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Studies of antikaon interactions with nucleons at DA Φ NE. Oton Vázquez Doce LNF - INFN. Friday, December 10, 2010. DA Φ NE AMADEUS KLOE data analysis. Colosseo 70–80 AD Ø 545 m. 17 km. DA Φ NE 2008 AD (upgrade) Ø 200 m.

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slide1

Studies of antikaon interactions

with nucleons at DAΦNE

Oton Vázquez Doce

LNF - INFN

Friday, December 10, 2010

slide2

DAΦNE AMADEUS KLOE data analysis

Colosseo

70–80 AD

Ø 545 m

17 km

DAΦNE

2008AD (upgrade)

Ø 200 m

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide3

DAΦNE AMADEUS KLOE data analysis

The DAΦNE e+e- collider

  • e+ e- beams at ~ 500 MeV/c
  • Φ → K+ K- (49.1%)
  • Monochromatic low-energy K- (~127 MeV/c)
  • Low hadronic background due to beam characteristics (compared with hadron beam lines, as KEK)

DAΦNE upgrade in 2008

Design of new interaction

region scheme

Top luminosity reached during SIDDHARTA run:

4x1032 pb-1 s-1

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide4

DAΦNE AMADEUS KLOE data analysis

next talk in this session by S. Okada

Experimental timeline at DAΦNE

DEAR kaonic hydrogen

past

KLOE CP violation

FINUDA hypernuclei

present

SIDDHARTA kaonic atoms

KLOE2

proposal for

the future

(KLOE2+) SIDDHARTA2*

AMADEUS* kaonic nuclei

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide5

DAΦNE AMADEUS KLOE data analysis

How deep is the KN potential?

KLOE DC

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide6

A hadron physics important and unresolved topic:

  • How the hadronic masses and interaction change in nuclear medium

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide7

A hadron physics important and unresolved topic:

  • How the hadronic masses and interaction change in nuclear medium

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

  • Discussion triggered by the prediction of the Deeply bound kaonic nuclear states
  • Strong attractive I=0 KN interactionfavors
  • discrete nuclear stateshigh Band small Γ.
  • Y. Akaishi and T. Yamazaki (Phys. Rev. C65 (2002) 044005)
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide8

A hadron physics important and unresolved topic:

  • How the hadronic masses and interaction change in nuclear medium

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

  • Discussion triggered by the prediction of the Deeply bound kaonic nuclear states
  • Strong attractive I=0 KN interactionfavors
  • discrete nuclear stateshigh Band small Γ.
  • Y. Akaishi and T. Yamazaki (Phys. Rev. C65 (2002) 044005)

Deeply bound kaonic nuclear states require the presence of a

strong attractive KN interaction in the isospin I=0 channel

From experimental data:

  • S-wave K-nucleon scattering
  • length is negative at threshold

“repulsive type” interaction

  • K line shift of kaonic
  • hydrogen is negative

KN potential strongly dependent on density: → repulsive in free space → attractive in nuclear matter

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide9

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

Studying the properties of the KN potential in the nuclear medium

  • A strong attractive potential will allow the formation of deeply bound kaonic clusters, with exotic features that would allow to investigate:
    • - spontaneous and explicit symmetry breaking of QCD
    • kaon condensation in nuclear matter (neutron stars)
    • super dense matter (x5 normal nuclear matter)
    • etc
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide10

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

Studying the properties of the KN potential in the nuclear medium

  • A strong attractive potential will allow the formation of deeply bound kaonic clusters, with exotic features that would allow to investigate:
    • - spontaneous and explicit symmetry breaking of QCD
    • kaon condensation in nuclear matter (neutron stars)
    • super dense matter (x5 normal nuclear matter)
    • etc
  • Intense theoretical debate with several different approaches:
    • - Few-body calculations solving Faddeev equations
    • - Variational calculations with phenomenological KN potential
    • - KN effective interactions based on Chiral SU(3) dynamics
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide11

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

Studying the properties of the KN potential in the nuclear medium

  • A strong attractive potential will allow the formation of deeply bound kaonic clusters, with exotic features that would allow to investigate:
    • - spontaneous and explicit symmetry breaking of QCD
    • kaon condensation in nuclear matter (neutron stars)
    • super dense matter (x5 normal nuclear matter)
    • etc
  • Intense theoretical debate with several different approaches:
    • - Few-body calculations solving Faddeev equations
    • - Variational calculations with phenomenological KN potential
    • - KN effective interactions based on Chiral SU(3) dynamics

For K-pp system, predicted values both for B and Γ

expand over the range from 0 to 200 MeV

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide12

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

Experimental data

kaonic 3-baryon state: ppnK-

kaonic dibaryon state: ppK-

KK

Λp

Experimental resultsfromFINUDA

K- stopped in light nuclei

Invariantmassspectroscopy

Λd

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide13

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

Experimental data

kaonic 3-baryon state: ppnK-

kaonic dibaryon state: ppK-

KK

Λp

Experimental resultsfromFINUDA

Λp

ResultsfromKEK:

K- stopped in light nuclei

Invariantmassspectroscopy

Λd

Λd

K- stopped in 4He

Invariantmassspectroscopy

Λd

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide14

DAΦNE AMADEUS: kaonic clusters KLOE analysis

Experimental data

kaonic 3-baryon state: ppnK-

kaonic dibaryon state: ppK-

KK

Λp

Experimental resultsfromFINUDA

Λp

ResultsfromKEK:

K- stopped in light nuclei

Invariantmassspectroscopy

Λd

Λd

K- stopped in 4He

Invariantmassspectroscopy

Λd

p¯ 4He annihilation

DISTO

OBELIX

Λp

Λp

p+p → K++X

(Λd)

p4He annihilation

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide15

DAΦNE AMADEUS: kaonic clusters KLOE analysis

Experimental data

kaonic 3-baryon state: ppnK-

kaonic dibaryon state: ppK-

KK

Λp

Experimental resultsfromFINUDA

KK

Λp

ResultsfromKEK:

K- stopped in light nuclei

Invariantmassspectroscopy

Λd

Λp

Λd

K- stopped in 4He

Invariantmassspectroscopy

Experimental results from FOPI

Λd

p¯ 4He annihilation

from HEAVY ION COLLISIONS

Λd

DISTO

OBELIX

Λp

Λp

p+p → K++X

(Λd)

p4He annihilation

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide16

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

Nucl.Phys.A835:51-58,2010. arXiv:1001.1300

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide17

DAΦNE AMADEUS: kaonic clusters KLOE data analysis

    • the future experiments in Japan at J-PARC will produce

kaonic nuclear states only with K--induced reactions in-

flight (E15; E17)

    • alternative approaches followed at GSI with FOPI using
  • proton-nucleus collisions at beam energies close to the
  • strangeness production threshold and with nucleus-
  • nucleus collisions
    • a dedicated facility – AMADEUS at DANE will study

antikaon-mediated bound nuclear systems with K- induced

reactions at rest

Nucl.Phys.A835:51-58,2010. arXiv:1001.1300

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide18

DAΦNE AMADEUS: experimental program KLOE data analysis

AMADEUS: The main program

kaonic dibaryon states:

ppK- and pnK-

produced in a 3He gas target

Study the most fundamental antikaon deeply bound systems in formation and decay processes:

kaonic 3-baryon states:

ppnK- and pnnK-

produced in a 4He gas target

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide19

DAΦNE AMADEUS: experimental program KLOE data analysis

AMADEUS: extended program

Low-energy charged kaon cross section on p, d, He-3 and He-4, for K-momentum lower than 100 MeV/c (missing today)

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

Properties of Λ and charged Σ´s for example decays in channels with a neutrino → astrophysics implications (cooling of compact stars)

Resonance states as Λ(1405) or the Σ(1385) could be understood with high statistics; their behaviour in nuclear medium can be studied too

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide20

DAΦNE AMADEUS: experimental program KLOE data analysis

AMADEUS: three key features

Full acceptancy

Pureness

Full reconstruction

Invariant mass

+

Missing mass

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide21

DAΦNE AMADEUS setup KLOE data analysis

  • Full acceptance and high precision measurements will be made by implementing the KLOE detector with an inner AMADEUS setup

From KLOE to AMADEUS

Almost full acceptancy 4π:

DRIFT CHAMBER

(50 cm. gap in KLOE DC around the beam pipe)

ELECTROMANETIC CALORIMETER

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide22

DAΦNE AMADEUS setup KLOE data analysis

  • Full acceptance and high precision measurements will be made by implementing the KLOE detector with an inner AMADEUS setup

From KLOE to AMADEUS

K-stopped + 4He → p + (K-pnn)

(50 cm. gap in KLOE DC around the beam pipe)

K-stopped + 4He → n + (K-ppn)

Setup for AMADEUSwithin KLOE:

  • Modification of the beam pipe of KLOE-2 in order to allow access
  • Target( A gaseous He target for a firstphase of study)
  • Trigger (1 or 2 layers of ScFisurroundingtheinteractionpoint)
  • Innertracker(eventually, a first tracking stagebeforethe DC)
  • The implementation of the AMADEUS dedicated setup around the beam pipe will modify the topology of the events, stopping the K- in a target inner to the DC.
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide23

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup: beam pipe

  • Central region made of CARBON FIBER:
    • Vacuum chamber
    • External part of cryostate and target walls
  • Aluminium for the peripheral part

KLOE2

AMADEUS

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide24

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup:target cell

Low-mass cryogenic

gas target cell:

T = 10 K

P = 1.0 bar

Rin = 5 cm

Rout = 15 cm

L = 20 cm

SIDDHARTA

AMADEUS:

working T 22 K working P 1.5 bar

Alu-grid

Side wall: Kapton50 µm

Entrance window: Kapton 50 µm

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide25

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup:target cell

AMADEUS Monte Carlo

Low-mass cryogenic

gas target cell:

T = 10 K

P = 1.0 bar

Rin = 5 cm

Rout = 15 cm

L = 20 cm

SIDDHARTA

AMADEUS:

SIDDHARTA Monte Carlo

working T 22 K working P 1.5 bar

Alu-grid

Side wall: Kapton50 µm

Entrance window: Kapton 50 µm

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide26

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup: Trigger system

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide27

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup: Trigger system

Silicon photomultipliers + scintilliating fibers

Ideal for ScFi couplin and high granularity detector

Time resolution below 1 ns

Insensitive to strong magnetic fields

High gain (>106) and quantum efficiency

  • Instrumented fibers: Saint Gobain BCF- 10 single cladding:
    • Emission peak 432 nm
    • Decay time 2,7 ns
    • 1/e 2.2 m
    • 80000 ph./MeV

MPPC Hamamatsu S10362-11-050U,

efective area 1mm2,,400 pixel

wlorking biases ̴ 70 V .

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide28

DAΦNE AMADEUS setup KLOE data analysis

SiPM + Pre-amp + scintilliating fiber

TIME RESOLUTION STUDY@ Roma3 University

Laser directly on fiber:

Resolution is slightly worse ≈ 80 ps due to internal reflexion

Laser directly on SiPM; 1 Khz

Res ≈ 40 ps

Amplifier is not worsening!

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide29

DAΦNE AMADEUS setup KLOE data analysis

tests installation at DAΦNE

SIDDHARTA setup

Siddharta Kaon Monitor

2Layers of Scintillators up&down

The interaction point detecting K+ K- emmited in opposite directions

DAΦNE

beam pipe

Our test setup

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide30

DAΦNE AMADEUS setup KLOE data analysis

tests installation at DAΦNE

SIDDHARTA setup

Siddharta Kaon Monitor

2Layers of Scintillators up&down

The interaction point detecting K+ K- emmited in opposite directions

DAΦNE

beam pipe

Our test setup

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide31

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup:Trigger system

New TEST SETUP

Test beam at BTF in Frascati and past at PSI (Zurich) wiht hadrons

2-rings of double layer 16 fibres

64 fast pre-amplifiers (64x)

2 boards of 32 constant fraction discriminator with zero jitter

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide32

DAΦNE AMADEUS setup KLOE data analysis

AMADEUS setup:Trigger system

New TEST SETUP

Test beam at BTF in Frascati and past at PSI (Zurich) wiht hadrons

2-rings of double layer 16 fibres

64 fast pre-amplifiers (64x)

2 boards of 32 constant fraction discriminator with zero jitter

Pion an electron fluxes in piM1

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide33

DAΦNE AMADEUS KLOE data analysis

Experimental timeline at DAΦNE

DEAR kaonic hydrogen

past

KLOE CP violation

FINUDA hypernuclei

present

SIDDHARTA kanonic atoms

KLOE2

proposal for

the future

(KLOE2+) SIDDHARTA2*

AMADEUS* kaonic nuclei

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide34

DAΦNE AMADEUS KLOE data analysis

for CPT symmetry and QM tests,

hadronic physics, and more

Almost full acceptancy 4π:

DRIFT CHAMBER

- 90% He

- momentum resolution ~ 0.4%

The KLOE detector

ELECTROMANETIC CALORIMETER

- σE/E= 5.7%/√E (GeV)

KLOE@ DAΦNE

by S. Miscetti @ Quark

Confinement IX. Madrid, 2010

Status of KLOE2. arXiv:1001.3591, G. Venanzoni for the KLOE2 collaboration

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide35

DAΦNE SIDDHARTA AMADEUS KLOE data analysis

  • - Test the behaviour of the KLOE detectorfor hadronic physics purposes
  • Possibility to study the phenomenon with an active target

KLOE data analysys:

how K+/K- events looks like nowadays in KLOE:

  • The implementation of the AMADEUS dedicated setup will modify the topology of the events, stopping the K- in a target inner to the DC.
  • The Drift Chamber of KLOE contains mailny 4He (90%, 10% isobutane)
  • From analysis of KLOE data and Monte Carlo: 0.1 % of K- should
  • stop in the DC volume
  • This would lead to hundreds
  • of events with K- hadronic interactions at rest
  • “AMADEUS Step-0”

EMC

4He

K-

e+

e-

Drift

Chamber

K+

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide36

DAΦNE AMADEUS KLOE data analysis

K-stopped +4He→ n + n + (K-pp)

Λ+ p

K-stopped +4He→ n + (K-ppn)

Λ+ d

  • Statistics: analyzing data up to an integrated luminosity
  • of ~1,7 fb-1 (80% KLOE RUNS 2004/2005)
  • Data analysis: search for hadronic interactions with Λ(1115):
        • Λ → p + π-(64% BR)
        • Construct a vertexwithΛ + an extra particle
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide37

DAΦNE AMADEUS KLOE data analysis

K-stopped +4He→ n + n + (K-pp)

Λ+ p

K-stopped +4He→ n + (K-ppn)

Λ+ d

  • Statistics: analyzing data up to an integrated luminosity
  • of ~1,7 fb-1 (80% KLOE RUNS 2004/2005)
  • Data analysis: search for hadronic interactions with Λ(1115):
        • Λ → p + π-(64% BR)
        • Construct a vertexwithΛ + an extra particle
  • Protons and deuterons are firstlyselectedfromthespectrum of particlesneartothe Lambda vertexbydE/dx

PID

deuterons

EMC

E (MeV/c)

DC

dE/dx (adc counts)

protons

protons

deuterons

charge * p(MeV/c)

charge * p(MeV/c)

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide38

DAΦNE AMADEUS KLOE data analysis

Selection of events

Λ+ p

y (cm)

Kaon is rarely tracked due to its low momentum or short track

Λ+ d

Cluster in the ECAL

(time info)

2 different vertices reconstrucion:

Λ -> p + pion

(K- + 4He) -> Λ + d

Ecal

DC volume

other

kaon

x (cm)

pion

proton

  • - Calculate p/d mass by TOF
  • Evaluate Σ0 background
  • Use Λ lifetime as quality cut

Proton from Λ

Are required to have at least 1 cluster

Deuteron /proton to reproduce the time of the event

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide39

DAΦNE AMADEUS KLOE data analysis

Selection of events

LAMBDA LIFETIME

  • Proton/deuteroncandidates are requiredtohaveanassociatedcluster in the EMC and itsmassismeasuredbytime of flight.

1/3.7 -> τ=0.25 ns

(PDG=0.26)

Time (ns)

Mdeuteron(MeV/c2)

Proton from Λ

Are required to have at least 1 cluster

Deuteron /proton to reproduce the time of the event

  • - Calculate p/d mass by TOF
  • Evaluate Σ0 background
  • Use Λ lifetime as quality cut
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide40

DAΦNE AMADEUS KLOE data analysis

Selection of events

Improved Λd vertex reconstruction

Improved selection of events in DC-gas

Λd vertex

Λ -> p+π

Λ vertex

Λ+d

LAMBDA LIFETIME

Vertex radial position (cm)

  • Proton/deuteroncandidates are requiredtohaveanassociatedcluster in the EMC and itsmassismeasuredbytime of flight.

1/3.7 -> τ=0.25 ns

(PDG=0.26)

Time (ns)

Mdeuteron(MeV/c2)

Proton from Λ

Are required to have at least 1 cluster

Deuteron /proton to reproduce the time of the event

  • - Calculate p/d mass by TOF
  • Evaluate Σ0 background
  • Use Λ lifetime as quality cut
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide41

DAΦNE AMADEUS KLOE data analysis

Invariant masses

Preliminary

Λ→ p + π-

KLOE: statistical error 0. 003 MeV/c2

PDG: MΛ= 1115,683 ± 0.006 stat ± 0.006 syst (MeV/c2)

σ = 0. 289 ± 0.003 MeV/c2

Minvpπ(MeV/c2)

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide42

DAΦNE AMADEUS KLOE data analysis

Invariant masses

Preliminary

Λ→ p + π-

KLOE: statistical error 0.003 MeV/c2

PDG: MΛ= 1115,683 ± 0.006 stat ± 0.006 syst (MeV/c2)

σ = 0. 289 ± 0.003 MeV/c2

Efficency for tracks with

P < 400 MeV improved increased acceptancy

Minvpπ(MeV/c2)

Total events in DC Volume 79

Λdanalysis

Pd(MeV/c)

MinvΛd(MeV/c2)

Md+ Mp+ Mπ-

Md + Mp+ MK

PΛ(MeV/c)

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide43

DAΦNE AMADEUS KLOE data analysis

Neutral particles detection

Λdanalysis

K-stopped +4He→ n+ (K-ppn)

Λ+ d

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide44

DAΦNE AMADEUS KLOE data analysis

Neutral particles detection

Λdanalysis

K-stopped +4He→ n+ (K-ppn)

Λ+ d

Λ-> n π0

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide45

DAΦNE AMADEUS KLOE data analysis

Neutral particles detection

Σ0 contamination in Λp events

Ecal

π

Use of the time information from the EMC

-With the extrapolation of the charged and

neutral (lambda) tracks the time of the

Interaction (Tk) is obtained

Time correlation between neutral clusters

(not associated to any charged track) and Tk

assuming a photon travelling:

p

proton

Λ

Σ0

Tk

Tphoton -Tk (MeV/c)

Minvγγ(MeV/c2)

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide46

DAΦNE AMADEUS KLOE data analysis

  • (Σπ)0 spectrum
  • 3-quark baryon?
  • KN quasibound state?
  • two pole KN-Σπ channel coupling?
  • ...on the nature of the Λ(1405)

π

D. Jido, E. Oset and T. Sekihara,``Kaonic production of Lambda(1405) off deuteron target in chiral dynamics''  arXiv:0904.3410 [nucl-th].

Ecal

p

γ

Λ

Σ0

  • possible task for AMADEUS?

Ecal

γ

γ

π0

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide47

DAΦNE AMADEUS KLOE data analysis

  • (Σπ)0 spectrum
  • 3-quark baryon?
  • KN quasibound state?
  • two pole KN-Σπ channel coupling?
  • ...on the nature of the Λ(1405)

π

  • pseudo-kinematic fit:
  • χ2computing:
    • -momentum of proton and pion
    • -Covariancematrixelementsforeverytrack
    • -time and positions plus resolutionsforphotons
  • Allowstorejectbackgroundselectingtherightcombination of photons
  • Constraints: Δt forthearrival time of photons
  • No massassumption -> unbiasedmassspectras

Ecal

p

γ

Λ

Σ0

Ecal

γ

γ

π0

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide48

DAΦNE AMADEUS KLOE data analysis

  • (Σπ)0 spectrum
  • 3-quark baryon?
  • KN quasibound state?
  • two pole KN-Σπ channel coupling?
  • ...on the nature of the Λ(1405)

π

  • Kinematicfit:
  • χ2computing:
    • -momentum of proton and pion
    • -Covariancematrixelementsforeverytrack
    • -time and positions plus resolutionsforphotons
  • Allowstorejectbackgroundselectingtherightcombination of photons
  • Constraints: Δt forthearrival time of photons
  • No massassumption -> unbiasedmassspectras

Minvγγ(MeV/c2)

Ecal

p

γ

Minvγγ(MeV/c2)

MinvΛγ(MeV/c2)

Λ

Σ0

MinvΛγ(MeV/c2)

Ecal

γ

γ

π0

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide49

DAΦNE AMADEUS KLOE data analysis

  • (Σπ)0 spectrum

Preliminary

Events in the

DC volume

DC wall

MinvΣ0π0(MeV/c2)

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide50

DAΦNE AMADEUS KLOE data analysis

K- He interactions in KLOE

PROVED

  • Capabilities of the KLOE detector for studying K- hadronic interactions
  • Possibility to study the phenomenon with an active target

TO DO LIST

  • Apply acceptance correction for invariant masses distributions
  • Evaluate background distributions (hadronic interaction, multi-nucleon absorption, etc) for the analises shown previously (Monte Carlo)
  • Exploit the neutral particles detection capabilities of KLOE (Kppn -> Λ d n, neutral decay of Λ , etc)
  • Determine rates for the different reactions in 4He and in 12C
  • Exotic (and not so) physics data:) hypernuclei, Σ(1385), etc.
  • New KLOE data!
  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide51

DAΦNE AMADEUS conclusions KLOE data analysis

Studies of antikaon interactions

with nucleons at DAΦNE

CONCLUSIONS

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide52

DAΦNE AMADEUS conclusions KLOE data analysis

Studies of antikaon interactions

with nucleons at DAΦNE

THANK-S

CONCLUSIONS

Minutes from last LNF Scientific Committee

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide54

DAΦNE SIDDHARTA AMADEUS: experimental setup KLOE

AMADEUS setup: TPG for inner tracking

Prototype tested last week at BTF

  • K‐N interactions @ DAΦNE Oton Vázquez Doce
slide55

Invariant mass

Λ p analysis

Preliminary

Total events in DC Volume 187

PΛ(MeV/c)

MinvΛp(MeV/c2)

2Mp+Mπ-

2Mp+MK

Pp(MeV/c)

protons

NO EMC-CLUSTER (mass by TOF)

requirement for protons !!!!

Rely only on DEDX in

the DC wires -->

Pp(MeV/c)

dE/dx (adc counts)

MinvΛp(MeV/c2)

charge * p(MeV/c)

slide56

Selection of triton

PID

dE/dx (adccounts)

protons

deuterons

Massby time of flight(MeV/c2)

triton

K‐He interactionsinKLOE Oton Vázquez Doce

slide57

Lambda-triton

Cosθ (Λt)

MΛ(MeV/c2)

triton

PΛ(MeV/c)

Mt (MeV/c2)

Pt(MeV/c)

K‐He interactionsinKLOE Oton Vázquez Doce

slide58

Lambda-triton

Cosθ (Λt)

MΛ(MeV/c2)

ρ > 40cm

DC volume

triton

PΛ(MeV/c)

MinvΛt(MeV/c2)

ρ < 40 cm

DC innerwall

Mt (MeV/c2)

Pt(MeV/c)

K‐He interactionsinKLOE Oton Vázquez Doce