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1.
G.I. Lykasov W. Cassing A. Sibirtsev M.V. Rzjanin 《The European Physical Journal A - Hadrons and Nuclei》1999,6(1):71-81
We calculate the elastic and inelastic ωN→ωN, →πN, →ρN, →ρπN, →ππN, →σN reactions within a boson exchange approximation where the ωρπ coupling constant and form factor are fixed by the reaction
πN→ωN in comparison to the experimental data. We find rather large ωN cross sections at low relative momenta of the ω-meson which
leads to a substantial broadening of the ω-meson width in nuclear matter. The implications of the ωN final state interactions are studied for ω production in 12C +12C, 40Ca +40Ca and 58Ni +58Ni reactions at about 2 · A GeV within the HSD transport approach; the drastic changes of the transverse mass spectra relative
to a general m
T-scaling (for π0 and η mesons) might be controlled experimentally by the TAPS Collaboration.
Received: 28 April 1999 / Revised version: 7 June 1999 相似文献
2.
Yu.Ts. Oganessian A.V. Yeremin G.G. Gulbekian S.L. Bogomolov V.I. Chepigin B.N. Gikal V.A. Gorshkov M.G. Itkis A.P. Kabachenko V.B. Kutner A.Yu. Lavrentev O.N. Malyshev A.G. Popeko J. Roháč R.N. Sagaidak S. Hofmann G. Münzenberg M. Veselsky S. Saro N. Iwasa K. Morita 《The European Physical Journal A - Hadrons and Nuclei》1999,5(1):63-68
The reaction 48Ca+238U was investigated at the recoil separator VASSILISSA at the Flerov Laboratory of Nuclear Reactions, JINR Dubna, in attempts
to synthesize new isotopes of element 112. The experiments were performed at two beam energies resulting in excitation energies
of the compound nucleus of 33 and 39 MeV. The collected beam dose was 3.5 × 1018 and 2.2 × 1018, respectively. Two spontaneous fission events were observed at the lower beam energy, which tentatively were assigned to
the new neutron rich isotope 283112 produced in the reaction 238U(48Ca,3n)283112. The measured cross-section is (5.0+6.3
−3.2) pb and the half–life is (81+147
−32) s. No event was observed at the higher beam energy resulting in the upper cross–section limit of 7.3 pb.
Received: 12 October 1998 / Revised version: 12 January 1999 相似文献
3.
For I
G
(J
PC)=1−(1−+) exotic waves in the reactions ρπ → ρπ, ρπ → ηπ, ρπ → η′π, and ρπ →
and in allied reactions, a model is constructed that satisfies the conditions of unitarity and analyticity and which employs,
as an input, an “anomalous” nondiagonal VPPP interaction relating the ρπ, ηπ, η′π, and
channels. The possibility of obtaining, within this simple field-theoretical model, a resonance behavior of the I
G(J
PC)=1−(1−+) amplitudes corresponding to the {10} −
and {8} representations of the SU(3) group and their mixing is demonstrated explicitly in the mass range 1.3–1.6 GeV, where data of present-day experiments
suggest a rich exoticism.
__________
Translated from Yadernaya Fizika, Vol. 65, No. 3, 2002, pp. 579–588.
Original Russian Text Copyright ? 2002 by Achasov, Shestakov. 相似文献
4.
V. F. Dmitriev 《Physics of Atomic Nuclei》2009,72(7):1165-1167
Using a simple phenomenological parametrization of the reaction amplitude we calculated α-particle spectrumin the reaction p + 11B → α + 8Be* → 3α at the resonance proton energy of 675 keV. The parametrization includes Breit-Wigner factor with an energy-dependent width
for intermediate 8Be* state and the Coulomb and the centrifugal factors in α-particle-emission vertices. The shape of the spectrum consists of a well-defined peak corresponding to emission of the primary
α and a flat shoulder going down to very low energy. We found that below 1.5MeV there are 17.5% of α’s and below 1MeV there are 11% of them.
The text was submitted by the author in English. 相似文献
5.
The correlations of the linear and circular polarizations in the system of two photons have been theoretically investigated.
The polarization of a two-photon state is described by the one-photon Stokes parameters and by the components of the correlation
“tensor” in the Stokes space. It is shown that in the case of two-photon decays π0 → 2γ, η → 2γ, K
L
0 → 2γ, K
S
0 → 2γ and the cascade process |0〉 → |1〉 + γ → |0〉 + 2γ(|0〉 and |1〉 are states with the spin 0 and 1, respectively) the final
two-photon state represents a characteristic example of the entangled (nonfactorizable) state, and the correlations between
the Stokes parameters in all these decays have the purely quantum character: the incoherence inequalities of the Bell type
for the components of the correlation “tensor”, established previously for the case of classical “mixtures”, are violated.
The general analysis of the registration procedure for two correlated photons by two one-photon detectors is performed. 相似文献
6.
The narrow NN-decoupled dibaryon resonance with a mass about 1956 MeV was reported in 2000 by DIB2γ Collaboration (JINR, Dubna) on the
basis of the measurement of the two-photon energy spectrum in the reaction pp → pp2γ at 216 MeV. The most probable quantum numbers J
P
= 1+ prevent the resonance from decaying into two protons due to the exclusion principle, while the pionic decays are impossible
energetically. The significance of this resonance (called d
1* (1956)) for the interpretation of a few other exclusive and inclusive reactions connected with the photon(s) production
in nucleon collisions with nucleons and nuclei at different energies is discussed. The importance is stressed of on-going
and planned studies of the elastic and inelastic Compton scattering on the lightest nuclei for collecting information on the
structure and dynamics of d
1* (1956) which can shed light on its nature. 相似文献
7.
A. N. Ivanov H. Oberhummer N. I. Troitskaya M. Faber 《The European Physical Journal A - Hadrons and Nuclei》2000,8(2):223-250
A dynamics of low-energy nuclear forces is investigated for low-energy electromagnetic and weak nuclear reactions with the
deuteron in the Nambu-Jona-Lasinio model of light nuclei by example of the neutron-proton radiative capture (M1-capture) n
+ p → D + γ, the photomagnetic disintegration of the deuteron γ + D → n + p and weak reactions of astrophysical interest. These are the solar proton burning p + p → D + e+ + ν
e, the pep-process p + e− + p → D + ν
e and the neutrino and antineutrino disintegration of the deuteron caused by charged ν
e + D → e− + p + p, + D → e+ + n + n and neutral ν
e() + D → ν
e() + n + p weak currents. 相似文献
8.
A. V. Derbin V. N. Muratova D. A. Semenov E. V. Unzhakov 《Physics of Atomic Nuclei》2011,74(4):596-602
Axions of energy 14.4 keV that originated from the M1 transition in 57Fe nuclei in the Sun were sought by using the resonance-absorption reaction A+57Fe → 57Fe* → 57Fe+γ (14.4 keV). Asectioned Si(Li) detector arranged in a low-background facility was used to record photons from this reaction.
This resulted in setting a new limit on the axion couplings to nucleons, |−1.19g
AN
0 + g
AN
3| ≤ 3.0×10−6. Within the hadronic-axion model, the respective constraint on the axion mass is m
A ≤ 145 eV (at a 95% C.L.). 相似文献
9.
Synthesis and decay properties of superheavy atoms in nuclear reactions induced by stable and radioactive ion beams 总被引:2,自引:0,他引:2
Yu. Oganessian 《The European Physical Journal A - Hadrons and Nuclei》2002,13(1-2):135-141
This talk consists of two parts. The first one presents the results of investigations performed in 1998-2000 in Dubna on the
synthesis of superheavy nuclei in reactions induced by 48Ca ions. The radioactive decay properties of the nuclei, indicating a considerable increase in the α-decay and spontaneous
fission half-lives of the isotopes of elements 110-116 when approaching the closed neutron shell at N = 184, are given. In the second part the possible ways of advancing into the region of more neutron-rich nuclei, using stable
and radioactive ion beams, are discussed. Since so far no intense radioactive ion beams are available, some experiments with
stable beams are considered as a test for the suggested ideas.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
10.
Absolute spectral luminosity from an O2–O2(a)-H2O gas flow formed by a chemical singlet oxygen generator was measured at 600–800 and 1230–1310 nm wavelengths. The results
were used to determine the rate constants for O2(a, 0) + O2(a, 0) → O2(X, 0) + O2(X, 0) + hν (λ = 634 nm) and O2(a, 0) + O2(a, 0) → O2(X, 1) + O2(X, 0) + hν (λ = 703 nm) collision-induced emission ((6.72 ± 0.8) × 10−23 and (7.17 ± 0.8) × 10−23 cm3/s, respectively). 相似文献
11.
M. V. Zagidullin 《Optics and Spectroscopy》2010,109(4):538-542
In the temperature range of T = 150–400 K, the dependence of spectral widths (cm−1) on temperature, 182 + 0.38(±0.01)T and 217 + 0.48(±0.01)T, respectively, has been obtained for dimole emission of O2(a, 0) + O2(a, 0) → O2(X, 1) + O2(X, 0) + hν (λ = 703 nm) and O2(a, 0) + O2(a, 0) → O2(X, 0) + O2(X, 0) + hν (λ = 634 nm). It was shown that the ratio of dimole emission rate constants does not depend on temperature in the range
of 150–400 K and is 1.06 ± 0.01. 相似文献
12.
Radiative decays π
0(π
0′) → γ + γ, π
0′ → ρ
0(ω) + γ, ρ
0′(ω′) → π
0 + γ, ρ
0′(ω′) → π
0′ + γ, and some processes of π
0′ production at lepton colliders are considered in the framework of the nonlocal SU(2) × SU(2) Nambu-Jona-Lasinio model. Mixing of the radially excited and the ground meson states is taken into account. Numerical
results for the decay and production processes are presented. 相似文献
13.
The radioactive decay of the isotopes 254-256Lr and their daughter products was investigated by means of α , prompt α -γ and delayed conversion electron-γ coincidence
spectroscopy. The isotopes were produced using the reaction 48Ca + 209Bi . 相似文献
14.
H Machner M Betigeri J Bojowald A Budzanowski A Chatterjee J Ernst L Freindl D Frekers W Garske K Grewer A Hamacher J Ilieva L Jarczyk K Kilian S Kliczewski W Klimala D Kolev T Kutsarova J Lieb H Machner A Magiera H Nann L Pentchev HS Plendl D Protić B Razen P Von Rossen BJ Roy R Siudak J Smyrski RV Srikantiah A Strzałkowski R Tsenov K Zwoll 《Pramana》2001,57(2-3):399-416
Total and differential cross sections for the reactions p + d → 3He + m
0 with m=π, η and p + d → 3H+π+ were measured with the GEM detector at COSY for beam momenta between threshold and the maximum of the corresponding baryon
resonance. For both reactions a strong forward-backward asymmetry was found. The data were compared with model calculations.
The aspect of isospin symmetry breaking is studied.
Representing the GEM Collaboration 相似文献
15.
V. I. Sharov A. A. Morozov R. A. Shindin E. V. Chernykh A. A. Nomofilov L. N. Strunov 《Physics of Atomic Nuclei》2009,72(6):1021-1025
Our new experimental results (see, e.g., Preprint JINR no. E1-2008-61 (Dubna, 2008)) on ratio R
dp
of the quasielastic charge-exchange yield at the proton emitting angle θ
p,lab = 0° for the nd → p(nn) reaction to the elastic np → pn charge-exchange yield were presented. The measurements were carried out at the Nuclotron of the Veksler and Baldin Laboratory
of High Energies of the JINR (Dubna) at the neutron-beam kinetic energies of 0.55, 0.8, 1.0, 1.2, 1.4, 1.8, and 2.0 GeV. In
this paper the comparison of the experimental R
dp
data with the obtained R
dp
calculations within the impulse approximation by using the invariant-amplitude sets from the GW/VPI phase-shift analysis
is made. The R
dp
values calculated using the set of invariant amplitude data for the elastic np → pn charge exchange at θ
p,CM = 0°, agree with the experimental data. This confirmed the nd → p(nn) process yield at θ
p,CM = 0° is caused by the contribution of the spin-dependent part of the elastic np → pn charge-exchange reaction. Thus, it has been shown that the obtained experimental R
dp
results can be used for the Delta-Sigma experimental program to reduce the total ambiguity in the extraction of the amplitude
real parts.
The text was submitted by the authors in English. 相似文献
16.
Summary The formation of NaNe molecule has been detected in a hollow cathode lamp containing traces of sodium and neon using the optogalvanic
technique. Two broad continuum peaks have been observed in the structure. They have been analysed to result due to transitions
{Na(3s) + Ne(2p
6)}2Σ1→ →{Na*(3p) + Ne(2p
6)}2Π,2Σ and {Na*(3p) + Ne(2p
6)}2Π,2Σ→{Na*(5s) + Ne(2p
6)}2Σ1. A third peak in between these is probably due to a two-photon transition from 3s→5s of Na in NaNe.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
17.
A. V. Derbin S. B. Bakhlanov A. I. Egorov I. A. Mitropolsky V. N. Muratova D. A. Semenov E. V. Unzhakov 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(4):481-486
We searched for resonant excitation of the first excited state of the 169Tm nucleus by axions formed inside the Sun by the Primakoff effect, A + 169Tm → 169Tm* → 169Tm + γ (8.41keV). Gamma quanta with an energy of 8.41keV were registered by a sectionalized Si(Li) detector installed in a
low-background setup. As a result, we set a new upper limit for the photon to axion coupling constant, g
Aγ
(GeV−1)m
A
(eV) ≤ 1.06 × 10−5, which for a hadronic axion model corresponds to a mass limit of m
A
≤ 169 eV at a 90% confidence level. 相似文献
18.
The 4
T
2→4
A
2 transition of the Mn4+ ion has been observed in the luminescence spectrum of Mn4+:Cd3Ga5O12 upon intense laser pumping. It is shown that an increase in the intensity of the 4
T
2→4
A
2 transition with respect to the 2
E→ 4
A
2 transition in these crystals with increasing pumping power relates to the increased role of induced transitions. The intensity
of this process is greater in the region where the 2
E→4
A
2 and 4
T
2→4
A
2 transition bands overlap most, which leads to an increase of the zero-phonon line of the latter transition, peaking at a
wavelength of 694 nm. The rates of radiative and nonradiative recombination involving the 4
T
2, 2
E, and 4
A
2 terms of the Mn4+ ion in gallium-gadolinium garnet (GGG) are calculated using data from luminescence spectra measured at different temperatures.
The Mn4+:GGG crystal is proposed for use as an active element of lasers with continuous frequency tuning.
__________
Translated from Optika i Spektroskopiya, Vol. 94, No. 4, 2003, pp. 590–596.
Original Russian Text Copyright ? 2003 by Bulyarskiĭ, Zhukov, Prikhod’ko. 相似文献
19.
The partial capture rates for the process,μ
− +16O (g·s) →16N (2−, 1−, 0−, 3−) +v
μ
have been calculated using the particle-hole wavefunctions obtained using self-consistent procedure. In deriving these wavefunctions,
the effectiveN-N interaction has been constructed from the bare Hamada-Johnston interaction. The terms in the muon capture Hamiltonian that
depend on the momentum of the capturing proton have been included and their importance in 0+ → 0− transition is exhibited. The agreement with the available experimental data is good. The need to incorporate meson exchange
effects in 0+ → 0− transition is pointed out. 相似文献
20.
The two-neutrino double beta decay of96Zr isotope for 0+ → 2+ transition has been studied in the PHFB model. In our earlier work, the reliability of the intrinsic wave functions of96Zr and96Mo isotopes has been established by obtaining an overall agreement between a number of theoretically calculated spectroscopic
properties as well as half-lives of 2vββ decay for 0+ → 0+ transition and the available experimental data. In the present work, the half-life of 2vββ decay for 0+ ar 2+ transition T
1
2/2v
(0+ →2+) has been calculated using the same set of intrinsic wave functions. 相似文献