55331667
The evolution of tensor polarization
Using the equation of motion for the vector polarization, the spin transfer matrix for spin tensor polarization is derived. We study the evolution equation for the tensor polarization in the presence of an isolated spin resonance and in the presence of a spin rotator, or snake.<<ETX>>
120908048
Comment on “Quasiperiodic spin-orbit motion and spin tunes in storage rings”
124338422
FIRST OBSERVATION OF A SNAKE DEPOLARIZING RESONANCE
Using a 104MeV stored polarized proton beam and a full Siberian snake, we recently found evidence for a so-called {open_quotes}snake{close_quotes} depolarizing resonance. A full Siberian snake forces the spin tune {nu}{sub s} to be a half integer. Thus, if the vertical betatron tune {nu}{sub y} is set near a quarter integer, then the {nu}{sub s}=n{plus_minus}2{nu}{sub y} second-order snake resonance can depolarize the beam. Indeed, with a full Siberian snake, we found a deep depolarization dip when {nu}{sub y} was equal to 4.756; moreover, when {nu}{sub y} was changed to 4.781, the deep dip disappeared and the polarization was preserved. {copyright} {ital 1997} {ital The American Physical Society}
117036088
Comparison of multipole expansion and exact form of the eddy current field of the AGS Booster
Studies are made on magnetic field representation using a multipole expansion as well as the exact form to calculate the magnetic field produced by eddy currents in the vacuum chamber of the AGS Booster as well as the field produced by three turn correction coils attached to the top and bottom of the vacuum chamber. The multiple representation of the chamber field does not converge to the next field when X > 30mm and limits the particle motion. When the exact form of the chamber field is used, initial amplitudes in the horizontal plane (measured at QF) can be nearly as large as the chamber half aperture. Use of three turn correction coils to compensate the eddy current fields seems to reduce rather than increase the acceptance. 6 figs., 3 tabs.
120417645
Snakes and spin rotators for high energy accelerators
Abstract A modification to the continuous family of snake and spin rotators, discovered by Steffen, is discussed. A compact snake configuration is found to have the advantages of requiring a smaller total integrated dipole magnet strength and a smaller transverse displacement for circulating particles. A split snake configuration has the advantage of allowing an entire experimental insertion region to be located between the two halves of the snake. Such configurations could serve as both a snake and a 90° spin rotator for experiments requiring different helicity states. General properties of these snake configurations are discussed.
96454816
Design and fabrication of a multi-purpose Panofsky magnet
A fast, flexible magnet system, consisting of a Panofsky style ferrite picture-frame magnet and pulsed power supply, has been developed. Magnet specifications are: 8 cm /spl times/8 cm aperture, 23 cm length, 500 A pulsed/l60 A DC, and 1 /spl mu/s risetime. Designed for general accelerator physics studies, the magnet may be quickly converted from dipole to quadrupole or sextupole and higher multipole configurations by easily changing winding end terminations. In the quadrupole configuration a field gradient of 0.5 T/m is achieved at 500 A. This magnet has become an important tool for nonlinear beam dynamics experiments at the IUCF Cooler Ring.<<ETX>>
119196758
Klebanov-Witten flows in M-theory
A bstractWe study renormalization group flows among three dimensional superconformal gauge theories which closely resemble the renowned Klebanov-Witten flow in four dimensions. In the large N limit, each theory appearing in the flow is holographically dual to M-theory on AdS4 times a toric Sasaki-Einstein seven-manifold. The theories are obtained through the so-called flavoring method, which adds some fundamental matter fields to the dimensionally reduced Klebanov-Witten theories. We reconfirm the matching between the gauge theories and the dual geometries by comparing the chiral ring structure. As a more refined test of the flows, we compute the three-sphere partition function of the gauge theories. The square of the free energy, inversely proportional to the volume of the seven-manifold, decreases by a universal ratio 16/27 for all flows considered in this paper.
119218989
Holographic description of quantum field theory
Abstract We propose that general D-dimensional quantum field theories are dual to ( D + 1 ) -dimensional local quantum theories which in general include objects with spin two or higher. Using a general prescription, we construct a ( D + 1 ) -dimensional theory which is holographically dual to the D-dimensional O ( N ) vector model. From the holographic theory, the phase transition and critical properties of the model in dimensions D > 2 are described.
120447270
LEE-WICK FIELD AS A DARK ENERGY CANDIDATE
As a possible alternative solution for the hierarchy problem in the standard model, Lee-Wick theory where a field has higher derivative kinetic operators has been paid attentions recently. Also in modern cosmology, the observations suggest that the current universe is under accelerating expansion dominated by dark energy. Furthermore, they marginally prefer the dark energy equation of state parameter ωDE to cross the phantom divide -1 at present. Lee-Wick theory has the same structure as so-called quintom model except the form of potentials and the sign of the slope of the potentials. Thus, this model can produce the stable late time phantom-dominated solution and maybe able to explain the current cosmology. However, without fine tuning of its mass we may not be able to produce the viable values of observational quantities in this model.
15011888
Effect on cosmic microwave background polarization of coupling of quintessence to pseudoscalar formed from the electromagnetic field and its dual.
We present the full set of power spectra of cosmic microwave background (CMB) temperature and polarization anisotropies due to the coupling between quintessence and pseudoscalar of electromagnetism. This coupling induces a rotation of the polarization plane of the CMB, thus resulting in a nonvanishing B mode and parity-violating TB and EB modes. Using the BOOMERANG data from the flight of 2003, we derive the most stringent constraint on the coupling strength. We find that in some cases the rotation-induced B mode can confuse the hunting for the gravitational lensing-induced B mode.
119501262
EMERGENCE OF GRAVITY FROM INTERACTING SIMPLICES
We consider a statistical model of interacting 4-simplices fluctuating in an N-dimensional target space. We argue that a gravitational theory may arise as a low energy effective theory in a strongly interacting phase where the simplices form clusters with an emergent space and time with the Euclidean signature. In the large N limit, two possible phases are discussed, that is, "gravitational Coulomb phase" and "gravitational Higgs phase."