6,663 research outputs found

    Born-Infeld Black Holes in 4D Einstein-Gauss-Bonnet Gravity

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    A novel four-dimensional Einstein-Gauss-Bonnet gravity was formulated by D. Glavan and C. Lin [Phys. Rev. Lett. 124, 081301 (2020)], which is intended to bypass the Lovelock's theorem and to yield a non-trivial contribution to the four-dimensional gravitational dynamics. However, the validity and consistency of this theory has been called into question recently. We study a static and spherically symmetric black hole charged by a Born-Infeld electric field in the novel four-dimensional Einstein-Gauss-Bonnet gravity. It is found that the black hole solution still suffers the singularity problem, since particles incident from infinity can reach the singularity. It is also demonstrated that the Born-Infeld charged black hole may be superior to the Maxwell charged black hole to be a charged extension of the Schwarzschild-AdS-like black hole in this new gravitational theory. Some basic thermodynamics of the black hole solution is also analyzed. Besides, we regain the black hole solution in the regularized four-dimensional Einstein-Gauss-Bonnet gravity proposed by H. L\"u and Y. Pang [arXiv:2003.11552].Comment: 13 pages and 18 figures, published versio

    Scalar form-factor of the proton with light-cone QCD sum rules

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    In this article, we calculate the scalar form-factor of the proton in the framework of the light-cone QCD sum rules approach with the three valence quark light-cone distribution amplitudes up to twist-6, and observe the scalar form-factor σ(t=Q2)\sigma(t=-Q^2) at intermediate and large momentum transfers Q2>2GeV2Q^2> 2GeV^2 has significant contributions from the end-point (or soft) terms. The numerical values for the σ(t=Q2)\sigma(t=-Q^2) are compatible with the calculations from the chiral quark model and lattice QCD at the region Q2>2GeV2Q^2>2GeV^2.Comment: 18 pages, 7 figures, revised versio

    Simulation Study on neutrino nucleus cross section measurement in Segmented Detector at Spallation Neutron Source

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    Knowledge of νe\nu_e-Fe/Pb\mathrm{Fe}/\mathrm{Pb} differential cross sections for νe\nu_e energy below several tens of MeV scale is believed to be crucial in understanding Supernova physics. In a segmented detector at Spallation Neutrino Source, νe\nu_e energy reconstructed from the electron range measurement is strongly affected because of both multiple scattering and electromagnetic showers occurring along the electron passage in target materials. In order to estimate the effect, a simulation study has been performed with a cube block model assuming a perfect tracking precision. The distortion of energy spectrum is observed to be proportional to the atomic number of target material. Feasibility of unfolding the distorted νe\nu_e energy spectrum is studied for both Fe and Pb cases. Evaluation of statistical accuracy attainable is therefore provided for a segmented detector.Comment: 6 pages, 6 figures, submitted to Chinese Physics

    Luminal B subtype: A key factor for the worse prognosis of young breast cancer patients in China

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    BACKGROUND: The prognoses of young breast cancer patients are poor. The purpose of this study is to evaluate the different characteristics and prognoses among different subtypes of young breast cancer patients. METHODS: The study included 1360 patients <40 years-old (y) and 3110 patients 40-50y with operable breast cancer in Shanghai Cancer Center, Fudan University. The characteristics, overall survival (OS) and disease-free survival (DFS) were compared. RESULTS: The median follow-up was 54.1 months. More grade III tumors and more lymph-vascular invasions (P < 0.01) were presented in <40y group when compared with 40-50y group. More patients <40y presented with Luminal B (25.3% vs. 17.5%, P < 0.01) and triple negative (16.7% vs. 13.4%, P < 0.05) breast cancer while fewer had Luminal A tumor (48.5% vs. 59.2%, P < 0.01). Younger patients with tumors of both Luminal A and Luminal B types were at increased risk for worse DFS (P = 0.03, HR = 1.69, 95% CI = 1.05-2.72; P < 0.01, HR = 3.61, 95% CI = 2.50-5.22) when compared with the older patients. Patients <40y with Luminal B tumor had a two point five fold higher risk of death compared with older counterparts (P < 0.01, HR = 2.54, 95% CI = 1.35-4.79), however, a worse overall survival rate was not observed in the younger women with Luminal A breast cancer (P > 0.05). In multivariate analysis, Luminal B subtype was also a strong predictor of disease relapse (HR = 1.09, 95% CI = 1.01 to 1.19, P < 0.01) in younger patients with Luminal subtype tumors. CONCLUSION: Characteristics of breast cancer suggested a more aggressive biology in Chinese patients with breast cancer diagnosed at young age. Luminal B subtype may have a negative effect on the prognosis of young patients in China which should be validated further
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