Upload
tyler-payne
View
225
Download
6
Embed Size (px)
Citation preview
Bonn, 04. September 2009
Mit
glie
d d
er
Helm
holt
z-G
em
ein
sch
aft
Pionic Deuterium
| Thomas Strauch
for the Pionic Hydrogen collaboration
Bonn, 04. September 2009 Folie 2
Experimental program of the Pionic Hydrogen collaboration
Pionic Hydrogen R-98.01 ECRIT (response function) Muonic Hydrogen Pionic Deuterium R-06.03
Bonn, 04. September 2009 Folie 3
Exotic atoms
Bohr radius: mp
mep13
11
102,2:
103,5:
Bonn, 04. September 2009 Folie 4
Atomic cascade of pionic deuterium
Hadronic interaction
shift ε1s ≈ - 2,5 eV
width Γ1s ≈ 1,2 eV
Aim:
1s /1s 1s /1s
3% ~ 1% 12% ~ 4%
D(3p - 1s) 3 keV
Deser:
n
a
r
Ei
LOA
B
nnsns
42/
Bonn, 04. September 2009 Folie 5
dppppdnnd
Pionic Deuterium
PMDa Im
Width Γ1s ~ Im aπD
directly related to pionproduction at threshold
charge symmetry detailed-balance
threshold parameter α (s-wave production)
0/ pp
Bonn, 04. September 2009 Folie 6
Pion-Nucleon Interaction
Isospin 1/2 or 3/2 system
At threshold: two parameters:
s-wave scattering lengths a1/2 und a3/2
choose isoscalar und isovector scattering lengths a+ und a- :
3/)(
3/)2(
2/32/1
2/32/1
aaa
aaa
Bonn, 04. September 2009 Folie 7
Pionic Hydrogen
1s :
1s :
+ NLO(%)
aaa
pp
2)(0
aa
np
Pionic Deuterium 1s : + NLO(~LO)
aaaannppd
NLO: a- appears
Bonn, 04. September 2009 Folie 8
N isospin scattering lengths
Constraint for N isospin scattering lengths a & a –
J.Gasser et al.:
Hadronic atoms in QCD+QED
Physics Reports 456(2008)167-251
Pionic Deuterium:
bandwidth mainly by LEC f1
bandwidth mainly by LEC f1
bandwidth mainly by experiment
Bonn, 04. September 2009 Folie 9
Experimental setup
High-resolution Bragg crystal-spectrometer
Bragg law:
Bonn, 04. September 2009 Folie 10
Experimental setup
spherically bent Bragg crystalbending radius ~ 3m
cyclotron trapsuperconducting magnetscryogenic target
large area detector6 CCDs with 600x600 pixelpixelsize 40x40 µm
N. Nelms et al., Nucl. Instr. Meth 484 (2002) 419
L. M. Simons, Hyperfine Interactions 81 (1993) 253
Bonn, 04. September 2009 Folie 11
Experimental setupPrecision measurement:→ low background→ concrete shielding
Bonn, 04. September 2009 Folie 12
Measurement
ADC-spectrum
Cluster analysis
Hit pattern onCCD detector
Hit pattern aftercurvature correction
Bonn, 04. September 2009 Folie 13
high-statistics measurement
of πD(3p-1s)
Spectrum after
cluster analysis,
ADC cuts,
curvature correction,
projection onto x-axis
rate: ≈ 30/h
Measurement
pressure
/ bar
number
of events
3,3 1500
10 4000
17,5 4800earlier measurementwithout concretewith concrete
Bonn, 04. September 2009 Folie 14
Molecular formation
(d)nl + D2 → [(dd)d]ee
radiative deexcitation out of these formations would falsify the extracted shift ε1s
→ density dependence
not seen in H, but predicted to be larger in D
Bonn, 04. September 2009 Folie 15
Energy calibration
Ga K1 9257.67 0.066 eV
K2 9224.84 0.027 eV
reflection in 3rd order
Deslattes et al.: X-ray transition energies,Rev. of Mod. Phys., Vol 75, Jan 2003
reflection in 1st order
Bonn, 04. September 2009 Folie 16
stability with Ga Kα2
high statistics Ga calibration measurements
810
811
812
813
814
815
816
80 130 180 230 280 330 380 430 480 530 580
No. of measurement
po
sit
ion
on
de
tec
tor
GaKa2
10bar
3,3bar
20bar
whole measure-time : 4 weeks
ΔE ≈ ±2,5 meV
Bonn, 04. September 2009 Folie 17
Results | transition energies
corrections:
e.g. index of refraction (3keV / 9keV)
crystal bending
penetration depth…
pressure in bar 3p-1s transition energy in eV
3.3 3075.509 ± 0.028
10.0 3075.594 ± 0.017
17.5 3075.599 ± 0.016
no evidence for radiative de-excitationout of molecular formationsε1s = Eexp. - EQED EQED = 3077.909±0.008 eV
P.Indelicato private communication
Bonn, 04. September 2009 Folie 18
Results | shift ε1s
dominant±0.002 QED calculation±0.007 pionmass
Bonn, 04. September 2009 Folie 19
Comparison to earlier measurements
Bonn, 04. September 2009 Folie 20
Extraction of the hadronic width from the line shape
spectrometer response-function
Doppler-broadening
Lorentzfunctionof transition
LDRFSi
i
Bonn, 04. September 2009 Folie 21
Spectrometer response function (RF)
RF = Rocking curve Geometry add. Gauss
Energy resolution:
ΔE = 436 ± 3 meV
ECRIT- measurementwith He-likeAr
Bonn, 04. September 2009 Folie 22
Doppler broadening
energy release of Coulomb transitions converted into kinetic energy of the πD-atoms
prediction
cascade-theory,
scaled from πH
Bonn, 04. September 2009 Folie 23
Doppler broadening
kinetic energy distribution: approximation by „boxes“
prediction
cascade-theory,
scaled from πH
Bonn, 04. September 2009 Folie 24
χ2 analysis
free fit one box two boxes
low energy box essential no evidence forhigh energy contribution
Bonn, 04. September 2009 Folie 25
Statistical studies | MC-simulations
intensity input of high energy contribution:
10% : red25% : blue
probability to miss a simulated contribution
Bonn, 04. September 2009 Folie 26
statistical error determination
Bonn, 04. September 2009 Folie 27
Results | Width Γ1s
→only one Low-energy-component identified,
no high-energetic parts
→numerous MC-simulations to determine systematic errors
Bonn, 04. September 2009 Folie 28
Comparison to earlier measurements
Bonn, 04. September 2009 Folie 29
Pionic Deuterium | Final results
1s = - 2325 31 meV ( ±3% → ±1,3%)
1s = 1171 meV (±12% → %)+ 23 - 49
+ 2,1 - 4,2
1312.026.0 1026,633,079,24
mia D
Bonn, 04. September 2009 Folie 30
threshold parameter α
α = 252 μb+5-11
χPT:expected uncertainty30% → 5%NNLO calculations
Bonn, 04. September 2009 Folie 31
Thank you for your attention!
Debrecen – Coimbra – Ioannina – Jülich – Paris – PSI – Vienna
PSI experiments R-98.01 and R-06.03
D. F. Anagnostopoulos, S. Biri, D. D. S. Covita, H. Gorke, D. Gotta, A. Gruber, M. Hennebach,
A. Hirtl, P. Indelicato, T. Ishiwatari, Th. Jensen, E.-O. Le Bigot, J. Marton, M. Nekipelov,
J. M. F. dos Santos, S. Schlesser, Ph. Schmid, L. M. Simons, Th. Strauch, M. Trassinelli,
J. F. C. A. Veloso, J. Zmeskal
PIONIC HYDROGEN collaboration
Bonn, 04. September 2009 Folie 32
Pionisches Deuterium
Appendix
Bonn, 04. September 2009 Folie 33
cascaden effects
Bonn, 04. September 2009 Folie 34
Origin of shift and width
Bonn, 04. September 2009 Folie 35
Pionic Deuterium
1s Pionproduktion an der Schwelle NN NN
Ladungssymmetrie Zeitumkehr-Invarianz
dppppdnnd
)( nndnndda
Pionproduktion Parametrisierung:
Atom:
und über optisches Theorem mit Wirkungsquerschnitt verknüpft
Panofsky Rate:Pd = 2.83±0.04
da
...321
20
CCdpp
m
pp
Pa np
dd
11
Bonn, 04. September 2009 Folie 36
Elastic scattering
Bonn, 04. September 2009 Folie 37
Experimental setup
Bonn, 04. September 2009 Folie 38
long range stability
results analysisinclination sensor data
evolution ofcrystal temperature
Bonn, 04. September 2009 Folie 39
corrections and error for ε1s
Bonn, 04. September 2009 Folie 40
Spectrometer responsefunction
D. Hitz et al., Rev. Sci. Instr., 71 (2000) 1116
CCD detector
He-like atoms
•narrow X-rays, few keV
•high rateS H(2p-1s)
Cl H(3p-1s)
Ar H(4p-1s)
D(3p-1s)
ECRIT
= cyclotron trap (4) + hexapole magnet (2) + high frquency (5)
6.4 GHz450 W
D.F.Anagnostopoulos et al., Nucl. Instr. Meth. B 205 (2003) 9D.F.Anagnostopoulos et al., Nucl. Instr. Meth. A 545 (2005) 217
Electron Cyclotron Resonance Ion Trap ( ECRIT )
Bonn, 04. September 2009 Folie 41
Kinetic energy → velocity distribution
Bonn, 04. September 2009 Folie 42
Appendices | NN threshold parameter
PTat present / 30%
few %
charge symmetry detailled balance
dppppdnnd )1()0( 1
31
3 IPISNN
V. Lensky et al., nucl-th/0511054,2005
p
nndnndD
m
a
6
1
321
20 ηCβηCασ dπpp
extrapolation to threshold
J. Hüfner, Phys. Rep. 21 (1975) 1
productionD atom
mk /
NLO
LO
[b
]
Bonn, 04. September 2009 Folie 43
Formulae D U.-G. Meißner, U. Raha, A. Rusetsky, Phys. Lett.B 639 (2006) 478
+ Coulomb corrections
Bonn, 04. September 2009 Folie 44
Deser formula
+ Coulomb corrections
from H 1s
from D 1s
D wave function
Single + multiple scattering
d