共查询到20条相似文献,搜索用时 140 毫秒
1.
A.O. Weissenberg O.K. Egorov Z.V. Minervina E.A. Pozharova V.A. Smirnitsky M.I. Dayon S.A. Krylov 《Nuclear Physics B》1976,115(1):55-60
The momenta of ~30 000 charged particles from K+ decays were measured using a magnetic spectrometer with streamer chambers. The ratio R = Γ(Kπ2+)/Γ(Kμ2+) = 0.3355 ± 0.0057 was obtained. Our values for the branching ratios are: (63.18±0.43)% for Kμ2+, (21.18±0.33)% for Kπ2+, (3.33±0.51)% for Kμ3+, (4.99±0.54)% for Ke3+. 相似文献
2.
S. F. Biagi M. Bourquin R. M. Brown H. J. Burckhart Ch. Doré P. Extermann M. Gailloud C. N. P. Gee W. M. Gibson R. J. Gray P. Jacot-Guillarmod P. W. Jeffreys T. Modis R. C. Owen J. Perrier K. J. Ragan Ph. Rosselet B. J. Saunders P. Schirato H. W. Siebert V. J. Smith K. P. Streit J. J. Thresher R. Weill A. T. Wood C. Yanagisawa 《Zeitschrift fur Physik C Particles and Fields》1986,31(1):33-38
In a experiment at the CERN SPS charged hyperon beam using incident Ξ?, we have obtained evidence for the production of two Ω* resonances decaying into Ξ?π+ K ?, with the following parameters:M 1=2251±12,Γ 1=48±20 MeV/c2, 78 ±23 events, andM 2=2284±12,Γ 2=26±23 MeV/c2 45±10 events. The first state is also observed as a 4.2σ effect in a subsample which contains an additionalK + orK 0 in the final state. Production cross sections and branching ratios to Ξ* K ? and Ξ? K * are presented. 相似文献
3.
H. Braun M. Cornelssen H.U. Martyn O. Erriquez S. Natali F. Romano D. Bertrand M. Csejthey-Barth J. Lemonne P. Renton P. Villain D.C. Cundy T.I. Pedersen D. Waldren 《Physics letters. [Part B]》1973,47(2):182-184
A sample of K+μ3 events, detected in the CERN 1.1 m3 heavy-liquid bubble chamber, has been used to investigate the q2 dependence of the form factors, giving ξ(0) = ?1.1 ± 1.0 and ξ(6.6m2π) = ?0.34 ± 0.20, for λ+ = 0.027. A three parameter fit gives a value for λ+ = 0.025 ± 0.017 in good agreement with the preceding Ke3 analysis. 相似文献
4.
A. Givernaud D. Denegri C. Lewin M. Loret L. Mosca J. Saudraix U. Gensch M. Walter M. Barth M. Van Immerseel F. Verbeure C. Dujardin R. Windmolders M. Yu. Bogolubski P. V. Chliapnikov M. S. Levitski D. I. Patalakha R. N. Riadovikov V. F. Tchunikhin A. P. Vorobjev B. Buschbeck H. Dibon M. Markytan J. Mac Naughton France-Soviet Union Collaboration CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1981,8(4):291-311
We present results of an investigation of diffraction dissociation in exclusive channels inK ± p interactions at 32 GeV/c. Total cross sections are determined forK ±→K ±π+π?,K ±2π+2π?,K 0π±π± K ±2π+π?,K ± K + K ?,K ±p \(\bar p\) , \(\bar \Lambda \) p, andp→pπ +π?,p2π+2π?,pK +K?,ΛK +,ΛK +π+π? dissociation modes, ranging from a high of ? 300 μb to ~ 3 μb. Thedσ/dt′ differential cross sections of most of the systems studied exhibit structure, with breaks of slope att′ ~ 0.2 to 0.5 GeV2; some modes have a sharp forward spike with a slope exceeding 10 GeV?2. A systematic investigation of two-body dissociation modesK→A+B andp→A′+B′ shows that these cross sections decrease with increasing threshold massM A+M B, that they are comparable for kaon and proton dissociations at similar diffractive excitation masses and are systematically suppressed by a factor 3–4 for dissociations requiring an \(s\bar s\) quark pair creation when compared to \(u\bar u\) pair creation indicating a breakdown ofSU 3 symmetry for the \(q\bar q\) sea. 相似文献
5.
A.M. Diamant-Berger P. Bloch B. Devaux N. Do-Duc G. Marel R. Turlay P. Extermann J. Fischer O. Guisan R. Mermod L. Rosselet R. Sachot 《Physics letters. [Part B]》1976,62(4):485-490
In a search for very rare decays of the K+ meson we observed the K+→μ+νe+e? and K+→e+ν e+e? modes with branching ratios of (10±3) ×10?7 and (2+2?2)×10?7 respectively. We also put new limits on a decay allowed by the alternate scheme of lepton conservation K+→π?μ+e+, on a decay with double charged weak current K+→π? e+e+ and on other forbidden decays K+→μ?νe+e+ and K+→π+μ±e±. 相似文献
6.
O. P. Yushchenko V. F. Kurshetsov A. P. Filin S. A. Akimenko A. V. Artamonov A. M. Blik V. V. Brekhovskikh V. S. Burtovoy S. V. Donskov A. V. Inyakin A. M. Gorin G. V. Khaustov S. A. Kholodenko V. N. Kolosov A. S. Konstantinov V. M. Leontiev V. A. Lishin M. V. Medynsky Yu. V. Mikhailov V. F. Obraztsov V. A. Polyakov A. V. Popov V. I. Romanovsky V. I. Rykalin A. S. Sadovsky V. D. Samoilenko V. K. Semenov O. V. Stenyakin O. G. Tchikilev V. A. Uvarov V. A. Duk S. N. Filippov E. N. Guschin Yu. G. Kudenko A. A. Khudyakov V. I. Kravtsov A. Yu. Polyarush V. N. Bychkov G. D. Kekelidze V. M. Lysan B. Zh. Zalikhanov 《JETP Letters》2018,107(3):139-142
Recent results from OKA setup concerning form factor studies in Ke3 decay are presented. About 5.25 M events obtained for decays of 17.7 GeV/cK+ are selected for the analysis. The linear and quadratic slopes for the decay form factor f+(t) are measured: λ'+ = 2.95 ± 0.022 ± 0.018 × 10 -2 for the linear slope fit and λ+ = 2.611 ± 0.035 ± 0.028 × 10 -2, λ"+ = 1.91 ± 0.19 ± 0.14 × 10 -3 for the quadratic one. The scalar and tensor contributions are compatible with zero. Several alternative parametrizations are tried: the Pole fit parameter is found to be M V = 891 ± 3 MeV; the parameter of the dispersive parametrization is measured to be Λ+ = 2.458 ± 0.018 × 10-2. 相似文献
7.
Penetration effects have been detected in205Tl by measuring theK, L and (M+N+...) internal conversion coefficients of the 204 keV, 3/2+→l/2+ transition. From the resulting values α K =0.29±0.04, α L =0.132±0.006 and α M+N+...=0.0397±0.0034 the penetration parameter and the mixing ratio have been deduced to be λ=13.1±2.7 andδ 2=1.40±0.46, respectively. 相似文献
8.
From the K±p forward B amplitude a new amplitude is constructed in such a way that its imaginary part can be calculated from the K±p polarization data. A prediction of the B amplitude is obtained and the hyperon coupling constants are determined with the result (GNΛK2+0.8GNΣK2)/4π = 12.2 ± 2.5. 相似文献
9.
J. Fischer P. Extermann O. Guisan R. Mermod L. Rosselet R. Sachot P. Bloch G. Bunce B. Devaux A.M. Diamant-Berger N. Do-Duc G. Marel R. Turlay 《Physics letters. [Part B]》1978,73(3):359-363
Using a magnetic spectrometer, we have studied 30 000 π0 → e+e?γ events coming from Kπ2+ decays in flight. We find a positive value for the slope of the neutral-pion electromagnetic form factor: a = +0.10 ± 0.03 (or a = +0.05 ± 0.03 without radiative corrections). This value is higher than the predictions of vector meson models. 相似文献
10.
A. S. Levchenko A. N. Khotjantsev A. P. Ivashkin M. Abe M. A. Aliev V. V. Anisimovsky M. Aoki I. Arai Y. Asano T. Baker M. Blecher P. Depommier M. Hasinoff K. Horie H. C. Huang Y. Igarashi T. Ikeda J. Imazato M. M. Khabibullin Yu. G. Kudenko Y. Kuno L. S. Lee G. Y. Lim J. A. Macdonald D. R. Marlow C. R. Mindas O. V. Mineev C. Rangacharyulu S. Shimizu Y. -M. Shin A. Suzuki A. Watanabe N. V. Yershov T. Yokoi 《Physics of Atomic Nuclei》2002,65(12):2232-2237
The form factors of the decay K + → π 0 e + ν e (K e3) have been determined from the comparison of the experimental and Monte Carlo Dalitz distributions containing about 105 K e3 events. The following values of the parameters were obtained: λ +=0.0278±0.0017 (stat.)±0.0015 (syst.), |f S/f +(0)|=0.0040±0.0160 (stat.)±0.0067 (syst.), and |f T/f +(0)|=0.019±0.080 (stat.)±0.038 (syst.). Both scalar f S and tensor f T form factors are consistent with the Standard Model predictions of zero values. 相似文献
11.
L. Baksay A. Böhm G.K. Chang R. Ellis H. Foeth S.Y. Fung A. Kernan J. Layter F. Muller B. Naroska B. Shen A. Staude P. Strolin V. Telegdi G. Trilling 《Physics letters. [Part B]》1976,61(4):405-408
The exclusive reaction pp→Λ°K+p has been studied at 0.1<?tpp<0.6 GeV2 and energies √s=45 GeV and 53 GeV at the CERN ISR. Diffractive excitation p→Λ°K+ occurs predominantly in the mass range M(Λ°K+)≈2.1 GeV and peaks at 1.7 GeV. The cross section for pp→Λ°K+p is 10±3μb for M(Λ°K+)<2.5 GeV, and the tpp dependence is exp (bt) with b=7.0±0.5 GeV?2. 相似文献
12.
M. Büscher R. Eßer A. Franzen L. v. Horn D. Kopyto H. Ohm H. Seyfarth K. Sistemich H. Müller B. Prietzschk B. Rimarzig C. Schneider C. Schneidereit A. Akindinov M. Chumakov V. Demechin V. Ergakov A. Gerasimov V. Goryachev Y. Kiselev V. Kostromin A. A. Sibirtsev V. Sopov V. Tchernyshev V. Kruglov A. Petrus V. Koptev S. Mikirtychyants 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):93-100
The production ofK + andπ + mesons and protons inpBe collisions atT p=2.9 GeV has been studied at the ITEP proton synchrotron. Ejectiles with a momentum ofp=545 MeV/c were observed under an emission angle ?=17°. The detectors which have been developed for the identification of kaons out of a six orders of magnitude more intense background of pions and protons are described. A cross-section ratio d2σ K +/dΩdp: d2 σ p /dΩdp: d2σ p /dΩdp of (1±0.34):(85±1):(31±1) has been measured. Normalization with existing pion data yields an invariant differential cross sectionE·d3σ K +/d3 p=(3.1±1.2) mbGeV?2c3sr?1 and a total cross section of σtot(pBe)=(3.7±1.5) mb. These cross sections are compared with existing data and theoretical predictions. TheA dependence ofK + production in the few-GeV range is analyzed. 相似文献
13.
J. Saudraix D. Denegri M. Loret L. Mosca J. C. Scheuer Z. Strachman I. V. Ajinenko Y. A. Belokopitov P. V. Chliapnikov P. A. Gorbunov V. N. Riadovikov A. P. Vorobjev C. Dujardin F. Grard J. Laurent R. Windmolders M. Barth E. A. De Wolf F. Verbeure France-Soviet Union Collaboration CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1980,5(2):105-116
We study single and double inclusive diffractive production in a 32 GeV/c K + p experiment in MIRABELLE at the Serpukhov accelerator. From reactionsK + p→K ++X + andK + p→X ++p we determine the total proton and kaon single diffractive dissociation cross sections \(\sigma (p\xrightarrow{{K^ + }}p_D ) = 0.90 \pm 0.12 mb\) and \(\sigma (K^ + \xrightarrow{p}K_D^ + ) = 0\) . 90±0.17 mb, respectively. In either case the only notable contributions come from dissociations into 1 and 3 charged particles. Kaon dissociation exhibits a pronounced slope-mass correlation. The search for double diffractive production in reactionsK + p→(K +π?π+)+X + andK + p→(pπ + π ?)+X + leads in either case to an estimated total double diffractive cross section σ(K +p→K D + pD) of ?220 μb. The double dissociation differential cross section exhibits a large slope of ?10GeV?2 in the nearthreshold mass region, rapidly decreasing to ?4 GeV?2 with increasing excitation mass. At our c.m. energy \((\sqrt s \simeq 8 GeV)\) the ratio σinel dif/σel is 0.85±0.10, the total diffractive cross section σdif≡σel+σinel dif=4.41±0.24 mb and the fraction σdif(K + p)/σtot(K + p) is 25±2%. TheK + andK ? diffractive excitation mass spectra, differential cross sections and total diffractive cross sections are very similar for both single and double dissociations. 相似文献
14.
Johann Wolfgang Hammer 《Zeitschrift für Physik A Hadrons and Nuclei》1968,216(4):355-371
The electron capture decay of Mn 54 and Zn 65 was investigated using Na I(Tl)-detectors. Spectroscopic-coincidence techniques were employed to examine theK-electron capture rates of Mn 54 and Zn 65, the branching ratio and positron rate of Zn 65. The experimental results are:P k ω k (Mn)=0.2492±0.0017,P k ω k (Zn)=0.3927±0.0026,EC * /EC 0(Zn)=53.2±1.0/46.8±1.0,γ/β +=35.1±1.7,K 0/β +=27.7±1.5. Thus electron capture to the excited state of Cu 65 occurs to the extent of 52.4±1.0% while electron capture and positron decay to the ground state were found to be associated with 46.1±1.0% and 1.49±0.05% of the disintegrations. These data partly disagree significantly from measurements of other authors. Using the fluorescence yieldsω k (Cr)=0.279 andω k (Cu)=0.4425, deduced from other measurements, values ofL+M/K of electron capture to the excited state could be derived:L+M/K(Mn 54)=0.120±0.015 andL+M/K(Zn 65)=0.127±0.015. These ratios agree with the calculations ofBahcall. The half-lives of Mn 54 and Zn 65 have been determined to beT 1/2(Mn 54)=312±5d,T 1/2(Zn 65)=243±4d The energy of the Zn 65-γ-rays was measured with a Ge(Li)-counter:E γ=1115.5±0.5 keV. 相似文献
15.
A.O. Weissenberg O.K. Egorov Z.V. Minervina E.A. Pozharova S.V. Skachkov V.A. Smirnitsky M.I. Dayon V.A. Euschenko S.A. Krilov 《Physics letters. [Part B]》1974,48(5):474-478
About 100 000 K+-decays were observed in a magnetic spectrometer with streamer chambers. The estimation for the radiative decay K+→μ+νμγ, Rexp = [W(K+→μ+νμγ)]/[W(K+→all)]=(5.8±3.5) x 10?3, at Eγ ? 9 MeV was obtained and the ratio R = [W(K+→π+π°)]/[W(K+→μ+νμ)] = 0.328 ± 0.005 was measured. 相似文献
16.
P. V. Chliapnikov L. N. Gerdyukov V. V. Kniazev V. N. Riadovikov A. M. Rybin O. G. Tchikilev V. F. Tchunikhin V. A. Uvarov A. P. Vorobjev M. Barth E. De Wolf M. Gijsen F. Verbeure C. Dujardin F. Grard R. Windmolders CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1980,3(4):285-287
Evidence is provided for a new resonance in theK s 0 K s 0 π+π? system with a mass of 1.97±0.01 GeV and width 40±20 MeV. It is produced with an inclusive cross section of ~6μb in the beam fragmentation process of 4-prongK + p interactions with at least 2 associatedV 0's at 32 GeV/c and decays dominantly into theK * ± (892)K s 0 π? mode. 相似文献
17.
S. Banerjee S. Beri S. N. Ganguli A. Gurtu P. K. Malhotra R. Raghavan A. Subramanian T. K. Chatterjee S. Dorje J. M. Kohli I. S. Mittra J. B. Singh P. M. Sood 《Zeitschrift fur Physik C Particles and Fields》1988,41(1):17-24
We have studied 70 GeV/cK + d interactions from about 10 K events. The inelastic cross-section for three or more prongs is found to be (28.9±0.4) mb. From odd-and even-prong topologies we have extracted topological break-up ofK + n interactions by taking into account spectator corrections, rescattering effects and Glauber screening. The rescattering fraction is found to be 0.06±0.01 which is substantially different from pion and proton interactions. Combining ourK + n data with other existing π± n andp ±n we find〈n ch 〉 ph ?〈n ch 〉 hn =0.33±0.04 andD/〈n ch 〉=0.529±0.003. 相似文献
18.
R. Brandelik W. Braunschweig K. Gather V. Kadansky K. Lübelsmeyer P. Mättig H.-U. Martyn G. Peise J. Rimkus H.G. Sander D. Schmitz A. Schultz von Dratzig D. Trines W. Wallraff H. Boerner H.M. Fischer H. Hartmann G. Zobernig 《Physics letters. [Part B]》1980,94(1):91-95
Inclusive K0-production has been measured in e+e- annihilation at a center of mass energy of about W = 30 GeV. The ratio of K0 + K0 production to μ+μ- production is RK0 = 5.6 ± 1.1 (statist. error) ± 0.8 (system.error) This value is about a factor of three higher than RK0 at W = 7 GeV. The cross sections (s/β) dσ/dx is consistent with a scaling behaviour. 相似文献
19.
Ts. Venkova T. Morek G. V. Martí H. Schnare A. Krämer-Flecken W. Gast A. Georgiev G. Hebbinghaus R. M. Lieder G. Sletten K. M. Spohr K. H. Maier W. Urban 《Zeitschrift für Physik A Hadrons and Nuclei》1993,344(4):417-423
Two new isomers have been observed in180Os. A high-K isomer withI, K ≧20 and a half-life ofT 1/2=12+4 ns have been established. It deexcites via two transitions into the 18+ level of the yrare band indicating an unusually smallK-hindrance factor. Evidence for an isomer withI, K>16 and a half-life ofT 1/2=41±10 ns was found. A half-life of 17±3 ns was measured for the previously known 7? state at 1862 keV. The decay scheme of the previously known 7? isomer at 1928 keV has been extended and a revised version is presented. 相似文献
20.
We remark that, using the Cabibbo transformation properties for the weak Hamiltonian we can obtain Δ0 = δ0(0) (s = MK(2) (s = MK2) from the experimental decay rates for Ks → 2π, K+ → π0π+, obtaining δ0 = 58.0° ± 4.6°. This result implies in particular a value of ≈ 0.6 for the S-wave isospin zero scattering length, in accordance with Ke4 results but in violent disagreement with Weinberg's calculation. 相似文献