Particle Physics with Neutrons

Hartmut Abele

Fundamental Interactions

June 22, 2004

Hartmut Abele 2

Fundamental InteractionsFundamental Interactions

The Standard Model– Two parameters:

Lambda = gA/gV

Vud, CKM matrix

Gravity and Quantum Mechanics

Observables:– The lifetime

– Spin of neutron and decay particles Half a dozen observables

– Momenta of decay particles}

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OutlineOutline Correlation measurements in beta-decay

– beta asymmetry A = 0.1170(13)

– neutrino-asymmetry B = 0.983(4)

– electron-neutrino angular correlation a = 0.102(5)

– triple correlation coefficient D = (0.6 ± 1.0)·10-3

– triple correlation coefficient R:

Axial to vector coupling (correlation A)– gA /gV = 1.2720(18)

Quark mixing and CKM Unitarity (A, lifetime) – Vud = 0.9725(13)

– unitarity of CKM-matrix: Vud2 + Vus

2 + Vub2 = 1(6.0 ± 2.8)·10-3

Neutrinos, left/right (A,B correlation) – mass of right-handed boson m(WR) > 281 GeV/c2 (90% c.l.)

– left-right mixing angle 0.20 < < 0.07 (90% c.l.)

New sources of CP violation, (D, R correlation, EDM, this conference) – phase between gA and gV = (180.08 ± 0.10)0

Speculation about CPT, (D, R correlation, EDM, this conference)

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PROCESSES WITH SAME FEYNMAN DIAGRAM:

• Solar cycle p p D e+ e

p p e D e

…

• Neutron star formation p e n e

•Primordial element formation n e+ p e'

p e n e

n p e e'

•Neutrino detectors p e' n e+

•Neutrino forward-scattering e p e+ n etc.

•W, Z-production p p' W e e' etc.D.Dubbers

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Outline IIOutline II

Baryon number violation– neutron-antineutron oscillation time n nbar > 0.86·108 s (90% c.l.)

Early Universe– number of neutrino families N = 2.6 ± 0.3

– baryonic matter in universe /crit = (4 ± 1) %

Search for extra dimensions in space time– Gravitational bound quantum states

– String theories

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Processes that violate baryon Processes that violate baryon numbernumber

Do neutrons oscillate? n nbarBaryon-number oscillations B B?

Process allowed in some Grand-Unified Theories

Observable: Antineutron Experimental

limit: n nbar > 0.86·108 s (90% c.l.)

Limit on neutron oscillations

probes 105 GeV range

D.Dubbers

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Correlation measurements in Correlation measurements in --decaydecay

Electron

Proton

Neutrino

Neutron SpinA

B

C Observables in neutron decay:

Lifetime SpinMomenta of decay particles

Observables in neutron decay:

Lifetime SpinMomenta of decay particles

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Transition probability

)]Ep

REEpp

DEp

BEp

A(...EEpp

a1[

dddE)EE(EpddWdE

ee

ee

e

e

ee

en

e

e

ee2

e0eeee

11% -11% 97% SM: 0

correlation

correlation asymmet

ry

asymmetry

triple correlation

triple correlationasymme

try

asymmetry

Triplecorrelation

Triplecorrelation

SM: 0

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Particles And FieldsParticles And Fields

)1()1(8

gT 522

2

5

2

fi e

w

w

duudmk

m

kkg

V

matrix for d-u transition:

lhud

eduud

JJV

V

2

G

)1()1(2

GT

F

55F

fi

AVJ udh )1( 5

aJ el v)1( 5

nPp

TAp

nsp

MVp

kkigkm

kgkgiA

kkigkm

kgkgiV

])(2

)()([

])(2

)()([

52

5

2

52

22

2

hadron and lepton currents:

vector- and axial vector currents:

V

Aud

F

enp

npp

Vint

gg

aAVVG

km

GL

).)((22

1

)1()2

)1((22

155

v

Lagrange function for neutron decay:

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Coefficient Coefficient AA

Coefficient A and lifetime determine Vud and

Electron

Neutron SpinA

ElectronNeutron SpinA

W()={1+v/cPAcos()}

231

)1(2

A 231

)1(2

A

NN

NNAexp

NN

NNAexp A

N N

N Nexp

A

N N

N Nexp

on flipper spin with spectrum electron

off flipper spin with spectrum electron

:N

:N

on flipper spin with spectrum electron

off flipper spin with spectrum electron

:N

:N

PfAAc

vexp PfAA

c

vexp

= gA/gV= gA/gV

No coincidences !

)31(

sec44908V

22

ud

)31(

sec44908V

22

ud

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SpectrometerSpectrometer

0

20

40

60

80

020

4060

80100

0,810

0,811

0,812

0,813

0,814

0,815

0,816

0,817

0,818

Z A

xis

X A

xis

020

40

60

80

1000

20

40

60

800

50

100

150

200

250

300

350

Cross section neutron beam

l e f t : r i g h t :

NN

NNA exp

AN N

N Ne x p

onflipper spin with spectrumelectron

offflipper spin with spectrumelektron

:

:

N

N

Magnetic field

Polarizer Spin flipper0 100 200 300 400 5000,0

0,2

0,4

0,6

0,8

1,0 flipper off flipper on background

Rat

e [H

z]

0 100 200 300 400 5000,0

0,2

0,4

0,6

0,8

Asymmetry in raw data

flipper off flipper on

Channel

Rat

e [H

z]

0 100 200 300 400 5000,0

0,2

0,4

0,6

0,8

1,0 flipper off flipper on background

Rat

e [H

z]

0 100 200 300 400 5000,0

0,2

0,4

0,6

0,8

Asymmetry in raw data

flipper off flipper on

Channel

Rat

e [H

z]

0 100 200 300 400 500 600 700 800 900 1000

0,0

0,2

0,4

0,6

(NON+NOff)/2

unpolarized neutron spectra

Det 1

Bet

a S

pect

rum

0 200 400 600 800 1000

0,0

0,2

0,4

0,6

Det 2

energy [keV]

Bet

a S

pect

rum

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A fit A fit

200 300 400 500 600 700 800

0,03

0,04

0,05

0,06

0,07

Det 1 A1=-0.11743(57)

Fit of the Asymmetry

exp.

Asy

mm

etry

200 300 400 500 600 700 800

0,03

0,04

0,05

0,06

0,07

Det 2 A2=-0.11625(57)

energy [keV]

exp.

Asy

mm

etry

A 1 0 1 1 7 4 6. ( ) A 2 0 1 1 6 3 6. ( )

A = - 0 . 1 1 6 8 ( 4 )

c o r r e c t i o n u n c e r t a i n t yp o l a r i z a t i o n 1 . 1 % 0 . 3 %f l i p p e r e f f i c i e n c y 0 . 3 % 0 . 1 %b a c k g r o u n d 0 . 5 % 0 . 2 5 %d e t e c t o r l i n e a r i t y 0 . 2 %

s u m 2 . 0 4 % 0 . 6 6 %

f i n a l r e s u l t : A = - 0 . 1 1 8 9 ( 7 ) = - 1 . 2 7 3 9 ( 1 9 )

Dissertation: J. Reich

Aexp = A v/c Pf

final result:A = -0.1189(7) = -1.2739(19)

final result:A = -0.1189(7) = -1.2739(19)

PRL 88 211801 (2002) PRL 88 211801 (2002)

Vud=0.9717(13) (4:)(12:A)(4:theory)Vud=0.9717(13) (4:)(12:A)(4:theory)

l e f t : r i g h t :

NN

NNA exp

AN N

N Ne x p

onflipper spin with spectrumelectron

offflipper spin with spectrumelektron

:

:

N

N

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Quark Mixing Quark Mixing and CKM Unitarityand CKM Unitarity

0%

50%

100%

'down' 's trange ' 'bottom'

down strange bottom

b

s

d

U

b

s

d

CKM

b

s

d

U

b

s

d

CKM

CKM MatrixCKM Matrix

Standard Model:quark-mixing should be 'zero-sum game':quark mixing = pure rotation in flavor spacei.e. CKM quark mixing matrix should be unitary

Vud from

•Nuclear beta decay Vud=0.9740(5), 2.3 sigma•Pi beta decay Vud=0.9717(56)•Neutron beta decay, 2.7 sigma•High energy physics assuming unitarity

Standard Model:quark-mixing should be 'zero-sum game':quark mixing = pure rotation in flavor spacei.e. CKM quark mixing matrix should be unitary

Vud from

•Nuclear beta decay Vud=0.9740(5), 2.3 sigma•Pi beta decay Vud=0.9717(56)•Neutron beta decay, 2.7 sigma•High energy physics assuming unitarity

ud

d

u ud

u

d

W

Vud

eu

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Free Parameters, Standard ModelFree Parameters, Standard Model

2

ub

2

usud VVV 1 2

ub

2

usud VVV 1

Ft-valuesFt-values

NeutronNeutron

Deviation from unitarityVisible in the “raw” data!

Deviation from unitarityVisible in the “raw” data!

Vud=0.9717(13) (4:)(12:A)(4:theory)Vud=0.9717(13) (4:)(12:A)(4:theory)

hep-ph/0312124

hep-ph/0312150

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Conclusion 2002Conclusion 2002 Nuclear beta-decay dominated by theoretical errors

= 0.0032 0.0014

– Restoration of unitarity: 2.3 sigma shift

Neutron beta decay dominated by experimental errors

= 0.0076 0.0028

– Restoration of unitarity: would require a 3 sigma shift in A

– a 8 sigma shift in lifetime

– radiative corrections are 8 sigma wrong

K decays: 3 sigma shift to explain nuclear beta decay, or

8 sigma shift to explain neutron results

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Free Parameters, Standard Model, 2004Free Parameters, Standard Model, 2004

2

ub

2

usud VVV 1 2

ub

2

usud VVV 1

Ft-valuesFt-values

NeutronNeutron

Deviation from unitarityVisible in the “raw” data!

Deviation from unitarityVisible in the “raw” data!

Vud=0.9717(13) (4:)(12:A)(4:theory)Vud=0.9717(13) (4:)(12:A)(4:theory)

hep-ph/0312124

hep-ph/0312150

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Neutron lifetime Neutron lifetime

# lifetime [s] Method year

-1 (750 + 330 - 200 Storage 2000)

0 881,0 1 3 storage method of ultra-cold neutrons

1999

1 885,4 0,9 0,4 storage method of ultra-cold neutrons

2000

2 889,2 4,8 beam method 1995

3 882,6 2,7 storage method of ultra-cold neutrons

1993

4 888,4 3,1 1,1 storage method of ultra-cold neutrons

1992

(4a 888.4 2,9 storage method of ultra-cold neutrons

1990 )

5 878 27 14 beam method 1989

6 887,6 3,0 storage method of ultra-cold neutrons

1989

7 877 10 storage method of ultra-cold neutrons

1989

8 876 10 19 beam method 1988

9 891 9 beam method 1988

10 870 17 beam method 1987

11 903 13 storage method of ultra-cold neutrons

1986

(11a 875 95 storage method of ultra-cold neutrons

1980)

(2a 937 18 beam method 1980)

(10a 881 8 beam method 1978 )

12 918 14 beam method 1972

885,7 0,8 world average PDG 2004

Munich:ri = 10 cmRa = 30 cmh = 60 cm

NIST:

Huffmann et al., Nature Mam

pe e

t al.,

PR

L 6

3 5

93

(1

98

9)

Hartmut Abele 18

Hartmut Abele 19

The new The new AA measurement measurement A new beam

– The ‘ballistic’ super-mirror cold-neutron guide

H113

– H. Haese et al., Nucl. Instr. Meth. A485, 453 (2002)

New Polarizers

New Geometry for Beam polarization – T. Soldner:

A perfectly polarized neutron beam

New analyzer with He cells

n

P1 P2R

BB

BY

ZX

nn

P1 P2R

BB

BY

ZX

n

We want

•More neutrons•No corrections to raw data •100% polarization•No background

We want

•More neutrons•No corrections to raw data •100% polarization•No background

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Polarization efficiencyPolarization efficiency

n

P1 P2R

BB

BY

ZX

n

Hartmut Abele 21

Coefficient BCoefficient B

Two Techinques

NN

NNBexp

NN

NNBexp

ElectronProton

Neutron Spin

Neutrino

Electron

Proton

Neutrino

Neutron Spin

Electron proton coincidence

Our method:

Hartmut Abele 22

Proton detectorProton detectorC foil Scintillator

Proton

Proton detection:•Measure electron energy•Wait for proton•Convert proton into electron signal

Proton detection:•Measure electron energy•Wait for proton•Convert proton into electron signal

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Proton “electron” spectrumProton “electron” spectrum

Dissertation: J. Reich

Hartmut Abele 24

ElectronProton

Neutron Spin

Neutrino

Electron

Proton

Neutrino

Neutron Spin

Hartmut Abele 25

Results: Results: B = 0.967±0.012B = 0.967±0.012 and and C=-0.238 C=-0.238 ±0.011±0.011

Dissertation Kreuz 2004Dissertation Kreuz 2004

 

B Detector 1   Detector 2  

  Correction [%] Error [%] Correction [%] Error [%]

Polarization & Flip Efficiency

(1.5) 0.5 (1.8) 0.5

Statistics 0.8   0.8

Accidental coincidences (3.0) 0.5 (3.5) 0.6

Additional Stop pulses -0.8 0.4 -0.9 0.5

Gain   0.01   0.01

Offset   0.03   0.05

Edge effect (-0.1) 0.05 (-0.1) 0.05

Electro magnetic mirror (0.5) 0.05 (0.5) 0.05

Grid effect (-0.05) 0.05 (-0.05) 0.05

Backscattering        

Coefficient A 0.03   0.03

Coefficient a   0.06   0.06

Sum -0.8 1.15 -0.9 1.4

BBPDGPDG = 0.983±0.004 = 0.983±0.004 and and CCtheorytheory=-0.239 =-0.239

Hartmut Abele 26

New developments: hep-ph/0312124 CKM-Workshop, Sep. 2002, PMSN-Workshop, NIST 2004

“little” a: aSpect, Mainz, Munich,2004 “little” a: Kurchatov Inst., NIST “Big” A,B,C: HD, 2004 “Big A + B”: Gatchina “Big” A: LANL,... “Big” R: PSI, ongoing “Big” D: emiT, “Big” D: Trine, 2003 “Big” A: HD, 2005

Angular correlationsAngular correlations in neutron decay in neutron decay

135° Geometry: emiT 2000

TRINE 2000

LANSL

Mainz, Munich

Hartmut Abele 27

CP and Time Reversal ViolationCP and Time Reversal Violation

Torsten Soldner: CKM Workshop

Left-right symmetric

Exotic fermions Leptoquarks

Standard Model

•GUTs•some SuSy models•some superstring models•some composite models

cossin

sincos

21R

21L

WWW

WWW

From CKM phase:

D10-12

From d199Hg:

D< 10 -4 …10 -5 D limits phases in LQ couplings!

From d199Hg:

D< 10 -4 …10 -5

e.g. SU(2)RU(1)L

•in some GUTs

P. Herczeg, Prog. Part. Nucl. Phys. 46 (2001) 413.P. Herczeg, Prog. Part. Nucl. Phys. 46 (2001) 413.

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Searches for electric dipole momentSearches for electric dipole moment

Why has so much matter survived the big bang?What is the origin of time reversal violation?

CPT = 1: CP-violation T-violation

THIS CONFERENCE

Hartmut Abele 29

FRM2 2004FRM2 2004

Cold neutrons at the FRM II– equivalent to existing source at the ILL

UCN source at the FRM II– 2 orders of magnitude higher density at FRM

Hartmut Abele 30

PSI, UCN Source, this workshopPSI, UCN Source, this workshop

F overall = 100 ,1.1,3.1,2,40

)(

2

12

FFFF

EPNd

PEN

Hartmut Abele 31

INPUT:NEUTRON BEAM CONSTANTS

    OUTPUT: NEUTRON RATES

 

capture flux Φ 1,4 E+10 cm-2 s-1

  intensity I0=ΦA 1,9 E+12 s-1

beam area A 120 cm2   density ρ=Φ/v 1,6 E+05 cm-3

mean velocity v

1000ms-1   no. of neutrons per beam length N/l=ρA=I0/v

1,9 E+09 m-1

neutr. lifetime

885 s   neutron decay rate/beam length n/l = I0/v/τ

2,2 E+06 sec-1

m-1

The ‘ballistic’ super-mirror cold-neutron guide H113

H. Haese et al., Nucl. Instr. Meth. A485, 453 (2002)

Hartmut Abele 32

proton orelectron detector

~2m, 150mTchopper

detector

beam stopdecay volumeneutron beam

neutron cloud

velocity selector

simulated electron trajectories

proton orelectron detector

The New PERKEO

Dubbers, Märkisch, H.A.

Hartmut Abele 33

The future with the New Perkeo

neutron beam observable method physics

pulsed

polarised

-asymmetry A , scint. spectr. CKM unitarity

weak magnetism

pulsed

unpol.

p-spectrum e- correlation a

p, TOF CKM unitarity

pulsed

polarised

p-asymmetry -asymmetry B

p, TOF mass of right handed W-boson

pulsed

unpol.

-spectrum , magn. spectr. radiative corrections

continous

unpol./pol.

-helicity , Mott-scatt. right-handed currents

continous

unpol.

p-helicity p, Mott-scatt.

Hartmut Abele 34

This work was done by ...This work was done by ... University of Heidelberg

M. Astruc Hoffmann Stefan Baeßler Dirk Dubbers Uta Peschke Jürgen Reich H.A.

Ulrich Mayer Daniela Mund Christian Plonka Christian Vogel H.A. Bernhard Brand Michael Kreuz

Daniela Mund Markus Brehm Marc Schumann Jochen Krempel H.A. Michael Kreuz Stefan Baeßler Bastian Märkisch

Bastian Märkisch, Dirk Dubbers, Marc Schumann, H.A.

Institut Laue-Langevin Torsten Soldner, Alexander Petoukhov

GSI, TUM Mayer-Komor, Kindler

Mainz Stefan Baeßler, Ferenc Glück,

A:B:A:

New PERKEO:

Hartmut Abele 35

Gravity on a MicronGravity on a Micronand Limits on Large Extra Dimensionsand Limits on Large Extra Dimensions

Galilei– Object: Neutron

– Fall height: ~ 50 m

Quantum aspect

)1()( /21 rer

mmGrV

)1()( /21 re

r

mmGrV

Hartmut Abele 36

WKB vs. Analytical perturbativeWKB vs. Analytical perturbative

Hartmut Abele 37

Effective potential close above the Effective potential close above the mirrormirror

2 4 6 8 10 12 14

0.2

0.4

0.6

0.8

1

)(2)( /)(/2 zhz eeGzgz )(2)( /)(/2 zhz eeGzgz

0.00001 0.00002 0.00003 0.00004 0.00005

0.0002

0.0004

0.0006

0.0008

0.00001 0.00002 0.00003 0.00004 0.00005

0.0002

0.0002

0.0004

z

)1()( /21 rer

mmGrV

)1()( /21 re

r

mmGrV

Hartmut Abele 38

1001 10

1012

1013

1014

1 2 5 10 20 50 100

1. 1012

1. 1013

1. 1014

Limits for alpha and lambdaLimits for alpha and lambda

H. A. et al., Lecture Notes in Physics, Springer, 2003

m

Hartmut Abele 39

The gravity work has been done The gravity work has been done by ...by ...

ILL, Grenoble:V. Nesvizhevsky, A. Petukhov, H. Boerner

Gatchina, St. PetersburgA. Gagarsky, G. Petrov, S. Soloviev

Mainz UniversityS. Baeßler

DESYA. Westphal,

Heidelberg University:G. Divkovic, N. Haverkamp, D. Mund, S. Nahrwold, F. Rueß, T. Stöferle, HA

CERN ISN JINRB. van der Vyver K. Protasov, Yu. Voronin Strelkov

Hartmut Abele 40

Summary: Galileo in QuantumlandSummary: Galileo in Quantumland

•Good limits for non-Newtonian interaction between 1m andm•Limits are comparable to other Limits, Complementary•Yukawa forces modify Airyfunction•And change energy of the state