318 research outputs found

    Oscillating Asymmetric Sneutrino Dark Matter from the Maximally U(1)LU(1)_L Supersymmetric Inverse Seesaw

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    The inverse seesaw mechanism provides an attractive approach to generate small neutrino mass, which origins from a tiny U(1)LU(1)_L breaking. In this paper, we work in the supersymmetric version of this mechanism, where the singlet-like sneutrino could be an asymmetric dark matter (ADM) candidate in the maximally U(1)LU(1)_{L} symmetric limit. However, even a tiny δm\delta m, the mass splitting between sneutrino and anti-sneutrino as a result of the tiny U(1)LU(1)_{L} breaking effect, could lead to fast oscillation between sneutrino and anti-sneutrino and thus spoils the ADM scenario. We study the evolution of this oscillation and find that a weak scale sneutrino, which tolerates a relatively larger δm105\delta m\sim 10^{-5} eV, is strongly favored. We also investigate possible natural ways to realize that small δm\delta m in the model.Comment: PLB versio

    Glueball relevant study on isoscalars from Nf=2N_f=2 lattice QCD

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    We perform a glueball-relevant study on isoscalars based on anisotropic Nf=2N_f=2 lattice QCD gauge configurations. In the scalar channel, we identify the ground state obtained through gluonic operators to be a single-particle state through its dispersion relation. When qqˉq\bar{q} operator is included, we find the mass of this state does not change, and the qqˉq\bar{q} operator couples very weakly to this state. So this state is most likely a glueball state. For pseudoscalars, along with the exiting lattice results, our study implies that both the conventional qqˉq\bar{q} state η2\eta_2 (or η\eta' in flavor SU(3)SU(3)) and a heavier glueball-like state with a mass of roughly 2.6 GeV exist in the spectrum of lattice QCD with dynamical quarks.Comment: 8 pages, 3 figures, 3 tables, talk presented at the 35th International Symposium on Lattice Field Theory, 18-24 June 2017, Granada, Spai

    Anatomy of the ρ\rho resonance from lattice QCD at the physical point

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    We propose a strategy to access the qqˉq\bar{q} component of the ρ\rho resonance in lattice QCD. Through a mixed action formalism (overlap valence on domain wall sea), the energy of the qqˉq\bar{q} component is derived at different valence quark masses, and shows a linear dependence on mπ2m_\pi^2. The slope is determined to be c1=0.505(3)GeV1c_1=0.505(3)\,{\rm GeV}^{-1}, from which the valence πρ\pi \rho sigma term is extracted to be σπρ(val)=9.82(6)\sigma_{\pi \rho}^{(\rm val)}=9.82(6) MeV using the Feynman-Hellman theorem. At the physical pion mass, the mass of the qqˉq\bar{q} component is interpolated to be mρ=775.9±6.0±1.8m_\rho=775.9\pm 6.0\pm 1.8 MeV, which is close to the ρ\rho resonance mass. We also obtain the leptonic decay constant of the qqˉq\bar{q} component to be fρ=208.5±5.5±0.9f_{\rho^-}=208.5\pm 5.5\pm 0.9 MeV, which can be compared with the experimental value fρexp221f_{\rho}^{\rm exp}\approx 221 MeV through the relation fρexp=Zρfρ±f_{\rho}^{\rm exp}=\sqrt{Z_\rho}f_{\rho^\pm} with Zρ1.13Z_\rho\approx 1.13 being the on-shell wavefunction renormalization of ρ\rho owing to the ρπ\rho-\pi interaction. We emphasize that mρm_\rho and fρf_\rho of the qqˉq\bar{q} component, which are obtained for the first time from QCD, can be taken as the input parameters of ρ\rho in effective field theory studies where ρ\rho acts as a fundamental degree of freedom.Comment: 7 pages, 4 figures. Considerably modified, more discussions, matching to the published versio

    Diquark mass differences from unquenched lattice QCD

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    We calculate diquark correlation functions in the Landau gauge on the lattice using overlap valence quarks and 2+1-flavor domain wall fermion configurations. Quark masses are extracted from the scalar part of quark propagators in the Landau gauge. Scalar diquark quark mass difference and axial vector scalar diquark mass difference are obtained for diquarks composed of two light quarks and of a strange and a light quark. Light sea quark mass dependence of the results is examined. Two lattice spacings are used to check the discretization effects. The coarse and fine lattices are of sizes 243×6424^3\times64 and 323×6432^3\times64 with inverse spacings 1/a=1.75(4) GeV1/a=1.75(4) {\rm~GeV} and 2.33(5) GeV2.33(5) {\rm~GeV}, respectively.Comment: 9 figure

    Unleashing the potential of prompt engineering in Large Language Models: a comprehensive review

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    This paper delves into the pivotal role of prompt engineering in unleashing the capabilities of Large Language Models (LLMs). Prompt engineering is the process of structuring input text for LLMs and is a technique integral to optimizing the efficacy of LLMs. This survey elucidates foundational principles of prompt engineering, such as role-prompting, one-shot, and few-shot prompting, as well as more advanced methodologies such as the chain-of-thought and tree-of-thoughts prompting. The paper sheds light on how external assistance in the form of plugins can assist in this task, and reduce machine hallucination by retrieving external knowledge. We subsequently delineate prospective directions in prompt engineering research, emphasizing the need for a deeper understanding of structures and the role of agents in Artificial Intelligence-Generated Content (AIGC) tools. We discuss how to assess the efficacy of prompt methods from different perspectives and using different methods. Finally, we gather information about the application of prompt engineering in such fields as education and programming, showing its transformative potential. This comprehensive survey aims to serve as a friendly guide for anyone venturing through the big world of LLMs and prompt engineering

    Proton Mass Decomposition from the QCD Energy Momentum Tensor

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    We report results on the proton mass decomposition and also on related quark and glue momentum fractions. The results are based on overlap valence fermions on four ensembles of Nf=2+1N_f = 2+1 DWF configurations with three lattice spacings and three volumes, and several pion masses including the physical pion mass. With fully non-perturbative renormalization (and universal normalization on both quark and gluon), we find that the quark energy and glue field energy contribute 33(4)(4)\% and 37(5)(4)\% respectively in the MS\overline{MS} scheme at μ=2\mu = 2 GeV. A quarter of the trace anomaly gives a 23(1)(1)\% contribution to the proton mass based on the sum rule, given 9(2)(1)\% contribution from the u,d,u, d, and ss quark scalar condensates. The u,d,su,d,s and glue momentum fractions in the MS\overline{MS} scheme are in good agreement with global analyses at μ=2\mu = 2 GeV.Comment: 10 pages, 6 figure
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