LHCb status and physics plans for 1 fb1
LHCb status and physics plans for 1 fb-1 run Eugeni Graugés (Universitat de Barcelona) IIas Jornadas CPAN – València 2010 November 2010 as 1
Menu Status 1. LHC machine 2. LHCb detector 3. Physics Analysis & Plans 1. LHC machine 2. LHCb detector 3. Physics Analysis Eugeni Graugés – IIas Jornadas CPAN 2
“NOMINAL” LHC Collider Eugeni Graugés – IIas Jornadas CPAN 3
“NOMINAL” LHC Collider 4 Eugeni Graugés – IIas Jornadas CPAN
5 November 2010 Eugeni Graugés – IIas Jornadas CPAN
LHC status: Rough chronology Oct 2008 – Oct 2009: recovered from s 34 incident 20 Nov 2009: Resuming (circulating) beam commissioning 6 Dec 2009: First physics collisions at 450 Ge. V/beam 13 -14 Dec 2009: Ramps and collisions to 1. 18 Te. V/beam Mid Dec 2009 – End Feb 2010 --- Technical stop 27 Feb 2010: Started LHC (first beams 2010), commissioning 20 Mar 2010: First ramps to 3. 5 Te. V 30 Mar 2010: First physics collisions at 3. 5 Te. V/beam 23 Apr 2010: First run with squeezed optics (beta* = 2 m) mid Jun 2010: Go to beta*=3. 5 m, push bunch&beam intensity 25 Jun 2010: First physics with nominal bunches(beta*=3. 5 m) 19 Aug 2010: Exceeded 2 MJ/beam in physics (2. 7 MJ). mid Sep 2010: Bunch trains, crossing angle end 2010: Reach ~1 e 32 Hz/cm 2 6 Eugeni Graugés – IIas Jornadas CPAN
Integrated lumi (delivered, in STABLE BEAMS) Plots at http: //cern. ch/lpc setting up nominal bunches 2 m / LHCf** ** LHCf: out since 20 july 2010 Goal end 2011: 1 fb-1 / LHCf** ** LHCf: out since fill 1250 Also: ~360 ub-1 at 450 Ge. V/beam and ~1 ub-1 data with 1. 18 Te. V/beam Eugeni Graugés – IIas Jornadas CPAN
Peak luminosity (delivered, in STABLE BEAMS) / LHCf** ** LHCf: out since 20 july 2010 / LHCf** ** LHCf: out since fill 1250 Goal end 2010: ~ 1 e 32 Hz/cm 2 = 100 Hz/ub During 2011: exceed 2 e 32 Hz/cm 2 = 200 Hz/ub Eugeni Graugés – IIas Jornadas CPAN 8
Increasing stored energy in the LHC beams linear Y scale apr may log Y scale jun jul aug apr may jun 3 MJ Reach approx 20 MJ by end of 2010, approx 30 MJ by end of 2011 Eugeni Graugés – IIas Jornadas CPAN jul aug
Beauty production at LHC November 2010 Eugeni Graugés – IIas Jornadas CPAN 10/30
Requirements to study b physics at LHC 11
The LHCb Detector Muon System RICH Detectors Vertex Locator Interaction Point Calorimeters Tracking System 12 Eugeni Graugés – IIas Jornadas CPAN
The LHCb Detector 13 Eugeni Graugés – IIas Jornadas CPAN
The LHCb Detector B 0→K*(Kπ)μμ B 0→X(K, π)γ B 0→K*μμ B 0 s→μμ Lifetime, B 0→Xγ B 0 →K*μμ B 0 s →μμ Interaction Point B 0 (s) →X γ Suppress background, σ(MB) B 0→Xγ B 0 →K*μμ B 0 s →μμ 14
LHC and LHCb performance LHC fill 14 Oct 2010: § § 248 bunches per beam Linst=9. 2 x 1031 cm-2 s-1 6 pb-1 in 6 days eff LHCb = 91. 3% 15 Eugeni Graugés – IIas Jornadas CPAN
Nominal LHC-LHCb running conditions • σbb ~ 500μb in pp collisions at √s = 14 Te. V 2 -5 x 1032 cm-2 s-1 § Luminosity limited to few 1032 cm-2 s-1 • Maximizes probability of single interaction per crossing • Achieved by defocusing the beams at LHCb: β* = 10 m • Average ~0. 4 visible int. per Beam Xing • Minimizing the pile-up events using a veto § 1012 bb produced per year (107 s) @ Lumi~ 2 x 1032 cm-2 s-1 • Rates at 2 x 1032 cm-2 s-1 § Bunch crossing rate 40 MHz (25 ns BX) • 30 MHz with bunches from both directions • 10 MHz of visible interactions (at least 2 tracks in the acceptance) 16 Eugeni Graugés – IIas Jornadas CPAN
Actual LHC-LHCb running conditions • σbb ~ 220μb in pp collisions at √s = 7 Te. V § Luminosity 1. 01 x 1032 cm-2 s -1 reached on Oct’ 14 th, 2010 § “Small” number of bunches § β* = 3. 5 m § Average ~2 visible interactions per Beam crossing § Flexible and Aggressive trigger 17 Eugeni Graugés – IIas Jornadas CPAN
Actual LHC-LHCb running conditions • An event with 4 PV 18 Eugeni Graugés – IIas Jornadas CPAN
Actual LHC-LHCb running conditions Pros vs Cons § Rare Decays analysis (e. g. Bs -> μμ) mostly get benefit from the increased luminosity § K*μμ “robust” against higher pile-up levels § B D X signal significance S/B worse by factor 2 in higher multiplicity events, but trigger seem able to handle it § Tagging not optimized for multiple PV Severe degradation 50% for n. PV>2 Work needed to re-optimize as much as possible § ϕs measurement: Proper time resolution worsens § Charm studies might suffer from higher pt trigger cuts § Sub-detectors might suffer from 4 x higher multiplicity, that sometimes might significant beam halo’s: (Muon Stations ? ) Still to be determined 19 Eugeni Graugés – IIas Jornadas CPAN
LHCb sub-detectors 15 < θ < 300 mrad (1. 9 < η < 4. 9) beam Pp Interaction Point VELO: Silicon vertex detector, very precise reco of Primary (PV) and Secondary (SV) vertices. TT. T 1, T 2, T 3 (IT+OT) : Tracking Detectors based on Silicon (ST = TT +IT) and gas (OT) Magnet: 4 Tm (10 m), 4, 2 MWs, d. B/B = 10 -4 RICH 1, RICH 2: Cerenkov Detectors separation π/K/p ECAL, HCAL, SPD/PS: M 1 -M 5: Muon ID stations Eugeni Graugés – IIas Jornadas CPAN
Silicon Tracker of LHCb Co-responsibility (including shifts) of USC 27%, LPHE Lausanne, U. Zurich y U. Heidelberg § § § Tracker Turicensis 4 stations (TT before the magnet, 3 IT afterwards) p-n silicon micro-strips. 12 m 2, 272 K RO channels 4 lplanes (0°, +5°, -5°, 0°). Spational Resolution 60 um IT : 5 x 1013 1 Me. V n/cm 2 eqv 10 years TT: 8 x 1013 1 Me. V n/cm 2 eqv 10 years Operación @ 5°C (C 6 F 14) • • • beam USC responsibilities: • • • Inner Tracker IT stations assembly (50%): Module micro-welding Burn-in station Faraday boxes contruction beam Control Electronics (ST) HV, LV systems(ST) Detector Control system (ST) ST project leader: Abraham Gallas ST on call expert: Daniel Esperante Eugeni Graugés – IIas Jornadas CPAN
Silicon Tracker de LHCb TT layer eff. § Detector runs reliably with a ~99% of working channels § Detector performance is excellent § S/N 16 -18 (IT) , 13 - 15 (TT) S/N in TT 4 § Eff. measured to be > 99 % with tracks § Valuable experience in achieving this gained with cosmics + TED runs in 2008/2009 Agreement @ 2% level Eugeni Graugés – IIas Jornadas CPAN 22
LHCb Calorimeter • (front view) ECAL HCAL PS/SPD • Y~7 m X~8. 5 m Ø 6000 pieces Z~2. 7 m spd e SPD/PS system determines the e/γ nature of energy deposited at L 0 trigger level. Its multiplicity is used to handle complicated events (with Multi-PV’s) ps ecal UB responsibilities: • spd LEAD • Preshower (PS)/Scintillator Pad Detector (SPD) Electromagnetic Calorimeter (ECAL) Hadronic Calorimeter (HCAL) ps ecal • SPD electronics - from PMT to trigger boards, - design, production, test, installation at CERN site, commissioning, calibration, monitoring & maintenance, … - full responsibility Coordination of ECS for the full calorimeter Eugeni Graugés – IIas Jornadas CPAN
SPD RO system Main Elements Ma. PMT’s (110) Characterized, tested (Gain, Uniformity, Linearity & X 64 ch signal output -talk) ASIC (8 dual channel, analog + digital) After 4 designed prototypes, the RUN 5 production resulted in 1300 produced + 600 unpacked Needed 800+160 (tested & mounted) Radiation qualification (with krypton beam) @GANIL: ASIC, VFE board, and all the other components 28 OCT 2009 LHCb - 1 a reunion de la red LHC - Xvc Rad-Hard design AMS Bi. CMOS 0. 8 um – 30 mm 2 24
Calorimeter detectors status Non working channels Non working LED ECAL 9/6016 15 unstable Fuses changed LED tuned HCAL 3/1448 2 noisy PS 2/6016 LED not used SPD 0/6016 10% channels LED not used 28/09/2010 LHCb week M. N Minard Modifications LED tuned HV changed 1/09 Threshold calibration on going 25
SPD key element for the trigger Flexible trigger has been required Trigger optimization – – Increase thresholds in L 0 Reduce the rate at the entrance of the HLT Introduce Global Event Cuts (GEC) – – – SPD multiplicity + number of VELO hits Remove events with a very hight multiplicity of tracks. Enter into a regime where the processing time is almost linear with mu Introduce the Hlt 1 Tracks + Remove almost alleys – – Reduce the processing time in HLT 1 Reduce the dependence of the processing to mu When required, downscale the remaining alleys without bias on proper time 26 Eugeni Graugés – IIas Jornadas CPAN
Key paramenters for a FLEX. Trigger • L 0 p. T cuts [Me. V] • L 0 SPD(Mult) < threshold In AND with electron, Photon, Hadron and Muon p. T thresholds Eugeni Graugés – IIas Jornadas CPAN 27
LHCb status: Vertexing 28 Eugeni Graugés – IIas Jornadas CPAN
LHCb status: Tracking 29 Eugeni Graugés – IIas Jornadas CPAN
LHCb status: Mass resolution 30 Eugeni Graugés – IIas Jornadas CPAN
LHCb status: Mass resolution 31 Eugeni Graugés – IIas Jornadas CPAN
Ecalo/P LHCb status: CALO objects π0 γγ J/ψ, ψ e+eχc J/ψγ 32 Eugeni Graugés – IIas Jornadas CPAN
LHCb status: Pi. D Rich 33 Eugeni Graugés – IIas Jornadas CPAN
LHCb status: Muon ID 34 Eugeni Graugés – IIas Jornadas CPAN
LHCb status: Flavour Tagging 35 Eugeni Graugés – IIas Jornadas CPAN
Status of First Results 36 Eugeni Graugés – IIas Jornadas CPAN
§ Status of First Results Published papers: 1. "Measurement of sigma(pp -> b anti-b X) at √s=7 Te. V in the forward region", Physics Letters B 694 (2010) 209. 37 Eugeni Graugés – IIas Jornadas CPAN
Status of First Results § Published papers: "Prompt K 0 S production in pp collisions at √s=0. 9 Te. V", Phys. Let. B 693 (2010) 69. 38 Eugeni Graugés – IIas Jornadas CPAN
Status of First Results § Published papers: "Prompt K 0 S production in pp collisions at √s=0. 9 Te. V", Phys. Let. B 693 (2010) 69. 39 Eugeni Graugés – IIas Jornadas CPAN
Status of First Results § Other selected results: Charm Production (IP used to separate prompt from secondary charm) 40 Eugeni Graugés – IIas Jornadas CPAN
§ Status of First Results Other selected results: Beauty semileptonic decays 41 Eugeni Graugés – IIas Jornadas CPAN
§ Status of First Results Other selected results: Spectroscopy 42 Eugeni Graugés – IIas Jornadas CPAN
Status of First Results § Other preliminary results on: § § § Charm production cross-section vs pt Production ration D+/D+s Inclusive J/ψ production Lambda/Anti-Lambda (V 0) production Still some work to do down the road to go from plotting peaks to measure cross-sections, CP asymmetries, UT angles, elements, etc… 43 Eugeni Graugés – IIas Jornadas CPAN
From plots to Cross-section measurements 44 November 2010 Eugeni Graugés – IIas Jornadas CPAN
Plans for 1 fb-1 run: - LHC and LHCb running conditions - LHCb physics plans 45 November 2010 Eugeni Graugés – IIas Jornadas CPAN
LHC Running Conditions • Possible Running Conditions • The actual LHC running will be agreed at/after the Chamonix workshop 46
LHC Running Conditions Ø Beam energy, will depend on latest understanding of splices and quench behaviour. Ø Luminosity and bunch scheme, will depend on analysis of e-cloud effects, collimation cleaning, aperture limitations. . . Ø Running only in 2011 or also in 2012, depending on integrated luminosity and physics reach. 47
Expected machine parameters ü reminder: how do luminosity and pile-up depend on machine parameters? ≈ nb ·f · μ /σvis μ = σvis · Lb / f ~ N 2 · β* · 1/εn (with Lb = L / nb ) ü typical values reached in this year’s running: Ø typical N ≈ 1. 15 · 1011 (= nominal) , with maximal N ≈ 1. 35 · 1011 Ø typical εn ≈ 2. 4 μm , (nominal εn ≈ 3. 75 μm) , with minimal εn ≈ 1. 8 μm Ø for most of data taking β* = 3. 5 and so far minimal β* = 2. 0 Ø maximum nb in machine: • 2808 with 25 ns, 1404 with 50 ns, 936 with 75 ns , 468 with 150 ns • maximum colliding = 344 reached so far with 150 ns scheme ü expected conditions for 2011 Ø 50 ns scheme with up to 1404 bunches Ø possibly increase energy to 4 Te. V (4. 5 Te. V? ) Ø push bunch charge and emmittance to extreme values LHCb workshop 8 -9 November 2010 48 Andreas Schopper
Expected pile-up and luminosity comment: end 2010 150 ns small beta 75 ns 50 ns large beta larger beta energy units Te. V Energy 3. 5 3. 5 4 n_b 344 450 900 1350 N 11. 5 11. 5 β* 3. 5 2 2 2 5 7 7 -1 -1 2. 4 2. 4 μm 63. 6 63. 6 65. 1 mbarn -740 -740 -673 Μrad 2. 6 4. 1 1. 9 1. 4 1. 6. E+32 2. 0. E+32 3. 3. E+32 6. 5. E+32 9. 8. E+32 4. 5. E+32 3. 3. E+32 3. 8. E+32 6 180 180 16 634 1016 2033 3049 1387 1019 1170 pb^-1 9. 9 13. 0 20. 8 41. 6 62. 3 28. 4 20. 8 24. 5 MHz 3. 9 5. 1 10. 1 15. 2 MHz polarity ε_n σ_vis effective full angle μ (visible) Lumi days running integrated Lumi pp interaction rate bb interaction rate LHCb workshop 8 -9 November 2010 49 Andreas Schopper 10^10/b cm^-1 s^-1
Expected pile-up and luminosity comment: energy 75 ns higher N smaller ε 50 ns large beta GPDs 4 4 4 4 n_b 1350 900 900 1350 1400 N 11. 5 13 13 13 7 7 7 10 2 -1 -1 -1 1 2. 4 1. 8 μm σ_vis 65. 1 65. 1 mbarn effective full angle -673 -673 273 μrad 1. 6 2. 1 2. 7 1. 9 9. 8 3. 8. E+32 2. 5. E+32 3. 2. E+32 4. 2. E+32 6. 3. E+32 4. 5. E+32 180 180 integrated Lumi 1170 780 997 1299 1948 1402 7357 pb^-1 pp interaction rate 24. 5 16. 3 20. 9 27. 2 40. 8 29. 4 154. 1 MHz bb interaction rate 15. 2 10. 1 15. 2 15. 7 MHz Energy β* polarity ε_n μ (visible) Lumi days running LHCb workshop 8 -9 November 2010 50 Te. V 10^10/b 2. 4. E+33 cm^-1 s^-1 Andreas Schopper
Means of tuning to our preferred conditions ü at β* ~ 2 of General Purpose Detectors (GPDs): Ø range of expected pile-up between μ ~ 4 to 10 Ø range of expected peak luminosity L ~ 3. 3 · 1032 to 2. 4 · 1033 in 2011 we cannot follow the luminosity evolution of GPDs! ü assuming the following peak values for LHCb for pile-up and luminosity: Ø μ ≤ 2 and L ≤ 5 · 1032 (a priory limitations) Ø MIGHT need a reduction factor of 2 5 as compared to GPDs • β* in the range of 4 10 (disadvantage: maximum 2 settings, not flexible!) • displace beams according to needs (by how much? is it feasible? ) 51
Displacing beams Separation needed for reduction of μ Reduction in luminosity as function of separation μ = 1. 5 Need to separate beams between ~1. 5 to 2. 5 σ LHCb workshop 8 -9 November 2010 52 Andreas Schopper
Displacing LHC beams at LHCb Ø Not easy, due to different effects to be considered: Ø Beam-Beam Interactions: beam-beam force for traversing beams. Ø Beam Perturbations are proportional to bunch intensity. Ø Some tests done with 50 ns BX Ø Magnet Polarity influences beam stability when trying to displace the beams and give them an external crossing angle 53
Plans for 1 fb-1 run: - LHCb physics plans 54 November 2010 Eugeni Graugés – III Prometeo Workshop
LHCb Key Measurements 55 November 2010 Eugeni Graugés – III Prometeo Workshop
CKM Angle γ measurement @ LHCb 56 November 2010 Eugeni Graugés – III Prometeo Workshop
Bs μμ 57 November 2010 Eugeni Graugés – III Prometeo Workshop
Bs μμ 58 November 2010 Eugeni Graugés – III Prometeo Workshop
Bs μμ 59 November 2010 Eugeni Graugés – III Prometeo Workshop
B hh 60 November 2010 Eugeni Graugés – III Prometeo Workshop
B Κπ 61 November 2010 Eugeni Graugés – III Prometeo Workshop
BS J/Ψ Φ 62 November 2010 Eugeni Graugés – III Prometeo Workshop
B 0 Κ*μμ 63 November 2010 Eugeni Graugés – III Prometeo Workshop
B 0 Κ*μμ 64 November 2010 Eugeni Graugés – III Prometeo Workshop
Summary ü LHC restarted operations in the fall 2009, and since: Ø LHCb has been integrating luminosity at very high efficiency Ø The first result from the analized data have already been published The LHC running conditions are not exactly those foreseen, but in LHCb we are happy to adapt to the new situation and take advantage of the data delivered By LHC ü The LHC prospects for next year are and increased L and perhaps increased E Ø Some NP sensitive channels could already very competitive with 1/fb LHCb data Ø Some work is needed to re-tune tagging and some analysis techniques to the higher-than-expected-mu scenario foreseen for next year • Nevertheless something will be needed to accommodate the a priory limit of 5 x 10 exp 32 cm-2 s-1 max. L and max mu==2 Stay tunned …. November 2010 Eugeni Graugés – III Prometeo Workshop 65
BACKUP Eugeni Graugés – III Prometeo Workshop 66/30
How do we use our detector 67 November 2010 Eugeni Graugés – IIas Jornadas CPAN
LHC and LHCb performance § LHCb show excellent perfomance § Results shown today use ~0. 5 pb-1 eff LHCb = 91. 3% 68 Eugeni Graugés – III Prometeo Workshop
Reversal of magnet polarity 2010 running conditions: αint = 270 μrad at 3. 5 Te. V αext = 100 μrad negative (good) polarity 75 ns crossings 150 ns crossings αext < αint for bad polarity parasitic encounters at 75 and 50 ns positive (bad) polarity For positive (bad) polarity: Ø with 150 ns, external angle can be smaller than internal angle Ø with 75 and 50 ns, external angle must be bigger than internal! increase αext > αint separate beams no parasitic encounters Beam energy LHCb workshop 8 -9 November 2010 69 Andreas Schopper
B 0→K*μμ: Motivation § § Hadronic uncertainties largely cancel in angular asymmetries Forward-backward asymmetry AFB easiest μ- μ+ θl K* (4/3) AFB Example: § Zero-crossing point particularly interesting: Ø Ø Eugeni Graugés – III Prometeo Workshop Small hadronic uncertainties Directly sensitive to C 7 and C 9 70/30
• Muon ID efficiency Ø Good agreement data, MC • K ID efficiency Ø Avg K id eff = 96% Ø Avg π misid rate = 7% • Trigger efficiency Muon ID efficiency (%) B 0→K*μμ: Detector performance J/ψ→μμ MC Data MC, before trigger MC, after trigger K+ ID efficiency (%) Nr of events (A. U. ) Ø No bias in θl introduced θl Eugeni Graugés – III Prometeo Workshop φ→K+K- Ks→π+πK+ momentum (Ge. V) 71/30
B 0→K*μμ: Lessons from early data D 0→Kπππ • Similar topology • Check bias introduced by trigger and selection L = 0. 5 pb-1 D 0→Kπππ Ø Good data mc agreement v Muon id not included L = 0. 5 pb-1 D 0→Kπππ Eugeni Graugés – III Prometeo Workshop 72/30
B 0→K*μμ: Lessons from early data L = 0. 5 pb-1 5280 ± 60 Me. V B 0→J/ψK* • Applied B 0→K*μμ event selection • Data and MC normalized to σbb • Efficiency estimates from MC reliable Eugeni Graugés – III Prometeo Workshop L= 0. 5 pb-1 73/30
B 0→K*μμ: Expectation • Expectation LHCb, 100 pb-1 § ~150 events § Statistical errors only § Compared to Belle and Ba. Bar Ø Assuming Belle central value: 1. 5σ SM exclusion SM LHCb expectation 100 pb-1 Belle Ba. Bar Eugeni Graugés – III Prometeo Workshop 74/30
B 0→K*μμ: Expectation • Expectation LHCb, 2 fb-1 § ~3000 events § Statistical errors only § Compared to Belle and Ba. Bar Ø Assuming Belle central value: 5. 4σ SM exclusion SM LHCb expectation 2 fb-1 Belle Ba. Bar Eugeni Graugés – III Prometeo Workshop 75/30
B 0→K*μμ: ? SUSY T. Hurth, hep-ph/0212304 Extra dimensions (Kaluza Klein modes in ACD model) SM Flavour Blind MSSM 5 / , 1 D AC A. Buras et al. , Nucl. Phys. B 678: 455 -490, 2004 A. Ali et al. , Phys. Rev. D 61: 074024, 2000 Minimal Flavour Violation 2 R= V e 0 G General MSSM (large Im(C 7’)) General MSSM (modified C 7, C 7’, C 10)) W. Altmannshofer et al. , JHEP 0901: 019, 2009 Eugeni Graugés – III Prometeo Workshop 76/30
Rare Decays Summary q LHCb detector in excellent position for exciting Rare Decay results soon: 1) In 100 pb-1 expect competitive measurement of direct CP asymmetry in B 0→K*γ 2) In 100 pb-1 could observe 1. 5σ deviation from SM in AFB with B 0→K*μμ (assuming central value from Belle) 3) With 50 pb-1 hope to approach or surpass world best sensitivity in B 0 s→μμ ± B 0→J/ψK* B 0→ K±π L=3 pb-1 B 0→J/ψK* σ=11 Me. V Mass (Me. V) B 0 s→Ds-π+ L=3 pb-1 B 0→K-π+ σ=24 Me. V Mass (Ge. V) Eugeni Graugés – III Prometeo Workshop L=0. 75 pb-1 B 0 s→Ds-π+ σ=26 Me. V Mass (Me. V) 77/30
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