共查询到20条相似文献,搜索用时 31 毫秒
1.
H. Kichimi M. Fukawa S. Kabe F. Ochiai R. Sugahara A. Suzuki Y. Yoshimura K. Takahashi T. Okusawa K. Tanahashi M. Teranaka O. Kusumoto T. Konishi H. Okabe J. Yokota 《Physics letters. [Part B]》1978,72(3):411-414
We have investigated inclusive Λ, and Σ±(1385) productions in 405 GeV/c pp interactions. The observed cross sections are σ(Λ)=4.05±0.39 mb, mb, σ(Σ+(1385))=0.74±0.17 mb and σ(Λ?(1385))=0.56±0.17 mb. production is dominant in a central region of ∣x∣≤0.4. The production ratio at ∣x∣≈0 is found to be 1.2±0.5. The excess, about 0.2 mb, of σ(Λ+(1385)) over σ(Λ?(1385)) is most likely attributed to proton fragmentations (∣x∣≥0.4), and gives an evidence for scaling. 相似文献
2.
W.D. Apel J. Ausländer H. Müller G. Sigurdsson H.M. Staudenmaier E. Bertolucci I. Mannelli G. Pierazzini P. Rehak A. Scribano F. Sergiampietri M.L. Vincelli 《Physics letters. [Part B]》1973,46(3):459-464
The ratio between the cross sections for the reactions and π?p → η→2γ n has been measured to be (2.4 ± 0.9) × 10?2, (2.1 ± 0.6) × 10?2 and (2.8 ± 1.3) × 10?2 at 3.8,6,8 and 12 GeV/c incident momentum respectively.At the same momenta the cross section for πt- p → neutrals is (1.48 ± 0.09) mb, (0.86 ± 0.05) mb, (0.64 ± 0.04) mb and (0.42±0.03) mb. 相似文献
3.
R. Sugahara F. Ochiai Y. Fukui A.M. Cooper M. Fukawa S. Kabe H. Kichimi A. Ono T. Sato A. Suzuki Y. Yoshimura K. Takahashi T. Okusawa K. Tanahashi S. Sasaki M. Teranaka O. Kusumoto T. Konishi 《Nuclear Physics B》1979,156(2):237-251
The inclusive production of Λ, KS0, Σ±(1385) and in π?p interactions at 6 GeV/c has been studied. The observed cross sections are: σ(Λ)=0.94±0.06 mb, σ(KS0)=0.98±0.06 mb, σ(Σ+(1385))=60±7 μb, σ(Σ?(1385))=90±9 μb, , respectively. The inclusive spectra of these particles are presented as functions of squared transverse momentum and Feynman scaling variable x. The polarization of Λ has also been investigated. It is found from a comparison with higher-energy data that the inclusive cross sections for Σ±(1385) and the production ratios Σ±(1385)/Λ in π?p at 6 GeV/c have not reached the high-energy limiting values. 相似文献
4.
V.K. Birulev V. Genchev N.N. Govorun T.S. Grigalashvili B.N. Guskov J. Hladky I.M. Ivanchenko V.D. Kekelidze D. Kiss V.G. Krivokhizhin V.V. Kukhtin M.F. Likhachev E. Nagy M. Novak A. Prokes Yu.I. Salomatin I.A. Savin L.V. Silvestrov J. Votruba 《Nuclear Physics B》1976,115(2):249-268
The energy dependence of the modulus and phase of the KL0-KS0 regeneration amplitude on hydrogen in the range of 14–50 GeV has been investigated at the Serpukhov 70 GeV accelerator.It has been established that the modulus of the modified regeneration amplitude decreases with increasing momentum as . The amplitude phase is energy-independent and its mean value is ?210 = ?132° ± 5°. The results obtained are compared with other experiments and with predictions of different theoretical models. 相似文献
5.
H.G. Kirk R. Schulte P. Sixel M. Klein M. Walter M.J. Counihan D.J. Kocher P. Kostka P.K. Malhotra D.R.O. Morrison H. Saarikko K.L. Wernhard K.W.J. Barnham R.M. Eason D.P. Dallman F. Mandl M. Markytan 《Nuclear Physics B》1976,116(1):99-117
The inclusive production of K?1(890) and K?1(1420) is studied in K??p interactions at 10 and 16 GeV/c. At 10 GeV/c an enhancement in the () mass distribution is found at 1.74 GeV, but no clear signal is seen at 16 GeV/c. The fraction of coming from decay of the is large, being (50 ± 6)% and (45 ± 5)% at 10 and 16 GeV/c, respectively. The inclusive cross sections for K1?(890) and production are almost constant with energy from 8 to 32 GeV/c with values of 3.5 and 3.3 mb, respectively. The production cross section is studied as a function of transverse and longitudinal variables and found to derive mainly from fragmentation of the incident K? meson. The spectra of resulting from the decay of are studied. 相似文献
6.
K. Böckmann J. Hofmann U. Idschok J. Lowsky B. Schröder V. Blobel H. Fesefeldt R. Schulte G. Kellner D.R.O. Morrison H. Saarikko T. Coghen 《Nuclear Physics B》1980,166(2):284-300
A study is presented of the inclusive production cross sections of K1±(892) vector mesons in pp interactions at 12 and 24 GeV/c and in π+p interactions at 16 GeV/c. The K1± inclusive cross section is ~0.9 mb for both pp at 24 GeV/c and π+p interactions at 16 GeV/c. For pp interactions, and are seen to rise with energy, showing a threshold behaviour. In both pp and π+p interactions, largely exceeds at these energies and this excess is interpreted as K1+ production by beam and target fragmentations. The decays of K1±0 yield ~30% of the K0 observed in the final states. The pT2 dependence of both K1+ and K1? cross sections is described by an exponential with slope of ~3.3 (GeV/c)?2. The longitudinal momentum spectra for K1+ in 16 GeV/cπ+p and 24 GeV/c pp interactions are similar in shape in the target hemisphere. The K1? spectra are similar over the whole kinematic region when viewed in the quark c.m.s. and point to a central production mechanism. Comparing K1+ and ρ0 production, striking similarities are found. 相似文献
7.
R.E. Ansorge C.P. Bust J.R. Carter W.W. Neale J.G. Rushbrooke C. Moore R. Raja L. Voyvodic R.J. Walker W. Morris B.Y. Oh D.L. Parker G.A. Smith J. Whitmore 《Physics letters. [Part B]》1975,59(3):299-302
Results are presented on the topological cross sections obtained for antiproton-proton interactions from an exposure of the Fermilab 30-inch bubble chamber to a 100 GeV/c negative beam enriched in 's. The p inelastic cross section is found to be σinel = 34.6 ± 0.4 mb, and the average inelastic charged particle multiplicity to be 〈n〉 = 6.74 ± 0.05. 相似文献
8.
W.D. Apel K.H. Augenstein M. Krüger H. Müller H. Schneider E. Bertolucci I. Mannelli G.M. Pierazzini M. Quaglia A. Scribano F. Sergiampetri M.L. Vincelli S.V. Donskov A.V. Inyakin V.A. Kachanov R.N. Krasnokutsky Yu.V. Mikhailov Yu.D. Prokoshkin G. Sigurdsson 《Physics letters. [Part B]》1977,72(1):132-134
New results on a high statistics measurement of pion-nucleon charge exchange scattering at 40 GeV/c, extending in momentum transfer up to ?t = 1.8 (GeV/c)2, are reported and compared with an optical impact parameter model, together with previous data for the reaction π?p → ηn at the same energy. The imaginary part of the pole trajectory b0(s) is determined from the slope of the tangent to the maxima of . The linear increase of Im b0(s) with log s, which has been observed at low energies, continues up to 40 GeV/c. 相似文献
9.
Results are reported on the reaction at six lab momenta spanning the region from 0.686 to 1.098 GeV/c. The cross section for this process drops from 5.2 ± 0.4 mb at 0.686 GeV/c to 2.9 ± 0.2 mb at 1.098 GeV/c. Resonance production is determined by means of a model which includes Bose symmetrization and Breit-Wigner amplitudes. The likelihood fit to the resonance channels yields a few per cent ?ππ, approximately 10% in each of the channels fππ, ??, and A2π, and about 40% ?f production, with errors on the order of 5%. Excellent fits to the mass distributions are obtained. Essentially all production and decay angular distributions are found to be uniform, with only a few small deviations from isotropy reported. The angular correlations between like and unlike charged pion pairs are also found to be fit extremely well by the simple model of resonance production with Bose symmetrization. 相似文献
10.
M. Ambrosio G. Anzivino G. Barbarino U. Becker G. Carboni V. Cavasinni T. Del Prete G. Kantardjian D. Lloyd Owen M. Morganti J. Paradiso G. Paternoster S. Patricelli M. Steuer M. Valdata-Nappi 《Physics letters. [Part B]》1982,113(4):347-352
We measured the elastic scattering of and of αp at . For αα, the differential cross section dσ/dt has a diffractive pattern minima at |t| = 0.10 and 0.38 GeV2. At small |t| = 0.05?0.07 GeV2, this cross section behaves like exp[(100 ± 10) t]. Extrapolating a fit to the data to the optical point, we obtained for the total cross section αtot(αα) = 250 ± 50 mb and an integrated elastic cross section σe1(αα) = 45 ± mb. Another method of estimating σtot(αα), based on measuring the interaction rate, yielded 295 ± 40 mb. For αp, dσ/dt has aminimum at |t| = 0.20 GeV2, and for 0.05 < |t| < 0.18 GeV2 behaves like exp[(41 ± 2) t]. Extrapolating this slope to |t| = 0, we found σtot(αp) = 130 ± 20 and σe1(αp) = 20 ± 4mb. Results on pp elastic scattering at agree with previous ISR experiments. 相似文献
11.
W. Bozzoli A. Bussière G. Giacomelli E. Lesquoy R. Meunier L. Moscoso A. Muller D.E. Plane F. Rimondi S. Zylberajch 《Nuclear Physics B》1979,159(3):363-382
A search for long-lived particles (τ ? 10?8 sec), with changes , produced in 200 GeV pN collisions was performed at the CERN-SPS in a secondary beam equipped with superconducting r.f. separators. Upper limits were obtained for the production of long-lived hadrons and leptons. For charge - 1 particles the limits are at the level of 10?7 of the pions at a mass m = 0.2 GeV and reach the 10?11 level from . The production of light antinuclei was measured. The cross sections for 3He production are (1.3 ± 0.3) and (1.9 ± 0.3) × 10?34 cm2/sr · GeV/c at 21 and 47.4 GeV/c respectively; for t the cross section is (7.6 ± 0.9) × 10?34 cm2/sr · GeV/c at 23.7 GeV/c. 相似文献
12.
R.R. Burns P.E. Condon J. Donahue M.A. Mandelkern L.R. Price J. Schultz 《Nuclear Physics B》1975,85(2):337-353
Results are reported on the reaction at six lab momenta spanning the region from 0.686 to 1.098 GeV/c. The cross section for this process drops from 20.3 ± 1.2 mb at 0.686 GeV/c to 13 1.0 mb at 1.098 GeV/c. Resonance production is determined by means of a model which includes Bose symmetrization, Breit-Wigner amplitudes and Bose-Einstein correlations for the like-charged pion pairs in the nonresonant part of the amplitude. The likelihood fit to the resonance channels yields about 0.8% ηππ, 12% ?±πππ, 2% fπππ, 8% ωππ, 22% ?±?0π, 13% ω?0 and 9% ωf with errors on the order of a few percent. Several percent A1±ππ and X(1440)π were also needed to obtain good fits. The ?0πππ and ?0?0π channels as well as A2ππ and A10ππ are consistent with zero. Reasonable fits to the mass distributions are obtained. Production angular distributions are found to be essentially uniform. The angular correlations between pion pairs are approximately fit by the simple model of resonance production with Bose symmetrization. 相似文献
13.
J.G. Rushbrooke R.E. Ansorge C.P. Bust J.R. Carter W.W. Neale C. Moore R. Raja L. Voyvodic R.J. Walker W. Morris B.Y. Oh D.L. Parker G.A. Smith J. Whitmore 《Physics letters. [Part B]》1975,59(3):303-307
New 100 GeV/cp data are used to find moments of the difference between the p and pp topological cross sections. The mean multiplicity for annihilations at 100 GeV/c is estimated to be 9.06 ± 0.56, and the value of the quantity 〈n〉/D to be 2.75 ± 0.33. It is shown that appears at 100 GeV/c to have acquired an asymptotic form, Rn = s?αβn, with α and β constant. 相似文献
14.
W.E. Cleland A. Delfosse P.-A. Dorsaz J.-L. Gloor M.N. Kienzle-Focacci G. Mancarella A.D. Martin M. Martin P. Muhlemann C. Nef T. Pal J. Rutschmann H. Zeidler 《Nuclear Physics B》1982,208(2):228-261
The mass and momentum transfer spectra of the charged system produced in the reaction π±p→Ks0K±p are analyzed. The data have been collected at the CERN SPS with the Geneva-Lausanne two-arm, non-magnetic spectrometer at 30 and 50 GeV/c incident momenta. The general features of the reactions at these energies and the results of partial-wave analyses of the two kaon system are presented.The channel is dominated by the diffractive production of even spin resonances. The spin 4 recurrence of the A2(1320) is clearly observed at 2040 MeV (Γ=380 MeV. A new resonance is observed with a mass M=2450MeV and a width Γ=400 MeV; the quantum numbers of this state are found to be IG(JPC)=1?(6++). The analysis also shows the decay of the decay of the meson ?′(1600) through the channel at both energies.The production amplitudes are determined both as a function of the effective mass and of the momentum transfer. Isoscalar natural parity exchange is dominant. The energy dependence between 10 and 50 GeV/c is shown to be well described by a Regge pole model based on the f-dominated pomeron hypothesis. We compare the production mechanisms of the 2+ resonances A2(1320) and K1(1430). Finally, we estimate the branching ratios of the spin 4 A2(2040) and spin 6 A2(2450) resonances. 相似文献
15.
16.
S. Sakai 《Physics letters. [Part B]》1974,48(5):427-430
The origin of the rise of p-p total cross section (σt(pp)) is investigated by making use of the inclusive sum rule. The contribution to the rise of σt(pp) from the development of sharp peak near the kinematical boundary in the process p+p→p+ “anything” is almost completely canceled out by the decrease of the cross section in other x-region between s=45 (GeV/c)2 and s=2820 (GeV/c)2. Then the net contribution to the rise of σt(pp) from the process p+p→p+ “anything” is very likely to be zero. The true origin of the rise of σt(pp) is found to be the increase of inclusive cross sections at x ? 0 between PS and ISR energies. The contribution from the process p+p→π+ “anything” at x ? 0 to the rise of σt(pp) is estimated to be 3.2 mb, that from the process p+p→K + “anything”, 0.71 mb and that from the process p+p→ “anything”, 0.62 mb. According to our conclusion we expect that all total cross sections will rise with energy at high energy. 相似文献
17.
K. Böckmann J. Hofmann U. Idschok B. Schröder V. Blobel H. Fesefeldt H. Franz 《Nuclear Physics B》1978,143(3):395-407
The inclusive production of Σ±(1385) is studied in pp interactions at 12 and 24 GeV/c. In this energy range, the inclusive cross sections for Σ+(1385) and Σ?(1385) rise from 0.20 ± 0.03 mb to 0.28 ± 0.03 mb and from 0.07 ± 0.02 mb to 0.12 ± 0.02 mb. The decays of Σ±(1385) account for ~20% of all observed Λ hyperons. The pT2 distributions are compatible with an exponential decrease and the slopes are in agreement with a common value of B ~ 3 (GeV/c)?2. The longitudinal spectra are significantly different: Σ?(1385) is mainly produced in the central region, whereas proton fragmentation contributes strongly to Σ+(1385) production. 相似文献
18.
C. Kourkoumelis L.K. Resvanis T.A. Filippas E. Fokitis A.M. Cnops S. Iwata R.B. Palmer D.C. Rahm P. Rehak I. Stumer C.W. Fabjan T. Fields D. Lissauer I. Mannelli P. Mouzourakis A. Nappi W.J. Willis M. Goldberg 《Physics letters. [Part B]》1979,84(2):277-280
The inclusive η production cross section at the CERN ISR has been measured for pT values of up to 11 GeV/c. We find that the cross-section ratio has an average value of 0.55 ± 0.07 and varies little with pT. 相似文献
19.
B. Alper H. Bℷgild P. Booth F. Bulos L.J. Carroll G. von Dardel G. Damgaard B. Duff F. Heymann J.N. Jackson G. Jarlskog L. Jonsson A. Klovning L. Leistam E. Lillethun G. Lynch G. Manning M. Prentice J.M. Weiss 《Physics letters. [Part B]》1973,46(2):265-268
Measurements have been performed on production of particles with mass 1.5 GeV/c2 and charge for θlab = 62.5° and . At pT = 0.7 GeV/c the relative rate of production of antideuterons to π? is (5 ± 1) × 10?5. The deuteron to antideuteron ratio is 3.7 ± 1.2. No new stable particle has been amongst 0.7 × 108 charged particles entering our detector. 相似文献
20.
J. Whitmore R.A. Lewis B.Y. Oh M. Pratap G.A. Smith J. Lach T. Kitagaki S. Tanaka H. Yuta K. Abe K. Hasegawa A. Yamaguchi T. Nozaki K. Tamai R. Kikuchi T. Maruyama Y. Unno S. Kunori J. Schneps 《Physics letters. [Part B]》1978,76(5):649-651
We present the results of a search for a resonance at 2.6 GeV decaying into KS0π±π+π? in the six-prong plus KS0 final state in 14.75 GeV/c interactions. We do not find confirming evidence, and with 95% confidence we quote an upper limit of σ·BR < 21 ub. 相似文献