Project of upgrade of the DANE accelerator and the associated programme Patrizia Rossi - INFN-Laboratori Nazionali di Frascati (ITALY) JINR Programme Advisory Committee for Particle Physics 25th meeting, Dubna 20 April 2006

PRESENT AND NEXT FUTURE e+e- COLLIDERS ADA 1960-1962 ADONE 1969-1993 DANE 1998-2009 LNF (Frascati) DANAE: DAfne New - Adjustable Energy PHI-factory + Wide energy range High luminosity at PHI energy

DANAE Energy and Luminosity Range Energy @ center of mass (GeV) 1.02 2.4 Integrated luminosity per year (fb-1) > 10 1 Total integrated luminosity (fb-1) > 50 3 Peak luminosity (cm-2 sec-1) > 1033 1032 Use of DANE builbings Use of DANE infrastructures Use of DANE injection system + upgrade of transfer lines Use of large part of magnets, diagnostics NEW Dipoles Wigglers RF system Vaccum chamber Interaction region Application of new technologies Use of DANE runs for R&D while increasing L for next experiments

High Luminosity Program PHYSICS PROSPECTS AT LNF WITH DANAE High Luminosity Program K physics (http://www.lnf.infn.it/kloe/kloe2) Ks rare decays Neutral kaon interferometry , ’ physics Kaonic nuclear physics (http://www.lnf.infn.it/esperimenti/siddharta/LOI_AMADEUS_March2006.pdf) Study of deeply bound kaonic nuclear states High Energy Program Time-Like Form Factors (http://www.lnf.infn.it/conference/nucleon05/FF/) Measurement of the nucleon and hyperons ( and ) form factors Hadronic cross section measurement Vector meson spectroscopy Radiative decays of excited vector meson (hep-ex/0603056)  physics

DANTE: DAnae Nucleon Time-like form factor Experiment http://www.lnf.infn.it/conference/nucleon05/FF/ Letter of Intent by 82 physicist from 25 institution in 8 countries: http://www.lnf.infn.it/conference/nucleon05/loi_06.pdf Very positive feedback from the international community at the Workshop on Nucleon Form Factors, 12-14 October 2005, Frascati

Hadron Electromagnetic Form Factors Different charge and magnetization distributions Quark angular momentum contribution? Rosenbluth polarization Linear deviation from dipole GE≠GM Hadron Electromagnetic Form Factors FFs are fundamental quantities describing the internal structure of the hadron (# point-like). In a P- and T-invariant theory, the EM structure of a particle of spin S is defined by 2S+1 form factors. FFs are closely connected with the generalized parton distribution (GPDs) the new non-perturbative formalism which gives a complete description of the nucleon structure, and are used to constraint GPDs models. FFs are important ingredient in a wide range of experiments, from neutrino physics to many other measurements involving nucleons. Since the Stern experiment in 1932 indicating that the proton was not a point-like particle they have been extensively measured but: - In the space-like region recent results obtained with polarized beam completely changed our knowledge showing a dramatically different picture. The charge and magnetization distribution inside the nucleon are different - In the time-like region they are still pratically unknown Space-like FFs are real, time-like are complex and they are connected by dispersion relations

NucleonTime-like FFs |GM| PROTON DATA |GM| NEUTRON DATA Early pQCD scaling |GM| ~ Q-4 NucleonTime-like FFs |GM| Assumption: |GE|=|GM | Ebeam (GeV) PROTON DATA Steep behaviour close threshold Time-like FF larger than space-like |GM| Assumption: GE=0 NEUTRON DATA neutron ~4 times the proton extrapolation pQCD predicts the limit |GMn|≈(qd/qu)2 |GMp|= | GMp|/4

Anomalous behavior in total cross section BaBar found steps in total cross section at s =2.2 and 2.9 GeV

Nucleon Time-Like FFs measurements FF extraction from cross section measurements in e+e- N N and p p  e+e- s=4M2  |GM|=|GE| s>>4M2  |GM|>>|GE| Up to now, no independent extraction of both TL FFs has been performed FF measurements are based on total cross section, under some theoretical assumption on their ratio |GM| can be more easily extracted, but it’s model-dependent |GE| remains unmeasured

Summaryzing:Nucleon Time-like FFS are basically unknown |GE|  |GM| in the space-like region (recent Jlab results). Why should be valid in the time-like region? |GEp|/|GMp| Ebeam (GeV) DANAE Phases of time-like FFs never measured Only one measurement for neutron magnetic FF Inconsistencies between data and pQCD expectations

Smaller cross section as for nucleon production: sTOT ~ 0.1 nbarn Hyperon Form Factors Smaller cross section as for nucleon production: sTOT ~ 0.1 nbarn Hyperon Energy th Decay ch L 2.231 Np (pp- , np0) S+ 2.378 Np (pp0 , np+) S0 2.385 Lg S- 2.395 Np (np-) Y Y final state could be identified by detecting the decay of one hyperon Angular distributions  moduli of FF For weakly decaying hyperons (L(1116), S±(1189)) the polarization measurement does not require a polarimeter (can be studied by looking at the angular distribution of the decay products)

DETECTOR REQUIREMENTS The DANE detectors KLOE FINUDA 1 m DETECTOR REQUIREMENTS high detection acceptance for charged and neutral particles good neutron detection efficiency polarimeter

Nucleon FF measurement: projected accuracy Integrated luminosity  700- 1000 pb-1 (~6 months measurements) proton Projected data assuming |GE| = |GM| or |GE|/|GM| from DR Integrated luminosity =100 pb-1 Constant detection efficiency =80% fit of angular distributions in the FINUDA coverage F(q)=A(1+cos2q)+Bsin2q neutron Statistical error of the order of few percent for all the 4 nucleon FFs in the whole explored region Projected data assuming |GE| = |GM| or |GE|=0 Integrated luminosity =100 pb-1 Constant detection efficiency =15% fit of angular distributions in the FINUDA coverage F(q)=A(1+cos2q)+Bsin2q

Induced polarization - extraction of FF relative phase The complex phases of the FFs in the TL region make it possible for a single outgoing baryon to be polarized in e+e-BB even without polarization in the initial state - extraction of FF relative phase non negligible polarization Py maximal at 45° and 135° high discriminating power between theories For ΔP/P 30 %: ~ 1 year measurement (total luminosity 2500 pb-1 )

Competitors VEPP2000 BEPC PANDA-PAX s (GeV) MN 2.0 2.4 4.2 proton neutron VEPP2000 max energy ~ 1 GeV per beam, luminosity ~ 1032 cm-2 s-1 pp and nn measurement start run ~ 2007 BEPC energy range ~ 2.4-4.2 GeV, luminosity ~ 1033 cm-2 s-1 only pp measurement start run ~ 2007 PANDA-PAX inverse reaction pp → e+e- (no neutron measurement) single and double polarization measurements start run >2013 DANAE

Other measurements made possible with DANAE @ high energy Study of angular asymmetry in pp (nn) distributions  look for 2-photon contribution Precision test of the SM: Measurement of the total cross section e+ e- →hadrons to get the hadronic contribution to (M2z) and  DANAE impact on R 1-2.5 GeV energy region Is the most poorly known (~15% uncertanty) and contributes ~40% to (M2z) Significant improvement from DANAE Threshold region: 2m - 0.5 GeV 2 fb-1 @ 1 GeV (ISR events) stat < 1%  peak region (0.5 - 1 GeV) DANE and VEPP2M have measured the hadronic total cross section at a percent level (even if there are discrepancies at about ±5% level). Babar is going to release its results No significant improvement from DANAE Request: R ~1% in the whole energy range from threshold to  (M2z) 

Other measurements made possible with DANAE @ high energy The search and study of narrow vector mesons in the 1-2.4 GeV mass range Several evidences of narrow (<100 MeV), unespected structures like for istance in e+ e- →3+3 - , e+ e- →2+2 - 20 , e+ e- →+ - 20 , e+ e- →2+2- and the corresponding channels in diffractive photoproduction, near the NNbar threshold e+ e- → 3p+ 3p- DM2 E687 @ FNAL g p → p 3p+ 3p- BaBar New vector meson? NN bound state? (baryonium) M~ 2mN Discrepancy in  _ Experiment Reaction M (GeV/c2) G (MeV) DM2 6 ~1.93 ~ 35 FENICE mh ~1.87 ~10 E687 3+3- 1.91±0.01 33± 13 BaBar 1.88±0.05 130± 30 2+2-20 1.86±0.02 160± 20 2+2- 1.88±0.01 180± 20 +-20 1.89±0.02 190± 20

DANAE tentative schedule (C DANAE tentative schedule (C. Biscari - Workshop on DISCOVERIES IN FLAVOUR PHYSICS AT e+e- COLLIDERS, Frascati, February 28 2006) To CDR and Project approval (2006) To + 1 year call for tender To + 2 years construction and delivery To + 3 years DANE decommissioning and DANAE installation To + 4 years 1st beam for commissioning and for 1st experiment (2010)

Conclusions A new project for an e+e- storage ring collider at the LNF (Italy) based on the actual DAFNE  factory, is been developping. The new machine will be amplified in energy and luminosity and it is designed to run in two modes: High energy (up to 1.2 GeV energy per beam) High luminosity (up to 1033 cm-2 sec-1 @ ) For both cases interesting physics programs has been proposed One of these is the measurement of the time-like nucleon and hyperon form factors - The proposed experiment will allow: Accurate measurement of pp and nn cross section  model-independent extraction of proton and neutron FFs at the few percent level for the proton and < 10% for the neutron. First measurement of outgoing proton (neutron) polarization  relative phase between GE and GM First measurement of Λ (Σ) baryon production (including polarization)  strange baryon FF