Date

Measurement of K* anti-K* production in two-photon interactions.

The ARGUS collaboration Albrecht, H. ; Hamacher, T. ; Hofmann, R.P. ; et al.
Eur.Phys.J.C 16 (2000) 435-444, 2000.
Inspire Record 511512 DOI 10.17182/hepdata.35113

A measurement of gamma–gamma production of the final states$K^+ K^- \pi^+ \pi ^-$,$K^+ K^- \pi^0 \pi ^0$,$

11 data tables

Cross sections for the partial waves from an analysis where the five (JP,LZ) states (0+,0), (2-,0), (2+,+-2), (2+,0) and (0-,0) are included.

Cross section obtained for the three partial waves obtained when the two with smallest amplitude in the previous table are set to zero.

Cross sections for the various final states from the 'five partial wave' analysis.

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The Isolated photon cross-section in p anti-p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 84 (2000) 2786-2791, 2000.
Inspire Record 511200 DOI 10.17182/hepdata.42075

We report a new measurement of the cross section for the production of isolated photons, with transverse energies (ET) above 10 GeV and pseudorapidities |eta| < 2.5, in p pbar collisions at sqrt{s} = 1.8 TeV. The results are based on a data sample of 107.6 pb-1 recorded during 1992--1995 with the D0 detector at the Fermilab Tevatron collider. The background, predominantly from jets which fragment to neutral mesons, was estimated using the longitudinal shower shape of photon candidates in the calorimeter. The measured cross section is in good agreement with the next-to-leading order (NLO) QCD calculation for ET > 36 GeV.

2 data tables

The measured isolated photon cross sections. The first error contains the statistics and uncorrelated systematic uncertainties, the DSYS error is the correlated systematic uncertainty.

The measured isolated photon cross sections. The first error contains the statistics and uncorrelated systematic uncertainties, the DSYS error is the correlated systematic uncertainty.


A Measurement of the differential dijet mass cross-section 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.D 61 (2000) 091101, 2000.
Inspire Record 511377 DOI 10.17182/hepdata.42047

We present a measurement of the cross section for production of two or more jets as a function of dijet mass, based on an integrated luminosity of 86 pb^-1 collected with the Collider Detector at Fermilab. Our dijet mass spectrum is described within errors by next-to-leading order QCD predictions using CTEQ4HJ parton distributions, and is in good agreement with a similar measurement from the D0 experiment.

1 data table

The differential cross section for two or more jets as a function of the dijet mass.


Investigation of power corrections to event shape variables measured in deep-inelastic scattering.

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Eur.Phys.J.C 14 (2000) 255-269, 2000.
Inspire Record 512347 DOI 10.17182/hepdata.43865

Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are used to study the event shape variables thrust, jet broadening, jet mass, C parameter and two kinds of differential two-jet rate. The data cover a large range of the four-momentum transfer Q, which is considered to be the relevant energy scale, between 7 GeV and 100 GeV. The Q dependences of the mean values are compared with second order calculations of perturbative QCD applying power law corrections proportional to 1/Q^p to account for hadronization effects. The concept of power corrections is investigated by fitting simultaneously a non-perturbative parameter alpha_p and the strong coupling constant alpha_s.

63 data tables

Corrected mean values of the (1-THRUST) distribution (w.r.t.current hemisphere axis) as a function of Q.

Corrected mean values of the Jet Broadenning (B) distribution (w.r.t.current hemisphere axis) as a function of Q.

Corrected mean values of the (1-THRUST) distribution (w.r.t.max long. momentum axis) as a function of Q.

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QCD studies with e+ e- annihilation data at 172-GeV to 189-GeV.

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 16 (2000) 185-210, 2000.
Inspire Record 513476 DOI 10.17182/hepdata.49000

We have studied hadronic events from e+e- annihilation data at centre-of-mass energies of sqrt{s}=172, 183 and 189 GeV. The total integrated luminosity of the three samples, measured with the OPAL detector, corresponds to 250 pb^-1. We present distributions of event shape variables, charged particle multiplicity and momentum, measured separately in the three data samples. From these we extract measurements of the strong coupling alpha_s, the mean charged particle multiplicity and the peak position xi_0 in the xi_p=ln(1/x_p) distribution. In general the data are described well by analytic QCD calculations and Monte Carlo models. Our measured values of alpha_s, and xi_0 are consistent with previous determinations at sqrt{s}=MZ.

20 data tables

Distribution of Thrust.

Distribution of Thrust Major.

Distribution of Thrust Minor.

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Hard photon production and tests of QED at LEP

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 475 (2000) 198-205, 2000.
Inspire Record 513397 DOI 10.17182/hepdata.48965

The total and differential cross sections of the process e+e- -> n gamma with n >= 2 are measured using data collected by the L3 experiment at centre-of-mass energies of \sqrt{s}=183 and 189 GeV. The results are in agreement with the Standard Model expectations. Limits are set on deviations from QED, contact interaction cut-off parameters and masses of excited electrons.

2 data tables

Measured cross section.

Measured differential cross sections corrected for efficiency and additional photons as a function of cos(theta) where theta is the polar angle of the event defined as. cos(theta)=ABS((sin(theta1-theta2)/2)/(sin(theta1+theta2)/2)).


Measurement of hadron and lepton pair production at 130-GeV less than S**(1/2) less than 189-GeV at LEP

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 479 (2000) 101-117, 2000.
Inspire Record 513676 DOI 10.17182/hepdata.48958

We report on measurements of e+e- annihilation into hadrons and lepton pairs. The data have been collected with the L3 detector at LEP at centre-of-mass energies between 130 and 189 GeV. Using a total integrated luminosity of 243.7 pb^-1, 25864 hadronic and 8573 lepton-pair events are selected for the measurement of cross sections and leptonic forward-backward asymmetries. The results are in good agreement with Standard Model predictions.

10 data tables

Measured cross sections for the hadronic events.

Measured cross sections for the muon-pair events.

Measured cross sections for the tau-pair events.

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Inclusive production of D*+- mesons in photon photon collisions at s**(1/2)(ee) = 183-GeV and 189-GeV and a first measurement of F2(c)(gamma).

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Akesson, P.F. ; et al.
Eur.Phys.J.C 16 (2000) 579-596, 2000.
Inspire Record 510531 DOI 10.17182/hepdata.35045

The inclusive production of D*+- mesons in photon-photon collisions has been measured using the OPAL detector at LEP at e+e- centre-of-mass energies of 183 and 189GeV. The D* mesons are reconstructed in their decay to D0pi+ with the D0 observed in the two decay modes Kpi+ and Kpi+pi-pi+. After background subtraction, 100.4+-12.6(stat) D*+- mesons have been selected in events without observed scattered beam electron ("anti-tagged") and 29.8+-5.9 (stat) D*+- mesons in events where one beam electron is scattered into the detector ("single-tagged"). Direct and single-resolved events are studied separately. Differential cross-sections as functions of the D* transverse momentum p_t and pseudorapidity \eta are presented in the kinematic region 2

7 data tables

Differential PT distribution for anti-tagged events for both D* decay modesand combined.

Differential ETARAP distribution for anti-tagged events for both D* decay modes and combined.

Integrated cross section using the anti-tagged events for D* production in the kinematic range of the experiment.

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Observation of orbitally excited B mesons 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.D 64 (2001) 072002, 2001.
Inspire Record 511161 DOI 10.17182/hepdata.42083

We measure the relative rate of production of orbitally excited (L=1) states of B mesons (B**) by observing their decays into Bπ±. We reconstruct B mesons through semileptonic decay channels using data collected in pp¯ collisions at s=1.8TeV. The fraction of light B mesons that are produced as L=1B** states is measured to be 0.28±0.06(stat)±0.03(syst). We also measure the collective mass of the B** states, and quantify the result by quoting the (model-dependent) mass of the lowest B** state to be m(B1)=5.71±0.02GeV/c2.

1 data table

FD is considered as a quark fragmentation fraction.


Lambda and Antilambda polarization from deep inelastic muon scattering

The E665 collaboration Adams, M.R. ; Aderholz, M. ; Aïd, S. ; et al.
Eur.Phys.J.C 17 (2000) 263-267, 2000.
Inspire Record 509690 DOI 10.17182/hepdata.43315

We report results of the first measurements of Lambda and Antilambda polarization produced in deep inelastic polarized muon scattering on the nucleon. The results are consistent with an expected trend towards positive polarization with increasing x_F. The polarizations of Lambda and Antilambda appear to have opposite signs. A large negative polarization for Lambda at low positive x_F is observed and is not explained by existing models.A possible interpretation is presented.

2 data tables

The measured and corrected (undiluted) polarizations.

The measured and corrected (undiluted) polarizations.