共查询到20条相似文献,搜索用时 92 毫秒
1.
G.A. Akopdjanov V.V. Babincev B. Baccari P. Beilliere P.V. Chliapnikov M. Csejthey-Barth A. Daudin B. Deler T. Dombeck J.J. Dumont P.F. Ermolov A.B. Fenjuk U. Gensch L.N. Gerdyukov C. Ghesquiere H. Graessler S.A. Gumenyuk R. Windmolders 《Nuclear Physics B》1974,75(3):401-412
Topological cross sections are presented for K+p, K?p and interations at 32 GeV/c and for π+p and π?p interactions at 50 GeV/c observed in the 4.5 m Mirabelle hydrogen bubble chamber at Serpukhov. Parameters characterizing the behaviour of the multiplicity distributions, namely 〈nc〉, D and f2 and the normalized moments are given. The dependence of these parameters on the energy and the nature of the beam particle is discussed. The multiplicity distributions obtained cannot be described by a single function in the KNO variables. 相似文献
2.
V.A. Bumazshnov P.F. Ermolov A.S. Fenyuk E.P. Kistenev A.M. Moiseev E.A. Starchenko E.V. Vlasov H. Blumenfeld J. Derre M.A. Jabiol A. Leveque S. Otwinowski E. Pauli E.G. Boos L.A. Sanjko Nguyen Huu Khanh J. Quinquard M. Sene J. Klugow 《Physics letters. [Part B]》1974,50(2):283-286
Inclusive spectra of π? production for pp interactions are discussed at 69 GeV/c both in the central and in the fragmentation region and are compared to data at lower and higher energies. The pT dependence of the invariant structure function is also analysed. 相似文献
3.
V.V. Abramov B.Yu. Baldin A.F. Buzulutskov S.I. Bityukov B.Yu. Glebov A.S. Dyshkant V.N. Evdokimov A.N. Krinitsyn V.I. Kryshkin N.Yu. Kulman V.M. Podstavkov R.M. Sulyaev L.K. Turchanovich Yu.N. Vrazhnov V.V. Zmushko 《Physics letters. [Part B]》1982,112(2):170-172
The invariant cross-section slope of the pp→π+π?+X process as a function of pT is found to have a break near 1 GeV/c. Fitting the cross section by a sum of two exponents gives the values of powers (12.3±0.9)(GeV/c)?1 and (8.7±0.6)(GeV/c)?1. The experimental points at pT?1 GeV/c are significantly higher than predictions based on hard scattering models such as QCD and CIM. 相似文献
4.
I.V. Ajinenko P.V. Chliapnikov L.N. Gerdyukov V.M. Kubic B.A. Manyukov N.G. Minaev A.M. Rybin V.N. Ryadovikov M. de Beer M. Loret J.C. Scheuer J. Laberrigue N.K. Nguyen Z. Strachman C. Dujardin J. Kesteman J. Laurent F. Vandenbogaert 《Nuclear Physics B》1976,114(3):380-386
The average charged particle multiplicities, 〈nR(MX2)〉, in the reactions K+p → π?X and K+p → K0X at 32 GeV/c are studied as functions of the mass squared MX2 of the “associated” system X. A comparison with the corresponding results obtained at lower incident momenta is presented. 相似文献
5.
P.V. Chliapnikov L.N. Gerdyukov V.V. Kniazev A.I. Kurnosenko V.N. Riadovikov A.M. Rybin V.A. Uvarov A.P. Vorobjev E.A. De Wolf M. Gysen F. Verbeure M. Van Immerseel J. Laurent R. Windmolders 《Nuclear Physics B》1980,176(2):303-320
Inclusive ?0 and φ production is investigated in K+p interactions at 32 GeV/c. Total and semi-inclusive ?0 and φ cross sections, longitudinal and transverse momentum distributions, including 〈PT versus x dependence are presented. No evidence for a sea-gull effect is observed. Comparison with quark models strongly suggests the possibility that a large fraction of the ?0 and vector mesons are produced as fragmentation products of the incident particles. Study of uncorrelated π+π? pairs in the ?0 mass range provides possible indirect evidence for the existence of diquarks in the proton. 相似文献
6.
T. P. McPharlin D. O. Caldwell J. P. Cumalat A. M. Eisner D. L. Fancher R. J. Morrison F. V. Murphy T. R. Risser S. J. Yellin 《Physics letters. [Part B]》1980,90(4):479-484
Using 20.5 GeV electrons on protons, we measured inclusive π0's (of transverse momentum, pT, from 0 to 1.4 GeV/c) produced by virtual photons of energy, ν, from 4 to 16.5 GeV and four-momentum squared, q2, from ?1.8 to ?8.5 (GeV/c)2. Comparing with charged pion data, we find , supporting the quark model. Photon knockout of a quark is favored as the interpretation of these data because of scaling in z = Eπ/ν and similarity in z-dependence of other pion production data. Consistent with this interpretation are the dependence of 〈pT〉 on q2, the azimuthal dependence, and fits to the constituent interchange model. We also observe a possible pT?4 dependence at large |q2| over a limited pT range. 相似文献
7.
A.L.S. Angelis H.-J. Besch B.J. Blumenfeld L. Camilleri T.J. Chapin R.L. Cool C. Del Papa L. Di Lella Z. Dimčovski R.J. Hollebeek L.M. Lederman D.A. Levinthal J.T. Linnemann C.B. Newman N. Phinney B.G. Pope S.H. Pordes K.K. Young 《Physics letters. [Part B]》1980,94(1):106-112
As part of a study of large pT phenomena in photon-proton collisions at the CERN ISR, a search for direct single photon production has been performed. A statistical division of the data sample into the fraction consistent with single photon and the fraction due to multiphoton decays of neutral hadrons is accomplished by measuring the average conversion probability for the sample in a one radiation length thick converter. The fraction of the sample attributable to direct single photon production is 〈γ/all〉 = 0.074 ± 0.012 for 6 GeV/c < pT 10 GeV/c, and 〈γ/all〉 = 0.26 ± 0.04 for pT > 10 GeV/c, with an additional systematic uncertainty of ±0.05 for both values. 相似文献
8.
N.N. Biswas P.D. Higgins R.L. Bolduc J.M. Bishop N.M. Cason V.P. Kenney R.C. Ruchti W.D. Shephard B.Y. Oh G.A. Smith J. Whitmore E.W. Anderson H.B. Crawley A. Firestone W.J. Kernan J.W. Lamsa D.L. Parker 《Physics letters. [Part B]》1980,97(2):333-336
Charged pion production in high energy π-π- interactions is studied in the pT region of 1–2 GeV/c. The characteristics of pion production in π-π- interactions are compared with those in π-p and pp interactions. The pT dependence of pion production in these reactions follows a systematic trend which indicates that high-pT pion production for ππ interactions as well as for πp and pp interactions proceeds via quark-quark scattering as predicted by QCD. 相似文献
9.
P. Girtler G. Otter G. Rudolph H. Böttcher R. Nahnhauer J. Figiel D.R.O. Morrison K.L. Wernhard K.W.J. Barnham R.M. Eason B. Pollock B. Buschbeck M. Markytan W. Mitaroff J. MacNaughton H. Rohringer 《Nuclear Physics B》1979,156(2):189-206
A new method to calculate diffractive mass spectra has been developed. It is applied to K-p interactions at 10 and 16 GeV/c. Cross sections and mass spectra are given for the difractive dissociation processes p→(N+iπ) and K-p→(K+iπ) for i = 1 to 5 and also summed over all multiplicities. In addition to the diffractive peak at low mass coming from low multiplicities, a long tail extending to high masses and high multiplicities has been found. The multiplicity structure of diffraction dissociation can be understood in the context of the two-step dynamical picture of Pokorsky and Van Hove. 相似文献
10.
J. Antille L. Dick L. Madansky D. Perret-Gallix M. Werlen A. Gonidec K. Kuroda P. Kyberd 《Physics letters. [Part B]》1980,94(4):523-526
The spin dependence of π0 inclusive production by 24 GeV/c protons has been measured using a polarized target for Fhe Feynman x near 0 in the transverse momentum range 1.0 < pT < 2.5 GeV/c. The results indicate a negative updown asymmetry growing strongly with pT and greater than 50% in absolute value for pT greater than 2 GeV/c. 相似文献
11.
V. Blobel H. Fesefeldt H. Franz W.M. Geist K. Von Holt U. Idschok N. Schmitz 《Nuclear Physics B》1978,135(3):379-404
A method for the determination of neutron spectra in a bubble chamber experiment is developed. Double differential cross sections for inclusive neutron and lambda production are presented. The n/Λ particle ratios are determined as functions of x and pT; at pT = 0 GeV/c they are compatible with the ratios measured in pCu interactions at 24 GeV/c. Our neutron spectra are compared with spectra for protons produced near the direction of the incident neutron in pn interactions at FNAL and with neutron spectra measured in pp interactions at the ISR. Exchange mechanisms are studied in the framework of single diffraction dissociation and the triple-Regge model. The scattering of virtual pions and kaons on real protons is investigated. 相似文献
12.
W.J. Metcalf I.J.R. Aitchison J. LeBritton D. McCal A.C. Melissinos A.P. Contogouris S. Papadopoulos J. Alspector S. Borenstein G.R. Kalbfleisch R.C. Strand A. Abashian 《Physics letters. [Part B]》1980,91(2):275-279
We analyze data on the transverse momentum distribution of dimuons produced by 22 GeV and 16 GeV π? incident on a Cu target. We evaluate the quantum chromodynamic lowest order perturbation contributions and also introduce an intrinsic transverse momentum kT on the partons relative to their parent hadrons. The analysis of our data leads to 〈kT〉=0.30?0.35 GeV. We discuss our result in comparison with analyses of data at higher energies. 相似文献
13.
A. N. Vasiliev V. N. Grishin A. A. Derevschikov V. I. Kravtsov Yu. A. Matulenko V. A. Medvedev Yu. M. Melnik A. P. Meschanin D. A. Morozov V. V. Mochalov A. I. Mysnik L. V. Nogach S. B. Nurushev A. F. Prudkoglyad P. A. Semenov L. F. Soloviev V. L. Solovianov M. N. Ukhanov Yu. V. Kharlov V. Yu. Khodyrev B. V. Chujko K. E. Shestermanov A. E. Yakutin N. S. Borisov V. N. Matafonov A. B. Neganov Yu. A. Plis Yu. A. Usov A. N. Fedorov A. A. Lukhanin 《Physics of Atomic Nuclei》2004,67(8):1495-1504
Data on the single-spin asymmetry (A N) of inclusive π 0 production in 40-GeV pion interactions with a polarized target, π? + ↑→π0+X, are presented for the target-fragmentation region. The result is A N=(?13.8±3.8)% for ?0.8<x F0.4 and 1<p T<2 GeV/c and is compatible with zero for ?0.4<x F0.1 and 0.5<p T<1.5 GeV/c. At a π 0 momentum of about 1.7 GeV/c in the c.m. frame, the asymmetry becomes nonzero both in the central and in the target-fragmentation region. The behavior of the asymmetry is similar to that observed in the beam-fragmentation region of the E-704 (FNAL, 200 GeV) and STAR (BNL, 20 TeV) experiments, which employed a polarized proton beam. 相似文献
14.
Jan idký 《Fortschritte der Physik》1988,36(10):707-780
A compilation of fits to the low pT hadron distributions is presented. The universality of the distributions is examined. The pT distributians of direct pions and resonances in the reaction p p → 2π+2π−π0 at 5.7 GeV/c are fitted separately. Indications are found that up to ISR energies there are three types oflow pT inclusive hadron distributions in hadron-hadron interactions. The inclusive pT distributions of different particles are divided into these three groups according to the particle mass. 相似文献
15.
B. Alper H. Boggild G. Jarlskog J.M. Weiss P. Booth L.J. Carroll J.N. Jackson M. Prentice G. von Dardel G. Damgaard F. Bulos W. Lee G. Manning P. Sharp L. Leistam A. Klovning E. Lillethun S. Sharrock 《Physics letters. [Part B]》1973,44(6):527-529
Preliminary measurements have been made at centre of mass energies √s = 31 and 44 GeV of the π, K and p production ratios at 90° for pT between 2.0 and 3.5 GeV/c. The (K+p)/π ratio is given down to pT = 1.4 GeV/c. No strong energy dependence is observed for these transverse momenta. 相似文献
16.
17.
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
18.
Partial cross sections are presented for the various topologies in 13.1 GeV/c pp interactions. The transverse and c.m. longitudinal momenta distributions for nucleons and pions are given. The variation of〈pT〉 and are presented as a function of the multiplicity The best fit of the pT and distributions is obtained with functions suggested by the thermodyanamical model. The collimation and asymmetry parameters are given. Di-pions and tripions correlations are studied. 相似文献
19.
B. M. Abramov L. Álvarez-Ruso Yu. A. Borodin S. A. Bulychjov I. A. Dukhovskoy A. I. Khanov A. P. Krutenkova V. V. Kulikov M. A. Matsuk I. A. Radkevich A. I. Sutormin E. N. Turdakina M. J. Vicente Vacas 《Physics of Atomic Nuclei》2002,65(2):229-235
The spectra of fast π + mesons from the π ? A → π + X reaction on A=6Li, 7Li, and 16O nuclei at a primary momentum of p 0=0.72 GeV/c (T 0=0.59 GeV) are measured at emission-angle values in the range ?=0°–14°. The results obtained in this way are compared with experimental data taken in other studies at lower energies and with the results of model calculations. The energy dependence of the cross sections and of shadowing effects is analyzed for the reactions in question that occur on lithium isotopes. 相似文献
20.
Thomas S. Ullrich 《Acta Physica Hungarica A》2004,21(2-4):143-150
Inclusive spectra of charged particles at midrapidity in Au+Au collisions at $\sqrt {s_{NN} } = 130$ GeV and 200 GeV were measured with the STAR detector at RHIC. The measured mean transverse momentum 〈p T 〉 shows a characteristic dependence on charged particle multiplicity and beam energy in Au+Au collisions that is distinctly different from pp, $p\bar p$ and e+e? collisions. A 32%±3%(syst) increase in 〈p T 〉 from pp to Au+Au collisions was observed at 200 GeV. While the charged multiplicity was found to increase by 19%±5%(syst) from $\sqrt {s_{NN} } = 130$ GeV to 200 GeV, no significant difference in 〈p T 〉 was found between the two energies. A comparison with model predictions is discussed. 相似文献