Alexa, C
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Production of J / psi mesons in p Be collisions at 530-GeV/c and 800-GeV/c

The E672 & E706 collaborations Gribushin, A. ; Abramov, V. ; Antipov, Yu. ; et al.
Phys.Rev.D 62 (2000) 012001, 2000.
Inspire Record 508006 DOI 10.17182/hepdata.42099

We report on the production of J/psi mesons in 530 and 800 GeV/c proton - Be collisions in the Feynman-x range 0.0 < xf < 0.6. The J/psi mesons were detected via decays into opposite sign muon pairs. Differential distributions for J/psi production have been measured as functions of xf, pT^2, and cosine of the Gottfried-Jackson decay angle. These distributions are compared with results on J/psi production obtained in 515 GeV/c pion - Be collisions, measured by the same experiment, as well as with results from other experiments using incident protons.

6 data tables
Table 1

Differential XL distribution for J/PSI production in 530 GeV pBe collisions. Errors are combined statistics and systematics.

Table 2

Differential PT**2 distribution for J/PSI production in 530 GeV pBe collisions. Errors are combined statistics and systematics.

Table 3

Differential COS(THETA) distribution for J/PSI production in 530 GeV pBe collisions. Errors are combined statistics and systematics.

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rivet Analysis
Measurement of the E(T,jet)**2/Q**2 dependence of forward-jet production at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Phys.Lett.B 474 (2000) 223-233, 2000.
Inspire Record 508906 DOI 10.17182/hepdata.43875

The forward-jet cross section in deep inelastic ep scattering has been measured using the ZEUS detector at HERA with an integrated luminosity of 6.36 pb^-1. The jet cross section is presented as a function of jet transverse energy squared, E(T,jet)^2, and Q^2 in the kinematic ranges 10^-2

2 data tables
Table 1

Forward jet cross section as a function of ET**2/Q**2. The second DSYS error is the uncertainty in the energy scale of the calorimeter.

Table 2

Measured forward-jet x distribution.


Measurement of diffractive photoproduction of vector mesons at large momentum transfer at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Eur.Phys.J.C 14 (2000) 213-238, 2000.
Inspire Record 508770 DOI 10.17182/hepdata.43866

Elastic and proton-dissociative photoproduction of $\rho^0$, $\phi$ and $J/\psi$ vector mesons ($\gamma p\to Vp$, $\gamma p\to VN$, respectively) have been measured in e^+p interactions at HERA up to -t=3 GeV$^2$, where t is the four-momentum transfer squared at the photon-vector meson vertex. The analysis is based on a data sample in which photoproduction reactions were tagged by detection of the scattered positron in a special-purpose calorimeter. This limits the photon virtuality, Q^2, to values less than 0.01 GeV$^2$, and selects a $\gamma p$ average center-of-mass energy of = 94 GeV. Results for the differential cross sections, d$\sigma$/d$t$, for $\rho^0$, $\phi$ and $J/\psi$ mesons are presented and compared to the results of recent QCD calculations. Results are also presented for the t-dependence of the pion-pair invariant-mass distribution in the $\rho^0$ mass region and of the spin-density matrix elements determined from the decay-angle distributions. The Pomeron trajectory has been derived from measurements of the W dependence of the elastic differential cross sections d$\sigma$/d$t$ for both $\rho^0$ and $\phi$ mesons.

18 data tables
Table 1

Differential cross section for proton-dissociative RHO0 photoproduction.

Table 2

Differential cross section for elastic RHO0 photoproduction.

Table 3

The ratio of the elastic to proton-dissociative cross sections for RHO0 photoproduction.

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Measurement of inclusive prompt photon photoproduction at HERA.

The ZEUS collaboration Breitweg, J. ; Chekanov, S. ; Derrick, M. ; et al.
Phys.Lett.B 472 (2000) 175-188, 2000.
Inspire Record 508908 DOI 10.17182/hepdata.43894

First inclusive measurements of isolated prompt photons in photoproduction at the HERA ep collider have been made with the ZEUS detector, using an integrated luminosity of 38.4 pb$^{-1}$. Cross sections are given as a function of the pseudorapidity and the transverse energy ($\eta^\gamma$, \eTg) of the photon, for $\eTg > $ 5 GeV in the $\gamma p$ centre-of-mass energy range 134-285 GeV. Comparisons are made with predictions from Monte Carlo models having leading-logarithm parton showers, and with next-to-leading-order QCD calculations, using currently available parameterisations of the photon structure. For forward $\eta^\gamma$ (proton direction) good agreement is found, but in the rear direction all predictions fall below the data.

2 data tables
Table 1

The differential cross section for inclusive photoproduction of isolated photons.

Table 2

Differential cross sections as a function pseudorapidity for the inclusive photoproduction of isolated photons with transverse energy from 5 to 10 GeV.


Measurement of the gluon fragmentation function and a comparison of the scaling violation in gluon and quark jets.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 13 (2000) 573-589, 2000.
Inspire Record 511099 DOI 10.17182/hepdata.49028

The fragmentation functions of quarks and gluons are measured in various three-jet topologies in Z decays from the full data set collected with the Delphi detector at the Z resonance between 1992 and

7 data tables
Table 1

Charged hadron XE(=Z) distributions. Durham algorithm. XISTAR is peak position in XI=LOG(-XE) distribution.

Table 2

Charged hadron XE(=Z) distributions. Durham algorithm. XISTAR is peak position in XI=LOG(-XE) distribution.

Table 3

Charged hadron XE(=Z) distributions. Durham algorithm. XISTAR is peak position in XI=LOG(-XE) distribution.

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Production of upsilon(1S) mesons from chi(b) decays in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 84 (2000) 2094-2099, 2000.
Inspire Record 508395 DOI 10.17182/hepdata.50106

We have reconstructed the radiative decays $\chi_{b}(1P) \to \Upsilon(1S) \gamma $ and $\chi_{b}(2P) \to \Upsilon(1S) \gamma $ in $p \bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV, and measured the fraction of $\Upsilon(1S)$ mesons that originate from these decays. For $\Upsilon(1S)$ mesons with $p^{\Upsilon}_{T}>8.0$ GeV/$c$, the fractions that come from $\chi_{b}(1P)$ and $\chi_{b}(2P)$ decays are $(27.1\pm6.9(stat)\pm4.4(sys))%$ and $(10.5\pm4.4(stat)\pm1.4(sys))%$, respectively. We have derived the fraction of directly produced $\Upsilon(1S)$ mesons to be $(50.9\pm8.2(stat)\pm9.0(sys))%$.

1 data table
Table 1

No description provided.


Measurement of the e+ e- --> Z Z production cross section at centre-of-mass energies of 183-GeV and 189-GeV.

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Phys.Lett.B 469 (1999) 287-302, 1999.
Inspire Record 509241 DOI 10.17182/hepdata.49034

The ee -> ZZ cross section at sqrt(s)=182.7 and 188.6 GeV has been measured using the ALEPH detector. The analysis covers all of the visible ZZ final states and yields cross section measurements of sigma_ZZ(182.7 GeV) = 0.11 +- (0.16,0.11) (stat.) +- 0.04 (syst.) pb and sigma_ZZ(188.6 GeV) = 0.67 +- 0.13 (stat.) +- 0.04 (syst.) pb consistent with the Standard Model expectations.

1 data table
Table 1

The combined cross sections for the 2Z0 (NC2) fixed state.


Parity violation in elastic electron proton scattering and the proton's strange magnetic form-factor.

The SAMPLE collaboration Spayde, D.T. ; Averett, T. ; Barkhuff, D. ; et al.
Phys.Rev.Lett. 84 (2000) 1106-1109, 2000.
Inspire Record 507265 DOI 10.17182/hepdata.31230

We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak axial radiative corrections. The new measurement of A=-4.92 +- 0.61 +- 0.73 ppm provides a significant constraint on these quantities. The implications for the strange magnetic form factor are discussed in the context of theoretical estimates for the axial corrections.

1 data table
Table 1

Polarized beam. FORMFACTOR(NAME=GM_S) is the strange quark contribution. FORMFACTOR(NAME=GM_S) is in nucleon magnetic FF.


Measurement of triple gauge boson couplings of the W boson at LEP

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 467 (1999) 171-184, 1999.
Inspire Record 508078 DOI 10.17182/hepdata.35044

We report on measurements of the triple-gauge-boson couplings of the W boson in e+e- collisions with the L3 detector at LEP. W-pair, single-W and single-photon events are analysed in a data sample corresponding to a total luminosity of 76.7 pb^{-1} collected at centre-of-mass energies between 161 GeV and 183 GeV. CP-conserving as well as both C- and P-conserving triple-gauge-boson couplings are determined. The results, in good agreement with the Standard-Model expectations, confirm the existence of the self coupling among the electroweak gauge bosons and constrain its structure.

12 data tables
Table 1

The errors are statistical. Two-parameter fit.

Table 2

The errors are statistical. Two-parameter fit.

Table 3

The errors are statistical. Two-parameter fit.

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Evidence for diffractive charm production in nu/mu Fe and anti-nu/mu Fe scattering at the Tevatron.

The NuTeV collaboration Adams, T. ; Alton, A. ; Bolton, T. ; et al.
Phys.Rev.D 61 (2000) 092001, 2000.
Inspire Record 507640 DOI 10.17182/hepdata.42093

We present evidence for the diffractive processes nu_mu Fe -> mu^- D_s^+ (D_s^*+) Fe and nubar_mu Fe -> mu^+ D_s^- (D_s^*-) Fe using the Fermilab SSQT neutrino beam and the Lab E neutrino detector. We observe the neutrino trident reactions nu_mu Fe -> nu_mu mu^- mu^+ Fe and nubar_mu Fe -> nubar_mu mu^+ mu^- Fe at rates consistent with Standard Model expectations. We see no evidence for neutral-current production of J/psi via either diffractive or deep inelastic scattering mechanisms.

5 data tables
Table 1

The quoted error are completely dominated by statistics. The cross section per nucleon.

Table 2

The quoted error are completely dominated by statistics. The cross section per nucleon.

Table 3

The quoted error are completely dominated by statistics. The cross section per nucleon.

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