Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.10
W. Bauer
Coupled kinetic equations for the time evolution of baryons and neutrinos are introduced in order to present a new solution approach for the problem of type II supernova core collapse and explosion. A test-particle method is introduced in order to cast these kinetic equations into numerically tractable form.
{"title":"Kinetic theory for supernova explosions","authors":"W. Bauer","doi":"10.1556/APH.22.2005.3-4.10","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.10","url":null,"abstract":"Coupled kinetic equations for the time evolution of baryons and neutrinos are introduced in order to present a new solution approach for the problem of type II supernova core collapse and explosion. A test-particle method is introduced in order to cast these kinetic equations into numerically tractable form.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125497858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.12
B. Lukács
Entropy balance is very important at ultra-high energy HIC’s, because there is not even approximate thermalisation there. Only a minor fragment of the incoming kinetic energy will be turned into “heat”, so internal energy, while the thermodynamic state variable is internal energy, not the total one. Here an approach is discussed calculating entropy directly, in a continuum physics scenario.
{"title":"Entropy in heavy ion collisions — A two-fluid scenario","authors":"B. Lukács","doi":"10.1556/APH.22.2005.3-4.12","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.12","url":null,"abstract":"Entropy balance is very important at ultra-high energy HIC’s, because there is not even approximate thermalisation there. Only a minor fragment of the incoming kinetic energy will be turned into “heat”, so internal energy, while the thermodynamic state variable is internal energy, not the total one. Here an approach is discussed calculating entropy directly, in a continuum physics scenario.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114246830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.16
G. David
Penetrating probes like direct photons were always considered a crucial tool to study the initial conditions established in relativistic heavy ion collisions and to possibly map out the entire time history of the collision. Technically, however, the direct photon measurement is very challenging, primarily due to the large photon background from hadron decays. Now that after the first three years of RHIC operations the hadron spectra are well established there is an increased interest in the community to extract the spectrum of direct (non-hadronic) photons both from p+p, d+Au and Au+Au data. This paper reports on the currently available results and assesses what new results might be expected in the near future.
{"title":"Direct photons at RHIC — Preliminary results and prospects","authors":"G. David","doi":"10.1556/APH.22.2005.3-4.16","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.16","url":null,"abstract":"Penetrating probes like direct photons were always considered a crucial tool to study the initial conditions established in relativistic heavy ion collisions and to possibly map out the entire time history of the collision. Technically, however, the direct photon measurement is very challenging, primarily due to the large photon background from hadron decays. Now that after the first three years of RHIC operations the hadron spectra are well established there is an increased interest in the community to extract the spectrum of direct (non-hadronic) photons both from p+p, d+Au and Au+Au data. This paper reports on the currently available results and assesses what new results might be expected in the near future.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125148966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.19
G. G. Barnaföldi, P. Lévai, G. Papp, G. Fai
Cronin effect — nuclear enhancement — on pion production in pA and dAu collisions is investigated in close-to-midrapidity regions, |η|≦1.5. Using a perturbative QCD improved parton model we analyze pion production in pBe and pCu collisions at energies E lab=500, 530 and 800 GeV in fix target FNAL-E706 experiment. Next we perform calculations at RHIC collider energy, √s NN =200 GeV, and the obtained nuclear modification factor for pions, R π dAu is compared to experimental data by PHOBOS. Our description contains conventional nuclear shadowing and multiscattering. Magnitudes and tendencies of the measured data are reproduced properly at the above energies.
在接近中速区域，研究了核增强效应对pA和dAu碰撞介子产生的影响，|η|≦1.5。利用微扰QCD改进的部分子模型，分析了固定目标FNAL-E706实验中能量为500,530和800gev的pBe和pCu碰撞产生的介子。接下来，我们在RHIC对撞机能量√s NN =200 GeV下进行了计算，并将得到的π子核修饰因子R π dAu与PHOBOS实验数据进行了比较。我们的描述包含常规的核阴影和多重散射。在上述能量下，测量数据的幅度和趋势得到了适当的再现。
{"title":"Cronin effect in close-to-midrapidity regions at FNAL and RHIC energies","authors":"G. G. Barnaföldi, P. Lévai, G. Papp, G. Fai","doi":"10.1556/APH.22.2005.3-4.19","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.19","url":null,"abstract":"Cronin effect — nuclear enhancement — on pion production in pA and dAu collisions is investigated in close-to-midrapidity regions, |η|≦1.5. Using a perturbative QCD improved parton model we analyze pion production in pBe and pCu collisions at energies E lab=500, 530 and 800 GeV in fix target FNAL-E706 experiment. Next we perform calculations at RHIC collider energy, √s NN =200 GeV, and the obtained nuclear modification factor for pions, R π dAu is compared to experimental data by PHOBOS. Our description contains conventional nuclear shadowing and multiscattering. Magnitudes and tendencies of the measured data are reproduced properly at the above energies.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130175820","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.18
S. Borsányi
The phenomenon of prethermalization and the subsequent steps of thermalization are analyzed in the framework of the chiral quark model. We solve the quantum equations of motion of the field theory derived from the 2PI effective action and study the time scales of equilibration. We find that already after a 0.6 fm/c long period of time some equilibrium features appear, even though the system is still far from equilibrium. This can be an important ingredient for understanding the success of ideal hydrodynamic description.
{"title":"Prethermalization and the First 1 fm/c of a Heavy Ion Collision","authors":"S. Borsányi","doi":"10.1556/APH.22.2005.3-4.18","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.18","url":null,"abstract":"The phenomenon of prethermalization and the subsequent steps of thermalization are analyzed in the framework of the chiral quark model. We solve the quantum equations of motion of the field theory derived from the 2PI effective action and study the time scales of equilibration. We find that already after a 0.6 fm/c long period of time some equilibrium features appear, even though the system is still far from equilibrium. This can be an important ingredient for understanding the success of ideal hydrodynamic description.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116541209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.17
Z.-B. Yin
We present the important observables from the BRAHMS experiment for establishing the properties of the hot and dense strongly interacting QCD matter with respect to its formation, evolution and its effects on high p Tparticle production.
{"title":"Important observables from the BRAHMS experiment","authors":"Z.-B. Yin","doi":"10.1556/APH.22.2005.3-4.17","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.17","url":null,"abstract":"We present the important observables from the BRAHMS experiment for establishing the properties of the hot and dense strongly interacting QCD matter with respect to its formation, evolution and its effects on high p Tparticle production.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131135265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.4
G. Veres
We review some of the latest results on identified and non-identified particle spectra for d+Au and Au+Au collisions at √s NN =200 GeV from the PHOBOS Experiment at RHIC. No enhancement of hadron yields at very low PT is observed. Analysis of the high-PT spectra in d+Au and Au+Au collisions reveal the strong final state effects for central Au+Au collisions. The first measurements of identified particle spectra and particle ratios from the PHOBOS Time of Flight (ToF) detector are presented for d+Au collisions. Detailed results on centrality and pseudorapidity dependence of transverse momentum spectra, which may have important physics implications. are also shown.
我们回顾了RHIC PHOBOS实验在√s NN =200 GeV下的d+Au和Au+Au碰撞中已识别和未识别的粒子光谱的一些最新结果。在极低PT下没有观察到强子产率的增强。d+Au和Au+Au碰撞的高pt光谱分析揭示了中心Au+Au碰撞的强终态效应。PHOBOS飞行时间(ToF)探测器首次测量了d+Au碰撞的粒子光谱和粒子比。关于横向动量谱中心性和伪快度依赖性的详细结果，可能具有重要的物理意义。也显示。
{"title":"Hadron Pt spectra from 0.03 to 6 GeV/c from PHOBOS","authors":"G. Veres","doi":"10.1556/APH.22.2005.3-4.4","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.4","url":null,"abstract":"We review some of the latest results on identified and non-identified particle spectra for d+Au and Au+Au collisions at √s NN =200 GeV from the PHOBOS Experiment at RHIC. No enhancement of hadron yields at very low PT is observed. Analysis of the high-PT spectra in d+Au and Au+Au collisions reveal the strong final state effects for central Au+Au collisions. The first measurements of identified particle spectra and particle ratios from the PHOBOS Time of Flight (ToF) detector are presented for d+Au collisions. Detailed results on centrality and pseudorapidity dependence of transverse momentum spectra, which may have important physics implications. are also shown.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128157091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.9
M. Zétényi, G. Wolf
A calculation of the Dalitz-decay width of baryon resonances is presented and applied to dilepton production in proton-proton collisions in the BEVALAC/SIS energy range. The results indicate, that for these energies the contribution of Dalitz decay of higher baryon resonances (i.e. other that the δ(1232)) are negligible.
{"title":"Baryonic channels of dilepton production","authors":"M. Zétényi, G. Wolf","doi":"10.1556/APH.22.2005.3-4.9","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.9","url":null,"abstract":"A calculation of the Dalitz-decay width of baryon resonances is presented and applied to dilepton production in proton-proton collisions in the BEVALAC/SIS energy range. The results indicate, that for these energies the contribution of Dalitz decay of higher baryon resonances (i.e. other that the δ(1232)) are negligible.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126481999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-07-01DOI: 10.1556/APH.22.2005.3-4.3
D. Barna
Since the recent observation of a pentaquark ((Theta ^ + = qqqqbar q)) state (see Nakano et al. (LEPS Collaboration), Phys. Rev. Lett. 91 (2003) 012002-1) several positive and negative experimental results have emerged. These results are overviewed, with a trial to find common features among them.
自从最近观测到五夸克((Theta ^ + = qqqqbar q))状态(见Nakano et al. (LEPS Collaboration)， Phys。Rev. Lett. 91(2003) 012002-1)出现了几个积极和消极的实验结果。对这些结果进行了概述，并试图找出它们之间的共同特征。
{"title":"Pentaquarks — An experimental overview","authors":"D. Barna","doi":"10.1556/APH.22.2005.3-4.3","DOIUrl":"https://doi.org/10.1556/APH.22.2005.3-4.3","url":null,"abstract":"Since the recent observation of a pentaquark ((Theta ^ + = qqqqbar q)) state (see Nakano et al. (LEPS Collaboration), Phys. Rev. Lett. 91 (2003) 012002-1) several positive and negative experimental results have emerged. These results are overviewed, with a trial to find common features among them.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129353447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-06-07DOI: 10.1556/APH.25.2006.1.12
T. Novak
The L3 data on Bose-Einstein correlations of equally charged pion pairs produced in hadronic Z decays are analyzed in terms of various parametrizations. Preliminary results are presented here.
{"title":"Improved description of Bose-Einstein correlation function","authors":"T. Novak","doi":"10.1556/APH.25.2006.1.12","DOIUrl":"https://doi.org/10.1556/APH.25.2006.1.12","url":null,"abstract":"The L3 data on Bose-Einstein correlations of equally charged pion pairs produced in hadronic Z decays are analyzed in terms of various parametrizations. Preliminary results are presented here.","PeriodicalId":201208,"journal":{"name":"Acta Physica Hungarica A) Heavy Ion Physics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128924970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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