Measurement of analyzing powers of pi + and pi - produced on a hydrogen and a carbon target with a 22-GeV/c incident polarized proton beam

Allgower, C.E. ; Krueger, K.W. ; Kasprzyk, T.E. ; et al.
Phys.Rev.D 65 (2002) 092008, 2002.
Inspire Record 587580 DOI 10.17182/hepdata.22221

The analyzing powers of π+ and π− were measured using an incident 22−GeV/c transversely polarized proton beam at the Brookhaven Alternating Gradient Synchrotron. A magnetic spectrometer measured π± inclusive asymmetries on a hydrogen and a carbon target. An elastic polarimeter with a CH2 target measured pp elastic-scattering asymmetries to determine the beam polarization using published data for the pp elastic analyzing power. Using the beam polarization determined from the elastic polarimeter and asymmetries from the inclusive spectrometer, analyzing powers AN for π± were determined in the xF and pT ranges (0.45–0.8) and (0.3–1.2 GeV/c), respectively. The analyzing power results are similar in both sign and character to other measurements at 200 and 11.7 GeV/c, confirming the expectation that high-energy pion inclusive analyzing powers remain large and relatively energy independent. This suggests that pion inclusive polarimetry may be a suitable method for measuring future beam polarizations at BNL RHIC or DESY HERA. Analyzing powers of π+ and π− produced on hydrogen and carbon targets are the same. Various models to explain inclusive analyzing powers are also discussed.

7 data tables

Analyzing power measurements for PI+ and PI- production on the carbon target at incident momentum 21.6 GeV. See text of article for definitions of method 'A' and 'B'.

Analyzing power measurements for inclusive PI- production from the hydrogen target.

Analyzing power measurements for inclusive PI+ production from the hydrogen target.

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Measurement of the Antilambda polarization in nu/mu charged current interactions in the NOMAD experiment.

The NOMAD collaboration Astier, P. ; Autiero, D. ; Baldisseri, A. ; et al.
Nucl.Phys.B 605 (2001) 3-14, 2001.
Inspire Record 554759 DOI 10.17182/hepdata.48928

We present a measurement of the polarization of Antilambda hyperons produced in nu_mu charged current interactions. The full data sample from the NOMAD experiment has been analyzed using the same V0 identification procedure and analysis method reported in a previous paper for the case of Lambda hyperons. The Antilambda polarization has been measured for the first time in a neutrino experiment. The polarization vector is found to be compatible with zero.

2 data tables

Lambdabar polarization in regions of Feynman X (XL).

Lambdabar polarization in regions of the Bjorken scaling variable X.