Field, J.H.
Max results
Sort by Reverse order

Showing 10 of 2316 results

Date

Measurement of the b forward-backward asymmetry and mixing using high-p(T) leptons.

The ALEPH collaboration Buskulic, D. ; De Bonis, I. ; Decamp, D. ; et al.
Phys.Lett.B 384 (1996) 96009264 414-426, 1996.
Inspire Record 419905 DOI 10.17182/hepdata.47806

The B0 - B̄0 average mixing parameter χ and b forward-backward asymmetry AFB0(b) are measured from a sample of about 4 200 000 Z → qq̄ events recorded with the ALEPH detector at LEP in the years 1990–1995. High transverse momentum electrons and muons produced in b semileptonic decays provide the tag of the quark flavour and of its charge. The average mixing parameter and the pole b asymmetry are measured to be χ = 0.1246 ± 0.0051stat ± 0.0052syst, AFB0(b) = 0.1008 ± 0.0043stat ± 0.0028syst. The value of sin2θweff = 0.23198 ± 0.00092 is extracted from the asymmetry measurement.

2 data tables
Table 1

ASYM(N=FB,C=OBSERVED) is observed asymmetry including BQ, CQ and backround.

Table 2

No description provided.


Search for anomalous production of single photons at s**(1/2) = 130-GeV and 136-GeV

The DELPHI collaboration Adam, W. ; Abreu, P. ; Adye, T. ; et al.
Phys.Lett.B 380 (1996) 471-479, 1996.
Inspire Record 418937 DOI 10.17182/hepdata.47517

This letter reports the results of the measurement of single photon production in the reaction e + e − → γ + invisible particles at centre-of-mass energies s =130 and 136 GeV and an integrated luminosity of 5.83 pb −1 , collected with the DELPHI detector at LEP. The signal is compatible with the prediction of the Standard Model for the process e + e − → ν ν γ , and the number of neutrino families has been determined to be N ν = 3.1 ± 0.6. Limits have been derived on anomalous neutral gauge boson couplings and on compositeness in the framework of a specific model.

1 data table
Table 1

SIG with C=HPC and C=FEMC correpond to the events in the barrel and forwardregion, respectively.


Study of radiative leptonic events with hard photons and search for excited charged leptons at s**(1/2) = 130-GeV to 136-GeV.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 380 (1996) 480-490, 1996.
Inspire Record 418939 DOI 10.17182/hepdata.47563

During the last 1995 data acquisition period at LEP, the DELPHI experiment collected an integrated luminosity of 5.9 pb −1 at centre-of-mass energies of 130 GeV and 136 GeV. Radiative leptonic events ( e , μ, τ) with high energy photons were studied and compared to Standard Model predictions. The data were used to search for charged excited leptons decaying through an electromagnetic transition. No significant signal was found. From the search for pair produced excited leptons, the limits m e ∗ > 62.5 GeV /c 2 , m μ ∗ > 62.6 GeV /c 2 and m τ ∗ > 62.2 GeV /c 2 at 95% confidence level were established. For single excited lepton production, upper limits on the ratio λ m l ∗ of the coupling of the excited charged lepton to its mass were derived.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Measurement of the pseudoscalar decay constant, f(D).

The BES collaboration Bai, J.Z. ; Bardon, O. ; Blum, Ira K. ; et al.
SLAC-PUB-7147, 1996.
Inspire Record 421008 DOI 10.17182/hepdata.18760

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Search for new particles in hadronic events with isolated photons.

The L3 collaboration Acciarri, M. ; Adam, A. ; Adriani, O. ; et al.
Phys.Lett.B 388 (1996) 409-418, 1996.
Inspire Record 418663 DOI 10.17182/hepdata.47562

A search for the neutral Higgs boson in the processes e + e − → Z → H 0 γ → q q γ and e + e − → Z → Z ∗ H 0 → q q γγ has been performed using 2.8 million hadronic Z decays collected with the L3 detector at LEP from 1991 through 1994. No evidence for these processes has been observed. Upper limits at 95% confidence level for the corresponding cross sections have been set and the results have been compared with theoretical predictions beyond the Standard Model.

1 data table
Table 1

The magnitude of the cross section is multiplied on the branching ratio.


Studies of QCD in e+ e- --> hadrons at E(cm) = 130-GeV and 136-GeV.

The ALEPH collaboration Buskulic, D. ; De Bonis, I. ; Decamp, D. ; et al.
Z.Phys.C 73 (1997) 409-420, 1997.
Inspire Record 421546 DOI 10.17182/hepdata.47802

None

8 data tables
Table 1

Inclusive charged particle distribution as a function of XP.

Table 2

Inclusive charged particle distribution as a function of rapidity (YRAP).

Table 3

Inclusive charged particle distribution as a function of PT in the event plane.

More…

Measurement of hadron and lepton pair production from e+ e- annihilation at center-of-mass energies of 130-GeV and 136-GeV

The ALEPH collaboration Buskulic, D. ; De Bonis, I. ; Decamp, D. ; et al.
Phys.Lett.B 378 (1996) 373-384, 1996.
Inspire Record 421552 DOI 10.17182/hepdata.47801

Hadronic and leptonic cross-sections and forward-backward asymmetries are measured using 5.7 pb −1 of data taken with the ALEPH detector at LEP at centre-of-mass energies of 130 and 136 GeV. The results agree with Standard Model expectations. The measurement of hadronic cross-sections far away from the Z resonance improves the determination of the interference between photon and Z exchange. Constraints on models with extra Z bosons are presented.

12 data tables
Table 1

Data with loose SPRIME cut.

Table 2

Data with tight SPRIME cut.

Table 3

Data with loose SPRIME cut.

More…

The Isolated photon cross-section in the central and forward rapidity regions in p anti-p collisions at s**(1/2) = 1.8-TeV

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 77 (1996) 5011-5015, 1996.
Inspire Record 417044 DOI 10.17182/hepdata.42312

A measurement of the cross section for production of single, isolated photons is reported for transverse energies in the range of 10-125 GeV, for two regions of pseudorapidity, |\eta|<0.9 and 1.6<|\eta|<2.5. The data represent 12.9 pb-1 of integrated luminosity accumulated in p-pbar collisions at sqrt{s} = 1.8 TeV and recorded with the D0 detector at the Fermilab Tevatron Collider.

2 data tables
Table 1

Numerical values supplied by J. Womersley.

Table 2

Numerical values supplied by J. Womersley.


rivet Analysis
The Azimuthal decorrelation of jets widely separated in rapidity

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 77 (1996) 595-600, 1996.
Inspire Record 416886 DOI 10.17182/hepdata.42315

This study reports the first measurement of the azimuthal decorrelation between jets with pseudorapidity separation up to five units. The data were accumulated using the D\O\ detector during the 1992--1993 collider run of the Fermilab Tevatron at $\sqrt{s}=$ 1.8 TeV. These results are compared to next--to--leading order (NLO) QCD predictions and to two leading--log approximations (LLA) where the leading--log terms are resummed to all orders in $\alpha_{\scriptscriptstyle S}$. The final state jets as predicted by NLO QCD show less azimuthal decorrelation than the data. The parton showering LLA Monte Carlo {\small HERWIG} describes the data well; an analytical LLA prediction based on BFKL resummation shows more decorrelation than the data.

3 data tables
Table 1

Distribution of the pseudorapidity interval of the two jets at the extremes of pseudorapidity. Data are read from the graph and the errors are statistical only.

Table 2

Normalized distributions of the azimuthal angle difference of the two jets at the extremes of pseudorapidity in 3 pseudorapididity difference intervals. Data are read from the graph and the errors are statistical only.

Table 3

The correlation between the PHI and ETARAP difference distributions as used in the analysis.Data are read from the graph and the errors include the statiucal and un-correlated systematic errors added in quadrature.


Observation of multiple hard photon final states at s**(1/2) = 130-GeV to 140-GeV at LEP.

The L3 collaboration Acciarri, M. ; Adam, A. ; Adriani, O. ; et al.
Phys.Lett.B 384 (1996) 96006120 323-332, 1996.
Inspire Record 418664 DOI 10.17182/hepdata.47566

We have studied the process e+e− → nγ (n ≥ 2) at an average center-of-mass energy of 133 GeV using the L3 detector at LEP. For an integrated luminosity of 4.95 pb−1 we find one γγγγ(γ) final state with only hard photons. The rates of both γγγ and γγ events are consistent with QED expectations. The cross section of the reaction e+e− → γγ(γ) in the polar range 16° < θγ < 164° is measured to be 22.6 ± 2.2 pb. Decays into photons of narrow scalar resonances with masses between 90 and 130 GeV are not observed. The observation of the event with four energetic photons is consistent with QED although the kinematic configuration of the photons is atypical.

2 data tables
Table 1

Cross section for process E+ E- --> GAMMA GAMMA (GAMMA) with two hard photons.Error is purely statistical, systematic effects are neglected.

Table 2

No description provided.