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1.
A. Sibirtsev J. Haidenbauer H. -W. Hammer U. -G. Meißner 《The European Physical Journal A - Hadrons and Nuclei》2006,29(3):363-367
We show that the recently measured asymmetry in helicity-angle spectra of the Λ-hyperons, produced in the reaction pp → K
+Λp reaction, and the energy dependence of the total pp → K
+Λp cross-section can be explained consistently by the same Λp final-state interaction. Assuming that there is no final-state interaction in the Σ0
p channel, as suggested by the available data for the reaction pp → K
+Σ0
p, we can also reproduce the energy dependence of the Λ/Σ0 production ratio and, in particular, the rather large ratio observed near the reaction thresholds. The nominal ratio of the
Λ and Σ0 production amplitudes squared, i.e. when disregarding the final-state interaction, turns out to be about 3, which is in line with hyperon production data from
proton and nuclear targets available at high energies. 相似文献
2.
S.P. Avdeyev V.A. Karnaukhov W.D. Kuznetsov L.A. Petrov V.K. Rodionov A.S. Zubkevich H. Oeschler O.V. Bochkarev L.V. Chulkov E.A. Kuzmin A. Budzanovski W. Karcz M. Janicki E. Norbeck A.S. Botvina W.A. Friedman W. Nörenberg G. Papp 《The European Physical Journal A - Hadrons and Nuclei》1998,3(1):75-83
Multiple emission of intermediate-mass fragments has been studied for the collisions p + Au at 2.16, 3.6 and 8.1 GeV with
the FASA setup. The mean IMF multiplicities for events with at least one IMF are equal to 1.7, 1.9 and 2.1 (±0.2) respectively.
The multiplicity, charge distributions and kinetic energy spectra of IMF are described in the framework of a intranuclear
cascade model followed by the statistical multifragmentation model. However, between the two parts of the calculation the
excitation energies and the residual masses and charges are modified to take into account the losses during expansion. The
results support a scenario of true thermal multifragmentation of a hot and expanded target spectator.
Received: 15 December 1997 / Revised version: 24 April 1998 相似文献
3.
Methods for determining the heat content E
*/A of hot nuclei formed in energetic nuclear reactions are discussed. The primary factors involved in converting raw data into
thermal physics distributions include: 1) design of the detector array, 2) constraints imposed by the physics of the reaction
mechanism, and 3) assumptions involved in converting the filtered data into E
*/A. The two primary sources of uncertainty in the calorimetry are the elimination of nonequilibrium emissions from the event
components and accounting for the contribution of neutron emission to the excitation energy sum. 相似文献
4.
J. Arnold B. van den Brandt M. Daum M. Finger M. Finger Jr. J. Franz N. Goujon-Naef P. Hautle R. Hess A. Janata J.A. Konter H. Lacker C. Lechanoine-Leluc F. Lehar S. Mango D. Rapin E. Rössle R. Schirmaier P.A. Schmelzbach M. Schmidt H. Schmitt P. Sereni M. Slunecka A. Teglia B. Vuaridel 《The European Physical Journal A - Hadrons and Nuclei》1998,2(4):411-415
Abstact: The kinetic energy spectrum and the polarization of the PSI neutron beam produced in the reaction 12C(p,n)X at 0° with 590 MeV polarized protons were investigated. A strong energy dependence of the neutron beam polarization is
observed which was not expected at the time the neutron beam was built.
Received: 3 April 1998 相似文献
5.
P. Winter M. Wolke H.-H. Adam A. Budzanowski R. Czyżykiewicz D. Grzonka M. Janusz L. Jarczyk B. Kamys A. Khoukaz K. Kilian P. Klaja P. Moskal W. Oelert C. Piskor-Ignatowicz J. Przerwa J. Ritman T. Rożek T. Sefzick M. Siemaszko J. Smyrski A. Täschner P. Wüstner Z. Zhang W. Zipper 《Physics letters. [Part B]》2006
The total cross section of the reaction pp→ppK+K− has been measured at excess energies Q=10 MeV and 28 MeV with the magnetic spectrometer COSY-11. The new data show a significant enhancement of the total cross section compared to pure phase space expectations or calculations within a one boson exchange model. In addition, we present invariant mass spectra of two particle subsystems. While the K+K− system is rather constant for different invariant masses, there is an enhancement in the pK− system towards lower masses which could at least be partially connected to the influence of the Λ(1405) resonance. 相似文献
6.
S.V. Golovkin A.P. Kozhevnikov V.P. Kubarovsky V.F. Kurshetsov L.G. Landsberg V.V. Molchanov V.A. Mukhin S.V. Petrenko V.A. Senko D.V. Vavilov V.A. Victorov V.Z. Kolganov G.S. Lomkatsi A.F. Nilov V.T. Smolyankin 《The European Physical Journal A - Hadrons and Nuclei》1999,5(4):409-416
New data for the diffractive reaction p+N→ [Σ0
K
+] +N at E
p= 70 GeV were obtained with partially upgraded SPHINX setup. The data are in a good agreement with the results of our previous
study of this reaction. In the mass spectrum M(Σ0
K
+) a structure at the threshold region with a mass ∼1810 MeV and a distinct X(2000) peak with M= 1989 ± 6 MeV and γ= 91 ± 20 MeV are observed. Unusual features of the massive X(2000) state (narrow decay width, anomalously
large branching ratio for the decay channel with strange particle emission) make it a serious candidate for cryptoexotic pentaquark
baryon with hidden strangeness |qqqsˉs>. We also present new results on the narrow threshold structure X(1810) with M= 1807 ± 7 MeV and γ= 62 ± 19 MeV which is produced in the region of very small P
2
T < 0.01 GeV2. The possibility of the Coulomb production mechanism for X(1810) is discussed.
Received: 28 April 1999 相似文献
7.
Hydrogen storage in sonicated carbon materials 总被引:6,自引:0,他引:6
M. Hirscher M. Becher M. Haluska U. Dettlaff-Weglikowska A. Quintel G.S. Duesberg Y.-M. Choi P. Downes M. Hulman S. Roth I. Stepanek P. Bernier 《Applied Physics A: Materials Science & Processing》2001,72(2):129-132
The hydrogen storage in purified single-wall carbon nanotubes (SWNTs), graphite and diamond powder was investigated at room
temperature and ambient pressure. The samples were sonicated in 5 M HNO3 for various periods of time using an ultrasonic probe of the alloy Ti-6Al-4V. The goal of this treatment was to open the
carbon nanotubes. The maximum value of overall hydrogen storage was found to be 1.5 wt %, as determined by thermal desorption
spectroscopy. The storage capacity increases with sonication time. The sonication treatment introduces particles of the Ti
alloy into the samples, as shown by X-ray diffraction, transmission electron microscopy, and chemical analysis. All of the
hydrogen uptake can be explained by the assumption that the hydrogen is only stored in the Ti-alloy particles. The presence
of Ti-alloy particles does not allow the determination of whether a small amount of hydrogen possibly is stored in the SWNTs
themselves, and the fraction of nanotubes opened by the sonication treatment is unknown.
Received: 18 December 2000 / Accepted: 18 December 2000 / Published online: 9 February 2001 相似文献
8.
T. Rożek D. Grzonka H.-H. Adam A. Budzanowski R. Czyżykiewicz M. Janusz L. Jarczyk B. Kamys A. Khoukaz K. Kilian P. Klaja P. Kowina P. Moskal W. Oelert C. Piskor-Ignatowicz J. Przerwa J. Ritman T. Sefzick M. Siemaszko J. Smyrski A. Täschner P. Winter M. Wolke P. Wüstner Z. Zhang W. Zipper 《Physics letters. [Part B]》2006
9.
M. Abdel-Bary S. Abdel-Samad R. Bilger K.-Th. Brinkmann H. Clement S. Dshemuchadse E. Dorochkevitch H. Dutz W. Eyrich A. Erhardt D. Filges A. Filippi H. Freiesleben M. Fritsch R. Geyer A. Gillitzer D. Hesselbarth B. Jakob L. Karsch K. Kilian H. Koch J. Kreß E. Kuhlmann S. Marcello S. Marwinski S. Mauro W. Meyer P. Michel K. Möller H. P. Morsch L. Naumann N. Paul M. Richter E. Roderburg M. Rogge A. Schamlott M. Schmitz P. Schönmeier M. Schulte-Wissermann W. Schroeder T. Sefzick F. Stinzing G.Y. Sun G.J. Wagner M. Wagner A. Wilms P. Wintz S. Wirth P. Zupranski 《The European Physical Journal A - Hadrons and Nuclei》2003,16(1):127-137
The reaction pp → ppη was measured at excess energies of 15 and 41 MeV at an external target of the Jülich Cooler Synchrotron COSY with the time-of-flight
spectrometer. About 25000 events were measured for the excess energy of 15 MeV and about 8000 for 41 MeV. Both protons of
the process ppη were detected with an acceptance of nearly 100% and the η was reconstructed by the missing-mass technique. For both excess
energies the angular distributions are found to be nearly isotropic. In the invariant-mass distributions strong deviations
from the pure phase space distributions are seen.
Received: 24 May 2002 / Accepted: 20 September 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: e.roderburg@fz-juelich.de
Communicated by M. Gar?on 相似文献
10.
Ya.?A.?Berdnikov V.?T.?Kim V.?F.?Kosmach M.?M.?RyzhinskiyEmail author V.?M.?Samsonov M.?E.?Zavatsky 《The European Physical Journal A - Hadrons and Nuclei》2005,26(2):179-184
Two important initial-state nuclear effects in hadron-nucleus collisions are considered. The ratios of inclusive differential
cross-sections for Drell-Yan dimuon production are calculated. The calculated results are compared to the E866 data. It is
shown that the consideration of multiple soft rescatterings of incident quarks in nuclei and initial-state quark energy loss
effects allow to get a good agreement between the calculated results and the experimental data. 相似文献