Rouven Essig C.N. Yang Institute for Theoretical Physics Stony - PowerPoint PPT Presentation

Current Limits & Prospects Axions & ALPs - 6 LSW H ALPS - I L S N - 8 axion band is well- Solar n YMCE Helioscopes H CAST L motivated target and HB Telescopes - 10 Log Coupling @ GeV - 1 D should be pursued TeV ALPS - II SN g- burst Transparency REAPR x ion IAXO - 12 other regions motivated WD cooling hint Haloscopes axion CDM Dish too Antenna ADMX - HF - 14 ALP CDM (theory+DM+astro hints) ADMX Intermediate string scale EBL - 16 KSVZ axion X - Rays - 18 - 12 - 10 - 8 - 6 - 4 - 2 0 2 4 6 Log Mass @ eV D Jaeckel, Redondo, Ringwald, …

Portals our focus today axions & axion-like 1 • “Axion” F µ ν ˜ F µ ν a particles (ALPs) f a • “Vector” ✏ F Y,µ ν F 0 dark photon A ′ µ ν • “Higgs” exotic Higgs decays? λ H 2 S 2 + µ H 2 S • “Neutrino” sterile neutrinos? κ ( HL ) N

Dark Photons Standard Model Dark Sector W ± , Z γ g Known Forces

Dark Photons consider a very simple Dark Sector Standard Model Dark Sector W ± , Z γ g (massive) A 0 New force: U(1) Known Forces

Dark Photons consider a very simple Dark Sector Standard Model Dark Sector W ± , Z γ g (massive) A 0 New force: U(1) Known Forces (+ possibly dark matter )

Dark Photons consider a very simple Dark Sector A 0 γ Standard Model X Dark Sector A 0 (massive) W ± , Z γ g ✏ ordinary photon & A ʹ can mix ∆ L = ✏ 2 F Y,µ ν F 0 “Kinetic Mixing” µ ν Holdom Galison, Manohar

Generating Kinetic Mixing e.g. loops of heavy particles charged under photon and A ′ γ A 0 ✏ ∼ 10 − 8 − 10 − 2 a motivated target

Mixing with photon allows:

Mixing with photon allows: A 0 ↔ γ “oscillation”

Mixing with photon allows: A 0 ↔ γ “oscillation” and A ʹ coupling to quarks and charged leptons: q, ` + ✏ e X A 0 γ ∗ q, ` −

low-mass (< MeV) A ʹ parameter space 0 0 Jupiter Earth AGN, SNR mwLSW Rydberg Coulomb - 3 - 3 LSW CMB Log 10 ✏ Sun Cosmology - 6 - 6 Non - zero FI - term Log 10 e ADMX UWA CERN - 9 - 9 ALPS - II non - Thermal DM Stückelberg isotropic H line L Thermal Haloscopes Stückelberg DM anisotropic - 12 - 12 DPB Hidden Higgs H m H h ª m ˝ ' L Dish Antenna ADMX - HF HB RG ADMX - 15 - 15 - 18 - 15 - 12 - 9 - 6 - 3 0 3 6 Log 10 m A ' @ eV D Log 10 m A � [eV] Jaeckel, Redondo, Ringwald, … Experimental techniques often similar to axion/ALP searches

Another well-motivated target: m A ʹ ~ MeV-GeV

Another well-motivated target: m A ʹ ~ MeV-GeV • origin of GeV-scale can be naturally related to Weak-scale in some models e.g. Arkani-Hamed & Weiner; Cheung, Ruderman, Wang, Yavin; Morrissey, Poland, Zurek; m A 0 ∼ √ ✏ M Z . 1 GeV

Another well-motivated target: m A ʹ ~ MeV-GeV • origin of GeV-scale can be naturally related to Weak-scale in some models e.g. Arkani-Hamed & Weiner; Cheung, Ruderman, Wang, Yavin; Morrissey, Poland, Zurek; m A 0 ∼ √ ✏ M Z . 1 GeV • A ′ may explain observed muon g-2 (>3 σ discrepancy) Pospelov Boehm, Fayet

Another well-motivated target: m A ʹ ~ MeV-GeV • origin of GeV-scale can be naturally related to Weak-scale in some models e.g. Arkani-Hamed & Weiner; Cheung, Ruderman, Wang, Yavin; Morrissey, Poland, Zurek; m A 0 ∼ √ ✏ M Z . 1 GeV • A ′ may explain observed muon g-2 (>3 σ discrepancy) Pospelov Boehm, Fayet • Hints of new dark matter interactions from various DM indirect and direct detection anomalies Arkani-Hamed et.al.; Cholis et.al.; Pospelov & Ritz; Hooper, Weiner, Xue

How look for A ʹ with MeV-GeV mass?

How look for A ʹ with MeV-GeV mass? RE, Schuster, Toro Batell, Pospelov,Ritz e + e - colliders Reece, Wang Borodatchenkova et.al. Fayet ✏ A 0 → e + e − , µ + µ − , π + π − , . . .

How look for A ʹ with MeV-GeV mass? RE, Schuster, Toro Batell, Pospelov,Ritz e + e - colliders Reece, Wang Borodatchenkova et.al. Fayet Rare meson decays φ → η A 0 A 0 π 0 → γ ✏ A 0 → e + e − , µ + µ − , π + π − , . . .

How look for A ʹ with MeV-GeV mass? RE, Schuster, Toro Batell, Pospelov,Ritz e + e - colliders Reece, Wang Borodatchenkova et.al. Fayet Rare meson decays φ → η A 0 A 0 π 0 → γ ✏ A 0 → e + e − , µ + µ − , π + π − , . . . B-factories, Phi-factories searches completed/ongoing/planned

How look for A ʹ with MeV-GeV mass? Bjorken, RE, Schuster, Toro Freytsis, Ovanesyan, Thaler Reece & Wang New & old e - fixed target experiments

How look for A ʹ with MeV-GeV mass? Bjorken, RE, Schuster, Toro Freytsis, Ovanesyan, Thaler Reece & Wang New & old e - fixed target experiments A ʹ A ʹ e - e - e + Target Detector

How look for A ʹ with MeV-GeV mass? Bjorken, RE, Schuster, Toro Freytsis, Ovanesyan, Thaler Reece & Wang New & old e - fixed target experiments A ʹ A ʹ e - e - e + Target Detector e.g. E137, APEX, HPS, DarkLight, MAMI, VEPP-3, …

How look for A ʹ with MeV-GeV mass? Proton -beam fixed target experiments Batell, Pospelov, Ritz RE, Harnik, Kaplan, Toro

How look for A ʹ with MeV-GeV mass? Proton -beam fixed target experiments Batell, Pospelov, Ritz RE, Harnik, Kaplan, Toro Example: produce A ʹ from pion decays p e - A ʹ π 0 → γ A 0 e + Target Detector Shield Decay pipe

How look for A ʹ with MeV-GeV mass? Proton -beam fixed target experiments Batell, Pospelov, Ritz RE, Harnik, Kaplan, Toro Example: produce A ʹ from pion decays p e - A ʹ π 0 → γ A 0 e + Target Detector Shield Decay pipe e.g. LSND, MINOS, MiniBooNE, Project X

Current constraints 10 - 3 10 - 2 10 - 1 1 10 - 2 10 - 2 a m , 5 s KLOE 10 - 3 10 - 3 a m , ± 2 s favored BaBar E774 APEX ê MAMI Test Runs 10 - 4 10 - 4 a e E141 Orsay 10 - 5 10 - 5 U70 10 - 6 10 - 6 CHARM e 10 - 7 10 - 7 E137 LSND 10 - 8 10 - 8 10 - 9 10 - 9 SN 10 - 10 10 - 10 10 - 11 10 - 11 10 - 3 10 - 2 10 - 1 1 m A ' H GeV L

Current constraints 10 - 3 10 - 2 10 - 1 1 10 - 2 10 - 2 a m , 5 s KLOE 10 - 3 10 - 3 a m , ± 2 s favored BaBar E774 APEX ê MAMI Test Runs 10 - 4 10 - 4 a e E141 Orsay past 10 - 5 10 - 5 U70 electron + proton 10 - 6 10 - 6 CHARM beam dumps e 10 - 7 10 - 7 E137 LSND 10 - 8 10 - 8 supernova 10 - 9 10 - 9 SN 10 - 10 10 - 10 Bjorken, RE, Schuster, Toro Andreas, Niebuhr, Ringwald 10 - 11 10 - 11 10 - 3 10 - 2 10 - 1 1 Batell, Pospelov, Ritz RE, Harnik, Kaplan, Toro m A ' H GeV L Blumlein, Brunner Dent, Ferrer, Krauss

Current constraints (zoomed in) 0.001 0.01 0.1 1 10 - 2 10 - 2 a m , 5 s KLOE a m , ± 2 s favored 10 - 3 10 - 3 BaBar APEX ê MAMI E774 Test Runs a e E141 e 10 - 4 10 - 4 Orsay 10 - 5 10 - 5 U70 Pospelov Bjorken, RE, Schuster, Toro 0.001 0.01 0.1 1 RE, Schuster, Toro, Wojtsekhowski KLOE Collaboration m A ' H GeV L APEX Collaboration MAMI/A1 Collaboration

Current constraints (zoomed in) 0.001 0.01 0.1 1 10 - 2 10 - 2 g-2 of e - , μ - a m , 5 s KLOE a m , ± 2 s favored 10 - 3 10 - 3 BaBar APEX ê MAMI E774 Test Runs a e E141 e 10 - 4 10 - 4 Orsay 10 - 5 10 - 5 U70 Pospelov Bjorken, RE, Schuster, Toro 0.001 0.01 0.1 1 RE, Schuster, Toro, Wojtsekhowski KLOE Collaboration m A ' H GeV L APEX Collaboration MAMI/A1 Collaboration

Current constraints (zoomed in) 0.001 0.01 0.1 1 10 - 2 10 - 2 g-2 of e - , μ - a m , 5 s KLOE a m , ± 2 s favored B/Phi-factory 10 - 3 10 - 3 BaBar APEX ê MAMI E774 searches Test Runs a e E141 e 10 - 4 10 - 4 Orsay 10 - 5 10 - 5 U70 Pospelov Bjorken, RE, Schuster, Toro 0.001 0.01 0.1 1 RE, Schuster, Toro, Wojtsekhowski KLOE Collaboration m A ' H GeV L APEX Collaboration MAMI/A1 Collaboration

Current constraints (zoomed in) 0.001 0.01 0.1 1 10 - 2 10 - 2 g-2 of e - , μ - a m , 5 s KLOE a m , ± 2 s favored B/Phi-factory 10 - 3 10 - 3 BaBar APEX ê MAMI E774 searches Test Runs a e E141 e Test runs of new 10 - 4 10 - 4 e - -FT experiments Orsay @ JLab/Mainz 10 - 5 10 - 5 U70 Pospelov Bjorken, RE, Schuster, Toro 0.001 0.01 0.1 1 RE, Schuster, Toro, Wojtsekhowski KLOE Collaboration m A ' H GeV L APEX Collaboration MAMI/A1 Collaboration

Current constraints (zoomed in) 0.001 0.01 0.1 1 10 - 2 10 - 2 a m , 5 s KLOE a m , ± 2 s favored need new 10 - 3 10 - 3 BaBar APEX ê MAMI E774 experiments Test Runs a e to probe this E141 e 10 - 4 10 - 4 region Orsay 10 - 5 10 - 5 Bjorken, RE, Schuster, Toro U70 0.001 0.01 0.1 1 m A ' H GeV L

New Experiments @JLab (USA): 0.001 0.01 0.1 1 10 - 2 10 - 2 APEX, HPS, a m , 5 s DarkLight KLOE a m , ± 2 s favored 10 - 3 10 - 3 BaBar in Russia: APEX ê MAMI E774 Test Runs a e VEPP-3 E141 e 10 - 4 10 - 4 in Germany: Orsay Mainz (not shown) 10 - 5 10 - 5 look for A ′ → e + e - U70 resonance or 0.001 0.01 0.1 1 displaced vertex m A ' H GeV L (unique to HPS)

How look for A ʹ with MeV-GeV mass? No time to discuss other searches, e.g. Dark Sector (“Hidden Valley”) explorations at Tevatron/LHC Strassler, Zurek Arkani-Hamed, Weiner Baumgart, Cheung, Ruderman, Wang, Yavin Shih, Thomas

Dark Photons Recall: simplest Dark Sector consists of just an A ′ at low energies X Standard Model Dark Sector A 0 (massive) W ± , Z γ g

Dark Photons Recall: simplest Dark Sector consists of just an A ′ at low energies X Standard Model Dark Sector A 0 (massive) W ± , Z γ g Dark Sector can easily be more complicated, so must look for other signals too

Dark Photons Recall: simplest Dark Sector consists of just an A ′ at low energies X Standard Model Dark Sector A 0 (massive) W ± , Z γ g Dark Sector can easily be more complicated, so must look for other signals too Example: sub-GeV Dark Matter + A ′

sub-GeV Dark Matter very rich phenomenology (much of it still under active investigation) Can probe in various ways: • colliders • fixed-target (p & e - ) • direct detection • indirect detection

Low-energy e + e - colliders RE, Mardon, Papucci, Volansky, Zhong (to appear) Example: ✏ A 0

Low-energy e + e - colliders RE, Mardon, Papucci, Volansky, Zhong (to appear) Example: ✏ A 0 → DM + DM (invisible!)

Low-energy e + e - colliders 0.001 0.01 0.1 1 10 RE, Mardon, Papucci, Volansky, Zhong 10 - 1 10 - 1 (to appear) SM PM a m , 5 s 10 - 2 10 - 2 a m , ± 2 s favored Example: e 10 - 3 10 - 3 BaBar U H 3S L Æ g A 0 a e A 0 → invisible 10 - 4 10 - 4 Preliminary 0.001 0.01 0.1 1 10 m A ' @ GeV D ✏ A 0 → DM + DM (invisible!)

Proton-beam fixed target experiments Batell, Pospelov, Ritz Deniverville, Pospelov, Ritz Aguilar-Arevalo et.al. (MiniBooNE proposal) p e - /N DM → DM+DM π 0 → γ A 0 DM Target Detector Decay Shield pipe

Proton-beam fixed target experiments Batell, Pospelov, Ritz Deniverville, Pospelov, Ritz Aguilar-Arevalo et.al. (MiniBooNE proposal) Example: produce A ʹ from pion decays p e - /N DM → DM+DM π 0 → γ A 0 DM Target Detector Decay Shield pipe

Proton-beam fixed target experiments Batell, Pospelov, Ritz Deniverville, Pospelov, Ritz Aguilar-Arevalo et.al. (MiniBooNE proposal) Example: produce A ʹ from pion decays A ′ → DM+DM p e - /N DM → DM+DM π 0 → γ A 0 DM Target Detector Decay Shield pipe

Proton-beam fixed target experiments Batell, Pospelov, Ritz Deniverville, Pospelov, Ritz Aguilar-Arevalo et.al. (MiniBooNE proposal) Example: produce A ʹ from pion decays A ′ → DM+DM DM recoils of e - /nucleon in detector p e - /N DM → DM+DM π 0 → γ A 0 DM Target Detector Decay Shield pipe

Proton-beam fixed target experiments Batell, Pospelov, Ritz Deniverville, Pospelov, Ritz Aguilar-Arevalo et.al. (MiniBooNE proposal) Example: produce A ʹ from pion decays A ′ → DM+DM DM recoils of e - /nucleon in detector p e - /N DM → DM+DM π 0 → γ A 0 DM Target Detector Decay Shield pipe plenty of room for exploration e.g. LSND, MINOS, MiniBooNE, Project X

Proton-beam fixed target experiments Proposal for more MiniBooNE running Aguilar-Arevalo et.al. (MiniBooNE proposal) ✏ m A 0 [GeV] m A 0 [GeV]

Electron-beam fixed target experiments to appear: Diamond, Schuster; Krnjaic, Izaguirre, Schuster, Toro Example: produce DM directly from on/off-shell A ʹ DM recoils of e - /nucleon in detector e - e - /N DM A ′ (*) → DM+DM DM Target Detector Shield plenty of room for future experiments e.g. JLab, Mainz, …

Direct Detection RE, Mardon, Volansky probe DM in our halo scattering off e.g. electrons in detector

Direct Detection RE, Mardon, Volansky probe DM in our halo scattering off e.g. electrons in detector first direct detection limits on sub-GeV DM, using 10 - 34 Excluded by published XENON10 data 10 - 35 XENON10 data 1 electron s e @ cm 2 D RE, Manalaysay, Mardon, 2 electrons 10 - 36 Sorensen, Volansky 3 electrons 10 - 37 Hidden - 10 - 38 Photon models 10 - 39 1 10 100 10 3 Dark Matter Mass @ MeV D MeV !

Direct Detection RE, Mardon, Volansky probe DM in our halo scattering off e.g. electrons in detector first direct detection limits on sub-GeV DM, using 10 - 34 Excluded by published XENON10 data 10 - 35 XENON10 data 1 electron s e @ cm 2 D RE, Manalaysay, Mardon, 2 electrons 10 - 36 Sorensen, Volansky 3 electrons 10 - 37 Hidden - 10 - 38 Photon models lots of potential 10 - 39 for current & new 1 10 100 10 3 experiments! Dark Matter Mass @ MeV D MeV ! see also Graham et.al.

Conclusions

Conclusions • Dark matter points to a Dark Sector

Conclusions • Dark matter points to a Dark Sector • New, light weakly-coupled particles are well-motivated • axions, ALPs, dark photons, … • motivated by DM, strong CP , muon g-2, astro anomalies, theory…

Conclusions • Dark matter points to a Dark Sector • New, light weakly-coupled particles are well-motivated • axions, ALPs, dark photons, … • motivated by DM, strong CP , muon g-2, astro anomalies, theory… • experiments use intense beams & sensitive detectors • often make use of existing facilities/technologies (i.e. ~inexpensive) • could benefit from further technological developments

Conclusions • Dark matter points to a Dark Sector • New, light weakly-coupled particles are well-motivated • axions, ALPs, dark photons, … • motivated by DM, strong CP , muon g-2, astro anomalies, theory… • experiments use intense beams & sensitive detectors • often make use of existing facilities/technologies (i.e. ~inexpensive) • could benefit from further technological developments • support for these explorations is crucial • we don’t know which guiding principle for finding new physics is reliable; must explore all motivated possibilities

Backup

Axion/ALPs: hints from astro puzzles? Is universe more transparent than expected γ γ a to high energy ɣ -rays? � � ɣ -ALP conversion? B B Roncadelli, de Angelis, … Do white dwarf stars cool faster than expected? Axion? cooling enhanced by WD axion/ALP radiation? ALP? Isern , Garcia–Berro, Torres , Catalan

How to look for Axion and ALPs? Best probes from ɣ -axion/ALP conversion “Light-shining-through-walls” Okun; Sikivie; Anselm; van Bibber; …. a x x LIPSS (Jlab) , BFRT (BNL), BMV (LULI), GammeV (Fermilab), ALPS (DESY), OSQAR (CERN), PVLAS (INFN), ... Need large magnets, powerful lasers, optical cavities

How to look for Axion and ALPs? Best probes from ɣ -axion/ALP conversion Helioscopes: stare at the sun Sikivie; …. Sun Detector a γ strong B -field SHIPS, CAST, SUMICO, IAXO, … Need large magnets, sensitive detectors

How to look for Axion and ALPs? Best probes from ɣ -axion/ALP conversion Resonant Cavities with Large Magnetic Field Sikivie; …. a a assume tunable axions are γ a Resonant dark matter Cavity a ADMX, ADMX-HF, …

How look for low-mass A ʹ ? “Light-shining-through-walls” (cf. axions) A 0 γ γ x x LIPSS (Jlab) , BFRT (BNL), BMV (LULI), GammeV (Fermilab), ALPS (DESY), OSQAR (CERN), PVLAS (INFN), ... Need powerful lasers but no magnets

How look for low-mass A ʹ ? Helioscopes: stare at the sun (cf. axions) Okun, … Sun Detector A 0 γ x TSHIPS, CAST, SUMICO, IAXO, …

Dark Photons Recall: simplest Dark Sector consists of just an A ′ X Standard Model Dark Sector A 0 (massive) W ± , Z γ g Dark Sector can easily be more complicated, so must look for other signals too Example 2 : non-Abelian or dark-higgs