Helland, Jerome A.
Max results
Sort by Reverse order

Showing 10 of 7162 results

Date

EXPERIMENTAL ANALYSIS OF THE PROPERTIES OF THE FIVE PION EFFECT OBSERVED IN ANTI-P P INTERACTIONS NEAR 1950-MEV/C**2

Espigat, P. ; Defoix, C. ; Dobrzynski, L. ; et al.
Nucl.Phys.B 162 (1980) 41-60, 1980.
Inspire Record 157037 DOI 10.17182/hepdata.34583

The properties of the effect observed in the reaction p p → π + π − π + π − π 0 at 1949 ± 10 MeV /c 2 (τ ≅ 80 MeV /c 2 ) are studied. The ω 0 ϱ 0 , A 2 0 π + π − and π + π − π + π − π 0 (non-resonant) channels are found to be coupled with this object. The assignment I G = 1 − is established and an analysis of the √ s behaviour of the density matrix elements for the final state ω 0 ϱ 0 clearly favour J P = 2 + , 4 + … Comparisons are made with present theoretical schemes describing this mass region.

1 data table
Table 1

MAJOR CONTRIBUTION TO STRUCTURE OBSERVED AT 1949 +- 10 MEV WITH WIDTH 80 +- 20 MEV.


EXPERIMENTAL ANALYSIS OF ANTI-P P INTERACTIONS BETWEEN 0-GEV AND 1.2-GEV/C: EVIDENCE FOR A ANTI-P P ---> 5 PI EFFECT NEAR 1950-MEV/C**2

Defoix, C. ; Dobrzynski, L. ; Espigat, P. ; et al.
Nucl.Phys.B 162 (1980) 12-40, 1980.
Inspire Record 157036 DOI 10.17182/hepdata.34609

An experimental analysis of p p interactions between the p p threshold (√ s = 1878 MeV) and √ s = 2 100 MeV leads to clear evidence for an s -channel effect in the reaction p p → π + π − π + π − π 0 at 1949 ± 10 MeV /c 2 (Γ ⋍ 80 MeV /c 2 ) . A comparison is made with the backward elastic scattering and charge-exchange behaviour. An interpretation in terms of an object strongly coupled to mesonic decay modes, with small or middle-sized elasticity ( x ⩽ 0.135 −0.06 +0.13 ) is given. No significant narrow structure is observed in the backward elastic scattering between 1.9 and 2 GeV. The experimental resolution of √ s in this case is 2 MeV.

1 data table
Table 1

LOWER MOMENTUM RESULTS WERE REPORTED IN CH. D'ANDLAU ET AL., PL 58B, 223 (1975). TABULATED NUMERICAL VALUES OF DATA ON FIGURES SUPPLIED BY M. LALOUM.


K*0 (890) POLARIZATION MEASUREMENTS IN THE HYPERCHARGE EXCHANGE REACTION PI- P ---> K*0 (890) LAMBDA0 / SIGMA0 AT 10-GEV/C

The BARI-BONN-CERN-DARESBURY-GLASGOW-LIVERPOOL-MILAN-VIENNA collaboration Evangelista, C. ; Ghidini, B. ; Palano, A. ; et al.
Nucl.Phys.B 165 (1980) 383-394, 1980.
Inspire Record 157497 DOI 10.17182/hepdata.34585

K ∗0 (890) production in the hyperchange exchange reaction π − p → K ∗0 (890) Λ 0 Σ 0 at 10 GeV/ c (28 448 events) is discussed. An amplitude analysis in the t ′ range up to 1 GeV 2 shows that the production mechanism is dominated by natural parity exchange (∼84%). Comparisons are made with predictions from a Regge model and a quark model.

2 data tables
Table 1

DENSITY MATRIX ELEMENTS IN THE GOTTFRIED-JACKSON SYSTEM ALLOWING FOR COHERENT S-WAVE BACKGROUND TO P-WAVE BREIT-WIGNER K*(892)0 RESONANCE.

Table 2

No description provided.


STUDY OF THE REACTION ANTI-P N ---> ANTI-P P PI- AT 2.98-GEV/C

Bettini, A. ; Mazzucato, M. ; Peruzzo, L. ; et al.
Nucl.Phys.B 164 (1980) 365-386, 1980.
Inspire Record 157276 DOI 10.17182/hepdata.34587

The reaction p n → p p π − at 2.98 GeV/ c is studied with high statistics. The dominant Δ −− production is found in the framework of the additive quark model to proceed mainly through unnatural parity exchange in the t -channel. A detailed comparison with the reaction K − p → K ∗0 n confirms, for the dominant part of the cross section, the predictions of the quark model.

2 data tables
Table 1

No description provided.

Table 2

MIN(-T) IS 0.015 +- 0.006 GEV**2.


INCLUSIVE AND SEMIINCLUSIVE PRODUCTION OF POSITIVE PIONS AND PROTONS IN ANTI-P P INTERACTIONS AT 22.4-GEV/C

The ALMA ATA-DUBNA-HELSINKI-MOSCOW-PRAGUE-TBILISI collaboration Boos, E.G. ; Ermilova, D.I. ; Samoilov, V.V. ; et al.
Nucl.Phys.B 174 (1980) 45-67, 1980.
Inspire Record 159212 DOI 10.17182/hepdata.7929

New results on the inclusive and semi-inclusive production of π + mesons and protons in the whole phase space are given for about 2.2 · 10 4 inelastic p p interactions at 22.4 GeV/ c . A method of statistical separation for spectra of particles of the same charge which are produced in CP -symmetrical reactions is discussed in detail. Experimental data are compared with quark-parton model predictions.

3 data tables
Table 1

No description provided.

Table 2

NON-ANNIHILATION EVENTS ONLY.

Table 3

No description provided.


NEUTRAL STRANGE PARTICLE PRODUCTION IN PI- P INTERACTIONS AT 16-GEV/C

Balea, E. ; Berceanu, S. ; Coca, C. ; et al.
Nucl.Phys.B 163 (1980) 21-45, 1980.
Inspire Record 157169 DOI 10.17182/hepdata.8077

The production of K S 0 , Λ and Λ in π − p ractions at 16 GeV/ c is investigated. Cross sections for single strange particles are determined, both inclusively and as functions of the charged multiplicity. Some characteristics of the multiplicity distributions are also discussed. Inclusive distributions are studied as a function of the longitudinal and transverse variables of V 0 and the missing mass squared. The average charged multiplicities of the systems recoiling against the Λ and K S 0 are presented.

12 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

ELECTROPRODUCTION CROSS-SECTIONS IN THE RESONANCE REGION MEASURED AT LARGE SCATTERING ANGLES

Gerhardt, B. ; Muller, H. ; Drees, J. ; et al.
Z.Phys.C 7 (1980) 11-15, 1980.
Inspire Record 160216 DOI 10.17182/hepdata.14097

To complete data on resonance electroproduction we constructed an electron spectrometer with large angular and momentum acceptance. As a first result inclusive cross sections for an invariant hadronic mass 1.2<W<1.7 GeV and a four momentum transfer squared 0.5<Q2<1.5 (GeV/c)2 and for values of the polarization parameter 0.1<ɛ<0.25 are presented. Combining our results with the SLAC 4°-data we obtain σL/σT in the specified kinematical range.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

STUDY OF THE LEADING PROTON SPECTRA IN EXPERIMENTS ON 6.8-GEV/C PROTON SCATTERING ON PROTONS AND C, AL, CU, SN, PB NUCLEI. (IN RUSSIAN)

Ableev, V.G. ; Bodyagin, V.A. ; Vorobev, G.G. ; et al.
Yad.Fiz. 32 (1980) 1351-1356, 1980.
Inspire Record 159804 DOI 10.17182/hepdata.18015

None

2 data tables
Table 1

No description provided.

Table 2

DATA ON THE SUM OF ELASTIC AND QUASIELASTIC CROSS SECTIONS.


MEASUREMENT OF THE AVERAGE ENERGY OF CHARGED PARTICLES IN C.M.S FOR THE ANTI-P P INTERACTIONS AT 22.4-GEV/C.

The ALMA ATA-DUBNA-MOSCOW-PRAGUE-TBILISI-HELSINKI collaboration Boos, E.G. ; Ermilova, D.I. ; Samoilov, V.V. ; et al.
Yad.Fiz. 31 (1980) 947-955, 1980.
Inspire Record 157619 DOI 10.17182/hepdata.18035

None

7 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

EXPERIMENTAL STUDY OF HEAVY CHARGED LEPTONS AT PETRA

Barber, D.P. ; Becker, U. ; Bei, G.D. ; et al.
Phys.Rev.Lett. 45 (1980) 1904-1907, 1980.
Inspire Record 158858 DOI 10.17182/hepdata.20675

Data from the MARK-J detector on the reactions e+e−→μ+μ−, τ+τ− in the center-of-mass energy range from 12 to 36.7 GeV are presented. The μ, τ radii are shown to be <10−16 cm. A search has been made for the production of a new heavy lepton and for the production of spin-0 supersymmetric partners of the muon. 95%-confidence-level lower limits of 16 GeV for the mass of a new charged heavy lepton and 15 GeV for the mass of the scalar partners of the muon are obtained.

1 data table
Table 1

No description provided.