VRVS MEETING

1
?????? ???????????? ??????? ?????????????? ?.
?.

• ?????????? ?????????-?????????? ????????
• (??????????????? ???????????)

VRVS MEETING
2

• ??????????
• ????????
• ??????? ???????? ? ?????? ? ???????? ???????
  ???????
• ???????????????-????????? ??????? ??
  ??????????????
• ????? RHIC
• ???????????? ??????? ????? ?? LHC
• ???????????????????? ???????????? ?? LHC
• ??????????

3
??????? ???????? ? ?????? ? ???????? ???????
???????
????????? ??????? ??? ??????? ???????????
??????? ????????? ????????? ???????? ???????
4
???????????????-????????? ??????? ????-???????
??????????????
197Au 197Au
5
??????? ?????? ????????? ????????
?????? (??????) (???????????? ???????,
??????????, ?????? ???????? ??????)
??????? ??????? (?????????? ?????????) (ee-,
?, ??, ?????, J/? ??????????)
??????? ???????
1. ?????????
SPS
RHIC
????? ????? ???????? ????????? ?????????? ??
?????? ?????? (?????-????????????? ???????????,
?????????????? ????????? ?????????)
6
??? ?? RHIC
?????? ??????
thermal
prompt
DATA prompt thermal
D. dEnterria, D. Perresounko nucl-th/0503054
7
?????????? ?????? ?????????????
?????
????????
4. ?????
????? ? ???????? ?????
g
g

q
q
q
q
qq ? qq
g
AA
jet quenching
????? ???????
pp
8
?????????? ?????????? J/? ? ?????????? ??????
???????? ??????
9
????? ? AuAu ? dAu ? pp
in ? out ????? ??????????? ?? ???????!
??? ?????????? ? pp ? dAu
10
???????? ???????? ?????? ????????? ????????
???????????? ???????
???????????? ????
????????????? ???????? ???
??????????? ?????
?????????????
blt7 fm (nch/nmaxgt0.5) p?lt1.5 ??? ?????????????
(????????? ????? ????????? ???????)
v2 ??????????? ???????? ??????? ? ??????? ? ?????
????? ?????????
11
The ATLAS detector
Length 44m Height 22m
12
ATLAS physics program

• Global variable measurement
• dN/d? dET/d? elliptic flow
• azimuthal distributions
• Jet measurement and jet quenching
• Quarkonia suppression
• J/? ?
• p-A physics
• Ultra-Peripheral Collisions (UPC)
• Idea take full advantage of the large
  calorimeter and µ-spectrometer

Direct information from QGP
13
Acceptance
14
ATLAS Physics Rates
A few key numbers and maybe a plot. 8,000
collisions per second luminosity 1027
cm-2s-1 1 month is 106 seconds implies
possible samping of 1010 min bias and 109
central Pb-Pb events. 5 bbar per central
event. Direct photons --gt With central barrel
in one month running for central events 1e3
counts at 60 GeV in 1 GeV pt bin! Jets --gt B
Jets--gt
15
Quarkonia suppression
Color screening prevents various ?, ?, ? states
to be formed when T?Ttrans to QGP (color
screening length lt size of resonance)
Modification of the potential can be studied by a
systematic measurement of heavy quarkonia states
characterized by different binding energies and
dissociation temperatures thermometer for the
plasma
Upsilon family
?(1s) ?(2s) ?(3s) Binding energies
(GeV) 1.1
0.54 0.2 Dissociation at the
temperature 2.5Ttrans
0.9Ttrans 0.7Ttrans gtImportant to separate
?(1s) and ?(2s)
16
Ultraperipheral collisions

• The two nuclei geometrically miss each other
• b gt 2RA
• Ions are source of fields
• photons sgg Z4
• pomerons sgp Z2A2 for heavy states
• sgp Z2A5/3 - for lighter mesons
• Photon and pomeron can couple coherently to the
  nuclei if its have
• Small transverse momentum
• pT lt h/RA 90 MeV
• Maximum longitudinal component pL lt gh/RA 100
  GeV

E? 3 (80) GeV at RHIC (LHC) W?? 6 (160)
GeV at RHIC (LHC)
Pomeron carry the strong interaction but is
colorless and it has the quantum number of the
vacuum JP 0
17
Vector meson production

• Vector mesons production (photon-pomeron
  interaction)

r, w, F, J/Y ,Y
s(AA-gtAAY) 150 mb L 41026 cm-2s-1, H 0.06
Hz, Br(Y-gtmm) 2.48 gt 1500 Y/month (month
106 sec)
18
AuAu -gt r0AuAu 200 GeV
Signal region pTlt0.15 GeV
STAR Preliminary

• 1.7 million ZDC coincidence triggers in 2002
• Require a 2 track vertex
• pp and p-p- model background
• scaled up to 2
• single (1n) and multiple (Xn) neutron
  production
• 1n mostly from Giant Dipole Resonance
• Cross section and rapidity distribution match
  soft Pomeron model

After detector simulation
r0 Rapidity
19
Interference

• 2 indistinguishable possibilities
• Interference!!
• 2-source interferometerwith separation b
• r is negative parity
• For pp, AA parity transform -gt
• s A1 - A2eipb2
• At y0 ss01 - cos(p?b)
• For pbar p CP transform -gt
• s A1 A2eipb2
• b is unknown
• Reduction for pT ltlt1/ltbgt

• r0 w/ mutual Coulomb dissoc.
• 0.1lt y lt 0.6

int
dN/dt
noint
t (GeV/c)2
20
Interference
0.1 lt y lt 0.5
Data (w/ fit) Noint Int
AuAu -gt r0AuAu 200 GeV

• Efficiency corrected t
• 1764 events total
• R(t) Int(t)/Noint(t)
• Fit with polynomial
• dN/dt Aexp(-bt)1c(R(t)-1)
• A is overall normalization
• b is slope of nuclear form factor
• b 301 /- 14 GeV-2 304
  /- 15 GeV-2
• syst. uncertainties 8(syst)15(theory)
• c0 -- gt no interference
• c1 -- gt full interference
• Data and interference model match
• c 1.01 /- 0.08 0.78 /- 0.13

dN/dt
STAR Preliminary
t (GeV2)
0.5 lt y lt 1.0
Data (w/ fit) Noint Int
dN/dt
STAR Preliminary
t (GeV2)
21
Types of trigger

• Topology trigger ZDCs (r0 in TPC signals in
  forward (zero degree calorimeters)
• Topology trigger West ZDC Aud-gtrAupn
• required break up d
• Topology trigger both ZDC AuAu-gtrAuAuXn
• Backgrounds
• peripheral hadronic events
• cosmic rays, beam gas interactions, pile-up

ZDC-West
ZDC-East
CTB-topology
22
Ygt µµ- (CombinedMuon)
MUID
etalt2.5
530 Y/month
23
Plans on LHC ALICE, ATLAS

• Cross-section,rate

ALICE
ATLAS
gA-gtJ/Y, YA in UPC AA