Axel Lindner, DESY An experimental Expedition into a new Particle Habitat at smallest Masses Cosmology Meets Particle Physics, DESY Theory Workshop, 28

Axel Lindner, DESY

An experimental Expeditioninto a new Particle Habitat

at smallest Masses

Cosmology Meets Particle Physics, DESY Theory Workshop, 28 September 2011

Axel Lindner | Cosmology meets Particle Physics | 28 Sept. 2011 | Page 2

The next 40 Minutes …> A collection of open questions

Phenomena in astrophysics

Understanding today‘s Universe

>What theory tells Weakly Interacting Sub-eV Particles: WISPs

> Selection of experiments searching for WISPs Astrophysics

Laboratory

Present Status of WISP seaches and future experiments

>Outlook and summary


corona

16 MK

5800 K

Open Questions: the Sun>Do we understand our Sun?

The solar corona heating

http://eo.nso.edu/MrSunspot/solarzoo/coronazoo.html

How is energy transferred into the corona?

Courtesy of K. Zioutas


Open Questions: the Sun> The Sun

X-ray spectra

How can one understand the X-ray emission, especially of the quite sun?Is there a new mechanism transporting energy from the core to the surface?

Courtesy of K. Zioutas


Open Questions: white Dwarfs>White dwarfs

Old burned-out stars.

Final stage of 97% of all stars.

Mass < 1.4 Msun

Thermally cooling down to black dwarfs(takes longer than the age of the Universe).

>Most simple star one could think of! Composition

Physics

htt

p:/

/un

ive

rse

-re

vie

w.c

a/I

08

-25

-wh

ited

wa

rf.jp

g

htt

p:/

/ph

ysic

s.u

ore

go

n.e

du

/~jim

bra

u/a

str1

22

/No

tes/

Ch

ap

ter2

0.h

tml


Open Questions: white Dwarfs>White dwarfs cool too fast!

Observed in individual cases.

Seen in samples.

> Is there an unknown energy loss channel at work? Emission of axions?

White dwarfs as physical laboratories: the axion case (J. Isern), 7th Patras Workshop on Axions, WIMPs and WISPs,http://axion-wimp.desy.de


Detection of BSM Physics in WD?

htt

p:/

/ww

w.in

dia

na

.ed

u/~

ge

ol1

05

/ima

ge

s/g

aia

_ch

ap

ter_

1/w

hite

-dw

arf

.jpg


Open Questions: Dark Matter>Dark matter

The axion was not invented to solve the Dark Matter problem!

H. Baer, presentation at 5th Patras Workshop on Axions, WIMPs and WISPs, 2009

Due to their non-thermal production in the universe light axions would constitute

cold dark matter.

Such axions couple extremely weakly to matter:the “invisible” axion.


Open Questions: TeV Propagation

TeV photons should be absorbed by e+e- pair production due to interaction with the extragalactic background light (EBL):TeV + eV → e+ + e-

However, the TeV spectra of distant galaxies do hardly show any absorption.

M. Meyer, 7th Patras Workshop on Axions, WIMPs and WISPs, 2011






TeV photons may “hide”





A new axion-like particle (ALP) could solve this issue.



Open Questions: Dark Energy>Dark energy drives the Universe apart.

> Is it real?



> Is it real?

http

://w

ww

.sof

tcom

.net

/use

rs/g

reeb

o/la

ugh.

htm

"Shhhh. That's the theoretical physicists' new particle uniform.If you can't see it, you won't be allowed to graduate."



> Is it real?

> If yes, it might be attributed to a new kindof scalar field corresponding to very light particles.

The cosmological constant problem,S. Weinberg, Rev. Mod. Phys. 61, 1–23 (1989)


Understanding the present Universe

> LHC probes the very early universe when it was very small, hot and dense.

> Dark energy was totally negligible at those times.

> Surprisingly, we understand the early universe from fractions of a second to minute scales better than today’s universe.

> Dedicated “low energy” experiments are required to get a clue on Dark Energy.

LHC

L. Verde, 6th PATRAS Workshop, 2010


Open Questions: Energy Scales>Neutrinos have masses

at the meV scale.

> The density of Dark Energyin our Universe is 10−29g/cm3, being equivalent to ρDE (2 meV)4

> Today‘s energy density of the universe is about (meV)4.

>Does this hint at BSM physics at the meV scale?

>We should strive for dedicated experiments to solve this issue!


Summary on open Questions> Very different phenomena may point at yet unknown particles:

Sun, white dwarfs, TeV transparency, dark matter and dark energy

ν-number excess in CMR data, polarization of light from distant quasars, vanishing electric dipole moment of the neutron, …

>None of these observations is really significant yet and / or a real contradiction to Standard Model physics. However, the number of observations is puzzling!

>New experiments (PLANCK, CTA) will improve experimental data, hopefully clarifying the situation.

Besides waiting for such new data:

> Is there a theoretical scenario combining (most of) the puzzling observations?

>How can one search with dedicated experiments for new low mass particles?







Laboratory




.

What Theory tells …

… should not be presented by an experimentalists …

… looks like bringing owls to Athens here …

So only some very brief remarks!

http

://w

ww

.gut

enbe

rg.o

rg/fi

les/

2039

2/20

392-

h/im

ages

/411

.png


A hidden sector of particle physics could exist very well:

These particles would be uncharged with respect to electroweak and strong interactions and hence appear to be “dark”.

> The unification of forces requires extended gauge structures which led to singlets charged under some new gauge group. Thus GUTs or string theories can‘t avoid a hidden sector.



A hidden sector of particle physics could exist very well:

These particles would be uncharged with respect to electroweak and strong interactions and hence appear to be dark.

> The unification of forces requires extended gauge structures which led to singlets charged under some new gauge group. Thus GUTs or string theories can‘t avoid a hidden sector.

>Gauge hierarchy problem:how could one understand the huge difference between the electroweak scale of 102 GeV and the Planck scale of 1019 GeV? A hidden sector introducing a dynamical SUSY breaking could take care for this.

> There could be complex physics within the hidden sector with new forces and charges.



Particles from a hidden sector could interact in different manners with Standard Model particles:

> By gravitation (dark matter in the universe).

> By heavy messengers charged under the Standard Model and the hidden sector.

> Standard Model particles could be charged also under the hidden sector. This would result in fifth forces.



A new Particle Habitat?> Probably (some / most of ?) the “open question” phenomena point at

physics beyond the Standard Model.

> There could be a hidden sector of very Weakly Interacting sub-eV Particles (WISPs): Axion

Axion-like particles ALPs

Hidden photons

Mini-charged particles

Chameleons

…

> Such a new habitat is motivated by theory and observations

>How to search for such a new particle habitat at low masses?







Laboratory




Seeing the “Invisible”: Primakoff Effect

> Axion and axion-like particles (ALPs):exploit the coupling to photons.

> photon + photon ↔ ALPphoton + ALP → photon

> photon + (virtual photon) → ALPALP + (virtual photon) → photon

A virtual photon can be provided byan electromagnetic field.

The Search for Axions, Carosi, van Bibber, Pivovaroff, Contemp. Phys. 49, No. 4, 2008


Seeing “invisible” WISPs>Neutral scalar or pseudoscalar WISPs: exploit the Primakoff effect

>Neutral vectorbosons (“hidden sector photons” HP): exploit mixing with “ordinary” photons.


Seeing “invisible” WISPs>Neutral scalar or pseudoscalar WISPs: exploit the Primakoff effect


>Minicharged particles (MCP, about 10-6 e): “loop effects”.


>Neutral scalar or pseudoscalar WISPs: exploit the Primakoff effect


>Minicharged particles (MCP, about 10-6 e): “loop effects”.

Seeing “invisible” WISPs

Axion-Like Particles, Hidden Photons, MiniCharged Particles


“Invisible” WISPs in Astrophysics

> Indirect:WISPs would open up new energy loss channels for hot dense plasmas stringent limits on WISP characteristics from the lifetime of stars, length of neutrino

pulse from SN and cosmic microwave background radiation for example.

>Direct: Search for axions

from the sun(CAST at CERN)

The

Sea

rch

for A

xion

s, C

aros

i, va

n B

ibbe

r, P

ivov

arof

f, C

onte

mp.

Phy

s. 4

9, N

o. 4

, 200

8





>Direct: Search for hidden

photons from the sun(SHIPS in Hamburg)

Search for halo dark matter axions(ADMX in the US)

The

Sea

rch

for A

xion

s, C

aros

i, va

n B

ibbe

r, P

ivov

arof

f, C

onte

mp.

Phy

s. 4

9, N

o. 4

, 200

8




>Direct: Search for axions

from the sun(CAST at CERN)

Search for halo dark matter axions(ADMX in the US)


http

://w

ww

.phy

s.w

ashi

ngto

n.ed

u/gr

oups

/adm

x/ho

me.

htm

lhtt

p://

cast

.web

.cer

n.ch


Okun 1982, Skivie 1983, Ansel‘m 1985, Van Bibber et al. 1987

“Invisible” WISPs in the Laboratory

“Light-shining-through-a-wall” (LSW)

G. Ruoso et al. (BFRT Experiment),Z. Phys. C 56 (1992) 505

Note:PΦ g4

g g


q = pγ – pΦ

l: length of B field

Axion Production in a magnetic Field

> The production (and re-conversion) of WISPs takes place in a coherent fashion.

For ALPs (Φ):

With PΦ = PΦ = P: g = (P)1/4 · 2 · / (l·B) / F1/2

Please take note: P(B field) / P(beam dump) = 106·(mm/λabs)·(B/T)2·(L/m)2

(A. Ringwald, J. Redondo, arXiv:1011.3741v1 [hep-ph])


ALPS @ DESY in Hamburg

ALPSPETRA III

FLASH

European XFEL

DORIS III

ALPS-II

In the HERA tunnel?

OLYMPUS

PETRA III-Extension

PETRA III-ExtensionFL

AS

H II


The ALPS Experiment

Any Light Particle Search @ DESY

Laser Container HERA Magnet Detektor

“Light-shining-through-a-wall” (LSW)


The ALPS Experiment

Any Light Particle Search @ DESY

A photon regeneration experiment

• DESY

• Max Planck Institute for Gravitational Physics (Albert Einstein Institute), and Institute for Gravitational Physics, Leibniz University Hannover

• Laserzentrum Hannover

• Hamburger Sternwarte


The ALPS Experiment

>New: realize an optical resonator inside the HERA dipole!

Lock by adapting the laser frequency to the distance fluctuations between the mirrors.

Lock by adapting the distance between the mirrors to the variations of the laser frequency.


ALPS Results(PLB Vol. 689 (2010), 149, or http://arxiv.org/abs/1004.1313)

>Unfortunately, no light is shining through the wall!

laser hut HERA dipole detector

3.5·1021 1/s < 10-3 1/s


ALPS Results

(PLB Vol. 689 (2010), 149, or http://arxiv.org/abs/1004.1313)

> ALPS is the most sensitive experiment for WISP searches in the laboratory.

pseudoscalarand

scalaraxion-like particles

hidden sector photonsand

minicharged particles

Filling a gap remaining from astrophysics and

other experiments!

PLB

689

(20

10),

149


Axion-like Particle Status

> Present experiments are hardly sensitive enough to probe forthe open questions discussed before.

> An ALP with a coupling around 10-11GeV-1 could be Dark Matter and solve the TeV transparency as well as the white dwarf riddles!

Work in progress by P. Arias, M. Goodsell, J. Jaeckel, J. Redondo and A. Ringwald

preliminary


Hidden Photon Status

> Present experiments are only partly sensitive enough to probe forthe hidden photon dark matter.

>Hidden photons with a mixing around 10-9 could be interesting!

Work in progress by P. Arias, M. Goodsell, J. Jaeckel, J. Redondo and A. Ringwald

prelim

inary


An Outlook to future Experiments

(my arbitrary selection)

> Light-shining-through-a-wall: ALPS-II

New possibilities at synchrotron radiation sources?

> Searching for WISPs from the sun: Axion and axion-like particles, chameleons

Hidden photons

>Novel dark matter searches utilizing HERA dipoles for example(work in progress, not covered here).


Prospects for ALPS-II @ DESY> Laser with optical cavity to recycle laser power,

switch from 532 nm to 1064 nm, increase effective power from 1 to 150 kW.

>Magnet:upgrade to 12+12 straightened HERA dipoles instead of ½+½ used for ALPS-I(LSW with straightened HERA dipoles cannot be surpassed by LSW with LHC dipoles!).

>Regeneration Cavity to increase WISP-photon conversions, single photon counter (transition edge sensor?).

laser hutH

ER

A dipole

detectorA

ll se

t up

in a

cle

an e

nviro

nmen

t!


> Search for“hidden photons”:

The ALPS-II Potential

prelim

inary


> Search for axion-like particles:

The ALPS-II Potential

preliminary


LSW at Synchrotron Sources

> Light-shining-through-a-wall with X-rays


LSW at Synchrotron Sources

> Light-shining-through-a-wall with X-rays

> Fluxes of up to 1019 photons per second in dedicated beamlines would allow to probe for Dark Energy chameleons in the laboratory!

Work in progress by P. Brax, A.L., K. Zioutas


WISPs from the Sun

>New Generation Axion Haloscope (CAST successor)

I. Irastorza, 7th Patras Workshop on Axions, WIMPs and WISPs, 2011

preliminary


WISPs from the Sun

> Solar Hidden Photon Search (Toy SHIPS)

Tube will be mounted piggyback on an existing telescopeat the observatory Bergedorf(east of Hamburg).

Courtesy of M. Schwarz


WISPs from the Sun

> Solar Hidden Photon Search (Toy SHIPS)

Courtesy of J. Redondo

prelim

inary


WISPs from the Sun

> Solar Hidden Photon Search (SHIPS)

A future larger version in the HERMES-hall at HERA?


Summary I

> There is a wealth of phenomena in astrophysics hinting at the existence of a new particle habitat at low masses.

>Many extensions of the Standard Model expect such a habitat of WISPs. Theory is passing the verge of giving detailed guidelines for experiments and relations

of WISP searches to unifying theories.

>WISPs could solve different phenomena in one go: Axion(-like) particles: Dark Matter, TeV-transparency, white dwarfs, strong CP problem

Chameleons: Dark Energy, solar corona heating, X-ray spectra of the sun


Summary II

> There are many different experimental approaches to search for WISPs in astrophysics and the laboratory.

>WISP experiments benefit strongly from the infrastructure of labs like DESY: Re-use of HERA components.

“Parasitic” use of accelerator based light sources.

> The next generation of WISP experiments will reach parameter regions predicted by theory. The next decade will decide on the future of WISP physics.

>WISP physics nicely complements physics at the energy frontier. Understanding the present and the early Universe.


Summary II

> There are many different experimental approaches to search for WISPs in astrophysics and the laboratory.

>WISP experiments benefit strongly from the infrastructure of labs like DESY: Re-use of HERA components

“Parasitic” use of accelerator based light sources

> The next generation of WISP experiments will reach parameter regions predicted by theory. The next decade will decide on the future of WISP physics.

>WISP physics nicely complements physics at the energy frontier. Understanding the present and early Universe.

Expect surprises!

Documents

Axel Lindner, DESY An experimental Expedition into a new Particle Habitat at smallest Masses Cosmology Meets Particle Physics, DESY Theory Workshop, 28