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Dalitz analysesDalitz analyses IntroductionBelle Analysis School
October 1-2 2009
Hi, could you talk b t D lit
Sure...A couple of months ago, somwehere on
about Dalitzat the BAS?
g ,the net....
A couple of weeks ago, somwehere on
Yes...?
WHO did you saythe net.... WHO did you say I should talk about...?
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 1 BAS, KEK, October 2009
Dalitz analysesDalitz analyses IntroductionBelle Analysis School
Botjan GolobBelle & Belle II
University of Ljubljana Joef Stefan Institute
October 1-2 2009
University of Ljubljana, Joef Stefan Institute
1. Introduction2. Kinematics3. Physics4. Parametrization4. Parametrization5. Experimental issues6. Specifics, Outlook
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 2 BAS, KEK, October 2009
IntroductionHistoryHistory
Richard Henry Dalitz (28 February 1925 13 January 2006);Australian physicist;Australian physicist;
@ Cornell introduced phase space plotsphase space plots, i.e. Dalitz technique (as called today), e a t tec que (as ca ed today),to study 3 tau (kaon) decays;
On the analysis of meson data and the nature of the mesonOn the analysis of -meson data and the nature of the -meson Author: R. H. Dalitz aAffiliation: a Department of Mathematical Physics, University of Birmingham, y gDOI: 10.1080/14786441008520365 Published in: Philosophical Magazine Series 7, Volume 44, Issue 357 October 1953 , pages 1068 - 1080
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 3 BAS, KEK, October 2009
Kinematicsn-body decayJ.D. Jackson, D.R. Tovey, Kinematics, in RPP
( )= nn
d
ppPdM
d
3
12
4
),;(22
KM
==
=ni i
i
niinn E
pdpPppPd,1
3
3
,1
41 2)2(
)(),;(
K LISP:Lorent InvariantPhase Sace
independent variables: 4-vectors: 4 n +
ti l 4 3 7n=3 2n=3 2
conservation laws: 4 = 3 n - 7final state masses: n -arbitrary rotations: 3
n=4 5n=5 8
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 4 BAS, KEK, October 2009
Kinematics3 body decay
J.D. Jackson, D.R. Tovey, Kinematics, in RPP,
3-body decay
take two inv. masses asindependent variables decaying particle:independent variables
213
212
233 32
1)2(
1 dmdmM
d M=
decaying particle:scalar or averagingover spin states33 32)2( M p
mij: inv. mass of part. i,j.23
22
21
2223
213
212 constmmmMmmm =+++=++
211 Md 33213
212 32)2(
MMdmdm
= standard form of Dalitz plot
if |M|2 const d/dm 2dm 2 const
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 5 BAS, KEK, October 2009
if |M|2 const. d/dm122dm132 const.
Kinematics Belle, PRL 99, 131803 (2007)
)
3-body decay
example: D0 Ks -+ m2 (
KS
+ )
cos2
non-uniformity of Dalitz plot contribution of intermediate states
Ki ti li itKinematic limitsD0 +K*- m2(KS-)J.D. Jackson, D.R. Tovey, Kinematics, in RPP
23*=
( ) ( ) 222 2mmm +23*=0
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 6 BAS, KEK, October 2009
( ) ( )( ) ( )min223max223
23max23min23*23
2cos
mmmmm
+
= 34
KinematicsM1
3-body decay
various intermediate states Mk
contributing to same final state interfereinterferenncece
Mn
|M|2 is not incoherent sum, (|M|2 |M1|2 + |M2|2 + ... ) ,
n
but a coherent sum, ( |M|2 = |M1+ M2 + ...|2 )
example: pp 30
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 7 BAS, KEK, October 2009
PhysicsCleo-c, arXiv:0903.1301
New states and propertiesof known states
,
Dalitz analysis usually not needed for narrow, non-overlapping
K*0
resonances(negligible interference)example: Ds K+K-+
(but interf. /KK, /f0important in precise Br(Ds )determination)
determination)
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 8 BAS, KEK, October 2009
another example: 37
PhysicsB KZ+(4430)
Belle, PRD 80, 031104(R) (2009)
New states and propertiesof known states
KZ (4430)
In most cases intermediate states strongly interfere
Z+(4430)example: B K+
by fitting fitting DalitzDalitz distributiondistributionobtain evidence of newobtain evidence of new states, measure properties(mass width spin)
B K*(892)
B K0*(1430)
(mass, width, spin)
projection of Dalitz disribution and fit to
24
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 9 BAS, KEK, October 2009
disribution and fit to M(+)
Physics20 )( tAyixqAefDd t ++= D0 Mixing and CPV
x, y: mixing parameters;
2tA
pAe
dt ff+=
due to mixing, D0 D0 fx, y
Physics Belle, PRL 99, 131803 (2007)t dependent
tt-dependent Dalitz analyses
t-dependence:t-dependence:regions of Dalitz plane specific t dependence F(x, y);
time evolution of Dalitz distribution x, y x, y
[ ]titiS
eemm
tDKtmm
21)(1
)(),,(
22
022
++
++=
=
A
MD0f
28
[ ]
[ ]titi eemmpq
eemm
21),(21
),(2
22 +
+
+
++=
A
AD0f
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 11 BAS, KEK, October 2009
p21,2=F(x,y); m2 = m2(KS),
PhysicsBelle, arXiv:0803.3375
measurement3 measurement
B- K- D0( f)B- K- D0( f)B K D0( f)interference |M|2 = F(3) f= +- KS
),(),())(( 22220)(
3
+
+= mmAremmAfDKB ii mm
M(A: D0 decays; r: ratio of two B amplitudes; : strong phase diff. of two B amplitudes
A from fit to Dalitz fit to Dalitz distribution of D0 decays;
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 12 BAS, KEK, October 2009
r, 3, (in principle) from fit to Dalitz fit to Dalitz distribution of B decays 30
sin 2 eff in b sqq
Physics SM:sin 21eff in b sqq
NP contrib. sin 21eff sin 21eff VtbVts* : no weak phase
quasi twoquasi two--bodybody, B 0(770)KS, f0(980)KSBelle, PRD76, 091103(R) (2007)BaBar, PRL99, 161802 (2007)B B PRL98 051803 (2007)
BBaBar, PRL98, 051803 (2007)
Vtd* 2: (mixing): sin21
NP:
[ ]tmqStmqAetP CPCPt
+=
sincos14
)(/||
interf. between various states and non-resonant contrib. Dalitz analysis
s
B0 g
g~b s
+( 23dRR)b
~R
s~
NP:
d d
s
s Ks
B0 gs~R
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 13 BAS, KEK, October 2009
S=sin21eff -sin21
Physicssin 2 eff in b sqqsin 21eff in b sqq
[ ]tmqStmqAetP CPCPt
+=
sincos14
)(/||
4
),( 22 mmmAA =
each point in Dalitz space has a specific time evolution depending onevolution, depending on |A|2-|A|2 (direct CPV)(direct CPV)and (AA*) (indirect CPVindirect CPV corresponding to
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 14 BAS, KEK, October 2009
(AA ) (indirect CPVindirect CPV, corresponding to specific two-body contribution sin 2sin 211effeff (i)(i))
Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution
a matter of statistics102 pp 30 events10 pp 3 events
Adopted from K. Peters, talk at Charm 2006, Beijing
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 15 BAS, KEK, October 2009
Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution
a matter of statistics103 pp 30 events10 pp 3 events
Adopted from K. Peters, talk at Charm 2006, Beijing
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 16 BAS, KEK, October 2009
Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution
a matter of statistics104 pp 30 events104 pp 30 events
Adopted from K. Peters, talk at Charm 2006, Beijing
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 17 BAS, KEK, October 2009
Parametrizationdescription of Dalitz distributiondescription of Dalitz distribution
a matter of statistics105 pp 30 events
larger stat. larger sensitivity to model details
Breit-Wigner resonances
10 pp 3 events
Breit Wigner resonancessimple consideration of spin 0 elastic scatteringleads to the Breit-Wigner amplitude for a b r a b
Adopted from K. Peters, talk at Charm 2006, Beijing
// 2
4/)(4/
2/2/
22
22
+
=
=
EmT
iEmT
rr
|T|2 |T|2
mr=1.0=0.3
mr=0.5=0.2
| |
mR
B. Golob, Ljubljana Univ., IJS Introd. to Dalitz analyses 18 BAS, KEK, October 2009
E E
ParametrizationBreit Wigner resonances
|T1+ T2 |2
Breit-Wigner resonances
several intermediate statesb ba b r1 a b
r2model amplitude as sum of BW amplitudes;
E
sum of BWs amplitudes; - the approach violates unitarity for wide overlapping resonances;
- the BW shape is distorted close
(isobar model)most commonly used most commonly used to model Dalitz distributionsthe BW shape is distorted close
to the thresholds;
parametrization of Dalitz distribution is
distributions
22
D0, B0 ABCpa model, phenomenological object;
it should provide adequate description adequate