, h, ti- d tml V 0. A , : e.h a 4 ery ted. , om r, and ering the ond mid- vy ion d v
t design of ucleus col- will b e in- . tmodeis e 2 /Welc ,co en y 5 GIOTOU : ed in hea y-ev ysics b ey y CZYK al 2 ucleus{n , S.N. FILIPPO thens, Hel las. ANA ussia. e, Poland. t-b c ery small acceptance T THE LHC AR ussia. en l mo del describing the g ob jects in the v terv OR THE us collisions is presen OD gica angelis/castor , A.B. KUREPIN ailable phase space whic L ions at the LHC, extends c uon detector yin v ow, R 3. Finally a small-ap erture , A.D. P : ucle olo V ted. a otvino, R ow, Poland. h/ 3 YUBSKY Pb teresting ph .c tation in the presen ac estigating n ed the idea of a dedicated for- 1 v ,Z.W 7.2 in an ev ern b
O AND STRANGELETS ted for hadron and photon iden olv ucleus-n ch, Mosc e.c will also b e installed on one side and y trigger. The v ar eV for 3 3
al University, Kielc UR : A ard detector to b e emplo ese ANSKI gic tify deeply p enetratin tralit gy Physics, Pr al 2 erse segmen OMANOLAKIS ar Physics, Cr An additional m ar R ttp://hom dago e it suitable for this purp ose only , M.YU. BOGOL : , YU.V. KHARLO
hep-ex/9901038 28 Jan 1999 terv t. Symp. on Multiparticle Dynamics, 6-11 Sep. 1998, Delphi. b VR 1 b . STEF er the pseudorapidit ery forw ARD DETECTOR F
S v y detector h is aimed to measure the hadronic and photonic h is aimed at in ,P tauro reball in n yin W c TKE j ulations of the exp ected resp onse of the calorimete
ted out that there is in j vide the cen OR ,G.MA , whic d 1 al VSKY ultiplicit A h phase space 5.6 yofaCen ation for a v Y ,J.BAR TION OF CENT teraction and to iden terv Institute of Nucle a ted at XXVI I I In YSZ-DZIADU b Institute for Nucle on t, to pro on-ric d rom these considerations ev Institute for High Ener Already at the early stages of the preparation of the ALICE yin c AD : L ar and Particle Physics Division, University of A .F 7 Institute of Physics, Pe Further information at: h Presen S.A. SADO : 5 e ysics motiv ; tofanin 4 er photon m er the pseudorapidit E. G ard, bary w k of longitudinal and transv Nucle y ten =8 tro ducti v CASTOR: A F a IN NUCLEUS{NUCLEUS COLLISIONS A j A.I. MAEVSKA This constitutes only a small part of the total a In forw describ ed. Results of sim in particular to the passage of strangelets, are presen The CASTOR detector whic collisions at the CERN LHC isformation and discussed. deca A phenomen con The ph
j IDENTIFICA teraction p oin A.L.S. ANGELIS cation only in thepseudorapidit limited angular region around mid-rapidit lisions at the LHC, will b e fully instrumen The ALICE detector 1 pre-sho stalled on one side and will co will co zero degree calorimeter is alsoin foreseen, at a distance of ab out 100 m from the at the designto b eam energy ofprop osal 2.75 some A of T us p oin the zero degree calorimeter mak and lac rapidit
6;7
ward detector, CASTOR , to provide physics information on hadrons and
photons emitted in the fragmentation region. At LHC Pb-ion energies this
region of phase space extends b eyond j j = 5 or 6, dep ending on the e ec-
tive baryonic stopping p ower which is di erent for the various Monte-Carlo
mo dels employed. In this region of extremely high baryon numb er density
one can exp ect to discover new phenomena related to the high baryochemical
p otential, in particular the formation of Decon ned Quark Matter DQM,
which could exist e.g. in the core of neutron stars, with characteristics di er-
ent from those exp ected in the much higher temp erature baryon-free region
around mid-rapidity,
17
The LHC, with an energy equivalentto10 eV for a moving proton im-
pinging on one at rest, will b e the rst accelerator to e ectively prob e the
highest cosmic ray energy domain. Cosmic ray exp eriments have detected
numerous most unusual events whose nature is still not understo o d. These
events, observed in the pro jectile fragmentation rapidity region, will b e pro-
duced and studied at the LHC in controlled conditions. Here we mention
8
the \Centauro" events and the \long- ying comp onent". Centauros exhibit
relatively small multiplicity, complete absence or strong suppression of the
electromagnetic comp onent and very high hp i. In addition, some hadron-rich
T
events are accompanied by a strongly p enetrating comp onent observed in the
9;10
form of halo, strongly p enetrating clusters or long-living cascades, whose
11;12
transition curves exhibit a characteristic form with many maxima .
2 A mo del for the pro duction of Centauro and Strangelets
A mo del has b een develop ed in which Centauros are considered to origi-
nate from the hadronization of a DQM reball of very high baryon density