检索结果-南通市图书馆

Possibility of observation of hidden-bottom pentaquark resonances in bottomonium photoproduction on protons and nuclei near threshold

引用

Chinese Physics C 2020年第10期44卷 87-97页

作者： e.Ya.Paryev Institute for Nuclear Research Russian Academy of SciencesMoscow 117312Russia Institute for Theoretical and experimental Physics Moscow 117218Russia

We study theΥ(1S)meson photoproduction on protons and nuclei at near-threshold center-of-mass energies below 11.4 GeV(or at the corresponding photon laboratory energies eγbelow 68.8 GeV).We calculate the absolute excitation functions for the nonresonant and resonant photoproduction ofΥ(1S)mesons off protons at incident photon laboratory energies of 63-68 GeV by considering direct(γp→Υ(1S)p)and two-step(γp→P^+b(11080)→Υ(1S)p,γp→P^+b(11125)→Υ(1S)p,γp→P^+b(11130)→Υ(1S)p)Υ(1S)production channels within different scenarios for the nonresonant total cross section of the elementary reactionγp→Υ(1S)p and for branching ratios of the decays P^+b(11080)→Υ(1S)p,P^+b(11125)→Υ(1S)p,and P^+b(11130)→Υ(1S)*** also calculate an analogous function for the photoproduction ofΥ(1S)mesons on the 12C and 208Pb target nuclei in the near-threshold center-of-mass beam energy region of 9.0-11.4 GeV by considering the respective incoherent direct(γN→Υ(1S)N)and two-step(γp→P^+b(11080)→Υ(1S)p,γp→P^+b(11125)→Υ(1S)p,γp→P^+b(11130)→Υ(1S)p andγn→P^0b(11080)→Υ(1S)n,γn→P^0b(11125)→Υ(1S)n,γn→P^0b(11130)→Υ(1S)n)Υ(1S))production processes using a nuclear spectral function *** demonstrate that a detailed scan of theΥ(1S)total photoproduction cross section on proton and nuclear targets in the near-threshold energy region in future high-precision experiments at the proposed high-luminosity electron-ion colliders eIC and eicC in the US and China should provide a definite result for or against the existence of the nonstrange hidden-bottom pentaquark statesP^+bi and P^0bi(i=1,2,3)as well as clarify their decay rates.

关键词： photon-nucleus reactions bottomonium production hidden-bottom pentaquarks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Near-threshold K^*(892)^+ meson production in the interaction of π−mesons with nuclei

引用

Chinese Physics C 2020年第11期44卷 168-178页

作者： e.Ya.Paryev Institute for Nuclear Research Russian Academy of SciencesMoscow 117312Russia Institute for Theoretical and experimental Physics Moscow 117218Russia

We study the inclusive production of strange vector K^∗(892)^+ mesons in π−A reactions at near-threshold laboratory incident pion momenta of 1.4-2.0 GeV/c via a nuclear spectral function *** approach accounts for incoherent primary π−meson-proton π−p→K^∗(892)^+Σ^− production processes as well as the influence of the scalar K^∗(892)^+-nucleus potential(or the K^∗(892)^+ in-medium mass shift)on these *** calculate the absolute differential and total cross sections for the production of K∗(892)+mesons from carbon and tungsten nuclei at laboratory angles of 0∘-45∘and at the aforementioned momenta in five scenarios for the aforenoted *** show that the K^∗(892)^+ momentum distributions and their excitation functions(absolute and relative)possess a high sensitivity to changes in the in-medium K^∗(892)^+ mass shift in the low-momentum region of 0.1-0.6 GeV/***,the measurement of such observables in a dedicated experiment at the GSI pion beam facility in the near-threshold momentum domain will allow us to get valuable information on the K^∗(892)^+ in-medium properties.

关键词： pion-nucleus reactions strange vector meson production in-medium effects

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigating the impact of the universal function of the nuclear proximity potential in heavy-ion fusion cross sections

引用

Communications in Theoretical Physics 2024年第5期76卷 86-93页

作者： R Gharaei e Sarvari Department of Physics Sciences FacultyHakim Sabzevari UniversityPO Box 397SabzevarIran Department of Physics Faculty of ScienceFerdowsi University of MashhadPO Box 91775-1436MashhadIran Science Faculty Department of PhysicsTarbiat Modares UniversityTehranIran

The fusion barriers and cross sections of 15 colliding systems with 320≤Z_(1)Z_(2)≤1512 are investigated in detail to understand the influence of the universal function of proximity potential formalism in the heavy-ion fusion *** realize this goal,we select three versions of the phenomenological proximity potentials,including Prox.77,Zhang 2013,and Guo 2013,to calculate the nucleus-nucleus *** experimental fusion cross sections for the selected reactions are analyzed using the standard coupled-channel calculations,including couplings to the low-lying 2^(+)and 3^(-)states in the target and *** calculated results show that the universal functions of the Guo 2013 and Prox.77 models provide the lowest and highest fusion barriers,*** addition,it is found that the height of the fusion barriers is enhanced by increasing the mass number of the projectile from light to heavy *** highest sensitivity to the mass number of the projectile belongs to the results of Prox.77.A discussion is also presented on the influence of the universal function on the radial behavior of the interaction potential in the allowed region for overlapping *** results reveal that the best fit to the experimental data of the fusion cross sections for the reactions involving light and medium nuclei is obtained using the universal function of the Zhang 2013 *** the heavier systems,the results of the Guo 2013 model at sub-barrier energies provide a good description of the available data.

关键词： fusion reactions proximity-type potentials universal function coupled-channel calculations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CLASSIFICATIONS OF DUPIN HYPeRSURFACeS IN LIe SPHeRe GeOMeTRY

引用

Acta Mathematica Scientia 2024年第1期44卷 1-36页

作者： Thomas e.CeCIL Department of Mathematics and Computer Science College of the Holy CrossWorcesterMA01610USA

This is a survey of local and global classification results concerning Dupin hypersurfaces in S^(n)(or R^(n))that have been obtained in the context of Lie sphere *** emphasis is on results that relate Dupin hypersurfaces to isoparametric hypersurfaces in *** with these classification results,many important concepts from Lie sphere geometry,such as curvature spheres,Lie curvatures,and Legendre lifts of submanifolds of S^(n)(or R^(n)),are described in *** paper also contains several important constructions of Dupin hypersurfaces with certain special properties.

关键词： Dupin hypersurfaces isoparametric hypersurfaces Lie sphere geometry Lie sphere transformations Lie curvatures

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Hydrologic Time Scale:A Fundamental Stream Characteristic

引用

Journal of earth Science 2022年第5期33卷 1291-1297页

作者： Robert e.Criss Department of earth and Planetary Sciences Washington University in St.LouisSt.LouisMO63130USA

A new,fundamental catchment attribute called the hydrologic time scaleτgoverns the rate of delivery of runoff to a particular site,and is equal to∫Qdt/∫|dQ|,where Q is discharge and t is *** value ofτfor any gauged site is readily calculated from tabulated discharge data by replacing the integrals with *** quantity,coupled with the square root of catchment area,√A,form a coordinate pair that embodies the characteristic time and length scales for any catchment,which govern its flow *** fitting constants used in several unit hydrograph models are simple multiples ofτ,so knowledge ofτallows rapid calibration of these models for the particular site,facilitating flow prediction from rainfall *** ofτreflect many different landscape attributes,but for multiple sub-basins in watersheds with homogeneous land use and lithologic conditions,they correlate linearly with √*** ratio √A/τprovides a characteristic velocity that is high for channelized,floodprone rivers,for flashy urban streams with high impervious cover,and for sites downstream of hydropower *** with low velocities are resistant to flooding,as their landscapes have a greater ability to delay the delivery of runoff by retention,detention,and infiltration into the groundwater system.

关键词： unit hydrograph time constant flash floods impervious cover urban streams flashiness hydrogeology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The effect of the concentration of plastic waste on the formation of reaction products of the Ti-PeT system

引用

Green Chemical engineering 2024年第3期5卷 374-382页

作者： Aleksey e.Matveev Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences 634055TomskAkademicheskii Prospekt 10/4Russia

The paper presents research results of the synthesis,phase composition,and structure of products obtained by highly exothermic reactions between Ti and C10H8O4mixture components,depending on the plastic waste concentration and Ti powder dispersiveness,density of initial samples,and synthesis *** dependence of the phase composition and structure of the synthesis products on the concentration of the polymer(plastic)component in the initial Ti-PeT(C10H8O4)system was *** the plastic waste content is 20 wt%to 25 wt%,synthesis products contain TiC0.5O0.5-TiC0.6-0.75particle *** growth in the polyethylene terephthalate content from 30 wt%to 45 wt%leads to the formation of synthesis products consisting of titanium carbide(TiC0.6-1.0).The gaseous byproduct composition of the exothermic reaction is investigated for the Ti--C10H8O4mixture *** is found that the gaseous by-product mostly contains hydrogen and carbon monoxide as well as impurities of different hydrocarbons(methane,acetylene,ethane,ethene)and carbon *** maximum adiabatic temperature of the gas combustion temperature is 2080℃,which demonstrates the possibility of using gas as a fuel for energy generation *** on the data obtained,it is possible to create a basis for a new plastic waste technology to fabricate carbide-containing materials.

关键词： Plastic waste Titanium carbide Green technology Hydrogen synthesis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Are hydrides under high-pressure-high-temperature superconductors?

引用

National Science Review 2024年第7期11卷 9-12页

作者： J.e.Hirsch Department of Physics University of California

Contrary to the current consensus, I argue that the existing evidence for high-temperature superconductivity in hydrides under high pressure is not compelling. I suggest that the focus of the field should urgently shift to establish unequivocally experimentally whether or not superconductivity in pressurized hydrides exists, instead of continuing to search for new materials that might show elusive signals of unproven superconductivity at ever higher temperatures. The implications of a negative finding for the theoretical understanding of superconductivity are discussed.

关键词： Hydrides

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

estimating costs of salvage logging for large-scale burned forest lands: A case study on Turkey's Mediterranean coast

引用

Journal of Forestry Research 2021年第5期32卷 1899-1909页

作者： Neşe Gülci Faculty of Forestry Kahramanmaras Sutcu Imam University46100 KahramanmarasTurkey

Different forest fires causing different degrees of effects occur in fire-sensitive forests due to various reasons such as climate *** as well as harmful aspects of forest fires are a multi-disciplinary research *** information systems(GIS)and remote sensing(RS)methods offer a number of benefits for researchers and operators in the field of forest fire *** present study analyses timber pricing based on forest contractor demands of post-salvage logging *** effect of timber obtained from compartment units on producers’pricing policy was *** forest fire area(2500 ha)located in Antalya in Turkey was selected as the main study *** parameters(aspect,slope and slope position),stand types(diameter class and crown closure),and burn severity were analyzed together using GIS and R software packages.A multi-linear regression model(R^(2)=0.752)demonstrated that factors that had the most impact on pricing were slope position,aspect,stand age,crown closure and burn *** model can be used to estimate salvage logging prices in Calabrian pine(Pinus brutia Ten.)stands with similar *** administrators and contractors may readily address the unit price of timber by estimating approximate costs in a given forest area for which they are going to *** will help reduce operational planning times of harvesting procedures in burned stands.

关键词： Timber extraction Forest fires Stumpage sale Cost estimation Sustainability Crown fire

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of the Choice of NN Potential Model on γd→τ~0d Observables near η-Threshold

引用

Chinese Physics Letters 2016年第4期33卷 14-18页

作者： e.M.Darwish Physics Department Faculty of ScienceTaibah University Physics Department Faculty of ScienceSohag University

Influence of the choice of the NN potential model governing the deuteron wave function on the observables for coherent π0-photoproduction on the deuteron near η-threshoM is investigated by using a three-body model for the intermediate ηN N system with separable two-body interactions. Results for unpolarized differential cross section and polarization observables are predicted. It is revealed that the choice of the NN potential model has a visible effect on the differential cross section and most of the polarization observables, especially in the photon energy range of 600-800 MeV and extreme backward pion angles. We find that the deviation among results obtained by using different deuteron wave functions is quite large. The use of the CD-Bonn NN potential for deuteron wave function doubles the differential cross section in this kinematic region. Compared with the experimental data from CLAS collaboration for differential cross section, sizeable discrepancies are found.

关键词： of in Observables near Threshold NN that for on CLAS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

exploring the mass gap:Black holes in green pea galaxies

引用

Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 170-171页

作者： James e.Rhoads School of earth and Space exploration Arizona State UniversityTempeAZ 85287USA

We know about black holes primarily on two mass scales(e.g.,see Figure 22 of ref.[1]).Supermassive black holes inhabit the centers of galaxies,where they sometimes power active galactic nuclei(AGN).Their populations can be probed through AGN surveys,tidal disruption event surveys,and(in the closest galaxies)stellar and gas dynamics in the innermost regions where the black hole dominates the gravitational potential.

关键词： galaxies tidal galactic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：