Mitg

lied

de

r H

elm

ho

ltz-G

em

ein

sch

aft

Detlev Gotta

Institut für Kernphysik, Forschungszentrum Jülich

NuPECC Physics Mini-Workshop

Jülich, March 15, 2013

Exotic Atoms

Folie 2

• INTRODUCTION

• EXPERIMENT

• 4 EXAMPLES

• ? ? ?

Folie 3

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

Folie 4

, , 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 + …

Folie 5

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

Folie 6

EXPERIMENT

Folie 7

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

Folie 8

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

Folie 9

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

Folie 10

µH from slow decay muons 𝝅 → 𝝁𝝂

kept in the magnetic bottle field

CYCLOTRON TRAP

Folie 11

H2

gas inlet

5m Mylar®

target cell

~1 bar

~22 K

density

equivalent

~12.5 bar

~293 K

𝒇𝒔𝒕𝒐𝒑𝝁

≈ 𝟎. 𝟐 × 𝒇𝒔𝒕𝒐𝒑𝝅

CYCLOTRON TRAP

Folie 12

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

Folie 14

HYDROGEN – LIKE ATOMS ?

Folie 15

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

Folie 16

muonic hydrogen

µp e + p

µp + n (0.1%)

Folie 17

µH LEVEL SCHEME

EKa = 2.25 keV

Coulomb de-excitation

– pnl + H2 – pn’l’ + H+H + kinetic energy

>>> Doppler broadening !

Folie 18

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

Folie 19

PION - NUCLEON

SCATTERING LENGTHS

HADRON – HADRON INTERACTION

Folie 20

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

Folie 21

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

Folie 22

pionic hydrogen

p 0 + n

g + n (39%)

Folie 23

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

Folie 24

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

Folie 25

PION PRODUCTION / ABSORPTION

NN NN

HADRON – HADRON INTERACTION

Folie 26

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

Folie 27

ATOMS

Folie 28

pn 1pn

X-radiation

ANTIPROTONIC XENON

internal Auger effect

34 EZX DG

212 /A EZ

DG

What happens when an antiproton meets 54 electrons ?

Folie 29

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

Folie 30

? ? ? …

Folie 31

• ͞pp / scattering length

• isospin ͞pp ͞pn

• „no“ Coulomb de-excitation D!

...

vague

puzzling

Folie 32

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

Folie 33

THANK YOU