Adolph, C.
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Analysing power A(y) in the reaction p(pol.) p --> p p eta close to threshold.

Winter, P. ; Adam, H.H. ; Bauer, F. ; et al.
Phys.Lett.B 544 (2002) 251-258, 2002.
Inspire Record 599591 DOI 10.17182/hepdata.31686

Measurements of the eta meson production with a polarised proton beam in the reaction p(pol) p --> p p eta have been carried out at an excess energy of Q = 40 MeV. The dependence of the analysing power A_y on the polar angle theta^*_q of the eta meson in the center of mass system (CMS) has been studied. The data indicate the possibility of an influence of p- and d-waves to the close to threshold eta production.

1 data table
Table 1

Averaged value of the analyzing power and cross section as a function of the emmission angle of the ETA meson is the CM system.


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
Table 1

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'.

Table 2

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

Table 3

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

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Upsilon production and polarization in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Acosta, D. ; Affolder, T. ; Akimoto, H. ; et al.
Phys.Rev.Lett. 88 (2002) 161802, 2002.
Inspire Record 569269 DOI 10.17182/hepdata.42894

We report on measurements of the ϒ(1S), ϒ(2S), and ϒ(3S) differential cross sections (d2σ/dpTdy)|y|<0.4, as well as on the ϒ(1S) polarization in pp¯ collisions at s=1.8TeV using a sample of 77±3pb−1 collected by the collider detector at Fermilab. The three resonances were reconstructed through the decay ϒ→μ+μ−. The measured angular distribution of the muons in the ϒ(1S) rest frame is consistent with unpolarized meson production.

4 data tables
Table 1

The differential cross section times the branching ratio into mu+ mu- for UPSILON(1S) production.

Table 2

The differential cross section times the branching ratio into mu+ mu- for UPSILON(2S) production. The first DSYS error is the systematic error due to the polarization of the UPSILON which is shown seperately from the other systematic errors.

Table 3

The differential cross section times the branching ratio into mu+ mu- for UPSILON(3S) production. The first DSYS error is the systematic error due to the polarization of the UPSILON which is shown seperately from the other systematic errors.

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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
Table 1

Lambdabar polarization in regions of Feynman X (XL).

Table 2

Lambdabar polarization in regions of the Bjorken scaling variable X.


rivet Analysis
Precision neutral current asymmetry parameter measurements from the tau polarization at LEP.

The OPAL collaboration Abbiendi, G. ; Ainsley, C. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 21 (2001) 1-21, 2001.
Inspire Record 554583 DOI 10.17182/hepdata.49765

Measurements of the tau lepton polarization and forward-backward polarization asymmetry near the Z resonance using the OPAL detector are described. The measurements are based on analyses of tau -> e nu_e nu_tau, tau -> mu nu_mu nu_tau, tau -> pi nu_tau, tau -> rho nu_tau and tau -> a1 nu_tau decays from a sample of 144810 e+e- -> tau+ tau- candidates corresponding to an integrated luminosity of 151 pb-1. Assuming that the tau lepton decays according to V-A theory, we measure the average tau polarization near Ecm = MZ to be <Ptau> = (-14.10 +/- 0.73 +/- 0.55)% and the tau polarization forward-backward asymmetry to be Afb = (-10.55 +/- 0.76 +/- 0.25)%, where the first error is statistical and the second systematic. Taking into account the small effects of the photon propagator, photon-Z interference and photonic radiative corrections, these results can be expressed in terms of the lepton neutral current asymmetry parameters: Atau = 0.1456 +/- 0.0076 +/- 0.0057, Ae = 0.1454 +/- 0.0108 +/- 0.0036. These measurements are consistent with the hypothesis of lepton universality and combine to give Al = 0.1455 +/- 0.0073. Within the context of the Standard Model this combined result corresponds to sin^2(theta)(lept,effective) = 0.23172 +/- 0.00092. Combing these results with those from the other OPAL neutral current measurements yields a value of sin^2(theta)(lept,effective) = 0.23211 +/- 0.00068.

1 data table
Table 1

No description provided.


Measurement of J / psi and psi(2S) polarization in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 85 (2000) 2886-2891, 2000.
Inspire Record 526553 DOI 10.17182/hepdata.42989

We have measured the polarization of J/Psi and Psi(2S) mesons produced in p\bar{p} collisions at \sqrt{s} = 1.8 TeV, using data collected at CDF during 1992-95. The polarization of promptly produced J/Psi [Psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4[5.5] < P_T < 20 GeV/c and |y| < 0.6. For P_T \gessim 12 GeV/c we do not observe significant polarization in the prompt component.

2 data tables
Table 1

Polarization for prompt J/PSIs (Q=PROMPT) and for J/PSI from B meson decays(NAME=BEAUTY).

Table 2

Polarization for prompt PSI(2S) (NAME=PROMPT) and for PSI(2S) from B meson decays (NAME=B).


Measurement of the vector analyzing power in elastic electron proton scattering as a probe of double photon exchange amplitudes.

The SAMPLE collaboration Wells, S.P. ; Averett, T. ; Barkhuff, D. ; et al.
Phys.Rev.C 63 (2001) 064001, 2001.
Inspire Record 524209 DOI 10.17182/hepdata.31444

We report the first measurement of the vector analyzing power in inclusive transversely polarized elastic electron-proton scattering at Q^2 = 0.1 (GeV/c)^2 and large scattering angles. This quantity should vanish in the single virtual photon exchange, plane wave impulse approximation for this reaction, and can therefore provide information on double photon exchange amplitudes for electromagnetic interactions with hadronic systems. We find a non-zero value of A=-15.4+/-5.4 ppm. No calculations of this observable for nuclei other than spin 0 have been carried out in these kinematics, and the calculation using the spin orbit interaction from a charged point nucleus of spin 0 cannot describe these data.

1 data table
Table 1

Polarized beam.


Measurement of tensor polarization elastic electron deuteron scattering at large momentum transfer.

The JLAB t(20) collaboration Abbott, D. ; Ahmidouch, A. ; Anklin, H. ; et al.
Phys.Rev.Lett. 84 (2000) 5053-5057, 2000.
Inspire Record 523086 DOI 10.17182/hepdata.40433

Tensor polarization observables (t20, t21 and t22) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c)^2. The experiment was performed at the Jefferson Laboratory in Hall C using the electron HMS Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q^2 the deuteron charge form factors G_C and G_Q. They are in good agreement with relativistic calculations and disagree with pQCD predictions.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Measurement of spin observables in neutron proton elastic scattering. I: Correlation parameters

Arnold, J. ; van den Brandt, B. ; Daum, M. ; et al.
Eur.Phys.J.C 17 (2000) 67-81, 2000.
Inspire Record 537914 DOI 10.17182/hepdata.43392

The spin correlation parameters$A_{oonn}, A_{ooss}, A_{oosk}, A_{ookk}$and the analyzing power$A_{oono}$have been measured i

6 data tables
Table 1

Values of the coefficients for the linear combinations of the spin correlation parameters Cpq measurements for the four different beam and target polarisation orientations. For the (z,z) and (y,y) configurations the coefficients are identical for all incident kinetic energies.

Table 2

Measurement of the analysing power. Statistical errors only are shown. For the systematic errors see the systematics section above. Note that there are two overlapping angular settings.

Table 3

Measurements of the spin correlation parameter CNN. Statistical errors onlyare shown. For the systematics see the systematic section above. Note the two overlapping angular settings.

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Lambda and Antilambda polarization from deep inelastic muon scattering

The E665 collaboration Adams, M.R. ; Aderholz, M. ; Aïd, S. ; et al.
Eur.Phys.J.C 17 (2000) 263-267, 2000.
Inspire Record 509690 DOI 10.17182/hepdata.43315

We report results of the first measurements of Lambda and Antilambda polarization produced in deep inelastic polarized muon scattering on the nucleon. The results are consistent with an expected trend towards positive polarization with increasing x_F. The polarizations of Lambda and Antilambda appear to have opposite signs. A large negative polarization for Lambda at low positive x_F is observed and is not explained by existing models.A possible interpretation is presented.

2 data tables
Table 1

The measured and corrected (undiluted) polarizations.

Table 2

The measured and corrected (undiluted) polarizations.