119257707
An extremal chiral primary three-point function at two-loops in ABJ(M)
A bstractI compute the leading correction to the structure constant for the three-point function of two length-two and one length-four chiral primary operators in planar ABJ(M) theory at weak ’t Hooft coupling. The computation is reduced to four-loop propagator type Feynman integrals via a manifestly finite integration over the position of the length-four operator.
56107782
Manifest SO(N) invariance and S-matrices of three-dimensional N=2,4,8 SYM
An on-shell formalism for the computation of S-matrices of SYM theories in three spacetime dimensions is presented. The framework is a generalization of the spinor-helicity formalism in four dimensions. The formalism is applied to establish the manifest SO(N) covariance of the on-shell superalgebra relevant to N =2,4 and 8 SYM theories in d=3. The results are then used to argue for the SO(N) invariance of the S-matrices of these theories: a claim which is proved explicitly for the four-particle scattering amplitudes. Recursion relations relating tree amplitudes of three-dimensional SYM theories are shown to follow from their four-dimensional counterparts. The results for the four-particle amplitudes are verified by tree-level perturbative computations and a unitarity based construction of the integrand corresponding to the leading perturbative correction is also presented for the N=8 theory. For N=8 SYM, the manifest SO(8) symmetry is used to develop a map between the color-ordered amplitudes of the SYM and superconformal Chern-Simons theories, providing a direct connection between on-shell observables of D2 and M2-brane theories.
204959354
Integrability and MHV diagrams in N = 4 supersymmetric Yang-Mills theory
We apply MHV diagrams to the derivation of the one-loop dilatation operator of N = 4 super Yang-Mills in the SO(6) sector. We find that in this approach the calculation reduces to the evaluation of a single MHV diagram in dimensional regularisation. This provides the first application of MHV diagrams to an off-shell quantity. We also discuss other applications of the method and future directions. § {a.brandhuber, b.penante, g.travaglini, d.young}@qmul.ac.uk ar X iv :1 41 2. 10 19 v2 [ he pth ] 2 F eb 2 01 5
119103237
ABJ(M) chiral primary three-point function at two-loops
A bstractWe compute the leading correction to the structure constant for the threepoint function of three length-two chiral primary operators in planar ABJ(M) theory at weak ’t Hooft coupling.
14615477
Exact 1/4 BPS loop- : Chiral primary correlator
Abstract Correlation functions of 1 / 4 BPS Wilson loops with the infinite family of 1 / 2 BPS chiral primary operators are computed in N = 4 super-Yang–Mills theory by summing planar ladder diagrams. Leading loop corrections to the sum are shown to vanish. The correlation functions are also computed in the strong-coupling limit by examining the supergravity dual of the loop–loop correlator. The strong coupling result is found to agree with the extrapolation of the planar ladders. The result is related to known correlators of 1 / 2 BPS Wilson loops and 1 / 2 BPS chiral primaries by a simple re-scaling of the coupling constant, similar to an observation of Drukker [N. Drukker, hep-th/0605151] for the case of the 1 / 4 BPS loop vacuum expectation value.
7242147
BPS Wilson Loops on S**2 at Higher Loops
archiveprefix: arXiv primaryclass: hep-th reportnumber: HU-EP-08-13 slaccitation: %%CITATION = ARXIV:0804.4098;%%
55291989
Low energy improvements to the Fermilab 400-MeV linear accelerator
Improvements in the Fermilab operating 400-MeV linear accelerator injector are required to achieve the beam intensity and emittance requirement of the Proton Driver design study. It has been determined that these requirements can be achieved by replacing the components in the linac below 10 MeV. An improved H/sup -/ ion source with an electrostatic transport to a two-section radio-frequency quadrupole (RFQ) accelerator, with the RFQ sections separated by a magnetic five-dimensional phase-space imaging system as used in an earlier Fermilab/SAIC PET Project, and a new 10-MeV drift-tube linac cavity have been studied. It appears possible that an H/sup -/ intensity of 4.5/spl times/10/sup 13/ ions per pulse with an improvement in beam emittance from the present system can be achieved with the proposed changes.
124960127
THE OPERATION OF THE FIRST SECTION OF THE NAL LINEAR ACCELERATOR.
101173164
MURA 50-MeV Electron AcceleratorGeneral Description and Review. I
General descriptions of the history, construction, and operation of the MURA 50‐MeV electron accelerator are given. In its operation, this accelerator has been used to stack large circulating currents of accelerated particles and to investigate multiturn injection, acceleration processes, resonant effects, and collective instabilities.
111257994
RF Perturbation Measurements in Long Linac Cavities
Equipment and procedures have been developed for measuring the axial accelerating electric field in proton linear accelerator cavities. The method used is the usual one of measuring the change in resonant frequency caused by a small perturbing sphere on the axis of the cavity. The frequency change is determined at millimeter intervals along the axis by measuring the corresponding period length using an on-line digital computer. The computation is carried out on the computer so that the derived fields can be obtained, integrated, plotted, and compared. The method is rapid and the increased precision of the measurement allows better knowledge of the fields in operating linear accelerators. This equipment has been used on the 50-MeV linac injector for the Zero Gradient Synchrotron at Argonne National Laboratory.1 It has also been used to measure the axial field in a cavity with fields which can be calculated using a field computational program.2 The measured and calculated field values have been compared.
123057920
Magnetic Guide Field Measurements and Corrections in the MURA 50‐MeV Electron Accelerator. VI
Methods of measurement and correction of the magnetic fields of the MURA 50‐MeV electron accelerator are described. Measurements of the vertical and horizontal field components were made and the field errors corrected. Correction coils, iron shims, and adjustment of magnet positions were used to produce fields within the required tolerances. Computer methods were used to calculate needed corrections and to evaluate the quality of the corrections achieved.