共查询到20条相似文献,搜索用时 76 毫秒
1.
T. F. Hoang 《Zeitschrift fur Physik C Particles and Fields》1991,49(1):109-114
The rapidity distributions of inclusive +
p –,K
0, 0 andK
* (892) atP
1ab=16 GeV/c of CERN experiments, are analyzed using the covariant partition temperatureT
p model. In the fireball system, apart fromK
* (892),T
p
*
m, no indication of thermal equilibrium, the average momentum
ofK
0 and
0 being approximately equal and in the opposite direction, the entropy density is practically the same forK
0 and
0 but less than that of –. It is found that the principle of equipartition holds rather for the momenta of ,K, and in the fireball system. 相似文献
2.
M. Aguilar-Benitez M. C. Albajar A. Ferrando J. A. Rubio J. Salicio I. Sjögren S. Rodebäck S. O. Holmgren R. Armenteros C. Dionisi Ph. Gavillet M. J. Losty P. F. Loverre M. Mazzucato L. Dobrzynski D. Pennino 《Zeitschrift fur Physik C Particles and Fields》1980,6(2):109-123
The reactionsπ ?p→K 0 ∑ 0(1385) andπ ? p→K + ∑ ?(1385) are studied at an incident momentum of 3.95 GeV/c using data from a high statistics bubble chamber experiment corresponding to approximately 90 events/μb. The total and differential cross sections and the density matrix elements of the Σ(1385) are presented. The results are compared with those obtained for the related processesπ pp→K + ∑ +(1385) and \(K^ - p \to \pi ^ \mp \sum ^ \pm (1385)\) in this energy range. Evidence is presented for the existence of production mechanisms with exotic exchanges in thet channel. 相似文献
3.
D. V. Amelin Yu. G. Gavrilov Yu. P. Gouz V. A. Dorofeev R. I. Dzhelyadin A. M. Zaitsev A. V. Zenin A. V. Ivashin I. A. Kachaev V. V. Kabachenko A. N. Karyukhin A. N. Konoplyannikov V. F. Konstantinov V. V. Kostyukhin V. D. Matveev V. I. Nikolaenko A. P. Ostankov B. F. Polyakov D. I. Ryabchikov A. A. Solodkov A. V. Solodkov O. V. Solovianov E. A. Starchenko A. B. Fenyuk Yu. A. Khokhlov 《Physics of Atomic Nuclei》2004,67(7):1408-1415
Results obtained by investigating the reaction π ? p → η′π 0 n at the VES spectrometer (Institute for High Energy Physics, Protvino) are presented. The effective-mass spectrum and angular distributions of η′π 0 events are compared with their counterparts for ηπ 0 and η′π ? events selected from the same data sample. The ratio R of the branching fractions for the decays of a 2 0 (1320) mesons into η′π and ηπ is measured. The result is R=0.047±0.018, which agrees with the value measured previously for a 2 ? . An investigation of P-wave production in the η′π 0 and ηπ 0 systems over the effective-mass interval 1.45–1.9 GeV/c2 leads to the conclusion that the coupling of the exotic object π 1 (1600) to the ρπ channel is suppressed in relation to its coupling to the η′π or the b 1(1235)π channel. 相似文献
4.
V. Karimäki R. Kinnunen M. Korkea-aho J. Tuominiemi G. W. van Apeldoorn D. Harting D. J. Holthuizen B. J. Pijlgroms P. Johnson P. Mason P. Michaelides Ch. Michaelidou H. Muirhead G. D. Patel G. Ekspong T. Moa S. Nilsson 《Zeitschrift fur Physik C Particles and Fields》1981,9(2):117-129
Inclusive production of ?0,K *±(892), andf is studied in \(\bar p\) p interactions at 12 GeV/c. The inclusive cross sections for ?0,K *±(892), andf are found to be 6.7±0.3 mb, 1.0±0.2 mb, and 1.4±0.3 mb, respectively. The differential cross sections are presented as a function of c.m. rapidity, Feynmanx and square of the transverse momentump T 2 . Comparison with the correspondingpp data shows some interesting differences which can be attributed to the \(\bar p\) p annihilation. The results are compared with the predictions of the quark fusion model. 相似文献
5.
D. Alde F. G. Binon M. Boutemeur C. Bricman S. V. Donskov M. Gouanère A. V. Inyakin V. A. Kachanov G. V. Khaustov E. A. Knapp A. V. Kulik G. L. Landsberg A. A. Lednev J. P. Peigneux S. A. Polovnikov M. Poulet Yu. D. Prokoshkin S. A. Sadovsky V. D. Samoylenko P. M. Shagin A. V. Shtannikov A. V. Singovsky J. P. Stroot V. P. Sugonyaev 《Zeitschrift fur Physik C Particles and Fields》1992,54(4):549-551
The production of
0 system in
–
p
charge-exchange interactions at
– momenta 38 GeV/c and 100 GeV/c has been studied. The 2 and
0
0 decay modes of
leading to 4 and 8 final states respectively have been detected. No statistically significant peak is observed in the
0 mass spectrum in the range of 1.2 GeV÷2.1 GeV. An upper limit of 6·10–3 has been established for thea
2
0
(1320)
0 branching ratio. 相似文献
6.
Significant mixing is expected between the neutral bottom mesons \(B_s^0 - \bar B_s^0 \) in the standard model of weak interactions. We propose measurements of the processes \(\left\{ {\begin{array}{*{20}c} {e^ + e^ - } \\ {p\bar p} \\ \end{array} } \right\} \to \begin{array}{*{20}c} {b\bar b} \\ {} \\ \end{array} \to l^ + K^ - K^ - X\) as a measure of such mixing. Rates are presented for energetic bottom quark jets, produced ine + e ? annihilation. 相似文献
7.
T. A. Armstrong R. P. Barnes M. Benayoun W. Beusch I. J. Bloodworth J. N. Carney D. DiBari C. J. Dodenhoff C. Evangelista D. Evans B. Ghidini B. R. French M. Girone A. Jacholkowski J. B. Kinson A. Kirk K. Knudson V. Lenti V. Manzari F. Navach A. Palano E. Quercigh M. Sené R. Sené G. Vassiliadis O. Villalobos Baillie M. F. Votruba 《Zeitschrift fur Physik C Particles and Fields》1992,54(3):371-376
The reactionppp
f
(
+
–
)p
s
, where the
+
–
system is centrally produced, has been studied at 300 GeV/c. The
+
–
mass spectrum shows evidence for a
0
decay mode of the (958) andf
1 (1285). The branching ratio (f
1(1285)
+
+)/(f
1(1285)
0
) is found to be 5.0±0.7. No evidence is found for a
0(770) decay mode of theE/f
1 (1420) for which an upper limit BR (E/f
1(1420)
0
)<0.08 at=" 95%=" cl=" is=">0.08> 相似文献
8.
L. I. Buravov 《Russian Physics Journal》2009,52(1):25-32
Masses of a number of elementary particles are calculated on the basis of the model suggested in [1] with the use of one parameter. In this model, an electron is considered as an electric cloud enclosed inside an elastic
lepton shell, electron neutrino ν
е
is considered as an elastic lepton shell contracted to a minimal size, and muon, pion and kaon are considered as resonators
for quanta of virtual neutrinos excited inside the elastic lepton shell. The number and type of these quanta are determined
from the decay scheme for μ, π, and K: 2 for the muon (ν
е
and ), 3 for the pion (ν
е
,
ν
μ, and ), and at least 21 for the kaon. The model allows mass ratios approximating the experimental data for these particles to be
obtained for the first time, with the ratio of μ and е masses equal to (6πℏс/е
2)2/3 ≅ 188, the ratio of π
0 and μ masses equal to (3/2)2/3, and the ratio of K
0 and π
0
equal masses to 72/3. The calculated e, μ
,
π
0, and K
0 masses are in the 0.547:105.707:134.963:493.87 (MeV) ratios (normalized by the neutral pion mass). This is in good agreement
with the available experimental data. The mass ν
е
(≅ 0.02 eV) is also estimated in this model, and the variety of K-meson decay schemes is naturally explained as a result of the variety of excited intrinsic neutrino field structures with
the same energy.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 23–29, January, 2009. 相似文献
9.
10.
M. R. Atayan I. V. Ajinenko Yu. A. Belokopytov H. Böttcher F. Botterweck M. M. Chapkin P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska A. M. F. Endler Z. G. Garutchava G. R. Gulkanyan P. van Hal T. Haupt J. K. Karamyan Z. A. Kirakosyan D. Kisielewska W. Kittel S. S. Megrabyan F. Meijers A. B. Michałowska I. V. Nikolaenko K. Olkiewicz V. M. Ronjin A. M. Rybin E. K. Shabalina L. Scholten O. G. Tchikilev A. G. Tomaradze L. A. Tikhonova V. A. Uvarov F. Verbeure R. Wischnewski S. A. Zotkin 《Zeitschrift fur Physik C Particles and Fields》1991,50(3):353-360
Using the ARGUS detector at thee
+
e
– storage ring DORIS II at DESY, we have measured the inclusive production ofD
0,D
+ andD
*(2010)+ mesons inB decays and in nonresonante
+
e
– annihilation around 10.6 GeV. The inclusive branching ratios forB decays toD
0,D
+ andD
*+ mesons are found to be (52.2±8.2±3.5)%, (27.2±6.3±3.5)% and (34.8±6.0±3.5)% respectively. Thus,D
0 andD
+ production account for about 70% of the charm produced inB decays, neglectingbu contributions to the total width. The production cross sections and momentum spectra for continuume
+
e
– annihilation are also presented.Supported by the German Bundesministerium für Forschung und Technologie, under contract number 054DO51P 相似文献
11.
J. Lindfors 《Zeitschrift fur Physik C Particles and Fields》1987,35(3):355-360
We presentW/Z-parton luminosities 1/s d L/dτ in the TeV energy region for suche + e ?,ep andpp collision processes where the intermediate vector bosonsW ± orZ 0 are in the initial state. 相似文献
12.
G. A. Akopdzhanov V. B. Anikeev V. A. Bezzubov I. A. Vasilyev Yu. V. Gilitsky S. N. Gurzhiev S. P. Denisov A. A. Durum S. A. Zvyagintsev A. V. Kozelov E. A. Kozlovsky V. M. Korablev V. I. Koreshev V. I. Kurbakov V. V. Lipaev V. A. Onuchin A. M. Rybin Yu. M. Sapunov M. M. Soldatov D. A. Stoyanova K. I. Trushin A. A. Schukin V. I. Yakimchuk 《Physics of Atomic Nuclei》2008,71(12):2074-2086
K ± → e ± νπ 0 decays have been studied using the KMN setup at the Institute for High Energy Physics (Protvino). The experiment has been performed in the 36-GeV/c hadron beams of the IHEP accelerator. The accumulated data allow us to select ~1.08M candidates for K e3 decays. Analyzing the Dalitz plot of these events, we estimate the linear slope of the charge form factor to be λ + = [30.44 ± 0.83(stat.) ± 0.74(syst.)] × 10?3. 相似文献
13.
14.
The problem of the ρ
±−ρ
0mass splitting is discussed. It is suggested to use the φ→ρπ→3π decay to measure the ρ
±−ρ
0 mass splitting.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 1, 8–11 (10 January 1999)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
15.
Hoi CT Chang P Aihara H Asner DM Aushev T Bakich AM Belous K Bhardwaj V Bhuyan B Bischofberger M Bondar A Bozek A Bračko M Browder TE Chang MC Chao Y Chen A Chen KF Chen P Cheon BG Chilikin K Cho K Choi Y Danilov M Drásal Z Drutskoy A Eidelman S Fast JE Gaur V Gabyshev N Goh YM Golob B Haba J Hayasaka K Hoshi Y Hou WS Hsiung YB Hyun HJ Inami K Ishikawa A Iwabuchi M Iwasaki Y Iwashita T Kang JH Kawasaki T Kim HJ Kim HO Kim JB Kim JH Kim KT Kim MJ Kinoshita K Ko BR Kobayashi N Kodyš P Korpar S 《Physical review letters》2012,108(3):031801
We report measurements of the branching fractions and CP asymmetries for B(±)→ηh(±) (h=K or π) and the observation of the decay B(0)→ηK(0) from the final data sample of 772×10(6) B ?B pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. The measured branching fractions are B(B(±)→ηK(±))=(2.12±0.23±0.11)×10(-6), B(B(±)→ηπ(±))=(4.07±0.26±0.21)×10(-6), and B(B(0)→ηK(0))=(1.27(-0.29)(+0.33)±0.08)×10(-6), where the last decay is observed for the first time with a significance of 5.4 standard deviations (σ). We also find evidence for CP violation in the charged B modes, A(CP)(B(±)→ηK(±))=-0.38±0.11±0.01 and A(CP)(B(±)→ηπ(±))=-0.19±0.06±0.01 with significances of 3.8 σ and 3.0 σ, respectively. For all measurements, the first and second uncertainties are statistical and systematic, respectively. 相似文献
16.
P. R. Burchat 《The European Physical Journal C - Particles and Fields》2000,15(1-4):543-580
17.
R. García-Martín B. Moussallam 《The European Physical Journal C - Particles and Fields》2010,70(1-2):155-175
We reconsider Muskhelishvili–Omnès (MO) dispersive representations of photon–photon scattering to two pions, motivated by the very high statistics results recently released by the Belle collaboration for charged as well as neutral pion pairs and also by recent progress in the determination of the low-energy π π scattering amplitude. Applicability of this formalism is extended beyond 1 GeV by taking into account inelasticity due to $K\bar{K}$ . A modified MO representation is derived which has the advantage that all polynomial ambiguities are collected into the subtraction constants and have simple relations to pion polarizabilities. It is obtained by treating differently the exactly known QED Born term and the other components of the left-hand cut. These components are approximated by a sum over resonances. All resonances up to spin two and masses up to ?1.3 GeV are included. The tensor contributions to the left-hand cut are found to be numerically important. We perform fits to the data imposing chiral constraints, in particular, using a model independent sum-rule result on the p 6 chiral coupling c 34. Such theoretical constraints are necessary because the experimental errors are dominantly systematic. Results on further p 6 couplings and pion dipole and quadrupole polarizabilities are then derived from the fit. The relevance of the new data for distinguishing between two possible scenarios of isospin breaking in the f 0(980) region is discussed. 相似文献
18.
I. Horn A. V. Anisovich G. Anton R. Bantes O. Bartholomy R. Beck Y. Beloglazov R. Bogendörfer R. Castelijns V. Credé A. Ehmanns J. Ernst I. Fabry H. Flemming A. Fösel M. Fuchs Ch. Funke R. Gothe A. Gridnev E. Gutz S. Höffgen J. Hößl J. Junkersfeld H. Kalinowsky F. Klein E. Klempt H. Koch M. Konrad B. Kopf B. Krusche J. Langheinrich H. Löhner I. Lopatin J. Lotz H. Matthäy D. Menze J. Messchendorp V. Metag V. A. Nikonov D. Novinski M. Ostrick H. van Pee A. V. Sarantsev C. Schmidt H. Schmieden B. Schoch G. Suft V. Sumachev T. Szczepanek U. Thoma D. Walther Ch. Weinheimer 《The European Physical Journal A - Hadrons and Nuclei》2008,38(2):173-186
The reaction γp → pπ0η has been studied with the CBELSA detector at the tagged photon beam of the Bonn electron stretcher facility. The reaction
shows contributions from Δ+(1232)η , N(1535)+π0 and pa
0(980) as intermediate states. A partial-wave analysis suggests that the reaction proceeds via formation of six Δ -resonances,
Δ(1600)P
33 , Δ(1920)P
33 , Δ(1700)D
33 , Δ(1940)D
33 , Δ(1905)F
35 , Δ(2360)D
33 , and two nucleon resonances N(1880)P
11 and N(2200)P
13 , for which pole positions and decay branching ratios are given. 相似文献
19.
S. Barlag H. Becker T. Böhringer M. Bosman V. Castillo V. Chabaud C. Damerell C. Daum H. Dietl A. Gillman R. Gilmore T. Gooch L. Görlich P. Gras Z. Hajduk E. Higon D. P. Kelsey R. Klanner S. Kwan B. Lücking G. Lütjens G. Lütz J. Malos W. Männer E. Neugebauer H. Palka M. Pepé J. Richardson K. Rybicki H. J. Seebrunner U. Stierlin H. G. Tiecke G. Waltermann S. Watts P. Weilhammer F. Wickens L. W. Wiggers M. Witek T. Zeludziewicz 《Zeitschrift fur Physik C Particles and Fields》1991,49(4):555-562
We have studied the hadronic production of charmed mesons in the NA 32 experiment at CERN. A special trigger together with a high resolution vertex detector consisting of charge coupled devices and silicon microstrip detectors allowed the selection of very clean samples of charmed mesons. We have collected 852 fully reconstructed decays: 60D s + →K + K ?π+, 543D°→K ?π+ andK ?π+π?π+ as well as 249D +→K ?π+π+ (or charge conjugate). 147 mesons out of our \({{D^0 } \mathord{\left/ {\vphantom {{D^0 } {\bar D^0 }}} \right. \kern-0em} {\bar D^0 }}\) sample were produced via chargedD * state. For all charmed mesons we determine the total production cross-section and study thex F andp t 2 distributions. 相似文献
20.
A.Ya. Berdnikov Ya.A. Berdnikov A.N. Ivanov V.A. Ivanova V.F. Kosmach M.D. Scadron N.I. Troitskaya 《The European Physical Journal A - Hadrons and Nuclei》2001,12(3):341-347
Polarization properties of strange baryons produced in pp reactions, p + p↦p + Λ0 + K+ and p + p↦p + Σ0 + K+, near thresholds of the final states pΛ0K+ and pΣ0K+ are analysed relative to polarizations of colliding protons. The cross-sections for pp reactions are calculated within the
effective Lagrangian approach accounting for strong pp rescattering in the initial state of colliding protons with a dominant
contribution of the one-pion exchange and strong final-state interaction of daughter hadrons (Eur. Phys. J. A 9, 425 (2000)).
Received: 22 October 2001 / Accepted: 14 November 2001 相似文献