Haddock, R.P.
Jet Production
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Ratios of multijet cross-sections 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. 86 (2001) 1955-1960, 2001.
Inspire Record 532905 DOI 10.17182/hepdata.42971

We report on a study of the ratio of inclusive three-jet to inclusive two-jet production cross sections as a function of total transverse energy in p-pbar collisions at a center-of-mass energy sqrt{s} = 1.8 TeV, using data collected with the D0 detector during the 1992-1993 run of the Fermilab Tevatron Collider. The measurements are used to deduce preferred renormalization scales in perturbative O(alpha_s^3) QCD calculations in modeling soft-jet emission.

1 data table
Table 1

First and second errors correspond to uncorrelated (C=UNCORR) and correlated (C=CORR) uncertainties. Uncorrelated uncertainties include statistical and uncorrelated systematic uncertainties added in quadrature.


Cross-section for b jet production in anti-p p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 85 (2000) 5068-5073, 2000.
Inspire Record 531669 DOI 10.17182/hepdata.42975

Bottom quark production in pbar-p collisions at sqrt(s)=1.8 TeV is studied with 5 inverse picobarns of data collected in 1995 by the DO detector at the Fermilab Tevatron Collider. The differential production cross section for b jets in the central rapidity region (|y(b)| < 1) as a function of jet transverse energy is extracted from a muon-tagged jet sample. Within experimental and theoretical uncertainties, DO results are found to be higher than, but compatible with, next-to-leading-order QCD predictions.

1 data table
Table 1

No description provided.


A measurement of the b-quark mass from hadronic Z decays.

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Eur.Phys.J.C 18 (2000) 1-13, 2000.
Inspire Record 531468 DOI 10.17182/hepdata.49909

Hadronic Z decay data taken with the ALEPH detector at LEP1 are used to measure the three-jet rate as well as moments of various event-shape variables. The ratios of the observables obtained from b-tagged events and from an inclusive sample are determined. The mass of the b quark is extracted from a fit to the measured ratios using a next-to-leading order prediction including mass effects. Taking the first moment of the y3 distribution, which is the observable with the smallest hadronization corrections and systematic uncertainties, the result is: mb(MZ) = [3.27+-0.22(stat) +-0.22(exp)+-0.38(had)+-0.16(theo)] GeV/c2. The measured ratio is alternatively employed to test the flavour independence of the strong coupling constant for b and light quarks.

1 data table
Table 1

No description provided.


rivet Analysis
Inclusive production of pi0, eta, eta'(958), K0(S) and Lambda in two- and three-jet events from hadronic Z decays.

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Eur.Phys.J.C 16 (2000) 613, 2000.
Inspire Record 507531 DOI 10.17182/hepdata.49106

The production rates and the inclusive cross sections of the isovector meson${\rm \pi^0}$, the isoscalar mesons$\eta$and

25 data tables
Table 1

Inclusive cross section for PI0 production in hadronic events.

Table 2

Inclusive cross section for ETA production in hadronic events.

Table 3

Inclusive cross section for ETAPRIME production in hadronic events.

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

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 82 (1999) 2451-2456, 1999.
Inspire Record 473457 DOI 10.17182/hepdata.42154

We have made a precise measurement of the central inclusive jet cross section at sqrt(s) = 1.8 TeV. The measurement is based on an integrated luminosity of 92 pb-1 collected at the Fermilab Tevatron pbar-p Collider with the D-Zero detector. The cross section, reported as a function of jet transverse energy (ET >= 60 GeV) in the pseudorapidity interval |eta| <= 0.5, is in good agreement with predictions from next-to-leading order quantum chromodynamics.

2 data tables
Table 1

Inclusive cross section for ABS(ETARAP)<0.5. The quoted systematic (DSYS) errors do not include the luminosity uncertainty of 6.1 PCT.

Table 2

Inclusive cross section for 0.1<=ABS(ETARAP)<=0.7. Data are taken from the AIP E-PAPS ftp site shown above. The quoted (DSYS) errors are the total systematic errors including the luminosity uncertainty.


The Dijet mass spectrum and a search for quark compositeness in anti-p p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 82 (1999) 2457-2462, 1999.
Inspire Record 473420 DOI 10.17182/hepdata.42143

Using the DZero detector at the 1.8 TeV pbarp Fermilab Tevatron collider, we have measured the inclusive dijet mass spectrum in the central pseudorapidity region |eta_jet| < 1.0 for dijet masses greater than 200 Gev/c^2. We have also measured the ratio of spectra sigma(|eta_jet| < 0.5)/sigma(0.5 < |eta_jet| < 1.0). The order alpha_s^3 QCD predictions are in good agreement with the data and we rule out models of quark compositeness with a contact interaction scale < 2.4 TeV at the 95% confidence level.

2 data tables
Table 1

Dijet cross section for ABS(ETARAP)<1.0.

Table 2

Ratio of cross sections for ABS(ETARAP) < 0.5 / 0.5 < ABS(ETARAP) < 1.0.


Determination of A(b)(FB) using jet charge measurements in Z decays.

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Phys.Lett.B 426 (1998) 217-230, 1998.
Inspire Record 468671 DOI 10.17182/hepdata.49559

An improved measurement of the forward-backward asymmetry in Z →b b ̄ decays is presented, based on a sample of 4.1 million hadronic Z decays collected by ALEPH between 1991 and 1995. Data are analysed as a function of polar angle of the event axis and b purity. The event tagging efficiency and mean b -jet hemisphere charge are measured directly from data. From the measured forward-backward jet charge asymmetry, the b quark asymmetry at s =m Z is determined to be: A b FB =0.1017±0.0038(stat.)±0.0032(syst.). In the context of the Standard Model this corresponds to a value of the effective weak mixing angle of sin 2 θ W eff =0.23109±0.00096.

3 data tables
Table 1

Only statistical errors are given for sqrt(s) = 89.43 and 92.97 GeV.

Table 2

The combination of the data on and off peak of Z-boson.

Table 3

The combination of the data on and off peak of Z-boson.


Measurements of the structure of quark and gluon jets in hadronic Z decays.

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Eur.Phys.J.C 17 (2000) 1-18, 2000.
Inspire Record 467225 DOI 10.17182/hepdata.49549

An experimental investigation of the structure of identified quark and gluon jets is presented. Observables related to both the global and internal structure of jets are measured; this allows for test

6 data tables
Table 1

The measured jet broadening distributions (B) in quark and gluon jets seperately.

Table 2

Measured distributions of -LN(Y2), where Y2 is the differential one-subjet rate, that is the value of the subjet scale parameter where 2 jets appear from the single jet.

Table 3

The mean subjet multiplicity (-1) for gluon jets and quark jets for different values of the subject resolution parameter Y0.

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A measurement of the QCD colour factors and a limit on the light gluino.

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Z.Phys.C 76 (1997) 1-14, 1997.
Inspire Record 440051 DOI 10.17182/hepdata.34162

Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios CA/CF and TF /CF and the strong coupling constant αs = CFαs(MZ)/(2π) has been performed by fitting theoretical predictions simultaneously to the measured differential two-jet rate and angular distributions in four-jet events. The result is found to be in excellent agreement with QCD, {fx4-1} Fixing CA/CF and TF/CF to the QCD values permits a determination of αs(MZ) and ηf, the number of active flavours. With this measurement the existence of a gluino with mass below 6.3 GeV/c2 is excluded at 95% confidence level.

3 data tables
Table 1

Fit A: using all kinematical distributions. NC, CF, and TF are the color factors for SU(3) group, NF is the number of the active flavors.

Table 2

Fit B: using all kinematical distributions, but QCD magnitudes for color factors are used: FA(DEF=NC/CF)) = 2.25 and TF/CF = 0.375. NC, CF, and TF are the color factors for SU(3) group, NF is the number of the active flavors.

Table 3

Fit C: the QCD magnitudes for color factors and NF = 5 are used.


Quark and gluon jet properties in symmetric three-jet events

The ALEPH collaboration Buskulic, D. ; Casper, D. ; De Bonis, I. ; et al.
Phys.Lett.B 384 (1996) 96008490 353-364, 1996.
Inspire Record 404562 DOI 10.17182/hepdata.48015

Quark and gluon jets with the same energy, 24 GeV, are compared in symmetric three-jet configurations from hadronic Z decays observed by the ALEPH detector. Jets are defined using the Durham algorithm. Gluon jets are identified using an anti-tag on b jets, based on a track impact parameter method. The comparison of gluon and mixed flavour quark jets shows that gluon jets have a softer fragmentation function, a larger angular width and a higher particle multiplicity, Evidence is presented which shows that the corresponding differences between gluon and b jets are significantly smaller. In a statistically limited comparison the multiplicity in c jets was found to be comparable with that observed for the jets of mixed quark flavour.

2 data tables
Table 1

B-jets are identified with the lepton-tag analysis.

Table 2

The same kinematics as in the table 1.