Cross Section and Tensor Analysing Power of the $\vec{d}d\to \eta\alpha$ Reaction Near Threshold

The GEM collaboration Budzanowski, A. ; Chatterjee, A. ; Gebel, R. ; et al.
Nucl.Phys.A 821 (2009) 193-209, 2009.
Inspire Record 803178 DOI 10.17182/hepdata.52401

The angular distributions of the unpolarised differential cross section and tensor analysing power $A_{xx}$ of the $\vec{d}d\to\alpha \eta$ reaction have been measured at an excess energy of 16.6 MeV. The ambiguities in the partial-wave description of these data are made explicit by using the invariant amplitude decomposition. This allows the magnitude of the s-wave amplitude to be extracted and compared with results published at lower energies. In this way, firmer bounds could be obtained on the scattering length of the $\eta \alpha$ system. The results do not, however, unambiguously prove the existence of a quasi-bound $\eta \alpha$ state.

3 data tables

Total cross section from fit to the differential angular distribution.

Differential angular distribution.

Analysing power measurements.


Precision measurements of the pp ---> pi+ pn and pp ---> pi+ d reactions: Importance of long-range and tensor force effects

The COSY-GEM collaboration Budzanowski, A. ; Chatterjee, A. ; Hawranek, P. ; et al.
Phys.Rev.C 79 (2009) 061001, 2009.
Inspire Record 818511 DOI 10.17182/hepdata.52961

Inclusive measurements of pion production in proton--proton collisions in the forward direction were undertaken at 400 and 600 MeV at COSY using the Big Karl spectrograph. The high resolution in the $\pi^+$ momentum ensured that there was an unambiguous separation of the $pp\to {\pi}^+d/\pi^+pn$ channels. Using these and earlier data, the ratio of the production cross sections could be followed through the $\Delta$ region and compared with the predictions of final state interaction theory. Deviations are strongly influenced by long-range terms in the production operator and the tensor force in the final $pn$ system. These have been investigated in a realistic $pp\to\pi^+d/\pi^+pn$ calculation that includes $S \rightleftharpoons D$ channel coupling between the final nucleons. A semi-quantitative understanding of the observed effects is achieved.

6 data tables

Forward differential cross section for P P --> PI+ P N for beam momenta 1640 MeV.

Forward differential cross section for P P --> PI+ P N for beam momenta 1220 MeV.

Forward differential cross section for P P --> PI+ P N for beam momenta 955 MeV.

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Cross-Sections of Large-Angle Hadron Production in Proton- and Pion-Nucleus Interactions III: Tantalum Nuclei and Beam Momenta from +/-3 Gev/c to +/-15 Gev/c

The HARP-CDP collaboration Bolshakova, A. ; Boyko, I. ; Chelkov, G. ; et al.
Eur.Phys.J.C 63 (2009) 549-609, 2009.
Inspire Record 822058 DOI 10.17182/hepdata.50528

We report on double-differential inclusive cross-sections of the production of secondary protons, charged pions, and deuterons, in the interactions with a 5% nuclear interaction length thick stationary tantalum target, of proton and pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for secondary particles with production angles between 20 and 125 degrees. They are of particular relevance for the optimization of the design parameters of the proton driver of a neutrino factory.

375 data tables

Measured cross section as a function of PT for P production from a P beam of momentum 3 GeV/c in the angular range 20 to 30 DEG.

Measured cross section as a function of PT for P production from a P beam of momentum 3 GeV/c in the angular range 30 to 40 DEG.

Measured cross section as a function of PT for P production from a P beam of momentum 3 GeV/c in the angular range 40 to 50 DEG.

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Measurement of the Inclusive ep Scattering Cross Section at Low $Q^2$ and x at HERA

The H1 collaboration Aaron, F.D. ; Alexa, C. ; Andreev, V. ; et al.
Eur.Phys.J.C 63 (2009) 625-678, 2009.
Inspire Record 817368 DOI 10.17182/hepdata.52425

A measurement of the inclusive ep scattering cross section is presented in the region of low momentum transfers, 0.2 GeV^2 < Q^2 < 12 GeV^2, and low Bjorken x, 5x10^-6 < x < 0.02. The result is based on two data sets collected in dedicated runs by the H1 Collaboration at HERA at beam energies of 27.6 GeV and 920 GeV for positrons and protons, respectively. A combination with data previously published by H1 leads to a cross section measurement of a few percent accuracy. A kinematic reconstruction method exploiting radiative ep events extends the measurement to lower Q^2 and larger x. The data are compared with theoretical models which apply to the transition region from photoproduction to deep inelastic scattering.

39 data tables

Reduced cross section as measured in the SVX data sample for Q**2 = 0.20 GeV**2. Additional 3 PCT luminosity uncertainty not included in the total error.

Reduced cross section as measured in the SVX data sample for Q**2 = 0.25 GeV**2. Additional 3 PCT luminosity uncertainty not included in the total error.

Reduced cross section as measured in the SVX data sample for Q**2 = 0.35 GeV**2. Additional 3 PCT luminosity uncertainty not included in the total error.

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Measurement of Particle Production and Inclusive Differential Cross Sections in $p\bar{p}$ Collisions at $\sqrt{s}=1.96$ TeV

The CDF collaboration Aaltonen, T. ; Adelman, J. ; Akimoto, T. ; et al.
Phys.Rev.D 79 (2009) 112005, 2009.
Inspire Record 817466 DOI 10.17182/hepdata.52134

We report a set of measurements of particle production in inelastic pbar{p} collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a Pythia prediction at the hadron level is performed. The inclusive charged particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.

3 data tables

Charged particle invariant distribution as a function of PT. This data is that given in the erratum with the systematic errors read from the plot.

Dependance of the average track PT on the event multiplicity.

The differential charged particle distribution as a function of the summed ET of charged particles.


Scaled momentum distributions of charged particles in dijet photoproduction at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
JHEP 08 (2009) 077, 2009.
Inspire Record 818528 DOI 10.17182/hepdata.52943

The scaled momentum distributions of charged particles in jets have been measured for dijet photoproduction with the ZEUS detector at HERA using an integrated luminosity of 359 pb-1. The distributions are compared to predictions based on perturbative QCD carried out in the framework of the modified leading-logarithmic approximation (MLLA) and assuming local parton-hadron duality (LPHD). The universal MLLA scale, Lambda_eff, and the LPHD parameter, kappa^ch, are extracted.

15 data tables

Distribution of multiplicity of charged particles in a jet as a function of LN(1/X) for mean jet energy 19 GeV and jet cone opening angle 0.23.

Distribution of multiplicity of charged particles in a jet as a function of LN(1/X) for mean jet energy 23 GeV and jet cone opening angle 0.23.

Distribution of multiplicity of charged particles in a jet as a function of LN(1/X) for mean jet energy 28 GeV and jet cone opening angle 0.23.

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Studies of strong and electroweak interactions using final state photon emission in hadronic Z0 decays

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 58 (1993) 405-418, 1993.
Inspire Record 343181 DOI 10.17182/hepdata.52379

The cross section and jet rates ofZ0 decays into photons and quarks are compared with matrix element Monte Carlos ofO(ααs). Good agreement is found between data and theoretical predic

4 data tables

Corrected number of hadronc events that have a final state photon per 1000 multhadronic Z0 decays, using the E0 scheme.

Corrected number of hadronc events that have a final state photon per 1000 multhadronic Z0 decays, using the Durham scheme.

Corrected number of events that have a final state photon with 1, 2, 3, or more jets per 1000 multhadronic Z0 decays, using the E0 scheme.

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Deep inelastic scattering with leading protons or large rapidity gaps at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
Nucl.Phys.B 816 (2009) 1-61, 2009.
Inspire Record 804915 DOI 10.17182/hepdata.52860

The dissociation of virtual photons, $\gamma^{\star} p \to X p$, in events with a large rapidity gap between $X$ and the outgoing proton, as well as in events in which the leading proton was directly measured, has been studied with the ZEUS detector at HERA. The data cover photon virtualities $Q^2>2$ GeV$^2$ and $\gamma^{\star} p$ centre-of-mass energies $40&lt;W&lt;240$ GeV, with $M_X>2$ GeV, where $M_X$ is the mass of the hadronic final state, $X$. Leading protons were detected in the ZEUS leading proton spectrometer. The cross section is presented as a function of $t$, the squared four-momentum transfer at the proton vertex and $\Phi$, the azimuthal angle between the positron scattering plane and the proton scattering plane. It is also shown as a function of $Q^2$ and $\xpom$, the fraction of the proton's momentum carried by the diffractive exchange, as well as $\beta$, the Bjorken variable defined with respect to the diffractive exchange.

48 data tables

The differential cross section DSIG/DT for the LRG and the LPS data samples.

The fitted exponential slope of the T distribution as a function of X(NAME=POMERON).

The fitted exponential slope of the T distribution as a function of X(NAME=POMERON).

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Measurement of $\sigma(e^+e^-\to\pi^+\pi^-\gamma(\gamma))$ and the dipion contribution to the muon anomaly with the KLOE detector

The KLOE collaboration Ambrosino, F. ; Antonelli, A. ; Antonelli, M. ; et al.
Phys.Lett.B 670 (2009) 285-291, 2009.
Inspire Record 797438 DOI 10.17182/hepdata.57088

We have measured the cross section $\sigma(e^+e^-\to\pi^+\pi^-\gamma(\gamma))$ at DA$\Phi$NE, the Frascati \phi-factory, using events with initial state radiation photons emitted at small angle and inclusive of final state radiation. We present the analysis of a new data set corresponding to an integrated luminosity of 240 pb$^{-1}$. We have achieved a reduced systematic uncertainty with respect to previously published KLOE results. From the cross section we obtain the pion form factor and the contribution to the muon magnetic anomaly from two pion states in the mass range $0.592 &lt; M_{\pi\pi} &lt; 0.975$ GeV. For the latter we find $\Delta a^{\pi\pi}_\mu = (387.2\pm0.5_{\rm stat}\pm2.4_{\rm exp}\pm2.3_{\rm th})\times 10^{-10}$

3 data tables

Differential cross section for E+ E- --> PI+ PI- GAMMA (GAMMA).

Total cross section for E+ E- --> PI+ PI-.

Pion form factor.


Measurement of J/psi photoproduction at large momentum transfer at HERA

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Magill, S. ; et al.
JHEP 05 (2010) 085, 2010.
Inspire Record 833339 DOI 10.17182/hepdata.55178

The proton-dissociative diffractive photoproduction of J/psi mesons has been studied in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 112 pb^-1. The cross section is presented as a function of the photon-proton centre-of-mass energy and of the squared four-momentum transfer at the proton vertex. The results are compared to perturbative QCD calculations.

14 data tables

The differential cross section DSIG/DT as a function of T.

The differential cross section DSIG/DT as a function of W in the ABS(T) range 2.0 to 2.5 GeV**2.

The differential cross section DSIG/DT as a function of W in the ABS(T) range 2.5 to 3.0 GeV**2.

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