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421.
Anisotropic strange quark star in Finch-Skea geometry and its maximum mass for non-zero strange quark mass (ms ≠ 0)
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A class of relativistic astrophysical compact objects is analyzed in the modified Finch-Skea geometry described by the MIT bag model equation of state of interior matter, \begin{document}$ p=\dfrac{1}{3}\left(\rho-4B\right) $\end{document} ![]()
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, where B is known as the bag constant. B plays an important role in determining the physical features and structure of strange stars. We consider the finite mass of the strange quark (\begin{document}$ m_{s} \neq 0 $\end{document} ![]()
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) and study its effects on the stability of quark matter inside a star. We note that the inclusion of strange quark mass affects the gross properties of the stellar configuration, such as maximum mass, surface red-shift, and the radius of strange quark stars. To apply our model physically, we consider three compact objects, namely, (i) VELA X-1, (ii) 4U 1820-30, and (iii) PSR J 1903+327, which are thought to be strange stars. The range of B is restricted from 57.55 to \begin{document}$B_{\rm stable}$\end{document} ![]()
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(\begin{document}$\rm MeV/fm^{3}$\end{document} ![]()
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), for which strange matter might be stable relative to iron (\begin{document}$^{56}{\rm Fe}$\end{document} ![]()
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). However, we also observe that metastable and unstable strange matter depend on B and \begin{document}$ m_{s} $\end{document} ![]()
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. All energy conditions hold well in this approach. Stability in terms of the Lagrangian perturbation of radial pressure is studied in this paper. 相似文献
422.
Owing to the significant difference between the experimental measurements and the theoretical predictions of the standard model (SM) for the value of \begin{document}$ {\cal{R}}(D) $\end{document} ![]()
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of the semileptonic decay \begin{document}$ B\to D\ell\bar{\nu}_{\ell} $\end{document} ![]()
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, researchers speculate that this decay may be evidence of new physics beyond the SM. Usually, the D-meson twist-2, 3 distribution amplitudes (DAs) \begin{document}$ \phi_{2;D}(x,\mu) $\end{document} ![]()
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, \begin{document}$ \phi_{3;D}^p(x,\mu) $\end{document} ![]()
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, and \begin{document}$ \phi_{3;D}^\sigma(x,\mu) $\end{document} ![]()
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are the main error sources when perturbative QCD factorization and light-cone QCD sum rules are used to study \begin{document}$ B\to D\ell\bar{\nu}_{\ell} $\end{document} ![]()
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. Therefore, it is important to obtain more reasonable and accurate behaviors for these DAs. Motivated by our previous work [Phys. Rev. D 104, no.1, 016021 (2021)] on pionic leading-twist DA, we revisit D-meson twist-2, 3 DAs \begin{document}$ \phi_{2;D}(x,\mu) $\end{document} ![]()
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, \begin{document}$ \phi_{3;D}^p(x,\mu) $\end{document} ![]()
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, and \begin{document}$ \phi_{3;D}^\sigma(x,\mu) $\end{document} ![]()
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. New sum rule formulae for the \begin{document}$\xi $\end{document} ![]()
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-moments of these three DAs are suggested for obtaining more accurate values. The light-cone harmonic oscillator models for the DAs are improved, and their parameters are determined by fitting the values of ξ -moments via the least squares method. 相似文献
423.
424.
425.
利用工作在北京正负电子对撞机(BEPC)上的北京谱仪(BES)收集到的33pb-1的Ψ(3770)数据,寻找D介子味道改变中性流(FCNC)和轻子数不守恒(LNV)的稀有衰变, 包括4个D0介子的衰变模式(K0e+e-,Φe+e-,ρ0e+e-和K*0e+e-)和6个D+介子的衰变模式(K-e+e+,K+e+e-,π-e+e+, π+e+e-,K*-e+e+和K*+e+e-). 没有发现信号,给出90%置信水平的上限. 其中, D+介子的两个衰变模式D+→K*-e+e+和D+→K*+e+e-的上限是首次测量. 相似文献
426.
D G Hitlin 《Pramana》2006,67(5):743-753
Heavy-flavor physics, in particular B and τ physics results from the B factories, currently provides strong constraints on models of physics beyond the Standard Model. A new generation of colliders,
Super B Factories, with 50 to 100 times the luminosity of existing colliders, can, in a dialog with LHC and ILC, provide unique clarification
of new physics phenomena seen at those machines. 相似文献
427.
Resonating-group method has been applied to calculate the ΩΩ (SIJ = -6,0,0) dibaryon state in theframework of the extended quark-delocalization color-screening model. The mass of the di-Ω is predicted to be about45 MeV lower than the Ω-Ω threshold. The effect of channel coupling due to the tensor force and sensitivity to mesonexchange short-range cutoff radius, ro have also been studied. 相似文献
428.
利用Belle与CLEO实验组的最新实验数据,分析了B→D(*)π衰变道的同位旋振幅与位相差,并确定了相关的因子化参数.结果表明这类衰变道中的强相互作用效应不可忽略,但是因子化近似对于单个同位旋振幅仍旧是合理与自洽的. 相似文献
429.
Swapan Das 《Pramana》2006,66(5):947-952
π0γ invariant mass distribution spectrum has been calculated for the (γ, π0γ) reaction on12C nucleus at 2.5 GeV beam energy. These π0 and γ are assumed to originate due to the decay of vector mesons produced in the photonuclear reaction. The nuclear medium
effect on vector mesons and the effect of π0 rescattering on the π0γ invariant mass spectrum have been investigated 相似文献
430.