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Cr-induced fusion reactions to synthesize superheavy elements

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Nuclear Science and Techniques 2024年第5期35卷 122-130页

作者： S.Madhu H.C.Manjunatha N.Sowmya B.M.Rajesh L.Seenappa R.S.Susheela department of physics R V College of EngineeringBangalore 560074India Visvesvaraya Technological University BelagaviKarnataka 590018India department of physics Government First Grade CollegeSrinivasapurKarnataka 563135India department of physics Government First Grade CollegeDevanahallyKarnataka 562110India department of physics Government First Grade CollegeMulbagalKarnataka 563131India department of physics Government First Grade collegeNanjangudOoty RoadMysore 571301India

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 *** cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior *** estimated cross sections from this analysis are consistent with the findings of prior *** the current study,the predicted cross section was found to be 42fb at 236 MeV for ^(53)Cr+^(243)Am,23.2 fb at 236 MeV for ^(54)Cr+^(247)Cm,95.6 fb at 240 MeV for ^(53)Cr+248Bk,and 1.33 fb at 242 MeV for ^(53)Cr+***,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.

关键词： Fusion cross sections Compound nucleus formation probability Survival probability Evaporation residue cross sections

A pseudoclassical theory for the wavepacket dynamics of the kicked rotor model

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Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 34-43页

作者： Zhixing Zou Jiao Wang department of physics and Key Laboratory of Low Dimensional Condensed Matter physics(department of Education of Fujian Province) Xiamen UniversityXiamen 361005China Lanzhou Center for Theoretical physics Lanzhou UniversityLanzhou 730000China

In this study, we propose a generalized pseudoclassical theory for the kicked rotor model in an attempt to discern the footprints of the classical dynamics in the deep quantum regime. Compared with the previous pseudoclassical theory that applies only in the neighborhoods of the lowest two quantum resonances, the proposed theory is applicable in the neighborhoods of all quantum resonances in principle by considering the quantum effect of the free rotation at a quantum resonance. In particular, it is confirmed by simulations that the quantum wavepacket dynamics can be successfully forecasted based on the generalized pseudoclassical dynamics, offering an intriguing example where it is feasible to bridge the dynamics in the deep quantum regime to the classical dynamics. The application of the generalized pseudoclassical theory to the PT-symmetric kicked rotor is also discussed.

关键词： quantum-classical correspondence kicked rotor model pseudoclassical theory wavepacket dynamics

Curvature-enhanced multipartite coherence in the multiverse

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Chinese physics C 2024年第7期48卷 259-272页

作者：吴树民王春旭王锐迪李金璇黄晓理曾浩生 department of physics Liaoning Normal UniversityDalian 116029China department of physics Hunan Normal UniversityChangsha 410081China

Here,we study the quantum coherence of N-partite Greenberger-Horne-Zeilinger(GHZ)and W states in the multiverse consisting of N causally disconnected de Sitter ***,N-partite coherence increases monotonically with curvature,whereas the curvature effect destroys quantum entanglement and discord,indicating that the curvature effect is beneficial to quantum coherence and harmful to quantum correlations in the *** find that with an increase in n expanding de Sitter spaces,the N-partite coherence of the GHZ state increases monotonically for any curvature,whereas the quantum coherence of the W state decreases or increases monotonically depending on the *** find a distribution relationship,which indicates that the correlated coherence of the N-partite W state is equal to the sum of all bipartite correlated coherence in the *** coherence exhibits unique properties in the multiverse,suggesting that it may provide some evidence for the existence of the multiverse.

关键词： multiverse curvature effect multipartite coherence

Footprints of axion-like particle in pulsar timing array data and James Webb Space Telescope observations

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Science China(physics,Mechanics & Astronomy) 2024年第11期67卷 55-62页

作者： Shu-Yuan Guo Maxim Khlopov Xuewen Liu Lei Wu Yongcheng Wu Bin Zhu department of physics Yantai UniversityYantai 264005 China Institute of physics Southern Federal UniversityRostov on Don 344090 Russia National Research Nuclear University MEPhI(Moscow Engineering physics Institute) Moscow 115409 Russia Virtual Institute of Astroparticle physics Paris 75018 France department of physics and Institute of Theoretical physics Nanjing Normal UniversityNanjing 210023 China

Several pulsar timing array(PTA) collaborations have recently reported the evidence for a stochastic gravitational-wave background(SGWB), which can unveil the formation of primordial seeds of inhomogeneities in the early universe. With the SGWB parameters inferred from PTAs data, we can make a prediction of the seeds for early galaxy formation from the domain walls in the axion-like particles(ALPs) field distribution. This also naturally provides a solution to the observation of high redshifts by the James Webb Space Telescope. The predicted photon coupling of the ALP is within the reach of future experimental searches.

关键词： stochastic gravitational-wave background pulsar timing array axion-like particle JWST

Point-symmetry in SNR G1.9+0.3:A Supernova that Destroyed its Planetary Nebula Progenitor

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Research in Astronomy and Astrophysics 2024年第1期24卷 165-172页

作者： Noam Soker department of physics TechnionHaifa3200003Israel

I analyze a new X-ray image of the youngest supernova remnant(SNR)in the Galaxy,which is the type Ia SNR G1.9+0.3,and reveal a very clear point-symmetrical *** explosion models of type Ia supernovae(SNe Ia)do not form such morphologies,the point-symmetrical morphology must come from the circumstellar material(CSM)into which the ejecta *** large-scale point-symmetry that I identify and the known substantial deceleration of the ejecta of SNR G1.9+0.3 suggest a relatively massive CSM of■1M⊙.I argue that the most likely explanation is the explosion of this SN Ia into a planetary *** scenario that predicts a large fraction of SN Ia inside PNe(SNIPs)is the core degenerate *** SN Ia scenarios might lead to only a very small fraction of SNIPs or none at all.

关键词： (stars:)supernovae:general ISM:supernova remnants (stars:)binaries(including multiple):close (ISM:)planetary nebulae:general stars:jets

Supernova 1987A's Keyhole:A Long-lived Jet-pair in the Final Explosion Phase of Core-collapse Supernovae

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Research in Astronomy and Astrophysics 2024年第7期24卷 89-94页

作者： Noam Soker department of physics TechnionHaifa3200003Israel

I further study the manner by which a pair of opposite jets shape the“keyhole”morphological structure of the core-collapse supernova(CCSN)SN 1997A,now the CCSN remnant(CCSNR)*** doing so,I strengthen the claim that the jittering-jet explosion mechanism accounts for most,likely all,***“keyhole”structure comprises a northern low-intensity zone closed with a bright rim on its front and an elongated low-intensity nozzle in the *** rim-nozzle asymmetry is observed in some cooling flow clusters and planetary nebulae that are observed to be shaped by jets.I build a toy model that uses the planar jittering jets pattern,where consecutive pairs of jets tend to jitter in a common plane,implying that the accreted gas onto the newly born neutron star at the late explosion phase flows perpendicular to that *** allows for a long-lived jet-launching *** long-lasting jet-launching episode launches more mass into the jets that can inflate larger pairs of ears or bubbles,forming the main jets'axis of the CCSNR that is not necessarily related to a possible pre-collapse core rotation.I discuss the relation of the main jets'axis to the neutron star's natal kick velocity.

关键词： stars massive-(stars)supernovae general-(stars)supernovae individual(SN 1987A)-ISM supernova remnants-stars jets

Two innovative equivalent statements of the third law of thermodynamics

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Chinese physics B 2024年第6期33卷 324-328页

作者：陈晓航周颖慧陈金灿 department of physics Xiamen UniversityXiamen 361005China

It is found from textbooks and literature that there are three different statements for the third law of thermodynamics,i.e., the Nernst theorem, the unattainability statement of absolute zero temperature, and the heat capacity statement. It is pointed out that such three statements correspond to three thermodynamic parameters, which are, respectively, the entropy,temperature, and heat capacity, and can be obtained by extrapolating the experimental results of different parameters at ultralow temperatures to absolute zero. It is expounded that because there is no need for additional assumptions in the derivation of the Nernst equation, the Nernst theorem should be renamed as the Nernst statement. Moreover, it is proved that both the Nernst statement and the heat capacity statement are mutually deducible and equivalent, while the unattainability of absolute zero temperature is only a corollary of the Nernst statement or the heat capacity statement so that it is unsuitably referred to as one statement of the third law of thermodynamics. The conclusion is that the Nernst statement and the heat capacity statement are two equivalent statements of the third law of thermodynamics.

关键词： Nernst statement heat capacity statement Nernst theorem absolute zero temperature the third law of thermodynamics

Testing the first law of black hole mechanics with gravitational waves

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Science China(physics,Mechanics & Astronomy) 2024年第10期67卷 76-82页

作者： Chao-Wan-Zhen Wang Jin-Bao Zhu Guo-Qing Huang Fu-Wen Shu department of physics Nanchang UniversityNanchang 330031China Center for Relativistic Astrophysics and High Energy physics Nanchang UniversityNanchang 330031China GCAP-CASPER Physics DepartmentBaylor UniversityWaco 76798-7316USA

The successful observation of gravitational waves has provided humanity with an additional method to explore the universe,particularly black *** this study,we utilize data from LIGO and Virgo gravitational wave observations to test the first law of black hole mechanics,employing two different *** consider the secondary compact object as a perturbation to the primary black hole before the merger,and the remnant black hole as a stationary black hole after the *** the pre-merger and post-merger analysis,our results demonstrate consistency with the first law,with an error level of approximate 25%at a68%credibility level for *** the full inspiral-merger-ringdown analysis,our results show consistency with the first law of black hole mechanics,with an error level of about 6%at a 68%credibility level and 10%at a 95%credibility level for ***,we observe that the higher the mass ratio of the gravitational wave source,the more consistent our results are with the first law of black hole ***,our study sheds light on the nature of compact binary coalescence and their implications for black hole mechanics.

关键词： gravitational waves black hole mechanics data analysis ringdown

Analysis of pseudo-random number generators in QMC-SSE method

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Chinese physics B 2024年第3期33卷 75-79页

作者：刘东旭徐维张学锋 department of physics Chongqing UniversityChongqing 401331China

In the quantum Monte Carlo(QMC)method,the pseudo-random number generator(PRNG)plays a crucial role in determining the computation ***,the hidden structure of the PRNG may lead to serious issues such as the breakdown of the Markov ***,we systematically analyze the performance of different PRNGs on the widely used QMC method known as the stochastic series expansion(SSE)*** quantitatively compare them,we introduce a quantity called QMC efficiency that can effectively reflect the efficiency of the *** testing several representative observables of the Heisenberg model in one and two dimensions,we recommend the linear congruential generator as the best choice of *** work not only helps improve the performance of the SSE method but also sheds light on the other Markov-chain-based numerical algorithms.

关键词： stochastic series expansion quantum Monte Carlo pseudo-random number generator