Records |
Author |
Ayala, C.; Cvetic, G. |
Title |
anQCD: Fortran programs for couplings at complex momenta in various analytic QCD models |
Type |
Journal Article |
Year |
2016 |
Publication |
Computer Physics Communications |
Abbreviated Journal |
Comput. Phys. Commun. |
Volume |
199 |
Issue |
|
Pages |
114-117 |
Keywords |
Analytic (holomorphic) QCD coupling; Fractional Analytic Perturbation Theory; Two-delta analytic QCD model; Massive Perturbation Theory; Perturbative QCD; Renormalization group evolution |
Abstract |
We provide three Fortran programs which evaluate the QCD analytic (holomorphic) couplings A(v)(Q(2)) for complex or real squared momenta Q(2). These couplings are holomorphic analogs of the powers a(Q(2))(v) of the underlying perturbative QCD (pQCD) coupling a(Q(2)) equivalent to alpha(s)(Q(2))/pi, in three analytic QCD models (anQCD): Fractional Analytic Perturbation Theory (FAPT), Two-delta analytic QCD (2 delta anQCD), and Massive Perturbation Theory (MPT). The index v can be noninteger. The provided programs do basically the same job as the Mathematica package anQCD.m published by us previously (Ayala and Cvetic, 2015), but are now written in Fortran. Program summary Program title: AanQCDext Catalogue identifier: AEYKv10 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEYICv1_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.: 12105 No. of bytes in distributed program, including test data, etc.: 98822 Distribution format: tar.gz Programming language: Fortran. Computer: Any work-station or PC where Fortran 95/200312008 (gfortran) is running. Operating system: Operating system Linux (Ubuntu and Scientific Linux), Windows (in all cases using gfortran). Classification: 11.1, 11.5. Nature of problem: Calculation of values of the running analytic couplings A(v)(Q(2); N-f) for general complex squared momenta Q(2) equivalent to -q(2), in three analytic QCD models, where A(v)(Q(2); N-f) is the analytic (holomorphic) analog of the power (alpha(s)(Q(2); N-f)/pi)(v). Here, A(v)(Q(2); N-f) is a holomorphic function in the Q(2) complex plane, with the exception of the negative semiaxis (-infinity, -M-thr(2)], reflecting the analyticity properties of the spacelike renormalization invariant quantities D(Q(2)) in QCD. In contrast, the perturbative QCD power (alpha(s)(Q(2); N-f)/pi)(v) has singularities even outside the negative semiaxis (Landau ghosts). The three considered models are: Analytic Perturbation theory (APT); Two-delta analytic QCD (2 delta anQCD); Massive Perturbation Theory (MPT). We refer to Ref. [1] for more details and literature. Solution method: The Fortran programs for FAPT and 2 delta anQCD models contain routines and functions needed to perform two-dimensional numerical integrations involving the spectral function, in order to evaluate A(v)(Q(2)) couplings. In MPT model, one-dimensional numerical integration involving A(1)(Q(2)) is sufficient to evaluate any A(v)(Q(2)) coupling. Restrictions: For unphysical choices of the input parameters the results are meaningless. When Q(2) is close to the cut region of the couplings (Q(2) real negative), the calculations can take more time and can have less precision. Running time: For evaluation of a set of about 10 related couplings, the times vary in the range t similar to 10(1)-10(2) s. MPT requires less time, t similar to 1-10(1) s. References: [1] C. Ayala and G. Cvetic, anQCD: a Mathematica package for calculations in general analytic QCD models, Comput. Phys. Commun. 190 (2015) 182. |
Address |
[Ayala, Cesar] Univ Valencia, Dept Theoret Phys, E-46100 Valencia, Spain, Email: c.ayala86@gmail.com; |
Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0010-4655 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000367113200012 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
2501 |
Permanent link to this record |
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Author |
Ayala, C.; Cvetic, G.; Kogerler, R. |
Title |
Lattice-motivated holomorphic nearly perturbative QCD |
Type |
Journal Article |
Year |
2017 |
Publication |
Journal of Physics G |
Abbreviated Journal |
J. Phys. G |
Volume |
44 |
Issue |
7 |
Pages |
075001 - 30pp |
Keywords |
perturbative QCD; lattice QCD; QCD phenomenology; resummation |
Abstract |
Newer lattice results indicate that, in the Landau gauge at low spacelike momenta, the gluon propagator and the ghost dressing function are finite non-zero. This leads to a definition of the QCD running coupling, in a specific scheme, that goes to zero at low spacelike momenta. We construct a running coupling which fulfills these conditions, and at the same time reproduces to a high precision the perturbative behavior at high momenta. The coupling is constructed in such a way that it reflects qualitatively correctly the holomorphic (analytic) behavior of spacelike observables in the complex plane of the squared momenta, as dictated by the general principles of quantum field theories. Further, we require the coupling to reproduce correctly the nonstrange semihadronic decay rate of tau lepton which is the best measured low-momentum QCD observable with small higher-twist effects. Subsequent application of the Borel sum rules to the V + A spectral functions of tau lepton decays, as measured by OPAL Collaboration, determines the values of the gluon condensate and of the V + A six-dimensional condensate, and reproduces the data to a significantly higher precision than the usual (MS) over bar running coupling. |
Address |
[Ayala, Cesar] Univ Valencia, Dept Theoret Phys, E-46100 Valencia, Spain, Email: Gorazd.Cvetic@usm.cl |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0954-3899 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000402509800001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3167 |
Permanent link to this record |
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Author |
Driencourt-Mangin, F.; Rodrigo, G.; Sborlini, G.F.R.; Torres Bobadilla, W.J. |
Title |
Universal four-dimensional representation of H -> gamma gamma at two loops through the Loop-Tree Duality |
Type |
Journal Article |
Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
02 |
Issue |
2 |
Pages |
143 - 39pp |
Keywords |
Scattering Amplitudes; Higgs Physics; Perturbative QCD |
Abstract |
We extend useful properties of the H unintegrated dual amplitudes from one- to two-loop level, using the Loop-Tree Duality formalism. In particular, we show that the universality of the functional form regardless of the nature of the internal particle still holds at this order. We also present an algorithmic way to renormalise two-loop amplitudes, by locally cancelling the ultraviolet singularities at integrand level, thus allowing a full four-dimensional numerical implementation of the method. Our results are compared with analytic expressions already available in the literature, finding a perfect numerical agreement. The success of this computation plays a crucial role for the development of a fully local four-dimensional framework to compute physical observables at Next-to-Next-to Leading order and beyond. |
Address |
[Driencourt-Mangin, Felix; Rodrigo, German; Sborlini, German F. R.; Bobadilla, William J. Torres] Univ Valencia, CSIC, IFIC, Apt Correus 22085, E-46071 Valencia, Spain, Email: felix.dm@ific.uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000459485300005 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3922 |
Permanent link to this record |
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Author |
Aguilera-Verdugo, J.J.; Driencourt-Mangin, F.; Plenter, J.; Ramirez-Uribe, S.; Rodrigo, G.; Sborlini, G.F.R.; Torres Bobadilla, W.J.; Tracz, S. |
Title |
Causality, unitarity thresholds, anomalous thresholds and infrared singularities from the loop-tree duality at higher orders |
Type |
Journal Article |
Year |
2019 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
12 |
Issue |
12 |
Pages |
163 - 12pp |
Keywords |
Duality in Gauge Field Theories; Perturbative QCD; Scattering Amplitudes |
Abstract |
We present the first comprehensive analysis of the unitarity thresholds and anomalous thresholds of scattering amplitudes at two loops and beyond based on the loop- tree duality, and show how non-causal unphysical thresholds are locally cancelled in an efficient way when the forest of all the dual on-shell cuts is considered as one. We also prove that soft and collinear singularities at two loops and beyond are restricted to a compact region of the loop three-momenta, which is a necessary condition for implementing a local cancellation of loop infrared singularities with the ones appearing in real emission; without relying on a subtraction formalism. |
Address |
[Aguilera-Verdugo, J. Jesus; Driencourt-Mangin, Felix; Plenter, Judith; Ramirez-Uribe, Selomit; Rodrigo, German; Sborlini, German F. R.; Torres Bobadilla, William J.; Tracz, Szymon] Univ Valencia, Consejo Super Invest Cient, Inst Fis Corpuscular, Parc Cient, E-46980 Valencia, Spain, Email: jesus.aguilera@ific.uv.es; |
Corporate Author |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000513535500003 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4288 |
Permanent link to this record |
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Author |
Baglio, J.; Campanario, F.; Glaus, S.; Muhlleitner, M.; Ronca, J.; Spira, M.; Streicher, J. |
Title |
Higgs-pair production via gluon fusion at hadron colliders: NLO QCD corrections |
Type |
Journal Article |
Year |
2020 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
Volume |
04 |
Issue |
4 |
Pages |
181-50pp |
Keywords |
Higgs Physics; Perturbative QCD |
Abstract |
Higgs-pair production via gluon fusion is the dominant production mechanism of Higgs-boson pairs at hadron colliders. In this work, we present details of our numerical determination of the full next-to-leading-order (NLO) QCD corrections to the leading top-quark loops. Since gluon fusion is a loop-induced process at leading order, the NLO calculation requires the calculation of massive two-loop diagrams with up to four different mass/energy scales involved. With the current methods, this can only be done numerically, if no approximations are used. We discuss the setup and details of our numerical integration. This will be followed by a phenomenological analysis of the NLO corrections and their impact on the total cross section and the invariant Higgs-pair mass distribution. The last part of our work will be devoted to the determination of the residual theoretical uncertainties with special emphasis on the uncertainties originating from the scheme and scale dependence of the (virtual) top mass. The impact of the trilinear Higgs-coupling variation on the total cross section will be discussed. |
Address |
[Baglio, Julien] CERN, Theoret Phys Dept, CH-1211 Geneva 23, Switzerland, Email: julien.baglio@cern.ch; |
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Thesis |
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Publisher |
Springer |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1029-8479 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000531394200002 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
4391 |
Permanent link to this record |