1,542 research outputs found

    B_{s1}(5830) and B_{s2}^*(5840)

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    In this paper we investigate the strong decays of the two newly observed bottom-strange mesons Bs1(5830)B_{s1}(5830) and Bs2βˆ—(5840)B_{s2}^*(5840) in the framework of the quark pair creation model. The two-body strong decay widths of Bs1(5830)0β†’Bβˆ—+Kβˆ’B_{s1}(5830)^0\to B^{*+}K^- and Bs2βˆ—(5840)0β†’B+Kβˆ’,Bβˆ—+Kβˆ’B_{s2}^*(5840)^0\to B^+K^-, B^{*+}K^- are calculated by considering Bs1(5830)B_{s1}(5830) to be a mixture between ∣1P1>|^1P_1> and ∣3P1>|^3P_1> states, and Bs2βˆ—(5840)B_{s2}^*(5840) to be a ∣3P2>|^3P_2> state. The double pion decay of Bs1(5830)B_{s1}(5830) and Bs2βˆ—(5840)B_{s2}^*(5840) is supposed to occur via the intermediate state Οƒ\sigma and f0(980)f_0(980). Although the double pion decay widths of Bs1(5830)B_{s1}(5830) and Bs2βˆ—(5840)B_{s2}^*(5840) are smaller than the two-body strong decay widths of Bs1(5830)B_{s1}(5830) and Bs2βˆ—(5840)B_{s2}^*(5840), one suggests future experiments to search the double pion decays of Bs1(5830)B_{s1}(5830) and Bs2βˆ—(5840)B_{s2}^*(5840) due to their sizable decay widths.Comment: 9 pages, 8 figures and 6 tables. More references and discussions added, typos corrected, some descriptions changed. Publication version in PR

    Emergence, Evolution and Scaling of Online Social Networks

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    This work was partially supported by AFOSR under Grant No. FA9550-10-1-0083, NSF under Grant No. CDI-1026710, NSF of China under Grants Nos. 61473060 and 11275003, and NBRPC under Grant No. 2010CB731403. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Possible Deuteron-like Molecular States Composed of Heavy Baryons

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    We perform a systematic study of the possible loosely bound states composed of two charmed baryons or a charmed baryon and an anti-charmed baryon within the framework of the one boson exchange (OBE) model. We consider not only the Ο€\pi exchange but also the Ξ·\eta, ρ\rho, Ο‰\omega, Ο•\phi and Οƒ\sigma exchanges. The Sβˆ’DS-D mixing effects for the spin-triplets are also taken into account. With the derived effective potentials, we calculate the binding energies and root-mean-square (RMS) radii for the systems Ξ›cΞ›c(Ξ›Λ‰c)\Lambda_c\Lambda_c(\bar{\Lambda}_c), ΞcΞc(ΞžΛ‰c)\Xi_c\Xi_c(\bar{\Xi}_c), Ξ£cΞ£c(Ξ£Λ‰c)\Sigma_c\Sigma_c(\bar{\Sigma}_c), Ξcβ€²Ξžcβ€²(ΞžΛ‰cβ€²)\Xi_c^\prime\Xi_c^\prime(\bar{\Xi}_c^\prime) and Ξ©cΞ©c(Ξ©Λ‰c)\Omega_c\Omega_c(\bar{\Omega}_c). Our numerical results indicate that: (1) the H-dibaryon-like state Ξ›cΞ›c\Lambda_c\Lambda_c does not exist; (2) there may exist four loosely bound deuteron-like states ΞcΞc\Xi_c\Xi_c and Ξcβ€²Ξžcβ€²\Xi_c^\prime\Xi_c^\prime with small binding energies and large RMS radii.Comment: 17 pages, 32 figure

    Algebraic higher symmetry and categorical symmetry -- a holographic and entanglement view of symmetry

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    We introduce the notion of algebraic higher symmetry, which generalizes higher symmetry and is beyond higher group. We show that an algebraic higher symmetry in a bosonic system in nn-dimensional space is characterized and classified by a local fusion nn-category. We find another way to describe algebraic higher symmetry by restricting to symmetric sub Hilbert space where symmetry transformations all become trivial. In this case, algebraic higher symmetry can be fully characterized by a non-invertible gravitational anomaly (i.e. an topological order in one higher dimension). Thus we also refer to non-invertible gravitational anomaly as categorical symmetry to stress its connection to symmetry. This provides a holographic and entanglement view of symmetries. For a system with a categorical symmetry, its gapped state must spontaneously break part (not all) of the symmetry, and the state with the full symmetry must be gapless. Using such a holographic point of view, we obtain (1) the gauging of the algebraic higher symmetry; (2) the classification of anomalies for an algebraic higher symmetry; (3) the equivalence between classes of systems, with different (potentially anomalous) algebraic higher symmetries or different sets of low energy excitations, as long as they have the same categorical symmetry; (4) the classification of gapped liquid phases for bosonic/fermionic systems with a categorical symmetry, as gapped boundaries of a topological order in one higher dimension (that corresponds to the categorical symmetry). This classification includes symmetry protected trivial (SPT) orders and symmetry enriched topological (SET) orders with an algebraic higher symmetry.Comment: 61 pages, 31 figure

    The single charmed pentaquark molecular states via the QCD sum rules

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    In this work, we systematically investigate the singly charmed pentaquark molecular states D(βˆ—)ND^{(*)}N, D(βˆ—)Ξ(βˆ—)D^{(*)}\Xi^{(*)} and Ds(βˆ—)Ξ(βˆ—)D_s^{(*)}\Xi^{(*)} with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 13 and taking fully account of the light-flavor SU(3)SU(3) breaking effects. The numerical results favor assigning the Ξ©c(3185)\Omega_c(3185) as the DΞD\Xi molecular state with the JP=12βˆ’J^P=\frac{1}{2}^- and ∣I,I3⟩=∣0,0⟩| I,I_3 \rangle=| 0,0 \rangle, assigning the Ξ©c(3327)\Omega_c(3327) as the Dβˆ—ΞžD^*\Xi molecular state with the JP=32βˆ’J^P=\frac{3}{2}^- and ∣I,I3⟩=∣0,0⟩|I,I_3 \rangle=| 0,0 \rangle, assigning the Ξ£c(2800)\Sigma_c(2800) as the DNDN molecular state with the JP=12βˆ’J^P=\frac{1}{2}^- and ∣I,I3⟩=∣1,0⟩| I,I_3 \rangle=| 1,0 \rangle, and assigning the Ξ›c(2940)/Ξ›c(2910)\Lambda_c(2940)/\Lambda_c(2910) as the Dβˆ—ND^*N molecular state with the JP=32βˆ’J^P=\frac{3}{2}^- and ∣I,I3⟩=∣0,0⟩| I,I_3 \rangle=| 0,0 \rangle. Other potential molecule candidates are also predicted, which may be observed in future experiments. For example, we can search for the DΞD\Xi and Dβˆ—ΞžD^*\Xi molecular states with the isospin ∣I,I3⟩=∣1,Β±1β€‰βŸ©| I,I_3 \rangle=| 1,\pm1 \,\rangle in the Ξc+KΛ‰0\Xi_c^+\bar{K}^0 and Ξc0KΛ‰βˆ’\Xi_c^0\bar{K}^- mass spectrum respectively in the future, which could shed light on the nature of the Ξ©c(3185/3327)\Omega_c(3185/3327).Comment: 20 pages, 6 figure

    Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions

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    The high-density behavior of nuclear symmetry energy is among the most uncertain properties of dense neutron-rich matter. Its accurate determination has significant ramifications in understanding not only the reaction dynamics of heavy-ion reactions especially those induced by radioactive beams but also many interesting phenomena in astrophysics, such as the explosion mechanism of supernova and the properties of neutron stars. The heavy-ion physics community has devoted much effort during the last few years to constrain the high-density symmetry using various probes. In particular, the pion-/pion+ ratio has been most extensively studied both theoretically and experimentally. All models have consistently predicted qualitatively that the pion-/pion+ ratio is a sensitive probe of the high-density symmetry energy especially with beam energies near the pion production threshold. However, the predicted values of the pion-/pion+ ratio are still quite model dependent mostly because of the complexity of modeling pion production and reabsorption dynamics in heavy-ion collisions, leading to currently still controversial conclusions regarding the high-density behavior of nuclear symmetry energy from comparing various model calculations with available experimental data. As more pion-/pion+ data become available and a deeper understanding about the pion dynamics in heavy-ion reactions is obtained, more penetrating probes, such as the kaon+/kaon0 ratio, eta meson and high energy photons are also being investigated or planned at several facilities. Here, we review some of our recent contributions to the community effort of constraining the high-density behavior of nuclear symmetry energy in heavy-ion collisions. In addition, the status of some worldwide experiments for studying the high-density symmetry energy, including the HIRFL-CSR external target experiment (CEE) are briefly introduced.Comment: 10 pages, 10 figures, Contribution to the Topical Issue on Nuclear Symmetry Energy in EPJA Special Volum

    A modified T. Chan’s preconditioner for Toeplitz systems

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    AbstractWe present a modified T. Chan’s preconditioner for solving Toeplitz linear systems by the preconditioned conjugate gradient (PCG) method in this paper. Especially, we give some results when the matrices are Hermitian positive definite Toeplitz matrices. The operation and convergence of the PCG method are discussed. Numerical examples presented illustrate the effectiveness of the preconditioner obtained

    On Nonuniform Polynomial Trichotomy of Linear Discrete-Time Systems in Banach Spaces

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    We study two nonuniform polynomial trichotomy concepts for linear discrete-time systems in Banach spaces. Our main objective is to give summation property for nonuniform polynomial trichotomies. As for applications we obtain characterization of these concepts in terms of Lyapunov functions

    Global analysis of measured and unmeasured hadronic two-body weak decays of antitriplet charmed baryons

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    A large amount of data on hadronic two body weak decays of anti-triplet charmed baryons Tc3Λ‰T_{c\bar 3} to an octet baryon T8T_8 and an octet or singlet pseudoscalar meson PP, Tc3Λ‰β†’T8PT_{c \bar 3} \to T_8 P, have been measured. The SU(3) flavor symmetry has been applied to study these decays to obtain insights about weak interactions for charm physics. However not all such decays needed to determine the SU(3) irreducible amplitudes have been measured forbidding a complete global analysis. Previously, it has been shown that data from measured decays can be used to do a global fit to determine all except one parity violating and one parity conserving amplitudes of the relevant SU(3) irreducible amplitudes causing 8 hadronic two body weak decay channels involving Ξc0\Xi^0_c to Ξ·\eta or Ξ·β€²\eta' transitions undetermined. It is important to obtain information about these decays in order to guide experimental searches. In this work using newly measured decay modes by BESIII and Belle in 2022, we carry out a global analysis and parameterize the unknown amplitudes to provide the ranges for the branching ratios of the 8 undetermined decays. Our results indicate that the SU(3) flavor symmetry can explain the measured data exceptionally well, with a remarkable minimal Ο‡2/d.o.f.\chi^2/d.o.f. of 1.21 and predict 80 observables in 45 decays for future experimental data to test. We then vary the unknown SU(3) amplitudes to obtain the allowed range of branching ratios for the 8 undetermined decays. We find that some of them are within reach of near future experimental capabilities. We urge our experimental colleagues to carry out related searches.Comment: 9pages, 2 figures, 3 table
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