Grachev, M.I.
Max results
Sort by Reverse order

Showing 10 of 835 results

Date

Measurement of alpha-s in hadronic Z decays using all orders resummed predictions

The ALEPH collaboration Decamp, D. ; Deschizeaux, B. ; Goy, C. ; et al.
Phys.Lett.B 284 (1992) 163-176, 1992.
Inspire Record 333334 DOI 10.17182/hepdata.48421

None

1 data table
Table 1

Three different methods are used for extraction Alphas value (see text for details). Systematical errors with C=HADR and C=THEOR are due to hadronization correction and theoretical uncertainties.


Evidence for the triple gluon vertex from measurements of the QCD color factors in Z decay into four jets

The ALEPH collaboration Decamp, D. ; Deschizeaux, B. ; Goy, C. ; et al.
Phys.Lett.B 284 (1992) 151-162, 1992.
Inspire Record 333127 DOI 10.17182/hepdata.48505

None

1 data table
Table 1

NC, CF, and TF are the color factors for SU(N) group. For SU(3) they are equal to: NC = 3, CF = 4/3, and TF = 1/2.


Ratio of J / psi production cross-sections in deep inelastic muon scattering from tin and carbon

The New Muon collaboration Amaudruz, P. ; Arneodo, M. ; Arvidson, A. ; et al.
Nucl.Phys.B 371 (1992) 553-566, 1992.
Inspire Record 322307 DOI 10.17182/hepdata.32968

We present results on J/ψ production in muon interactions with tin and carbon targets at incident muon energies of 200 and 280 GeV. The ratio of cross sections per nucleon for J/ψ production on tin and carbon, R (Sn/C), is studied as a function of p T 2 , z and x . We find an enhancement for coherent J/ψ production R coh (Sn/C) = 1.54 ± 0.07, a suppression for quasielastic production R qe (Sn/C) = 0.79 ± 0.06 and for inelastic production R in (Sn/C) = 1.13 ± 0.08. The inelastic cross section ratio can be interpreted within the Colour Singlet model as an enhancement of the gluon distribution in tin with respect to that in carbon. The dependence of the ratio on z and p T 2 can explain the discrepancy between the results obtained in previous experiments.

3 data tables
Table 1

Data for coherent events.

Table 2

Data for quasielastic events.

Table 3

Data for inelastic events.


The ratio F2(n) / F2(p) in deep inelastic muon scattering

The New Muon collaboration Amaudruz, P. ; Arneodo, M. ; Arvidson, A. ; et al.
Nucl.Phys.B 371 (1992) 3-31, 1992.
Inspire Record 321412 DOI 10.17182/hepdata.32955

Results are presented on the ratio of neutron and proton structure functions, F 2 n / F 2 p , deduced from deep inelastic scattering of muon from hydrogen and deuterium. The data, which were obtained at the CERN muon beam at 90 and 280 GeV incident energy, cover the kinematic range x = 0.002−0.80 and Q 2 = 0.1−190 GeV 2 . The measured structure function ratios have small statistical and systematic errors, particularly at small and intermediate x . The observed Q 2 dependence in the range x = 0.1−0.4 is stronger than predicted by perturbative QCD. From the present data together with results from other experiments it is suggested that the twist-four coefficient for the proton is smaller than that for the neutron for x larger than 0.2.

16 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

Merged 90 and 280 GeV data.

More…

pi- meson production in the interaction of deuterons at 1-GeV per nucleon with carbon and beryllium extended targets

Viryasov, N.M. ; Gulkanian, G.R. ; Kakoyan, V.G. ; et al.
JINR-P1-91-455, 1991.
Inspire Record 322742 DOI 10.17182/hepdata.38652

None

6 data tables
Table 1

Axis error includes +- 0.0/0.0 contribution (?////).

Table 2

No description provided.

Table 3

No description provided.

More…

Precision measurement of structure function ratios for Li-6, C-12 and Ca-40

The New Muon collaboration Amaudruz, P. ; Arneodo, M. ; Arvidson, A. ; et al.
Z.Phys.C 53 (1992) 73-78, 1992.
Inspire Record 319669 DOI 10.17182/hepdata.14706

The structure function ratiosF2C/F2Li,F2Ca/F2Li andF2Ca/F2C were measured in deep inelastic muonnucleus scattering at an incident muon energy of 90 GeV, covering the kinematic range 0.0085<x<0.6 and 0.8<Q2<17GeV2. The sensitivity of the nuclear structure functions to the size and mean density of the target nucleus is discussed.

3 data tables
Table 1

Overall normalization error of 0.7%, due to uncertainties in target thickness, not included in the table.

Table 2

Overall normalization error of 0.8%, due to uncertainties in target thickness, not included in the table.

Table 3

Overall normalization error of 0.5%, due to uncertainties in target thickness, not included in the table.


Central Mg + Mg collisions with Lambda production at a momentum of 4.3-GeV/c per nucleon

Avramenko, S.A. ; Abdurakhimov, A.U. ; Aksinenko, V.D. ; et al.
Sov.J.Nucl.Phys. 55 (1992) 400-407, 1992.
Inspire Record 319240 DOI 10.17182/hepdata.38716

None

2 data tables
Table 1

CENTRAL COLLISIONS.

Table 2

CENTRAL COLLISIONS.


Forward produced hadrons in mu p and mu d scattering and investigation of the charge structure of the nucleon

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, G. ; et al.
Z.Phys.C 52 (1991) 361-388, 1991.
Inspire Record 314883 DOI 10.17182/hepdata.1432

Final data measured with the EMC forward spectrometer are presented on the production of forward charged hadrons in μp and μd scattering at incident beam energies between 100 and 280 GeV. The large statistic of 373 000 events allows a study of the semi-inclusive hadron production as a function ofz,pT2 and 〈pT2〉 in smallQ2,xBj andW bins. Charge multiplicity ratios and differences as a function ofz andxBj are given forp, d andn-targets. From the differences of charge multiplicities the ratio of the valence quark distributions of the protondv(x)/uv(x) is determined for the first time in charged lepton scattering. The Gronau et al. sum rule is tested, the measured sum being 0.31±0.06 stat. ±0.05 syst., compared with the theoretical expectation of 2/7≈0.286. The measured sum corresponds to an absolute value of the ratio of thed andu quark charge of 0.44±0.10 stat.±0.08 syst.

129 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Precision measurement of the structure function ratios F2 (He) / F2 (D), F2 (C) / F2 (D) and F2 (Ca) / F2 (D)

The New Muon collaboration Amaudruz, P. ; Arneodo, M. ; Arvidson, A. ; et al.
Z.Phys.C 51 (1991) 387-394, 1991.
Inspire Record 314878 DOI 10.17182/hepdata.14935

We present the structure function ratiosF2He/F2D,F2C/F2D andF2Ca/F2D measured in deep inelastic muon-nucleus scattering at an incident muon momentum of 200 GeV. The kinematic range 0.0035<x<0.65 and 0.5<Q2<90 GeV2 is covered. At lowx the three ratios are significantly smaller than unity and the size of the depletion grows with decreasingx and increasing mass numberA. At intermediatex the ratios show an enhancement of about 2% above unity for C/D and Ca/D, possibly less for He/D. There are indications of someQ2 dependence in the Ca/D data. The integrals of the structure function differencesF2A−F2D are discussed.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Inclusive particle production in 400-GeV/c p p interactions

Aguilar-Benitez, M. ; Allison, W.W. W. ; Batalov, A.A. ; et al.
Z.Phys.C 50 (1991) 405-426, 1991.
Inspire Record 314091 DOI 10.17182/hepdata.1435

We report on a study of inclusive particle production in pp-interactions at 400 GeV/c. The data are based on 472 K reconstructed events recorded in the NA 27 experiment using the LEBC-EHS facility at CERN. The production cross sections are determined of pseudo scalar (π±,0, η andK±), scalar (f0(975)), vector (ρ±,0(770), ω(783), ϕ(1020),K*0(892), and\(\bar K^{ * 0} \)(892)), and tensorf0 mesons, of protons and antiprotons, and theΔ++,+,0(1232), and Λ(1520) baryon resonances in the forward hemisphere of the center of mass system, as well as longitudinal and transverse momentum distributions. The results are compared with predictions of the FRITIOF model and with other experimental data.

61 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…