Transcript Folie 1

7th DESY Workshop on Elementary Particle Theory
Loops and Legs in Quantum Field Theory
April 25 -30, 2004
Zinnowitz (Insel Usedom)
Physics with DAFNE
Wolfgang Kluge
Institut für Experimentelle Kernphysik, Universität Karlsruhe
Content
1. DAFNE
2. Experiments at DAFNE
3. Physics with DAFNE
3.1. DEAR
3.2. FINUDA
3.3. KLOE
(DAFNE Exotic Atoms Research)
(FIsica NUcleare a DAFNE)
(K LOng Experiment)
3.3.1. Neutral Kaon decays
_
3.3.2. Hadronic cross sections e+ e-  q q
4. DAFNE-2
5. Conclusions
1. DAFNE
e+ e-
_
 g*  q q  f(1020)
Te  Te  510 MeV
e-
g
*
e+
f(1020)  K+ K49.5 %
o
o
f(1020)  K Lo KSo ( K K ) 34.4 %
f(1020)  r p
f(1020)  p+ p- po
f(1020)  h g
12.9 %
1.9 %
1.3 %
f(1020), JPC = 1-
-
_
q q (f)
hadrons
well defined quantum state: C(f) = -1
Ko K o 
1
( K pL
2
 interferometry
KSp  K pS KLp )
DAFNE
Cross section sf  3 mb , f-rate of 1.5 kHz at L = 5 ∙ 1032 cm-2 s-1
DAFNE
Design
number of bunches
120
2002
(KLOE)
51
lifetime (min)
120
40
70
bunch current (mA)
40
20
20
1.5 ∙1030
1.8 ∙1030
L bunch (cm-2s-1)
4.4 ·1030
2004
(KLOE)
110
L peak (cm-2s-1)
5.3 ∙1032
0.8 ∙1032
2.0 ∙1032
L integrated (fb-1)
5 (1 yr)
0.3
2
Main merit: tagging
Ko
Ko
_
(KL KS, K+ K-) and vice versa
2. Experiments at DAFNE
Detectors:
0. DEAR
nuclear physics
Kaonic hydrogen
1. KLOE
particle physics
hadronic cross sections
2. FINUDA nuclear physics
hypernuclei, KN, K-atoms
DEAR
3. Physics with DAFNE
Production and decays of the lightest mesons (simplified scheme)
p p
p
g
0-
1--
BR 49% / 34%
f(1020)
K+ KKo Ko
g
h(958)
g
h(547)
g
p
po
p
g
fo (980)
ao (980)
po
w(782)
BR 1%
0++
BR 15%
r(770)
3.1. DEAR (DAFNE Exotic Atoms Research, not triggerable)






Low-energy Kaon Nucleon scattering
Test of chiral perturbation theory
KN s-terms (extent of chiral symmetry breaking) ?
Strangeness content of the nucleon from KN s-terms ?
1 % measurement of the shift e and a few percent
measurement of the width G of the Ka line of Kaonic
hydrogen and the first measurement of Kaonic deuterium
e + i G/2 = 412 aK-p eV fm-1
e + i G/2 = 614 aK-d eV fm-1
From the shift the isospin dependent KN scattering lengths
(with a few %) are obtained
aK-p = (ao + a1) / 2 (isovector, isoscalar)
aK-n = a1
Kaonic hydrogen
DEAR results: Kaonic hydrogen
Kaonic hydrogen spectrum after background subtraction:
Kaonic hydrogen (world‘s best measurement)
1000
repulsive
800
X-ray
600
KpX
0
-500
DEAR
G = 250 ±137 eV
200
e = - 323 ± 63 ± 11 eV
G = 407 ± 208 ± 100 eV
400
attractive
Iwasaki et al. 1997
e = - 200 ±45 eV
width G[eV]
0
shift e [eV]
500
SIDDHARTA (future plans 2005-06)
(SIlicon Drift Detector for Hadronic Atoms Research by Timing Application,
being triggerable)

precision measurement at the level of a few eV of 1s level shift
of Kaonic hydrogen and first measurement of Kaonic deuterium

measurement of the charged Kaon mass at the level of 10 keV

light Kaonic atoms (He, Li, Be,…)

other hadronic exotic atoms (Sigmonic hydrogen)
3.2. FINUDA (FIsica NUcleare a DAFNE)
a fixed target experiment at a collider, uses K+ K- pairs (pK = 127 MeV / c)

 AZLAZ  p
L hypernuclei are produced via K stop

hypernuclear spectroscopy to test theoretical models of LN potentials (measuring pp)

hypernuclear decays to study weak processes in nuclear matter

Weak decays of hypernuclei

basic weak decays and reactions:
L  n  po
L n  n n

and
and
L  p  p
L p  n p
G p :
mesonic weak decays of hypernuclei,
suppressed by Pauli blocking in medium heavy nuclei G o :
p


nonmesonic weak decays of hypernuclei
(dominant in medium heavy nuclei,
test of DI = 1/2 rule ?)
lifetimes of hypernuclei
  / G tot
A
A

L Z ( Z  1)  p
A
A
o
L Z Z  p
Gn :
A
( A 2)
Z
L Z
Gp :
A
( A2)
( Z  1)  n 
L Z
 n n
G tot  G n  G p  G p-  G p
there exist very few measurements of Gn , Gp , Gp-, Gp+
p
FINUDA hypernucleus formation:
e+ e-  g*  f(1020)  K+K-

K stop
 AZLAZ  p
p-
A
ZZ
p
 ( A 2)( Z  1)  n  p
e+ e-  K+ K-
FINUDA hypernucleus formation:
  6 Li  6 Li  
K stop
p
L
d
6
L
Li  L4 He  n+p
4
L
He  d+d
K+
+n
stop  m
Km+ d
K+
d
  12C 
K stop
12
L
C  p
BL  0
preliminary
BL = -10 MeV
pp [ GeV/c]
3.3. KLOE (K LOng Experiment)
2000 statistics: 25 pb-1
KS physics:
BR(KS  p± e n)
BR(KS  p+ p-(g)) / BR(KS  p p)
7 publications in Phys. Lett. B
f radiative decays
f
f
 fo g, ao g
 h g,
scalar mesons
h g
pseudoscalar mesons
2001 + 2002 statistics
f  r p  p+ p- p
r-parameters
KS decays ( g g, p p p)
KL decays, KL  p p, KL  g g
KL lifetime
Vus from K± and KL decays
500 pb-1
analyses in progress,
first publications submitted
s(e+e- p+ p-) via Initial State Radiation
DAFNE-2
?
double ratio e (e/ e)
semileptonic asymmetries (CPT test)
KL KS interferometry
future ?
KLOE data taking in 2000-2002
pb-1
2000:
25 pb-1
80 106 f decays
2002
2001
2000
days of running
5 months of KLOE data taking in 2002:
best value of Lpeak:
0.78 ∙ 1032 cm-2s-1
best L dt per day:
4.5 pb-1
2001:
170 pb-1
530 106 f decays
2002:
280 pb-1
870 106 f decays
Events
CP – invariance violating event
KS  p+ ptagging!
KL  p+ p-
Initial State Radiation (ISR)
e+ e-  p+ p- g
p+
KL
ppp-
KS
p+
g
p
+
3.3.1 Neutral Kaon decays
(tests of discrete symmetries and cPT)

and Vus


Semileptonic decays Ko  p±
e n
: CPT test
KS  po po po: CP and CPT test
R = G(KS  p+
p): double ratio,
do-d2
p-(g))
/
G(KS  p
strong phase shifts
KLOE: hep-ex / 0402030
chiral perturbation theory
Test of

DS = DQ rule (1st order weak interaction)

CPT invariance
Ko  p± e n
DS = DQ
A(Ko  p-e+ n) = a + b
A(Ko  p+e- n) = a*- b*
DS  DQ
A(Ko  p+e- n) = c + d
A(Ko  p-e+ n) = c*- d*
= 0 if CPT holds
Charge asymmetries
AS,L 
G(p-e+n)
S,L
-
G
G(p-e+n)S,L + G
AS += e2-(e
K+
(p
n)e
S,L
e dK + e b / a -
-2n)
(eS,L eK (pA+Le=
CP
AS - AL = 4 e dK  0 implies CPT
e d*/ a)
e dK + e b / a + e d*/ a)
CPT in CPT in DS  DQ
CPT
mixing decay
KS  p± e n
events / MeV
L  500 pb-1
events / MeV
KS  p-p+
 data
__ MC
KS  p-p+
 data
__ MC
KS  p-e+n
KS  p+e-n
Emiss – c |pmiss| (MeV)
N(p-e+ n) = 11531  181
Emiss – c |pmiss| (MeV)
N(p+ e- n) = 11805  177
radiative corrections included in MC (no Eg cutoff)
KS  p± e n
KLOE (L = 170 pb-1, 2001 data)
BR(p- e+ n) = (3.54 ± 0.05stat ± 0.06syst)  10-4
BR(p+ e- n) = (3.54 ± 0.05stat ± 0.04syst)  10-4
BR(p e n) = (7.09 ± 0.07stat ± 0.08syst)  10-4
CMD-2:
BR(p e n) = (7.2 ± 1.4)  10-4
BR(KS  p
e
n) = BR(KL  p
e
Phys. Lett. B 456 (1999) 90
n)
(GL /
GS) = (6.704 ± 0.071)  10-4
PDG group 2003
CMD-2 1999
L ??
PDG evaluation from KL
KLOE 2002
KLOE 2003
6
7
8 10-4
Phys. Lett. B 535 (2002) 37
KS  p± e n
charge asymmetry
AS - AL ~ 4 e dK  0 implies CPT
KLOE:
170 pb-1
AS = (-2 ± 9stat ± 6syst)  10-3
AS not yet measured so far
KTeV 2002:
AL = (3.322  0.058  0.047)  10-3
CP LEAR:
Re dK = (2.9  2.7)  10-3 if DQ = DS
Re dK = (3.0  3.4)  10-3 if DQ  DS
KTeV 2002
AL ∙ 102
KLOE
AS ∙ 102
CKM unitarity and Vus
G.Isidori, hep-ph / 0311044
± 1.2 %
Most precise test of CKM unitarity comes from 1st row:
PDG 2002: |Vud|2 + |Vus|2 + |Vub|2 ~ |Vud|2 + |Vus|2 = 1 – D = 0.9957 ± 0.0026
D = 0.0043 ± 0.0019 using |Vus|= 0.2196 ± 0.0026 and |Vud | = 0.9739 ± 0.0005
Brookhaven experiment E865 (2003)
BR(K+  po e+ n (g)
(4.87 ± 0.06) %
by 2.3 s higher than PDG 2002:
|Vus|E865 = 0.2272 ± 0.0023rate ±
|Vus|E865 = 0.2238 ± 0.0033
|Vus|E865 = 0.2275 ± 0.0030
) = (5.13 ± 0.02stat + 0.09syst + 0.04norm) %
0.0023lt ± 0.0007f+
BR(K+

p e+
n
D = 0.0001 ± 0.0016
(g)
A. Ali hep-ph/0312303
D = 0.0024 ± 0.0021
V. Cirigliano, H. Neufeld, H. Pichl, hep-ph/0401173
D = 0.0002 ± 0.0030
D. Bećirević, G. Isidori et al., hep-ph/0403217
)
=
KS 
p± e 
n
Unitarity band, based on Vud
E 865
KLOE
PDG 2002 (average)
Vus
0.235
0.230
2s
0.225
0.220
0.215
1
0.210
1
Ke3
cPT up to p4
Keo3
2
Ke3
Keo3
H. Leutwyler, M. Roos, Z. Phys. C 25 (1984) 91
confirmed by lattice calculation
D. Bećirević et al., hep-ph/0403217
K o p
Vus f
(0)
= 0.960 ± 0.009
2
cPT up to p6
V. Cirigliano et.al. hep-ph/0401173
J. Bijnens and P. Talavera, Nucl. Phys. B 669 (2003) 341
K o p
Vus f
(0)
= 0.981 ± 0.010
KLOE result in better agreement with Brookhaven K+ data than with PDG 2002 analysis

S,L
S,L
K e3 K m
K
K
3
e3
m3 work in progress
KS  po p p :
test of CP and CPT
Uncertainty on KS  p p p amplitude limits precision of CPT test (d).
SM prediction:
BR(KS  po p p) = 1.9 10-9
present published result:
BR(KS  po p p) < 1.4  10-5
NA 48
BR(KS  p p p) < 3.0  10-7
KLOE:
BR(KS  p p p) < 2.1  10-7
Unitarity (Bell-Steinberger relation):
 i ( lS  lL )  K S | K L  
results in G S (1  i tan fsw) (ee i m d) 
f A (KS  f )


f
A( K L
A ( K S  f ) A( K L  f )
(eS,L
 f)
=
e
A limit on BR(KS  p p p) at the level of 10-7 translates into a 2.5 fold
improvement on the accuracy of m d ( < 2  10-5)
assuming CPT invariance in the decay G o  G o:
K
K
D( mK o  mK o )
mK
 18
 2  10
improvement D( m

Ko
 mK o )
mK
 5  1019
compare
with
mK
 4  10 20
mPlanck
R = G(KS  p+ p-(g))
/ G(KS  p p)
2.221  0.014
2.236  0.003  0.015
PDG 2003
KLOE 2002
Phys. Lett. B 538 (2002) 21
KLOE 2002
 half of double ratio R for e e/ e
de e/
e
R
=
1.6
∙·10-4)
N( K L  p p )
N( K S  p p )
N( K L  po po )
h

N( K S  po po ) hoo
(dR / RKLOE  0.1 %
2
2
2
e e
'
e
'
'

 1 3
 1  6 e e
e
e 2e
'
e
 e. m. isospin breaking in K  p p
 extract do – d2 taking into account radiative corrections

Extraction of strong phase shifts do – d2 from KS  p
A - 
Ao ei do 
2
3
Aoo  
A o 
1
3
3
4
1
3
Ao ei do 
A2 ei d2
2
3
p
 extraction of K  p p amplitudes must take into
account effective cutoff on Eg for g in final state
A2 ei d2
 include isospin-breaking e.m. effects
cI  dI  g
AI ei dI  ( AI  dAI ) ei cI
I
A2 ei d2
gI = e.m. phase shift
 K  p p decays actually measure co – c2 ,
for do – d2 theoretical input (go – g2) needed
R
 
G(KS  p p )
o o
G(KS  p p )

2 pc.m.
c.m.
poo
2
(56  8)
Cirigliano et al. 2001
/
G(p
with w = A2 / Ao  1 / 20
do (47.7 d
 21.5)
cPT ,
scattering
p
p
Colangelo et al. 2001
KLOE 2002 value for
p-)
2 cos( do  d2 )
1  2 w  2 2 w cos( do  d2 )
co c2
PDG
G(p+
2
1  w2  w
p)
(48  3)
3.3.2. Hadronic cross sections e+ e-  q q
Experiment:
Theory:
KLOE
PHOKHARA
H. Czyż, J. H. Kühn, G. Rodrigo et al.
F. Jegerlehner et al.
S. Jadach et al.
Hadronic cross sections e+ e-  q q
g
Determination of the hadronic vacuum polarisation,
a contribution to precision tests of the SM of particle physics
a) Precision experiment (g – 2)m
Brookhaven E821
b) Running fine structure constant
aQED (MZ)
 constraint on Higgs mass mHiggs
 effective Weinberg angle etc.
Anomalous magnetic moment of muons
am (gm 2) / 2  a/ 2p ...

B field

m+

q

g q
m+

g
hadrons
QED
had
weak
new
atheor

a

a

a

a
m
m
m
m
m
 QED
aQED
m
 hadronic vacuum polarisation ahad
m
 weak contribution
aweak
m
 contribution beyond SM
anew
m
Hadronic vacuum polarisation

The hadronic contribution to vacuum polarisation is dominated by low energy effects
which cannot be obtained by perturbative QCD for low s
but rather
 by experimental data of e+ e- annihilation into hadrons and / or by -decays
evaluating the dispersion integral
 amm


ahad

m
 3p 


R( s) 
2


2
4 mp
ds
R( s) Kˆ ( s)
s2
s tot (e e  g
*  q q  hadrons)
s tot (e e  g
*  m m )
up to some sufficiently high energies, typically 2…5 GeV, and by pQCD for higher energies
2
ˆ ( s)  0.63 at s  4mp
ˆ ( s)  1.0 at s   )
Kˆ ( s) being a smooth function ( K
and K

The energy denominator 1 / s  1 / E2 enhances dramatically low energy
(non perturbative) contributions
Status of g-2 as of Jan. 2004
hep-ex / 0401008
 new value from BNL for m-
Jan. 2004
 previous result from BNL for m+
Aug. 2003
 averaging the BNL results
Jan. 2004
am- = 11 659 214 (8) (3)  10-10
am+ = 11 659 203 (6) (5)  10-10
am = 11 659 208 (6)  10-10
 SM with e+ e- data
am = (11 659 180.9  7.2had  3.5LBL  0-4QED+ew)  10-10
am = (11 659 179.4  8.6had  3.5LBL  0-4QED+ew)  10-10
am = (11 659 176.3  7.4had  3.5LBL  0-4QED+ew)  10-10
 SM with  data
am = 11 659 195.6  5.8had  3.5LBL  0-4QED+ew) (6)  10-10
Davier et al., Dez. 2003
Jegerlehner et al., Dez. 2003
Hagiwara et al., Dez. 2003
Davier et al., Dez. 2003
Status of g-2 as of Jan. 2004
hep-ex / 0401008
Comparison between experimental values and theoretical predictions
230
220
210
e+ e-
200
190
m+ m-
180
average

D J H
170
160
150
am - 11 659 000  10-10
SM using e+ e- data and E821 disagree by 2.7…3.0 s
SM using  data and E821 disagree by 1.4 s
 data from ALEPH, OPAL, CLEO, e+ e- data dominated by
 Davier et al., hep-ex / 0312065
 Hagiwara et al., hep-ph / 0312250
 Jegerlehner et al., Phys. Lett. B 583 (2004) 222
CMD-2
= (696.3  6.2aexphad
,LO
3.6rad) ∙ 10-10

,LO
= (692.4  5.9exp  2.4rad) ∙ 10-10
ahad

,LO = (694.8  8.6exp) ∙ 10-10
ahad

Determination of s(e+ e- p+ p-) by using the emission of
photons in the initial state (Initial State Radiation ISR) e+ e- p+ p- g
Radiative return to the resonances r, w (an alternative to the energy scan)
J. H. Kühn et al.



2
Conventionally s(e+ e-  hadrons,Qhadr
) is measured as a function of energy
making an ‘energy scan’
at DAFNE not foreseen for the foreseeable future, DAFNE has been designed for high
luminosity at the f resonance
alternative approach (‘radiative return’):
Run at fixed energy s  mf and exploit the process e+ e- hadrons + g with the g
emitted in the initial state (ISR) to reduce centre of mass energies of the colliding
e+ e- and consequently the energy of the hadronic final state (here two pions)
2
2
2
2mp
 Mpp
 mf
2
2
Q2  Mpp
 mf
 2mfEg
Radiative return (Initial State Radiation)
g
es = m2
f
g
*
e+
DAFNE : radiative return to r, w :
(w) g p+ p- g
J p=1-
p-
_
qq
(r, w)
e+ e-
g*
_
p+s' =
2
M pp
g qq gr
Radiative return
 The ISR-method (‚radiative return’) needs precise calculations of higher order
radiative corrections (Monte Carlo generators EVA1, PHOKHARA2, KK MC3)
 Final State Radiation has to be taken into account1-4
1, 2
H. Czyż, J. H. Kühn, G. Rodrigo et al.
3 S. Jadach et al.
4 J. Gluza, F. Jegerlehner et al.
But
 the radiative corrections and the absolute luminosity have to be known only
for one fixed energy (1020 MeV)
Hadronic cross section
e+ e-  p+ p- g
Measurement: s(e+ e-  p+ p-
ng)
Goal by applying PHOKHARA  s(e+ e-
 p+
,LO
p)
and
ahad
m
First analysis: small photon angles
50 < qp < 130 
qg < 15 ( > 165), Eg > 10 MeV
detection of two charged
pions
no photon detection
qg
2
dN / dQpp
L = 140 pb-1
r,
w

high statistics
 high resolution
2
low
M
kinematically suppressed
2
Qpp
(GeV2 )
+ +
Hadronic cross section e e  p p g
nb
2
Qpp
(GeV2 )
Total experimental and theoretical error : 1.3 %
experimental systematic error:
theoretical error:
1.0 %
0.8 %
Bare cross section (measured cross section corrected for vacuum polarisation)
The cross section to be inserted in the dispersion integral has to be the bare cross section
1.08
g
ee+
g
*
e+
p
_
g qq
*
+
d(s)
1.06
1.04
e-
p
Vacuum polarisation
-
1.02
1
0.2
0.4
0.6
0.8
1.0
2
2
Mpp(GeV )
2


ao
  d( s)  ao2  s bare( s)
s ( s)  a2 ( s)  
 1  Da ( s)  Da ( s) 
lep
had


d(s) from F. Jegerlehner
Hadronic cross section
e+ e-  p+ p-
Integrating the bare cross section in the region 0.35 GeV2 <
KLOE:
22
< 0.95 GeV
Qpp
pp
- 0.95 GeV2) = (389.2  0.8stat  3.9syst ± 3.1theor)  10-10
a(0.35
m
Comparison with CMD-2 in the energy interval 0.37 <
KLOE:
pp
(0.37 - 0.93) = (376.5  0.8stat  4.8syst+theor)  10-10
am
CMD-2:
(0.37- 0.93) = (378.6  2.7stat  2.3syst+theor)  10-10
app
m
2 GeV2
<Q0.93
pp
(± 4.9)
(± 3.6)
KLOE confirms discrepancy of 10 % between e+ e- and  data in the region above r-peak
Origin: different masses and widths of charged and neutral r mesons, not observed so far ?
S. Ghozzi and F. Jegerlehner, Phys. Lett. B 583 (2004) 222
M. Davier, hep-ex/0312064
FSR corrections
For the evaluation of the dispersion integral for ahad
one needs s(e+e-  p+ p-)
m
including FSR e+ e-  p+ p- gFSR (ISR+ FSR)
g
_
qq
p
+
p
-
B field

g
g
*

m+
g

g
q
*

g q
hadrons
m+

g
Treatment of FSR corrections
(2 complementary approaches using PHOKHARA)
approach 1: ‘FSR excluding’
N(e+e-  p+ p- gISR gFSR)
subtract FSR contribution
approach 2: ‘FSR left included’
N(e+e-  p+ p- gISR gFSR )
event analysis
PHOKHARA: ISR
event analysis
PHOKHARA: ISR+FSR
luminosity
luminosity
s(e+e-  p+ p- gISR)
s(e+e-  p+ p- gISR gFSR )
radiator H
radiator H
s(e+e-  p+ p-gFS )
R
‘added by hand’ 0.8 …0.9% (Schwinger
1990)
s(e+e-  p+ p- gFSR )
How well do these two approaches agree?
Treatment of FSR corrections
Comparison of the two approaches, differ by < 0.2%
line = approach 1
+ = approach 2
 scalar QED
is assumed in
PHOKHARA to simulate FSR processes
 charge asymmetries test scalar QED
ratio = approach 1 / approach 2
2
M 
(GeV2 )
2
M 
(GeV2 )
+ +
Hadronic cross section e e  p p g
Charge asymmetries due to FSR-ISR interference, test of FSR models
(e. g. scalar QED = pointlike pions)
Second analysis: large photon angles qg
detection of two charged pions
detection of one photon
0.9 – 1.0 GeV2
A( qp) 




50 < qp < 130
50 < qg < 130, Eg > 10 MeV
Nip ( qp)  Nip ( qp)
Nip ( qp)  Nip ( qp)
MC (ppg+mmg+ppp)
data
0.8 – 0.9 GeV2
d(MC-data) < 13%
qp
MC (ppg+mmg+ppp)
MC (ppg only)
data
low M 2 populated

Summary
Kaon physics:

BR(KS) at the 10-7 level (KS  p p p)

semileptonic K3 decay modes (KS,L , K±) under investigation (1 % level)
Hadronic physics:

hadronic cross section s(e+e-  p+ p-) determined by radiative return
with 1.3exp.+theo % confirms difference between data and SM for am
(so far small photon angle analysis covering M 2 > 0.37 GeV2)


Radiative return at large photon angles, work in progress:
Contribution of am in the energy interval M 2 < 0.37 GeV2

4. DAFNE-2









DAFNE-2 at the horizon ?
energy up to 2 GeV
luminosity up to 5 ∙ 1034 cm-2 s-1 = 50 nb-1 s-1 = 50 000 mb-1 s-1
corresponding to 5  1011 KS (KL) / year (1 ‚technical year = 107 s)
lower machine background
rich physics program for KLOE (original proposal and present program continueing)
KS  po p p, first evidence CP for in KS decays, BR ~ 2  10-9
semileptonic decays KS  p± e n
 |Vus|
interference patterns to determine hi = A(KL  i) / A(KS  i),
e d,
m d, phases to study CP and CPT
K±  p p+ p- and K±  p± p p, slopes and asymme
Alghero Workshop on e+ e- in the 1 - 2 GeV range, 2003, Sept. 10-13
5. Conclusion


first successful production runs for DEAR, FINUDA
500 pb-1 for KLOE in 2001-2003
many KLOE results already better than current PDG numbers
in spite of a luminosity, by almost an order of magnitude lower than
originally specified
hadronic vacuum polarisation in agreement with CMD-2 results


DAFNE on the track to the fb-1 era in 2004
DAFNE-2 at the horizon (energy up to 2 GeV,
luminosity up to 5 ∙ 1034 cm-2 s-1, lower machine background) ?
KS  p e n

x  c / a 
 p e n H weak K o 
 
 p e n H weak K o 
x  12 ( x  x) with
2x 
DS = DQ rule (SM: |x+| ~ 10-6)
x
c * d * c *

a b
a
(CPTassumed)
and
x
c* d * c*

a b
a
G S( p-e n)  G S( p+e n)  G L ( p-e n)  G L ( p+e n)
- 
+ 
- 
+ 
G S( p e n)  G S( p e n)  G L ( p e n)  G L ( p e n)
KLOE (170 pb-1 of 2002)
Re x+ = (3.3 ± 5.2stat ± 3.5syst) ∙ 10-3
CP LEAR 1998
Re x+ = (-1.8 ± 4.1stat ± 4.5syst) ∙ 10-3
(CPassumed)
CPLEAR
CP
LEAR 1998
KLOE
DS  DQ (2nd order weak interaction)
·
d
S=1
Q=0
Ko
W
s
u
+
W
S=1
Q=0
d
K
o
s
A( K o  p e n)
A( K o  p e n)
 7  10 7
-
·

n
-

W

p
d
u
· ·
u

S=0
Q=1

n
W

u
+
p
d
S=0
Q=1
calculated with cPT, M. Luke, Phys. Lett. B 256 (1991) 265
KS  p± e n
Comparison of Brookhaven () and KLOE ()
o 
of Vus fK p (0) with PDG 2002:
K o p
Vus f
(0)
 PDG 2002 data
G(K+  po e+ n)
G(KL  p- e+ n)
G(K+  po m+ n)
G(KL  p- m+ n)
Ke3
Keo3
K m3
K om3
KS  p± e n: Vus
E 865
KLOE
PDG 2002
Ke3
cPT calculation up to p4
Keo3
H. Leutwyler, M. Roos, Z. Phys. C 25 (1984) 91
confirmed by lattice calculation
cPT up to p6:
G. Isidori
et al., hep-ph/0403217
o 
Cirigliano et.al. hep-ph/0401173
Vus fK
p
(0) = 0.961 ± 0.008
Vus fK
Final analysis being ahead
o
p
(0) = 0.981 ± 0.010
p


G(KL  g g) /
p), KL lifetime
G(KL 
p
dominated by long-distance contributions (p, h, h)
cPT calculation sensitive to qP
dominates long distance contribution to KL  m+ m-
KL  g
g
KL  po po po
362 pb-1
KLOE: L = 51.6 ± 0.4 ns
PDG: L = 51.7± 0.4 ns
KLOE 2003: ratio = (2.79 ± 0.02 ± 0.02)10-3
Phys. Lett. B 566 (2003) 61
NA48 2002: (2.81 ± 0.01 ± 0.02)10-3
PDG 2003: (2.81 ± 0.02)10-3
Measurement of KS mass
f peak scan
(e+e- KS KL ) (mb)
f  KS KL
K S  p + p-
KLOE:
m(KS) = 497.583  0.005  0.020 MeV
W2


m ( K S) 
 ( p   p  )2
4
2
s
(MeV)
CMD-2
W (MeV)
momentum scale calibrated with CMD-2 2001: m(f) = 1019.483  0.011  0.025 MeV
NA48
KLOE
KL  charged particles
BR
KL  p+

p
KL  pp m
n
KL  p e n
KL  p+ p-
KLOE
PDG 2003
0.132  0.002
0.1257  0.0019
0.271  0.002
0.2717  0.0025
0.384  0.002
0.3878  0.0027
(2.04  0.04) ∙ 10-3
(2.081  0.026) ∙10-3
78 pb-1 2002 data
KL  p
KL  p+ p-
K L  p+ p- p
m n
KL  p
en
Theory:
H. Czyż, J. H. Kühn, G. Rodrigo et al.
EVA
tree level ISR  LO FSR  interference
PHOKHARA 1
ISR NLO
PHOKHARA 2
ISR NLO  LO FSR (EVA)
PHOKHARA 3
ISR NLO  (FSR + ISR)  LO FSR
FSR: scalar QED, pointlike pions
PHOKHARA
with 2 photons no distinction between ISR+ISR or ISR+FSR photons
LO FSR (no ISR): e+ and e- collide with mf
2
 the virtual g* has Q2 =mf
leading order (LO ISR)
g
g
*
_
qq
p
g
*
+
_
qq
p
+
g
p
p
+ virtual corrections
-
-
NLO (ISR+FSR):
simultaneous initial state and final state photons
next to leading order (NLO)
g
g
g
*
_
qq
p
+
p
-
g
*
_
qq
p
+
p
-
g
+ virtual corrections
Experimental systematic errors
efficiencies
trigger:
tracking:
vertex:
likelihood:
trackmass mtrack:
acceptance:
background:
unfolding:
0.6 %
0.3 %
0.3 %
0.1 %
0.2 %
0.3 %
0.5 %
0.3 %
total:
1.0 %
Theoretical errors
radiator function H:
vacuum polarization:
Luminosity:
FSR:
0.5 %
0.2 %
0.5 %
0.3 %
total:
0.8 %
error of FSR:
d(proposal 1-2):
d(MC-data) < 20 % of a
total contribution of FSR
of < 1%
0.2 %
total:
0.3 %
Total experimental and theoretical error : 1.3 %
0.2 %
FSR corrections
NLO (ISR+FSR)
FSR / ISR
LO - FSR (no ISR)
LO FSR is a background to be subtracted,
it is lower < 1 % due to our acceptance cuts
%
before trackmass cut
FSR / (FSR+ISR)
after trackmass cut
2
Mpp
(GeV2 )
2
Mpp
(GeV2 )
trackmass cut very efficient in cutting FSR:
2 = 0.35 GeV2
before the cut there are up to 4 % at Qpp
FSR enhanced due to two-step process:
e+ e-  r g  (p+ p- g)
g
e+ e- data versus -decays (after correction of CMD-2 in Aug. 2003)
| F | 2e e  | F | 2
| F | 2
s ( GeV2)
above the r-peak -data are systematically higher by 
10%
sbare(KLOE-CMD2) / KLOE
s (GeV2)
Total efficiency in %
,LO
ahad
m
80
60
2
Mpp
(GeV2 )
The future ?


final goal is the experimental determination of s(e+ e-  p+ p-) with
an error of 0.3…0.5 %, in order to determine
to better than 3.5 ∙ 10-10 (0.5 %)
ahadr
m
KLOE group collaborates with several theoretical groups
Institut für Theoretische Teilchenphysik, Universität Karlsruhe (J. H. Kühn, G. Rodrigo et al.)
Institute of Physics, University of Silesia, Katowice (H. Czyż et al.)
DESY Zeuthen (F. Jegerlehner et al.)
Henryk Niewodniczanski Institute of Nuclear Physics, Cracow (S. Jadach)
  12C 
K stop
12
L
C  p
preliminary
excited state
@ 261 MeV/c
ground state
@ 275 MeV/c
pp [ GeV/c]