BTeV Physics Reach LHC 2003 Symposium K. Honscheid Ohio State University LHC2003 K. Honscheid Ohio State

B Physics Today CKM Picture okay CP Violation observed No conflict with SM Vud Vus Vub VCKM = Vcd Vcs Vcb Vtd Vts Vtb sin(2b) = 0.734 +/- 0.054 LHC2003 K. Honscheid Ohio State

Surprising B Physics tb Year Item Theory Prediction ~Value # B’s 1983 Too small to be observed ~ < 0.1ps 1 ps 2x104 1987 Bo-Bo mixing Too small to see (~ < 1%) as mtop is believed to be ~30 GeV 20% 2x105 2001 sin(2b) No direct prediction, but consistent with other measurements 3/4 107 a,b,g >1011 b hadrons (including Bs) LHC2003 K. Honscheid Ohio State

B Physics at Hadron Colliders The Tevatron as b (and c) source b cross section ~100 mb, c cross section ~1000 mb b fraction 2x10-3 Inst. Luminosity 2x1032 Bunch spacing 132 ns (396 ns) Int./crossing <2> (<6>) Luminous region sz = 30 cm Forward Geometry 2x1011 b pairs/year bg b production angle b production angle LHC2003 K. Honscheid Ohio State

The BTeV Detector Pixel Detector RICH Detector PbWO4 EM Calorimeter Beam Line Pixel Detector Vacuum Vessel 60 pixel planes inside magnet s = 5-10 mm Proper time resolution: 46 fs RICH Detector Gas (C4F10) + Liquid Radiator (C5F12) HPD + PMT read-out p/K/p separation up to 70 GeV/c e/m separation at low momenta PbWO4 EM Calorimeter CLEO/BaBar/BELLE-like performance in a hadron Collider environment! s(h->gg) ~ 5 MeV s(p->gg) ~ 3 MeV 10500 crystals 220 mm long, 28x28 mm2 LHC2003 K. Honscheid Ohio State

Efficiencies and Tagging For a requirement of at least 2 tracks detached by more than 6s, we trigger on only 1% of the beam crossings and achieve the following trigger efficiencies for these states (<2> int. per crossing): e  efficiency; D  Dilution or (Nright-Nwrong)/(Nright+Nwrong) Effective tagging efficiency  eD2 Extensive study for BTeV uses Opposite sign K± Jet Charge Same side p± (for Bo) or K± for (Bs) Leptons Conclusion: eD2 (Bo) = 0.10, eD2 (Bs) = 0.13, difference due to same side tagging Decay efficiency(%) Decay efficiency(%) B  p+p- 63 Bo  K+p- 63 Bs  DsK 74 Bo  J/y Ks 50 B-  DoK- 70 Bs  J/yK* 68 B-  Ksp- 27 Bo  K*g 40 B->pipi efficiency = 0.04 (reconstruction) x 0.82 (PID) x 0.55 (L1+L2) = 1.8% LHC2003 K. Honscheid Ohio State

The Physics Goals There is New Physics out there: Baryon Asymmetry of Universe & by Dark Matter Hierarchy problem Plethora of fundamental parameters … BTeV is in a unique position to: Perform precision measurements of CKM Elements with small model dependence. Search for New Physics via CP phases Search for New Physics via Rare Decays Help interpret new results found elsewhere (LHC, neutrinos) Complete a broad program in heavy flavor physics Weak decay processes, B’s, polarization, Dalitz plots, QCD… Semileptonic decays including Lb b & c quark Production Structure: B baryon states Bc decays LHC2003 K. Honscheid Ohio State

Part 1: Is the CKM Picture correct? Use different sets of measurements to define apex of triangle (adopted from Peskin) Also have eK (CP in KL system) Bd mixing phase Magnitudes Bs mixing phase Can also measure g via B-DoK- LHC2003 K. Honscheid Ohio State

Measuring a Using Borp  p+p-po A Dalitz Plot analysis gives both sin(2a) and cos(2a) (Snyder & Quinn) Measured branching ratios are: B(B-rop-) = ~10-5 B(Bor-p+ + r+p-) = ~3x10-5 B(Boropo) <0.5x10-5 Snyder & Quinn showed that 1000-2000 tagged events are sufficient Not easy to measure p0 reconstruction Not easy to analyze 9 parameter likelihood fit Nearly empty (r polarization) Slow p0’s Dalitz Plot for Borp LHC2003 K. Honscheid Ohio State

Yields for Borp Signal Background Based 9.9x106 background events Bor+p- 5400 events, S/B = 4.1 Boropo 780 events, S/B = 0.3 Boropo Background Signal Get updated plots, to have better S/B numbers po g g LHC2003 K. Honscheid Ohio State mB (GeV) mB (GeV)

Our Estimate of Accuracy on a Geant simulation of Borp, (for 1.4x107 s) a (gen) Rres Rnon a (recon) Da 77.3o 0.2 77.2o 1.6o 0.4 77.1o 1.8o 93.0o 93.3o 1.9o 2.1o 111.0o 111.7o 3.9o 110.4o 4.3o minimum c2 non-resonant non-rp bkgrd resonant Example: 1000 Borp signal + backgrounds With input a=77.3o LHC2003 K. Honscheid Ohio State

Bs Mixing (Vtd/Vts) BTeV reaches sensitivity to xs of 80 in 3.2 years 6 5 4 3 2 1 LHC2003 K. Honscheid Ohio State

c is the phase of Vts -> Bs Mixing Measuring c In the SM the phases and magnitudes are correlated: l = |Vus| = 0.2205±0.0018 c is the phase of Vts -> Bs Mixing Good: Bs->J/yf plus non-trivial angular analysis Better: Bs -> CP eigenstate such as BsJ/yh() , hgg, hrg Silva & Wolfenstein (hep-ph/9610208) Aleksan, Kayser & London LHC2003 K. Honscheid Ohio State

Measuring c II BTeV can reconstruct h and h’ Yield in one year BsJ/y h: 2,800 events with S/B = 15 BsJ/y h: 9,800 events with S/B = 30 Error on sin(2c) = 0.024 With c ~ 2o a precision measurement will require a few years. LHC2003 K. Honscheid Ohio State

Physics Reach (CKM) in 107 s Reaction B(B) (x10-6) # of Events S/B Parameter Error or (Value) Bs Ds K- 300 7500 7 g - 2c 8o Bs Ds p- 3000 59,000 3 xs (75) BoJ/y KS J/y l+ l - 445 168,000 10 sin(2b) 0.017 BoJ/y Ko, Ko  p l n 250 2.3 cos(2b) ~0.5 B-Do (K+p-) K- 0.17 170 1 B-Do (K+K-) K- 1.1 1,000 >10 g 13o BsJ/y h, 330 2,800 15 BsJ/y h 670 9,800 30 sin(2c) 0.024 Bor+p- 28 5,400 4.1 Boropo 5 780 0.3 a ~4o Point out that there are several ways to measure gamma, so can resolve ambiguities; other ways of resolving ambiguities in beta. Error estimate on alpha is a guess. Can do better on chi by using electron modes. Reaction B(B) (x10-6) # of Events S/B Parameter Error B-KS p- 12.1 4,600 1 <4o + BoK+p- 18.8 62,100 20 g Theory err. Bop+p- 4.5 14,600 3 Asymmetry 0.030 BoK+ K- 17 18,900 6.6 0.020 LHC2003 K. Honscheid Ohio State

Part II: Search for New Physics For a nice overview see: S. Stone “BTeV Physics” at http://doe-hep.hep.net/P5StoneMarch2003.pdf LHC2003 K. Honscheid Ohio State

First Example: Supersymmetry Supersymmetry: In general 80 constants & 43 phases MSSM: 2 phases (Nir, hep-ph/9911321) New Physics in Bo mixing: qD , Bo decay: qA, Do mixing: fKp Process Quantity SM New Physics BoJ/yKs CP asym sin(2b) sin2(b+qD) BofKs sin2(b+qD+qA) DoK-p+ ~sin(fKp) Difference  NP New Physics LHC2003 K. Honscheid Ohio State

Rare b Decays g, l+l- Search for New Physics in Loop diagrams New fermion like objects in addition to t, c or u New Gauge-like objects in addition to W, Z or g Inclusive Rare Decays including bsg bdg bsl+l- Exclusive Rare Decays such as Brg, K*g BK*l+l- Dalitz plot & polarization g, l+l- LHC2003 K. Honscheid Ohio State BoK*g

Yield, S/B for Rare b Decays Reaction B (10-6) Signal S/B Physics BoK*om+m- 1.5 2530 11 Polarization; Rate B-K-m+m- 0.4 1470 3.2 Rate bsm+m- 5.7 4140 0.13 Rate; Wilson coefficents Discovery potential here LHC2003 K. Honscheid Ohio State

Polarization in BoK*om+m- BTeV data compared to Burdman et al calculation Dilepton invariant mass distributions, forward-backward asymmetry discriminate among the SM and various supersymmetric theories. (Ali, Lunghi, Greub & Hiller, hep-ph/0112300) One year for K*l+l-, enough to determine if New Physics is present Ali et. al, hep-ph/9910221 LHC2003 K. Honscheid Ohio State

Second Example: Extra Dimensions Aranda & Lorenzo Diaz-Cruz, “Flavor Symmetries in Extra Dimensions” (hep-ph/0207059) (Buras et al. hep-ph/0212143) Extra spatial dimension is compactified at scale 1/R = 250 GeV on up No effect on |Vub/Vcb|, DMd/DMs , sin(2b) Bs -> mm –100 –8% g +72% |Vtd| LHC2003 K. Honscheid Ohio State

Summary Heavy quark physics at hadron colliders provides a unique opportunity to measure fundamental parameters of the Standard Model with no or only small model dependence discover new physics in CP violating amplitudes or rare decays. interpret new phenomena found elsewhere (e.g. LHC) Some scenarios are clear others will be a surprise This program requires a general purpose detector like BTeV with an efficient, unbiased trigger and a high performance DAQ a superb charged particle tracking system good particle identification excellent photon detection LHC2003 K. Honscheid Ohio State

Changes wrt Proposal in Event Yields & Sensitivities We lost one arm, factor = 0.5 We gained on dileptons From RICH ID in proposal we used only m+m-, now we include e+e- factor = 2.4 (or 3.9), depending on whether analysis used single (dilepton) id We gained on DAQ bandwidth, factor = 1.15 Gained on eD2 for Bs only, factor = 1.3 Mode Yield proposal factor one-arm Quantity Err(prop) (eD2) Err(1arm) (eD2) BoJ/y Ks 80,500 0.5*3.9* 1.15=2.24 168,000 sin(2b) 0.025 (0.10) 0.017 (0.10) BsJ/yh() 9,940 0.5*2.4* 1.15=1.38 12,600 sin(2c) 0.033 (0.10) 0.024 (0.13) Bs Ds K- 13,100 0.5*1.15 =0.58 7,500 g 6o (0.10) 8o (0.13) LHC2003 K. Honscheid Ohio State