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1.
H. Dekker 《Zeitschrift für Physik B Condensed Matter》1976,3(2):211-218
Magnetic circular dichroism (MCD) of theA- andB-absorption band region has been obtained at 4.2 K and 50 kG in KI:Ga+, KI:In+, and KI:Sn2+. The MCD spectra indicate the complex nature of these bands more clearly than the absorption spectra themselves do. TheA-band MCD consists in all cases of a positive and a negative part reflecting the structure of the absorption band. TheB-band MCD shows three peaks, two positive peaks at 4.34 and 4.415 eV (4.09 and 4.175 eV) and a negative peak at 4.38 eV (4.125 eV) in KI:Ga+ (KI:In+). TheB-band in KI:Sn2+ consists of a shoulder (b
0) at 3.76 eV and a main band which has at least 5 sub-peaks (b
1~b
5) at 3.821, 3.841, 3.861, 3.880, and 3.895 eV; each of the subpeaks (b
1~b
5) gives a derivative-like MCD.The MCD shape functionf() for the transitiona
1g
2
a
1g
t
1u
has been obtained for one set of parameter values by using the classical Franck-Condon approximation and the Monte Carlo integration method. The result can explain the observed salient features of theB- as well asA-band MCD's, indicating the validity of the Franck-Condon approximation and the interaction mode coordinates. 相似文献
2.
For deformed even-mass nuclei the model of the axial-symmetric vibrating top with rotation-vibration-interaction is compared to the Davydov-model without and with aβ-band. TheE2-transition-probabilities are calculated. The coefficientsB ze andC fromE=A I(I+1) ?B ze I 2(I+1)2+C I 3(I+1)3 are obtained. For the transition-probabilities from the states of the γ-band to the states of the ground state band as well as forB andC the Davydov-model yields values only about half of those obtained from the RV-theory. A comparision to the present availuable experimental data is made. In the RV-model the agreement is better than in the Davydov-theory. 相似文献
3.
D. Bimberg W. Dultz K. Fussgänger W. Gebhardt 《Zeitschrift für Physik A Hadrons and Nuclei》1969,224(4):364-382
The electron-lattice interaction of NaCl:Tl+, KCl:Tl+, KBr:Tl+, and KI:Tl+ is discussed using the moments of the absorption bands. The discussion is based on a theory ofToyozawa andInoue andHonma. Consistency of the data is found for the absorption measurements. An analysis of the band shift under applied stress shows for theA-band in KCl and KBr and for theA- andB-band in KI that the electronlattice coupling constants derived from these data assuming next neighbour interaction differ considerably from those derived from the second moments of the bands. 相似文献
4.
TheA band of Tl+ centers in mixed crystals of KCl—KBr, KBr—KI, and KCl—KI is split into several subbands at low temperatures. The degree of the splitting increases with the difference of the anion radii. The relative size of the subbands strongly depends on the mixture ratio and on the thermal history. Each of the subbands gives its own fluorescence spectrum. As in pure crystals it consists of two subbands. The shorter wavelength band dominates at low temperatures. We interpret the results by considering complexes of the general form TlXnY6?n (n=1, ..., 5). Their symmetry is lower than in a uniform surrounding (n=0; 6). As a consequence the degeneracies of the excited electronic states are lifted. In KCl with a sufficient low content of KI we get only TlICl5 in addition to TlCl6. From the equilibrium at different temperatures we find 0.07 eV for the energy of association of I? to Tl+. TlICl5 centers absorb in theA 0 band, which is equivalent to theA band of the pure TlCl6, and in anA 1 band at longer wavelength. TheA n1 fluorescence can be linearly polarized up to 60% in [100] direction. By applying uniaxial stress to the crystal in [100] direction at higher temperatures the TlICl5 complexes can be partially oriented parallel to [100]. This gives a slight dichroism in theA 1 band. 相似文献
5.
The body frame fixed nuclei and the laboratory frame rotational close coupling approximations have been employed to calculate electronic excitation of H2 (X1
g
+
B1
u
+
) by positron impact. Two electronic states (X1
g
+
and B1
u
+
) and three rotational states in both the elastic and excitation channels are retained in the calculations. Results are reported for electronically elastic, excitation and rotational cross sections up to the incident energy 75.0 eV. The elastic cross sections are found to be influenced significantly with the addition of B1
u
+
state in the expansion scheme, in both the models used. Above the incident energy of 25.0 eV, the electronic excitation cross sections using the laboratory frame differ significantly from those of the fixed nuclei model. 相似文献
6.
The branching ratios and differential distributions for the four-leptonic decays \({B^ - } \to {\mu ^ + }{\mu ^ - }{\bar v_e}{e^ - }\), \({B^ - } \to {e^ + }{e^ - }{\bar v_\mu }{\mu ^ - }\), and \({B^ - } \to {\mu ^ + }{\bar v_\mu }{\mu ^ - }{\mu ^ - }\) are calculated within the Standard Model. The branching ratios for the rare decays Bd,s → e+e?μ+μ? and Bd,s → μ+μ?μ+μ? are estimated. Methods for testing the lepton universality in rare multileptonic decays of charged and neutral B mesons are proposed. 相似文献
7.
The He/N2 system lasing on the N
2
+
(B)N
2
+
(X, 0) transition at 391 nm and on the N
2
+
(B)N
2
+
(X, 1) transition at 428 nm was investigated by e-beam excitation. By adding H2 the lower laser state is efficiently quenched, which leads to a drastic improvement of the laser properties. A kinetic model is proposed which accounts for the experimental results. For a laser amplifier operated at 5 bar total efficiencies of 0.6% and 0.7% are predicted for the 391 nm and the 428 nm transitions respectively. 相似文献
8.
Motivated by the experimental accessibility of rareB decays in the ongoing and planned experiments, we propose to undertake a model-independent analysis of the inclusive decay rates and distributions in the processesBX
s
andBX
s
+– (B=B
± orB
d
0
). We show how measurements of the decay rates and distributions in these processes would allow us to extract the magnitude and sign of the dominant Wilson coefficients of the magnetic moment operator
and the fourfermion operators
and
. Non-standard-model effects could thus manifest themselves at low energy in rareB decays through the Wilson coefficient having values distinctly different from their standard-model counterparts. We illustrate this possibility using the examples of the two-doublet Higgs models and the minimal supersymmetric models. The dilepton invariant mass spectrum and the forward-backward asymmetry of + in the centre-of-mass system of the dilepton pair in the decayBX
s
+– are also worked out for the standard model and some representative solutions for the other two models. 相似文献
9.
TheA
1
–X
1
+ system of SnO is studied by laser- induced fluorescence excitation spectroscopy using isotopically enriched tin Sn116. The rotational structure analysis has been carried out for 6-0, 5-0, 2-0 bands. All these spectra were well resolved only with few perturbed lines in 2-0 band. Rotational constantsB
2,B
5,B
6 and henceB
e
,
e
e
have been obtained for the Sn116O molecule. An extension of perturbation study on 4-0 band has been made showing the maximum perturbation occurs at different J values for different isotopes. 相似文献
10.
M. Kobel D. Antreasyan H. W. Bartels D. Besset Ch. Bieler J. K. Bienlein A. Bizetti E. D. Bloom I. Brock K. Brockmüller et al. 《Zeitschrift fur Physik C Particles and Fields》1992,53(2):193-205
Using the Crystal Ball detector at thee
+
e
– storage ring DORIS II, we have measured the branching fraction to muon pairsB
of the (1S) and (2S) resonances and for the first time the product of the muonic partial width
and the branching fraction to electronsB
ee
for both resonances. We obtain
相似文献
11.
Th. Woike S. Haussühl B. Sugg R. A. Rupp J. Beckers M. Imlau R. Schieder 《Applied physics. B, Lasers and optics》1996,63(3):243-248
Phase and amplitude gratings in the visible and near-infrared spectral range can be written in SodiumNitro-Prusside (SNP), Na2[Fe(CN)5NO] · 2H2O, single crystals by optical excitation of infinitely long-living metastable electronic states, localized in the [Fe(CN)5NO]2– anions. Hence, its photorefractive effect does not depend on dopants or defects. The refractive index is modulated by more thann = 1 × 10–3 in the red (632.8 nm) andn = 5 × 10–4 in the near-infrared region (1047 nm). The absorption coefficient is modulated by about = 100 m–1 at 632.8 nm and 40 m–1 at 1047 nm. The wavelength dependence ofn can be explained by strong absorption bands in the ultraviolet considering Kramers-Kronig dispersive analysis. The time constant of the write-read-erase processes and the diffraction efficiency depend on light intensity, wavelength and polarization of the light with respect to the crystallographic axes. After excitation of the metastable states the indicatrix is modulated only along thea- andb-axis of the orthorhombic system. 相似文献
12.
13.
V. L. Lepore 《Foundations of Physics Letters》1989,2(1):15-26
The probabilistic formulation of local realism is shown to imply the existence of physically meaningful limits for arbitrary linear combinations of joint probabilities. The set of the so generated inequalities (setA) is wider than the previously known set of inequalities for linear combinations of correlation functions (setB). One particular inequality of the setA is shown to be violated by the probabilities of the Garg-Mermin model. The same model satisfies instead all the inequalities of the setB. As a consequence, the Garg-Mermin model is nonlocal and the setA provides physical restrictions not contained in the setB.
1. In the adopted formalism it is implicitly assumed that physical properties of the type are not created in the act of measurement. IfB(b) is measured on the systems, the setT is split into two parts,T(b
±), corresponding to the resultsB(b) = ±1, respectively. AlsoS is split intoS(b
±) from the existing correlation between and systems. If it is possible to predict that a measurement ofA(a) on the's of, say,S(b
+) will give the results ±1 with respective probabilitiesP
±, then, on the basis of the probabilistic criterion of reality, we can attribute a physical property + toS(b
+) such that
p(a
+, +) is the probability ofA(a) = +1 inS(b
+),
p(a
–, +) is the probability ofA(a) = –1 inS(b
+).It is natural to assume that + belongs toS(b
+) also ifA(a) isnot measured. In so doing, we exclude that future measurements create, with a retroaction in time, the physical properties of the statistical ensembles on which these measurements are performed. 相似文献
14.
B. Ackermann H. Baltzer K. Freitag C. Günther P. Herzog J. Manns U. Müller R. Panlsen P. Sevenich T. Weber B. Will J. de Boer G. Graw A. I. Levon M. Loewe A. Lösch E. Müller-Zanotti 《Zeitschrift für Physik A Hadrons and Nuclei》1994,350(1):13-28
Nuclear levels in230Th have been investigated in the decay of230Pa, the230Th(d, pn) reaction and the232Th(p, t) reaction. TheK
=0
1
+
, 2
1
+
, and 2
2
+
bands with band heads at 635, 781, and 1010 keV were observed up to the 8+, 9+, and 7+ levels, respectively. A second excited 0+ level was identified at 1297 keV which might be interpreted as the usual shape-oscillation. The branching ratios of theE2 transitions from the 0
1
+
, 2
1
+
, and 2
2
+
bands are explained in the framework of the rotational model by taking into account the coupling of these bands with the ground-state band, and the coupling between the 0
1
+
and 2
1
+
band. A strong enhancement ofE2 transitions from the 2
1
+
to the 0
1
+
band reported earlier is not confirmed. For the octupole vibrations withK
=0–, 1–, and 2– theE1 branching ratios are analyzed in terms of the Coriolis coupling of these bands. An almost complete experimental set ofE1 transition moments from these negative-parity bands to the 0
g
+
, 0
1
+
, and 2
1
+
bands was obtained. It is suggested that octupole correlations might be important in explaining theseE1 moments.We appreciate the help of Mr. Assmus with the proton irradiations and the financial support of the Kernforschungszentrum Karlsruhe GmbH. This work was supported by the Deutsche Forschungsgemeinschaft (grants Bo 1109/1-1, Gr 894/2-1, Gu 179/3-1 and He 1316/2-3) and by the Volkswagen Stiftung. 相似文献
15.
Employing inverse photoemission we have remeasured the energy dispersionE(k) of the lowest-lying image state on Ag(100) with improved energy resolution (electrons and photons, E=0.35 eV) andk-resolution (k<0.1 Å–1). In a least-square fit with the binding energyE
B
atk=0 and the effective massm
* as parameters we obtainE
B
=E
vac –0.67 eV andm
*=1.5 m in agreement with our earlier findings but differing from the two-photon photoemission values (0.53 eV and 1.15 m). 相似文献
16.
I. Haslingerová 《Czechoslovak Journal of Physics》1977,27(12):1389-1393
Estimations of the bond energies from Mulliken overlap populations are taken. The strength of a bond is undoubtedly connected with the density of electrons constituting this bond. In the present paper the electron densities
i
bond
belonging to the particular bonds are represented by the total overlap populations defined byMulliken. The heat of atomization of the molecule is subdivide in the ratio of these electron densities
i
bond
belonging to the individual bond.My thanks are due to Drs. S.erný, Z.Knor, J.Pancí and R.Zahradník for their interest and stimulating discussions. 相似文献
17.
P. Abreu W. Adam T. Adye E. Agasi G. D. Alekseev A. Algeri P. Allen S. Almehed S. J. Alvsvaag U. Amaldi et al. 《Zeitschrift fur Physik C Particles and Fields》1993,57(2):181-195
A study ofB meson decays intoDl
X final states is presented. In these events, neutral and chargedD mesons originate predominantly fromB
+ andB
0 decays, respectively. The dilution of this correlation due toD
** production has been taken into account. From 263 700 hadronicZ
0 decays collected in 1991 with the DELPHI detector at the LEP collider, 92D
0K
-+, 35D
+K
-++ and 61D
*0D
0+ followed byD
0K
-+ orD
0K
-++-, are found with an associated lepton of the same charge as the kaon. From theD
0
l
- andD
*+
l
-, the probabilityf
d that ab quark hadronizes into aB
– (or
) meson is found to be 0.44 ±0.08±0.09, corresponding to a total (B
s+
b
) hadronization fraction of 0.12
–0.12
+0.24
. By reconstructing the energy of eachB meson, theb quark fragmentation is directly measured for the first time. The mean value of theB meson energy fraction is:
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