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Probing valence quark width of the proton in deeply virtual Compton scattering at high energies

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Chinese physics C 2024年第5期48卷 235-243页

作者：向文昌曹德文周代翠 physics Division Guangzhou Maritime UniversityGuangzhou 510725China Key Laboratory of Quark and Lepton physics(MOE) and Institute of Particle PhysicsCentral China Normal UniversityWuhan 430079China

We use the refined hot spot model to study the valence quark shape of the proton with the deeply virtual Compton scattering at high energies in the color glass condensate *** investigate the individual valence quark shape,a novel treatment of the valence quark width is *** calculate the cross-sections for coherent and incoherent deeply virtual Compton scattering using,for the first time,different widths(Bu and Bd)for the profile density distributions of the up and down quarks instead of using the same width as in the *** find that the cross-sections calculated with Bu≥Bd at each collision energy are consistent with each other,which is in agreement with theoretical expectations,whereas those computed with Bu

关键词： gluon saturation physics color glass condensate proton shape fluctuations

Tensor perturbations from bounce inflation scenario in f(Q)gravity

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Science China(physics,Mechanics & Astronomy) 2024年第2期67卷 78-92页

作者： Kun Hu Tanmoy Paul Taotao Qiu institute of Astrophysics Central China Normal UniversityWuhan 430079China School of physics Huazhong University of Science and TechnologyWuhan 430074China National institute of Technology Jamshedpur Department of PhysicsJamshedpur 831014India

In this paper,we construct a bounce inflation cosmological scenario in the framework of the modified symmetric teleparallel gravity,namely f(Q)theory,and investigate the tensor perturbations *** is well-known,the tensor perturbations generated in the very early Universe(inflation and pre-inflation regions)can account for the primordial gravitational waves(PGWs)that are to be detected by the next generation of GW *** discuss the stability condition of the tensor perturbations in the bounce inflation process and investigate in detail the evolution of the perturbation *** general form of the tensor power spectrum is obtained both for large as well as small scale *** a result,we show both kinds of modes(short or long wavelength modes),and the tensor spectrum may get a positive tilt in the parametric range where the tensor perturbation proves to be stable—this interestingly hints an enhancement of gravitational waves’amplitude in the background of the f(Q)bounce-inflation ***,we study the LQC-like scenario as a specific case of our model,in which,the primordial tensor power spectrum turns out to be nearly scale-invariant on both small and large scales.

关键词： bounce cosmology modified gravity cosmological perturbations

Constant-roll inflation with non-minimally derivative coupling

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Communications in Theoretical physics 2024年第9期76卷 57-64页

作者： Jie Liu Yungui Gong Zhu Yi School of physics and Electronic Engineering Hainan Normal University Department of physics School of Physical Science and Technology Ningbo University School of physics Huazhong University of Science and Technology Faculty of Arts and Sciences Beijing Normal University Advanced institute of Natural Sciences Beijing Normal University

We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein *** the slow-roll parameter ■ being a constant,we calculate the power spectra for scalar and tensor perturbations,and derive the expressions for the scalar spectral tilt ns,the tensor spectral tilt nT,and the tensor-to-scalar ratio *** find that the expressions for nsare different with different ordering of taking the derivative of the scalar power spectrum with respect to the scale k and the horizon crossing condition csk=a H in the constant-roll inflation,the consistency relation r=-8nTdoes not hold if|ηφ|is not small,and the duality of the tensorto-scalar ratio between the slow-roll inflation and ultra-slow-roll inflation does not exist in inflationary models with non-minimally derivative *** result offers a fresh perspective on the understanding of the inflationary models with non-minimally derivative coupling and is helpful for the production of scalar induced gravitational waves in the framework of ultra-slowroll inflation with non-minimally derivative coupling.

关键词： constant-roll inflation inflation non-minimally derivative coupling inflation

Quenching and flow of charm and bottom quarks via semi-leptonic decay of D and B mesons in Pb+Pb collisions at the LHC

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Chinese physics C 2024年第8期48卷 190-197页

作者： Shu-Qing Li Wen-Jing Xing Shanshan Cao Guang-You Qin School of physics and Electronic Engineering Jining UniversityQufu 273155China institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China institute of particle physics and Key Laboratory of Quark and Lepton physics(MOE) Central China Normal UniversityWuhan 430079China

Heavy flavor particles provide important probes of the microscopic structure and thermodynamic properties of the quark-gluon plasma(QGP)produced in high-energy nucleus-nucleus *** studied the energy loss and flow of charm and bottom quarks inside the QGP via the nuclear modification factor(R_(AA))and elliptic flow coefficient(v_(2))of their decayed leptons in heavy-ion collisions at the *** dynamical evolution of the QGP was performed using the CLVisc(3+1)-dimensional viscous hydrodynamics model;the evolution of heavy quarks inside the QGP was simulated with our improved Langevin model that considers both collisional and radiative energy loss of heavy quarks;the hadronization of heavy quarks was simulated via our hybrid coalescence-fragmentation model;and the semi-leptonic decay of D and B mesons was simulated via *** the same spatial diffusion coefficient for charm and bottom quarks,we obtained smaller R_(AA) and larger v_(2) of charm decayed leptons than bottom decayed leptons,indicating stronger energy loss of charm quarks than bottom quarks inside the QGP within our current model setup.

关键词： quark-gluon plasma heavy-ion collisions jet quenching anisotropic flow heavy quark heavy flavor muon

Isoscaling properties for neutron-rich fragments in highly asymmetric heavy ion collision systems

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Chinese physics C 2024年第6期48卷 136-144页

作者：彭丹马春旺乔春源刘星泉魏慧玲 institute of particle and Nuclear physics College of PhysicsHenan Normal UniversityXinxiang 453007China institute of Nuclear Science and Technology Henan Academy of SciencesZhengzhou 450046China Key Laboratory of Radiation physics and Technology of the Ministry of Education Sichuan UniversityChengdu 610064China

Traditionally,isoscaling has been interpreted and applied within the framework of the grand canonical ensemble,based on the assumption that fragment production occurs following the attainment of a statistical equilibrium ***,the influence of the symmetry energy can lead to differences in the neutron and density distribution in neutron-rich *** in turn may impact the iso scaling parameters(usually denoted byαandβ).We examine the isoscaling properties for neutron-rich fragments produced in highly asymmetric systems on inverse kinematics,namely^(40,48)Ca and ^(58,64)Ni+^(9)Be at 140 MeV per *** evaluate α and β values and sort them as a function of the neutron excess I≡*** significant differences in a extracted from fragments within different ranges of I emphasize the importance of understanding the dependence of isoscaling parameters on fragments generated in various collision ***,the|β(N)|/α(Z)value for a specific fragment in small size and highly iso spin asymmetry systems can serve as a probe to detect the variations in neutron density and proton density in different regions of the nucleus and indicate the limitations of theoretical models in investigating these issues.

关键词： isoscaling symmetry energy nuclear density neutron-rich fragment heavy ion collision

QCD Chiral Phase Transition and Its Microscopic Origin

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原子核物理评论 2024年第1期41卷 109-116页

作者： DING Hengtong Key Laboratory of Quark and Lepton physics(MOE)and institute of particle physics Central China Normal UniversityWuhan 430079China

The transition of strong-interaction matter from the hadronic phase to the quark-gluon plasma phase is a rapid crossover but not a true phase transition in *** true phase transition of strong-interaction matter is expected to exist only in certain limits,*** limit of massless quarks and *** this contribution to CNPC2023 Special Issue we present our recent studies on the true phase transition of strong-interaction matter in the chiral limit of massless quarks as well as its microscopic *** study is based on(2+1)-flavor lattice QCD simulations using highly improved staggered fermions,with pion masses ranging from 160 MeV down to 55 *** a newly proposed method to compute the quark mass derivatives of the Dirac eigenvalue spectrum on the lattice,it is found that the axial U(1)anomaly is still manifested at 1.6T_(c),with a microscopic origin consistent with the dilute instanton gas ***,based on lattice QCD results and a generalized Banks-Casher relation,it is found that the macroscopic singularity of the chiral phase transition is encoded in the correlation of the Dirac eigenvalue *** research directions along these findings are also discussed,including the investigation of the temperature range between T_(c) and 1.6 T_(c) to understand the breakdown of the dilute instanton gas approximation and its connection to the chiral phase transition.

关键词： QCD phase structure Dirac eigenvalue spectrum axial anomaly chiral symmetry criticality

A discussion on the anomalous threshold enhancement of J/ψ–ψ(3770)couplings and X(6900)peak

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Chinese physics C 2024年第4期48卷 1-5页

作者：陆业陈畅秦广友郑汉青 institute of particle physics and Key Laboratory of Quark and Lepton physics(MOE) Central China Normal UniversityWuhan 430079China Department of physics Peking UniversityBeijing 100871China College of physics Sichuan UniversityChengdu 610065China

The attractive interaction between J/ψandψ(3770)has to be strong enough if X(6900)is of the molecule *** argue that sinceψ(3770)decays predominantly into a DD^(¯)pair,the interactions between J/ψandψ(3770)may be significantly enhanced owing to the three point DD^(¯)loop *** enhancement originates from the anomalous threshold located at t=−1.288 GeV^(2),whose effect propagates into the s-channel partial wave amplitude in the vicinity of √s≃6.94 *** effect may be helpful in the formation of the X(6900)peak.

关键词： exotic hadrons hadron molecule X(6900)

Carbon-based nanomaterials cause toxicity by oxidative stress to the liver and brain in Sprague-Dawley rats

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Nuclear Science and Techniques 2024年第6期35卷 54-64页

作者： Ying-Ying Xu Chan Jin Meng Wu Jian-Ye Zhou Hui-Ling Wei Department of Gastroenterology China-Japan Friendship HospitalBeijing 100029China Shanghai institute of Applied physics Chinese Academy of SciencesShanghai 201800China institute of particle and Nuclear physics College of PhysicsHenan Normal UniversityXinxiang 453007China

Carbon-based nanomaterials have important research significance in various disciplines,such as composite materials,nanoelectronic devices,biosensors,biological imaging,and drug ***,the human and ecological risks associated with carbon-based nanomaterials have received increasing ***,the biological safety of carbon based nanomaterials has not been systematically *** this study,we used different types of carbon materials,namely,graphene oxide(GO),single-walled carbon nanotubes(SWCNTs),and multiwalled carbon nanotubes(MWCNTs),as models to observe their distribution and oxidative damage in *** results of Histopathological and ultrastructural examinations indicated that the liver and lungs were the main accumulation targets of these ***-μ-XRF analysis revealed that SWCNTs and MWCNTs might be present in the *** shows that the three types of carbon-based nanomaterials could cross the gas-blood barrier and eventually reach the liver *** addition,SWCNTs and MWCNTs could cross the blood-brain barrier and accumulate in the cerebral *** increase in ROS and MDA levels and the decrease in GSH,SOD,and CAT levels indicated that the three types of nanomaterials might cause oxidative stress in the *** suggests that direct instillation of these carbon-based nanomaterials into rats could induce ROS *** addition,iron(Fe)contaminants in these nanomaterials were a definite source of free ***,these nanomaterials did not cause obvious damage to the rat brain *** deposition of selenoprotein in the rat brain was found to be related to oxidative stress and Fe *** information may support the development of secure and reasonable applications of the studied carbon-based nanomaterials.

关键词： Carbon-based nanomaterials Oxidative stress Trace element distribution TEM SR-μ-XRF

Temporal and Spectral Characteristics of Persistent Emission and Special Bursts of Magnetar SGR J1935+2154 Based on Insight-HXMT

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Research in Astronomy and Astrophysics 2024年第6期24卷 225-233页

作者： Xue-Feng Lu Li-Ming Song Ming-Yu Ge Shuang-Nan Zhang Jin-Lu Qu Ce Cai Cong-Zhan Liu Cheng-Kui Li Yu-Cong Fu Ying-Chen Xu Key Laboratory of particle Astrophysics Institute of High Energy PhysicsBeijing 100049China university of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China College of physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal UniversityShijiazhuang 050024China Department of Astronomy Beijing Normal UniversityBeijing 100875China

In October 2022,the magnetar SGR J1935+2154 entered the active outburst *** the episode,the InsightHXMT satellite carried out a long observation that lasted for 20 *** than 300 bursts were detected,and a certain amount of persistent radiation signals were also *** paper mainly introduces the results of persistent radiation profile folding and period search based on Insight-HXMT *** the same time,the burst phase distribution characteristics,spectral lag results of burst,the spectral characteristics of zero-lag bursts and the time-resolved spectral evolution characteristics of high-flux bursts are *** found that there is no significant delay feature during different energy bands for the bursts of SGR J1935+*** observed zero-lag burst does not have a unique *** time-resolved spectrum of the individual burst has consistent spectral types and spectral parameters at different time periods of the *** also find that the burst number phase distribution and the burst photon phase distribution have the same tendency to concentrate in specific regions of the persistent emission profile.

关键词： radiation mechanisms:general dense matter magnetic fields