分类: 物理学 >> 核物理学 提交时间: 2023-06-09 合作期刊: 《Nuclear Science and Techniques》
摘要: Research performed during the past decade revealed an important role of symmetry energy in the equation of state (EOS) of strange quark matter (SQM). By introducing an isospin-dependent term into the quark mass scaling, the SQM stability window in the equivparticle model was studied. The results show that a sufficiently strong isospin dependence CI can significantly widen the SQM region of absolute stability, yielding results that simultaneously satisfy the constraints of the astrophysical observations of PSR J1614-2230 with 1:928 0:017 M and tidal deformability 70 1:4 580 measured in the event GW170817. With increasing CI , the difference between the u, d, and s quark fractions for the SQM in equilibrium becomes inconspicuous for C > 0, leading to small isospin asymmetry , and further resulting in similar EOS and structures of strange quark stars (SQSs). Moreover, unlike the behavior of the maximum mass of u–d QSs, which varies with CI depending on the sign of the parameter C, the maximum mass of the SQSs decreases monotonously with increasing CI .
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-11-10
摘要: We take the JUNO experiment as an example to explore nuclearites in the future large liquid scintillator detector. Comparing to the previous calculations, the visible energy of nuclearites across the liquid scintillator will be reestimated for the liquid scintillator based detector. Then the JUNO sensitivities to the nuclearite flux are presented. It is found that the JUNO projected sensitivities can be better than 7.7×10−17cm−2s−1sr−1 for the nuclearite mass 1015 GeV ≤ M ≤ 1024 GeV and initial velocity 10−4 ≤ β0 ≤ 10−1 with a 20 year running. Note that the JUNO will give the most stringent limits for downgoing nuclearites with 1.6 × 1013 GeV ≤ M ≤ 4.0 × 1015 GeV and a typical galactic velocity β0 = 10−3.
分类: 物理学 >> 核物理学 提交时间: 2017-08-22
摘要: The stability of excited superheavy nuclei (SHN) with 100 Z 134 against neutron emission and fission is investigated by using a statistical model. In particular, a systematic study of the survival probability against fission in the 1n-channel of these SHN is made. In present calculations the neutron separation energies and shell correction energies are consistently taken from the calculated results of the finite range droplet model which predicts an island of stability of SHN around Z = 115 and N = 179. It turns out that this island of stability persists for excited SHN in the sense that the calculated survival probabilities in the 1n-channel of excited SHN at the optimal excitation energy are maximized around Z = 115 and N = 179. This indicates that the survival probability in the 1n-channel is mainly determined by the nuclear shell effects.
分类: 物理学 >> 核物理学 提交时间: 2017-07-30
摘要: The conventionally separated treatments for strangelets and strange stars are now unified with a more comprehensive theoretical description for objects ranging from strangelets to strange stars. After constraining the model parameter according to the Witten-Bodmer hypothesis and observational mass-radius probability distribution of pulsars, we investigate the properties of this kind of objects. It is found that the energy per baryon decreases monotonously for increasing baryon number and reaches its minimum at the maximum baryon number, corresponding to the most massive strange star. Due to the quark depletion, an electric potential well for negatively charged particles is formed on the surface of the quark part, which may provide some unique observables. For a rotational bare strange star, a magnetic field with the typical strength of pulsars is generated.
分类: 物理学 >> 核物理学 分类: 物理学 >> 地球物理学、天文学和天体物理学 提交时间: 2024-01-09
摘要: According to the recent studies, the gravitational wave (GW) echoes are expected to be generated by quark stars composed of ultrastif quark matter. The ultrastif equations of state (EOS) for quark matter were usually obtained either by a simple bag model with artifcially assigned sound velocity or by employing interacting strange quark matter (SQM) depicted by simple reparameterization and rescaling. In this study, we investigate GW echoes with EOSs for SQM in the framework of the equivparticle model with density-dependent quark masses and pairing efects. We conclude that strange quark stars (SQSs) can be sufciently compact to possess a photon sphere capable of generating GW echoes with frequencies in the range of approximately 20 kHz. However, SQSs cannot account for the observed 72 Hz signal in GW170817 event. Furthermore, we determined that quark-pairing efects play a crucial role in enabling SQSs to satisfy the necessary conditions for producing these types of echoes.