119284900
Dressed Wilson Loops on S^2
We present a new, two-parameter family of string solutions corresponding to the holographic duals of specic 1/8-BPS Wilson loops on S 2 inN = 4 supersymmetric Yang-Mills theory. The solutions are obtained using the dressing method on the known longitude solution in the context of the auxiliary -model on S 3 put forth in arXiv:0905.0665[hep-th]. We verify that the regularized area of the world-sheets are consistent with expectations.
2023869
Free energy and phase transition of the matrix model on a plane wave
It has recently been observed that the weakly coupled plane-wave matrix model has a density of states which grows exponentially at high energy. This implies that the model has a phase transition. The transition appears to be of first order. However, its exact nature is sensitive to interactions. In this paper, we analyze the effect of interactions by computing the relevant parts of the effective potential for the Polyakov loop operator in the finite temperature plane-wave matrix model to three-loop order. We show that the phase transition is indeed of first order. We also compute the correction to the Hagedorn temperature to order two loops.
55184082
Chiral primary one-point functions in the D3-D7 defect conformal field theory
A bstractWe compute the one-point functions of chiral primary operators in the non-supersymmetric defect conformal field theory that is dual to the IIB string theory on AdS5 × S5 background with a probe D7 brane with internal gauge field flux, both in perturbative Yang-Mills theory and in the string theory dual. The former is expected to be accurate at weak coupling whereas the latter should be accurate in the planar strong coupling limit of the gauge theory. We consider the distinct cases where the D7 brane has geometry AdS4 × S4 with an instanton bundle of the worldvolume gauge fields on S4 and AdS4 × S2 × S2 with Dirac monopole bundles on each S2. The gauge theory computation and the string theory computation can be compared directly in the planar limit and then a subsequent limit where the worldvolume flux is large. We find that there is exact agreement between the two in the leading order.
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.
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.
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.
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.
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.
117804340
DESIGN OF PROTON LINEAR ACCELERATORS FOR ENERGIES UP TO 300 Mev
Extension of the conventional 2 pi structure for particle acceleration to 200 Mev or higher requires minimization of power losses by optimizing cavity and drift-tube parameters. Using a previously developed method, an optimization of the cavity drift-tube dimensions was made at 200 Mc and at energies of 50, 100, 150, and 200 Mev to give minimum power losses for cylindrical tubes. Drift tubes of other shapes may reduce observed high-energy power losses due to currents in the drift-tube surface. Ellipsoidal tubes appear more efficient than the cylindrical tubes. (D.C.W.)
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.
118976170
Operating experience with the NAL 200-MeV linac.