Zieger, A.
MIXING-PARAM
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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.


Measurement of the heavy quark forward - backward asymmetries and average B mixing using leptons in multi - hadronic events

The OPAL collaboration Alexander, G. ; Allison, John ; Altekamp, N. ; et al.
Z.Phys.C 70 (1996) 357-370, 1996.
Inspire Record 404106 DOI 10.17182/hepdata.48046

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Measurement of b anti-b correlations at the CERN p anti-p collider

The UA1 collaboration Albajar, C. ; Ankoviak, K. ; Bartha, S. ; et al.
Z.Phys.C 61 (1994) 41-52, 1994.
Inspire Record 359461 DOI 10.17182/hepdata.14368

We report on measurements of correlated\(b\bar b\) production in\(p\bar p\) collisions at\(\sqrt s = 630GeV\), using dimuon data to tag both theb and\(\bar b\) quarks. Starting from an inclusive dimuon sample we obtain improved cross-sections for single inclusive beauty production and confirm our earlier results on\(B^0 - \bar B^0\) mixing. From a study of\(b\bar b\) correlations we derive explicit cross-sections for semi-differential\(b\bar b\) production. We compare the measured cross-sections and correlations to\(\mathcal{O}\left( {\alpha _s^3 } \right)\) QCD predictions and find good quantitative agreement. From the measured angular distributions we establish a size-able contribution from higher order QCD processes with a significance of about seven standard deviations. A large nonperturbative contribution to these higher order corrections is excluded.

17 data tables
Table 1

The first error is PT-dependent, and the second is PT-independent. Dimuons from different b-quarks.

Table 2

The first error is PT-dependent, and the second is PT-independent. Dimuons from b chain decays (b --> c + mu, c --> mu).

Table 3

Total cross-section for single b-quark production in the restricted rapidity range.

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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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