booming of new technologies, biomedical science has transformed into digitalized, data intensive science. Massive amount of data need to be analyzed and interpreted, demand a complete pipeline to train next generation data scientists. To meet this need, the transinstitutional Big Data to Knowledge (BD2K) Initiative has been implemented since 2014, complementing other NIH institutional efforts. In this report, we give an overview the BD2K K01 mentored scientist career awards, which have demonstrated early success. We address the specific trainings needed in representative data science areas, in order to make the next generation of data scientists in biomedicine.
NNLO coefficient functions of Higgs and Drell-Yan cross sections in Mellin space
International Nuclear Information System (INIS)
Bluemlein, J.; Ravindran, V.
2004-06-01
We calculate the Mellin moments of next-to-next-to-leading order coefficient functions of the Drell-Yan and Higgs production cross sections. The results can be expressed in term of finite harmonic sums which are maximally threefold up to weight four. Various algebraic relations among these finite sums reduce the complexity of the results suitable for fast numerical evaluations. It is shown that only five non-trivial functions occur besides Euler's ψ-function in the representation of these Wilson coefficients. (orig.)
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.
Advanced Electric Propulsion NextSTEP BAA Activity
National Aeronautics and Space Administration — The goal of the AES Advanced Electric Propulsion Next Space Technologies for Exploration Partnerships (NextSTEP) Broad Agency Announcement (BAA) activity is to...
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...
Consistent, high-quality two-nucleon potentials up to fifth order of the chiral expansion
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.
45 CFR 211.4 - Notification to legal guardian, spouse, next of kin, or interested persons.
2010-10-01
... 45 Public Welfare 2 2010-10-01 2010-10-01 false Notification to legal guardian, spouse, next of..., RETURNED FROM FOREIGN COUNTRIES § 211.4 Notification to legal guardian, spouse, next of kin, or interested... (or in advance thereof, if possible), provide for notification of his legal guardian, or in the...
Next decade in external dosimetry
International Nuclear Information System (INIS)
Griffith, R.V.
1988-01-01
In recent years, a number of external dosimetry problems have been solved. However, changes in standards and legal concepts relating to the application of dosimetry results will require further enhancements in measurement techniques and philosophy in the next 10 y. The introduction of effective dose equivalent and the legal use of probability of causation will require that much greater attention be given to determination of weighted organ dose from external exposure. An imminent change--an increase in the fast neutron quality factor--will require a new round of technology development in a field that has just received a decade of close scrutiny. For the future, we must take advantage of developments in microelectronics. The use of random access memory (RAM) and metal-on-silicon (MOS) devices as detector elements, particularly for neutron dosimetry, has exciting possibilities that are just beginning to be explored. Advances in microcircuitry are leading, and will continue to lead, in the development of a new generation of small, rugged and smart radiation survey instruments that will make the most of detector data. It has become possible with very compact instruments to obtain energy spectra, linear-energy-transfer (LET) spectra, and quality factors in addition to the usual integrated dosimetric quantities: exposure, absorbed dose, and dose equivalent. These instruments will be reliable and easy to use. The user will be able to select the level of sophistication that is required for any specific application. Moreover, since the processing algorithms can be changed, changes in conversion factors can be accommodated with relative ease. During the next decade, the use of computers will continue to grow in value to the health physicist
DEFF Research Database (Denmark)
Jørgensen, Bo Nørregaard; Ottosen, Carl-Otto; Dam-Hansen, Carsten
2016-01-01
The project aims to develop the next generation of energy cost-efficient artificial lighting control that enables greenhouse growers to adapt their use of artificial lighting dynamically to fluctuations in the price of electricity. This is a necessity as fluctuations in the price of electricity c...
Applying Next Generation Sequencing to Skeletal Development and Disease
Bowen, Margot Elizabeth
2013-01-01
Next Generation Sequencing (NGS) technologies have dramatically increased the throughput and lowered the cost of DNA sequencing. In this thesis, I apply these technologies to unresolved questions in skeletal development and disease. Firstly, I use targeted re-sequencing of genomic DNA to identify the genetic cause of the cartilage tumor syndrome, metachondromatosis (MC). I show that the majority of MC patients carry heterozygous loss-of-function mutations in the PTPN11 gene, which encodes a p...
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.)
NNLO QCD corrections to the $B\\to X_s \\gamma$ matrix elements using interpolation in $m_c$
Misiak, M; Misiak, Mikolaj; Steinhauser, Matthias
2007-01-01
One of the most troublesome contributions to the NNLO QCD corrections to B -> X_s gamma originates from three-loop matrix elements of four-quark operators. A part of this contribution that is proportional to the QCD beta-function coefficient beta_0 was found in 2003 as an expansion in m_c/m_b. In the present paper, we evaluate the asymptotic behaviour of the complete contribution for m_c >> m_b/2. The asymptotic form of the beta_0-part matches the small-m_c expansion very well at the threshold m_c = m_b/2. For the remaining part, we perform an interpolation down to the measured value of m_c, assuming that the beta_0-part is a good approximation at m_c=0. Combining our results with other contributions to the NNLO QCD corrections, we find BR(B -> X_s gamma) = (3.15 +_ 0.23) x 10^-4 for E_gamma > 1.6 GeV in the B-meson rest frame. The indicated error has been obtained by adding in quadrature the following uncertainties: non-perturbative (5%), parametric (3%), higher-order perturbative (3%), and the interpolation...
Next-Generation Tools For Next-Generation Surveys
Murray, S. G.
2017-04-01
The next generation of large-scale galaxy surveys, across the electromagnetic spectrum, loom on the horizon as explosively game-changing datasets, in terms of our understanding of cosmology and structure formation. We are on the brink of a torrent of data that is set to both confirm and constrain current theories to an unprecedented level, and potentially overturn many of our conceptions. One of the great challenges of this forthcoming deluge is to extract maximal scientific content from the vast array of raw data. This challenge requires not only well-understood and robust physical models, but a commensurate network of software implementations with which to efficiently apply them. The halo model, a semi-analytic treatment of cosmological spatial statistics down to nonlinear scales, provides an excellent mathematical framework for exploring the nature of dark matter. This thesis presents a next-generation toolkit based on the halo model formalism, intended to fulfil the requirements of next-generation surveys. Our toolkit comprises three tools: (i) hmf, a comprehensive and flexible calculator for halo mass functions (HMFs) within extended Press-Schechter theory, (ii) the MRP distribution for extremely efficient analytic characterisation of HMFs, and (iii) halomod, an extension of hmf which provides support for the full range of halo model components. In addition to the development and technical presentation of these tools, we apply each to the task of physical modelling. With hmf, we determine the precision of our knowledge of the HMF, due to uncertainty in our knowledge of the cosmological parameters, over the past decade of cosmic microwave background (CMB) experiments. We place rule-of-thumb uncertainties on the predicted HMF for the Planck cosmology, and find that current limits on the precision are driven by modeling uncertainties rather than those from cosmological parameters. With the MRP, we create and test a method for robustly fitting the HMF to observed
Progress on next generation linear colliders
International Nuclear Information System (INIS)
Ruth, R.D.
1989-01-01
In this paper, I focus on reviewing the issues and progress on a next generation linear collider with the general parameters of energy, luminosity, length, power, technology. The energy range is dictated by physics with a mass reach well beyond LEP, although somewhat short of SSC. The luminosity is that required to obtain 10 3 /minus/ 10 4 units of R 0 per year. The length is consistent with a site on Stanford land with collisions occurring on the SLAC site. The power was determined by economic considerations. Finally, the technology was limited by the desire to have a next generation linear collider before the next century. 25 refs., 3 figs., 6 tabs
Tailoring next-generation biofuels and their combustion in next-generation engines
Energy Technology Data Exchange (ETDEWEB)
Gladden, John Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wu, Weihua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Taatjes, Craig A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Scheer, Adam Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Turner, Kevin M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Yu, Eizadora T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); O' Bryan, Greg [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Powell, Amy Jo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gao, Connie W. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
2013-11-01
Increasing energy costs, the dependence on foreign oil supplies, and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. The strategy for producing next-generation biofuels must include efficient processes for biomass conversion to liquid fuels and the fuels must be compatible with current and future engines. Unfortunately, biofuel development generally takes place without any consideration of combustion characteristics, and combustion scientists typically measure biofuels properties without any feedback to the production design. We seek to optimize the fuel/engine system by bringing combustion performance, specifically for advanced next-generation engines, into the development of novel biosynthetic fuel pathways. Here we report an innovative coupling of combustion chemistry, from fundamentals to engine measurements, to the optimization of fuel production using metabolic engineering. We have established the necessary connections among the fundamental chemistry, engine science, and synthetic biology for fuel production, building a powerful framework for co-development of engines and biofuels.
A study to identify winning strategies for the business community during the next pandemic.
Spriggs, Martin
2013-01-01
This study examines the relationship between the healthcare system and the corporate sector to answer the following research question: how does the healthcare system best prepare small to medium-sized businesses for the next pandemic influenza? Data were collected and collated through a literature review, electronic survey and semi-structured follow-up telephone interviews. The participants were businesses with membership in the Alberta Chambers of Commerce, a provincial lobby group in Alberta, Canada. The findings indicate strategies that were effective in minimising impact to the business community during the H1N1 pandemic and suggest areas for the business community to improve in preparation for the next pandemic influenza. Recommendations focus on establishing new links for communication between the business community and the healthcare sector and improving strategies to increase the resilience of small to medium-sized businesses for the next pandemic influenza.
The method of regions and next-to-soft corrections in Drell-Yan production
Bonocore, D.; Laenen, E.; Magnea, L.; Vernazza, L.; White, C. D.
2015-01-01
We perform a case study of the behaviour of gluon radiation beyond the soft approximation, using as an example the Drell-Yan production cross section at NNLO. We draw a careful distinction between the eikonal expansion, which is in powers of the soft gluon energies, and the expansion in powers of
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.
Outlook: The Next Twenty Years
Energy Technology Data Exchange (ETDEWEB)
Murayama, Hitoshi
2003-12-07
I present an outlook for the next twenty years in particle physics. I start with the big questions in our field, broken down into four categories: horizontal, vertical, heaven, and hell. Then I discuss how we attack the bigquestions in each category during the next twenty years. I argue for a synergy between many different approaches taken in our field.
Energy Technology Data Exchange (ETDEWEB)
Park, Jong Kyun; Chang, Moon Heuy; Hwang, Yung Dong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); and others
1993-09-01
The project, development of next generation reactor, aims overall related technology development and obtainment of related license in 2001. The development direction is to determine the reactor type and to build up the design concept in 1994. For development trend analysis of foreign next generation reactor, level-1 PSA, fuel cycle analysis and computer code development are performed on System 80+ and AP 600. Especially for design characteristics analysis and volume upgrade of AP 600, nuclear fuel and reactor core design analysis, coolant circuit design analysis, mechanical structure design analysis and safety analysis etc. are performed. (Author).
Cluster cosmology with next-generation surveys.
Ascaso, B.
2017-03-01
The advent of next-generation surveys will provide a large number of cluster detections that will serve the basis for constraining cos mological parameters using cluster counts. The main two observational ingredients needed are the cluster selection function and the calibration of the mass-observable relation. In this talk, we present the methodology designed to obtain robust predictions of both ingredients based on realistic cosmological simulations mimicking the following next-generation surveys: J-PAS, LSST and Euclid. We display recent results on the selection functions for these mentioned surveys together with others coming from other next-generation surveys such as eROSITA, ACTpol and SPTpol. We notice that the optical and IR surveys will reach the lowest masses between 0.3
Next Generation Sequencing of Ancient DNA: Requirements, Strategies and Perspectives
Directory of Open Access Journals (Sweden)
Michael Knapp
2010-07-01
Full Text Available The invention of next-generation-sequencing has revolutionized almost all fields of genetics, but few have profited from it as much as the field of ancient DNA research. From its beginnings as an interesting but rather marginal discipline, ancient DNA research is now on its way into the centre of evolutionary biology. In less than a year from its invention next-generation-sequencing had increased the amount of DNA sequence data available from extinct organisms by several orders of magnitude. Ancient DNA research is now not only adding a temporal aspect to evolutionary studies and allowing for the observation of evolution in real time, it also provides important data to help understand the origins of our own species. Here we review progress that has been made in next-generation-sequencing of ancient DNA over the past five years and evaluate sequencing strategies and future directions.
Analytic integration of real-virtual counterterms in NNLO jet cross sections II
Energy Technology Data Exchange (ETDEWEB)
Bolzoni, Paolo; Moch, Sven-Olaf [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Somogyi, Gabor [Zurich Univ. (Switzerland). Inst. fuer Theoretische Physik; Trocsanyi, Zoltan [Debrecen Univ. (Hungary); Hungarian Academy of Sciences, Debrecen (Hungary). Inst. of Nuclear Research
2009-05-15
We present analytic expressions of all integrals required to complete the explicit evaluation of the real-virtual integrated counterterms needed to define a recently proposed subtraction scheme for jet cross sections at next-to-next-to-leading order in QCD. We use the Mellin-Barnes representation of these integrals in 4-2{epsilon} dimensions to obtain the coefficients of their Laurent expansions around {epsilon}=0. These coefficients are given by linear combinations of multidimensional Mellin-Barnes integrals. We compute the coefficients of such expansions in {epsilon} both numerically and analytically by complex integration over the Mellin-Barnes contours. (orig.)
Analytic integration of real-virtual counterterms in NNLO jet cross sections II
International Nuclear Information System (INIS)
Bolzoni, Paolo; Moch, Sven-Olaf; Somogyi, Gabor; Trocsanyi, Zoltan
2009-01-01
We present analytic expressions of all integrals required to complete the explicit evaluation of the real-virtual integrated counterterms needed to define a recently proposed subtraction scheme for jet cross sections at next-to-next-to-leading order in QCD. We use the Mellin-Barnes representation of these integrals in 4 - 2ε dimensions to obtain the coefficients of their Laurent expansions around ε = 0. These coefficients are given by linear combinations of multidimensional Mellin-Barnes integrals. We compute the coefficients of such expansions in ε both numerically and analytically by complex integration over the Mellin-Barnes contours.
Analytic integration of real-virtual counterterms in NNLO jet cross sections II
Bolzoni, Paolo; Moch, Sven-Olaf; Somogyi, Gábor; Trócsányi, Zoltán
2009-08-01
We present analytic expressions of all integrals required to complete the explicit evaluation of the real-virtual integrated counterterms needed to define a recently proposed subtraction scheme for jet cross sections at next-to-next-to-leading order in QCD. We use the Mellin-Barnes representation of these integrals in 4 - 2epsilon dimensions to obtain the coefficients of their Laurent expansions around epsilon = 0. These coefficients are given by linear combinations of multidimensional Mellin-Barnes integrals. We compute the coefficients of such expansions in epsilon both numerically and analytically by complex integration over the Mellin-Barnes contours.
Analytic integration of real-virtual counterterms in NNLO jet cross sections II
International Nuclear Information System (INIS)
Bolzoni, Paolo; Moch, Sven-Olaf; Somogyi, Gabor; Trocsanyi, Zoltan; Hungarian Academy of Sciences, Debrecen
2009-05-01
We present analytic expressions of all integrals required to complete the explicit evaluation of the real-virtual integrated counterterms needed to define a recently proposed subtraction scheme for jet cross sections at next-to-next-to-leading order in QCD. We use the Mellin-Barnes representation of these integrals in 4-2ε dimensions to obtain the coefficients of their Laurent expansions around ε=0. These coefficients are given by linear combinations of multidimensional Mellin-Barnes integrals. We compute the coefficients of such expansions in ε both numerically and analytically by complex integration over the Mellin-Barnes contours. (orig.)
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
Heterogeneous next-generation wireless network interference model-and its applications
Mahmood, Nurul Huda
2014-04-01
Next-generation wireless systems facilitating better utilisation of the scarce radio spectrum have emerged as a response to inefficient and rigid spectrum assignment policies. These are comprised of intelligent radio nodes that opportunistically operate in the radio spectrum of existing primary systems, yet unwanted interference at the primary receivers is unavoidable. In order to design efficient next-generation systems and to minimise the adverse effect of their interference, it is necessary to realise how the resulting interference impacts the performance of the primary systems. In this work, a generalised framework for the interference analysis of such a next-generation system is presented where the nextgeneration transmitters may transmit randomly with different transmit powers. The analysis is built around a model developed for the statistical representation of the interference at the primary receivers, which is then used to evaluate various performance measures of the primary system. Applications of the derived interference model in designing the next-generation network system parameters are also demonstrated. Such approach provides a unified and generalised framework, the use of which allows a wide range of performance metrics can be evaluated. Findings of the analytical performance analyses are confirmed through extensive computer-based Monte-Carlo simulations. © 2012 John Wiley & Sons, Ltd.
ERP II: Next-generation Extended Enterprise Resource Planning
DEFF Research Database (Denmark)
Møller, Charles
2004-01-01
ERP II (ERP/2) systems is a new concept introduced by Gartner Group in 2000 in order to label the latest extensions of the ERP-systems. The purpose of this paper is to explore the next-generation of ERP systems, the Extended Enterprise Resource Planning (EERP or as we prefer to use: e...... impact on extended enterprise architecture.....
ERP II - Next-generation Extended Enterprise Resource Planning
DEFF Research Database (Denmark)
Møller, Charles
2003-01-01
ERP II (ERP/2) systems is a new concept introduced by Gartner Group in 2000 in order to label the latest extensions of the ERP-systems. The purpose of this paper is to explore the next-generation of ERP systems, the Extended Enterprise Resource Planning (EERP or as we prefer to use: e...... impact on extended enterprise architecture....
BR(B{sub s} → μ{sup +}μ{sup -}) to NNLO in QCD
Energy Technology Data Exchange (ETDEWEB)
Hermann, Thomas; Steinhauser, Matthias [Institut fuer Theoretische Teilchenphysik, Karlsruher Institut fuer Technologie (KIT) (Germany)
2013-07-01
The recently measured rare decay B{sub s} → μ{sup +}μ{sup -} is very sensitive to physics beyond the Standard Model (SM). Therefore, it is important to reduce the SM uncertainties. NNLO QCD corrections to this branching ratio reduce current uncertainties due to the dependence on the matching scale. In this talk, we present the calculation of the Wilson coefficient C{sub 1} to NNLO in QCD, which includes corrections to W-boson box and Z-boson penguin contributions. In particular, we provide details on the matching procedure and the calculation of the coefficient function of the evanescent operator.
Threshold resummation of the rapidity distribution for Higgs production at NNLO +NNLL
Banerjee, Pulak; Das, Goutam; Dhani, Prasanna K.; Ravindran, V.
2018-03-01
We present a formalism that resums threshold-enhanced logarithms to all orders in perturbative QCD for the rapidity distribution of any colorless particle produced in hadron colliders. We achieve this by exploiting the factorization properties and K +G equations satisfied by the soft and virtual parts of the cross section. We compute for the first time compact and most general expressions in two-dimensional Mellin space for the resummed coefficients. Using various state-of-the-art multiloop and multileg results, we demonstrate the numerical impact of our resummed results up to next-to-next-to-leading order for the rapidity distribution of the Higgs boson at the LHC. We find that inclusion of these threshold logs through resummation improves the reliability of perturbative predictions.
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.
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
Performance of back supportless CCDs for the NeXT mission
International Nuclear Information System (INIS)
Takagi, Shin-ichiro; Go Tsuru, Takeshi; Matsumoto, Hironori; Koyama, Katsuji; Tsunemi, Hiroshi; Miyata, Emi; Miyazaki, Satoshi; Kamata, Yukiko; Muramatsu, Masaharu; Suzuki, Hisanori; Miyaguchi, Kazuhisa
2005-01-01
New X-ray Telescope (NeXT) will be the next Japanese X-ray astronomical satellite, which will be launched around 2010. A multilayer super mirror will give NeXT a large effective area across the 0.1-80keV band. This wide bandpass requires a focal plane detector that is also sensitive along the entire energy band. As the focal plane detector for NeXT, we have been developing a Wideband hybrid X-ray Imager (WXI) consisting of X-ray CCDs and pixelized CdTe detector. The X-ray CCD of the WXI is required to maintain high quantum efficiency up to the high-energy band while allowing hard X-rays to pass undetected through the depletion (sensitive) layer. In order to meet these requirements, we have been developing a back supportless CCD (BS-CCD) which has a thick depletion layer, a thinned Si wafer and a back supportless structure. As the first step, we manufactured a test model of BS-CCD in order to (1) learn the handling and thinning process and (2) confirm that there is no change of the performance. For the mechanical strength and the safe handling of the wafer, we decided to thin the wafer to ∼200μm. We verified the thickness of the depletion layer and wafer of the BS-CCD to be about 70 and 190μm, respectively. The energy resolution at 5.9keV of 144eV and the read-out noise of 7 electrons (rms) are equal to those of an un-thinned CCD, hence, we confirmed that our thinning process has no effect on the performance
Prospects for next-generation e+e- linear colliders
International Nuclear Information System (INIS)
Ruth, R.D.
1990-02-01
The purpose of this paper is to review progress in the US towards a next generation linear collider. During 1988, there were three workshops held on linear colliders: ''Physics of Linear Colliders,'' in Capri, Italy, June 14--18, 1988; Snowmass 88 (Linear Collider subsection) June 27--July 15, 1988; and SLAC International Workshop on Next Generation Linear Colliders, November 28--December 9, 1988. In this paper, I focus on reviewing the issues and progress on a next generation linear collider. The energy range is dictated by physics with a mass reach well beyond LEP, although somewhat short of SSC. The luminosity is that required to obtain 10 3 --10 4 units of R 0 per year. The length is consistent with a site on Stanford land with collision occurring on the SLAC site; the power was determined by economic considerations. Finally, the technology as limited by the desire to have a next generation linear collider by the next century. 37 refs., 3 figs., 6 tabs
Next Generation Science Standards: Adoption and Implementation Workbook
Peltzman, Alissa; Rodriguez, Nick
2013-01-01
The Next Generation Science Standards (NGSS) represent the culmination of years of collaboration and effort by states, science educators and experts from across the United States. Based on the National Research Council's "A Framework for K-12 Science Education" and developed in partnership with 26 lead states, the NGSS, when…
Inclusive jet spectrum for small-radius jets
Dasgupta, Mrinal; Salam, Gavin P.; Soyez, Gregory
2016-01-01
Following on our earlier work on leading-logarithmic (LLR) resummations for the properties of jets with a small radius, R, we here examine the phenomenological considerations for the inclusive jet spectrum. We discuss how to match the NLO predictions with small-R resummation. As part of the study we propose a new, physically-inspired prescription for fixed-order predictions and their uncertainties. We investigate the R-dependent part of the next-to-next-to-leading order (NNLO) corrections, which is found to be substantial, and comment on the implications for scale choices in inclusive jet calculations. We also examine hadronisation corrections, identifying potential limitations of earlier analytical work with regards to their $p_t$-dependence. Finally we assemble these different elements in order to compare matched (N)NLO+LLR predictions to data from ALICE and ATLAS, finding improved consistency for the R-dependence of the results relative to NLO predictions.
Nurses' health, age and the wish to leave the profession--findings from the European NEXT-Study
DEFF Research Database (Denmark)
Hasselhorn, H M; Tackenberg, P; Kuemmerling, Angelika
2006-01-01
In many industrialised countries the number of workers with low health is expected to increase in the nursing profession. This will have implications for occupational health work in health care. The European NEXT-Study (www. next-study. net, funded by EU) investigates working conditions of nurses...
A Next Generation BioPhotonics Workstation
DEFF Research Database (Denmark)
Glückstad, Jesper; Palima, Darwin; Tauro, Sandeep
2011-01-01
We are developing a Next Generation BioPhotonics Workstation to be applied in research on regulated microbial cell growth including their underlying physiological mechanisms, in vivo characterization of cell constituents and manufacturing of nanostructures and meta-materials.......We are developing a Next Generation BioPhotonics Workstation to be applied in research on regulated microbial cell growth including their underlying physiological mechanisms, in vivo characterization of cell constituents and manufacturing of nanostructures and meta-materials....
Tandem mirror next step: remote maintenance
International Nuclear Information System (INIS)
Doggett, J.N.; Damm, C.C.; Hanson, C.L.
1980-01-01
This study of the next proposed experiment in the Mirror Fusion Program, the Tandem Mirror Next Step (TMNS), has included serious consideration of the maintenance requirements of such a large source of high energy neutrons with its attendant throughput of tritium. Although maintenance will be costly in time and money, our conclusion is that with careful attention to a design for maintenance plan such a device can be reliably operated
Leading the Development of Concepts of Operations for Next-Generation Remotely Piloted Aircraft
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
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
Energy Technology Data Exchange (ETDEWEB)
Zhao, Zilai [General Motors LLC, Detroit, MI (United States); Gough, Charles [General Motors LLC, Detroit, MI (United States)
2016-04-22
The goal of this Cooperative Agreement was the development of a Next Generation Inverter for General Motors’ electrified vehicles, including battery electric vehicles, range extended electric vehicles, plug-in hybrid electric vehicles and hybrid electric vehicles. The inverter is a critical electronics component that converts battery power (DC) to and from the electric power for the motor (AC).
Technical presentation: Next Generation Oscilloscopes
PH Department
2011-01-01
Rohde & Schwarz "Next Generation Oscilloscopes" - Introduction and Presentation Agenda: Wednesday 23 March - 09:30 to 11:30 (open end) Bldg. 13-2-005 Language: English 09.30 Presentation "Next Generation Oscilloscopes" from Rohde & Schwarz RTO / RTM in theory and practice Gerard Walker 10.15 Technical design details from R&D Dr. Markus Freidhof 10.45 Scope and Probe Roadmap (confidential) Guido Schulze 11.00 Open Discussion Feedback, first impression, wishes, needs and requirements from CERN All 11.30 Expert Talks, Hands on All Mr. Dr. Markus Freidhof, Head of R&D Oscilloscopes, Rohde & Schwarz, Germany; Mr. Guido Schulze, ...
vh@nnlo-v2: new physics in Higgs Strahlung
Harlander, Robert V.; Klappert, Jonas; Liebler, Stefan; Simon, Lukas
2018-05-01
Introducing version 2 of the code vh@nnlo [1], we study the effects of a number of new-physics scenarios on the Higgs-Strahlung process. In particular, the cross section is evaluated within a general 2HDM and the MSSM. While the Drell-Yan-like contributions are consistently taken into account by a simple rescaling of the SM result, the gluon-initiated contribution is supplemented by squark-loop mediated amplitudes, and by the s-channel exchange of additional scalars which may lead to conspicuous interference effects. The latter holds as well for bottom-quark initiated Higgs Strahlung, which is also included in the new version of vh@nnlo. Using an orthogonal rotation of the three Higgs CP eigenstates in the 2HDM and the MSSM, vh@nnlo incorporates a simple means of CP mixing in these models. Moreover, the effect of vector-like quarks in the SM on the gluon-initiated contribution can be studied. Beyond concrete models, vh@nnlo allows to include the effect of higher-dimensional operators on the production of CP-even Higgs bosons. Transverse momentum distributions of the final state Higgs boson and invariant mass distributions of the Vϕ final state for the gluon- and bottom-quark initiated contributions can be studied. Distributions for the Drell-Yan-like component of Higgs Strahlung can be included through a link to MCFM. vh@nnlo can also be linked to FeynHiggs and 2HDMC for the calculation of Higgs masses and mixing angles. It can also read these parameters from an SLHA-file as produced by standard spectrum generators. Throughout the manuscript, we highlight new-physics effects in various numerical examples, both at the inclusive level and for distributions.
Next Generation NASA Initiative for Space Geodesy
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.;
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
Dr Fabiola Gianotti has been selected by CERN Council to become next CERN Director General
Brice, Maximilien
2014-01-01
With the next Director-General announced, watch the press conference starting in a few minutes via http://cern.ch/webcast/ and send your questions via Twitter to @CERNpressoffice CERN Council selects Italian physicist, Dr Fabiola Gianotti, as CERN’s next Director-General. Dr Gianotti’s mandate will begin on 1 January 2016 and run for a period of five years, read more: http://cern.ch/go/tN09F
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.)
Directory of Open Access Journals (Sweden)
Iselin Reknes
2017-01-01
Full Text Available Although workplace violence and aggression have been identified as important stressors in the nursing profession, studies simultaneously comparing patient-initiated aggression and exposure to bullying behaviors at work are rather scarce. The aim of this study was to compare aggression from patients or next of kin and exposure to bullying behaviors in terms of prevalence, health-related quality of life outcomes, and potential overlap in those targeted. In the period of 2008-2009, data were collected among 2059 members of the Norwegian Nurses Organization. Latent class (LC analysis and a multivariate analysis of variance (MANOVA were used to investigate the proposed relationships. The results showed that aggression from patients or next of kin and exposure to bullying behaviors were perceived as separate and independent stressors. Although aggression from patients or next of kin was more frequent than workplace bullying, the latter was the only significant stressor related to health-related quality of life in terms of reduced mental health functioning. Although being a rather infrequent experience, exposure to bullying behaviors seems to have more severe health-related outcomes for nurses than aggression from patients or next of kin. Hence, the results of the study strengthen previous findings and suggest that managers must aim to maintain a positive psychosocial work environment with zero-tolerance for bullying.
Building next-generation converged networks theory and practice
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
Recycling Flight Hardware Components and Systems to Reduce Next Generation Research Costs
Turner, Wlat
2011-01-01
With the recent 'new direction' put forth by President Obama identifying NASA's new focus in research rather than continuing on a path to return to the Moon and Mars, the focus of work at Kennedy Space Center (KSC) may be changing dramatically. Research opportunities within the micro-gravity community potentially stands at the threshold of resurgence when the new direction of the agency takes hold for the next generation of experimenters. This presentation defines a strategy for recycling flight experiment components or part numbers, in order to reduce research project costs, not just in component selection and fabrication, but in expediting qualification of hardware for flight. A key component of the strategy is effective communication of relevant flight hardware information and available flight hardware components to researchers, with the goal of 'short circuiting' the design process for flight experiments
Canada is helping to find the next Einstein in Africa | IDRC ...
International Development Research Centre (IDRC) Digital Library (Canada)
2012-10-23
Oct 23, 2012 ... The belief is that the world's next genius could just as easily come from Africa ... one million students graduate from African universities each year, but high-level ... Among the professors are four Nobel Prize winners as well as ...
Next-Generation Sequencing for Binary Protein-Protein Interactions
Directory of Open Access Journals (Sweden)
Bernhard eSuter
2015-12-01
Full Text Available The yeast two-hybrid (Y2H system exploits host cell genetics in order to display binary protein-protein interactions (PPIs via defined and selectable phenotypes. Numerous improvements have been made to this method, adapting the screening principle for diverse applications, including drug discovery and the scale-up for proteome wide interaction screens in human and other organisms. Here we discuss a systematic workflow and analysis scheme for screening data generated by Y2H and related assays that includes high-throughput selection procedures, readout of comprehensive results via next-generation sequencing (NGS, and the interpretation of interaction data via quantitative statistics. The novel assays and tools will serve the broader scientific community to harness the power of NGS technology to address PPI networks in health and disease. We discuss examples of how this next-generation platform can be applied to address specific questions in diverse fields of biology and medicine.
Next Linear Collider Test Accelerator conceptual design report
International Nuclear Information System (INIS)
1993-08-01
This document presents the scientific justification and the conceptual design for the open-quotes Next Linear Collider Test Acceleratorclose quotes (NLCTA) at SLAC. The goals of the NLCTA are to integrate the new technologies of X-band accelerator structures and rf systems being developed for the Next Linear Collider, to measure the growth of the open-quotes dark currentclose quotes generated by rf field emission in the accelerator, to demonstrate multi-bunch beam-loading energy compensation and suppression of higher-order deflecting modes, and to measure any transverse components of the accelerating field. The NLCTA will be a 42-meter-long beam line consisting, consecutively, of a thermionic-cathode gun, an X-band buncher, a magnetic chicane, six 1.8-meter-long sections of 11.4-GHz accelerator structure, and a magnetic spectrometer. Initially, the unloaded accelerating gradient will be 50 MV/m. A higher-gradient upgrade option eventually would increase the unloaded gradient to 100 MV/m
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
Converged Wireless Networking and Optimization for Next Generation Services
Directory of Open Access Journals (Sweden)
J. Rodriguez
2010-01-01
Full Text Available The Next Generation Network (NGN vision is tending towards the convergence of internet and mobile services providing the impetus for new market opportunities in combining the appealing services of internet with the roaming capability of mobile networks. However, this convergence does not go far enough, and with the emergence of new coexistence scenarios, there is a clear need to evolve the current architecture to provide cost-effective end-to-end communication. The LOOP project, a EUREKA-CELTIC driven initiative, is one piece in the jigsaw by helping European industry to sustain a leading role in telecommunications and manufacturing of high-value products and machinery by delivering pioneering converged wireless networking solutions that can be successfully demonstrated. This paper provides an overview of the LOOP project and the key achievements that have been tunneled into first prototypes for showcasing next generation services for operators and process manufacturers.
Next Generation Social Networks
DEFF Research Database (Denmark)
Sørensen, Lene Tolstrup; Skouby, Knud Erik
2008-01-01
different online networks for communities of people who share interests or individuals who presents themselves through user produced content is what makes up the social networking of today. The purpose of this paper is to discuss perceived user requirements to the next generation social networks. The paper...
Quantitative miRNA expression analysis: comparing microarrays with next-generation sequencing
DEFF Research Database (Denmark)
Willenbrock, Hanni; Salomon, Jesper; Søkilde, Rolf
2009-01-01
Recently, next-generation sequencing has been introduced as a promising, new platform for assessing the copy number of transcripts, while the existing microarray technology is considered less reliable for absolute, quantitative expression measurements. Nonetheless, so far, results from the two...... technologies have only been compared based on biological data, leading to the conclusion that, although they are somewhat correlated, expression values differ significantly. Here, we use synthetic RNA samples, resembling human microRNA samples, to find that microarray expression measures actually correlate...... better with sample RNA content than expression measures obtained from sequencing data. In addition, microarrays appear highly sensitive and perform equivalently to next-generation sequencing in terms of reproducibility and relative ratio quantification....
Beaton, Kara H.; Chappell, Steven P.; Bekdash, Omar S.; Gernhardt, Michael L.
2018-01-01
The NASA Next Space Technologies for Exploration Partnerships (NextSTEP) program is a public-private partnership model that seeks commercial development of deep space exploration capabilities to support extensive human spaceflight missions around and beyond cislunar space. NASA first issued the Phase 1 NextSTEP Broad Agency Announcement to U.S. industries in 2014, which called for innovative cislunar habitation concepts that leveraged commercialization plans for low Earth orbit. These habitats will be part of the Deep Space Gateway (DSG), the cislunar space station planned by NASA for construction in the 2020s. In 2016, Phase 2 of the NextSTEP program selected five commercial partners to develop ground prototypes. A team of NASA research engineers and subject matter experts have been tasked with developing the ground test protocol that will serve as the primary means by which these Phase 2 prototype habitats will be evaluated. Since 2008, this core test team has successfully conducted multiple spaceflight analog mission evaluations utilizing a consistent set of operational products, tools, methods, and metrics to enable the iterative development, testing, analysis, and validation of evolving exploration architectures, operations concepts, and vehicle designs. The purpose of implementing a similar evaluation process for the NextSTEP Phase 2 Habitation Concepts is to consistently evaluate the different commercial partner ground prototypes to provide data-driven, actionable recommendations for Phase 3.
Optical Subsystems for Next Generation Access Networks
DEFF Research Database (Denmark)
Lazaro, J.A; Polo, V.; Schrenk, B.
2011-01-01
Recent optical technologies are providing higher flexibility to next generation access networks: on the one hand, providing progressive FTTx and specifically FTTH deployment, progressively shortening the copper access network; on the other hand, also opening fixed-mobile convergence solutions...... in next generation PON architectures. It is provided an overview of the optical subsystems developed for the implementation of the proposed NG-Access Networks....
International Nuclear Information System (INIS)
Hedges, K.R.; Yu, S.K.W.
1998-01-01
Future CANDU designs will continue to meet the emerging design and performance requirements expected by the operating utilities. The next generation CANDU products will integrate new technologies into both the product features as well as into the engineering and construction work processes associated with delivering the products. The timely incorporation of advanced design features is the approach adopted for the development of the next generation of CANDU. AECL's current products consist of 700MW Class CANDU 6 and 900 MW Class CANDU 9. Evolutionary improvements are continuing with our CANDU products to enhance their adaptability to meet customers ever increasing need for higher output. Our key product drivers are for improved safety, environmental protection and improved cost effectiveness. Towards these goals we have made excellent progress in Research and Development and our investments are continuing in areas such as fuel channels and passive safety. Our long term focus is utilizing the fuel cycle flexibility of CANDU reactors as part of the long term energy mix
Inclusive jet spectrum for small-radius jets
Energy Technology Data Exchange (ETDEWEB)
Dasgupta, Mrinal [Consortium for Fundamental Physics, School of Physics & Astronomy, University of Manchester,Manchester M13 9PL (United Kingdom); Dreyer, Frédéric A. [Sorbonne Universités, UPMC Univ Paris 06, UMR 7589, LPTHE,F-75005, Paris (France); CNRS, UMR 7589, LPTHE,F-75005, Paris (France); CERN, Theoretical Physics Department,CH-1211 Geneva 23 (Switzerland); Salam, Gavin P. [CERN, Theoretical Physics Department,CH-1211 Geneva 23 (Switzerland); Soyez, Gregory [IPhT, CEA Saclay, CNRS UMR 3681,F-91191 Gif-sur-Yvette (France)
2016-06-09
Following on our earlier work on leading-logarithmic (LL{sub R}) resummations for the properties of jets with a small radius, R, we here examine the phenomenological considerations for the inclusive jet spectrum. We discuss how to match the NLO predictions with small-R resummation. As part of the study we propose a new, physically-inspired prescription for fixed-order predictions and their uncertainties. We investigate the R-dependent part of the next-to-next-to-leading order (NNLO) corrections, which is found to be substantial, and comment on the implications for scale choices in inclusive jet calculations. We also examine hadronisation corrections, identifying potential limitations of earlier analytical work with regards to their p{sub t}-dependence. Finally we assemble these different elements in order to compare matched (N)NLO+LL{sub R} predictions to data from ALICE and ATLAS, finding improved consistency for the R-dependence of the results relative to NLO predictions.
Using next generation sequencing to tackle non-typhoidal Salmonella infections
DEFF Research Database (Denmark)
Wain, John; Keddy, Karen H.; Hendriksen, Rene S.
2013-01-01
The publication of studies using next generation sequencing to analyse large numbers of bacterial isolates from global epidemics is transforming microbiology, epidemiology and public health. The emergence of multidrug resistant Salmonella Typhimurium ST313 is one example. While the epidemiology...... in Africa appears to be human-to-human spread and the association with invasive disease almost absolute, more needs to be done to exclude the possibility of animal reservoirs and to transfer the ability to track all Salmonella infections to the laboratories in the front line. In this mini-review we...
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.
Next Generation Solar Collectors for CSP
Energy Technology Data Exchange (ETDEWEB)
Molnar, Attila [3M Company, St. Paul, MN (United States); Charles, Ruth [3M Company, St. Paul, MN (United States)
2014-07-31
The intent of “Next Generation Solar Collectors for CSP” program was to develop key technology elements for collectors in Phase 1 (Budget Period 1), design these elements in Phase 2 (Budget Period 2) and to deploy and test the final collector in Phase 3 (Budget Period 3). 3M and DOE mutually agreed to terminate the program at the end of Budget Period 1, primarily due to timeline issues. However, significant advancements were achieved in developing a next generation reflective material and panel that has the potential to significantly improve the efficiency of CSP systems.
Recent progress in nanostructured next-generation field emission devices
International Nuclear Information System (INIS)
Mittal, Gaurav; Lahiri, Indranil
2014-01-01
Field emission has been known to mankind for more than a century, and extensive research in this field for the last 40–50 years has led to development of exciting applications such as electron sources, miniature x-ray devices, display materials, etc. In the last decade, large-area field emitters were projected as an important material to revolutionize healthcare and medical devices, and space research. With the advent of nanotechnology and advancements related to carbon nanotubes, field emitters are demonstrating highly enhanced performance and novel applications. Next-generation emitters need ultra-high emission current density, high brightness, excellent stability and reproducible performance. Novel design considerations and application of new materials can lead to achievement of these capabilities. This article presents an overview of recent developments in this field and their effects on improved performance of field emitters. These advancements are demonstrated to hold great potential for application in next-generation field emission devices. (topical review)
Recent progress in nanostructured next-generation field emission devices
Mittal, Gaurav; Lahiri, Indranil
2014-08-01
Field emission has been known to mankind for more than a century, and extensive research in this field for the last 40-50 years has led to development of exciting applications such as electron sources, miniature x-ray devices, display materials, etc. In the last decade, large-area field emitters were projected as an important material to revolutionize healthcare and medical devices, and space research. With the advent of nanotechnology and advancements related to carbon nanotubes, field emitters are demonstrating highly enhanced performance and novel applications. Next-generation emitters need ultra-high emission current density, high brightness, excellent stability and reproducible performance. Novel design considerations and application of new materials can lead to achievement of these capabilities. This article presents an overview of recent developments in this field and their effects on improved performance of field emitters. These advancements are demonstrated to hold great potential for application in next-generation field emission devices.
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
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.
Next Generation Biopharmaceuticals: Product Development.
Mathaes, Roman; Mahler, Hanns-Christian
2018-04-11
Therapeutic proteins show a rapid market growth. The relatively young biotech industry already represents 20 % of the total global pharma market. The biotech industry environment has traditionally been fast-pasted and intellectually stimulated. Nowadays the top ten best selling drugs are dominated by monoclonal antibodies (mABs).Despite mABs being the biggest medical breakthrough in the last 25 years, technical innovation does not stand still.The goal remains to preserve the benefits of a conventional mAB (serum half-life and specificity) whilst further improving efficacy and safety and to open new and better avenues for treating patients, e.g., improving the potency of molecules, target binding, tissue penetration, tailored pharmacokinetics, and reduced adverse effects or immunogenicity.The next generation of biopharmaceuticals can pose specific chemistry, manufacturing, and control (CMC) challenges. In contrast to conventional proteins, next-generation biopharmaceuticals often require lyophilization of the final drug product to ensure storage stability over shelf-life time. In addition, next-generation biopharmaceuticals require analytical methods that cover different ways of possible degradation patterns and pathways, and product development is a long way from being straight forward. The element of "prior knowledge" does not exist equally for most novel formats compared to antibodies, and thus the assessment of critical quality attributes (CQAs) and the definition of CQA assessment criteria and specifications is difficult, especially in early-stage development.
The Next Linear Collider: NLC2001
International Nuclear Information System (INIS)
Burke, D.
2002-01-01
Recent studies in elementary particle physics have made the need for an e + e - linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR
The Next Linear Collider: NLC2001
Energy Technology Data Exchange (ETDEWEB)
D. Burke et al.
2002-01-14
Recent studies in elementary particle physics have made the need for an e{sup +}e{sup -} linear collider able to reach energies of 500 GeV and above with high luminosity more compelling than ever [1]. Observations and measurements completed in the last five years at the SLC (SLAC), LEP (CERN), and the Tevatron (FNAL) can be explained only by the existence of at least one particle or interaction that has not yet been directly observed in experiment. The Higgs boson of the Standard Model could be that particle. The data point strongly to a mass for the Higgs boson that is just beyond the reach of existing colliders. This brings great urgency and excitement to the potential for discovery at the upgraded Tevatron early in this decade, and almost assures that later experiments at the LHC will find new physics. But the next generation of experiments to be mounted by the world-wide particle physics community must not only find this new physics, they must find out what it is. These experiments must also define the next important threshold in energy. The need is to understand physics at the TeV energy scale as well as the physics at the 100-GeV energy scale is now understood. This will require both the LHC and a companion linear electron-positron collider. A first Zeroth-Order Design Report (ZDR) [2] for a second-generation electron-positron linear collider, the Next Linear Collider (NLC), was published five years ago. The NLC design is based on a high-frequency room-temperature rf accelerator. Its goal is exploration of elementary particle physics at the TeV center-of-mass energy, while learning how to design and build colliders at still higher energies. Many advances in accelerator technologies and improvements in the design of the NLC have been made since 1996. This Report is a brief update of the ZDR.
Todd, Michael A.; Donohue, Paul P.; Watton, Rex; Williams, Dennis J.; Anthony, Carl J.; Blamire, Mark G.
2002-12-01
This paper discusses the potential thermal imaging performance achievable from thermal detector arrays and concludes that the current generation of thin-film ferroelectric and resistance bolometer based detector arrays are limited by the detector materials used. It is proposed that the next generation of large uncooled focal plane arrays will need to look towards higher performance detector materials - particularly if they aim to approach the fundamental performance limits and compete with cooled photon detector arrays. Two examples of bolometer thin-film materials are described that achieve high performance from operating around phase transitions. The material Lead Scandium Tantalate (PST) has a paraelectric-to-ferroelectric phase transition around room temperature and is used with an applied field in the dielectric bolometer mode for thermal imaging. PST films grown by sputtering and liquid-source CVD have shown merit figures for thermal imaging a factor of 2 to 3 times higher than PZT-based pyroelectric thin films. The material Lanthanum Calcium Manganite (LCMO) has a paramagnetic to ferromagnetic phase transition around -20oC. This paper describes recent measurements of TCR and 1/f noise in pulsed laser-deposited LCMO films on Neodymium Gallate substrates. These results show that LCMO not only has high TCR's - up to 30%/K - but also low 1/f excess noise, with bolometer merit figures at least an order of magnitude higher than Vanadium Oxide, making it ideal for the next generation of microbolometer arrays. These high performance properties come at the expense of processing complexities and novel device designs will need to be introduced to realize the potential of these materials in the next generation of thermal detectors.
Thermal Development Test of the NEXT PM1 Ion Engine
Anderson, John R.; Snyder, John S.; VanNoord, Jonathan L.; Soulas, George C.
2010-01-01
NASA's Evolutionary Xenon Thruster (NEXT) is a next-generation high-power ion propulsion system under development by NASA as a part of the In-Space Propulsion Technology Program. NEXT is designed for use on robotic exploration missions of the solar system using solar electric power. Potential mission destinations that could benefit from a NEXT Solar Electric Propulsion (SEP) system include inner planets, small bodies, and outer planets and their moons. This range of robotic exploration missions generally calls for ion propulsion systems with deep throttling capability and system input power ranging from 0.6 to 25 kW, as referenced to solar array output at 1 Astronomical Unit (AU). Thermal development testing of the NEXT prototype model 1 (PM1) was conducted at JPL to assist in developing and validating a thruster thermal model and assessing the thermal design margins. NEXT PM1 performance prior to, during and subsequent to thermal testing are presented. Test results are compared to the predicted hot and cold environments expected missions and the functionality of the thruster for these missions is discussed.
Maintaining Space Situational Awareness and Taking it to the Next Level
2013-10-01
Power Journal | 52 Baird The Importance of Maintaining Space Situational Awareness and Taking It to the Next Level FeatureSpace Focus junction ...Communications (BMC3) infrastructure. We must build a new space superiority enterprise around SSA sensors that utilize com- mon data models to...vehicle, a modified version of China’s DF-21 medium-range ballistic missile, and launcher system en- gaged the satellite at a closing velocity of
Kaon decay physics in the next decade
International Nuclear Information System (INIS)
Bryman, D.
1993-05-01
Rare and CP violating kaon decays provide important access to fundamental issues in particle physics. Experiments at BNL, CERN, Fermilab and KEK have recently reported results dealing with stringent tests of the standard model and sensitive searches for novel effects which probe very high mass scales. The next generation of experiments is now being constructed to establish the presence of direct CP violation as predicted in the standard model, to unambiguously examine higher order weak interaction effects and to search for lepton flavor violation with unprecedented sensitivity. In addition, new accelerator facilities are being built and planned which will allow orders of magnitude gains in sensitivity for the most critical measurements. (author). 45 refs., 7 figs
Rhamnolipids--next generation surfactants?
Müller, Markus Michael; Kügler, Johannes H; Henkel, Marius; Gerlitzki, Melanie; Hörmann, Barbara; Pöhnlein, Martin; Syldatk, Christoph; Hausmann, Rudolf
2012-12-31
The demand for bio-based processes and materials in the petrochemical industry has significantly increased during the last decade because of the expected running out of petroleum. This trend can be ascribed to three main causes: (1) the increased use of renewable resources for chemical synthesis of already established product classes, (2) the replacement of chemical synthesis of already established product classes by new biotechnological processes based on renewable resources, and (3) the biotechnological production of new molecules with new features or better performances than already established comparable chemically synthesized products. All three approaches are currently being pursued for surfactant production. Biosurfactants are a very promising and interesting substance class because they are based on renewable resources, sustainable, and biologically degradable. Alkyl polyglycosides are chemically synthesized biosurfactants established on the surfactant market. The first microbiological biosurfactants on the market were sophorolipids. Of all currently known biosurfactants, rhamnolipids have the highest potential for becoming the next generation of biosurfactants introduced on the market. Although the metabolic pathways and genetic regulation of biosynthesis are known qualitatively, the quantitative understanding relevant for bioreactor cultivation is still missing. Additionally, high product titers have been exclusively described with vegetable oil as sole carbon source in combination with Pseudomonas aeruginosa strains. Competitive productivity is still out of reach for heterologous hosts or non-pathogenic natural producer strains. Thus, on the one hand there is a need to gain a deeper understanding of the regulation of rhamnolipid production on process and cellular level during bioreactor cultivations. On the other hand, there is a need for metabolizable renewable substrates, which do not compete with food and feed. A sustainable bioeconomy approach should
NASA's Next Generation Space Geodesy Network
Desai, S. D.; Gross, R. S.; Hilliard, L.; Lemoine, F. G.; Long, J. L.; Ma, C.; McGarry, J. F.; Merkowitz, S. M.; Murphy, D.; Noll, C. E.;
2012-01-01
NASA's Space Geodesy Project (SGP) is developing a prototype core site for a next generation Space Geodetic Network (SGN). Each of the sites in this planned network co-locate current state-of-the-art stations from all four space geodetic observing systems, GNSS, SLR, VLBI, and DORIS, with the goal of achieving modern requirements for the International Terrestrial Reference Frame (ITRF). In particular, the driving ITRF requirements for this network are 1.0 mm in accuracy and 0.1 mm/yr in stability, a factor of 10-20 beyond current capabilities. Development of the prototype core site, located at NASA's Geophysical and Astronomical Observatory at the Goddard Space Flight Center, started in 2011 and will be completed by the end of 2013. In January 2012, two operational GNSS stations, GODS and GOON, were established at the prototype site within 100 m of each other. Both stations are being proposed for inclusion into the IGS network. In addition, work is underway for the inclusion of next generation SLR and VLBI stations along with a modern DORIS station. An automated survey system is being developed to measure inter-technique vectorties, and network design studies are being performed to define the appropriate number and distribution of these next generation space geodetic core sites that are required to achieve the driving ITRF requirements. We present the status of this prototype next generation space geodetic core site, results from the analysis of data from the established geodetic stations, and results from the ongoing network design studies.
NDT in Canada - the next 20 years
International Nuclear Information System (INIS)
Kittmer, C.A.
1985-01-01
The theme for the Fifth Canadian Conference on Nondestructive Testing was 'NDT in Canada - The Next 20 years'. The three day conference with 42 presentations provided a short overview of NDT in Canada, a look at NDT in pipeline, materials, offshore, nuclear and training applications, and a glimpse into the next 20 years with recent advances in research and development as related to this 'hi-tech' field of work
Mellin moments of heavy flavor contributions to F2(x,Q2) at NNLO
International Nuclear Information System (INIS)
Klein, Sebastian Werner Gerhard
2009-10-01
The main parts of this thesis are the extension of the description of the contributions of heavy quark mass-effects to the deep-inelastic Wilson coefficients to NNLO. In course of that, we also obtain a first independent calculation of fixed moments of the fermionic parts of the NNLO anomalous dimensions. The calculation of the 3-loop heavy flavor Wilson coefficients in the whole Q 2 region is currently not within reach. However, a very precise description of the heavy flavor Wilson coefficients contributing to the structure function F 2 (x,Q 2 ) at NLO is obtained for Q 2 >or similar 10 m Q 2 , disregarding the power corrections ∝(m Q 2 /Q 2 ) k , k ≥ 1. If one considers the charm quark, this covers an important region for deep-inelastic physics at HERA. In this limit, the massive Wilson coefficients factorize into universal massive operator matrix elements (OMEs) A ij (x, μ 2 /m Q 2 ) and the light flavor Wilson coefficients C (q,g),(2,L) (x,Q 2 /μ 2 ). The former are process independent quantities and describe all quark mass effects. They are given by matrix elements of the leading twist local composite operators O i between partonic states j (i, j = q, g), including quark masses. The process dependence is described by the massless Wilson coefficients. (orig.)
Understanding reproducibility of human IVF traits to predict next IVF cycle outcome.
Wu, Bin; Shi, Juanzi; Zhao, Wanqiu; Lu, Suzhen; Silva, Marta; Gelety, Timothy J
2014-10-01
Evaluating the failed IVF cycle often provides useful prognostic information. Before undergoing another attempt, patients experiencing an unsuccessful IVF cycle frequently request information about the probability of future success. Here, we introduced the concept of reproducibility and formulae to predict the next IVF cycle outcome. The experimental design was based on the retrospective review of IVF cycle data from 2006 to 2013 in two different IVF centers and statistical analysis. The reproducibility coefficients (r) of IVF traits including number of oocytes retrieved, oocyte maturity, fertilization, embryo quality and pregnancy were estimated using the interclass correlation coefficient between the repeated IVF cycle measurements for the same patient by variance component analysis. The formulae were designed to predict next IVF cycle outcome. The number of oocytes retrieved from patients and their fertilization rate had the highest reproducibility coefficients (r = 0.81 ~ 0.84), which indicated a very close correlation between the first retrieval cycle and subsequent IVF cycles. Oocyte maturity and number of top quality embryos had middle level reproducibility (r = 0.38 ~ 0.76) and pregnancy rate had a relative lower reproducibility (r = 0.23 ~ 0.27). Based on these parameters, the next outcome for these IVF traits might be accurately predicted by the designed formulae. The introduction of the concept of reproducibility to our human IVF program allows us to predict future IVF cycle outcomes. The traits of oocyte numbers retrieved, oocyte maturity, fertilization, and top quality embryos had higher or middle reproducibility, which provides a basis for accurate prediction of future IVF outcomes. Based on this prediction, physicians may counsel their patients or change patient's stimulation plans, and laboratory embryologists may improve their IVF techniques accordingly.
International Nuclear Information System (INIS)
Hopwood, J.M.
1999-01-01
AECL's product line of CANDU 6 and CANDU 9 nuclear power plants are adapted to respond to changing market conditions, experience feedback and technological development by a continuous improvement process of design evolution. The CANDU 6 Nuclear Power Plant design is a successful family of nuclear units, with the first four units entering service in 1983, and the most recent entering service this year. A further four CANDU 6 units are under construction. Starting in 1996, a focused forward-looking development program is under way at AECL to incorporate a series of individual improvements and integrate them into the CANDU 6, leading to the evolutionary development of the next-generation enhanced CANDU 6. The CANDU 6 improvements program includes all aspects of an NPP project, including engineering tools improvements, design for improved constructability, scheduling for faster, more streamlined commissioning, and improved operating performance. This enhanced CANDU 6 product will combine the benefits of design provenness (drawing on the more than 70 reactor-years experience of the seven operating CANDU 6 units), with the advantages of an evolutionary next-generation design. Features of the enhanced CANDU 6 design include: Advanced Human Machine Interface - built around the Advanced CANDU Control Centre; Advanced fuel design - using the newly demonstrated CANFLEX fuel bundle; Improved Efficiency based on improved utilization of waste heat; Streamlined System Design - including simplifications to improve performance and safety system reliability; Advanced Engineering Tools, -- featuring linked electronic databases from 3D CADDS, equipment specification and material management; Advanced Construction Techniques - based on open top equipment installation and the use of small skid mounted modules; Options defined for Passive Heat Sink capability and low-enrichment core optimization. (author)
Gupta, Amardeep
2005-01-01
Current search engines--even the constantly surprising Google--seem unable to leap the next big barrier in search: the trillions of bytes of dynamically generated data created by individual web sites around the world, or what some researchers call the "deep web." The challenge now is not information overload, but information overlook.…
Higgs mass implications on the stability of the electroweak vacuum: a NNLO analysis
International Nuclear Information System (INIS)
Elias-Miro, J.
2014-01-01
The mass range M n ≅ 124.5 - 126.5 GeV, of the discovered Higgs-like particle is a specially interesting range from the stability of the electroweak vacuum point of view. As we will show, for such mass range and assuming a Standard Model Higgs, the electroweak vacuum lies almost in between being absolutely stable up to the Planck scale and unstable, i.e. the Standard Mode effective potential presents a second minimum, deeper than the electroweak one, below the Planck scale. This observation motivates a higher order precision analysis of the Standard Model effective potential. We will review the first complete next-to-next-to-leading order analysis of the Standard Model Higgs potential made recently. Then, we will be able to conclude whether or not the SM can be consistently extrapolated up to the Planck scale. (author)
Engineering microbes for tolerance to next-generation biofuels
Directory of Open Access Journals (Sweden)
Dunlop Mary J
2011-09-01
Full Text Available Abstract A major challenge when using microorganisms to produce bulk chemicals such as biofuels is that the production targets are often toxic to cells. Many biofuels are known to reduce cell viability through damage to the cell membrane and interference with essential physiological processes. Therefore, cells must trade off biofuel production and survival, reducing potential yields. Recently, there have been several efforts towards engineering strains for biofuel tolerance. Promising methods include engineering biofuel export systems, heat shock proteins, membrane modifications, more general stress responses, and approaches that integrate multiple tolerance strategies. In addition, in situ recovery methods and media supplements can help to ease the burden of end-product toxicity and may be used in combination with genetic approaches. Recent advances in systems and synthetic biology provide a framework for tolerance engineering. This review highlights recent targeted approaches towards improving microbial tolerance to next-generation biofuels with a particular emphasis on strategies that will improve production.
Development of LHCD launcher for next stage tokamak
International Nuclear Information System (INIS)
Seki, M.; Obara, K.; Maebara, S.
1994-01-01
In next stage LHCD experiment, long pulse RF injection is required for studying quasi-steady state tokamaks. The suppression of outgassing from waveguides is one of the main issues for LHCD launchers to transmit RF power in the waveguides continuously and stably. In order to know the parameters which control outgassing rate and to investigate how to reduce outgassing rate, JAERI and CEA have performed outgassing experiment by using four divided waveguides. The experimental setup and the results are reported. Steady state outgassing was observed in long duration up to 1800s when RF heat was removed by water cooling. In next generation LHCD launchers, it should be demanded to launch the high directive and sharp spectra, and to make the structure simple and compact. But these spectra require many waveguides in front of plasma, and this situation is not compatible with the compact structure which is necessary for low cost and easy maintenance. Moreover, the launchers are advantageous if the controllability is wide, and the low RF power density at grill mouth makes power launching easy. In order to realize the above features, a new launcher was devised. The conceptual structure is shown. The main R and D item is to divide RF power into three waveguides lined in poloidal direction. The RF property is discussed. (K.I.)
Likelihood analysis of the next-to-minimal supergravity motivated model
International Nuclear Information System (INIS)
Balazs, Csaba; Carter, Daniel
2009-01-01
In anticipation of data from the Large Hadron Collider (LHC) and the potential discovery of supersymmetry, we calculate the odds of the next-to-minimal version of the popular supergravity motivated model (NmSuGra) being discovered at the LHC to be 4:3 (57%). We also demonstrate that viable regions of the NmSuGra parameter space outside the LHC reach can be covered by upgraded versions of dark matter direct detection experiments, such as super-CDMS, at 99% confidence level. Due to the similarities of the models, we expect very similar results for the constrained minimal supersymmetric standard model (CMSSM).
Addressing Three Common Myths about the Next Generation Science Standards
Huff, Kenneth L.
2016-01-01
Although the "Next Generation Science Standards" (NGSS Lead States 2013) were released over two years ago, misconceptions about what they are--and are not--persist. The "NGSS" provide for consistent science education opportunities for all students--regardless of demographics--with a level of rigor expected in every location and…
Next Generation Microchannel Heat Exchangers
Ohadi, Michael; Dessiatoun, Serguei; Cetegen, Edvin
2013-01-01
In Next Generation Microchannel Heat Exchangers, the authors’ focus on the new generation highly efficient heat exchangers and presentation of novel data and technical expertise not available in the open literature. Next generation micro channels offer record high heat transfer coefficients with pressure drops much less than conventional micro channel heat exchangers. These inherent features promise fast penetration into many mew markets, including high heat flux cooling of electronics, waste heat recovery and energy efficiency enhancement applications, alternative energy systems, as well as applications in mass exchangers and chemical reactor systems. The combination of up to the minute research findings and technical know-how make this book very timely as the search for high performance heat and mass exchangers that can cut costs in materials consumption intensifies.
International Nuclear Information System (INIS)
Scaldwell, Reg
1995-01-01
The General Manager of the reactor division of Centronics, a world class manufacturer of reactor control systems and radiation detectors, describes its achievements and looks forward to speculate on what the next fifty years may mean in terms of technological development. Tables are given of the locations of Centronics Fission Chambers and of reactors controlled with Centronic Detectors. (UK)
Supersymmetry: the Next Spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Peskin, Michael E
2002-12-16
I describe the picture by which supersymmetry--the possible symmetry of Nature that converts fermions to bosons and vice versa--accounts for the next stage of physics beyond the Standard Model. I then survey the future experimental program implied by this theory, in which the spectrum of particles associated with supersymmetry will be determined with precision.
B{yields}V{gamma} decays at NNLO in SCET
Energy Technology Data Exchange (ETDEWEB)
Ali, A.; Pecjak, B.D. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Greub, C. [Bern Univ. (Switzerland). Inst. fuer Theoretische Physik
2007-09-15
We compute NNLO (O({alpha}{sup 2}{sub s})) corrections to the hard-scattering kernels entering the QCD factorization formula for B {yields} V{gamma} decays, where V is a light vector meson. We give complete NNLO results for the dipole operators Q{sub 7} and Q{sub 8}, and partial results for Q{sub 1} valid in the large-{beta}{sub 0} limit and neglecting the NNLO correction from hard spectator scattering. Large perturbative logarithms in the hard-scattering kernels are identified and resummed using soft-collinear effective theory. We use our results to estimate the branching fractions for B {yields} K{sup *}{gamma} and B{sub s} {yields} {phi}{gamma} decays at NNLO and compare them with the current experimental data. (orig.)
Next generation of accelerators
International Nuclear Information System (INIS)
Richter, B.
1979-01-01
Existing high-energy accelerators are reviewed, along with those under construction or being designed. Finally, some of the physics issues which go into setting machine parameters, and some of the features of the design of next generation electron and proton machines are discussed
Building a multidisciplinary e-infrastructure for the NextData Community
Nativi, Stefano; Rorro, Marco; Mazzetti, Paolo; Fiameni, Giuseppe; Papeschi, Fabrizio; Carpenè, Michele
2014-05-01
In 2012, Italy decided to launch a national initiative called NextData (http://www.nextdataproject.it/): a national system for the retrieval, storage, access and diffusion of environmental and climate data from mountain and marine areas. NextData is funded by the Research and University Ministry, as a "Project of Interest". In 2013, NextData funded a "special project", the NextData System of Systems Infrastructure project (ND-SoS-Ina). The main objective is to design, build and operate in production the NextData multidisciplinary and multi-organizational e-infrastructure for the publication and sharing of its resources (e.g. data, services, vocabularies, models). SoS-Ina realizes the NextData general portal implementing the interoperability among the data archives carried out by NextData. The Florentine Division of the Institute of Atmospheric Pollution Research of CNR (CNR-IIA) and CINECA run the project. SoS-Ina (http://essi-lab.eu/nextdata/sosina/) decided to adopt a "System of Systems" (SoS) approach based on a brokering architecture. This has been pursued by applying the brokering technology first developed by the EC-FP7 EuroGEOSS project (http://www.eurogeoss.eu/broker/Pages/AbouttheEuroGEOSSBroker.aspx) and more recently consolidated by the international programme GEOSS (Global Earth Observation System of Systems) of GEO (Group oh Earth Observation) -see http://www.earthobservations.org/documents/geo_ix/20111122_geoss_implementation_highlights.pdf. The NextData general Portal architecture definition will proceed accordingly with the requirements elicited by user communities. The portal will rely on services and interfaces being offered by the brokering middleware and will be based on Liferay (http://www.liferay.com/). Liferay is free and open source, it provides many built-in applications for social collaboration, content and document management. Liferay is also configurable for high availability. The project considers three distinct phases and related
2004-01-01
and Development Supporting the Next Industrial Revolution Supplement to the President’s FY 2004 Budget National Science and Technology Council...potential to profoundly change our economy, to improve our standard of living, and to bring about the next industrial revolution . Nanotechnology: From
Next generation framework for aquatic modeling of the Earth System
Fekete, B. M.; Wollheim, W. M.; Wisser, D.; Vörösmarty, C. J.
2009-03-01
Earth System model development is becoming an increasingly complex task. As scientists attempt to represent the physical and bio-geochemical processes and various feedback mechanisms in unprecedented detail, the models themselves are becoming increasingly complex. At the same time, the complexity of the surrounding IT infrastructure is growing as well. Earth System models must manage a vast amount of data in heterogeneous computing environments. Numerous development efforts are on the way to ease that burden and offer model development platforms that reduce IT challenges and allow scientists to focus on their science. While these new modeling frameworks (e.g. FMS, ESMF, CCA, OpenMI) do provide solutions to many IT challenges (performing input/output, managing space and time, establishing model coupling, etc.), they are still considerably complex and often have steep learning curves. The Next generation Framework for Aquatic Modeling of the Earth System (NextFrAMES, a revised version of FrAMES) have numerous similarities to those developed by other teams, but represents a novel model development paradigm. NextFrAMES is built around a modeling XML that lets modelers to express the overall model structure and provides an API for dynamically linked plugins to represent the processes. The model XML is executed by the NextFrAMES run-time engine that parses the model definition, loads the module plugins, performs the model I/O and executes the model calculations. NextFrAMES has a minimalistic view representing spatial domains and treats every domain (regardless of its layout such as grid, network tree, individual points, polygons, etc.) as vector of objects. NextFrAMES performs computations on multiple domains and interactions between different spatial domains are carried out through couplers. NextFrAMES allows processes to operate at different frequencies by providing rudimentary aggregation and disaggregation facilities. NextFrAMES was designed primarily for
Perspectives on the development of next generation reactor systems safety analysis codes
International Nuclear Information System (INIS)
Zhang, H.
2015-01-01
tackle the deficiencies in the existing codes. 3) Software design of the next-generation codes needs to take into consideration of having the flexibility to add new models if necessary, as well as to allow for embedded uncertainty quantification, and capability of multi-physics coupling with other codes. 4) The next generation codes need proper verification and validation (V & V) before they can be used to plant applications. New approaches need to be developed to verify and validate complex multi-physics models with multiple time and length scales and advanced modeling techniques. 5) The next generation system analysis codes should be designed to be integrated into probabilistic evaluation to enable a risk-informed safety margin characterization (RISMC) process in order to optimize plant safety and performance by incorporating plant impacts, aging, and degradation processes into the safety analysis. (author)
Perspectives on the development of next generation reactor systems safety analysis codes
Energy Technology Data Exchange (ETDEWEB)
Zhang, H., E-mail: Hongbin.Zhang@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States)
2015-07-01
tackle the deficiencies in the existing codes. 3) Software design of the next-generation codes needs to take into consideration of having the flexibility to add new models if necessary, as well as to allow for embedded uncertainty quantification, and capability of multi-physics coupling with other codes. 4) The next generation codes need proper verification and validation (V & V) before they can be used to plant applications. New approaches need to be developed to verify and validate complex multi-physics models with multiple time and length scales and advanced modeling techniques. 5) The next generation system analysis codes should be designed to be integrated into probabilistic evaluation to enable a risk-informed safety margin characterization (RISMC) process in order to optimize plant safety and performance by incorporating plant impacts, aging, and degradation processes into the safety analysis. (author)
Key thrusts in next generation CANDU. Annex 10
International Nuclear Information System (INIS)
Shalaby, B.A.; Torgerson, D.F.; Duffey, R.B.
2002-01-01
Current electricity markets and the competitiveness of other generation options such as CCGT have influenced the directions of future nuclear generation. The next generation CANDU has used its key characteristics as the basis to leap frog into a new design featuring improved economics, enhanced passive safety, enhanced operability and demonstrated fuel cycle flexibility. Many enabling technologies spinning of current CANDU design features are used in the next generation design. Some of these technologies have been developed in support of existing plants and near term designs while others will need to be developed and tested. This paper will discuss the key principles driving the next generation CANDU design and the fuel cycle flexibility of the CANDU system which provide synergism with the PWR fuel cycle. (author)
Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Ackers, Mario; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Akesson, Torsten Paul; Akimoto, Ginga; Akimov, Andrei; Alam, Mohammad; Alam, Muhammad Aftab; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Aleppo, Mario; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alonso, Jose; Alviggi, Mariagrazia; Amako, Katsuya; Amaral, Pedro; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amoros, Gabriel; Amram, Nir; Anastopoulos, Christos; Andeen, Timothy; Anders, Christoph Falk; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonelli, Stefano; Antos, Jaroslav; Anulli, Fabio; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Archambault, John-Paul; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arms, Kregg; Armstrong, Stephen Randolph; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Asman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Atoian, Grigor; Aubert, Bernard; Auerbach, Benjamin; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Austin, Nicholas; 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Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenfield, Debbie; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregor, Ingrid-Maria; Grenier, Philippe; Griesmayer, Erich; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Gris, Philippe Luc Yves; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Grognuz, Joel; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Gruwe, Magali; Grybel, Kai; Guarino, Victor; Guicheney, Christophe; Guida, Angelo; Guillemin, Thibault; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Andrea; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hackenburg, Robert; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Haller, Johannes; Hamacher, Klaus; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, Christian Johan; Hansen, John Renner; Hansen, Jorgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Karl; Hart, John; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Donovan; Hayakawa, Takashi; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heldmann, Michael; Heller, Mathieu; Hellman, Sten; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frederic; Hensel, Carsten; Henss, Tobias; Hernandez Jimenez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hessey, Nigel; Hidvegi, Attila; Higon-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmes, Alan; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Homer, Jim; Homma, Yasuhiro; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Horton, Katherine; Hostachy, Jean-Yves; Hott, Thomas; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Idzik, Marek; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Imbault, Didier; Imhaeuser, Martin; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Ionescu, Gelu; Irles Quiles, Adrian; Ishii, Koji; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Isobe, Tadaaki; Issever, Cigdem; Istin, Serhat; Itoh, Yuki; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jantsch, Andreas; Janus, Michel; Jarlskog, Goran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jez, Pavel; Jezequel, Stephane; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Johnson, Andrew; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joo, Kwang; Joram, Christian; Jorge, Pedro; Joseph, John; Ju, Xiangyang; Juranek, Vojtech; Jussel, Patrick; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Kazi, Sandor Istvan; Keates, James Robert; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kelly, Marc; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kersevan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Ketterer, Christian; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kilvington, Graham; Kim, Hyeon Jin; Kim, Min Suk; Kim, Peter; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Guillaume; Kirsch, Lawrence; Kiryunin, Andrey; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kiyamura, Hironori; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimentov, Alexei; Klingenberg, Reiner; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Kneringer, Emmerich; Knobloch, Juergen; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Koblitz, Birger; Kocian, Martin; Kocnar, Antonin; Kodys, Peter; Koneke, Karsten; Konig, Adriaan; Koenig, Sebastian; Konig, Stefan; Kopke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollar, Daniel; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komaragiri, Jyothsna Rani; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Kopikov, Sergey; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamaki, Miikka Juhani; Kotov, Serguei; Kotov, Vladislav; Kourkoumelis, Christine; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasel, Olaf; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Kruger, Hans; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuykendall, William; Kuze, Masahiro; Kuzhir, Polina; Kvasnicka, Ondrej; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramon; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Landsman, Hagar; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lapin, Vladimir; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Lau, Wing; Laurelli, Paolo; Lavorato, Antonia; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Lazzaro, Alfio; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Leahu, Marius; Lebedev, Alexander; Lebel, Celine; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lehto, Mark; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Lellouch, Jeremie; Leltchouk, Mikhail; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Leveque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewandowska, Marta; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhihua; Liang, Zhijun; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Lilley, Joseph; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Shengli; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Lockwitz, Sarah; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Losada, Marta; Loscutoff, Peter; Sterzo, Francesco Lo; Losty, Michael; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lu, Jiansen; Lu, Liang; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dorthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Bjorn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lupi, Anna; Lutz, Gerhard; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Massen, Michael; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Macek, Bostjan; Machado Miguens, Joana; Macina, Daniela; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mattig, Peter; Mattig, Stefan; Magalhaes Martins, Paulo Jorge; Magnoni, Luca; Magradze, Erekle; Magrath, Caroline; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amelia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandic, Igor; Mandrysch, Rocco; Maneira, Jose; Mangeard, Pierre-Simon; Manjavidze, Ioseb; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchesotti, Marco; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian Thomas; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; Martin, Tim; Martin Dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Mass, Martin; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastroberardino, Anna; Masubuchi, Tatsuya; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maxfield, Stephen; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McMahon, Tania; McMahon, Tom; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meinhardt, Jens; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Merkl, Doris; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meuser, Stefan; Meyer, Carsten; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W.Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Miele, Paola; Migas, Sylwia; Mijovic, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikulec, Bettina; Mikuz, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Minano, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Misiejuk, Andrzej; Mitra, Ankush; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A.; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjornmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Monig, Klaus; Moser, Nicolas; Mohapatra, Soumya; Mohn, Bjarte; Mohr, Wolfgang; Mohrdieck-Mock, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Moneta, Lorenzo; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morais, Antonio; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morii, Masahiro; Morin, Jerome; Morita, Youhei; Morley, Anthony Keith; Mornacchi, Giuseppe; Morone, Maria-Christina; Morris, John; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Muller, Thomas; Muenstermann, Daniel; Muijs, Sandra; Muir, Alex; Munwes, Yonathan; Murakami, Koichi; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagasaka, Yasushi; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Nash, Michael; Nasteva, Irina; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Nesterov, Stanislav; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nomoto, Hiroshi; Nordberg, Markus; Nordkvist, Bjoern; Norniella Francisco, Olga; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozicka, Miroslav; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; Nyman, Tommi; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Odino, Gian Andrea; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohska, Tokio Kenneth; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olcese, Marco; Olchevski, Alexander; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, Antonio; Onyisi, Peter; Oram, Christopher; Ordonez, Gustavo; Oreglia, Mark; Orellana, Frederik; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Ortega, Eduardo; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Owen, Mark; Owen, Simon; Oyarzun, Alejandro; Oye, Ola; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Paganis, Efstathios; Paige, Frank; Pajchel, Katarina; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Paoloni, Alessandro; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Park, Su-Jung; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pasztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Cavalcanti, Tiago Perez; Perez Codina, Estel; Perez Garcia-Estan, Maria Teresa; Perez Reale, Valeria; Peric, Ivan; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Perus, Antoine; Peshekhonov, Vladimir; Peters, Onne; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Alan; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Pickford, Andrew; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pina, Joao Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Plano, Will; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommes, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Bueso, Xavier Portell; Porter, Robert; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Prabhu, Robindra; Pralavorio, Pascal; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Lawrence; Price, Michael John; Prichard, Paul; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rajagopalan, Srinivasan; Rajek, Silke; Rammensee, Michael; Rammes, Marcus; Ramstedt, Magnus; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rauter, Emanuel; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Reljic, Dusan; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rensch, Bertram; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rieke, Stefan; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodier, Stephane; Rodriguez, Diego; Rodriguez Garcia, Yohany; Roe, Adam; Roe, Shaun; Rohne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romanov, Victor; Romeo, Gaston; Romero Maltrana, Diego; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rose, Matthew; Rosenbaum, Gabriel; Rosenberg, Eli; Rosendahl, Peter Lundgaard; Rosselet, Laurent; Rossetti, Valerio; Rossi, Elvira; Rossi, Leonardo Paolo; Rossi, Lucio; Rotaru, Marina; Roth, Itamar; Rothberg, Joseph; Rottlander, Iris; Rousseau, David; Royon, Christophe; Rozanov, Alexander; Rozen, Yoram; Ruan, Xifeng; Rubinskiy, Igor; Ruckert, Benjamin; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Gerald; Ruhr, Frederik; Ruiz-Martinez, Aranzazu; Rulikowska-Zarebska, Elzbieta; Rumiantsev, Viktor; Rumyantsev, Leonid; Runge, Kay; Runolfsson, Ogmundur; Rurikova, Zuzana; Rusakovich, Nikolai; Rust, Dave; Rutherfoord, John; Ruwiedel, Christoph; Ruzicka, Pavel; Ryabov, Yury; Ryadovikov, Vasily; Ryan, Patrick; Rybar, Martin; Rybkin, Grigori; Ryder, Nick; Rzaeva, Sevda; Saavedra, Aldo; Sadeh, Iftach; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salihagic, Denis; Salnikov, Andrei; Salt, Jose; Salvachua Ferrando, Belen; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Bjorn Hallvard; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandhu, Pawan; Sandoval, Tanya; Sandstroem, Rikard; Sandvoss, Stephan; Sankey, Dave; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Santos, Helena; Saraiva, Joao; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sartisohn, Georg; Sasaki, Osamu; Sasaki, Takashi; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Sauvan, Jean-Baptiste; Savard, Pierre; Savinov, Vladimir; Savva, Panagiota; Sawyer, Lee; Saxon, David; Says, Louis-Pierre; Sbarra, Carla; Sbrizzi, Antonio; Scallon, Olivia; Scannicchio, Diana; Schaarschmidt, Jana; Schacht, Peter; Schafer, Uli; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R. Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schlereth, James; Schmidt, Evelyn; Schmidt, Michael; Schmieden, Kristof; Schmitt, Christian; Schmitz, Martin; Schoning, Andre; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schreiner, Alexander; Schroeder, Christian; Schroer, Nicolai; Schuh, Silvia; Schuler, Georges; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schulz, Holger; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Scott, Bill; Searcy, Jacob; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, Jose; Sekhniaidze, Givi; Seliverstov, Dmitry; Sellden, Bjoern; Sellers, Graham; Seman, Michal; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaver, Leif; Shaw, Christian; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shimizu, Shima; Shimojima, Makoto; Shin, Taeksu; Shmeleva, Alevtina; Shochet, Mel; Short, Daniel; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siebel, Anca-Mirela; Siegert, Frank; Siegrist, James; Sijacki, Djordje; Silbert, Ohad; Silva, Jose; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sisakyan, Alexei; Sivoklokov, Serguei; Sjolin, Jorgen; Sjursen, Therese; Skinnari, Louise Anastasia; Skovpen, Kirill; Skubic, Patrick; Skvorodnev, Nikolai; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloan, Terrence; Sloper, John erik; Smakhtin, Vladimir; Smirnov, Sergei; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Soldevila, Urmila; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Sondericker, John; Soni, Nitesh; Sopko, Vit; Sopko, Bruno; Sorbi, Massimo; Sosebee, Mark; Soukharev, Andrey; Spagnolo, Stefania; Spano, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiriti, Eleuterio; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St. Denis, Richard Dante; Stahl, Thorsten; Stahlman, Jonathan; Stamen, Rainer; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Staude, Arnold; Stavina, Pavel; Stavropoulos, Georgios; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stevenson, Kyle; Stewart, Graeme; Stockmanns, Tobias; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strang, Michael; Strauss, Emanuel; Strauss, Michael; Strizenec, Pavol; Strohmer, Raimund; Strom, David; Strong, John; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Stumer, Iuliu; Stupak, John; Sturm, Philipp; Soh, Dart-yin; Su, Dong; Subramania, Siva; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suita, Koichi; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Yu; Sviridov, Yuri; Swedish, Stephen; Sykora, Ivan; Sykora, Tomas; Szeless, Balazs; Sanchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taga, Adrian; Taiblum, Nimrod; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tanaka, Yoshito; Tani, Kazutoshi; Tannoury, Nancy; Tappern, Geoffrey; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Taylor, Christopher; Taylor, Frank; Taylor, Gary; Taylor, Geoffrey; Taylor, Wendy; Teixeira Dias Castanheira, Matilde; Teixeira-Dias, Pedro; Temming, Kim Katrin; Ten Kate, Herman; Teng, Ping-Kun; Tennenbaum-Katan, Yaniv-David; Terada, Susumu; Terashi, Koji; Terron, Juan; Terwort, Mark; Testa, Marianna; Teuscher, Richard; Tevlin, Christopher; Thadome, Jocelyn; Therhaag, Jan; Theveneaux-Pelzer, Timothee; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Emily; Thompson, Paul; Thompson, Peter; Thompson, Stan; Thomson, Evelyn; Thomson, Mark; Thun, Rudolf; Tic, Tomas; Tikhomirov, Vladimir; Tikhonov, Yury; Timmermans, Charles; Tipton, Paul; Viegas, Florbela De Jes Tique Aires; Tisserant, Sylvain; Tobias, Jurgen; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokar, Stanislav; Tokunaga, Kaoru; Tokushuku, Katsuo; Tollefson, Kirsten; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonazzo, Alessandra; Tong, Guoliang; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torro Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Traynor, Daniel; Trefzger, Thomas; Treis, Johannes; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trivedi, Arjun; Trocme, Benjamin; Troncon, Clara; Trottier-McDonald, Michel; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tua, Alan; Tuggle, Joseph; Turala, Michal; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Tuts, Michael; Tykhonov, Andrii; Tylmad, Maja; Tyndel, Mike; Typaldos, Dimitrios; Tyrvainen, Harri; Tzanakos, George; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Underwood, David; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urkovsky, Evgeny; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valderanis, Chrysostomos; Valenta, Jan; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Ferrer, Juan Antonio Valls; Van der Graaf, Harry; van der Kraaij, Erik; van der Poel, Egge; van der Ster, Daniel; Van Eijk, Bob; van Eldik, Niels; Van Gemmeren, Peter; van Kesteren, Zdenko; Van Vulpen, Ivo; Vandelli, Wainer; Vandoni, Giovanna; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Varela Rodriguez, Fernando; Vari, Riccardo; Varnes, Erich; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vassilakopoulos, Vassilios; Vazeille, Francois; Vegni, Guido; Veillet, Jean-Jacques; Vellidis, Constantine; Veloso, Filipe; Veness, Raymond; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Ventura, Silvia; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vest, Anja; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Viehhauser, Georg; Viel, Simon; Villa, Mauro; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Virchaux, Marc; Viret, Sebastien; Virzi, Joseph; Vitale, Antonio; Vitells, Ofer; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vlasak, Michal; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Matteo; Volpini, Giovanni; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorobiev, Alexander; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vovenko, Anatoly; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Anh, Tuan Vu; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Wolfgang; Wagner, Peter; Wahlen, Helmut; Wakabayashi, Jun; Walbersloh, Jorg; Walch, Shannon; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Waller, Peter; Wang, Chiho; Wang, Haichen; Wang, Jike; Wang, Jin; Wang, Joshua C.; Wang, Rui; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Jens; Weber, Marc; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wen, Mei; Wenaus, Torre; Wendler, Shanti; Weng, Zhili; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Wessels, Martin; Whalen, Kathleen; Wheeler-Ellis, Sarah Jane; Whitaker, Scott; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik, Liv Antje Mari; Wildauer, Andreas; Wildt, Martin Andre; Wilhelm, Ivan; Wilkens, Henric George; Will, Jonas Zacharias; Williams, Eric; Williams, Hugh; Willis, William; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winkelmann, Stefan; Winklmeier, Frank; Wittgen, Matthias; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wooden, Gemma; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wraight, Kenneth; Wright, Catherine; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wu, Yusheng; Wulf, Evan; Wunstorf, Renate; Wynne, Benjamin; Xaplanteris, Leonidas; Xella, Stefania; Xie, Song; Xie, Yigang; Xu, Chao; Xu, Da; Xu, Guofa; Yabsley, Bruce; Yamada, Miho; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Yi; Yang, Yi; Yang, Zhaoyu; Yanush, Serguei; Yao, Weiming; Yao, Yushu; Yasu, Yoshiji; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Riktura; Young, Charles; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yu, Jie; Yuan, Li; Yurkewicz, Adam; Zaets, Vassilli; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zalite, Youris; Zanello, Lucia; Zarzhitsky, Pavel; Zaytsev, Alexander; Zdrazil, Marian; Zeitnitz, Christian; Zeller, Michael; Zema, Pasquale Federico; Zemla, Andrzej; Zendler, Carolin; Zenin, Anton; Zenin, Oleg; Zenis, Tibor; Zenonos, Zenonas; Zenz, Seth; Zerwas, Dirk; Zevi Della Porta, Giovanni; Zhan, Zhichao; Zhang, Dongliang; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Xueyao; Zhang, Zhiqing; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zheng, Shuchen; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zieminska, Daria; Zilka, Branislav; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zitoun, Robert; Zivkovic, Lidija; Zmouchko, Viatcheslav; Zobernig, Georg; Zoccoli, Antonio; Zolnierowski, Yves; Zsenei, Andras; zur Nedden, Martin; Zutshi, Vishnu; Zwalinski, Lukasz
2013-07-16
This Letter reports on a first measurement of the inclusive W+jets cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC, with the ATLAS detector. Cross sections, in both the electron and muon decay modes of the W boson, are presented as a function of jet multiplicity and of the transverse momentum of the leading and next-to-leading jets in the event. Measurements are also presented of the ratio of cross sections sigma(W+ \\ge n) / sigma(W+ \\ge n-1) for inclusive jet multiplicities n=1-4. The results, based on an integrated luminosity of 1.3 pb-1, have been corrected for all known detector effects and are quoted in a limited and well-defined range of jet and lepton kinematics. The measured cross sections are compared to particle-level predictions based on perturbative QCD. Next-to-leading order calculations, studied here for n \\le 2, are found in good agreement with the data. Leading-order multiparton event generators, normalized to the NNLO total cross section, describe the ...
Trajectory Assessment and Modification Tools for Next Generation Air Traffic Management Operations
Brasil, Connie; Lee, Paul; Mainini, Matthew; Lee, Homola; Lee, Hwasoo; Prevot, Thomas; Smith, Nancy
2011-01-01
This paper reviews three Next Generation Air Transportation System (NextGen) based high fidelity air traffic control human-in-the-loop (HITL) simulations, with a focus on the expected requirement of enhanced automated trajectory assessment and modification tools to support future air traffic flow management (ATFM) planning positions. The simulations were conducted at the National Aeronautics and Space Administration (NASA) Ames Research Centers Airspace Operations Laboratory (AOL) in 2009 and 2010. The test airspace for all three simulations assumed the mid-term NextGenEn-Route high altitude environment utilizing high altitude sectors from the Kansas City and Memphis Air Route Traffic Control Centers. Trajectory assessment, modification and coordination decision support tools were developed at the AOL in order to perform future ATFM tasks. Overall tool usage results and user acceptability ratings were collected across three areas of NextGen operatoins to evaluate the tools. In addition to the usefulness and usability feedback, feasibility issues, benefits, and future requirements were also addressed. Overall, the tool sets were rated very useful and usable, and many elements of the tools received high scores and were used frequently and successfully. Tool utilization results in all three HITLs showed both user and system benefits including better airspace throughput, reduced controller workload, and highly effective communication protocols in both full Data Comm and mixed-equipage environments.
National Aeronautics and Space Administration — NextSTEP Phase I Hybrid Life Support Systems (HLSS) effort assessed options, performance, and reliability for various mission scenarios using contractor-developed...
To give the invisible child priority: children as next of kin in general practice.
Gullbrå, Frøydis; Smith-Sivertsen, Tone; Rortveit, Guri; Anderssen, Norman; Hafting, Marit
2014-03-01
To explore general practitioners' (GPs') experiences in helping children as next of kin of drug-addicted, mentally ill, or severely somatic ill adults. These children are at risk of long-term mental and somatic health problems. Qualitative focus-group study. Focus-group interviews were conducted in western Norway with a total of 27 GPs. Participants were encouraged to share stories from clinical encounters with parents who had one of the above-mentioned problems and to discuss the GP's role in relation to helping the patients' children. The GPs brought up many examples of how they could aid children as next of kin, including identifying children at risk, counselling the parents, and taking part in collaboration with other healthcare professionals and social workers. They also experienced some barriers in fulfilling their potential. There were time constraints, the GPs had their main focus on the patient present in a consultation, and the child was often outside the attention of the doctors, or the GPs could be afraid of hurting or losing their vulnerable patients, thus avoiding bringing up the patients' children as a subject for discussion. Norwegian GPs are in a good position to help children as next of kin and doctors make a great effort to support many of them. Still, support of these children by GPs often seems to depend not on careful consideration of what is best for the patient and the child in the long run, but more on short-term convenience reasons.
Mobility management techniques for the next-generation wireless networks
Sun, Junzhao; Howie, Douglas P.; Sauvola, Jaakko J.
2001-10-01
The tremendous demands from social market are pushing the booming development of mobile communications faster than ever before, leading to plenty of new advanced techniques emerging. With the converging of mobile and wireless communications with Internet services, the boundary between mobile personal telecommunications and wireless computer networks is disappearing. Wireless networks of the next generation need the support of all the advances on new architectures, standards, and protocols. Mobility management is an important issue in the area of mobile communications, which can be best solved at the network layer. One of the key features of the next generation wireless networks is all-IP infrastructure. This paper discusses the mobility management schemes for the next generation mobile networks through extending IP's functions with mobility support. A global hierarchical framework model for the mobility management of wireless networks is presented, in which the mobility management is divided into two complementary tasks: macro mobility and micro mobility. As the macro mobility solution, a basic principle of Mobile IP is introduced, together with the optimal schemes and the advances in IPv6. The disadvantages of the Mobile IP on solving the micro mobility problem are analyzed, on the basis of which three main proposals are discussed as the micro mobility solutions for mobile communications, including Hierarchical Mobile IP (HMIP), Cellular IP, and Handoff-Aware Wireless Access Internet Infrastructure (HAWAII). A unified model is also described in which the different micro mobility solutions can coexist simultaneously in mobile networks.
Research and Development Supporting a Next Generation Germanium Double Beta Decay Experiment
Rielage, Keith; Elliott, Steve; Chu, Pinghan; Goett, Johnny; Massarczyk, Ralph; Xu, Wenqin
2015-10-01
To improve the search for neutrinoless double beta decay, the next-generation experiments will increase in source mass and continue to reduce backgrounds in the region of interest. A promising technology for the next generation experiment is large arrays of Germanium p-type point contact detectors enriched in 76-Ge. The experience, expertise and lessons learned from the MAJORANA DEMONSTRATOR and GERDA experiments naturally lead to a number of research and development activities that will be useful in guiding a future experiment utilizing Germanium. We will discuss some R&D activities including a hybrid cryostat design, background reduction in cabling, connectors and electronics, and modifications to reduce assembly time. We acknowledge the support of the U.S. Department of Energy through the LANL/LDRD Program.
Big Bang Day: 5 Particles - 5. The Next Particle
Franck Close
2008-01-01
Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.
Next-Generation Mitogenomics: A Comparison of Approaches Applied to Caecilian Amphibian Phylogeny
Maddock, Simon T.; Briscoe, Andrew G.; Wilkinson, Mark; Waeschenbach, Andrea; San Mauro, Diego; Day, Julia J.; Littlewood, D. Tim J.; Foster, Peter G.; Nussbaum, Ronald A.; Gower, David J.
2016-01-01
Mitochondrial genome (mitogenome) sequences are being generated with increasing speed due to the advances of next-generation sequencing (NGS) technology and associated analytical tools. However, detailed comparisons to explore the utility of alternative NGS approaches applied to the same taxa have not been undertaken. We compared a ‘traditional’ Sanger sequencing method with two NGS approaches (shotgun sequencing and non-indexed, multiplex amplicon sequencing) on four different sequencing pla...
After the Big Bang: What's Next in Design Education? Time to Relax?
Fleischmann, Katja
2015-01-01
The article "Big Bang technology: What's next in design education, radical innovation or incremental change?" (Fleischmann, 2013) appeared in the "Journal of Learning Design" Volume 6, Issue 3 in 2013. Two years on, Associate Professor Fleischmann reflects upon her original article within this article. Although it has only been…
Physical Configuration of the Next Generation Home Network
Terada, Shohei; Kakishima, Yu; Hanawa, Dai; Oguchi, Kimio
The number of broadband users is rapidly increasing worldwide. Japan already has over 10 million FTTH users. Another trend is the rapid digitalization of home electrical equipment e. g. digital cameras and hard disc recorders. These trends will encourage the emergence of the next generation home network. In this paper, we introduce the next generation home network image and describe the five domains into which home devices can be classified. We then clarify the optimum medium with which to configure the network given the requirements imposed by the home environment. Wiring cable lengths for three network topologies are calculated. The results gained from the next generation home network implemented on the first phase testbed are shown. Finally, our conclusions are given.
The quark induced Mueller-Tang jet impact factor at next-to-leading order
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.
A Hybrid Strategy for the Lattice Evaluation of the Leading Order Hadronic Contribution to (g - 2)μ
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.
Three-nucleon scattering by using chiral perturbation theory potential
International Nuclear Information System (INIS)
Kamata, Hiroyuki
2003-01-01
Three-nucleon scattering problems are studied by using two-nucleon and three-nucleon potentials derived from chiral perturbation theory. The three-nucleon term is shown to appear in the effective potential of the rank of next-to-next-to-leading order (NNLO). New three-nucleon forces are taken into consideration in addition to the conventional Fujita-Miyazawa (FM) type three-nucleon potential. Two-nucleon potential of the chiral perturbation theory is as precise as the conventional ones in low energy region. The FM type three-nucleon force which explains Sagara discrepancy in high energy region is introduced automatically. Concerning the Ay puzzle, the results seems to behave as if the puzzle has been solved at the level of NLO, but at the NNLO (without three-nucleon force) level the result is similar to the cases of conventional potential indicating the need of three-nucleon force. In contrast to the FM type three-nucleon force, five free parameters exist in the new D and E type three-nucleon forces introduced by the NNLO, but they are reduced to two independent parameters by antisymmetrization, which are found to be sensitive to the coupling energy of tritons and to the nd scattering length (spin doublet state). Parameters determined from them cannot give satisfactory answer to the A y puzzle. It seems, however, too hasty to conclude that A y puzzle cannot be solved by the chiral perturbation theory. (S. Funahashi)
Next of kin’s experiences of sudden and unexpected death from stroke - a study of narratives
2013-01-01
Background Death always evokes feelings in those close to the afflicted person. When death comes suddenly the time for preparation is minimal and the next of kin have to cope with the situation despite their own sorrow. The suddenness is found to be stressful for the next of kin and communication both with healthcare professionals and information about what has happened has been found helpful. The aim of this study was to illuminate the experiences of next of kin from the sudden and unexpected death of a relative from acute stroke. Methods Data was collected over a 12-month period in 2009–2010. Twelve next of kin of patients cared for in stroke units who died suddenly and unexpectedly from stroke were interviewed using a narrative method. The narratives were analyzed using narrative thematic analysis. Results Three themes emerged showing facets of next of kin’s experiences of a relative’s sudden and unexpected death from stroke: Divided feelings about the sudden and unexpected death; Perception of time and directed attention when keeping vigil; Contradictions and arbitrary memories when searching for understanding. Conclusions To have to live in the aftermath of severe stroke is absolute horror in people’s imagination and death is seen as the lesser of two evils. The sudden and unexpected death totally pervades the next of kin’s life, directs their attention to the dying person and even causes them to forget themselves and their own needs, and leads to difficulties in information intake. It is a challenge for the healthcare professionals to be able to identify the individual needs of the next of kin in this situation. PMID:23590246
International Nuclear Information System (INIS)
Tanaka, Toshihiko; Fukuda, Toshihiko; Usui, Shuji
2001-01-01
Development of LWR for power generation in Japan has been intended to upgrade its reliability, safety, operability, maintenance and economy as well as to increase its capacity in order, since nuclear power generation for commercial use was begun on 1970, to steadily increase its generation power. And, in Japan, ABWR (advanced BWR) of the most promising LWR in the world, was already used actually and APWR (advanced PWR) with the largest output in the world is also at a step of its actual use. And, development of the APWR in Japan was begun on 1980s, and is at a step of plan on construction of its first machine at early of this century. However, by large change of social affairs, economy of nuclear power generation is extremely required, to be positioned at an APWR improved development reactor promoted by collaboration of five PWR generation companies and the Mitsubishi Electric Co., Ltd. Therefore, on its development, investigation on effect of change in social affairs on nuclear power stations was at first carried out, to establish a design requirement for the next generation PWR. Here were described on outline, reactor core design, safety concept, and safety evaluation of APWR+ and development of an innovative PWR. (G.K.)
Desktop Video: Multi-Media on the NeXT Computer.
Stammen, Ronald M.; Richardson, Jolene
A new course, Independent Study Research and Writing via Telecommunications, is being developed by the Division of Independent Study (DIS) of the North Dakota Department of Public Instruction to teach telepublishing skills utilizing the NeXT telecommunicating (interpersonal computing) techniques, i.e., NeXT Mail. This multimedia electronic-mail…
High-Luminosity LHC moves to the next phase
2015-01-01
This week saw several meetings vital for the medium-term future of CERN. From Monday to Wednesday, the Resource Review Board, RRB, that oversees resource allocation in the LHC experiments, had a series of meetings. Thursday then saw the close-out meeting for the Hi-Lumi LHC design study, which was partially funded by the European Commission. These meetings focused on the High Luminosity upgrade for the LHC, which responds to the top priority of the European Strategy for Particle Physics adopted by the CERN Council in 2013. This upgrade will transform the LHC into a facility for precision studies, the logical next step for the high-energy frontier of particle physics. It is a challenging upgrade, both for the LHC and the detectors. The LHC is already the highest luminosity hadron collider ever constructed, generating up to a billion collisions per second at the heart of the detectors. The High Luminosity upgrade will see that number rise by a factor of five from 2025. For the detectors...
High Throughput Line-of-Sight MIMO Systems for Next Generation Backhaul Applications
Song, Xiaohang; Cvetkovski, Darko; Hälsig, Tim; Rave, Wolfgang; Fettweis, Gerhard; Grass, Eckhard; Lankl, Berthold
2017-09-01
The evolution to ultra-dense next generation networks requires a massive increase in throughput and deployment flexibility. Therefore, novel wireless backhaul solutions that can support these demands are needed. In this work we present an approach for a millimeter wave line-of-sight MIMO backhaul design, targeting transmission rates in the order of 100 Gbit/s. We provide theoretical foundations for the concept showcasing its potential, which are confirmed through channel measurements. Furthermore, we provide insights into the system design with respect to antenna array setup, baseband processing, synchronization, and channel equalization. Implementation in a 60 GHz demonstrator setup proves the feasibility of the system concept for high throughput backhauling in next generation networks.
Nucleic acid reactivity : challenges for next-generation semiempirical quantum models
Huang, Ming; Giese, Timothy J.; York, Darrin M.
2015-01-01
Semiempirical quantum models are routinely used to study mechanisms of RNA catalysis and phosphoryl transfer reactions using combined quantum mechanical/molecular mechanical methods. Herein, we provide a broad assessment of the performance of existing semiempirical quantum models to describe nucleic acid structure and reactivity in order to quantify their limitations and guide the development of next-generation quantum models with improved accuracy. Neglect of diatomic diffierential overlap (...
Energy Technology Data Exchange (ETDEWEB)
none,
2008-03-01
This roadmap to “Next Generation Hydrocarbon Biorefineries” outlines a number of novel process pathways for biofuels production based on sound scientific and engineering proofs of concept demonstrated in laboratories around the world. This report was based on the workshop of the same name held June 25-26, 2007 in Washington, DC.
A Relational, Indirect, Meso-Level Approach to CSCL Design in the next Decade
Jones, Chris; Dirckinck-Holmfeld, Lone; Lindstrom, Berner
2006-01-01
This paper reviews some foundational issues that we believe will affect the progress of CSCL over the next ten years. In particular, we examine the terms "technology", "affordance", and "infrastructure" and we propose a relational approach to their use in CSCL. Following a consideration of networks, space, and trust as conditions of productive…
Miller, Stephen P.
2014-01-01
The multigenerational survival rate for family-owned businesses is not good. Lack of a shared vision for the family enterprise and weak next-generation leadership are often cited as two of the leading reasons for the failure of family firms to successfully transition from one generation of family ownership to the next. The climate of the business-owning family has also been suggested as important to the performance of the family enterprise. Despite these commonly held tenets, there is a la...