Study of Phi(1020), D*+- and B* spin alignment in hadronic Z0 decays.

The OPAL collaboration Ackerstaff, K. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 74 (1997) 437-449, 1997.
Inspire Record 440103 DOI 10.17182/hepdata.47515

Measurements of helicity density matrix elements have been made for the φ(1020), D*± and B* vector mesons in multihadronic Z0 decays in the OPAL experiment at LEP. Results for inclusive φ produced with high energy show evidence for production preferentially in the helicity zero state, with ρ00 = 0.54 ± 0.08, compared to the value of 1/3 expected for no spin alignment. The corresponding element for the D*± has a value of 0.40 ± 0.02, also suggesting a deviation from 1/3. The B* result, with ρ00 = 0.36 ± 0.09, is consistent with no spin alignment. Off-diagonal elements have been measured for the f and D* mesons; for the D* the element Re ρ1−1 is non-zero, indicating non-independent fragmentation of the primary quarks.

4 data tables

Helicity density matrices elements. Helicity beam frame is used.

Charge conjugated states are understood.

Helicity density matrices elements. Charge conjugated states are understood.

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Measurement of f(c --> D*+ X), f(b --> D*+ X) and Gamma(c anti-c)/Gamma(had) using D*+- mesons.

The OPAL collaboration Ackerstaff, K. ; Alexander, G. ; Allison, John ; et al.
Eur.Phys.J.C 1 (1998) 439-459, 1998.
Inspire Record 447145 DOI 10.17182/hepdata.47409

The production rates of D^*+/- mesons in charm and bottom events at centre-of-mass energies of about 91 GeV and the partial width of primary cc(bar) pairs in hadronic Z^0 decays have been measured at LEP using almost 4.4 million hadronic Z^0 decays collected with the OPAL detector between 1990 and 1995. Using a combination of several charm quark tagging methods based on fully and partially reconstructed D^*+/- mesons, and a bottom tag based on identified muons and electrons, the hadronisation fractions of charm and bottom quarks into D^*+/- mesons have been found to be: f(b -> D^*+ X) = 0.173 +/- 0.016 +/- 0.012 and f(c -> D^*+ X) = 0.222 +/- 0.014 +/- 0.014 The fraction of cc(bar) events in hadronic Z^0 decays, Gamma_cc(bar)/Gamma_had = Gamma(Z^0 -> cc(bar))/Gamma(Z^0 -> hadrons), is determined to be Gamma_cc(bar)/Gamma_had = 0.180 +/- 0.011 +/- 0.012 +/- 0.006 In all cases the first error is statistical, and the second one systematic. The last error quoted for Gamma_cc(bar)/Gamma_had is due to external branching ratios.

3 data tables

No description provided.

No description provided.

The second syst. errors results due to extranal branching ratios. Charge conjugated states are implied. FD is considered as a quark fragmentation fraction. Sqrt(s(E+ E-)) = 91.2 GeV.


Measurement of the forward - backward asymmetry of e+ e- ---> c anti-c at s**(1/2) = 57.95-GeV

The TOPAZ collaboration Nakano, E. ; Enomoto, R. ; Abe, K. ; et al.
Phys.Lett.B 314 (1993) 471-476, 1993.
Inspire Record 361662 DOI 10.17182/hepdata.28846

Measurements of the forward-backward asymmetry of e + e − → cc events were carried out at a mean √s energy of 57.95 GeV at TRISTAN, KEK. The cc events were tagged either by the full-reconstruction of D ∗± or the inclusive P T spectrum of π s ± from D ∗± → D 0 ( D 0 )π s ± . The forward-backward asymmetry was measured to be A FB c = −0.49 −0.13 +0.14 (stat.) ± 0.06 (syst.), consistent with the standard model.

1 data table

No description provided.


Production Cross-section and Electroweak Asymmetry of $D^*$ and $D$ Mesons Produced in $e^+ e^-$ Annihilations at 29-{GeV}

Baringer, Philip S. ; Bylsma, B.G. ; DeBonte, R. ; et al.
Phys.Lett.B 206 (1988) 551-556, 1988.
Inspire Record 23360 DOI 10.17182/hepdata.6192

The production of D * and D mesons has been studied in e + e − annihilations at √s = 29GeV. The data, corresponding to an integrated luminosity of 300 pb −1 , were obtained using the HRS detector at PEP. The cross section is measured to be R (D 0 + D + ) = 2.40±0.35 and we determine the electroweak asymmetry to be −9.9 ± 2.7%, which corresponds to an axial vector coupling constant product g e g c = 0.26 ± 0.07.

11 data tables

No description provided.

No description provided.

No description provided.

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Measurement of the Spin Density Matrix of $D^*$ Mesons Produced in $e^+ e^-$ Annihilations

The HRS collaboration Abachi, S. ; Akerlof, C. ; Baringer, P. ; et al.
Phys.Lett.B 199 (1987) 585-590, 1987.
Inspire Record 250823 DOI 10.17182/hepdata.30012

Vector mesons produced in the reaction e + e − →V+X at √ s =29 GeV were isolated by observing D ∗ mesons through the D ∗+ → D 0 π + decay. The D 0 decay modes used are D 0 →K3 π , K π , K π , and K π ( π 0 ). The data, which correspond to an integrated luminosity of 300 pb −1 , were collected by the High Resolution Spectrometer at PEP. Spin density matrix elements for the D ∗ meson are measured as a function of the energy sharing variable Z D ∗ . There is no evidence for alignment of D ∗ mesons produced in e + e − annihilation at our energy.

6 data tables

Spin density matrix for D0 --> K PI decay mode.

Spin density matrix for D0 --> K 3PI decay mode.

Spin density matrix for D0 --> K PI (PI0) decay mode.

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Charm Quark Production and Fragmentation in $e^+ e^-$ Annihilation at 29-{GeV}

Derrick, M. ; Fernandez, E. ; Fries, R. ; et al.
Phys.Lett.B 146 (1984) 261-265, 1984.
Inspire Record 202898 DOI 10.17182/hepdata.51261

The electroweak production asymmetry and the decay fragmentation function for e + e − → c c have been measured at s = 29 GeV using charged D ∗ production over the full kinematic range. The data were taken at PEP using the High Resolution Spectrometer. The measured asymmetry is −0.12 ± 0.08. The total production cross section in units of the point cross section corrected for initial state radiation is R D ∗ = 2.7 ± 0.9 .

2 data tables

ASSUMES SIG(D*+) = SIG(D*0). (EXPT. MEASURES D*+ PRODUCTION ONLY). R VALUE CORRECTED FOR INITIAL STATE RADIATION.

No description provided.


PROPERTIES OF D* PRODUCTION IN e+ e- ANNIHILATION AT 29-GeV

The HRS collaboration Ahlen, S.P. ; Akerlof, C. ; Baranko, G. ; et al.
HRS-CP-83-3, 1983.
Inspire Record 192098 DOI 10.17182/hepdata.13343

None

2 data tables

D* FRAGMENTATION FUNCTION.

R VALUE IS RADIATIVELY CORRECTED (BUT NOT CROSS SECTION).


Inclusive $D$ and $D^*$ Production in $e^+ e^-$ Annihilation at 29-{GeV}

The HRS collaboration Ahlen, S.P. ; Akerlof, C. ; Baranko, G. ; et al.
Phys.Rev.Lett. 51 (1983) 1147, 1983.
Inspire Record 191536 DOI 10.17182/hepdata.20523

Inclusive production of (D0, D¯0) and D± mesons have been observed in e+e− annihilation at 29 GeV. The signals correspond to R values of R(D0+D¯0)=3.25±1.2 and R(D++D−)=1.35±0.6. D*± production is also observed via the process D*+→D0π+ and its charge conjugate. The D and D* production rates are compared.

7 data tables

EXTRAPOLATION TO ALL Z.

EXTRAPOLATION TO ALL Z.

EXTRAPOLATION TO ALL Z.

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