Girod, F.X.
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Precision measurements of $g_1$ of the proton and the deuteron with 6 GeV electrons

The CLAS collaboration Prok, Y. ; Bosted, P. ; Kvaltine, N. ; et al.
Phys.Rev.C 90 (2014) 025212, 2014.
Inspire Record 1292133 DOI 10.17182/hepdata.64411

The inclusive polarized structure functions of the proton and deuteron, g1p and g1d, were measured with high statistical precision using polarized 6 GeV electrons incident on a polarized ammonia target in Hall B at Jefferson Laboratory. Electrons scattered at lab angles between 18 and 45 degrees were detected using the CEBAF Large Acceptance Spectrometer (CLAS). For the usual DIS kinematics, Q^2>1 GeV^2 and the final-state invariant mass W>2 GeV, the ratio of polarized to unpolarized structure functions g1/F1 is found to be nearly independent of Q^2 at fixed x. Significant resonant structure is apparent at values of W up to 2.3 GeV. In the framework of perturbative QCD, the high-W results can be used to better constrain the polarization of quarks and gluons in the nucleon, as well as high-twist contributions.

4 data tables
Table 1

Results for G1(P)/F1(P) for the proton in bins of (XB;Q**2), along with average kinematic values and correction factors for each bin. All values are averaged over the event distribution.

Table 2

Results for G1(DEUT)/F1(DEUT) for the deuteron in bins of (XB;Q**2), along with average kinematic values and correction factors for each bin. All values are averaged over the event distribution.

Table 3

Results for G1(P)/F1(P) for the proton in bins of (W;Q**2), along with average kinematic values and correction factors for each bin. All values are averaged over the event distribution.

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Separated structure functions for the exclusive electroproduction of K+ Lambda and K+ Sigma0 final states.

The CLAS collaboration Ambrozewicz, P. ; Carman, D.S. ; Feuerbach, R.J. ; et al.
Phys.Rev.C 75 (2007) 045203, 2007.
Inspire Record 732363 DOI 10.17182/hepdata.4994

We report measurements of the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from a proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions $\sigma_T$, $\sigma_L$, $\sigma_{TT}$, and $\sigma_{LT}$ were extracted from the $\Phi$- and $\epsilon$-dependent differential cross sections taken with electron beam energies of 2.567, 4.056, and 4.247 GeV. This analysis represents the first $\sigma_L/\sigma_T$ separation with the CLAS detector, and the first measurement of the kaon electroproduction structure functions away from parallel kinematics. The data span a broad range of momentum transfers from $0.5\leq Q^2\leq 2.8$ GeV$^2$ and invariant energy from $1.6\leq W\leq 2.4$ GeV, while spanning nearly the full center-of-mass angular range of the kaon. The separated structure functions reveal clear differences between the production dynamics for the $\Lambda$ and $\Sigma^0$ hyperons. These results provide an unprecedented data sample with which to constrain current and future models for the associated production of strangeness, which will allow for a better understanding of the underlying resonant and non-resonant contributions to hyperon production.

531 data tables
Table 1

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.6 to 1.7 GeV.

Table 2

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.70 to 1.75 GeV.

Table 3

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.75 to 1.80 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
Table 1

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

Table 2

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

Table 3

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

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Measurement of the deuteron structure function F2 in the resonance region and evaluation of its moments.

The CLAS collaboration Osipenko, M. ; Ricco, G. ; Simula, S. ; et al.
Phys.Rev.C 73 (2006) 045205, 2006.
Inspire Record 684005 DOI 10.17182/hepdata.12254

Inclusive electron scattering off the deuteron has been measured to extract the deuteron structure function F2 with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. The measurement covers the entire resonance region from the quasi-elastic peak up to the invariant mass of the final-state hadronic system W~2.7 GeV with four-momentum transfers Q2 from 0.4 to 6 (GeV/c)^2. These data are complementary to previous measurements of the proton structure function F2 and cover a similar two-dimensional region of Q2 and Bjorken variable x. Determination of the deuteron F2 over a large x interval including the quasi-elastic peak as a function of Q2, together with the other world data, permit a direct evaluation of the structure function moments for the first time. By fitting the Q2 evolution of these moments with an OPE-based twist expansion we have obtained a separation of the leading twist and higher twist terms. The observed Q2 behaviour of the higher twist contribution suggests a partial cancellation of different higher twists entering into the expansion with opposite signs. This cancellation, found also in the proton moments, is a manifestation of the duality phenomenon in the F2 structure function.

113 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
Production and decay of XI(c)0 at BABAR

The BaBar collaboration Aubert, Bernard ; Barate, R. ; Boutigny, D. ; et al.
Phys.Rev.Lett. 95 (2005) 142003, 2005.
Inspire Record 679961 DOI 10.17182/hepdata.27164

Using 116.1 fb^-1 of data collected by the BABAR detector, we present an analysis of Xic0 production in B decays and from the ccbar continuum, with the Xic0 decaying into Omega- K+ and Xi- pi+ final states. We measure the ratio of branching fractions B(Xic0 -> Omega- K+)/B(Xic0 -> Xi- pi+) to be 0.294 +- 0.018 +- 0.016, where the first uncertainty is statistical and the second is systematic. The Xic0 momentum spectrum is measured on and 40 MeV below the Upsilon(4S) resonance. From these spectra the branching fraction product B(B -> Xic0 X) x B(Xic0 -> Xi- pi+) is measured to be (2.11 +- 0.19 +- 0.25) x 10^-4 and the cross-section product sigma(e+ e- -> Xic0 X) x B(Xic0 -> Xi- pi+) from the continuum is measured to be (388 +- 39 +- 41) fb at a center-of-mass energy of 10.58 GeV.

3 data tables
Table 1

Measured cross section on the UPSILON(4S) resonance for the inclusive producton of XI/C0 times its branching ratio to XI- PI+.

Table 2

Measured cross section on and off the UPSILON(4S) resonance for the inclusive producton of XI/C0 times its branching ratio to XI- PI+. with the off-resonacne data are scaled to a centre-of-mass energy of 10.580 GeV.

Table 3

Total measured cross section for XI/C0 production for the continuum data scaled to a centre-of-mass energy of 10.580 GeV.


rivet Analysis
Measurement of j / psi production in continuum e+ e- annihilations near s**(1/2) = 10.6-GeV

The BaBar collaboration Aubert, Bernard ; Boutigny, D. ; Gaillard, J.M. ; et al.
Phys.Rev.Lett. 87 (2001) 162002, 2001.
Inspire Record 558091 DOI 10.17182/hepdata.19450

The production of $J/\psi$ mesons in continuum $e^+e^-$ annihilations has been studied with the BABAR detector at energies near the $\Upsilon(4S)$ resonance, approximately 10.6 GeV. The mesons are distinguished from $J/\psi$ production in B decays through their center-of-mass momentum and energy. We measure the cross section $e^+e^-\to J/\psi X$ to be $2.52\pm 0.21\pm 0.21$ pb: for momentum above 2 GeV/c, it is $1.87\pm 0.10\pm 0.15$ pb. We set a 90% confidence level upper limit on the branching fraction for direct $\Upsilon(4S)$\to J/\psi X$ decays at $4.7\times 10^{-4}$.

1 data table
Table 1

Cross section measurement.


Measurement of CP violating asymmetries in B0 decays to CP eigenstates

The BaBar collaboration Aubert, Bernard ; Boutigny, D. ; De Bonis, I. ; et al.
Phys.Rev.Lett. 86 (2001) 2515-2522, 2001.
Inspire Record 553002 DOI 10.17182/hepdata.50471

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23 million Upsilon(4S)-->B-anti-B decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events where one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2beta, is derived from the decay time distributions in such events. The result is sin2beta=0.34 +/- 0.20 (stat) +/- 0.05 (syst).

1 data table
Table 1

Standard Model predicts the time-dependent rate asymmetry as follows: A(t) = (B0(t)-BBAR0(t))/(B0(t)+BBAR0(t)) = SIN(2*BETA)*SIN(Delta(M)*t), where Delta(M) is the mass difference between the two B0 mass eigenstates. The total systematic error equals +0.50 -0.46.


Spin asymmetries from O-16(gamma(pol.),p pi-) near Delta resonance energies

Hicks, K. ; Baghaei, H. ; Caracappa, A. ; et al.
Phys.Rev.C 55 (1997) R12-R15, 1997.
Inspire Record 456890 DOI 10.17182/hepdata.25766

Spin asymmetries for the 16O(γ→,pπ−) reaction are reported for incident photon energies of 293 ± 20 MeV, proton angles ranging from 28° to 140° (lab), and pion angles of 35° to 115°. The data are compared with calculations in a quasifree plane-wave impulse approximation model. This model is in good agreement with the data at small momentum transfer q, but does not follow the trend of the data at large q. Sensitivity to the Δ-nucleus potential and to modification of the Δ lifetime from nuclear medium effects are explored using a simple modification of the Δ propagator in the calculations.

6 data tables
Table 1

The data are extracted from the figures by S.Slabospitsky. ASYM is the spin asymmetry. It is the ratio of the difference to the sum of the cross sections with the photon's linear polarization oriented parallel or perpendicular to the scattering plane.

Table 2

The data are extracted from the figures by S.Slabospitsky. ASYM is the spin asymmetry. It is the ratio of the difference to the sum of the cross sections with the photon's linear polarization oriented parallel or perpendicular to the scattering plane.

Table 3

The data are extracted from the figures by S.Slabospitsky. ASYM is the spin asymmetry. It is the ratio of the difference to the sum of the cross sections with the photon's linear polarization oriented parallel or perpendicular to the scattering plane.

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rivet Analysis
Study of Phi(1020), D*+- and B* spin alignment in hadronic Z0 decays.

The OPAL collaboration Ackerstaff, K. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 74 (1997) 437-449, 1997.
Inspire Record 440103 DOI 10.17182/hepdata.47515

Measurements of helicity density matrix elements have been made for the φ(1020), D*± and B* vector mesons in multihadronic Z0 decays in the OPAL experiment at LEP. Results for inclusive φ produced with high energy show evidence for production preferentially in the helicity zero state, with ρ00 = 0.54 ± 0.08, compared to the value of 1/3 expected for no spin alignment. The corresponding element for the D*± has a value of 0.40 ± 0.02, also suggesting a deviation from 1/3. The B* result, with ρ00 = 0.36 ± 0.09, is consistent with no spin alignment. Off-diagonal elements have been measured for the f and D* mesons; for the D* the element Re ρ1−1 is non-zero, indicating non-independent fragmentation of the primary quarks.

4 data tables
Table 1

Helicity density matrices elements. Helicity beam frame is used.

Table 2

Charge conjugated states are understood.

Table 3

Helicity density matrices elements. Charge conjugated states are understood.

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Inclusive jet production in photon-photon collisions at s**(1/2) = 130-GeV and 136-GeV

The OPAL collaboration Ackerstaff, K. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 73 (1997) 433-442, 1997.
Inspire Record 424635 DOI 10.17182/hepdata.47713

The inclusive one- and two-jet production cross-sections are measured in collisions of quasi-real photons radiated from the LEP beams at e+e− centre-of-mass energies \(\sqrt{s}_{\rm ee}=130\) and 136 GeV using the OPAL detector at LEP. Hard jets are reconstructed using a cone jet finding algorithm. The differential jet cross-sections \({\rm d}\sigma /{\rm d}E_{T}^{\rm jet}\) are compared to next-to-leading order perturbative QCD calculations. Transverse energy flows in jets are studied separately for direct and resolved two-photon events.

4 data tables
Table 1

Inclusive one-jet cross section.

Table 2

One-jet rapidity distribution.

Table 3

Inclusive two-jet cross section.

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