A PROPOSAL FOR IMPROVING THE HADRONIZATION OF QCD
CURRENTS IN TAUOLA
Work done in collaboration with D. Gómez-Dumm, A. Pich, J. Portolés
See Phys.Rev.D69:073002,2004 ; AIP Conf.Proc.964:40-46,2007 ; Work to appear soon
Pablo Roig [email protected]
Instituto de FÍsica Corpuscular
CSIC-UVEG València (Spain)
PHI PSI 08 Frascati
April 10th 2008
• Hadronic decays of the lepton • Kühn-Santamaría Model in TAUOLA• Tools : PT, Large Nc , RT
•
• Outlook :
SUMMARY:
(Gómez Dumm, Pich, Portolés, R. to appear)
(h1h2h3)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
• Hadronic decays of the lepton • Kühn-Santamaría Model in TAUOLA• Tools : PT, Large Nc , RT
•
• Outlook :
SUMMARY:
(Gómez Dumm, Pich, Portolés, R. to appear)
(h1h2h3) h1h2h3=3K,2
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
PHI PSI 08 Frascati
5( ) (1 ) ( )2F
CKMG V u u T
M
..
.Hadrons
W --
hn
QCD
h1T=<Hadrons|(V-A) eiSQCD|0>=
=i(Lorentz Structure)i Fi(Q2,sj)
HADRONIC DECAYS OF THE LEPTON
22 ( 1) *
2 | | 4
nFCKM
Gd V d L T TM
IMPROVING HADRONIZATION IN TAUOLAPablo Roig (IFIC)
PHI PSI 08 Frascati
5( ) (1 ) ( )2F
CKMG V u u T
M
..
.Hadrons
-
hn
QCD
h1
QCD= QCD (qi,Ga;gs,mi)
?
W -
T=<Hadrons|(V-A) eiSQCD|0>=
=i(Lorentz Structure)i Fi(Q2,sj)
22 ( 1) *
2 | | 4
nFCKM
Gd V d L T TM
IMPROVING HADRONIZATION IN TAUOLAPablo Roig (IFIC)
HADRONIC DECAYS OF THE LEPTON
PHI PSI 08 Frascati
5( ) (1 ) ( )2F
CKMG V u u T
M
..
.Hadrons
-
hn
QCD
h1
PhTR
22 ( 1) *
2 | | 4
nFCKM
Gd V d L T TM
W -
T=<Hadrons|(V-A) eiSQCD|0>=
=i(Lorentz Structure)i Fi(Q2,sj)
IMPROVING HADRONIZATION IN TAUOLAPablo Roig (IFIC)
HADRONIC DECAYS OF THE LEPTON
PHI PSI 08 Frascati
5( ) (1 ) ( )2F
CKMG V u u T
M
-
h3
QCD
h1
W -
IMPROVING HADRONIZATION IN TAUOLAPablo Roig (IFIC)
HADRONIC DECAYS OF THE LEPTON
h2
Hadrons
1 2 3
1 2 3 1 2 122 3
1 2 1 2 3
2 2
1 2
2 13
1
15
2 3
0
( ) ( ) ( )
( ) , ( )
| | , ,128(2 )
P
KM
V
F C
F F F F
p p p
Q Qp p p Q V g p p
Q
T V V Q i p p p
G Vd dsdt f I I IdQ M
h h h
(Kühn, Santamaría ’90)(KS)
(Gómez-Cadenas, González-García, Pich ’90) (GGP)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
KÜHN-SANTAMARÍA MODEL
KS
PT O(p2)
Vector Meson Dominance
22
2 2 2 2( )
( )R
R
R R
MBW xM x i x x
?
PT O(p4)
Asymptotic behaviour ruled by QCD
(Kühn-Santamaría ‘90)
(Brodsky-Farrar ’73, B-Lepage ‘80)
(Gounaris-Sakurai ‘68)
(Sakurai ’69, Kühn & Wagner ’84, Pich ’87)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
KÜHN-SANTAMARÍA-like MODELS & TAUOLA
(Decker, Mirkes, Sauer, Was ‘92)
(Decker, Mirkes ‘92)
(Decker, Finkemeier, Mirkes ’93)
(Decker, Finkemeier ’93, ‘94)
(Decker, Finkemeier, Heiliger, Jonsson ‘94)
(Finkemeier, Mirkes ’95,’96)
(Finkemeier, Kühn, Mirkes ‘96)
(Mirkes, Urech ‘97)
(Kühn, Mirkes, Willibald ‘97)
(Jadach, Was ’90, ‘93)
(Jadach, Kühn, Was ‘90)
(Jezabeck, Was, Jadach, Kühn ‘90)
(Jadach, Was, Decker, Kühn ‘90)
(Bondar, Eidelman, Milstein, Pierzchala, Root, Was, Worek ‘02)
(Golonka, Kersevan, Pierzchala, Richter-Was, Was, Worek ‘06)
(Kühn, Was ‘06)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
K-S-like works & HADRONIZATION IN TAUOLA(Finkemeier, Mirkes ’95,’96)
(Finkemeier, Kühn, Mirkes ‘96)
A
V
a
V
V
v
1 2 3i p p p
1 2 122 3
( )Q Q
V g p pQ
2 21 2
2 2 2 2 2 2 2 21 1 2 2( ) ( )
R R
R R R R
M M
M x i x x M y i y y ,1R & 2R
obtained from:
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
K-S-like works & HADRONIZATION IN TAUOLA(Finkemeier, Mirkes ’95,’96)
(Finkemeier, Kühn, Mirkes ‘96)
A
V
a
Some allowed contributions are lacking:
V-exchanged missing in
K+K-- 0 V2
K*0 V1
K-K00 K*0 V1
- V1
K--+ V1K*0
K00- - V1
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
K-S-like works & HADRONIZATION IN TAUOLA(Finkemeier, Mirkes ’95,’96)
(Finkemeier, Kühn, Mirkes ‘96)
V
V
v
' 'V AM M
3 2V AMultiplets Multiplets
Our aim is to tackle an ambitious program for describing within a theoretical framework as close as possible to QCD the
considered decays.
' 'V A
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
QQCCDDLow energy expansion Intermediate region
PT c
2 2 2 2
2 2
, , , (4 ) R
p m p mF M Tree level diagrams
Matching the OPE
(Gasser & Leutwyler ’84, ’85)
(‘t Hooft ’74, Witten ‘79)
EFT PhT
TOOLS: EFFECTIVE FIELD THEORIES
# 0-width resonances
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
QQCCDD
PT c
2 2 2 2
2 2
, , , (4 ) R
p m p mF M Tree level diagrams
Matching the OPE
(Gasser & Leutwyler ’84, ’85)
EFT PhT
TOOLS: EFFECTIVE FIELD THEORIES
Only one 9 (SRA)Off-shell width
RT
(‘t Hooft ’74, Witten ‘79)
# 0-width resonances
Low energy expansion Intermediate region
(Peris, Perrottet, de Rafael ‘98)
(Gómez-Dumm, Pich, Portolés ‘00)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
PT: The low-energy EFT of QCD (Gasser & Leutwyler ’84, ’85)
08
008
0 8
† †
† †
† †
2( )
0
1( )
44 2
2
2 6
( )2 6
26
( )( ) exp , u ( ) ( )2
2 ( ),
4...
L R
K
x K
K K
i xu x i u i u u i u
s ip u uF
B
L
r
u u
f uF u u F u
F u u
u u u uL
l
L
L4
2
( ),
7 9 ... ... ...
in the odd-intrinsic parity sectorWZW
L Li f u u
L
PGB
(3) (3) (3)L R VSU SU SU
†( , ) ( , )X h g X h g
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
(Ecker, Gasser, Pich, De Rafael ‘89)
(Ecker, Gasser, Leutwyler, Pich, De Rafael ‘89)
2
4
( ) ( )
5
1
,
1
( ) (
5
( )
1
7
)
;
2 2 2
2 2
( , , ) [ , ] ...
;
( , , )
I
I
P kinR T V A V A VAP
V
A
iVAP
i
PR T WZW VJP VVP VPP
V V
A
i
P
iVJP
i V V
i
L L L L L
if u uV V
A
V A V
F G
A
V
F f
O
L L L L
OM
c cM
j
L
L
L
L
L
L
5
5
1
1
4
1
, ...
( , , ) , ...
( , ) , ...
iVVP
i
iVPPP
i V V
i
i
f u
O u
V
V V V V
V V
d d
g gO u uM M
L
L
0*8
0*08
* *0 8
2 6
( )2 6
26
K
x K
K
V
K
Antisymmetric tensor formalism
(Ruiz-Femenía, Pich, Portolés ’03)
(Gómez Dumm, Pich, Portolés ’04)
(Gómez Dumm, Pich, Portolés, R. in progress)
Resonances+ PGB
VMDVMD
TOOLS : RT
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
V
TOOLS : RT
5
1
75
( ) ( ),
1
( ) (
2
))
1
4(
;
2 2 2
2 2
( , , ) [ , ] ...
;
( , , )
I
I
P kinR T V A V A VAP
V
A
iVAP
i
PR T WZW VJP VVP VP
V V
PP
iVJP
i V V
A
i
i
V V
L L L L L L
iL f u u
L f
L
A
VO
L L L L L
L
F G
F
c c
A V A
V jOM M
1
5
1
54
1
, ...
( , , ) , ...
( , ) , ...
iVVP
i
iVPPP
i
i
i
V V
f u
L O u
L O
V
V V V V
V V
d
ug uM
d
Mg
V
v V V
A V
V
a
A
(Ecker, Gasser, Pich, De Rafael ‘89)
(Ecker, Gasser, Leutwyler, Pich, De Rafael ‘89) ,…
Resonances+ PGB
V
a A
Vv
A
V
V V
V V
V
V
cigi di
i
GV, FV
F
v
v
v
v
a
a
a
a
a
RT APPLIED
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
A
V
V V
V V
V
V
cigi di
i
GV, FV
F
v
v
v
v
a
a
a
a
a
RT APPLIED
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
24 24 couplingscouplings
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
First work on this already in ’90 (González-García, Gómez-Cadenas, Pich)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
The phenomenological approach of KS-like works (Finkemeier and Mirkes ’95, ‘96) do not include all possible contributions for the exchanged resonances and
depend noticeably on the excited resonances parameters.
First work on this already in ’90 (González-García, Gómez-Cadenas, Pich)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
CLEO (Liu ’03, CLEO ‘04) could not fit their data using FM expressions and reshaped the model violating the normalization of
the WZ term (i.e. low-energy QCD).
First work on this already in ’90 (González-García, Gómez-Cadenas, Pich)
The phenomenological approach of KS-like works (Finkemeier and Mirkes ’95, ‘96) do not include all possible contributions for the exchanged resonances and
depend noticeably on the excited resonances parameters.
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
CLEO (Liu ’03, CLEO ‘04) could not fit their data using FM expressions and reshaped the model violating the normalization of
the WZ term (i.e. low-energy QCD).
BaBar presented their data on these modes in TAU’06. However the plot of the spectral function vs. invariant mass of the hadronic system was not
at the Proc. (Nugent ‘06) and they have not submitted the paper yet.
First work on this already in ’90 (González-García, Gómez-Cadenas, Pich)
The phenomenological approach of KS-like works (Finkemeier and Mirkes ’95, ‘96) do not include all possible contributions for the exchanged resonances and
depend noticeably on the excited resonances parameters.
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
CLEO (Liu ’03, CLEO ‘04) could not fit their data using FM expressions and reshaped the model violating the normalization of
the WZ term (i.e. low-energy QCD).
BaBar presented their data on these modes in TAU’06. However the plot of the spectral function vs. invariant mass of the hadronic system was not
at the Proc. (Nugent ‘06) and they have not submitted the paper yet.
First work on this already in ’90 (González-García, Gómez-Cadenas, Pich)
BaBar has recently (BaBar ‘07) published very precise data on e+e- KK using ISR events. Furthermore, their Dalitz-plot fit has allowed to separate cleanly the I=0,1 contributions. Assuming CVC and comparing to ALEPH ’99 allows to derive (V/T) = 0.167+0.024 in Under CVC one can relate e+e- data to the decay.(Davier, Descotes-Genon, Höcker, Malaescu, Zhang ‘08)
The phenomenological approach of KS-like works (Finkemeier and Mirkes ’95, ‘96) do not include all possible contributions for the exchanged resonances and
depend noticeably on the excited resonances parameters.
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
1. Computation of the involved process within RT(15 couplings).
2. Brodsky-Lepage behaviour demanded to the Form Factors (6 couplings).
3. Computation and fit to Br(3) completing (Pich, Portolés, Ruiz-Femenía ‘03). Use of some constraints from this work for <VVP> (3 couplings).
4. Axial-form factor fixed by 3(2 couplings). (Gómez-Dumm, Pich, Portolés ‘04) (Cirigliano, Ecker, Eidemüller, Pich, Portolés ‘04).
5. Vector-form factor fixed thanks to BaBar data on e+e- and ALEPH’99’s full spectrum.
Our work: (Gómez Dumm, Pich,
Portolés, R. in progress)
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
1. Computation of the involved process within RT(15 couplings).
2. Brodsky-Lepage behaviour demanded to the Form Factors (6 couplings).
3. Computation and fit to Br(3) completing (Pich, Portolés, Ruiz-Femenía ‘03). Use of some constraints from this work for <VVP> (3 couplings).
4. Axial-form factor fixed by 3(2 couplings). (Gómez-Dumm, Pich, Portolés ‘04) (Cirigliano, Ecker, Eidemüller, Pich, Portolés ‘04).
5. Vector-form factor fixed thanks to BaBar data on e+e- and ALEPH’99’s full spectrum.
Our work: (Gómez Dumm, Pich,
Portolés, R. in progress)
Thus, we can concentrate on improving the most challenging aspect in decays into three mesons: The axial-vector form factors and, specifically, the off-shell width of the a1.
Easy to extend to the e+e- scattering below 2 GeV.
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)
OUTLOOK: hhh
hhh
3
2K
K 2
2
K
3K
FA FV
Vus, ms
m
Vus, ms Vus, ms
CONCLUSIONS• Current analyses of data using TAUOLA have shown
theoretical inconsistencies. We would like to improve the hadronic matrix elements in TAUOLA and PHOKARA.
• We have studied these decays within RT with a Large NC-inspired model guided by QCD.
• We have used BaBar data on e+e- to fix our free parametres on the Vector Current sector. We will improve our analysis once data are published.
• We aim to improve our off-shell a1 width in order to revisit .
• Our results have been implemented in SHERPA (LHC and TEVATRON) and may be used by the B-factories.
• LHC, BABAR, BELLE, BES…are promising facilities to test our predictions.
• The future looks even more promising and exciting: Vus, ms, mand, of course,
hadronization of QCD currents.
PHI PSI 08 FrascatiIMPROVING HADRONIZATION IN TAUOLA
Pablo Roig (IFIC)