118829634
Analysis of the X(1835) and related baryonium states with Bethe-Salpeter equation
Abstract.In this article, we study the mass spectrum of the baryon-antibaryon bound states p$ \bar{{p}}$ , $ \Sigma$$ \bar{{\Sigma}}$ , $ \Xi$$ \bar{{\Xi}}$ , $ \Lambda$$ \bar{{\Lambda}}$ , p$ \bar{{N}}$(1440) , $ \Sigma$$ \bar{{\Sigma}}$(1660) , $ \Xi$$ \bar{{\Xi}}^{{\prime}}_{}$ and $ \Lambda$$ \bar{{\Lambda}}$(1600) with the Bethe-Salpeter equation. The numerical results indicate that the p$ \bar{{p}}$ , $ \Sigma$$ \bar{{\Sigma}}$ , $ \Xi$$ \bar{{\Xi}}$ , p$ \bar{{N}}$(1440) , $ \Sigma$$ \bar{{\Sigma}}$(1660) , $ \Xi$$ \bar{{\Xi}}^{{\prime}}_{}$ bound states maybe exist, and the new resonances X(1835) and X(2370) can be tentatively identified as the p$ \bar{{p}}$ and p$ \bar{{N}}$(1440) (or N(1400)$ \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 $ \eta^{{\prime}}_{}$(958) mesons with the radial quantum numbers n = 3 , 4 and 5, respectively.
119252067
Next-to-leading Order Perturbative Contributions in the QCD Sum Rules for Mesonic Two-point Correlation Functions with Unequal Quark Masses
In this article, we assume that the two quarks have unequal masses and calculate the next-to-leading order contributions to the spectral densities of the mesonic two-point correlation functions of the vector, axialvector, scalar and pseudoscalar currents. We take dimensional regularization to regularize both the ultraviolet and infrared divergences, and use optical theorem to obtain the spectral densities directly, furthermore, we present some necessary technical details for readers convenience. The analytical expressions are applicable in many phenomenological analysis besides the QCD sum rules.
118430852
Analysis of mass difference of the $\pi$ and $\rho$ with Bethe-Salpeter equation
In this article, we take into account the one-pion exchange force besides the onegluon exchange force to study the mass difference of the π and ρ mesons with the Bethe-Salpeter equation. After projecting the Bethe-Salpeter equation into an simple form, we can see explicitly that the bound energy |Eπ| ≫ |Eρ|. PACS number: 12.39.Ki, 12.39.Pn
119121085
ANALYSIS OF THE $B \to K^*_2(1430), a_2(1320), f_2(1270)$ FORM-FACTORS WITH LIGHT-CONE QCD SUM RULES
In this paper, we study the form-factors with the light-cone QCD sum rules, where the B-meson light-cone distribution amplitudes are used. In calculations, we observe that the line-shapes of the B-meson light-cone distribution amplitude ϕ+(ω) have significant impacts on the values of the form-factors, and expect to obtain severe constraints on the parameters of the B-meson light-cone distribution amplitudes from the experimental data in the future.
15122700
Analysis of the Y(2175) as a tetraquark state with QCD sum rules
Abstract In this article, we take the point of view that Y ( 2175 ) be a tetraquark state which consists of color octet constituents, and calculate its mass and decay constant within the framework of the QCD sum rule approach. We release standard criterion in the QCD sum rules approach and take more phenomenological analysis, the value of the mass of Y ( 2175 ) is consistent with experimental data; there may be some tetraquark components in the state Y ( 2175 ) . If we retain standard criterion, larger mass than experimental data can be obtained, the current J μ ( x ) can interpolate a tetraquark state with larger mass, or Y ( 2175 ) has some components with larger mass. The dominating contribution comes from the perturbative term, which is in contrast to the sum rules with interpolating currents constructed from diquark pairs. The tetraquark states may consist of color octet constituents rather than diquark pairs.
118179000
Magnetic moment of the pentaquark state $\Theta^+(1540)$
In this article, we study the magnetic moment of the pentaquark $ \Theta^+(1540)$ as (scalar)diquark-(pseudoscalar)diquark-antiquark state with the QCD sum rules approach in the external electromagnetic field. Due to the special structure of the interpolating current, only the electromagnetic interactions of the $s$ quark with the external field have contributions to the magnetic moment with tensor structure $\{\sigma_{\mu\nu} {\hat p} +{\hat p}\sigma_{\mu\nu}\}$. The numerical results indicate the magnetic moment of the pentaquark state $ \Theta^+(1540)$ is about $\mu_{\Theta^+}=(0.16\pm0.03)\mu_N$.
117851662
The emergence of Hopf term and the marginality of Dirac model
The subtle relation of the marginality of Dirac model and the emergence of the Hopf term through a Yukawa-type interaction is revealed in this work. We show that the improvement of the marginality of Dirac mode through an infinitesimal non-relativistic term, which is irrelevant for renormalization group, is necessary to emerge the Hopf term. It is found that the appearance of the Hopf term is always accompanied with chiral boundary modes, and the sign of the coupling constant of the infinitesimal non-relativistic term decides their chirality. A lattice Dirac model is also constructed to realize the Hopf term.
279557
Topological quantum phase transitions and edge states in spin-orbital coupled Fermi gases
We study superconducting states in the presence of spin-orbital coupling and Zeeman field. It is found that a phase transition from a Fulde-Ferrell-Larkin-Ovchinnikov state to the topological superconducting state occurs upon increasing the spin-orbital coupling. The nature of this topological phase transition and its critical property are investigated numerically. Physical properties of the topological superconducting phase are also explored. Moreover, the local density of states is calculated, through which the topological feature may be tested experimentally.
11394439
Identifying topological order by entanglement entropy
Topological entanglement entropy provides a robust measure for detecting the long-range entanglement that characterizes quantum ground states displaying topological order. A new method for calculating this entropy isolates minimally entangled states from the ground states of a topological phase—offering a reliable test for identifying topological spin liquids.
67805671
Projective ribbon permutation statistics: A remnant of non-Abelian braiding in higher dimensions
In a recent paper, Teo and Kane [Phys. Rev. Lett. 104, 046401 (2010)] proposed a three-dimensional (3D) model in which the defects support Majorana fermion zero modes. They argued that exchanging and twisting these defects would implement a set R of unitary transformations on the zero-mode Hilbert space which is a “ghostly” recollection of the action of the braid group on Ising anyons in two dimensions. In this paper, we find the group T2n, which governs the statistics of these defects by analyzing the topology of the space K2n of configurations of 2n defects in a slowly spatially varying gapped free-fermion Hamiltonian: T2n ≡ π1(K2n). We find that the group T2n = Z × T r
8434175
X-Ray Observation and Analysis of the Composite Supernova Remnant G327.1–1.1
Based on the data from the observation of the supernova remnant (SNR) G327.1-1.1 by the Advanced Satellite for Cosmology and Astrophysics (ASCA) and ROSAT, we find that G327.1-1.1 is a composite remnant with both a nonthermal emission component and a diffuse thermal emission component. The nonthermal component is well fitted by a power-law model with photon index Γ~2.2. This component is attributed to the emission from the synchrotron nebula powered by an undiscovered central pulsar. The thermal component has a temperature of about 0.4 keV. We attribute it to the emission from the shock-heat swept-up interstellar medium (ISM). Its age, explosion energy, and density of ambient medium are derived from the observed thermal component. Some characteristics of the synchrotron nebula are also derived. We have searched for the pulsed signal but have not found it. The soft X-ray (0.4-2 keV) and hard X-ray (2-10 keV) images are different, but they both elongate in the southeast-northwest direction. And this X-ray southeast-northwest elongation is in positional coincidence with the radio ridge in the Molonglo Observatory Synthesis Telescope (MOST) 843 MHz radio map. We present a possibility that the X-ray nonthermal emission mainly comes from the trail produced by a quickly moving undiscovered pulsar, and the long radio ridge is formed when the pulsar is moving out of the boundary of the plerionic structure.