Overview of Processes Involved in Spin Transfer Collisions

Barber, D. P.; Buttimore, N. H.; Chattopadhyay, S; Court, G.R.; Steffens, E.

doi:10.1063/1.2932261

Cited by 3 publications

(3 citation statements)

References 15 publications

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“…Second, an important application of CNI-generated azimuthal asymmetry is the possibility to measure the polarization of the beam, in particular at RHIC. The usage of CNI as a polarimeter has been intensively studied in [8][9][10][11][12][13][14][15][16][17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Probing the Pomeron spin structure with Coulomb-nuclear interference

2021

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Section: Introductionmentioning

confidence: 99%

Probing the Pomeron spin structure with Coulomb-nuclear interference

2021

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Section: Introductionmentioning

confidence: 99%

Coulomb-Nuclear Interference in Polarized pA Scattering

Kopeliovich,

Krelina,

Potashnikova

2024

Universe

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We made the first attempt to understand the observed unusual t dependence of single-spin asymmetry observed in the HJET experiment at RHIC. Usually, the interaction of hadrons is presented as a long-range Coulomb interaction and a short-range strong interaction with Coulomb corrections. Such a division gives rise to a Coulomb phase of the hadronic term. Conversely, here we consider short-range hadronic interaction as a correction to the long-range electromagnetic term, i.e., we treat it as an absorptive correction. This significantly affects the Coulomb-nuclear interference, which is a source of single-spin azimuthal asymmetry at small angles.

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“…Small angle elastic scattering of hadrons in the Coulomb-Nuclear Interference(CNI) region has long been advocated for polarimetry [1]. The predicted analyzing power is not large but due to the large cross section, the figure of merit ¾ is large.…”

Section: è-Cni Elastic Scatteringmentioning

confidence: 99%

A new relative proton polarimeter for RHIC

Huang

Alekseev

Bunce

et al.

PACS2001. Proceedings of the 2001 Particle Accelerator Conference (Cat. No.01CH37268)

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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 in September, 2000. The polarimeter consists of ultra-thin carbon targets and four silicon detectors. All elements are in a 1.6 meter vacuum chamber. This paper summarizes the polarimeter design issues and recent commissioning results. È-CNI ELASTIC SCATTERINGSmall angle elastic scattering of hadrons in the Coulomb-Nuclear Interference(CNI) region has long been advocated for polarimetry [1]. The predicted analyzing power is not large but due to the large cross section, the figure of merit ¾ is large. The analyzing power is also predicted to be largely independent of energy for energy above a few GeV. At high energies, it is expected that hadronic spin flip is small, which in turn formulates the basis of this prediction. However, for Ô-CNI, a typical ( Ø) value of 0.002 to 0.01 GeV ¾ results at high energy in a very small angle of the forward scattered proton relative to the beam direction and also a very low kinetic energy of the Carbon recoil of about 0.1-1 MeV. It is impossible to measure the forward scattered proton without drastically reducing the beam size at the target. It therefore necessitates reliance only on the measurement of the recoil Carbon nuclei to identify elastic scattering. The low energy carbon nuclei would stop in most targets. The very thin ribbon carbon target developed at IUCF[2] was crucial to the Ô-CNI polarimeter: both for survival in the RHIC beam and to get the carbon nuclei out of the target in the CNI region, as the recoil carbon carries only hundreds of keV kinetic energy. The known analyzing power, large cross section and advantages of a solid ribbon target makes this process ideal OVERALL DESIGNThe SSD had a thickness of 400 m and was segmented into twelve strips. This segmentation provides angular information and reduces the event rate per strip which becomes exceedingly high at full luminosity. The surface of the SSD had a special feature of a very thin Boron implantation with small aluminum evaporation electrodes so that low energy recoil carbon could penetrate the surface without being hindered by the electrodes.The warm straight section between Q3 and Q4 at section 12 in RHIC was assigned for installation of polarimeters in both Blue and Yellow rings. Both target chambers are located near Q4 where the vertical and horizontal lattice ¬ functions are small, thus reducing the effect of multiple scattering on emittance dilution. Circulating beams are in opposite directions in the two rings. Both target chambers have been placed upstream of each other and therefore, the detectors for both polarimeters are not in each other's scattering showers.It is desirable for the polarimeter to measure both horizontal and vertical beam polarization profiles, which requires separate targets scanning both vertically and horizontally. Since the thin carbon ta...

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Overview of Processes Involved in Spin Transfer Collisions

Cited by 3 publications

References 15 publications

Probing the Pomeron spin structure with Coulomb-nuclear interference

Probing the Pomeron spin structure with Coulomb-nuclear interference

Coulomb-Nuclear Interference in Polarized pA Scattering

A new relative proton polarimeter for RHIC

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