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First measurement of beam-recoil observables C(x) and C(z) in hyperon photoproduction.

The CLAS collaboration Bradford, R.K. ; Schumacher, R.A. ; Adams, G. ; et al.
Phys.Rev.C 75 (2007) 035205, 2007.
Inspire Record 732402 DOI 10.17182/hepdata.31496

Spin transfer from circularly polarized real photons to recoiling hyperons has been measured for the reactions $\vec\gamma + p \to K^+ + \vec\Lambda$ and $\vec\gamma + p \to K^+ + \vec\Sigma^0$. The data were obtained using the CLAS detector at Jefferson Lab for center-of-mass energies $W$ between 1.6 and 2.53 GeV, and for $-0.85<\cos\theta_{K^+}^{c.m.}< +0.95$. For the $\Lambda$, the polarization transfer coefficient along the photon momentum axis, $C_z$, was found to be near unity for a wide range of energy and kaon production angles. The associated transverse polarization coefficient, $C_x$, is smaller than $C_z$ by a roughly constant difference of unity. Most significantly, the {\it total} $\Lambda$ polarization vector, including the induced polarization $P$, has magnitude consistent with unity at all measured energies and production angles when the beam is fully polarized. For the $\Sigma^0$ this simple phenomenology does not hold. All existing hadrodynamic models are in poor agreement with these results.

34 data tables match query

Coefficients Cx and Cz for the reaction GAMMA P --> K+ LAMBDA for incident energy = 1.032 GeV and W = 1.679 GeV.

Coefficients Cx and Cz for the reaction GAMMA P --> K+ LAMBDA for incident energy = 1.132 GeV and W = 1.734 GeV.

Coefficients Cx and Cz for the reaction GAMMA P --> K+ LAMBDA for incident energy = 1.232 GeV and W = 1.787 GeV.

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Photoproduction of the omega meson on the proton at large momentum transfer.

The CLAS collaboration Battaglieri, M. ; Brunoldi, M. ; De Vita, R. ; et al.
Phys.Rev.Lett. 90 (2003) 022002, 2003.
Inspire Record 599053 DOI 10.17182/hepdata.19351

The differential cross section, $d\sigma/dt$ for $\omega$ meson exclusive photoproduction on the proton above the resonance region ($2.6

4 data tables match query

Differential cross section in the energy region 3.20 to 3.38 GeV.

Differential cross section in the energy region 3.38 to 3.56 GeV.

Differential cross section in the energy region 3.56 to 3.74 GeV.

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Measurement of the proton spin structure function g1(x,Q**2) for Q**2 from 0.15-GeV**2 to 1.6-GeV**2 with CLAS.

The CLAS collaboration Fatemi, R. ; Skabelin, A.V. ; Burkert, V.D. ; et al.
Phys.Rev.Lett. 91 (2003) 222002, 2003.
Inspire Record 621221 DOI 10.17182/hepdata.41917

Double-polarization asymmetries for inclusive $ep$ scattering were measured at Jefferson Lab using 2.6 and 4.3 GeV longitudinally polarized electrons incident on a longitudinally polarized NH$_3$ target in the CLAS detector. The polarized structure function $g_1(x,Q^2)$ was extracted throughout the nucleon resonance region and into the deep inelastic regime, for $Q^2 = 0.15 -1.64 $GeV$^2$. The contributions to the first moment $\Gamma_1(Q^2) = \int g_1(x,Q^2)dx$ were determined up to $Q^2=1.2$ GeV$^2$. Using a parametrization for $g_1$ in the unmeasured low $x$ regions, the complete first moment was estimated over this $Q^2$ region. A rapid change in $\Gamma_1$ is observed for $Q^2 < 1 $GeV$^2$, with a sign change near $Q^2 = 0.3 $GeV$^2$, indicating dominant contributions from the resonance region. At $Q^2=1.2$ GeV$^2$ our data are below the pQCD evolved scaling value.

8 data tables match query

The measured photon asymmetry (A1+ETA*A2) for the Q**2 region 0.15 to 0.22 GeV**2 obtained with a beam energy of 2.6 GeV.

The measured photon asymmetry (A1+ETA*A2) for the Q**2 region 0.6 to 1.10 GeV**2 obtained with a beam energy of 4.3 GeV.

The polarized structure function G1 as a function of Bjorken X for the Q**2range 0.15 to 0.27 GeV.

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eta' photoproduction on the proton for photon energies from 1.527-GeV to 2.227-GeV.

The CLAS collaboration Dugger, M. ; Ball, J.P. ; Collins, P. ; et al.
Phys.Rev.Lett. 96 (2006) 062001, 2006.
Inspire Record 700399 DOI 10.17182/hepdata.31553

Differential cross sections for the reaction gamma p -> eta-prime p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than previous measurements. Analyses of these data indicate for the first time the coupling of the etaprime N channel to both the S_11(1535) and P_11(1710) resonances, known to couple strongly to the eta N channel in photoproduction on the proton, and the importance of j=3/2 resonances in the process.

5 data tables match query

Differential cross sections for ETAPRIME photoproduction on the proton at photon energies 1.527, 1.577 and 1.627 GeV. The errors shown are combined statistical and systematic.

Differential cross sections for ETAPRIME photoproduction on the proton at photon energies 1.677, 1.728 and 1.779 GeV. The errors shown are combined statistical and systematic.

Differential cross sections for ETAPRIME photoproduction on the proton at photon energies 1.829, 1.879 and 1.930 GeV. The errors shown are combined statistical and systematic.

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Eta photoproduction on the proton for photon energies from 0.75-GeV to 1.95-GeV

The CLAS collaboration Dugger, M. ; Ritchie, B.G. ; Ball, J. ; et al.
Phys.Rev.Lett. 89 (2002) 222002, 2002.
Inspire Record 603904 DOI 10.17182/hepdata.19406

Differential cross sections for γp→ηp have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W=1.75  GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass ∼1.8  GeV couples to the ηN channel.

6 data tables match query

Cross sections for photon energies 0.775 to 0.925 GeV.

Cross sections for photon energies 0.975 to 1.125 GeV.

Cross sections for photon energies 1.175 to 1.325 GeV.

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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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Complete angular distribution measurements of two-body deuteron photodisintegration between 0.5-GeV and 3-GeV.

The CLAS collaboration Mirazita, M. ; Ronchetti, F. ; Rossi, P. ; et al.
Phys.Rev.C 70 (2004) 014005, 2004.
Inspire Record 650821 DOI 10.17182/hepdata.31633

Nearly complete angular distributions of the two-body deuteron photodisintegration differential cross section have been measured using the CLAS detector and the tagged photon beam at JLab. The data cover photon energies between 0.5 and 3.0 GeV and center-of-mass proton scattering angles 10-160 degrees. The data show a persistent forward-backward angle asymmetry over the explored energy range, and are well-described by the non-perturbative Quark Gluon String Model.

4 data tables match query

Angular distributions of the photodisintegration cross section for angle between 10 and 50 degrees in the CM.

Angular distributions of the photodisintegration cross section for angle between 50 and 90 degrees in the CM.

Angular distributions of the photodisintegration cross section for angle between 90 and 130 degrees in the CM.

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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.

46 data tables match query

No description provided.

No description provided.

No description provided.

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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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Electroproduction of $\phi(1020)$ mesons at $1.4\leq Q^2\leq$ 3.8 GeV$^2$ measured with the CLAS spectrometer

The CLAS collaboration Santoro, J.P. ; Smith, E.S. ; Garc con, M. ; et al.
Phys.Rev.C 78 (2008) 025210, 2008.
Inspire Record 781974 DOI 10.17182/hepdata.50913

Electroproduction of exclusive $\phi$ vector mesons has been studied with the CLAS detector in the kinematical range $1.6\leq Q^2\leq 3.8$ GeV$^{2}$, $0.0\leq t^{\prime}\leq 3.6$ GeV$^{2}$, and $2.0\leq W\leq 3.0$ GeV. The scaling exponent for the total cross section as $1/(Q^2+M_{\phi}^2)^n$ was determined to be $n=2.49\pm 0.33$. The slope of the four-momentum transfer $t'$ distribution is $b_{\phi}=0.98 \pm 0.17$ GeV$^{-2}$. The data are consistent with the assumption of s-channel helicity conservation (SCHC). Under this assumption, we determine the ratio of longitudinal to transverse cross sections to be $R=0.86 \pm 0.24$. A 2-gluon exchange model is able to reproduce the main features of the data.

5 data tables match query

Axis error includes +- 18.6/18.6 contribution.

Axis error includes +- 18.6/18.6 contribution.

Axis error includes +- 18.6/18.6 contribution.

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