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1.
I. I. Strakovsky 《Czechoslovak Journal of Physics》1986,36(2):225-229
Conclusion The joint efforts of the laboratories with intermediate energies accelerators at ANL, KEK, LANL, LNPI, Saclay, SIN and TRIUMF produced a rather definite picture of the
+pp reaction in the isobar region. However the problem of anomalies for the square-root branch point due to the production of isobar in the intermediate state have not been resolved so far. The poles obtained in different phenomenological analyses could be just the effective parametrization of these cuts (see e.g. [13]). Anyway, some singularities are definitely necessary to describe the data.The experimental data in regions s < 2·05 GeV and s < 2·25 GeV are clearly insufficient. Further accumulation of the data in these regions is necessary. Polarized deuteron data are badly needed in the whole kinematical range [13]. Besides as it was mentioned before it is necessary to measure accurately cross sections of other inelastic reactions which are important for the investigation (observation?) of dibaryonsNN N, NN andd N, NN [21]. It would be of interest also to measure cross sections of non quasi two-particle channels likeNN N, 2N andd N, 2N [22]. (In the case ofNN scattering quasi two-particle channels are known to dominate in a wide energy range.)Presented at the symposium Mesons and Light Nuclei, Bechyn, Czechoslovakia, May 27–June 1, 1985.I am grateful to L. A. Kondratyuk, M. G. Ryskin and M. I. Strikman for valuable discussions of the considered problems. 相似文献
2.
R. N. Mukherjee T. K. De B. B. Baliga 《Zeitschrift für Physik A Hadrons and Nuclei》1995,352(4):417-420
The energy spectra of12C and16O fragments emitted in 50 and 60 MeV-induced reactions on27Al have been measured using Solid State Nuclear Track Detectors. These data are in good agreement with the predictions of a simple moving source model, indicating statistical emission of the fragments from a nearly equilibrated compound nucleus.We are thankful to Dr. C. Bhattacharya and Dr. S. Bhattacharya of VECC for some useful discussions. The cooperation and help extended by the crew of the VECC and of the Pelletron, Bombay, is thankfully acknowledged. Special thanks are due to Sri P.K. Das for his etching and scanning assistance, and to Sri T.K. Das for his help during the experiments. Our thanks are also due to the Director of Saha Institute for providing the facilities. 相似文献
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4.
O. Dumbrajs W. Dutty J. Franz E. Rössle H. Schmitt L. Schmitt 《Zeitschrift für Physik A Hadrons and Nuclei》1984,316(1):43-47
Experimental values of the differential cross section for the reactionn+d→π 0+t at large angles (θ?50°) in the neutron energy range 460–560 MeV and the known values of the coupling constants \(G_{nn\pi ^O }^2 \) andG tdn 2 are used to predictdσ/dΩ at smaller angles. The method is based on the use of general analytic properties of the differential cross section in the cosgq-plane. 相似文献
5.
Effect of reagent vibrational excitation and isotope substitution on the stereo-dynamics of the Ba+HF→BaF+H reaction
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Based on an extended London-Eyring-Polanyi-Sato (LEPS) potential energy surface (PES), the Ba + HF reaction has been studied by the quasi-classical trajectory (QCT) method. The reaction integral cross section as a function of collision energy for the Ba + HF → BaF + H reaction is presented and the influence of isotope substitution on the differential cross sections (DCSs) and alignments of the product's rotational angular momentum have also been studied. The results suggest that the integral cross sections increase with increasing collision energy, and the vibrational excitation of the reagent has great influence on the DCS. In addition, the product's rotational polarization is very strong as a result of heavy-heavy-light (HHL) mass combination, and the distinct effect of isotope substitution on the stereodynamics is also revealed. 相似文献
6.
《Nuclear Physics A》1988,485(2):369-379
The evaporation residues from the reaction 32S on 27Al were measured at 142, 153, 175, 187 and 227 MeV incident sulphur energies, using a time-of-flight spectrometer. The measured fusion-evaporation residue excitation function shows a maximum around Elab = 170 MeV, which corresponds to a limiting angular momentum of 43 ħ. Several possible mechanisms were investigated as being responsible for this limitation. It was found that both fission and entrance channel effects could be the limiting factors for the fusion-evaporation cross section at high energies. 相似文献
7.
C. Van den Abeele D. Ryckbosch G. De Meyer J. F. Dias L. Van Hoorebeke R. Van de Vyver J. -O. Adler K. Hansen L. Isaksson H. Ruijter P. Svensson B. Schröder 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(2):133-136
The values of the angle-integrated cross section for the decay to various low-lying states in39K following the40Ca(,) reaction at a mean photon energy of 60 MeV are reported on, together with the values of the reduced Legendre coefficientsa
i
. The40Ca(,gp) and40Ca(,n) reactions yield the same angular cross-section values and these agree with the corresponding RPA-calculations.Senior Research Associate NFWO 相似文献
8.
Berteloite C Lara M Bergeat A Le Picard SD Dayou F Hickson KM Canosa A Naulin C Launay JM Sims IR Costes M 《Physical review letters》2010,105(20):203201
We report combined studies on the prototypical S(1D2) + H2 insertion reaction. Kinetics and crossed-beam experiments are performed in experimental conditions approaching the cold energy regime, yielding absolute rate coefficients down to 5.8 K and relative integral cross sections to collision energies as low as 0.68 meV. They are supported by quantum calculations on a potential energy surface treating long-range interactions accurately. All results are consistent and the excitation function behavior is explained in terms of the cumulative contribution of various partial waves. 相似文献
9.
P. Corvisiero M. Anghinolfi L. Z. Dzhilavyan G. Gervino G. Ricco M. Ripani M. Sanzone M. Taiuti A. Zucchiatti 《Few-Body Systems》1991,10(4):135-141
The2H(d, )4He differential cross section was measured at deuteron laboratory energies of 20, 24, and 28 MeV between cm=45° and cm=135°. AtE
d
=28 MeV a complete angular distribution was determined and fitted with Legendre polynomials. The ratioR=d/d (cm=90°)/d/d (cm=135°) was measured for each deuteron energy. 相似文献
10.
N. B. Ladygina 《Physics of Particles and Nuclei》2014,45(1):187-189
The dd → 3He n reaction is considered at the energies between 200 and 520 MeV. The calculations are performed within relativistic multiple scattering model based on the Alt-Grassberger-Sandhas equations. The angular dependences of the differential cross section and vector and tensor analyzing powers are given in comparison with the experimental data. 相似文献
11.
F. W. Wieland J. Barth K. -H. Glander J. Hannappel N. Jöpen F. Klein E. Klempt R. Lawall D. Menze M. Ostrick E. Paul I. Schulday W. J. Schwille 《The European Physical Journal A - Hadrons and Nuclei》2011,47(4):1-11
The reaction γp → K + Λ(1520) was measured in the energy range from threshold to 2.65 GeV with the SAPHIR detector at the electron stretcher facility ELSA in Bonn. The Λ(1520) production cross-section was analyzed in the decay modes pK ?, $ n\bar K^0 $ , Σ ± π ?, and Λπ + π ? as a function of the photon energy and the squared four-momentum transfer t . While the cross-sections for the inclusive reactions rise steadily with energy, the cross-section of the process γp → K + Λ(1520) peaks at a photon energy of about 2.0 GeV, falls off exponentially with t , and shows a slope flattening with increasing photon energy. The angular distributions in the t-channel helicity system indicate neither a K nor a K * exchange dominance. Rather, the rapid change of the angular distribution with energy suggests that, in addition to t -channel K and K* exchange, amplitudes for formation of nucleon resonances in the s-channel play an important role. 相似文献
12.
A. M. Gorbatov A. V. Germanov D. V. Nechaev P. V. Komarov P. Yu. Nikishov 《Physics of Atomic Nuclei》2000,63(3):431-439
A collective adiabatic approach is used to explore the total and differential cross sections for the reactions d + d → p + 3H and d + d → n + 3He at incident-deuteron energies of up to 6 MeV. All substantially contributing partial waves of order not higher than that of G waves are taken into account. The experimental value of the difference of the cross sections for the above mirror reactions is reproduced theoretically under the assumption that nuclear forces obey the condition of isotopic invariance. The positions and amplitudes of the maxima in the calculated total cross sections virtually coincide with those of the corresponding experimental values. It is shown that, around the maxima of the cross sections under study, dominant contributions to them come from the P wave. The sensitivity of observables to the parameters of nucleon-nucleon interaction is analyzed. 相似文献
13.
T. Skorodko M. Bashkanov D. Bogoslawsky H. Calén H. Clement E. Doroshkevich L. Demiroers C. Ekström K. Fransson L. Gustafsson B. Höistad G. Ivanov M. Jacewicz E. Jiganov T. Johansson O. Khakimova S. Keleta I. Koch F. Kren S. Kullander A. Kupść P. Marciniewski R. Meier B. Morosov C. Pauly H. Petrén Y. Petukhov A. Povtorejko R. J. M. Y. Ruber K. Schönning W. Scobel B. Shwartz J. Stepaniak P. Thörngren-Engblom V. Tikhomirov G. J. Wagner M. Wolke A. Yamamoto J. Zabierowski J. Zlomanczuk 《The European Physical Journal A - Hadrons and Nuclei》2011,47(9):1-6
First exclusive data for the $\ensuremath{pp \to nn\pi^+\pi^+}$ reaction have been obtained at CELSIUS with the WASA detector setup at a beam energy of Tp = 1.1 GeV. Total and differential cross-sections disagree with theoretical calculations, which predict the $ \Delta$ $ \Delta$ excitation to be the dominant process at this beam energy. Instead, the data require the excitation of one of the nucleons to a higher-lying $ \Delta$ state, preferably the $\ensuremath{\Delta(1600)P_{33}}$ , to be the leading process. 相似文献
14.
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
15.
M.N.A. Abdullah M.S. Mahbub S.K. Das A.S.B. Tariq M.A. Uddin A.K. Basak H.M. Sen Gupta F.B. Malik 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):477-486
Full finite-range macroscopic calculations in the distorted-wave Born approximation have been performed using the molecular
and Michel α-nucleus potentials to analyze the angular distributions of cross-sections of the 27Al(α, d)29Si reaction, at 26.5 and 27.2 MeV incident energies, leading to seven transitions up to the excitation energy E
X = 4.08 MeV of the final nucleus. The parameters of the two types of the α-nucleus potentials are determined from the elastic-scattering
data. Both the molecular and Michel potentials, without any adjustment to the parameters needed to fit the elastic-scattering
data, are able in most cases to reproduce, simultaneously, the absolute cross-sections particularly at large angles, where
the previous calculations failed to reproduce by orders of magnitude, and the gross pattern of angular distributions of the
reaction. The deuteron-cluster spectroscopic factors for most of the seven transitions, deduced using the two α-27Al potentials, differ from those obtained in earlier works. The spectroscopic factor for the ground-state transition, deduced
in the present work for the 25.8 MeV data, agrees well with the shell model prediction.
Received: 15 July 2002 / Accepted: 8 August 2002 / Published online: 10 December 2002
RID="a"
ID="a"e-mail: akbasak2001@Yahoo.com
Communicated by G. Orlandini 相似文献
16.
17.
A. S. Solovyev S. Yu. Igashov Yu. M. Tchuvil’sky 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(5):433-437
The radiative capture reaction t + α → 7Li + γ is investigated in the framework of the algebraic version of the resonating group method at low energies. The Hasegawa-Nagata nucleon-nucleon potential is used in calculations. The lowest compatible with the Pauli exclusion principle wave functions of a translationally invariant shell model are adopted as the internal wave functions for α and t clusters. The obtained results are in reasonable agreement with the experimental data. 相似文献
18.
I. Zborovsky 《Zeitschrift für Physik A Hadrons and Nuclei》1992,343(3):347-353
Secondary effects in deuteron breakup reactions are reexamined for the process1
H(d, p) pn with a proton detected at 0° and for the process1
H (d, pp)n with two fast forward moving protons fixed at the beam line. Sensitivity of the cross section and the tensor asymmetryT
20 to the double-scattering and final-state-interaction corrections is demonstrated. The nonrelativistic method used here incorporates both the energy-conserving and the principal-value part of the free nucleon propagator. The calculations are compared with the inclusive experimental data1
H(d, p)X at the 1.25 and 2.1 GeV deuteron kinetic energy.The author would like to express his thanks to Prof. B. Tecoult for valuable ideas stimulating this work and Yu.Panebratsev and A. Litvinenko for many helpful discussions. For ideas and advice concerning Sect. 4, I thank to G. Lykasov and S. Shimansky. 相似文献
19.
R. Lawall J. Barth C. Bennhold K. -H. Glander S. Goers J. Hannappel N. Jöpen F. Klein E. Klempt T. Mart D. Menze M. Ostrick E. Paul I. Schulday W. J. Schwille F. W. Wieland C. Wu 《The European Physical Journal A - Hadrons and Nuclei》2005,24(2):275-285
The reaction p K0+ was measured in the photon energy range from threshold up to 2.6 GeV with the SAPHIR detector at the electron stretcher facility, ELSA, in Bonn. Results are presented on the reaction cross-section and the polarization of the + as a function of the kaon production angle in the centre-of-mass system, cosc.m.K, and the photon energy. The cross-section is lower and varies less with photon energy and kaon production angle than that of p K+0. The + is polarized predominantly at cosc.m.K 0. The data presented here are more precise than previous ones obtained with SAPHIR and extend the photon energy range to higher values. They are compared to isobar model calculations. 相似文献
20.
《Nuclear Physics A》1986,460(2):341-351
Excitation functions and angular distributions have been measured at energies near the Coulomb barrier for the elastic scattering of 16O from 16O and for the (16O, 12C) α-transfer reaction to the ground state and first excited state of 20Ne. No evidence for (quasi-molecular) resonances was found in the transfer excitation functions. Exact-finite-range DWBA calculations were performed employing double-folded real and Woods-Saxon optical potentials for the distorted waves. The α-transfer reaction was found to be sensitive to the choice of the optical potential and generally better fits were obtained with the folded potentials. 相似文献