Alessandro Scordo SNP201412/12/2014 Advances and perspectives in the low-energy kaon-nucleon/nuclei interaction studies at the DAFNE collider
The key role of KN interaction in low energy QCD
The unexplained nature of (1405) Its nature is being a puzzle for decades: 1) three quark state: expected mass ~ 1700 MeV 2) penta quark: more unobserved excited baryons 3) unstable KN bound state Only at rest events (cut at mass limit)
The 2 poles picture of (1405) two poles: (z1 = – i ; z2 = – i ) MeV mainly coupled to KN mainly coupled to → line-shape depends on production mechanism Pure I=0 (free from (1385) background) Line-shape also depends on the decay channel :
The DA NE accelerator e + e - at 510 MeV -> at-rest resonance decays at 49.2 % in K + K - back to back pair Monochromatic beam of low momentum K - (p k = 127 MeV/c) Currents of 2 A (e - ) and 1 A (e + ) KLOE detector
What was done at DA NE Past experiments Kaonic atoms Hypernuclei Low-energy Kaon-nuclei processes DEAR SIDDHARTA FINUDA AMADEUS – step 0
What DA NE Kaonic atoms Hypernuclei Low-energy Kaon-nuclei (deeply bound ) SIDDHARTA-2 AMADEUS? AMADEUS Kaon mass
DEAR and SIDDHARTA SIlicon Drift Detector for Hadronic Atom Research by Timing Applications LNF- INFN, Frascati, Italy SMI- ÖAW, Vienna, Austria IFIN – HH, Bucharest, Romania Politecnico, Milano, Italy MPE, Garching, Germany PNSensors, Munich, Germany RIKEN, Japan Univ. Tokyo, Japan Victoria Univ., Canada
Exotic atoms
s p d f K keV = E 2p 1s E 1s } E 2p n KK Exotic atoms Strong interaction causes a shifting of the energy of the lowest atomic level from its purely electromagnetic value Absorption reduces the lifetime of the state, so Xray transitions to this final atomic level are broadened.
SIDDHARTA - main results: - Kaonic Hydrogen: 400pb -1, most precise measurement ever,Phys. Lett. B 704 (2011) 113, Nucl. Phys. A881 (2012) 88; Ph D 78 citations - Kaonic deuterium: 100 pb -1, as an exploratory first measurement ever, Nucl. Phys. A907 (2013) 69; Ph D - Kaonic helium 4 – first measurement ever in gaseous target; published in Phys. Lett. B 681 (2009) 310; NIM A628 (2011) 264 and Phys. Lett. B 697 (2011); PhD 51 citations - Kaonic helium 3 – 10 pb -1, first measurement in the world, published in Phys. Lett. B 697 (2011) 199; Ph D - Widths and yields of KHe3 and KHe4 - Phys. Lett. B714 (2012) 40;; kaonic kapton yields DEAR & SIDDHARTA – important TRAINING for young researchers - 8 Ph Ds
\ K-p threshold = 1432 MeV
Exotic Atoms: Future Perspectives Bonus) Kaonic hydrogen at precision better than 10 eV (calib. For Kd) pb -1 1) Kaonic deuterium measurement : 800 pb -1 (500 pb -1 ) 2) Kaonic helium 3 and 4 transitions to the 1s level and 2p level 400 pb -1 3) Other kaonic atoms (KC, KSi, KNi, KSn, KPb…) – 200 pb -1 /each (could be done in parallel) 4) Kaon mass precision measurement at the level of <10 keV 5) Investigate the possibility of the measurement of other types of hadronic exotic atoms (sigmonic hydrogen ?)
AMADEUS AMADEUS collaboration 116 scientists from 14 Countries and 34 Institutes lnf.infn.it/esperimenti/siddhartaand LNF-07/24(IR) Report on lnf.infn.it web-page (Library) AMADEUS started in 2005 and was presented and discussed in all the LNF Scientific Committees Antikaon Matter At DA NE: Experiments with Unraveling Spectroscopy EU Fundings FP7 – I3HP2 and HP3: Network WP9 – LEANNIS; WP24 (SiPM JRA); WP28 (GEM JRA)
Low-energy K - hadronic interactions studies with KLOE data MC simulations show that : ~ 0.1 of K - stopped in the DC gas (90% He, 10% C 4 H 10 ) ~ 2% of K - stopped in the DC wall (750 mm c. f., 150 mm Al foil). K+K+ K-K- Possibility to use KLOE materials as an active target Advantage: unprecedent resolution : p /p ~ 0.4 MeV/c 4 -geometry with ~ 96% acceptance Calorimeter optimized for : m ~ 18 MeV/c 2 Vertex position resolution ~ 1 mm (in DC) Disadvantage: Non dedicated target → different nuclei contamination → complex interpretation.. but → new features.. K - in flight absorption.
DC wall (C+H) Beam Sphere (Be+Al) DC gas (C+H+ 4 He) Beam Pipe inner part (Be) DC entrance wall (C+H) H, 4 He, 8 Be, 12 C The reaction can be studied on several different materials: H, 4 He, 8 Be, 12 C KLOE data
AMADEUS step-0: Pure Carbon target inside KLOE (2012) Advantages: gain in statistics ( ~ 90 pb -1 ; analyzed 37 pb -1, x1.5 statistics) K - absorptions occur in Carbon absorptions at-rest. Dedicated run in november/december 2012 with a Carbon target 4/6 mm thickness DC wall (C+H) BP (Be+Al) DC gas (C+H+ 4 He) 2005 data: at-rest + in-flight events 2012 data: ONLY at-rest events Carbon target (C)
Investigation of K - interactions on light nuclei (H, 4 He, 8 Be, 12 C) (H, 4 He, 8 Be, 12 C) Reactions: K - 'p' → 0 0 (non resonant) OR K - 'p' → (1405) → 0 0 (resonant) K - 'p' → + - (non resonant) OR K - 'p' → (1405)/ (1385) → + - (resonant) K - ‘p' → 0 (non resonant) OR K - 'p' → (1385) → 0 (resonant) p/ d/ t correlations → 2NA, 3NA, 4NA AT-REST (K - absorbed from atomic orbit) or IN-FLIGHT
MC calculation in collaboration with prof. Wycech (Cracow)