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Expectation experiments ...

Expectation experiments. Overview proton run goals for 2011 desiderata Special runs intermediate energy * = 90m runs luminosity calibration runs Schedule / scenari. Unless otherwise stated, the units for luminosity are in Hz/cm 2. Experiments  expectations. Overview proton run

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Expectation experiments ...

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  1. Expectation experiments... Overview proton run goals for 2011 desiderata Special runs intermediate energy * = 90m runs luminosity calibration runs Schedule / scenari Unless otherwise stated, the units for luminosity are in Hz/cm2

  2. Experiments expectations Overview proton run goals for 2011 desiderata Special runs intermediate energy * = 90m runs luminosity calibration runs Schedule / scenari

  3. 2010 vs 2011 2010 was and will remain a pivot year for the LHC 2e32 Hz/cm2 Lucy in High Clouds Yes, She can fly!

  4. 2010 vs 2011 2011 could be a pivot year for physics See Bill Murray’s talk (session 4) Exclusion limit @ 90% C.L. New Physics ?

  5. 2011-2012 run Focus has to be on discoveries ! Accommodate other physics requests without substantially reducing the potential for discoveries • ALICE run at 1.38TeV/beam • TOTEM programme • precise lumi calib

  6. Goals for 2011 Proton running • Goal for 2011 was already set a year ago: 1 fb-1 delivered to each of IP1, IP5 and IP8 at 3.5 TeV(or >3.5TeV) • Can probably do better for IP1 and IP5 Gimme five … fb-1 ? • You can make the SM Higgs visible or … history • But it will actually be a challenge to deliver 1fb-1 to IP8 • consider maximum luminosity and pile-up tolerable to LHCb • Already a big effort from LHCb side to “help” reaching the target: Lmax: from 2e32 to 3e32 and µmax : from 0.5 to 2.5 • One fb-1 will be just reachable if we make proper choices • with lumi leveling (no decay): 3e32 * 110 days * 0.35 = 1 fb-1 fraction in stable beams

  7. Goals for 2011 second part Pb running: ALICE’s main requirements: • maximisation of luminosity • opening of IR2 tertiary collimators (TCTVB) • want data at two magnetic field polarities (~ 50-50%) Additional preferences: • zero real crossing angle • crossing angle acceptable in case of substantial gain in luminosity • bunch separation of 100 ns or larger • smaller separation acceptable in case of substantial gain in luminosity ALICE support a p-Pb exploration MD during 2011 ion run (for 2012)

  8. Pb run: Goals for 2011 30 µb-1 delivered to each of IP1, IP2 and IP5 at 3.5 TeV (or higher energy) sounds like a reasonable target. • quadruple statistics • * = 1.5 m or smaller ? L x 2.3 • nominal scheme L x 2-5 ? N/N loss ?

  9. General statements on beam conditions • Energy: the higher the better => Bill Murray’s talk • But watch out the overhead or inefficiency w.r.t. the gain • Bunch spacing • Expts can accept any considered spacing, 150ns, 75 or 50ns (… 25 ns ) • Choice of *: • ATLAS/CMS: the smaller the better (as long as maximizes Lint) • ALICE: 10m • LHCb: 3m (I come back to that later) • Choice of N and N: (basically, pile-up) • ATLAS/CMS built for µ up to ~20 • LHCb built for µ ~0.5, but contorting to cope with ~2.5 • ALICE will use µ < ~0.05 In general: for equal luminosity, less pile-up is better, for example if … • Lint is bigger when N is reduced (thanks to nb or uptime?), or • increasing Nby x2 allows putting x2 more bunches (stability ?), then running with the lower pile-up option is better! choose  such that OK for all these spacings reduce by separation

  10. Filling patterns Trains • 150ns and 50ns: • start from: maximize collisions in IP1,5,8 => no collisions in IP2 • then, add or shift a few trains to give 10-20 bunches colliding in ALICE • 75 ns: • full collision schedule everywhere => slightly larger separation required for ALICE when exceeding ~600 bunches TOTEM request • Add 1 (or up to 4) small bunches (~1-2e10) that collide in IP1/5, as long as does not reduce space available for the main bunch trains. • seq: 1 probe, 4b ~1us spacing, intermediate batch, bunch trains

  11. Lumi decay and lumi leveling • Typical 2010 fill at 150ns and 368b For LHCb 2011: recover this part by luminosity leveling Factor ~1.4 in integrated lumi per fill.

  12. The LHCb case, pictorially Remember: LHCb was designed for 2808b, L~2e32 and µ~0.5 • LHCb limited to: (any time during the fill) • L(t) ~ 3e32 Hz/cm2 = Lmax • µ(t)  ~2.5 = µmax • Three possible scenari: B) A less bad but not cheap scenario: - 3 * values - No separation allowed A) The undesired scenario: - Fixed * - No separation allowed C) The best scenario: - Fixed * - With separation leveling Must be defined for whole of 2011 based on a guess of absolute 2011 maximum N2/N Lmax Lmax Lmax lost due to fill lumi decay Gain factor in Lint(IP8) of ~1.4 Average fill luminosity ¼ Lmax Months (push nb, N, N) Months (push nb, N,N) Months (push nb, N, N)

  13. What separation ? • Proposal: • Start with a chosen and fixed set of values for { * , N , N } why not use something like what we had end of 2010 ? N = 2.5um, N = 1.15e11 and increase nb ~900 (75ns) • In parallel, MDs to push N , N. • After X weeks, decide on new { N , N } values and verify if need to change IP8 * (probably not). • IP8: See Werner’s talk * = 3 m seems to be a good guess (implement such that minimum impact if need to increase * later) Typical range ALICE 4 TeV, ~12 bunches,10m n=2-3.75um N=1.1-1.2e11 Typical range LHCb 4 TeV, 3m n=2-3.75um N=1.1-1.2e11

  14. Experiments expectations Overview proton run goals for 2011 desiderata Special runs intermediate energy * = 90m runs luminosity calibration runs Schedule / scenari

  15. Intermediate energy proton run E=1.38TeV/beam 3.5 ZTeV/beam Requestor: ALICE • 50 M events to tape Conditions: • R = 3…10 kHz inelastic interaction rate • * = 10 m IP2/8 (11 m IP1/5) • NB: All expts want to take data • Pile-up: µ < 0.05 • R = f nbµ nb= (3…10kHz)/(11kHz 0.05) = 5…18 b •  = 2um: N = (0.05 4 10m 1.36nm/55mb)1/2 = 4e10 p/b • Needed: ~35 h of stable beams • Setup time: 3 shifts (Mike Lamont) Details: • One polarity • ALICE: any • LHCb: one polarity gives larger net angle, to be decided • VdM scans during one of the fills (<10% lumi accuracy) Pb: Z=82 A=208 Equivalent NN centre of mass energy 1.38TeV proposed: 24b equalitarian scheme 16 collisions at each IP => 200kJ i.e. like 4 nominal bunches at 3.5 TeV

  16. Intermediate energy proton run WHEN ? ALICE point of view • Asap! Needed to extract the best from 2010 Pb data (combined analysis) ATLAS/CMS point of view • Priority should be on establishing asap LHC as 1e33 Hz/cm2 machine! • Schedule special runs after having reached 1e33 and collected 1 fb-1 LPC point of view • Run was recommended by LHCC and endorsed by RB  To be scheduled in 2011, with minimal impact on mainstream • My hope: use this run as part of the “warm-up” physics period, if this allows to ramp up the intensity faster than presently proposed  schedule it after the 3-weeks commissioning (when ready for physics) • give the EiCs/OPs something less intimidating to start with • 5 days to digest the 3-week commissioning • If not a valid proposal, then put the run before/after a TS+MD block. • NB: machine runs better and better lumi production more fruitful in second part of the year…

  17. Intermediate energy run to be scheduled back to 1.38TeV energy run Mike’s original proposal scrub week LPC proposal with complement 1e33 300b 40/pb 1/fb DONE DEAL ?

  18. TOTEM • See M. Deile in LHC 2010 LUMI DAYS here

  19. T1 is in

  20. TOTEM wishes for 2011 (ALFA much the same) detectors commissioning not complete before end of august ? • Extended configuration: T1 and RP147 (12 additional pots) + ALFA (8) • Repeat RP alignment at nominal conditions note: needed after each collimator re-alignment • extend the exercise for some taking data close to the beam1 nominal bunch • Special runs with low intensity and normal optics: • - approach RP to ~5 s to reach lowest |t| around 0.2 GeV2 • - pileup-free data for T2 and T1 (m ~ 10-2)  diffractive phys with T1, T2, RP  need more statistics for DPE mass spectrum2 pilots (1x1010 ) + 4 bigger bunches (7x1010 )  L = 10 nb-1 / 3 h (4 TeV, b*= 2.5m)(3 runs of 6 hours would give 60 nb -1 ) • Constant running at 15 s in normal runs - improve statistics at large |t|-values • -add one pilot bunch to the standard bunch scheme if possible- 50 ns operation should be OK for RP & T2- T1 will mainly operate with the pilot • Prepare the b* = 90 m optics •  measure the total cross-section and luminosity in special runs dedicated Replace by adding one probe in above fill. Possibly, some other opportunities later. dedicated parallel dedicated

  21. TOTEM-desired Scenario for Runs at b* = 90 m • ALFA/ATLAS also interested • ALICE/LHCb/CMS will profit to take data during these fills as well (10m) • In particular: LHCb beam-gas imaging lumi calibration => probably more than one bunch Dominated by systematics  small RP distance much more important than luminosity ! Crucial: good knowledge of the optical functions Relatively wide beams: sx = 0.4 mm, sy = 0.6 mm (at roman pots) Contribution from optical functions not larger than angle resolution limit from beam divergence dLy / Ly < 1.1 % or dby / by < 1.1 % dLx / Lx < 0.2 % or dbx / bx < 0.2 % (error estimates are based on 1%: sufficient)

  22. 90m optics summary Requestor: TOTEM+ALFA • 4 physics fills (see previous slide) Conditions: • N, N, nb : small, see previous slide. • * = 90 m IP1/5 (10m IP2/8) • NB: All expts want to take data • E = 4 TeV • Setup time (MD): 5 shifts (Helmut Burkhardt) • including RP beam-based alignment at 90m Proposal: • one MD per block (as long as it is needed) • first MD shift, no physics run • following ones, followed immediately by a physics fill (if works) • NB: count on more than one bunch for the physics fills

  23. 90m optics: when ? physics with a partially filled machine RP beam-based alignment, 1.5m after collimators MD 90m: 1 shift per block ? possibly followed by physics (depending on readiness)

  24. Special lumi calibration fills • 2010: have (already!) reached ~5% lumi uncertainty at 3.5 TeV • 2011: aim for 1-2% level => see LHC 2010 LUMI DAYS • How ? => see Simon White’s talk later in this session • Will benefit from: • (a) “parasitic” studies, mainly end-of-fill, short measurements • in physics conditions • vdm scans, position reproducibility studies, profit from emittance and charge spread to check systematics, co-moving TCTs, etc. • (b) dedicated fills (~2), in optimal conditions (yet to be agreed upon) • likely: “10/11m” optics or “1.5m”, with or without crossing angle (per IP), ~19 bunches of ~6-12e10 p, emittance 2-4 um, “private” bunches per IP • assume: no set up time (shadow of arc, benefit from co-moving TCT) • Scheduling: • If E=3.5 TeV, no urgency for any vdm scan • If E=4 TeV, urgent to get at least some first results (type (a) above) • In both cases, the ultimate (type (b) above) could be in second part of 2011 ONLY IF THE EXPERIMENTS SUPPORT THIS see also MFL session1

  25. summary special requests • E=1.38TeV run 3 shifts setup 35h in stable beams • 90m optics 5 shifts MD/setup 4 fills in stable beams • dedicated lumi calibration 2 fills in stable beams some “eof” studies this is <10% of mainstream physics time

  26. Experiments expectations Overview proton run goals for 2011 desiderata Special runs intermediate energy * = 90m runs luminosity calibration runs Schedule / scenari

  27. Intensity ramp up • seen in Evian and elsewhere: • Intensity steps: 75 ns operation: 50b steps to monitor the pressure and instabilities (50-100-150-200-250-300). Only one fill if all O.K. - 2 weeks • After scrubbing run: 300 – 400 – 600 – 800 – 900 – 2.5 weeks • …. Depending on observations includes x0.7 for lumi decay here is when the airship can no longer fail Input: E = 4 TeV N = 1.15e11 N = 2.5um * = 1.5m /2 = 120 urad µ = 8.6 Please, minimize! No physics request for this. remember: you gave us already 45 pb-1 here is when physics starts max of 150ns probably driven by e-cloud…

  28. How many physics days ? Or …. Wandering around CERN EVIAN CHAMONIX (see Malika) PREVESSIN Definitely, there is progress…

  29. Scenari push up N and push down N 50ns 1.1e11p ~2.5um up to ~1400b 1.5m/10m/3m 150ns 1.1e11p 2.5um ~400b 1.5m/10m/3m 50ns successful 75ns OK 50ns not OK 75ns 1.1e11p 2.5um up to ~900b 1.5m/10m/3m scrubbing run (then test all spacings) 75ns 1.1e11p 2.5um ~400b 1.5m/10m/3m 50ns 1.2e11p ~2um up to 1400b 1.5m/10m/3m scrub in physics? unsuccessful preferred by experiments 150ns 1.1e11p 2.5um up to ~430b 1.5m/10m/3m how many hours ? 10 ? 20 ?

  30. How to project integrated luminosity ? Assume Lstart = start luminosity for physics production = 4.5e32 we know you can do that Lyeah = luminosity you think could be achieved fairly quickly (even if it takes a week of scrubbing) Lyeswecan! = the “asymptotic” luminosity, seems feasible but there are several unknowns… 124 – 144 days high lumi physics days

  31. Luminosities at s1/2 = 8 TeV f nb N2 L = –––––––– S()rr = e-d2/22 d = separation 4 N* Example: * = 1.5 m N = 1.15  1011Estored = 70 MJ N = 2.5 um S() = 0.96 µ= 8.6 (inelastic, 75 mb) nb= 936 r = 1 = 26.5 um (beam sizes) 1.21033 cm-2 s-1 ~ 30 pb-1 / 10h fill Try with 1400 bunches, 2um, 1.2e11 … and pick out your Lyeah and Lyeswecan! . including overall factor 0.7 for lumi decay

  32. Pro-jection • Suppose: Lstart = 4.5e32 Lyeah = ~1.2e33 Lyeswecan! = 2e33 • 124 days high lumi physics days • 35% of that in stable beams, decay factor 0.7 144 high lumi physics days Lyeswecan! Lyeah Lstart SM Higgs is discovered or SM Higgs is history 5 fb-1 going to Lyeah asap can make quite a difference at the end high lumi physics days

  33. Contra-jection • Suppose: Lstart = 4.5e32 Lyeah = ~7e32 Lyeswecan! = 1e33 • 124 days high lumi physics days • 35% of that in stable beams, decay factor 0.7 144 high lumi physics days high lumi physics days

  34. LET’S BE AMBITIOUS fast, secure and far-reaching

  35. backup

  36. Protons: Main requests by the four large experiments … beyond the obvious max integrated lumi • ATLAS/CMS: • ATLAS: one low µ fill, µ < 0.01 , 1 µb-1 • both: non-colliding bunch (far behind others) • ALICE: • pp run: 5e29 < L < 5e30, µ < 0.05 (at nb ~650, L limit overtakes µ limit) • polarity flips (~ at TS) • intermediate energy run, 50M events on tape • LHCb • polarity flips. The more often the conditions changes, the more frequent the reversals needed • Lmax = ~3e32 , µmax = ~ 2.5 (at nb ~800, L limit overtakes µ limit) • Use lumi leveling to maximize integrated lumiBig gain! • All: • possibly, accurate lumi calibration measurements not needed if small bunch present

  37. 2011: aim at dL/L ~ 1-2% ??? will need some studies • A few “eof” studies (as much as possible in nominal stable beams) • All-IP //scans and systematic effects due to IR steering “cross-talk” • Position reproducibility effects (hysteresis ?) • Co-moving TCTs • Minimizing (and measuring) charge outside the nominal RF buckets • B-by-b emittance ctrl (to equalize emittances between beams and bunches) • VdM scan reproducibility tests (to be agreed upon machine & experiments) • scans more useful if can go to +/- 3 sigma separation • the faster, the better (<1 hour) • probe and nominal bunch in same fill: compare small vs large N2 in IP1&5 • requires BCTs to work in physics conditions (short spacing) • exact conditions & procedure to be defined • Complementarity: VdM and beam-gas imaging methods (LHCb) • mostly different systematics, but correlated BCT systematics • Complementarity: Direct (Vdm/BGI) vs Indirect methods (elastic/total) • widely different systematics, comparable accuracy reach

  38. How far can we go in separation ? (lumi stability) Assume expt requests a relative stability of luminosity of |dL/L| < s At separation x, the lumi leveling factor is F = e-(x/2)2 = e-(/2)2 where  = x/ F-1 dF/d = -  / 2 Imposing |dF/F| < s gives (dx/)  (x/) < 2 s Small  : get hit twice

  39. Condition for changing energy: • Tchge/(Tchge+T4tev) < 0.2 => Tchge < T4tev / 4 • sfv L3.5tev 0.8*L3.5tev E=3.5TeV E=4TeV Linzepocket set to 0 time to change E 3.5 to 4 TeV same peak lumi Tchge T4tev

  40. Elastic scattering, total cross section Measurement of stot via the Optical Theorem with increasing precision. Several runs to study the systematics. Gives also absolute luminosity “indirectly” => complentary to vdm scans

  41. Projections Higgs  See Bill Murray’s talk

  42. But Higgs is not everything  See Bill Murray’s talk • Beauty also counts • LHCb expectations for Bs µ µ (FCNC) Possible enhancement by New Physics!! Strongly suppressed in Standard Model!! And the Bs equivalent of the “Bd CKM angle” (from B factories) Exclusion limit @ 90% C.L. New Physics ?

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