Electroweak Axion in Light of GRB221009A

Very high energy(VHE)photons may have a higher survival rate than that expected in standard-model physics,as suggested by the recently reported gamma ray burst GRB221009A.While a photon-axion like particle(ALP)oscillation can boost the survival rate of the VHE photons,current works have not been based on concrete particle models,leaving the identity of the corresponding ALP unclear.Here,we show that the required ALP scenario is consistent with the electroweak axion with an anomaly free Z_(10)Froggatt–Nielsen symmetry.

Neutrino Mass Constraints from Reconstructing the Large-scale Structure:Systematic Uncertainty

We examine the possibility of applying the baryonic acoustic oscillation reconstruction method to improve the neutrino massΣm_νconstraint.Thanks to the Gaussianization of the process,we demonstrate that the reconstruction algorithm could improve the measurement accuracy by roughly a factor of two.On the other hand,the reconstruction process itself becomes a source of systematic error.While the algorithm is supposed to produce the displacement field from a density distribution,various approximations cause the reconstructed output to deviate on intermediate scales.Nevertheless,it is still possible to benefit from this Gaussianized field,given that we can carefully calibrate the“transfer function”between the reconstruction output and theoretical displacement divergence from simulations.The limitation of this approach is then set by the numerical stability of this transfer function.With an ensemble of simulations,we show that such systematic error could become comparable to statistical uncertainties for a DESI-like survey and be safely neglected for other less ambitious surveys.

暗晕子结构的数值搜寻与统计性质

宇宙学数值模拟预言的暗晕及其子结构的统计性质,被广泛应用于星系形成模型、近邻宇宙学、红移巡天、宇宙大尺度结构、引力透镜和暗物质搜寻等研究领域。在精确宇宙学时代,随着天文观测能力的不断增长,人们对模型精度提出了更高的要求,因此,数值模拟及其分析工具将继续起到不可替代的巨大作用。数值模拟中物质结构的性质往往与具体的搜寻算法有关,从最初通过数值模拟发现子晕到现在的20年里,结构搜寻算法有了极大的发展,新算法不断涌现。了解不同数值搜寻算法的实现及其差异,有助于分析模拟结果的系统差和不确定性,增强研究的可重复性。通过总结现代子晕数值搜寻的基本方法,并以几种典型的搜寻算法为例,探讨了它们之间的异同,及其对相关研究的影响;回顾了子晕的基本统计性质,包括质量函数、空间分布和密度轮廓等,以及这些统计结果对搜寻算法的依赖。此外,还讨论了重子物理的影响。

Féeton(B-L gauge boson)dark matter for the 511-keV gamma-ray excess and the prediction of low-energy neutrino flux

The féeton is the gauge boson of the U(1)_(B−L) gauge theory.If the gauge coupling constant is extremely small,the féeton becomes a candidate for dark matter.We show that its decay to a pair of an electron and a positron explains the observed Galactic 511-keV gamma-ray excess in a consistent manner.This féeton dark matter decays mainly into pairs neutrino and anti-neutrino.Future low-energy experiments with improved directional capability will enable capturing these neutrino signals.The seesaw-motivated parameter space predicts a relatively short féeton lifetime that is comparable to the current cosmological constraint.

The anomalous shift of the weak boson mass and the quintessence electroweak axion

One of the simplest ways to account for the observed W-boson mass shift is to introduce the SU(2)L triplet Higgs boson with zero hypercharge,whose vacuum expectation value is about 3 GeV.If the triplet is heavy enough at O(1) TeV,it essentially contributes only to T parameter without any conflict with the observation.The presence of a complex triplet Higgs boson raises the SU(2)_(L) gauge coupling constant toα_(2)(M_(PL))≃1/44 at the Planck scale.Thanks to this larger gauge coupling constant,we show that the electroweak axion vacuum energy explains the observed cosmological constant provided that the axion field is located near the hill top of the potential at present.

The mass of our Milky Way

We perform an extensive review of the numerous studies and methods used to determine the total mass of the Milky Way.We group the various studies into seven broad classes according to their modeling approaches.The classes include:i)estimating Galactic escape velocity using high velocity objects;ii)measuring the rotation curve through terminal and circular velocities;iii)modeling halo stars,globular clusters and satellite galaxies with the spherical Jeans equation and iv)with phase-space distribution functions;v)simulating and modeling the dynamics of stellar streams and their progenitors;vi)modeling the motion of the Milky Way,M31 and other distant satellites under the framework of Local Group timing argument;and vii)measurements made by linking the brightest Galactic satellites to their counterparts in simulations.For each class of methods,we introduce their theoretical and observational background,the method itself,the sample of available tracer objects,model assumptions,uncertainties,limits and the corresponding measurements that have been achieved in the past.Both the measured total masses within the radial range probed by tracer objects and the extrapolated virial masses are discussed and quoted.We also discuss the role of modern numerical simulations in terms of helping to validate model assumptions,understanding systematic uncertainties and calibrating the measurements.While measurements in the last two decades show a factor of two scatters,recent measurements using Gaia DR2 data are approaching a higher precision.We end with a detailed discussion of future developments in the field,especially as the size and quality of the observational data will increase tremendously with current and future surveys.In such cases,the systematic uncertainties will be dominant and thus will necessitate a much more rigorous testing and characterization of the various mass determination methods.

SUSY effects in Higgs production at high energy e^+e^-colliders

Considering the constraints from collider experiments and dark matter detection, we investigate the SUSY effects in the Higgs production channels e＋e-, Zh at an e＋e- collider with a center-of-mass energy above 240 GeV and YY-- h - bb at a photon collider with a center-of-mass energy above 125 GeV. In the parameter space allowed by current experiments, we find that the SUSY corrections to e＋e- Zh can reach a few percent and the production rate of YY- h - bb can be enhanced by a factor of 1.2 over the SM prediction. We also calculate the exotic Higgs production e＋e- - Zhl in the next-to-minimal supersymmetric model （NMSSM） （h is the SM-like Higgs, hi is the CP-even Higgs bosons which can be much lighter than h）. We find that at a 250 GeV e＋e- collider the production rates of e＋e- -- Zhl can reach 60 fb.

Precision Higgs physics at the CEPC

The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of the ongoing LHC program.At the same time,lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC,with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson.The Circular Electron Positron Collider(CEPC)is one of such proposed Higgs factories.The CEPC is an e^+e^- circular collider proposed by and to be hosted in China.Located in a tunnel of approximately 100 km in circumference,it will operate at a center-of-mass energy of 240 GeV as the Higgs factory.In this paper,we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.

NEUTRINO MASS, MIXING, AND OSCILLATIONS

The experiments with solar, atmospheric, reactor and accelerator neutrinos have provided compelling evidences for oscillations of neutrinos caused by nonzero neutrino masses and neutrino mixing. The data imply the existence of 3-neutrino mixing in vacuum. We review the theory of neutrino oscillations, the phenomenology of neutrino mixing, the problem of the nature - Dirac or Majorana, of massive neutrinos, the issue of CP violation in the lepton sector, and the current data on the neutrino masses and mixing parameters. The open questions and the main goals of future research in the field of neutrino mixing and oscillations are outlined.

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.

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 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：

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.

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.

CHARMED BARYONS(C=+1)∧_c^+=udc,∑_c^(++)=uuc,∑_c^+=udc,∑_c^0=ddc,≡_c^+=usc,≡_c^0=dsc,Ω_c^0=ssc

CHARMED BARYONS Revised March 2012 by C.G. Wohl （LBNL）. There are 17 known charmed baryons, and four other candidates not well enough established to be promoted to the Summary Tables.＊ Fig. l（a） shows the mass spectrum,

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.

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.