A Comparison of jet production rates on the Z0 resonance to perturbative QCD

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Phys.Lett.B 247 (1990) 167-176, 1990.
Inspire Record 297698 DOI 10.17182/hepdata.29653

The production rates for 2-, 3-, 4- and 5-jet hadronic final states have been measured with the DELPHI detector at the e + e − storage ring LEP at centre of mass energies around 91.5 GeV. Fully corrected data are compared to O(α 2 s ) QCD matrix element calculations and the QCD scale parameter Λ MS is determined for different parametrizations of the renormalization scale ω 2 . Including all uncertainties our result is α s ( M 2 Z )=0.114±0.003[stat.]±0.004[syst.]±0.012[theor.].

2 data tables match query

Corrected jet rates.

Second systematic error is theoretical.


Photon Events with Missing Energy at sqrt(s) = 183 to 189 GeV

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 17 (2000) 53-65, 2000.
Inspire Record 537913 DOI 10.17182/hepdata.32093

The production of single photons has been studied in the reaction e+e- -> gamma + invisible particles at centre-of-mass energies of 183 GeV and 189 GeV. A previously published analysis of events with multi-photon final states accompanied by missing energy has been updated with 189 GeV data. The data were collected with the DELPHI detector and correspond to integrated luminosities of about 51 pb^{-1} and 158 pb^{-1} at the two energies. The number of light neutrino families is measured to be 2.84 +/- 0.15(stat) +/- 0.14(syst). The absence of an excess of events beyond that expected from Standard Model processes is used to set limits on new physics as described by supersymmetric and composite models. A limit on the gravitational scale is also determined.

2 data tables match query

No description provided.

Combined result.


Masses, lifetimes and production rates of Xi- and anti-Xi+ at LEP 1.

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Phys.Lett.B 639 (2006) 179-191, 2006.
Inspire Record 719387 DOI 10.17182/hepdata.26952

Measurements of the Xi- and anti-Xi+ masses, mass differences, lifetimes and lifetime differences are presented. The anti-Xi+ sample used is much larger than those used previously for such measurements. In addition, the Xi production rates in Z -> b anti-b and Z -> q anti-q events are compared and the position xi* of the maximum of the xi distribution in Z -> q anti-q events is measured.

3 data tables match query

Corrected LN(1/X) distribution for (XI- + XIBAR+) production.

Measured and extrapoplated production rates.

Extrapolated production rate in b-bbar events.


Charged and Identified Particles in the Hadronic Decay of W Bosons and in e+e- -> q qbar from 130 to 200 GeV

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 18 (2000) 203-228, 2000.
Inspire Record 526164 DOI 10.17182/hepdata.43294

Inclusive distributions of charged particles in hadronic W decays are experimentally investigated using the statistics collected by the DELPHI experiment at LEP during 1997, 1998 and 1999, at centre-of-mass energies from 183 to around 200 GeV. The possible effects of interconnection between the hadronic decays of two Ws are not observed. Measurements of the average multiplicity for charged and identified particles in q qbar and WW events at centre-of-mass energies from 130 to 200 GeV and in W decays are presented. The results on the average multiplicity of identified particles and on the position xi^* of the maximum of the xi_p = -log(2p/sqrt(s)) distribution are compared with predictions of JETSET and MLLA calculations.

16 data tables match query

Corrected multiplicites and dispersions of charged particles produced in hadronic decays from QQBAR events. The 200 GeV results are a weighted average fromthe 192, 196 and 200 GeV data.

Average multiplicities of identified hadrons produced in hadronic decays from QQBAR events.

Corrected multiplicites and dispersions of charged particles produced in fully hadronic W decays from two W 4Q and 2Q events.

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Search for new phenomena using single photon events in the DELPHI detector at LEP

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Z.Phys.C 74 (1997) 577-586, 1997.
Inspire Record 415746 DOI 10.17182/hepdata.41128

Data are presented on the reaction e+e− → γ + no other detected particle at centre-of-mass energies of 89.48, 91.26 and 93.08 GeV. The cross-section for this reaction is related directly to the number of light neutrino generations which couple to the Z° boson, and to several other possible phenomena such as the production of excited neutrinos, the production of any invisible ‘X’ particle, and the magnetic moment of the tau neutrino. Based on the observed number of single photon events, the number of light neutrinos that couple to the Z° is measured to be Nv = 2.89 ± 0.38. No evidence is found for anomalous production of energetic single photons, and upper limits at 95% confidence level are determined for excited neutrino production (BR < 4 − 8 × 10−6 depending on its mass), production of an invisible ‘X’ particle (σ, < 0.1 pb for masses below 60 GeV), and the magnetic moment of the tau neutrino (< 5.1 × 10-6 μB).

3 data tables match query

No description provided.

Limit on an anomalous magnetic moment for tau-neutrino from '1GAMMA + nothing' events. Magnetic moment in Bohr magnetons.

Here UNSPEC is invisible particle.


A Precise Measurement of the $Z$ Resonance Parameters Through Its Hadronic Decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
Phys.Lett.B 241 (1990) 435-448, 1990.
Inspire Record 295501 DOI 10.17182/hepdata.29722

A measurement of the cross section for e + e - → hadrons using 11 000 hadronic decays of the Z boson at ten different center-of-mass energies is presented. A three-parameter fit gives the following values for the Z mass M z , the total width Γ z , the product of the electronic and hadronic partial widths Γ e Γ h , and the unfolded pole cross section σ 0 : M Z =91.171±0.030(stat)±0.030 (beam) GeV, Γ Z =2.511±0.065 GeV, Γ e Γ h =0.148±0.006 (stat.)±0.004 (syst.) GeV 2 , σ 0 =41.6±0.7(stat.)±1.1 (syst.) nb,

1 data table match query

No description provided.


Measurement and interpretation of fermion pair production at LEP energies from 130-GeV to 172-GeV

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 11 (1999) 383-407, 1999.
Inspire Record 495462 DOI 10.17182/hepdata.34520

None

9 data tables match query

No description provided.

No description provided.

No description provided.

More…

DELPHI results on the Z0 resonance parameters through its hadronic and leptonic decay modes

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.
CERN-PPE-90-119, 1990.
Inspire Record 298840 DOI 10.17182/hepdata.47313

None

7 data tables match query

Overall systematic error is 2.3 pct.

Overall systematic error is 2.6 pct.

Overall systematic error is 2.8 pct.

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Charged particle multiplicity in e+ e- --> q anti-q events at 161-GeV and 172-GeV and from the decay of the W boson.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 416 (1998) 233-246, 1998.
Inspire Record 449290 DOI 10.17182/hepdata.47398

The data collected by DELPHI in 1996 have been used to measure the average charged particle multiplicities and dispersions in q q ̄ events at centre-of-mass energies of s =161 GeV and s =172 GeV, and the average charge multiplicity in WW events at s =172 GeV. The multiplicities in q q ̄ events are consistent with the evolution predicted by QCD. The dispersions in the multiplicity distributions are consistent with Koba-Nielsen-Olesen (KNO) scaling. The average multiplicity of charged particles in hadronic W decays has been measured for the first time; its value, 19.23±0.74(stat+syst), is consistent with that expected for an e + e − interaction at a centre-of-mass energy equal to the W mass. The charged particle multiplicity in W decays shows no evidence of effects of colour reconnection between partons from different W's at the present level of statistics.

3 data tables match query

No description provided.

No description provided.

No description provided.


Measurement of the spin density matrix for the rho0, K*(892)0 and Phi produced in Z0 decays.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 406 (1997) 271-286, 1997.
Inspire Record 444150 DOI 10.17182/hepdata.47452

The spin density matrix elements for the ϱ 0 , K ∗0 (892) and F produced in hadronic Z 0 decays are measured in the DELPHI detector. There is no evidence for spin alignment of the K ∗0 (892) and F in the region x p ≤ 0.3 ( x p = p p beam ), where ϱ 00 = 0.33 ± 0.05 and ϱ 00 = 0.30 ± 0.04, respectively. In the fragmentation region, x p ≥ 0.4, there is some indication for spin alignment of the ϱ 0 and K ∗0 (892), since ϱ 00 = 0.43 ± 0.05 and ϱ 00 = 0.46 ± 0.08, respectively. These values are compared with those found in meson-induced hadronic reactions. For the F, ϱ 00 = 0.30 ± 0.04 for x p ≥ 0.4 and 0.55 ± 0.10 for x p ≥ 0.7. The off-diagonal spin density matrix element ϱ 1-1 is consistent with zero in all cases.

3 data tables match query

Helicity density matrices elements. The statistical and systematic errors are combined quadratically.

Helicity density matrices elements. The statistical and systematic errors are combined quadratically.

Helicity density matrices elements. The statistical and systematic errors are combined quadratically.