1 / 42

Searching for axions and ALPs from string theory .

Searching for axions and ALPs from string theory . Particles beyond the Standard Model?!. Standard Model of P article Physics : Fundamental des- cription of known matter par- ticles and gauge forces. Particles beyond the Standard Model?!.

mimir
Download Presentation

Searching for axions and ALPs from string theory .

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. SearchingforaxionsandALPs fromstringtheory.

  2. Particlesbeyondthe Standard Model?! • Standard Model ofParticlePhysics: Fundamental des-criptionofknown matter par-ticlesandgaugeforces

  3. Particlesbeyondthe Standard Model?! • Standard Model ofParticlePhysics: Fundamental des-criptionofknown matter par-ticlesandgaugeforces • Standard Model ofCosmolo-gy: onlyabout 5 % ofenergycontentofpresentuniverseconsistsofknownparticles

  4. Particlesbeyondthe Standard Model?! • Standard Model ofParticlePhysics: Fundamental des-criptionofknown matter par-ticlesandgaugeforces • Standard Model ofCosmolo-gy: onlyabout 5 % ofenergycontentofpresentuniverseconsistsofknownparticles • Extensionsofthe Standard Model ofParticlePhysics: severalgoodmotivatedcan-didatesforconstituentsofdark matter • SUSY: Neutralino, Gravitino • Peccei Quinn: Axion

  5. Peccei-Quinn extensionofthe Standard Model • Motivation: Explanation ofunnaturalsmallness, ,, ofCP-violatingtopologicalterm in QCDLagrangian, • Axionfield

  6. Peccei-Quinn extensionofthe Standard Model • Motivation: Explanation ofunnaturalsmallness, ,, ofCP-violatingtopologicalterm in QCDLagrangian, • Axionfield • Axion: ultralightparticle, cf. Weinberg `78; Wilczek `78

  7. Peccei-Quinn extensionofthe Standard Model • Motivation: Explanation ofunnaturalsmallness, ,, ofCP-violatingtopologicalterm in QCDLagrangian, • Axionfield • Axion: ultralightparticle, cf. Weinberg `78; Wilczek `78 • extremelyweakinteractionswith Standard Model particles

  8. Peccei-Quinn extensionofthe Standard Model • Motivation: Explanation ofunnaturalsmallness, ,, ofCP-violatingtopologicalterm in QCDLagrangian, • Axionfield • Axion: ultralightparticle, cf. Weinberg `78; Wilczek `78 • extremelyweakinteractionswith Standard Model particles • Welcome sideeffect: • Axion: candidatefordark matter: created non-thermally via misa-lignmentmechanism in form ofcoherentoscillationsofaxionfield

  9. Coexistence: SUSY and PQ extension in stringtheory • Particularlystronglymotivatedextensionsof Standard Model based on stringtheory: • Unificationof all forces • Quantum gravity

  10. Coexistence: SUSY and PQ extension in stringtheory • Particularlystronglymotivatedextensionsof Standard Model based on stringtheory: • Unificationof all forces • Quantum gravity • Spectrumoflow-energyeffec-tivetheory in (3+1)-dimensionsissupersymmetricandpossiblycontainsseveralkindsofveryweaklyinteractingslimparticles (WISPs): Axion, ALPs (Axion-LikeParticles • ifthecompactspacecomprisedofthe 6 extra dimensionshascertaingeometricalandtopological proper-ties (Calabi-Yau; severalcycles)

  11. Axions in stringtheory • String compactificationsgenericallycontain pseudo-scalarfieldswithaxioniccouplingtogaugefieldsandanomalous global shiftsymmetry • These axionandaxion-likeparticle (ALP) candidatesarise in stringcompactificationsas KK zeromodesofantisymmetrictensorfields: cf. Witten `84

  12. Axions in IIB stringtheory • Concentrate on IIB case (moduli stabilisation best understood): Realisationof brane-world scenarios in string theory • KK reduction (expansion in harmonicforms): • Numberofaxionicfieldsdeterminedbyto-pologyof CY orientifold: numberoftopolo-gically non-equivalent 2-cycles or 4-cycles

  13. Axions in IIB stringtheory • Numberofcyclesgenerically O(100):

  14. Axions in IIB stringtheory • Cycles can be wrapped by space-time filling D-branes • Each of these branes gives rise to a gauge theory at low energy • Visible sector gauge theory realized by stacks of D7 branes wrapping small 4-cycles • Hidden sectors, in particular hidden photons, realized by branes wrapping cycles not intersecting visible sector branes

  15. Axions in IIB stringtheory • Eachaxionicfieldcomesalongwith a real scalarfield– saxion– whichis real partoflowestcomponentofchiralsuperfield, • … Kähler modulusmeasuringthevolumeof 4-cycle • 4D EFT from KK reductionof D-braneaction • isgaugekineticfunctionfortheory on D7-brane: • volumemeasuresgaugecoupling, • hasaxioniccoupling,

  16. Axions in IIB stringtheory • 4D effectivefieldtheory, cf. Jockers, Louis `05 • Decayconstantsandcouplingtogaugebosons via canonicalnormali-zationofaxionandgaugekinetictermsandmatchingto:

  17. IIB axiverse • An axiverse - QCD axion plus possiblymanyultra-light ALPs whosemassspectrumislogarithmicallyhierarchical – maynaturallyarisefromstrings, cf. Arvanitaki et al. `09 • Challengestoobtain an axiverse: • Onlyaxionswhichare not projected out byorientifoldprojectionappear in LE EFT • Onlyaxionswhich do not gettoo heavy by Kähler modulistabilisationcanbecandidatesfor QCD axionandother light ALPs, cf. Conlon `06 • Onlyaxionswhichare not eatenbyStückelbergmechanismtogivemassestobrane-localizedanomalous U(1) gaugebosons will appear in LE EFT • Acharya, Bobkov, Kumar `11: Modulistabilisation via single non-pertur-bativecorrectionto superpotential (cf. Bobkov,Braun, Kumar, Raby `10) fixes all Kähler moduli plus oneaxioncombination: axiversewithand • Cicoli, Goodsell, AR, 1206.0819: Modulistabilisationofthe so-called LARGE Volume Scenario (LVS) whichexploitsbothperturbativeand non-perturbativeeffectsto fix Kähler moduligivesriseto an axiversewithand

  18. LVS axiverse • Strategyto fix moduli in LVS: (cf. Cicoli, Mayrhofer, Valandro `11) • Exploit del Pezzofour-cyclesupportingsingle non-perturbativeeffect; dPmodulusfixedatsmallsize, dPsaxionandaxion heavy; interplaywithleadingorderalpha´ correctionyieldsexponentially large CY volume • Visible sectorwithchiralitybuiltbywrapping mag-netised D7-branes around rigid but not del Pezzofourcycles; D-term conditionsstabilise d combi-nationsof Kähler moduli, leaving . flat directions; latterfixedbypert. corrections • LVS requires : oneoftheremainingcyclesshouldbesmalltoobtaincorrectvalueof . , whilethereshouldbeat least onefurtherwhichcanbelarge; latterfixedat • More on this: talkbyMichele Cicoli

  19. LVS axiverse • Massscalesfor : • Nocosmologicalmoduliproblemsincedilutedbyentropyproduction due todecayof . reheatinguniverseto O(GeV)

  20. LVS axiverse • Scalingofaxiondecayconstantsandcouplings: • : QCD axionwith • : essentiallymassless ALP with , but nearlydecoupled,

  21. LVS axiverse • Scalingofaxiondecayconstantsandcouplings: • : QCD axionwith • : essentiallymassless ALP with , but nearlydecoupled, • Possiblymoreultralight, , ALPs with

  22. Axionand ALPs with intermediate scaledecayconstant? • Currentlimitsandpossiblehintsfromastrophysicsandcosmology:

  23. Hintsforaxionor ALP effects in propagationofTeVphotonsthroughuniverse? • TeVphotonsofdistantActiveGa-lactic Nuclei (AGN) shouldfeatureabsorptionbreaks due toelectron-positron pairproduction on the Ex-tragalacticBackground Light (EBL)

  24. Hintsforaxionor ALP effects in propagationofTeVphotonsthroughuniverse? • TeVphotonsofdistantActiveGa-lactic Nuclei (AGN) shouldfeatureabsorptionbreaks due toelectron-positron pairproduction on the Ex-tragalacticBackground Light (EBL) • Not thecase: (e.g. Horns, Meyer `12) • 50 spectra (HESS, MAGIC, Veritas), assumption: minimal EBL; absorptionruled out bymorethan 4 sigma

  25. Hintsforaxionor ALP effects in propagationofTeVphotonsthroughuniverse? • TeVphotonsofdistantActiveGa-lactic Nuclei (AGN) shouldfeatureabsorptionbreaks due toelectron-positron pairproduction on the Ex-tragalacticBackground Light (EBL) • Not thecase: (e.g. Horns, Meyer `12) • 50 spectra (HESS, MAGIC, Veritas), assumption: minimal EBL; absorptionruled out bymorethan 4 sigma • Possibleexplanation: Photon <-> ALP conversion in astrophysicalmagneticfields(Roncadelli et al.,Sanchez-Conde et al.)

  26. Hintsforaxionor ALP effects in propagationofTeVphotonsthroughuniverse? • TeVphotonsofdistantActiveGa-lactic Nuclei (AGN) shouldfeatureabsorptionbreaks due toelectron-positron pairproduction on the Ex-tragalacticBackground Light (EBL) • Not thecase: (e.g. Horns, Meyer `12) • 50 spectra (HESS, MAGIC, Veritas), assumption: minimal EBL; absorptionruled out bymorethan 4 sigma • Possibleexplanation: Photon <-> ALP conversion in astrophysicalmagneticfields(Roncadelli et al.,Sanchez-Conde et al.) • Hastobe an ALP: too light for a QCD axionwith such a decaycon-stant

  27. Hintforaxion/ALP-production in whitedwarfs? • Non-standard energie-lossmechanism in whitedwarfs, cf. Isern et al. • Compatiblewithaxionor ALP production in electron-bremsstrahlung

  28. Can weexplainthesehintswithin IIB axiverse? • Anomaloustransparencyofuniverseandanomalousenergylossofwhitedwarfscouldbeexplainedby • Model wherevisiblesectorbuildfromintersectingbranes in geometricregime • Yieldsrequiredvaluesfor • ALP masscouldbegeneratedbysingle Kähler potential instanton, e.g. requires • Astrophyicalhintscompatiblewith intermediate string-scalescenario

  29. Laboratory probesofaxionand ALPs with intermediate scaledecayconstant?

  30. Search for solar axionsand ALPs • Sun strong sourceofaxionsand ALPs • Helioscopesearchesforaxions/ALPs and HPs

  31. Search for solar axionsand ALPs • Sun strong sourceofaxionsand ALPs • Helioscopesearchesforaxions/ALPs and HPs • CAST … CERN Axion Solar Telescope

  32. Search for solar axionsand ALPs • Sun strong sourceofaxionsand ALPs • Helioscopesearchesforaxions/ALPs and HPs • CAST … CERN Axion Solar Telescope • IAXO … International Axion Observatory (underinvestigation)

  33. Search for solar axionsand ALPs

  34. Search for ALPs via light-shining-through-walls • ALPs can pass walls • Light-shining-through-walls experiments: (here ALPS (@DESY)):

  35. Search for ALPs via light-shining-through-walls • ALPS: • HERA dipole (8.4 m, 5 T) • Primary laser: enhanced LIGO laser (1064 nm, 35 W) • Frequencydoubled: 523 nm • 300-fold power build-up in cavity

  36. Search for ALPs via light-shining-through-walls • ALPS: • HERA dipole (8.4 m, 5 T) • Primary laser: enhanced LIGO laser (1064 nm, 35 W) • Frequencydoubled: 523 nm • 300-fold power build-up in cavity

  37. Search for ALPs via light-shining-through-walls • ALPS: • HERA dipole (8.4 m, 5 T) • Primary laser: enhanced LIGO laser (1064 nm, 35 W) • Frequencydoubled: 523 nm • 300-fold power build-up in cavity • ALPS-II plans (2016+): • 12 + 12 HERA dipoles • Increased power build-up (~5000) • Cavity also on regenerationpart

  38. Search for ALPs via light-shining-through-walls • ALPS: • HERA dipole (8.4 m, 5 T) • Primary laser: enhanced LIGO laser (1064 nm, 35 W) • Frequencydoubled: 523 nm • 300-fold power build-up in cavity • ALPS-II plans (2016+): • 12 + 12 HERA dipoles • Increased power build-up (~5000) • Cavity also on regenerationpart • Similarplans also atFermilab (REAPR)

  39. Summary andconclusions • String phenomenologyholdsthepromiseof an axiverse – the QCD axion plus a (possibly large) numberoffurtherultralightaxion-like par-ticles, possiblypopulatingeachdecadeofmass down tothe Hubble scale • Promisefulfilled in LARGE Volume Scenario of IIB stringcompactifi-cations • Models thatexhibit a QCD axionwith an intermediate-scaledecayconstantand additional evenlighteraxion-likeparticleshavingthe same decayconstantandcouplingtothephotoncanexplainastrophysicalanomaliesandbetested in thenextgenerationofhelioscopesand light-shining-through-walls experiments • Cosmologyof LVS axiverse still tobeinvestigated in detail

  40. Backup: Hidden photons

  41. Backup: Hidden photons

  42. Backup: More probesofultralightaxionsand ALPs cf. Arvanitaki, Dimopoulos, Dubovsky, Kaloper, March-Russell `09

More Related