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LMVM RBUB numbers (HW update)

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LMVM RBUB numbers (HW update)

R. Seto

Light-Heavy PWG

July 6, 2006

- HW
- Lum (not finalized)
- Most data sets will be DAQ limited (5kHz)
- NOT true for low energy (63 GeV) AuAu
- Propose to run 63 GeV Iodine on Iodine (A=127) to increase rate; we will then be DAQ limited for 63 GeV Iodine on Iodine
- Eg. Run 7: AuAu 200, Run 8: 63 GeV Iodine, Run 9: something else(dAu…) or some permutation

- Some assumptions
- 63 GeV 10% of 200 GeV
- Iodine is 10x Au
- production scales with Nch

NA60

NA60

- rate = 2x
- bkg integration = 600 MeV

- Use Kozlov post-QM numbers shown at the pwg last week
- 1030M min bias
- 1740 , S/B=1/76

- Some volunteer should go through last year's BUP and this year's CAD guidance and formulate the prescription for the assumed evts recorded that all people should be using in formulating their contributions to this year's BUP.
- Eff~0.36=0.6(RHIC)*0.6(PHENIX)
- Min Bias recorded ~ 5kHz
- Use CAD delivered Lum/week
- 0.290 nb-1/wk for 200 GeV AuAu

Assumptions:

DAQ 5 KHz recorded

RHIC Z vertex = 20 cm, 80% in central peak

Eff for phenix =0.6

Eff for RHIC 0.6

For 200 GeV AuAu

L/week=0.290 nb-1

L(avg)=8E26 L(max)=3.6E27

min bias rate

avg= 5.0 kHz (4.5-round up)

max = 20. kHz

so limit to 5kHz

63 GeV AuAU

L=10% of 200 GeV

Min bias

0.5kHz (avg)

2.kHz (max)

63 GeV Iodine on Iodine

L=13x AuAuGeV

Min bias =5.8b

5kHz (avg) (4.8-round up)

20.kHz (max)

so limit to 5kHz

- DAQ limited
- 5kHz*6Msecs(10 weeks) *0.6(phenix eff)*0.6(RHIC eff)= 1.1E10 events

- Rate limited, e.g. AuAu at 63
- L/week*bbcz *10 weeks * *PHENIX eff=
- .029 nb-1/week*0.8*10weeks*7b*0.6=9.7E8 ~1B events

Ozawa et al

700M evts

Counted events 30 MeV=60 MeV

Saw 644 330

S/B=644/100K

Saw 748 200

S./B=750/40K

Kozlov et al

1740M events

Counted events 0.997 to 1.041=44 MeV

Saw 1740

S./B=1/76=1740/132K

Kozlov should have seen

1502

Background 196K

(see spares for calculation)

- Scale signal with dN/dy
- Scale background with (dN/dy)2
- AuAu min bias Np=109
- 200 GeV dN/dy=332
- 63 GeV dN/dy=223

- II min bias Np=94 (guess)
- 63 GeV II dN/dy=188

- HBD
- Signal eff 0.4
- S/B in central AuAu improves by factor 100
- Signal suppressed by 0.4
- background suppressed by .004
- .06 for background electrons

From Milov Analysis note

Iodine 63 GeV

Au 200 GeV

Au 63 GeV

HBD A

HBD B

HBD A – HBD as in CDR

HBD B – HBD 4x poorer in rejecting bkg, i.e. 2x worse per electron

For RHO: Good measurement at 200 GeV AuAu, 63 GeV Iodine

i.e. ~ 5K events can be broken up into bins of pt and centrality and still

Give a reasonable signal

Iodine at 63 will give connection to NA 60 result.

- Kozlov new has a different “looser” cut for electrons – which means
- He keeps more electrons in the case of both signal and background
- He also introduces more π’s for bkg

- Signal
- Let a=eff old, b=eff new (a<b) and X is the total number of events with ’s (or equivalently the number of ’s total
- a2X=748 b2X=1740
- So in the case of the ,X is different (call it X’), but the old to new ratio of ’s is just a2/b2 or the ratio of old to new ’s

- Bkg
- Let M=# ee pairs per event N=M=#ππpairs, c,d be prob that π is misidentified as an electron in the “old” and “new” schemes respectively
- Bkg (M+ M)2= (1+ )2M2 if you take everything
- Bkg old (aM+cN)2~ (a+ c)2M2 ~40K
- Bkg new (bM+dN)2~ (b+ d)2M2 ~1320K
- In the case of the we have a new M and N, i.e. M’ and N’
- N=M N’= ’M’

- BIG Assumption? = ’
- Then in you work out the algebra you can just use the ratios i.e.

- I assume phi production proportional to dNch/dy at energies greater than 60

63

200

Full energy

63 GeV

- Increase in lum going to lower A is balanced by Ncoll to factor of 2
- Find ncoll, npart for lighter species
- Milov/workarea/tmp

- Ask Roser et al for RHIC lums at lower energy, lighter species, specifically 62 GeV AuAu, II, CuCu, SiSi, dAu, pp

- Find ncoll, npart for lighter species