Pfeifenschneider, P.
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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<xF<+0.15 and 1<pT<4.5 GeV/c. Improvements in the data analysis showed that our earlier large asymmetries at pT≳3 GeV/c were not correct. These data indicate that PQCD expectations seem confirmed and the higher-twist contribution to the single-spin asymmetry in π0 production at xF=0 is not large. Additional evidence for such a conclusion comes from the measurement of a semi-inclusive π0 asymmetry, where associated charged particles are detected opposite to the π0 azimuthal direction. This experiment also provides high-statistics data on the inclusive π0 cross sections for pp and p¯p collisions at √s≊19.4 GeV. © 1996 The American Physical Society.

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.


A Precision measurement of the prompt photon cross-section in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amidei, D. ; et al.
Phys.Rev.Lett. 73 (1994) 2662-2666, 1994.
Inspire Record 375582 DOI 10.17182/hepdata.19680

A prompt photon cross section measurement from the Collider Detector at Fermilab experiment is presented. Detector and trigger upgrades, as well as 6 times the integrated luminosity compared with our previous publication, have contributed to a much more precise measurement and extended PT range. As before, QCD calculations agree qualitatively with the measured cross section, but the data has a steeper slope than the calculations.

1 data table
Table 1

Note that the sytematic uncertainties are approximately 100 pct correlated bin to bin.


Spin asymmetry in muon - proton deep inelastic scattering on a transversely polarized target

The Spin Muon (SMC) collaboration Adams, D. ; Adeva, B. ; Arik, E. ; et al.
Phys.Lett.B 336 (1994) 125-130, 1994.
Inspire Record 375478 DOI 10.17182/hepdata.48344

We measured the spin asymmetry in the scattering of 100 GeV longitudinally-polarized muons on transversely polarized protons. The asymmetry was found to be compatible with zero in the kinematic range $0.006<x<0.6$, $1<Q~2<30\,\mbox{GeV}~2$. {}From this result we derive the upper limits for the virtual photon--proton asymmetry $A_2$, and for the spin structure function $g_2$. For $x<0.15$, $A_2$ is significantly smaller than its positivity limit $\sqrt{R}$.

2 data tables
Table 1

No description provided.

Table 2

Nucleon spin structure function g2.


rivet Analysis
Measurement of the electromagnetic form-factor of the proton in the timelike region

Antonelli, A. ; Baldini, R. ; Bertani, M. ; et al.
Phys.Lett.B 334 (1994) 431-434, 1994.
Inspire Record 377833 DOI 10.17182/hepdata.28572

The cross section for the process e + e − → p p has been measured in the s range 3.6–5.9 GeV 2 by the FENICE experiment at the e + e − Adone storage ring and the proton electromagnetic form factor has been extracted.

2 data tables
Table 1

Cross section measurement.

Table 2

Proton form-factor measurement.


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.


Measurements of cross-section and charge asymmetry for e+ e- ---> mu+ mu- and e+ e- ---> tau+ tau- at s**(1/2) = 57.8-GeV

The AMY collaboration Velissaris, C. ; Lusin, S. ; Chung, Y.S. ; et al.
Phys.Lett.B 331 (1994) 227-235, 1994.
Inspire Record 373861 DOI 10.17182/hepdata.38344

With data corresponding to 142 pb −1 accumulated at s = 57.8 GeV by the AMY detector at TRISTAN we measure the cross section of the reactions e + e − → μ + μ − and e + e − → τ + τ − and the symmetry in the angular distributions. For the lowest order cross section we obtain σ μμ = 27.54 ± 0.65 ± 0.95 pb and σ ττ = 28.27 ± 0.87 ± 0.69 pb, and for the forward-backward asymmetry, A μμ = 0.303 ± 0.027 ± 0.008 and A ττ = −0.291 ± 0.040 ± 0.019. These measurements agree with the standard model. Assuming e − μ − τ univrsality we extract the vector and axial coupling constants | gν | = 0.00 ± 0.09 and | g A | = 0.476 ± 0.024. A fit of data to composite models places lower bounds (95% confidence level) on the compositeness scale of 2–4 TeV.

5 data tables
Table 1

Lowest order cross section and forward-backward asymmetry.

Table 2

Errors are statistical only.

Table 3

Lowest order cross section and forward-backward asymmetry.

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Evidence for top quark production in anti-p p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.Lett. 73 (1994) 225-231, 1994.
Inspire Record 373362 DOI 10.17182/hepdata.42494

We summarize a search for the top quark with the Collider Detector at Fermilab (CDF) in a sample of $\bar{p}p$ collisions at $\sqrt{s}$= 1.8 TeV with an integrated luminosity of 19.3pb$~{-1}$. We find 12 events consistent with either two $W$ bosons, or a $W$ boson and at least one $b$ jet. The probability that the measured yield is consistent with the background is 0.26\%. Though the statistics are too limited to establish firmly the existence of the top quark, a natural interpretation of the excess is that it is due to $t\bar{t}$ production. Under this assumption, constrained fits to individual events yield a top quark mass of $174 \pm 10~{+13}_{-12}$ GeV/c$~2$. The $t\bar{t}$ production cross section is measured to be $13.9~{+6.1}_{-4.8}$pb. (Submitted to Physical Review Letters on May 16, 1994).

1 data table
Table 1

No description provided.


W boson + jet angular distribution in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, M.G. ; Amidei, D. ; et al.
Phys.Rev.Lett. 73 (1994) 2296-2300, 1994.
Inspire Record 374152 DOI 10.17182/hepdata.42492

The W+jet angular distribution is measured using W→eν events recorded with the Collider Detector at Fermilab (CDF) during the 1988-89 and 1992-93 Tevatron runs. The data agree well with both a leading order and a next-to-leading order theoretical prediction. The shape of the angular distribution is similar to that observed in photon + jet data and significantly different from that observed in dijet data.

2 data tables
Table 1

Data normalized to 1 in the cos(theta) range -0.6 to 0.6.

Table 2

Data normalized to 1 in the abs(cos(theta)) range <0.3.


Global transverse energy distributions in Si + Al, Au at 14.6-A/GeV/c and Au + Au at 11.6-A.GeV/c

The E-802 collaboration Ahle, L. ; Akiba, Y. ; Beavis, D. ; et al.
Phys.Lett.B 332 (1994) 258-264, 1994.
Inspire Record 374156 DOI 10.17182/hepdata.28663

Measurements of the global transverse energy distributions dσ / dE T and dE T / dη using the new AGS beam of 197 Au at 11.6 A GeV/ c on a Au target, as well as a beam of 28 Si at 14.6 A GeV/ c on Al and Au targets, are presented for a leadglass detector with acceptance 1.3 ≤ η ≤ 2.4 and 0 ≤ φ < 2 π . The dσ / dE T spectra are observed to have different shapes for the different systems and simple energy rescaling does not account for the projectile dependence. The Au+Au dσ / dE T spectrum is satisfactorily constructed from the upper edge of Si+Au by the geometric Wounded Projectile Nucleon Model after applying a correction for the beam energy.

6 data tables
Table 1

Incident energy is 14.6 GeV/nucleon.

Table 2

Incident energy is 14.6 GeV/nucleon.

Table 3

Incident energy is 11.6 GeV/nucleon.

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