/*===================================================================*/ /* NRDF D0189 Data No.4 */ /*===================================================================*/ /* Bibliography */ /*===================================================================*/ \\BIB,4; /* 2007-03-05 N.OTUKA: INST-ATH corrected */ D#=D189; TITLE=/THE J-PI=3- DOUBLET AT EX=6241 KEV IN 18F: ISOSPIN MIXING/; ATH=(W.E.KIESER'1',R.E.AZUMA'1',I.BERKA'1',K.P.JACKSON'1', A.B.MCDONALD'2',H.B.MAK'3',W.MCLATCHIE'3'); INST-ATH=(1CANTOR'1',1CANCRC'2',1CANKQU'3'); REF=NP/A; VLP=327(1979)172; RCTS=(17O(P,GAMMA)18F,17O(P,ALPHA)14N,14N(ALPHA,GAMMA)18F, 4HE(14N,ALPHA)14N); /*@33@*/ /*===================================================================*/ /* Experimental Conditions */ /*===================================================================*/ \\EXP,4; ENR=98%; THK-TGT=X'2'; BAC=W'2'; THK-BAC=2.3UG/CM**2; /*@2@*/ /*@3@*/ ACC=(VDG); INST-ACC=1CANTOR; INC-ENGY-RANGE=[0.666MEV[0.675MEV; DELTA-INC-ENGY=[1.2KEV; BEAM-INTNSTY=[50UA; DET-PARTCL=(GAMMA,ALPHA); DET-SYS=(MAG+PS-SI'5',SI'5',X'3'); ERS-DET=1.2KEV; /*@3@*/ /*@5@*/ ANL=(RMTRX-THEORY); PHQ=(EXC-FUNCT,ANGL-DSTRN'3',EXC-ENGY,RESN-ENGY,TOT-WDTH,PART-WDTH,WDTH -RATIO,SPIN,PTY,TRANSN-STRGTH'3',YLD'3',BRANCH'3'); /*@3@*/ RCT=17O(P,ALPHA)14N; /*===================================================================*/ /* Descriptive Parameters */ /*===================================================================*/ \\DATA,4; CMPD=18F; RSD=14N; EXC-ENGY=XMEV; THE 14N(ALPHA,ALPHA)14N SCATTERING MEASUREMENTS. @@15; 'P' PARTIAL WIDTHS FOR PROTON DECAY @@16; 'A' PARTIAL WIDTHS FOR ALPHA DECAY @@17; 'G' PARTIAL WIDTHS FOR GAMMA DECAY @@21; '21' DATA FROM (P,GAMMA),(P,ALPHA),(ALPHA,GAMMA) MEASUREMENTS @@22; '22' DATA FROM HIGH RESOLUTION (ALPHA,ALPHA) MEASUREMENTS @@23; '23' DATA FROM LOW RESOLUTION (ALPHA,ALPHA) MEASUREMENTS @@24; '24' DATA FROM AVERAGE OF (ALPHA,ALPHA) MEASUREMENTS @@18; '18' THE DIFFERENTIALLY PUMPED GAS TARGET AT CRNL. SEE A.B.MCDONALD ET AL. NUCL. PHYS. A287(1977)189. @@19; '19' MONITOR: IN ORDER TO MONITOR THE INCOMING BEAM CURRENTS AND TO TAKE I NTO ACCOUNT ANY FLUCTUATIONS IN TARGET PRESSURE, KRYPTON GAS WAS ADDE D(2 % BY VOLUME) TO THE 4HE TARGET GAS. THE ELASTIC SCATTERING OF THE 14N BEAM BY THE KRYPTON, OBSERVED IN THE THETA(LAB)=35 DEG. DETECTOR ,WAS USED AS A MONITOR @@25; '25' GAUSSIAN WIDTH (DELTA) @@26; '26' LANDAU PARAMETER (ZETA) @@20; '20' LOW RESOLUTION DATA @@27; '27' HIGH RESOLUTION DATA @@28; '28' CONVERTED TO EQUIVALENT ALPHA INCIDENT ENERGIES FOR THE REACTION, 14N (ALPHA,ALPHA)14N, TO FACILITATE COMPARISON WITH PREVIOUS DATA. @@29; '29' TOTAL STRENGTH OF GAMMA TRANSITION @@30; '30' ISOSPIN MIXING PARAMETER FOR THE DOUBLET OF J-PI=3- WITH T=1 OR 0. @@31; '31' ERROR ARISES PREDOMINANTLY FROM UNCERTAIN E2 CONTRIBUTION. @@32; '32' TABLE 4: ISOVECTOR TRANSION STRENGTHS AND THE DEGREE OF ISOSPIN MIXING DERIVED FROM THE DECAYS OF THE J-PI=3- DOUBLET AT 6240 AND 624 2 KEV. @@33; '33' CONCLUSION; REEXAMINATION OF THE EXCITATION FUNCTIONS FOR REACTI ONS 17O(P,GAMMA)18F AND 17O(P,ALPHA)14N, USING THIN TARGETS REVEALED THE EXISTENCE OF TWO CLOSELY SPACED RESONANCES SEPARATED BY DELTA-EXC =2.09+-0.04 KEV. THE SIMILAR BRANCHING RATIOS OBSERVED FOR THE GAMMA- RAY DECAYS OF THE TWO RESONANCES SUGGESTED THE POSSIBILITY THAT THESE WERE THE TWO MEMBERS OF THE ISOSPIN-MIXED J-PI=3- DOUBLET. THIS WAS CONFIRMED BY FURTHER EXPERIMENTS UTILIZING THE 14N(ALPHA,GAMMA)18F AN D 4HE(14N,ALPHA)14N REACTIONS. THIS DOUBLET CAN BE DESCRIBED WITH THE COMPLELE MIXING OF T=0 AND T=1 STATES. /*===================================================================*/ /* Data Table */ /*===================================================================*/ \DATA; DATA2'2,L' DATA-ERR DATA2'2,U' DATA2-ERR (EV) (EV) (EV) (EV) 358 +-42 237 +-28 \END; /*===================================================================*/ |