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🏛 | Shiori Yamao announces retirement from politics for a limited term. "I feel uncomfortable with'politicians are the standard model'many times."


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Shiori Yamao announces retirement from politics for a limited term. "I feel uncomfortable with" a politician is the standard model "many times."

 
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As for the reason, "I felt uncomfortable many times that the career of a politician was the standard model.
 

Shiori Yamao, a member of the House of Representatives of the Democratic Party for the People, has announced that he will retire from politics for a limited term. "A star from a different standpoint than a politician ... → Continue reading

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Discomfort

Standard model

Standard model(Hyojun Mokei,British: Standard Model, Abbreviation: SM)Particle physicsAtStrong interaction,weak interaction,Electromagnetic interactionTwo ofBasic interactionTo describeモデルIs one of the.

Standard theory(Hyojun Riron) orStandard modelAlso called (Hyojun model).Depicts many physical phenomena almost accuratelyhypothesis.

Overview

The standard model isStrong interactionaboutQuantum chromodynamics,weak interactionElectromagnetic interactionaboutWeinberg-Salam theorySU (3) combined withc× SU (2)L× U (1)Y Gauge symmetryBased onHiggs mechanismbyVacuum symmetry breakingAnd fermion mass acquisition,AnomalyBy request for offsettingFermionGeneration structure and intergenerational mixingCP violationaboutKobayashi-Maskawa theoryTheories such as[1]..The standard model isSpecial relativityConsistent withQuantum theoryAs,Quantum field theoryIt is described in a specific way, and so far, except for gravity, it accurately describes all the phenomena used in quantum field theory.[2].

Standard model elementary particles

Standard modelElementary particlesMediates powerspin1'sGauge particles, Spin 0 that breaks symmetryHiggs boson, Spin 1/2 of the substanceFermionConsists of.

Gauge particles

Standard model gauge boson
Particle namesymbolGauge symmetry
GluonGSU (3)c
W bosonWSU (2)L× U (1)Y
Z bosonZ
PhotonA

The standard model isYang-Mills theoryTherefore, there are gauge particles corresponding to each gauge group.

SU (3)CThe gauge boson corresponding toGluonIt is called.

SU (2)LAnd U (1)YAs for the gauge boson corresponding to, the Higgs mechanism causes mixing of the gauge field and acquisition of mass, so that the appearance is somewhat complicated.Week isospin SU (2)L The off-diagonal components of the gain massW bosonAnd with the diagonal componentWeak hypercharge U (1)Y Mix and gain massZ bosonAnd do not gain massPhotonbecome.

Fermion

Standard model fermion
Particle namesymbolPerformance
quarkQ(3,2)1/6
Upper series antiquarkU(3*, 1)-2/3
Lower series antiquarkD(3*, 1)1/3
LeptonL(1,2)-1/2
Anti-charged leptonsE(1,1)1

FermionStrong interactiondoquarkAnd do not interact stronglyLeptonIt is divided into.Furthermore, quarks and leptons can be classified into left-handed particles and right-handed particles, respectively.The left-handed particles in the Standard ModelElectroweak interaction OfWeek isospinHas, but does not have right-handed particles.Therefore, the form of gauge interaction differs between left-handed particles and right-handed particles, and the Standard Model is a chiral theory regarding gauge interaction.Also, due to this property, all quarks and leptons cannot have mass unless the electroweak symmetry is broken by the Higgs mechanism.All quarks and charged leptons gain mass by the Higgs mechanism.Neutrinos do not have mass within the Standard Model

Fermions consist of left-handed quarks and left-handed leptons, right-handed up quarks and right-handed down quarks, and right-handed charged leptons, forming a group called generations.In general, for models that include gauge interactions,Gravity anomalyNeed to be offset, but the anomaly is offset among the fermions that make up the generation.The standard model has three generations of quarks and leptons.Kobayashi-Maskawa theoryAccording to the mixture of fermionsCP violationTo do this, you need three or more generations of fermions.In fact, CP violation due to fermion mixing has been experimentally confirmed and confirmed to be in good agreement with the Standard Model prophecies.

Higgs boson

In the standard model,Higgs mechanismThis causes the electroweak symmetry to break spontaneously.Field fluctuations are generally interpreted as particles, but three of the four degrees of freedom of fluctuations in the Higgs field areW bosonZ bosonAs it has mass, it is absorbed as its longitudinal wave component.The remaining 1 degree of freedom is a 0-spin scalar particle.Higgs bosonAppears as.2012In 7 monthGenevaSuburbsEuropean Nuclear Research Organization It is done in (CERN)LHC experimentAnnounced the discovery of new particles[3]..The properties of this new particle are in good agreement with the Higgs boson. Certified.

History

Unresolved issues

The Standard Model can explain almost all the experimental results on particle physics conducted up to 2014 without any contradiction, but on the other hand, it should be solved from a theoretical or experimental / observational point of view. I have some problems.This isPhysics beyond the Standard ModelSuggests the existence of.This section lists the unsolved problems in the Standard Model.

Quantization of gravity

The Standard Model has succeeded in describing three of the four basic interactions, electromagnetic force, weak force, and strong force, in a quantum theory based on the Yang-Mills theory.But the remaining one重力Is lacking in that description.In other words, it is said to mediate gravityGravity childIs not included in the standard model particle list.This is because the cancellation of divergence due to quantum effects in quantum field theory, which is the basic framework of the Standard Model, cannot be applied to gravity theory.As a candidate for a framework that can handle gravity quantum-mechanically,Superstring theory,Loop quantum gravityAnd so on.

Grand Unified Theory

Of the three forces described by the Standard Model, the strong force is described by gauge symmetry, which is different from the electromagnetic force and the weak force.For this reason, it is difficult to understand the three forces in a unified manner.However, the U (3) gauge symmetry that describes the electromagnetic forceThe gauge symmetry of the standard model appears as a result of the gauge symmetry being spontaneously broken by the Higgs mechanism.It has been pointed out that the larger gauge symmetry may be the result of spontaneous breaking.A theory based on this possibility is called the Grand Unified Theory.There are several candidates for the gauge symmetry of the Grand Unified Theory, which is the basis of SU (5), SO (10),Etc. have been proposed.The Grand Unified Theory, which describes the strong force and electroweak interaction in a unified manner, enables interactions such as converting quarks into leptons.As a specific phenomenonProton decayIs predicted.KamiokandeExperiments to demonstrate proton decay are ongoing, but as of 2014, no experimental evidence has been obtained.

Hierarchy problem (fine tuning problem)

The standard model isQuantum field theoryBecause it is a model based on, to calculate a physically meaningful quantityrenormalizationAn operation called is required.In connection with this, in the Standard ModelHiggs mechanismbyElectroweak symmetry OfSpontaneous tearThe parameters of the theory need to be adjusted very precisely in order to match the magnitude of.This problem,Planck scale(1019 GeV) and scale (10) that breaks electroweak symmetry2 It is called a hierarchical problem because there is a large gap between GeV).There are several models proposed to solve this problem, but one of them is typical.Supersymmetry model.

Strong CP problem

neutron OfElectric dipole momentIt is known that the magnitude is lower than the observation accuracy as of 2014.This indicates that the CP symmetry is well established in the parts other than the weak interaction of the standard model, and the values ​​related to the strong interaction and the phase of the Yukawa matrix of the quark are such that the CP symmetry is well established. It means that it is set to.In the Standard Model, these two parameters are not particularly related, and the situation of being precisely adjusted is unnatural.It is believed that this unnatural problem should be solved by some mechanism,Strong CP problemIt is called.One of the most promising solutions is(English editionIs.By this mechanismAxionThe existence of a new particle called is predicted.

The mystery of the generation structure

The standard model fermions gain mass by combining with the Higgs vacuum expectation value (commonly called the Yukawa coupling), but the three generations are not independently coupled.For example, there are three-point couplings of charged leptons, 3st and 1nd generations, and Higgs, and when the 2 generations are combined, the mass is obtained as a mass matrix that can be written as a 3 × 3 matrix.A physical mode, that is, a mode such as an electron or a muon, can be written as a mass eigenstate after diagonalizing this mass matrix.The elements of the mass matrix of the Standard Model are free parameters, and their values ​​have a difference of several digits.In addition, the structure of the mass matrix differs greatly between leptons and quarks, the off-diagonal elements are large in the lepton mass matrix, and the off-diagonal elements are relatively small in the quark mass matrix.That is, in order to describe the actual particle picture using the standard model, it is necessary to make fine adjustments to the mass parameters.Research is widely underway to reproduce this structure from theory using symmetry and order 3 parameters.

The generation in the standard model is commonly called flavor, and it is widely used by the names such as flavor structure, flavor physics, and flavor mixing.

Neutrino oscillation

1998ToKamioka MineWas installed inSuper KamiokandeDiscovered neutrino oscillations[27]However, this proves the existence of neutrinos with mass.In the standard modelNeutrinoSince the mass of is exactly 0, this experimental result is important as one of the indications that the Standard Model needs some modification.If you simply want to add the neutrino mass term to the standard model framework, you can introduce a right-handed neutrino, but if you use the standard model charge, the right-handed neutrino willMajorana particlesNext, a mass term (Majorana mass term) that is composed only of right-handed neutrinos appears, and the mass structure becomes complicated.One of the typical frameworks incorporating this isSeesaw mechanism.

Dark matter

It has been clarified that dark matter occupies about a quarter of the current energy density of the universe, but there are no particles that can be candidates for dark matter in the Standard Model.Therefore, it is necessary to extend the standard model when finding the true nature of dark matter from elementary particles.As hypothetical particles, "Z'boson", which has the role of connecting ordinary matter and dark matter, and other "axions" are considered. Some of the "Gaugino" and "Higgsino" among the "supersymmetric particles" that have not been discovered as of 4 are listed as candidates for dark matter.

Baryon number asymmetry

Fermions included in the Standard Model are particlesAntiparticleIt is classified into two types.Particles and antiparticles are almost equal, but in the universe we live in, the amount of particles is larger than that of antiparticles.This asymmetryBaryon numberKnown as asymmetry.It is known that the standard model can cause CP violation through the coupling of Higgs and fermions, which can create asymmetry of the number of particles and antiparticles, but the phase of the standard model alone is sufficient. It is known that it is not possible to produce a sufficient number of baryons.[28]It is believed to suggest the existence of physics beyond the Standard Model.

Muon precession shift

2001 years,Brookhaven National LaboratoryIt is,MuonWe reported the experimental results that the precession of the standard model deviates from the prediction of the standard model. In 2021Fermi National Accelerator Laboratory OfMuong-2 experimentBut similar results were shown[29].

footnote

  1. ^ Southern et al. Chapter 3 (Jiro Maki (Author)
  2. ^ "Amazing Physics Lecture" Kawade Bunko, 2019, p.168.
  3. ^ “Latest update in the search for the Higgs boson”. CERN. (July 2012, 7). http://indico.cern.ch/conferenceDisplay.py?confId=197461 2012/7/4Browse. 
  4. ^ Chen-Ning Yang and Robert L. Mills (1954). “Conservation of Isotopic Spin and Isotopic Gauge Invariance”. Physical Review 96: 191. two:10.1103 / PhysRev.96.191. 
  5. ^ TD Lee and Chen-Ning Yang (1956). “Question of Parity Conservation in Weak Interactions”. Physical Review 104: 254. two:10.1103 / PhysRev.104.254. 
  6. ^ CL Cowan, F. Reines, FB Harrison, HW Kruse and AD McGuire (1956). “Detection of the free neutrino: A Confirmation”. Science 124: 103. two:10.1126 / science.124.3212.103. 
  7. ^ CS Wu, E. Ambler, RW Harvard, DD Hoppes and RP Hudson (1957). “Experimental Test Of Parity Conservation In Beta Decay”. Physical Review 105: 1413. two:10.1103 / PhysRev.105.1413. 
  8. ^ JH Christenson, JW Cronin, VL Fitch and R. Turlay (1964). “Evidence for the 2 pi Decay of the k (2) 0 Meson”. Physical Review Letters 13: 138. two:10.1103 / PhysRevLett.13.138. 
  9. ^ Murrey Gell-Mann (1964). “A Schematic Model of Baryons and Mesons”. Physics Letters 8: 214. two:10.1016 / S0031-9163 (64) 92001-3. 
  10. ^ Peter W. Higgs (1964). “Broken symmetryes, massless particles and gauge fields”. Physics Letters 12: 132. two:10.1016 / 0031-9163 (64) 91136-9. 
  11. ^ Steven Weiberg (1967). “A Model of Leptons”. Physical Review Letters 19: 1264. two:10.1103 / PhysRevLett.19.1264. 
  12. ^ Abdus Salam (1968). “Weak and Electromagnetic Interactions”. Conf.Proc. C680519: 367 s. 
  13. ^ Gerard't Hooft (1971). “Renormalizable Lagrangians for Massive Yang-Mills Fields”. Nuclear Physics B 35: 167. two:10.1016 / 0550-3213 (71) 90139-8. 
  14. ^ Gerard't Hooft and MJG Veltman (1972). “Regularization and Renormalization of Gauge Fields”. Nuclear Physics B 44: 189. two:10.1016 / 0550-3213 (72) 90279-9. 
  15. ^ Makoto Kobayashi and Toshihide Maskawa (1973). “CP Violation in the Renormalizable Theory of Weak Interaction”. Progress of Theoretical Physics 49: 652. two:10.1143 / PTP.49.652. 
  16. ^ DJ Gross and Frank Wilczek (1973). “Ultraviolet Behavior of Nonabelian Gauge Theories”. Physical Review Letters 30: 1343. two:10.1103 / PhysRevLett.30.1343. 
  17. ^ H. David Politzer (1973). “Reliable Perturbative Results for Strong Interactions?”. Physical Review Letters 30: 1346. two:10.1103 / PhysRevLett.30.1346. 
  18. ^ E598 Collaboration (1974). “Experimental Observation of a Heavy Particle J”. Physical Review Letters 33: 1404. two:10.1103 / PhysRevLett.33.1404. 
  19. ^ SLAC-SP-017 Collaboration (1974). “Discovery of a Narrow Resonance in e + e- Annihilation”. Physical Review Letters 33: 1406. two:10.1103 / PhysRevLett.33.1406. 
  20. ^ SW Herb, DC Hom, LM Lederman, JC Sens, HD Snyder, JK Yoh, JA Appel, BC Brown, CN Brown, WR Innes, K. Ueno, T. Yamanouchi, AS Itoh, H. Jostlein, DM Kaplan and RD Kephart (1977). “Observation of a Dimuon Resonance at 9.5-GeV in 400-GeV Proton-Nucleus Collisions”. Physical Review Letters 39: 252. two:10.1103 / PhysRevLett.39.252. 
  21. ^ UA1 Collaboration (1983). “Experimental Observation of Isolated Large Transverse Energy Electrons with Associated Missing Energy at s ** (1/2) = 540-GeV”. Physics Letters B 122: 103. two:10.1016 / 0370-2693 (83) 91177-2. 
  22. ^ UA1 Collaboration (1983). “Experimental Observation of Lepton Pairs of Invariant Mass Around 95-GeV / c ** 2 at the CERN SPS Collider”. Physics Letters B 126: 398. two:10.1016 / 0370-2693 (83) 90188-0. 
  23. ^ CDF Collaboration (1995). “Observation of top quark production in ppbar collisions”. Physical Review Letters 74: 2626. two:10.1103 / PhysRevLett.74.2626. 
  24. ^ D0 Collaboration (1995). “Observation of the top quark”. Physical Review Letters 74: 2632. two:10.1103 / PhysRevLett.74.2632. 
  25. ^ ATLAS Collaboration (2012). “Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC”. Physics Letters B 716: 1. two:10.1016 / j.physletb.2012.08.020. 
  26. ^ CMS Collaboration (2012). “Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC”. Physics Letters B 716: 30. two:10.1016 / j.physletb.2012.08.021. 
  27. ^ Super-Kamiokande Collaboration (1998). “Evidence for oscillation of atmospheric neutrinos”. Physical Review Letters 81: 1562. two:10.1103 / PhysRevLett.81.1562. 
  28. ^ Sacha Davidson, Enrico Nardi and, Yosef Nir (2008). “Leptogenesis”. Physics Report 466: 105. two:10.1016 / j.physrep.2008.06.002. 
  29. ^ "Muon behavior that overturns particle physics, is there an unknown physical law?". National geographicJapanese version (July 2021, 4). 2021/4/27Browse.

References

paper

  • Beringer, J .; Arguin, J .; Barnett, R .; Copic, K .; Dahl, O .; Groom, D .; Lin, C .; Lys, J. et al. (2012). “Review of Particles” Physics ”. Physical Review D 86 (1). two:10.1103 / PhysRevD.86.010001. ISSN 1550 7998. 

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