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1.
In this article, we study the Λ
c
and Λ
b
baryons in the nuclear matter using the QCD sum rules, and obtain the in-medium masses
M\varLambda c*=2.335 GeVM_{\varLambda _{c}}^{*}=2.335~\mathrm{GeV},
M\varLambda b*=5.678 GeVM_{\varLambda _{b}}^{*}=5.678~\mathrm{GeV}, the in-medium vector self-energies
\varSigma \varLambda cv=34 MeV\varSigma ^{\varLambda _{c}}_{v}=34~\mathrm{MeV},
\varSigma \varLambda bv=32 MeV\varSigma ^{\varLambda _{b}}_{v}=32~\mathrm {MeV}, and the in-medium pole residues
l \varLambda c*=0.021 GeV 3\lambda_{\varLambda _{c}}^{*}=0.021~\mathrm{GeV}^{3},
l \varLambda b*=0.026 GeV 3\lambda_{\varLambda _{b}}^{*}=0.026~\mathrm{GeV}^{3}. The mass-shifts are
M\varLambda c*- M\varLambda c=51 MeVM_{\varLambda _{c}}^{*}-M_{\varLambda _{c}}=51~\mathrm{MeV} and
M\varLambda b*- M\varLambda b=60 MeVM_{\varLambda _{b}}^{*}-M_{\varLambda _{b}}=60~\mathrm{MeV}, respectively. 相似文献
2.
We theoretically study the squeezing effect in a 3-wave mixing process, generated by the operator S3 o exp[m( a1a2- a1fa2f)+n( a1a3- a1fa3f)]S_{3}\equiv \exp[\mu(a_{1}a_{2}-a_{1}^{\dagger}a_{2}^{\dagger})+\nu(a_{1}a_{3}-a_{1}^{\dagger}a_{3}^{\dagger})]. The corresponding 3-mode squeezed vacuum state in Fock space and its uncertainty relation are presented. It turns out that S 3 may exhibit enhanced squeezing. By virtue of integration within an ordered product (IWOP) of operators, we also give the S 3’s normally ordered expansion. Finally, we calculate the Wigner function of 3-mode squeezed vacuum state by using the Weyl ordering invariance under similar transformations. 相似文献
3.
In this article, we assume that there exist scalar D*[`( D)] *{D}^{\ast}{\bar {D}}^{\ast}, Ds*[`( D)] s*{D}_{s}^{\ast}{\bar{D}}_{s}^{\ast}, B*[`( B)] *{B}^{\ast}{\bar {B}}^{\ast} and Bs*[`( B)] s*{B}_{s}^{\ast}{\bar{B}}_{s}^{\ast} molecular states, and study their masses using the QCD sum rules. The numerical results indicate that the masses are about
(250–500) MeV above the corresponding D
*–[`( D)] *{\bar{D}}^{\ast}, D
s
*–[`( D)] s*{\bar {D}}_{s}^{\ast}, B
*–[`( B)] *{\bar{B}}^{\ast} and B
s
*–[`( B)] s*{\bar {B}}_{s}^{\ast} thresholds, the Y(4140) is unlikely a scalar Ds*[`( D)] s*{D}_{s}^{\ast}{\bar{D}}_{s}^{\ast} molecular state. The scalar D*[`( D)] *D^{\ast}{\bar{D}}^{\ast}, Ds*[`( D)] s*D_{s}^{\ast}{\bar{D}}_{s}^{\ast}, B*[`( B)] *B^{\ast}{\bar{B}}^{\ast} and Bs*[`( B)] s*B_{s}^{\ast}{\bar{B}}_{s}^{\ast} molecular states maybe not exist, while the scalar D¢ *[`( D)] ¢*{D'}^{\ast}{\bar{D}}^{\prime\ast}, Ds¢*[`( D)] s¢*{D}_{s}^{\prime\ast}{\bar{D}}_{s}^{\prime\ast}, B¢*[`( B)] ¢*{B}^{\prime\ast}{\bar{B}}^{\prime\ast} and Bs¢*[`( B)] s¢*{B}_{s}^{\prime\ast}{\bar{B}}_{s}^{\prime\ast} molecular states maybe exist. 相似文献
4.
To date, the fastest lithium ion-conducting solid electrolytes known are the perovskite-type ABO3 oxide, with A = Li, La and B = Ti, lithium lanthanum titanate (LLTO)
Li3x La( 2 \mathord | / |
\vphantom 2 3 3 ) - x [¯]( 1 \mathord | / |
\vphantom 1 3 3 ) - x TiO3 {\rm Li}_{3x} {\rm La}_{\left( {{2 \mathord{\left/ {\vphantom {2 3}} \right. \kern-\nulldelimiterspace} 3}} \right) - x} \Box_{\left( {{1 \mathord{\left/ {\vphantom {1 3}} \right. \kern-\nulldelimiterspace} 3}} \right) - x} {\rm TiO}_3 and its structurally related materials. In this formula, [¯]\Box represents the vacancy. These materials have attracted much attention due to their application in lithium ion batteries used
as energy sources in microelectronic and information technologies. In addition to the well-established simple cubic, tetragonal
and orthorhombic perovskite type distorted cell structures, the hexagonal unit cell was reported in a recent study for Li0.5 La0.5 TiO3 − δ
, ( 0 £ d £ 0.06 )\left( {0 \le \delta \le 0.06} \right). We investigated the ionic conductivity in hexagonal La0.5 Li0.5 TiO3{\rm La}_{0.5} {\rm Li}_{0.5}\- {\rm TiO}_3 by molecular dynamics. We confirmed that ionic conductivity in this compound is due to the motion of lithium ions. We show
that both Arrhenius and Vogel–Tamman–Fulcher-type relationships could be used to express the high-temperature conductivity
of this compound. From our results, hexagonal LLTO exhibits almost 1.7–1.9 ×10 − 3 S cm − 1 at room temperature. Thus, due to its high ionic conductivity, this compound is expected to show some advantages in comparison
with the best conductors of this family, for usual applications of ionic conductors. 相似文献
5.
This paper starts with a self-contained discussion of the so-called Akulov–Volkov action SAV\mathcal{S}_{\mathrm{AV}}, which is traditionally taken to be the leading-order action of the Goldstino field. Explicit expressions for SAV\mathcal{S}_{\mathrm{AV}} and its chiral version SAVch\mathcal{S}_{\mathrm{AV}}^{\mathrm{ch}} are presented. We then turn to the issue on how these actions are related to the leading-order action SNL\mathcal{S}_{\mathrm{NL}} proposed in the newly proposed constrained superfield formalism. We show that SNL\mathcal{S}_{\mathrm{NL}} may yield SAV/ SAVch\mathcal{S}_{\mathrm {AV}}/\mathcal{S}_{\mathrm{AV}}^{\mathrm{ch}} or a totally different action SKS\mathcal{S}_{\mathrm{KS}}, depending on how the auxiliary field in the former is integrated out. However, SKS\mathcal{S}_{\mathrm{KS}} and SAV/ SAVch\mathcal{S}_{\mathrm {AV}}/\mathcal{S}_{\mathrm{AV}}^{\mathrm{ch}} always yield the same S-matrix elements, as one would have expected from general considerations in quantum field theory. 相似文献
6.
In this paper, two modified Ricci models are considered as the candidates of unified dark matter–dark energy. In model one,
the energy density is given by r MR=3 Mpl(a H2+b[( H)\dot])\rho_{\mathrm{MR}}=3M_{\mathrm{pl}}(\alpha H^{2}+\beta\dot{H}), whereas, in model two, by
r MR=3 Mpl(\fraca6 R+g[( H)\ddot] H-1)\rho_{\mathrm{MR}}=3M_{\mathrm{pl}}(\frac{\alpha}{6} R+\gamma\ddot{H}H^{-1}). We find that they can explain both dark matter and dark energy successfully. A constant equation of state of dark energy
is obtained in model one, which means that it gives the same background evolution as the wCDM model, while model two can give an evolutionary equation of state of dark energy with the phantom divide line crossing
in the near past. 相似文献
7.
We study the small- x behaviour of the polarized photon structure function F3gF_3^{\gamma}, measuring the gluon transversity distribution, in the leading logarithmic approximation of perturbative QCD. There are two contributions, both arising from two-gluon exchange. The leading contribution to small- x is related to the BFKL pomeron and behaves like x-1-w2x^{-1-\omega_2}, w 2 = O(a S)\omega_2 ={\cal O}(\alpha_S). The other contribution includes in particular the ones summed by the DGLAP equation and behaves like x1-w0(+)x^{1-\omega_0^{(+)}}, w 0(+) = O(?{a S})\omega_0^{(+)} = {\cal O}(\sqrt{\alpha_S}). 相似文献
9.
Measurements of α
s, the coupling strength of the Strong Interaction between quarks and gluons, are summarised and an updated value of the world
average of a s( MZ0)\alpha_{\mathrm{s}}(M_{\mathrm{Z}^{0}}) is derived. Special emphasis is laid on the most recent determinations of α
s. These are obtained from τ-decays, from global fits of electroweak precision data and from measurements of the proton structure function F 2, which are based on perturbative QCD calculations up to O(a s4)\mathcal{O}(\alpha_{\mathrm{s}}^{4}); from hadronic event shapes and jet production in e +e − annihilation, based on O(a s3)\mathcal{O}(\alpha_{\mathrm{s}}^{3}) QCD; from jet production in deep inelastic scattering and from ϒ decays, based on O(a s2)\mathcal{O}(\alpha_{\mathrm{s}}^{2}) QCD; and from heavy quarkonia based on unquenched QCD lattice calculations. A pragmatic method is chosen to obtain the world
average and an estimate of its overall uncertainty, resulting in
as(MZ0)=0.1184±0.0007.\alpha_\mathrm{s}(M_{\mathrm{Z}^0})=0.1184\pm 0.0007. 相似文献
10.
Optical activity of xenon atoms in the vacuum UV range induced by circularly polarized laser light is studied theoretically.
The optical activity arises in the vicinity of the autoionizing state 5 p
5( 2
P
1/2)8 s′$
\left[ {\frac{1}
{2}} \right]_1
$
\left[ {\frac{1}
{2}} \right]_1
as a result of its coupling via the laser field with the discrete state 5 p
5( 2
P
3/2)7 p
$
\left[ {\frac{1}
{2}} \right]_1
$
\left[ {\frac{1}
{2}} \right]_1
. Polarization variations of the vacuum UV radiation upon its propagation through the atomic medium are calculated, and the
possibility of controlling this polarization is discussed. Manifestations of nonresonant coupling of the discrete state with
the broad autoionizing state 5 p
5( 2
P
1/2)6 d′$
\left[ {\frac{1}
{2}} \right]_1
$
\left[ {\frac{1}
{2}} \right]_1
induced by the overlap of the Rydberg autoionizing series in xenon are studied. 相似文献
11.
The electric quadrupole coupling constants eqQ/ h of 8B (, T
1/2 = 769 ms) and 13B (, T
1/2 = 17.4 ms) in single crystal TiO 2 have been precisely measured by the β-NQR technique. The ratios of these Q moments to Q( 12B) were determined as ∣ Q( 8B)/ Q( 12B)∣ = 4.882(32) and ∣ Q( 13B)/ Q( 12B)∣ = 2.768(24). 相似文献
12.
The conductivity of glasses in the
50\text P\text2 \text O\text5 - x\text V\text2 \text O\text5 - ( 50 - x )\text Li\text2 \text O50{\text{P}}_{\text{2}} {\text{O}}_{\text{5}} - x{\text{V}}_{\text{2}} {\text{O}}_{\text{5}} - \left( {50 - x} \right){\text{Li}}_{\text{2}} {\text{O}} system was studied as a function of temperature and composition. For all compositions, the conductivity variation as a function
of temperature followed an Arrhenius type relationship. Isothermal variation of conductivity as a function of composition
showed a minimum for a molar ratio x near 20. Probable mechanisms for decrease of conductivity with decrease of vanadium oxide concentration were explained. The
minimum in room temperature was attributed to increase of V 4+/V 5+ with decrease of vanadium oxide in specific concentrations of vanadium oxide. Activation energy increased with decrease of
V 2O 5 content. This behavior was attributed to increase of average spacing between vanadium ions. 相似文献
13.
The chemical shift D EKb1 \Delta E_{K_{\beta 1} } and the exchange splitting Δ E
split of the emission X-ray Mn K
β1 line in mixed manganites Ln
1 − x
Sr
x
MnO 3 ( Ln = La, Sm, and Ce) have been systematically studied for the first time. It has been found that D EKb1 \Delta E_{K_{\beta 1} } and Δ E
split are almost the same in the range x < 0.4–0.5, as is the case in Mn 2O 3, and then they decrease relatively quickly to the values characteristic of MnO 2. It has been assumed that such a behavior corresponds to the model where in the region of hole doping ( x < 0.5), the ground state is a mixture of configurations Mn 3+ 3 d
4 and $3d^4 \underset{\raise0.3em\hbox{$3d^4 \underset{\raise0.3em\hbox{, so that the second configuration fraction increases with x. At high values of x, the configuration Mn 4+ 3 d
3 should be taken into account; the contribution of this configuration increases with increasing degree of doping, and it becomes
dominant at x = 1. In all cases, the manganese state is high-spin. 相似文献
14.
The polarizations of Λ and
[`\varLambda]{\bar{\varLambda}} are thought to retain memories of the spins of their parent s quarks and [`( s)]{\bar{s}} antiquarks, and are readily measurable via the angular distributions of their daughter protons and antiprotons. Correlations between the spins of Λ and
[`\varLambda]{\bar{\varLambda}} produced at low relative momenta may therefore be used to probe the spin states of s [`( s)]s {\bar{s}} pairs produced during hadronization. We consider the possibilities that they are produced in a 3P 0 state, as might result from fluctuations in the magnitude of á[`( s)] s ?\langle {\bar{s}} s \rangle, a 1S 0 state, as might result from chiral fluctuations, or a 3S 1 or other spin state, as might result from production by a quark–antiquark or gluon pair. We provide templates for the p [`( p)]p {\bar{p}} angular correlations that would be expected in each of these cases, and discuss how they might be used to distinguish s [`( s)]s {\bar{s}} production mechanisms in pp and heavy-ion collisions. 相似文献
15.
In this article, we assume that there exists a scalar
Ds*[`( D)] s*D_{s}^{\ast}{\bar{D}}_{s}^{\ast}
molecular state in the J/ ψ
φ invariant mass distribution, and we study its mass using the QCD sum rules. The predictions depend heavily on the two criteria
(pole dominance and convergence of the operator product expansion) of the QCD sum rules. The value of the mass is about
MDs*[`(D)]s*=(4.43±0.16)M_{D_{s}^{\ast}{\bar{D}}_{s}^{\ast}}=(4.43\pm0.16)
GeV, which is inconsistent with the experimental data. The
Ds*[`( D)] s*D_{s}^{\ast}{\bar{D}}_{s}^{\ast}
is probably a virtual state and is not related to the meson Y(4140). Another possibility, such as a hybrid charmonium, is not excluded. 相似文献
16.
The momentum dependences of the nuclear spin polarization P and alignment A of 13B(, T
1/2 = 17.36 ms) produced in the 100 A MeV 15N + Be collisions have been measured by detecting β-ray asymmetry. Because both the P and A were significantly smaller than the prediction from a simple kinematical model, some relaxation mechanisms must be take into
account. Comparing the signs of the observed alignment of 12B, the sign of the quadrupole coupling constant eqQ of 13B in TiO 2 was determined to be positive. 相似文献
17.
The precipitation of lanthanum and neodymium phosphate phases from supersaturated aqueous solutions at pH ~1.9 was studied
at 5, 25, 50, and 100 °C in batch reactors for up to 168 h. Crystalline La and Nd–rhabdophane phases precipitated immediately
upon mixing of the initial aqueous La or Nd and PO 4 solutions. Changes in aqueous PO 4 and Rare Earth Element (REE) concentrations during the experiments were determined by ICP-MS and UV–Vis spectrophotometry,
while the resulting solids were characterized via powder XRD, SEM, TEM, and FTIR. All precipitated crystals exhibited a nano-rod
morphology and their initial size depended on temperature and REE identity. At 5 °C and immediately after mixing the La and
Nd–rhabdophane crystals averaged ~44 and 40 nm in length, respectively, while at 100 °C lengths were ~105 and 94 nm. After
168 h of reaction, the average length of the La and Nd rhabdophanes increased by 23 and 53% at 5 °C and 11 and 59% at 100 °C,
respectively. The initial reactive solutions in all experiments had activity quotients for rhabdophane precipitation:
\text REE 3+ + \text PO43 - + n\text H2 \text O = \text REEPO4 · n\text H2 \text O {\text{REE}}^{ 3+ } + {\text{PO}}_{4}^{3 - } + n{\text{H}}_{2} {\text{O}} = {\text{REEPO}}_{4} \cdot\;n{\text{H}}_{2} {\text{O}} of ~10 −20.5. This activity quotient decreased with time, consistent with rhabdophane precipitation. The rapid equilibration of rhabdophane
supersaturated solutions and the progressive rhabdophane crystal growth observed suggests that the REE concentrations of many
natural waters may be buffered by rhabdophane precipitation. In addition, this data can be used to guide crystallization reactions
in industrial processes where monodisperse and crystalline La or Nd rhabdophane materials are the target. 相似文献
18.
For trivalent praseodymium (Pr 3+) and quadrivalent praseodymium (Pr 4+) codoped CaMO 4 (M = W, Mo) powders, the luminescence propriety of matrix is obviously influenced by carrier concentration. The light emission
intensity of CaWO 4 matrix decreases exponentially with increasing of Pr concentration because oxygen-deficient (WO 3· VO··\mathrm{WO}_{3}\cdot V_{\mathrm{O}}^{\bullet \bullet}) obtains an electron supplied by Pr 3+ (5 d). However, the light emission intensity of CaMoO 4 is enhanced by Pr codoping because the quasi-free electrons increase the probability of radiative combination. The difference
of photoluminescence properties in the two materials are attributed to the bonding character of M and O in the CaMO 4 structure. 相似文献
19.
The angular deflection of light and radar echo delay are famous results predicted by general relativity. The gravitational
lensing problems depend on the deviation of light from its straight line path in its basic equation. Using the Robertson-McVittie
spacetime metric, which coincides thoroughly with the Schwarzschild metric in the isotropic coordinate and the FLRW metric
for curvature parameter k=0 when M=0, we discuss the correction of cosmological expansion to the angular deviation of light path and the radar echo delay. The
deviation terms arising from the expansion of universe are found to be simply
-\frac4 GMrminc2(\frac H022 c2rmin2)-\frac{4GM}{r_{\mathit{min}}c^{2}}(\frac{H_{0}^{2}}{2c^{2}}r_{\mathit{min}}^{2}) for angular deviation and
\frac2 H023 c3( rA3+ rB3)\frac{2H_{0}^{2}}{3c^{3}}(r_{A}^{3}+r_{B}^{3}) for radar echo delay. 相似文献
20.
The temperature dependences of magnetic entropy change and refrigerant capacity have been calculated for a maximum field change
of Δ
H=30 kOe in as-quenched ribbons of the ferromagnetic shape memory alloy Ni 50.4Mn 34.9In 14.7 around the structural reverse martensitic transformation and magnetic transition of austenite. The ribbons crystallize into
a single-phase austenite with the L2 1-type crystal structure and Curie point of 284 K. At 262 K austenite starts its transformation into a 10-layered structurally
modulated monoclinic martensite. The first- and second-order character of the structural and magnetic transitions was confirmed
by the Arrott plot method. Despite the superior absolute value of the maximum magnetic entropy change obtained in the temperature
interval where the reverse martensitic transformation occurs
(|\varDelta SMmax|=7.2 J kg -1 K -1)(|\varDelta S_{\mathrm{M}}^{\max}|=7.2\mbox{ J}\,\mbox{kg}^{-1}\,\mbox{K}^{-1}) with respect to that obtained around the ferromagnetic transition of austenite
(|\varDelta SMmax|=2.6 J kg -1 K -1)(|\varDelta S_{\mathrm{M}}^{\max}|=2.6\mbox{ J}\,\mbox{kg}^{-1}\,\mbox{K}^{-1}), the large average hysteretic losses due to the effect of the magnetic field on the phase transformation as well as the narrow
thermal dependence of the magnetic entropy change make the temperature interval around the ferromagnetic transition of austenite
of a higher effective refrigerant capacity (RC magneff=95J kg -1\mathrm{RC}^{\mathrm{magn}}_{\mathrm{eff}}=95\mbox{J}\,\mbox{kg}^{-1} versus RC structeff=60J kg -1)\mathrm{RC}^{\mathrm{struct}}_{\mathrm{eff}}=60\mbox{J}\,\mbox{kg}^{-1}). 相似文献
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