PIONIC HYDROGEN

PIONIC HYDROGEN

• goal of the measurements

• experimental approach and challenge

• strong-interaction shift 1s and width 1s

D. Gotta, IKP, FZ Jülich

for the PIONIC HYDROGEN collaboration

Debrecen – Coimbra – Ioannina – Jülich – Paris – PSI – Vienna

CSB 2005 Trento - 15. 6. 2005

2

2 isospin scattering length

a = a-p-p a+p+p

isospin invariance: mu = md

a-p-p + a+p+p = - 2 a-pon

PIONIC HYDROGEN - N scattering at „rest“

strong interaction observable as

shift and broadening

1s + 7 eV attractive

1s 1 eV

1s a - p - p

a + + a –

1s (1+1/ P)(a - p o n) 2

(1+1/ P)( a – ) 2

PANOFSKY ratio P

–p on/ –p n = 1.546 0.009

J. Spuller et al., Phys. Lett. 67 B (1977) 479

EK = 2.5 keV

ATOMIC CASCADE

1s / 1s 0.2% & 1s / 1s 1-2%

N isospin scattering lengths a & a –

N coupling constant

N sigma term N

2Nf

GOAL

4

current algebra

Weinberg,Tomozawa:

chiral limit mquark 0

Goldberger-Treiman relationN coupling constant fN

Sigma termcontentspssppdduup

M4

m

072.0F

g

4

mf

m/079.0a

0a

dN

2

2A

2

N

u

2

m

PTordershigher

constantdecaypionF

_____________________

N sigma-term N

Goldberger- Miyazawa-Oehme

(GMO)

sum rule 1%

0

2222

2

)(2

)()(

2

1

)2/(

2)1(

dk

k

kk

Mmm

f

m

a

M

mtot

ptot

pN

NM4

2Ag

d2m

N2f4

2ma)

M

m1(

EXPERIMENT

6

high stop density

high X - ray line yields

bright X - ray source

position & energy resolution

background reductionby analysis of hit pattern

spherically bent Bragg crystal

ultimate energy resolution

7

SET-UP at PSI

crystal spectrometer

spherically bent crystals

CCD X-ray detector

2 3 matrix 75 50 mm2

X-ray tube

cryogenic target

0 – 40 stp H2

cyclotron trap II more muons

8

DEGRADERS and CRYOGENIC TARGET

inside

CYCLOTRON TRAPsuper-conducting split coil magnet

X - rays

beam

stop efficiency

fstop density

1% @ stp

= 26 ns

109 /s

9

Spherically curved Bragg crystal

radius of curvature 3 m

100 mm

crystal cuts

used

Si 111

Si 110

quartz 10-1

to be used

quartz 1-20

10

Large - Area Focal Plane Detector

N. Nelms et al., Nucl. Instr. Meth 484 (2002) 419

2 3 CCD 22 array with frame buffer

pixel size 40 m 40 m

600 600 pixels per chip

frame transfer 10 ms

data processing 2.4 s

operates at – 100°C

150 eV @ 4 keVX 90%

image area

storage area

flexible boards

cooling (LN2)

11

previous experiment

new experiment

Lorentz tails

Doppler broadening

PEAK / BACKGROUND and FIT INTERVAL !

PEAK-TO-BACKGROUND ratio improved by one order of magnitude !

massive concrete shielding

+large area X-ray detector

ATOMIC CASCADE and

STRONG-INTERACTION EFFECTS

13

1. [(pp)p]ee – molecule formation („DH“)

radiative de-excitation ?

had

p not an isolated system !

CASCADE - COLLISIONAL PROCESSES p + H2

2. Coulomb de-excitation !non radiative process ni nf + kinetic energy

Doppler broadening

had

» dangerous effects «

14

1. MOLECULAR POTENTIALS

consequences for H (np 1s) transitions

EX EX - E ?(how many) bound states below

dissociation limit of 4.5 eV ?

Jonsell, Froelich and Wallenius for n=1,2,3 Phys. Rev A 59 (1999) 3440

ppµ ddµ

X-ray / total 0.03 1

Lindroth, Wallenius and Jonsell Phys. Rev A 68 (2003) 032502

Kilic, Karr and Hilico to be published

"Vesman“ mechanism for excited states: pnl + H2 [(pp) njvp] ee K

experiment R. Pohl et al., Hyp. Int. 138 (2001) 35 theory S.Hara et al.

I.Shinamura

quenching of p 2s via [(pp)p]ee formation V.I.Korobov, …

X-ray transitions from slightly shifted bound states ?

I.

1s

unbiased energy determination

16

H(3p - 1s) - density dependence

mixture H2 / 16O2

(98%/2%)

1.2 bar @ T = 85K

4 bar equivalent density

H2

2 bar @ T = 20K

28.5 bar equivalent density

H2

1 bar @ T = 17K

LH2

first time

H / O energy calibration

simultanuously

____________________

alternately H / O

mixture 4He / 16O2 / 18O2

( 80%/10%/10%)

2 bar @ T = 86K

17

H(3p-1s) energy no density dependence identified

EQED = ± 0.006 eV old!EQED = ± 0.001 eV new!P. Indelicato, priv. comm.

piH shift

7,00

7,10

7,20

1 10 100 1000

density equivalent / bar

/ e

V

previous experiment

LH2

previous experiment – Ar KETHZ-PSI H.-Ch.Schröder et al.

Eur.Phys.J.C 1(2001)473

R-98.01

Maik Hennebach, thesis Cologne 2003

1s = + 7.120 0.008 0.009 eV

0.007 eV

II.

LINE WIDTH

MEASURED LINE SHAPE = R L D

crystal 1s Doppler broadening

resolution Coulomb de-excitation

ECRIT H muonic hydrogen

RESPONSE FUNCTION

diffraction theory

XOP2 codeplane crystal

387 meV

similar to a Lorentzian in the tails

21

T = 295K

closest to energy of H(4p-1s)

3500 events

3 days

EXOTIC ATOM

RESPONSE FUNCTION I

22

CRYSTAL SPECTROMETER and PSI ECRIT

Electron Cyclotron Resonance Ion Trap cyclotron trap (4) + hexapole magnet (2)

CCD detector

aperture

6.4 GHz, 450 W

D. Hitz et al., Rev. Sci. Instr., 71 (2000) 1116

Tion 5 eV "cold" plasma !

He-like electronic atoms

narrow X-ray transitions

X = 10 - 40 meV

D.F.Anagnostopoulos et al., Nucl. Instr. Meth. B 205 (2003) 9to be publ. In Nucl. Instr. Meth. A

RESPONSE FUNCTION II

23

ECRIT measurements 2004

= 10 –8 s

M1 transitions in He-like S H(2p-1s)

Cl H(3p-1s)

Ar H(4p-1s)

30000 events in line tails can be fixed with sufficient accuracy

2 3S1 1 1S0

M1 transition

24

LINE WIDTH and INITIAL STATE

crystal resolution

subtracted

1s < 850 meV

Maik Hennebach, thesis Cologne 2003

not corrected for

Coulomb de-excitation

piH total line width

800

1000

1200

1400

1 10 100 1000

equivalent density / bar

wid

th /

meV

2-1

3-1

4-1

3-1 ETHZ-PSI

previous experiment

ECRIT results confirm C data

COULOMB DE-EXCITATION

26

1. [(pp)p]ee – molecule formation („DH“)

radiative de-excitation ?

had

p not an isolated system !

CASCADE - COLLISIONAL PROCESSES p + H2

2. Coulomb de-excitation !non radiative process ni nf + kinetic energy

Doppler broadening

had

» dangerous effects «

27

NEUTRON - TOF

(– p)ns 0 n

non-radiative transitions

quasi-discrete

velocity profile

2. COULOMB DE-EXCITATION

n – TOF / ns

A. Badertscher et al., Eur. Phys. Lett. 54 (2001) 313

(–H)n + H=H (–H)n-1 + H + H + kinetic energy

28

MUONIC HYDROGEN

- to quantify Coulomb de-excitation

- to identify other possible cascade effects

from X-ray line shape

Monte-Carlo simulation

µ –H (2p-1s) @ 15 bar

1.89 keV


cascade model calculation (V.E. Markushin – PSI)

29

MUONIC HYDROGEN RUN 12/2004

analysis in progress

----- crystal response ECRIT 2004


low-energy component

high-energy component

50%

of e

nvisa

ged s

tatis

tics

intermediate-energy component

no satellites from

molecular formationidentified

triplet / singlet = 3.00.2

30

KINETIC ENERGY DISTRIBUTIONS

- prediction -Jensen / Markushin

µH H

at the moment of the 3p - 1s transition

... 5-4 4-3 ... 5-4 4-3

experiment cascade theoryH H

limits "box" assumptions

31

EXTRACTION Of THE NATURAL LINE SHAPE

goodpeak / background essential!

--- Doppler „boxes“ natural line width 1s

- - total

H(3p-1s)

response function subtracted

Coulomb de-excitation4 - 3

HADRONIC BROADENING

33

ECRIT RESULTS and HADRONIC WIDTH

Fit to boxes from


and

ECRITcrystal

resolution subtracted

R-98.01 1s 785 27 meV preliminary

previous experiment

1s 865 69 meV (7%)

H.-Ch.Schröder et al.Eur.Phys.J.C 1(2001)473

piH hadronic width

700

800

900

1000

1 10 100 1000

equivalent density / bar

/ m

eV

2-1

3-1

4-1

3-1 ETHZ-PSI

34

R-98.01 PT + Panofsky

previous achieved in finally exp.* 1. step envisaged

1s /1s 0.5% 0.2% 0.2% 2.9 %

to be done

final high statistics run

1s /1s 7 % 3 - 4% 1-2% 0.8 %

PIONIC HYDROGEN - status

SCATTERING LENGTHS

1s [ a + a – ] (1 + ) = 7.2 2.9 %

J. Gasser et al.,Eur. Phys. J. C 26 (2003) 13

1s [ a – (1 + ) ] 2 = + 0.6 0.2 %

P. Zemp, thesis Bern‘04

PT theory

f1 problem

no f1 problem

36

2nd order PT

O(2) in = q, =1/137,

(md-mu)

LECs f1 , f2 , c1

contribute to isospin breaking in O(2)

f1 accuracy of prediction O(10%)

V.E. Lyubovitskij & A. Rusetsky, Phys. Lett. B 494(2000)9

V.E. Lyubovitskij et al.,

Phys. Lett. B 520(2001)204

H - hadronic shift 1s &

N s-wave isospin scattering lengths

Deser formula incl. Coulomb - strong-int. interference

Trueman (1961), …

37

piN isospin scattering length

-0,03

-0,02

-0,01

0,00

0,01

0,02

0,07 0,08 0,09 0,10 0,11 0,12

a-

a+

theory / PSA

experiment

opt. pot. fits

current algebra

R-98.01

deeply bound

pionic statesKH80/86

ChPTWeinberg

Tomozawa

N scattering lengths a I

corrections = (-7.22.9)%


= (+0.60.2)%P. Zemp, thesis University of Bern 2004

R-98.01 - prelim

inary !

38

D LT

a & a – ELTphenomenologicalanalysis +multiple scattering

Ericson et al.Phy.Scr.T87(2000)71

from (H + D)

current algebra Weinberg, Tomozawa ‘66 N phase shift KH80

- - HBPT 3rd order Fettes, Meissner, Steininger

NP A640(1998)199

multiple scattering Thomas & LandauPhys.Rep.58(1980)121

R-98.1

PT analysis

Beane et al.Nucl.Phys.A 720(2003)399

from (H + D)

correction

= -7.22.9%


= +0.60.2% P. Zemp, thesis Bern‘04

N scattering lengths a II

39

N coupling constant 2Nf

2Nf

02222

2

22

1

2

21 dk

)k(

)k()k(

)M/m(m

f

m

a)

M

m(

totp

totpN

Goldberger- Miyazawa-Oehme (GMO) sum rule

1%

previous H + D exp.

H.-Ch. Schröder et al., Eur. Phys. J. C 21 (2001) 473

1s H a-p-p

1s D a + = a-p-p + a+p+p

a-p-p + a-n-n

charge symmetry

Ericson, Loiseau & Thomas

Phys. Rev. C 66, 014005 (2002)

shift H+D

13.89 + 0.23 14.110.20 - 0.11

13.21 + 0.11 - 0.05

R-98.01

PIONIC DEUTERIUM

1s /1s 1s /1s

D D. Chatellard et al. (1994) 2% 12%P.Hauser et al. (1998)

41

D - hadronic shift 1s &

N s-wave isospin scattering lengths

d p + n corrections! a - p + a - n = (a1/2 + 2a3/2 ) /3

= 2 a+ isoscalar scatt. length

Deser formula

SS single scatteringDS double scattering ( 60% )HC higher ordersAB absorptive corrections

experiments

ad = - 0.0261 0.0005 / m D. Chatellard et al., NPA 625(1997)855

P. Hauser et al., PRC 58(1998)R1869

calculations

ad a Beane, Bernard, Lee, Meissner, PR 57 (1998) 424

Ericson, Loiseau & Thomas, PR C 66, 014005 (2002) Beane, Bernard, Epelbaum, Meissner, Phillips NPA 720 (2003)399 Rusetski et al., in progress

...

hadd

Bs1

s1 ar

4

B

ABHCDSSSamM2

mM4ahad

d

42

nuclei T / 3He with ... without external pions

a + , a – e. g. 4He

H

–p scattering at „rest“

1s a - p - p

a + + a –

1s (a - p o n) 2

( a – ) 2

D

1s a - p - p + a - n - n

a +

0

1s >> 0 d p + n

N

Meissner, Raha, Rusetski, Eur. Phys. J. C41 (2005) 213

Baru, Haidenbauer,Hanhart, Niskanen,Eur. Phys. J. A16 (2003) 437

f0

!12.0aa

dd

f0 problem

43

1. MOLECULAR POTENTIALS

consequences for H (np 1s) transitions

EX EX - E ?(how many) bound states below

dissociation limit of 4.5 eV ?

Jonsell, Froelich and Wallenius for n=1,2,3 Phys. Rev A 59 (1999) 3440

ppµ ddµ

X-ray / total 0.03 1

Lindroth, Wallenius and Jonsell Phys. Rev A 68 (2003) 032502

Kilic, Karr and Hilico to be published

"Vesman“ mechanism for excited states: pnl + H2 [(pp) njvp] ee K

experiment R. Pohl et al., Hyp. Int. 138 (2001) 35 theory S.Hara et al.

I.Shinamura

quenching of p 2s via [(pp)p]ee formation V.I.Korobov, …

X-ray transitions from slightly shifted bound states ?

44

response function I

energy calibration I

strong interaction

Cl K2.62 keV

15 min

Ne(7-6)2.72 keV

12 h

D(2p-1s)2.60 keV

15 h

1s = – 2.469 0.055 eV1s = 1.093 0.129 eV

P. Hauser et al., PR C 58 (1998)R1869

PIONIC DEUTERIUM

45

1s /1s 1s /1s

3He I.Schwanner et al. (1979) 10% 25%NP A 412 (1984) 253

T --- ---

4He G.Backenstoss et al. (1974) 3% 7%

LIGHT PIONIC ATOMS - A = 3, 4

46

SUMMARY

HYDROGEN

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

1970 1980 1990 2000

year

sh

ift,

wid

th /

eV

DEUTERIUM

-6,5

-5,5

-4,5

-3,5

-2,5

-1,5

-0,5

0,5

1,5

1970 1980 1990 2000

year

sh

ift,

wid

th /

eV

X-r

ays

iden

tifi

ed

2006

?2006

Increase of precision to the 1% also for A=3,4 desirable ?

PIONIC HYDROGEN ISOTOPES - TIME" DEPENDENCE ,

PIONIC HYDROGEN

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