Abreu, P.
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First measurement of the anti-p p ---> anti-n n depolarization parameter D(0n0n) at 546-MeV/c and 875-MeV/c

Ahmidouch, A. ; Heer, E. ; Hess, R. ; et al.
Nucl.Phys.B 444 (1995) 27-58, 1995.
Inspire Record 405013 DOI 10.17182/hepdata.32839

The depolarization parameter Donon of the p dash p → n dash n charge exchange reaction has been measured for the first time at the CERN Low Energy Antiproton Ring (LEAR) at two antiproton momenta, 546 and 875 MeV/ c . The transverse polarization of the recoil neutron was analyzed using a large-acceptance neutron polarimeter made up of two parallel plastic scintillator planes. D 0 n 0 n is usually less than 0.35 which suggests that the spin-spin amplitudes dominate in the scattering matrix. Results are compared with the predictions of various N dash N potential models. The agreement is in general satisfactory.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Measurement of single spin asymmetry for direct photon production in p p collisions at 200-GeV/c

The E704 collaboration Adams, D.L. ; Achurin, N. ; Belikov, N.I. ; et al.
Phys.Lett.B 345 (1995) 569-575, 1995.
Inspire Record 399938 DOI 10.17182/hepdata.28766

The single spin asymmetry for inclusive direct-photon production has been measured using a polarized proton beam of 200 GeV/c with an unpolarized proton target at −0.15 < xf < 0.15 and 2.5 < pt < 3.1 GeV/c at Fermilab. The data on the cross section for pp → γX at 2.5 < pt < 3.8 GeV/c are also provided. The measurement was done using lead-glass calorimeters and photon detectors which surrounded the fiducial area of the calorimeters. Background rejection has been done using these surrounding photon detectors. The cross section obtained is consistent with the results of previous measurements assuming a nuclear dependence of A 1.0 . The single spin asymmetry, A N , for the direct-photon production is consistent with zero within experimental uncertainty.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Analyzing power measurement in inclusive Lambda0 production with a 200-GeV/c polarized proton beam

The E704 collaboration Bravar, A. ; Adams, D.L. ; Akchurin, N. ; et al.
Phys.Rev.Lett. 75 (1995) 3073-3077, 1995.
Inspire Record 406598 DOI 10.17182/hepdata.19610

The considerable polarization of hyperons produced at high xF has been known for a long time and has been interpreted with various theoretical models in terms of the constituents' spin. Recently, the analyzing power in inclusive Λ0 hyperon production has also been measured using the 200GeV/c Fermilab polarized proton beam. The covered kinematic range is 0.2≤xF≤1.0 and 0.1≤pT≤1.5GeV/c. The data indicate a negative asymmetry at large xF and moderate pT. These results can further test the current ideas on the underlying mechanisms for hyperon polarization.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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A Search for jet handedness in hadronic Z0 decays

The SLD collaboration Abe, K. ; Abt, I. ; Ahn, C.J. ; et al.
Phys.Rev.Lett. 74 (1995) 1512-1516, 1995.
Inspire Record 378343 DOI 10.17182/hepdata.19666

We have searched for signatures of polarization in hadronic jets from $Z~0 \rightarrow q \bar{q}$ decays using the ``jet handedness'' method. The polar angle asymmetry induced by the high SLC electron-beam polarization was used to separate quark jets from antiquark jets, expected to be left- and right-polarized, respectively. We find no evidence for jet handedness in our global sample or in a sample of light quark jets and we set upper limits at the 95\% C.L. of 0.063 and 0.099 respectively on the magnitude of the analyzing power of the method proposed by Efremov {\it et al.}

1 data table
Table 1

Polarized E- beam. Events were classified as being of light or heavy flavors based on impact parameters of charged tracks measured in the vertex detector. Jet handedness are measured for helicity-based and chirality-based analysis (seetext). C=95PCT CL indicates the upper limits at the 95 PCT C.L. on the magnitudes.


A High statistics measurement of the anti-p p ---> anti-n n charge exchange reaction at 875-MeV/c

Lamanna, M. ; Ahmidouch, A. ; Birsa, R. ; et al.
Nucl.Phys.B 434 (1995) 479-502, 1995.
Inspire Record 379991 DOI 10.17182/hepdata.48341

A new measurement of the differential cross section and of the analysing power A 0 n of the charge-exchange reaction p − p → n − n at 875 MeV/ c is presented. The A 0 n data cover the entire angular range and constitute a considerable improvement over previously published data, both in the forward and in the backward hemisphere. The cross-section data cover only the backward region, but are unique at this energy. A careful study of the long-term drifts of the apparatus has allowed to fully exploit the good statistics of the data.

3 data tables
Table 1

Forward hemisphere measurement. Additional systematic error of 4 pct due to target polarization uncertainty.

Table 2

Backward hemisphere measurement. Additional systematic error of 15 pct.

Table 3

Differential cross section in the backward hemisphere. Additional systematic error of 15 pct.


Single spin asymmetries and invariant cross-sections of the high transverse momentum inclusive pi0 production in 200-GeV/c p p and anti-p p interactions

The FNAL E704 collaboration Adams, D.L. ; Akchurin, N. ; Belikov, N.I. ; et al.
Phys.Rev.D 53 (1996) 4747-4755, 1996.
Inspire Record 382392 DOI 10.17182/hepdata.40544

The π0 inclusive and semi-inclusive, single-spin asymmetries have been measured using transversely polarized, 200-GeV/c proton and antiproton beams colliding with an unpolarized hydrogen target. The measured asymmetries are consistent with zero within the experimental uncertainties for the kinematic region -0.15

3 data tables
Table 1

No description provided.

Table 2

Pure inclusive reaction.

Table 3

Semi-inclusive reaction where at least on associated charged particle is produced at (180+-30) degrees relative to the pi0.


Measurement of the polarization of Lambda0, anti-Lambda0, Sigma+ and Xi- produced in a Sigma- beam of 330-GeV/c

The WA89 collaboration Adamovich, M.I. ; Albertson, E. ; Alexandrov, Yu. A. ; et al.
Z.Phys.A 350 (1995) 379-386, 1995.
Inspire Record 375458 DOI 10.17182/hepdata.48194

The polarization of Lambda0, AntiLambda0, Sigma+ and Xi- inclusively produced in Sigma- induced interactions at 330 GeV has been measured in the experiment WA89 at CERN. This is the first measurement of polarization of baryons produced by a hyperon beam. No polarization of AntiLambda is observed, as was also the case in proton beam data. At transverse momenta of about 1GeV/c Lambda0 and Sigma+ show little polarization, significantly lower than in the proton beam data, while Xi- have a polarization comparable to the polarization of Lambda0 produced in proton beams.

3 data tables
Table 1

Target Consisted of a copper and a carbon block arranged side by side.

Table 2

Target Consisted of a copper and a carbon block arranged side by side.

Table 3

Target Consisted of a copper and a carbon block arranged side by side.


Vector analyzing power iT11 in pi d elastic scattering at 49 MeV

Kohler, M. ; King, B.E. ; Stevenson, N.R. ; et al.
Phys.Rev.C 49 (1994) 1715-1717, 1994.
Inspire Record 389448 DOI 10.17182/hepdata.25990

Measurements of the vector analyzing power iT11 in πd elastic scattering at 49 MeV have been performed using a dynamically polarized target and a magnetic spectrometer. Data at seven π+ laboratory scattering angles between 50° and 130° were taken together with a complementary measurement at 60° for π−d elastic scattering. In general, we find agreement with models that include the πN P11 amplitude and disagreement with models that exclude or suppress it.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Polarization of $\Lambda$ and $\bar{\Lambda}$ Produced by 800 GeV Protons

Ramberg, E.J. ; Bock, G.J. ; Coleman, R. ; et al.
Phys.Lett.B 338 (1994) 403-408, 1994.
Inspire Record 372108 DOI 10.17182/hepdata.42451

We have measured the polarization of Λ and Λ hyperons produced by 800 GeV protons on a Be target at a fixed targeting angle of 4.8 mrad. Comparison with previous data at 400 GeV production energy and twice the targeting angle shows no significant energy dependence for the Λ polarization. This is in striking contrast to the energy dependence found for σ + and Ξ − polarizations. We find no evidence for Λ polarization at 800 GeV.

2 data tables
Table 1

Errors are combined statistics and systematics.

Table 2

No description provided.


A Study of the transverse polarization of Lambda0 and Anti-lambda0 hyperons produced in pi- Cu interactions at 230-GeV/c

The ACCMOR collaboration Barlag, S. ; Becker, H. ; Bożek, A. ; et al.
Phys.Lett.B 325 (1994) 531-535, 1994.
Inspire Record 377671 DOI 10.17182/hepdata.28729

We study the polarization with respect to the normal to the production plane for a very clean sample of 27217 Λ 0 / Λ 0 hyperons produced in 230 GeV/ c π −  Cu interactions. In general we find P(Λ 0 ) ≈ P( Λ 0 ap; 0 except for x F > 0, p T > 1GeV/ c where P ( Λ 0 ) = −0.28±0.09(stat.)±0.02(syst.).

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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