Measurement of the Nucleon Structure Function F2 in the Nuclear Medium and Evaluation of its Moments

The CLAS collaboration Osipenko, M. ; Ricco, G. ; Simula, S. ; et al.
Nucl.Phys.A 845 (2010) 1-32, 2010.
Inspire Record 846170 DOI 10.17182/hepdata.55369

We report on the measurement of inclusive electron scattering off a carbon target performed with CLAS at Jefferson Laboratory. A combination of three different beam energies 1.161, 2.261 and 4.461 GeV allowed us to reach an invariant mass of the final-state hadronic system W~2.4 GeV with four-momentum transfers Q2 ranging from 0.2 to 5 GeV2. These data, together with previous measurements of the inclusive electron scattering off proton and deuteron, which cover a similar continuous two-dimensional region of Q2 and Bjorken variable x, permit the study of nuclear modifications of the nucleon structure. By using these, as well as other world data, we evaluated the F2 structure function and its moments. Using an OPE-based twist expansion, we studied the Q2-evolution of the moments, obtaining a separation of the leading-twist and the total higher-twist terms. The carbon-to-deuteron ratio of the leading-twist contributions to the F2 moments exhibits the well known EMC effect, compatible with that discovered previously in x-space. The total higher-twist term in the carbon nucleus appears, although with large systematic uncertainites, to be smaller with respect to the deuteron case for n<7, suggesting partial parton deconfinement in nuclear matter. We speculate that the spatial extension of the nucleon is changed when it is immersed in the nuclear medium.

57 data tables

F2 measurements for a Q**2 of 0.175 GeV**2.

F2 measurements for a Q**2 of 0.225 GeV**2.

F2 measurements for a Q**2 of 0.275 GeV**2.

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The proton and deuteron F_2 structure function at low Q^2

Tvaskis, V. ; Arrington, J. ; Asaturyan, R. ; et al.
Phys.Rev.C 81 (2010) 055207, 2010.
Inspire Record 844968 DOI 10.17182/hepdata.56742

Measurements of the proton and deuteron $F_2$ structure functions are presented. The data, taken at Jefferson Lab Hall C, span the four-momentum transfer range $0.06 < Q^2 < 2.8$ GeV$^2$, and Bjorken $x$ values from 0.009 to 0.45, thus extending the knowledge of $F_2$ to low values of $Q^2$ at low $x$. Next-to-next-to-leading order calculations using recent parton distribution functions start to deviate from the data for $Q^2<2$ GeV$^2$ at the low and high $x$-values. Down to the lowest value of $Q^2$, the structure function is in good agreement with a parameterization of $F_2$ based on data that have been taken at much higher values of $Q^2$ or much lower values of $x$, and which is constrained by data at the photon point. The ratio of the deuteron and proton structure functions at low $x$ remains well described by a logarithmic dependence on $Q^2$ at low $Q^2$.

62 data tables

Proton and Deuteron F2 structure function for an x value of 0.040, determined via the Rosenbluth separation method. Error is shown without the contribution from radiative corrections.

Proton and Deuteron F2 structure function for an x value of 0.060, determined via the Rosenbluth separation method. Error is shown without the contribution from radiative corrections.

Proton and Deuteron F2 structure function for an x value of 0.080, determined via the Rosenbluth separation method. Error is shown without the contribution from radiative corrections.

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Nuclear structure function in carbon near x = 1

The BCDMS collaboration Benvenuti, A.C. ; Bollini, D. ; Camporesi, T. ; et al.
Z.Phys.C 63 (1994) 29-36, 1994.
Inspire Record 374300 DOI 10.17182/hepdata.48235

Data from deep inelastic scattering of 200 GeV muons on a carbon target with squared four-momentum transfer 52 GeV2≤Q2≤200 GeV2 were analysed in the region of the Bjorken variable close tox=1, which is the kinematic limit for scattering on a free nucleon. At this value ofx, the carbon structure function is found to beF2C≈1.2·10−4. Thex dependence of the structure function forx>0.8 is well described by an exponentialF2C∞exp(−sx) withs=16.5±0.6.

5 data tables

No description provided.

Multiplicative factors by which F2 has to be multiplied or divided to allow for a systematic uncertainty in detector resolution.

Multiplicative factors by which F2 has to be multiplied or divided to allow for a systematic uncertainty in the beam energy.

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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

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

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

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


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

No description provided.

No description provided.

No description provided.


The Gottfried sum from the ratio F2(n) / F2(p)

The New Muon collaboration Amaudruz, P. ; Arneodo, M. ; Arvidson, A. ; et al.
Phys.Rev.Lett. 66 (1991) 2712-2715, 1991.
Inspire Record 313931 DOI 10.17182/hepdata.19908

Experimental results obtained at the CERN Super Proton Synchrotron on the structure-function ratio F2n/F2p in the kinematic range 0.004<x<0.8 and 0.4<Q2<190 GeV2, together with the structure function F2d determined from a fit to published data, are used to derive the difference F2p(x)-F2n(x). The value of the Gottfried sum F(F2p-F2n)dx/x=0.240±0.016 is below the quark-parton-model expectation of 1/3.

1 data table

No description provided.


A COMBINED ANALYSIS OF SLAC EXPERIMENTS ON DEEP INELASTIC e p AND e d SCATTERING

Whitlow, L.W. ; Bodek, A. ; Rock, Stephen ; et al.
Nucl.Phys.B Proc.Suppl. 16 (1990) 215-216, 1990.
Inspire Record 280954 DOI 10.17182/hepdata.2721

None

44 data tables

No description provided.

No description provided.

No description provided.

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Precision Measurement of R = $\sigma^-$l / $\sigma^- T$ and F(2) in Deep Inelastic Electron Scattering

Dasu, S. ; De Barbaro, P. ; Bodek, A. ; et al.
Phys.Rev.Lett. 61 (1988) 1061, 1988.
Inspire Record 262063 DOI 10.17182/hepdata.20079

We report new results on a precision measurement of the ratio R=σLσT and the structure function F2 for 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 and F2 results are in good agreement with QCD predictions only when corrections for target-mass effects are included.

9 data tables

2.6 pct rad length target.

2.6 pct rad length target.

2.6 pct rad length target.

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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.


Nuclear Effects in Deep Inelastic Muon Scattering on Deuterium and Iron Targets

The BCDMS collaboration Benvenuti, A.C. ; Bollini, D. ; Bruni, G. ; et al.
Phys.Lett.B 189 (1987) 483-487, 1987.
Inspire Record 244886 DOI 10.17182/hepdata.30200

New Results are presented on nuclear effects in deep inelastic muon scattering on deuterium and iron targets at large Q 2 . The ratio F Fe 2 (x) F D 2 2 (x) measured in the kinematic range 0.06⩽ x ⩽0.70, 14GeV 2 ⩽ Q 2 ⩽70 GeV 2 is in good agreement with earlier measurements in the region of x > 0.25. At lower x , the structure function ratio exhibits an enhancement of ≈5%.

1 data table

Q**2 RANGE FOR EACH X BIN IS AS FOLLOWS: 14 TO 20, 16 TO 30, 18 TO 35, 18 TO 46, 20 TO 106, 23 TO 106, 23 TO 150, 26 TO 200, 26 TO 200, 26 TO 200 GEV**2.