2th Korea-China joint workshop 2007Collaboration Meeting

KIMS collaboration2007. 11. 23

S. Ryu,

2th Korea-China joint workshop 2007Collaboration Meeting

Rotation curve of Spiral Galaxies Cosmic microwave background

◦ COBE, BOOMERANG, WMAP Modern X-ray Search

◦ Gravitational Lensing

23-4-18 화요일Collaboration Meeting 2

2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 3

ρχ= 0.3 GeV cm-3

from the rotation curve of Milky Way Galaxy

8 x 8 x 30 cm3, ~8 kg

30 km/s

220 km/s

60o

2th Korea-China joint workshop 2007Collaboration Meeting

1. Double signature = recoil + γ2. Threshold Energy (57.6 keV for 127I)3. Lower cross section, but no quenching effect

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Vg AgAg

χχχ

j jj

Elastic scattering of DM Elastic scattering of spin-coupled DM Inelastic scattering of spin-coupled DM

γ

A Z N EG Mult Eli JPli t_1/2 ELf JPl

127 53 74 57.61 M1+E2 57.608 7/2+

1.95ns 0 5/2+

127 53 74 116.2 744.71 9/2+

2.79ps 6.28.69 7/2+

127 53 74 145.252

E2 202.860

3/2+

0.387ns

57.608 7/2+

127 53 74 172.132

M1+E2 374.992

½+ 31ps 202.860

3/2+

127 53 74 202.860

M1+E2 202.860

3/2+

0.387ns

0.0 5/2+

2th Korea-China joint workshop 2007Collaboration Meeting

Low internal background Good Pulse Shape Discrimination (PSD) Quenching

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5

2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 6

(a) Beijing0501A(b) Beijing0501B(c) Shanghai040

6

Coincidence event rejection ~ 6cpd level (20keV - 100keV)

2th Korea-China joint workshop 2007Collaboration Meeting

241Am source used (59.54 keV, 26.34 keV)

ΔE = 5.07 at 59.54 keVΔE/E = 0.36/√E + 0.026

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2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 8

ELEGANT V,

NaI(Tl) : 10 x 10 x 102.3 cm,

47kg17 crystals used

β from 210Pb, 46.5 keV γ of 210Bi

( )2876

55

44

33

2210

)(exp ppxp

xpxpxpxpxpp

−+

+++++

KIMS,

CsI(Tl) : 8 x 8 x 23 cm, 6.02 kg

1 crystal used

2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 9

KIMS0.79±0.74 cpd / kg ,

1.76 cpd / kg ( 90% C.L.)

ELEGANT V0.098 cpd / kg (90%

C.L.)

2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 10

2

2

1v

vv th

in −=σσ )( NMNgG AFin 1222 *μσ ≡

20

2)(2/3

20

1),( v

vv

E

E

ev

vvdv

dn+

−

⎟⎟⎠

⎞⎜⎜⎝

⎛=

π

Total Event Rate

EcvM

EMM

T

TWthr Δ−

Δ=

22

22max

Mass threshold :

11.9 GeV for 129Xe

18.2 GeV for 127I

€

R =ρ χMχ

NTσ in v f F2(q)

€

f =1

vv 1− (v thr

2 v 2)dn

dvv,vE( )

vth

vmax∫ dv

2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 11

Event for different WIMP mass

(a) 50GeV

(b) 100GeV

(c) 500GeV

∫= max

)min(

),()(v

v ERTinT

R RE

dvvvfv

EFM

MN

dE

dR 12

22μ

σρ

χ

χ

1. Edet = ER x f + E*,2. Energy Resolution

Quenching (f) : 0.2 ~ 0.05 (20 – 140 keV)

2th Korea-China joint workshop 2007Collaboration Meeting 23-4-18 화요일Collaboration Meeting 12

a. KIMS experiment (2007): 1.76 cpd (90% C.L)

b. ELEGANT V experiment (1994): 9.8 x 10-2 cpd

c. DAMA 129Xe experiment (2000): 1.16 x 10-2 cpd

More data are ready to be analyzed :

SET4 (2122.9 kg day)+ SET6 (1728.6 kg day)+ SET8 (3096 kg day)+ SET9 (2322 kg day)= Total 9269.5 kg day

New installation ( 12 crystals)103.2 kg x 1 year ~ 37600 kg

day

Project Limit

DAMA Xe : 2530.2 kg

days

KIMS project: 9269 kg

days

KIMS Project : 37600 kg

days

Elegant V : 61390 kg

days

KIMS : 319.1 kg days

2th Korea-China joint workshop 2007Collaboration Meeting

CsI(Tl) Single Crystal (Shanghai0406, 6.02 kg) 319.1 kg day, 6 cpd level (20~100 keV) 0.79±0.74 cpd / kg, 1.76 cpd (90% C.L.) The limit can be improved by the analysis of the remaining

data.

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