Mitglied der Helmholtz-Gemeinschaft July 7, 2014 | Hans Ströher (Forschungszentrum Jülich) 10 Years of Georgian-German Science Bridge Examples from the

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July 7, 2014 | Hans Ströher (Forschungszentrum Jülich)

10 Years of Georgian-German Science Bridge

Examples from the“Precision Frontier”

21. April 2023 Institut für Kernphysik (IKP) Folie 2

New

ResearchNew

Research

Science – The Endless Frontier

OURKNOWLEDGE

PrecisionPrecision


An „Experiment“

Characterization of the different outcomes


Measurements – General

Characterization of the results of measurements



Accuracy and Precision



Physical Quantity = Numerical Value x Unit

Degree of uncertainty: measurement errors




International System of Units (SI): „metric system“


Measurements – Length


Unit of Length: „Meter“ (m)

urmeter

Unit of Length: „Meter“ (m); Tools: scales


Measurements – Time


Unit of Time: „Second“ (s); Tools: clocks


Measurements – Time


Unit of Time: „Second“ (s); Tools: clocks


Measurements – Speed

Measurements of speed; control of speed limits

Speed (m/s) = Distance (m) / Time (s)


1


Measurements – Speed-of-light (c)

c is a constant of Nature: only fixed expt´ly !



(1) Galileo Galilei (1638): c > 10 vsound



(2) Ole Rømer (1677): c ~ 213 000 km/s

Moon Io (1,769 days)



(3) Middle 19th century: c = (298 000 +- 500) km/s



(4) Modern (1970´s): c = (299 792 457.4 +- 1.0) m/s

year of measurement

c (k

m/s

)



year of measurement

c (k

m/s

)

1983: fix c =: 299 792 458 m/s defines length unit

!


2


Measurements – Neutron Lifetime

Free neutron is an „unstable“ particle

e



n: very important for light element (H, He) production

How many of the neutrons decay per time intervall? „lifetime“



Reference value has changed over the years!

~ 2 min

PDG entry


3


Increased precison led to a new theory: QED

Measurements – H-Atom „Lamb-Shift“

En

erg

y


Measurements – µ Magnetic Moment

Discrepancy (~3) between experiment and theory!?

Theoreticalpredictions(„StandardModel of

EPP“)

Most preciseexpt´l data


4


Measurements – EDM

Particle „Electric Dipole Moments“ (EDM)

+-



EDM´s must exist – but they are very small!

Size of the nucleon:

D =10-15 mEDM: 10-15 e m

Nature violates symmetries: expectation:

EDM < 10-25 e m


< 10-3 m


Measurements up to now: „upper limits“ (zero)

1

Nucleon

1022



EDMs & matter-antimatter asymmetry of our Universe

Physics: the puzzle of our existence!



EDMs & matter-antimatter asymmetry of our Universe

JEDIJülich Electric Dipole Moment Investigations


Accuracy, Precision, Error and Uncertainty

Measurements – Summary


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Mitglied der Helmholtz-Gemeinschaft July 7, 2014 | Hans Ströher (Forschungszentrum Jülich) 10 Years of Georgian-German Science Bridge Examples from the