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1.
The hyperfine splittings in heavy quarkonia are studied in a model-independent way using experimental data on dielectron widths.
Relativistic correlations are taken into account together with the smearing of spin-spin interaction. The radius of smearing
is fixed by known G/ψ−η
c(1S), ψ(2S)−η
c′(2S) splittings, which appears to be small, r
ss ≅ 0.06 fm. Nevertheless, even with such a small radius, substantial suppression of hyperfine splittings (∼50%) is observed
in bottomonium. For nS b
states (n = 1, 2, ..., 6), our predicted splittings (in MeV) are 28, 12, 10, 5, 6, 3. For the 3S and 4S charmonium states, the splittings 16(2) and 12(4) MeV are obtained.
The text was submitted by the authors in English. 相似文献
2.
3.
Yu. A. Simonov 《JETP Letters》2008,87(3):121-123
The dipion spectrum for the ϒ(nS) → ϒ(n′S) transition with n < 4 has the form dw/dq ∼ (phase space) |η − x|2, with x = q
2 − 4m
π2 / (ΔM)2 − 4m
π2 < q
2 ≡ M
ππ2, and ΔM = M(nS) − M(n′S). The parameter η is calculated and the spectrum is shown to reproduce the experimental data for all three types of decays:
3 → 1, 2 → 1, and 3 → 2 with η ≈ 0.5, 0, and −3, respectively.
The text was submitted by the author in English. 相似文献
4.
Gui-Jun Ding 《The European Physical Journal C - Particles and Fields》2009,64(2):297-308
The interpretation of Y(4140) as a D*s[`(D)]*sD^{*}_{s}\bar{D}^{*}_{s} molecule is studied dynamically in the one boson exchange approach, where σ, η and φ exchange are included. Ten allowed D*s[`(D)]*sD^{*}_{s}\bar{D}^{*}_{s} states with low spin parity are considered, and we find that the J
PC
=0++, 1+−, 0−+, 2++ and 1−−
D*s[`(D)]*sD^{*}_{s}\bar{D}^{*}_{s} configurations are most tightly bound. We suggest that the most favorable quantum numbers are J
PC
=0++ for Y(4140) as a D*s[`(D)]*sD^{*}_{s}\bar{D}^{*}_{s} molecule; however, J
PC
=0−+ and 2++ cannot be excluded. We propose to search for the 1+− and 1−− partners in the J/ψ
η and J/ψ
η′ final states, which is an important test of the molecular hypothesis of Y(4140) and the reasonability of our model. The 0++
B*s[`(B)]*sB^{*}_{s}\bar{B}^{*}_{s} molecule should be deeply bound; experimental search in the ϒ(1S)φ channel at Tevatron and LHC is suggested. 相似文献
5.
V. V. Anisovich L. G. Dakhno M. A. Matveev V. A. Nikonov A. V. Sarantsev 《Physics of Atomic Nuclei》2007,70(1):63-92
In the framework of the spectral integral equation, we consider the
states and their radiative transitions. We reconstruct the
interaction on the basis of data for the levels of the bottomonium states with J
PC = 0−+, 1−−, 0++, 1++, 2++ as well as the data for the radiative transitions γ (3S) → γχbJ(2P) and γ(2S) → γχbJ(1P) with J = 0, 1, 2. We calculate bottomonium levels with the radial quantum numbers n ≤ 6, their wave functions, and corresponding radiative transitions. The ratios Br[χbJ(2P) → γγ(2S)]/Br[χbJ(2P) → γγ(1S)] for J = 0, 1, 2 are found to be in agreement with data. We determine the
component of the photon wave function using the data for the e
+
e
− annihilation, e
+
e
− → γ(9460), γ(10 023), γ(10 036), γ(10 580), γ(10 865), γ(11 019), and predict partial widths of the two-photon decays ηb0 → γγ, χb0 → γγ, χb2 → γγ for the radial excitation states below the
threshold (n ≤ 3).
The text was submitted by the authors in English. 相似文献
6.
Riccardo Barbieri Paolo Campli Gino Isidori Filippo Sala David M. Straub 《The European Physical Journal C - Particles and Fields》2011,71(12):1812
We study CP asymmetries in rare B decays within supersymmetry with a U(2)3 flavour symmetry, motivated by the SUSY flavour and CP problems, the hierarchies in the Yukawa couplings and the absence
so far of any direct evidence for SUSY. Even in the absence of flavour-blind phases, we find potentially sizable CP violating
contributions to b→s decay amplitudes. The effects in the mixing-induced CP asymmetries in B→ϕK
S
and B→η′K
S
, angular CP asymmetries in B→K
∗
μ
+
μ
− and the direct CP asymmetry in B→X
s
γ can be in the region to be probed by LHCb and next generation B factories. At the same time, these effects in B decays are compatible with CP violating contributions to meson mixing, including
a non-standard B
s
mixing phase hinted by current tensions in the CKM fit mostly between SyKS, eKS_{\psi K_{S}}, \epsilon_{K} and DMBs/DMBd\Delta M_{B_{s}}/\Delta M_{B_{d}}. 相似文献
7.
Bo Zhang Xiang Liu Wei-Zhen Deng Shi-Lin Zhu 《The European Physical Journal C - Particles and Fields》2007,50(3):617-628
Recently the Babar Collaboration reported a new cs̄ state, DsJ(2860), and the Belle Collaboration observed DsJ(2715). We investigate the strong decays of the excited cs̄ states using the 3
P
0 model. After comparing the theoretical decay widths and decay patterns with the available experimental data, we are inclined
to conclude that: (1) DsJ(2715) is probably the 1-(13
D
1) cs̄ state, although the 1-(23
S
1) assignment is not completely excluded; (2) DsJ(2860) seems unlikely to be the 1-(23
S
1) and 1-(13
D
1) candidate; (3) to consider DsJ(2860) either as a 0+(23
P
0) or as a 3-(13
D
3) cs̄ state is consistent with the experimental data; (4) the experimental search of DsJ(2860) in the channels Dsη, DK*, D*K and Ds
*η will be crucial to distinguish the above two possibilities.
PACS 13.25.Ft; 12.39.-x 相似文献
8.
Let us have a finite set B (basin) with n>1 elements, which we call points, and a map M:B→B. Following Vladimir Arnold, we call such pairs (B,M) monads. Here we study a class of random monads, where the values of M(⋅) are independently distributed in B as follows: for all a,b∈B the probability of M(a)=a is s and the probability of M(a)=b, where a≠b, is (1−s)/(n−1). Here s is a parameter in [0,1]. 相似文献
9.
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
10.
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
11.
The newly observed open-charm states in quark model 总被引:1,自引:0,他引:1
De-Min Li Peng-Fei Ji Bing Ma 《The European Physical Journal C - Particles and Fields》2011,71(3):1582
Comparing the measured properties of the newly observed open-charm states D(2550), D(2600), D(2750), D(2760), D
s1(2710), D
sJ
(2860), and D
sJ
(3040) with our predicted spectroscopy and strong decays in a constituent quark model, we find that (1) the D(2 1
S
0) assignment to D(2550) remains open for its too broad width determined by experiment; (2) the D(2600) and D
s1(2710) can be identified as the 2 3
S
1–1 3
D
1 mixtures; (3) if the D(2760) and D(2750) are indeed the same resonance, they would be the D(1 3
D
3); otherwise, they could be assigned as the D(1 3
D
3) and D¢2(1D)D^{\prime}_{2}(1D), respectively; (4) the D
sJ
(2860) could be either the D
s1(2710)’s partner or the D
s
(1 3
D
3); and (5) both the D
s1(2P) and D¢s1(2P)D^{\prime}_{s1}(2P) interpretations for the D
sJ
(3040) seem likely. The E1 and M1 radiative decays of these sates are also studied. Further experimental efforts are needed to test the present quarkonium
assignments for these new open-charm states. 相似文献
12.
It is shown that a 25(20)% difference between the decay constants
(
) and f
D
(f
B
) occurs due to large differences in the pole masses of the s and d(u) quarks. The values η
D
=
/f
D
∼ 1.23(15), recently observed in the CLEO experiment, and η
B
=
/f
B
∼ 1.20, obtained in unquenched lattice QCD, can be reached only if, in the relativistic Hamiltonian the running mass, m
s
at low scale is m
s
(∼0.5 GeV) = 170–200 MeV. Our results follow from the analytical expression for the pseudoscalar decay constant f
P based on the path-integral representation of the meson Green’s function.
The text was submitted by the authors in English. 相似文献
13.
14.
Yu. M. Smirnov 《Optics and Spectroscopy》2012,112(1):50-55
The electron-impact excitation of doublet D-levels of the lutetium atom is studied by the method of extended crossing beams. At the exciting electron energy of 50 eV,
64 excitation cross sections are measured. In the electron energy range of 0–250 eV, nine excitation optical functions are
recorded. The occurrence of perturbations in the spectral series 6s
2(1
S)6p
2
P
12/○ − 6s
2(1
S)nd
2
D
3/2 is discussed. 相似文献
15.
Approximating the shape of the magneto-thermoelectric power (TEP) ΔS(T,H) measured in Bi2Sr2CaCu2Oy by an asymmetric linear triangle of the form ΔS(T,H)≃S
p
(H)±B
±(H)(T
c
−T) with positive B
−(H) and B
+(H) defined below and above T
c
, we observe that B
+(H) ≃2B
−(H). To account for this asymmetry, we explicitly introduce the field-dependent chemical potential μ(H) of holes into the Ginzburg-Landau theory and calculate both an average ΔS
av(T,H) and fluctuation contribution ΔS
fl(T,H) to the total magneto-TEP ΔS(T,H). As a result, we find a rather simple relationship between the field-induced variation of the chemical potential in this
material and the above-mentioned magneto-TEP data around T
c
, viz. Δ μ(H)∝S
p
(H).
Zh. éksp. Teor. Fiz. 116, 257–262 (July 1999)
Published in English in the original Russian journal. Reproduced here with stylistic changes by the Translation Editor. 相似文献
16.
V. V. Anisovich L. G. Dakhno M. A. Matveev V. A. Nikonov A. V. Sarantsev 《Physics of Atomic Nuclei》2007,70(2):364-381
Earlier by the authors (Yad. Fiz. 70, 68 (2007)), the bƃ states were treated in the framework of the spectral integral equation, together with simultaneous calculations of radiative
decays of the considered bottomonia. In the present paper, such a study is carried out for the charmonium
states. We reconstruct the interaction in the c-c sector on the basis of the data for the charmonium levels with J
PC = 0−+, 1−−, 0++, 1++, 2++, 1+− and radiative transitions ψ(2S) → γχ
c0(1P), γχ
c1(1P), γχ
c2(1P), γχ
c(1S) and χ
c0(1P), χ
c1(1P), χ
c2(1P) → γJ/ψ. The c-c levels and their wave functions are calculated for the radial excitations with n ≤ 6. Also, we determine the c-c component of the photon wave function using the e
+
e
−-annihilation data: e
+
e
− → J/ψ(3097), ψ(3686), ψ(3770), ψ(4040), ψ(4160), ψ(4415) and perform the calculations of the partial widths of the two-photon decays for the n = 1 states η
c0(1S), χ
c0(1P), χ
c2(1P) → γγ and n = 2 states η
c0(2S) → γγ, χ
c0(2P) → γγ. We discuss the status of the recently observed c-c states X(3872) and Y(3941): according to our results, the X(3872) can be either χ
c1(2P) or η
c2(1D), while Y(3941) is χ
c2(2P).
The text was submitted by the authors in English. 相似文献
17.
A. S. Demidov 《Russian Journal of Mathematical Physics》2010,17(2):145-153
For a given domain ω ⋐ ℝ2 with boundary γ = ∂ω, we study the cardinality of the set $
\mathfrak{A}_\eta \left( \Phi \right)
$
\mathfrak{A}_\eta \left( \Phi \right)
of pairs of numbers (a, b) for which there is a function u = u
(a,b): ω → ℝ such that ∇2
u(x) = au(x) + b ⩾ 0 for x ∈ ω, u|
γ
= 0, and ||∇u(s)| − Φ(s) ⩽ η for s ∈ γ. Here η ⩾ 0 stands for a very small number, Φ(s) = |∇(s)| / ∫
γ
|∇v| d
γ, and v is the solution of the problem ∇2
v = a
0
v + 1 ⩾ 0 on ω with v|
γ
= 0, where a
0 is a given number. The fundamental difference between the case η = 0 and the physically meaningful case η > 0 is proved. Namely, for η = 0, the set $
\mathfrak{A}_\eta \left( \Phi \right)
$
\mathfrak{A}_\eta \left( \Phi \right)
contains only one element (a, b) for a broad class of domains ω, and a = a
0. On the contrary, for an arbitrarily small η > 0, there is a sequence of pairs (a
j
, b
j
) ∈ $
\mathfrak{A}_\eta \left( \Phi \right)
$
\mathfrak{A}_\eta \left( \Phi \right)
and the corresponding functions u
j
such that ‖f
u
j+1‖ − ‖f
u
j
‖ > 1, where ‖f
u
j
= max
x∈ω
|f
u
j
(x)| and f
u
j
(x) = a
j
u
j
(x) + b
j
. Here the mappings f
u
j
: ω → ℝ necessarily tend as j → ∞ to the δ-function concentrated on γ. 相似文献
18.
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
19.
V. P. Ruban 《Journal of Experimental and Theoretical Physics》2010,111(5):776-785
We consider slow, compared to the speed of sound, motions of an ideal compressible fluid (gas) in a gravitational field in
the presence of two isentropic layers with a small specific-entropy difference between them. Assuming the flow to be potential
in each of the layers (v
1, 2 = ▿ϕ1, 2) and neglecting the acoustic degrees of freedom (div($
\bar \rho
$
\bar \rho
(z)▿ϕ1, 2) ≈ 0, where $
\bar \rho
$
\bar \rho
(z) is the average equilibrium density), we derive the equations of motion for the boundary in terms of the shape of the surface
z = η(x, y, t) itself and the difference between the boundary values of the two velocity field potentials: ψ(x, y, t) = ψ1 − ψ2. We prove the Hamilto nian structure of the derived equations specified by a Lagrangian of the form ℒ = ∫$
\bar \rho
$
\bar \rho
(η)η
t
ψdxdy − ℋ{η, ψ}. The system under consideration is the simplest theoretical model for studying internal waves in a sharply stratified
atmosphere in which the decrease in equilibrium gas density due to gas compressibility with increasing height is essentially
taken into account. For plane flows, we make a generalization to the case where each of the layers has its own constant potential
vorticity. We investigate a system with a model dependence $
\bar \rho
$
\bar \rho
(z) ∝ e
−2αz
with which the Hamiltonian ℋ{η, ψ} can be represented explicitly. We consider a long-wavelength dynamic regime with dispersion
corrections and derive an approximate nonlinear equation of the form u
t
+ auu
x
− b[−$
\hat \partial _x^2
$
\hat \partial _x^2
+ α2]1/2
u
x
= 0 (Smith’s equation) for the slow evolution of a traveling wave. 相似文献
20.
Yu Zhang 《Journal of statistical physics》2012,146(2):466-473
We consider bond percolation on the Z
d
lattice. Let M
n
be the number of open clusters in B(n)=[−n,n]
d
. It is well known that E
p
M
n
/(2n+1)
d
converges to the free energy function κ(p) at the zero field. In this paper, we show that s2p(Mn)/(2n+1)d\sigma^{2}_{p}(M_{n})/(2n+1)^{d} converges to −p(1−p)κ′(p). 相似文献