Proton-proton analyzing power and spin correlation measurements between 250 and 450 MeV at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>7</mml:mn><mml:mi>°</mml:mi><mml:mo>&lt;~</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi>θ</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant="normal">c</mml:mi><mml:mo>.</mml:mo><mml:mi mathvariant="normal">m</mml:mi><mml:mo>.</mml:mo><mml:mn /></mml:mrow></mml:msub></mml:mrow><mml:mo>&lt;~</mml:mo><mml:mn>90</mml:mn><mml:mi>°</mml:mi></mm

Przewoski, B. von; Rathmann, F.; Dezarn, W.A.; Doskow, J.; Džemidžić, Mario; Haeberli, W.; Hardie, J.; Lorentz, B.; Meyer, H. O.; Pancella, P. V.; Pollock, R.E.; Rinckel, T.; Sperisen, F.; Wise, T.

doi:10.1103/physrevc.58.1897

Cited by 43 publications

(23 citation statements)

References 42 publications

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“…Indeed, using this technology, IUCF has produced a large number of pp spin-correlation parameters of very high precision, see for example Ref. [14]. It is worth noting that the AV18 potential, as an example, fits the post-1992 and both pre-and post-1992 pp (np) data with χ 2 's of 1.74 (1.02) and 1.35 (1.07), respectively [11].…”

Section: Parity-conserving and Parity-violating Potentialsmentioning

confidence: 99%

Parity-violating interaction effects in thenpsystem

2004

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We investigate parity-violating observables in the np system, including the longitudinal asymmetry and neutron-spin rotation in np elastic scattering, the photon asymmetry in np radiative capture, and the asymmetries in deuteron photo-disintegration d( γ, n)p in the threshold region and electrodisintegration d( e, e ′ )np in quasi-elastic kinematics. To have an estimate of the model dependence for the various predictions, a number of different, latest-generation strong-interaction potentials-Argonne v 18 , Bonn 2000, and Nijmegen I-are used in combination with a weak-interaction potential consisting of π-, ρ-, and ω-meson exchanges-the model known as DDH. The complete bound and scattering problems in the presence of parity-conserving, including electromagnetic, and parity-violating potentials is solved in both configuration and momentum space. The issue of electromagnetic current conservation is examined carefully. We find large cancellations between the asymmetries induced by the parity-violating interactions and those arising from the associated pion-exchange currents. In the np capture, the model dependence is nevertheless quite small, because of constraints arising through the Siegert evaluation of the relevant E 1 matrix elements. In quasi-elastic electron scattering these processes are found to be insignificant compared to the asymmetry produced by γ-Z interference on individual nucleons. These two experiments, then, provide clean probes of different aspects of weakinteraction physics associated with parity violation in the np system. Finally, we find that the neutron spin rotation in np elastic scattering and asymmetry in deuteron disintegration by circularly-polarized photons exhibit significant sensitivity both to the values used for the weak vector-meson couplings in the DDH model and to the input strong-interaction potential adopted in the calculation. This reinforces the conclusion that these short-ranged meson couplings are not in themselves physical observables, rather the parity-violating 1 mixings are the physically relevant parameters. 21.30.+y, 25.40.Cm

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Section: Parity-conserving and Parity-violating Potentialsmentioning

confidence: 99%

Parity-violating interaction effects in thenpsystem

2004

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“…Polarized beam experiments have become an important part of the programs in storage rings such as the IUCF Cooler Ring [1], AmPS at NIKHEF [2], the MIT-Bates Storage Ring [3], COSY [4], LEP at CERN [5], RHIC at BNL [6] and HERA at DESY [7,8]. To reduce their systematic errors, polarized scattering experiments require frequent spin-direction reversals (spin flips) while the polarized beam is stored.…”

Section: Introductionmentioning

confidence: 99%

Unexpected enhancements and reductions of rf spin resonance strengths

Леонова

Morozov

Krisch

et al. 2006

Phys. Rev. ST Accel. Beams

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We recently analyzed all available data on spin-flipping stored beams of polarized protons, electrons, and deuterons. Fitting the modified Froissart-Stora equation to the measured polarization data after crossing an rf-induced spin resonance, we found 10 -20-fold deviations from the depolarizing resonance strength equations used for many years. The polarization was typically manipulated by linearly sweeping the frequency of an rf dipole or rf solenoid through an rf-induced spin resonance; spin-flip efficiencies of up to 99:9% were obtained. The Lorentz invariance of an rf dipole's transverse R Bdl and the weak energy dependence of its spin resonance strength E together imply that even a small rf dipole should allow efficient spin flipping in 100 GeV or even TeV storage rings; thus, it is important to understand these large deviations. Therefore, we recently studied the resonance strength deviations experimentally by varying the size and vertical betatron tune of a 2:1 GeV=c polarized proton beam stored in COSY. We found no dependence of E on beam size, but we did find almost 100-fold enhancements when the rf spin resonance was near an intrinsic spin resonance.

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“…During the past decade, polarized beam experiments have become an important part of the programs in storage rings such as the IUCF Cooler Ring [1], AmPS at NIKHEF [2], the MIT-Bates Storage Ring [3], COSY [4], the e e ÿ collider LEP at CERN [5], the Relativistic Heavy Ion Collider at BNL [6], and the ep collider HERA at DESY [7,8]. Many polarized scattering experiments require frequent spin-direction reversals (spin flips), while the polarized beam is stored, to reduce their systematic errors.…”

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confidence: 99%

Achieving 99.9% Proton Spin-Flip Efficiency At Higher Energy With A Small rf Dipole

et al. 2004

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We recently used a new ferrite rf dipole to study spin flipping of a 2:1 GeV=c vertically polarized proton beam stored in the COSY Cooler Synchrotron in Jülich, Germany. We swept the rf dipole's frequency through an rf-induced spin resonance to flip the beam's polarization direction. After determining the resonance's frequency, we varied the frequency range, frequency ramp time, and number of flips. At the rf dipole's maximum strength and optimum frequency range and ramp time, we measured a spin-flip efficiency of 99:92 0:04%. This result, along with a similar 0:49 GeV=c IUCF result, indicates that, due to the Lorentz invariance of an rf dipole's transverse R Bdl and the weak energy dependence of its spin-resonance strength, an only 35% stronger rf dipole should allow efficient spin flipping in the 100 GeV BNL RHIC Collider or even the 7 TeV CERN Large Hadron Collider. [7,8]. Many polarized scattering experiments require frequent spin-direction reversals (spin flips), while the polarized beam is stored, to reduce their systematic errors. Spin resonances [9,10] induced by either an rf solenoid or rf dipole can produce these spin flips in a well controlled way [11][12][13][14][15][16][17][18][19][20][21].An rf dipole was earlier used [19] to spin flip 120 MeV (490 MeV=c) polarized protons stored in the IUCF Cooler Ring with a 99:93 0:02% spin-flip efficiency. At very high energy, the spin-flip efficiency with an rf dipole should become almost independent of energy, mostly due to the Lorentz invariance of a magnet's transverse R Bdl [22]; this invariance is quite important for very high energy polarized proton rings [23]. To confirm this we recently used an rf dipole to study the spin flipping of 2:1 GeV=c polarized protons stored in the COSY ring.In any flat storage ring or circular accelerator with no horizontal magnetic fields, each proton's spin precesses around the vertical fields of the ring's dipole magnets. The spin tune s , which is the number of spin precessions during one turn around the ring, is proportional to the proton's energywhere G g ÿ 2=2 1:792 847 is the proton's gyromagnetic anomaly and is its Lorentz energy factor. The vertical polarization can be perturbed by an rf dipole's horizontal rf magnetic field. This perturbation can induce an rf depolarizing resonance, which can flip the spin direction of the stored polarized protons [11][12][13][14][15][16][17][18][19][20][21]; the resonance's frequency iswhere f c is the protons's circulation frequency and k is an integer. Adiabatically ramping the rf magnet's frequency through f r can flip each proton's spin. The Froissart-Stora equation [9] relates the beam's initial polarization P i to its final polarization P f after crossing the resonance,the ratio f=t is the resonance crossing rate, where f is the ramp's full-frequency range during the ramp time t. The resonance strength is given bywhere e is the proton's charge, p is its momentum, and R B rms dl is the rf dipole's rms magnetic field integral. The apparatus used for this experiment, includin...

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Proton-proton analyzing power and spin correlation measurements between 250 and 450 MeV at7°<~θc.m.<~90°

Cited by 43 publications

References 42 publications

Parity-violating interaction effects in thenpsystem

Parity-violating interaction effects in thenpsystem

Unexpected enhancements and reductions of rf spin resonance strengths

Achieving 99.9% Proton Spin-Flip Efficiency At Higher Energy With A Small rf Dipole

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