Himel, T.
E+ E- Scattering
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Observation of Semileptonic Decays of Charmed Baryons

Vella, E. ; Trilling, G. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 48 (1982) 1515, 1982.
Inspire Record 176986 DOI 10.17182/hepdata.19674

Direct electrons are observed in baryon events produced in e+e− annihilation at center-of-mass energies above the ΛcΛ¯c threshold. These events are attributed to charmed-baryon pair production and subsequent Λc semileptonic decay. Various semileptonic branching ratios of the Λc are determined, including B(Λc→e+X)=(4.5±1.7)%.

1 data table match query
Table 2

No description provided.


Observation of Charmed Baryon Production in e+ e- Annihilation

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.Lett. 44 (1980) 10, 1980.
Inspire Record 142743 DOI 10.17182/hepdata.20754

A peak in the pK−π+ and p¯K+π− invariant-mass spectra at 2.285±0.006 GeV/c2 is observed, which is associated with the lowest-lying charmed baryon (Λc). A cross section times branching ratio of 0.037±0.012 nb at Ec.m.=5.2 GeV is measured with a substantial fraction of the events produced with an equal recoiling mass. New measurements of inclusive p and Λ cross sections are also presented, allowing an estimate of the branching ratio B(Λc→pK−π+)=0.022±0.010.

3 data tables match query
Table 1

THE TOTAL INCLUSIVE CHARMED LAMBDA CROSS SECTION IS DERIVED FROM THE OBSERVED PRODUCTION RATE VIA THE <P K- PI+> CHANNEL USING THE STEP IN INCLUSIVE PROTON PRODUCTION AT THE CHARMED-BARYON THRESHOLD AND REASONABLE ASSUMPTIONS. THE BRANCHING RATIO (LAMBDA/C+ --> P K- PI+) IS THEN 2.2 +- 1.0 PCT.

Table 2

ACTUALLY TWICE THE INCLUSIVE ANTI-PROTON CROSS SECTION (EACH BARYON PAIR IS COUNTED TWICE).

Table 3

EACH BARYON PAIR PRODUCED IS OF COURSE COUNTED TWICE IN THIS CROSS SECTION.


Measurements of the Properties of d Meson Decays

Schindler, R.H. ; Alam, M.S. ; Boyarski, A. ; et al.
Phys.Rev.D 24 (1981) 78, 1981.
Inspire Record 156644 DOI 10.17182/hepdata.24006

We present a study of the decay properties of charmed D mesons produced near the peak of the ψ′′(3770) resonance in e+e− annihilation. Branching fractions for nine Cabibbo-favored and three Cabibbo-suppressed decay modes are presented along with upper limits on one additional Cabibbo-favored and four additional Cabibbo-suppressed decay modes. A study of Kππ-decay-mode Dalitz plots reveals a large quasi-two-body pseudoscalar-vector component for the D0 decays and an apparent nonuniform population on the Dalitz plot for the D+ decay into K−π+π+. Using tagged events, we measure the charged-particle multiplicity and strange-particle content of D decays. A measurement of the D+ and D0 semileptonic decay fractions indicates that the D+ has a significantly longer lifetime than the D0.

1 data table match query
Table 1

INCLUSIVE CROSS SECTIONS UNCORRECTED FOR RADIATIVE EFFECTS.


Direct Photon Production at the $\psi$

Scharre, D.L. ; Alam, M.S. ; Boyarski, A. ; et al.
Phys.Rev.D 23 (1981) 43, 1981.
Inspire Record 153865 DOI 10.17182/hepdata.24079

We present results of a detailed analysis of inclusive direct photon production at the ψ(3095). The direct-photon momentum distribution for x>0.4 is presented and compared with the leading-order quantum-chromodynamic prediction. The total production rate is found to be consistent with theoretical expectations, but the observed momentum distribution is considerably softer. Results of an analysis of some inclusive properties of the hadronic system recoiling against the direct photon are presented. The mean charged-particle and Ks multiplicities are presented as functions of the invariant mass of the hadronic system. These data agree well with the corresponding mean multiplicities measured in e+e− annihilations at center-of-mass energies comparable to the invariant mass of the hadronic system.

4 data tables match query
Table 1

TOTAL INCLUSIVE PHOTON MOMENTUM SPECTRUM. ERRORS ARE STATISTICAL ONLY.

Table 2

PHOTON SPECTRUM PREDICTED FROM MEASUREMENT OF THE PI0 AND ETA DISTRIBUTIONS. ERRORS INCLUDE BOTH STATISTICAL AND RELATIVE SYSTEMATIC COMPONENTS.

Table 3

INCLUSIVE PI0 MOMENTUM DISTRIBUTION. QUOTED ERRORS ARE STATISTICAL ONLY. OVERALL AND RELATIVE SYSTEMATIC ERRORS ARE LESS THAN 30 PCT AND MAY VARY SLOWLY WITH X.

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Measurement of the Parameters of the $\psi^{\prime\prime}$(3770) Resonance

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.D 21 (1980) 2716, 1980.
Inspire Record 142644 DOI 10.17182/hepdata.24185

We present a measurement of the cross section for hadron production by e+e− annihilation in the vicinity of the previously observed resonance near 3.77 GeV. The data are used to determine the parameters of the ψ(3770) resonance. The values found are: mass, 3764±5 MeV/c2, total width, 23.5±5 MeV, and partial width to electron pairs, 276±50 eV.

1 data table match query
Table 3

PEAK CROSS SECTION FOR D MESON PAIR PRODUCTION AT PSI(3770) RESONANCE. J/PSI, PSI(3684) AND CONTINUUM BACKGROUND (R=2.5) SUBTRACTED.


RESONANCE PRODUCTION BY TWO PHOTON INTERACTIONS AT SPEAR

Jenni, P. ; Burke, D.L. ; Telnov, Valery I. ; et al.
Phys.Rev.D 27 (1983) 1031, 1983.
Inspire Record 173430 DOI 10.17182/hepdata.23843

Two-photon interactions have been studied with the SLAC-LBL Mark II magnetic detector at SPEAR. The cross section for η′ production by the reaction e+e−→e+e−η′ has been measured at beam energies from 2.0 to 3.7 GeV. The radiative width Γγγ(η′) has been determined to be 5.8±1.1 keV (±20% systematic uncertainty). Upper limits on the radiative widths of the f(1270), A2(1310), and f′(1515) tensor mesons have been determined. A search has been made for production of the E(1420) by γγ collisions, but no signal is observed.

2 data tables match query
Table 1

No description provided.

Table 2

NO SIGNAL ABOVE BACKGROUND SEEN. UPPER LIMITS AT 95 PCT CL GIVEN.


$D$ Meson Production in $e^+ e^-$ Annihilation at Ecm Between 3.8-{GeV} and 6.7-{GeV}

Coles, M.W. ; Abrams, G.S. ; Blocker, C.A. ; et al.
Phys.Rev.D 26 (1982) 2190, 1982.
Inspire Record 178099 DOI 10.17182/hepdata.23943

The Mark II detector at SPEAR has been used to study D-meson production in e+e− annihilation at center-of-mass energies between 3.8 and 6.7 GeV. The neutral and charged D mesons are identified from their K∓π± and K∓π±π± decay modes. Measurements of RD and of the inclusive differential cross section s dσdz are presented. The quasi-two-body cross sections σDD¯, σD*D¯, and σD*D¯* are derived from an overall fit to the D recoil spectra. No evidence was found for the associated production of charmed mesons and charmed baryons.

3 data tables match query
Table 1

No description provided.

Table 2

No description provided.

Table 4

EXCLUSIVE D AD PRODUCTION CROSS SECTIONS FROM THE RECOIL SPECTRA FITS. METHOD 1 ASSUMES AN ISOTROPIC ANGULAR DISTRIBUTION OF THE D RELATIVE TO THE PARENT D* DIRECTION OF MOTION. METHOD 2 ASSUMES THE ANGULAR DISTRIBUTION IS 1 + A COS(THETA)**2.


rivet Analysis
Measurement of $s d \sigma$ / Dx for Hadron Production by $e^+ e^-$ Annihilation at $\sqrt{s}=5$.2-{GeV}, 6.5-{GeV} and 29.0-{GeV}

Patrick, J.F. ; Luth, V. ; Siegrist, J. ; et al.
Phys.Rev.Lett. 49 (1982) 1232, 1982.
Inspire Record 178416 DOI 10.17182/hepdata.20599

Measurements are presented of the inclusive charged-particle cross sections s dσdx for e+e− annihilation at center-of-mass energies of 5.2, 6.5, and 29.0 GeV. Significant scale breaking is observed in these cross sections.

1 data table match query
Table 1

CROSS SECTION S*D(SIG)/DX FOR CHARGED PARTICLES AT SQRT(S) = 5.2, 6.5 AND 29.0 GEV. NUMERICAL VALUES OF DATA TAKEN FROM THESIS OF J.F. PATRICK LBL-14585.


rivet Analysis
Measurement of $K^\pm$ and $K^0$ Inclusive Rates in $e^+ e^-$ Annihilation at 29-{GeV}

Schellman, H. ; Trilling, G. ; Abrams, G.S. ; et al.
Phys.Rev.D 31 (1985) 3013, 1985.
Inspire Record 207785 DOI 10.17182/hepdata.23580

We have measured the K0+K¯ 0 inclusive cross section in e+e− annihilation at 29 GeV with the Mark II detector SLAC PEP. We find 1.27±0.03±0.15 K0+K¯ 0 per hadronic event. We have also used time-of-flight particle identification to measure the K± rate over the momentum range 300–900 MeV/c.

4 data tables match query
Table 1

Extrapolated to full momentum range by Monte-Carlo.

Table 2

Statistical errors only.

Table 3

No description provided.

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Studies of Jet Production Rates in $e^+ e^-$ Annihilation at $e$({CM}) = 29-{GeV}

Bethke, S. ; Abrams, G. ; Adolphsen, C.E. ; et al.
Z.Phys.C 43 (1989) 325, 1989.
Inspire Record 277772 DOI 10.17182/hepdata.15472

Production rates of multijet hadronic final states are studied ine+e− annihilation at 29 GeV center of mass energy. QCD shower model calculations with exact first order matrix element weighting at the first gluon vertex are capable of reproducing the observed multijet event rates over a large range of jet pair masses. The method used to reconstruct jets is well suited for directly comparing experimental jet rates with parton rates calculated in perturbative QCD. Evidence for the energy dependene of αs is obtained by comparing the observed production rates of 3-jet events with results of similar studies performed at higher center of mass energies.

2 data tables match query
Table 1

Observed production rates relative to the total hadronic cross section.

Table 2

Production rates corrected for fragmentation, initial state radiation and detector effects.