共查询到20条相似文献,搜索用时 610 毫秒
1.
C.P. Bust J.R. Carter W.W. Neale J.G. Rushbrooke D.R. Ward R.E. Ansorge B.Y. Oh M. Pratap G. Sionakides G.A. Smith J. Whitmore R. Raja L. Voyvodic 《Nuclear Physics B》1978,140(3):409-422
We have investigated the reactions . The final state is dominated by diffractive production of a system which shows a strong tendency to form . The process is also observed in this reaction, indicating an energy dependence of s?1.5±0.1. The channel shows less single diffraction, and has a doubly diffractive component consistent with pomeron factorization. Strong Δ++(Δ++) production is agoain seen, but in contrast to the channel we also observe considerable ?0 production. 相似文献
2.
Y. Eisenberg A. Engler B. Haber U. Karshon G. Mikenberg S. Pitluck E.E. Ronat A. Shapira G. Yekutieli 《Physics letters. [Part B]》1974,52(2):239-242
Rare decay modes of the f meson are studied in the final states Δ++π+π?π+π?, Δ++π+π?MM and Δ++π+π?π+π?MM. The ratio is 0.23 ± 0.09 and Γ(f → 4 π) saturates the f inelasticity. A 2 s.d. upper limit of 0.09 is found for the branching ratio . 相似文献
3.
P.M. Heinen J.J. Engelen E.W. Kittel W.J. Metzger M.M. Schouten J.S.M. Vergeest R.T. Van De Walle B. Jongejans H. Voorthuis M. Cerrada R.J. Hemingway S.O. Holmgren M.J. Losty 《Nuclear Physics B》1977,122(3):443-463
A partial-wave analysis of the low-mass (π+π?p) system produced in the reaction K?p → K?(π+π?p) at 4.2 GeV/c incident momentum is performed in order to study the two (π+π?p) enhancements around 1500 and 1700 MeV. It is found that the low-mass (π+π?p) system can be described using the spin-parity states and only. In the 1500 MeV region contributions are observed from the wave decaying into p? and the wave decaying into Δ++π?; in the 1700 MeV region contributions are found from the wave decaying into Δ++π?, the wave decaying into p?, and the wave decaying into p?. 相似文献
4.
Y. Pons D. Denegri J.M. Laffaille M. Spiro B. Chaurand G. Labrosse R. Lestienne K. Paler C. Comber S. Tovey 《Nuclear Physics B》1977,123(3):349-360
We discuss the structure of the momentum transfer distributions for the diffractive dissociation processes p → nπ+, p → Δ++π? and . In the near-threshold mass region a clear break of slope is found around t′KK ~ 0.25 GeV2 for the two baryonic channels, whereas no comparable structure is seen for the mesonic system. The differential cross section exhibits a nearly exponential behaviour up to t′pp ~ 0.6 GeV2, falling over three orders of magnitude. The slope variations and breaks are strongly correlated both to the mass region considered and to the decay angle of the fragmentation system. 相似文献
5.
Yu.M. Antipov G. Ascoli R. Baud R. Busnello G. Damgaard M.N. Kienzle-Focacci W. Kienzle R. Klanner L.G. Landsberg A.A. Lebedev C. Lechanoine P. Lecomte M. Martin V.N. Roinishvili R.D. Sard A. Snyder F.A. Yotch 《Nuclear Physics B》1975,99(2):189-210
The reaction has been studied at 25 and 40 GeV/c at the Serpukhov proton synchroton using the CERN-IHEP spectrometer. The differential cross section has been determined as a function of four-momentum transfer to the proton (0.05–0.30 (GeV/c)2) and mass (up to 2.2 and 2.6 GeV/c2). At both energies there is a broad low-mass maximum with an enhancement at 1.6–1.8 GeV/c2. The cross section in a given mass band falls rapidly with |t|, with an exponential slope that decreases with increasing mass. In both the background and the 1.7 GeV/c2 peak there is a strong component. Possible spin-parity (JP) contributions to it are discussed. Throughout the range 1.5–2.2 GeV there is at least one state of and there is interference between states of opposite P, |ΔJ| ? 1. At the peak there is a component. There are striking parallels between this reaction and the boson reactions π?p→π?π?π+p and K? → K?π?π+p. 相似文献
6.
H. Braun J.-P. Gerber G. Maurer A. Michalon B. Schiby R. Strub D.M. Chew C. Ouannes Z. Strachman 《Nuclear Physics B》1975,95(3):481-502
A study of elastic scattering, one-pion production and annihilation reactions in p interactions at 5.7 GeV/c was carried out, from the two-prong events, obtained in the hydrogen bubble chamber exposed at CERN.Single particle distributions for the reactions and are presented. The study of the squared momentum transfer distributions with and without charge exchange in the cross channel shows different behavior of the slope parameters versus the mass of the produced (Nπ) system. The cross sections for isobar production and for diffractive dissociation in the one-pion production reactions are obtained from a detailed Dalitz plot analysis. The results of the analysis of the decay angular distributions for the N(1510) and for the N(1680) produced in these reactions are in agreement with assignment, respectively. The cross sections of the annihilation reactions are determined. Finally, we give some as aspects of the mass distributions for the last reaction. 相似文献
7.
J.N. Carney D.C. Colley M.F. James M. Jobes G.T. Jones J.B. Kinson K.M. Storr D.C. Watkins W. Dunwoodie A. Grant Y. Goldschmidt-Clermont F. Muller M. Nikolic Z. Sekera A. Stergiou 《Nuclear Physics B》1976,107(3):381-421
The reactions , and K+p → K0Δ++ have been systematically studied for eleven incident momenta between 3.0 and 16.0 GeV/c. Cross sections, differential cross sections and density matrix elements are presented. For K1(890) production the contributions from natural and unnatural parity exchanges have also been separated into I = 0 and I = 1 components. Effective trajectories have been extracted in the case of natural parity exchange, and also for Δ++ production. 相似文献
8.
T. Fujii T. Kondo F. Takasaki S. Yamada S. Homma K. Huke S. Kato H. Okuno I. Endo H. Fujii 《Nuclear Physics B》1977,120(3):395-422
The differential cross sections for γp→π+n from hydrogen and the ratios from deuterium were measured at nine c.m. angles between 30° and 150° for laboratory photon energies between 260 and 800 MeV. A magnetic spectrometer with three layers of scintillation hodoscope was used to detect charged π mesons. The cross section for γn→π?p was obtained as a product of and the ratio. The overall features in the cross sections of the two reactions, γp→π+n and γn→π?p, and in the ratios, , agree with predictions by Moorhouse, Oberlack and Rosenfeld, and Metcalf and Walker. An investigation of the possible existence of an isotensor current was made and a negative result was found. In detailed balance comparison with the new results on the inverse reaction π?p→γn, no apparent violation of time-reversal invariance was observed. 相似文献
9.
C. Bruneton J. Bystricky G. Cozzika J. Deregel A. Derevschikov Y. Ducros A. Gaidot M.Yu. Kazarinov V.P. Kanavets F. Khantine-Langlois B. Khatchaturov F. Lehar A. De Lesquen Yu. Matulenko J.P. Merlo A.P. Meschanin S. Miyashita J. Movchet J. Strachota 《Nuclear Physics B》1977,124(4):391-408
The differential cross sections for elastic scattering at 39 and 44.5 GeV/c, respectively, have been measured in the interval of momentum transfer squared 0.15 ≤ ovbt| ≤ 2 (GeV/c)2. 相似文献
10.
D. Denegri Y. Pons R. Barloutaud A. Borg C. Louedec M. Spiro K. Paler T.P. Shah S.N. Tovey B. Chaurand B. Drevillon G. Labrosse R. Lestienne R.A. Salmeron 《Nuclear Physics B》1975,91(1):54-68
We have studied the reaction K-p → K-π+π-π+π-p at 14.3 GeV/c to search for evidence of the double dissociation process . In the channel π1-π2-Δ++ (1236) there is evidence for simultaneous production of low-mass enhancements in the and Δ++(1236)π2- subsystems which correspond to the and decay modes. In this particular final state the double fragmentation system is produced with a cross section of the order of a few microbarns. Our data are consistent with the factorizable pomeron exchange model of double diffractive dissociation. 相似文献
11.
R. Davis R. Ammar W. Kropac H. Yarger B. Werner Y. Cho D. Johnson B. Musgrave T. Wangler 《Nuclear Physics B》1975,96(3):426-434
A search has been made for exotic states produced in K?d interactions at 5.5 GeV/c. The reactions investigated were: K?d→X??pp, and K?d→ M??Σ+p. Upper limits are set for the production cross sections. 相似文献
12.
A. Givernaud D. Denegri C. Lewin J. Prevost M.L. Turluer U. Kriegel U. Gensch J. Klabuhn M. Walter P. Sixel P. Porth F.A. Triantis Yu. Arestov M. Bogolyubsky M. Levitsky D. Patalakha J. MacNaughton 《Nuclear Physics B》1979,160(2):445-466
We present a systematic investigation of channel cross sections in K?p interactions at 32 GeV/c. The energy dependence of these cross sections is discussed. We also investigate a few non-diffractive two-body reactions. The total cross sections of the two reactions have a markedly different energy behaviour. There is clear evidence for the reaction ; its differnttial cross section exhibits a sharp forward slope of 24 ± 3 GeV?2. 相似文献
13.
R. Barloutaud A. Borg F. Brun D. Denegri C. Louedec F. Pierre M. Spiro B. Drevillon B. Chaurand G. Labrosse R. Lestienne D. Linglin R.A. Salmeron T.P. Shah K. Paler R.J. Miller J.J. Phelan 《Nuclear Physics B》1973,59(2):374-411
We have studied the system in the 14.3 GeV/c reactions K?p → K?π+π?p, . The data have been obtained from a 500 000 picture exposure of the CERN 2m HBC. The first two final states are dominated by Q-production in the Kππ system; there is also an L-signal at M (Kππ) ~ 1.75 GeV. The reaction cross sections are compared to K?p data at other energies. We discuss the Kππ mass dependence of the diffractive production slope. Evidence is presented for a Q?p versus Q+p differential cross section cross-over around |t| = 0.17 GeV2. A t-channel isospin analysis for the channels in the Q-region shows that the I = 1 exchange amplitude is of the dominant I = 0 exchange amplitude. The Kππ decay distributions indicate a predominant JP = 1+ state in the Q-region, and an important JP = 2? contribution in the L-region. We find neither s-channel nor t-channel helicity conservation at the meson vertex in the Q- or L-regions. The Kπ angular correlation moments within the Kππ diffractive system are characteristic of Kπ elastic scattering, suggesting a π-exchange Deck-type production mechanism. There is evidence for a Kf0 and κπ contribution (where κ is the JP(Kπ) = 0+ state) to the diffractive Kππ system. A fit to the Dalitz-plot distributions for the Q-re gion indicates that the ratio of decay amplitudes decreases with increasing Kππ mass. 相似文献
14.
D.B. Bastien M.F. Hodous R.I. Hulsizer A. Napier I.A. Pless J.P. Silverman J. Wolfson P.L. Bastien L.D. Kirkpatrick H.J. Lubatti 《Physics letters. [Part B]》1974,50(2):290-294
We have investigated the interaction at 5.1 GeV/c using the prism plot method. In addition to the final state, we isolate the three particle diffractive dissociation of the proton and antiproton into (pπ+π?) and respectively. We estimate this process accounts for 30% of the final state. 相似文献
15.
J. Boucrot B. Bouquet B. DAlmage A. Ferrer A. Jacholkowski A. Lahellec P. Petroff P. Roudeau J. Six F. Navach P. Sonderegger D. Treille P. Rivet A. Volte P. Benkheiri G. de Rosny A. Rouge R. Salmeron H. Yoshida 《Nuclear Physics B》1977,121(2):251-269
Negative results on backward production, via baryon exchange, of exotic non-strange mesons are presented. The reactions π?p→pforwardX?and π?n→ pforwardX?? have been studied with a 12 GeV/cπ? beam in the Omega spectrometer at CERN. No resonant peak in has been seen. The upper limits obtained on cross sections for exotic meson production are lower than the ?? backward production cross section in the π?p→p?? reaction; this result seems to contradict the predictions of the two-component duality model. Compared to already published experiments in the search for exotics produced via baryon exchange, the sensitivity of this experiment is increased by an order of magnitude. 相似文献
16.
A.A. Carter M. Coupland E. Eisenhandler C. Franklyn W.R. Gibson C. Hojvat D.R. Jeremiah P.I.P. Kalmus T.W. Pritchard M. Atkinson P.J. Duke D.T. Williams J.N. Woulds G.T.J. Arnison A. Astbury D. Hill D.P. Jones 《Nuclear Physics B》1977,127(2):202-241
The polarization parameter P for the reactions and has been measured over essentially the full angular range at ll laboratory momenta between 1.0 and 2.2. GeV/c, using a proton target polarized perpendicular to the scattering plane. The angles and momenta of both final state particles were determined from wire spark chambers, using the deflection caused by the polarized target magnet. Between 1000 and 5300 π?π+ events, and 140 and 1300 K?K+ events, were measured at each momentum. Differential cross sections for were obtained. These are in excellent agreement with previous results. The polarization parameter for both channels is very close to +1 over much of the angular range. Legendre polynomial fits to the data are presented. 相似文献
17.
18.
M.J. Corden J.D. Dowell D. Eastwood J. Garvey R.J. Homer M. Jobes I.R. Kenyon T. McMahon R.J. Vallance P.M. Watkins J.A. Wilson J. Gago M. Jung P. Sonderegger D. Treille P.L. Woodworth V. Eckardt J. Fent K.C.T.O. Sumorok 《Physics letters. [Part B]》1977,68(1):96-100
Measurements have been made of relative production cross sections of the by π±, K±, p and p? at 39.5 GeV/c incident on copper. production rates from π?, K? and p? are similar. The relative particle/anti-particle production cross sections for x>0 are , σ(K+)/σ(K?)=(0.85±0.5) and . The small p/p? cross section ratio disagrees with models of J/ψ production by gluon amalgamation. 相似文献
19.
A.A. Carter 《Nuclear Physics B》1978,141(4):467-476
The differential cross sections for provide new evidence for mesons with masses between 2.1 and 2.5 GeV/c2. The zeros of the cross sections suggest the existence of JP = 3? states with both I = 1 and I = 0 at masses between 2.1 and 2.18 GeV/c2. The results also support a JP = 4+ state near 2.34 GeV and are consistent with 5? states in both I = 1 and I = 0 close to 2.5 GeV. This analysis confirms the I = 1 3?, 5? and I = 0 4+ states seen previously in and is in agreement with the existing data for the non-annihilation processes. 相似文献
20.
An empirical investigation of data provides evidence for a dynamical variable connected with the boundary of the physical region. Absence of a fixed u = ?0.2 dip in recent high-energy data disagrees with nucleon-exchange (N) line-reversal expectations from π+p→pπ+ backward scattering. We notice however that the π+p→pπ+ dip is not located at fixed u but remains with a surprising accuracy at a fixed distance u' = u ? umin from the physical boundary. Conjecturing that dips associated with particle exchanges occur at fixed u', we predict that the N-exchange dip in will be considerably displaced at non-asymptotic energies. Our conjecture places the fixed u' = ?0.2 dip near for momenta around 2 GeV/c. Folded distributions exhibit a dip structure at this location. These observations suggest that the failure of line reversal at low energies is due to direct-channel effects, since fixed u' dips occur naturally in geometrical and direct-channel models. 相似文献