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1.
L. Gonzalez-Sanchez M. Tacconi E. Bodo F. A. Gianturco 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(1):85-92
A newly computed potential energy surface, which describes the forces at play between the OH− (X
1Σ+) anionic molecule (treated as a rigid rotor at its equilibrium geometry) and the Rb(2S) atomic gas was obtained from fully ab initio methods, yielding highly correlated electronic wavefunctions for the interacting
partners. It is in turn employed to calculate their rotationally quenching collision cross sections at ultralow energies and
for different initial rotational states of the molecular anion. The results suggest that these strongly interacting partners
are among the most efficient systems in providing very large internal de-excitation rates whenever the collision regime of
an ultracold trap can occur for the partners. The collision encounters at such vanishing values of translational energies
are seen to be strongly controlled by the behaviour of the real part of the scattering length as a function of the initial
rotational state: the latter indicates, in fact, the presence of several virtual states close to the dissociation threshold
of the complex. 相似文献
2.
W. Szajna M. Zachwieja 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(3):549-555
The high-resolution emission spectrum of the A1
Π–X1Σ+ transition of AlH was observed in the 18 000–25 000 cm-1 spectral region using a conventional spectroscopic
technique. The AlH molecules were excited in an Al hollow-cathode
lamp filled with a mixture of Ne carried gas and a trace amount of
NH3. The emission from the discharge was observed with a plane
grating spectrograph and recorded by a photomultiplier tube. In
total 163 transition wave numbers belonging to six bands (0-0,1
and 1-0,1,2,3) were precisely measured and rotationally
analysed. In the final fit the present data have been combined
with available high-resolution measurements of the
vibration-rotation bands by White et al. [J. Chem. Phys. 99,
8371 (1993)]. This procedure enabled extracting molecular
constants for the A1
Π and X1
Σ+ states of AlH. A very
slight local perturbation has been discovered in the v=1
vibration level of the A1
Π state at J=5. This was probably
caused by the interaction with the a3Π state. 相似文献
3.
Numerical simulation of the effect of intramolecular electrostatic interactions on redistribution of relative intensities in the vibrational structure of (1 ~ 2)1Π–X1Σ+ rotationally resolved transitions of the KRb molecule is performed within the precision nonadiabatic model of coupled vibrational channels. It is established that mutual perturbation of electronically excited states modifies in a nontrivial way a nodal structure of nonadiabatic wavefunction of the (1 ~ 2)1Π complex, which is possible to use for rising efficiency of twostep laser synthesis and stabilization of ultracold ensembles of KRb molecules in the ground electronic state. 相似文献
4.
Zhi-Gang Wang Shao-Long Wan 《The European Physical Journal C - Particles and Fields》2007,50(4):781-791
In this article, we calculate the vector form factors f+
Kπ(Q2) and f-
Kπ(Q2) within the framework of the light-cone QCD sum rule approach. The numerical values of f+
Kπ(Q2) are compatible with existing theoretical calculations, and the central value of f+
Kπ(0) (f+
Kπ(0)=0.97) is in excellent agreement with the values from chiral perturbation theory and lattice QCD. The values of |f-
Kπ(0)| are very large compared to the theoretical calculations and experimental data, and they cannot give any reliable prediction.
At large momentum transfer with Q2 > 5 GeV2, the form factors f+
Kπ(Q2) and |f-
Kπ(Q2)| can either show the asymptotic behavior of or decrease more quickly than ; more experimental data are needed to select the ideal sum rules.
PACS 12.38.Lg; 12.38.Bx; 12.15.Hh 相似文献
5.
X. T. Xu X. Shao C. H. Yu C. Y. Sun W. Huang E. Feng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(3):383-390
The cross sections for rotational, fine-structure and projection-change transitions in
collision of MgH (2Σ+)
molecule with 3He and 4He atoms were computed at cold and ultracold
temperatures using the ab initio potential energy surface. The significant suppression
feature and resonance pattern caused by spin-rotation interaction were found and
discussed. The collisions exhibit a strong isotope effect in the ultracold regime. The
rotational relaxations of the fine-structure excited energy levels tendentiously preserve
the F index. The ratio of the cross sections for elastic and
spin-flipping collision with 3He partner is always greater than seven orders of
magnitude for the energy range 10-6−1cm-1 and suggests the
MgH molecule is a good candidate for 3He buffer gas cooling. 相似文献
6.
S.-W. Xu Y.-X. Xie Z.-K. Li X.-D. Wang B. Guo C.-G. Leng C.-F. Wang Y. Yu 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):347-351
The 1/2+ ground state and a 11/2- isomer of very neutron-deficient isotope 143Dy were produced by irradiation of an enriched target of 106Cd with 40Ca and studied by using a helium-jet fast tape-transport system in combination with proton-γ, X-γ and γ-γ coincidence measurements.
A simple ( EC + β+) decay scheme of 143mDy with a half-life of 3.0(3) s and a tentative ( EC + β+) decay scheme of 143gDy with a half-life of 5.6(10) s are proposed. As a by-product, the 347- and 545-keV γ transitions in 138Sm following the β-delayed proton emission of 139Gd decay and the 323-keV γ transition in 139Eu following the β-delayed proton emission of 140Tb decay could be observed for the first time.
Received: 20 August 2002 / Accepted: 28 October 2002 / Published online: 11 February 2003
RID="a"
ID="a"e-mail: xsw@ns.lzb.ac.cn
Communicated by D. Schwalm 相似文献
7.
We present a first detailed experimental study of the C(3)1Σ+ state of the NaRb molecule converging
to the Na(3p) + Rb(5s) states of separated atoms. Two different high resolution spectroscopic methods
have been applied: the Fourier transform spectroscopy of laser induced fluorescence and the V-type
optical-optical double resonance polarization labeling spectroscopy. The entire data field for the
C1Σ+ state of Na85Rb and Na87Rb consists of rovibrational levels with v'=0–64
and J'=4–123. The data were incorporated into a direct fit of a single potential energy curve to the level
energies using the Inverted Perturbation Approach method. As the experimental data extend to the
“shelf" region of the potential at large internuclear separations of 8.5 ?, the C state's suitability
for photoassociation yielding cold heteronuclear NaRb is discussed.
Electronic supplementary material Online Material 相似文献
8.
Lukáš Pichl 《Czechoslovak Journal of Physics》2005,55(2):167-171
An accurate calculation of the lowest negative electronic state of H
2
-
(fixed nuclei) is reported using the CCSD(T) method and doubly augmented cc-pv5z basis set. Comparison has been made with the reference data by Senekowitsch et al. [Chem. Phys. Lett. 111 (1984) 211]. Owing to larger size of the basisset and inclusion of triple excitations, no vertical shift in this work is necessary to reproduce the asymptotics of H + H -. In addition, the effect of basis-set truncation is estimated, based on the complete-basis-set extrapolation method. The contribution of correlated electron-proton motion to the electron-energy curve for H2
– dynamics is pointed out.Dedicated to Prof. Jií Horáek on the occasion of his 60th birthday. 相似文献
9.
A. B. Arbuzov E. A. Kuraev M. K. Volkov 《The European Physical Journal A - Hadrons and Nuclei》2011,47(9):103
The processes of electron-positron annihilation into π0γ and into π′(1300)γ are considered within an extended NJL model. The intermediate vector mesons ρ
0, ω
ρ′(1450), and ω(1420) are taken into account. The latter two mesons are treated as the first radial excited states. They are incorporated
into the NJL model by means of a polynomial form factor. Numerical predictions for the cross-sections of these processes are
received for the center-of-mass energies below 2 GeV. Our results for the π0γ production are in agreement with experimental data obtained in the energy region 600–1020 MeV. 相似文献
10.
The violated supersymmetry property of the pairing interaction between nucleons were restored using the Pyatov method [Pyatov
and Salamov, Nucleonica
22, 127 (1977)]. The eigenvalues and eigenfunctions of the restored Hamiltonian with the separable residual Gamow-Teller effective
interactions in the particle-hole and particle-particle channels were solved within the framework of proton-neutron quasirandom
phase approximation (pnQRPA). The Gamow-Teller resonance energies for 112–124Sb isotopes and the differential cross-sections for Sn(3He, t)Sb reactions at E(3He) = 200 MeV occurring by the excitation of the Gamow-Teller resonance state were calculated. The calculated values were
compared with other calculations and the corresponding experimental data. 相似文献
11.
We perform a systematic analysis of exclusive hadronic channels in e+e− collisions at center-of-mass energies between 2.1 and 2.6 GeV within the statistical hadronization model. Because of the
low multiplicities involved, calculations have been carried out in the full microcanonical ensemble, including conservation
of energy-momentum, angular momentum, parity, isospin, and all relevant charges. We show that the data are in an overall good
agreement with the model for an energy density of about 0.5 GeV/fm3 and an extra-strangeness suppression parameter γ
S
∼0.7, essentially the same values found with fits to inclusive multiplicities at higher energy. 相似文献
12.
I.?Man?ev 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(2):213-218
The total cross sections for charge transfer in Li2+-H and He+-He+ collisions have been calculated, using the four body first Born approximation with correct boundary conditions (CB1-4B) and
four body continuum distorted wave method (CDW-4B) in the energy range 10–5000 keV/amu. The role of dynamic electron correlations
is examined as a function of the impact energy. The present results call for additional experimental data at higher impact
energies than presently available. 相似文献
13.
Combining the Okubo-Zweig-Iizuka rule in the decay φ→ρπ→π+π?π0 with the ρ→4π decay amplitudes, we calculate the φ→2π+2π?π0 and φ→π+π?3π0 ones. The partial widths of the above φ decays are evaluated, and the excitation curves in e+e? annihilation are obtained, assuming reasonable particular relations among the parameters characterizing the anomalous terms of the HLS Lagrangian. The evaluated branching ratios Bφ→π+π?3π0 ≈ 2 × 10?7 and Bφ→2π+2π?π0 ≈ 7 × 10?7 are such that, with the luminosity L=500 pb?1 attained at DAΦNE φ factory, one may already possess about 1685 events of the decays φ→5π. 相似文献
14.
In this work, the femtosecond time-resolved photoelectron spectra and the coupling between the A2Σ+ and B2Π states of the NO molecule in a strong laser field have been investigated by the time-dependent wave packet method. We demonstrate
that the weak coupling between the A2Σ+ and B2Π states of NO plays a key role on the peak centered at 0.37 eV of the photoelectron spectra in the 2+1’ channel. 相似文献
15.
Tianyun Chen Ningjiu Zhao Weiping Zhang Xinqiang Wang 《Central European Journal of Physics》2011,9(5):1221-1227
Quasiclassical trajectory method for the title reaction He +H2+ → HeH+ + H was carried out on the potential energy surface which was revised by Aquilanti et al. [Chem. Phys. Lett. 469, 26 (2009)].
The initial vibrational quantum number of reactant was set as v=1, v=2 and v=3. Stereodynamics information of the reaction
was obtained, such as the distributions of product angular momentum P(θ
r
), P(ϕ
r
),p(ϕ
r
, θ
r
) and the two commonly used polarization-dependent differential cross sections (PDDCSs) (2π/σ)(dσ
00/dω
t
) and (2π/σ)(dσ
20/dω
t
), to get the alignment and orientation of product molecules. The results show that the influence of both the collision energy
and vibrational quantum number (v) to the reaction are highly sensitive. 相似文献
16.
Bose-Einstein correlations (BEC) between final state particles in the reaction
have been studied. Data corresponding to a total integrated luminosity of 550 pb-1, recorded by the DELPHI detector at centre-of-mass energies ranging from 189 to 209 GeV, were analysed. An indication for
inter-W BEC between like-sign particles has been found at the level of 2.4 standard deviations of the combined statistical
and systematic uncertainties.
Received: 11 January 2005, Revised: 13 July 2005, Published online: 13 September 2005
This paper is dedicated to the late Frans Verbeure.
Frans was a very active member of the DELPHI collaboration and its QCD
and WW working groups. The loss of Frans touched us all deeply. 相似文献
17.
L. González-Sánchez E. Bodo F. A. Gianturco 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(1):65-72
An ab initio computed potential energy surface is employed to
evaluate the interaction of the OH+(3Σ -) molecule with
4He(1S) atom and an analytic fitting of the raw points is
directly employed in quantum scattering calculations at ultralow
collision energies. The Hund's case (b) chosen to handle the
spin-rotation coupling allows to extract from the numerous inelastic
cross sections the relative importance of pure “spin flip" vis-à-
vis rotational cooling cross sections. The final rates of all the
above processes as a function of the initial |N〉 state are
analysed in detail and possible propensity rules are discussed. 相似文献
18.
S. Gentile H. Bilokon V. Chiarella G. Nicoletti 《The European Physical Journal C - Particles and Fields》2007,52(1):229-245
Results are presented on the discovery potential for MSSM neutral Higgs bosons in the mh-max scenario. The region of large cosβ, between 15 and 50, and mass between ≈95 and 130 GeV is considered in the framework
of the ATLAS experiment at the large hadron collider (LHC), for a centre-of-mass energy = 14 TeV. This parameter region is not fully covered by the present data either from LEP or from Tevatron. The h/A bosons,
supposed to be very close in mass in that region, are studied in the channel h/A→μ+μ- accompanied by two b-jets. The study includes a method to control the most copious background, Z→μ+μ- accompanied by two b-jets. A possible contribution of the H boson to the signal is also considered. 相似文献
19.
The contributions of various mechanisms to the production of the final nucleus 12C in the reaction 13C(3He, α)12C are estimated. These are neutron stripping and the transfer of the heavy cluster 9Be in the pole approximation or via a sequential transfer of virtual 8Be and a neutron. It is shown that the sequential mechanism of heavy-cluster transfer must be taken into account in order to describe correctly experimental data over the whole angular range. 相似文献
20.
G. V. Golubkov M. G. Golubkov R. J. Buenker 《Russian Journal of Physical Chemistry B, Focus on Physics》2011,5(6):921-924
The dissociative recombination theory of slow electrons with molecular ions in a strong monochromatic light field is developed.
Classifications of all possible transitions and reaction mechanisms are presented. The potential energy curves of the oxygen
molecule O2** dissociative states and partial cross sections are calculated. 相似文献