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Author Bordes, J.; Dominguez, C.A.; Moodley, P.; Peñarrocha, J.; Schilcher, K.
Title Chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes-Renner relation Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 064 - 16pp
Keywords QCD Phenomenology
Abstract The next to leading order chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes- Renner (GMOR) relation are obtained using the pseudoscalar correlator to five-loop order in perturbative QCD, together with new finite energy sum rules (FESR) incorporating polynomial, Legendre type, integration kernels. The purpose of these kernels is to suppress hadronic contributions in the region where they are least known. This reduces considerably the systematic uncertainties arising from the lack of direct experimental information on the hadronic resonance spectral function. Three different methods are used to compute the FESR contour integral in the complex energy (squared) s-plane, i.e. Fixed Order Perturbation Theory, Contour Improved Perturbation Theory, and a fixed renormalization scale scheme. We obtain for the corrections to the GMOR relation, delta(pi), the value delta(pi) = (6.2 +/- 1.6)%. This result is substantially more accurate than previous determinations based on QCD sum rules; it is also more reliable as it is basically free of systematic uncertainties. It implies a light quark condensate < 0 vertical bar(u) over baru vertical bar 0 > similar or equal to < 0 vertical bar(d) over bard vertical bar 0 > < 0 vertical bar(q) over barq vertical bar 0 >vertical bar(2GeV) = (-267 +/- 5MeV)(3). As a byproduct, the chiral perturbation theory (unphysical) low energy constant H-2(r) is predicted to be H-2(r)(nu(X) = M-p) = -(5.1 +/- 1.8) x10(-3), or H-2(r) (nu(X) = M-eta) = -(5.7 +/- 2.0) x10(-3).
Address (up) [Bordes, J.; Penarrocha, J.] Univ Valencia, Dept Fis Teor, CSICE, E-46100 Burjassot, Spain, Email: bordes@uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes ISI:000278250000044 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 434
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Author Bordes, J.; Dominguez, C.A.; Moodley, P.; Peñarrocha, J.; Schilcher, K.
Title Corrections to the SU(3) x SU(3) Gell-Mann-Oakes-Renner relation and chiral couplings L-8(r) and H-r(2) Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 102 - 11pp
Keywords Sum Rules; QCD
Abstract Next to leading order corrections to the SU(3) x SU(3) Gell-Mann-OakesRenner relation (GMOR) are obtained using weighted QCD Finite Energy Sum Rules (FESR) involving the pseudoscalar current correlator. Two types of integration kernels in the FESR are used to suppress the contribution of the kaon radial excitations to the hadronic spectral function, one with local and the other with global constraints. The result for the pseudoscalar current correlator at zero momentum is psi(5)(0) = (2.8 +/- 0.3) x 10(-3) GeV4, leading to the chiral corrections to GMOR: delta(K) = (55 +/- 5)%. The resulting uncertainties are mostly due to variations in the upper limit of integration in the FESR, within the stability regions, and to a much lesser extent due to the uncertainties in the strong coupling and the strange quark mass. Higher order quark mass corrections, vacuum condensates, and the hadronic resonance sector play a negligible role in this determination. These results confirm an independent determination from chiral perturbation theory giving also very large corrections, i.e. roughly an order of magnitude larger than the corresponding corrections in chiral SU(2) x SU(2). Combining these results with our previous determination of the corrections to GMOR in chiral SU(2) x SU(2), delta(pi), we are able to determine two low energy constants of chiral perturbation theory, i.e. L-8(r) = (1.0 +/- 0.3) x 10(-3), and H-2(r) = -(4.7 +/- 0.6) x 10(-3), both at the scale of the rho-meson mass.
Address (up) [Bordes, J.; Penarrocha, J.] Univ Valencia, Dept Fis Teor, Valencia, Spain, Email: Jose.M.Bordes@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000310851600031 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1257
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Author Buchta, S.; Chachamis, G.; Draggiotis, P.; Malamos, I.; Rodrigo, G.
Title On the singular behaviour of scattering amplitudes in quantum field theory Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 014 - 13pp
Keywords QCD Phenomenology; NLO Computations
Abstract We analyse the singular behaviour of one-loop integrals and scattering amplitudes in the framework of the loop-tree duality approach. We show that there is a partial cancellation of singularities at the loop integrand level among the different components of the corresponding dual representation that can be interpreted in terms of causality. The remaining threshold and infrared singularities are restricted to a finite region of the loop momentum space, which is of the size of the external momenta and can be mapped to the phase-space of real corrections to cancel the soft and collinear divergences.
Address (up) [Buchta, Sebastian; Chachamis, Grigorios; Malamos, Ioannis; Rodrigo, German] Univ Valencia, CSIC, Inst Fis Corpuscular, E-46980 Valencia, Spain, Email: sbuchta@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000344788000003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2065
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Author Campanario, F.; Kubocz, M.
Title Higgs boson CP-properties of the gluonic contributions in Higgs plus three jet production via gluon fusion at the LHC Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 173 - 16pp
Keywords QCD Phenomenology; Monte Carlo Simulations
Abstract in high energy hadronic collisions, a general CP-violating Higgs boson Phi with accompanying jets can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. In this article, we study the dominant sub-channel gg -> ggg Phi of the gluon fusion production process with triple real emission corrections at order alpha(5)(s). We go beyond the heavy top-quark approximation and include the full mass dependence of the top- and bottom-quark contributions. Furthermore, in a specific model we demonstrate the features of our program and show the impact of bottom-quark loop contributions in combination with large values of tan beta on differential distributions sensitive to CP-rneasurements of the Higgs boson.
Address (up) [Campanario, Francisco] Univ Valencia CSIC, IFIC, Div Theory, E-46100 Valencia, Spain, Email: francisco.campanario@ific.uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000344652800003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2007
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Author Carrasco, N.; Ciuchini, M.; Dimopoulos, P.; Frezzotti, R.; Gimenez, V.; Herdoiza, G.; Lubicz, V.; Michael, C.; Picca, E.; Rossi, G.C.; Sanfilippo, F.; Shindler, A.; Silvestrini, L.; Simula, S.; Tarantino, C.
Title B-physics from N-f=2 tmQCD: the Standard Model and beyond Type Journal Article
Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 016 - 52pp
Keywords Lattice QCD; B-Physics; Beyond Standard Model; Quark Masses and SM Parameters
Abstract We present a lattice QCD computation of the b-quark mass, the B and B-s decay constants, the B-mixing bag parameters for the full four-fermion operator basis as well as determinations for xi and f(Bq) root B-i((q)) extrapolated to the continuum limit and to the physical pion mass. We used N-f = 2 twisted mass Wilson fermions at four values of the lattice spacing with pion masses ranging from 280 to 500 MeV. Extrapolation in the heavy quark mass from the charm to the bottom quark region has been carried out on ratios of physical quantities computed at nearby quark masses, exploiting the fact that they have an exactly known infinite mass limit. Our results are m(b)(m(b), (MS) over bar) = 4.29(12) GeV, f(Bs) = 228(8) MeV, f(B) = 189(8) MeV and f(Bs)/f(B) = 1.206(24). Moreover with our results for the bag-parameters we find xi = 1.225(31), B-1((s))/B-1((d)) = 1.01(2), f (Bd) root(B) over cap ((d))(1) = 216(10) MeV and integral Bs root(B) over cap ((s))(1) = 262(10) MeV. We also computed the bag parameters for the complete basis of the four-fermion operators which are required in beyond the SM theories. By using these results for the bag parameters we are able to provide a refined Unitarity Triangle analysis in the presence of New Physics, improving the bounds coming from B-(s) -(B) over bar ((s)) mixing.
Address (up) [Carrasco, N.; Gimenez, V.] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Valencia, Spain, Email: nuria.carrasco@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000347824200001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2086
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