Evidence for Different Polarization Properties of the rho K and K* (890) pi States of the 1+ Wave in the Q Region

The Aachen-Berlin-CERN-London-Vienna collaboration Otter, G. ; Rudolph, G. ; Rumph, K. ; et al.
Nucl.Phys.B 93 (1975) 365-386, 1975.
Inspire Record 99251 DOI 10.17182/hepdata.32005

A partial-wave analysis has been performed on the (K − π − π + ) system produced in the reaction K − p → K − π − π + p at 10 and 16 GeV/ c . In the Q mass region it is found that the two dominant states, K ∗ π and Kπ, both in 1 + S wave, are produced with different polarisations, helicity being approximately conserved in the t -channel for K ∗ π and in the s -channel for Kπ. This is in contradiction with the assumption that the amplitude can be factorised into “production” and “decay” parts, and hence that the two amplitudes are fully coherent. The phase variation of the two states do not indicate simple resonance behaviour. It is concluded that the Q-mass enhancement is composite.

2 data tables

No description provided.

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A Comparison of pi pi pi, anti-K pi pi, pi K anti-K, anti-K K anti-K Systems Produced in the Reactions Meson + p --> 3 Mesons + p

The Aachen-Berlin-Bonn-CERN-Heidelberg-London-Vienna collaboration Bosetti, P. ; Otter, G. ; Rudolph, G. ; et al.
Nucl.Phys.B 101 (1975) 304-332, 1975.
Inspire Record 100226 DOI 10.17182/hepdata.36082

A comparison is made of the low-mass three-meson systems (πππ), (Kππ), (π K K ) and ( K K K ) diffractively produced in the reaction meson + proton → three mesons + proton. Several striking similarities and a few important differences are observed: (i) the reactions are consistent with the assumption that the three mesons decay entirely into a 0 − meson and a 0 + , 1 − or 2 + resonance; (ii) the three-meson mass spectra have a peak ≈ 250 MeV above the effective threshold M eff of the dominant decay mode and then fall off approximately as (mass) −3 ;(iii) the average spin 〈 J 〉 = 0.55 + 1.1 Q eff , where Q eff = M - M eff ; (iv) the average orbital angular momentum 〈 l 〉 increases according to 〈 l 〉 = 0.75 Q eff ; (v) the three-meson states are produced dominantly in unnatural spin-parity states and no evidence for their being resonant is found; (vi) the only natural spin-parity states found are the well-established 2 + resonances A 2 and K ∗ (1420); they have similar properties to the non-resonant unnatural parity states except for a dip at t = 0 in the dσ/d t distributions; (vii) both the unnatural and natural spin-parity states are produced mostly by an exchange of natural parity; (viii) there is evidence for two types of production mechanism with different polarization properties, one approximately conserving helicity in the t -channel and the other in the s -channel.

1 data table

No description provided.


Delta0 rho- Production in the pi- n --> p pi- pi- pi0 Reaction at 9.1-GeV/c

Armenise, N. ; Fogli-Muciaccia, M.T. ; Nuzzo, S. ; et al.
Nuovo Cim.A 34 (1976) 37-47, 1976.
Inspire Record 115803 DOI 10.17182/hepdata.37636

From the reaction π−n→pπ−π−π0 at 9.140 GeV/c the Δ0ϱ− reaction has been selected. The upper limit in the cross-section ofμb

6 data tables

A SMALL CORRECTION FOR THE DEL0 TAIL IS NOT PERFORMED.

No description provided.

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Resonance Production in the Reaction K+ p --> K0 p pi+ at 5-GeV/c, 8.25-GeV/c and 16-GeV/c

Colley, D.C. ; Carney, J.N. ; James, M.F. ; et al.
Nucl.Phys.B 110 (1976) 333-354, 1976.
Inspire Record 108770 DOI 10.17182/hepdata.35742

We present a systematic analysis of the production of K ∗+ (892) and Δ ++ (1236) resonances in the K + p → K 0 p π + reaction at 5, 8.25 and 16 GeV/ c . We have measured total cross sections, differential cross sections, density matrix elements and examined resonance production mechanisms in terms of the exchange of states with definite naturality. Some results on the reaction K + p → K ∗+ (1420) p are also given.

6 data tables

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First Results on Diffraction Dissociation of Neutrons at the ISR

Mantovani, G.C. ; Cavalli-Sforza, M. ; Conta, C. ; et al.
Phys.Lett.B 64 (1976) 471-474, 1976.
Inspire Record 110024 DOI 10.17182/hepdata.27617

Neutron diffraction dissociation has been measured at the ISR in proton-neutron interactions at 37 GeV c.m. energy. The data were taken with the Split Field Magnet detector, during a short deuteron storage test run with colliding p-d beams. Differential mass and momentum transfer distributions are reported; the value of the total cross-section shows a weak s -dependence when compared to lower energy data.

2 data tables

ERROR IS MOSTLY SYSTEMATIC.

No description provided.


Observation of Neutron Neutron Interactions with Double Diffraction Dissociation at the ISR

Mantovani, G.C. ; Cavalli-Sforza, M. ; Conta, C. ; et al.
Phys.Lett.B 65 (1976) 401-404, 1976.
Inspire Record 110581 DOI 10.17182/hepdata.27598

Neutron-neutron interactions have been observed at the CERN ISR with deutron colliding beams. The double - diffraction dissociation process →(p π p − )( pπ − ) has been measured with the Split Field Magnet at √ s = 26 GeV detecting all final state particles, including the two spectator protons. Mass and t distributions are presented and compared with corresponding spectra observed in single neutron diffraction in the same energy range with supporting evidence for factorization. The cross-section of the process is 11.5±2.8 μ b and can be directly related to the corresponding value for double diffraction dissociation of protons in the same energy range.

2 data tables

ERROR IS MOSTLY SYSTEMATIC. DEUTERON CORRECTIONS APPLIED.

No description provided.


Analysis of the omega pi- System Produced in the Reaction pi- p --> pi- pi- pi+ pi0 p at 11.2-GeV/c

Gessaroli, R. ; Quareni-Vignudelli, A. ; Berti, S. ; et al.
Nucl.Phys.B 126 (1977) 382-396, 1977.
Inspire Record 119128 DOI 10.17182/hepdata.41905

The ωπ − mass spectrum, in the reaction π −p → ωπ − pat 11.2 GeV/ c , shows the production of the B − meson with a cross section of 27 ± 5 μb as well as a clear enhancement around 1670 MeV. In the differential cross section for B − production, there is a strong forward peak and a change of slope at t ' t 0.2 GeV 2 .

3 data tables

CORRECTED FOR BACKGROUND AND OMEGA TAILS.

No description provided.

ABS(D-WAVE/S-WAVE) = 0.4 +- 0.1 FOR B DECAY.


NONDIFFRACTIVE TWO-BODY CHANNELS IN REACTIONS K+ P ---> K0 PI+ P AND K+ P ---> K+ PI- PI+ P AT 32-GeV/c. FRANCE-SOVIET UNION AND CERN-SOVIET UNION COLLABORATIONS

Givernaud, A. ; Cochet, C. ; Denegri, D. ; et al.
Nucl.Phys.B 153 (1979) 280-298, 1979.
Inspire Record 146578 DOI 10.17182/hepdata.34765

We present results on a number of non-diffractive two-body channels contributing to reactions K + p→K 0 π + p and K + p→K + π − π + p. The data come from an exposure of the Mirabelle bubble chamber to an r.f. separated K + beam of 32 GeV/ c at the Serpukhov accelerator. Total cross sections are given for the final states K ∗+ (890) p , K ∗+ (1420) p , K 0 Δ ++ (1232), K ∗+ (890) p , Δ ++ (1232), K ∗0 (1420) Δ ++ (1232), K ∗0 (1780) Δ ++ (1232) and K ∗0 (890) Δ ++ (1950) . The differential cross sections are given for all channels with sufficient statistics. The energy dependence of the total and differential cross sections is studied.

3 data tables

FROM K0 P PI+ FINAL STATE.

DOUBLE RESONANCE CHANNEL CROSS SECTIONS CORRECTED FOR BACKGROUND, BREIT-WIGNER TAILS AND DIFFRACTIVE PROCESSES.

No description provided.


Elastic and total $\pi^{+}\pi^{-}$ cross-sections from a high statistics measurement of the reaction $\pi^{-}p \to \pi^{+}\pi^{-}n$ at 63 GeV/c

Weilhammer, P. ; Berglund, A. ; Chabaud, V. ; et al.
2 (1979) 628-635, 1979.
Inspire Record 148986 DOI 10.17182/hepdata.75420

A sample of about 230000 events of the reaction pi /sup -/p to pi /sup +/ pi /sup -/n, measured with a magnetic forward spectrometer set up in an unseparated pi /sup -/ beam with a momentum of 63 GeV/c at the SPS has been analysed in terms of one pion exchange. The elastic pi /sup +/ pi /sup -/ cross section has been determined using an extrapolation to the pion pole in the mass range up to m( pi /sup +/ pi /sup -/)=4 GeV. The total pi /sup +/ pi /sup -/ cross section is obtained via the optical theorem. (7 refs).

5 data tables

INTEGRATED 2- S-WAVE INTENSITY FOR 1500 TO 1800 MEV, INCLUDING SIGNIFICANT BACKGROUND.

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Study of Electron - Positron Collisions at the Highest {PETRA} Energy

The Aachen-DESY-Annecy(LAPP)-MIT-NIKHEF-Beijing collaboration Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Lett.B 85 (1979) 463-466, 1979.
Inspire Record 141976 DOI 10.17182/hepdata.27332

We report on the results of the study of e + e − collisions at the highest PETRA energy of √ s = 31.57 GeV, using the 4π sr, electromagnetic and calorimetric detector Mark J. Based on 88 hadron events, and an integrated luminosity of 243 nb −1 we obtain R = σ (e + e − → hadrons)/ σ (e + e − → μ + μ − ) = 4.0 ± 0.5 (statistical) ± 6 (systematic). The R value, the measured thrust distribution and average spherocity show no evidence for the production of new quark flavors.

2 data tables

CORRECTIONS FOR TWO-PHOTON PROCESSES, TAU HEAVY LEPTON PRODUCTION AND INITIAL STATE RADIATIVE CORRECTIONS HAVE BEEN APPLIED.

THRUST DISTRIBUTION (1/N)*DN/DTHRUST AT 31.57 GEV. THESE DATA ARE RATHER DETECTOR DEPENDENT.