118613924
Reanalysis of the $Z_c(4020)$, $Z_c(4025)$, $Z(4050)$ and $Z(4250)$ as tetraquark states with QCD sum rules
In this article, we calculate the contributions of the vacuum condensates up to dimension10 in the operator product expansion, and study the Cγμ −Cγν type scalar, axial-vector and tensor tetraquark states in details with the QCD sum rules. In calculations, we use the formula μ = √ M X/Y/Z − (2Mc) 2 to determine the energy scales of the QCD spectral densities, the μ can be interpreted as the virtuality (or bound energy not as robust) in the heavy quark limit. The predictions MJ=2 = ( 4.02 −0.09 ) GeV, MJ=1 = ( 4.02 −0.08 ) GeV are consistent with the experimental values MZc(4025) = (4026.3±2.6±3.7) MeV, MZc(4020) = (4022.9±0.8±2.7) MeV from the BESIII collaboration, which favor assigning the Zc(4020) and Zc(4025) as the J PC = 1 or 2 diquark-antidiquark type tetraquark states. Furthermore, the predictions disfavor assigning the Z(4050) and Z(4250) as the J = 0 diquark-antidiquark type tetraquark states. More experimental data on the spin and parity are stilled needed to identify the Zc(4020) and Zc(4025), while the Z(4050) and Z(4250) still need confirmation. The prediction MJ=0 = ( 3.85 −0.09 ) GeV can be confronted with the experimental data in the futures. PACS number: 12.39.Mk, 12.38.Lg
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 $\mu_{\Theta^+}=(0.16\pm0.03)\mu_N$.
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.
20940257
Universal quantum computation with weakly integral anyons
Harnessing non-abelian statistics of anyons to perform quantum computational tasks is getting closer to reality. While the existence of universal anyons by braiding alone such as the Fibonacci anyon is theoretically a possibility, accessible anyons with current technology all belong to a class that is called weakly integral—anyons whose squared quantum dimensions are integers. We analyze the computational power of the first non-abelian anyon system with only integral quantum dimensions—$$D(S_3)$$D(S3), the quantum double of $$S_3$$S3. Since all anyons in $$D(S_3)$$D(S3) have finite images of braid group representations, they cannot be universal for quantum computation by braiding alone. Based on our knowledge of the images of the braid group representations, we set up three qutrit computational models. Supplementing braidings with some measurements and ancillary states, we find a universal gate set for each model.
121348798
Scaling theory of the Hall coefficient near the metal-insulator transition, a renormalization-group approach
Abstract We investigate the critical properties of the Hall conduxtivity in weak magetic fields near the disorder driven metal-insulator transition. We derive an effective lagrangian governing the interactions of the diffusive modes in the presence of time-reversal and particle-hole symmetry breaking and identify a new operator relevant to the scaling behavior of the weak-field Hall conductivity. A Wilson-Polyakov renormalization-group analysis is carried out and the flow equations are obtained near two dimensions. We show that the perturbative behavior of the Hall conductivity in the weakly localized regime, in two dimensions, is not simply related to the critical behavior of the Hall conductivity, due to the role played by a new scaling variable. Solving the renormalization-group equations close to the zero-field fixed point, our theory predicts that the Hall number vanishes at the mobility edge with an exponent g = 1 in agreement with several experimental observations. We clarify the connection between the field-theoretic approach and the conventional perturbative approach and elucidate why perturbation in the disorder, which is valid in the weak localization regime fails to predict the correct critical behavior.
118954426
Calculation of the quark condensate through Schwinger-Dyson equation
In this letter, we clarify the algebra expression for calculating the quark condensate based on the non-perturbative quark propagator calculated through Schwinger-Dyson equation. The quark condensates, which characterize the low energy QCD vacuum, should not get a divergent quantity at large energy scale; the re-normalization group evolution behaviour at large energy scale therefore should be interpreted as "smeared collective effects" for it contains both perturbative and non-perturbative parts. 
We prefer the integral expression and get a quantity which is both convergent and scale dependent.
121922038
The dilepton spectrometer
Abstract The dilepton spectrometer (DLS) at Lawrence Berkeley Laboratory's Bevalac has been designed and constructed to investigate the production of electron-positron pairs with low mass and low transverse momentum in proton-nucleus and nucleus-nucleus collisions for incident-beam kinetic energies of 5 A GeV and less. This article briefly recalls the physics objectives of the program, discusses the methodology of the measurement, presents details of the design of the spectrometer and the detector elements, and reports on their performance. Selected experimental results are given to illustrate the capability of the DLS and to demonstrate the level to which it is possible to realize the physics objectives with the spectrometer.
19017470
Topological properties of Abelian and non-Abelian quantum Hall states classified using patterns of zeros
It has been shown that different Abelian and non-Abelian fractional quantum Hall states can be characterized by patterns of zeros described by sequences of integers ${{S}_{a}}$. In this paper, we will show how to use the data ${{S}_{a}}$ to calculate various topological properties of the corresponding fraction quantum Hall state, such as the number of possible quasiparticle types and their quantum numbers, as well as the actions of the quasiparticle tunneling and modular transformations on the degenerate ground states on torus.