Allen%2C N.J.
[0.0, 1.0]
Max results
Sort by Reverse order

Showing 10 of 32 results

A Determination of alpha-s (M (Z0)) at LEP using resummed QCD calculations

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 59 (1993) 1-20, 1993.
Inspire Record 354188 DOI 10.17182/hepdata.14427

The strong coupling constant, αs, has been determined in hadronic decays of theZ0 resonance, using measurements of seven observables relating to global event shapes, energy correlatio

7 data tables match query
Table 1

Data corrected for finite acceptance and resolution of the detector and for intial state photon radiation. No corrections for hadronic effects are applied.. Errors include statistical and systematic uncertainties, added in quadrature.

Table 2

Data corrected for finite acceptance and resolution of the detector and for intial state photon radiation. No corrections for hadronic effects are applied.. Errors include statistical and systematic uncertainties, added in quadrature.

Table 3

Data corrected for finite acceptance and resolution of the detector and for intial state photon radiation. No corrections for hadronic effects are applied.. Errors include statistical and systematic uncertainties, added in quadrature.

More…

Measurement of V(cb) from the decay process anti-B0 --> D*+ l- anti-nu.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 510 (2001) 55-74, 2001.
Inspire Record 555430 DOI 10.17182/hepdata.49795

A new precise measurement of |V_{cb}| and of the branching ratio BR(\bar{B^0} -> D^{*+} \ell^- \bar{\nu_\ell}) has been performed using a sample of about 5000 semileptonic decays \bar{B^0} -> D^{*+} \ell^- \bar{\nu_\ell}, selected by the DELPHI detector at LEP I by tagging the soft pion from D^{*+} -> D^0 \pi^+. The results are: V_{cb}=(39.0 +/- 1.5 (stat.) ^{+2.5}_{-2.6} (syst. exp.) +/- 1.3 (syst. th.)) x 10^{-3} BR(\bar{B^0} -> D^{*+} \ell^- \bar{\nu_\ell})=(4.70 +/- 0.13 (stat.) ^{+0.36}_{-0.31} (syst. exp.))% The analytic dependences of the differential cross-section and of the Isgur Wise form factor as functions of the variable w = v_{B^0}.v_{D^*} have also been obtained by unfolding the experimental resolution.

1 data table match query
Table 1

The formfactors are evaluated at zero recoil of D meson. VCB is the V-CKM (Cabibbo-Kobayashi-Maskawa) mixing matrix element. The value of FORMFACTOR(1) = 0.91 +- 0.03.


Di-jet production in gamma-gamma collisions at LEP2

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Eur.Phys.J.C 58 (2008) 531-541, 2008.
Inspire Record 806241 DOI 10.17182/hepdata.51688

The production of two high-p_T jets in the interactions of quasi-real photons in e+e- collisions at sqrt{s_ee} from 189 GeV to 209 GeV is studied with data corresponding to an integrated e+e- luminosity of 550 pb^{-1}. The jets reconstructed by the k_T cluster algorithm are defined within the pseudo-rapidity range -1 < eta < 1 and with jet transverse momentum, p_T, above 3 GeV/c. The differential di-jet cross-section is measured as a function of the mean transverse momentum ptmean of the jets and is compared to perturbative QCD calculations.

11 data tables match query
Table 1

Total cross section for dijet production. Errors are combined statistics and systematics.

Table 2

Measured dijet production cross section as a function of the mean jet transverse momentum. Errors include both statistics and systematics.

Table 3

Measured dijet production cross section as a function of jet pseudorapiditydifference. Errors include both statistics and systematics.

More…

Measurement of the average b baryon lifetime and the product branching ratio f (b --> Lambda(b)) x BR (Lambda(b) --> Lambda lepton- anti-neutrino X)

The OPAL collaboration Akers, R. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 69 (1996) 195-214, 1996.
Inspire Record 397395 DOI 10.17182/hepdata.51966

None

1 data table match query
Table 1

Charged conjugate state is assumed.


Cross-sections and leptonic forward-backward asymmetries from the Z0 running of LEP.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 16 (2000) 371-405, 2000.
Inspire Record 527605 DOI 10.17182/hepdata.49969

During 1993 and 1995 LEP was run at 3 energies near the Z$^0$peak in order to give improved measurements of the mass and width of the resonance. During 1994, LEP o

14 data tables match query
Table 1

Hadronic cross section measured with the 1993 data. Additional systematic error of 0.10 PCT (efficiencies and backgrounds) and 0.29 PCT (absolute luminosity).

Table 2

Hadronic cross section measured with the 1994 data. Additional systematic error of 0.11 PCT (efficiencies and backgrounds) and 0.11 PCT (absolute luminosity).

Table 3

Hadronic cross section measured with the 1995 data. Additional systematic error of 0.10 PCT (efficiencies and backgrounds) and 0.11 PCT (absolute luminosity).

More…

A Measurement of Muon Neutrino Electron Elastic Scattering in the {Fermilab} 15-foot Bubble Chamber

Baker, N.J. ; Connolly, P.L. ; Kahn, S.A. ; et al.
Phys.Rev.D 40 (1989) 2753, 1989.
Inspire Record 281020 DOI 10.17182/hepdata.23078

A total of 22 muon-neutrino-electron elastic-scattering events (νμe→νμe) have been observed in an exposure of the Fermilab 15-foot bubble chamber filled with a heavy neon-hydrogen mixture to a wide-band neutrino beam. The elastic-scattering cross section is measured to be 1.67±0.44×10−42Eν cm2 GeV−1. The value of the weak mixing angle (sin2θW) determined from this cross section, which is consistent with other measurements of this angle, is 0.20−0.05+0.06.

1 data table match query
Table 1

No description provided.


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
Table 1

No description provided.

Table 2

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

Table 3

Here UNSPEC is invisible particle.


QCD coherence studies using two particle azimuthal correlations

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 58 (1993) 207-218, 1993.
Inspire Record 343082 DOI 10.17182/hepdata.14494

From a sample of 146900 hadronicZ0 decays recorded by the OPAL detector at LEP, we have studied the azimuthal correlations of particles in hadronic events. It is expected that these correlations are sensitive to interference effects in QCD. We have compared the data to QCD Monte Carlo models which include and which do not include interference effects. We find that the distributions of azimuthal correlations are not reproduced by the parton shower models we have tested unless interference effects are included, no matter which hadronisation scheme is used.

2 data tables match query
Table 1

Corrected data for the EMMC.

Table 2

Corrected data for the TPAC.


A Global determination of alpha-s (M(z0)) at LEP

The OPAL collaboration Acton, P.D. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 55 (1992) 1-24, 1992.
Inspire Record 333079 DOI 10.17182/hepdata.14606

The value of the strong coupling constant,$$\alpha _s (M_{Z^0 } )$$, is determined from a study of 15 d

16 data tables match query
Table 1

Differential jet mass distribution for the heavier jet using method T. The data are corrected for the finite acceptance and resolution of the detector and for initial state photon radiation.

Table 2

Differential jet mass distribution for the jet mass difference using methodT. The data are corrected for the finite acceptance and resolution of the detec tor and for initial state photon radiation.

Table 3

Differential jet mass distribution for the heavier jet using method M. The data are corrected for the finite acceptance and resolution of the detector and for initial state photon radiation.

More…

PROMPT ELECTRON PRODUCTION IN e+ e- ANNIHILATIONS AT 29-GeV

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Badtke, D.H. ; et al.
Z.Phys.C 27 (1985) 39, 1985.
Inspire Record 200040 DOI 10.17182/hepdata.1895

We have measured the inclusive prompt electron cross section over a wide momentum range (P>0.5 GeV/c) with the PEP-4 TPC detector. The semielectronic branching fractions of thec andb quarks are (9.1±0.9 (stat.)±1.3 (syst.))% and (11.0±1.8±1.0)%, respectively. Theb quark fragmentation function peaks at highz with 〈zb〉=0.74±0.05±0.03. The axial couplings to the neutral current areac=2.3±1.4±1.0 for thec quark andab=−2.0±1.9±0.5 for theb quark.

3 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.