123090437
Spin resonance strength of a localized rf magnetic field
Spin-resonance strength produced by a localized rf field has been a focus of recent publications [V. S. Morozov et al., Phys. Rev. ST Accel. Beams 7, 024002 (2004).; M. A. Leonova et al. (to be published).; T. Roser, in Handbook of Accelerator Physics and Engineering, edited by A. W. Chao and M. Tigner (World Scientific, Singapore, 1999), p. 151.; M. Bai, W. W. MacKay, and T. Roser, Phys. Rev. ST Accel. Beams 8, 099001 (2005).; V. S. Morozov et al., Phys. Rev. ST Accel. Beams 8, 099002 (2005).]. This paper discusses the debated factor of 2, and provides a formula to calculate the component enhanced by the induced betatron motion.
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>>
120908048
Comment on “Quasiperiodic spin-orbit motion and spin tunes in storage rings”
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.
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.
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}
431553
Dyonic instantons in 5-dim Yang-Mills Chern-Simons theories
We consider the BPS dyonic instantons in the 5-dim supersymmetric Yang-Mills Chern-Simons theories. Its field theoretic structures and the moduli space dynamics in term of the ADHM data have been explored in detail. We find that the field theoretic Chern-Simons term leads to an effective magnetic field on instanton moduli space.
14407999
Lee Wick Dark Energy
We consider the cosmological application of Lee-Wick theory where a field has a higher derivative kinetic operators. The higher derivative term can be eliminated by introducing a set of auxiliary fields. We investigate the cosmological evolutions of these fields as a candidate of dark energy. This model has the same structure as so called ``quintom' model except the form of potentials and the sign of the slope of the potentials. This model can give the stable late time phantom dominated scaling solution ($\omega_{\DE} < -1$) or tracking attractors ($\omega_{\DE} = 0$) depending on the choice of the slopes of the potential. In order to be a viable dark energy candidate, the present energy density contrast of dark energy ($\Omega_{\DE}^{(0)}$) should be close to an observed value (0.73) at the same time. However, a simple toy model of the theory can not satisfy both $\omega_{\DE}^{(0)} \simeq -1$ and $\Omega_{\DE}^{(0)} = 0.73$. If we include the self interaction term of Lee Wick field, then we are able to produce the observed values of those quantities. However, in this case we are not be able to have the stable solutions and we need to suffer from the fine tuning of its mass.
18287866
Properties of the exact analytic solution of the growth factor and its applications
There have been the approximate analytic solution [V. Silveira and I. Waga, Phys. Rev. D 50, 4890 (1994).] and several approximate analytic forms [W. J. Percival, Astron. Astrophys. 443, 819 (2005).][S. M. Carroll, W. H. Press, and E. L. Turner, Annu. Rev. Astron. Astrophys. 30, 499 (1992).][S. Basilakos, Astrophys. J. 590, 636 (2003).] of the growth factor ${D}_{g}$ for the general dark energy models with the constant values of its equation of state ${\ensuremath{\omega}}_{\mathrm{de}}$ after Heath found the exact integral form of the solution of ${D}_{g}$ for the Universe including the cosmological constant or the curvature term. Recently, we obtained the exact analytic solutions of the growth factor for both ${\ensuremath{\omega}}_{\mathrm{de}}=\ensuremath{-}1$ or $\ensuremath{-}\frac{1}{3}$ [S. Lee and K.-W. Ng, arXiv:0905.1522.] and the general dark energy models with the constant equation of state ${\ensuremath{\omega}}_{\mathrm{de}}$ [S. Lee and K.-W. Ng, Phys. Lett. B 688, 1 (2010).] independently. We compare the exact analytic solution of ${D}_{g}$ with the other well known approximate solutions. We also prove that the analytic solutions for ${\ensuremath{\omega}}_{\mathrm{de}}=\ensuremath{-}1$ or $\ensuremath{-}\frac{1}{3}$ in [S. Lee and K.-W. Ng, arXiv:0905.1522.] are the specific solutions of the exact solutions of the growth factor for general ${\ensuremath{\omega}}_{\mathrm{de}}$ models in [S. Lee and K.-W. Ng, Phys. Lett. B 688, 1 (2010).] even though they look quite different. Comparison with the numerical solution obtained from the public code is done. We also investigate the possible extensions of the exact solution of ${D}_{g}$ to the time-varying ${\ensuremath{\omega}}_{\mathrm{de}}$ for the comparison with observations.
119274668
Growth index with the exact analytic solution of sub-horizon scale linear perturbation for dark energy models with constant equation of state
Abstract Three decades ago Heath found the integral form of the exact analytic growing mode solution of the linear density perturbation δ on sub-horizon scales including the cosmological constant or the curvature term. Recently, we obtained the exact analytic form of this solution in our previous work [1] . Interestingly, we are able to extend this solution for general dark energy models with the constant equation of state ω de in a flat universe. This analytic solution provides the accurate and efficient tools for probing the properties of dark energy models such as the behavior of the growth factor and the growth index. We investigate the growth index and its parameter at any epoch with this exact solution for different dark energy models and find that the growth index is quite model dependent in the redshift space, 0.25 ⩽ z ⩽ 1.5 , so observations of the structure growth around this epoch would be very interesting. Also one may be able to rule out some dark energy models by using the analysis from this exact solution. Thus, the analytic solution for the growth factor provides the very useful tools for future observations to constrain the exact values of observational quantities at any epoch related to the growth factor in the dark energy models.
119268040
Constraining RS Models by Future Flavor and Collider Measurements: A Snowmass Whitepaper
Randall-Sundrum models are models of quark flavor, because they explain the hierarchies in the quark masses and mixings in terms of order one localization parameters of extra dimensional wavefunctions. The same small numbers which generate the light quark masses suppress contributions to flavor violating tree level amplitudes. In this note we update universal constraints from electroweak precision parameters and demonstrate how future measurements of flavor violation in ultra rare decay channels of Kaons and B mesons will constrain the parameter space of this type of models. We show how collider signatures are correlated with these flavor measurements and compute projected limits for direct searches at the 14 TeV LHC run, a 14 TeV LHC luminosity upgrade, a 33 TeV LHC energy upgrade, and a potential 100 TeV machine. We further discuss the effects of a warped model of leptons in future measurements of lepton flavor violation.