-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
R. Caliandro,
M Campbell, [......],
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: 35.9> g , R.A. Loconsole b , G. Løvhøiden j , M. Lupt'ak g , I. M'acha n , V. Mack i , V. Manzari b , P. Martinengo e , M.A. Mazzoni o , F. Meddi o , A. Michalon r , M.E. Michalon-Mentzer r , P. Middelkamp e , M. Morando k , M.T. Muciaccia b , E. Nappi b , F. Navach b , K. Norman d , B. Osculati f , B. Pastirc'ak g , F. Pellegrini k , K. P'iska m , F. Posa b , E. Quercigh e , R.A. Ricci h , G. Romano p , G. Rosa p , L. Rossi f , H. Rotscheidt e , K. Safar'ik e , S. Saladino b
04/1999;
-
E. Andersen,
F. Antinori,
N Armenise,
H. Bakke,
J Ban,
D Barberis,
H Beker,
W. Beusch,
I J Bloodworth,
J Bohm, [......],
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
A. Diaczek,
D Di Bari,
S Di Liberto,
B C. Earl,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: F5.98> e , M.A. Mazzoni n , F. Meddi n , A. Michalon p , M.E. Michalon-Mentzer p , P. Middelkamp e , M. Morando k , M.T. Muciaccia a , E. Nappi a , F. Navach a , P.I. Norman d , B. Osculati f , B. Pastircak g , F. Pellegrini k , K. Pska m , F. Posa a , E. Quercigh e , R.A. Ricci h , G. Romano o , G. Rosa n , L. Rossi f , H. Rotscheidt e , K. Safark e , S. Saladino a , C. Salvo f , L. Sandor g,e , G. Segato k , M. Sene l , R. Sene l , S. Simone a , W. Snoeys e , P. Staroba m , S. Szafran<F5.
04/1999;
-
E. Andersen,
F. Antinori,
N Armenise,
H. Bakke,
J Ban,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
R. Caliandro, [......],
E. Cantatore,
N. Carrer,
E. Chesi,
M Dameri,
G Darbo,
A. Diaczek,
D Di Bari,
S Di Liberto,
B C. Earl,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: K 0 S , #, #,# and negative particle yields and transverse mass spectra have been measured at central rapidity in Pb-Pb and p-Pb collisions at 158 A GeV/c. Yields are studied as a function of the number of nucleons participating in the collision N part , which is estimated with the Glauber model. From p-Pb to Pb-Pb collisions the particle yields per participant increase substantially. The enhancement is more pronounced for multistrange particles, and exceeds an order of magnitude for the# . For a number of participants, N part , greater than 100, however, all yields per participant appear to be constant. To be published in Physics Letters B 1) Dipartimento I.A. di Fisica dell'Universita e del Politecnico di Bari and Sezione INFN, Bari, Italy 2) Fysisk institutt, Universitetet i Bergen, Bergen, Norway 3) Hgskolen i Bergen, Bergen, Norway 4) School of Physics and Astronomy, University of Birmingham, Birmingham, UK 5) CERN, European Laboratory for Particle Physics, Geneva, S...
04/1999;
-
E. Andersen,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
I. G. Bloodworth,
J Bohm,
E. Cantatore,
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
A. Diaczek,
D Di Bari,
S Di Liberto,
D. Elia,
K. Fanebust
[show abstract]
[hide abstract]
ABSTRACT: The WA85, WA94 and WA97 experiments at the CERN OMEGA spectrometer have studied the production of strange and multistrange particles in both nucleus-nucleus and protonnucleus reactions as a possible signature of a quark-gluon plasma phase. Recent results from WA97 on , Xi andOmega production in Pb-Pb and p-Pb collisions at 158 A GeV/c are presented. The enhancement of strange baryon production, observed when going from proton to nucleus initiated reactions, will be discussed. 1 Introduction In collisions of heavy nuclei at relativistic energy the nuclear matter is compressed and significantly excited. In such extreme conditions novel physical phenomena can arise and it is believed that the quarks confined in hadrons can dissolve forming a macroscopic space time region filled with free quarks and gluons: the quark gluon plasma state of matter (QGP). One of the sensitive signatures for the phase transition to a QGP state is the enhanced yield of strange particles in nucleus-nucleus ...
03/1999;
-
R. Caliandro,
Collaboration, E. Andersen,
F. Antinori,
N. Armenise,
H. Bakke,
J. Bán,
D. Barberis,
H. Beker,
W. Beusch, [......],
G. Tomasicchio,
G. D. Torrieri,
T. S. Tveter,
J. Urban,
M. Venables,
O. Villalobos Baillie,
T. Virgili,
A. Volte,
M. F. Votruba,
P. Zavada
[show abstract]
[hide abstract]
ABSTRACT: img5.gif, img6.gif and img7.gif yields and transverse mass spectra
measured at central rapidity in Pb-Pb and p-Pb collisions at 158 A GeV/c
are presented. The yields in Pb-Pb interactions are given as a function
of the collision centrality and compared with those obtained from p-Pb
collisions. The dependence of hyperon yields on the centrality of the
impact and on the strangeness content of the hyperon are discussed.
Journal of Physics G Nuclear and Particle Physics 01/1999; 25:171-180. · 4.18 Impact Factor
-
Mark Venables,
S Abatzis, E Andersen,
A Andrighetto,
F Antinori,
A C Bayes,
M Benayoun,
W Beusch,
S J Böhm,
J N Carney, [......],
P Sennels,
A V Singovski,
T F Thorsteinsen,
J Urbán,
G Vassiliadis,
M Venables,
O Villalobos Baillie,
A Volte,
M F Votruba,
P Závada
[show abstract]
[hide abstract]
ABSTRACT: The WA94 experiment has taken data using both a sulphur ion beam and a proton beam incident on a sulphur target in an attempt to form a quark - gluon plasma. Two different approaches have been used to measure the relative production ratios and inverse slopes of and their anti-particles. These results are presented in this paper.
Journal of Physics G Nuclear and Particle Physics 12/1998; 23(12):1857. · 4.18 Impact Factor
-
Presented by A K Holme for the Collaboration, E Andersen,
A Andrighetto,
F Antinori,
N Armenise,
J Bán,
D Barberis,
H Beker,
W Beusch,
J Böhm, [......],
J Urbán,
M Vanícková,
G Vassiliadis,
M Venables,
O Villalobos Baillie,
T Virgili,
A Volte,
C Voltolini,
M F Votruba,
P Závada
[show abstract]
[hide abstract]
ABSTRACT: The first results on fully corrected ratios and production cross sections of Ω−, , Ξ− and detected by the WA97 experiment in Pb - Pb collisions are presented.
Journal of Physics G Nuclear and Particle Physics 12/1998; 23(12):1851. · 4.18 Impact Factor
-
Presented by R Caliandro, E Andersen,
F Antinori,
N Armenise,
H Bakke,
J Bán,
D Barberis,
H Beker,
W Beusch,
I J Bloodworth, [......],
G Tomasicchio,
G D Torrieri,
T S Tveter,
J Urban,
M Venables,
O Villalobos Baillie,
T Virgili,
A Volte,
M F Votruba,
P Zavada
[show abstract]
[hide abstract]
ABSTRACT: Λ, Ξ and Ω yields and transverse mass spectra measured at central rapidity in Pb-Pb and p-Pb collisions at 158 A GeV/c are presented. The yields in Pb-Pb interactions are given as a function of the collision centrality and compared with those obtained from p-Pb collisions. The dependence of hyperon yields on the centrality of the impact and on the strangeness content of the hyperon are discussed.
Journal of Physics G Nuclear and Particle Physics 12/1998; 25(2):171. · 4.18 Impact Factor
-
Presented by A Jacholkowski, E Andersen,
F Antinori,
N Armenise,
H Bakke,
J Bán,
D Barberis,
H Beker,
W Beusch,
I J Bloodworth, [......],
G Tomasicchio,
G D Torrieri,
T S Tveter,
J Urbán,
M Venables,
O Villalobos Baillie,
T Virgili,
A Volte,
M F Votruba,
P Závada
[show abstract]
[hide abstract]
ABSTRACT: The first results on V0-V0 pairs, namely invariant masses and HBT correlations, obtained by the WA97 experiment in Pb-Pb collisions are presented. There is no evidence for any resonance signal.
Journal of Physics G Nuclear and Particle Physics 12/1998; 25(2):423. · 4.18 Impact Factor
-
Presented by T Virgili, E Andersen,
F Antinori,
N Armenise,
H Bakke,
J Bán,
D Barberis,
H Beker,
W Beusch,
I J Bloodworth, [......],
G Tomasicchio,
G D Torrieri,
T S Tveter,
J Urbán,
M Venables,
O Villalobos Baillie,
T Virgili,
A Volte,
M F Votruba,
P Závada
[show abstract]
[hide abstract]
ABSTRACT: Λ, Ξ and Ω yields measured by the WA97 experiment at central rapidity in p-Pb interactions at 158 GeV/c are compared to those predicted by VENUS 4.12. The VENUS model, although in reasonable agreement with the Λ and the negative particle data, fails to reproduce the data on multistrange baryons and anti-baryons.
Journal of Physics G Nuclear and Particle Physics 12/1998; 25(2):345. · 4.18 Impact Factor
-
E. Andersen,
F. Antinori,
N Armenise,
H. Bakke,
J Ban,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
R. Caliandro,
M Campbell,
E. Cantatore,
N. Carrer,
E. Chesi,
M Dameri,
G Darbo,
A. Diaczek,
D Di Bari,
S Di Liberto
[show abstract]
[hide abstract]
ABSTRACT: , Xi andOmega yields and transverse mass spectra have been measured at central rapidity in Pb-Pb and p-Pb collisions at 158 A GeV/c. The yields in Pb-Pb interactions are presented as a function of the collision centrality and compared with those obtained from p-Pb collisions. Strangeness enhancement is observed which increases with centrality and with the strangeness content of the hyperon. To be submitted to Physics Letters B 1) Nuclear Physics Department, Athens University, Athens, Greece 2) Dipartimento I.A. di Fisica dell'Universita e del Politecnico di Bari and Sezione INFN, Bari, Italy 3) Fysisk institutt, Universitetet i Bergen, Bergen, Norway 4) Høgskolen i Bergen, Bergen, Norway 5) University of Birmingham, Birmingham, UK 6) CERN, European Laboratory for Particle Physics, Geneva, Switzerland 7) Dipartimento di Fisica dell'Universita and Sezione INFN, Genoa, Italy 8) Institute of Experimental Physics, Kosice, Slovakia 9) INFN, Laboratori Nazionali di Legna...
09/1998;
-
E. Andersen,
F. Antinori,
N. Armenise,
H. Bakke,
J. Bán,
D. Barberis,
H. Beker,
W. Beusch,
I. J. Bloodworth,
J. Böhm, [......],
G. D. Torrieri,
T. S. Tveter,
J. Urbán,
G. Vassiliadis,
M. Venables,
O. Villalobos Baillie,
T. Virgili,
A. Volte,
M. F. Votruba,
P. Závada
[show abstract]
[hide abstract]
ABSTRACT: A, Ξ and Ω yields and transverse mass spectra have been measured in Pb-Pb and p-Pb collisions at 158A GeV/c. The yields in Pb-Pb interactions are presented as a function of the collision centrality and compared with those obtained
from p-Pb collisions. Strangeness enhancement is observed which increases with centrality and with the strangeness content
of the hyperon.
Il Nuovo Cimento A 04/1998; 111(8):955-962.
-
E. Andersen,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
I. G. Bloodworth,
J Bohm,
M Campbell,
E. Cantatore,
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: Løvhøiden j , M. Lupt'ak g , V. Mack i , V. Manzari b , P. Martinengo e , M.A. Mazzoni n , F. Meddi n , A. Michalon q , M.E. Michalon-Mentzer q , P. Middelkamp e , M. Morando k , M.T. Muciaccia b , E. Nappi b , F. Navach b , P.I. Norman d , B. Osculati f , B. Pastirc'ak g , F. Pellegrini k , K. P'iska m , F. Posa b , E. Quercigh e , R.A. Ricci h , G. Romano o , G. Rosa o , L. Rossi f , H. Rotscheidt e , K. Safar'ik e , S. Saladino b , C. Salvo f , L. S'andor e;g
03/1998;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
E. Cantatore,
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: The first results on fully corrected , Xi, andOmega particle production obtained by the WA97 experiment in Pb--Pb and p--Pb collisions are presented. 1 Introduction An enhanced production of strange particles has been suggested long ago as a useful diagnostic tool in heavy ion reactions since flavour equilibration times are expected to be much shorter in a Quark--Gluon Plasma(QGP) than in a Hadron Gas [1, 2, 3, 4]. In particular, multi-strange (anti-)baryons can be expected to probe the early phase of the collision [5], since hadronic production of such particles is suppressed due to high mass thresholds while in a QGP scenario they can be easily created due to a copious production of strange quark pairs from gluons. An enhanced production of multistrange (anti-)baryons has already been observed in sulphur initiated reactions by the WA85 and WA94 collaborations [6, 7] and the WA97 experiment has extended this study to a Pb--Pb system. We shall present a comparison of the Pb--Pb resu...
09/1997;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
E. Cantatore,
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: The first results on fully corrected ratios and production cross sections ofOmega Gamma ,Omega + , Xi Gamma and Xi + detected by the WA97 experiment in Pb--Pb collisions are presented. 1 Introduction An enhanced production of strange particles has long been suggested as a tool to identify the establishment of a flavour equilibrated system in particle reactions [1, 2]. The equilibration times are expected to be much shorter in a Quark--Gluon Plasma than in a Hadron Gas [3, 4]. In particular, multistrange (anti-)baryons have been suggested as a useful probe of the early phases of the collision [5], since hadronic production of such particles is strongly suppressed due to high mass thresholds. An enhanced production of multistrange (anti-)baryons has already been observed in sulphur initiated reactions by the WA85 and WA94 collaborations [6, 7]. 2 The experimental setup The WA97 set-up, shown schematically in figure 1, is described in detail in ref. [8]. The target and mos...
07/1997;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
E. Cantatore,
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: The first results on the fully corrected ratios ofOmega Gamma ,Omega + , Xi Gamma and Xi + detected by the WA97 experiment in Pb-Pb collisions are presented. 1 Introduction The analysis of strange particles yields has been proposed as a useful tool to study the properties of the hot and dense hadronic fireball formed in nuclear collisions. Enhancement of the production of strange particles in nuclear collisions with respect to hadronic collisions has been proposed as a signature of the onset of a quark-gluon plasma (QGP) phase. In particular multi--strange baryons and anti--baryons are interesting since they are especially difficult to be produced in purely hadronic interactions [1, 2]. The WA85 and WA94 experiments reported an enhanced Xi (jsj = 2) over (jsj = 1) production in S--W and S--S interactions with respect to pp and pA collisions (fig. 1). 0 0.1 0.2 0.3 0.4 pp pS SS pS SS pW SW pW SW AFS WA94 WA85 X ¾ + /L ¾ X - /L X - /L X ¾ + /L ¾ X ¾ + /...
07/1997;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
W. Beusch,
J Bohm,
E. Cantatore,
N. Carrer,
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro
[show abstract]
[hide abstract]
ABSTRACT: A series of experiments at the CERN OMEGA Spectrometer (WA85, WA94, WA97) have studied the production of strange particles (kaons, , Xi Gamma ,Omega Gamma and their antiparticles) in both nucleus--nucleus and proton-- nucleus reactions. Strange (anti-)baryon enhancements at central rapidity have been reported by WA85 and WA94 in S--W and S--S with respect to p--A reactions. Recently WA97 has presented a study of Xi andOmega produced in Pb--Pb and in p--Pb collisions at 160 A GeV/c. The first results suggest a significant enhancement ofOmega over Xi production when going from p--Pb to Pb--Pb. This contribution aims to summarize the results obtained up to now and to present the latest results from the analysis of the Pb--Pb data. 1 Introduction The study of the strange particle production in high-energy nucleus-nucleus collisions provides important information on the behaviour of hot and dense hadronic matter. The enhanced relative yield of strange and, particularly, multi-s...
03/1997;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
M Benayoun,
W. Beusch,
J Bohm,
J.-M. Brom, [......],
N. Carrer,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
12/1996;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
D Barberis,
H Beker,
M Benayoun,
W. Beusch,
J Bohm,
M Campbell, [......],
M G Catanesi,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: Leruste l , J.A. Lien j , R. Lietava g , R.A. Loconsole b , L. Lopez e , G. Løvhøiden j , M. Lupt'ak g , I. M'acha n , V. Mack i , V. Manzari b , P. Martinengo e , M.A. Mazzoni o , F. Meddi o , A. Michalon r , M.E. Michalon-Mentzer r , P. Middelkamp e , M. Morando k , M.T. Muciaccia b , E. Nappi b , J.L. Narjoux l , F. Navach b , K. Norman d , B. Osculati f , B. Pastirc'ak g , F. Pellegrini k , K. P'iska m , F. Posa b , E. Quercigh e , R.A. Ricci h , G. Romano p<F
12/1996;
-
E. Andersen,
A. Andrighetto,
F. Antinori,
N Armenise,
J Ban,
D Barberis,
H Beker,
M Benayoun,
W. Beusch,
J Bohm, [......],
N. Carrer,
E. Chesi,
M Dameri,
G Darbo,
J P Davies,
A. Diaczek,
D Di Bari,
S Di Liberto,
A. Di Mauro,
D. Elia
[show abstract]
[hide abstract]
ABSTRACT: e , J.C. Lassalle e , V. Lenti b , Ph. Leruste l , J.A. Lien j , R. Lietava g , R.A. Loconsole b , L. Lopez e , G. Løvhøiden j , M. Luptak g , I. Macha n , V. Mack i , V. Manzari b , P. Martinengo e , M.A. Mazzoni o , F. Meddi o , A. Michalon r , M.E. Michalon-Mentzer r , P. Middelkamp e , M. Morando k , M.T. Muciaccia b , E. Nappi b , J.L. Narjoux l , F. Navach b , K. Norman d , B. Osculati f , B. Pastircak g , F. Pellegrini k , K. Pska m , F. Posa b , E. Quercig
10/1996;
