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1.
Summary A universal thermal conductance of charge carriersK=2π2
k
B
2
T/(3h) is rigorously derived within a correlation-function formalism. Similar to the case of the universal electrical conductanceG=2e
2
/h this result pertains to one-dimensional, ballistic, and degenerate conditions for non-interacting particles. 相似文献
2.
Y. H. Zhang T. Hayakawa M. Oshima Y. Toh J. Katakura Y. Hatsukawa M. Matsuda N. Shinohara T. Ishii H. Kusakari M. Sugawara T. Komatsubara 《The European Physical Journal A - Hadrons and Nuclei》2000,8(4):439-442
High spin states in 178Ir have been studied via the 152Sm(31P, 5nγ)178Ir reaction through excitation functions, X-γ and γ-γ-t coincidence measurements. According to the band structure characteristics
and the measured intraband B(M1)/B(E2) ratios, two rotational bands are identified and assigned to be associated with the πh
9/2⊗νi
13/2 and πh
11/2⊗νi
13/2 configurations, respectively. Both bands show the signature inversion feature.
Received: 23 March 2000 / Accepted: 31 July 2000 相似文献
3.
Two metastable states of a multilayer Ge/p-Ge1−x
Six heterosystem with wide (∼ 35 nm) potential wells (Ge) are observed in strong magnetic fields B at low temperatures. In the first state, the Hall resistivity exhibits an inflection near the value ρxy=h/e
2 scaled to one Ge layer. The longitudinal magnetoresistivity ρxx(B) possesses a minimum in the range of fields where this inflection occurs. The temperature evolution of the inflection in
ρxy(B), the minimum of ρ xx(B), and the value of ρxy at the inflection indicates a weakly expressed state of the quantum Hall effect with a uniform current distribution over
the layers. In the second metastable state, an unusually wide plateau near h/2e
2 with a very weak field dependence is observed in ρxy(B). Estimates show that in these samples the Fermi level lies below but close to the top of the inflection in the bottom of
the well. For this reason, the second state can be explained by separation of a hole gas in the Ge layers into two sublayers,
and the saturation of ρxy(B) near h/2e
2 can be explained by the formation of a quantum Hall insulator state.
Pis’ma Zh. éksp. Teor. Fiz. 70, No. 4, 290–297 (25 August 1999) 相似文献
4.
M. Cleven F. -K. Guo C. Hanhart U. -G. Meißner 《The European Physical Journal A - Hadrons and Nuclei》2011,47(10):120
The assumption that the newly observed charged bottomonia states Z
b(10610) and Z
b(10650) are of molecular nature is confronted with the measured invariant-mass distributions for the transitions of the ϒ(5S) to the final states h
b
π
+
π
− and h
b(2P)π
+
π
−. It is shown that the assumption that the Z
b(10610) and Z
b(10650) are B
[`(B)]*\bar B* + c.c. and B
*
[`(B)]*\bar B* bound states, respectively, with very small binding energies is consistent with the data. The calculation is based on a power
counting for bottom meson loops, which is explicitly given up to two-loop in the framework of a nonrelativistic effective-field
theory. We also show that if the Zb states are of molecular nature, then the data should not be analyzed by using a Breit-Wigner parametrization. 相似文献
5.
K. Singh S. Sihotra S. S. Malik J. Goswamy D. Mehta N. Singh R. Kumar R. P. Singh S. Muralithar E. S. Paul J. A. Sheikh C. R. Praharaj 《The European Physical Journal A - Hadrons and Nuclei》2006,27(3):321-324
The collective band structures of the 125Cs nucleus have been investigated by in-beam γ-ray spectroscopic techniques following the 110Pd ( 19F, 4n) reaction at 75MeV. The previously known level scheme, with rotational bands built on πg7/2, πg9/2 and πh11/2 orbitals, has been extended and evolves into bands involving rotationally aligned ν(h11/2)2 and π(h11/2)2 quasiparticles. A strongly coupled band has been reassigned a high-K πh11/2 ⊗ νg7/2 ⊗ νh11/2 three-quasiparticle configuration and a new side band likely to be its chiral partner has been identified. Configurations
assigned to various bands are discussed in the framework of Principal/Tilted Axis Cranking (PAC/TAC) model calculations. 相似文献
6.
D.V. Bugg 《The European Physical Journal C - Particles and Fields》2006,47(1):57-64
Ratios of coupling constants for these decays are compared with qq̄ predictions and Jaffe’s q2q̄2 model. In both models, the predicted ratio g2(κ→Kπ)/g2(σ→ππ) is much too small. Also, for qq̄, the predicted ratio g2(κ→Kη’)/g2(κ→Kπ) is much larger than observed. Both models fail for g2(f0→KK)/g2(a0→KK). This ratio requires that f0 has a dominant KK component. It arises naturally because the f0 pole lies very close to the KK threshold, giving its wave function a long KK tail.
PACS 13.25.Gv, 14.40.Gx, 13.40.Hq 相似文献
7.
Kuljeet Singh Z. Naik R. Kumar J. Goswamy D. Mehta N. Singh C. R. Praharaj E. S. Paul K. P. Singh R. P. Singh S. Muralithar N. Madhavan J. J. Das S. Nath A. Jhingan P. Sugathan R. K. Bhowmik 《The European Physical Journal A - Hadrons and Nuclei》2005,25(3):345-354
High-spin states in 123Cs, populated via the 100Mo ( 28Si, p4n) fusion-evaporation reaction at E
lab = 130 MeV, have been investigated employing in-beam γ-ray spectroscopic techniques. Rotational bands, built on πg
7/2, πg
9/2 and the unique-parity πh
11/2 orbitals, have been extended and evolve into bands involving rotationally aligned ν(h
11/2)2 and π(h
11/2)2 quasiparticles. A three-quasiparticle band based on the high-K πh
11/2 ⊗ νg
7/2 ⊗ νh
11/2 configuration has also been observed. Total Routhian Surface (TRS) calculations have been used to predict the nuclear shape
parameters ( β2, β4, γ) for the various assigned configurations. The assigned configurations have been discussed in the framework of a microscopic
theory based on the deformed Hartree-Fock (HF) and angular-momentum projection techniques. 相似文献
8.
Zhong Liu Yuhu Zhang Yingjun Ma Y. Sasaki K. Yamada H. Oshima H. Yokose M. Ishizuka T. Komatsubara K. Furuno 《中国科学G辑(英文版)》2003,46(4):390-397
Excited states of125Sb have been studied using in-beam γ spectroscopy techniques via the124Sn(7Li, α2n) reaction at a beam energy of 32 MeV. A high-spin level scheme including 21 new γ-transitions and 14 new excited states
have been established. Three isomers have been identified at 1970, 2110 and 2471 keV and the ranges of their half-lives have
been estimated from the delayed coincidence data. The level structure of125Sb is discussed in terms of particle-core excitation coupling. With the help of empirical shell model calculations the three
isomers are proposed to have three-quasiparticle πg7/2⊗v(h
11/2
s
1/2)5−, πg7/2⊗v(h
11/2
d
3/2)7− and πg7/2⊗v(h
112/2)10
+ configurations, respectively. 相似文献
9.
BES II data for J/Ψ↦K
*(890)Kπ reveal a strong κ peak in the Kπ S-wave near threshold. Both magnitude and phase are determined in slices of Kπ mass by interferences with strong K
0(1430), K
1(1270) and K
1(1400) signals. The phase variation with mass agrees within errors with LASS data for Kπ elastic scattering. A combined fit is presented to both BES and LASS data. The fit uses a Breit-Wigner amplitude with an
s-dependent width containing an Adler zero. The κ pole is at (760±20(stat)±40(syst)) - i(420±45(stat)±60(syst)) MeV. The S-wave I = 0 scattering length a
0 = 0.23±0.04 m
π
-1 is close to the prediction 0.19±0.02 m
π
-1 of Chiral Perturbation Theory at O(p
4).
An erratum to this article can be found at . 相似文献
10.
J. Genevey J.A. Pinston H. Faust C. Foin S. Oberstedt M. Rejmund 《The European Physical Journal A - Hadrons and Nuclei》2000,9(2):191-195
In this work we have identified and studied the decay of two new microsecond isomers 19/2- and 23/2+ in 131Sb. This neutron-rich nucleus was produced by thermal neutron-induced fission of 241Pu. The detection is based on time correlation between fission fragments selected by the LOHENGRIN spectrometer at ILL (Grenoble)
and the γ-rays or conversion electrons from isomers. These new data on high-spin states complete the level scheme previously
obtained from β-decay. A large fraction of the members of the πg
7/2ν(h
11/2
-1
d
3/2
-1) and πg
7/2νh
11/2
-2 multiplets are now known and were compared with a multi-particle shell model calculation.
Received: 7 June 2000 / Accepted: 19 September 2000 相似文献
11.
G. Fabritius G. Flik J. Golczewski D. Herlach G. Jünemann M. Krenke K. Maier A. P. Pathak H. Rempp A. Seeger W. Sigle E. Widmann D. W. Cooke 《Hyperfine Interactions》1986,31(1-4):229-234
By means of π+/μ+ channelling, positive pions (π+) implanted intoTa, Mo, andW are investigated up to high temperatures. A striking observation is that the channelling effect disappears in a rather narrow
temperature interval centred at 0.26 (Ta) to 0.51 (W) of the melting temperature. From studies of π+ trapping by oxygen atoms inTa estimates for the low-temperature π+ diffusivity inTa [D
π(23K)=1.4·10−10±0.3 m2s−1,D
π(47K)=5.7·10−10±0.3 m2s−1] as well as for the binding enthalpy of π+ to 0 atoms (H
B=7·10−2 eV) have been obtained. The diffusion data are in reasonable agreement with the theory of phonon-assisted tunnelling. 相似文献
12.
A. Margaryan O. Hashimoto V. Kakoyan S. Knyazyan L. Tang 《Physics of Atomic Nuclei》2011,74(2):216-220
A new “tagged-weak π method” is proposed for determination of electromagnetic transition probabilities B(E2) and B(M1) of the hypernuclear states with lifetimes of ∼10−10 s. With this method, we are planning to measure B(E2) and B(M1) for light hypernuclei at JLab. The results of Monte Carlo simulations for the case of E2(5/2+, 3/2+ → 1/2+) transitions in Λ7He hypernuclei are presented. 相似文献
13.
M. Yasin Akhtar Raja Wade N. Sisk Mohammad Yousaf David Allen 《Applied physics. B, Lasers and optics》1996,64(1):79-84
Experimental investigations of the photon’s B
(3)-field (third longitudinal polarization) are reported. The existence of an “axial magnetostatic field of photon” has been
predicted in B
π or B
(3)-theory as the fundamental property of the circularly polarized light, and reported in numerous papers and monographs. High-sensitivity
detection has been employed in photomagnetic induction, Faraday, and inverse Faraday effects (IFE) originating from such a
field. The results of all three experiments clearly disprove the claims of B
π-theory. Putting together these results and theoretical calculations in perspective, it is concluded that such fields are
non-existent.
Received: 25 January 1996 / Revised version: 24 May 1996 相似文献
14.
S. S. Murzin 《JETP Letters》1998,67(3):216-221
The conductance of doped n-GaAs films is studied experimentally as a function of magnetic field and temperature in strong magnetic fields right up to
the quantum limit (ħωc = E
F). The Hall conductance G
xy is virtually independent of temperature T until the transverse conductance G
xx is quite large compared with e
2/h. In strong fields, when G
xx becomes comparable to e
2/h, G
xy starts to depend on T. The difference between the conductances G
xx at the two temperatures 4.2 and 0.35 K depends only weakly on the magnetic field H over a wide range of magnetic fields, while the conductances G
xx themselves vary strongly. The results can be explained by quantum corrections to the conductance as a result of the electron-electron
interaction in the diffusion channel. The possibility of quantization of the Hall conductance as a result of the electron-electron
interaction is discussed.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 3, 201–206 (10 February 1998) 相似文献
15.
Two-and three-body decays of γ(5S) into BB, BB*, B*B*, B
s
B
s
, B
s
B
s
*, and BB*π, B*B*π are evaluated using the theory developed earlier for dipion-bottomonium transitions. The theory contains only two parameters—vertex
masses M
br
and M
ω—known from the dipion spectra and width. Predicted values of Γtot(5S) and six partial widths Γ
k
(5S), k = BB, BB*, ... are in agreement with the experiment. The decay widths Γ5S
(πBB*) and Γ5S
(πB*B*) are also calculated and found to be on the order of 10 keV.
The text was submitted by the authors in English. 相似文献
16.
R. Kumar D. Mehta N. Singh H. Kaur A. Görgen S. Chmel R.P. Singh S. Murlithar 《The European Physical Journal A - Hadrons and Nuclei》2001,12(1):5-8
The band structures built on the 5- isomeric state ( T
1/2 = 3.46 m) in the doubly odd 130Cs nucleus have been established up to I = 24? via the 124Sn(11B, 5n)130Cs reaction. The previously observed bands based on the πh
11/2⊗νh
11/2, πg
7/2⊗νh
11/2 and πd
5/2⊗νh
11/2 configurations and a positive-parity side band with multiple connections to the α = 0 signature partner of the yrast πh
11/2⊗νh
11/2 band have been extended to higher spins. A new band based on the πh
11/2⊗νg
7/2 configuration is observed. The yrast πh
11/2⊗νh
11/2 band exhibits anomalous signature splitting whose magnitude decreases up to spin 15 and then increases without restoring
the normal signature splitting.
Received: 20 February 2001 / Accepted: 9 May 2001 相似文献
17.
S. Cohen 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(1):67-74
The systematics of perturbative semiclassical quantum
defect expansions corresponding to a hydrogenic potential plus a perturbing
term of the form -A/2rκ,
k\geqslant 2\kappa \geqslant 2, are studied as a function
of expansion order N. Towards this task the expansions μ
Nare first used
as input for constructing associated N-dependent atomic RKR-QDT potential
curves. Subsequently the coordinate Fisher information for the energy levels
supported by those curves as well as its rate ε with respect to N is
semiclassically computed. Then, the plot of relative quantum defect error
between successive orders, δμ
N+1,N, with respect to ε serves as
convergence indicator for both approximate potentials and quantum defects.
For a given κ and when the quantum defect expansion proves to be of limited
accuracy the plot reveals an A- and N-dependent scatter of points and
“saturation” (the relative error remains almost constant with respect to
ε). More importantly, when ε is equal to or lower than the value of
ε (N=1) for which πμ
1\leqslant 1/2_{1}\leqslant 1/2 the relative error exhibits a κ-, A- and
N-independent power-law dependence, δμ
N+1,N∝ ε
m, clearly
distinguishing the N=1 order (m=1/2) from all other N>1 orders (m=1). These
power-laws may be employed for setting-up confidence level bounds on
perturbative expansions. 相似文献
18.
X. H. Zhou L. Ma Y. B. Xing Y. H. Zhang Y. X. Guo X. G. Lei C. Y. Xie M. Oshima Y. Toh M. Koizumi A. Osa Y. Hatsukawa M. Sugawara M. M. Ndontchueng 《The European Physical Journal A - Hadrons and Nuclei》2006,28(3):271-275
Excited states in 188Tl have been studied experimentally using the 157Gd (35Cl, 4n) reaction at a beam energy of 170MeV. A rotational band built on the πh
9/2 ⊗ νi
13/2 configuration with oblate deformation has been established for 188Tl. Based on the structure systematics of the oblate πh
9/2 ⊗ νi
13/2 bands in the heavier odd-odd Tl nuclei, we have tentatively proposed spin values for the new band in 188Tl. The πh
9/2 ⊗ νi
13/2 oblate band in 188Tl shows low-spin signature inversion, and it can be interpreted qualitatively by the two-quasiparticle plus rotor model including
a J-dependent p-n residual interaction. 相似文献
19.
Murugesh Duraisamy Alexander L. Kagan 《The European Physical Journal C - Particles and Fields》2010,70(4):921-925
CLEO-c measurements of the timelike form factors F
π
, F
K
at ?s=3.671\sqrt{s}=3.671 GeV provide a direct probe of power corrections (PC’s) at energies near m
B
. PC’s in F
π,K
and B→Kπ,ππ are separated into perturbative and soft parts. In F
π,K
the latter are ≥O(10) larger. A PC fit to the B→Kπ,ππ data also yields a ≥O(10) soft-to-perturbative hierarchy for the QCD penguin PC’s. Hence, both can be attributed to dominance of the soft-overlap
between energetic (approximately) back-to-back collinear partons, and consistency of the B→Kπ,ππ fit with the Standard Model appears to be naturally realized. The CP asymmetries SKs p0S_{K_{s} \pi^{0}}, CKs p0C_{K_{s} \pi^{0}} are well determined, providing a clean test for new physics. 相似文献
20.
Minamisono T. Matsuta K. Minamisono K. Kudo S. Ogura M. Fukuda S. Sato K. Mihara M. Fukuda M. 《Hyperfine Interactions》2001,136(3-8):225-231
In order to precisely determine the |eqQ(41Sc)/h| of 41Sc(I
π=7/2−, T
1/2=0.596 s) implanted in a TiO2 single crystal the electric field gradient tensor and anisotropic chemical shift were determined by detecting the Fourier
Transformed Pulse-NMR of 45Sc(I
π=7/2−, stable) in the crystal at a high field of 7.0 T and 9.4 T. Combining the new |eqQ(41Sc)/h| value with the Q(45Sc)=−(23.6±0.2) fm2, also renewed by using the known atomic hyperfine interaction constants and Sternheimer polarization effect, the |Q(41Sc;I
π=7/2−,T
1/2=0.596 s)|=(15.6±0.3) fm2 has been precisely determined. The value is compared with the theoretical Q(41Sc) given by a shell model code.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献