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 PS Transition FF  Physics: /f0(600) Study of (S/PS ) Pion FF from e+e- / C. Di Donato - Rencontres de Moriond QCD

KLOE and KLOE-2 @ DAFNE e.m. calorimeter resolution d.c. performances DAFNE: e+e- collider @ s 1020 MeV ; peak3.1 b C. Di Donato - Rencontres de Moriond QCD

U-Boson Search U C. Di Donato - Rencontres de Moriond QCD

[Arkani-Hamed et al. PRD79 015014 (2009)] Low Energy Dark Forces 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: [Arkani-Hamed et al. PRD79 015014 (2009)] [Essig et al. PRD80 015003 (2009)] U mass range: 1 MeV – few GeV Coupling constant of electric charge to U:   10-3 U production/decay through photon mixing C. Di Donato - Rencontres de Moriond QCD

Search for U boson @ KLOE 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: for Irreducible background:  Dalitz decay l+l- , ( = 0.7 nb) C. Di Donato - Rencontres de Moriond QCD

 e+ e- , with +-0 L = 1.5 fb-1 BR(e+e-)=1.15  10-4 : PLB706 (2012) 251-255  e+ e- , with +-0 L = 1.5 fb-1 BR(e+e-)=1.15  10-4 : produced events  106 e+e- C. Di Donato - Rencontres de Moriond QCD

PLB706 (2012) 251-255  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 data C. Di Donato - Rencontres de Moriond QCD

Fit to Mee Shape Using decay parametrization from Landsberg85 and F(q2) approx. from Achasov, Kozhevnikov, Sov. J. Nucl. Phys. 55 (1992) 449 C. Di Donato - Rencontres de Moriond QCD

Exclusion plot for  PLB706 (2012) 251-255 Exclusion plot for  Evaluation of    UL takes into account: Kinematic factors [Reece-Wang, JHEP0907:051 (200)] Opening of U+- threshold PLB706 (2012)   2  10-5 @ 90% C.L. for 50 < MU < 420 MeV PRL107 (2011) PRL106 (2011) C. Di Donato - Rencontres de Moriond QCD

U.L. can be improved by a factor 2  e+ e- , with  /000 Preliminary studies on  and 000 decay channels produce encouraging results U.L. can be improved by a factor 2 C. Di Donato - Rencontres de Moriond QCD

Light Meson spectroscopy +- decay C. Di Donato - Rencontres de Moriond QCD

Light Mesons: +-  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 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 + / - +   - + /  VMD CT Model independent method based on ChPT and dispersive analysis: do not fix relative strength between tree level contribution and resonance contribution (Stollenwerk, Hanhart, Kupsc, Meiner and Wirzba PLB707 (2012) 184-190) C. Di Donato - Rencontres de Moriond QCD

+- ++0  Theory HLS-Model: ()w = (56.31.7) eV ()wo = (100.92.8) eV () = (604) eV [PDG] provide strong evidence in favour of BOX Anomaly This analysis: L = 558 pb-1  2107  mesons (4.6% ) 14 C. Di Donato - Rencontres de Moriond QCD

, +-   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 Events/4 MeV M Signal in M +- window (539.5÷554.5) MeV C. Di Donato - Rencontres de Moriond QCD

+-  Data sample L = 558 pb-1 Ng =204 950 =(21.310.04)%; B/S=10% Signal counting from fit to E-P C. Di Donato - Rencontres de Moriond QCD

Normalization Sample: +- 0  L = 558 pb-1 N =1´190103 =(22.770.02)%; B/S=0.65% e+e- =41.8 0.2 nb Composition BR() = (22.41 0.03 0.35)% (systematics include: 0.5% (lumy)1%(x-sec.) 1% (evcl) 0,43% (cut analysis) = 1.56% ) PDG’10:BR() = (22.74 0.28)% C. Di Donato - Rencontres de Moriond QCD

+- ++0  Measurement has been performed on L=558pb-1 N=204´950 and N = 1´190´000 Systematics at level of 1.5% Theory HLS-Model: ()w = (56.31.7) eV ()wo = (100.92.8) eV () = (604) eV [PDG] C. Di Donato - Rencontres de Moriond QCD

+-  d/dM Fit with Model independent method based on ChPT and dispersive analysis: (Stollenwerk, Hanhart, Kupsc, Meiner and Wirzba PLB707 (2012) 184-190) C. Di Donato - Rencontres de Moriond QCD

Dipion Invariant Mass PLB707 (2012) C. Di Donato - Rencontres de Moriond QCD

PRELIMINARY Dipion Invariant Mass NTeo (taking into account efficiency and smearing) Ndata PRELIMINARY [WASA Coll. PLB707 (2012) 243-249] C. Di Donato - Rencontres de Moriond QCD

DAFNE-Upgrade DANE upgrade -New interaction scheme: large beam crossing angle + sextupoles for crab waist Luminosity increase: factor ~ 3;  Ldt  1 pb-1/hour New scheme Old scheme C. Di Donato - Rencontres de Moriond QCD

KLOE Upgrade Inner Tracker: 4 layers of cylindrical triple GEM 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-g*g*→e+e-X Q-CALT/C-CALT: Increase acceptance for ’s from IP (21°→10°) C. Di Donato - Rencontres de Moriond QCD

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: f → hU, h → p+p-p0 [PLB706 (2012) 251-255] h → p+p-g [Preliminary in arXiv: 1107.5733 hep-ex] gg → h/gg → p0p0 [arXiv: 1107.3782 hep-ex]  e+e- taggers in KLOE-2 p+p-g/m+m-g New data taking@KLOE-2 in 2012: not stable running yet C. Di Donato - Rencontres de Moriond QCD

SPARE C. Di Donato - Rencontres de Moriond QCD

PLB706 (2012) 251-255  e+ e- , with +-0 BR(e+e-)=1.15  10-4 : produced events  106 e+e-  Ks KL  peak C. Di Donato - Rencontres de Moriond QCD

PLB706 (2012) 251-255  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 data C. Di Donato - Rencontres de Moriond QCD

Weizsäcker-Williams approx, |q2| << W2  Physics: Weizsäcker-Williams approx, |q2| << W2 Tagger is essential to reduce bckg from f and to close kinematics  KLOE-2 X Lint = 1 fb-1 2011/06/14

 Fusion @KLOE without tagger C. Di Donato - Rencontres de Moriond QCD

 Fusion C. Di Donato - Rencontres de Moriond QCD

 Fusion C. Di Donato - Rencontres de Moriond QCD

 Fusion: 2011/06/14

 Fusion: PRELIMINARY @KLOE without tagger 240 pb-1 @ s = 1 GeV 8090 events after selections Bkg normalized using x-sections KSKL ωπ0 f0γ