Date

Measurement of e p --> e' p pi+ pi- and baryon resonance analysis.

The CLAS collaboration Ripani, M. ; Burkert, V.D. ; Mokeev, V. ; et al.
Phys.Rev.Lett. 91 (2003) 022002, 2003.
Inspire Record 600451 DOI 10.17182/hepdata.11116

The cross section for the reaction $ e p \to e^{\prime} p \pi^{+} \pi^{-}$ was measured in the resonance region for 1.4$<$W$<$2.1 GeV and 0.5$

84 data tables match query

Measured cross section DSIG/DM(PI+PI-) for the W range 1400 to 1425GeV.

Measured cross section DSIG/DM(PI+PI-) for the W range 1425 to 1450GeV.

Measured cross section DSIG/DM(PI+PI-) for the W range 1450 to 1475GeV.

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A kinematically complete measurement of the proton structure function F2 in the resonance region and evaluation of its moments.

The CLAS collaboration Osipenko, M. ; Ricco, G. ; Taiuti, M. ; et al.
Phys.Rev.D 67 (2003) 092001, 2003.
Inspire Record 612145 DOI 10.17182/hepdata.12253

We measured the inclusive electron-proton cross section in the nucleon resonance region (W < 2.5 GeV) at momentum transfers Q**2 below 4.5 (GeV/c)**2 with the CLAS detector. The large acceptance of CLAS allowed for the first time the measurement of the cross section in a large, contiguous two-dimensional range of Q**2 and x, making it possible to perform an integration of the data at fixed Q**2 over the whole significant x-interval. From these data we extracted the structure function F2 and, by including other world data, we studied the Q**2 evolution of its moments, Mn(Q**2), in order to estimate higher twist contributions. The small statistical and systematic uncertainties of the CLAS data allow a precise extraction of the higher twists and demand significant improvements in theoretical predictions for a meaningful comparison with new experimental results.

0 data tables match query

Measurement of neutral current cross sections at high Bjorken-x with the ZEUS detector at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Eur.Phys.J.C 49 (2007) 523-544, 2007.
Inspire Record 723329 DOI 10.17182/hepdata.11718

A new method is employed to measure the neutral current cross section up to Bjorken-x values of one with the ZEUS detector at HERA using an integrated luminosity of 65.1 pb-1 for e+p collisions and 16.7 pb-1 for e-p collisions at sqrt{s}=318 GeV and 38.6 pb-1 for e+p collisions at sqrt{s}=300 GeV. Cross sections have been extracted for Q2 >= 648 GeV2 and are compared to predictions using different parton density functions. For the highest x bins, the data have a tendency to lie above the expectations using recent parton density function parametrizations.

100 data tables match query

The double differential cross section for the 96-97 E+ P NC scattering data.

The double differential cross section for the 96-97 E+ P NC scattering data.

The double differential cross section for the 96-97 E+ P NC scattering data.

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PROTON PRODUCTION CROSS-SECTION WITH 70-MEV - 230-MEV ENERGIES IN P A ---> P X REACTIONS FOR 1-GEV/C - 9-GEV/C, PI+ A ---> P X FOR FOR 1-GEV/C - 6-GEV/C AND PI- A ---> P X FOR 1.4-GEV/C AND 5-GEV/C. (IN RUSSIAN)

Bayukov, Yu.D. ; Gavrilov, V.B. ; Goryainov, N.A. ; et al.
Moscow Inst. Theor. Exp. Phys. Gkae - ITEF-83-148 (83,REC.NOV.) 99p, 1983.
Inspire Record 196222 DOI 10.17182/hepdata.9995

None

131 data tables match query

No description provided.

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Event shapes in deep inelastic scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 767 (2007) 1-28, 2007.
Inspire Record 714503 DOI 10.17182/hepdata.11818

Mean values and differential distributions of event-shape variables have been studied in neutral current deep inelastic scattering using an integrated {luminosity} of 82.2 pb$^{-1}$ collected with the ZEUS detector at HERA. The kinematic range was $80 < Q^2 < 20 480\gev^2$ and $0.0024 < x < 0.6$, where $Q^2$ is the virtuality of the exchanged boson and $x$ is the Bjorken variable. The data are compared with a model based on a combination of next-to-leading-order QCD calculations with next-to-leading-logarithm corrections and the Dokshitzer-Webber non-perturbative power corrections. The power-correction method provides a reasonable description of the data for all event-shape variables studied. Nevertheless, the lack of consistency of the determination of $\alpha_s$ and of the non-perturbative parameter of the model, $\albar$, suggests the importance of higher-order processes that are not yet included in the model.

6 data tables match query

Mean value of the event shape variable 1-THRUST(C=T).

Mean value of the event shape variable B(C=T).

Mean value of the event shape variable RHO**2.

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Study of deep inelastic inclusive and diffractive scattering with the ZEUS forward plug calorimeter.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 713 (2005) 3-80, 2005.
Inspire Record 675372 DOI 10.17182/hepdata.11816

Deep inelastic scattering and its diffractive component, ep -> e'gamma*p ->e'XN, have been studied at HERA with the ZEUS detector using an integrated luminosity of 4.2 pb-1. The measurement covers a wide range in the gamma*p c.m. energy W (37 - 245 GeV), photon virtuality Q2 (2.2 - 80 GeV2) and mass Mx. The diffractive cross section for Mx > 2 GeV rises strongly with W: the rise is steeper with increasing Q2. The latter observation excludes the description of diffractive deep inelastic scattering in terms of the exchange of a single Pomeron. The ratio of diffractive to total cross section is constant as a function of W, in contradiction to the expectation of Regge phenomenology combined with a naive extension of the optical theorem to gamma*p scattering. Above Mx of 8 GeV, the ratio is flat with Q2, indicating a leading-twist behaviour of the diffractive cross section. The data are also presented in terms of the diffractive structure function, F2D(3)(beta,xpom,Q2), of the proton. For fixed beta, the Q2 dependence of xpom F2D(3) changes with xpom in violation of Regge factorisation. For fixed xpom, xpom F2D(3) rises as beta -> 0, the rise accelerating with increasing Q2. These positive scaling violations suggest substantial contributions of perturbative effects in the diffractive DIS cross section.

7 data tables match query

Measurement of the proton structure function F2 at Q**2 = 2.7 GeV**2.

Measurement of the proton structure function F2 at Q**2 = 4.0 GeV**2.

Measurement of the proton structure function F2 at Q**2 = 6.0 GeV**2.

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Study of intranuclear collision effects in interactions of K+ / pi+ mesons with Al and Au nuclei at 250-GeV/c.

The EHS/NA22 collaboration Agababyan, N.M. ; Ajinenko, I.V. ; Botterweck, F. ; et al.
Z.Phys.C 56 (1992) 371-380, 1992.
Inspire Record 345620 DOI 10.17182/hepdata.14529

Multiplicity, inclusive, correlation and collective characteristics of multiparticle production processes inK+ Al,K+ Au, π+ Al and π+ Au interactions at 250 GeV/c are studied with the European Hybrid Spectrometer, providing high statistics and almost 4 π acceptance for final state charged particles. It is shown that the proton energy spectrum practically does not depend on the target atomic weight, but the proton angular distributions reveal a strongA-dependence. In a model independent way, the average number of intranuclear collisions is extracted, and it is shown that their dominant part (60% for Al and 80% for Au) is caused by interactions of the non-leading particles produced in the target fragmentation. The multiplication ratio of the produced particles for the Au nucleus changes fromR≃40 at the smallest rapidities in the target fragmentation region, down toR=0.37±0.06 at the largest rapidities in the beam fragmentation region. It is found that the average total longitudinal momentum of the charged products of the beam fragmentation depends weakly on the number of leading hadron (cluster) intranuclear collisions which are characterized by a low inelasticity coefficient 〈k〉=0.17±0.03.

1 data table match query

No description provided.


Measurement of the $x$- and $Q^2$-Dependence of the Asymmetry $A_1$ on the Nucleon

The CLAS collaboration Dharmawardane, K.V. ; Kuhn, S.E. ; Bosted, Peter E. ; et al.
Phys.Lett.B 641 (2006) 11-17, 2006.
Inspire Record 717523 DOI 10.17182/hepdata.6726

We report results for the virtual photon asymmetry $A_1$ on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton ($^{15}$NH$_3$) and deuteron ($^{15}$ND$_3$) targets, collected data with a longitudinally polarized electron beam at energies between 1.6 GeV and 5.7 GeV. In the present paper, we concentrate on our results for $A_1(x,Q^2)$ and the related ratio $g_1/F_1(x,Q^2)$ in the resonance and the deep inelastic regions for our lowest and highest beam energies, covering a range in momentum transfer $Q^2$ from 0.05 to 5.0 GeV$^2$ and in final-state invariant mass $W$ up to about 3 GeV. Our data show detailed structure in the resonance region, which leads to a strong $Q^2$--dependence of $A_1(x,Q^2)$ for $W$ below 2 GeV. At higher $W$, a smooth approach to the scaling limit, established by earlier experiments, can be seen, but $A_1(x,Q^2)$ is not strictly $Q^2$--independent. We add significantly to the world data set at high $x$, up to $x = 0.6$. Our data exceed the SU(6)-symmetric quark model expectation for both the proton and the deuteron while being consistent with a negative $d$-quark polarization up to our highest $x$. This data setshould improve next-to-leading order (NLO) pQCD fits of the parton polarization distributions.

306 data tables match query

A1 and g1/F1 for the P target at incident energy 1.6000 GeV and W = 1.1300 GeV.

A1 and g1/F1 for the P target at incident energy 1.6000 GeV and W = 1.1500 GeV.

A1 and g1/F1 for the P target at incident energy 1.6000 GeV and W = 1.1700 GeV.

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No description provided.

No description provided.

No description provided.

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Single pi+ electroproduction on the proton in the first and second resonance regions at 0.25-GeV**2 < Q**2 < 0.65-GeV**2 using CLAS.

The CLAS collaboration Egiyan, H. ; Aznauryan, I.G. ; Burkert, V.D. ; et al.
Phys.Rev.C 73 (2006) 025204, 2006.
Inspire Record 707883 DOI 10.17182/hepdata.6748

The ep -> e'pi^+n reaction was studied in the first and second nucleon resonance regions in the 0.25 GeV^2 < Q^2 < 0.65 GeV^2 range using the CLAS detector at Thomas Jefferson National Accelerator Facility. For the first time the absolute cross sections were measured covering nearly the full angular range in the hadronic center-of-mass frame. The structure functions sigma_TL, sigma_TT and the linear combination sigma_T+epsilon*sigma_L were extracted by fitting the phi-dependence of the measured cross sections, and were compared to the MAID and Sato-Lee models.

345 data tables match query

Structure functions for Q**2 = 0.30 GeV**2 and W = 1.11 GeV.

Structure functions for Q**2 = 0.30 GeV**2 and W = 1.13 GeV.

Structure functions for Q**2 = 0.30 GeV**2 and W = 1.15 GeV.

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