AMADEUS: Status Report C. Curceanu and O. Vazquez Doce for the AMADEUS collaboration

AMADEUS: Status Report

C. Curceanu and O. Vazquez Docefor the AMADEUS collaboration

22 November, LNF-INFN22 November, LNF-INFN3535thth LNF Scientific Committee LNF Scientific Committee

1) Preliminary KLOE data analyses by the AMADEUS group

Oton Vazquez Doce

2) AMADEUS PHASE-1: PHYSICS, SETUP AND ROLL-IN

PROPOSAL Catalina Curceanu

Preliminary Preliminary KLOE data analysisKLOE data analysisin the search for Kaonic Nucleiin the search for Kaonic Nuclei

by the by the AMADEUSAMADEUS collaboration collaboration

Oton Vázquez Doce35th LNF Scientific Committee

November 22, 2007

Oton Vázquez DoceKLOE data analysis by AMADEUS collaboration

LAMBDA selection Lambda-PROTON analysis Lambda-DEUTERON analysis


IntroductionIntroduction

•Total amount of data analyzed up to an integrated luminosity of

400 pb-1 from KLOE data (K-charged group)

•Special ntuples of KLOE data were created, with kaons tagged by 2-body decay or by the dE/dx signature in the DC gas.

•Strategy: Search for hadronic interactions with Λ(1116) as products:

• Λ → p + - (64% BR) vertex made by KLOE reconstruction• Construct a vertex with Λ + an extra particle

Lambda selection criteria: Λ → p + -

Search for vertices (by KLOE reconstruction) inside the Drift Chamber:•negative particle: - identified by low dE/dx in DC gas•protons:

protons with EMC-cluster associated


Lambda-PROTON analysis Lambda-DEUTERON analysisIntroduction LAMBDA selectionLAMBDA selection

protons without EMC-cluster+ protons with EMC-cluster

For protons, if no cluster associated, require:track reaching the calorimeter region + “proton signature” in the dE/dx of DC gas


pions


For more details:KLOE memo 337


Minv = 1115,717 ± 0. 004 MeV/c2

-Flat background-Gaussian describing the resonance-2nd Gaussian to account for E.lossin the DC wall


Lambda invariant mass Λ → p + -

σ = 0. 398 ± 0.005 MeV/c2

Fit

PDG: MΛ = 1115,683 ± 0.006 MeV/c2

Minv = 1115,717 ± 0. 004 MeV/c2


-Flat background-Gaussian describing the resonance-2nd Gaussian to account for E.lossin the DC wall



σ = 0. 398 ± 0.005 MeV/c2

Fit

PDG: MΛ = 1115,683 ± 0.006 MeV/c2

Split data sample:

•ρ < 35 cm → Λ from the DC inner wall•ρ > 35 cm → Λ from the DC volume

ρ > 35 cm

ρ < 35 cm


Λs from DC inner wall

Λs from DC vol.

Minv = 1115,722 ± 0. 005 MeV/c2

σ = 0. 398 ± 0.005 MeV/c2



PΛ (MeV/c)

PΛ (MeV/c)

Minv pπ (MeV/c2)

31203 events

5878 eventsMinv=1115,704 ± 0. 009 MeV/c2

σ = 0. 382 ± 0.011 MeV/c2

K-stopped + 4He → n + n + (K-pp)

Deeply Bound Kaonic States formation process


LAMBDA selection Lambda-DEUTERON analysisIntroduction Lambda-PROTON analysisLambda-PROTON analysis

p +π-

Λ + p




p +π-

Λ + p




?

p

Λ

p +π-

Λ + p




?

p

Λ

• Search for the proton with first DC measurement around the lambda vertex (30 cm. cylinder)

• Vertex lambda+proton assumption

• Proton is required to have an associated cluster in the EMC and

its mass is measured by time of flight.

p +π-

Λ + p




?

p

Λ

• Search for the proton with first DC measurement around the lambda vertex (30 cm. cylinder)

• Vertex lambda+proton assumption

• Proton is required to have an associated cluster in the EMC and

its mass is measured by time of flight.Pproton (MeV/c)

Mproton (MeV/c2)


Λ p analysisInvariant mass


2Mp+M-

Minv Λp (MeV/c2)

ρ < 35 cmDC inner

wall

ρ > 35 cmDC vol.

2Mp+MK

1156 events

215 events

Missing massFrom 4He+K-

(Mev/c2)


Invariant mass correlationsρ < 35 cm (DC inner wall)

Angular correlationCos θ (Λp)

cosθ < -0.8(back to back)


Λ p analysis

Mn+Mn+M0

Minv Λp (MeV/c2)


Invariant mass correlationsρ > 35 cm (DC volume)



Λ p analysis

Minv Λp (MeV/c2)


(Mev/c2)


Mn+Mn+M0

ρ > 35 cm(DC volume)

ρ < 35 cm(DC inner wall)


Invariant mass

Back to back(cos θ < -0.8)


Λ p analysis

2Mp+MK

2Mp+Mπ-

Minv Λp (MeV/c2)

2Mp+MK

2Mp+Mπ-

total Events 1156back to back 379

total Events 215 back to back 86

Total Yield = 0.03%BtB Yield = 0.01%(per stopped K-)




K-ppn

Λd Λnp Σ-pp Σ0d Σ0np

K-stopped + 4He → n + (K-ppn)

Tri-baryonic state possible decay channels:

LAMBDA selection Lambda-PROTON analysis Lambda-DEUTERON analysisLambda-DEUTERON analysisIntroduction




p + π-

Λ+ d?

p

Λ

• Search for the deuteron with first DC measurement around the lambda vertex (30 cm. cylinder)

• Vertex lambda+deuteron assumption

• Deuteron is required to have an associated cluster in the EMC

and its mass is measured by time of flight.




p + π-

Λ+ d?

p

Λ



• Deuteron is required to have an associated cluster in the EMC

and its mass is measured by time of flight.



Mdeuteron (MeV/c2)

Pdeuteron (MeV/c)



Mdeuteron (MeV/c2)

Pdeuteron (MeV/c)

Invariant mass



Λ d analysis

Minv Λd (MeV/c2)

Md+ Mp+ M-

ρ < 35 cmDC inner

wall

ρ > 35 cmDC vol.

Md + Mp+ MK

156 events

23 events

Invariant mass correlationsρ < 35 cm (DC inner wall)



Λ d analysis


(Mev/c2)


Minv Λd (MeV/c2)


Invariant mass correlationsρ > 35 cm (DC volume)



Λ d analysis


(Mev/c2)


Minv Λd (MeV/c2)


Invariant mass



Λ d analysis

Md+Mp+MK

Md+Mp+M

Minv Λd (MeV/c2)

156 total Events 69 back to back

23 total Events 12 back to back

Md+Mp+M-

Md+Mp+MK





Back to back(cos θ < -0.8)

AMADEUS global strategy:

AMADEUS phase-1: start end 2009 (after KLOE2 step0), study di- and tri – baryon kaonic nuclei and low-energy kaon-nucleon/nuclei interactions

AMADEUS phase-2: after 2010, higher integrated luminosity, refine study of di- tri-baryon kaonic nuclei; extend to other nuclei (spectroscopy of kaonic nuclei along the periodic table…)

AMADEUS collaboration:

119 scientists from 13 Countries and 34 Institutes

(+ JINR)(+ JINR)

Contents

1) The AMADEUS Phase –1: Scientific case

2) The AMADEUS phase-1 experimental setup

3) Monte Carlo simulations

4) AMADEUS Phase-1: luminosity request, implementation plan and proposal for the roll-in

5) Conclusions

The scientific case of the so-called “deeply bound kaonic nuclear states” is hotter than ever, both in the theoretical (intensive debate) and experimental sectors.

What emerges is the strong need for a complete experimental study of the scientific case, i.e. a clear and clean experiment, measuring kaonic clusters both in formation and in the decay processes.

AMADEUS’s main aim is to perform the first full acceptance, high precision measurement of DBKNS both in formation and in the decay processes, by implementing the KLOE detector with an inner AMADEUS-dedicated setup, containing a cryogenic target and a trigger system,

DBKNS physic (existent or not!) related to fundamental physics issues

• information on the modification of the kaon mass and on KN interaction in a nuclear medium, important

for the further understanding of aspects of low-energy

QCD in strangeness sector;

• gain information on the QCD phase-diagram changes of vacuum properties of QCD and

the quark condensate

• kaon condensation in a nuclear medium implication on astrophysics:

neutron stars, strange stars

• nuclear dynamics under extreme conditions could be investigated (e.g. nuclear compressibility)

Experimental programmeAMADEUS phase-1 (1)

• study of the (most) fundamental antikaon deeply bound nuclear systems, the

kaonic dibaryon states: ppK- and (pnK-)produced in a 3He gas target, in formation and decay processes

• as next step, the kaonic 3-baryon states: ppnK- and

pnnK-

produced in a 4He gas target, in formation and decay processes

n-detection: KLONE: NIM. A 581, 368 (2007)Results of KLOE data analyses (, p, d)

Experimental programmeAMADEUS phase-1 (2)

• Low-energy charged kaon cross sections on Helium(3 and 4), for K- momentum lower than 100 MeV/c (missing today);

• The K- nuclear interactions in Helium reactions (poorly known – based on one paper from 1970 …)

• Properties of (1116) and charged – for example decays in channels with neutrino -> astrophysics implications (cooling of compact stars)

• Resonance states as the elusive-in-nature but so important (1405) or the (1385) could be better understood with high statistics; their behaviour in the nuclear medium can be studied too.

AMADEUS @ KLOE, phase-1

Low-mass cryogenic gas target cell:T = 10 KP = 1.0 barRin = 5 cmRout = 15 cmL = 20 cm

Kaon trigger:two layers ofscint. fibers,stereo angel = 30°

readout on both sides with SiPM

AMADEUS @ KLOE, phase-1

SIDDHARTA Cryogenic target cell

Alu-grid

Side wall:Kapton 50 µm

Kaon entranceWindow:Kapton 50 µm

Working T 22 KWorking P 2.0 bar

Trigger test:Scintillating Fibers and APDs:

- tests are undergoing in SMI Vienna- BTF test in January 2008:FOPI - test

Technical items needing special attention• The beam pipe: we plan to develop (with KLOE and DAFNE) a technical solution which should be easy to extract/implement. Special attention will be dedicated to the mechanical supports.• Cryogenic target: dedicated studies not only for the target itself,but for its mechanical supports and cooling power needed and how to bring the cryogeny inside.• Trigger system: a technical solution for the trigger system, including the optimization of geometry and cabling.• Slow controls: we study the slow control system (to be complemented to the KLOE one) for the specific AMADEUS items.• DAQ: software and hardware. We are aware and started already to collaborate with KLOE on the item of DAQ needs, from software and hardware points of view. We will rely on KLOE solution for the software, eventually developing dedicated on-line and (mostly) off-line analyses and Monte Carlo simulations, the hardware should be care of AMADEUS, with expertize from KLOE.

Monte Carlo simulation

20% of all K- stop inside target

Monte Carlo simulation:

Momenta for particles from chain:

K- 4He -> (K-pp) + n

(K-pp) -> d

with BE = 120 MeV = 24 MeV

Well accessible for KLOE

Background under studyTo be integrated with KLOE MC

Luminosity request, implementation plan and proposal for the roll-in

Number of events in the “golden channel”K- 4He --> (K-pp) + n with (K-pp) --> d

20% Stopped kaonsY = 0.1 % for DBKNS formationBR to decay to this channel: 10% (with -> p-)

For 2 fb-1 integrated luminosity the number of events:

2 fb-1 x 3 b x 0.5 (Kch) x 0.2 (stop) x 0.001 (y) x 0.1 (BR) = 60000 ev

detection efficiency (20-40%) -> 12000 – 24000 events

Neutron efficiency (30%) -> 3600 – 7200 events for which both missing and invariant mass can be reconstructed, allowing so to have a complete information regarding the formation and decay of DBKNS in light systems.

The luminosity request for AMADEUS Phase-1 is:

• 2 fb-1 of integrated luminosity with He4 target in order to study the tribaryon DBKNS

• 1-2 fb-1 of integrated luminosity with He3 target in order to study the dibaryon DBKNS

• 0.5 fb-1 of integrated luminosity for low-energy kaon-nuclear dedicated measurements

for an overall integrated luminosity of 3.5 - 4 fb-1

With the luminosity upgrade of DAFNE, the machine should deliver at least 600 pb-1/month, which means that the overall AMADEUS Phase-1 program could be completed in about 8 months (considering installation).

Implementation plan and roll-in proposal (1)

• Cryogenic Target preparation: a first prototype will be built and tested within 2008; the final target will be built and tested in the first half of 2009.

• Trigger system: a first prototype containing 20 fibers read at both ends by APDs, is being prepared and will be tested on BTF in early 2008; a second prototype, with greater dimensions and two layers , will be built and tested at BTF within 2008; the final detector will be designed and built within first half of 2009.

• Beam pipe: a mixed team KLOE-DAFNE-AMADEUS will study this delicated item and will provide technical solution for the beam pipe and its mechanical sup-port; the beam pipe for AMADEUS will be ready in the first half of 2009.


• Monte Carlo simulations: will be developed continuously in parallel with the preparation of the setup and in collaboration with KLOE.

• Slow Control and DAQ (software and hardware): will be done in collaboration with KLOE; work already started.

• training to use KLOE detector: AMADEUS group offers to participate – in modalities to be optimized and decided - to the first phase of KLOE installation and DAQ in 2009 (a MoU is being prepared).


• AMADEUS assembly: the AMADEUS inner setup - the specific one - will be assembled and tested in the second half of 2009 so as to be ready for:

• roll-in of AMADEUS: roll in at the end of 2009 - beginning 2010, compatible with KLOE end of step 0.

• AMADEUS DAQ: for an integrated luminosity of about 4 fb-1 in 2010.

AMADEUS Phase-2 (after 2010)• Improve and complement the setup with different possible technical solutions, in order either to reduce the background and/or to perform more refined (better reso-lution) dedicated measurements;• eventually to install an inner tracker inside the DC of KLOE: we are considering two possible solutions, either cylindrical GEM detectors or a TPC-GEM combination (in collaboration with KLOE);• increase the statistics for di- tri-baryon DBKNS following the suggestions which will come out from Phase-1 of the experiment;• study DBKNS produced in heavier targets as: Li, B, Be, C …• complete the physics program by:binding energies, decay widths and – determination of quantum numbers of all states, including excited ones, measurement of the spin-orbit interaction, determination of partial widths of kaonic nuclear states by observation of all decay channels, Dalitz plots Continue studies of kaon-nucleon/nuclei interactionIntegrated luminosity request of about 10-20 fb-1

AMADEUS phase-2 Tracking device:

TPC-GEM or3-4 C-GEMs

Target system:cylindrical

cryogenic cellin vacuum chamber

Kaon trigger:Scint. fiberswith SiPMs

Conclusions (1)

Th proposal for the Phase-1 of the AMADEUS experiment at DAFNE was presented.

It has the goal to perform the first complete measurement ever (in formation and decay processes) of di - and tri-baryon DBKNS in Helium (3 and 4). It will give definite answers to the controversed item of the existence of DBKNS in light systems and measure their parameters.

Other important measurements in strangeness hadronic/nuclear physics will be as well performed.

Conclusions (2)

The AMADEUS Phase-1 setup implements the actual KLOE detector in the inner region with a cryogenic target and a trigger system. The technical items were clearly identified and a schedule for their construction and implementation put forward.

The luminosity request is of about 4 fb-1, with a roll-in schedule to start at the end of 2009. It was estimated that the DAQ period should last about 8 months (for an upgraded DANE delivering about 3 times the integrated luminosity per month achieved in the first half of 2007).

This phase will be followed by a second AMADEUS phase, in which AMADEUS will be implemented with an inner tracker and will perform higher statistics measurements in 3He, 4He, and investigate DBKNS in heavier nuclei.

Conclusions (3)

DAFNE could become the only place in the world where such measurements (DBKNS complemented with low-energy kaonic nuclei physics) could be performed in a complete and unambigous way, and this will be done by AMADEUS



Λ + d

p + π-

LAMBDA selectionLAMBDA selection Lambda-PROTON analysisLambda-PROTON analysis Lambda-DEUTERON analysis


IntroductionIntroduction

Search for partners?

πp

Λ20 cm. radius bubble

proton

pion

kaons

other

Proton is required to have an associated cluster in the EMC and its mass is measured by time of flight.

ρ < 28 cm

ρ > 28 cm

Minv Λd (MeV/c2)

Minv Λp (MeV/c2)

PΛp (MeV/c) PΛd (MeV/c)



AMADEUS: Status Report C. Curceanu and O. Vazquez Doce for the AMADEUS collaboration

Documents

Transcript of AMADEUS: Status Report C. Curceanu and O. Vazquez Doce for the AMADEUS collaboration