1. CANDIDATI DI MATERIA OSCURA DA NUOVA FISICA DELLE PARTICELLE
MATERIA OSCURA, BOLOGNA, 14 DICEMBRE, 2007
CANDIDATI DI MATERIA OSCURA DA NUOVA FISICA DELLE PARTICELLE
Antonio Masiero
Univ. di Padova
INFN, Padova

2. UNIFICATION of FUNDAMENTAL INTERACTIONS

3. THE G-W-S STANDARD MODEL

4. The HIGGS BOSON CONDENSATE
“SOMETHING” fills the Universe: it “disturbs” Weak interactions making them SHORT-RANGED, while it does NOT affect gravity or electromagnetism.
WHAT IS IT?
Analogy with SUPERCONDUCTIVITY: in a superconductor the magnetic field gets repelled ( Meissner effect) and penetrates only over the “penetration length”, i.e. the magnetic field is short-ranged source which disturbs are the boson condensates, Cooper pairs.
We are “swimming” in Higgs Boson Condensates its value at the minimum of its potential determines the masses of all particles!

5. Where all masses come from: the HIGGS mechanism
THE HIGGS MECHANISM CAN BE REALIZED BY THE PRESENCE OF AN ELEMENTARY HIGGS PARTICLE
The Higgs has already “shown up” as a VIRTUAL particle in electroweak radiative effects

6. INDICAZIONI DI NUOVA FISICA AL DI LA’ DEL MODELLO STANDARD
MASSA DEI NEUTRINI
ESISTENZA DI MATERIA OSCURA NON COSTITUITA DALLA “SOLITA” MATERIA (protoni, neutroni)
ASIMMETRIA COSMICA TRA MATERIA E ANTIMATERIA: ESISTENZA DI UNA NUOVA SORGENTE DI VIOLAZIONE DI CP OLTRE A QUELLA PREVISTA DAL MODELLO STANDARD
DOMANDE “FONDAMENTALI” A CUI IL MODELLO STANDARD NON RISPONDE:
- UNIFICAZIONE DELLE FORZE FONDAMENTALI
- MASSE E MESCOLAMENTI DEI FERMIONI
- “STABILITA’” DELLA SCALA DI ENERGIA A CUI I BOSONI W e Z PRENDONO MASSA ( circa 100 GeV)

7. MICRO MACRO PARTICLE PHYSICS COSMOLOGY HOT BIG BANG STANDARD MODEL
GWS STANDARD MODEL
HAPPY MARRIAGE
Ex: NUCLEOSYNTHESIS
POINTS OF
FRICTION
BUT ALSO
COSMIC MATTER-ANTIMATTER ASYMMETRY
INFLATION
- DARK MATTER + DARK ENERGY
“OBSERVATIONAL” EVIDENCE FOR NEW PHYSICS BEYOND THE (PARTICLE PHYSICS) STANDARD MODEL

8. THE ENERGY BUDGET OF THE UNIVERSE (as of Dec. 2007)

9. DM: the most impressive evidence at the “quantitative” and “qualitative” levels of New Physics beyond SM
QUANTITATIVE: Taking into account the latest WMAP data which in combination with LSS data provide stringent bounds on DM and B EVIDENCE FOR NON-BARYONIC DM AT MORE THAN 10 STANDARD DEVIATIONS!! THE SM DOES NOT PROVIDE ANY CANDIDATE FOR SUCH NON-BARYONIC DM
QUALITATIVE: it is NOT enough to provide a mass to neutrinos to obtain a valid DM candidate; LSS formation requires DM to be COLD NEW PARTICLES NOT INCLUDED IN THE SPECTRUM OF THE FUNDAMENTAL BUILDING BLOCKS OF THE SM !

10. THE RISE AND FALL OF NEUTRINOS AS DARK MATTER
Massive neutrinos: only candidates in the SM to account for DM. From here the “prejudice” of neutrinos of a few eV to correctly account for DM
Neutrinos decouple at ~1 MeV ; being their mass<<decoupling temperature, neutrinos remain relativistic for a long time. Being very fast, they smooth out any possible growth of density fluctuation forbidding the formation of proto-structures.
The “weight” of neutrinos in the DM budget is severely limited by the observations disfavoring scenarios where first superlarge structures arise and then galaxies originate from their fragmentation

11. LSS PATTERN AND NEUTRINO MASSES
(E..g., Ma 1996)
m = 0 eV
m = 1 eV
m = 7 eV
m = 4 eV

12. Cosmological Bounds on the sum of the masses of the 3 neutrinos from increasingly rich samples of data sets

13. TEN COMMANDMENTS TO BE A “GOOD” DM CANDIDATE
BERTONE, A.M., TAOSO
TO MATCH THE APPROPRIATE RELIC DENSITY
TO BE COLD
TO BE NEUTRAL
TO BE CONSISTENT WITH BBN
TO LEAVE STELLAR EVOLUTION UNCHANGED
TO BE COMPATIBLE WITH CONSTRAINTS ON SELF – INTERACTIONS
TO BE CONSISTENT WITH DIRECT DM SEARCHES
TO BE COMPATIBLE WITH GAMMA – RAY CONSTRAINTS
TO BE COMPATIBLE WITH OTHER ASTROPHYSICAL BOUNDS
“TO BE PROBED EXPERIMENTALLY”

14. WIMPS (Weakly Interacting Massive Particles)
# exp(-m/T)
# does not change any more
#~# m 
Tdecoupl. typically ~ m /20 
  depends on particle physics (annih.) and “cosmological” quantities (H, T0, …
10-3
 h2_ ~
<(annih.) V  > TeV2
From T0 MPlanck
~ 2 / M2 
h2 in the range to be cosmologically interesting (for DM)
m ~ GeV (weak interaction) h2 ~ !!!

15. INDICAZIONI DI NUOVA FISICA AL DI LA’ DEL MODELLO STANDARD
MASSA DEI NEUTRINI
ESISTENZA DI MATERIA OSCURA NON COSTITUITA DALLA “SOLITA” MATERIA (protoni, neutroni)
ASIMMETRIA COSMICA TRA MATERIA E ANTIMATERIA: ESISTENZA DI UNA NUOVA SORGENTE DI VIOLAZIONE DI CP OLTRE A QUELLA PREVISTA DAL MODELLO STANDARD
DOMANDE “FONDAMENTALI” A CUI IL MODELLO STANDARD NON RISPONDE:
- UNIFICAZIONE DELLE FORZE FONDAMENTALI
- MASSE E MESCOLAMENTI DEI FERMIONI
- “STABILITA’” DELLA SCALA DI ENERGIA A CUI I BOSONI W e Z PRENDONO MASSA ( circa 100 GeV)

16. LOW-ENERGY SUSY AND UNIFICATION

17. “MASS PROTECTION” For FERMIONS, VECTOR (GAUGE) and SCALAR BOSONS
FERMIONS chiral symmetry
fL fR not invariant
under SU(2)x U(1)
SIMMETRY PROTECTION
-VECTOR BOSONS gauge symmetry
FERMIONS and W,Z VECTOR BOSONS can get a mass only when the elw. symmetry is broken mf, mw ≤ <H>
NO SYMMETRY PROTECTION FOR SCALAR MASSES
“INDUCED MASS PROTECTION”
Create a symmetry (SUPERSIMMETRY)
Such that FERMIONS BOSONS
So that the fermion mass “protection” acts also on bosons as long
as SUSY is exact
SUSY BREAKING ~ SCALE OF 0 ( Gev)
LOW ENERGY SUSY

18. The Energy Scale from the “Observational” New Physics
neutrino masses
dark matter
baryogenesis
inflation
NO NEED FOR THE NP SCALE TO BE CLOSE TO THE ELW. SCALE
The Energy Scale from the “Theoretical” New Physics
Stabilization of the electroweak symmetry breaking at MW calls for an ULTRAVIOLET COMPLETION of the SM already at the TeV scale
CORRECT GRAND UNIFICATION “CALLS” FOR NEW PARTICLES AT THE ELW. SCALE

19. IS THE FINE-TUNING A REAL PROBLEM?
WARNING: THERE EXISTS AN EVEN “LARGER” HIERARCHY OR FINE -TUNING OR NATURALNESS PROBLEM: THE COSMOLOGICAL CONSTANT PROBLEM (“ THE MOTHER” OF ALL NATURALNESS PROBLEMS); SO FAR, WE SIMPLY “ACCEPT” SUCH FINE-TUNING!
(OUTRAGEOUS) POSSIBILITY: THE “THEORY OF EVERYTHING” COULD BE UNIQUE, BUT WITH MANY (INFINITE?) VACUA EACH GIVING RISE TO A DIFFERENT UNI-VERSE ( MULTI-VERSE POSSIBILITY). WE CAN LIVE ONLY IN THE VERY RESTRICTED CLASS OF THE “MULTI-VERSE SPACE” WHERE THE “BOUDARY CONDITIONS” ( FOR INSTANCE, THE VALUE OF THE COSMOLOGICAL CONSTANT OR THE SCALE OF THE ELW.SYMMETRY BREAKING AND, HENCE, THE HIGGS MASS) EXHIBIT VALUES ALLOWING FOR THE CORRECT BBN, LSS,… OUR LIFE!
ANTHROPIC PRINCIPLE

20. HOW TO COPE WITH THE HIERARCHY PROBLEM
LOW-ENERGY SUSY
LARGE EXTRA DIMENSIONS
DYNAMICAL SYMMETRY BREAKING OF THE ELW. SYMMETRY
LANDSCAPE APPROACH (ANTHROPIC PRINCIPLE)

21. STRADE PER ANDARE AL DI LA’ DEL MODELLO STANDARD
1) NON ESISTE NESSUNA SCALA DI ENERGIA OLTRE QUELLA DEL MS: la gravita’ e’ una forza molto debole perche’ esistono NUOVE DIMENSIONI oltre alle 3+1 spazio-temporali “nostre”
VISIBILITA’ A LHC: ESISTONO STATI ECCITATI ( DI KALUZA-KLEIN) ED ALCUNI SONO A SCALA ACCESSIBILE A LHC ( il piu’ leggero KK puo’ essere una particella stabile e costituire la materia oscura)

22. STRADE OLTRE SM (II)
2) NON ESISTE IL PROBLEMA DI “TRATTENERE” LA MASSA DEL BOSONE DI HIGGS A 100 GEV PERCHE’ L’HIGGS E’ UN OGGETTO COMPOSTO
VISIBILITA’ A LHC: NUOVE INTERAZIONI CHE PRODUCONO IL CONDENSATO DI FERMIONI CHE CHIAMIAMO HIGGS ( nuove risonanze, nuovi stati legati, una nuova QCD a 1 TeV)

23. STRADE OLTRE SM (III)
3) LA MASSA DELL’HIGGS E’ “PROTETTA” A 100 – 1000 GEV PERCHE’ ESISTE UNA NUOVA SIMMETRIA, LA SUPERSIMMETRIA
VISIBILITA’ A LHC: VEDREMO LE PARTICELLE SUPERSIMMETRICHE E LE LORO INTERAZIONI. LA PIU’ LEGGERA PARTICELLA SUSY PUO’ ESSERE STABILE E COSTITUIRE LA MATERIA OSCURA. AL TEMPO STESSO POTREMMO SCOPRIRE SUSY E LA SORGENTE DEL 90% DELLA MATERIA PRESENTE NELL’UNIVERSO

24. HIERARCHY PROBLEM: THE SUSY WAY
SUSY HAS TO BE BROKEN AT A SCALE CLOSE TO 1TeV LOW ENERGY SUSY
m2  2
Scale of susy breaking F B f f B F  
Sm2  ~( B - 2f ) 2
16 2
[m2 B - m2F ]1/2 ~ 1/√GF B
In SUSY multiplet F
SPLITTING IN MASS BETWEEN B and F of O ( ELW. SCALE)

25. IS SUSY PRESENT IN NATURE?
I think that it is very likely that SUSY is present as a fundamental symmetry of Nature: it is the most general symmetry compatible with a good and honest QFT, it is likely to be needed to have a consistent STRING theory ( super-string), in its local version ( local supersymmetry or supergravity) it paves the way to introduce and quantize GRAVITY in a unified picture of ALL FUNDAMENTAL INTERACTIONS
Much more debatable is whether it should be a LOW-ENERGY SYMMETRY ( i.e. effectively broken at the elw. Scale) or a HIGH-ENERGY SYMMETRY (i.e. broken at the Planck scale, or at the string compactification scale)

26. D. KAZAKOV

28. IN SUSY WE NEED TO INTRODUCE AT LEAST TWO HIGGS DOUBLETS IN ORDER TO PROVIDE A MASS FOR BOTH THE UP- AND DOWN- QUARKS

29. BREAKING SUSY The world is clearly not supersymmetric:
for instance, we have not seen a scalar of Q=1 and a mass of ½ MeV, i.e. the
selectron has to be heavier than the electron and, hence, SUSU has to be broken
SUSY HAS TO BE BROKEN AT A SCALE > 100 GeV
SINCE NO SUSY PARTNERS HAVE BEEN SEEN
UP TO THOSE ENERGIES, roughly
COLORED S-PARTICLE MASSES > 200 GeV
UNCOLORED S- PARTICLE MASSES > 100 GeV

30. WHICH SUSY F = (105 - 106) GeV F = MW MPl MESSENGERS GRAVITY
HIDDEN
SECTOR SUSY
BREAKING AT
SCALE F
F = ( ) GeV
F = MW MPl
GRAVITY
MESSENGERS
GAUGE INTERACTIONS
Mgravitino ~ F/MPl ~
( )eV
Mgravitino ~ F/MPl ~ ( ) GeV
OBSERVABLE
SECTOR
SM + superpartners
MSSM : minimal content
of superfields

31. THE FATE OF B AND L IN THE SM AND MSSM
IN THE SM B AND L ARE “AUTOMATIC” SYMMETRIES: NO B or L VIOLATING OPERATOR OF DIM.≤4 INVARIANT UNDER THE GAUGE SIMMETRY SU(3) X SU(2) X U(1) IS ALLOWED ( B AND L ARE CONSERVED AT ANY ORDER IN PERTURBATION THEORY, BUT ARE VIOLATED AT THE QUANTUM LEVEL (ONLY B – L IS EXACTLY PRESERVED )
IN THE MSSM, THANKS TO THE EXTENDED PARTICLE SPECTRUM WITH NEW SUSY PARTNERS CARRYING B AND L, IT IS POSSIBLE TO WRITE ( RENORMALIZABLE) OPERATORS WHICH VIOLATE EITHER B OR L
IF BOTH B AND L VIOLATING OPERATORS ARE PRESENT, GIVEN THAT SUSY PARTNER MASSES ARE OF O(TEV), THERE IS NO WAY TO PREVENT A TOO FAST PROTON DECAY UNLESS THE YUKAWA COUPLINGS ARE INCREDIBLY SMALL!

32. D. kAZAKOV

33. ADDITIONAL DISCRETE SYMMETRY IN THE MSSM TO SLOW DOWN P - DECAY
SIMPLEST (and nicest) SOLUTION: ADD A SYMMETRY WHICH FORBIDS ALL B AND L VIOLATING OPERATORS
R PARITY
SINCE B AND L 4-DIM. OPERATORS INVOLVE 2 ORDINARY FERMIONS AND A SUSY SCALAR PARTICLE, THE SIMPLEST WAY TO ELIMINATE ALL OF THEM:
R = +1 FOR ORDINARY PARTICLES
R = - 1 FOR SUSY PARTNERS
IMPLICATIONS OF IMPOSING R PARITY:
i) The superpartners are created or destroyed in pairs;
ii) THE LIGHTEST SUPERPARTNER (LSP) IS ABSOLUTELY STABLE

34. BROKEN R PARITY PROTON DECAY REQUIRES THE VIOLATION OF BOTH B AND L
NOT NECESSARY TO HAVE R PARITY TO KILL B AND L VIOLATING OPERATORS
ENOUGH TO IMPOSE AN ADDITIONAL DISCRETE SYMMETRY TO FORBID EITHER B OR L VIOLATING OPERATORS; RESTRICTIONS ON THE YUKAWA COUPLINGS OF THE SURVIVING B OR L VIOLATING OPERATORS

35. 124 FREE PARAM.
D. KAZAKOV

36. CMSSM + RADIATIVE ELW. BREAKING: A 4 – PARAMETER WORLD
FREE PARAM. IN THE CMSSM :
IMPOSING THE RAD. BREAKING OF THE ELW. SYMMETRY ONE ESTABLISHES A RELATION BETWEEN THE ELW. BREAKING SCALE AND THE SOFT SUSY PARAMETERS FURTHER REDUCING THE NUMBER OF THE FREE PARAM. IN THE CMSSM TO FOUR , FOR INSTANCE THE FIRST FOUR PARAM. ABOVE + THE SIGN OF µ ( THE ELW. SYMM. BREAKING FIXES ONLY THE SQUARE OF µ

37. A FEW % FINE-TUNING ON THE SUSY PARAM
A FEW % FINE-TUNING ON THE SUSY PARAM. IS NEEDED TO AVOID CONFLICT WITH SUSY AND HIGGS SEARCHES

38. SUSY & DM : a successful marriage
Supersymmetrizing the SM does not lead necessarily to a stable SUSY particle to be a DM candidate.
However, the mere SUSY version of the SM is known to lead to a too fast p-decay. Hence, necessarily, the SUSY version of the SM has to be supplemented with some additional ( ad hoc?) symmetry to prevent the p-decay catastrophe.
Certainly the simplest and maybe also the most attractive solution is to impose the discrete R-parity symmetry
MSSM + R PARITY LIGHTEST SUSY PARTICLE (LSP) IS STABLE .
The LSP can constitute an interesting DM candidate in several interesting realizations of the MSSM ( i.e., with different SUSY breaking mechanisms including gravity, gaugino, gauge, anomaly mediations, and in various regions of the parameter space).

39. STABLE ELW. SCALE WIMPs from PARTICLE PHYSICS
SUSY EXTRA DIM LITTLE HIGGS.
1) ENLARGEMENT OF THE SM
(x, ) (x, ji) SM part + new part
Anticomm New bosonic to cancel 2
Coord Coord at 1-Loop
2) SELECTION RULE
DISCRETE SYMM.
STABLE NEW PART.
R-PARITY LSP KK-PARITY LKP T-PARITY LTP
Neutralino spin 1/ spin spin0
mLSP
~ GeV *
3) FIND REGION (S) PARAM. SPACE WHERE THE “L” NEW PART. IS NEUTRAL + ΩL h2 OK
mLKP ~
GeV
mLTP ~
GeV
* But abandoning gaugino-masss unif Possible to have mLSP down to 7 GeV
Bottino, Donato, Fornengo, Scopel

40. WHO IS THE LSP? In CMSSM: the LSP neutralino is almost entirely a BINO
SUPERGRAVITY ( transmission of the SUSY breaking from the hidden to the obsevable sector occurring via gravitational interactions): best candidate to play the role of LSP:
NEUTRALINO ( i.e., the lightest of the four eigenstates of the 4x4 neutralino mass matrix)
In CMSSM: the LSP neutralino is almost entirely a BINO

41. GRAVITINO LSP? GAUGE MEDIATED SUSY BREAKING
(GMSB) : LSP likely to be the GRAVITINO ( it can be so light that it is more a warm DM than a cold DM candidate )
Although we cannot directly detect the
gravitino, there could be interesting signatures
from the next to the LSP ( NLSP) : for instance
the s-tau could decay into tau and gravitino,
Possibly with a very long life time, even of the order of
days or months

42. WIMPS escape the detector MISSING ENERGY SIGNATURE
SEARCHING FOR WIMPs
LHC, ILC may
PRODUCE WIMPS
WIMPS escape the detector MISSING ENERGY SIGNATURE
WIMPS HYPOTHESIS
DM made of particles with mass 10Gev - 1Tev
ELW scale
With WEAK INTERACT.
FROM “KNOWN” COSM. ABUNDANCE OF WIMPs PREDICTION FOR WIMP PRODUCTION AT COLLIDERS WITHOUT SPECYFING THE PART. PHYSICS MODEL OF WIMPs
BIRKEDAL, MATCHEV, PERELSTEIN , FENG,SU, TAKAYAMA

43. Tightness of the DM constraints in Minimal Supergravity
Ellis, Olive, Santoso, Spanos

44. LFV - DM CONSTRAINTS IN MINIMAL SUPERGRAVITY
A.M., Profumo, Vempati, Yaguna

45. DM SUSY:HOW FAR ARE WE IN DIRECT SEARCHES?
Ellis et al.

46. A.M., PROFUMO, ULLIO

47. SPIN - INDEPENDENT NEUTRALINO - PROTON CROSS SECTION FOR ONE OF THE SUSY PARAM. FIXED AT 10 TEV

48. A.M., PROFUMO,ULLIO

51. DM DE DO THEY “KNOW” EACH OTHER?
DIRECT INTERACTION  (quintessence) WITH DARK MATTER
DANGER:
Very LIGHT
m ~ H0-1 ~ eV
Threat of violation of the equivalence principle constancy of the fundamental “constants”,…
INFLUENCE OF  ON THE NATURE AND THE ABUNDANCE OF CDM
Modifications of the standard picture of
WIMPs FREEZE - OUT
CATENA, FORNENGO, A.M., PIETRONI, SCHELKE
CDM CANDIDATES

52. NEUTRALINO RELIC ABUNDANCE IN GR AND
S-T THEORIES OF GRAVITY WITH ENHANCED H

53. IF H IS REDUCED W.R.T. THE GR CASE
REGIONS OF THE BULK SUSY PARAM. SPACE WHERE THE NEUTRALINO RELIC ABUNDANCE FALLS IN THE COSMOLOGICAL INTERVAL FOR COLD DM
TANBETA=10
A=0 AND µ > 0
ST WITH REDUCED H GR
CATENA, FORNENFO, A.M., PIETRONI, SCHELKE (in progress)

54. I L C TEVATRON LHC DM - FLAVOR for DISCOVERY and/or FUND. TH.
RECONSTRUCTION
A MAJOR LEAP AHEAD IS NEEDED
NEW
PHYSICS AT
THE ELW
SCALE
DARK MATTER
"LOW ENERGY"
PRECISION PHYSICS
m n …
LINKED TO COSMOLOGICAL EVOLUTION
FCNC, CP ≠, (g-2), ()0
LFV
Possible interplay with dynamical DE
INFLATION
LEPTOGENESIS
NEUTRINO PHYSICS

55. BACK-UP SLIDES

56. Tightness of the DM constraint on minimal supergravity
Ellis, Olive, Santoso, Spanos

57. Tightness …3

58. REACH OF FUTURE FACILITIES FOR NEUTRALINO DETECTION
THROUGH ANTIMATTER SEARCHES WITH FIXED M1 = 500 GEV
N03 adiabatically contracted profile
Burkert profile