DAMA

1

Roma2, Roma1, LNGS, IHEP/Beijing
(in some activities INR-Kiev, IIT-Kharapur,
ENEA-Frascati)
DAMA an observatory for rare processes _at_LNGS
Low-bckg DAMA/Ge for sample meas.
DAMA/ RD
DAMA/LXe
DAMA/NaI DAMA/ LIBRA
(RD-III towards possible DAMA/1ton in progress)
2
DAMA/LXe
Unique low-background 6.5 kg LXe set-up operating
as pure scintillator filled by Kr-free Xenon
enriched either in 129Xe (99.5) or in 136Xe
(68.8)

• DARK MATTER investigations ...
• Limits on recoils investigating the DMp-129Xe
  elastic scattering by PSD PLB436(1998)379
• Limits on DMp-129Xe inelastic scattering
  PLB387(1996)222, NJP2(2000)15.1
• Neutron calibrations PLB436(1998)379,
  EPJdirectC11(2001)1

(NIMA482(2002)728)
... and other rare processes

• Electron decay into invisible channels
  AstroP5(1996)217
• Nuclear level excitation of 129Xe during CNC
  processes PLB465(1999)315
• N, NN decay into invisible channels in 129Xe
  PLB493(2000)12
• Electron decay e- ? neg PRD61(2000)117301
• 2b decay in 134Xe PLB527(2002)182
• 2b in 134Xe 136Xe PLB546(2002)23
• CNC decay 136Xe ? 136Cs Beyond the Desert (2003)
  365
• N, NN, NNN decay into invisible channels in 136Xe
  
• 
  EPJA27 s01 (2006)35

• stand-by during all the period of the problems
  related to the use of liquids underground
  because of Borexino accident.
• restarted on May 2004, running till December
  2004 then stopped again waiting for the
  necessary restoring of circulating water in the
  underground lab.
• Full revision new chiller - restart of data
  taking in 2007

DAMA/RD
DAMA/Ge LNGS Ge facility

• Particle Dark Matter search with CaF2(Eu)
  NPB563(1999)97, AP7(1997)73
• 2b decay in 136Ce and in 142Ce Il
  N.Cim.A110(1997)189
• 2EC2n 40Ca decay AstroP7(1999)73
• 2b decay in 46Ca and in 40Ca NPB563(1999)97
• 2b decay in 106Cd AstroP10(1999)115

• low background Ge detector operative in the Ge
  facility of LNGS mainly devoted to measurements
  and selections for
• RD-I, RD-II and now RD-III on highly radiopure
  NaI(Tl) set-ups
• several RDs on low background PMTs
• qualification of many materials
• measurements with a Li6Eu(BO3)3 crystal
  (NIMA572(2007)734)

• 2b and b decay in 48Ca NPA705(2002)29
• 2EC2n in 136Ce, in 138Ce and a decay in 142Ce
• 
  NIMA498(2003)352
• 2b 0n and EC b 0n decay in 130Ba
• 
  NIMA525(2004)535
• Cluster decay in LaCl3(Ce) NIMA555(2005)270
• CNC decay 139La ?139Ce UkrJP51(2006)1037
• Rare a decay of 151Eu to appear on NPA

• measurements with 100Mo sample investigating
  some double beta decay mode in progress in the 4p
  low-background HP Ge facility of LNGS (to appear
  on Nucl. Phys. and Atomic Energy)
• Many other meas. already scheduled for
  incoming years

several other results under analysis data
taking in progress many other meas. scheduled
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DAMA/NaI(Tl) 100 kg
Performances N.Cim.A112(1999)545-575,
EPJC18(2000)283, Riv.N.Cim.26 n. 1(2003)1-73,
IJMPD13(2004)2127
Results on rare processes

• Possible Pauli exclusion principle violation
• CNC processes
• Electron stability and non-paulian transitions in
  Iodine atoms (by L-shell)
• Search for solar axions
• Exotic Matter search
• Search for superdense nuclear matter
• Search for heavy clusters decays

• PLB408(1997)439
• PRC60(1999)065501
• PLB460(1999)235
• PLB515(2001)6
• EPJdirect C14(2002)1
• EPJA23(2005)7
• EPJA24(2005)51

Results on DM particles

• PSD PLB389(1996)757
• Investigation on diurnal effect
• N.Cim.A112(1999)1541
• Exotic Dark Matter search PRL83(1999)4918
• Annual Modulation Signature
• PLB424(1998)195, PLB450(1999)448,
  PRD61(1999)023512, PLB480(2000)23,
  EPJC18(2000)283, PLB509(2001)197, EPJ C23
  (2002)61, PRD66(2002)043503, Riv.N.Cim.26 n.1
  (2003)1-73, IJMPD13(2004)2127, IJMPA21(2006)1445,
  EPJC47(2006)263 others in progress

data taking completed on July 2002
total exposure collected in 7 annual cycles
107731 kgd
4
Final model independent result by DAMA/NaI
7 annual cycles total exposure 1.1 x 105 kgd
Experimental residual rate of the single hit
events in 2-6 keV over 7 annual cycles
Riv. N. Cim. 26 n. 1 (2003) 1-73, IJMPD 13 (2004)
2127
Power spectrum
experimental residual rate of the multiple hit
events (DAMA/NaI-6 and 7) in the 2-6 keV energy
interval A -(3.9?7.9) 10-4 cpd/kg/keV
2-6 keV
2-6 keV
6-14 keV
Acosw(t-t0)
P(A0) 7?10-4 Solid line t0 152.5 days, T
1.00 years from the fit A (0.0192 ? 0.0031)
cpd/kg/keV
Principal mode ? 2.737 10-3 d-1 1 y-1

from the fit with all the parameters free A
(0.0200 ? 0.0032) cpd/kg/keV t0 (140 ?
22) d T (1.00 ? 0.01) y
experimental residual rate of the single hit
events (DAMA/NaI-1 to 7) in the 2-6 keV energy
interval A (0.0195?0.0031) cpd/kg/keV
This result offers an additional strong support
for the presence of DM particles in the galactic
halo further excluding any side effect either
from hardware or from software procedures or from
background
Multiple hits events Dark Matter particle
switched off
No systematics or side reaction able to account
for the measured modulation amplitude and to
satisfy all the peculiarities of the signature
All the peculiarities of the signature satisfied
model independent evidence of a particle Dark
Matter component in the galactic halo at 6.3s
C.L.
5
Some of the possible corollary quests for the
candidate - I
Riv. N. Cim. 26 n. 1 (2003) 1-73, IJMPD 13
(2004) 2127
WIMP class some examples of slices of the
allowed volumes
DM particle with dominant SI coupling
DM particle with elastic SISD interactions
DM particle with preferred inelastic interaction
DM particle with dominant SD coupling
Already most of the allowed volumes are
unexplorable e.g. by Ge, Si, TeO2, Ar, Xe, CaWO4
targets
not exhaustive different scenarios? different
halo features?
Investigating the effect of Sagittarius Dwarf
satellite galaxy (SagDEG)
EPJC47(2006)263
Few examples for some SagDEG modelling
Possible contributions due to the tidal stream of
Sagittarius Dwarf satellite (SagDEG) galaxy of
Milky Way
pure SI case
green areas no SagDEG
pure SD case examples of slices of the 3-dim
allowed volume
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DAMA/NaI vs ...
... supersymmetric expectations in MSSM
PRD69(2004)037302

• Assuming for the neutralino a dominant purely SI
  coupling
• when releasing the gaugino mass unification at
  GUT scale M1/M2?0.5 (and SU(2) gaugino masses) low mass configurations
  are obtained

scatter plot of theoretical configurations vs
DAMA/NaI allowed region in the given model
frameworks for the total DAMA/NaI exposure (area
inside the green line)
... other DM candidate particle, as (see
literature)
the sneutrino in the Smith and Weiner scenario
self-interacting dark matter

mirror dark matter
a heavy n of the 4-th family
Kaluza-Klein particles (LKK)
heavy exotic canditates, as 4th family atoms,
...
even a suitable particle not yet foreseen by
theories
compatibility
light bosons
... indirect searches of DM particles in the space
see later

• Positron excess (see e.g. HEAT)
• Excess of Diffuse Galactic Gamma Rays for
  energies above 1 GeV in the galactic disk and for
  all sky directions (see EGRET).

interpretation, evidence itself, derived mW and
cross sections depend e.g. on bckg modeling, on
DM spatial velocity distribution in the galactic
halo, etc.
Hints from indirect searches are not in conflict
with DAMA/NaI for the WIMP class candidate
7
Some of the possible corollary quests for the
candidate - II
IJMP A21(2006)1445
Light axion-like bosons class examples of
allowed volumes/regions
Light bosons Axion-like particles, similar
phenomenology with ordinary matter as the axion,
but significantly different values for mass and
coupling constants are allowed.
The detection is based on the total conversion of
the absorbed bosonic mass into electromagnetic
radiation.
In these processes the target nuclear recoil is
negligible and not involved in the detection
process (i.e. signals from these candidates are
lost in experiments applying rejection procedures
of the electromagnetic contribution)
A wide literature is available and various
candidate particles have been and can be
considered.
A complete data analysis of the total 107731
kgxday exposure from DAMA/NaI has been performed
for pseudoscalar (a) and scalar (h) candidates in
some of the possible scenarios.
Allowed multi-dimensional volume
The pseudoscalar case (a)
The scalar case (h)
Maximum allowed photon coupling
DAMA/NaI allowed region in the considered
framework
only electron coupling
cosmological interest at least below
Di Lella, Zioutas AP19(2003)145
UHECR - PRD64(2001)096005
Majoron as in PLB99(1981)411
Many configurations are of cosmological interest
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(all operations involving crystals and PMTs
-including photos- in HP N2 atmosphere)
detectors during installation in the central and
right up detectors the new shaped Cu shield
surrounding light guides (acting also as optical
windows) and PMTs was not yet applied
DAMA/LIBRA (about 250 kg radiopure
NaI(Tl)) running since March 2003 ...waiting for
a larger exposure than DAMA/NaI
installing LIBRA detectors
assembling a DAMA/ LIBRA detector
filling the inner Cu box with further shield
view at end of detectors installation in the Cu
box
closing the Cu box housing the detectors
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DAMA/LIBRA perspectives
DAMA/LIBRA (250kg NaI(Tl)), running since March
2003, can allow to

• achieve higher C.L. for the annual modulation
  effect (model independent result)
• investigate many topics on the corollary model
  dependent quests for the candidate particle
  (continuing and improving past and present
  efforts on the data of the previous DAMA/NaI
  experiment)

investigations e.g. on - velocity and
position distribution of DM particles in the
galactic halo - on more complete astrophysical
scenarios DM streams and/or caustics in the
halo, effects due to clumpiness and
possible distorsion due to the Sun gravitational
field, etc. - the nature of the candidate
particles - the phenomenology of the candidate
particles and their interactions with ordinary
matter - scaling laws and cross sections. -
... and more

• competitive limits on many rare processes can
  also be obtained
• wait for an exposure larger than DAMA/NaI

• ...and beyond?
• RD-III approved and funded by INFN towards a
  possible multi-purpose NaI(Tl) ton set-up we
  proposed in 1996 ? work in progress

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Status and perspectives
DAMA/LXe
DAMA/LIBRA
status
status
In operation since March 2003 e.g. up to March
2006 exposure of order of 105 kg x d overall
sources data of order of 4 x 107 events

• In full revision new chiller ? restart of data
  taking in 2007

Few examples of operational features (here from
March 2003 to August 2005) Stability of the low
energy calibration factors
perspectives
frequency
ratio of the peaks positions

• Measurements with 129Xe and 136Xe for a
  comparison analysis
• Larger exposures, higher sensitivity for 2b decay
  modes in 134Xe and 136Xe
• Towards further data and analyses also on other
  processes

perspectives
s0.4

• First data release foreseen not later than 2008.
• Installation of the new daq, TDs and upgrading
• Several years of further data taking

DAMA/RD
DAMA/1Ton

• In progress
• i) analysis of the data taken with CdWO4
• ii) data taking with ZnWO4

To complete RD-III, RD-IV and RD on PMTs in
2007-2008
RDs Positive results
perspectives
submit an updated operative report in 2007-2008
and possibly start detectors production at the
end of 2008
Further data taking in incoming years with new
larger BaF2, ZnWO4, CdWO4 with enriched 106Cd,
etc.
RDs Negative results
DAMA/Ge
running the quarter of ton DAMA/LIBRA for many
years

• In progress
• i) sample measurements
• ii) measurements with Li2MoO4
• iii) measurement with 100Mo sample in the
  fourfold low-background HP Ge facility of LNGS

first year of data taking planned for 2009/2010
Physical Goals
perspectives
DAMA/1Ton
Further data taking with samples, LiF, etc.
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Aims of DAMA/1 ton for Dark Matter

• Goals of 1 ton NaI detector
• Extremely high C.L. for the model independent
  signal
• Model independent investigation on other
  peculiarities of the signal
• High exposure for the investigation and test of
  different astrophysical, nuclear and particle
  physics models

Improved sensitivity and competitiveness in DM
investigation with respect to DAMA/LIBRA

• Further investigation on astrophysical models
• velocity and position distribution of DM
  particles in the galactic halo
• effects due to
• i) satellite galaxies (as Sagittarius and Canis
  Major Dwarves) tidal streams
• ii) caustics in the halo
• iii) gravitational focusing effect of the Sun
  enhancing the DM flow (spike and skirt)
• iv) possible structures as clumpiness with
  small scale size

• Further investigation on Dark Matter candidates
  (further on neutralino, bosonic DM, mirror DM,
  inelastic DM, neutrino of 4th family, etc.)
• high exposure can allow to disantangle among the
  different astrophysical, nuclear and particle
  physics models (nature of the candidate,
  couplings, inelastic interaction, particle
  conversion processes, , form factors,
  spin-factors and more on new scenarios)
• scaling laws and cross sections
• multi-componente DM particles halo?

second-order effects
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... DAMA/1 ton as a general purpose experiment
(in few years exposure)

• Possible PEP violating processes maximal
  reachable sensitivity 3x1027 y
• Possible CNC processes in 23Na, 127I
• in case of a rate 0.1 cpd/kg/keV in the
  region
• of interest and of the same duty cycle as at
  present
• a) reachable sensitivity for CNC EC 1024y 90
  C.L. (or higher depending on r)
• b) reachable sensitivity for e- disappearance
  1025y at 90C.L.(or higher depending on r)
• Nucleon, di-nucleon, tri-nucleon
• decay into invisible channels maximal
  reachable sensitivity ?n ? 1027y
• SIMP investigation maximal explorable mass
  above 1017 GeV
• Neutral nuclearities maximal explorable flux
  5x10-12s-1cm-2ster-1
• Investigation on inelastic scattering reachable
  sensitivity for bckg 0.1 cpd/kg/keV in the
  region of interest and the same duty cycle as at
  present 5 GeV/cm3 lower rate can allow to
  explore physical regions
• Solar axion investigation maximal reachable
  sensitivity ga? ? 10-10 GeV-1

and beyond (e.g. ?? decays with passive and
active sources, tests for?? physics with
artificial ? source, neutrino magnetic moment
measurement, solar neutrino spectroscopy, etc.)
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Towards DAMA/1ton

• Proposed since 1996 (DAMA/NaI and DAMA/LIBRA
  intermediate steps)
• Technology largely at hand (large experiences
  and fruitful collaborations among INFN and
  companies/industries)
• Still room for further improvements in the
  low-background characteristics of the set-up
  (NaI(Tl) crystals, PMTs, shields, etc.)
• 1 ton detector cheapest, highest duty cycle,
  clear signature, fast realization in few years

A possible design DAMA/1 ton can be realized by
four replicas of DAMA/LIBRA

• the detectors could be of similar size than those
  already used
• the features of low-radioactivity of the set-up
  and of all the used materials would be assured by
  many years of experience in the field
• electronic chain and controls would profit by the
  previous experience and by the use of compact
  devices already developped, tested and used.
• new digitizers will offer high expandibility and
  high performances
• the daq can be a replica of that of DAMA/LIBRA

DC270 Acqiris Digitizers
Electronic chain and example of the trigger system
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Advantages of NaI detector for Dark Matter

• Well known technology
• Very high duty cycle
• Ecological clean set-up no safety problems
• Cheaper than other techniques considered in the
  field
• Neither re-purification procedure nor cooling
  down/warming up (reproducibility, stability, ...)
  
• Absence of microphonic noise effective noise
  rejection at threshold (t of NaI(Tl) pulses
  hundreds ns, while t of noise pulses tens ns)
• High light response (5.5 -7.5 ph.e./keV)
• High radiopurity by selections, chem./phys.
  purifications, protocols (still large room for
  improvements)
• Well controlled operational condition feasible
• Routine calibrations feasible down to keV range
• Feasibility proved up to 250 kg RDIII in
  progress
• Large mass feasible
• Nominal sensitivity (calculated - as usual -
  assuming absence of signal) e.g. for SI particle
  sp
• Sensitive to SI, SD, SISD couplings and to
  other existing scenarios, on the contrary
• of many other proposed target-materials
• Sensitive to both high (by Iodine target) and low
  mass (by Na target) candidates
• PSD feasible at reasonable level
• Effective investigation of the annual modulation
  signature feasible
• Feasible in few years