共查询到20条相似文献,搜索用时 578 毫秒
1.
Zhi-Gang Wang Zhi-Cheng Liu Xiao-Hong Zhang 《The European Physical Journal C - Particles and Fields》2009,64(3):373-386
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
2.
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
3.
Zhi-Gang Wang 《The European Physical Journal C - Particles and Fields》2009,63(1):115-122
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
4.
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 3P0 state, as might result from fluctuations in the magnitude of á[`(s)] s ?\langle {\bar{s}} s \rangle, a 1S0 state, as might result from chiral fluctuations, or a 3S1 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
5.
A gauge model featuring a chiral color symmetry of quarks was considered, and possible manifestations of this symmetry in
proton-antiproton and proton-proton collisions at the Tevatron and LHC energies were studied. The cross section st[`(t)]\sigma _{t\bar t} for the production of t[`(t)]t\bar t quark pairs at the Tevatron and the forward-backward asymmetry AFBp[`(p)]A_{FB}^{p\bar p} in this process were calculated and analyzed with allowance for the contributions of the G′-boson predicted by the chiral color symmetry of quarks, the G′-boson massm
G′ and the mixing angle θ
G
being treated as free parameters of the model. Limits on m
G′ versus θ
G
were studied on the basis of data from the Tevatron on st[`(t)]\sigma _{t\bar t} and AFBp[`(p)]A_{FB}^{p\bar p}, and the region compatible with these data within one standard deviation was found in the m
G′-θ
G
plane. The region ofm
G′-mass values that is appropriate for observing the G′-boson at LHC is discussed. 相似文献
6.
In this paper we consider a quark-antiquark (q[`(q)]q\bar{q}) pair which can be interpreted as a meson in N=4{\mathcal{N}}=4 SYM thermal plasma. We assume that the string moves at speed v and rotates around its center of mass simultaneously. By using the AdS/CFT correspondence, we obtain the momentum densities
of the rotating string and determine its motion for small angular velocities. Then in general case, we calculate the screening
length of q[`(q)]q\bar{q} pair numerically and show that its velocity dependance is in consistent with the well known formula L
s
T∼(1−v
2)1/4 in the literature. 相似文献
7.
8.
R. Komendarczyk 《Communications in Mathematical Physics》2009,292(2):431-456
We introduce an alternative approach to the third order helicity of a volume preserving vector field B, which leads us to a lower bound for the L
2-energy of B. The proposed approach exploits correspondence between the Milnor [`(m)]123{\bar{\mu}_{123}} -invariant for 3-component links and the homotopy invariants of maps to configuration spaces, and we provide a simple geometric
proof of this fact in the case of Borromean links. Based on these connections we develop a formulation for the third order
helicity of B on invariant unlinked domains of B, and provide Arnold’s style ergodic interpretation of this invariant as an average asymptotic [`(m)]123{\bar{\mu}_{123}} -invariant of orbits of B. 相似文献
9.
We argue that the mass, production, total decay width, and decay pattern of the η
2(1870) do not appear to contradict with the picture of it as being the conventional 2 1
D
2
q[`(q)]q\bar{q}
state. The possibility of the η
2(1870) being a mixture of the conventional
q[`(q)]q\bar{q}
and a hybrid is also discussed. 相似文献
10.
11.
A model-independent analysis of anomalous gauge coupling constants of W
± bosons is presented and the corresponding restrictions on them and on the electromagnetic characteristics of W
± bosons following from the experiments on measuring the e+ e- ? W+ W- ? ( e