Pepin, M.
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Search for narrow structure in proton‐antiproton annihilation cross sections from 1900 to 1960 MeV

Lowenstein, D.I. ; Pealsee, D.C. ; Miller, R.J. ; et al.
Phys.Lett.B 158 (1985) 505-510, 1985.
Inspire Record 221435 DOI 10.17182/hepdata.30389

The p̄p annihilation cross section has been measured with good resolution (∼2 MeV rms) in the mass range 1900–1960 MeV. No narrow structures are seen, the 90% confidence level upper limit being 8–12 mb‐MeV for the integrated area of a resonance in this mass range. However, we do not rule out a very narrow bump‐dip structure seen in an earlier experiment in the 1935–1941 MeV mass interval. The data also do not support the existence of a broad structure previously reported at 1937 MeV.

1 data table
Table 1

Fit of form A + B/D gives A = 8.5 +- 2.5mb and B = 40.7 +- 1.3mb in the mass range 1900 to 1960 MeV.


Results of the experiments from the neutral detector at the VEPP-2M storage ring in the energy region 2E$_{0}$ = 1.05 - 1.40 GeV

Dolinski, S.I. ; Druzhinin, V P ; Dubrovin, M S ; et al.
IYAF-85-98, 1985.
Inspire Record 1393709 DOI 10.17182/hepdata.982

None

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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MEASUREMENT OF THE REAL TO IMAGINARY RATIO OF THE ANTI-P P FORWARD SCATTERING AMPLITUDES

Ashford, V. ; Sainio, M.E. ; Sakitt, M. ; et al.
Phys.Rev.Lett. 54 (1985) 518-521, 1985.
Inspire Record 216074 DOI 10.17182/hepdata.20329

We have measured the ratio of the real to the imaginary parts of the p¯p forward-scattering amplitude in the incident-momentum range 360 to 650 MeV/c. These results are in good agreement with predictions of the Paris nucleon-antinucleon potential model which include spin-flip effects.

3 data tables
Table 2

RESULTS OF FITS TO THE FORWARD-SCATTERING DIFFERENTIAL CROSS SECTIONS ASSUMING THE RATIO OF THE SPIN-FLIP TO NON-SPIN-FLIP PARTS OF THE FORWARD AMPLITUDE IS ZERO.

Table 3

RESULTS OF FITS TO THE FORWARD-SCATTERING DIFFERENTIAL CROSS SECTIONS ASSUMING THE RATIO OF THE SPIN-FLIP TO NON-SPIN-FLIP PARTS OF THE FORWARD AMPLITUDE IS PARAMATERISED AS 0.3698-0.1384*PLAB(IN GEV).


EXCLUSIVE PRODUCTION OF K+ K- pi+ pi- IN PHOTON-PHOTON COLLISIONS

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Armitage, J.C. ; et al.
Phys.Rev.Lett. 54 (1985) 2564, 1985.
Inspire Record 213402 DOI 10.17182/hepdata.20345

We report a measurement of the reaction γγ→K+K−π+π− in both tagged and untagged events at PEP. The cross section rises with invariant γγ mass to about 15 nb at 2 GeV and falls slowly at higher masses. We find clear evidence for the processes γγ→φπ+π− and γγ→K*0(892)Kπ. Upper limits (95% C.L.) of 1.5 and 5.7 nb in the mass range from 1.7 to 3.7 GeV are obtained for φρ0 and K*0K¯*0 production, respectively.

8 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

Untagged sample, (non-resonant).

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Search for Monochromatic Pion Emission in $\bar{p} p$ Annihilation From Atomic $p$ States

The ASTERIX collaboration Ahmad, S. ; Amsler, Claude ; Armenteros, R. ; et al.
Phys.Lett.B 152 (1985) 135-139, 1985.
Inspire Record 207457 DOI 10.17182/hepdata.49644

Narrow states observable through the emission of monoenergetic charged pions have been searched for in p p annihilation at rest in a gaseous hydrogen target where annihilation from atomic angular momentum L = 1 states dominates. No structure is observed. The 5σ upper limit for the production of narrow states in the mass range 1100–1670 MeV is 2 × 10 −3 of all annihilations.

1 data table
Table 1

X means a narrow state.


Photoproduction of $\phi$ Mesons by Linearly Polarized Photons of Energy 20-{GeV} to 40-{GeV} and Further Evidence for a Photoproduced High Mass $K K$ Enhancement

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Z.Phys.C 27 (1985) 233, 1985.
Inspire Record 204590 DOI 10.17182/hepdata.16067

A study of ϕ-meson photoproduction by partially polarized photons of energy 20–40 GeV is reported. The production mechanism is found to conserves-channel helicity and to proceed via natural-parity exchange in thet channel. In the photoproduction of high-massK+K− states with photons of energy 20–70 GeV, there is evidence for an enhancement at a mass of 1.76 GeV with width 0.08 GeV.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Pion Pair Production From $\gamma \gamma$ Interactions at {PEP} and the Radiative Width of the F0 Meson

The DELCO collaboration Courau, A. ; Johnson, R.P. ; Sherman, S.S. ; et al.
Phys.Lett.B 147 (1984) 227-231, 1984.
Inspire Record 202552 DOI 10.17182/hepdata.30498

Results are presented of an untagged e + e − → e + e − + π + π − experiment performed at PEP with the DELCO detector. In the invariant-mass range 0.7 ⩽ W ππ < 2.0 GeV/ c 2 , the QED e + e − background is identified and eliminated, and both the π + π − predictions and the μ + μ − and K + K − background substractions are normalized to the measurement of the e e + e − events. The results agree with a simple model of superposition and interference of the f 0 (1270) resonance, produced with helicity 2, with a Born-term continuum. From a fit of the model to the data, the radiative width of the f 0 is determined to be Γ f 0 → γγ = 2.70 ± 0.21 keV.

1 data table
Table 1

Data read from graph.


The Reactions $K^- p \to \pi^\mp \Sigma^\pm$ (1385) at 8.25-{GeV}/$c$

The Birmingham-CERN-Glasgow-Michigan State-Paris collaboration Baubillier, M. ; Bloodworth, I.J. ; Burns, A. ; et al.
Z.Phys.C 23 (1984) 213, 1984.
Inspire Record 199642 DOI 10.17182/hepdata.16327

The reactionsK−p→π∓Σ(1385)± are studied at an incident laboratory momentum of 8.25 GeV/c using data from a high statistics (≃180 events/μb) bubble chamber experiment. In the case of the reactionK−p→π−Σ(1385)+ an amplitude analysis is performed and the complete Σ(1385)+ spin density matrix is extracted as a function oft′. The results are compared with the predictions of the additive quark model. In the case of the reactionK−p→π+Σ(1385)− the cross-sections for forward and backward production are determined.

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Limit on the B ---> u Coupling from Semileptonic B Decay

The CLEO collaboration Chen, A. ; Goldberg, M. ; Horwitz, N. ; et al.
Phys.Rev.Lett. 52 (1984) 1084, 1984.
Inspire Record 199380 DOI 10.17182/hepdata.20474

We have used the momentum spectrum of leptons produced in semileptonic B-meson decays to set a 90%-confidence-level upper limit on Γ(b→ulν)Γ(b→clν) of 4%. We also measure the semileptonic branching fractions of the B meson to be (12.0±0.7±0.5)% for electrons and (10.8±0.6±1.0)% for muons.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


SEARCH FOR NARROW STRUCTURES IN ANTI-P P TOTAL CROSS-SECTION FROM 395-MEV/C TO 740-MEV/C

Nakamura, K. ; Aihara, H. ; Chiba, J. ; et al.
Phys.Rev.D 29 (1984) 349-362, 1984.
Inspire Record 202201 DOI 10.17182/hepdata.23686

We report the final results of a search for narrow structures in the p¯p total cross section between 395 and 740 MeV/c with a rms mass resolution of 1.5 MeV around the S-resonance region. A reanalysis of the data significantly improved the statistical accuracy. No evidence is found for narrow structures and a 90%-confidence-level upper limit of 24 mb MeV is set at around 500 MeV/c for the integrated cross section of a Breit-Wigner-type resonance of width ≲4 MeV.

1 data table
Table 1

No description provided.