Download or read book Two Loop Helicity Amplitudes for Quark Quark Scattering in QCD and Gluino Gluino Scattering in Supersymmetric Yang Mills Theory written by Abilio De Freitas and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two loop Helicity Amplitudes for Quark gluon Scattering in QCD and Gluino gluon Scattering in Supersymmetric Yang Mills Theory written by Zvi Bern and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two Loop Helicity Amplitudes for Quark Gluon Scattering in QCD and Supersymmetric Yang Mills Theory written by and published by . This book was released on 2003 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the two-loop QCD helicity amplitudes for quark-gluon scattering, and for quark-antiquark annihilation into two gluons. These amplitudes are relevant for next-to-next-to-leading order corrections to (polarized) jet production at hadron colliders. We give the results in the 't Hooft-Veltman and four-dimensional helicity (FDH) variants of dimensional regularization. The transition rules for converting the amplitudes between the different variants are much more intricate than for the previously discussed case of gluon-gluon scattering. Summing our two-loop expressions over helicities and colors, and converting to conventional dimensional regularization, gives results in complete agreement with those of Anastasiou, Glover, Oleari and Tejeda-Yeomans. We describe the amplitudes for 2 --> 2 scattering in pure N = 1 supersymmetric Yang-Mills theory, obtained from the QCD amplitudes by modifying the color representation and multiplicities, and verify supersymmetry Ward identities in the FDH scheme.
Download or read book Scattering Amplitudes in Gauge Theory and Gravity written by Henriette Elvang and published by Cambridge University Press. This book was released on 2015-02-05 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive, pedagogical introduction to scattering amplitudes in gauge theory and gravity for graduate students.
Download or read book Introduction to Soft Collinear Effective Theory written by Thomas Becher and published by Springer. This book was released on 2015-03-04 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Among resummation techniques for perturbative QCD in the context of collider and flavor physics, soft-collinear effective theory (SCET) has emerged as both a powerful and versatile tool, having been applied to a large variety of processes, from B-meson decays to jet production at the LHC. This book provides a concise, pedagogical introduction to this technique. It discusses the expansion of Feynman diagrams around the high-energy limit, followed by the explicit construction of the effective Lagrangian - first for a scalar theory, then for QCD. The underlying concepts are illustrated with the quark vector form factor at large momentum transfer, and the formalism is applied to compute soft-gluon resummation and to perform transverse-momentum resummation for the Drell-Yan process utilizing renormalization group evolution in SCET. Finally, the infrared structure of n-point gauge-theory amplitudes is analyzed by relating them to effective-theory operators. This text is suitable for graduate students and non-specialist researchers alike as it requires only basic knowledge of perturbative QCD.
Download or read book 50 Years of Yang Mills Theory written by G. 't Hooft and published by World Scientific. This book was released on 2005 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Roman Catholic faith has inspired some of the world's greatest creative works and has been a powerful force in history from the Roman Empire to the present. Catholic writers reflect their heritage in their works, and generations of readers have continued to appreciate the Catholic literary tradition. Many works by Catholic writers hold a high place in the literary canon and have exerted a tremendous cultural and political influence. Still others continue to be widely read by contemporary readers and quietly shape modern society. Some works, too, reflect the conflicts of the Catholic Church in the 21st century and capture the struggles of individual Catholics in a secular society. This encyclopedia covers the vast riches of the Catholic literary tradition from its origins to the present day. Included are substantial entries on more than 70 major works from around the world. A special effort has been made to cover women writers and writers of diverse racial and ethnic backgrounds, whose works reflect the many dimensions of the Catholic experience. The encyclopedia provides entries on such writers and works as St. Augustine's Confessions, Catherine of Siena's Dialogue, Dante's The Divine Comedy, Sandra Cisneros' The House on Mango Street, J.R.R. Tolkien's The Lord of the Rings, and Muriel Spark's Memento Mori. Each entry is written by an expert contributor and includes a biography of the writer, a plot summary of a major work, an extended critical discussion, an overview of the work's critical reception, and a selected bibliography. The entries give detailed attention to particular works and explore their relation to Catholic thought. The encyclopedia concludes with a selected, general bibliography.
Download or read book Two Loop Helicity Amplitudes for Gluon Gluon Scattering in QCD and Supersymmetric Yang Mills Theory written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the two-loop helicity amplitudes for the scattering of two gluons into two gluons in QCD, which are relevant for next-to-next-to-leading order corrections to jet production at hadron colliders. We give the results in the 't Hooft-Veltman and four-dimensional helicity variants of dimensional regularization. Summing our expressions over helicities and colors, and converting to conventional dimensional regularization, gives results in complete agreement with those of Glover, Oleari and Tejeda-Yeomans. We also present the amplitudes for 2 --> 2 scattering in pure N = 1 supersymmetric Yang-Mills theory.
Download or read book Loops and Legs in Quantum Field Theory written by Johannes Blümlein and published by . This book was released on 2004 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Frontiers in Particle Physics written by Jean-Marc Gérard and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of a NATO ASI held in Cargese, France, August 1-13, 1994
Download or read book Advances in Theoretical and Mathematical Physics written by and published by . This book was released on 2004 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mathematical Reviews written by and published by . This book was released on 2004 with total page 1574 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heavy Quark Production in Massless Quark Scattering at Two Loops in QCD written by Michal Czakon and published by . This book was released on 2007 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Two loop Four gluon Helicity Amplitude in QCD written by and published by . This book was released on 2000 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors present the two-loop pure gauge contribution to the gluon-gluon scattering amplitude with maximal helicity violation. The construction of the amplitude does not rely directly on Feynman diagrams, but instead uses its analytic properties 4--2[epsilon] dimensions. The authors evaluate the loop integrals appearing in the amplitude through order([epsilon]°)in terms of polylogarithms.
Download or read book Topics in Scattering Amplitudes in Gauge and Gravity Theories written by Scott Tadashi Davies and published by . This book was released on 2013 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: In Chapter 1, we combine the six-dimensional helicity formalism of Cheung and O'Connell with D-dimensional generalized unitarity to obtain a formalism for computing one-loop amplitudes in dimensionally regularized Quantum Chromodynamics (QCD). We illustrate the procedure through various examples, including a next-to-leading order QCD correction to a Higgs process in the large top-quark mass limit. In Chapter 2, we review the duality between color and kinematics and give our general procedure for extracting ultraviolet divergences in preparation for the following chapters. In Chapter 3, we construct a form of the one-loop four-point amplitude in pure Yang-Mills, valid in any dimension, that makes the conjectured duality between color and kinematics manifest. We also describe a two-loop example. We then use these to obtain gravity integrands for a theory containing a graviton, dilaton and antisymmetric tensor, with which we study the ultraviolet structure at one and two loops. In Chapters 4-6, we use the duality between color and kinematics to study the ultraviolet properties of half-maximal supergravity with and without matter. At one and two loops, we link cancellations to forbidden color tensors in pure Yang-Mills. Principal results for the pure theory (without matter) are the finiteness at two loops in D=5 and at three loops in D=4. These results are unexpected based on standard symmetry arguments. We also show that both cases are divergent when matter is included, which contradicts the conjectured existence of a superspace formalism used to explain the finite results in the pure theory.
Download or read book The Last of the Finite Loop Amplitudes in QCD written by and published by . This book was released on 2005 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: We use on-shell recursion relations to determine the one-loop QCD scattering amplitudes with a massless external quark pair and an arbitrary number (n - 2) of positive-helicity gluons. These amplitudes are the last of the unknown infrared- and ultraviolet-finite loop amplitudes of QCD. The recursion relations are similar to ones applied at tree level, but contain new non-trivial features corresponding to poles present for complex momentum arguments but absent for real momenta. We present the relations and the compact solutions to them, valid for all n. We also present compact forms for the previously-computed one-loop n-gluon amplitudes with a single negative helicity and the rest positive helicity.
Download or read book Two Loop Gluon to Gluon Gluon Splitting Amplitudes in QCD written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Splitting amplitudes are universal functions governing the collinear behavior of scattering amplitudes for massless particles. We compute the two-loop g [yields] gg splitting amplitudes in QCD, N = 1, and N = 4 super-Yang-Mills theories, which describe the limits of two-loop n-point amplitudes where two gluon momenta become parallel. They also represent an ingredient in a direct x-space computation of DGLAP evolution kernels at next-to-next-to-leading order. To obtain the splitting amplitudes, we use the unitarity sewing method. In contrast to the usual light-cone gauge treatment, our calculation does not rely on the principal-value or Mandelstam-Leibbrandt prescriptions, even though the loop integrals contain some of the denominators typically encountered in light-cone gauge. We reduce the integrals to a set of 13 master integrals using integration-by-parts and Lorentz invariance identities. The master integrals are computed with the aid of differential equations in the splitting momentum fraction z. The [epsilon]-poles of the splitting amplitudes are consistent with a formula due to Catani for the infrared singularities of two-loop scattering amplitudes. This consistency essentially provides an inductive proof of Catani's formula, as well as an ansatz for previously-unknown 1/[epsilon] pole terms having non-trivial color structure. Finite terms in the splitting amplitudes determine the collinear behavior of finite remainders in this formula.
Download or read book Two loop Helicity Amplitudes in QCD written by Lee W. Garland and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
