English
Related papers

Related papers: Calculation of Universal Amplitude Ratios in three…

200 papers

We study numerically the zero temperature Random Field Ising Model on cubic lattices of various linear sizes $ 6 \le L \le 90 $ in three dimensions with the purpose of verifying the validity of universality for disordered systems. For each…

Statistical Mechanics · Physics 2016-08-31 Nicolas Sourlas

We calculate gauge theory one-loop amplitudes with the aid of the complex shift used in the Britto-Cachazo-Feng-Witten (BCFW) recursion relations of tree amplitudes. We apply the shift to the integrand and show that the contribution from…

High Energy Physics - Theory · Physics 2013-05-30 Savan Kharel , George Siopsis

Using loop-tree duality, we relate a renormalised $n$-point $l$-loop amplitude in a quantum field theory to a phase-space integral of a regularised $l$-fold forward limit of a UV-subtracted $(n+2l)$-point tree-amplitude-like object. We show…

High Energy Physics - Phenomenology · Physics 2020-07-01 Robert Runkel , Zoltán Szőr , Juan Pablo Vesga , Stefan Weinzierl

This work is a contribution to the study of universality in out-of-equilibrium lattice models undergoing a second-order phase transition at equilibrium. The experimental protocol that we have chosen is the following: the system is prepared…

Statistical Mechanics · Physics 2007-05-23 Christophe Chatelain

The critical properties of systems under constraint differ from their ideal counterparts through Fisher renormalization. The mathematical properties of Fisher renormalization applied to critical exponents are well known: the renormalized…

Statistical Mechanics · Physics 2015-06-18 N. Sh. Izmailian , R. Kenna

We present a method for the integrand-level reduction of two-loop helicity amplitudes in both $d=4-2\epsilon$ and $d=4$ dimensions. The amplitude is expressed in terms of a set of Feynman integrals and their coefficients that depend on the…

High Energy Physics - Phenomenology · Physics 2025-11-14 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos , Aris Spourdalakis

We establish a systematic way to calculate multiloop amplitudes of infrared safe massless models with Implicit Regularization (IR), with a direct cancelation of the fictitious mass introduced by the procedure. The ultraviolet content of…

High Energy Physics - Theory · Physics 2015-05-14 E. W. Dias , A. P. Baeta Scarpelli , L. C. T. Brito , H. G. Fargnoli

We show that the parametric correlations of the conductance peak amplitudes of a chaotic or weakly disordered quantum dot in the Coulomb blockade regime become universal upon an appropriate scaling of the parameter. We compute the universal…

Condensed Matter · Physics 2009-10-28 Y. Alhassid , H. Attias

We study the universal properties of the phase diagram of QCD near the critical point using the exact renormalization group. For two-flavour QCD and zero quark masses we derive the universal equation of state in the vicinity of the…

High Energy Physics - Theory · Physics 2009-11-10 N. Brouzakis , N. Tetradis

The properties of the amplitude method for $\Bs$ oscillation analyses are studied in detail. The world combination of measured amplitudes is converted into a likelihood profile as a function of oscillation frequency. A procedure is proposed…

High Energy Physics - Experiment · Physics 2010-02-03 G. Boix , D. Abbaneo

Strongly-interacting systems consisting of particles that interact through a large scattering length satisfy universal relations that relate many of their central properties to the contact, which measures the number of pairs with small…

Quantum Gases · Physics 2014-01-09 Eric Braaten , H. -W. Hammer

Power-suppressed corrections coming from the end-point integration regions in the amplitude of the process $\gamma^{*}\gamma \to \pi \pi$ at large $Q^2$ and small squared center-of-mass energy $W^2$ are calculated in the QCD hard-scattering…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. S. Agaev , M. Guidal , B. Pire

We study the application of recursion relations to the calculation of finite one-loop gravity amplitudes. It is shown explicitly that the known four, five, and six graviton one-loop amplitudes for which the external legs have identical…

High Energy Physics - Theory · Physics 2010-10-27 Andreas Brandhuber , Simon McNamara , Bill Spence , Gabriele Travaglini

We consider a perturbed integrable system with one frequency, and the approximate dynamics for the actions given by averaging over the angle. The classical theory grants that, for a perturbation of order epsilon, the error of this…

Mathematical Physics · Physics 2009-11-11 Carlo Morosi , Livio Pizzocchero

We address the question of weak versus strong universality scenarios for the random-bond Ising model in two dimensions. A finite-size scaling theory is proposed, which explicitly incorporates $\ln L$ corrections ($L$ is the linear finite…

Statistical Mechanics · Physics 2008-02-03 F. D. A. Aarao Reis , S. L. A. de Queiroz , Raimundo R. dos Santos

We present a brief review of current methods for the calculation of multi-loop amplitudes including recent developments. As an example we present the calculation of the second moment of the heavy quark current correlator and the extraction…

High Energy Physics - Phenomenology · Physics 2008-10-21 P. Marquard

It was recently shown [Phys. Rev. Lett. {\bf 110}, 227201 (2013)] that the critical behavior of the random-field Ising model in three dimensions is ruled by a single universality class. This conclusion was reached only after a proper taming…

Disordered Systems and Neural Networks · Physics 2016-06-21 Nikolaos G. Fytas , Victor Martin-Mayor

I will review some of the recent intense activity concerning infrared and collinear divergences in gauge theory amplitudes. The central quantity in these studies is the multi-particle soft anomalous dimension matrix, which is completely…

High Energy Physics - Phenomenology · Physics 2014-08-05 Lorenzo Magnea

We determine the complete three-loop QCD soft anomalous dimension for multileg amplitudes involving a single massive coloured particle and any number of massless ones. This is achieved by applying a novel strategy based on a lightcone…

High Energy Physics - Phenomenology · Physics 2025-11-03 Einan Gardi , Zehao Zhu

The scalar-isoscalar, scalar-isotensor and vector-isovector pi-pi amplitudes are fitted simultaneously to experimental data and to Roy's equations. The resulting amplitudes are compared with those fitted only to experimental data. No…

High Energy Physics - Phenomenology · Physics 2009-11-10 Robert Kaminski , Leonard Lesniak , Benoit Loiseau