A FIRST MEASUREMENT OF THE LAMBDA(LAMBDA)OVER-BAR AND LAMBDA-LAMBDA ((LAMBDA)OVER-BAR(LAMBDA)OVER-BAR) SPIN COMPOSITIONS IN HADRONIC Z(0) DECAYS

Authors
ALEXANDER G ALLISON J ALTEKAMP N AMETEWEE K ANDERSON KJ ANDERSON S ARCELLI S ASAI S AXEN D AZUELOS G BALL AH BARBERIO E BARLOW RJ BARTOLDUS R BATLEY JR BEAUDOIN G BECHTLUFT J BEESTON C BEHNKE T BELL AN BELL KW BELLA G BENTVELSEN S BERLICH P BETHKE S BIEBEL O BLOBEL V BLOODWORTH IJ BLOOMER JE BOCK P BOSCH HM BOUTEMEUR M BOUWENS BT BRAIBANT S BROWN RM BURCKHART HJ BURGARD C BURGIN R CAPILUPPI P CARNEGIE RK CARTER AA CARTER JR CHANG CY CHARLESWORTH C CHARLTON DG CHRISMAN D CHU SL CLARKE PEL COHEN I CONBOY JE COOKE OC CUFFIANI M DADO S DALLAPICCOLA C DALLAVALLE GM DEJONG S DELPOZO LA DESCH K DIXIT MS SILVA EDCE DOUCET M DUCHOVNI E DUCKECK G DUERDOTH IP EDWARDS JEG ESTABROOKS PG EVANS HG EVANS M FABBRI F FATH P FIEDLER F FIERRO M FISCHER HM FOLMAN R FONG DG FOUCHER M FUKUI H FURTJES A GAGNON P GAIDOT A GARY JW GASCON J GASCONSHOTKIN SM GEDDES NI GEICHGIMBEL C GENTIT FX GERALIS T GIACOMELLI G GIACOMELLI P GIACOMELLI R GIBSON V GIBSON WR GINGRICH DM GOLDBERG J GOODRICK MJ GORN W GRANDI C GROSS E GRUWE M HAJDU C HANSON GG HANSROUL M HAPKE M HARGROVE CK HART PA HARTMANN C HAUSCHILD M HAWKES CM HAWKINGS R HEMINGWAY RJ HERTEN G HEUER RD HILDRETH MD HILL JC HILLIER SJ HILSE T HOARE J HOBSON PR HOMER RJ HONMA AK HORVATH D HOWARD R HUGHESJONES RE HUTCHCROFT DE IGOKEMENES P IMRIE DC INGRAM MR JAWAHERY A JEFFREYS PW JEREMIE H JIMACK M JOLY A JONES CR JONES G JONES M JONES RWL JOST U JOVANOVIC P JUNK TR KARLEN D KAWAGOE K KAWAMOTO T KEELER RK KELLOGG RG KENNEDY BW KING BJ KIRK J KLUTH S KOBAYASHI T KOBEL M KOETKE DS KOKOTT TP KOMAMIYA S KOWALEWSKI R KRESS T KRIEGER P VONKROGH J KYBERD P LAFFERTY GD LAFOUX H LAHMANN R LAI WP LANSKE D LAUBER J LAUTENSCHLAGER SR LAYTER JG LAZIC D LEE AM LEFEBVRE E LELLOUCH D LETTS J LEVINSON L LEWIS C LLOYD SL LOEBINGER FK LONG GD LOSTY MJ LUDWIG J LUIG A MALIK A MANNELLI M MARCELLINI S MARKUS C MARTIN AJ MARTIN JP MARTINEZ G MASHIMO T MATTHEWS W MATTIG P MCDONALD WJ MCKENNA J MCKIGNEY EA MCMAHON TJ MCNAB AI MCPHERSON RA MEIJERS F MENKE S MERRITT FS MES H MEYER J MICHELINI A MIKENBERG G MILLER DJ MIR R MOHR W MONTANARI A MORI T MORII M MULLER U NEAL HA NELLEN B NIJJHAR B NISIUS R ONEALE SW OAKHAM FG ODORICI F OGREN HO OMORI T OREGLIA MJ ORITO S PALINKAS J PANSART JP PASZTOR G PATER JR PATRICK GN PEARCE MJ PETZOLD S PFEIFENSCHNEIDER P PILCHER JE PINFOLD J PLANE DE POFFENBERGER P POLI B POSTHAUS A PRZYSIEZNIAK H REES DL RIGBY D ROBINS SA RODNING N RONEY JM ROOKE A ROS E ROSSI AM ROSVICK M ROUTENBURG P ROZEN Y RUNGE K RUNOLFSSON O RUPPEL U RUST DR RYLKO R SARKISYAN EKG SASAKI M SBARRA C SCHAILE AD SCHAILE O SCHARF F SCHARFFHANSEN P SCHENK P SCHMITT B SCHMITT S SCHRODER M SCHULTZCOULON HC SCHULZ M SCHUTZ P SCOTT WG SHEARS TG SHEN BC SHEPHERDTHEMISTOCLEOUS CH SHERWOOD P SIROLI GP SITTLER A SKILLMAN A SKUJA A SMITH AM SMITH TJ SNOW GA SOBIE R SOLDNERREMBOLD S SPRINGER RW SPROSTON M STAHL A STARKS M STEIERT M STEPHENS K STEUERER J STOCKHAUSEN B STROM D STRUMIA F SZYMANSKI P TAFIROUT R TALBOT SD TANAKA S TARAS P TAREM S TECCHIO M THIERGEN M THOMSON MA VONTORNE E TOWERS S TSCHEULIN M TSUKAMOTO T TSUR E TURCOT AS TURNERWATSON MF UTZAT P VANKOOTEN R VASSEUR G VERZOCCHI M VIKAS P VINCTER M VOKURKA EH WACKERLE F WAGNER A WARD CP WARD DR WARD JJ WATKINS PM WATSON AT WATSON NK WEBER P WELLS PS WERMES N WHITE JS WILKENS B WILSON GW WILSON JA WLODEK T WOLF G WOTTON S WYATT TR YAMASHITA S YEKUTIELI G ZACEK V
Citation
G. Alexander et al., A FIRST MEASUREMENT OF THE LAMBDA(LAMBDA)OVER-BAR AND LAMBDA-LAMBDA ((LAMBDA)OVER-BAR(LAMBDA)OVER-BAR) SPIN COMPOSITIONS IN HADRONIC Z(0) DECAYS, Physics letters. Section B, 384(1-4), 1996, pp. 377-387
Citations number
32
Categorie Soggetti
Physics
Journal title
Physics letters. Section B → ACNP
ISSN journal
03702693
Volume
384
Issue
1-4
Year of publication
1996
Pages
377 - 387
Database
ISI
SICI code
0370-2693(1996)384:1-4<377:AFMOTL>2.0.ZU;2-P
Abstract
The spin composition of <Lambda(Lambda)over bar>, Lambda Lambda and <( Lambda)over bar><(Lambda)over bar> pairs at low invariant mass values has been measured for the first time in multihadronic Z(0) decays with the OPAL detector at LEP. No single spin state has been observed in t he <Lambda(Lambda)over bar> sample, verifying that the low mass enhanc ement in this sample, attributed to local baryon number compensation, is not a resonance state. The fraction of the spin 1 contribution to t he <Lambda(Lambda)over bar> pairs was found to be consistent with the value 0.75, as expected from a statistical spin mixture. This may be t he net effect of many different QCD processes which contribute to the hyperon anti-hyperon pair production. The spin composition of the iden tical Lambda Lambda and <(Lambda)over bar(Lambda)over bar> pairs, well above threshold, is found to be similar to that of the <Lambda(Lambda )over bar> sample. A Lambda Lambda emitter dimension is estimated from the data assuming the onset of the Pauli exclusion principle near thr eshold.