117084548
Determinations of the mass of the top quark.
120554497
Inside-out tracking at CDF
The Central Outer Tracker (COT) at the Collider Detector at Fermilab (CDF) is used to reconstruct charged particles in the central rapidity region. The silicon tracker is used to improve the central track measurement and to reconstruct charged particles in the forward rapidity region. We describe the inside-out tracking algorithm, which improves the track measurement in the intermediate rapidity region by attaching COT hits to reconstructed silicon tracks.
6593967
String interactions on the random lattice
Abstract We combine two partons on a random lattice as a vector state. In the ladder approximation, we find that such states have 1 / p 2 propagators (after tuning the mass to vanish). We also construct some diagrams which are very similar to 3-string vertices in string field theory for the first oscillator mode. Attaching 3 such lattice states to these vertices, we get Yang–Mills and F 3 interactions up to 3-point as from bosonic string (field) theory. This gives another view of a gauge field as a bound state in a theory whose only fundamental fields are scalars.
118444935
The two-loop six-point amplitude in ABJM theory
A bstractIn this paper we present the first analytic computation of the six-point two-loop amplitude of ABJM theory. We show that the two-loop amplitude consists of corrections proportional to two distinct local Yangian invariants which can be identified as the tree- and the one-loop amplitude respectively. The two-loop correction proportional to the tree-amplitude is identical to the one-loop BDS result of $ \mathcal{N}=4 $ SYM plus an additional remainder function, while the correction proportional to the one-loop amplitude is finite. Both the remainder and the finite correction are dual conformal invariant, which implies that the two-loop dual conformal anomaly equation for ABJM is again identical to that of one-loop $ \mathcal{N}=4 $ super Yang-Mills, as was first observed at four-point. We discuss the theory on the Higgs branch, showing that its amplitudes are infrared finite, but equal, in the small mass limit, to those obtained in dimensional regularization.
51263888
Dualities for loop amplitudes of N = 6 Chern-Simons matter theory
A bstractIn this paper we study the one- and two-loop corrections to the four-point amplitude of $ \mathcal{N}{ = 6} $ Chern-Simons matter theory. Using generalized unitarity methods we express the one- and two-loop amplitudes in terms of dual-conformal integrals. Explicit integration by using dimensional reduction gives vanishing one-loop result as expected, while the two-loop result is non-vanishing and matches with the Wilson loop computation. Furthermore, the two-loop correction takes the same form as the one-loop correction to the four-point amplitude of N = 4 super Yang-Mills. We discuss possible higher loop extensions of this correspondence between the two theories. As a side result, we extend the method of dimensional reduction for three dimensions to five dimensions where dual conformal symmetry is most manifest, demonstrating significant simplification to the computation of integrals.
118414756
The Positive orthogonal Grassmannian and loop amplitudes of ABJM
In this paper we study the combinatorics associated with the positive orthog- onal Grassmannian OGk and its connection to ABJM scattering amplitudes. We present a canonical embedding of OGk into the Grassmannian Gr(k; 2k), from which we deduce the canonical volume form that is invariant under equivalence moves. Remarkably the canon- ical forms of all reducible graphs can be converted into irreducible ones with products of d log forms. Unlike N = 4 super Yang-Mills, here the Jacobian plays a crucial role to ensure the d log form of the reduced representation. Furthermore in the positive region, we identify the functional map that arises from the triangle equivalence move as a 3-string scattering S-matrix which satises the tetrahedron equations by Zamolodchikov, implying (2+1)-dimensional integrability. We study the solution to the BCFW recursion relation for loop amplitudes, and demonstrate the presence of all physical singularities as well as the absence of all spurious ones. The on-shell diagram solution to the loop recursion relation exhibits manifest two-site cyclic symmetry and reveals that, to all loop, four and six-point amplitudes only have logarithmic singularities.
17646476
Running anti-de Sitter radius from QCD-like strings
We consider renormalization effects for a bosonic QCD-like string, whose partons have 1/p2 propagators instead of Gaussian. Classically this model resembles (the bosonic part of) the projective light-cone (zero-radius) limit of a string on an AdS5 background, where Schwinger parameters give rise to the fifth dimension. Quantum effects generate dynamics for this dimension, producing an AdS5 background with a running radius. The projective light-cone is the high-energy limit: Holography is enforced dynamically.