neutron-neutron correlations in the dissociation of halo systems: 6 he
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Neutron-Neutron Correlations in the Dissociation of Halo Systems: 6 He. Group " Exotiques " LPC-Caen Collaboration LPC-CHARISSA-DEMON. Neutron-Neutron Correlations in the Dissociation of Halo Systems: 6 He. Motivation + History Principles of neutron-neutron interferometry 6 He breakup - PowerPoint PPT PresentationTRANSCRIPT
Neutron-Neutron Correlations in the Neutron-Neutron Correlations in the Dissociation of Halo Systems: Dissociation of Halo Systems: 66HeHe
Group Group ""ExotiquesExotiques" LPC-Caen" LPC-Caen
Collaboration LPC-CHARISSA-DEMONCollaboration LPC-CHARISSA-DEMON
• Motivation + HistoryMotivation + History
• Principles of neutron-neutron Principles of neutron-neutron
interferometryinterferometry
• 66He breakupHe breakup
• Limitations – coherence, theory…Limitations – coherence, theory…
• Conclusions & PerspectivesConclusions & Perspectives
Neutron-Neutron Correlations in the Neutron-Neutron Correlations in the Dissociation of Halo Systems: Dissociation of Halo Systems: 66HeHe
Jean-Luc Lecouey, Seminar““Borromean”Borromean”
Two-Neutron Halo Systems Two-Neutron Halo Systems
Jean-Luc Lecouey, Seminar
Two-Neutron Halo Systems Two-Neutron Halo Systems
n-n interaction in field of core binds n-n interaction in field of core binds the system ...the system ...
Jean-Luc Lecouey, Seminar
Two-Neutron Halo Systems Two-Neutron Halo Systems
Halo neutron correlationsHalo neutron correlations … ? … ?
rrnnnn
Jean-Luc Lecouey, Seminar
Halo n-n Spatial ConfigurationHalo n-n Spatial Configuration
RNBT Collaboration – 3-body FaddeevRNBT Collaboration – 3-body Faddeev
6He
““cigarcigar”” ““dineutrondineutron””
Jean-Luc Lecouey, Seminar
3-body Model Calculations 3-body Model Calculations ** : : 66He = He = + n +n + n +n
** Hagino, Sagawa, Phys Rev C72 (2005)Hagino, Sagawa, Phys Rev C72 (2005)
ground stateground state wavefunction wavefunction
rrc-nnc-nn = 3.6 fm = 3.6 fm ; rrnn nn = 4.6 fm= 4.6 fm
““dineutrondineutron””
““cigarcigar””
rr1 1 == rr2 2 =
Jean-Luc Lecouey, Seminar
A History of Probes …A History of Probes …
• dissociation:dissociation: p pcorecore v’s p v’s pnn [Hansen][Hansen]
• dissociation:dissociation: ppnnnn [Ieki [Ieki et alet al.].]
• very high Every high EBB dissociation: dissociation: -2n-2n v’s v’s -1n-1n [Bertsch [Bertsch et alet al.] .]
see also JA Tostevin see also JA Tostevin (today)(today)
• 2n transfer 2n transfer [Oganessian [Oganessian et alet al.] .]
see also T Roger, N Keeley see also T Roger, N Keeley (yesterday)(yesterday)
• radiative capture radiative capture [Sauvan [Sauvan et alet al.].]
• dissociation:dissociation: E1 strength + RE1 strength + Rrmsrms [Hagino, Sagawa][Hagino, Sagawa]
• RRrmsrms charge charge [Mueller [Mueller et alet al.].]
• …………
Jean-Luc Lecouey, Seminar
““That was the beginning, and the idea seemed so That was the beginning, and the idea seemed so
obvious to me and so elegant that I fell deeply in love obvious to me and so elegant that I fell deeply in love
with it. And, like falling in love with a woman, it is only with it. And, like falling in love with a woman, it is only
possible if you do not know much about her, so you possible if you do not know much about her, so you
cannot see her faults. The faults will become apparent cannot see her faults. The faults will become apparent
later, but after the love is strong enough to hold you to later, but after the love is strong enough to hold you to
her."her."
Richard FeynmanRichard Feynman
Nobel Lecture Nobel Lecture (1965)(1965)
Jean-Luc Lecouey, Seminar
Intensity Interferometry - HBT EffectIntensity Interferometry - HBT Effect** : : Source SizeSource Size
FM Marqués et al., PLB (2000)FM Marqués et al., PLB (2000)
Correlation Function - CCorrelation Function - Cnnnn
CCnn nn dominated dominated by n-n FSIby n-n FSI ** incoherentincoherent emission emission
Jean-Luc Lecouey, Seminar
CCnnnn(r,t) : r(r,t) : r00 = 3 fm= 3 fm ; ; = 0, 100, 300*, 1000 = 0, 100, 300*, 1000
fm/cfm/c
Group Exotiques - G. Normand Group Exotiques - G. Normand et al.et al.
* * 55HeHegsgs ~ 0.7 MeV~ 0.7 MeV
Jean-Luc Lecouey, Seminar
3-Body Breakup: 3-Body Breakup: ““Complete KinematicsComplete Kinematics””
Target
vcore
v0
ppn-nn-n = p = pn1 n1 - p- pn2n2
EErelrel = = (v(vcorecore- v- vnnnn))22/2/2
vn2
vn1
Jean-Luc Lecouey, Seminar
Intensity Interferometry - HBT EffectIntensity Interferometry - HBT Effect
U. of Sydney Stellar Interferometer, Narrabri, NSWU. of Sydney Stellar Interferometer, Narrabri, NSW
““Hanbury-Brown’s Steamroller“ D Kleppner, Physics Today, August 2008Hanbury-Brown’s Steamroller“ D Kleppner, Physics Today, August 2008
Jean-Luc Lecouey, Seminar + + Cross-talk RejectionCross-talk Rejection !! !!
DEMONDEMON
90 modules (NE213) 90 modules (NE213)
ToF & positionToF & position
nn ~ 10% ~ 10% nnnn ~ 1% ~ 1%
Setup: Kinematically “CompleteSetup: Kinematically “Complete”” MeasurementMeasurement
FM Marqués FM Marqués et al.,et al., NIMA450 (2000) NIMA450 (2000)
Jean-Luc Lecouey, Seminar
n-n Separation : EMD + Cn-n Separation : EMD + Cnnnn + + Gaussian SourceGaussian Source**
Event mixing – residual Event mixing – residual correlationscorrelations FM Marqués FM Marqués et al.,et al., PLB (2000) PLB (2000)
* * R Lednicky, VL Lyuboshits, Yad. Fiz. R Lednicky, VL Lyuboshits, Yad. Fiz. (1982)(1982)
Jean-Luc Lecouey, Seminar
CC//Pb(Pb(66He,He,+n+n)X +n+n)X @@ 30 30 MeV/uMeV/u : C : Cnnnn + + Gaussian SourceGaussian Source
** **
** r rnnnn average of n-n configurations of average of n-n configurations of 66He He breakup statesbreakup states
Group Exotiques - G. Normand Group Exotiques - G. Normand et al.et al.
Jean-Luc Lecouey, SeminarGroup Exotiques - G. Normand Group Exotiques - G. Normand et al.et al.
CC//Pb(Pb(66He,He,+n+n)X +n+n)X @@ 30 30 MeV/nucleonMeV/nucleon
22++
22++ ((11--,, …… ) )
Jean-Luc Lecouey, SeminarGroupe Exotiques - G. Normand Groupe Exotiques - G. Normand et al.et al.
CC//Pb(Pb(66He,He,+n+n)X +n+n)X @@ 30 30 MeV/nucleonMeV/nucleon
22++ 22++
EEdd((66He) after He) after subtractionsubtraction of uncorrelated distribution of uncorrelated distribution
Jean-Luc Lecouey, Seminar
Three-body continuum spatial correlations in Three-body continuum spatial correlations in 66He He **
** B Danilin B Danilin et al.,et al., PRC69 (2004) PRC69 (2004)
Jean-Luc Lecouey, Seminar
Effects of a coherent n-n source Effects of a coherent n-n source **
* * Yamashita et al., PRC72 (2005), NUPA735 (2004)Yamashita et al., PRC72 (2005), NUPA735 (2004)
[ Data: FMM et al. PLB (2000) ] [ Data: FMM et al. PLB (2000) ]
Conclusions & PerspectivesConclusions & Perspectives
Neutron-neutron correlations …Neutron-neutron correlations …
• breakup + “interferometry˝ (Cbreakup + “interferometry˝ (Cnnnn) as a possible tool ) as a possible tool
to explore halo n-n correlations in to explore halo n-n correlations in unbound unbound
Ex/continuumEx/continuum
Improvements …Improvements …
• First stepFirst step : account for : account for coherencecoherence in emission in emission
• IdeallyIdeally : realistic structure + reaction + FSI to : realistic structure + reaction + FSI to
generate pgenerate pnnnn, , CCnnnn,, ppcorecore, d, d/dE/dE, …, …
Jean-Luc Lecouey, SeminarH Esbensen H Esbensen et al.,et al., PRC48 (1993) PRC48 (1993)
Pb(Pb(1111Li,Li,99Li+n+n)X Li+n+n)X @@ 28 28 MeV/nucleonMeV/nucleon
3-body model wave function3-body model wave function + EMD + FSI+ EMD + FSI (c-n et (c-n et nn)nn)
Jean-Luc Lecouey, Seminar
Jean-Luc Lecouey, Seminar
CC//Pb(Pb(66He,He,+n+n)X +n+n)X @@ 30 30 MeV/nucleonMeV/nucleon
Group Exotiques - G. Normand Group Exotiques - G. Normand et al.et al.
Jean-Luc Lecouey, SeminarGSI/LAND – T. Aumann GSI/LAND – T. Aumann et al.et al.
CC//Pb(Pb(66He,He,+n+n)X +n+n)X @@ 240240 MeV/nucleonMeV/nucleon