Correcting systematic errors in high-sensitivity deuteron polarization measurements

Brantjes, N. P. M.; Dzordzhadze, V.; Gebel, R.; Gonnella, F.; Gray, F.; Hoek, D.J. van der; Imig, A.; Kruithof, W.L.; Lazarus, D. M.; Lehrach, A.; Lorentz, B.; Messi, R.; Moricciani, D.; Morse, W. M.; Noid, G.; Onderwater, C. J. G.; Özben, C.; Prasuhn, D.; Sandri, P. Levi; Semertzidis, Yannis K.; Silva, M. da Silva e; Stephenson, E. J.; Stockhorst, H.; Venanzoni, G.; Versolato, Oscar

doi:10.1016/j.nima.2011.09.055

Cited by 45 publications

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References 33 publications

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“…Reactions that produce lower energy particles, usually a deuteron or a proton, are removed with an absorbing medium between the target and the detector. A similar arrangement was achieved in a previous experiment [7] using the scintillators of the EDDA detector [4,5]. Long scintillators, called ''bars,'' ran parallel to the beam and were read out with photomultiplier tubes mounted on the downstream end.…”

Section: Methodsmentioning

confidence: 99%

“…The scattering target for the polarimeter was a carbon tube 15 mm long that surrounded the beam [7]. Slow extraction of the beam onto the target was achieved by locally steering the beam vertically upward into the top edge of the tube.…”

Section: Methodsmentioning

confidence: 99%

“…This combination of count rates tends to suppress errors that arise as first-order contributions from geometric misalignments due to beam position or angle, or from detector acceptance. During the run, a more extensive calibration of the polarimeter sensitivity to systematic geometric and rate problems was conducted in the manner proscribed in Brantjes et al [7]. Subsequent investigation showed that systematic errors from the use of the cross ratio formula were typically much less than 10 À4 .…”

Section: Vertical Polarization Measurementsmentioning

confidence: 99%

“…In addition, there must be methods to reduce and/ or correct systematic polarimeter errors under conditions where the beam-target geometry and instantaneous counting rate are changing. In a recent experiment using the scintillators of the EDDA detector [4,5] located at the cooler synchrotron (COSY) at the Forschungszentrum Jülich [6], a thick carbon target located at the edge of the circulating beam was used to demonstrate efficient operation, high spin sensitivity, and the ability to correct systematic errors at levels below 10 À5 in the polarization measurement [7]. By arranging for a continuous, slow extraction of the beam onto the carbon block, this arrangement provided a means of continuously monitoring the beam polarization during the time that the beam was captured in the storage ring.…”

Section: Introductionmentioning

confidence: 99%

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Synchrotron oscillation effects on an rf-solenoid spin resonance

Benati¹,

Chiladze²,

Dietrich³

et al. 2012

Phys. Rev. ST Accel. Beams

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New measurements are reported for the time dependence of the vertical polarization of a 0:97 GeV=c deuteron beam circulating in a storage ring and perturbed by an rf solenoid. The storage ring is the cooler synchrotron (COSY) located at the Forschungszentrum Jülich. The beam polarization was measured continuously using a 1.5 cm thick carbon target located at the edge of the circulating deuteron beam and the scintillators of the EDDA detector. An rf solenoid mounted on the ring was used to generate fields at and near the frequency of the 1 À G spin resonance. Measurements were made of the vertical beam polarization as a function of time with the operation of the rf solenoid in either fixed or continuously variable frequency mode. Using rf-solenoid strengths as large as 2:66 Â 10 À5 revolutions=turn, slow oscillations ($ 1 Hz) were observed in the vertical beam polarization. When the circulating beam was continuously electron cooled, these oscillations completely reversed the polarization and showed no sign of diminishing in amplitude. But for the uncooled beam, the oscillation amplitude was damped to nearly zero within a few seconds. A simple spin-tracking model without the details of the COSY ring lattice was successful in reproducing these oscillations and demonstrating the sensitivity of the damping to the magnitude of the synchrotron motion of the beam particles. The model demonstrates that the characteristic features of measurements made in the presence of large synchrotron oscillations are distinct from the features of such measurements when made off resonance. These data were collected in preparation for a study of the spin coherence time, a beam property that needs to become long to enable a search for an electric dipole moment using a storage ring.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Vertical Polarization Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Synchrotron oscillation effects on an rf-solenoid spin resonance

Benati¹,

Chiladze²,

Dietrich³

et al. 2012

Phys. Rev. ST Accel. Beams

Self Cite

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show abstract

“…A lower limit on the spin coherence time of 75 s was demonstrated already, just one order of magnitude below the goal for the proton and deuteron EDM experiments [29]. Also at COSY a scheme to efficiently measure deuteron polarization and to correct for systematic errors was demonstrated [30]. The demonstrated sensitivity is sufficient to reach the proposed sensitivity of d d = 10…”

Section: Discussionmentioning

confidence: 90%

Search for electric dipole moments at storage rings

Onderwater

2012

Hyperfine Interact

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Permanent electric dipole moments (EDMs) violate parity and timereversal symmetry. Within the Standard Model (SM) they are many orders of magnitude below present experimental sensitivity. Many extensions of the SM predict much larger EDMs, which are therefore an excellent probe for the existence of "new physics". Until recently it was believed that only electrically neutral systems could be used for sensitive searches of EDMs. With the introduction of a novel experimental method, high precision for charged systems will be within reach as well. The features of this method and its possibilities are discussed.Keywords Permanent electric dipole moment · Standard model test · New physics search MotivationThe symmetry properties of fundamental processes and particles are a strong guide to understand the underlying interactions. The QED Lagrangian in the current Standard Model (SM) predicts that all electromagnetic observables are even under the discrete symmetries C (charge conjugation), P (parity) and T (time reversal) individually and thus under each combinations of them. Strong interaction observables, described by QCD, are also predicted to be even under C, P and T , with the exception of those proportional toθ which are P and T -odd [1]. The weak interaction violates both P and C because of the handedness of the coupling of the W and Z-bosons. Many observables are even under their combination CP. Nevertheless, the weak interaction also predicts CP-odd ones. These are all proportional to the Jarlskog invariant, J ∝ sin 2 θ 12 sin θ 23 sin θ 13 sin δ ∼ 3 × 10 −5 [2]. Here θ 12 , θ 23 and θ 13 are the quark flavor mixing angles and δ the CP-violating complex phase associated

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Searching for electric dipole moments

Jungmann

2013

Annalen der Physik

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Searches for a permanent Electric Dipole Moment (EDM) of a fundamental particle provide a wide window for the discovery of potential New Physics. Within todays Standard Model in particle physics the well established violation of CP symmetry gives rise to EDMs which are several orders of magnitude below the present experimentally established upper bounds. On the other hand, EDMs appear quite naturally within many modern speculative theories, which have been suggested to improve the known shortcomings of the present Standard Model, e.g., the lack of giving reasons for certain established facts such as the mass hierarchy of the fundamental fermions or the number of three particle generations. They could be almost as large as the present experimental bounds. The speculative models provide for EDMs of different fundamental particles in specific ways. As there is no convincing indication, yet, which of the various extensions to the present standard theory may be more successful, a larger number of EDM searches is very well motivated. Still, even with the discovery of an EDM in one system several experiments will be required to pin down the precise nature and the underlying processes. Therefore searches are going on presently in a variety of systems, ranging from free leptons to complex condensed matter samples. These experiments utilize typically state of the art precision measurements which are often based on forefront technological developments. The experimental efforts are complemented and guided by the further development and refinement of particle theory. Here a few aspects of recent developments in this exciting field are summarized.

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Correcting systematic errors in high-sensitivity deuteron polarization measurements

Cited by 45 publications

References 33 publications

Synchrotron oscillation effects on an rf-solenoid spin resonance

Synchrotron oscillation effects on an rf-solenoid spin resonance

Search for electric dipole moments at storage rings

Searching for electric dipole moments

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