Study of baryon number transport dynamics and strangeness conservation effects using Ω-hadron correlations

In nuclear collisions at RHIC energies, an excess of Ω hyperons over ■ is observed, indicating that Ω has a net baryon number despite s and s quarks being produced in pairs. The baryon number in Ω may have been transported from the incident nuclei and/or produced in the baryon-pair production of Ω with other types of anti-hyperons such as Ξ. To investigate these two scenarios, we propose to measure the correlations between Ω and K and between Ω and anti-hyperons. We use two versions, the default and string-melting, of a multiphase transport(AMPT) model to illustrate the method for measuring the correlation and to demonstrate the general shape of the correlation. We present the Ω-hadron correlations from simulated Au+Au collisions at ■ =7.7 and 14.6 Ge V and discuss the dependence on the collision energy and on the hadronization scheme in these two AMPT versions. These correlations can be used to explore the mechanism of baryon number transport and the effects of baryon number and strangeness conservation on nuclear collisions.

Strangeness to increase the density of finite nuclear systems in constraining the high-density nuclear equation of state

As the high-density nuclear equation of state(EOS) is not very well constrained, we suggest that the structural properties from the finite systems can be used to extract a more accurate constraint. By including the strangeness degrees of freedom, the hyperon or anti-kaon, the finite systems can then have a rather high-density core which is relevant to the nuclear EOS at high densities directly. It is found that the density dependence of the symmetry energy is sensitive to the properties of multi-K hypernuclei, while the high-density EOS of symmetric matter correlates sensitively to the properties of kaonic nuclei.

Sigma Terms and Strangeness Contents of Baryon Octet in Modified Chiral Perturbation Theory

In the frame work of chiral perturbation theory, a modified effective Lagrangian for meson-baryon system is constructed, where the SU（3） breaking effect for meson is considered. The difference between physical and chiral limlt decay constants is taken into account. Calculated to one 1ooi） at O（p^3）, the sigma terms and strangeness contents of baryon octet are obtained.

1-4 Strangeness Production in Antiproton Induced Nuclear Reactions.

More localized energy deposition is able to be produced in antiproton-nucleus collisions in comparison withheavy-ion collisions due to annihilation reactions. Searching for the cold quark-gluon plasma (QGP) with antiprotonbeamshas been considered as a hot topic both in experiments and in theretical calculations over the past severaldecades. Strangeness production and hypernucleus formation in antiproton-induced nuclear reactions are importancein exploring the hyperon (antihyperon)-nucleon (HN) potential and the antinucleon-nucleon interaction, whichhave been hot topics in the forthcoming experiments at PANDA in Germany.

Observation of the Z_(cs)(3985) Strange Four-quark Meson:The first hidden-charm tetraquark state with non-zero strangeness

In the March 12.2021 issue of Plvvsical Rerievr Letters.the BES111 collaboration reports the.diseovery of an cxolic multiquark strtture,dubsled Z_(cs)(3985).that is produced in the process of e^(+)e^(-)→K+(D_(s)^(-)D^(*0)+D_(s)^(*-)D^(0))at a e+e center-of-mass cneryof+4.68 GeV.

Strangeness production in pA and AA collisions at 158 A GeV

LUCIAE, a hadronic and string cascade model and its corresponding event generator are used to analyse strangeness production singly and multiply in p-Pb and Pb-Pb collisions at 158 A GeV. Spectra of multiplicity and transverse mass for single $(\Lambda ,\overline \Lambda )$ and multiple $(\Xi ^ - ,\overline {\Xi ^ - } ,\Omega ^ - ,\overline {\Omega ^ - } )$ strangeness are given. In LUCIAE model it suggests a physical mechanism, i.e. the dependence of the strange quark suppression factor on incident energy, projectile mass and centrality of colliding system might result in increase of yield of strange particles with increasing the above three parameters. Calculations from the model reconstruct well the WA97 experimental data: increase of yield of strange particles with increasing centrality and increase of strangeness enhancement with increasing number of strange quarks, in relativistic nucleus-nucleus collisions.

On the Proof of the Contradiction of Set Theory

The article is devoted to proving the inconsistency of set theory arising from the existence of strange trees. All steps of the proof rely on common informal set-theoretic reasoning, but they take into account the prohibitions that were introduced into axiomatic set theories in order to overcome the difficulties encountered by the naive Cantor set theory. Therefore, in fact, the article is about proving the inconsistency of existing axiomatic set theories, in particular, the ZFC theory.

Spectroscopic study of strangeness=-3Ω^(-)baryon

Ω^(-)baryon with sss quarks has been investigated through many theoretical studies so far but scarcely observed in experiments.Here,an attempt has been made to explore properties of Ω with hypercentral Constituent Quark Model(hCQM)with a linear confining term.The resonance mass spectra have been obtained for 1S-4S,1P-4P,1D-3D,and IF-2F.The Regge trajectory has been investigated for the linear nature based on calculated data along with the magnetic moment.The present work has been compared with various approaches and known experimental findings.

Recent results on strangeness,charm and beauty production at HERA

Based on the data collected with the H1 and ZEUS detectors at HERA, recent results on strangeness, charm and beauty production in ep collision are presented.

Precision measurements of strangeness photoproduction at threshold energies with the Crystal Ball at MAMI-C

The photoproduction of K＋ mesons from the nucleon provides important constraints on the nucleon excitation spectrum and at threshold energies challenges effective field theories based on chiral perturbation in the strange quark sector. Preliminary cross-section measurements for γ（P, K＋）A are presented at an unprecedented beam energy resolution. The data was collected at the MAMI-C facility in Mainz using the Crystal Ball Detector. A new method of K＋ detection was used in which the K＋ is tagged from its weak decay products in the detector crystals. This technique has application with other calorimeters at present and future hadron facilities.

The Strangeness Of Sleep

A strange thing happens to nearly everybody at night. They turn off the lights,pull up the covers and close their eyes. Six or seven sleeping hours later,they wake up again.Strange,isn’t it?Sleep puzzles scientists. Scientists and doctors would rather talk about why one can’t fall asleep. They are not sure what causes sleep.

Novel Parameter Identification Method for Basis Weight Control Loop of Papermaking Process

The basis weight control loop of the papermaking process is a non-linear system with time-delay and time-varying.It is impractical to identify a model that can restore the model of real papermaking process.Determining a more accurate identification model is very important for designing the controller of the control system and maintaining the stable operation of the papermaking process.In this study,a strange nonchaotic particle swarm optimization(SNPSO)algorithm is proposed to identify the models of real papermaking processes,and this identification ability is significantly enhanced compared with particle swarm optimization(PSO).First,random particles are initialized by strange nonchaotic sequences to obtain high-quality solutions.Furthermore,the weight of linear attenuation is replaced by strange nonchaotic sequence and the time-varying acceleration coefficients and a mutation rule with strange nonchaotic characteristics are utilized in SNPSO.The above strategies effectively improve the global and local search ability of particles and the ability to escape from local optimization.To illustrate the effectiveness of SNPSO,step response data are used to identify the models of real industrial processes.Compared with classical PSO,PSO with timevarying acceleration coefficients(PSO-TVAC)and modified particle swarm optimization(MPSO),the simulation results demonstrate that SNPSO has stronger identification ability,faster convergence speed,and better robustness.

Gravitational wave echoes from strange quark stars in the equation of state with density-dependent quark masses

According to the recent studies,the gravitational wave(GW)echoes are expected to be generated by quark stars composed of ultrastiff quark matter.The ultrastiff equations of state(EOS)for quark matter were usually obtained either by a simple bag model with artificially 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 effects.We conclude that strange quark stars(SQSs)can be sufficiently 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 effects play a crucial role in enabling SQSs to satisfy the necessary conditions for producing these types of echoes.

About the Strange Tree Paradox and Possible Inconsistency of Set Theory

The existence of “strange trees” is proven and their paradoxical nature is discussed, due to which set theory is suspected of being contradictory. All proofs rely on informal set-theoretic reasoning, but without using elements that were prohibited in axiomatic set theories in order to overcome the difficulties encountered by Cantor’s naive set theory. Therefore, in fact, the article deals with the possible inconsistency of existing axiomatic set theories, in particular, the ZFC theory. Strange trees appear when uncountable cardinals appear.

爆轰波模拟中一个保正的有限体积WENO格式

对一维爆轰波的数值模拟设计了一种保正的有限体积WENO格式.以一维反应欧拉方程组作为描述爆轰波的控制方程,对方程组在空间离散上采用三阶WENO重构的有限体积法,时间离散上采用Strang分裂法和二阶龙格库塔法.从爆轰波的数值模拟中可以观察到,在压力快速变化的区域使用一般的WENO重构方法会使得压力出现负值.提出了一种简单且有效的策略,使得重构的压力具有保正性.通过数值算例验证了所提出的数值格式的稳定性和收敛性,以及对爆轰波结构变化捕捉的良好能力.

Nuclear dynamics and particle production near threshold energies in heavy-ion collisions

Recent progress of the quantum molecular dynamics model for describing the dynamics of heavy-ion collisions is viewed, in particular the nuclear fragmentation, isospin physics, particle production and in-medium effect, hadron-induced nuclear reactions, hypernucleus, etc.The neck fragmentation in Fermi-energy heavy-ion collisions is investigated for extracting the symmetry energy at subsaturation densities. The isospin effects, in-medium properties, and the behavior of high-density symmetry energy in medium-and high-energy heavy-ion collisions are thoroughly discussed. The hypernuclide dynamics formed in heavy-ion collisions and in hadron-induced reactions is analyzed and addressed in the future experiments at the high-intensity heavy-ion accelerator facility(HIAF).

加拿大纽芬兰省稀有稀土矿化特征与勘查进展

纽芬兰省稀有稀土成矿地质条件优越,矿化主要与侵入的过碱性长英质岩及其喷出岩有关,矿化围岩为中元古代火成岩系,矿床成因类型为岩浆型和热液交代型,且以前者为主,典型矿床为世界级大型原生Strange Lake(Nd-Y-Zr-REE)矿床。目前,地球化学方法是区内寻找稀有稀土矿床最有效的勘探工具,拉布拉多主要勘查区为Letitia Lake、Red Wine Mountains、Flowers River和Strange Lake,纽芬兰岛主要勘查区为Fortune Bay、Clode Sound、Trinity Bay和Lost Pond。

The Origin of the Color Charge into Quarks

Showing the origin of the mass in an additional coupling between field quantum oscillators, we formulate a hypothesis of a geometrical structure of the oscillators of “fields-particles”. In this way, we define the possible structure of quarks and hadrons (as the proton). This hypothesis is reasonable if one admits field oscillators composed by sub-oscillators at semi-quantum (IQuO) and in which a degree of internal freedom is definable. Using the IQuO model, we find the origin of the sign of electric charge in to particles and, in quarks, the isospin, the strangeness and colour charge. Finally, we formulate the structure of the gluons and the variation modality of the colour charge in quarks.

Hard Photons from a Non-Equilibrated Quark-Gluon Plasma with Finite Baryon Density at a Two-Loop Level

We study hard photon production from a two-loop level （bremsstrahlung and annihilation with scattering） in a chemically equilibrating quark-gluon plasma at finite baryon density based on Jüttner distribution of partons of the system. We find that the photon yield from the two-loop level increases obviously with the increasing initial quark chemical potential.