共查询到20条相似文献,搜索用时 31 毫秒
1.
In this article, we study the mass spectrum of the baryon-antibaryon bound states p
[`(p)] \bar{{p}} , S \Sigma
[`(S)] \bar{{\Sigma}} , X \Xi
[`(X)] \bar{{\Xi}} , L \Lambda
[`(L)] \bar{{\Lambda}} , p
[`(N)] \bar{{N}}(1440) , S \Sigma
[`(S)] \bar{{\Sigma}}(1660) , X \Xi
[`(X)]¢ \bar{{\Xi}}^{{\prime}}_{} and L \Lambda
[`(L)] \bar{{\Lambda}}(1600) with the Bethe-Salpeter equation. The numerical results indicate that the p
[`(p)] \bar{{p}} , S \Sigma
[`(S)] \bar{{\Sigma}} , X \Xi
[`(X)] \bar{{\Xi}} , p
[`(N)] \bar{{N}}(1440) , S \Sigma
[`(S)] \bar{{\Sigma}}(1660) , X \Xi
[`(X)]¢ \bar{{\Xi}}^{{\prime}}_{} bound states maybe exist, and the new resonances X(1835) and X(2370) can be tentatively identified as the p
[`(p)] \bar{{p}} and p
[`(N)] \bar{{N}}(1440) (or N(1400)[`(p)] \bar{{p}} bound states, respectively, with some gluon constituents, and the new resonance X(2120) may be a pseudoscalar glueball. On the other hand, the Regge trajectory favors identifying the X(1835) , X(2120) and X(2370) as the excited h¢ \eta^{{\prime}}_{}(958) mesons with the radial quantum numbers n = 3 , 4 and 5, respectively. 相似文献
2.
Zhi Yang Xing-Gang Wu Li-Cheng Deng Jia-Wei Zhang Gu Chen 《The European Physical Journal C - Particles and Fields》2011,71(3):1563
In Deng et al. (Eur. Phys. J. C 70:113, 2010), we have dealt with the production of the two color-singlet S-wave (c[`(b)])(c\bar{b})-quarkonium states Bc(|(c[`(b)])1[1S0]?)B_{c}(|(c\bar {b})_{\mathbf{1}}[^{1}S_{0}]\rangle) and B*c(|(c[`(b)])1[3S1]?)B^{*}_{c}(|(c\bar{b})_{\mathbf{1}}[^{3}S_{1}]\rangle) through the Z
0 boson decays. As an important sequential work, we make a further discussion on the production of the more complicated P-wave excited (c[`(b)])(c\bar{b})-quarkonium states, i.e. |(c[`(b)])1[1P1]?|(c\bar{b})_{\mathbf{1}}[^{1}P_{1}]\rangle and |(c[`(b)])1[3PJ]?|(c\bar{b})_{\mathbf{1}}[^{3}P_{J}]\rangle (with J=(1,2,3)). More over, we also calculate the channel with the two color-octet quarkonium states |(c[`(b)])8[1S0]g?|(c\bar{b})_{\mathbf{8}}[^{1}S_{0}]g\rangle and |(c[`(b)])8[3S1]g?|(c\bar{b})_{\mathbf{8}}[^{3}S_{1}]g\rangle, whose contributions to the decay width maybe at the same order of magnitude as that of the color-singlet P-wave states according to the naive nonrelativistic quantum chromodynamics scaling rules. The P-wave states shall provide sizable contributions to the B
c
production, whose decay width is about 20% of the total decay width
\varGamma Z0? Bc\varGamma _{Z^{0}\to B_{c}}. After summing up all the mentioned (c[`(b)])(c\bar {b})-quarkonium states’ contributions, we obtain
\varGamma Z0? Bc=235.9+352.8-122.0\varGamma _{Z^{0}\to B_{c}}=235.9^{+352.8}_{-122.0} KeV, where the errors are caused by the main sources of uncertainty. 相似文献
3.
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
4.
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
5.
Su Houng Lee Shigehiro Yasui 《The European Physical Journal C - Particles and Fields》2009,64(2):283-295
Based on the color–spin interaction in diquarks, we argue why some multiquark configurations could be stable against strong
decay when heavy quarks are included. After showing the stability of previously discussed states we identify new possible
stable states. These are the T0cb(ud[`(c)][`(b)])T^{0}_{cb}(ud\bar{c}\bar{b}) tetraquark, the
\varTheta bs(udus[`(b)])\varTheta _{bs}(udus\bar{b}) pentaquark and the H
c
(udusuc) dibaryon, and so forth. 相似文献
6.
J. Haidenbauer G. Krein U. -G. Meißner L. Tolos 《The European Physical Journal A - Hadrons and Nuclei》2011,47(2):18
A model of the DN interaction is presented which is developed in close analogy to the meson-exchange [`(K)] \bar{{K}}
N potential of the Jülich group utilizing SU(4) symmetry constraints. The main ingredients of the interaction are provided by vector meson (r \rho , w \omega exchange and higher-order box diagrams involving D
*
N , D
D \Delta , and D
*
D \Delta intermediate states. The coupling of DN to the p \pi
Lc \Lambda_{c}^{} and p \pi
Sc \Sigma_{c}^{} channels is taken into account. The interaction model generates the Lc \Lambda_{c}^{}(2595) -resonance dynamically as a DN quasi-bound state. Results for DN total and differential cross sections are presented and compared with predictions of two interaction models that are based
on the leading-order Weinberg-Tomozawa term. Some features of the Lc \Lambda_{c}^{}(2595) -resonance are discussed and the role of the near-by p \pi
Sc \Sigma_{c}^{} threshold is emphasized. Selected predictions of the orginal [`(K)] \bar{{K}}
N model are reported too. Specifically, it is pointed out that the model generates two poles in the partial wave corresponding
to the L \Lambda(1405) -resonance. 相似文献
7.
V. A. Kartoshkin 《Optics and Spectroscopy》2011,111(6):881-884
Singlet (X
1Σ+) and triplet (a
3Σ+) potentials of interaction of two potassium atoms residing in the ground state (4s
2
S
1/2) are presented. Based on the given interaction potentials, the complex cross sections of spin exchange q = [`(q)] + i[`([`(q)])]q = \bar q + i\overline{\overline q} for the system under investigation are calculated. Obtained dependences of the real and imaginary parts of the spin-exchange
cross section on temperature allow one to obtain information both on the broadening of a magnetic resonance line of K atoms
and on the frequency shift of the magnetic resonance during collision. 相似文献
8.
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
9.
A recent experimental analysis suggested to represent the X(3872) -resonance as a c
[`(c)] \bar{{c}} 11
D
2 state but this attribution is being hotly debated. We calculate the mass values for that state by means of a previously studied
constituent-quark model. The different contributions of the model Hamiltonian to the total mass are also explicitly shown. 相似文献
10.
We study the properties of D and [`(D)] \bar{{D}} mesons in hot isospin asymmetric strange hadronic matter, arising due to their interactions with the hadrons in the hyperonic
medium. The interactions of D and [`(D)] \bar{{D}} mesons with these light hadrons are derived by generalizing the chiral SU(3) model used for the study of hyperonic matter to SU(4). The nucleons, hyperons, the scalar isoscalar meson, σ and the scalar-isovector meson, d \delta as modified in the strange hadronic matter, modify the masses of D and [`(D)] \bar{{D}} mesons. It is found that, as compared to the [`(D)] \bar{{D}} mesons ([`(D0)] \bar{{D^0}}, D
−), the properties of the D mesons (D
0, D
+) are more sensitive to the isospin asymmetry at high densities. On the other hand, the effects of strangeness fraction are
found to be more dominant for the [`(D)] \bar{{D}} mesons as compared to the D mesons and these modifications are observed to be particularly appreciable at high densities. We also study the mass modifications
of the charmonium states J/ψ, ψ(3686) and ψ(3770) in the isospin asymmetric strange hadronic matter at finite temperatures and investigate the possibility of the decay
of the charmonium states into D
[`(D)] \bar{{D}} pairs in the hot hadronic medium. The mass modifications of these charmonium states arise due to their interaction with the
gluon condensates of QCD, simulated by a scalar dilaton field introduced to incorporate the broken scale invariance of QCD
within the effective chiral model. The effects of finite quark masses are taken into account in the trace of the energy momentum
tensor in QCD, while investigating the medium modification of the charmonium masses through the modification of the gluon
condensate in the medium. We also compute the partial decay widths of the charmonium states to the D
[`(D)] \bar{{D}} pairs in the hadronic medium. The strong dependence on density of the in-medium properties of the D, [`(D)] \bar{{D}} and the charmonium states, as well as the partial decay widths of charmonium states to D
[`(D)] \bar{{D}} pairs, found in the present investigation, will be of direct relevance in observables like open charm enhancement as well
as J/ψ suppression in the compressed baryonic matter (CBM) experiments at the future Facility for Antiproton and Ion Research, GSI,
where the baryonic matter at high densities is planned to be produced. 相似文献
11.
An intense circularly polarised g \gamma -beam interacts with a cooled antiproton beam in a storage ring. Due to spin-dependent absorption cross-sections for the
reaction g+[`(p)]?p-+[`(n)]\ensuremath \gamma+\overline{p}\rightarrow\pi^{-}+\overline{n} a built-up of polarisation of the stored antiprotons takes place. Figures of merit around 0.1 can be reached in principle
over a wide range of antiproton energies. In this process polarised antineutrons with polarisation
P[`(n)] \succ 70%\ensuremath P_{\overline{n}} \succ 70\% emerge. The method is presented for the case of a 300MeV/c cooled antiproton beam. 相似文献
12.
In this paper, we consider a rotating heavy quark-antiquark (q[`(q)]q\bar{q}) pair in a N=4{\mathcal{N}}=4 SYM thermal plasma. We assume that q[`(q)]q\bar{q} center of mass moves at the speed v and furthermore they rotate around the center of mass. We use the AdS/CFT correspondence and consider the effect of external
electromagnetic field on the motion of the rotating meson. Then we calculate the jet-quenching parameter corresponding to
the rotating meson in the constant electric field. 相似文献
13.
M. Yu. Barabanov A. S. Vodopyanov V. Kh. Dodokhov 《Physics of Particles and Nuclei Letters》2011,8(10):1069-1072
The elaborated analysis of spectrum of scalar and vector charmonium states in the mass region above D[`(D)]D\bar D — threshold is given. The combined approach based on the potential model and relativistic spherical symmetric top model for
decay products has been proposed. Ten radial excited states of charmonium in the mass region above D[`(D)]D\bar D — threshold are anticipated to exist in the framework of the combined approach. The experimental data from different collaborations
were analyzed. Especial attention was given to the new states with the hidden charm discovered recently. Eight of these states
may be interpreted as higher laying radial excited charmonium states. But much more data on different decay modes are needed
for deeper analysis. These data can be derived directly from the experiments using high quality antiproton beam with the momentum
ranging from 1 GeV/c to 15 GeV/c (PANDA experiment at FAIR). 相似文献
14.
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
15.
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
16.
17.
18.
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
19.
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