Bonn, 04. September 2009 Mitglied der Helmholtz-Gemeinschaft Pionic Deuterium | Thomas Strauch for...

Bonn, 04. September 2009

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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