作者机构:
[Zheng, Xiao-Ping; Cheng, Quan] Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.;[Fan, Xi-Long] Wuhan Univ, Sch Phys & Technol, Wuhan 430072, Peoples R China.;[Huang, Xi] Wuhan Text Univ, Sch Math & Phys Sci, Wuhan 430200, Peoples R China.
关键词:
stars: neutron;stars: magnetars;stars: magnetic field;gravitational waves
摘要:
The observed electromagnetic radiation from some long and short gamma-ray bursts, and neutron stars (NSs), and the theoretical models proposed to interpret these observations together point to a very interesting but confusing problem, namely, whether fall-back accretion could lead to dipole field decay of newborn NSs. In this paper, we investigate the gravitational wave (GW) radiation of newborn magnetars with a fall-back disk formed in both the core-collapse of massive stars and the merger of binary NSs. We make a comparison of the results obtained with and without fall-back accretion-induced dipole-field decay (FADD) involved. Depending on the fall-back parameters, initial parameters of newborn magnetars, and models used to describe FADD, FADD may indeed occur in newborn magnetars. Because of the low dipole fields caused by FADD, the newborn magnetars will be spun up to higher frequencies and have larger masses in comparison with the non-decay cases. Thus the GW radiation of newborn accreting magnetars would be remarkably enhanced. We propose that observation of GW signals from newborn magnetars using future GW detectors may help to reveal whether FADD could occur in newborn accreting magnetars. Our model is also applied to the discussion of the remnant of GW170817. From the post-merger GW searching results of Advanced LIGO and Advanced Virgo we cannot confirm the remnant is a low-dipole-field long-lived NS. Future detection of GWs from GW170817-like events using more sensitive detectors may help to clarify the FADD puzzle.
作者机构:
[Yang, Shu-Yun; Ren, Hai-Cang; Hou, De-Fu] Cent China Normal Univ, Inst Particle Phys, Key Lab Quark & Lepton Phys MOS, Wuhan 430079, Peoples R China.;[Fang, Ren-Hong] Shandong Univ, Inst Frontier & Interdisciplinary Sci, Key Lab Particle Phys & Particle Irradiat MOE, Qingdao 266237, Peoples R China.;[Ren, Hai-Cang] Rockefeller Univ, Phys Dept, 1230 York Ave, New York, NY 10021 USA.
通讯机构:
[Hou, D.-F.; Ren, H.-C.] I;Institute of Particle Physics, China
关键词:
heavy ion collisions;quark-gluon plasmas;axial-chiral-vortical-effect
摘要:
We investigate the axial vortical effect in a uniformly rotating sphere subject to finite size. We use MIT boundary condition to limit the boundary of the sphere. For massless fermions inside the sphere, we obtain the exact axial vector current far from the boundary that matches the expression obtained in cylindrical coordinates in the literature. On the spherical boundary, we find both the longitudinal and transverse(with respect to the rotation axis) components with magnitude depending on the colatitude angle. For massive fermions, we derive an expansion of the axial conductivity far from the boundary to all orders of mass whose leading order term agrees with the mass correction reported in the literature. We also obtain the leading order mass correction on the boundary which is linear, and stronger than the quadratic dependence far from the boundary. The qualitative implications on the phenomenology of heavy ion collisions are speculated. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
作者机构:
[Liu, Lian; Zheng, Liang] China Univ Geosci Wuhan, Sch Math & Phys, Wuhan 430074, Peoples R China.;[Yin, Zhong-Bao; Zheng, Liang] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Yin, Zhong-Bao; Zheng, Liang] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
关键词:
Blast-Wave model;Tsallis statistics;transverse momentum spectra;small system
摘要:
In this study, we perform Tsallis Blast-Wave analysis on the transverse momentum spectra of identified hadrons produced in a wide range of collision systems at the Large Hadron Collider (LHC) including pp, pPb, XeXe, and PbPb collisions. The kinetic freeze-out properties varying with event multiplicity are investigated across these systems. We find that the extracted kinetic freeze-out temperature, radial flow velocity, and non-extensive parameter exhibit a universal scaling behavior for these systems with very different geometric sizes, especially when the independent baryon Tsallis non-extensive parameter is considered. This universality may indicate the existence of a unified partonic evolution stage in different collision systems at the LHC energies.
摘要:
In this work, we study the impact of jet quenching on $p_{T}$ dispersion($p_{T}D$) of inclusive jets ($R=0.2$) in Pb+Pb collisions at $\sqrt{s}=2.76$~TeV. The partonic spectrum in the initial hard scattering of elementary collisions are obtained by an event generator POWHEG+PYTHIA, which matches the next-to-leading (NLO) matrix elements with parton showering, and energy loss of fast parton traversing in hot/dense QCD medium is calculated by Monte Carlo simulation within Higher-Twist formalism of jet quenching in heavy-ion collisions. We present the model calculations of normalized $p_{T}D$ distributions for inclusive jets in p+p and Pb+Pb collisions at $\sqrt{s}=2.76$~TeV, which give nice descriptions of ALICE measurements. It is shown that the $p_{T}D$ distributions of inclusive jets in Pb+Pb significantly shifts to higher $p_{T}D$ region relative to that in p+p. Thus the nuclear modification ratio of $p_{T}D$ distributions for inclusive jets is smaller than unity at small $p_{T}D$ region, while larger than one at large $p_{T}D$ region. This behavior results from more uneven $p_T$ distribution of jet constituents as well as the fraction alteration of quark/gluon initiated jets in heavy-ion collisions. The difference of $p_{T}D$ distributions between groomed and ungroomed jets in Pb+Pb collisions are also discussed. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Article funded by SCOAP3 and published under licence by Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Science and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
作者机构:
[Liu, Ze-Kun; Banik, Amit Dutta; Chen, Shao-Long] Cent China Normal Univ, Key Lab Quark & Lepton Phys MoE, Wuhan 430079, Peoples R China.;[Liu, Ze-Kun; Banik, Amit Dutta; Chen, Shao-Long] Cent China Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;[Chen, Shao-Long] Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China.
关键词:
dark matter;triplet Higgs;neutrino mass;electron and positron excesses
摘要:
We perform a detailed study of scalar dark matter with triplet Higgs extensions of the Standard Model in order to explain the cosmic ray electron and positron excesses reported by AMS-02 and DAMPE. A detailed analysis of the AMS-02 positron excess reveals that for different orderings (normal, inverted, and quasi-degenerate) of neutrino mass, the hybrid triplet Higgs portal framework is more favored with respect to the single triplet Higgs portal for TeV scale dark matter. We also show that the resonant peak and continuous excess in DAMPE cosmic ray data can be well explained with the hybrid triplet Higgs portal dark matter when a dark matter sub-halo nearby is taken into account.
作者:
Qing Zhang;Wei Dai;Lei Wang;Ben-Wei Zhang;Enke Wang
期刊:
中国物理C,2022年46(10):174-181 ISSN:1674-1137
作者机构:
[Ben-Wei Zhang; Enke Wang] Key Laboratory of Quark&Lepton Physics(MOE)and Institute of Particle Physics,Central China Normal University,Wuhan 430079,China;School of Mathematics and Physics,China University of Geosciences(Wuhan),Wuhan 430074,China;[Ben-Wei Zhang; Enke Wang] Guangdong Provincial Key Laboratory of Nuclear Science,Institute of Quantum Matter,South China Normal University,Guangzhou 510006,China;[Enke Wang] Guangdong-Hong Kong Joint Laboratory of Quantum Matter,Southern Nuclear Science Computing Center,South China Normal University,Guangzhou 510006,China;[Wei Dai] 中国地质大学(武汉)
摘要:
For photocatalytic materials, the composites formed by metal oxides and heteroatom-doped carbon have outstanding activity. Among them, metal-organic framework (MOF) derived composites, usually composed of metal oxide and nitrogen-doped carbon, is not only simple to prepare, but also have far-exceeding catalytic performance than homogenous semiconductor. However, the relationship between the structure and performance in the photocatalytic system is still not clear. Here, we explored the tunable nitrogen configurations in sample N-ZnO@NC by controlling the thermal conversion of ZIF-8. Crucially, through ex situ and in-situ XPS characterization, it is found that the ZnO and nitrogen-doped carbon in N-ZnO@NC are connected by C-N-Zn bond, which enhances charge separation efficiency and becomes the origin of superior photocatalytic performance. DFT calculations further reveal the influence of different Zn-bonding nitrogen configurations on the adjusting of Fermi level and electron transfer. This study exhibits that the pyridine-N configuration in MOF-derived material is the main contributor for the improved performance and tunes Fermi level more appropriately than the pyrrolic-N, which can hold the key for future design of next-generation photocatalysts. (c) 2021 Published by Elsevier Ltd on behalf of Chinese Society for Metals.