共查询到20条相似文献,搜索用时 31 毫秒
1.
P. V. Chliapnikov L. N. Gerdyukov G. N. Khromova A. I. Kurnosenko V. N. Riadovikov G. I. Sorokin V. F. Tchunikhin V. A. Uvarov A. P. Vorobjev M. Barth E. A. De Wolf F. Verbeure F. Grard K. Kesteman CERN-USSR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1982,12(2):99-103
New experimental results are presented on inclusive production properties of \(\bar \Sigma ^{ * + } \) (1385) and \(\bar \Sigma ^{ * + } \) (1385) inK + p interactions at 32 GeV/c. The analysis is based on significantly larger statistics than previously available. A comparison is also made of invariantx-distributions ofK 0/ \(\bar K^0 \) , \(\bar \Lambda \) and \(\bar \Xi ^ + \) and of \(\bar \Sigma ^{ * \pm } \) (1385) andK *+(892). These spectra exhibit regularities expected from the quark-recombination picture when it is assumed that the strange mesons and antibaryons are produced off the strange \(\bar s\) -valence-quark in the incidentK + meson. Transverse momentum distributions are also presented forK *+(892) and \(\bar \Sigma ^{ * \pm } \) (1385) and found to be very similar. The results on strange antibaryon average multiplicities disagree strongly with a recent version of the additive quark model. 相似文献
2.
3.
R. Göttgens G. Ransoné P. Sixel R. Contri H. Drevermann Y. Goldschmidt-Clermont R. T. Ross S. Squarcia T. Coghen K. Dziunikowska P. Malecki K. W. J. Barnham J. Wells P. R. S. Wright M. Zomorrodian F. Kröner F. Mandl M. Markytan M. Bardadin-Otwinowska A. Jachołkowska M. Szczekowski 《Zeitschrift fur Physik C Particles and Fields》1982,12(4):323-331
Total and differential cross sections ofK *?(890),K *?(890), \(\bar K^{ * 0} \) (890),K *0(890), \(\bar K^{ * 0} \) (1430) and? 0(770) produced inK ? p interactions at 110 GeV/c are presented. The cross sections of the neutral resonances show a smooth increase with energy from 10 to 110 GeV/c incident momentum. For theK *+(890) and theK *0(890), i.e. the resonances with strangenessS=+1, this rise is quite significant: their cross sections practically double between 32 GeV/c and 110 GeV/c incidentK ? momentum. About 50% of the neutral kaons and 30% of charged pions produced inK ? p interactions at our energy are found to be decay products of the resonances considered. 相似文献
4.
E. A. De Wolf J. J. Dumont F. Verbeure I. V. Ajinenko P. V. Chliapnikov V. P. Falaleev L. N. Gerdyukov A. E. Kurnosenko V. N. Riadovikov V. F. Tchumikin V. A. Uvarov A. P. Vorobjev F. Grard CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1982,12(2):105-112
Results are presented on inclusive production of resonant and non-resonant particle systems produced inK + p interactions at 32 GeV/c. We compareK *+(892), \(\bar \Sigma ^{ * - } \) (1385), Σ*±(1385), and ?0 inclusivex-spectra with the ones of non-resonantK s 0 π±, \(\bar \Lambda \pi ^ - \) , Λπ± and π+π? pairs at the same effective mass. Resonance-particle pairsK *+π±, Σ*+π?, and \(\bar \Sigma ^{ * - } \pi ^ - \) are also studied together with non-resonant tripletsK s 0 π±, Λπ+π?, \(\bar \Lambda \pi ^ - \pi ^ - \) . The invariantx-spectra of resonant particle pairs decrease less rapidly withx then the corresponding non-resonant pairs. Comparison with quark-recombination predictions indicates that the particles, resonances and multiparticle systems are probably created off a single valence quark or diquark instead of carrying all possible valence-quarks. 相似文献
5.
CP violation in partial-decay-rate asymmetries are examined for some two-body baryonic decays of \(B_d^0 - \bar B_d^0 \) system. We discuss two feasible experimental circumstances: the symmetrice + e ? collisions (i) on theZ 0 resonance to produce incoherent \(B_d^0 \bar B_d^0 \) states, and (ii) just above the ?(4S) resonance to produceC=even \(B_d^0 \bar B_d^0 \) states. Using the quark-diagram scheme, we estimate the branching ratios of those decays, and the numbers ofb \(\bar b\) pairs needed for testing theCP-violating effects for 3σ signature. We find that the promising channels may beB d 0 , \(\bar B_d^0 \to p\bar p\) , \(\Delta ^ + \bar \Delta ^ - \) , \(p\bar \Delta ^ - \) , \(\Delta ^ + \bar p\) , \(n\bar n\) , \(\Delta ^0 \bar \Delta ^0 \) , \(n\bar \Delta ^0 \) , \(\Delta ^0 \bar n\) , \(\Sigma _c^ + \bar \Sigma _c^ - \) , \(\Lambda _c^ + \bar \Lambda _c^ - \) , \(\Sigma _c^ + \bar \Lambda _c^ - \) , \(\Lambda _c^ + \bar \Sigma _c^ - \) , \(\Sigma _c^0 \bar \Sigma _c^0 \) , \(\Xi _c^0 \bar \Xi _c^0 \) , which should be interesting for experimental observation. 相似文献
6.
J. Lemonnc G. Vanhomwegen J. Wickens V. M. Hagman P. Keski-Kuha J. Tuominiemi K. Valtonen J. A. Estruch P. Mason J. F. Baland C. Poiret G. Ekspong B. Sellden L. Szilly N. Yamdagni M. Bogoljubsky N. Ivanova A. Moiseev M. Ukhanov 《Zeitschrift fur Physik C Particles and Fields》1984,24(2):103-110
The inclusive production ofK s 0 , Λ and \(\bar \Lambda \) particles is investigated in 70 GeV/c \(\bar pp\) interactions in an experiment performed at CERN using BEBC equipped with a TST. Differential cross-sections are studied and compared with corresponding data at surrounding energies. Differences withpp data obtained at the same energy allow an estimate of theK s 0 , production cross-section in annihilation processes. Evidence is also given for central \(\Lambda \bar \Lambda \) production. 相似文献
7.
S. Furui 《Zeitschrift fur Physik C Particles and Fields》1990,46(4):621-635
\(N\bar N\) annihilation into three pseudoscalar mesons especially πππ and \(K\bar K\pi \) are studied in the quark pair creation model or the3 P 0 model in which two \(q\bar q\) pairs are annihilated and two \(q\bar q\) pairs are created with quantum numbers of the vacuum or3 P 0. The correlations of two pions to form ?,f 2 and the resonance AX(1565) which is recently found by the ASTERIX group are taken into account. A proper treatment of the symmetry among the three pions in the final state shows that the \({}^{31}S_0 p\bar p\) annihilation into ?π is suppressed in agreement with the experiment. We calculate the cosθ distribution or the distribution of the Dalitz plot as the function of the angle between the direction of emission of one decay pion in the resonance centre of mass and the line of flight of the resonance. The interferences of π+ρ+, π?ρ+ and π0ρ0 in the isospin 0 channels and π±ρ? and π0 f 2 in the isospin 1 channel reproduce the peaks. The cos θ distribution for the P-wave \(p\bar p\) annihilation into πAX depends strongly on the size of the pion since the amplitude interfers with the π±ρ? amplitude which is sensitive to the size of the pion. The same model qualitatively explains the \(p\bar p\) annihilation into \(K\bar K\pi \) in whichK or \(\bar K\) and π are correlated to formK* \(\bar K\) or \(\bar K\) *K final states. We can qualitatively reproduce different patterns of the cos θ distribution for theK *+ andK *0. 相似文献
8.
We interpret the recently observedU(3.1) mesons with the \(\Lambda \bar p\) + pions decays as the bound state of \(\Lambda ,\bar p\) andX 0(1480). TheX 0(1480) is a mesonium with \(Q^2 \bar Q^2 \) structures observed in γγ reactions and \(\bar pn\) annihilations. With this interpretation, we can understand its decay modes. Furthermore, we predict the ratio of \(\sigma (\Lambda \bar p\pi ^ + \pi ^ - )/\sigma (\Lambda \bar p\pi ^ + \pi ^ + )\) to be ?3.1 for centrally produced events and that the width of \(U^ - (\Lambda \bar p\pi ^ + \pi ^ - )\) to be greater than that of \(U^ + (\Lambda \bar p\pi ^ + \pi ^ + )\) . Both predictions seem to be in reasonable accord with the available data. We call for the detection of the \(\Lambda \bar p\pi ^ - \pi ^ - \) mode to verify the present interpretation. 相似文献
9.
U. Gensch R. Klein H. J. Schreiber M. Walter H. Graessler D. Kuhn D. R. O. Morrison F. Triantis R. Barloutaud C. Cochet D. Denegri M. L. Faccini-Turluer A. Givernaud E. P. Kistenev A. A. Minaenko D. I. Patalakha E. Kozlovsky J. Macnaughton France-Soviet Union Collaboration CERN-Soviet Union Collaboration 《Zeitschrift fur Physik C Particles and Fields》1979,2(1):7-10
Antilambda production is studied inK ? p interactions at 32 GeV/c. Both total and differential cross sections are presented. The inclusive \(\bar \Lambda \) production cross section amounts to 109±7 μb. A remarkable energy dependence is observed, σ( \(\bar \Lambda \) ) increasing by a factor of four between 14.3 and 32 GeV/c. Thep ⊥ 2 distribution exhibits an exponential fall-off with a slope of 3.3±0.2 (GeV/c)?2. Most of the \(\bar \Lambda \) 's are emitted in the forward hemisphere. The invariantx distribution increases between 14.3 and 32 GeV/c. Data are presented for \(\bar \Lambda \) production inK - p→Λ \(\bar \Lambda \) +X K - p→ \(\bar \Lambda \) K n +X, andK - p→ \(\bar \Lambda \) p+X. 相似文献
10.
The asymmetry parameters \(\alpha _{\beta ^ \mp } \) of the beta-ray emitted from aligned12B and12N are evaluated as a function of the energy. The agreement with experimental differential data is excellent for both \(\alpha _{\beta ^ - } \) (W) and \(\alpha _{\beta ^ + } \) (W). This work confirms, using available nuclear model information, that no induced pseudotensor (IPT) interaction is required for a correct theoretical interpretation of the data. An upper limit for the IPT coupling constantf T is determined from a simultaneous fit of \(\alpha _{\beta ^ - } \) (W) and \(\alpha _{\beta ^ + } \) (W). 相似文献
11.
Morimitsu Tanimoto Yoshirou Suetaka Kei Senba 《Zeitschrift fur Physik C Particles and Fields》1988,40(4):539-546
We study the mixings and CP violations in the \(B^0 - \bar B^0 \) system together with the \(K^0 - \bar K^0 \) one in the four-generation model, taking into account the ARGUS data for the \(B_d^0 - \bar B_d^0 \) mixing. We take typical six cases of the mixing hierarchy and search for the allowed regions of three phases in the 4×4KM matrix. The CP violating parameter ? K in the \(K^0 - \bar K^0 \) system gives a severe constraint for the phases, and the smaller mixing than that in the three-generation model is predicted for the \(B_s^0 - \bar B_s^0 \) system. The asymmetry parameters for the two-body non-leptonic decays of theB 0 and \(\bar B^0 \) mesons are also predicted. 相似文献
12.
Ch. de la Vaissière H. Muirhead S. N. Ganguli Ph. Gavillet M. Mazzucato C. Dionisi R. Blokzijl J. C. Kluyver G. F. Wolters E. W. Kittel M. Zralek B. Foster P. Grossman 《Zeitschrift fur Physik C Particles and Fields》1979,1(1):3-17
We have investigated the properties of off-shell \(\bar K\) K and \(\bar p\) p annihilations into pions by using the interactionsK ? p → Λ + pions at 4.2 GeV/c. The properties considered are multiplicities, hadronic temperatures and angular distributions. These properties appear more akin to those of \(\bar p\) p annihilations in flight than to that of \(\bar p\) p annihilation at rest despite the fact that the annihilation energy is small. 相似文献
13.
Kinoshita Kisei Minaka Akira Sumiyoshi Hiroyuki 《Zeitschrift fur Physik C Particles and Fields》1981,10(3):205-213
Inclusive and semi-inclusive production of Λ and \(\bar \Lambda\) inK + p interactions is studied at an incident momentum of 70 GeV/c. Cross sections and single particle distributions are presented and compared with data at lower energies. Scaling is observed between 32 and 70 GeV/c in the Feynmanx variable in the target and the beam fragmentation regions for Λ and \(\bar \Lambda\) inclusive production respectively. An increase of Λ ( \(\bar \Lambda\) ) production is observed in the beam (target) fragmentation regions, whereas the data at 70 and 32 GeV/c are reasonably close in the central region. The dependence of the Λ( \(\bar \Lambda\) ) polarization as a function ofx is measured and found to be in general agreement with the results at 32 GeV/c. The (Λ \(\bar \Lambda\) ) pair production cross section increases significantly from 32 to 70 GeV/c. The Λ and \(\bar \Lambda\) production associated with an identified proton is also studied. 相似文献
14.
S. Banerjee S. N. Ganguli P. K. Malhotra R. Raghavan K. Sudhakar 《Zeitschrift fur Physik C Particles and Fields》1979,3(1):1-8
We present a study of the inclusive production ofK *(892) and ∑t+-(1385)+cc at 3.6 GeV/c from \(\bar p\) p interactions. The sensitivity of the exposure is 35.4 events/μb. Longitudinal and transverse momentum distributions are presented. The indirect production ofK s 0 from parentK * and that of Λ's from parent Σ(1385) are studied. The shape of thex distribution of Λ's for \(p\xrightarrow{{\bar p}}\Lambda \) are calculated from \(p\xrightarrow{p}\Lambda \) and \(p\xrightarrow{{\pi ^ - }}\Lambda \) and compared with the experimental distributions. The difference of antiparticle production cross-section ofK s 0 in the central region is compared with the expectation from Mueller-Regge formalism. 相似文献
15.
S. F. Biagi M. Bourquin R. M. Brown H. J. Burckhart P. Extermann M. Gailloud C. N. P. Gee W. M. Gibson P. Jacot-Guillarmod J. Perrier K. J. Ragan Ph. Rosselet P. Schirato H. W. Siebert V. J. Smith K. P. Streit J. J. Thresher A. T. Wood C. Yanagisawa 《Zeitschrift fur Physik C Particles and Fields》1987,34(2):175-185
In an experiment at the CERN-SPS charged hyperon beam, we have investigated the inclusive \(\Lambda \bar K^0 \) and \(\Sigma ^0 \bar K^0 \) final states formed in Ξ? Be interactions. In the \(\Lambda \bar K^0 \) channel, we observe a signal at 1826 MeV/c2 which can be identified with the known Ξ(1820) resonance. We determine its mass and width to be:M=1826±4 MeV/c2, Г=12±14 MeV/c2. A moment analysis is consistent with a spin of 3/2 and indicates a negative parity for this spin assignment. Also in the \(\Lambda \bar K^0 \) channel, we observe a 3.6σ signal with the following parameters:M=1963±5 MeV/c2, Г=25±15 MeV/c2. This state, which we call Ξ(1960), is not observed in the \(\Sigma ^0 \bar K^0 \) channel, leading to an upper limit on the ratio of partial widths \(\Sigma \bar K/\Lambda \bar K\) of 2.3 (90% confidence level). A moment analysis of the \(\Lambda \bar K^0 \) final state indicates a spin of 5/2 or greater in the natural spin-parity series 5/2+, 7/2?, etc. 相似文献
16.
Hadron temperatures ofe + e ?→h \(\bar h\) from PEP experiments at 29 GeV are estimated using theP ⊥ distribution; rather small fluctuations are found for temperatures of π,K,..., Ξ with respect to the average \(\bar T = 196 \pm 7\) MeV. A semi-empirical formula including quark content ofh is proposed to account for multiplicities of π,K, ..., Δ in terms of a unique temperature \(\bar T\) . The formula is further extended to charmed particlesD, F, J/Ψ andΛ c without free parameters. The property \(\bar T\) ~E cm 1/4 holds for other experiments of DESY andCESR. 相似文献
17.
K. Hagiwara A. D. Martin M. F. Wade 《Zeitschrift fur Physik C Particles and Fields》1990,46(2):299-304
We show how data on \(\bar B \to M\tau \bar v\) can be used to probe models for the hadronic form-factors which describe the \(\bar B \to M\) transition, whereM isD,D * etc. Extra form-factors contribute to \(\bar B \to M\tau \bar v\) , as compared to \(\bar B \to Me\bar v\) , and these may be studied by observing the polarisation of the outgoing τ. Model predictions for the decay rate and the τ polarisation are presented. 相似文献
18.
By unfolding theγ-γ coincidence spectra from the reaction154Sm(12C, 4n)162Er at a beam energy of 64 MeV the mean energy of the continuousγ-ray spectrum feeding the ground state rotational band was determined as about 1.2 MeV. The averageγ-ray multiplicity \(\bar v\) including the rotational band transitions was measured for each of the levelsJ through which the cascade passed. The values for \(\bar v\) were found to increase regularly from \(\bar v = 8\) forJ=4 to \(\bar v = 14\) forJ=18. 相似文献
19.
Considering the signals detected at 4.03 and 4.16 GeV as radial excitations of charmonium, we study their relative decay rates intoD \(\bar D\) ,D \(\bar D^* \) ,D * \(\bar D\) ,D * \(\bar D^* \) . We point out that one can understand these two peaks as ac \(\bar c\) 3S?2D wave state system with a large mixing angle in a Coulomb+linear interquark potential. We also examine the possibility that these two signals are respectively 3S and 4S wave excitations by studying a logarithmic charmonium potential model. We show that both these interpretations lead to drastically different predictions for the Ψ (4.16) decay rates (eitherD \(\bar D^* \) +D * \(\bar D\) orD \(\bar D\) mode is strongly suppressed) which would be very instructive to test experimentally. 相似文献