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This project aims to upgrade the DANE accelerator and associated program in Frascati, Italy, to improve energy range, luminosity, and physics prospects. It includes the use of existing infrastructure, new technologies, and applications of DANE runs for R&D purposes. Physics prospects include high energy program, time-like form factors, hadronic cross-section measurement, radiative decays, and kaonic nuclear physics.
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Project of upgrade of the DANE 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 LNF (Frascati) ADA 1960-1962 ADONE 1969-1993 DANE 1998-2009 DANAE: DAfne New - Adjustable Energy PHI-factory + Wide energy range High luminosity at PHI energy
Use of DANE builbings • Use of DANE infrastructures • Use of DANE 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 DANE runs for R&D while increasing L for next experiments DANAEEnergy and Luminosity Range
PHYSICS PROSPECTS AT LNF WITH DANAE • 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 • 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
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
Rosenbluth polarization Linear deviation from dipole GE≠GM • Different charge and magnetization distributions • Quark angular momentum contribution? • - 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 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 time-likeregion they are still pratically unknown Space-likeFFs arereal, time-likeare complex and they are connected bydispersion relations
|GM| |GM| • Early pQCD scaling |GM| ~ Q-4 • Time-like FF larger than space-like Assumption:GE=0 Assumption: |GE|=|GM | NEUTRON DATA neutron ~4 times the proton extrapolation pQCD predicts the limit |GMn|≈(qd/qu)2 |GMp|= | GMp|/4 Ebeam (GeV) NucleonTime-like FFs PROTON DATA • Steep behaviour close threshold
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
|GEp|/|GMp| DANAE Ebeam (GeV) 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? • 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 • 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)
1 m The DANE detectors KLOE FINUDA • DETECTOR REQUIREMENTS • high detection acceptance for charged and neutral particles • good neutron detection efficiency • polarimeter
proton neutron Nucleon FF measurement: projected accuracy Integrated luminosity 700- 1000 pb-1 (~6 months measurements) • 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 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
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 - Induced polarization • 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 )
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 proton neutron s (GeV) 2.0 2.4 4.2 MN Competitors
DANAE impact on R Threshold region: 2m - 0.5 GeV 2 fb-1 @ 1 GeV (ISR events) stat < 1% peak region (0.5 - 1 GeV) DANE 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 1-2.5 GeV energy region Is the most poorly known (~15% uncertanty) and contributes ~40% to (M2z) Significant improvement from DANAE (M2z) 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-→hadronsto get the hadronic contribution to (M2z) and Request: R ~1% in the whole energy range from threshold to
BaBar DM2 E687 @ FNAL e+ e-→ 3p+ 3p- e+ e-→ 3p+ 3p- g p → p 3p+ 3p- M~ 2mN Discrepancy in • New vector meson? • NN bound state? (baryonium) _ 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 - 20 , e+ e-→+ - 20 , e+ e-→2+2- • and the corresponding channels in diffractive photoproduction, near the NNbar threshold
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 DANE decommissioning and DANAE installation • To + 4 years 1st beam for commissioning and for 1st experiment (2010)
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 • Firstmeasurement of Λ (Σ)baryon production (including polarization) • strange baryon FF - - 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 themeasurement of the time-like nucleon and hyperon form factors