Date

$\Lambda$(c)+ Production and Semileptonic Decay in 29-{GeV} $e^+ e^-$ Annihilation

Klein, S. ; Himel, T. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 62 (1989) 2444, 1989.
Inspire Record 277034 DOI 10.17182/hepdata.20042

We present results on Λc+ production in 29-GeV e+e− annihilation. The Λc+ are observed via their semileptonic decays to Λe+X and Λμ+X. With radiative corrections, we find σ(e+e−→Λc+X)〉BΛc+→eΛX)= 1.5±0.6±0.5 pb or 0.0038±0.0015±0.0012 Λc+→Λe+X decay per hadronic event, and σ(e+e−Λc+X)B(Λc+→μΛX)= 1.4±1.4±0.4 pb or 0.0035±0.0035±0.0011 Λc+→Λμ+X decay per hadronic event. These results can be used to place constraints on the predictions of various production models.

2 data tables match query

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA E+ decay channel.

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA MU+ decay channel.


A Determination of electroweak parameters from Z0 decays into charged leptons

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 250 (1990) 183-192, 1990.
Inspire Record 299253 DOI 10.17182/hepdata.29552

We have measured the partial widths for the three reactions e + e − → Z 0 → e + e − , μ + μ − , τ + τ − . The results are Γ ee = 84.3±1.3 MeV, √ Γ ee Γ μμ =83.9±1.4 MeV, and √ Γ ee Γ ττ =83.9±1.4 MeV, where the errors are statistical. The systematic errors are estimated to be 1.0 MeV, 0.9 MeV, and 1.4 MeV, respectively. We perform a simultaneous fit to the cross sections for the e + e − →e + e − , μ + μ − , and τ + τ − data, the differential cross section as a function of polar angle for the electron data, and the forward- backward asymmetry for the muon data. We obtain the leptonic partial with Γ ℓℓ =84.0±0.9 (stat.) MeV. The systematic error is estimated to be 0.8 MeV. Also, we obtain the axial-vector and vector weak coupling constants of charged leptons, g A =−0.500±0.003 and g ν =−0.064 −0.013 +0.017 .

5 data tables match query

Cross section from 1990 data.

Visible cross section obtained using the cuts required by Method I (see text of paper). (1989 and 1990 data).

Visible cross section obtained using the cuts required by Method II (see text of paper). (1989 and 1990 data). RE = E+ E- --> E+ E- (GAMMA).

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Study of the $e^+ e^- \to \pi^+ \pi^- K^+ K^-$ Reaction From 1.4-{GeV} to 2.18-{GeV}

Cordier, A. ; Bisello, D. ; Bizot, J.C. ; et al.
Phys.Lett.B 110 (1982) 335-338, 1982.
Inspire Record 169382 DOI 10.17182/hepdata.30957

First measurements of the e + e − → π + π − K + K − cross section have been performed by the DM1 on DCI in the total energy range 1.4–2.18 GeV. π + π − K + K − production is dominated by K ∗ Kπ dynamics. The cross section is rather large around 1.9 GeV. Comparison with K 0 S inclusive production shows an isospin interference. Upper limits on φππ production are compatible with the OZI rule.

2 data tables match query

No description provided.

UPPER LIMITS TO PHI CROSS SECTIONS WITH CL=90 PCT.


The $e^+ e^-\to K^+ K^- \pi^+\pi^-$, $K^+ K^- \pi^0\pi^0$ and $K^+ K^- K^+ K^-$ Cross Sections Measured with Initial-State Radiation

The BaBar collaboration Aubert, Bernard ; Bona, M. ; Boutigny, D. ; et al.
Phys.Rev.D 76 (2007) 012008, 2007.
Inspire Record 747875 DOI 10.17182/hepdata.50373

We study the processes $e^+ e^-\to K^+ K^- \pi^+\pi^-\gamma$, $K^+K^-\pi^0\pi^0\gamma$ and $K^+ K^- K^+ K^-\gamma$, where the photon is radiated from the initial state. About 34600, 4400 and 2300 fully reconstructed events, respectively, are selected from 232 \invfb of \babar data. The invariant mass of the hadronic final state defines the effective \epem center-of-mass energy, so that the $K^+ K^- \pi^+\pi^-\gamma$ data can be compared with direct measurements of the $e^+ e^-\to K^+K^- \pipi$ reaction/ no direct measurements exist for the $e^+ e^-\to K^+ K^- \pi^0\pi^0$ or $\epem\to K^+ K^- K^+ K^-$ reactions. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from $e^+ e^-\to\phi(1020) f_{0}(980)$ and study its structure near threshold. In the charmonium region, we observe the $J/\psi$ in all three final states and several intermediate states, as well as the $\psi(2S)$ in some modes, and measure the corresponding branching fractions. We see no signal for the Y(4260) and obtain an upper limit of $\BR_{Y(4260)\to\phi\pi^+\pi^-}\cdot\Gamma^{Y}_{ee}<0.4 \ev$ at 90% C.L.

7 data tables match query

Measurement of the E+ E- --> K+ K- PI+ PI- cross section. Statistical errors only.

Measurement of the E+ E- --> K(892)0 K PI cross section. Statistical errors only.

Measurement of the E+ E- --> PHI PI+ PI- cross section. Statistical errors only.

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Measurement of inclusive D*+- production in two photon collisions at LEP

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 467 (1999) 137-146, 1999.
Inspire Record 505281 DOI 10.17182/hepdata.28070

Inclusive production of $\mathrm{D^{*\pm}}$ mesons in two-photon collisions was measured by the L3 experiment at LEP. The data were collected at a centre-of-mass energy $\sqrt{s} = 189$ GeV with an integrated luminosity of $176.4 \mathrm{pb^{-1}}$. Differential cross sections of the process $\mathrm{e^+e^- \to D^{*\pm} X}$ are determined as functions of the transverse momentum and pseudorapidity of the $\mathrm{D^{*\pm}}$ mesons in the kinematic region 1 GeV $&lt; p_{T}^{\mathrm{D^*}} &lt; 5 $ GeV and $\mathrm{|\eta^{D^*}|} &lt; 1.4$. The cross section integrated over this phase space domain is measured to be $132 \pm 22(stat.) \pm 26(syst.)$ pb. The differential cross sections are compared with next-to-leading order perturbative QCD calculations.

3 data tables match query

The measured cross sections, as a function of PT over the bin ranges and the differential cross sections after bin-centre corrections.

The measured cross sections, as a function of pseudorapidity over the bin ranges and the differential cross sections after bin-centre corrections.

Integrated cross section in the visible kinematic region.


Initial Measurements of Z Boson Resonance Parameters in e+ e- Annihilation

Abrams, G.S. ; Adolphsen, Chris ; Aleksan, R. ; et al.
Phys.Rev.Lett. 63 (1989) 724, 1989.
Inspire Record 280007 DOI 10.17182/hepdata.20034

We have measured the mass of the Z boson to be 91.11±0.23 GeV/c2, and its width to be 1.61−0.43+0.60 GeV. If we constrain the visible width to its standard-model value, we find the partial width to invisible decay modes to be 0.62±0.23 GeV, corresponding to 3.8±1.4 neutrino species.

0 data tables match query

Observation of the Charmed Baryon $\Lambda(c$) in $e^+ e^-$ Annihilation at 10-{GeV}

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.
Phys.Lett.B 207 (1988) 109-114, 1988.
Inspire Record 260826 DOI 10.17182/hepdata.29980

Using the ARGUS detector at DORIS II, we have studied the production of the charmed baryon Λ c in e + e − annihilation at centre-of-mass energies near 10 GeV. The Λ c + was seen in the three decay modes pK − π + , Λπ + π − π + and K̄ 0 p, with products of normalized cross section times branching ratio [ R ·Br] of (10.8±1.4±1.2)×10 −3 , 6.6±1.5±0.9)×10 −3 and (6.7±1.4±0.8)×10 −3 respectively. The measured mass for the Λ c was (2283.1±1.7±2.0) MeV/ c 2 . A limit on the decay rates to Λπ + is reported. The fragmentation function of the Λ c was measured.

1 data table match query

No description provided.


The Forward - backward asymmetry for charm quarks at the Z pole

The ALEPH collaboration Buskulic, D. ; Casper, D. ; De Bonis, I. ; et al.
Phys.Lett.B 352 (1995) 479-486, 1995.
Inspire Record 394753 DOI 10.17182/hepdata.47932

From 1.4 million hadronic Z decays collected by the ALEPH detector at LEP, an enriched sample of Z → cc̄ events is extracted by requiring the presence of a high momentum D ∗± . The charm quark forward-backward charge asymmetry at the Z pole is measured to be A FB 0. c = (8.0 ± 2.4) % corresponding to an effective electroweak mixing angle of sin 2 θ W eff = 0.2302 ± 0.0054.

2 data tables match query

Value of SIN2TW(eff) from CQ-quark asymmetries.

No description provided.


Study of the $e^+ e^- \to \pi^+ \pi^- \pi^+ \pi^-$ Reaction in the 1.4-{GeV} to 2.18-{GeV} Energy Range

Cordier, A. ; Bisello, D. ; Bizot, J.C. ; et al.
Phys.Lett.B 109 (1982) 129-132, 1982.
Inspire Record 168552 DOI 10.17182/hepdata.30995

New measurements of thee + e − → π + π − π + π − cross section have been performed by the magnetic detector DM1 at DCI (ORSAY) in the 1.4−2.18 GeV total energy range with statistics of 11000 events. Assuming the4 π ± production is dominated by the ϱ′(1.6) we determine its parameters: M = 1.57 ± 0.02 (stat.) −0.00 +0.06 (syst.) GeV,Γ = 0.51 ± 0.04 (stat.) −0.01 +0.04 (syst.)GeV,Γ ρ ′ee B ϱ′→ ρ 0 π + π − = 2.67 ± 0.19 (stat.) −0.36 +0.27 (syst.)keV.

1 data table match query

No description provided.


Evidence for Lambda/c(2593)+ production.

The ARGUS collaboration Albrecht, H. ; Hamacher, T. ; Hofmann, R.P. ; et al.
Phys.Lett.B 402 (1997) 207-212, 1997.
Inspire Record 440304 DOI 10.17182/hepdata.44624

Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have found evidence for the production of the excited charmed baryon state Λ c (2593) + in the channel Λ c + π + π − . Its mass was determined to be (2594.6±0.9±0.4) MeV/c 2 , and the natural width measured to be Γ = (2.9 −2.1−1.4 +2.9+1.8 ) MeV. The production cross section times the branching ratios of σ ( e + e − → Λ c (2593) + X ) × Br ( Λ c (2593) + → Λ c + π + π − ) × Br ( Λ c + → pK − π + ) was measured to be (0.25 −0.13 +0.24 ±0.13) pb. The fractions of Λ c (2593) + decays proceeding through the Σ c 0 π + and Σ c ++ π − channels were determined to be 0.29±0.10±0.11 and 0.37±0.12±0.13, respectively.

1 data table match query

Results with and without extrapolation.