Maxim Yu. KhlopovMoscow Engineering and Physics Institute (State

University) Centre for Cosmoparticle physics “Cosmion”,

Moscow, Russiaand

VIA, APC Laboratory, Paris, France

Physical reasons for new stable quarks and/or leptons

Exotic forms of composite dark matter, their cosmological evolution and effects

Cosmic-ray and accelerator search for charged components of composite dark matter

TT

DM

baryonst

Cosmological Dark Matter explains:• virial paradox in galaxy clusters,• rotation curves of galaxies• dark halos of galaxies• effects of macro-lensingBut first of all it provides formation of galaxies from small densityfluctuations, corresponding to the observed fluctuations of CMB

To fulfil these duties Dark Matter should interact sufficiently weakly with baryonic matter and radiation and it should be sufficiently stable on cosmological timescale

2Pl

PlmM mm

However, if charged particels are heavy, stable and bound within neutral « atomic » states they can play the role of composite Dark matter.

Physical models, underlying such scenarios, their problems and nontrivial solutions as well as the possibilities for their test are the subject of the present talk.

By definition Dark Matter is non-luminous, while charged particles are the source of electromagnetic radiation. Therefore, neutral weakly interacting elementary particles are usually considered as Dark Matter candidates. If such neutral particles with mass m are stable, they freeze out in early Universe and form structure of inhomogeneities with the minimal characterstic scale

ComponentsComponents of composite dark of composite dark matter:matter:

• Tera-fermions E and U of S.L.Glashow’sTera-fermions E and U of S.L.Glashow’s• Stable U-quark of 4-th familyStable U-quark of 4-th family•AC-leptons from models, based on almost AC-leptons from models, based on almost commutative geometrycommutative geometry•Techniparticles of Walking Technicolor Techniparticles of Walking Technicolor ModelsModels

6vevvev

UE D

e u d

mm m Sm m m

EN

DU

Very heavy and unstableVery heavy and unstable

m~500 m~500 GeVGeV, , stablestable

m~3 m~3 TeVTeV, , ((metameta))stablestable

m~5 m~5 TeVTeV, , D D U +… U +…

SU(3)xSU(2)xSU(2)xU(1)SU(3)xSU(2)xSU(2)xU(1)Tera-fermionsTera-fermions ((N,E,U,DN,E,U,D) ) W’, W’, Z’Z’, , H’, H’, and g and g

101066

++ problem of CP-violation in QCDproblem of CP-violation in QCD ++ problem of neutrino problem of neutrino massmass

++ (?) (?) DM DM asas [( [(UUU)EEUUU)EE] tera-helium ] tera-helium (NO!)(NO!)

( ) 0.224UUUEE CDM

0.044b

To saturate the observed dark matter of the Universe Glashow assumed tera-U-quark and tera-electron excess generated in the early Universe.

The model assumes tera-fermion asymmetry of the Universe, which should be generated together with the observed baryon (and lepton) asymmetry

However, this asymmetry can not suppress primordial antiparticles, as it is the case for antibaryons due to baryon asymmetry

In the expanding Universe no binding or annihilation is complete. Significant fraction of products of incomplete burning remains. In Sinister model they are: (UUU), (UUu), (Uud), [(UUU)E], [(UUu)E], [(Uud)E], as well as tera-positrons and tera-antibaryons

Glashow’s hope was that at T<25keV all free E bind with protons and (Ep) « atom » plays the role of catalyzer, eliminating all these free species, in reactions like

pEEEpE

pEEUUUEpEUUU

][][

But this hope can not be realized, since much earlier all the free E are trapped by He

HE-cage for negatively charged HE-cage for negatively charged components of composite dark matter components of composite dark matter

– No go theorem for -1 charge – No go theorem for -1 charge componentscomponents

• If composite dark matter particles are « atoms », binding If composite dark matter particles are « atoms », binding positive P and negative E charges, all the free primordial positive P and negative E charges, all the free primordial negative charges E bind with He-4, as soon as helium is negative charges E bind with He-4, as soon as helium is created in SBBN.created in SBBN.• Particles E with electric charge -1 form +1 ion [E He]Particles E with electric charge -1 form +1 ion [E He]..• This ion is a form of anomalous hydrogenThis ion is a form of anomalous hydrogen..• Its Coulomb barrier prevents effective binding of positively Its Coulomb barrier prevents effective binding of positively charged particles P with E. These positively charged particles, charged particles P with E. These positively charged particles, bound with electrons, become atoms of anomalous istotopes bound with electrons, become atoms of anomalous istotopes • Positively charged ion is not formed, if negatively charged Positively charged ion is not formed, if negatively charged particles E have electric charge -2.particles E have electric charge -2.

4th family can follow from heterotic string phenomenology as naturally as SUSY.

GUT group has rank (number of conserved quantities) 6, while SM, which it must embed, has rank 4. This difference means that new conserved quantities can exist.

Euler characterics of compact manifold (or orbifold) defines the number of fermion families. This number can be 3, but it also can be 4.

The difference of the 4th family from the 3 known light generations can be explained by the new conserved quantity, which 4th generation fermions possess.

If this new quantum number is strictly conserved, the lightest fermion of the 4th generation (4th neutrino, N) should be absolutely stable.

The next-to-lightest fermion (which is assumed to be U-quark) can decay to N owing to GUT interaction and can have life time, exceeding the age of the Universe.

If baryon asymmetry in 4th family has negative sign and the excess of anti-U quarks with charge -2/3 is generated in early Universe, composite dark matter from 4th generation can exist and dominate in large scale structure formation.

6E

EN

DU

UUU UUU

m~50 m~50 GeVGeV, (, (quasiquasi))stablestable

100 100 GeVGeV <m<~1<m<~1 TeVTeV, , E ->N lE ->N l,…,… unstableunstable220 220 GeVGeV <m<~1<m<~1 TeVTeV, , U ->U -> N + light fermions N + light fermions Long-Long-living wihout mixing with light generationsliving wihout mixing with light generations220 220 GeVGeV <m<~1<m<~1 TeVTeV, , D ->D -> U lU l,… ,… unstableunstable

Precision measurements of SM parameters admit existence of 4th family, if 4th neutrino has mass around 50 GeV and masses of E, U and D are near their experimental bounds.If U-quark has lifetime, exceeding the age of the Universe, and in the early Universe excess of anti-U quarks is generated, primordial U-matter in the form of ANti-U-Tripple-Ions of Unknown Matter (anutium).

can become a -2 charge constituent of composite dark matter

4th neutrino with mass 50 GeV can not be dominant form of dark matter. But even its sparse dark matter component can help to resolve the puzzles of direct and indirect WIMP searches.

Cosmic positrons from 4th neutrino annihilation in Galaxy

4UUU He UUU He

oT I

131/ 2 10o He HeR ZZ m cm

But it goes only after He is formed at T ~100 keVThe size of O-helium is

2 2 2 1.6o He HeI Z Z m MeV

It catalyzes exponential suppression of all the remaining U-baryons with positive charge and causes new types of nuclear transformations

Example 1: Heavy quarksExample 1: Heavy quarksO-Helium formationO-Helium formation

Dominant forms of dark Dominant forms of dark mattermatter

O-helium looks like an alpha particle with shielded electric charge. It can closely approach nuclei due to the absence of a Coulomb barrier. For this reason, in the presence of O-helium, the character of SBBN processes can change drastically.

This transformation can take place if , 4, 2He oM A Z m I M A Z

, 4, 2A Z UUU He A Z UUU

This condition is not valid for stable nuclids, participating in SBBN processes, but unstable tritium gives rise to a chain of O-helium catalyzed nuclear reactions towards heavy nuclides.

After K-39 the chain of transformations starts to create unstable isotopes and gives rise to an extensive tree of transitions along the table of nuclides

Successive works by Pospelov (2006) and Kohri, Takayama (2006) revealed the uncertainties even in the roots of this tree.

The « Bohr orbit » value is claimed as good approximation by Kohri, Takayama, while Pospelov offers reduced value for this binding energy. Then the tree, starting from D is possible.

The self-consistent treatment assumes the framework, much more complicated, than in SBBN.

2 2 2 1.6o He HeI Z Z m MeV

1odT T keV

1RMT eV

Energy and momentum transfer from baryons to O-helium is not effective and O-helium gas decouples from plasma and radiation

O-helium dark matter starts to dominate

On scales, smaller than this scale composite nature of O-helium results in suppression of density fluctuations, making O-helium gas Warmer Than Cold (WTC) dark matter

1b p on v m m t

2

910PlRMod Pl

od od

mTM m MT T

74 10UUUHe

Galactic cosmic rays

destroy O-helium. This can lead to appearance of a free anutium component in cosmic rays.

Such flux can be accessible to PAMELA and AMS-02 experiments

Difference in rigidity provides discrimination of U-helium and nuclear component

In the reaction , 4, 2A Z UUU He A Z UUU

235 10or

The final nucleus is formed in the excited [He, M(A, Z)] state, which can rapidly experience αlpha decay, giving rise to (OHe) regeneration and to effective quasi-elastic process of (OHe)-nucleus scattering.

If quasi-elastic channel dominates the in-falling flux sinks down the center of Earth and there should be no more than

of anomalous isotopes around us, being below the experimental upper limits for elements with Z ≥ 2.

In underground detectors, (OHe) “atoms” are slowed down to thermal energies far below the threshold for direct dark matter detection. However, (OHe) destruction can result in observable effects. O-helium gives rise to less than 0.1 of expected background events in XQC experiment, thus avoiding severe constraints on Strongly Interacting Massive Particles (SIMPs), obtained from the results of this experiment.

It implies development of specific strategy for direct experimental search for O-helium.

Superfluid He-3 detectors are sensitive to energy release above 1 keV. If not slowed down in atmosphere O-helium from halo, falling down the Earth, causes energy release of 6 keV.

Even a few g existing device in CRTBT-Grenoble can be sensitive and exclude heavy O-helium, leaving an allowed range of U-quark masses, accessible to search in cosmic rays and at LHC and Tevatron

The proposed scenario is the minimal for composite dark matter. It assumes only the existence of a heavy stable U-quark and of an anti-U excess generated in the early Universe to saturate the modern dark matter density. Most of its signatures are determined by the nontrivial application of known physics. It might be too simple and too pronounced to be real. With respect to nuclear transformations, O-helium looks like the “philosopher’s stone,” the alchemist’s dream. That might be the main reason why it cannot exist.

However, its exciting properties put us in mind of Voltaire: “Se O-helium n’existai pas, il faudrai l’inventer.”

Their charge is not fixed and is chosen +-2 from the above cosmological arguments.

Their absolute stability can be protected by a strictly conserved new U(1) charge, which they possess.

In the early Universe formation of AC-atoms is inevitably accompanied by a fraction of charged leptons, remaining free. Free A form Ole-helium.

++ follows from unification of General Relativity and gauge follows from unification of General Relativity and gauge symmetries on the basis of almost commutative (AC) geometry symmetries on the basis of almost commutative (AC) geometry (Alain Connes) (Alain Connes)

++ DM DM ((AC AC ) “atoms”) “atoms”

Extension of Standard model by two new doubly charged « leptons »Extension of Standard model by two new doubly charged « leptons »

They are leptons, since they possess only They are leptons, since they possess only and Z (and new, y-) and Z (and new, y-) interactions interactions

Form neutral atoms (AC, O-helium,….)-> composite dark matter Form neutral atoms (AC, O-helium,….)-> composite dark matter candidates!candidates!

The ideas of Technicolor are revived with the use of SU(2) group for “walking” (not running ) TC gauge constant. U and D techniquarks transform under the adjoint representation of an SU(2) technicolor gauge group. The chiral condensate of the techniquarks breaks the electroweak symmetry. There are nine Goldstone bosons emerging from the symmetry breaking. Three of them are eaten by the W and the Z bosons. The remaining six Goldstone bosons (UU, UD, DD and their corresponding antiparticles) are technibaryons and corresponding techniantibaryons. The electric charges of UU, UD, and DD are given in general by y+1, y, and y-1 respectively, where y is an arbitrary real number.To cancel the Witten global anomaly model requires in addition the existence of a fourth family of leptons ( and ). Their electric charges are in terms of y respectively (1 - 3y)/2 and (-1 - 3y)/2.

If y=1, and UU is the lightest it has charge +2, while its stable antiparticle has charge -2.

In addition for y = 1, the electric charges of and are respectively -1 and -2.

If TB is conserved, is the main constituent of composite dark matter.

If L’ is conserved, composite dark matter is provided by

Their mixture if both the technilepton number L’ and are TB conserved.

The advantage of WTC framework is that it provides definite relationship between baryon asymmetry and techniparticle excess.

Here are statistical factors in equilibrium relationship between, TB, B, L and L’

L’=0, T*=150 GeV =0.1; 1; 4/3; 2; 3

L’=0, T*=150, 200, 250 GeV

x denotes the fraction of dark matter given by the technibaryon

TB<0, L’>0 – two types of -2 charged techniparticles.

The case TB>0, L’>0 (TB<0, L’<0 ) gives an interesting possibility of (-2 +2) atom-like WIMPs, similar to AC model. For TB>L’ (TB<L’) no problem of free +2 charges

Even minimal, WTC model gives a wide variety of possibilities for composite dark matter scenario.

It provides relationship between baryon asymmetry and dark matter.

It makes possible Warmer Than Cold DM (techni-O-helium)

Techni-O-helium is necessary (and even dominant) element of such scenarios

In underground detectors equilibrium concentration of O-helium is reached at a timescale of a day. Therefore it should possess annual modulations due to Earth’s motion. The inelastic process

changes the charge of the nucleus (A,Z) from Z to (Z-2) with the corresponding change of electronic 1S levels. It results in ionization energy

which is about 2 keV for I and 4 keV for Tl.This inelastic process does not lead to phonon effect in CDMS and thus can be masked as background in direct searches for WIMPs

Invisble decay of Higgs bosonInvisble decay of Higgs boson H H ->-> NNNN

Search for unstable quarks and Search for unstable quarks and leptons of new families are well leptons of new families are well elaboratedelaborated..

Search for Search for 4-4-thth generationgeneration on LHCon LHC

Uud

Uud

dU~

0~uU

0~uU

sU~

duU ~~~

0~uU

Mesons

Baryons

MU

+0.2

+0.4

+0.6

GeV

Usu 0Usd

Uud Uuu Udd

,l

e

)( U

)( 0/M

The same for U-hadrons

dU~ dU~

sU~ sU~

0/~~~ qsU

0/Usq

8%

40%

40%

12%

~1%

Yields of U-hadrons in ATLAS

/0/0 ~~ MM

/0~~ MU UU UM /0

Particle transformation during propagation through the detector material

This signature is substantially different from that of R-hadrons

S. Helman, D. Milstead, M. Ramstedt, ATL-COM-PHYS-2005-065

Muon detector

ID&EC&HC

U-hadron does not change charge (+) after 1-3 nuclear interaction lengths (being in form of baryon)

U-hadron changes its charge (0-) during propagation through the detectors (being in form of meson)

,...~~ /0 MNU

,...~~ /0/0 NMNM

,...~ NNU

,.../0 NNMNU

,.../0/0 NMNM

,... U

sU~ UsuUsd 0

U-baryon will be converted into U-meson

U-mesons will experience inter-conversion

U-baryon will not be converted

U-mesons will experience inter-conversion and convert to U-baryon

Strange U-hadrons will get the form and

suppressedsuppressed

“+” - 60%“0” - 40%“-” - 60%“0” - 40%

U-quark registration efficiency: effect of the detector acceptance (-

2.5<η<2.5)

*

* E4 is unstable

(U) vs (U)_

*) A.C.Kraan, J.B.Hansen, P.Nevski SN-ATLAS-2005-053

0.5 TeV

2 TeV

U-quark registration efficiency: effect of beta-cut >0.7*) (muon-trigger efficiency)

U

from DY+jet

from DY

from DY

from DY

from DY+jet

from DY+jet

U

U

PT, GeV

2 TeV

0.5 TeV

1 TeV

from ttblνX (T2 background (T2 background sample sample of ROME dataof ROME data))

PT, GeV

from ZZ4 (Pythia & ATLFAST(Pythia & ATLFAST))

Background distributionBackground distributionT2 ROME dataT2 ROME data

0.5 TeV

1 TeV

2 TeV

P, GeVη

P, GeV η

In the context of composite dark matter search for new (meta)stable quarks and leptons acquires the meaning of crucial test for its basic constituents

The level of abscissa axis corresponds to the minimal level of LHC sensitivity during 1year of operation

• Composite dark matter and its basic Composite dark matter and its basic constituents are not excluded either by constituents are not excluded either by experimental, or by cosmological arguments experimental, or by cosmological arguments and are the challenge for cosmic ray and and are the challenge for cosmic ray and accelerator search accelerator search • Small fraction or even dominant part of Small fraction or even dominant part of composite dark matter can be in the form of composite dark matter can be in the form of O-helium, catalyzing new form of nuclear O-helium, catalyzing new form of nuclear transformationtransformation• The program of test for composite dark The program of test for composite dark matter in cosmoparticle physics analysis of matter in cosmoparticle physics analysis of its signatures and experimental search for its signatures and experimental search for stable charged particles in cosmic rays and at stable charged particles in cosmic rays and at accelerators is availableaccelerators is available