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Detlev Gotta
Institut für Kernphysik, Forschungszentrum Jülich
NuPECC Physics Mini-Workshop
Jülich, March 15, 2013
Exotic Atoms
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• INTRODUCTION
• EXPERIMENT
• 4 EXAMPLES
• ? ? ?
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COLLABORATIONS
LEAR PS 207 PSI R - 94.01
PSI R - 97.02
PSI R - 98.01
PSI R - 06.03
Coimbra – Debrecen – Ioannina – Islamabad – Jülich
– Leicester – Moscow (MSU) – Neuchâtel – Paris VI (LKB) – PSI – Vienna(SMI) – ETH Zürich
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, , K, p, ... –
particle-nucleus scattering length aA , …
QED
atomic physics - cascade
X-ray experiments measure energy line width
line yield
EXOTIC ATOM
e
G
strong interaction e – i G / 2 aA + …
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hadron – hadron interaction
͞p ͞pH p͞D ͞pHe
H D He
NN NN D
hydrogen - like atoms
: HFS population µH
pion mass 2ppm N
atoms & molecules
X - ray standards Ne Ti Ka
noble gases ͞pNe ͞pAr ͞pKr ͞pXe
molecules N2 ,O2, CH4, C2H2 µO C N
x = µ, x N2 x N + N
x H + H2 x H‘ + H + H µH H
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EXPERIMENT
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Balmer series
a
from high
(n,l=2) states
Ka
pH 30 mbar
Si(Li)
–
e, G 40 meV 1 keV 1 eV
ENERGY RANGE access to strong interaction effects
H 10 stp
fast CCD
Lyman series
from high
(n,l=1) states
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JOHANN-TYPE SET-UP
high stop density
high X - ray line yields
bright X - ray source
position & energy resolution
background reduction I
by analysis of hit pattern
ultimate energy resolution
L. Simons, Physica Scripta 90 (1988), Hyperfine Int. 81 (1993) 253
rate! X-ray single pixel
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BRAGG CRYSTAL Si, quartz
spherically
bent
pion stops in gas: few % of 10 8/s
5 neutrons /
PIONIC HYDROGEN collaboration - SET-UP at PSI
PSI experiments R-98.01 and R-06.03
crystal spectrometer setup
H(4-1) and D(3-1) QBragg 40°
CCD
crystal cyclotron trap
FOCAL PLANE DETECTOR
32 CCD array
pixel size
40 µm 40 µm
R = 3 m
F = 10 cm
N. Nelms et al.Nucl. Instr. Meth.A484 (2002)419
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µH from slow decay muons 𝝅 → 𝝁𝝂
kept in the magnetic bottle field
CYCLOTRON TRAP
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H2
gas inlet
5m Mylar®
target cell
~1 bar
~22 K
density
equivalent
~12.5 bar
~293 K
𝒇𝒔𝒕𝒐𝒑𝝁
≈ 𝟎. 𝟐 × 𝒇𝒔𝒕𝒐𝒑𝝅
CYCLOTRON TRAP
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fluorescence X-rays
excited by means of X-ray tubes
BRAGG CRYSTAL
large natural line width
and
satellite lines
rocking curve DE = 286 7 meV
exotic-atom X-rays
from hydrogen-like systems
problem
rate
problem solution: M1 transitions
in He - like S H(2p-1s)
Cl H(3p-1s)
Ar H(4p-1s)
D.F.Anagnostopoulos et al.,
Nucl. Instr. Meth. B 205 (2003) 9;
Nucl. Instr. Meth. A 545 (2005) 217
ECRIS
Electron Cyclotron Resonance Ion “Source”
= cyclotron trap + hexapole magnet
-
„burning“ argon
Ar / O2 (1/9)
1.410-6 mbar
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HYDROGEN – LIKE ATOMS ?
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MUONIC HYDROGEN
/ population = 3 : 1
? LINE SHAPE
spectrometer
resolution
PhD thesis: D. Covita, Coimbra 2008
D.S. Covita et al., Phys. Rev. Lett. 102 (2009) 023401
molecular formation
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muonic hydrogen
µp e + p
µp + n (0.1%)
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µH LEVEL SCHEME
EKa = 2.25 keV
Coulomb de-excitation
– pnl + H2 – pn’l’ + H+H + kinetic energy
>>> Doppler broadening !
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KINETIC ENERGY DISTRIBUTION
ESCM: extended standard cascade calculation and cross sections
T.S.Jensen and V.E.Markushin, Eur. Phys. J. D 19,165 (2002); ibid.D 21,261 (2002); ibid.D 21,271 (2002)
new cross sections G.Ya. Koreman, V.N. Pomerantsev and V.P. Popov, JETP. Lett. 81, 543 (2005)
V.N. Pomerantsev and V.P. Popov, Phys. Rev A 73, 040501 (2006)
V.P. Popov and V.N. Pomerantsev, arXiv:0712.3111v1[nucl-th] (2007)
V.P. Popov and V.N. Pomerantsev, Phys. Rev A 86, 052520 (2012)
low-Tkin: 61 ± 2 %
medium-Tkin 25 ± 3 %
high-Tkin 14 ± 4 %
55% vs.
35%
„box“ fits
=
model free fit
re-calculation of cross sections
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PION - NUCLEON
SCATTERING LENGTHS
HADRON – HADRON INTERACTION
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strong interaction
repulsive
strong interaction
attractive
PIONIC HYDROGEN and DEUTERIUM
D(3p - 1s)
3.075 keV
H(3p - 1s)
2.885 keV
a p p
ap 0n a-d -d
a p p + an n
two independent scattering length - all others linked by isospin
ad nn+nng
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3p-1s TRANSITION
scattering lengths
H e1s a-p -p a + a + …
G1s (a-p0n)2 (a )2 + …
D e1s a-d -d 2a + …
Trueman correction *
… 1% + (9.0 3.5)%
… 1% + (+0.5 1.0)%
… 1% + 4%
experiment
0.2%
2.5%
1.3%
e = +7 eV
G = 0.8 eV
* J. Gasser et al., Phys. Rep. 456 (2008) 167
M. Hoferichter et al., Phys. Lett. B 678 (2009) 65
V. Baru et al., Phys. Lett. B 694 (2011) 473
EQED
e = - 2 eV
G = 1.2 eV
energy calibration
Ga Ka2
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pionic hydrogen
p 0 + n
g + n (39%)
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N isospin scattering lengths a+ and a
PT: V. Baru, C. Hanhart, M. Hoferichter, B. Kubis, A. Nogga, and D. R. Phillips, Phys. Lett. B 694 (2011) 473
data: H - R-98.01 : D. Gotta et al., Lect. Notes Phys. 745 (208) 165 (preliminary)
D - R-06.03 : Th. Strauch et al., Eur. Phys. J. A 47 (2011) 88 (final)
D exp 2 D theory - no LEC f1 in NLO
D exp
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electric dipole amplitude
threshold pion photo production
G1s
PION-NUCLEON SCATTERING LENGTHS related quantities
GP
2
NfsN
E0+
induced pseudoscalar coupling
muon capture
pion-nucleon sigma term
explicit chiral symmetry breaking
e1s
a a+
THEORETICAL FRAME WORK
CHIRAL PERTURBATION THEORY
GTD
N coupling constant
Goldberger-Treiman discrepancy pion-nucleon scattering
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PION PRODUCTION / ABSORPTION
NN NN
HADRON – HADRON INTERACTION
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production experiments D
NN NN threshold parameter a
charge symmetry detailed balance
dppppdnnd sss
)1()0( 13
13 IPISNN
ag
GG nndnndD
a32
12
0 ηCβηCασ dπpp
extrapolation
to threshold mk /
3 keV
direct from G
Th. Strauch,
PhD thesis, Cologne 2009
Th. Strauch et al.,
Phys.Rev.Lett.104 (2010)142503
Th. Strauch et al.,
Eur.J.Phys.47 (2011)88
PT
at present
Da /a 30%
few %
V. Lensky et al.,
Eur. Phys. J. A 27 (2006) 37
PT LO
PT NLO
exotic-atom results
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ATOMS
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pn 1pn
X-radiation
ANTIPROTONIC XENON
internal Auger effect
34 EZX DG
212 /A EZ
DG
What happens when an antiproton meets 54 electrons ?
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ELECTRONIC & ANTIPROTONIC X-RAYS - XENON
many unresolved lines ?
pXe
19 mbar
–
L X
-ra
ys
K X
-ra
ys
many remaining
electrons K
X-r
ay
s
data: PS175 Ar, Kr, Xe
analysis: D.G., K.Rashid, B. Fricke, P. Indelicato, L.M. Simons,
Eur. Phys. D 47 (2008) 11
13 2 per formed atom
competition between AUGER and RADIATIVE DE-EXCITATION
electrons are peeled off like onion shells
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? ? ? …
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• ͞pp / scattering length
• isospin ͞pp ͞pn
• „no“ Coulomb de-excitation D!
...
vague
puzzling
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0
500
1000
1500
2000
1970 1980 1990 2000 2010
year
sh
ift, w
idth
/ e
V
HYDROGEN
0,0
1,0
2,0
3,0
4,0
5,0
6,0
7,0
8,0
1970 1980 1990 2000 2010
year
sh
ift,
wid
th /
eV
PIONIC HYDROGEN ANTIPROTONIC s-wave
X-r
ays
iden
tifi
ed
2005
e
G
e
G
almost 40 years
LEAR
1S0
1S0 3S1
3S1
HYDROGEN HFS no unbiased analysis
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THANK YOU