Beauty Production with the ZEUS HERA II Data

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1 Outline Introduction Beauty Production with the HERA II Data Oliver Maria Kind On Behalf of the Collaboration Physikalisches Institut der Rheinischen Friedrich-Wilhelms-Universität Bonn XIV International Workshop on Deep Inelastic Scattering KEK Tsukuba, Japan April, 006 DESY Oliver Maria Kind Beauty Production at / 3

2 Outline Outline Introduction Introduction HERA II Running Motivation Beauty Extraction Methods Previous Results Beauty in Photoproduction Dijet PhP Event Selection Beauty Extraction Results Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction by p rel Results Summary Oliver Maria Kind Beauty Production at / 3

3 Outline Introduction HERA II Motivation B Extraction Previous Results and HERA II Running e Jet Jet 7.5 GeV 90 GeV µ p Integrated Luminosity (pb ) HERA delivered Results shown here 0 50 MVD days of running Beam-pipe HERA II upgrade: large increase of luminosity micro-vertex detector taking data since 003 ( life-time tag) x Si-Ladder Oliver Maria Kind Beauty Production at 3 / 3

4 Motivation Outline Introduction HERA II Motivation B Extraction Previous Results Beauty production at HERA is good testing ground for pqcd Multiple scales: m b, p b and Q Probe the b contribution to the proton structure function, F b b PYTHIA MC: LO + PS (includes flavour excitation diagrams) NLO QCD calculations available (FMNR, HVQDIS) e e e e e e γ, Z b γ, Z X b γ, Z X g p X b p b X p X b, b Oliver Maria Kind Beauty Production at 4 / 3

5 Outline Introduction HERA II Motivation B Extraction Previous Results Beauty Extraction Methods Component of µ momentum transverse to jet axis, p rel Large for B decays because of large B mass e + Jet axis p rel t µ p Signed µ impact parameter, δ Symmetrically distributed around zero for light flavours Positive tail for beauty and charm due to life-time δ < 0 Beam spot δ > 0 µ helix Jet axis Oliver Maria Kind Beauty Production at 5 / 3

6 Previous Results Outline Introduction HERA II Motivation B Extraction Previous Results Situation: Most measurements agree with NLO QCD within σ Overall, NLO tends to somewhat underestimate the data especially towards low p investigate Statistics still low Aim of HERA II: σ bb_ / σ bb_ NLO QCD QCD NLO (massive) γp (Q ~ 0) Prel. D*µ Correlations H D*µ Correlations Prel. µµ Correlations H bb F (low Q ) Impact Par. H bb F (high Q ) Impact Par. γp: b ex p rel t γp: σ vis (jjµx) p rel t H γp: σ vis (jjµx) p rel t Impact Par. H Prel. γp: dijets Impact Par. H DIS: σ vis (ejµx) p rel t Impact Par. DIS: σ vis (ejµx) p rel t MRST04 CTEQ6HQ 0 Q [GeV ] Increase statistics single- and double-differential x-sections Reduce systematics by complementary measurements (B life-time) Oliver Maria Kind Beauty Production at 6 / 3

7 Beauty in Photoproduction Part I Beauty in Photoproduction Oliver Maria Kind Beauty Production at 7 / 3

8 Dijet PhP + µ Event Selection Beauty in Photoproduction Event Selection Beauty Extraction Results 004 e + p data: L = 33 pb Photoproduction: Veto on scattered e + 0. < y JB < 0.8 Jet finding: k -clustering N jets p > 7(6) GeV η <.5 Associated µ: µ inside jet p µ >.5 GeV.6 < η µ <.3 µ-chambers + central tracking Oliver Maria Kind Beauty Production at 8 / 3

9 Dijet PhP + µ Event Selection Beauty in Photoproduction Event Selection Beauty Extraction Results Events selected: 800 Signal: µ from SL decays of b and c Background: Fake-µ from punch-through and in-flight decays from π, K Shapes reproduced by PYTHIA 6. muons jets µ p T (GeV) (prel.) 004 LF+cc _ +bb _ MC bb _ MC muons jets η µ p T (µ-jet) (GeV) η(µ-jet) Oliver Maria Kind Beauty Production at 8 / 3

10 Beauty Extraction Beauty in Photoproduction Event Selection Beauty Extraction Results Combined fit of p rel and impact parameter, δ muons 3 (prel.) 004 LF+cc _ +bb _ MC LF MC cc _ MC bb _ MC muons 3 (prel.) 004 LF+cc _ +bb _ MC LF MC cc _ MC bb _ MC p T rel (GeV) δ (cm) Oliver Maria Kind Beauty Production at 9 / 3

11 Beauty Extraction Beauty in Photoproduction Event Selection Beauty Extraction Results Result: f b = (6.7 ±.6) % f c = (5 ± ) % Remarks: PYTHIA 6. templates used for b, c and light-flavours shape of light-flavour MC corrected by inclusive dijet data p rel c fraction (prel.) % prob. contours rel p T δ rel p T vs δ Beam position measured run-by-run Resolution of δ in MC modeled on inclusive data (latest MVD alignment not in) b fraction Oliver Maria Kind Beauty Production at 9 / 3

12 Beauty in Photoproduction Event Selection Beauty Extraction Results Results for e + p e + + b b + X e + + dijet + µ + X Kinematic region: Q < GeV 0. < y < 0.8 p jet > 7(6) GeV ηjet <.5 p µ >.5 GeV.6 < ηµ <.3 Conclusions: Agreement with NLO QCD prediction (FMNR) Agreement with data from HERA I running only 3 statistics than 04 analysis p rel dσ/dp T µ (pb/gev) (prel.) NLO QCD x had p T µ (GeV) Oliver Maria Kind Beauty Production at / 3

13 Beauty in Deep Inelastic Scattering Part II Beauty in Deep Inelastic Scattering Oliver Maria Kind Beauty Production at / 3

14 Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results Event Selection: ep e + b b + X e + jet + µ + X 003/4 ep data: L = 39 pb DIS: Q > 4 GeV E e > GeV y el < < (E p z ) < 65 GeV Jet finding: k -clustering jet with associated µ E > 5 GeV.0 < η <.5 Associated µ: dσ/dp T µ (pb/gev) ) µ inside jet p µ >.5 GeV µ-chambers + inner tracking (a) 0.05 < y < NLO QCD Had.Corr. NLO QCD (HVQDIS) -0.9 < η µ <.3, p T µ > GeV -.6 < η µ < -0.9, p µ > GeV E Breit > 6 GeV, - < η lab <.5 T,jet Jet 5 5 p T µ (GeV) Oliver Maria Kind Beauty Production at / 330 dσ/dη µ (pb) )

15 Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results Event Selection: ep e + b b + X e + jet + µ + X 003/4 ep data: L = 39 pb DIS: Q > 4 GeV E e > GeV y el < < (E p z ) < 65 GeV Jet finding: k -clustering jet with associated µ E > 5 GeV.0 < η <.5 Associated µ: dσ/dp T µ (pb/gev) ) µ inside jet p µ >.5 GeV µ-chambers + inner tracking (a) 0.05 < y < NLO QCD Had.Corr. NLO QCD (HVQDIS) -0.9 < η µ <.3, p T µ > GeV -.6 < η µ < -0.9, p µ > GeV E Breit > 6 GeV, - < η lab <.5 T,jet Jet 5 5 p T µ (GeV) Oliver Maria Kind Beauty Production at / 330 dσ/dη µ (pb) )

16 Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results Control Plots Events 3 - (prel.) 39 pb MC bb MC bb+cc MC bb+cc+lf Events (prel.) 39 pb MC bb MC bb+cc MC bb+cc+lf µ p T (GeV) µ η Events (prel.) 39 pb 400 MC bb MC bb+cc MC bb+cc+lf Events 3 - (prel.) 39 pb MC bb MC bb+cc MC bb+cc+lf jet η jet E T (GeV) Oliver Maria Kind Beauty Production at 3 / 3

17 Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results Beauty Extraction by p rel Events 3 - (prel.) 39 pb MC bb MC bb+cc MC bb+cc+lf rel (GeV) p T Fit result: f b = (.4 ±.) % i.e. 00 b events/39 pb K-factor for Beauty LO+PS MC (RAPGAP) of.49 Impact parameter analysis ongoing Oliver Maria Kind Beauty Production at 4 / 3

18 Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results Results for ep e + b b + X e + jet + µ + X (pb/gev dσ/dq ) (prel.) 39 pb RAPGAP x log (Q (GeV )) Kinematic region: Q > 4 GeV 0.05 < y < 0.7 > 5 GeV < η jet <.5 E jet,lab >.5 GeV η µ >.6 p µ Result: σ b b = (77. ± ) pb NLO predictions not yet calculated (in progress) Oliver Maria Kind Beauty Production at 5 / 3

19 Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results Results for ep e + b b + X e + jet + µ + X (pb/gev) µ dσ/dp T (pb/gev) jet dσ/dp T - - (prel.) 39 pb RAPGAP x µ p T (GeV) - (prel.) 39 pb RAPGAP x jet p T (GeV) (pb) µ dσ/dη (pb) jet dσ/dη (prel.) 39 pb RAPGAP x µ η (prel.) 39 pb RAPGAP x jet η Oliver Maria Kind Beauty Production at 5 / 3

20 ) ) Beauty in Deep Inelastic Scattering Event Selection Control Plots Beauty Extraction Results ) Results for ep e + b b + X e + jet + µ + X dx (pb/gev σ/dq d (prel.) 39 pb RAPGAP x.49 4 GeV < Q < 5 GeV dx (pb/gev σ/dq d (prel.) 39 pb RAPGAP x.49 5 GeV < Q < 0 GeV dx (pb/gev σ/dq d log (x) (prel.) 39 pb RAPGAP x.49 0 GeV < Q < 36 GeV log (x) log (x) double-differential x-sections in x and Q Oliver Maria Kind Beauty Production at 5 / 3

21 Summary Summary PhP analysis: st B exploiting the MVD B extraction by combining p rel and impact parameter Results consistent with NLO QCD and HERA I measurements DIS analysis: p rel -analysis of 003/04 data Results consistent with LO+PS MC shapes NLO calculations in progress Looking forward to F b b measurement Oliver Maria Kind Beauty Production at 6 / 3

22 Beauty in PhP Beauty in DIS Part IV Back-up Slides Oliver Maria Kind Beauty Production at 7 / 3

23 Event Selection in Detail Beauty in PhP Beauty in DIS Event Selection Prev.Results Pre-selection: All good events Trigger on jets in PhP SL µ in PhP jets + µ Vertex: 40 < Z vtx < 4 cm Tracking: vtx tracks No. of all tracks No. of vtx tracks Veto on e : P > 0.9 E e > 5 GeV y el < 0.9 EFOs: 0. < y JB < 0.8 Calorimetry: E inner rings GeV p /E < 0.5 Oliver Maria Kind Beauty Production at 8 / 3

24 Event Selection in Detail Beauty in PhP Beauty in DIS Event Selection Prev.Results Jets: jets found with k -clustering in E recombination scheme (massive mode, 3) and µ finding: p µ p > 7(6) GeV η <.5 >.5 GeV.6 < η <.3 Oliver Maria Kind Beauty Production at 8 / 3

25 Previous Results Beauty in PhP Beauty in DIS Event Selection Prev.Results dσ/dp µ t [pb/gev] H < η µ <. -.6 < η µ <.3 NLO QCD Had: < η µ <. -.6 < η µ <.3 dσ/dη µ [pb] 40 ep ebb X ejjµx Q < GeV 0. < y < 0.8 p µ t >.5 GeV p jet() t > 7(6) GeV η jet <.5 H NLO QCD Q < GeV ; 0. < y < 0.8 p jet() t > 7(6) GeV; ηjet < p µ t [GeV] 0-0 η µ Oliver Maria Kind Beauty Production at 9 / 3

26 Data Sets Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results Set 003/04 data 39 pb Beauty MC RAPGAP 990 pb Charm MC RAPGAP 990 pb Light-flavour MC ARIADNE 990 pb L MCs comprise LO matrix-elements with DGLAP parton showers Shapes are described but not normalisation Normalisation by fitting the MC p rel -distributions to data Oliver Maria Kind Beauty Production at 0 / 3

27 Event Selection in Detail Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results Pre-selection: All good events No explicit trigger Vertex: 50 < Z vtx < 50 cm Electron finder: P > 0.9 E e > GeV Q > 4 GeV el y el < 0.7 y JB > 0.05 EFOs: 40 < (E p z ) < 65 GeV p/ < GeV Calorimetry: E cone GeV Tracking: p rel N trk > 8 calculation: use all jets with > 5 GeV E jet Oliver Maria Kind Beauty Production at / 3

28 Event Selection in Detail Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results µ finding: p µ.5 GeV GMuon quality > 4 Forward track muon quality modification µ regions forward:. < η barrel: 0.9 < η <. rear:.6 < η < 0.9 HAC (rear) > 0.3 GeV and no MV HAC (forward) > 0.4 GeV Jets: jet found with k -clustering in E recombination scheme (massive mode, 3), w/o DIS electron EFO and < η <.5 > 5 GeV E lab p jet p µ > 0.7 GeV anti-isolation Oliver Maria Kind Beauty Production at / 3

29 Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results µ-efficiency Corrections µ-efficiencies differences between data and MC Correction factors obtained by independend J/ψ, Bethe-Heitler data-sets Binned in p µ and ηµ Efficiencies/inefficienies combined for all µ-detectors MC µ weighted with combined correction factors Significant improvement of µ description Half of the correction assigned as syst. error (± %) Oliver Maria Kind Beauty Production at / 3

30 Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results Previous Results of Beauty in DIS (pb/gev) (a) NLO QCD Had.Corr. NLO QCD (HVQDIS) (pb/gev) (b) CASCADE, m b =4.75 GeV RAPGAP, m b =5 GeV Breit dσ/de T,jet 0.05 < y < < η µ <.3, p T µ > GeV -.6 < η µ < -0.9, p µ > GeV E Breit > 6 GeV, - < η lab <.5 T,jet Jet Breit dσ/de T,jet E Breit (GeV) T,jet E Breit (GeV) T,jet Oliver Maria Kind Beauty Production at 3 / 3

31 Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results Previous Results of Beauty in DIS dσ/dp T µ (pb/gev) (a) NLO QCD Had.Corr. NLO QCD (HVQDIS) 0.05 < y < 0.7 dσ/dη µ (pb) (b) -0.9 < η µ <.3, p T µ > GeV -.6 < η µ < -0.9, p µ > GeV E Breit > 6 GeV, - < η lab <.5 T,jet Jet 5 dσ/dp T µ (pb/gev) (c) 5 5 µ p T (GeV) CASCADE, m b =4.75 GeV RAPGAP, m b =5 GeV dσ/dη µ (pb) (d) - 0 η µ p T µ (GeV) - 0 η µ Oliver Maria Kind Beauty Production at 3 / 3

32 Beauty in PhP Beauty in DIS Data Sets Event Selection µ-efficiencies Prev. Results Previous Results of Beauty in DIS dσ/dq (pb/gev ) - (a) NLO QCD Had.Corr. NLO QCD (HVQDIS) 0.05 < y < < η µ µ <.3, p T > GeV dσ/dlog (x) (pb) (b) -.6 < η µ < -0.9, p µ > GeV - E Breit > 6 GeV, - < η T,jet Jet lab <.5 5 dσ/dq (pb/gev ) -3 - (c) 3 Q (GeV ) CASCADE, m b =4.75 GeV RAPGAP, m b =5 GeV dσ/dlog (x) (pb) (d) log (x) Q (GeV ) log (x) Oliver Maria Kind Beauty Production at 3 / 3