Letter of Intent AGATAGSI Letter of Intent Isospin

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Letter of Intent: AGATA@GSI Letter of Intent: Isospin Symmetry and Transition Rates in Isobaric

Letter of Intent: AGATA@GSI Letter of Intent: Isospin Symmetry and Transition Rates in Isobaric Multiplets M. A. Bentley, R. Wadsworth et al (Univ. York) D. Rudolph et al (Lund) A. M. Bruce et al (Brighton) P. Reiter et al (Koln) S. Lenzi et al (Padova) G. de. Angelis, E. Sahin et al (INFN) A. Obertelli et al (CEA Saclay) M. Labiche, J. Simpson (STFC Daresbury Lab. ) + PRESPEC TEAM (GSI) Bentley et al - Istanbul May 7 th 2010 1

AIMS Topic: Isospin dependence of B(E 2) strengths in T=1 triplets. . . Aims:

AIMS Topic: Isospin dependence of B(E 2) strengths in T=1 triplets. . . Aims: • To test a direct prediction (largely untested) of isospin formalism: dependence of B(E 2) with Tz for IAS transitions • To search for isospin mixing effects at the ~ few % level • Examine precision lifetime measurements of T=1 2+ to 0+ transtions in T=1 Triplet Assume no isospin mixing (hence T=1 to T=1 transitions only) IS IV Bentley et al - Istanbul May 7 th 2010 2

LINEAR DEPENDENCE of ME with Tz et al. . . Bentley PRESPEC et al

LINEAR DEPENDENCE of ME with Tz et al. . . Bentley PRESPEC et al Meeting: - Istanbul. S 363 May Report 7 th 2010 3

Effect of Isospin Mixing Effect of isospin mixing on B(E 2) strengths in T=1

Effect of Isospin Mixing Effect of isospin mixing on B(E 2) strengths in T=1 triplets. . . ? ? • Proximity of T=1 and T=0 states in odd-odd N=Z system • T=0 admixtures possible in both 0+ and 2+ states • Introduces isovector components in B(E 2) in N=Z oddodd (Tz=0) Bentley et al - Istanbul May 7 th 2010 4

AIMS • Perform high-precision RELATIVE measurement of B(E 2) in T=1 TRIPLET • Use

AIMS • Perform high-precision RELATIVE measurement of B(E 2) in T=1 TRIPLET • Use identical method for B(E 2) measurement • Use identical population method for states of interest • Try to eliminate direct/side feeding • Use identical experimental conditions • PERFORM in same EXPERIMENT TWO POSSIBLE CASES. . . • A=46 T=1 triplet • A=62 T=1 triplet Bentley et al - Istanbul May 7 th 2010 5

A=46 Isobaric Triplet B(E 2)’s known only at ± 20% level T 1/2 =

A=46 Isobaric Triplet B(E 2)’s known only at ± 20% level T 1/2 = 8 -9 ps 46 Cr - P. J. Garrett et al Phys. Rev. Lett. 87(2001)132502 Bentley et al - Istanbul May 7 th 2010 6

Proposed Method 46 Cr Stack of 3 gold foils (~500 mg/cm 2) separated by

Proposed Method 46 Cr Stack of 3 gold foils (~500 mg/cm 2) separated by ~1 mm (Sort of) differential plunger Designed for specific case/lifetime Key points: 2+ states all populated directly by Coulex Lifetime determined from lineshape alone Can use 2, 3, 4 foils. . . Could use Koln plunger. . . Bentley et al - Istanbul May 7 th 2010 7

Preliminary Simulation 15. 9 degrees • Performed for “Euroball” RISING • Assumes 2% energy

Preliminary Simulation 15. 9 degrees • Performed for “Euroball” RISING • Assumes 2% energy resolution • 10, 000 counts in triple-peak • 2 x 750 mg/cm 2 + 1 x 500 mg/cm 2 • 1 mm gap • 915 ke. V transition in 46 V 36. 0 degrees • 150 Mev/u ± 20% in B(E 2)

RATES • Make 46 Cr, 46 V and 46 Ti from fragmentation of 78

RATES • Make 46 Cr, 46 V and 46 Ti from fragmentation of 78 Kr or 58 Ni primary beam • Assume 1 x 1010 pps 78 Kr, 4 g/cm 2 primary Be target • Assume FRS transmission efficiency of 20% (LISE) • 3% efficiency in a ring with 2% energy resolution • 450 mb Coulex cross section (measured) • 50 k. Hz secondary beam limit • 2000 mg/cm 2 Au in total. . . GIVES: 1. 5 k. Hz 46 Cr → 25, 000 counts in line-shape in 3 days 50 k. Hz 46 V → 100, 000 counts in line-shape in 1 day 50 k. Hz 46 Ti → 100, 000 counts in line-shape in 1 day

A=62 Isobaric Triplet D. Rudolph et al N=Z+2

A=62 Isobaric Triplet D. Rudolph et al N=Z+2

A=62 Isobaric Triplet D. Rudolph et al • 62 Ge: 2+ state only tentatively

A=62 Isobaric Triplet D. Rudolph et al • 62 Ge: 2+ state only tentatively assigned – needs confirmation • 62 Ga: • 62 Ge: 2+ state only tentatively assigned – needs confirmation 2+ state is non-YRAST – Coulex ideal to populate state Key points: • Isospin-mixing predicted to increase with Z 2 • Confirmation of 2+ states in 62 Ga and 62 Ge • Shorter half-life (~3 ps) • Not as high-statistics as A=46, but larger effect?

RATES • Make 62 Ge, 62 Ga and 62 Zn from fragmentation of 78

RATES • Make 62 Ge, 62 Ga and 62 Zn from fragmentation of 78 Kr primary beam • Assume 1 x 1010 pps 78 Kr, 4 g/cm 2 primary Be target • Assume FRS transmission efficiency of 20% (LISE) • 3% efficiency in a ring with 2% energy resolution • 450 mb Coulex cross section (assumed same as A=46) • 50 k. Hz secondary beam limit • 2000 mg/cm 2 Au in total. . . GET: 1. 5 k. Hz 62 Ge → 1, 000 counts in line-shape in 3 days 50 k. Hz 62 Ga → >100, 000 counts in line-shape in 1 day 50 k. Hz 62 Zn → >100, 000 counts in line-shape in 1 day

UNIQUENESS? Key Points: 1. Technique requires high-energy / high β • Allows thick targets,

UNIQUENESS? Key Points: 1. Technique requires high-energy / high β • Allows thick targets, large gaps, short lifetimes • Gives more pronounced line-shape 2. Position-resolution of AGATA benefits technique (improves line-shape, allows for definition of effective “rings”) BOTH give major advantage over MSU capability (for example)