Upload
holland
View
64
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Hadron Physics at KLOE and KLOE-2. Camilla Di donato Sez. infn napoli On behalf of kloe and kloe-2 collaborations. Outline. Hadron Physics @ KLOE/2 U-boson Search : e + e - / U Light Meson Spectroscopy : and physics Other KLOE/2 results not discussed here - PowerPoint PPT Presentation
Citation preview
CAMILLA DI DONATOSEZ. INFN NAPOLI
ON BEHALF OF KLOE AND KLOE-2 COLLABORATIONS
Hadron Physics at KLOE and KLOE-2
Outline
C. Di Donato - Rencontres de Moriond QCD 2
Hadron Physics @ KLOE/2U-boson Search: e+e-/ULight Meson Spectroscopy: and physicsOther KLOE/2 results not discussed herePS Transition FF Physics: /f0(600) Study of (S/PS )
Pion FF from e+e- /
KLOE and KLOE-2 @ DAFNE
e.m. calorimeter resolution
d.c. performances
mm
m
z
xy
2
150
ps
GeVE
psT 100
57
GeVEEE %7.5
C. Di Donato - Rencontres de Moriond QCD 3
mm
pp
VTX
TT
3
%4.0
DAFNE: e+e- collider @ s 1020 MeV ; peak3.1 b
U
U-Boson Search
C. Di Donato - Rencontres de Moriond QCD 4
Low Energy Dark Forces
C. Di Donato - Rencontres de Moriond QCD 5
Several unexpected astrophysical observations (PAMELA, ATIC, INTEGRAL, DAMA/LIBRA, CoGent...) could be explained with the existence of a hidden gauge sector weakly coupled with SM through a mixing mechanism of a new GAUGE BOSON (U, A, V) with the photon:
• U mass range: 1 MeV – few GeV• Coupling constant of electric charge to U: 10-3
• U production/decay through photon mixing
[Arkani-Hamed et al. PRD79 015014 (2009)]
[Essig et al. PRD80 015003 (2009)]
Search for U boson @ KLOE
C. Di Donato - Rencontres de Moriond QCD 6
Meson Decays: U, U, 0 U … Peculiar of a light meson factory
e+e- collisions: e+e- U x-sec 1/s : 100 times higher at DAFNE w.r.t. b-factories/
compensate lower luminosity
h-strahlung: e+e- U* Uh If the hidden simmetry is spontaneously broken by a Higgs-
like mechanism, the existence of at least one other scalar particle , can be postulated h
Meson can decay to a U boson with: YXBRFFYUXBR XY 22
fbU 40 310,1 FFfor
Irreducible background: Dalitz decay l+l- , ( = 0.7 nb)
BRFFUBR22
e+ e- , with +-0
BR(e+e-)=1.15 10-
4 : produced events 106 e+e-
L = 1.5 fb-1
PLB706 (2012) 251-255
C. Di Donato - Rencontres de Moriond QCD 7
e+ e- , with +-0
• We have 14000 candidates: e+e- with + - 0
• Very small residual contamination from • MC Mee shape from VMD with FF slope from SND (213 events) [PLB504
(2001) 275]
Background extracted directly from dataC. Di Donato - Rencontres de Moriond QCD 8
PLB706 (2012) 251-255
Fit to Mee Shape
Using decay parametrizationfrom Landsberg85 and F(q2) approx. from Achasov, Kozhevnikov, Sov. J. Nucl.Phys. 55 (1992) 449
23
222
222
22
22
2
222
2
41
21
41
3
mm
qm
mm
q
q
m
q
m
q
qFee
dq
dqq
22
2
1
1
qqF
222
0
2
11
2
GeVmb
dqdFbq
C. Di Donato - Rencontres de Moriond QCD 9
Exclusion plot for
Kinematic factors [Reece-Wang, JHEP0907:051 (200)]
Opening of U+- threshold
0,,
,,2223
22223222
mm
mmmmF
U UU
2 10-5 @ 90% C.L. for 50 < MU < 420 MeV
Evaluation of UL takes into account:
C. Di Donato - Rencontres de Moriond QCD 10
PLB706 (2012) 251-255
PRL107 (2011)PRL106 (2011)
PLB706 (2012)
e+ e- , with /000
Preliminary studies on and 000 decay channels produce encouraging results
U.L. can be improved by a factor 2C. Di Donato - Rencontres de Moriond QCD 11
+- DECAY
Light Meson spectroscopy
C. Di Donato - Rencontres de Moriond QCD 12
Light Mesons: +-
C. Di Donato - Rencontres de Moriond QCD 13
Box Anomaly: are expected to get contribution from anomaly, Wess Zumino Witten term in ChPT Lagrangian
According to Effective Theory (HLS: Benayoun, Eur. Phys. J. C31 (2003) 525), they could be described by VMD + a direct term
/
+
-
VMD CT
+
Studies of final state interaction by unitarized extensions:
Picciotto, Phys. Rev. D45 (1992) 1569; Benayoun, Eur. Phys. J. C31 (2003) 525 Holstein, Phys. Scripta, T99 (2002) 55 Borasoy, Nissler, Nucl. Phys. A740 (2004) 362
Model independent method based on ChPT and dispersive analysis: do not fix relative strength between tree level contribution and resonance contribution
(Stollenwerk, Hanhart, Kupsc, Meiner and Wirzba PLB707 (2012) 184-190)
+- ++0
C. Di Donato - Rencontres de Moriond QCD
This analysis:L = 558 pb-1
2107 mesons
(4.6%
• Theory HLS-Model: (w = (56.31.7)
eV (wo = (100.92.8) eV
• ( = (604) eV [PDG] provide strong evidence in favour of BOX Anomaly 14
, +-
M
Even
ts/4
M
eV
2 clusters: |tcl-lcl/c|<5 2 Tracks closest to IP 1 clusters: E>250 MeV
Two body decays constrain E
Kinematic from decays constrain
Main background +-0
BKG feature: in the 0 rest frame are back to back ( < 165°)
TOF to reject e+e- background Signal in M+- window (539.5÷554.5)
MeVC. Di Donato - Rencontres de Moriond QCD 15
+-
C. Di Donato - Rencontres de Moriond QCD
Pmiss=Pφ−Pπ+−Pπ−
−Pγφ
missmiss PE
16
Data sample L = 558 pb-1
N =204 950
=(21.310.04)%; B/S=10% Signal counting from fit to E-P
pppp
EEEsE
Composition
Normalization Sample: +- 0
C. Di Donato - Rencontres de Moriond QCD 17
L = 558 pb-1
N =1´190103
=(22.770.02)%; B/S=0.65% e+e-=41.8 0.2 nb
BR() = (22.41 0.03 0.35)%
(systematics include: 0.5% (lumy)1%(x-sec.) 1% (evcl) 0,43% (cut analysis) = 1.56% )
Pmiss=Pφ−Pπ+−Pπ−
−Pγφ
PDG’10:BR() = (22.74 0.28)%
+- ++0
C. Di Donato - Rencontres de Moriond QCD 18
Measurement has been performed on L=558pb-1
•N=204´950 and N = 1´190´000• Systematics at level of 1.5%
0.00280.00050.1856
0±±=
πππηΓ
γππηΓ+
+
eV±=γππηΓ + )355(• Theory HLS-Model:
(w = (56.31.7) eV (wo = (100.92.8) eV
• ( = (604) eV [PDG]
+-
C. Di Donato - Rencontres de Moriond QCD 19
Fit with Model independent method based on ChPT and dispersive analysis: (Stollenwerk, Hanhart, Kupsc, Meiner and Wirzba PLB707 (2012) 184-190)
d/
dM
Dipion Invariant Mass
sms
sssmm
s
2
33233110
41
23
1
ssFsAP
ds
dV 0
2
ssP
ssssFV
1
)14.080.13()01.013.2()01.012.2(1 32
ssFsAPs
sd
d
V 0
2
2
1
C. Di Donato - Rencontres de Moriond QCD 20
PLB707 (2012)
202.059.025.089.1 GeVWASA
NTeo (taking into account efficiency and smearing)
Nbin
i i
Nbin
jijj
Teoj
datai SNN
12
2
2
ssP 1
202.040.008.031.1 GeVthsyststat
Dipion Invariant Mass
Ndata
PRELIMINARY
[WASA Coll. PLB707 (2012) 243-249]
6783
2
Ndf
C. Di Donato - Rencontres de Moriond QCD 21
DAFNE-Upgrade
New scheme
Old scheme
C. Di Donato - Rencontres de Moriond QCD
DANE upgrade -New interaction scheme: large beam crossing angle + sextupoles for crab waist Luminosity increase: factor ~ 3; Ldt 1 pb-1/hour
22
KLOE Upgrade
C. Di Donato - Rencontres de Moriond QCD 23
Minimal detector upgrade for first KLOE-2 run (≈5 fb-1 in 1 year):
taggers to detect momentum of leptons in e+e→e+e→e+eX
Inner Tracker:4 layers of cylindrical triple GEM
Q-CALT/C-CALT: Increase acceptance for ’s from IP (21°→10°)
Conclusions
High statistic samples of light mesons produced @KLOE allowed to perform precision measurement and to look for very rare decays
Analysis on full KLOE data set:→ U,→[PLB706 (2012) 251-255]→ [Preliminary in arXiv: 1107.5733 hep-ex]→ → [arXiv: 1107.3782 hep-ex]
e+e- taggers in KLOE-2
New data taking@KLOE-2 in 2012: not stable running yet
C. Di Donato - Rencontres de Moriond QCD 24
SPARE
C. Di Donato - Rencontres de Moriond QCD 25
e+ e- , with +-0
BR(e+e-)=1.15 10-4 : produced events 106 e+e-
PLB706 (2012) 251-255
C. Di Donato - Rencontres de Moriond QCD 26
peak
Ks KL
e+ e- , with +-0
• We have 14000 candidates: e+e- with + - 0
• Very small residual contamination from • MC Mee shape from VMD with FF slope from SND (213 events) [PLB504
(2001) 275]
Background extracted directly from dataC. Di Donato - Rencontres de Moriond QCD 27
PLB706 (2012) 251-255
2011/06/14 28
Physics:
Ne e e e X XX
Weizsäcker-Williams approx, |q2|
<< W2
Tagger is essential to reduce bckg from and to close kinematics KLOE-2
Lint = 1 fb
Xeeee
Fusion
C. Di Donato - Rencontres de Moriond QCD 29
eeee 0
sE
psEMsM
T
LTmiss
222 2
@KLOE without tagger
Fusion
C. Di Donato - Rencontres de Moriond QCD 30
eeee 000
C. Di Donato - Rencontres de Moriond QCD 31
Fusion00 eeee
Fusion:
2011/06/14 32
00 eeee
33
Fusion: 00 eeeePRELIMINARY
@KLOE without tagger
KSKL
ωπ0
f0γ
• 240 pb-1 @ s = 1 GeV• 8090 events after selections• Bkg normalized using x-sections