HEPData Search

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rivet Analysis
Measurement of inclusive production of neutral hadrons from Z decays

The L3 collaboration Acciarri, M. ; Adam, A. ; Adriani, O. ; et al.

Phys.Lett.B 328 (1994) 223-233, 1994.

Inspire Record 374698 DOI 10.17182/hepdata.48189

We present a study of the inclusive production of π 0 , η, K s 0 and Λ based on 929,000 hadronic Z decays recorded with the L3 detector at LEP. The measured inclusive momentum distributions have been compared with predictions from parton shower models as well as an analytical Quantum Chromodynamics calculation. Comparing to low energy e + e - data, we find that QCD describes the energy evolution of the hadron spectrum.

10 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Two measurements of B0 anti-B0 mixing

The CLEO collaboration Bartelt, John E. ; Csorna, S.E. ; Egyed, Z. ; et al.

Phys.Rev.Lett. 71 (1993) 1680-1684, 1993.

Inspire Record 354226 DOI 10.17182/hepdata.47247

We have measured the B0B¯0 mixing probability, χd, using a sample of 965 000 BB¯ pairs from Υ(4S) decays. Counting dilepton events, we find χd=0.157±0.016±0.018−0.021+0.028. Using tagged B0 events, we find χd=0.149±0.023±0.019±0.010. The first (second) error is statistical (systematic). The third error reflects a ±15% uncertainty in the assumption, made in both cases, that charged and neutral B pairs contribute equally to dilepton events. We also obtain a limit on the CP impurity in the Bd0 system, ‖Re(εB0)‖<0.045 at 90% C.L.

4 data tables

Table 1

No description provided.

Table 2

Mixing parameter from counting dilepton events. CONST(N=MIXING PARAM) = 1/(1 - LAMBDA(C,N)) * (N(2LEPTON+) + N(2LEPTON-))/(N(LEPTON+,LEPTON-) + N(2LEPTON+) + N(2LEPTON-)). LAMBDA(C,N) is the fraction of dilepton events coming from B+B- decays, LAMBDA(C,N) = f(B+)*Br(B+)**2/(f(B+)*Br(B+)**2 + f(B0)*Br(B0)**2), where f(B+),f(B0) are the productiron fractions of the charged and neutral B's at the UPSI(4S), and Br(B+), Br(B0) are the semileptonic brancing fractions.

Table 3

Mixing parameter from tagged B0 events.

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Measurement of the spin dependent structure function g1(x) of the deuteron.

The Spin Muon collaboration Adeva, B. ; Ahmad, S. ; Arvidson, A. ; et al.

Phys.Lett.B 302 (1993) 533-539, 1993.

Inspire Record 354911 DOI 10.17182/hepdata.28926

We report on the first measurement of the spin-dependent structure function g 1 d of the deuteron in the deep inelastic scattering of polarised muons off polarised deuterons, in the kinematical range 0.006< x <0.6, 1 GeV 2 < Q 2 <30 GeV 2 . The first moment, Γ 1 d =ʃ 0 1 g 1 d d x=0.023±0.020 ( stat. ) ± 0.015 ( syst. ) , is smaller than the prediction of the Ellis-Jaffe sum rules. Using earlier measurements of g 1 p , we infer the first moment of the spin-dependent neutron structure function g 1 n . The difference Γ 1 p − Γ 1 n =0.20±0.05 (stat.) ± 0.04 (syst.) agrees with the prediction of the Bjorken sum rule, Γ 1 p − Γ 1 n =0.191±0.002.

2 data tables

Table 1

Virtual photon asymmetry A1.

Table 2

Spin-dependent structure function G1.

rivet Analysis
Measurement of inclusive eta production in hadronic decays of the Z0

The L3 collaboration Adriani, O. ; Aguilar-Benitez, M. ; Ahlen, S. ; et al.

Phys.Lett.B 286 (1992) 403-412, 1992.

Inspire Record 336180 DOI 10.17182/hepdata.29161

We present a study of the inclusive η production based on 300 000 hadronic Z 0 decays. The measured inclusive momentum distribution can be reproduced by parton shower Monte Carlo programs and also by an analytical QCD calculation. Comparing our results with low energy e + e − data, we find that QCD describes both the shape and the energy evolution of the η spectrum. The comparison of η production rates in quark- and gluon-enriched jet samples does not show statistically significant evidence for more abundant production of η mesons in gluon fragmentation.

2 data tables

Table 1

Differential cross section for inclusive eta production, normalized to the total hadronic cross section.

Table 2

Differential cross section for inclusive eta production, normalized to the total hadronic cross section.

CENTRAL INTERACTIONS OF Ne-22 NUCLEI WITH HEAVY PHOTOEMULSION NUCLEI AT P(0) = 4.1/A-GeV/c

The Alma Ata-Bucharest-Gatchina:Dubna-Dushanbe-Yerevan-Zernograd- Kosice-Cracow-Leningrad-Moscow-Tashkent-Tbilisi-Ulan Bator collaboration Andreeva, N.P. ; Anzon, Z.V. ; Ameeva, B.U. ; et al.

JINR-P1-89-213, 1989.

Inspire Record 281512 DOI 10.17182/hepdata.38837

None

5 data tables

Table 1

NUCLEUS IS NUCLEAR PHOTOEMULSION. EVENT WITH A TOTAL CHARGE OF ALL SPECTATOR FRAGMENTS OF A PROJECTILE = 0.

Table 2

NUCLEUS IS NUCLEAR PHOTOEMULSION. EVENT WITH A TOTAL CHARGET OF ALL SPECTATOR FRAGMENTS OF A PROJECTILE = 1.

Table 3

NUCLEUS IS NUCLEAR PHOTOEMULSION.

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THE STUDY OF TOTAL DISINTEGRATION OF LEAD NUCLEI WITH Mg-24 NUCLEI AT 4.5-a/GeV/c

The Dubna-Cairo-Kosice-Rez collaboration Krasnov, S.A. ; Tolstov, K.D. ; Shabratova, G.S. ; et al.

JINR-P1-88-389, 1988.

Inspire Record 265668 DOI 10.17182/hepdata.38868

None

9 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
$\eta$ and $\eta^\prime$ Production in $e^+ e^-$ Annihilation at 29-{GeV}: Indications for the $D(s$)+- Decays Into $\eta \pi^\pm$ and $\eta^\prime \pi^\pm$

Wormser, G. ; Abrams, G.S. ; Amidei, D. ; et al.

Phys.Rev.Lett. 61 (1988) 1057, 1988.

Inspire Record 261194 DOI 10.17182/hepdata.20080

η production has been investigated by the Mark II collaboration at the SLAC e+e− storage ring PEP. η particles are reconstructed by their γγ decay mode. The η fragmentation function has been measured and found to be in good agreement with the Lund-model prediction. η′ production has been measured for the first time in high-energy e+e− annihilation. There is evidence at the 3σ level for Ds± decay into ηπ± and η′π±.

4 data tables

Table 1

Numerical values supplied by G.Wormser.

Table 2

Z = 0.0 point extrapolated using LUND fragmentation model.

Table 3

Z = 0.0 point extrapolated using LUND fragmentation model.

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