1RXPJ160338＋1554．1：一个明亮的低电离核发射线区星系

X射线卫星ROSAT观测得到的X射线源1RXP J160338+1554.1,经过美国基特峰国立天文台的4 m光学望远镜的分光观测得到了它的光谱.通过光谱分析发现,该源具有较强的低电离发射线,从发射线的强度比以及谱线形态来看,该源完全符合低电离核发射线区(LINERs)星系的判据.这是第一次完全证实它是一个LINER.

ROSAT巡天X射线选活动星系核的光学证认

获得完备的样本一直是类星体统计分析工作中至关重要的第一步。类星体巡天选择候选体的方法主要有射电波段筛选、色指数筛选、无缝光谱筛选、X射线波段筛选、对红外源或变源进行筛选和零自行的方法。单独运用任一方法都有选择效应,采用多波段方法可以极大地提高样本的完备性。阐述了使用多波段方法选择活动星系核样本的研究现状,提出多波段类星体巡天方法和选源判据,给出ROSAT巡天中F.1002,F.Coma,F.836和F.Leo 4个天区以及空源的15年来X射线选活动星系核的选源和光学新证认的AGN结果,表明多波段类星体巡天方法能有效地提高观测效率。

XMM-Newton observation of the eclipsing binary Algol

We present an XMM-Newton observation of the eclipsing binary Algol which contains an X-ray dark B8V primary and an X-ray bright K2IV secondary. The observation covered the optical secondary eclipse and captured an X-ray flare that was eclipsed by the B star. The XMM-Newton European Photon Imaging Camera and Reflection Grating Spectrometer spectra of Algol in its quiescent state are described by a two-temperature plasma model. The cool component has a temperature around 6.4× 106 K while that of the hot component ranges from 2 to 4.0× 107 K. Coronal abundances of C, N, O, Ne, Mg, Si and Fe were obtained for each component for both the quiescent and the flare phases, generally with upper limits for S and Ar, and upper limits for C, N, and O from the hot component. F-tests show that the abundances do not need to be different between the cool and the hot component and between the quiescent and the flare phase with the exception of Fe. Although the Fe abundance of the cool component remains constant at -0.14, the hot component shows an Fe abundance of -0.28, which increases to -0.44 during the flare. This increase is expected from the chromospheric evaporation model. The absorbing column density NH of the quiescent emission is 2.5 - 1020 cm-2, while that of the flare-only emission is significantly lower and consistent with the column density of the interstellar medium. This observation substantiates earlier suggestions of the presence of X-ray absorbing material in the Algol system.

Hysteresis Loops and Phase Diagrams of the Spin-1 Ising Model in a Transverse Crystal Field

Within the framework of the effective-field theory with a probability distribution technique,which accounts for the self-spin correlation functions,the ferromagnetic spin-1 Ising model with a transverse crystal field on honeycomb,square and simple cubic lattices is studied.We have investigated the effect of the transverse crystal field on the phase diagrams,magnetization,hysteresis loops and χ_(z,h) of the system.A number of interesting phenomena of the system are discussed.

On the X-Ray Edge Problem in Graphene

We calculate the core-hole spectral density in a pristine graphene, where the density of states of itinerant electrons goes linearly to zero at the Fermi level. We consider explicitly two models of electron-hole interaction. In the unscreened Coulomb interaction model, the spectral density is similar to that in metal (for local interaction). Thus there is no δ-function singularity in the core-hole spectral density. In the local interaction model, the δ-function singularity survives, but the interaction leads to the appearance of the background in the spectral density.

M dwarf stars—the by-product of X-ray selected AGN candidates

X-ray loud M dwarfs are a major source of by-products （contamination） in the X-ray band of the multiwavelength quasar survey. As a by-product, the low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16 sources are taken for the first time. The spectral types and distances of the sample are given based on spectral indices CaH2, CaH3, and TiO5. The parameter ζ TiO/CaH is calculated to separate the different metallicity classes among dwarfs, subdwarfs and extreme subdwarfs. We also discuss the distributions in the diagrams of log（L x /L bol ）, the ratio between X-ray and bolometric luminosity versus spectral type and infrared colors.

Methods for a blind analysis of isobar data collected by the STAR collaboration

In 2018,the STAR collaboration collected data from^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zr at√^(S)NN=200 Ge V to search for the presence of the chiral magnetic effect in collisions of nuclei.The isobar collision species alternated frequently between 9644 Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zr.In order to conduct blind analyses of studies related to the chiral magnetic effect in these isobar data,STAR developed a three-step blind analysis procedure.Analysts are initially provided a"reference sample"of data,comprised of a mix of events from the two species,the order of which respects time-dependent changes in run conditions.After tuning analysis codes and performing time-dependent quality assurance on the reference sample,analysts are provided a species-blind sample suitable for calculating efficiencies and corrections for individual≈30-min data-taking runs.For this sample,species-specific information is disguised,but individual output files contain data from a single isobar species.Only run-by-run corrections and code alteration subsequent to these corrections are allowed at this stage.Following these modifications,the"frozen"code is passed over the fully un-blind data,completing the blind analysis.As a check of the feasibility of the blind analysis procedure,analysts completed a"mock data challenge,"analyzing data from Au+Au collisions at√^(S)NN=27 Ge V,collected in 2018.The Au+Au data were prepared in the same manner intended for the isobar blind data.The details of the blind analysis procedure and results from the mock data challenge are presented.

The Multi-Wavelength Quasar Survey IV. Quasars in the Leo Cluster

We aim to provide a quasar sample that is more complete than any previous surveys by using a combined selection technique to reduce the selection effects. Here we present the observational results for the X-ray candidates in the field of the Leo Cluster. We found 33 X-ray AGNs in this field of which 10 are new discoveries. The X-ray data and optical spectra of these AGNs are given. We also study the near-IR properties of the X-ray-selected AGNs by using the data from 2MASS. Most of the AGNs in our sample span the color range 0.0〈B-J〈2.5,1.0〈 J-Ks 〈2.0 and 0.5〈H-Ks〈1.2.

Measuring a dynamical topological order parameter in quantum walks

Quantum processes of inherent dynamical nature,such as quantum walks,defy a description in terms of an equilibrium statistical physics ensemble.Until now,identifying the general principles behind the underlying unitary quantum dynamics has remained a key challenge.Here,we show and experimentally observe that split-step quantum walks admit a characterization in terms of a dynamical topological order parameter(DTOP).This integer-quantized DTOP measures,at a given time,the winding of the geometric phase accumulated by the wavefunction during a quantum walk.We observe distinct dynamical regimes in our experimentally realized quantum walks,and each regime can be attributed to a qualitatively different temporal behavior of the DTOP.Upon identifying an equivalent manybody problem,we reveal an intriguing connection between the nonanalytic changes of the DTOP in quantum walks and the occurrence of dynamical quantum phase transitions.

BOTTOM MESONS(B=±1)B^+=u,B^0=d,B^0=db,B^-=b,similarly for B~*'s

Many measurements of B decays involve admixtures of B hadrons. Previously we arbitrarily included such admixtures in the B±section, but because of their importance we have created two new sections：

N BARYONS(S=0,I=1/2)p,N^+=uud;n,N^0=udd

p MASS （atomic mass units u）The mass is known much more precisely in u （atomic mass units） than in MeV. See the next data block.

BOTTOM,CHARMED MESONS(B=C=±1)B_c^+=c,B_c^-=cb,similarly for B_c~*'s

I（JP） = 0（0-）I, J, P need confirmation.Quantum numbers shown are quark-model predictions.

REVIEW OF PARTICLE PHYSICS

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on： Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews （and errata） are also available on the Particle Data Group website： http ：//pdg. lbl. gov.

CLEBSCH-GORDAN COEFFICIENTS,SPHERICAL HARMONICS,AND d FUNCTIONS

Note： A square-root sign is to be understood over every coefficient, e.g., for -8/15 read - √8√15.

SU(3) ISOSCALAR FACTORS AND REPRESENTATION MATRICES

Written by R.L. Kelly （LBNL）. The most commonly used SU（3） isoscalar factors, corresponding to the singlet, octet, and deeuplet content of 8 8 and 10 8, are shown at the right. The notation uses particle names to identify the coefficients, so that the pattern of relative couplings may be seen at a glance. We illustrate the use of the coefficients below.

BOTTOM BARYONS(B=-1)∧_b^0=udb,≡_b^0=usb,≡_b^-=dsb,Ω_b^-=ssb

In the quark model, a ∧b0 is an isospin-0 udb state. The lowest ∧b0 ought to have JP = 1/2＋. None of I, J, or P have actually been measured.

INTRODUCTION

1. Overview The Review of Particle Physics and the abbreviated version, the Particle Physics Booklet, are reviews of the field of Particle Physics. This complete Review includes a compilation/evaluation of data on particle properties, called the ＂Particle Listings.＂ These Listings include 3,283 new measurements from 899 papers, in addition to the 32,153 measurements from 8,944 papers that first appeared in previous editions [1].

∧ BARYONS(S=-1,I=0)∧~0=uds

We have omitted some results that have been superseded by later experiments. See our earlier editions.

PARTICLE DETECTORS AT ACCELERATORS

33.1. Introduction This review summarizes the detector technologies employed at accelerator particle physics experiments. Several of these detectors are also used in a non-accelerator context and examples of such applications will be provided. The detector techniques which are specific to non-accelerator particle physics experiments are the subject of Chap.

KINEMATICS

Revised January 2000 by J.D. Jackson （LBNL） and June 2008 by D.R. Tovey （Sheffield）.