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Photoproduction and hadroproduction of phi (1020), K0 (892) and anti-K0 (892) mesons in the energy range 65-GeV to 175-GeV

The Omega Photon collaboration Apsimon, R.J. ; Atkinson, M. ; Baake, M. ; et al.

Z.Phys.C 61 (1994) 383-398, 1994.

Inspire Record 362483 DOI 10.17182/hepdata.12881

Inclusive production of ϕ,K*0, and$\overline {K*^0 } $ mesons has been measured in γp, π±p andK± p collisions at beam energies of 65 GeV

30 data tables

Table 1

Statistical errors only.

Table 2

Statistical errors only.

Table 3

Statistical errors only.. An entry 0.00 indicates a statistical error of < 0.005.

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First results of the CERES electron pair spectrometer from p + Be, P + Au and S + Au collisions

The CERES/NA45 collaboration Drees, A. ; Baur, R. ; Breskin, A. ; et al.

Nucl.Phys.A 566 (1994) 87C-94C, 1994.

Inspire Record 362492 DOI 10.17182/hepdata.8728

The CERES experiment (CErenkov Ring Electron Spectrometer) studies the production of low mass e + e − pairs in proton-proton, proton-nucleus and nucleus-nucleus interactions at the CERN SPS. The CERES spectrometer, has a novel design based on two Ring Imaging Cherenkov (RICH) counters, and it operates close to its design specifications. Data were recorded with 200 GeV u sulfur beam and 450 GeV proton beam. The analysis is in progress. We have extracted first e + − -pairs samples for p+Be, p+Au and S+Au collisions. In addition other physics topics were addressed. Inclusive photon spectra were measured in S+Au interactions. No excess over known hadronic sources was found within our present systematic error of 11%. Results on high p i charged pion spectra are presented up to 4 GeV c . We also studied the production of e + e − -pairs m the strong electromagnetic fields of very peripheral S+Pt collisions. The data are well described by a first-order perturbative QED-calculation.

2 data tables

Table 1

NON-DISRUPTIVE S+PT COLLISIONS.

Table 2

No description provided.

Scaling violations of the proton structure function f2 at small x

The H1 collaboration Abt, I. ; Ahmed, T. ; Andreev, V. ; et al.

Phys.Lett.B 321 (1994) 161-167, 1994.

Inspire Record 360235 DOI 10.17182/hepdata.45140

An analysis is presented of scaling violations of the proton structure function F 2 ( x , Q 2 ) measured with the H1 detector at HERA in the range of Bjorken x values between x = 3 × 10 −4 and 10 −2 for four-momentum transfers Q > 2 larger than 8.7 GeV 2 . The structure function F 2 ( x , Q 2 ) is observed to rise linearly with ln Q 2 . Under the assumption that the observed scaling violations at small x ⩽ 0.01 are described correctly by perturbative QCD, an estimate is obtained of the gluon distribution function G ( x , Q 0 2 ) at Q 2 2 = 20 GeV 2 .

1 data table

Table 1

No description provided.

Enhanced leading production of D+- and D*+- in 250-GeV pi+- - nucleon interactions

The E769 collaboration Alves, G.A. ; Amato, S. ; Anjos, J.C. ; et al.

Phys.Rev.Lett. 72 (1994) 812-815, 1994.

Inspire Record 361344 DOI 10.17182/hepdata.42499

A leading charm meson is one with longitudinal momentum fraction, xF>0, whose light quark (or antiquark) is of the same type as one of the quarks in the beam particles. We report on the production asymmetry, A=[σ(leading-σ(nonleading)]/[σ(leading)+σ(nonleading)] as a function of xF. The data consist of 1500 fully reconstructed D± and D*± decays in Fermilab experiment E 769. We find a significant asymmetry for the production of charm quarks is not expected in perturbative quantum chromodynamics.

2 data tables

Table 1

Asymmetry as function of XL.

Table 2

Asymmetry as function of PT**2.

Measurements of the proton elastic form-factors for 1-GeV/c2 <= Q2 <= 3-GeV/C**2 at SLAC

Walker, R.C. ; Filippone, B. ; Jourdan, J. ; et al.

Phys.Rev.D 49 (1994) 5671-5689, 1994.

Inspire Record 360764 DOI 10.17182/hepdata.22469

We report measurements of the proton form factors GEp and GMp extracted from elastic scattering in the range 1≤Q2≤3 (GeV/c)2 with total uncertainties < 15% in GEp and < 3% in GMp. Comparisons are made to theoretical models, including those based on perturbative QCD, vector-meson dominance, QCD sum rules, and diquark constituents in the proton. The results for GEp are somewhat larger than indicated by most theoretical parametrizations, and the ratios of the Pauli and Dirac form factors Q2(F2pF1p) are lower in value and demonstrate a weaker Q2 dependence than those predictions. A global extraction of the elastic form factors from several experiments in the range 0.1 0.1

6 data tables

Table 1

Point-to-point systematic uncertainty is 0.5%, overall normailzation uncertainty is 1.9%.

Table 2

Point-to-point systematic uncertainty is 0.5%, overall normailzation uncertainty is 1.9%.

Table 3

Point-to-point systematic uncertainty is 0.5%, overall normailzation uncertainty is 1.9%.

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Measurement of kinematic and nuclear dependence of R = sigma-L / sigma-t in deep inelastic electron scattering

Dasu, S. ; deBarbaro, P. ; Bodek, A. ; et al.

Phys.Rev.D 49 (1994) 5641-5670, 1994.

Inspire Record 360765 DOI 10.17182/hepdata.22468

We report results on a precision measurement of the ratio R=σLσT in deep inelastic electron-nucleon scattering in the kinematic range 0.2≤x≤0.5 and 1≤Q2≤10 (GeV/c)2. Our results show, for the first time, a clear falloff of R with increasing Q2. Our R results are in agreement with QCD predictions only when corrections for target mass effects and some additional higher twist effects are included. At small x, the data on R favor structure functions with a large gluon contribution. We also report results on the differences RA−RD and the cross section ratio σAσD between Fe and Au nuclei and the deuteron. Our results for RA−RD are consistent with zero for all x, Q2 indicating that possible contributions to R from nuclear higher twist effects and spin-0 constituents in nuclei are not different from those in nucleons. The ratios σAσD from all recent experiments, at all x, Q2 values, are now in agreement.

31 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Search for excited quarks in p anti-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. 72 (1994) 3004-3008, 1994.

Inspire Record 360332 DOI 10.17182/hepdata.42507

If quarks are composite particles then excited states are expected. We have searched in pp¯ collisions for excited quarks (q*) which decay to common quarks by emitting a W boson (q*→qW) or a photon (q*→qγ). The simplest model of excited quarks has been excluded for mass M*<540 GeV/c2 at 95% confidence level.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Single photon and neutral meson production from WA80

The WA80 collaboration Santo, R. ; Albrecht, R. ; Awes, T.C. ; et al.

Nucl.Phys.A 566 (1994) 61C-68C, 1994.

Inspire Record 36273 DOI 10.17182/hepdata.9268

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Production of neutral strange particles in muon - nucleon scattering at 490-GeV

The E665 collaboration Adams, M.R. ; Aderholz, M. ; Aïd, S. ; et al.

Z.Phys.C 61 (1994) 539-550, 1994.

Inspire Record 362429 DOI 10.17182/hepdata.42473

The production ofK0, Λ and$\bar \Lambda $ particles is studied in the E665 muon-nucleon experiment at Fermilab. The average multiplicities and squared transverse momenta are measured as a function ofxF andW2. Most features of the data can be well described by the Lund model. Within this model, the data on the K0/π± ratios and on the averageK0 multiplicity in the forward region favor a strangeness suppression factors/u in the fragmentation process near 0.20. Clear evidence for QCD effects is seen in the average squared transverse momentum ofK0 and Λ particles.

10 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.