A Measurement of the ratio of the nucleon structure function in copper and deuterium

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, G. ; et al.
Z.Phys.C 57 (1993) 211-218, 1993.
Inspire Record 341575 DOI 10.17182/hepdata.14499

Results are presented on the ratios of the nucleon structure function in copper to deuterium from two separate experiments. The data confirm that the nucleon structure function,F2, is different for bound nucleons than for the quasi-free ones in the deuteron. The redistribution in the fraction of the nucleon's momentum carried by quarks is investigated and it is found that the data are compatible with no integral loss of quark momenta due to nuclear effects.

3 data tables

Results from the 'chariot' experiment.

Results from the 'addendum' experiment.

Merged 'chariot' and 'addendum' ratio.. Errors are combined statistics and systematics.


Muoproduction of J / psi and the gluon distribution of the nucleon

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, G. ; et al.
Z.Phys.C 56 (1992) 21-28, 1991.
Inspire Record 336767 DOI 10.17182/hepdata.14559

Measurements are presented of the inclusive distributions of theJ/Ψ meson produced by muons of energy 200 GeV from an ammonia target. The gluon distribution of the nucleon has been derived from the data in the range 0.04<x<0.36 using a technique based on the colour singlet model. An arbitrary normalisation factor is required to obtain a reasonable integral of the gluon distribution. Some comments are made on the use ofJ/Ψ productionby virtual photons to extract the gluon distribution at HERA.

7 data tables

Data are normalized to total cross section of 36 nb (not corrected for coherence).

Data are normalized to total cross section of 36 nb (not corrected for coherence).

Data are normalized to total cross section of 36 nb (not corrected for coherence).

More…

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

No description provided.

No description provided.

No description provided.

More…

Measurements of the Nucleon Structure Function in the Range 0.002-GeV**2 < x < 0.17-GeV**2 and 0.2-GeV**2 < q**2 < 8-GeV**2 in Deuterium, Carbon and Calcium

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Nucl.Phys.B 333 (1990) 1-47, 1990.
Inspire Record 283347 DOI 10.17182/hepdata.33074

Small angle scattering of 280 GeV positive muons by deuterium, carbon and calcium has been measured at scattering angles down to 2 mrad. The nucleon structure function F 2 extracted from deuterium does not show a significant x dependence in the measured range of Q 2 and its Q 2 dependence is linear in log Q 2 . For calcium, a depletion of F 2 is observed at low x by 30% as compared with the values at x = 0.1 where F 2 (Ca) and F 2 (D) are not significantly different. This depletion is attributed to shadowing. The carbon structure function exhibits a similar, but less pronounced, x dependence. Such behaviour is observed to be independent of Q 2 . The data are consistent with those obtained from other charged lepton experiments both at similar and higher values of x and Q 2 and considerably extend the range of the measurements down to the low values of x to be measured in forthcoming experiments at HERA.

33 data tables

Deuterium data. Overall normalization error of 7 pct not included.

Deuterium data. Overall normalization error of 7 pct not included.

Deuterium data. Overall normalization error of 7 pct not included.

More…

An investigation of the spin structure of the proton in deep inelastic scattering of polarized muons on polarized protons.

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, Guenter ; et al.
Nucl.Phys.B 328 (1989) 1, 1989.
Inspire Record 280143 DOI 10.17182/hepdata.49587

The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured in the range 0.01<×<0.7. The spin dependent structure function g 1 ( x ) for the proton has been determined and, combining the data with earlier SLAC measurements, its integral over x found to be 0.126±0.010(stat.)±0.015(syst.), in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Biorken sum rule, this result implies a significant negative value for the integral of g 1 for the neutron. These integrals lead to the conclusion, in the naïve quark parton model, that the total quark spin constitutes a rather small fraction of the spin of the nucleon. Results are also presented on the asymmetries in inclusive hadron production which are consistent with the above picture.

7 data tables

THE MEAN Q**2 FOR EACH OF THE 10 VALUES OF X BELOW ARE 3.5,4.5,6.0, 8.010.3,12.9,15.2,18.0,22.5,29.5.

No description provided.

No description provided.

More…

Measurements of the $u$ Valence Quark Distribution Function in the Proton and $u$ Quark Fragmentation Functions

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Nucl.Phys.B 321 (1989) 541-560, 1989.
Inspire Record 276746 DOI 10.17182/hepdata.33218

A new determination of the u valence quark distribution function in the proton is obtained from the analysis of identified charged pions, kaons, protons and antiprotons produced in muon-proton and muon-deuteron scattering. The comparison with results obtained in inclusive deep inelastic lepton-nucleon scattering provides a further test of the quark-parton model. The u quark fragmentation functions into positive and negative pions, kaons, protons and antiprotons are also measured.

6 data tables

No description provided.

No description provided.

No description provided.

More…

Shadowing in deep inelastic muon scattering from nuclear targets

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Phys.Lett.B 211 (1988) 493-499, 1988.
Inspire Record 262246 DOI 10.17182/hepdata.29908

Results are presented on the ratio of the inelastic muon-nucleus cross section per nucleon for carbon and calcium relative to that for deuterium. The measurements were made in the kinematic range of low x (0.003–0.1) and low Q 2 (0.3–3.2 GeV 2 ) at an incident muon energy of 280 GeV. The calcium to deuterium ratio shows a significant x dependence which is interpreted as a shadowing effect. No strong Q 2 dependence is observed. This suggests that the effect is due at least partially to parton interactions within the nucleus.

4 data tables

VALUES OF Q**2 AT EACH POINT ARE:- 0.52,0.60,0.61,0.61,0.63,0.68,0.90.

VALUES OF Q**2 AT EACH POINT ARE:- 1.09,1.25,1.54,1.74,1.76,1.68,1.71, 2.29.

VALUES OF X AT EACH POINT ARE:- 0.009,0.011,0.010,0.010,0.010,0.011, 0.013,0.015.

More…

Evidence for Anomalous Prompt Photons in Deep Inelastic Muon Scattering at 200-{GeV}

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Phys.Lett.B 218 (1989) 248-256, 1989.
Inspire Record 261250 DOI 10.17182/hepdata.29855

The inclusive yield of photons has been measured from deep inelastic interactions of 200 GeV muons on hydrogen. After subtracting the contributions from hadron electromagnetic decays and Bethe-Heitler muon bremsstrahlung, residual photons are observed at low p T and low z at a mean level of 0.15±0.06 per interaction. The quark Compton scattering process is unable to explain the data, thus indicating an anomalous photon production.

2 data tables

Z distribution of anomalous direct photons.

PT distribution of anomalous direct photons.


Measurement of the Ratios of Deep Inelastic Muon - Nucleus Cross-Sections on Various Nuclei Compared to Deuterium

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, Guenter ; et al.
Phys.Lett.B 202 (1988) 603-610, 1988.
Inspire Record 260668 DOI 10.17182/hepdata.29991

Results are presented on the ratios of the deep inelastic muon-nucleus cross sections for carbon, copper and tin nuclei to those measured on deuterium. The data confirm that the structure functions of the nucleon measured in nuclei are different from those measured on quasi-free nucleons in deuterium. The kinematic range of the data is such that 〈 Q 2 〉 ∼ 5 GeV 2 at x ∼ 0.03, increasing to 〈 Q 2 〉 ∼ 35 GeV 2 for x ∼ 0.65. The measured cross section ratios are less than unity for x ≲ 0.05 and for 0.25 ≲ x < 0.7. The decrease of the ratio below unity for low x becomes larger as A increases as might be expected from nuclear shadowing. However, this occurs at relatively large values of Q 2 (∼ 5 GeV 2 ) indicating that such shadowing is of patrionic origin.

3 data tables

Q**2= 5.1,7.8,11.4,14.4,17.3,20.2,24.1,29.8,33.6 GEV**2.

Q**2= 4.4,8.4,13.5,17.9,21.1,24.4,29.5,34.0,40.4 GEV**2.

Q**2= 4.0,7.7,11.1,14.6,17.1,19.8,24.8,32.4 GEV**2.


A measurement of the spin asymmetry and determination of the structure function g(1) in deep inelastic muon proton scattering.

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, Guenter ; et al.
Phys.Lett.B 206 (1988) 364, 1988.
Inspire Record 252744 DOI 10.17182/hepdata.29952

The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured over a large x range (0.01< x <0.7). The spin-dependent structure function g 1 ( x ) for the proton has been determined and its integral over x found to be 0.114±0.012±0.026, in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Bjorken sum rule, this result implies a significant negative value for the integral of g 1 for the neutron. These values for the integrals of g 1 lead to the conclusion that the total quark spin constitutes a rather small fraction of the spin of the nucleon.

1 data table

THE AVERAGE VALUES OF Q**2 IN EACH X-BIN ARE AS FOLLOWS: X=0.015,Q2=3.5: X=0.025,Q2=4.5: X=0.035,Q2=6.0: X=0.050,Q2=8.0: X=0.078,Q2=10.3: X=0.124,Q2=12.9: X=0.175,Q2=15.2: X=0.248,Q2=18.0: X=0.344,Q2=22.5: X=0.466,Q2=29.5.