April-June 2007

1) Oscillations:

2) Kinematics in weak decays:

3) 0 double beta decay:

222

2*

',

*'' 2

exp

kiik

iklkklli

kiilll

mmmE

xmiUUUUP

iik mU ,

Majorana

Dirac

iei

N

iei

iLei

N

i

Lei mUU

mUUm

1

2

1

0

92.02sineV10)4.35.1(m

93.066.02sineV10)8.87.7(m

atm2232

atm

sol2252

sole

?

solar

Kamland Kamland + solar

Favored channel:

Global fit to all existing data

atmospheric, reactors (SBL) solar

accelerators accelerators reactors (LBL)221m2

32231 mm 2

32231 mm

013

23132

232232

3231

122252

21

13

9202104351

9306602108877

)(e

)(

)(e

m)SBL(reac

.sineV)..(maccel,atm

..sineV)..(m)LBL(reac,solar

To improve on T120 and <m>: need large source mass

lower background, better event signature

)n(d)p(u

W

e

e

beta decay:

ee)1Z,A(

)Z,A(

For more information:

Commins and Bucksbaum,

Weak interaction of leptons and quarks

Integral electrostaticspectrometer

max

min

B

B

EE

Mainzfrozen T2 source, E=4.8 eV

Troitskgaseous T2 source, E=3.5 eV

Reported anomaly most likely experimentalartifact

CL) % (95eV 2.2 m

eV2.12.21.2 m 22

CL) % (95eV 2.2 m

eV2.02.52.3 m 22

Katrin(Karlsruhe)

eV 0.2 y sensitiviteV1E

23 m in final version

T2 injection (27 K)

10 m

217d cm/molecule105

start data taking 2010

Katrin, main spectrometer transport

Thermistor R(T) measure heat pulse

Stopping particle(ionizing or non ionizing)

phonons

heat sink ( 8 mK)

crystal

V

3

V

C

ET

TC

i

•Wide choice of materials

•Good energy resolution

Cryogenic detectors (bolometers)

187Re 187Os + e- + e E0=2.5 keV, 43 Gyr, abundance 62.8 %

Milano: 10 AgReO4 crystals (250-300 g each)

as cryogenic bolometers (T=10 mK)

E(FWHM)=28 eV at 2.5 keV

m< 15 eV at 90 % CL

(complication: ‘’ forbidden ’’ transition)

Next version: MARE (Microcalorimeter Array for a Rhenium Experiment)

1) 300 calorimeters of a few 100 g, with E=10-20 eV

in progress, start data taking in 2010 for a few years

2) R&D for new thermistors

goal 5x104 calorimeters with E< 5 eV

Like KATRIN, but with completely different systematics!

eV2m

eV2.0m

Global fit to all existing data

atmospheric, reactors (SBL) solar

accelerators accelerators reactors (LBL)221m2

32231 mm 2

32231 mm

013

23132

232232

3231

122252

21

13

9202104351

9306602108877

)(e

)(

)(e

m)SBL(reac

.sineV)..(maccel,atm

..sineV)..(m)LBL(reac,solar