IS DARK MATTER IS DARK MATTER COMPOSED OF STABLE COMPOSED OF STABLE CHARGED PARTICLES?CHARGED PARTICLES?

Maxim Yu. KhlopovMaxim Yu. Khlopov

Moscow Engineering and Physics Institute (State Moscow Engineering and Physics Institute (State University) and Centre for Cosmoparticle physics University) and Centre for Cosmoparticle physics

“Cosmion”“Cosmion”

Moscow, RussiaMoscow, Russia

OutlinesOutlines• Cosmological reflections of particle Cosmological reflections of particle

symmetry symmetry

• Physical reasons for new stable Physical reasons for new stable quarks and/or leptonsquarks and/or leptons

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

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

Basic ideas of cosmoparticle physics in Basic ideas of cosmoparticle physics in studies of New Physics, underlying Modern studies of New Physics, underlying Modern

CosmologyCosmology

• Physics beyond the Standard model can be studied in combination of indirect Physics beyond the Standard model can be studied in combination of indirect physical, astrophysical and cosmological effectsphysical, astrophysical and cosmological effects

• New symmetries imply new conserved charges. Strictly conserved charge implies New symmetries imply new conserved charges. Strictly conserved charge implies stability of the lightest particle, possessing it.stability of the lightest particle, possessing it.

• New New stable particlesstable particles should be present in the Universe. Breaking of new should be present in the Universe. Breaking of new symmetries implies cosmological symmetries implies cosmological phase transitionsphase transitions. Cosmological and . Cosmological and astrophysical constraints are supplementary to direct experimental search and astrophysical constraints are supplementary to direct experimental search and probe the fundamental structure of particle theory probe the fundamental structure of particle theory

• Combination of physical, cosmological and astrophysical effects provide an over-Combination of physical, cosmological and astrophysical effects provide an over-determined system of equations for parameters of particle theorydetermined system of equations for parameters of particle theory

COSMOlogyCOSMOlogy PARTICLE PARTICLE PHYSICSPHYSICS

New physicsPhysical scale

Extremes of physical knowledge converge in the mystical Uhrohboros wrong circle of problems, which can be resolved by methods of Cosmoparticle physics

Cosmological Reflections of Cosmological Reflections of Microworld StructureMicroworld Structure

• Dark Matter should be present in the modern Dark Matter should be present in the modern Universe, and thus be stable on cosmological scale. Universe, and thus be stable on cosmological scale. This stability reflects some Conservation Law, which This stability reflects some Conservation Law, which prohibits DM decay. Following Noether’s theorem this prohibits DM decay. Following Noether’s theorem this Conservation Law should correspond to a (nearly) Conservation Law should correspond to a (nearly) strict symmetry of microworld. Indeed, all the strict symmetry of microworld. Indeed, all the particles - candidates for DM reflect the extension of particles - candidates for DM reflect the extension of particle symmetry beyond the Standard Model.particle symmetry beyond the Standard Model.

• In the early Universe at high temperature particle In the early Universe at high temperature particle symmetry was restored. Transition to phase of symmetry was restored. Transition to phase of broken symmetry in the course of expansion is the broken symmetry in the course of expansion is the source of topological defects (monopoles, strings, source of topological defects (monopoles, strings, walls…).walls…).

Cosmological Dark MatterCosmological Dark Matter

T

T

DM

baryons

t

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

Dark Matter – Cosmological Dark Matter – Cosmological Reflection of Microworld Reflection of Microworld

StructureStructure Dark Matter should be present in the Dark Matter should be present in the

modern Universe, and thus is stable on modern Universe, and thus is stable on cosmological scale.cosmological scale.

This stabilty reflects some Conservation This stabilty reflects some Conservation Law, which prohibits DM decay.Law, which prohibits DM decay.

Following Noether’s theorem this Following Noether’s theorem this cosnservation law should correspond to cosnservation law should correspond to a (nearly) strict symmetry of microworlda (nearly) strict symmetry of microworld

Dark Matter CandidatesDark Matter Candidates• Massive neutrinos (m<1eV, M>46 GeV) probably exist but Massive neutrinos (m<1eV, M>46 GeV) probably exist but

they can be only a subdominant DM component they can be only a subdominant DM component • LSSP, mostly neutralino, though even stop is possible (SUSY LSSP, mostly neutralino, though even stop is possible (SUSY

– solution for divergence of Higgs mass)– solution for divergence of Higgs mass)• Invisible axion (Solution for strong CP violation in QCD)Invisible axion (Solution for strong CP violation in QCD)• Mirror matter (Solution for equivalence of L and R Mirror matter (Solution for equivalence of L and R

coordinate systems) – strictly symmetric to ordinary coordinate systems) – strictly symmetric to ordinary particles, and Shadow matter in more general asymmetric particles, and Shadow matter in more general asymmetric casecase

• Topological defects, Q-balls, PBHs, …Topological defects, Q-balls, PBHs, …

They follow from different extentions of Standard They follow from different extentions of Standard Model Model

and, in general, from physical viewpoint should co-and, in general, from physical viewpoint should co-exist.exist.

Therefore from physical viewpoint Dark Matter is most probably multi-component

Dark Matter from Charged Dark Matter from Charged Particles?Particles?

2

PlPl

mM m

m

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

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

Glashow’s tera-fermionsGlashow’s tera-fermions

E

N

D

U

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!)

6

vev

vevUE D

e u d

mm mS

m m m

Cosmological tera-fermion asymmetryCosmological tera-fermion asymmetry

( ) 0.224UUUEE CDM

0.044b

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

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

However, this asymmetry can not suppress primordial antiparticles, as

it is the case for antibaryons due to baryon asymmetry

(Ep) catalyzer(Ep) catalyzer

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

• Glashow’s hope was that at T<25keV all free E bind with Glashow’s hope was that at T<25keV all free E bind with protons and (Ep) « atom » plays the role of catalyzer, protons and (Ep) « atom » plays the role of catalyzer, eliminating all these free species, in reactions likeeliminating 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 from heterotic string 4th family from heterotic string

phenomenologyphenomenology • 4th family can follow from heterotic string phenomenology as naturally 4th family can follow from heterotic string phenomenology as naturally

as SUSY.as SUSY.• GUT group has rank (number of conserved quantities) 6, while SM, GUT group has rank (number of conserved quantities) 6, while SM,

which it must embed, has rank 4. This difference means that new which it must embed, has rank 4. This difference means that new conserved quantities can exist.conserved quantities can exist.

• Euler characterics of compact manifold (or orbifold) defines the number Euler characterics of compact manifold (or orbifold) defines the number of fermion families. This number can be 3, but it also can be 4.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 The difference of the 4th family from the 3 known light generations can be explained by the new conserved quantity, which 4th generation be explained by the new conserved quantity, which 4th generation fermions possess.fermions possess.

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

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

• IfIf baryon asymmetry in 4th family has negative sign and the excess of anti-UU 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

4-4-th familyth family

E

N

D

U

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

100 100 GeVGeV <m<~1<m<~1 TeVTeV, , E ->N lE ->N l,…,… unstableunstable

220 220 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 generations

220 220 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). UUU UUU can become a -2 charge constituent of composite

dark matter4th 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.

Stable neutrinoStable neutrino of 4th generation and of 4th generation and cosmic gamma backgroundcosmic gamma background

• Annihilation in Annihilation in Galaxy of even Galaxy of even small fraction of small fraction of primordial 4th primordial 4th generation generation neutrinos with neutrinos with mass 50 GeV can mass 50 GeV can provide explanation provide explanation for the EGRET data for the EGRET data from the center of from the center of Galaxy and from Galaxy and from galactic halo.galactic halo.

Stable neutrino of 4th generation and Stable neutrino of 4th generation and cosmic ray positrons and antiprotonscosmic ray positrons and antiprotons

• Annihilation in Galaxy Annihilation in Galaxy of even small fraction of even small fraction of primordial 4th of primordial 4th generation neutrinos generation neutrinos with mass 50 GeV can with mass 50 GeV can provide explanation for provide explanation for the HEAT data on the HEAT data on coamic postitrons and coamic postitrons and BESS data on cosmic BESS data on cosmic antiprotons, as well as antiprotons, as well as it can provide it can provide simultaneous simultaneous explanation for positive explanation for positive and negative results of and negative results of direct WIMP searchesdirect WIMP searches

4UUU He UUU He

But it goes only after He is formed at T ~100 keV

131/ 2 10o He HeR ZZ m cm

The size of O-helium is

2 2 2 1.6o He HeI Z Z m MeV oT I

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: alpha particle with O-Helium: alpha particle with zero chargezero charge

• O-helium looks like an alpha particle with shielded electric charge. It can closely 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 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.presence of O-helium, the character of SBBN processes can change drastically.

• This transformation can take place ifThis transformation can take place if

, 4, 2A Z UUU He A Z UUU

, 4, 2He oM A Z m I M A Z 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.

OHe catalysis of heavy element OHe catalysis of heavy element

production in SBBNproduction in SBBN

OHe induced tree of OHe induced tree of transitions transitions

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

Complicated set of problemsComplicated set of problems

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

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

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

2 2 2 1.6o He HeI Z Z m MeV

O-helium warm dark matterO-helium warm dark matter

1odT T keV • Energy and momentum Energy and momentum transfer from baryons to O-transfer from baryons to O-helium is not effective and O-helium is not effective and O-helium gas decouples from helium gas decouples from plasma and radiation plasma and radiation

• O-helium dark matter starts to O-helium dark matter starts to dominatedominate

• On scales, smaller than this On scales, smaller than this scale composite nature of O-scale composite nature of O-helium results in suppression helium results in suppression of density fluctuations, of density fluctuations, making O-helium gas more making O-helium gas more close to warm dark matterclose to warm dark matter

1b p on v m m t

1RMT eV

2

910PlRMod Pl

od od

mTM m M

T T

Anutium component of cosmic Anutium component of cosmic raysrays

74

10UUU

He

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

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

O-helium in EarthO-helium in Earth

• In the reactionIn the reaction

, 4, 2A Z UUU He A Z UUU

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

235 10or

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

O-helium experimental O-helium experimental search?search?• In underground detectors, (OHe) “atoms” are slowed down to In underground detectors, (OHe) “atoms” are slowed down to

thermal energies far below the threshold for direct dark matter thermal energies far below the threshold for direct dark matter detection. However, (OHe) destruction can result in observable detection. However, (OHe) destruction can result in observable effects.effects.

• O-helium gives rise to less than 0.1 of expected background O-helium gives rise to less than 0.1 of expected background events in XQC experiment, thus avoiding severe constraints on events in XQC experiment, thus avoiding severe constraints on Strongly Interacting Massive Particles (SIMPs), obtained from Strongly Interacting Massive Particles (SIMPs), obtained from the results of this experiment.the results of this experiment.

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

Superfluid He-3 search for O-Superfluid He-3 search for O-heliumhelium

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

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

O-helium Universe?O-helium Universe?

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

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

Example 2: AC-modelExample 2: AC-model

Mass of AC-leptons has « geometric origin ». Experimental constraint Mass of AC-leptons has « geometric origin ». Experimental constraint

We take m=100GeVWe take m=100GeV Their charge is not fixed and is chosen Their charge is not fixed and is chosen +-2+-2 from the above cosmological arguments. from the above cosmological arguments. Their absolute stability can be protected by a strictly conserved new U(1) charge, Their absolute stability can be protected by a strictly conserved new U(1) charge,

which they possess.which they possess.In the early Universe formation of AC-atoms is inevitably accompanied by a fraction In the early Universe formation of AC-atoms is inevitably accompanied by a fraction

of charged leptons, remaining free. of charged leptons, remaining free.

100A Cm m m GeV

++ 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

2S

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

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

Expected mass spectrum and physical properties of Expected mass spectrum and physical properties of heavy hadrons heavy hadrons containing (quasi)stable new quarkscontaining (quasi)stable new quarks..

Mesons

Baryons

Uud

dU~ 0~uU

MU

+0.2

+0.4

+0.6

GeV

sU~

Usu 0Usd

Uud Uuu Udd

,l

e

)( U

)( 0/M

The same for U-hadrons

Uud

0~uU duU ~~~

dU~ dU~

sU~ sU~

0/~~~ qsU

0/Usq

0~uU

8%

40%

40%

12%

~1%

Yields of U-hadrons in ATLAS

Expected physical properties of heavy hadrons Expected physical properties of heavy hadrons Possible signature.Possible signature.

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)

/0/0 ~~MM

UU UM /0

/0~~MU

,...~~ /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

suppressed

suppressed

“+” - 60%

“0” - 40%

“-” - 60%

“0” - 40%

Estimation of production cross sectionsEstimation of production cross sections

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

2.5<η<2.5)

*

* E4 is unstable

Beta-distribution of U-quarks as producedBeta-distribution of U-quarks as produced

(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)

Distribution of U in PDistribution of U in PT T as producedas produced

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))

P P vs ηη scatter plot

Background distributionBackground distribution

T2 ROME dataT2 ROME data

0.5 TeV

1 TeV

2 TeV

P, GeVη

P, GeV η

LHC discovery potential for components LHC discovery potential for components

of composite dark matterof composite dark matter

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

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

ConclusionsConclusions• 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

A possible regular interactive form of collaboration A possible regular interactive form of collaboration in cross-disciplinary study of fundamental in cross-disciplinary study of fundamental

relationship between micro- and macro-worldsrelationship between micro- and macro-worlds

International Virtual International Virtual Laboratory on Laboratory on astroparticle Physics -astroparticle Physics -