Beyond the Standard Model of Particle Physics  

In General > s.a. particle physics and standard model [anomalies].
* Idea: Many unified models and extensions have been proposed, requiring varying degrees of theory overhaul; Some of the proposals for physics beyond the standard model are supersymmetry/supergravity, extra dimensions, string theory, quark constituent models, Lorentz non-invariance, violations of the weak equivalence principle, and variation of fundamental constants.
* 2002: Evidence for neutrino oscillations (\(\nu_\mu-\nu_\tau\)); Anomalous muon magnetic moment (g–2) reported (indication of supersymmetry?).
* 2014, supersymmetry: An extension of the standard model involving supersymmetry is widely believed to be the solution to many problems, such as the instability of the Higgs boson and the arbitrariness of particle masses; But the most popular supersymmetric theories predict new particles not much heavier than the Higgs, which ought to have been seen by now at the LHC; Physicists have been hunting for such particles for years and have ruled out almost all of the predicted mass range for such theories; They have cornered themselves experimentally, and new ideas will be needed if supersymmetry is not detected.
* 2014, other: A hint of departure from the standard model is seen in results from a test of lepton universality.
* 2018: There are no convincing signs of new physics from the LHC, and only theoretical hints of new physics happening near the Planck scale.
* Scales: The SM remains a valid effective field theory up to the Planck energy, which may be the next energy frontier (strong and electroweak interaction coupling constants approximately meet 1 or 2 orders of magnitude below, and the self-coupling of the Higgs boson flows to zero near it); > s.a. unification.
@ Reviews: Kane SA(03)jun, hp/04-proc [status]; Kazakov IJMPA(07); Iliopoulos a0807; Mangano IJMPA(08); Nojiri yr(14)-a1407-conf; Ricciardi et al a1507 [and dark matter].
@ General references: Ramond 00; Dijkgraaf ht/97-ln [conformal field theory, topological field theory, strings]; Chalmers ht/02 [M-theory based general relativity + standard model]; Goldhaber IJMPA(04); Pokorski hp/05-ln; van der Bij PLB(06); Greenberg hp/06 [3-generation model]; Jenkins PhD(06)ht [and spontaneous Lorentz violation]; Ellis et al PLB(09)-a0906 [fate of standard model]; Grinstein PoS-a1102 [non-mainstream ideas]; Tiwari CP(11); Sannino a1201 [new strong dynamics in particle physics and cosmology]; Fukuyama IJMPA(12)-a1201 [search using electric dipole moments]; Hajdukovic MPLA(13) [new physics?]; de Blas et al JHEP(18)-a1711 [effective description].
@ Phenomenology / experiments: Gallo IJMPA(07); Grivaz IJMPA(08); Brooijmans MPLA(09) [and the LHC]; news at(12)apr [indications in hints of Higgs particle]; news stfc(12)jun [hints in BaBar data on B-meson decay]; news PhysOrg(15)aug [more hints]; Afshordi et al a1703 [pulsar timing constraints]; Rong et al nComm(18)-a1706 [new approach, and constraints on axion-mediated electron-nucleon coupling]; Kimball Phy(17) [comagnetometry experiment]; news sn(18)sep [Belle II, KATRIN, muon \(g-2\)]; Gorham et al PRL(18) [inverted cosmic-ray-like event]; > s.a. lorentz-symmetry violations; Nightmare Scenario.

Specific Proposals > s.a. composite models; gravitation; GUTs; nuclear physics; time [2-time physics]; unified theories; variation of fundamental constants.
* Stückelberg extension: An extension of the electroweak gauge group with an extra abelian U(1)X factor.
* Standard model extension: A parametrized framework describing Lorentz-symmetry violations; > s.a. modified lorentz symmetry.
* Hidden sector: A collection of particles that are only weakly coupled to the standard model ones; For an example, > see dark matter and Wikipedia page.
* Preon and other constituent models: 1996, Evidence in high ET jets at Fermilab? (> s.a. QCD).
* With extra dimensions: Possibilities are Kaluza-Klein models, supergravity, strings and branes, non-compact extensions (with localization).
* Supergravity: Not to be tested soon (> supergravity).
@ Mini-charged particles: Jaeckel PRL(09) [Cavendish-type experiments]; Burrage et al JCAP(09)-a0909 [constraints from late-time CMB anisotropies].
@ Standard model extension: Bonder a1607-conf, Bailey a1607-conf [gravitational sector]; Tasson Symm-a1610 [and gravitational tests]; Eichhorn et al a1810 [asymptotically safe, near-perturbative completion of the Standard Model with gravity].
@ Conformality approach: Frampton hp/06-conf [phenomenology]; Frampton & Kephart PRP(08)-a0706 [rev, quiver gauge theory].
@ Scale-invariance and conformal symmetry: Alexander-Nunneley & Pilaftsis JHEP(10)-a1008 [minimal scale-invariant extension]; 't Hooft FP(11)-a1104 [local conformal invariance as a spontaneously broken exact symmetry]; Fabbri GRG(12) [conformal theory of metric-torsional gravitation]; Costantini a1704-PhD [and superconformal]; Faria a1903.
@ Beyond three generations: Frampton et al PRP(00); Belotsky et al ap/06-proc [and dark matter]; Holdom JHEP(06) [implications of a possible 4th family]; Erler & Langacker PRL(10) [constraints from electroweak precision data]; > s.a. standard model; types of dark matter [many copies of standard model].
@ Gauge theory and gravity: Dell & Smolin in(86); Chang & Soo PRD(96)ht/94 [connection variables]; Anandan PRL(98)ht/97 [global topology and discrete symmetries]; Besprosvany IJTP(00)ht/02 [gauge and spacetime symmetry]; Wu CTP(03)ht [?], CTP(03)ht [with massive graviton]; Anselmi PLB(04)ht [dimensional regularization]; Ruhdorfer et al JHEP-a1908 [effective field theory].
@ And string theory: Kane Nat(11)dec [Higgs and strings]; Schellekens RMP(13)-a1306.
@ With extra dimensions: Pomarol & Quirós PLB(98) [extra dimensions]; > s.a. branes; kaluza-klein theory and phenomenology.
@ Supersymmetric: Beenakker et al a1409 [non-commutative supersymmetric Standard Model]; > s.a. supergravity; supersymmetric theories [MSSM].
@ Other theories: Roepstorff ht/98 [in terms of superconnections]; Ribarič & Šušteršič Fiz(99)ht/98 [underlying theory]; Körs & Nath PLB(04), JHEP(05) [Stückelberg extension]; Asaka & Shaposhnikov PLB(05)hp [neutrino minimal standard model, νMSM]; Maher & Beck CSF(08)-a0801 [larger theory, chaotic quantization]; Mankoč Borštnik FdP(17)-a1607-proc [spin-charge-family theory]; Ballesteros et al PRL(17)-a1608, JCAP(17)-a1610, a1904 [Standard Model Axion Seesaw Higgs, SMASH]; Herrera & Quintero a1707 [U(2) × U(3) gauge theory extension]; Kerner PAN(18)-a1801-proc; Moffat EPJP(19)-a1812 [ultraviolet complete model]; Miković & Vojinović EPL(21)-a2008 [categorification scheme, 4-groups]; van der Bij APP-a2104 [minimalistic extensions].
blue bullet Other theories: see axions; fifth force; lattice gauge theory; Leptoquark; physics [TOEs]; renormalization [asymptotic safety, UV completions].

Based on Other Mathematical Structures > s.a. non-commutative gauge theories.
@ Non-associative geometry: Wulkenhaar ht/96 [and grand unification]; Wulkenhaar PLB(97)ht/96 [standard model], ht/96 [GUTs]; Boyle & Farnsworth NJP(14)-a1401 [and non-commutative geometry].
@ Related topics: Boyle & Farnsworth JHEP-a1604 [new algebraic structure]; Furey a1611-PhD [from the algebra \({\mathbb R}\otimes{\mathbb C}\otimes{\mathbb H}\otimes{\mathbb O}\)]; Dubois-Violette & Todorov NPB(18)-a1808 [exceptional Jordan algebra J\(^8_3\)].

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