Hidden Photons in String Theory, in Cosmology, and in the Laboratory

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1 Hidden Photons in String Theory, in Cosmology, and in the Laboratory Andreas Ringwald DESY Theorietreffen, February 28, 211, Hamburg, D

2 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 1 Particle Cosmology in HH DESY T Staff members: Buchmüller, Lebedev, AR, Westphal, NN Research: Early Universe: inflation leptogenesis Dark Matter: WIMPs, superwimps, and decaying dark matter: top down motivation for gravitinos, hidden gauginos, axinos,... direct and indirect detection connection to collider searches WISPs: top down motivation for axions, hidden U(1)s,... astrophysical and cosmological probes phenomenology for local experiments

3 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 2 Hidden Sector in String Phenomenology In all major attempts to obtain the (Minimal Supersymmetric) Standard Model as a low energy limit of string theory, e.g. from the heterotic string, type II strings with D-branes, F-theory, there arises also a hidden sector of gauge bosons (and possibly matter particles) which interact with the visible sector only very weakly because there are no light messenger states charged under both gauge sectors

4 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 3 Hidden-Sector Abelian Gauge Bosons Direct effects associated with hidden sector unobservably small at low energies, since interactions between SM and hidden sector particles occur via operators of mass dimension n > 4 arising from integrating out messenger fields suppressed at low energies by powers (E/M s ) n 4 Notable exception: hidden-sector Abelian gauge bosons, arising in heterotic string theory from breaking the hidden E 8 gauge factor, type II/F theory as Kaluza-Klein zero modes of closed string form fields excitations of space-time filling D-branes wrapping cycles in the extra dimensions, because they can be massless or light (Higgs or Stückelberg mechanism) mix kinetically with the visible sector hypercharge U(1) gauge boson, corresponding to a mass dimension four term in the low energy effective

5 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 4 Lagrangian unsuppressed at low energies [Holdom 85] L 1 4 F (vis) µν F µν (vis) 1 4 F (hid) µν F µν (hid) + χ 2 F (vis) µν F (hid)µν + m 2 γ A (hid) µ A (hid)µ χ 1 generated at loop level via messenger exchange, 1 12 < χ g Y g h (16π) 2 f < 1 3 g h and f depend on the type of messenger: µ Va ν Vb

6 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 5 Predictions of hidden U(1)s from type II string compactifications: [Abel,Goodsell,Jaeckel,AR 8; Goodsell,Jaeckel,Redondo,AR 9; Cicoli,Goodsell,Jaeckel,AR in prep.] Hidden U(1) string phenomenology in HH DESY T: Cicoli, Goodsell, AR

7 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 6 Current constraints and phenomenologically interesting parameter ranges [Bartlett,.. 88; Kumar,.. 6; Ahlers,.. 7;...;Redondo,.. 8;Pospelov 8;Bjorken,Essig,Schuster,Toro 9;Jaeckel,.. 1;...] [Jaeckel,Redondo,AR 8;Arkani-Hamed,.. 8;Ibarra,AR,Weniger 8;...]

8 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 7 Signatures of a Hidden CMB?! [Jaeckel,Redondo,AR 8] Kinetic mixing of hidden photons with m γ γ γ oscillations Cosmic plasma induces an anomalous dispersion relation for photons, i.e. they acquire a plasma mass, ω 2 P = 4παn e/m e For mev masses, γ γ oscillations occur resonantly (m γ = ω P ) after BBN but before CMB decoupling, producing a hidden CMB, with x ρ γ /ρ γ (χ/1 6 ) 2, leading to an increase of the cosmic energy density in invisible radiation at decoupling, often quoted as the effective number of neutrino species, N ν eff ρrad total ρ γ ρ ν = NSM ν 1 x + x 1 x 8 7 ( ) 4/3 11 ;Nν SM =

9 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 8 Additional relativistic degrees of freedom at decoupling would enhance first two peaks/suppress third and higher acoustic peaks shift peak positions to higher l (smaller angular scales) in CMB angular power spectrum [Atacama Cosmology Telescope: Cosmological Parameters]

10 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 9 Additional relativistic degrees of freedom at decoupling would enhance first two peaks/suppress third and higher acoustic peaks shift peak positions to higher l (smaller angular scales) in CMB angular power spectrum Neff ν can be further constrained by adding constraints from baryon acoustic oscillations (BAO) and the Hubble constant H Observations seem to favor N ν eff > NSM ν = 3.46: this may be explained by mev mass hidden photon with χ 1 6 Data Neff ν x χ WMAP+BAO+H ACT+WMAP+BAO+H PLANCK: expect better sensitivity, N ν eff.7 stay tuned!

11 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 1 mev mass hidden photons can be searched for in light-shiningthrough a wall (LSW) experiment ALPS (Any Light Particle Search) [AEI Hannover, DESY, Hamburg Observatory, Laser Zentrum Hannover, Uni HH] γ γ γ γ ( ) L P(γ γ ) = 4χ 2 sin 2 L osc ; L osc = 4ω m 2 γ =.79 m ( ω ev ) ( mev m γ ) 2

12 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 11 Current ALPS limits on LSW exclude large portion of parameter space compatible with hidden photon explanation of Nν eff excess, but there is still room for it: [ALPS Collaboration 1]

13 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 12 ALPS upgrade: dedicated γ search in 212 in HERA Hall West higher laser power buildup (PB g 5) exploiting also resonant cavity behind the wall (PB r ) better detector prototype for future (> 214) large scale axion-like particles search experiment exploiting superconducting HERA dipoles

14 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 13 ALPS upgrade: dedicated γ search in 212 in HERA Hall West Projected sensitivity: 1 5 Coulomb LSW Sun 1 6 FIRAS hcmb Χ 1 7 ALPS m Γ ev Phenomenology for ALPS in HH DESY T: [Arias 11] Arias, AR

15 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 14 SHIPS (Solar Hidden Photon Search) may probe hidden CMB parameter space already in 211: [Hamburg Observatory, Uni HH, DESY] γ γ oscillations in the solar interior would lead to sizeable flux of solar hidden photons at Earth, [Redondo 8] dφ γ dω > cm 2 sev ( m γ.18 mev ) 4 ( χ for m γ <.1 ev, ω = 1 1 ev these solar hidden photons may be detected by their oscillation into photons inside a light-tight and evacuated tube, exploiting collecting optics and a sensitive photodetector magnetic field ) 2 ; detector photon axion oscillation Sun detector photon hidden sector photon

16 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 15 SHIPS (Solar Hidden Photon Search) may probe hidden CMB parameter space already in 211: [Hamburg Observatory, Uni HH, DESY] toyships presently being assembled and soon to be mounted on Oskar Lühning Telescope at Hamburg Observatory vacuum tube (2 m length, 26 cm diameter) 2 Fresnel lenses 2 photomultipliers

17 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 16 SHIPS (Solar Hidden Photon Search) may probe hidden CMB parameter space already in 211: [Hamburg Observatory, Uni HH, DESY] projected sensitivities of toyships and CAST: Χ m Γ' ev exploit predictions of solar γ flux also from photosphere Phenomenology for SHIPS in HH DESY T: [Redondo in prep.] [Cadamuro,Redonde 1 and in prep.] Arias, AR

18 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 17 Sub-GeV Scale Dark Forces?! MeV-GeV scale hidden photon (dark force, dark photon,...) may explain (g 2) µ anomaly, if χ [Pospelov 8] may explain [Arkani-Hamed et al. 8; Pospelov,Ritz 8; Morrissey et al. 9;...] terrestrial (DAMA, CoGeNT vs. CDMS, XENON) and cosmic ray (PAMELA, FERMI) DM anomalies if DM charged under hidden U(1) and χ 1 6 DM-nucleus scattering dominated by exchange of γ DM annihiliation dominated by DM + DM γ + γ can be searched for in new fixed-target experiments

19 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 18 Fixed-target experiments with intense electron beams particularly sensitive to MeV-GeV scale hidden photon [Heinemeyer,Kahn,Schmitt,Velasco 7; Reece,Wang 9; Bjorken,Essig,Schuster,Toro 9] Sizeable cross section of γ Bremsstrahlung: σ en enγ α3 Z 2 χ 2 m 2 γ 1 pb ( χ 1 5 ) 2 ( 1 MeV m γ Sizeable decay length of γ e + e, ( ) ( ) E ( 1 MeV l d = γcτ 8 cm GeV χ m γ ) 2 ) 2

20 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 19 Limits from beam dumps: [Bjorken,Essig,Schuster,Toro 9] SLAC E137: 3 C, 2 GeV, 2 m, 2 m SLAC E141:.3 mc, 9 GeV, 1 cm, 35 m Fermilab E774:.8 nc, 275 GeV (p), 3 cm, 7 m

21 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 2 HIPS (HIdden Particle Search): towards a new beam dump experiment at DESY II (1 na,.45 7 GeV)

22 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 21 HIPS (HIdden Particle Search): towards a new beam dump experiment at DESY II (1 na,.45 7 GeV) Current status: HIPS beam extraction chamber installed in Winter shutdown first measurements with scintillators beyond pure Pb beam dump last week; proper development of beam dump (target + shielding) started currently exploring if we can use H1 Spacal super module for calorimetry ZEUS MVD module for tracking (alternatives: SiLC module; MediTPC)

23 HIPS at DESY Il MR-8 dipole HIPS beam extraction chamber replaced in DESY Winter shutdown HIPS Test Setup HIPS carsten.niebuhr@desy.de

24 HIPS Detector Considerations dst dt Principle Setup dec dtr Ebeam 1 Spacal Details on the silicon sensors, their characteristics and performance are described in Section 2. Two sensors are glued together and one sensor is electrically connected to the other as shown in Figure 1, forming a half module. For various reasons we chose to orient the readout strips of the Pb While the sensors overlap by 4.8 mm, the sensifig. 1. Two silicon sensors are assembled into a half module; the two half modules are mounted on top of each other and form a full module Barrel modules two sensors within one half module perpendicular to each other as shown in Figure 1. A Cirlex [2] strip ( mm,.4 mm thick) glued at the edge in between the sensors, forms the mechanical connection between the two. The use of this material ensures a good insulation of the HV side of one sensor from the ground plane of the other one Support tube The MVD had to fit inside the inner cylinder of the Central Tracking Detector (CTD), a cylinder with a diameter of 324 mm. The only available support points are located at the forward and the rear side of the CTD, a span of 2 m. To make efficient use of the available space it was decided to install the MVD and the beampipe together; the support in two halves. then to beonmade has mounted the MVD Fig. 12.for Silicon sensors ladder The two half cylinders are joined together, provida stiff support for the whole assembly. During 4.3. Forwarding modules and after installation the weight of the beampipe has to be taken by external supports. weight Apart from The theirsupport shapetube theis silicon sensors covof light an assembly via flanges. to each half cylinders ering the forward regionconnected are similar to other the barrel layer is glued between honeycomb A 4 mm thick sensors as described in Section 2. Fourteen wedgetwo carbonfiber (.4 mm thick) sheets and preshaped sensors cover a circular plane around the formed on a cylindrical mold in an autoclave. Durbeampipe. Figure shows the geometry onetube of the and outsideof the inside process ing this14 ith a 25 µm thick aluminium layer for two sensors within one half module perpendicular to each other as shown in Figure 1. A Cirlex [2] strip ( mm,.4 mm thick) glued at the edge in between the sensors, forms the mechanical connection between the two. The use of this material ensures a good insulation of the HV side of one sensor from the ground plane of the other one.!" #$%&'() "* +$(,-.('(/') %',123 Super Module 12.4 cm Figure 2.4: 4)5' 67(8 9 '$( :%/;8%)< =&%>$(''7 #%?)7@('()* +$( /(??A %)( >)B&(< 75' AB&()C@<B?(A 87'$ D D /(??A 75 Alternatives: SiLC Module or MediTPC? HIPS H1 Spacal Super Module for calorimetry pointing to the inside of the HERA ring and the Y -axis pointing upwards. The barrel section, centered at the interaction point, is about 63 cm long. The silicon sensors are arranged in three concentric cylindric layers. As shown in Figure 8, approximately 25% of the azimutal angle is covered by only two layers due to limited space. The polar angular coverage for tracks with three hits ranges from 3 to 15. The modules in the forward section are arranged in four vertical planes extending the angular coverage down to 7 from the beam line. Exits for cables and cooling is arranged from the rear. Many details, design drawings and pictures can be found in [19]. pointing to the inside of the HERA ring and the Y -axis pointing upwards. The barrel section, centered at the interaction point, is about 63 cm long. The silicon sensors are arranged in three concentric cylindric layers. As shown in Figure 8, approximately 25% of the azimutal angle is covered by only two layers due to limited space. The polar angular coverage for tracks with three hits ranges from 3 to 15. The modules in the forward section are arranged in four vertical planes extending the angular coverage down to 7 from the beam line. Exits for cables and cooling is arranged from the rear. Many details, design drawings and pictures can be found in [19] Support tube The MVD had to fit inside the inner cylinder of the Central Tracking Detector (CTD), a cylinder with a diameter of 324 mm. The only available support points are located at the forward and the rear side of the CTD, a span of 2 m. To make efficient use of the available space it was decided to install the MVD and the beampipe together; the support for the MVD has then to be made in two halves. The two half cylinders are joined together, providing a stiff support for the whole assembly. During and after installation the weight of the beampipe has to be taken by external supports. The support tube is an assembly of light weight half cylinders connected to each other via flanges. A 4 mm thick honeycomb layer is glued between two carbonfiber (.4 mm thick) sheets and preformed on a cylindrical mold in an autoclave. During this process the inside and outside of the tube is covered with a 25 µm thick aluminium layer for electric shielding. Figure 9 shows a sketch of one half of the support tube. ZEUS MVD module for tracking 1cm 2 (?(/')5E$%<)5 A(&%)%'75 ')%5A6()A( A$8() &)!?(A* +$( /(?? <(&'$ 9 "G /@ 75 '$( z <7)(/'75 /))(A&5<75> ' "H*DH )%<7%'75?(5>'$(A 7A AB9!/7(5' 9) (?(/')@%>5('7/ A$8()A ' <(&A7' '$(7) 8$?( (5()>F B& '!I J(K 75A7<( '$( A(/'75* +$( B5/()'%75'F 9 '$( (5()>F A/%?( 7A A'B<7(<L 75 &%)'7/B?%)L 75 '$( 9)%@(8); 9 '$7A %5%?FA7A %5<?7(A 87'$75 I*GM %' /?BA'() (5()>7(A %:6( -H J(K %5< 75/)(%A(A B& ' "*GM %' G J(K NA(( A(/'* D*OP* +$( /%?)7@('() H*- I*" M E J(K -*I I*- M* %5< %?8 (Q/(?A 87'$ %5 (5()>F )(A?B'75 9 σ E 57A(?(6(? 9 %:B'! R(K* 3 $7>$ '7@( )(A?B'75 9?(AA '$%5-5A &()@7'A AB&&)(AA75 9 '$( :(%@ 75<B/(< :%/;>)B5<* " 16 cm carsten.niebuhr@desy.de

25 Example for Ebeam=3GeV and MVD Module x/y [cm] E=3. dt=36.4 N=1 dxt=6.2 drc=8 dec=18 dst=195 A=9 8 2nd tracker plane 6 E=3. dt=36.4 N=1 dxt=6.2 drc=8 dec= Spacal SM y2nd trk, yspacal [cm] zvtx (all/accepted) [cm] HIPS E E-2 4 decay vertices -6 ID Entries Mean RMS zvtx, z2nd trk, zspacal [cm] 8 RMoliere=2.55cm Invariant mass [GeV] x2nd trk, xspacal [cm] min(e-,e+) [GeV] carsten.niebuhr@desy.de

26 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 22 HIPS and planned dark forces attacks of our allies at JLab and MAMI: [Andreas,AR 1] Phenomenology for HIPS in HH DESY T: A. Ringwald (DESY) Andreas, Pla tzer, AR Hamburg, February 211

27 Hidden Photons in String Theory, in Cosmology, and in the Laboratory 23 Conclusions Hidden photons are strongly motivated from particle theory, particle phenomenology, particle cosmology, and astroparticle physics, e.g. theory: hidden sectors from string compactifications,... phenomenology: (g 2) µ,... cosmology: hidden CMB,... astroparticle physics: dark forces in direct and indirect DM searches,... Local low-energy particle physics experiments (ALPS, SHIPS, HIPS) have a large discovery potential for hidden photons Currently, DESY is on the WISP forefront both in theory and experiment Competitors (CERN, FNAL, MAMI, JLab,...) do not sleep: have to work hard in order to stay at forefront!