5,838 research outputs found

    The anomalous ZbbˉZb\bar{b} couplings at the HERA and EIC

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    To resolve the long-standing discrepancy between the precision measurement of bottom quark forward-backward asymmetry at LEP/SLC and the Standard Model prediction, we propose a novel method to probe the ZbbˉZb\bar{b} coupling by measuring the single-spin asymmetry AebA_e^b of the polarized lepton cross section in neutral current DIS processes with a bb-tagged jet at HERA and EIC. Depending on the tagging efficiency of the final state bb-jet, the measurement of AebA_e^b at HERA can already partially break the degeneracy found in the anomalous ZbbˉZb\bar{b} coupling, as implied by the LEP and SLC precision electroweak data. In the first year run of the EIC, the measurement of AebA_e^b can already break the degeneracy, due to its much larger luminosity and higher electron beam polarization. With enough integrated luminosity collected at the EIC, it is possible to either verify or exclude the LEP data and resolve the AFBbA_{\rm FB}^b puzzle. We also discuss the complementary roles between the proposed AebA_e^b measurement at EIC and the measurement of ggZhgg \to Zh cross section at the HL-LHC in constraining the anomalous ZbbˉZb\bar{b} coupling.Comment: 6 pages, 2 figures, the published version in PL

    Single Transverse Spin Asymmetry as a New Probe of SMEFT Dipole Operators

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    Electroweak dipole operators in the Standard Model Effective Field Theory (SMEFT) are important indirect probes of quantum effects of new physics beyond the Standard Model (SM), yet they remain poorly constrained by current experimental analyses for lack of interference with the SM amplitudes in constructing cross section observables. In this Letter, we point out that dipole operators flip fermion helicities so are ideally studied through single transverse spin asymmetries. We illustrate this at a future electron-positron collider with transversely polarized beams, where such effect exhibits as azimuthal cosϕ\cos\phi and sinϕ\sin\phi distributions which originate from the interference of the electron dipole operators with the SM and are linearly dependent on their Wilson coefficients. This new method can improve the current constraints on the electron dipole couplings by one to two orders of magnitude, without depending on other new physics operators, and can also simultaneously constrain both their real and imaginary parts, offering a new opportunity for probing potential CPCP-violating effects.Comment: 5 pages, 1 figur

    Alternating minimization algorithms for graph regularized tensor completion

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    We consider a low-rank tensor completion (LRTC) problem which aims to recover a tensor from incomplete observations. LRTC plays an important role in many applications such as signal processing, computer vision, machine learning, and neuroscience. A widely used approach is to combine the tensor completion data fitting term with a regularizer based on a convex relaxation of the multilinear ranks of the tensor. For the data fitting function, we model the tensor variable by using the Canonical Polyadic (CP) decomposition and for the low-rank promoting regularization function, we consider a graph Laplacian-based function which exploits correlations between the rows of the matrix unfoldings. For solving our LRTC model, we propose an efficient alternating minimization algorithm. Furthermore, based on the Kurdyka-{\L}ojasiewicz property, we show that the sequence generated by the proposed algorithm globally converges to a critical point of the objective function. Besides, an alternating direction method of multipliers algorithm is also developed for the LRTC model. Extensive numerical experiments on synthetic and real data indicate that the proposed algorithms are effective and efficient

    Emergence of agent-based referral networks

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    Enhanced squeezing with parity kicks

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    Using exponential quadratic operators, we present a general framework for studying the exact dynamics of system-bath interaction in which the Hamiltonian is described by the quadratic form of bosonic operators. To demonstrate the versatility of the approach, we study how the environment affects the squeezing of quadrature components of the system. We further propose that the squeezing can be enhanced when parity kicks are applied to the system.Comment: 4 pages, 2 figure

    Soliton with a Pion Field in the Global Color Symmetry Model

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    We calculate the property of the global color symmetry model soliton with the pion field being included explicitly. The calculated results indicate that the pion field provides a strong attraction so that the eigen-energy of a quark and the mass of a soliton reduce drastically, in contrast to those with only the sigma field.Comment: 15 pages, 2 figure
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