#### Filter Results:

- Full text PDF available (61)

#### Publication Year

1992

2017

#### Publication Type

#### Co-author

#### Publication Venue

#### Key Phrases

Learn More

- ZVI BERN
- 1994

We present a technique which utilizes unitarity and collinear limits to construct ansätze for one-loop amplitudes in gauge theory. As an example, we obtain the one-loop contribution to amplitudes for n gluon scattering in N = 4 supersymmetric Yang-Mills theory with the helicity configuration of the Parke-Taylor tree amplitudes. We prove that our N = 4… (More)

- ZVI BERN
- 1995

We identify a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes, without any ambiguities. One-loop amplitudes for massless supersymmetric gauge theories fall into this class; in addition, many non-supersymmetric amplitudes can be rearranged to take advantage of the result. As applications,… (More)

- C Anastasiou, L Dixon, Z Bern, D A Kosower
- Physical review letters
- 2003

The collinear factorization properties of two-loop scattering amplitudes in dimensionally regulated N=4 super-Yang-Mills theory suggest that, in the planar ('t Hooft) limit, higher-loop contributions can be expressed entirely in terms of one-loop amplitudes. We demonstrate this relation explicitly for the two-loop four-point amplitude and, based on the… (More)

- Zvi Bern
- 1998

We present methods for evaluating the Feynman parameter integrals associated with the pentagon diagram in 4 − 2ǫ dimensions, along with explicit results for the integrals with all masses vanishing or with one non-vanishing external mass. The scalar pentagon integral can be expressed as a linear combination of box integrals, up to O(ǫ) corrections, a result… (More)

- Z. Bern
- 1996

We show, for previously uncalculated examples containing a uniform mass in the loop, that it is possible to obtain complete massive one-loop gauge theory amplitudes solely from unitarity and known ultraviolet or infrared mass singularities. In particular, we calculate four-gluon scattering via massive quark loops in QCD. The contribution of a heavy quark to… (More)

- Zvi Bern
- 1993

We present the one-loop helicity amplitudes with five external gluons. The computation employs string-based methods, new techniques for performing tensor integrals, and improvements in the spinor helicity method.

- Z Bern, J S Rozowsky, B Yan
- 1997

Using cutting techniques we obtain the two-loop N = 4 super-Yang-Mills helicity amplitudes for four-gluon scattering in terms of scalar integral functions. The N = 4 amplitudes are considerably simpler than corresponding QCD amplitudes and therefore provide a testing ground for exploring two-loop amplitudes. The amplitudes are constructed directly in terms… (More)

- Zvi Bern
- 1997

We present the first explicit formulae for the complete set of one-loop helicity amplitudes necessary for computing next-to-leading order corrections for e + e − annihilation into four jets, for W , Z or Drell-Yan production in association with two jets at hadron colliders, and for three-jet production in deeply inelastic scattering experiments. We include… (More)

Splitting amplitudes are universal functions governing the collinear behavior of scattering amplitudes for massless particles. We compute the two-loop g → 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… (More)

- Z. Bern
- 2000

We present the two-loop pure gauge contribution to the gluon-gluon scattering amplitude with maximal helicity violation. Our construction of the amplitude does not rely directly on Feynman diagrams, but instead uses its analytic properties in 4 − 2ǫ dimensions. We evaluate the loop integrals appearing in the amplitude through O(ǫ 0) in terms of… (More)