Arefev, V.A.
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Production of e, mu and tau pairs in untagged two-photon collisions at LEP.

The L3 collaboration Acciarri, M. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 407 (1997) 341-350, 1997.
Inspire Record 443564 DOI 10.17182/hepdata.47467

The two-photon collision reaction e + e − → e + e − l + l − has been studied at 2 ≈91 GeV using the L3 detector at LEP for l = e, μ , τ . We have analysed untagged configurations where the two photons are quasi-real. Good agreement is found between our measurements and the O (α 4 ) QED expectation.

2 data tables
Table 1

No description provided.

Table 2

The cross section values are corrected for the branching ratios of the decay channels : 6.36 PCT for EMU and 18.3 PCT for LPI channels, respectively.


QCD studies and determination of alpha(s) in e+ e- collisions at s**(1/2) = 161-GeV and 172-GeV.

The L3 collaboration Acciarri, M. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 404 (1997) 390-402, 1997.
Inspire Record 443563 DOI 10.17182/hepdata.47483

We present a study of the structure of hadronic events recorded by the L3 detector at LEP at the center of mass energies of 161 and 172 GeV. The data sample corresponds to an integrated luminosity of 21.25 pb −1 collected during the high energy runs of 1996. The distributions of event shape variables and the energy dependence of their mean values are well reproduced by QCD models. From a comparison of the data with resummed O ( α s 2 ) QCD calculations, we determine the strong coupling constant at the two energies. Combining this with our earlier measurements we find that the strong coupling constant decreases with increasing energy as expected in QCD.

8 data tables
Table 1

No description provided.

Table 2

Average jet multiplicity using JADE algorithm.

Table 3

Average jet multiplicity using Durham algorithm.

More…

Pair production of W bosons in e+ e- interactions at s**(1/2) = 161-GeV

The L3 collaboration Acciarri, M. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 398 (1997) 223-238, 1997.
Inspire Record 440408 DOI 10.17182/hepdata.47356

We report on the measurement of W-boson pair-production with the L3 detector at LEP at a centre-of-mass energy of 161.34 GeV. In a data sample corresponding to a total luminosity of 11 pb −1 , we select four-fermion events with high invariant masses of pairs of hadronic jets or leptons. Combining all final states, the measured total cross section for W-pair production is: sigma WW = 2.89 −0.70 +0.81 (stat.) ± 0.14 (syst.) pb. Within the Standard Model, this corresponds to a mass of the W boson of: M W = 80.80 −0.42 +0.48 (exp.) ± 0.03 (LEP) GeV. Limits on anomalous triple-vector-boson couplings are derived.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Differential cross sections of D*-+ photoproduction in e p collisions at HERA.

The ZEUS collaboration Breitweg, J. ; Derrick, M. ; Krakauer, D. ; et al.
Phys.Lett.B 401 (1997) 192-206, 1997.
Inspire Record 441088 DOI 10.17182/hepdata.44632

Inclusive photoproduction of $\dspm$ in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range \linebreak \wrang and photon virtuality Q~2 < 4 \g2. The cross section $\sigma_{ep \to \ds X} $ integrated over the kinematic region \ptrangand \etarang is {\xsecs}. Differential cross sections as functions of $p_{\perp}~{\ds}$, $\eta~{\ds}$ and W are given. The data are compared with two next-to-leading order perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data.

6 data tables
Table 1

Data from the (Kpi)pi channel.

Table 2

Data from the (Kpipipi)pi channel.

Table 3

Data from the (Kpi)pi channel.

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Charged particle production in S S collisions at 200-GeV/c per nucleon

The WA94 collaboration Andrighetto, A. ; Antinori, F. ; Bayes, A.C. ; et al.
Phys.Lett.B 412 (1997) 148-154, 1997.
Inspire Record 460283 DOI 10.17182/hepdata.28242

Charged particle production in central S-S collisions at 200 GeV/ c per nucleon has been studied by the WA94 experiment at the CERN-SPS. Particle identification has been provided by the Omega RICH, while a silicon telescope in the Omega spectrometer and an array of MultiWire Proportional Chambers have been used to trace particles through the RICH detector. Production ratios and transverse mass spectra for π ± , K ± and p( p ) at central rapidity and p T > 1.3 GeV/ c are presented.

3 data tables
Table 1

Distributions are fitted with (1/MT**1.5)*DSIG/DMT = CONST*EXP(-MT/SLOPE).

Table 2

1.54 GeV ratio is calculated from the fit to the MT distribution.

Table 3

1.54 GeV ratio is calculated from the fit to the MT distribution.


Correlation between longitudinal and transversal momenta in pion nucleon and pion nucleus interactions with strange particle production. (In Russian)

Bylekov, O.V. ; Endalov, A.L. ; Kiselevich, I.L. ; et al.
ITEP-25-97, 1997.
Inspire Record 448028 DOI 10.17182/hepdata.39970

None

1 data table
Table 1

No description provided.


Measurement of the probability of the decay K+ ---> pi0 pi0 e+ neutrino

Barmin, V.V. ; Barylov, V.G. ; Davidenko, G.V. ; et al.
Sov.J.Nucl.Phys. 48 (1988) 1032-1034, 1988.
Inspire Record 457321 DOI 10.17182/hepdata.40034

None

1 data table
Table 1

No description provided.


Analyzing power of collisions between polarized protons with energies in the range 0.71-GeV to 3.61-GeV and carbon nuclei

Anoshina, E.V. ; Bodyagin, V.A. ; Vardanian, I.N. ; et al.
Phys.Atom.Nucl. 60 (1997) 224-229, 1997.
Inspire Record 457394 DOI 10.17182/hepdata.17091

None

3 data tables
Table 1

(C=EXP1) and (C=EXP2) correspond to two different method of event's registration. See text for details.

Table 2

(C=EXP1) and (C=EXP2) correspond to two different method of event's registration. See text for details. Quasielastic events.

Table 3

(C=EXP1) and (C=EXP2) correspond to two different method of event's registration. See text for details. Quasielastic events.


Search for top squark pair production in the dielectron channel

The D0 collaboration Abachi, S. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.D 57 (1998) 589-593, 1998.
Inspire Record 427311 DOI 10.17182/hepdata.41662

This report describes the first search for top squark pair production in the channel stop_1 stopbar_1 -> b bbar chargino_1 chargino_1 -> ee+jets+MEt using 74.9 +- 8.9 pb~-1 of data collected using the D0 detector. A 95% confidence level upper limit on sigma*B is presented. The limit is above the theoretical expectation for sigma*B for this process, but does show the sensitivity of the current D0 data set to a particular topology for new physics.

1 data table
Table 1

Data are extracted from the figure. Sigma*Br.


rivet Analysis
A measurement of alpha(s) from the scaling violation in e+ e- annihilation.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 398 (1997) 194-206, 1997.
Inspire Record 428178 DOI 10.17182/hepdata.47581

The hadronic fragmentation functions of the various quark flavours and of gluons are measured in a study of the inclusive hadron production from Z 0 decays with the DELPHI detector and are compared with the fragmentation functions measured elsewhere at energies between 14 GeV and 91 GeV. A large scaling violation is observed, which is used to extract the strong coupling constant from a fit using a numerical integration of the second order DGLAP evolution equations. The result is α s ( M Z ) = 0.124 −0.007 +0.006 (exp) ± 0.009(theory) where the first error represents the experimental uncertainty and the second error is due to the factorization and renormalization scale dependence.

2 data tables
Table 1

SIG(Q=BQ, Q=CQ, Q=UDS) corresponds to BQ, CQ, and U,D,S quarks fragmentation into charged hadron.

Table 2

alpha_s was evaluated from the scaling violation of the fragmentation func tions. The data from other experiments are used for the fitting procedure.