Cowan, C.A.
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Observation of a Narrow Hyperon State of Mass 3.17-{GeV}

The Birmingham-CERN-Glasgow-Michigan State-Paris & Cambridge-Michigan State collaborations Amirzadeh, J. ; Ansorge, R.E. ; Baubillier, M. ; et al.
Phys.Lett.B 89 (1979) 125-130, 1979.
Inspire Record 143109 DOI 10.17182/hepdata.27296

We present evidence for a narrow Y ∗ with a mass of 3.17 GeV and a width ⩽ 20 MeV decaying to ΣKK̄ + pions, ΛKK̄ + pions and ΞK + pions. The data come from two high statistics K − p bubble chamber experiments with a sensitivity of ≈100 eV/ μb at 8.25 GeV/ c and ≈ 45 eV/ μb at 6.5 GeV/ c .

1 data table
Table 1

OBSERVATION OF R(3170) ONLY DECAYING INTO 5 OR 6 PARTICLES (CROSS SECTION NOT CORRECTED FOR DECAYS WITH MORE THAN ONE UNSEEN FINAL STATE PARTICLE).


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
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.


Observation of a Xi* (2370) Produced in 8.25-{GeV}/$c K^- p$ Interactions

The Birmingham-CERN-Glasgow-Michigan State-Paris collaboration Amirzadeh, J. ; Baubillier, M. ; Bloodworth, I.J. ; et al.
Phys.Lett.B 90 (1980) 324-326, 1980.
Inspire Record 143786 DOI 10.17182/hepdata.27255

We observe production of a Ξ * (2370) in the reactions K − p→ [YK¯π] K, [YK¯π] Kπ and [ΩK] (K or Kπ) at 8.25 GeV/ c in a high statistics bubble chamber experiment. The mass and width are determined to be 2373 ± 8 MeV and 80 ± 25 MeV, respectively. The I = 1/2 assignment is strongly favoured.

1 data table
Table 1

CROSS SECTIONS FOR PRODUCTION OF XI(2370) --> (LAMBDA + SIGMA) AK PI. BREIT-WIGNER FIT WITH POLYNOMIAL BACKGROUND. XI(2370) PRODUCED BY BARYON EXCHANGE. CORRECTED FOR NEUTRAL DECAYS AND GEOMETRICAL LOSSES. <OMEGA-KAON> DECAY SEEN. OBSERVED RATIO OF CHARGED TO NEUTRAL XI(2370) PRODUCTION IS 2.7 +- 0.9.


Measurement of High-energy Direct Photons in $\psi$ Decays

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.Lett. 44 (1980) 114, 1980.
Inspire Record 142835 DOI 10.17182/hepdata.20729

The inclusive γ and π0 momentum distributions at the ψ have been measured. Using these data and estimates of η production, it is found that (4.1 ± 0.8)% of ψ decays contain a direct photon with energy greater than 60% of the beam energy. The expected momentum distribution for direct photons calculated to lowest order in quantum chromodynamics is qualitatively different from that observed in the data.

1 data table
Table 1

INCLUSIVE PHOTON AND PI0 MOMENTUM DISTRIBUTION.


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.

3 data tables
Table 1

THESE RESULTS ARE ALSO IN THE THESIS OF R. H. SCHINDLER, SLAC-219 (1979), THE RECORD OF WHICH CONTAINS THE TABULATED CROSS SECTIONS.

Table 2

BREIT-WIGNER RESONANCE PLUS BACKGROUND FIT TO RADIATIVELY CORRECTED DATA YIELDS RESONANCE MASS OF 3764 +- 5 MEV, TOTAL WIDTH OF 23.5 +- 5 MEV AND PARTIAL WIDTH TO ELECTRON PAIRS OF 276 +- 50 EV.

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.


OBSERVATION OF THE REACTION K- P ---> B- Y*+ AT 8.25-GeV/c

The BIRMINGHAM-CERN-GLASGOW-MICHIGAN STATE-PARIS collaboration Bloodworth, I.J. ; Carney, J.N. ; Cowan, C.A. ; et al.
Lett.Nuovo Cim. 27 (1980) 555-561, 1980.
Inspire Record 157726 DOI 10.17182/hepdata.37367

None

4 data tables
Table 1

No description provided.

Table 2

DOMINANT NATURAL PARITY EXCHANGE.

Table 3

EVIDENCE FOR FORWARD DIP FOR -TP < 0.1 GEV**2.

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MEASUREMENT OF PI- P ---> PI- PI+ N NEAR THRESHOLD AND CHIRAL SYMMETRY BREAKING

Bjork, C.W. ; Jones, S.E. ; King, T.R. ; et al.
Phys.Rev.Lett. 44 (1980) 62-65, 1980.
Inspire Record 157275 DOI 10.17182/hepdata.20699

d2σdΩdT for π+ mesons produced in π−p→π−π+n was measured at seven incident energies between 203 and 357 MeV and the integrated reaction cross section was calculated. The matrix element, when extrapolated to threshold and compared with soft-pion calculations, determined the chiral-symmetry-breaking parameter ξ=0.05±0.26, which is consistent with the Weinberg Lagrangian. The large hard-pion contributions at 203 MeV demonstrated the absolute necessity for comparing at threshold.

1 data table
Table 1

Axis error includes +- 0.0/0.0 contribution (?////).


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
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
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 $\pi^-$ Form-factor

Dally, E.B. ; Drickey, Darrell James ; Hauptman, J.M. ; et al.
Phys.Rev.D 24 (1981) 1718-1735, 1981.
Inspire Record 172687 DOI 10.17182/hepdata.26467

An experiment to measure the electromagnetic form factor of the negative π meson has been carried out at Fermilab by elastically scattering 100-GeV/c pions from the atomic electrons in a liquid-hydrogen target. We find that the elastic differential scattering cross section is characterized by a root-mean-square pion charge radius of 0.56±0.04 fm. This paper described our experimental design, measurement resolutions, event triggering logic, event reconstruction, experimental corrections, and form-factor results.

3 data tables
Table 1

No description provided.

Table 2

Axis error includes +- 0.54/0.54 contribution (EVENT-FINDING CORRECTIONS).

Table 3

No description provided.