Date

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Measurement of the photon structure function F2(gamma) with the L3 detector at LEP.

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 622 (2005) 249-264, 2005.
Inspire Record 687095 DOI 10.17182/hepdata.48675

The e+e- -> e+e- hadrons reaction, where one of the two electrons is detected in a low polar-angle calorimeter, is analysed in order to measure the hadronic photon structure function F2gamma . The full high-energy and high-luminosity data set, collected with the L3 detector at centre-of-mass energies 189-209GeV, corresponding to an integrated luminosity of 608/pb is used. The Q^2 range 11-34GeV^2 and the x range 0.006-0.556 are considered. The data are compared with recent parton density functions.

16 data tables

Cross sections DELTA(SIG)/DELTA(X) in the Q**2 range 11 TO 14 GeV**2.

Cross sections DELTA(SIG)/DELTA(X) in the Q**2 range 14 TO 20 GeV**2.

Cross sections DELTA(SIG)/DELTA(X) in the Q**2 range 20 TO 34 GeV**2.

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Measurement of D*+- production in deep inelastic e+- p scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Phys.Rev.D 69 (2004) 012004, 2004.
Inspire Record 626816 DOI 10.17182/hepdata.46419

Inclusive production of $D^*(2010)$ mesons in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 81.9 pb$^{-1}$. The decay channel $D^{* +}\to D^0 \pi^+ $ with $D^0\to K^-\pi^+$ and corresponding antiparticle decay were used to identify $D^*$ mesons. Differential $D^*$ cross sections with $1.5

17 data tables

Overall total cross section. The second DSYS error is due to the uncertainty in the BR for D* and D0 decay.

Measured differential cross section as a function of Q**2.

Measured differential cross section as a function of X.

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Measurement of the open-charm contribution to the diffractive proton structure function.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Nucl.Phys.B 672 (2003) 3-35, 2003.
Inspire Record 624128 DOI 10.17182/hepdata.43831

Production of D*+/-(2010) mesons in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb^{-1}. Diffractive events were identified by the presence of a large rapidity gap in the final state. Differential cross sections have been measured in the kinematic region 1.5 < Q^2 < 200 GeV^2, 0.02 < y < 0.7, x_{IP} < 0.035, beta < 0.8, p_T(D*+/-) > 1.5 GeV and |\eta(D*+/-)| < 1.5. The measured cross sections are compared to theoretical predictions. The results are presented in terms of the open-charm contribution to the diffractive proton structure function. The data demonstrate a strong sensitivity to the diffractive parton densities.

18 data tables

Total cross section for diffractive D*+- production in the stated kinematicregion.. The second DSYS uncertainty arises from the subtraction of the proton-dissociative background.

The differential cross section as a function of X(NAME=POMERON).

The differential cross section as a function of transverse momentum.

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Measurement of high-Q**2 e- p neutral current cross sections at HERA and the extraction of xF3.

The ZEUS collaboration Chekanov, S. ; Krakauer, D. ; Magill, S. ; et al.
Eur.Phys.J.C 28 (2003) 175-201, 2003.
Inspire Record 593481 DOI 10.17182/hepdata.46560

Cross sections for e^-p neutral current deep inelastic scattering have been measured at a centre-of-mass energy of 318 GeV using an integrated luminosity of 15.9 pb^-1 collected with the ZEUS detector at HERA. Results on the double-differential cross-section d^2s/dxdQ^2 in the range 185 < Q^2 < 50000 GeV^2 and 0.0037 < x < 0.75, as well as the single-differential cross-sections ds/dQ^2, ds/dx and ds/dy for Q^2 > 200 GeV^2, are presented. To study the effect of Z-boson exchange, ds/dx has also been measured for Q^2 > 10000 GeV^2. The structure function xF_3 has been extracted by combining the e^-p results presented here with the recent ZEUS measurements of e^+p neutral current deep inelastic scattering. All results agree well with the predictions of the Standard Model.

32 data tables

Differential cross section DSIG/DQ**2.

Differential cross section DSIG/DX for two Q**2 regions.

Differential cross section DSIG/DY.

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Observation of diffractive J / psi production at the Fermilab Tevatron

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 87 (2001) 241802, 2001.
Inspire Record 560628 DOI 10.17182/hepdata.55764

We report the first observation of diffractive $J/\psi(\to \mu^+\mu^-)$ production in $\bar pp$ collisions at $\sqrt{s}$=1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum $p_T^{\mu}>2$ GeV/$c$ within the pseudorapidity region $|\eta|<$1.0, the ratio of diffractive to total $J/\psi$ production rates is found to be $R_{J/\psi}= [1.45\pm 0.25]%$. The ratio $R_{J/\psi}(x)$ is presented as a function of $x$-Bjorken. By combining it with our previously measured corresponding ratio $R_{jj}(x)$ for diffractive dijet production, we extract a value of $0.59\pm 0.15$ for the gluon fraction of the diffractive structure function of the proton.

3 data tables

Diffractive to total J/psi production ratio.

Ratio of diffractive to total J/psi rate, per unit of the fractional momentum loss of the leading (anti)proton, and as a function of x-Bjorken of the struck parton of the (anti)proton adjacent to the rapidity gap and participating in the J/psi production.

Gluon fraction of the diffractive structure function of the (anti)proton.


Measurement of the neutral current cross section and F2 structure function for deep inelastic e+ p scattering at HERA.

The ZEUS collaboration Chekanov, S. ; Derrick, M. ; Krakauer, D. ; et al.
Eur.Phys.J.C 21 (2001) 443-471, 2001.
Inspire Record 557597 DOI 10.17182/hepdata.46774

The cross section and the proton structure function F2 for neutral current deep inelastic e+p scattering have been measured with the ZEUS detector at HERA using an integrated luminosity of 30 pb-1. The data were collected in 1996 and 1997 at a centre-of-mass energy of 300 GeV. They cover the kinematic range 2.7 < Q^2 < 30000 GeV2 and 6.10^-5 < x < 0.65. The variation of F2 with x and Q2 is well described by next-to-leading-order perturbative QCD as implemented in the DGLAP evolution equations.

6 data tables

The electromagnetic structure function, F2(C=EM), in NC DIS scattering at Q**2 from 2.7 to 30000 GeV**2.

The corrections to the structure function, F2(C=EM), in NC DIS scattering at Q**2 from 2.7 to 30000 GeV**2.

The relative uncertainties in the reduced cross section. See text of paper for more details. There is an additional 2 PCT overall normalization error not included, andan addtional uncertainty of 1 PCT at low Q**2.. DUNC - Uncorrelated systematic error. Correlated Systematic Errors:. D1 - positron finding and efficiency. D2 - positron scattering angle - A. D3 - positron scattering angle - B. D4 - positron energy scale. D5 - hadronic energy measurment - FCAL. D6 - hadronic energy measurment - BCAL. D7 - hadronic energy measurment - RCAL. D8 - hadronic energy flow - A. D9 - background subtractions. D10 - hadronic energy flow - B.

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Measurement of the proton structure function F2 at very low Q**2 at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Phys.Lett.B 487 (2000) 53-73, 2000.
Inspire Record 527095 DOI 10.17182/hepdata.46969

A measurement of the proton structure function F_2(x,Q^2) is presented in the kinematic range 0.045 GeV^2 < Q^2 < 0.65 GeV^2 and 6*10^{-7} < x < 1*10^{-3}. The results were obtained using a data sample corresponding to an integrated luminosity of 3.9pb^-1 in e^+p reactions recorded with the ZEUS detector at HERA. Information from a silicon-strip tracking detector, installed in front of the small electromagnetic calorimeter used to measure the energy of the final-state positron at small scattering angles, together with an enhanced simulation of the hadronic final state, has permitted the extension of the kinematic range beyond that of previous measurements. The uncertainties in F_2 are typically less than 4%. At the low Q^2 values of the present measurement, the rise of F_2 at low x is slower than observed in HERA data at higher Q^2 and can be described by Regge theory with a constant logarithmic slope. The dependence of F_2 on Q^2 is stronger than at higher Q^2 values, approaching, at the lowest Q^2 values of this measurement, a region where F_2 becomes nearly proportional to Q^2.

24 data tables

Measured values of F2 at Q**2 = 0.045 GeV**2 as a function of X.

Measured values of F2 at Q**2 = 0.065 GeV**2 as a function of X.

Measured values of F2 at Q**2 = 0.085 GeV**2 as a function of X.

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Measurement of the photon structure function at high Q**2 at LEP

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 483 (2000) 373-386, 2000.
Inspire Record 525764 DOI 10.17182/hepdata.49964

The structure functions of real and virtual photons are derived from cross section measurements of the reaction e^+e^ -> e^+e^- + hadrons at LEP. The reaction is studied at \sqrt{s} ~ 91 GeV with the L3 detector. One of the final state electrons is detected at a large angle relative to the beam direction, leading to Q^2 values between 40 GeV^2 and 500 GeV^2. The other final state electron is either undetected or it is detected at a four-momentum transfer squared P^2 between 1 GeV^2 and 8 GeV^2. These measurements are compared with predictions of the Quark Parton Model and other QCD based models.

4 data tables

Measured values of F2 for the single-tag data as a function of X for the full Q**2 range.

Measured values of F2 for the single-tag data as a function of Q**2 for different X ranges.

The effective F2 measured in double-tag events as a function of X.

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Measurement of D*+- production and the charm contribution to F2 in deep inelastic scattering at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Eur.Phys.J.C 12 (2000) 35-52, 2000.
Inspire Record 505056 DOI 10.17182/hepdata.43895

The production of D*+-(2010) mesons in deep inelastic scattering has been measured in the ZEUS detector at HERA using an integrated luminosity of 37 pb^-1. The decay channels D*+ -> D0 pi+(+c.c.), with D0 -> K- pi+ or D0 ->K- pi- pi+ pi+, have been used to identify the D mesons. The e+p cross section for inclusive D*+- production with 1

22 data tables

The measured cross section for D* production. The first is derived from theK2PI final state and the second from the K4PI final state.

The differential cross section w.r.t. Q**2 from the K2PI final state. The asymmetric errors are the quadratic sum of the statistical and systematic errors. The statistical errors are also shown separately.

The differential cross section w.r.t. X from the K2PI final state. The asymmetric errors are the quadratic sum of the statistical and systematic errors. The statistical errors are also shown separately.

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The Q**2 evolution of the hadronic photon structure function F2(gamma) at LEP.

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 447 (1999) 147-156, 1999.
Inspire Record 479052 DOI 10.17182/hepdata.49323

New measurements at a centre-of-mass energy s ≃183 GeV of the hadronic photon structure function F γ 2 ( x ) in the Q 2 interval, 9 GeV 2 ≤ Q 2 ≤30 GeV 2 , are presented. The data, collected in 1997 with the L3 detector, correspond to an integrated luminosity of 51.9 pb −1 . Combining with the data taken at a centre-of-mass energy of 91 GeV, the evolution of F γ 2 with Q 2 is measured in the Q 2 range from 1.2 GeV 2 to 30 GeV 2 . F γ 2 shows a linear growth with ln Q 2 ; the value of the slope α −1 d F γ 2 ( Q 2 )/dln Q 2 is measured in two x bins from 0.01 to 0.2 and is somewhat higher than predicted.

1 data table

Measured values of F2/ALPHA as a function of x. The second systematic error (DSYS) is that due to the model dependence and is the difference between the results obtained with PHOJET and TWOGAM. The full systematic error is the quadrature sum of the two systematic errors.