Gao, W.X
SIG/SIG
[10.0, 100.0]
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Production of upsilon(1S) mesons from chi(b) decays in p anti-p collisions at S**(1/2) = 1.8-TeV

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 84 (2000) 2094-2099, 2000.
Inspire Record 508395 DOI 10.17182/hepdata.50106

We have reconstructed the radiative decays $\chi_{b}(1P) \to \Upsilon(1S) \gamma $ and $\chi_{b}(2P) \to \Upsilon(1S) \gamma $ in $p \bar{p}$ collisions at $\sqrt{s} = 1.8$ TeV, and measured the fraction of $\Upsilon(1S)$ mesons that originate from these decays. For $\Upsilon(1S)$ mesons with $p^{\Upsilon}_{T}>8.0$ GeV/$c$, the fractions that come from $\chi_{b}(1P)$ and $\chi_{b}(2P)$ decays are $(27.1\pm6.9(stat)\pm4.4(sys))%$ and $(10.5\pm4.4(stat)\pm1.4(sys))%$, respectively. We have derived the fraction of directly produced $\Upsilon(1S)$ mesons to be $(50.9\pm8.2(stat)\pm9.0(sys))%$.

1 data table
Table 1

No description provided.


Measurement of the effective b quark fragmentation function at the Z resonance

The ALEPH collaboration Buskulic, D. ; Casper, D. ; De Bonis, I. ; et al.
Phys.Lett.B 357 (1995) 699-714, 1995.
Inspire Record 398319 DOI 10.17182/hepdata.48137

Using a sample of about 1.46 million hadronic Z decays collected between 1991 and 1993 with the ALEPH detector at LEP, the energy distribution of the B 0 and B ± mesons produced at the Z resonance is measured by reconstructing semileptonic decays B → ℓ ν ℓ D(X) or B → ℓν ℓ D ∗+ (X) . The charmed mesons are reconstructed through the decay modes D 0 → K − π + , D 0 → K − π + π − π + , D + → K − π + π + and D ∗+ → D 0 π + . The neutrino energy is estimated from the missing energy in the lepton hemisphere. Accounting for B ∗ and B ∗∗ production, the shape of the scaled energy distribution x E (b) for mesons containing a b quark is compared to the predictions of different fragmentation models. The mean value of x E (b) is found to be 〈 x E (b) 〉 = 0.715 ± 0.007(stat) ± 0.013(syst).

1 data table
Table 1

SIG/SIG(C=ALL-X-INTERVAL) is fraction of events in bin. Third and fourth systematic errors are due to variation of D** and B** contributions respectively (model dependent, see text).


Observation of the Cabibbo suppressed charmed baryon decay lambda(c)+ ---> p phi

The CLEO collaboration Alexander, J.P. ; Bebek, C. ; Berger, B.E. ; et al.
Phys.Rev.D 53 (1996) 1013-1017, 1996.
Inspire Record 397665 DOI 10.17182/hepdata.47234

We report the observation of the Cabibbo-suppressed decays \lcpkk\ and \lcpphi\ using data collected with the CLEO II detector at CESR. The latter mode, observed for the first time with significant statistics, is of interest as a test of color-suppression in charm decays. We have determined the branching ratios for these modes relative to \lcpkpi\ and compared our results with theory.

1 data table
Table 1

Branching ratio of Cabibbo-suppressed and resolved modes.


rivet Analysis
Observation of excited baryon states decaying to Lambda(c)+ pi+ pi-

The CLEO collaboration Edwards, K.W. ; Ogg, M. ; Bellerive, A. ; et al.
Phys.Rev.Lett. 74 (1995) 3331-3335, 1995.
Inspire Record 381696 DOI 10.17182/hepdata.47248

Using data collected by the CLEO II detector, we have observed two states decaying to Λc+π+π−. Relative to the Λc+, their mass splittings are measured to be +307.5±0.4±1.0 and +342.2±0.2±0.5MeV/c2, respectively; this represents the first measurement of the less massive state. These two states are consistent with being orbitally excited, isospin zero Λc+ states.

4 data tables
Table 1

CONST(NAME=EPS) is the parameter of the Peterson fragmentation function (C.Peterson et al., PR D27, 105 (1983)) D(N)/D(Z) = FD(Z) = const * (1/Z)*1/(1 - (1/Z)-CONST(NAME=EPS)/(1-Z))**2. Charged conjugated states are understood.

Table 2

Charged conjugated states are understood.

Table 3

Charged conjugated states are understood.

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