Cosmological Constraints! on! Very Dark Photons

Transcription

1 Cosmological Constraints on Very Dark Photons Anthony Fradette work presented in AF, Maxim Pospelov, Josef Pradler, Adam Ritz : PRD Aug 204 (arxiv: ) Cosmo Chicago, IL

2 Plan Dark Photon review and motivation Very Dark Photon (VDP) thermal production VDP and Big Bang Nucleosynthesis VDP and Cosmic Microwave Background Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 2

3 Motivation Standard Model Dark Sector Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 3

4 Motivation Hello? Standard Model Dark Sector Portals Leading SM coupling to Neutral Hidden Sector Scalar Right-Handed neutrino U() O s H H LHN R B µ V µ Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 4

5 Motivation Hello? Standard Model Dark Sector Portals Leading SM coupling to Neutral Hidden Sector Scalar Right-Handed neutrino U() O s H H LHN R B µ V µ Dark Photon For m V m Z, only mixes kinetically with photons L Vint = apple 2 F µ V µ = eapplev µ J µ em L Vmass B. Holdom, Phys. Lett. B 66, 96 (986) Stueckelberg Higgs e 0 = applee e = apple 2 Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 5

6 Dark Photon Landscape 2 a µ a µ,fav WASA KLOE 4 a e E4 APEX/ MAMI BABAR U70 6 CHARM See Review from: Essig et al., Snowmass E37 LSND SN m V < 2m e m V (M ev ) m V > 2m e -6-6 Log e Log m Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 6

7 Very Dark Photon? 2 a µ a µ,fav WASA KLOE Can we use the Universe as a detector? 4 a e E4 APEX/ MAMI U70 BABAR 6 CHARM 8 E37 LSND SN m V (M ev ) 3 4 Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 7

8 Very Dark Photon? 2 a µ a µ,fav WASA KLOE Can we use the Universe as a detector? 4 a e E4 APEX/ MAMI U70 BABAR V ' 3 e m V =6 5 yr MeV m V 35 e 6 8 CHARM E37 LSND Recombination Very Dark SN -2 V [s] m V (M ev ) 3 4 Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 8

9 Very Dark Photon? 2 a µ a µ,fav WASA KLOE Can we use the Universe as a detector? 4 a e E4 APEX/ MAMI U70 BABAR V ' 3 e m V =6 5 yr MeV m V 35 e 6 8 CHARM E37 LSND Recombination Very Dark SN -2 Postma and Redondo, 2008 No explicit bounds derived 2 V [s] -6 BBN? Can it been seen on Earth? e + e prod e E 2 c.m. V cm CMB? 2 m V (M ev ) 3 4 Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 9

10 VDP Thermal Production Dominant contribution from coalescence sẏ = Y = n V s The Boltzmann equation Y i=l, l,v Z d 3 p i (2 ) 3 (N l N l N V )(2 ) 4 (4) (p l + p l p V ) X M 2E l l 2 i is modified because of darkness l l κ A µ V µ time Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette -

11 Abundance found by integrating the Boltzmann equation for the reaction in fig. VDP Thermal Production Thermal bath induces a resonant production through the photon self-energy Dominant contribution from coalescence Tranverse and longitudinal modes behave di erently The Boltzmann d 2 equation prod sẏ = Y = n V s m 4 v m 4 v dêdt à 3 mv 2 L mv 2 T 2 Subleading due to T r,t (L) & 8.m v,parametricallyhigher i=l, l,v Y Z d 3 p i (2 ) 3 2E i (N l N l N V )(2 ) 4 (4) (p l + p l p V ) X M l l 2 is modified than bulkbecause production of darkness [2] l l A µ V µ V not in equilibrium κ time Freeze-in production -8 0 transverse longitudinal dy v /dωdt (MeV -2 ) m v = MeV m v = 20 MeV d 2 Log(T r /m v ) 50 prod 30 ddt / m 4 V m 2 V L m 4 V m 2 V T T (MeV) Log(ω/m v ) Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette -

12 2 a µ WASA KLOE VDP Thermal Production 4 a e a µ,fav E4 APEX/ MAMI BABAR Basic QCD transition model Free meson gas Free quarks T c = 57 MeV 6 8 U70 CHARM E37 LSND SN E p.b. (ev) 0. total e + e - µ + µ - τ + τ - π + π - K + K - u/d + u/d - s + s - c + c - α eff = n V n b E p.b. (ev) Γ V - = 4 s m V (MeV) m V (M ev ) 3 4 Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 2

13 VDP and Big Bang Nucleosynthesis BBN is a good probe for New Physics Minimal assumptions b parameter : (Planck, WMAP) Pospelov and Pradler, 20 Provides constraints on any modification to nuclear reaction network e.g. energy injection from non-sm particle decays t/sec H Db.n. N SBBN f.o. ν dec. n/p dec. e ± ann. Y p D/H 3 He/H T/H 7 Be/H 7 Li/H 6 Li/H 00 0 T/keV p n p n D D p DD 3 He 7 Be 3 He D 4 He 3 He 4 He 3 He n 7 Be n m V < 2m Electromagnetic energy injection m V > 2m Hadronic energy injection DD2 T T D 4 He T 7 Li p 7 Li Opposing trends in Y V V Localized constraints in m V apple Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 3

14 VDP and Big Bang Nucleosynthesis Injection of e + e (µ + µ ) quickly transfers energy to photons via inverse Compton scattering + bgd e + e allowed for E & m 2 e/22t For smaller E, the energy is dissipated through photodestruction of nuclei t ph ' m V < 2m : EM energy injection 8 < : 2 4 s, 7 Be + 3 He + 4 He (.59 MeV), 5 4 s, D+ n + p (2.22 MeV), 4 6 s, 4 He + 3 He/T+n/p (20 MeV), Region Ia Reduction of 7 Li (3-4 x - ) Underproduction of D D/H =(2.53 ± 0.04) 5 3 He/D < Cooke et al., Ia Region Ib Increase of 6 Li by O(0) Not a constraint Region Ic Creation of 3 He ruled out by 3 He/D < Ib Ic 2 m V (M ev ) He 3 He/ D D/ H 7 Li/H 6 Li/H V /sec n V /n b Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 4

15 VDP and Big Bang Nucleosynthesis m V > 2m : Hadronic energy injection Simplified by considering long-lived mesons ±, K ±, KL 0 and (anti-)nucleons Important reactions κ Ia II III 4 He 3 He/D D/H 7 Li/H 6 Li/H τ V / sec n V /n b Charge exchange Lithium depletion + p 0 + n 7 Be + n 7 Li + p Ib Ic 7 Li + p 4 He + 4 He Region II 5 2 m V (MeV) Region III Short lifetime Extra neutrons from (before D-bottleneck) or indirect production Additional p $ n, n/p rises Lithium depletion Y p apple 0.26 Extra neutrons yield more D D/H apple 3 5 D/H apple V n n 4 Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 5

16 VDP and Cosmic Microwave Background The CMB is an integrated image over the recombination epoch Provides constraints on any modification to visibility function e.g. energy injection from non-sm particle decays eg.: Chen and Kamionkowski, 2004 Slatyer et al., 2009 Planck, 203 Partial reionization enhances late scatterings of CMB photons Washes out small scale TT correlation X e CDM m V = MeV, = 2x z Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 6 C TT l(l+)/2 e-09 9e- 8e- 7e- 6e- 5e- 4e- 3e- 2e- e- 0 m V = MeV, = 2x -7 CDM 0 00 l

17 VDP and Cosmic Microwave Background Generic constraints on decaying particle Energy output f eff Br e + e - µ + µ - π + π - total de dtdv =3 m p m V (MeV) e ionization heating Energy is not deposited right away For eg. Zhang et al., 2007 t Slatyer, 202 κ Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette Planck + WMAP 9 Pol WMAP 7 + SPT WMAP 3 Planck forecast (2007) [sec - ] Planck WMAP7 0 m V (MeV) τ V n v /n b

18 2 a µ WASA KLOE Summary 4 a e a µ,fav E4 APEX/ MAMI BABAR U70 The Universe is a great particle detector Minimal assumptions V T O( 00 MeV) Additional contributions can only strengthen constraints Present-day decays? Abundance falls short by many orders of magnitude (antimatter, gamma-ray, neutrino signals ) κ CMB BBN CHARM E37 LSND SN Planck 4 He 3 He/D D/H 7 Li/H m V (MeV) Cosmo Chicago, IL Cosmological Constraints on Very Dark Photons - Anthony Fradette - 8 8