$\psi \psi$ Production and Limits on Beauty Meson Production From 400-{GeV}/$c$ Protons

The NA3 collaboration Badier, J. ; Boucrot, J. ; Bourotte, J. ; et al.
Phys.Lett.B 158 (1985) 85, 1985.
Inspire Record 213878 DOI 10.17182/hepdata.30379

From a study of multimuon events obtained in a high luminosity proton-platinum experiment at 400 GeV/ c , we find 5 ± 4 ψψ events, which correspond to a production cross section σ ( ψψ = 27 ± 10 pb. The observed production is compared to the ψψ events previously found in the same apparatus from incoming π − ; a comparison with QCD predictions is performed, giving a good agreement with expectations from gluon-gluon fusion. Finally, using like-sign dimuon, trimuon and quadrimuon events, we give model-dependent upper limits on beauty meson production: 2 nb/nucleon for central models, 20 nb/nucleon for diffractive production.

1 data table

No description provided.


A Measurement of Nuclear Effects in Deep Inelastic Muon Scattering on Deuterium, Nitrogen and Iron Targets

The BCDMS collaboration Bari, G. ; Benvenuti, A.C. ; Bollini, D. ; et al.
Phys.Lett.B 163 (1985) 282, 1985.
Inspire Record 216817 DOI 10.17182/hepdata.30331

New data is presented on the ratios of structure functions F 2 ( x , Q 2 ) measured in deep inelastic muon scattering with deuterium, nitrogen, and iron targets. The existence of nuclear effects at large Q 2 is confirmed with improved systematic accuracy. The ratio F 2 Fe ( x ) F 2 D 2 ( x ) covers the range 0.20 ⩽ x ⩽ 0.70 and is in agreement with earlier measurements. The ratio F 2 N 2 ( x )/ F 2 D 2 ( x ) is measured over the range 0.08 ⩽ x ⩽ 0.70 and is compatible with unity below x = 0.3.

2 data tables

VALUES OF Q2 CORRESPONDING TO THE X-BINS IN THIS TABLE ARE:- 46-106,46-106,53-150,53-200,70-200,80-200 RESPECTIVELY.

VALUES OF Q2 CORRESPONDING TO THE X-BINS IN THIS TABLE ARE:- 26-40,26-61,30-80,30-106,30-106,30-150,30-200,35-200,46-200.


Measurement of the s**(1/2) Dependence of Jet Production at the CERN anti-p p Collider

The UA2 collaboration Appel, J.A. ; Bagnaia, P. ; Banner, M. ; et al.
Phys.Lett.B 160 (1985) 349, 1985.
Inspire Record 216590 DOI 10.17182/hepdata.30354

The production of very large transverse momentum ( p T ) hadron jets has been measured in the UA2 experiment at the CERN p p Collider for s =630 GeV . The inclusive jet production cross sections exhibit a p T -dependent increase with respect to the s =546 GeV data from previous Collider runs. This increase can be described both by QCD calculations and by approximate x T =2 p T /√ s scaling. No significant deviation of the data from QCD predictions is observed at very large p T , placing a lower limit on the characteristic scale Λ c of a hypothetical superstrong contact interaction responsible for the binding of preons in the quark ( Λ c >370 GeV at 95% CL).

1 data table

No description provided.


Inclusive Properties of d Mesons Produced in 360-GeV pi- p Interactions

The NA27 & LEBC-EHS collaborations Aguilar-Benitez, M. ; Allison, W.W. ; Baland, J.F. ; et al.
Phys.Lett.B 161 (1985) 400-406, 1985.
Inspire Record 216596 DOI 10.17182/hepdata.30352

The inclusive cross sections for forward D meson production at s =26 GeV in π − p interactions have been measured to be: σ(π − p → D 0 / D 0 + X ) x F >0 = (10.1±2.2)μ b , σ(π − p → D ±+ X ) x F >0 = (5.7±1.6)μ b . The distribution in x F for all D and for x F >0 has the form d σ/ d x F =107 −37 +39 (1−x F ) 7.5 −1.7 +2.5 +5.4 −3.8 +6.0 (1−x F ) 0.7 −0.7 1.0 μ b , with evidence for leading D production. The p T 2 distribution is exponential with slope parameter [−1.18 −0.16 +0.18 ]( GeV / c) −2 . The data are compared with predictions from first-order quark/gluon fusion calculations.

3 data tables

No description provided.

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Comparison of Three Jet and Two Jet Cross-Sections in p anti-p Collisions at the CERN SPS p anti-p Collider

The UA1 collaboration Arnison, G. ; Allkofer, O.C. ; Astbury, A. ; et al.
Phys.Lett.B 158 (1985) 494, 1985.
Inspire Record 214736 DOI 10.17182/hepdata.30390

Results are presented on two-jet and three-jet cross sections, measured in the UA1 experiment at the CERN Super Proton Synchrotron (SPS) pp̄ Collider, at the highest available subprocess cms energies ( s ̂ >150 GeV ). Precise measurements of the two-jet angular distribution are consistent with previous results but show significant scale-breaking effects. The three-jet Dalitz plot and the three-jet angular distributions show evidence for final- and initial-state bremsstrahlung processes, in agreement with the leading-order QCD predictions. A comparison of the yield of wide-angle three-jet events with the yield of two-jet events at smaller scattering angles gives for the strong interaction coupling constant: α s ( K 3J K 2J )=0.16±0.02±0.03 at Q 2 ≈4000 GeV 2 , where the factor K 3J K 2J may plausibly be assumed to be close to unity.

2 data tables

No description provided.

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Upper Limits for $B \bar{B}$ Production in $\pi^-$ Tungsten Interactions at 194-{GeV}/$c$

The NA10 collaboration Ereditato, A. ; Gorini, E. ; Strolin, Paolo Emilio ; et al.
Phys.Lett.B 157 (1985) 463-468, 1985.
Inspire Record 213161 DOI 10.17182/hepdata.30393

We present a study of events with three muons in the final state, produced in π − -tungsten interactions at 194 GeV/ c . Trimuons can be attributed to B-meson pair production, and this allows us to set (model-dependent) upper limits for the corresponding cross section. Assuming a correlated central production model, we obtain the limit of 1.5 nb per nucleon at the 95% confidence level.

1 data table

No description provided.


A MEASUREMENT OF THE DIFFERENCE BETWEEN THE SINGLE NUCLEON CROSS-SECTIONS FOR j / psi MUOPRODUCTION IN IRON AND IN H-2, D-2 TARGETS

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Phys.Lett.B 152 (1985) 433-438, 1985.
Inspire Record 207459 DOI 10.17182/hepdata.30432

The cross sections for J ψ production have been measured in interactions of 280 GeV μ + on hydrogen and deuterium (H, D) and also in interactions of 250 GeV μ + on iron. The single-nucleon cross sections in iron are found to be larger than those in H, D. The mean ratio of the iron to H, D photoproduction cross sections in the range 60 < v < 200 GeV is 1.45 ±0.12 (statistical) ±0.22 (systematic error). Within the framework of the photon-gluon fusion model, this indicates that the gluon density per nucleon is ∼45% larger in iron than in H, D in the range 0.026 < x < 0.085, on a mass scale Q 2 eff ∼M 2 J ψ .

3 data tables

First table is from combined H and DEUT data at 280 Gev. Second table is from FE data at 250 Gev.

First table is from combined H and DEUT data at 280 Gev. Second table is from FE data at 250 Gev.

THIS TABLE IS THE RATIO OF THE EFFECTIVE GLUON DISTRIBUTIONS IN IRON AND HYDROGEN(DEUTERIUM) ASSUMING THAT PHOTON-GLUON FUSION IS THE RELEVANT MECHANISM FOR J/PSI PRODUCTION.


Measurement and analysis of the reaction gamma gamma ---> 3 pi+ 3 pi-

The JADE collaboration Pust, R. ; Olsson, J. ; Allison, J. ; et al.
Z.Phys.C 51 (1991) 531-540, 1991.
Inspire Record 314005 DOI 10.17182/hepdata.14926

The reactionγγ→3π+3π- has been studied usig the JADE detector at PETRA. The topological cross sectionσ(γγ→3π+3π-) was measured in the CM energy range 1.5–5.5 GeV. The production ofρ0,s was observed and the average number ofρ0,s per event measured. The contributions of the subprocessesγγ→ρ02π+2π-,γγ→ρ0ρ0π+2π- andγγ→ 3π+3π- (phase space) were studied and 95% C.L. upper limits for the cross sectionσ(γγ→ρ0ρ0π+π- determined. Finally the Bose-Einstein correlation for pairs of like signed pions was observed. A fit to a standard parametrization gave results consistent with other studies of this effect in pion systems.

4 data tables

Topological cross section.

Fractions of events for different final states resulting from the extended liklihood fit using incoherent weights.

Fractions of events for different final states resulting from the extended liklihood fit using coherent weights.

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Experimental Study of Low $P_t$ Hadron Fragmentation

Cutts, D. ; Dulude, R.S. ; Lanou, R.E., Jr. ; et al.
Phys.Rev.Lett. 43 (1979) 319, 1979.
Inspire Record 141771 DOI 10.17182/hepdata.9274

We present high-statistics results on the reactions a+p→c+X where a and c can be any of π±, K±, p, or p¯. The data were taken at 100 and 175 GeV/c incident momenta using the Fermilab Single-Arm Spectrometer operated over the kinematic range 0.2<x<1.0 and pt<~1.0 GeV/c. Investigating the x dependence of the data, we find agreement with a quark-parton picture, namely the cross sections have a power-law behavior in 1−x independent of pbeam and pt.

75 data tables

No description provided.

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Production of gamma rays in K- p and K+ p Interactions at 32-GeV/c

The French-Soviet & CERN-Soviet collaborations Beilliere, P. ; Cochet, Christian ; Dumont, J J ; et al.
Nucl.Phys.B 91 (1975) 219-231, 1975.
Inspire Record 2852 DOI 10.17182/hepdata.6709

Inclusive cross sections and longitudinal momentum distributions are presented for γ rays produced in K − p and K + p interactions at 32 GeV/c in the 4.5 m Mirabelle hydrogen bubble chamber at the Serpukhov accelerator. The average longitudinal and transverse momentum of neutral pions and the average π 0 multiplicity ▪ 〈 n π 0〉 are estimated. It is found that 〈 n π 0〉 is an increasing function of the number of charged prongs.

2 data tables

No description provided.

No description provided.