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This Note reports on the first, and successful, simulations of particle and spin dynamics in the AGS in presence of the two helical snakes and of the tune-jump quadrupoles, using the ray-tracing code Zgoubi. It includes DA tracking in the absence or in the presence of the two helical snakes, simulation of particle and spin motion in the snakes using their magnetic field maps, spin flipping at integer resonances in the 36+Qy depolarizing resonance region, with and without tune-jump quadrupole gymnastics. It also includes details on the setting-up of Zgoubi input data files and on the various numerical methods of concern in and available from Zgoubi.

This Note reports on the first simulations of and spin dynamics in the AGS using the ray-tracing code Zgoubi. It includes lattice analysis, comparisons with MAD, DA tracking, numerical calculation of depolarizing resonance strengths and comparisons with analytical models, etc. It also includes details on the setting-up of Zgoubi input data files and on the various numerical methods of concern in and available from Zgoubi. Simulations of crossing and neighboring of spin resonances in AGS ring, bare lattice, without snake, have been performed, in order to assess the capabilities of Zgoubi in that matter, and are reported here. This yields a rather long document. The two main reasons for that are, on the one hand the desire of an extended investigation of the energy span, and on the other hand a thorough comparison of Zgoubi results with analytical models as the 'thin lens' approximation, the weak resonance approximation, and the static case. Section 2 details the working hypothesis : AGS lattice data, formulae used for deriving various resonance related quantities from the ray-tracing based 'numerical experiments', etc. Section 3 gives inventories of the intrinsic and imperfection resonances together with, in a number of cases, the strengths derived from the ray-tracing.more » Section 4 gives the details of the numerical simulations of resonance crossing, including behavior of various quantities (closed orbit, synchrotron motion, etc.) aimed at controlling that the conditions of particle and spin motions are correct. In a similar manner Section 5 gives the details of the numerical simulations of spin motion in the static case: fixed energy in the neighboring of the resonance. In Section 6, weak resonances are explored, Zgoubi results are compared with the Fresnel integrals model. Section 7 shows the computation of the {rvec n} vector in the AGS lattice and tuning considered. Many details on the numerical conditions as data files etc. are given in the Appendix Section, pages A and sqs.« less

Even though RHIC has two full Siberian snakes in each ring, there are various perturbations to the ideal case including orbit errors at the snakes, experiment solenoids, injection bumps, and interlaced horizontal‐vertical bumps at the hydrogen jet polarimeter. These errors can cause depolarization by shifting the spin tune and tilting the stable spin direction away from vertical. Tilting of the stable spin axis can enhance horizontal depolarizing resonances. This paper presents preliminary results for some of these error scenarios, as well as their impact on the stable spin directions at STAR and PHENIX.

A dual partial snake scheme has been used for AGS polarized proton operation for several years. It has provided polarized proton beams with 1.5×1011 protons per bunch and 65% polarization for the RHIC spin program. There is still residual polarization loss due to both snake resonances and horizontal resonances as shown in the data. Several schemes were tested or proposed in the AGS to mitigate the loss, such as putting horizontal tune into the spin tune gap, injection into a accelerating bucket, and tune jump across the horizontal resonances. This paper presents the experiment and simulation results and analyses.

During Run‐8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin‐polarized proton beams at two interaction regions. Physics data were taken with vertical orientation of the beam polarization, which in the “Yellow” RHIC ring was significantly lower than in previous years. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run‐8, and we discuss possible causes of the not as high as previously achieved polarization performance of the “Yellow” ring.

The Booster to AGS (BtA) transfer line [Ref for BtA line] transports the beam bunches from the AGS-Booster to the AGS synchrotron, and also matches the beam parameters ({beta}{sub x,y}, {alpha}{sub x,y}) and dispersion functions ({eta}{sub x,y}, {eta}{prime}{sub x,y}) of the transported beam to the corresponding quantities of the circulating beam in AGS, at the AGS injection point. In this technical note we describe in details, the calculations of the matching procedure of the BtA line to the bare-AGS, and provide magnet settings for the MAD-model of the BtA transfer line which is 'matched' to the bare-AGS. In a separate but more concise technical note (Part II) we will present results on the beam optics of the BtA beam line which is 'matched' to the AGS with two helical snakes.

In order to study the spin structure of the neutron at high energy, a beam rich in polarized neutrons needs to be developed. The neutron has no charge and cannot be accelerated, so either deuterons or helions must be considered. When it comes to spin manipulation and stability of the polarization in a circular accelerator, it is the anomalous part of the magnetic moment which is important. If the anomaly is too small, then manipulation becomes difficult as in the case of deuterons—spin rotators and Siberian snakes become ineffective. 3He nuclei appear to be the easiest choice for a polarized neutron beam. In this paper I discuss the prospects for both helions and deuterons as polarized beams in RHIC or in an electron‐ion collider.

We present the design, simulations and measurements of a prototype passive RF cavity for a polarimeter with a transversely polarized electron beam interacting with the longitudinal gradient of the transverse component of magnetic field in the TE011 mode of the cavity. Magnetic coupling of a polarized electron beam at the Bates accelerator may produce signals of the order of a microwatt, permitting fast and accurate polarization measurement.

Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20 - 30 % partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

Meyer [Phys. Rev. E 50, 1485 (1994)] analyzed the filtering mechanism of polarizing a stored beam by scattering from an internal polarized target. We noticed in Meyer's derivation of Eq. (4) of that paper that he had added a new twist to an old argument [W. Bruckner, Physics with Antiprotons at LEAR in the ACOL Era: Proceedings of the Third LEAR Workshop, Tignes, Savoie, France, January 19-26, 1985 (Editions Frontieres, Gif-sur-Yvette, France, 1985), p. 245] by allowing some particles that are spin flipped to be kept in the beam. We show that this invalidates the old result and leads to a more complicated expression for the buildup of polarization.

Preliminary results from the ’03 RHIC Proton Spin Run on the spin dependence in the elastic scatterring of polarized protons off a carbon target at very low momentum transfer (0.005 < |t| < 0.05 GeV2/c2) are presented and discussed. Proton polarimeters based on this process are used in RHIC and AGS to measure reliably and in very short times the polarization of the proton beams. Polarimetry results from the just completed RHIC polarized proton run are also presented.

A conceptual lattice design for a very compact superconducting synchrotron dedicated to X-ray lithography is presented. The synchrotron radiation produced in the high field superconducting magnets has a critical wavelength of 10 AA at a beam energy of about 787 MeV. The size and angular divergence of the beam in this lattice can satisfy the future requirements for X-ray lithography: sigma /sub x,y/ >

Materials which incorporate regular macroscopic features superposed on the underlying crystal lattice are of potential interest in connection with application to crystal accelerators and coherent radiation sources. The authors have begun an investigation of one such material, porous Si, in which pores of radii up to a few tens of lattice spacings are etched through finite volumes of a single crystal. The potential reduction of losses to particles hyperchanneled along the pores makes this a very interesting material in crystal accelerators for relativistic, positively charged particles. Results on material properties which are important in this context are presented. The consequences for particle transport are discussed. >

A new polarimeter is being installed in the Brookhaven AGS, based on the successful proton‐carbon polarimeters in RHIC. The polarimeter will measure the left‐right asymmetry for proton—carbon elastic scattering in the Coulomb‐nuclear interference (CNI) region, for vertically polarized protons in the AGS. The polarimeter offers a much higher figure of merit than the existing AGS polarimeter which is based on larger angle proton—proton elastic scattering. We expect to measure the polarization in the AGS with a single or a few acceleration cycles. We also plan to measure the polarization in 2 ms bins during the AGS acceleration ramp. Multiple ramps will be necessary, probably over 30 minutes to an hour.

Polarimeters using the proton carbon elastic scattering process in Coulomb Nuclear Interference (CNI) region were installed in two RHIC rings. Polarization measurements were successfully carried out with the high energy polarized proton beams for the first polarized pp collision run. The physics principles, performance, and polarization measurements are presented.

The relativistic Stern‐Gerlach interaction is here considered as a tool for obtaining the spin state separation of an unpolarized (anti)proton beam circulating in a ring. Drawbacks, such as spin precessions within the TE rf cavity, spurious kicks due to the transverse electric field and, worst of all, filamentation in the longitudinal phase plane are analyzed. Possible remedies are proposed and their feasibility is discussed.

Status of the H‐jet polarimeter development is reviewed. A number of design issues are discussed including vacuum system, integration into the RHIC storage ring, scattering chamber, and uniform vertical holding field magnet design. The absolute proton polarization of the atomic hydrogen‐jet target will be measured to 3% accuracy by a Breit‐ systematic error contribution to the jet‐target polarization measurements is also discussed.

With a partial Siberian snake in the AGS and transport lines with interspersed horizontal and vertical bends, the incoming spin direction at the injection points of both the collider rings is not likely to match the ideal vertical stable spin direction of RHIC which has two full helical Siberian snakes per ring. In this paper we examine the matching of a polarized beam transfered from the AGS into RHIC. The present 5% partial solenoidal snake as well as a proposed 20% superconducting helical are considered for the AGS. Solutions with retuned snakes in RHIC to better match the incoming beam have been found.

The time varying relativistic Stern‐Gerlach force, which acts over a charged particle endowed with a magnetic moment, is deduced from the Dirac Hamiltonian finding its coincidence with the classical expression. Possible drawbacks related to the Heisenberg uncertainty principle are discussed.

An innovative polarimeter based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region has been installed and commissioned in the Blue ring of RHIC during the first RHIC polarized proton commissioning. The polarimeter consists of ultra-thin carbon targets and four silicon detectors. All elements are in a 1.6 meter target chamber. It worked very well as a pivotal tool during the commissioning. It demonstrated that the RHIC snake magnets rotate spin to the expected direction. The results also show that polarized proton beam has been accelerated in RHIC and the polarization is maintained up to 29 GeV.

The Stern-Gerlach interaction, between a moving charged particle endowed with a magnetic moment and a radio-frequency e.m. field, is studied by means of a semi-classical approach. Theoretical results are presented, and a possible experimental check of this theory is discussed.

We have detected the polarization of the positron beam in the Cornell Electron Storage Ring (CESR) with a polarimeter which detects back-scattered laser light. The beam was resonantly depolarized using a vertical shaker magnet with a rf field, thus measuring the $g\ensuremath{-}2$ frequency. This gave us a precise value for the beam energy in CESR. By scanning the $\ensuremath{\Upsilon}$ resonance with the CUSB detector, we obtained a mass ${M}_{\ensuremath{\Upsilon}}=9459.97\ifmmode\pm\else\textpm\fi{}0.11\ifmmode\pm\else\textpm\fi{}0.07$ MeV. We also give rescaled values for the excited $\ensuremath{\Upsilon}$ states.

We consider three broad classes of nonstandard models for b quark decay: (1) b → llq with charged or neutral leptons of arbitrary flavor; (2) b → l q q ; and (3) b → qa − where a − is a Higgs boson or hyperpion. For these classes of models we have calculated the charged energy fraction and the inclusive yields of electrons, muons, protons, and lambdas. We demonstrate that these model predictions are inconsistent with CLEO measurements at the γ (4S).

Using the CLEO detector at the Cornell Electron Storage Ring, the authors have measured the leptonic branching fraction, B/sub mumu/, of the UPSILON(1S), UPSILON(2S), and UPSILON(3S) to be 2.7 +- 0.3 +- 0.3%, 1.9 +- 1.3 +- 0.5%, and 3.3 +- 1.3 +- 0.7%, respectively. Combining these values of B/sub mumu/ with previous measurements of the leptonic widths of these resonances, the authors find the total width of the UPSILON(1S), UPSILON(2S), and UPSILON(3S) to be 48 +- 4 +- 4, 27 +- 17 +- 6, and 13 +- 4 +- 3 keV.

We have studied the production of B mesons in e/sup +/e/sup -/ annihilations and present new measurements of the semileptonic branching fractions for B-meson decay. We find B(B..-->..e..nu..X) = 0.127 +- 0.017 +- 0.013 and B(B..--> mu nu..X) = 0.122 +- 0.017 +- 0.031, where the errors are statistical and systematic, respectively. The observed lepton momentum spectra from B decays are presented. From these spectra we find the mean hadronic mass (M/sub X/) recoiling against the detected lepton to be M/sub X/ = 2.2 +- 0.2 GeV/c/sup 2/. We have also observed an enhancement in the lepton yield from the continuum above BB-bar threshold. This enhancement is interpreted as continuum B production and is consistent with what is expected from the naive quark model.

A detailed investigation of the decay UPSILON(2S)..--> pi../sup +/..pi../sup -/UPSILON(1S) has been made from 128 000 UPSILON(2S) decays observed in the CLEO detector at the Cornell Electron Storage Ring (CESR). We find this branching ratio to be (19.1 +- 1.2 +- 0.6)%. The properties of the ..pi pi.. system have been studied using 491 exclusive events of the type UPSILON(2S)..--> pi../sup +/..pi../sup -/UPSILON(1S), UPSILON(1S)..-->..e/sup +/e/sup -/ or ..mu../sup +/..mu../sup -/. Assuming e-..mu.. universality we find B(UPSILON(1S)..--> mu../sup +/..mu../sup -/) = (2.84 +- 0.18 +- 0.20)%. A search for UPSILON(2S)..-->..etaUPSILON(1S) yields an upper limit of 1% at the 90% confidence level for this branching ratio. We have also searched for (UPSILON(2S) or UPSILON(3S))..--> pi../sup +/..pi../sup -/UPSILON(1S), UPSILON(1S)..-->..noninteracting particles.

A measurement is presented of the inclusive production of charged ${D}^{*}$ and neutral $D$ mesons from nonresonant ${e}^{+}{e}^{\ensuremath{-}}$ annihilation in the energy region near the $\ensuremath{\Upsilon}(4S)$ resonance. The momentum distribution shows a large contribution at high momenta as expected for heavy quark production. Comparison of the spectrum with several phenomenological models is made. The relative yields of the ${D}^{*}$ and $D$ mesons indicate that the charm cross section is dominated by the ${D}^{*}$ contribution.

The decay B-bar /sup 0/..-->..D/sup asterisk+/rho/sup -/ has been observed and the branching ratio is found to be (8.1 +- 2.9/sub -2.4//sup +5.9/)%. The result is compared with theoretical predictions.

We have searched in the decays of the ϒ(1S), ϒ(2S) and B mesons for the narrow state, γ, seen by the Mark II group in radiative ψ decay. We find the product branching fractions B[ϒ(1S) → γγ]·B[γ → K+K−], B[ϒ(2S) → γ γ]· B[γ → K+K−] and B[B → γX]·B[γ → K+K−] to be less than 2×10−4, 9×10−5 and 3×10−3, respectively at 90% confidence level. These limits constrain theoretical models if the γ is interpreted as a Higgs boson.

We report measurements made with the CLEO detector at the Cornell Electron Storage Ring (CESR) of the total cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}$ at the $\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(2S)$, and $\ensuremath{\Upsilon}(3S)$, and in the nearby nonresonant continuum. We find $R=3.77\ifmmode\pm\else\textpm\fi{}0.06 (\mathrm{statistical}) \ifmmode\pm\else\textpm\fi{} 0.24 (\mathrm{systematic})$ for the ratio of the nonresonant hadronic cross section to the cross section for muon-pair production at a center-of-mass total energy $W=10.4$ GeV. For the leptonic decay widths ${\ensuremath{\Gamma}}_{\mathrm{ee}}$ of the $\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(2S)$, and $\ensuremath{\Upsilon}(3S)$ we obtain 1.30\ifmmode\pm\else\textpm\fi{}0.05\ifmmode\pm\else\textpm\fi{}0.08, 0.52\ifmmode\pm\else\textpm\fi{}0.03\ifmmode\pm\else\textpm\fi{}0.04, and 0.42\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.03 keV, respectively.

$B$-meson decays to final states consisting of a ${D}^{0}$ or ${D}^{*\ifmmode\pm\else\textpm\fi{}}$ and one or two charged pions have been observed. The charged-$B$ mass is 5270.8 \ifmmode\pm\else\textpm\fi{} 2.3 \ifmmode\pm\else\textpm\fi{} 2.0 MeV and the neutral-$B$ mass is 5274.2 \ifmmode\pm\else\textpm\fi{} 1.9 \ifmmode\pm\else\textpm\fi{} 2.0 MeV.

We have observed the decay of the UPSILON(2S) into the UPSILON(1S), obtaining a branching ratio of 19.1 +- 3.1 +- 2.9% for the mode UPSILON(2S)..--> pi../sup +/..pi../sup -/UPSILON(1S). The di-pion mass spectrum peaks at large invariant mass, and the angular distribution of the di-pion system is consistent with s-wave production.

We report measurements from CLEO detector of the rate of ..xi.. and ..lambda.. production in e/sup +/e/sup -/ interactions in the upsilon region. Hyperon production from the decay of the UPSILON(1S) is compared with continuum e/sup +/e/sup -/ data. The ratio of the production rates of ..lambda.. (and Lambda-bar) to K/sup 0/ (and K-bar /sup 0/) on the UPSILON(1S) is 0.21 +- 0.03, much larger than in the continuum, 0.07 +- 0.01. The ratios of the production rates of the ..xi.. and the ..lambda.. are comparable, 0.10 +- 0.02 (UPSILON(1S)) and 0.07 +- 0.02 (continuum). We discuss some implications of the data for gluon and quark fragmentation models.

The branching ratio of UPSILON(3S)..--> pi../sup +/..pi../sup -/UPSILON(1S) has been measured to be (4.9 +- 0.9 +- 0.5)%. The di-pion invariant-mass distribution for this decay is flatter than that for the decays UPSILON(2S)..--> pi../sup +/..pi../sup -/UPSILON(1S) and psi'..--> pi../sup +/..pi../sup -/psi.

Evidence is presented for a narrow meson resonance of mass 1970\ifmmode\pm\else\textpm\fi{}5\ifmmode\pm\else\textpm\fi{}5 MeV produced in continuum ${e}^{+}{e}^{\ensuremath{-}}$ annihilations at $\sqrt{s}$ of 10.5 GeV, and decaying into a $\ensuremath{\phi}$ and a charged $\ensuremath{\pi}$.

The inclusive branching fraction for B-meson decay into D/sup 0/ mesons and the momentum spectrum of the D/sup 0/'s have been measured. 0.8 +- 0.2 +- 0.2 D/sup 0/ per B decay was found. The shape of the spectrum suggests an interesting picture of B-meson decay.