Direct detection of WIMP dark matter

The question of the nature of dark matter in the universe is perhaps the greatest problem facing cosmology and particle physics at present. New observations of the cosmic microwave background radiation and distant supernovae show that more that 90% of the mass in the universe is in the form of some unknown matter. Many lines of evidence from cosmology and particle physics suggest that the best candidate for this dark matter is a weakly interacting massive particle, or WIMP. Such particles are predicted by supersymmetry, a theory extending the Standard Model of particle physics, and many experiments around the world are now trying to directly detect these WIMPs. This article reviews the reasons for believing WIMPs to be the dark matter, and considers the challenges involved in detecting their rare low-energy interactions with normal matter. Current experimental searches are reviewed with regard to the claimed detection of WIMPs by the DAMA group. These experiments are just beginning to reach the sensitivity needed to detect, or rule out, supersymmetric WIMPs, and higher sensitivity future experiments are also discussed.     

Degenerate limit thermodynamics beyond leading order for models of dense matter

Analytical formulas for next-to-leading order temperature corrections to the thermal state variables of interacting nucleons in bulk matter are derived in the degenerate limit. The formalism developed is applicable to a wide class of non-relativistic and relativistic models of hot and dense matter currently used in nuclear physics and astrophysics (supernovae, proto-neutron stars and neutron star mergers) as well as in condensed matter physics. We consider the general case of arbitrary dimensionality of momentum space and an arbitrary degree of relativity (for relativistic models). For non-relativistic zero-range interactions, knowledge of the Landau effective mass suffices to compute next-to-leading order effects, but for finite-range interactions, momentum derivatives of the Landau effective mass function up to second order are required. Results from our analytical formulas are compared with the exact results for zero- and finite-range potential and relativistic mean-field theoretical models. In all cases, inclusion of next-to-leading order temperature effects substantially extends the ranges of partial degeneracy for which the analytical treatment remains valid. Effects of many-body correlations that deserve further investigation are highlighted.     

超新星研究进展

本文先介绍超新星巡天和分类,简要地论述历史超新星SN 1006一千年,接着讨论核心塌缩超新星物理和具体事例（SN1987A 20年、 SN2006gy、 2008D）及超新星与γ射线暴的联系,文章重点讨论SNIa 和宇宙学,评述了SNIa在宇宙学中的应用和哈勃常数的确定,最后指出超新星研究目前存在的问题。     

SNO and the new SNOLAB

A new international science laboratory, SNOLAB, has recently begun operation 2 km underground at the site of the Sudbury Neutrino Observatory (SNO), near Sudbury, Canada. The laboratory incorporates the SNO detector and includes several new experimental areas with a total excavated volume about three times larger than the original SNO cavity. The SNO detector has now completed operation with heavy water and data analysis is being completed with improved accuracy by combining all three phases of the project. A new project, SNO +, has recently been funded and will provide high sensitivity for neutrino-less double beta decay, low energy solar neutrinos, geoneutrinos, supernovae and other physics measurements. A number of dark matter measurements are in progress or preparing for deployment and a new supernova measurement, HALO is also being deployed. The status and physics objectives of the experimental program is outlined.     

Links between heavy ion and astrophysics

Heavy-ion experiments provide important data to test astrophysical models. The high-density equation of state can be probed in HI collisions and applied to the hot protoneutron star formed in core collapse supernovae. The parity radius experiment (PREX) aims to accurately measure the neutron radius of ²⁰⁸Pb with parity-violating electron scattering. This determines the pressure of neutron-rich matter and the density dependence of the symmetry energy. Competition between nuclear attraction and Coulomb repulsion can form exotic shapes called nuclear pasta in neutron star crusts and supernovae. This competition can be probed with multifragmentation HI reactions. We use large-scale semiclassical simulations to study nonuniform neutron-rich matter in supernovae. We find that the Coulomb interactions in astrophysical systems suppress density fluctuations. As a result, there is no first-order liquid-vapor phase transition. Finally, the virial expansion for low-density matter shows that the nuclear vapor phase is complex with significant concentrations of alpha particles and other light nuclei in addition to free nucleons.     

Writing the Biography of Hans Bethe: Contextual History and Paul Forman1

Some facets of the life of Hans Bethe after World War II are presented to illustrate how Paul Forman’s works, and in particular his various theses—on mathematics and physics in Wilhelmine and Weimar Germany, on physics in the immediate post-World War II period, and on postmodernity—have influenced my biography of Bethe. Some aspects of the history of post-World War II quantum field theory, of solid state/condensed matter physics, and of the development of neoliberalism—the commitment to the belief that the market knows best, to free trade, to enhanced privatization, and to a drastic reduction of the government’s role in regulating the economy—are reviewed in order to make some observations regarding certain “top-down” views in solid state physics in postmodernity, the economic and cultural condition of many Western societies since the 1980s, the decade in which many historians assume modernity to have ended.     

活力物质的非平衡结构和动力学

活力物质是一类典型的非平衡态体系,已成为软凝聚态物理新近发展的一个重要研究方向.活力物质由微驱动粒子组成,驱动力独立地施加在体系中的每个粒子上.文章概述了作者平时研究中所关注的一些活力物质系统中出现的十分有意义的现象,着重介绍了活力物质系统的构成,以及活力物质的气液态、铁磁态、向列相态和凝胶状态中涌现出的非平衡结构及其特殊的动力学行为.     

Addendum to: Gen. Rel. Grav. 28 (1996) 1161, First Prize Essay for 1996: Neutrino Oscillations and Supernovae

In a 1996 JRO Fellowship Research Proposal (Los Alamos), the author suggested that neutrino oscillations may provide a powerful indirect energy transport mechanism to supernovae explosions. The principal aim of this addendum is to present the relevant unedited text of Section 1 of that proposal. We then briefly remind, (a) of an early suggestion of Mazurek on vacuum neutrino oscillations and their relevance to supernovae explosion, and (b) Wolfenstein's result on suppression of the effect by matter effects. We conclude that whether or not neutrino oscillations play a significant role in supernovae explosions shall depend if there are shells/regions of space in stellar collapse where matter effects play no essential role. Should such regions exist in actual astrophysical situations, the final outcome of neutrino oscillations on supernovae explosions shall depend, in part, on whether or not the LNSD signal is confirmed. Importantly, the reader is reminded that neutrino oscillations form a set of flavor-oscillation clocks and these clock suffer gravitational redshift which can be as large as 20 percent. This effect must be incorporated fully into any calculation of supernova explosion.     

Sinn und Möglichkeiten der Theoretischen Physik. Zum 300. Jahrestag von Newtons „Philosophiae Naturalis Principia Mathematica”︁

The Meaning and Abilities of Theoretical Physics The Newtonean principles and — derived from them — the congnition of the exixtence of elementary constants according to Planck, Einstein and Bohr increasingly prove to be a strong base not only of physics and its apllication in technology but also of each kind of “exact” sciences in the broadest sense of the word. Since Newton the clarification of concepts with regard so their physical takes place in close connection with the development of mathematical methods. This combination proves to be further productive and ensures the progress of physics an of the “exact” sciences. Most likely all problems which may be of importance in the realm of life can be treated successfully — adequate expenditure taken for granted — with the existing fund of knowledge and methods. The connection between law and accident resting on reality proves to be a relation of complementarity (“there is no absolute accident”). This becomes evident in all branches in all branches of physics, not only in thermodynamics and quantum physics, and can be treated already on the level of the Newtonean principles and elementary constants. Theoretical physics as initiated by newton was designed to comprise all parts of nature. About that there is no contrast between classical physics and quantum physics. It is only a matter of differentiation with regard to the different physical contents and the appropriate mathematical methods, dependent of course on the choice problems. Theoretical physics represents a generally available concentration of the reliable knowledge of physics, which is at the same time the foundation of the “exact” sciences. In this way theoretical physics is the means of communication within the cooperation necessary for the solution of the great complex tasks of science and technology.     

Complex energy plane and topological invariant in non-Hermitian systems

Non-Hermitian systems as theoretical models of open or dissipative systems exhibit rich novel physical properties and fundamental issues in condensed matter physics. We propose a generalized local–global correspondence between the pseudo-boundary states in the complex energy plane and topological invariants of quantum states. We find that the patterns of the pseudo-boundary states in the complex energy plane mapped to the Brillouin zone are topological invariants against the parameter deformation. We demonstrate this approach by the non-Hermitian Chern insulator model. We give the consistent topological phases obtained from the Chern number and vorticity. We also find some novel topological invariants embedded in the topological phases of the Chern insulator model, which enrich the phase diagram of the non-Hermitian Chern insulators model beyond that predicted by the Chern number and vorticity. We also propose a generalized vorticity and its flipping index to understand physics behind this novel local–global correspondence and discuss the relationships between the local–global correspondence and the Chern number as well as the transformation between the Brillouin zone and the complex energy plane. These novel approaches provide insights to how topological invariants may be obtained from local information as well as the global property of quantum states, which is expected to be applicable in more generic non-Hermitian systems.     

Ⅱ型超新星爆发的中微子过程

本文总结了在Ⅱ型超新星爆发过程中可能发生的中微子与物质相互作用,综述了Ⅱ型超新星爆发的各个阶段的中微子过程,介绍了有关的中微子输运理论和几种主要近似方案。     

Model of vectorlike technicolor

The authors consider the mechanism of formation of techniquark states which have a vectorlike interaction with the standard bosons. It is shown that the simplest variant of the vectorlike technicolor does not contradict to the new physics restrictions. It is suggested that the technibaryon scalar states are regarded as dark matter candidates.     

AMS在核物理与天体物理研究中的应用

加速器质谱学方法在核物理与天体物理研究中有重要应用.主要介绍了该方法在寻找泡利不相容原理的违背事例和超新星活动研究等工作中的应用. As an ultra high sensitive analyzing method, accelerator mass spectrometry is playing an important role in the studies of nuclear physics and astrophysics. In this article, accelerator mass spectrometry (AMS) applications in searching for violation of Pauli exclusion principle and study on supernovae are discussed as examples.     

Properties of SN Ia progenitors from light curves and spectra

With recent advances in theory and observations, direct connections emerge between the progenitors of Type Ia Supernovae (SNe Ia) and the observed light curves and spectra. A direct link is important for our understanding of the supernovae physics, the diversity of SNe Ia and the use of SNe Ia for high-precision cosmology because the details of the explosion depends sensitively on the initial conditions and the explosion scenario(s) realized in nature. Do SNe Ia originate from SD- or DD systems, and do they lead to M_Ch mass explosions or dynamical mergers? Does the statistical distribtion of SNe Ia depend on their environment which can be expected to change with redshift? In this contribution, we will exam from the theoretical point of view the tell-tails for this connection, their consistency with the observations, and future directions. In a first section, we present the physics of the explosion, light curves and spectral formation in a nutshell to help understanding the connection. For details of the progenitor evolution and explosion physics, we refer to reviews and the other contributions in this issue. Each of the topical sections starts with a brief general review followed by a more detailed discussion of specific results. Because the youth of the field, some bias is unavoidable towards results obtained within our collaborations (and FSU). The imprint of the metallicity, progenitor stars and properties such as the central density of the exploding WD are presented. IR spectroscopy, polarimetry and imaging of SNR remnants are discussed as a tool to test for the WD properties, magnetic fields and asymmetries. We discuss different classes of Type Ia supernovae, and their environment. Possible correlations between the spectroscopic and light curve properties of SN Ia are discussed. Finally, the overall emerging picture and future developments are discussed.     

Particle accelerator physics and technology for high energy density physics research

Interaction phenomena of intense ion- and laser radiation with matter have a large range of application in different fields of science, extending from basic research of plasma properties to applications in energy science, especially in inertial fusion. The heavy ion synchrotron at GSI now routinely delivers intense uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Our simulations show that the new accelerator complex FAIR (Facility for Antiproton and Ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. A natural example of hot dense plasma is provided by our neighbouring star the sun, and allows a deep insight into the physics of fusion, the properties of matter at high energy density, and is moreover an excellent laboratory for astroparticle physics. As such the sun's interior plasma can even be used to probe the existence of novel particles and dark matter candidates. We present an overview on recent results and developments of dense plasma physics addressed with heavy ion and laser beams combined with accelerator- and nuclear physics technology.     

Neutrino interactions in dense stellar matter

Weak-interaction rates play an important role in the birth of neutron stars in core collapse supernova and their subsequent thermal evolution. In this paper, I highlight the role of strong interactions and phase transitions in calculations of neutrino scattering and emission rates in dense stellar matter.Received: 1 November 2002, Published online: 15 July 2003PACS: 13.15.+g Neutrino interactions - 13.20.-v Leptonic and semileptonic decays of mesons - 26.50.+x Nuclear physics aspects of novae, supernovae, and other explosive environments - 26.60.+c Nuclear matter aspects of neutron starsPresent address: Los Alamos National Laboratory, P.O. Box 1663, MS B283, Los Alamos, NM 87545, USA     

Supernovae and cosmology

The extreme luminosity and their fairly unique temporal behaviour have made supernovae a superb tool to measure distances in the universe. As complex astrophysical events they provide interesting insights into explosion physics, explosive nucleosynthesis, hydrodynamics of the explosion and radiation transport. They are an end product of stellar evolution and provide clues to the stellar composition. Since they can be observed at large distances they have become critical probes to further explore astrophysical effects, like dust properties in external galaxies and the star formation history of galaxies. Some of the astrophysics interferes with the cosmological applications of supernovae. The local velocity field, distorted by the gravitational attraction of the local large scale structure, and the reddening law appear at the moment the major limitations in the accuracy with which cosmological parameters can be determined. These absorption effects can introduce a secondary bias into the observations of the distant supernovae, which needs to be carefully evaluated. Supernovae have been used for the measurement of the Hubble constant, i.e. the current expansion rate of the universe, and the accelerated cosmic expansion directly inferred from the apparent faintness of the distant supernovae.     

耗散粒子动力学模拟方法在软物质体系研究中的一些进展与应用

软物质是指处于固体和理想流体之间的复杂态物质,主要包括聚合物、表面活性剂、液晶、胶体悬浮液、以及生物大分子等。软物质能够对外界微小的作用产生强烈的非线性响应,并展现出丰富的有序自组装相态。作为一种新颖的模拟技术,耗散粒子动力学方法非常适合在介观尺度上对软物质体系的复杂行为进行合理的描述。本文对耗散粒子动力学模拟方法的发展及一些应用进行了系统评述。耗散粒子动力学模拟方法体现了分子动力学与格子Boltzmann模型的优点,通过与其它理论模型（如Flory-Huggins理论、Smoothed particle hydrodynamics模型等）相结合,该方法能够在介观尺度上有效地研究聚合物熔体和溶液体系、生物膜及囊泡体系以及胶体悬浮液等体系的行为。这些研究结果,对新材料的研发、特殊材料的制备、以及材料加工条件的选择具有十分重要的科学意义和实际应用价值。     

The dark components of the Universe are slowly clarified

The dark sector of the Universe is beginning to be clarified step by step. If the dark energy is vacuum energy, then 123 orders of this energy are reduced by ordinary physical processes. For many years, these unexplained orders were called a crisis of physics. There was indeed a “crisis” before the introduction of the holographic principle and entropic force in physics. The vacuum energy was spent on the generation of new quantum states during the entire life of the Universe, but in the initial period of its evolution the vacuum energy (78 orders) were reduced more effectively by the vacuum condensates produced by phase transitions, because the Universe lost the high symmetry during its expansion. Important problems of physical cosmology can be solved if the quarks, leptons, and gauge bosons are composite particles. The dark matter, partially or all consisting of familon-type pseudo-Goldstone bosons with a mass of 10^—5–10^–3 eV, can be explained in the composite model. Three generations of elementary particles are absolutely necessary in this model. In addition, this model realizes three relativistic phase transitions in a medium of familons at different redshifts, forming a large-scale structure of dark matter that was “repeated” by baryons. We predict the detection of dark energy dynamics, the detection of familons as dark matter particles, and the development of spectroscopy for the dark medium due to the probable presence of dark atoms in it. Other viewpoints on the dark components of the Universe are also discussed briefly.